JPH112085A - Drilling rig - Google Patents

Abstract

(57) [Problem] To provide a high-strength excavator capable of easily and surely changing the excavation diameter at a desired position. A pair of plate-like flange portions (14, 14) are provided on an outer peripheral surface of a shaft portion (13) connected detachably substantially coaxially to an end of an auger shaft body (2). Flange parts 14, 14
A shaft portion 18 having an excavating claw portion 20 provided integrally therewith,
18 is rotatably supported on the flange portions 14 and 14 in a vertically slidable and rotatable manner. The wing expansion restricting portion 23 is expanded into a wall shape having first and second relief portions 25 and 27 for locking the locking claw portion 21 of the excavation claw portion 20 and positioning the locking claw portion 21 in the first state A and the second state B. Provided on the radial rotation side. The wing expansion restricting portion 23 restricts the excavation claw portion 20 to rotate in the first state A to the middle wing expansion state and restricts the rotation to the maximum wing expansion state in the second state B. A wall-shaped diameter-reducing restricting portion 28 is provided on the diameter-reducing rotary side to restrict the rotation to the middle-stage diameter reducing state in the first state A. The expansion / contraction state of the excavation claw portion 20 can be easily changed only by the forward / reverse rotation of the auger shaft 2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an excavator having an excavating claw portion which is detachably attached to a tip of an auger shaft body and is used in a middle excavation method and has a wing-spreading blade.

[0002]

2. Description of the Related Art Conventionally, as an excavator of this type, for example, a configuration described in Japanese Utility Model Publication No. 59-5111 is known.

The excavating apparatus described in Japanese Utility Model Publication No. 59-5111 has a substantially cylindrical shape which is rotatable relative to a shaft portion which is detachably connected to the tip of an auger shaft body used in the excavation method. The outer cylinder is fitted coaxially, and one end side of a substantially rod-shaped excavating claw having a projection on one end on the outer peripheral surface of the outer cylinder is vertically oriented in which the axial direction of the excavating claw is the axial direction of the shaft. Along the other end, a pair of shafts are rotatably supported such that the other end side expands upward. In addition, the outer peripheral surface of the shaft body has an inclined surface with which the projection abuts when the excavation claw portion expands the wing, and has a concave portion that locks the projection when the excavation claw portion is in the maximum wing-spread state. A locking claw is provided.

[0004] Then, the auger shaft is inserted into the hollow pile, the excavator attached to the end of the auger shaft is exposed from the end of the hollow pile, and when the ground is excavated, the excavation claw rotates due to earth pressure. The projection abuts on the inclined surface of the locking claw, and the excavation claw expands and excavates in the middle-stage widening state where the diameter at the tip side of the excavation claw is about the outer diameter of the hollow pile. Stakes are being laid down. Also, at the time of excavation to a predetermined depth, the auger shaft is reversed to rotate the outer cylinder relatively receiving the resistance from the ground due to the earth pressure of the excavation claw, and the projection of the excavation claw is formed. Is removed from the inclined surface of the engaging claw portion to be brought into contact. Thereafter, the auger shaft is lowered and the excavation claw is further rotated to expand the wing into a maximum wing-spreading state having a diameter larger than the outer diameter of the hollow pile. The projection is engaged with the concave portion of the locking claw portion, and the tip root compaction bulb portion is excavated. Then, the end of the excavation, the auger shaft is reversed again, the projection of the excavation claw is removed from the recess of the locking claw, the diameter of the excavation claw at the free end is reduced, and the auger shaft is pulled out from the hollow pile. Pull the drilling rig through the hollow pile.

[0005]

However, in the conventional excavator described in Japanese Utility Model Publication No. 59-5111, when the excavation claw portion is expanded, the auger shaft is lowered and expanded by earth pressure. Due to the wings, the excavation position for expanding the wings tends to be shifted to the descending side due to the descending distance of the auger shaft body, and there is a possibility that the tip-consolidating bulb portion, which is the diametrical excavation at the desired position, cannot be formed. In addition, since the tip of the excavation claw does not bite into the peripheral surface of the ground and cannot slide on the peripheral surface of the ground to expand the wings, there is a possibility that the tip-fixing bulb portion may not be reliably formed, so It is necessary to configure the excavation claw so that the blade can be spread to the maximum spread state, which complicates the structure. further,
Due to the complexity of the structure, it is difficult to obtain high strength. For example, when lowering the auger shaft and expanding the excavation claw by earth pressure, the tip expands so that the tip bites into the peripheral surface of the ground Therefore, when the earth pressure is very large, there is a problem that each part may be damaged, for example, a large stress is applied to the excavation claw and the excavation claw is damaged.

The present invention has been made in view of the above problems, and has as its object to provide a high-strength excavator capable of easily and reliably changing the excavation diameter at a desired position.

[0007]

The excavator according to the present invention is used in an underground excavation method in which a cylindrical pile is buried while excavating the ground, and a spiral scraping is carried out on a peripheral surface of a substantially cylindrical main shaft. An excavating device detachably attached to a tip of an auger shaft having a flying wing, wherein a substantially cylindrical shaft portion detachably attached to a tip of the auger shaft so as to be substantially coaxial with the tip of the auger shaft; A shaft portion provided substantially parallel to the axial direction of the shaft portion; a shaft support portion provided on a peripheral surface of the shaft portion for supporting the shaft portion substantially parallel to the axial direction of the shaft portion; A digging claw part whose one end is rotatable about the shaft part as a center axis, and the digging claw part is moved from the center of the shaft part when the digging claw part rotates in the wing-spreading direction. The maximum wingspan is such that the distance to one end of the pile is greater than the outer diameter of the pile. State, and restricting the rotation to a middle-stage widening state in which the distance is smaller than the maximum widening state and the diameter is larger than the inner diameter of the pile, and the rotation of the excavation claw in the diameter-reducing direction is restricted. At this time, rotation restricting means for restricting rotation to a minimum diameter reduction state in which a distance from the center of the shaft portion to one end of the excavation claw portion is a distance equal to or smaller than the outer diameter of the shaft support portion. The rotation restricting means maintains the state in which the rotation of the excavation claw part is restricted to the maximum wing-spreading state and the middle-stage wing-spreading state when the shaft part rotates forward in the direction of excavating the ground. And positioning means for releasing the restriction on the rotation of the excavation claw when the shaft is rotated in the reverse direction.

When the ground is excavated by attaching the auger shaft to the tip of the auger shaft and rotating the auger shaft forward, the excavation claw expands its wings due to the earth pressure from the ground, and the excavation claw is rotated by the rotation restricting means. Of the pile is smaller than the maximum wing-spreading state in which the diameter is larger than the outer diameter of the pile, and the rotation is restricted to the middle wing-spreading state in which the diameter is larger than the inner diameter of the pile. Excavation is performed while maintaining the wing state by the positioning means. When expanding the excavation claw, the rotation of the excavation claw in the middle-stage widening state is released by reversing the auger shaft body, and the excavation claw is reduced in the diameter reduction direction by earth pressure. The excavation claw part expands due to the earth pressure from the ground, and the rotation is restricted to the maximum wing-spread state by the rotation restricting means. This maximum wing-spread state is determined by the positioning means. Excavation while maintaining the diameter. Then, when excavating and pulling out the pile after subsidence, the auger shaft is reversed to release the regulation of the rotation in the maximum wing expansion state by the positioning means, and the excavation claw is reduced in the diameter reduction direction by earth pressure. By rotating the pile, the distance from the center of the shaft to one end of the excavation claw is smaller than or equal to the outer diameter of the shaft support. In other words, the excavation claw portion is rotated to expand the blade and reduce the diameter by utilizing the earth pressure by reversing the auger shaft, and the rotation is restricted to a different expanding state by the rotation of the expanding blade and the rotation of the reduced diameter. Therefore, it is possible to perform the diameter excavation and the diameter reduction from a desired excavation position.

According to a second aspect of the present invention, in the first aspect of the present invention, a pair of shaft support portions are provided so as to face each other in the axial direction of the shaft portion and in the vertical direction. The positioning means is provided between the shaft support parts so as to be rotatable around the shaft part and movable in the axial direction of the shaft part, and the positioning means is such that the excavation claw part is close to the upper shaft support part side. The first excavation portion or the excavation claw portion is detachably held in the second state in which the excavation claw portion is close to the lower shaft support portion side, and when the excavation claw portion is located in the first state, One end of the excavation claw is rotated in the range of a middle diameter reduction state and a middle expansion state in which one end side of the excavation claw is located in a range smaller in diameter than the middle wing expansion state and larger in diameter than the outer diameter of the shaft support part. And the excavation claw is in the second state. Then, it restricts the rotation of the excavation teeth portion to a range of minimum diameter-reduced state and the maximum 拡翼 state.

When the ground is excavated by attaching the auger shaft to the tip of the auger shaft and rotating the auger shaft forward, the excavation claw moves relatively upward with respect to the shaft due to earth pressure from the ground. While maintaining the first state located above this by the positioning means, the excavation claw part is rotated in the wing-spreading direction by earth pressure,
The excavation claw is controlled to rotate to the middle-stage widened state by the rotation restricting means, and excavation is performed. In the case of expanding the wings, the auger shaft is rotated in the reverse direction so that the excavation claw rotates in the diameter reducing direction due to the earth pressure, and the tip of the excavation claw is in the middle-stage expanded state by the rotation restricting means. The rotation is restricted to the middle-stage reduced diameter state where the diameter is smaller and the diameter is larger than the outer diameter of the shaft supporting portion, and the excavation claw portion is disengaged from the positioning means and is relatively lowered with respect to the shaft body by its own weight. Go to By rotating the auger shaft body forward in this state, the excavation claw part is rotated in the wing-spreading direction by the earth pressure, and is held in the second state located below the digging claw part by the positioning means. In the above, the tip end side of the excavation claw portion is controlled to rotate to a maximum wing-spreading state in which the distance from the center of the shaft portion to one end of the excavation claw portion is increased, and the diameter is excavated. Also, when excavating and pulling out the pile after subsidence, the auger shaft is reversed to release the restriction of rotation in the maximum wing expansion state by the positioning means, and the excavation claw is reduced in the diameter reduction direction by earth pressure. By rotating the pile, the distance from the center of the shaft to one end of the excavation claw is smaller than or equal to the outer diameter of the shaft support. For this reason, the diameter of the shaft supporting portion that supports the shaft irrespective of the diameter can be set to be thicker by simply expanding the auger shaft body once and then rotating the auger shaft from the desired diameter expanding digging position by simply rotating the auger shaft forward and backward.
By increasing the thickness of the shaft support, the strength can be improved.

According to a third aspect of the present invention, there is provided the excavating apparatus according to the second aspect, wherein the rotation restricting means includes a first excavating claw portion.
When the excavating claw is rotated in the diameter reducing direction only when the excavating claw is positioned in the state, the excavating claw comes into contact with the diameter reducing rotating direction side of the excavating claw, and the rotation of the excavating claw in the diameter reducing direction is reduced to the middle diameter. It is provided with a diameter-reducing regulating section for regulating the state.

Then, only when the excavation claw is in the first state, when the excavation claw rotates in the diameter reducing direction, the abutment contacts the side of the excavation claw in the diameter reduction rotation direction, and the excavation claw contracts. Since the rotation restricting means is provided in the rotation restricting means for restricting the rotation in the radial direction to the middle diameter reduction state, when the blade is once reduced in diameter for expanding the wing, and is then rotated again by the earth pressure when the blade is expanded. Then, the earth pressure is efficiently applied to the excavation claw portion, and the excavation claw portion easily swings and rotates. In addition, by reversing the auger shaft from the maximum wing expansion state, it becomes the minimum diameter reduction state for pulling out from the pile, so different diameter reduction states can be easily obtained with a simple structure, and the wing expansion state and the diameter reduction state Change easily.

According to a fourth aspect of the present invention, there is provided the excavator according to the second or third aspect, wherein the shaft portion is slidably provided on the shaft support portion in the axial direction, and the excavation claw is provided together with the shaft portion. It is provided integrally with the shaft portion so as to be rotatable about the shaft portion and movable in the axial direction of the shaft portion.

Since the excavation claw is integrally provided on the shaft portion slidably provided in the shaft support portion in the axial direction, the excavation claw is rotated by the positioning means by the rotation of the excavation claw and the reverse rotation of the auger shaft. When the restricted state is released, the movement of the shaft portion in the axial direction causes the shaft portion and the excavation claw portion to operate integrally, thereby preventing excavated earth and sand from biting and hindering the movement of the excavation claw portion. The state of the wing spread changes smoothly and reliably.

According to a fifth aspect of the present invention, there is provided an excavator according to any one of the first to fourth aspects, wherein the positioning means is provided on one of the excavating claw part and the rotation restricting means or the shaft part. It has a locking claw that locks to the other.

The positioning means locks the locking claw provided on one of the excavating claw or the rotation restricting means and the shaft with the other, and the excavating claw by rotation of the auger shaft body. Since the state of the rotation restriction of the portion is maintained and released, the configuration of maintaining and releasing the state of the rotation restriction is simplified, and the maintenance and release of the state of the rotation restriction can be easily performed only by the rotation operation of the auger shaft body. .

According to a sixth aspect of the present invention, there is provided the excavating apparatus according to the first aspect, wherein a pair of shaft supporting portions are provided movably while maintaining a distance facing the shaft portion along the axial direction, and positioning means. Comprises an urging means for urging the pair of shaft support parts toward the auger shaft body, and a rotation restricting means, wherein the pair of shaft support parts is provided on the shaft against the urging of the urging means. When moved to the tip side of the portion, the rotation of the excavation claw portion is restricted to be rotatable in the range of the minimum diameter reduction state and the maximum wing expansion state, and the pair of shaft support portions are biased by the biasing means. When it moves to the auger shaft side, the rotation of the excavation claw is restricted to the range of the minimum diameter reduction state and the middle stage widening state and the maximum widening state.

When the ground is excavated by attaching the auger shaft to the tip of the auger shaft and rotating the auger shaft forward, the excavation claw is rotated in the wing-spreading direction by the earth pressure from the ground, and is controlled by the rotation restricting means. The excavation claw is rotated and restricted to a middle-stage wing-spreading state in which the tip portion has a distance larger than the inner diameter of the pile, and excavation is performed. When expanding the wings, the auger shaft is once pulled out, the excavation claw portion located in the middle wing expansion state is brought into contact with the lower end of the pile, and the pair of shaft support portions are biased by the biasing means. In contrast, the shaft is moved while maintaining a distance facing the shaft in the axial direction. In this state, the rotation restricting state is released, and the excavation claw becomes rotatable in the range of the minimum diameter reducing state and the maximum wing expanding state. Then, the auger shaft is rotated forward again, and the excavation claw is rotated in the wing-spreading direction by the earth pressure, and the excavation claw is moved by the rotation restricting means so that the tip becomes larger in diameter than the outer diameter of the pile. Rotation is controlled to the maximum wing-spreading state, and the diameter is excavated. In addition, when the pile is excavated and pulled out after being laid, the excavation claw portion located in the maximum wing spread state is again brought into contact with the lower end portion of the pile, and the pair of shaft support portions is opposed to the biasing means. The shaft is moved while maintaining a distance facing the shaft along the axial direction. By reversing the auger shaft in this state, the rotation restricting state is released, and the excavation claw that is rotatable in the range of the minimum diameter reduction state and the maximum wing expansion state is reduced in diameter at the lower end of the pile. In the minimum diameter reduction state located below the outer diameter of the shaft support having a smaller diameter than the inner diameter of the pile. In this minimum diameter reduction state, the excavation claw portion is located on the inner diameter side of the pile from the lower end of the pile, is in a state where it can be inserted, and is pulled out. That is, by simply moving the auger shaft so as to be pulled out once and bringing the excavation claw into contact with the lower end of the pile and rotating the excavator forward and backward, it is possible to perform excavation from a desired enlarged excavation position. Further, since the shaft support is moved against the urging of the urging means and the rotation restriction by the rotation restricting means is released, the middle stage widening state and the maximum widening state can be appropriately selected.

According to a seventh aspect of the present invention, there is provided the excavator according to the sixth aspect, wherein the excavation claw has a contact surface that abuts on a lower end surface of the pile.

Further, since the contact surface for contacting the lower end surface of the pile is provided on the excavation claw portion, the contact area between the excavation claw portion and the lower end surface of the pile is increased, and the excavation claw portion is easily provided on the lower end portion of the pile. Abuts without damage, and the wing expansion and contraction state change easily.

According to an eighth aspect of the present invention, there is provided the excavator according to the sixth or seventh aspect, wherein the excavation claw has a concave portion at a tip end side of the shaft portion and an edge on the side of the diameter reducing rotation. The movement restricting means is provided between the pair of shaft supporting parts on the rotation side of the excavating claw part in the diameter reducing direction and protruded from the shaft part, and the shaft supporting part resists the urging of the urging means. Then, when the excavation claw rotates in the diameter reducing direction while moving to the tip end side of the shaft portion, the abutment comes into contact with the diameter reduction rotation direction side of the excavation claw, and has a smaller diameter than the middle-stage widening state. The excavation is performed in a state where the rotation is restricted to a middle-stage reduced diameter state located in a range larger than the outer diameter of the shaft support portion, and the shaft support portion moves toward the auger shaft body by the urging of the urging means. When the claw rotates in the diameter reducing direction, the claw includes a diameter reduction restricting portion inserted into the concave portion of the excavation claw.

When the excavation claw is expanded and reduced in diameter, the excavation claw is moved in the diameter reduction direction in a state where the shaft support is moved toward the tip of the shaft against the urging of the urging means. When rotated, the diameter-reducing restricting portion of the rotation restricting means protruding from the shaft portion and located between the pair of shaft support portions on the rotation side in the diameter-reducing direction of the excavating claw portion contracts the excavating claw portion. Rotation is restricted to the middle stage reduced diameter state, which is in contact with the radial rotation direction side and located in a range smaller in diameter than the middle stage expanded state and larger in diameter than the outer diameter of the shaft support. The earth pressure is efficiently applied to the excavation claw when the blade is turned to rotate the blade with the earth pressure, and the excavation claw is easily rotated with the blade. Also, in order to pull out from the pile, in order to make it the minimum diameter reduction state, after making it the middle diameter reduction state located between the range of the middle wing expansion state and the minimum diameter reduction state, move by urging by the urging means. By reversing the auger shaft body, a minimum diameter reduction state is obtained by earth pressure, a different diameter reduction state can be easily obtained with a simple structure, and the wing expansion state and the diameter reduction state can be easily changed.

According to a ninth aspect of the present invention, in the digging apparatus according to any one of the first to eighth aspects, the rotation restricting means is located on the side of rotation of the excavation claw in the wing-spreading direction. And when the digging claw rotates in the wing-spreading direction, the wing-spreading restricting portion abuts on the wing-spreading rotation direction side of the digging claw to restrict the rotation of the digging claw in the middle-stage wing-extended state and the maximum wing-spreading state. It is provided with.

[0024] The rotation restricting means is located on the rotation side of the excavation claw in the wing-spreading direction. The blades are controlled to be in the middle-stage widening state and the maximum-widening state, so that the widening state can be easily changed with a simple structure.

According to a tenth aspect of the present invention, there is provided the excavator according to any one of the first to ninth aspects, wherein the shaft portion is located between the pair of shaft support portions and communicates with the inner peripheral side so that the fluid The discharge port which can circulate is opened.

[0026] Since the discharge port, which is located between the pair of shaft support portions on the shaft portion and communicates with the inner peripheral side and through which the fluid can flow, is opened, the excavated soil is discharged by discharging the fluid from the discharge port. Prevention of accumulation between the shaft support portions prevents the excavation claw portion from smoothly expanding and contracting, and also improves excavation efficiency.

[0027]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view showing a configuration of an excavator according to an embodiment of the present invention.

In FIG. 2, reference numeral 1 denotes a base vehicle, and a substantially cylindrical auger shaft 2 is connected to the base vehicle 1 along a substantially vertical axial direction, and a driving means 3 for rotating the auger shaft 2 is provided. Are supported. The auger shaft 2 is formed in a substantially cylindrical shape on the center axis so that water, cement milk as a cement-based solidifying material, compressed air, etc. can flow therethrough, and a spirally-raised wing 5 is provided on the peripheral surface. ing. The scraping wings 5 are formed in a spiral shape in a direction in which the auger shaft 2 is rotated in one direction, that is, when the auger shaft 2 is normally rotated, in which the earth and sand are scraped. A bit 6 as a drilling device capable of expanding the diameter is detachably attached to the tip of the auger shaft 2.

Then, the bit 6 is, as shown in FIG.
An inner peripheral side is formed in a substantially cylindrical shape communicating with the inner peripheral side of the auger shaft body 2, and a joint portion 11 connected to the auger shaft body 2 at one end.
And a shaft portion 13 having an excavating blade 12 projecting toward the tip at the other end. A pair of plate-like flange portions 14, 14 serving as shaft support portions that oppose each other along the vertical direction that is the axial direction of the shaft portion 13 are protruded from the outer peripheral surface at substantially the center of the shaft portion 13. . The flange portions 14 are formed in a substantially oval shape in plan view, which are cut out at substantially parallel chord positions. The shaft portion 13 has a pair of flange portions 1 on the inner circumferential side extending from the inner circumferential side of the joint portion 11 to the central portion of the shaft portion 13.
A discharge port 15 is provided which communicates with the outer surface between 4 and 14.

Near the longitudinal ends of the flange portions 14, 14, substantially circular insertion holes 16, 16 are provided at opposing positions, respectively. The substantially cylindrical shaft portions 18, 18 are slidably fitted in the pair of opposed through holes 16, 16 in the axial direction along the vertical direction.

Further, the shaft portion 18 has an excavating claw portion 20 which is thinner toward one end side and has a hard member 19 provided at one end portion thereof is located between the flange portions 14 and 14 and the other end portion is integrally formed. The excavation claw 20 is rotatable on one end side with the shaft 18 as a central axis together with the shaft 18. As shown in FIGS. 3 to 6, the excavation claw portion 20 is curved in the turning direction in the diameter reducing direction, that is, curved in the normal rotation direction so as to excavate in the normal rotation direction of the auger shaft body 2. It is formed in the shape which does. The excavation claw 20 is provided with a locking claw 21 which constitutes a positioning means on the side surface on the rotation side in the radially expanding direction.

The outer peripheral surface of the shaft 13 has a flange 1
A substantially wall-shaped wing expansion restricting portion 23 is provided between the positions 4 and 14 in the vertical direction. The upper edge of the wing expansion restricting portion 23 on the side protruding from the shaft portion 13 has an excavating claw portion 20 on the shaft portion.
When the excavation claw 20 is moved in the first state A, that is, in a state in which the excavation claw 20 is in the vicinity of the upper flange 14 shown by a solid line in FIG. When the excavating claw 20 is rotated in the radial direction, the excavating claw 20 is brought into contact with the side surface of the excavating claw 20 on the radially expanding rotation side to restrict the rotation of the excavating claw 20 to the middle-stage widening state a shown by a solid line in FIG. Shaft 13 indicated by solid line inside
The protrusion-shaped first blade expansion restricting portion that constitutes the blade expansion restricting portion that restricts the rotation so that the distance from the center of the excavation claw portion 20 to the tip of the excavation claw portion 20 is smaller than the maximum blade-expanding state b in which the maximum. Department
24.

When the excavation claw 20 comes into contact with the first wing expansion restricting portion 24 and is in the middle wing expansion state a, the locking claw 21 is attached to the wing expansion restricting portion 23. The locking claw 21 is engaged so as not to abut on the locking claw 21, that is, as shown in FIG.
There is provided a concave first relief portion 25 which constitutes a positioning means for inserting the device into a state in which it is placed on the upper surface portion. Note that the locking claw 21 is engaged with the first escape portion 25, that is, the first claw 21 is inserted into the first escape portion 25 to form the lower surface side of the first escape portion 25. By being placed on the upper surface of the wing expansion restricting portion 24, the excavation claw portion 20 is prevented from moving downward by its own weight together with the shaft portion 18 so that the middle stage wing expanding state a
And the first state A is maintained.

Further, the lower edge of the wing expansion restricting portion 23 is located in the second state B, that is, the lower position shown by the two-dot chain line in FIG. When the excavation claw 20 is rotated in the radially increasing direction when the excavation claw 20 is rotated in the diameter increasing direction, the excavation claw 20 is brought into contact with the side surface of the excavation claw 20 on the radially expanding rotation side, and the excavation claw 20 is moved in FIG. The rotation is restricted to the maximum blade expansion state b shown by the solid line in the middle, and a second blade expansion restriction unit 26 that constitutes the blade expansion restriction unit 23 together with the first blade expansion restriction unit 24 is formed. When the excavation claw 20 comes into contact with the second wing expansion restricting portion 26 and is positioned in the maximum wing expansion state b, the locking claw 21 contacts the wing expansion restricting portion 23. Locking claw 21 so that it does not touch
As shown in FIG. 6, there is provided a concave second escape portion 27 which constitutes a positioning means for inserting the locking claw portion 21 without abutting. Note that even if an upward force acts on the excavation claw 20 or the shaft 18 due to the earth pressure from the ground 34 or the like, the upper surface of the excavation claw 20 constitutes the upper surface of the second escape portion 27. (1) The movement is restricted by contacting the lower surface of the wing expansion restricting portion 24, and the excavation claw 20 is restricted from moving upward together with the shaft portion 18 and is positioned so as to maintain the maximum wing expanding state b. Hold B. Here, the positioning can be performed by the locking claw portion 21, but the lowering of the excavation claw portion 20 on the lower surface of the first wing expansion regulating portion 24 on the side of the second wing expansion regulating portion 26 is restricted. Therefore, positioning can be performed with a high-strength structure.

The positioning means is constituted by the lower surface of the locking claw portion 21, the first escape portion 25, the second escape portion 27, and the first wing expansion regulating portion 24.

The outer peripheral surface of the shaft 13 has a flange 1
A tongue-shaped diameter-reducing restricting portion 28 having a flat surface facing the flange portion 14 at a position close to the flange portion 14 located above between the portions 4 and 14.
Is provided. When the excavation claw portion 20 is in the first state A, when the excavation claw portion 20 rotates in the diameter reducing direction, the diameter-reducing restricting portion 28 comes into contact with the side surface of the excavation claw portion 20 on the diameter-reduction rotating side. The rotation of the excavation claw 20 is restricted to the middle-stage reduced diameter state c shown by the two-dot chain line in FIG. 3, that is, the tip of the excavation claw 20 is located in a range larger in diameter than the outer diameter range d of the flange portion 14. Restrict rotation to the state.
When the excavation claw 20 is in the second state B, the excavation claw 20
There is no special portion that restricts the excavation claw portion 20 by contacting the side surface of the excavation claw portion 20 on the diameter reduction rotation side when rotating in the diameter reducing direction,
As shown by the two-dot chain line in FIG. 5, the excavation claw portion 20 contacts the outer peripheral surface of the shaft portion 13 and is in the minimum reduced diameter state, that is, the tip of the excavation claw portion 20 is smaller than the outer diameter range d of the flange portion 14. The rotation is restricted to a state of being located in a small diameter range.

The wing expansion restricting section 23 and the diameter reducing restricting section 28
The rotation restricting means 29 is constituted by.

Further, the outer peripheral surface of the shaft 13 has a flange 1
Flange part 1 located at both ends, that is, above, from 4, 14
On the outer peripheral surface of the shaft portion 13 located above the flange portion 14 located below and below the flange portion 14, a spiral-shaped scraping auxiliary wing is formed in the same direction as the spiral direction of the scraping blade 5 of the auger shaft body 2. 31 and 31 are provided.

Next, the excavation operation of the ground 34 using the bit 6 will be described with reference to the drawings.

First, as shown in FIG. 2, a concrete pile 33 as a pile is
The auger shaft body 2 fitted with the bit 6 at the tip end thereof is fitted so as to be substantially vertical in the axial direction. The outer diameter of the flange portion 14, which is the diameter of the bit 6, is slightly smaller than the inner diameter of the concrete pile 33.

Then, as shown in FIGS. 2 and 7, at least one of water and compressed air is appropriately discharged from the discharge port 15 of the bit 6 through the inner peripheral side of the auger shaft body 2, and The body 2 is lowered together with the concrete pile 33, and the driving means 3 is driven in the normal direction to excavate a predetermined position of the ground 34, and the concrete pile 33 is laid down. During this excavation, the ground due to the lowering of the auger shaft 2
Due to the earth pressure from 34, the excavation claw portion 20 moves upward together with the shaft portion 18 to be in the first state A close to the flange portion 14 located above.

Further, the ground 34 due to the normal rotation of the auger shaft 2
The excavation claw 20 is moved by the earth pressure and friction from the shaft 18
At the same time, it rotates in the radially expanding direction about the shaft portion 18 as a central axis. Then, in the first state A, by turning in the diameter increasing direction,
As shown by the solid line in FIG. 3 and FIG. 4, the locking claw portion 21 of the excavation claw portion 20 is engaged with the first escape portion 25 of the wing expansion restricting portion 23, and the first state A is maintained. Then, the side surface of the excavation claw portion 20 on the radially expanding rotation side comes into contact with the first blade expansion restricting portion 24 of the rotation restricting means 29, whereby the rotation is restricted and the middle stage widening state a is established. The first state A is maintained when the locking claw 21 is engaged with the first escape portion 25, that is, the locking claw 21 is inserted into the first escape portion 25 and the first escape portion 25 Is placed on the upper surface of the first wing expansion restricting portion 24 that constitutes the lower surface side of the shaft, and the excavation claw portion 20 is prevented from moving downward by its own weight together with the shaft portion 18.
State A is maintained. The middle stage widening state a is the shaft portion 13
The diameter from the center to the tip of the excavation claw 20 is substantially the same as or slightly smaller than the outer diameter of the concrete pile 33.

When the excavation position reaches the support layer 35 which is a hard part of the ground 34, the lowering of the auger shaft 2 is stopped and the auger shaft 2 is reversed. Due to the reversal of the auger shaft 2, the excavation claw 20 rotates together with the shaft 18 in the diameter reducing direction around the shaft 18 by the earth pressure and friction from the ground 34. By the rotation in the diameter reducing direction in the first state A, as shown in FIG.
The rotation-restricted side surface of the excavation claw portion 20 comes into contact with 28 and the rotation is restricted, so that the state becomes the middle-stage reduced-diameter state c shown by a two-dot chain line in FIG. 21 is the first of the wing expansion control section 23
From the escape part 25. By expulsion of at least one of water and compressed air from the discharge port 15, earth and sand do not stick between the flange portions 14, 14, and the excavation claw portion 20 can be reliably rotated in the diameter reducing direction.

Further, the own weight of the shaft portion 18 and the excavating claw portion 20, the scraping wings 5 and the scraping auxiliary wings 31 of the auger shaft body 2 and the like.
Of the earth and sand in the middle of frying due to the reversal of
Only the auger shaft 2 is pulled up and moved relatively to the concrete pile 33,
The excavation claw portion 20 moves downward together with the shaft portion 18 by bringing the excavation claw portion 20 into contact with the lower end, which is the tip end, to enter the second state B. By rotating the auger shaft 2 forward again in this state, the earth pressure and friction from the ground 34
The excavation claw portion 20 rotates together with the shaft portion 18 in the radially expanding direction about the shaft portion 18 as a central axis. Then, by the rotation in the radially expanding direction in the second state B, as shown by the solid line in FIG. 5, and FIG. 6 and FIG.
The second state B is maintained by being locked by the second escape portion 27 of the excavator 23, and the side surface of the excavation claw portion 20 on the wing-spreading rotation side is formed by the second wing-spreading restriction portion 26 of the rotation restricting means 29. The rotation is restricted by the contact, and the maximum wing-spreading state b is set. Note that this maximum wing spreading state b
The diameter from the center of 13 to the tip of the excavation claw 20 is larger than the outer diameter 9 of the concrete pile 33.

Then, the auger shaft 2 is lowered again together with the concrete pile 33 and excavated to a large diameter. Even if the excavating claw 20 is subjected to earth pressure so as to be pushed upward by lowering the auger shaft body 2, the locking claw 21 of the excavating claw 20 is moved to the second escape position of the wing expansion restricting section 23. The locking claw portion 21 is inserted into the second escape portion 27 so as to be engaged with the excavation claw portion.
A first wing expansion restricting portion 24 in which the upper surface of 20 constitutes a second escape portion 27
The movement is restricted by contacting the lower surface of the shaft, and the upward movement of the excavation claw portion 20 together with the shaft portion 18 is restricted, and the maximum wing spreading state b in the second state B is maintained. Diameter excavation can be performed in the maximum wing expansion state b.

Thereafter, when the tip of the concrete pile 33 reaches a predetermined depth, as shown in FIG. 10, only the auger shaft 2 is lowered and excavated, and at least one of water and compressed air is excavated. Instead, the cement slurry is poured out from the discharge port 15, and when excavated to a predetermined depth, the auger shaft 2 is moved up and down, and the excavated soil and the cement slurry are mixed to form soil cement, and the diameter is increased. The excavated portion forms a tip root compaction bulb portion 36 buried with the soil cement.

Then, when the excavation is completed, the pouring of the cement slurry is stopped, and the vertical movement of the auger shaft 2 is stopped and reversed. Due to this reversal, the excavation claw portion 20 located in the second state B causes the earth pressure and the friction from the ground 34,
Alternatively, the shaft 18 rotates together with the shaft 18 in the diameter reducing direction with the shaft 18 as a central axis due to friction with the soil cement, and the side surface on the diameter reducing rotation side of the excavation claw 20 contacts the outer peripheral surface of the shaft 13. The excavation claw 20 indicated by a two-dot chain line in FIG.
Is the minimum diameter reduction state located within the outer diameter range d. In this minimum diameter reduction state, the diameter of the bit 6 is located within the range d of the diameter of the flange portion 14, so that the inner peripheral side of the concrete pile 33 can be inserted.
Then, as shown in FIG. 11, the auger shaft 2 was pulled out from the concrete pile 33 while rotating the auger shaft 2 in the minimum diameter reduced state.
The setting of the concrete pile 33 by the excavation method is completed.

When the soil cement is hardened, the tip root-fixing bulb 36 is integrally fixed to the concrete pile 33, and the concrete pile 33 is supported by the support layer 35 of the ground 34. Further, since the flange portions 14 and 14 are cut out substantially in parallel at the position of the chord, the soil scraped down from the cut portion falls below the bit 6 and the auger shaft 2 is pulled out. At this time, the excavated soil does not overflow from the inner peripheral side of the concrete pile 33 and is put into the concrete pile 33.

As described above, the pair of flange portions 14, 14
A shaft portion 18 integrally provided with an excavating claw portion 20 having a locking claw portion 21 protruding therefrom is held slidably in the vertical direction along the vertical direction in the flange portions 14 and 14 along the vertical direction. , Locking claw 21
Are provided, and a first escape portion 25 and a second escape portion 27 are provided to hold the first state A in which the excavation claw 20 has moved upward or the second state B in which the excavation claw 20 has moved downward. At the same time, in the first state A, from the middle-stage reduced diameter state c to the middle-stage expanded state a
In the second state B, the rotation of the excavation claw 20 is restricted to the rotation range from the minimum diameter reduction state to the maximum wing expansion state b. Since the regulating means 29 is provided, a hydraulic circuit or the like is not required, and the diameter can be enlarged and reduced only by once rotating the auger shaft body 2 without moving it up and down, and the excavation can be performed from the enlarged excavation position which is a desired depth position. The thickness of the flanges 14, 14 irrespective of the diameter of the bit 6 can be set to be large, and the strength of the bit 6 can be improved by increasing the thickness of the flanges 14, 14.

Further, since the excavation claw 20 is rotated in the circumferential direction of the shaft 13, like the flanges 14, 14,
The thickness along the axial direction of 13 can be formed thicker, preventing the excavation claw 20 from being damaged even if a large earth pressure or friction is applied during excavation, improving the life of the excavation claw 20 and improving the excavation efficiency. Can be improved.

Further, since the excavation claw 20 has a shape curved in the excavation direction, as shown in FIG. 12, the excavation claw 20 has a wider wing as compared with the case where the excavation claw 20 is straight. While the tip of 20 faces the excavation direction,
The distance s from the wing expansion restricting portion 23 on the straight line between the rotation center serving as the fulcrum and the wing expanding restricting portion 23 to the tip to which an external force is applied during excavation becomes shorter than the distance t of the linear excavating claw portion 20. In addition, external force due to excavation applied to the shaft portion 18 and the wing expansion regulating portion 23, which are the center of rotation of the excavation claw portion 20, can be reduced, damage at each part can be prevented, and the life and excavation efficiency can be improved.

Further, the rotation restricting means 29 is located on the rotation side of the excavating claw part 20 in the radially expanding direction, and is provided in a wall shape.
And a diameter-reducing restricting portion 28 provided on the rotating side in the diameter-reducing direction and provided in a tongue shape corresponding to the first state A. The part 24 restricts the rotation of the wings to the middle stage widening state a in the first state A, and the second wing expansion restricting part 26 of the wing expansion restricting part 23 sets the maximum wingspan state b in the second state B. In the first state A, the rotation of the blade is restricted to the middle diameter reduction state c, and in the second state B, the rotation of the blade is not restricted and is brought into direct contact with the shaft portion 13 to achieve the minimum diameter reduction state. Therefore, it is possible to easily change the wing-spread state only by reversing the auger shaft body 2 without moving it up and down with a simple structure.

Since the wing expansion restricting portion 23 is located on the wing expansion direction side of the excavation claw portion 20 and the surface on the wing expansion rotation side of the digging claw portion 20 abuts, a large earth pressure during excavation is reduced. Even in the state of being applied to the excavation claw portion 20, the wing expansion restricting portion 23 is not damaged, and the life can be improved.

When the wing expansion state is changed to a reduced diameter state once, the reduced diameter state is not reduced to the minimum reduced diameter state by providing a diameter reduction restricting portion 28, and the diameter is larger than the outer diameter of the flange portion 18. Since the rotation is restricted to the middle stage reduced diameter state c, the earth pressure and friction are easily applied to the excavation claw portion 20 efficiently when the blade is expanded again, and the blade can be smoothly and reliably expanded. And, since the diameter-reducing regulating portion 28 is protruded from the shaft portion 13 without projecting from the excavating claw portion 20, the diameter-reducing regulating portion 28 hinders excavation at the time of excavation by the excavating claw portion 20, and the excavation efficiency is reduced. Can also be prevented.

Further, as a configuration for positioning and holding in the first state A and the second state B, a locking claw provided on the excavation claw 20 is formed by turning the excavation claw 20 for excavation in the radial direction.
21 is locked to the first escape portion 25 and the second escape portion 27 provided in the wing expansion restricting portion 23 to maintain the wing expansion state, and the excavating claw portion 20 is contracted to change the wing expansion state. Since the locking state is released by rotating in the radial direction, that is, the wing-spreading state is released, positioning in the vertical direction with the rotation of the excavation claw portion 20 can be easily performed with a simple configuration, and a simple With the configuration, it is possible to easily change the wing-spread state only by reversing the auger shaft body 2 without moving it up and down.

Further, since a discharge port 15 which is located between the pair of flange portions 14 and 14 and communicates with the inner peripheral side of the shaft portion 13 and through which a fluid such as water or cement slurry can flow is opened, the discharge port 15 By allowing fluids such as water and cement slurry to flow out, excavated soil can be prevented from accumulating between the flanges 14 and 14, and the excavation claw 20 can be smoothly expanded and contracted, and the excavated soil can be efficiently removed. It can be scraped and the excavation efficiency can be improved.

Further, since the excavation claw 20 is integrally provided on the shaft portion 18 and the excavation claw portion 20 is moved up and down together with the shaft portion 18, earth and sand excavated between the shaft portion 18 and the excavation claw portion 20 bite. Therefore, it is possible to prevent the excavation claw portion 20 from being unable to move up and down, and to smoothly and reliably change the wing-spreading state.

In the above embodiment, the excavation claw portion
Although a pair of shaft portions 18 integrally provided with 20 have been described, a plurality of shaft portions 18 may be provided. Further, the shaft portion 18 may be provided integrally with the flange portions 14, 14, and the excavation claw portion 20 may be pivotally supported on the shaft portion 18 so as to be able to rotate and slide vertically.

Further, the shaft supporting portion is not limited to the flange portions 14 and 14 provided in a flange shape, but supports the shaft portion 18 such as a tongue-shaped projecting shape. May be formed to have a size smaller than the inner diameter so that the shaft portion 18 can be inserted. The shape is not limited to a pair, and may be one as long as the shaft portion 18 can be supported.

Further, as the positioning means, the locking claw 21 is projected from the excavation claw 20, and the first escape portion 25 and the second escape portion 27 are provided on the wing expansion regulating portion 23. The first state A and the second state B, for example, by providing a projection or the like for holding the excavation claw section 20 on the wing expansion regulating section 23 such as the first wing expansion regulating section 24.
Any configuration that holds is possible.

Further, the rotation restricting means 29 may have any structure for restricting the rotation to the wing-expanded state and the reduced-diameter state. It is not limited to the two stages of b, and it may be possible to expand the wings in multiple stages.

In the middle-stage reduced diameter state c, the diameter may be larger than the inner diameter of the concrete pile 33, and the lower end of the concrete pile 33 may be hit with the excavation claw portion 20 to set the second state B.

Next, another embodiment of the present invention will be described with reference to FIGS.

The embodiment shown in FIG. 13 and FIG. 14 is a diameter reduction in which the rotation of the excavation claw portion 20 in the diameter reduction direction of the embodiment shown in FIGS. In this configuration, the restricting portion 28 is not provided, and the diameter is reduced to the minimum diameter by rotating in the diameter reducing direction.

That is, reference numeral 41 denotes a digging claw portion.
In the embodiment 41, the curved excavation claw 41 of the embodiment shown in FIGS. 1 to 12 is formed in a substantially rod shape without being curved substantially, and the distal end side is gradually narrowed to provide the hard member 19 at the distal end. .

Then, the excavation claw portion 41 is the first claw shown in FIG.
From the middle stage widening state a in the state A to the second state B shown in FIG.
When the auger shaft body 2 is reversed in order to change the spread state to the maximum spread state b, the surface of the excavation claw portion 41 on the diameter reducing side abuts on the outer peripheral surface of the shaft portion 13 and the tip portion is 1 and is rotated to a position having a small diameter substantially equal to or less than the outer diameter of the flange portions 14, 14.
3 and a minimum diameter reduction state as shown in FIG. Due to the rotation in the diameter reducing direction, similarly to the embodiment shown in FIGS. 1 to 12, the locking claw 21 of the excavation claw 41 is disengaged from the first escape portion 25 and the lower flange 14 side And moves to the second state B.

In this minimum diameter reduction state, FIGS.
The space between the inner surface of the excavation claw 41 on the rotation side and the shaft 13 is wider than in the case of the embodiment shown in FIG. For this reason, when the auger shaft 2 is rotated forward again, earth pressure and friction are applied to the excavation claw portion 41, and the auger shaft 2 is reliably rotated in the wing-spreading direction. And the second state B
As a result, the excavation claw portion 41 is brought into the maximum wing-spreading state b as shown in FIG.

As described above, the shape of the excavation claw portion 41 eliminates the need for the diameter-reducing regulating portion 28 for restricting the rotation to the middle-stage diameter-reducing state c shown in FIGS. Is improved.

Next, still another embodiment of the present invention will be described with reference to the drawings.

In FIG. 15 to FIG. 21, reference numeral 51 denotes a bit as an excavator.
As in the embodiment shown in FIG. 2, the inner peripheral side is formed in a substantially cylindrical shape communicating with the inner peripheral side of the auger shaft body 2, and has a joint portion 11 connected to the auger shaft body 2 at one end and a distal end at the other end. The shaft 52 has the excavating blade 12 protruding toward the shaft 52. In addition, a sliding portion 53 having an outer peripheral surface having a substantially hexagonal column shape and a diameter smaller than both end portions is provided at an intermediate portion of the shaft portion 52. Further, on the outer peripheral surface of the cylindrical large-diameter portion 54 of the shaft portion 52, spiral-shaped scraping auxiliary wings 31, 31 are provided in the same direction as the spiral direction of the scraping blade 5 of the auger shaft body 2. . Also, the sliding portion of the large-diameter portion 54 located below the tip end side of the shaft portion 52
A pressing plate 55 is integrally provided on the 53-side edge in a flange shape. The sliding portion 53 of the shaft portion 52 has an opening (not shown) formed in the same manner as in the embodiment shown in FIGS.

Then, on the outer peripheral surface of the sliding portion 53 of the shaft portion 52,
A pair of plate-shaped flange portions 56, 56 facing each other along the vertical direction which is the axial direction of the shaft portion 52 is provided. These flange portions 56, 56 are formed in a substantially disk shape and symmetrically with respect to the center, and are provided with projecting tongue pieces 57, 57 as shaft support portions in the diameter direction. A substantially hexagonal insertion hole 58 into which the moving part 53 is inserted is formed, and the shaft part 52 is movable in the opposite direction along the axial direction of the shaft part 52 and cannot rotate with respect to the shaft part 52. Are provided on the sliding portion 53 of the. Further, notches 59 are formed in the flanges 56, 56, respectively, at one edge of a symmetrical position on the base end side of the shaft tongue pieces 57, 57.

The distance d from the center, which is the outermost diameter of the flanges 56, 56, to the tips of the tongue pieces 57, 57 is slightly smaller than the inner diameter of the concrete pile 33.

Further, the tongue piece portions 57, 57 of the flange portions 56, 56
At the center of 57, substantially circular insertion holes 16, 16 are provided, respectively, and substantially cylindrical shaft portions 61, 61 are rotatably provided in the pair of opposed insertion holes 16, 16, respectively. These shaft portions 61, 61 are provided at one end with a flange 62 which is larger in diameter than the insertion hole 16 and is locked to the flange 56, and the flange 62 is locked to the upper surface of the flange 56 located above. And is rotatably supported in a state where it is prevented from falling off.

Further, the shaft portions 61, 61 have excavation claw portions.
63 is located between the flange portions 56, 56, the other end is integrally fixed, and one end is provided rotatably with the shaft portion 61, respectively. These excavation claws 63, 63 include a cylindrical portion 64 fitted to the shaft portion 61, an arm portion 65 protruding outward on the outer peripheral surface of the cylindrical portion 64, and a lower side which is one side of a tip of the arm portion 65. The excavation blade portion 66 is formed on the shaft portions 61 and 61 so that the excavation blade portion 66 protrudes downward from the flange portion 56 located below. The arm
On the upper surface side of 65, a planar contact surface 67 is provided in a rotation direction which is a substantially horizontal direction. Furthermore, the excavation claw 63 has an arm
A locking claw 69 constituting the rotation restricting means 68 is provided so as to protrude from the side from which the protrusion 65 protrudes in the radial direction.

Further, a coil spring 70 as a biasing means constituting a positioning means is sandwiched between the pressing plate 55 and the lower flange portion 56 on the sliding portion 53 of the shaft portion 52. It is always urged toward the auger shaft 2 side.
Further, on the outer peripheral surface side of the coil spring 70, a pair of cylindrical cover portions which are substantially cylindrical and one of which is freely insertable into the other is provided.
71, 71 are provided. One of these cover portions 71, 71 is provided integrally with the lower surface of the lower flange portion 56, and the other is provided integrally with the presser plate 55, and the fitted state is changed corresponding to expansion and contraction of the coil spring 70. The earth and sand do not contact the coil spring 70.

The lower flange portion 56 of the coil spring 70 is urged upward, so that the excavation claw portions 63, 63 provided so as to be substantially sandwiched between the pair of flange portions 56, 56 are formed. The upper flange portion 56 is urged upward through the upper portion and abuts against the end surface of the large diameter portion 54 of the upper shaft portion 52, and the pair of flange portions 56, 56 are integrated without changing the facing distance. Move.

Further, between the flange portions 56, 56, the locking claw portions 69 are located on the side facing the sliding portion 53 of the shaft portion 52, and the excavation claw portions 63, 63 rotate in the wing-spreading direction. , 69 constitute a pair of plate-like first members forming a wing-spreading restricting portion of the rotation restricting means 68 with which they contact.
The wing expansion restricting portions 73, 73 are provided so as to connect the flange portions 56, 56.

Further, the large-diameter portion located above the shaft portion 52
The notch of the flanges 56, 56
59, and project downward in a wall shape so as to engage with the notches, and engage with the locking claws 6 when the excavating claws 63, 63 rotate.
A second wing expansion restricting portion 74 that constitutes the wing expansion restricting portion of the rotation restricting means 68 with which the 9, 69 contacts is provided. The second wing expansion restricting portion 74 is urged by the coil spring 70 to be in the first state A in which the flange portion 56 is in contact with the upper large-diameter portion 54.
And projecting between the flanges 56, 56 so as to retreat from between the flanges 56, 56 when the flanges 56, 56 move downward by a predetermined distance against the bias of the coil spring 70. ing. Note that a gap is provided between the first wing expansion restricting portion 73 and the second wing expansion restricting portion 74 so that the locking claw portion 69 can be interposed therebetween. Then, the first blade expansion restricting portion 73, the second blade expansion restricting portion 74, and the locking claw portion 69 of the excavation claw portion 63 turn the rotation restricting means 68.
Is configured.

Next, the excavation operation of the embodiment shown in FIGS. 15 to 21 will be described with reference to the drawings.

First, similarly to the embodiment shown in FIG. 1 to FIG. 12, a bit 51 is inserted into the support pillar 4 erected on the base vehicle 1 on the inner peripheral side of the concrete pile 33 serving as a pile. The auger shaft body 2 to which is attached is mounted so that the axial direction is substantially vertical. In this state, the flange portions 56 are urged upward by the urging of the coil spring 70, and the excavation claw portion 63 is located in the first state A on the upper side.

The auger shaft 2 is lowered together with the concrete pile 33 and driven while at least one of water and compressed air is appropriately discharged from the discharge port of the bit 51 through the inner peripheral side of the auger shaft 2. The concrete pile 33 is laid while excavating a predetermined position of the ground 34 by driving the means 3 in the normal rotation direction. During this excavation, even if the earth pressure is applied from the ground 34 due to the lowering of the auger shaft 2,
Since the coil spring 70 is in the biasing direction, the flange portions 56 do not move, and the first state A is maintained.

Further, the forward rotation of the auger shaft 2 causes the ground 34 to rotate.
The excavation claw 63 receives shaft pressure and friction from
It rotates with the shaft part 61 in the radially expanding direction about the shaft part 61 as a central axis. Then, by the rotation in the radially expanding direction in the first state A, as shown in FIGS. 15 and 16, the locking claw 69 of the excavation claw 63 is moved to the first position of the wing expansion restricting portion of the rotation restricting means 68. (2) A middle-stage wing that comes into contact with the outer surface side of the wing expansion restricting portion 74, and whose diameter from the center of the shaft portion 52 to the tip of the excavation claw portion 63 is substantially the same as or slightly smaller than the outer diameter of the concrete pile 33. The state becomes a.

Further, as shown in FIG.
When the auger shaft 2 reaches the intermediate layer 75 which is a hard part of 34, the lowering and rotation of the auger shaft 2 are stopped. Then, the auger shaft body 2 is once pulled up, the contact surface 67 of the excavation claw 63 in the middle-stage widened state a is brought into contact with the lower end surface of the concrete pile 33, and further raised by a predetermined distance. That is, the second wing expansion restricting section 74
Is longer than the distance protruding between the flanges 56, 56, and
Increase the distance until the coil spring 70 expands and contracts to the maximum.

With the lifting of the auger shaft 2, the excavation claw 63 is pushed downward relative to the shaft 52. For this reason, this excavation claw 63 is
By being pushed downward at the lower end surface of 33,
A pair of flanges 5 against the bias of the coil spring 70
6 and 56 move downward relative to the shaft 52, and the second state B is reached in which the excavation claw 63 is located below.

Then, due to the relative downward movement of the flanges 56, 56, the second wing expansion restricting portion 74 provided on the shaft 52 is retracted from between the flanges 56, 56. By rotating the auger shaft 2 forward again in the second state B, the excavation claw 63 rotates again in the wing-spreading direction due to friction with the lower end surface of the concrete pile 33, earth pressure, and the like. And flange part 5
6 and 56 move below the shaft portion 52, and the second blade expansion restricting portion 74 is retracted from between the flange portions 56 and 56, so that the rotation from the minimum diameter reduction state to the maximum blade expansion state b is performed. There is no member to restrict, and the excavation claws 63, 63 rotate in the wing-spreading direction, so that the locking claws 69 of the excavation claws 63, 63 abut on the first wing-expansion restricting portion 73 to be restricted in rotation. , The maximum wing-spread state b.

Thereafter, the auger shaft 2 is lowered again while rotating forward. By the lowering of the auger shaft 2, the force for pressing the excavation claw 63 downward at the lower end of the concrete pile 33 is released, and the urging of the coil spring 70, the earth pressure, etc., together with the flanges 56, 56 are performed again. Drilling claw 6
3 and 63 move upward with respect to the shaft portion 52 and enter the first state A.

The excavation claw 63 in the maximum wing spreading state b,
When 63 is in the first state A, the second widening restricting section is again activated.
74 protrudes between the flanges 56, 56, and the locking claw 69 is positioned so as to be sandwiched between the first wing expansion restricting portion 73 and the second wing expansion restricting portion 74. Rotation of the excavation claw 63 in the diameter reducing direction is restricted, the maximum wing expanding state b is maintained, and digging is performed in the maximum wing expanding state b. By this diameter excavation, the friction between the concrete pile 33 and the hard intermediate layer is reduced and minimized, and the concrete pile 33 can be easily laid.

Then, at the point where the position of the diameter excavation has passed the intermediate layer 75 which is a hard part of the ground 34, the lowering and rotation of the auger shaft 2 are stopped again, the auger shaft 2 is pulled up, and the maximum expansion is performed. The abutting surfaces 67, 67 of the excavating claws 63, 63 in the wing state b are abutted so as to be pressed down by the lower end surface of the concrete pile 33, and a pair of flange portions 56 are pressed against the bias of the coil spring 70. , 56 are moved downward relative to the shaft 52, and the excavation claws 63, 63 are brought into the second state B located below. The auger shaft body is in a second state B in which the second wing expansion restricting portion 74 is retracted from between the flange portions 56 and 56 and there is no member for restricting rotation from the minimum diameter reduction state to the maximum wing expansion state b. 2
And the excavation claws 63, 63 are rotated in the diameter reducing direction by friction with the lower end surface of the concrete pile 33, earth pressure, or the like. Due to the reverse rotation of the auger shaft 2, the surfaces of the excavation claws 63, 63 on the diameter reduction rotation direction side contact the first blade expansion restricting portion 73 to be in the minimum diameter reduction state.

Thereafter, the auger shaft 2 is lowered, and the abutting surfaces 67, 63 of the excavating claws 63, 63 extend from the lower end surface of the concrete pile 33.
The excavation claw portions 63 and 63 are moved upward with respect to the shaft portion 52 together with the flange portions 56 and 56 by the bias of the coil spring 70 again, and the second wing expansion restricting portion 74 is moved by the flange portions 56 and 56.
The first state A is protruded between. Then, in this first state A, the auger shaft 2 is lowered while rotating forward, and the excavation claws 63, 63 are rotated in the radially expanding direction by the earth pressure and friction from the ground 34, so that the locking claws 69 , 69 abut on the outer surface side of the second blade expansion restricting portion 74 to expand the blade to the middle-stage widening state a and excavate.

Further, when the excavation position reaches the support layer 35, which is a hard part of the ground 34, as shown in FIG. 21, the auger shaft 2 is pulled up similarly to the case where the excavation position reaches the middle layer 75. The auger shaft 2 is lowered to the first state A at the time when the state is changed to the second state B and the maximum wing state is reached by the forward rotation, and the diameter is excavated in the maximum wing state b.

When the tip of the concrete pile 33 reaches a predetermined depth, similarly to the embodiment shown in FIGS. 1 to 12, only the auger shaft 2 is lowered and excavated, and water and water are excavated. A cement slurry is discharged from a discharge port (not shown) instead of at least one of the compressed air, and the auger shaft 2 is moved up and down at the time of excavation to a predetermined depth to mix the excavated soil with the cement slurry. The cement is formed, and a portion excavated to a large diameter forms a tip root-fixing bulb portion 36 in a state of being buried with the soil cement.

When the excavation is completed, the pouring of the cement slurry is stopped, the auger shaft 2 is once pulled up, and the contact surfaces 67, 67 of the excavation claws 63, 63 in the maximum wing-spreading state b are concreted. The lower end surface of the pile 33 abuts against the state of being pressed down, and the pair of flange portions 56, 56 moves downward relative to the shaft portion 52 against the bias of the coil spring 70,
The excavation claw portions 63 are set to the second state B located below. The auger shaft body is in a second state B in which the second wing expansion restricting portion 74 is retracted from between the flange portions 56 and 56 and there is no member for restricting rotation from the minimum diameter reduction state to the maximum wing expansion state b. The excavation claws 63 are rotated in the diameter reducing direction by friction with the lower end surface of the concrete pile 33, earth pressure, or the like. Due to the reverse rotation of the auger shaft body 2, the surface of the excavation claw portions 63, 63 on the diameter reduction rotation direction side comes into contact with the shaft portion 52 to be in a minimum diameter reduction state.

In this minimum diameter reduction state, the diameter of the bit 51 is located within the range d of the diameter of the flanges 56, 56 slightly smaller than the inner circumference of the concrete pile 33. The inner peripheral side of the concrete pile 33 can be inserted. That is, the abutting surface of the excavation claw portion 41 is separated from the lower end surface of the concrete pile 33 and located on the inner diameter side. Then, the auger shaft body 2 is rotated in the minimum reduced diameter state and pulled out from the concrete pile 33 while maintaining the minimum reduced diameter state to complete the subsidence of the concrete pile 33 by the excavation method.

Then, by hardening of the soil cement, the tip root-fixing bulb 36 is integrally fixed to the concrete pile 33, and the concrete pile 33 is supported by the support layer 35 of the ground 34. Further, since the flange portions 56, 56 are cut out substantially in parallel at the positions of the strings, the soil scraped down from the cut-out portion falls below the bit 51, and the auger shaft 2 is pulled out. At this time, the excavated soil does not overflow from the inner peripheral side of the concrete pile 33 and is put into the concrete pile 33.

As described above, FIGS.
According to the embodiment shown, when the hard intermediate layer 75 is located before reaching the support layer 35 supporting the concrete pile 33, the concrete pile is once excavated, so that the concrete pile
Since the friction between 33 and the intermediate layer 75 is reduced and minimized, it is possible to prevent the concrete pile 33 from being unable to be laid, and to lay the concrete pile 33 easily.

Further, since the diameter can be reduced again to the middle-stage widening state a after passing through the middle layer 75, in the configuration in which once the maximum widening state b is reached, the widening state cannot be changed to the middle-stage widening state a. The excavation of the concrete pile 33 from 75 to the support layer 35 in the maximum wing state b can be prevented from lowering, so that the concrete pile 33 can be stably laid down.

Then, a pair of movable flanges 56 urged by a coil spring 70 as urging means,
The excavation claws 63, 63 pivotally supported in the radial direction between 56,
Since the rotation is restricted by the second wing expansion restricting portion 74 which advances and retreats by the movement of the flange portions 56, the switching between the middle wing expansion state a and the maximum wing expansion state b can be appropriately performed with a simple configuration.

Further, as the excavation claw 63, the excavation blade 66 is provided at the end of the arm 65 so as to project obliquely and obliquely downward, so that the excavation claw 63 is rotatably supported in the radial direction. However, the excavation blade portion 66 protrudes in the excavation direction side, which is the descending direction of the auger shaft 2, so that the excavation efficiency is improved, the earth pressure and friction from the ground 34 are easily received, and the wing expansion and diameter reduction are performed. Rotation in the direction can be performed smoothly and reliably.

In the embodiment shown in FIGS. 15 to 21, the urging means is a coil spring.
The configuration is not limited to 70, and may be any configuration that restricts the movement of the flange portions 56, 56 by an urging force, such as an elastic member having elasticity or a leaf spring.

The excavation claw portions 63 may have any structure such as the excavation claw portion 20 of the embodiment shown in FIGS.

Although the excavation claw 63 is provided integrally with the shaft 61, the shaft 61 may be fixed to the flange 56 and rotatably supported on the shaft 61.

As the structure for restricting the rotation of the excavation claw 63, the second wing expansion restricting portion 74 has been described as projecting from the shaft 52. For example, the flanges 56, 56 are fixed to the shaft 52. Then, by pulling out the auger shaft 2, the second wing expansion restricting portion 74 moves against the urging force of the urging means such as the coil spring 70 and retreats from between the flange portions 56. The flange portions 56, 56 and the second wing expansion restricting portion 74 are relatively movable against the urging of the urging means, thereby restricting the rotation of the excavation claw portions 63, and releasing the restriction of the rotation. Any structure that can be used.

The sliding portion 53 of the shaft portion 52 is formed in a substantially hexagonal column shape, and the locking claw portions of the excavation claw portions 63, 63 are provided between the flange portions 56, 56.
The first for restricting the rotation to the maximum wing-spreading state b when the 69 and 69 come into contact with each other
Although the wing expansion regulating portion 73 is provided so as to be in sliding contact with the outer peripheral surface of the shaft portion 52, the symmetric surface of the shaft portion 52 is formed into a bulged flat hexagonal column, and the bulging portion is formed by the first wing expansion restricting member. The locking claw 69 as a part 73 abuts on the first wing expansion restricting part 73 of the bulged part which is the outer peripheral surface of the shaft part 52, thereby restricting the rotation to the maximum wing-spreading state b. The shaft part is the turning side in the diameter reduction direction of
The rotation may be restricted to the minimum diameter reduced state by contacting the first wing expansion restricting part 73 which is a part of the part 52.

Next, still another embodiment of the present invention will be described with reference to FIGS.

The embodiment shown in FIGS. 22 to 26 is different from the embodiment shown in FIGS.
Excavation claw 6 similar to the embodiment shown in FIGS.
A diameter reducing portion 81 for restricting the rotation of the members 3 and 63 in the diameter reducing direction is provided.

That is, in FIGS. 22 to 26,
The diameter reducing portion 81 is provided between the flange portions 56 on the outer peripheral surface of the sliding portion 53 of the shaft portion 52 so as to be located on the rotation side in the diameter reducing direction of the excavating claws 63, 63. When the portions 63, 63 rotate in the diameter reduction direction, they have a diameter reduction restricting projection 82 that comes into contact with the surface on the diameter reduction rotation side to restrict the diameter reduction rotation. In addition, the diameter-reducing regulating projection 82 is
When the excavation claw portions 63, 63 between the flange portions 56, 56 are positioned in the first state A by the bias of the coil spring 70, the excavation claw portions 63, 63 are located close to the flange portion 56 located below, and
The flange portion 56 is located above in the second state B in which the 56 moves downward with respect to the shaft portion 52 against the bias of the coil spring 70.
It protrudes so as to be located close to 56.

[0107] The lower end surface of the excavation claw 63 is provided with a diameter-reducing restricting recess 83 which is recessed downward.
The diameter-reducing restricting concave portion 83 is formed by an excavating claw portion between the flange portions 56, 56.
When the excavation claw portions 63, 63 rotate in the diameter reducing direction in a state where the 63, 63 are located in the first state A, the diameter reduction restricting projection 82 is inserted into the diameter reduction concave portion 83, and the excavation claw portion 63 is inserted. , 63 is the shaft part
The diameter of the excavation claws 63, 63 is reduced in the diameter reducing direction while the flange portions 56, 56 are located in the second state B, in a state where the diameter of the excavation claws 63, 56 is in the second state B. 25, the diameter-reducing restricting projection 82 is not inserted into the diameter-reducing restricting recess 83, but comes into contact with the surface of the excavating claws 63, 63 on the diameter-reducing rotating side, and the middle-step diameter reducing state c shown in FIG. To restrict the diameter reduction rotation.

[0108] In this middle stage reduced diameter state c, the excavation claw 6
In this state, the distal ends of 3, 63 are located in a range larger in diameter than the range d of the outer diameter of the flange portions 56, 56 and smaller in diameter than the middle stage widening state a.

The diameter-reducing regulating projection 81 and the diameter-reducing regulating recess 83 constitute a diameter-reducing regulating section 81.

Next, the operation of the embodiment shown in FIGS. 22 to 26 will be described.

As a result of the earth pressure and friction from the ground 34 due to the excavation, as shown in FIGS.
The locking claws 69, 69 abut against the outer surfaces of the second wing expansion restricting portions 74, 74, respectively, so that the excavating claws 63,
63 excavates by expanding the wing to the middle stage widening state a.

When the excavation position reaches the middle layer 75 which is a hard part of the ground 34, the lowering and rotation of the auger shaft 2 are stopped, and the auger shaft 2 is pulled up. As shown, the excavation claws 63 in the middle stage widening state a,
The abutting surfaces 67, 67 of the concrete pile 33 are pressed down by the lower end surface of the concrete pile 33, and the pair of flange portions 56, 56 are pivoted against the bias of the coil spring 70.
The excavation claw portions 63 move to a second state B located below the excavation claw portions 63, 63. This second wing expansion restricting part 7
The auger shaft 2 is rotated forward in the second state B in which the members 4 and 74 are retracted from the flange portions 56 and 56 and have no member for restricting the rotation from the minimum diameter reduction state to the maximum wing expansion state b. As shown in FIG. 26, the excavation claws 63 are rotated in the wing-spreading direction by friction with the lower end surface of the concrete pile 33, earth pressure, or the like,
The auger shaft 2 is lowered while the maximum wing-spreading state b is set, and the excavation claws 63, 63 are moved upward with respect to the shaft 52 together with the flanges 56, 56 by the urging of the coil spring 70.
The state A is set to the state A, and the maximum wing expanding state b is maintained to perform the diameter excavation.

When the intermediate stage 75 is returned to the middle-stage widening state a again, the lowering and rotation of the auger shaft 2 are stopped again, the auger shaft 2 is pulled up, and the excavation in the maximum widening state b is performed. The contact surfaces 67, 67 of the claws 63, 63 are pressed down by the lower end surface of the concrete pile 33, respectively.
A pair of flanges 5 against the bias of the coil spring 70
6, 56 are moved relatively downward with respect to the shaft 52, and the excavation claws 63, 63 are brought into the second state B located below. This second
The auger shaft 2 is reversed in a state where the second wing expansion restricting portion 74 in the state B is retracted from between the flange portions 56, 56, and the excavation claw portions 63, 63 are caused by friction with the lower end surface of the concrete pile 33 or earth pressure. Rotate 63 in the diameter reducing direction. Due to the reverse rotation of the auger shaft 2, as shown in FIG. 25, the surfaces of the excavation claws 63, 63 on the side of the diameter-reducing rotation contact the distal end of the diameter-reducing restricting projection 82 so that the middle-stage reduced state c Becomes

Thereafter, the auger shaft 2 is lowered, and the abutting surfaces 67, 63 of the excavating claws 63, 63 extend from the lower end surface of the concrete pile 33.
The excavation claw portions 63 and 63 are moved upward with respect to the shaft portion 52 together with the flange portions 56 and 56 by the bias of the coil spring 70 again, and the second wing expansion restricting portion 74 is moved by the flange portions 56 and 56.
The first state A is protruded between. Then, in the first state A of the middle-stage reduced diameter state c, the auger shaft body 2 descends while rotating forward, and the excavation claws 63, 63 are caused by the earth pressure and the friction from the ground 34.
Is rotated in the diameter-expanding direction, and the engaging claw 69 abuts on the outer surface side of the second wing expansion restricting portion 74 to expand the wing into the middle wing expansion state a and excavate.

Further, when the excavation position reaches the support layer 35 which is a hard part of the ground 34, the auger shaft 2 is pulled up to the second state B as in the case where the excavation position reaches the intermediate layer 75, and The auger shaft 2 is lowered to the first state A at the point of time when the rolled state reaches the maximum wing-spreading state b, and the diameter is excavated in the maximum wing-spreading state b.

When the tip of the concrete pile 33 reaches a predetermined depth, similarly to the embodiment shown in FIGS. 1 to 12, only the auger shaft 2 is lowered and excavated, and water and A cement slurry is discharged from a discharge port (not shown) instead of at least one of the compressed air, and the auger shaft 2 is moved up and down at the time of excavation to a predetermined depth to mix the excavated soil with the cement slurry. The cement is formed, and a portion excavated to a large diameter forms a tip root-fixing bulb portion 36 in a state of being buried with the soil cement.

When the excavation is completed, the pouring of the cement slurry is stopped, the auger shaft 2 is once pulled up, and the contact surfaces 67, 67 of the excavation claws 63, 63 in the maximum wing-spread state b are concreted. The lower end face of the pile 33 abuts on the lower surface, and the pair of flange portions 56, 56 move downward relative to the shaft portion 52 against the bias of the coil spring 70, thereby excavating. The claw portions 63 are set to the second state B located below. In the second state B in which the second wing expansion restricting portion 74 is retracted from between the flange portions 56 and 56 and there is no member for restricting the rotation from the middle-stage reduced diameter state c to the maximum wing expansion state b, the auger shaft The body 2 is reversed, and the excavation claws 63, 63 are rotated in the diameter reducing direction by friction with the lower end surface of the concrete pile 33, earth pressure, or the like. Due to the reverse rotation of the auger shaft 2, the surface of the excavation claw portions 63, 63 on the diameter reduction rotation direction side comes into contact with the diameter reduction restricting projection 82 to be in the middle-stage reduced diameter state c.

Thereafter, the auger shaft 2 is lowered, the contact surfaces 67, 67 of the excavation claw 63 are separated from the lower end surface of the concrete pile 33, and together with the flanges 56, 56 by the urging of the coil spring 70 again. The excavation claw portion 63 is moved upward with respect to the shaft portion 52, so that the second wing expansion restricting portion 74 is in the first state A in which it protrudes between the flange portions 56, 56. In this first state A, the shaft portion
The diameter-reducing regulating projection 82 protruding from the outer peripheral surface of the 52 and the diameter-reducing regulating concave portion 83 of the excavation claw 63 face each other. By further reversing the auger shaft 2 in the first state A in the middle-stage reduced diameter state, the excavation claw portion is formed by the earth pressure and friction from the ground 34.
The diameter-reducing regulating projections 82, 82 are inserted into the diameter-reducing regulating recesses 83, 83 of the 63, 63, respectively. The first wing expansion restricting portion 73 bulges integrally with the first wing-spreading restricting portion 73 to be brought into a minimum diameter reduced state.

Then, the auger shaft body 2 is pulled out from the concrete pile 33 while rotating the auger shaft 2 in the minimum reduced diameter state while rotating the auger shaft 2 in a reverse direction so as not to expand the wings, thereby completing the setting of the concrete pile 33 by the digging method.

According to the embodiment shown in FIGS. 22 to 26, when the diameter is reduced at the time of switching between the middle stage expanded state a and the maximum expanded state b, the diameter is reduced from the minimum reduced state by the diameter reduction regulating unit 81. Since the diameter reduction is regulated to the middle diameter reduction state c where the diameter is large and the earth pressure is easily received, the excavation claws 63, 63 are easily and surely formed by the earth pressure when rotating forward and rotating in the diameter increasing direction again. Can expand the wings.

[0121]

According to the first aspect of the present invention, the excavation claw portion rotatably provided around the shaft portion supported by the shaft support portion of the shaft portion in the direction of the wing-spreading is maximized. A rotation restricting means for restricting the rotation to the widening state and the middle-stage widening state, and restricting the rotation in the diameter reducing direction to the minimum diameter reducing state. Maintains the state where the rotation of the excavation claw is restricted to the maximum widening state and the middle stage widening state when the shaft rotates forward, and releases the restriction on the rotation of the excavation claw when the shaft rotates reversely Since the positioning means is provided, the diameter can be increased and reduced from a desired excavation position only by forward / reverse rotation of the shaft portion.

According to the digging device of the second aspect, in addition to the effect of the digging device of the first aspect, the excavating claw portion movably provided in the axial direction between the shaft support portions opposed in the axial direction is provided.
When the excavation claw is positioned in the first state, the excavation claw is held by the positioning means in a first state close to the upper shaft support and a second state proximate to the lower shaft support. When the excavation claw is located in the second state, the rotation of the excavation claw is restricted to the range of the minimum diameter reduction state and the maximum expansion state. Since the rotation restricting means for restricting the rotation is provided, the diameter can be expanded and reduced from the desired excavation position only by rotating the shaft forward and backward, and the thickness of the shaft support can be set thicker, thereby simplifying the structure for improving the strength. And can be easily obtained.

According to the third aspect of the present invention, in addition to the effect of the second aspect, only when the excavation claw is located in the first state, the excavation claw is rotated in the diameter reducing direction. Since the rotation restricting means is provided in the rotation restricting means for restricting the rotation in the diameter reduction direction to the middle diameter reduction state by abutting, once the diameter is reduced for the wing expansion, the wing expansion rotation is again performed by the earth pressure. When moving, the earth pressure is efficiently applied to the excavation claw, and the excavation claw can easily rotate the wings, and by reversing from the maximum wing expansion state, it becomes the minimum diameter reduction state for pulling out from the pile Therefore, different diameter reduction states can be easily obtained with a simple structure, and the wing expansion state and the diameter reduction state can be easily changed.

According to the excavator of the fourth aspect, in addition to the effects of the excavator of the second or third aspect, in addition to the excavator, the excavation claw is integrated with the shaft portion provided on the shaft support portion so as to be slidable in the axial direction. Since the rotation restricting state is released by the positioning means by the rotation of the excavation claw and the reverse rotation of the shaft, the movement along the axial direction of the shaft is integrated with the shaft and the excavation claw. It is possible to prevent the excavated earth and sand from biting and hindering the movement of the excavation claw portion, and to smoothly and reliably change the wing-spread state.

According to the excavator of the fifth aspect, in addition to the effect of the excavator of the first aspect, the positioning means may be any one of the excavation claw, the rotation restricting means and the shaft. In order to maintain and release the state of rotation control of the excavation claw part by the rotation of the auger shaft body by locking the locking claw part provided on one side to the other, the maintenance and release of the state of rotation restriction are performed. The configuration can be simplified, and the rotation restricted state can be easily maintained and released only by the rotation operation of the auger shaft body.

According to the excavator of the sixth aspect, in addition to the effect of the excavator of the first aspect, a pair of shaft supports movably provided on the shaft while maintaining a distance facing the shaft in the axial direction. The positioning means for biasing the portion toward the auger shaft body is provided, and when the shaft supporting portion moves toward the tip end of the shaft portion against the biasing of the biasing means, the excavating claw portion is Rotation is restricted so as to be freely rotatable in the range of the minimum diameter reduction state and the maximum wing expansion state, and the rotation of the excavation claw is minimized when the shaft support moves toward the auger shaft body by the biasing means. Rotation restricting means for restricting the range between the reduced diameter state and the middle stage expanded state and the maximum expanded state is provided. Diameter excavation is possible.

According to the excavating device of the seventh aspect, in addition to the effect of the excavating device of the sixth aspect, since the excavating claw is provided with a contact surface which is in contact with the lower end surface of the pile, the excavating claw and the pile can be connected to each other. The contact area with the lower end surface increases, and the excavation claw portion can be easily brought into contact with the lower end portion of the pile without being damaged, and the wing expansion and the reduced diameter state can be easily changed.

According to the excavator of the eighth aspect, in addition to the effects of the excavator of the sixth or seventh aspect, a concave portion is formed at the tip of the shaft of the excavation claw and on the edge on the side of the diameter reducing rotation. When the excavation claw is rotated in the diameter reduction direction in a state where the shaft support is moved toward the distal end of the shaft portion against the urging of the urging means, the diameter of the excavation claw is reduced. When the excavation claw rotates in the diameter-reducing direction while the shaft supporting portion moves toward the auger shaft body by the urging of the urging means, excavation is performed. Since the diameter-reducing regulating portion to be inserted into the concave portion of the claw portion is located between the pair of shaft support portions on the turning side of the excavating claw portion in the diameter-reducing direction and protrudes from the shaft portion, the shaft portion is easily configured with a simple configuration. The diameter expansion and diameter reduction excavation can be performed from a desired excavation position only by the forward / reverse rotation of.

According to the digging device of the ninth aspect, in addition to the effect of the digging device of the first aspect, the rotation restricting means is located on the rotation side of the excavation claw in the wing-spreading direction. And
A wall-shaped wide-spreading restricting section is provided to control the widening of the excavation claw portion between the middle-stage widening state and the maximum widening state by abutting the widening rotation side of the excavation claw. Can be easily changed.

According to the excavator of the tenth aspect, in addition to the effect of the excavator of the first aspect,
Because the shaft portion is located between the pair of shaft support portions and the discharge port through which the fluid can flow through the inner peripheral side is opened, the soil excavated by flowing the fluid from the discharge port is between the shaft support portions. Accumulation can be prevented, the excavation claw portion can be smoothly expanded and contracted, and the excavation efficiency can be improved.

[Brief description of the drawings]

FIG. 1 is a front view showing a bit according to an embodiment of the present invention.

FIG. 2 is an explanatory diagram showing a construction state of the above-mentioned middle excavation method.

FIG. 3 is an explanatory diagram showing a scaled state in a first state of the bit.

FIG. 4 is a side view of the bit in the first state with a part cut away.

FIG. 5 is an explanatory diagram showing a scaled state in a second state of the bit.

FIG. 6 is a side view of the bit in a second state with a part cut away.

FIG. 7 is an explanatory diagram showing a construction state of the above-described middle digging method.

FIG. 8 is an explanatory diagram showing the construction status of the above-mentioned middle excavation method.

FIG. 9 is an explanatory diagram showing a construction state of the above-described middle digging method.

FIG. 10 is an explanatory diagram showing a construction state of the above-described middle digging method.

FIG. 11 is an explanatory diagram showing a construction state of the above-described middle digging method.

FIG. 12 is an explanatory diagram for explaining a difference in load depending on the shape of the excavation claw part.

FIG. 13 is an explanatory diagram showing a scaled state in a first state of a bit according to another embodiment of the present invention.

FIG. 14 is an explanatory diagram showing an enlarged / reduced state of the bit in the second state.

FIG. 15 is a partially cutaway side view showing a state of excavation in a middle stage widening state in a first state of a bit according to still another embodiment of the present invention.

FIG. 16 is an explanatory diagram showing an enlarged / reduced state of the bit in the first state.

FIG. 17 is a partially cutaway side view showing the state of expansion and contraction of the excavation claw in the second state of the bit.

FIG. 18 is an explanatory diagram showing a scaling state of the bit in a second state.

FIG. 19 is a partially cutaway side view showing the state of excavation in the maximum wing spread state in the first state of the bit.

FIG. 20 is an explanatory diagram showing a maximum wing spread state in the first state of the bit.

FIG. 21 is an explanatory view showing a state in which the concrete pile is buried.

FIG. 22 is a partially cutaway side view showing a state of excavation in a middle-stage widening state in a first state of a bit according to still another embodiment of the present invention.

FIG. 23 is an explanatory diagram showing an enlarged / reduced state of the bit in the first state.

FIG. 24 is a partially cutaway side view showing the state of expansion and contraction of the excavation claw in the second state of the bit.

FIG. 25 is an explanatory diagram showing a state of expansion and contraction and a middle stage diameter reduction state of the bit in the second state.

FIG. 26 is a partially cutaway side view showing a state of excavation in a maximum wing spread state in the first state of the bit.

[Explanation of symbols]

2 Auger shaft body 5 Raised wings 6,51 Bits 13 and 52 as excavators 13 and 52 Shaft portions 14 and 56 Flange portions 18 and 61 as shaft support portions Shaft portions 20 and 41 and 63 Excavation claw portions 21 Constructs positioning means Engagement claw portion 23 Spreading restricting portion 25 First relief portion constituting positioning means 27 Second relief portion constituting positioning means 28, 81 Reducing diameter regulating portion 29, 68 Rotation regulating means 33 Concrete as pile Pile 34 Ground 57 Shaft support tongue piece as shaft support 70 Coil spring as urging means constituting positioning means 73 First wing expansion restrictor constituting wing expansion restrictor 74 First wing expansion restrictor constituting wing expansion restrictor 2 Wide-spread regulating section a Middle-stage wide-spread state b Maximum-wide-spread state c Middle-stage reduced-diameter state d Dimension range of flange as outer diameter of shaft support

Continuation of the front page (72) Inventor Akira Oshima 1-27-2 Konan, Minato-ku, Tokyo Inside of Concrete Industry Co., Ltd. (72) Inventor Takeyuki Kabazawa 1-27-27 Konan, Minato-ku, Tokyo Cleat Industry Co., Ltd.

Claims (10)

[Claims] 1. An auger shaft that is used in a digging method in which a cylindrical pile is buried while excavating the ground, and has a spiral-shaped lifter wing on a peripheral surface of a substantially cylindrical main shaft. A drilling device attached to the auger shaft, a substantially cylindrical shaft portion detachably mounted on the distal end of the auger shaft body substantially coaxially, and a shaft portion provided with an axial direction substantially parallel to the axial direction of the shaft portion. A shaft support portion provided on a peripheral surface of the shaft portion to support the shaft portion substantially in parallel with the axial direction of the shaft portion; and a shaft portion provided with the other end portion, and one end portion centered on the shaft portion. An excavating claw that is rotatable as a shaft, and when the excavating claw rotates in the wing-spreading direction, the distance from the center of the shaft to one end of the excavating claw is the outer diameter of the pile. The maximum spreading condition with a larger diameter and smaller than this maximum spreading condition The rotation is restricted to a middle-stage widening state in which the distance is larger than the inner diameter of the pile, and when the excavation claw is rotated in the diameter reduction direction, the excavation is performed from the center of the shaft. Rotation restricting means for restricting rotation to a minimum diameter reduced state in which the distance to one end of the claw is equal to or less than the outer diameter of the shaft support, and excavating the ground by the rotation restricting means While maintaining the state in which the rotation of the excavation claw part is restricted to the maximum wing-spreading state and the middle-stage wing-spreading state during the forward rotation of the shaft part in the direction in which the shaft part reversely rotates, An excavator comprising: a positioning means for canceling the restriction of the rotation of the excavation claw. 2. A shaft support portion is provided in a pair facing each other in the axial direction of the shaft portion and in the vertical direction, and the excavation claw portion is located between the shaft support portions and rotates around the shaft portion as a central axis. The positioning means is provided so as to be movable and movable in the axial direction of the shaft portion, wherein the excavating claw portion is in a first state in which the excavating claw portion is close to the upper shaft supporting portion side or the excavating claw portion is in the lower shaft supporting portion. A second state proximate to the side, the rotation restricting means being configured to rotate the excavation claw when the excavation claw is positioned in the first state at one end of the excavation claw in the middle stage; When the excavation claw is positioned in the second state, the diameter of the excavation claw is restricted to a range of a middle-stage reduced diameter state and a middle-stage widened state which are smaller in diameter than the widened state and larger than the outer diameter of the shaft support. The rotation of the excavation claw is minimized and the maximum wing is expanded. The excavator according to claim 1, wherein the excavator is restricted to a range of the state. 3. The rotation restricting means contacts the digging claw on the side of the digging claw when the digging claw is turned in the diameter reducing direction only when the digging claw is in the first state. 3. The excavator according to claim 2, further comprising a diameter-reducing restricting portion that restricts rotation of the excavating claw portion in the diameter-reducing direction to a middle-stage diameter-reducing state. 4. A shaft portion is provided on a shaft support portion so as to be slidable in the axial direction. The excavation claw portion is rotatable with the shaft portion around the shaft portion as a center axis and in the axial direction of the shaft portion. The excavator according to claim 2 or 3, wherein the excavator is movably provided integrally with the shaft portion. 5. The positioning device according to claim 1, wherein said positioning means has a locking claw provided on one of said excavation claw and said rotation restricting means and said shaft for locking said other. 4. The excavator according to any one of 4 above. 6. A pair of shaft support portions are provided movably while maintaining a distance facing the shaft portion along the axial direction, and the positioning means attaches the pair of shaft support portions to the auger shaft body. And a rotation restricting unit that minimizes the rotation of the excavation claw when the pair of shaft supports moves toward the tip of the shaft against the urging of the urging unit. When the pair of shaft support portions move toward the auger shaft side by the biasing of the biasing means, the rotation of the excavation claw portion is restricted in the range of the reduced diameter state and the maximum wing expanding state. The excavator according to claim 1, wherein the excavator is restricted to a range of a minimum diameter reducing state and a middle stage expanding state, and the maximum expanding state. 7. The excavator according to claim 6, wherein the excavation claw portion has a contact surface that contacts the lower end surface of the pile. 8. The excavation claw portion has a concave portion at a tip end side of the shaft portion and on an edge on the side of the diameter-reduction rotating direction, and the rotation restricting means is configured to reduce the excavation claw portion between a pair of shaft support portions. The excavation claw portion is located on the rotation side in the radial direction and protruded from the shaft portion, and the excavation claw portion is moved in a state where the shaft support portion moves to the tip end side of the shaft portion against the bias of the biasing means. When rotated in the diameter reduction direction, the middle diameter reduction part located in a range smaller in diameter than the middle wing expansion state and larger in diameter than the outer diameter of the shaft support part in contact with the diameter reduction rotation direction side of the excavation claw part. When the excavation claw rotates in the diameter reducing direction in a state where the shaft support is moved toward the auger shaft body by the urging of the urging means, the rotation is restricted to a recess of the excavation claw. The excavator according to claim 6 or 7, further comprising a diameter-reducing regulating portion to be inserted. 9. The rotation restricting means is provided in a wall shape at a position on the rotation side of the excavation claw in the wing-spreading direction. The excavator according to any one of claims 1 to 8, further comprising a wing expansion restricting portion that abuts on the side of the wing expansion rotation direction to restrict the rotation to the middle-stage wing expansion state and the maximum wing expansion state. 10. The shaft portion is located between a pair of provided shaft support portions, and has an opening which communicates with the inner peripheral side and allows a fluid to flow therethrough. A drilling rig according to any one of the preceding claims.