JPH102181A - Method and apparatus for excavating a vertical hole and excavator - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To enhance excavation efficiency by causing earth and sand in an outer peripheral area to fall down into a central area previously excavated by excavation means. A method of excavating a vertical hole includes a first step of excavating a central region of a vertical hole to be excavated by a first excavation unit prior to an outer peripheral region around the central region, and an outer peripheral region by a second excavation unit. Excavating a second step. In the second step, the second excavating means is rotated downward so as to draw a frusto-conical trajectory in which the excavated portion gradually decreases from the center side of the vertical hole toward the outer peripheral side, while lowering the second excavating means. By pressing the outer peripheral area, the outer peripheral area is collapsed into the preceding excavation trace by the second excavation means.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for excavating a vertically extending vertical hole and an excavator.

[0002]

2. Description of the Related Art As one of devices for drilling deep vertical holes used for foundations for concrete structures, foundations for steel towers, foundations for bridge piers, etc., a vertical hole to be drilled is provided in a central region and an outer peripheral region around the central region. There are devices for excavating separately by separate excavation means (for example, Japanese Patent Application Laid-Open Nos. 6-146768, 6-294276, and 6-129180).
No.).

In this type of excavator, a central region of a vertical hole is excavated by a first excavating means prior to an outer peripheral region, and an outer peripheral region is excavated by rotating a second excavating means around the axis of the vertical hole. Then, the excavated material by the second excavation means is moved by the second excavation means into the preceding excavation site by the first excavation means with the rotational movement of the second excavation means.

However, in this type of conventional excavator, the outer peripheral area is excavated in a frusto-conical shape (a mortar shape) which gradually increases from the center of the vertical hole toward the outer peripheral side or horizontally. By moving the excavated material of the first excavating means toward the central region side by the second excavating means with the rotational movement of the second excavating means, it is only pushed into the preceding excavation trace by the first excavating means, Excavation efficiency is low because it is limited by the capacity of the excavator, especially when excavating ground with gravel and cobblestone.

[0005]

SUMMARY OF THE INVENTION It is an object of the present invention to enhance excavation efficiency by causing earth and sand in an outer peripheral area to fall down into a central area previously excavated by an excavating means.

[0006]

A method for excavating a vertical hole according to the present invention comprises the steps of:
A first step of excavating a central area of a vertical hole to be excavated by a first excavating means ahead of an outer peripheral area around the central area; and a second step of excavating the outer peripheral area by a second excavating means. The second step comprises rotating the second excavating means so that the excavated portion draws a frusto-conical trajectory gradually lowering from the center side to the outer peripheral side of the vertical hole, and Pushing down the excavation means.

According to a first aspect of the present invention, there is provided a vertical excavation apparatus for excavating a central area of a vertical hole to be excavated before an outer peripheral area surrounding the central area, and a second excavating means for excavating the outer peripheral area. Driving means for pushing the second excavating means downward while rotating the second excavating means around the axis of the vertical hole,
The excavating means has an excavating part that draws a frustum-shaped rotation locus that becomes gradually lower from the center of the vertical hole toward the outer periphery.

The second excavating means is pushed downward while being rotated about the axis of the vertical hole so as to draw a locus of a truncated cone (inverted mortar) gradually decreasing from the center side toward the outer peripheral side. Not only excavates the outer peripheral area of the vertical hole to be excavated, but also pushes the outer peripheral area toward the center area to
And fall into the previous excavation site by the excavation means. For this reason, according to the present invention, the excavation efficiency is significantly higher than that of a conventional excavator in which the outer peripheral region is excavated in a mortar shape or horizontally.

Preferably, the first excavating means has a function of excavating the central area and a function of carrying out the excavated material in the preceding excavation site to the ground. In particular, it is preferable that the first excavating means itself can move to the ground side when carrying out the excavated object. Thus, when a large rock that cannot be excavated by the first excavating means exists at the bottom of the hole, the first excavating means can be moved to the ground side, and the rock at the bottom of the hole can be blown up by explosive in that state.

[0010] A preferred excavator for a vertical hole is an excavator for excavating an outer peripheral area around a central area to be excavated first among vertical holes to be excavated, and comprises: a tubular body; An excavating head rotatably supported at the lower end portion about the axis of the vertical hole, driving means for rotating the excavating head about the axis, and moving means for pushing the excavating head downward; The head has a digging portion that draws a frusto-conical rotation trajectory that gradually decreases from the center of the vertical hole toward the outer periphery.

In a preferred embodiment, the excavating head has an annular head body that forms a frusto-conical surface that gradually decreases from the center side to the outer peripheral side of the vertical hole and forms a cutting edge on the outer periphery at the lower end. And a plurality of excavating cutters disposed on the frusto-conical surface of the head body and the cutting edge.

In a preferred embodiment, the driving means comprises: a first gear coaxially disposed with the tubular body at an upper end of the excavating head; and a space provided around the axis of the tubular body in the tubular body. A plurality of drive sources arranged at the same time, and a second gear connected to each drive source and meshing with the first gear,
The moving means includes a plurality of jacks for pushing the head body downward with respect to the tubular body.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to FIGS. 1 and 2, an excavator 10 includes a first excavating means 12 for excavating a central region of a vertical hole prior to excavation of an outer peripheral region therearound; Second excavation means 14 for excavating the outer peripheral area.

The first excavating means 12 is a well-known excavator having a function of holding and carrying excavated materials and a function of excavating earth and sand, such as a clamshell bucket and a backhoe with a telescopic core. The excavation part, ie, the bucket part 16, of the first excavation means 12 is operated on the ground side by an operation and drive machine installed on the ground, excavating the central area of the vertical hole ahead of the outer peripheral area, and Excavates are discharged to the ground side.

As shown in FIGS. 1 to 6, the second excavating means or excavator 14 has an axis 20 extending in the vertical direction, and coaxially receives a casing 22 disposed on the upper part. As the casing 22, a short cylindrical casing, a casing in which a plurality of plates curved in an arc shape are connected in a short cylindrical shape, a casing in which a plurality of liner plates are connected in a short cylindrical shape, and the like are used.

The excavator 14 includes a short cylindrical tubular body 24 coaxial with the axis 20, an annular excavating head 26 rotatably disposed around the axis 20 below the tubular body, It includes a driving mechanism 28 for rotating the head 26, a moving mechanism 30 for moving the tubular body 26 in the vertical direction, and a receiving means 32 for receiving the casing 22 disposed above the driving mechanism 28.

An annular floor 34 is coaxially connected to the lower end of the cylindrical body 24 in an inward flange shape by a plurality of screw members such as bolts and nuts (not shown). The operator can use the ladder to move from the ground to the floor 34 and vice versa. Therefore, the worker can move the floor 34
Can be used as a work floor for checking the state of the hole bottom, checking the excavator 14, and the like.

On the floor 34, a cylindrical bucket guide 3 is provided.
6 are installed. When raising and lowering the bucket portion 16 of the first excavating means 12, the bucket guide 36 moves the cylindrical body 24, the excavating head 26, the driving mechanism 28, and the moving mechanism 3.
0, the bucket unit 16 is guided so as not to collide with the receiving means 32 and the floor 34. The upper end portion of the bucket guide 36 is formed as a trumpet-shaped inclined portion which is bent so as to be more outward in the radial direction of the tubular body 24 as it goes upward. A wearable hard metal plate 37 is attached.

Although not shown, the tubular body 24 and the floor 34 can be divided into a plurality of members around the axis 20 of the tubular body 24, preferably three or more members, respectively. Are connected separably by a plurality of screw members such as bolts and nuts. This allows
The tubular body 24 and the floor 34 can be easily transported,
They can also be disassembled and removed. Cylindrical body 2
The number of divisions of the floor 4 and the floor 34 can be set to an appropriate value according to the diameter of the vertical hole.

Although not shown, the divided members of the tubular body 24 are separably connected to the divided members of the floor 34 by a plurality of screw members such as bolts and nuts. Thereby, the joining strength of the members adjacent in the circumferential direction is increased.

As shown in FIG. 3 to FIG.
Is attached to the lower end of the cylindrical body 24 by the
It is supported rotatably around zero. In the example shown,
The bearing 38 is arranged on the inner periphery of the floor 34. Therefore, the excavating head 26 is supported on the floor 34.
As shown in FIG. 12, the excavating head 26 can also be divided into a plurality of members 26a to 26e around the axis, and adjacent divided members are connected by a plurality of screw members operable from the bucket 16 side. The number of divisions of the excavation head 26 can be set to an appropriate value according to the diameter of the vertical hole.

The excavating head 26 has a cylindrical outer wall portion 40 having substantially the same diameter as the cylindrical body 24, an upper wall portion 42 connected to the upper surface of the outer wall portion in an inward flange shape, and an outer wall portion. A ring-shaped head main body is formed by a trumpet-shaped conical wall portion 44 connecting the lower end of 40 and the inner end of the upper wall portion 42.

The lower end of the outer wall portion 40 is a cutting edge to which a plurality of cutters 46 are attached at intervals around the axis 20. The upper wall portion 42 is in contact with a plurality of rollers 48 attached to the lower surface of the floor 34 at intervals around the axis 20 at the outer peripheral portion of the upper surface. The lower surface of the conical wall portion 44 is a frustoconical (inverted mortar-shaped) surface that gradually decreases from the center side toward the outer peripheral side. A plurality of cutters 46 are also attached to the lower surface of the conical wall portion 44. Each cutter 46 extends downward from the head body.

An annular external gear 50 is attached to the upper wall 42. The external gear 50 is mounted on the upper surface of the upper wall portion 42 by a plurality of screw members and mounting members so as to rise from the inner peripheral portion of the upper wall portion 42, and also acts as an inner race of the bearing 38.

The floor 34, the excavating head 26 and the external gear 5
Numerals 0 are formed in an annular shape so as not to hinder raising and lowering of the bucket portion 16 and form a space following the bucket passage area of the bucket guide 36 in cooperation with each other.

The drive mechanism 28 includes a plurality of rotation mechanisms 52 having a speed reducer, and a gear 54 mounted on an output shaft of each rotation mechanism 52. The rotation mechanism 52 is mounted on the floor 34 such that the gears 54 are equiangularly spaced around the axis 20. Each gear 54 meshes with the gear 50. Thus, when the rotation mechanism 52 is rotated, the gear 54 rotates the gear 50 around the axis 20, and thus the excavating head 26 is rotated around the axis 20.

As shown in FIG. 1 to FIG.
Is a cylindrical frame body 60 fitted outside the upper part of the cylindrical body 24.
Is provided. The cylindrical body 24 and the frame body 60 can be relatively displaced in the direction of the axis 20 by one or more detent means, but cannot be rotated about the axis 20.

FIGS. 10 and 11 show an example of such a detent means. In the illustrated example, the detent means includes a stopper 62 attached to the inside of the lower end of the frame body 60 so as to extend in the vertical direction, and the cylindrical body 24 extending in the vertical direction.
And a groove 64 formed on the outside of the upper part. Stopper 6
The groove 2 and the groove 64 extend in the up-down direction, and are fitted so as to be relatively slidable in the up-down direction.

The frame member 60 can be divided into a plurality of members in the circumferential direction of the frame member.
As shown in FIG. 9, a plurality of bolts 66 and nuts 68 are provided.
Are connected so as to be separable. The number of divisions of the frame body 60 can be an appropriate value according to the diameter of the vertical hole.

The frame body 60 has a plurality of concave portions 70 which are open on the outer peripheral side at a plurality of locations on the lower outer periphery. Each of the recesses 70 extends in the circumferential direction at a position slightly above the height position of the groove 64, and the recesses 70 that are adjacent in the circumferential direction are separated by connecting portions of adjacent divided members of the frame body 60. .

In each recess 70, a pressing body 72 for reaction force is arranged. Each pressing body 72 is curved in an arc shape so as to fit into the corresponding recess 70, and the axis 2.
It has an arcuate surface extending in an arc around 0 on the outside. In the illustrated example, the width dimension of the arcuate surface, that is, the outer surface, that is, the dimension in the direction of the axis 20 is large, and
Has a large area.

The pressing members 72 that are adjacent to each other in the circumferential direction are connected by a group of reaction force jacks, that is, a first jack group, so that their circumferential ends are relatively displaced in directions in which the pressing members 72 are separated from each other. I have. Each first jack group includes a plurality of reaction force jacks or first jacks 74 that are vertically spaced. Each first jack 74 is a hydraulic jack such as a hydraulic jack, and a cylinder is pivotally connected to an end of one pressing body 72 by a plate-shaped connecting member 76, and a piston rod is connected to the other end. Is pivotally connected to the end of the pressing body 72.

Each connecting member 76 is connected to the frame 6 via an opening 78 of the frame 60 from the circumferential end of the corresponding pressing body 72.
Extends inside zero. Each connecting member 76 and the pressing body 72
They are connected together or by welding. The plurality of first jacks 74 and the plurality of connecting members 76 of each first jack group that displace the same pressing body 72 can swing by a common pivot 80 in order to synchronize the expansion and contraction of the first jack 74. It is connected to.

The cylindrical body 24 and the frame body 60 are pressed down at a plurality of locations around the axis 20 by a jack, ie, a second jack.
Are connected by a jack 82. The cylinder of each second jack 82 is pivotally connected to the floor 34 by a pin-based connector 84, and the piston rod is pivotally connected to the frame 60 by a pin-based connector 86. The stroke of the second jack 82 is, as shown in the illustrated example, a vertical dimension (width dimension) of the outer surface of the pressing body 72.
Although it is preferably the following, it may be larger than the vertical dimension (width dimension) of the outer surface of the pressing body 72.

In the moving mechanism 30, the first jack 7
When the pressure member 4 is contracted, the adjacent pressing members 72 are drawn, so that each pressing member 72 is accommodated in the corresponding recess 70 as shown by a solid line in FIGS.

On the other hand, when the first jacks 74 are extended, the adjacent pressing members 72 are separated from each other. Therefore, each pressing member 72 is shown by a two-dot chain line in FIGS. 3 to 6 and a solid line in FIG. As shown by, the frame body 60 is moved outward in the radial direction. As a result, each pressing body 72 is partially
, It is pressed against the surrounding ground.

Therefore, the moving mechanism 30 presses the pressing body 72 against the surrounding ground by the first jack 74 to obtain a reaction force on the surrounding ground, and the cylindrical body 24 by the second jack 82. Press down. Thereby, the drilling head 26
Is pushed downward by the second jack 82 via the tubular body 24. Further, the surrounding ground is made smoother by the outer surface of the pressing body 72.

As shown in FIGS. 3 and 5, the receiving means 3
Reference numeral 2 denotes an inward flange formed inside the upper portion of the frame body 60, and is fixed to the frame body 60 by welding or the like. In the illustrated example, the casing 22 is formed by connecting a plurality of liner plates into a short tubular shape.
The lowermost liner plate is separably connected to the receiving means 32 by a plurality of screw members. The liner plates adjacent in the circumferential direction and the vertical direction are connected to each other in a separable manner by a plurality of screw members.

As shown in FIG. 3 to FIG.
An annular seal member 90 is provided on the upper surface of the.
The sealing member 90 extends outside the lower end of the tubular body 24 along the outer peripheral edge of the upper surface of the excavating head 26, and cooperates with the lower end of the tubular body 24 to form an excavation with the tubular body 24. It acts as a sealing means such as a labyrinth seal that closes the space between the head 26.

In the excavator 10, the first excavating means 1
The second bucket section 16 is operated on the ground, excavates the central area of the vertical hole prior to the excavation of the outer peripheral area by the second excavating means 14, grasps the excavated object, and is moved to the ground in that state. , And discharges the excavated material that has been grabbed to the ground. The state of excavation by the first excavation means 12 can be photographed by one or more television cameras 88 attached to the bucket guide 36 and monitored by a monitor provided on the ground side.

When the predetermined excavation by the first excavation means 12 is performed, the excavation of the outer peripheral area by the second excavation means 14 is performed in parallel with the advance excavation of the central area by the first excavation means 12 and the discharge of the excavated material. It is done. Second excavation means 1
The excavation by 4 is performed by rotating the excavation head 26 around the axis 20 by the drive mechanism 28, synchronizingly extending the second jack 82 and pushing the cylindrical body 24 downward.

Thus, the excavating head 26 has its cutting edge,
Since the cutter 46 and the conical wall portion 44 are rotated around the axis 20 while being pressed against the outer peripheral area of the vertical hole to be excavated, the outer peripheral area of the vertical hole to be excavated is excavated by the excavating head 26 in an inverted mortar shape. At this time, all cutters 46
Is a frustoconical shape (inverted mortar shape) in which the rotation trajectory is gradually lowered from the center side to the outer peripheral side, and the conical wall portion 44 has such a surface. , The cutter 46 and the conical wall portion 44 push down and push to the center.

As a result, the outer peripheral area of the vertical hole to be excavated is collapsed by the excavation head 26 into the preceding excavation site by the first excavation means 12. For this reason, the excavation efficiency is significantly higher than that of a conventional excavator that excavates the outer peripheral area in a mortar shape or horizontally. The earth and sand that has fallen into the preceding excavation site is subjected to the first excavation by the bucket 16 of the first excavation means 12.
Along with the excavated material by the excavating means 12 of the above.

When the second jack 82 is completely extended, an operation of connecting a new casing to the upper side of the uppermost casing and an operation of lowering the casing 22 and the moving mechanism 30 are performed. The new casing is connected above the uppermost casing on the ground side. Therefore, the connecting operation of the casing is safe.

The operation of lowering the casing 22 and the moving mechanism 30 is performed by contracting the second jack 82 with the first jack 74 contracted. Thereafter, the preceding excavation of the central area by the first excavation means 12 and the excavation of the outer area by the second excavation means 14 are restarted.

The reaction force of the excavation by the second excavation means 14 is as follows:
At the beginning of excavation, it can be subjected to appropriate means. However, when a vertical hole capable of pressing the pressing body 72 into the surrounding wall surface is excavated, excavation of the outer peripheral region by the second excavating means 14 causes the pressing body 72 to be pressed against the surrounding ground by the first jack 74. The reaction is performed with the reaction force obtained on the surrounding ground.

When the vertical hole having the desired depth is formed, at least the first and second excavating means 12, 14 are removed from the vertical hole. The casing 22 may be buried or removed from the vertical hole. Second excavation means 1
4 can be disassembled and removed.

When a large rock exists at the bottom of the hole during excavation, the rock is moved to the becket portion 16 and the excavation head 26 by the explosive while the bucket portion 16 is moved to the ground side.
Can be crushed so that it can be excavated.

As in the case of the excavator 14, if a pair of adjacent pressing members 72 are displaced by a plurality of first jacks 74 which are arranged in parallel at an interval in the vertical direction, the pair of adjacent pressing members 72 is Compared to the case of displacing with a single jack, the space in the excavator can be effectively used in addition to the fact that a small jack can be used.

However, a pair of adjacent pressing bodies may be displaced by one first jack. Further, the means for displacing the pressing body in the radial direction of the frame body may be not only a jack for moving the adjacent pressing bodies in a direction in which they are close to each other but also a means for directly displacing the pressing body in the radial direction. The moving mechanism may be a mechanism that obtains a lowering and rotating reaction force on the casing.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing one embodiment of an excavator according to the present invention.

FIG. 2 is a plan view of the excavator shown in FIG.

FIG. 3 is an enlarged longitudinal sectional view of an upper left portion in FIG.

FIG. 4 is an enlarged longitudinal sectional view of a lower left portion in FIG.

FIG. 5 is an enlarged longitudinal sectional view of an upper right portion in FIG.

FIG. 6 is an enlarged longitudinal sectional view of a lower right portion in FIG. 1;

FIG. 7 is a cross-sectional view taken along the line 7-7 in FIG. 1, showing an embodiment of the moving mechanism.

FIG. 8 is a cross-sectional view showing a state where the pressing body of the moving mechanism is retracted.

FIG. 9 is a cross-sectional view showing a state where the pressing body of the moving mechanism is protruded.

FIG. 10 is a cross-sectional view showing one embodiment of a rotation stopping means.

11 is a sectional view taken along line 11-11 of FIG.

FIG. 12 is a bottom view of the drilling head.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Excavating apparatus 12 1st excavating means 14 2nd excavating means (excavator) 16 Bucket part of 1st excavating means 22 Casing 24 Cylindrical body of excavator 26 Excavator head 28 Excavator drive mechanism 30 Excavator moving mechanism 44 Drilling head conical wall 46 Drilling head cutter

Claims (5)

[Claims] 1. A first step of excavating a vertical hole to be excavated by a first excavating means in a central area prior to an outer peripheral area around the central area, and a second step of excavating the outer peripheral area by a second excavating means. Wherein the second step is the second step.
Pushing the second excavating means downward while rotating the excavating means so that the excavated part draws a frusto-conical trajectory gradually decreasing from the center side of the vertical hole toward the outer peripheral side, How to drill vertical holes. 2. A first excavating means for excavating a central area of a vertical hole to be excavated before an outer peripheral area therearound, a second excavating means for excavating the outer peripheral area, and the second excavating means. And a driving means for pushing down while rotating about the axis of the vertical hole, wherein the second excavating means draws a frusto-conical rotation trajectory that gradually decreases from the center side to the outer peripheral side of the vertical hole. Vertical hole drilling rig with drilling section. 3. An excavator for excavating an outer peripheral area around a central area to be excavated among vertical holes to be excavated, the excavator comprising: a tubular body; An excavating head rotatably supported about an axis, driving means for rotating the excavating head about the axis, and moving means for pushing the excavating head downward, wherein the excavating head is located at the center of the vertical hole. An excavator with a vertical hole, which has an excavation part that draws a frusto-conical rotation trajectory that gradually decreases from the side toward the outer periphery. 4. An excavating head comprising: an annular head body having a frusto-conical surface gradually lowering from a center side to an outer peripheral side of the vertical hole, and a cutting edge formed on an outer periphery of a lower end; The excavator according to claim 3, comprising a plurality of excavating cutters disposed on the frusto-conical surface of the body and the cutting edge. 5. A driving means, comprising: a first gear coaxially disposed with the tubular body at an upper end of the excavation head; and a space provided around the axis of the tubular body on the tubular body. A plurality of driving sources disposed, and a second gear connected to each driving source and meshing with the first gear, wherein the moving means presses the head body downward with respect to the cylindrical body. The excavator according to claim 4, comprising a jack.