JP7724111B2 - pile driver - Google Patents

Description

Article 30, paragraph 2 of the Patent Act applies. Sales date: January 20, 2021. Sales location: Funtech Co., Ltd. (312-2 Saho, Ibaraki City, Osaka Prefecture)

The present invention relates to a pile driver, and more specifically to a pile driver equipped with an anti-vibration member that supports a steel pipe pile attached to a working device so that the pile can rotate and move axially.

Pile drivers used to install steel pipe piles are equipped with anti-vibration members to prevent the steel pipe pile from tilting or becoming misaligned during installation. These anti-vibration members have a pair of left and right pivoting arms attached to the bottom of the leader in an openable and closable manner. The tips of both pivoting arms are each provided with a connecting section that connects the two tips together. By rotating the arms to connect the connecting sections and embracing the steel pipe pile in the arc-shaped recesses of the arms, the steel pipe pile attached to the work device can be supported rotatably and axially movable (see, for example, Patent Document 1).

JP 2015-218538 A

The anti-vibration devices mentioned above are available in multiple collars of different dimensions to accommodate piles of different diameters. However, as the number of collar types increases, not only does it require more time to rearrange them, but it also creates management issues, such as where to store unused collars.

The present invention therefore aims to provide a pile driver equipped with anti-vibration members that can accommodate multiple pile diameters with simple setup changes.

In order to achieve the above object, the pile driver of the present invention is a pile driver having a working device that can be raised and lowered along a leader erected at the front of a base machine, and an anti-vibration member attached to the lower part of the leader that holds the outer surface of a steel pipe pile that is rotated by the working device, wherein the anti-vibration member is provided with a pair of rotating arms having a large-diameter arc-shaped recess that can abut against the outer surface of the steel pipe pile, and is formed so as to be rotatable about a pair of rotating shafts attached to the lower part of the leader between a closed state in which the rotating ends of the pair of rotating arms are close to each other and an open state in which they are separated, and the pair of rotating arms are provided with a pair of arms that are arranged opposite each other in the closed state and that can be moved in accordance with the outer diameter of the steel pipe pile. a plurality of collars that can be rearranged according to the needs of the user, each of which has a small-diameter arc-shaped recess that is concentrically formed inside the large-diameter arc-shaped recess, a support arm that radially penetrates the large-diameter arc-shaped recess and supports the small-diameter arc-shaped recess so that it can advance and retreat relative to the arc center of the large-diameter arc-shaped recess, and a fixing means that fixes the small- diameter arc-shaped recess at a moving position, the support arm being rod-shaped with a rectangular cross section and having a plurality of key grooves formed in its upper surface, the large-diameter arc-shaped recess having an arm through-hole that matches the cross-sectional width of the support arm, and the fixing means being a key engagement that is fixed by fitting a key plate into the key groove .

Furthermore, when the pair of pivot arms are in the closed state, an opening is provided between the large-diameter arc-shaped recesses on the pivot base side, and the position of the small-diameter arc-shaped recess relative to the support arm is eccentric to one side in the circumferential direction toward the pivot end.

With the pile driver of the present invention, the multiple collars on the anti-vibration member have small-diameter arc-shaped recesses that can move forward and backward relative to the center of the large-diameter arc-shaped recess, making it possible to provide a wide adjustment range to accommodate multiple pile diameters with the same type of collar. This reduces the number of types required compared to the conventional method, in which collars were prepared for each pile diameter, and minimizes the storage space for unused collars. Furthermore, because the collars can be held in their new position simply by operating the fixing means, it also contributes to reducing the effort and time required for setup changes.

Furthermore, because the small-diameter arc-shaped recesses are eccentric to one side of the circumference toward the rotation end relative to the support arms that radially penetrate the large-diameter arc-shaped recesses, it is possible to create openings between the small-diameter arc-shaped recesses that are similar to the openings created between the large-diameter arc-shaped recesses, eliminating unnecessary interference between the collars and steel pipe piles when opening and closing the anti-vibration member. In particular, even in the closed state with openings created between the collars, the space for arranging the support arms is not obstructed, and a well-balanced support state can be achieved with four support arms spaced equally apart circumferentially.

Furthermore, the large-diameter arc-shaped recess has an arm through-hole that matches the cross-sectional width of the support arm, and a key engagement is used as a means of securing the small-diameter arc-shaped recess. Therefore, of the impacts applied to the support arm by the rotating steel pipe pile, the rotational force is absorbed by the wall of the arm through-hole, and the direction of force transmission from the steel pipe pile is limited to the arm axial direction. This allows for stable key engagement through simple surface contact, despite the unique behavior of rotating piles, which are prone to fluctuations in the direction and magnitude of force. In particular, the structure uses multiple key grooves into which the key plates selectively fit, making it easy to expand the range of options for various pile diameters. In other words, an anti-vibration member is achieved that both maintains the collar's connection state and improves the ease of reassembly.

1 is a side view of a pile driver showing an example of an embodiment of the present invention. FIG. FIG. FIG. FIG. 10 is a plan view showing the assembled state of the collar corresponding to the first steel pipe pile. FIG. 6 is a cross-sectional view taken along line VI-VI of FIG. 5. 7 is a cross-sectional view of FIG. 6 taken along line VII-VII. FIG. 8 is a cross-sectional view taken along line VIII-VIII in FIG. 6. FIG. FIG. 10 is a plan view showing the assembled state of the collar corresponding to the second steel pipe pile. 11 is a cross-sectional view taken along the line XI-XI in FIG. FIG. 10 is a plan view showing the assembled state of the collar corresponding to the third steel pipe pile. This is a cross-sectional view taken along line XIII-XIII in Figure 12. FIG. 10 is a plan view showing the assembled state of the collar corresponding to the fourth steel pipe pile. 15 is a cross-sectional view of FIG. 14 taken along the line XV-XV. FIG. 10 is a plan view showing the assembled state of the collar corresponding to the fifth steel pipe pile. 17 is a cross-sectional view of FIG. 16 taken along line XVII-XVII. FIG. 10 is a plan view showing the assembled state of the collar corresponding to the sixth steel pipe pile. 19 is a cross-sectional view taken along line XIX-XIX in FIG. 10.

Figures 1 to 19 show one embodiment of the pile driver of the present invention. As shown in Figure 1, the pile driver 11 is a dual-purpose machine that can switch between steel pipe pile construction and ground improvement construction. It is equipped with a base machine 14 consisting of a lower track body 12 equipped with crawlers and an upper rotating body 13 rotatably mounted on the lower track body 12, a leader 15 mounted to the front of the upper rotating body 13 so that it can be raised and lowered, and a raising and lowering cylinder 16 that supports the leader 15 from the rear. A leader support 17 that supports the leader 15 so that it can be raised and lowered is provided at the front of the upper rotating body 13, and a driver's cab 18 is provided on the right side of the upper rotating body 13, and an equipment room 19 that houses the engine and hydraulic unit is provided on the left side.

The leader 15 is made up of multiple interconnected leader components, each with a rectangular cylindrical cross section, and is rotatably attached to a support shaft in the width direction of the vehicle provided on the leader support 17. A top sheave 20, around which the lifting rope is wound, is located at the upper end of the leader 15, and an anti-vibration member 22, which prevents the steel pipe pile 21 from swinging as it rotates, is located at the front lower part. A pair of left and right guide pipes 23, 23 are continuously installed along the entire length of the leader 15 at the front ends of both sides of the leader 15.

An auger 24, which serves as a working device, is attached to the front of the leader 15. The auger 24 can connect steel pipe piles 21 of multiple sizes (different diameters) via adapters 25. A pair of left and right guide gibs 24a, 24a that slide against the guide pipes 23, 23 protrude rearward, and can be raised and lowered along the front of the leader 15 by a lifting chain 28 that is stretched across a drive sprocket 26 and a driven sprocket 27 provided above and below the leader 15.

As shown in Figures 2 to 4, the anti-vibration member 22 is attached via a bracket 29 provided at the lower end of the leader 15. A first vertical pivot shaft 30 and a second vertical pivot shaft 31 are provided on both sides of the bracket 29, with a first pivot arm 32 rotatably attached to the first pivot shaft 30 and a second pivot arm 33 rotatably attached to the second pivot shaft 31. The first pivot shaft 30 and the second pivot shaft 31 are located in front of both widthwise sides of the leader 15, and the distance between the two pivot shafts 30, 31 is greater than the outer diameter of the steel pipe pile 21.

Each pivot arm 32, 33 is substantially bilaterally symmetrical, and each is a flattened structure consisting of two arm-shaped plates arranged at a fixed distance and facing each other above and below. It comprises a first pivot base 32a and a second pivot base 33a that are pivotally connected to the first pivot shaft 30 and the second pivot shaft 31, respectively; a first pile-holding portion 32b and a second pile-holding portion 33b formed at the tip of the pivot bases 32a, 33a and equipped with a first large-diameter arc-shaped recess 34 and a second large-diameter arc-shaped recess 35 on the inside that embrace the outer surface of the steel pipe pile 21; and a first connecting portion 32c and a second connecting portion 33c provided at the tip of the pile-holding portions 32b, 33b, i.e., at the pivot ends of each pivot arm 32, 33, that overlap each other and through which a connecting pin 36 is inserted.

Each pivot arm 32, 33 can rotate around the first pivot shaft 30 and the second pivot shaft 31 between a closed state in which the pivot ends are close together and pin-connected, as shown by the solid lines in Figure 3, and an open state in which the pin connection is released and the pivot ends are separated, as shown by the imaginary lines in Figure 3. During the opening operation, the attached fixing pin 37 is inserted or removed, and the fixing pin 37 engages with the overlapping portion with the bracket 29, thereby maintaining each pivot arm 32, 33 in the open state.

In this open state, the first large-diameter arc-shaped recess 34 and the second large-diameter arc-shaped recess 35 are separated by the greatest distance on both sides of the bracket 29, preventing contact with the outer circumferential surface of the buried steel pipe pile 21 even when the upper rotating body 13 is rotated in place. In contrast, in the closed state, the ends 34a, 35a of the large-diameter arc-shaped recesses 34, 35 on the rotation end side are abutted against each other, while the ends 34b, 35b on the rotation base side are spaced apart, with a large-diameter opening 38 provided between them. This prevents the rotation base sides of the large-diameter arc-shaped recesses 34, 35 from coming into contact with the steel pipe pile 21 when the anti-vibration member 22 is opened or closed.

When using the pile driver 11 configured in this manner to install, for example, a large-diameter steel pipe pile 21 (outer diameter 355.6 mm), after connecting the upper end of the steel pipe pile 21 to the adapter 25, as shown in Figure 3, the anti-vibration member 22 is closed and the rotating ends of the two pivoting arms 32, 33 are pin-connected to each other so that the lower part of the steel pipe pile 21 is embraced by the two large-diameter arc-shaped recesses 34, 35. In this closed state, the steel pipe pile 21 is buried in the ground by rotating and lowering the auger 24. At this time, the outer surface of the steel pipe pile 21 abuts against the inner arc-shaped surfaces 34c, 35c of the large-diameter arc-shaped recesses 34, 35, suppressing vibration caused by rotation.

When extending a steel pipe pile 21, the upper end of the buried steel pipe pile 21 is separated from the adapter 25, the anti-vibration member 22 is opened in the reverse order described above, and the upper rotating body 13 is rotated in place. At this point, the prepared steel pipe pile 21 to be extended is connected at its upper end to the adapter 25 at a position to the side of the base machine 14 (lifting position), and then carried to the construction position (pile core) by rotating in the opposite direction.

However, when installing a variety of steel pipe piles with different outer diameters at the same site, it would be wasteful to prepare collars of different dimensions to match the pile diameter, and it would also be a hassle to attach and remove collars every time the pile diameter changes. Therefore, the anti-vibration member 22 is equipped with an adjustment member that can accommodate multiple pile diameters with a simple setup change. This adjustment member consists of four retractable collars that can be rearranged depending on the outer diameter of the steel pipe pile.

The retractable collars, details of which will be described later, are compatible with six different outer diameters of small-diameter steel pipe piles 71-76. In descending order of outer diameter, a set of four collars 39, 40, 41, and 42 are used for the first steel pipe pile 71 (outer diameter 318.5 mm), the second steel pipe pile 72 (outer diameter 267.4 mm), and the third steel pipe pile 73 (outer diameter 216.3 mm). A set of four collars 43, 44, 45, and 46 are used for the fourth steel pipe pile 74 (outer diameter 190.7 mm), the fifth steel pipe pile 75 (outer diameter 165.2 mm), and the sixth steel pipe pile 76 (outer diameter 139.8 mm). In other words, the retractable collars can be interchanged with each other, or by rearranging the installation positions within the same set, to accommodate six different pile diameters.

Figures 5 to 13 show the assembly state of the first set of retractable collars corresponding to the first steel pipe pile 71, second steel pipe pile 72, and third steel pipe pile 73, which have relatively large outer diameters among the small-diameter steel pipe piles 71 to 76. As shown in Figure 5, the four collars 39, 40, 41, and 42 are positioned opposite each other at equal circumferential intervals (every 90 degrees) when the anti-vibration member 22 is closed. Basically, all four collars are made of the same material, and when assembled to each pivot arm 32, 33, they are symmetrical in the left-right direction (up-down direction in Figure 5).

Each collar 39, 40, 41, 42 has a small-diameter arc-shaped recess 47 that is concentrically located inside the large-diameter arc-shaped recess 34, 35, a support arm 48 that radially penetrates the large-diameter arc-shaped recess 34, 35 and supports the small-diameter arc-shaped recess 47 so that it can move back and forth relative to the arc center C of the large-diameter arc-shaped recess 34, 35, i.e., the axis of the steel pipe pile 71, 72, 73, and a fixing means 49 that fixes the small-diameter arc-shaped recess 47 in a moving position.

The small-diameter arc-shaped recess 47 is made of a steel plate with a size (thickness and circumferential length) that does not impair the adjustment margin. As shown in Figure 9 and other figures, it has an inner arc-shaped circumferential surface 47a that can abut against the outer periphery of the steel pipe piles 71-73, and an outer arc-shaped circumferential surface (not shown) that is fixed to the tip of the support arm 48. Both circumferential ends of the inner arc-shaped circumferential surface 47a are chamfered. Furthermore, as shown in Figure 5, the position of the small-diameter arc-shaped recess 47 relative to the support arm 48 is eccentric to one circumferential side toward the rotation end. As a result, on the rotation base side, between the plate ends 47b of the small-diameter arc-shaped recesses 47, 47, a small-diameter opening 50 corresponding to the first steel pipe pile 71 of the same type as the large-diameter opening 38 corresponding to the large-diameter steel pipe pile 21 is provided, for example, when the collar corresponding to the first steel pipe pile 71 is assembled.

The support arm 48 is a solid rod with a rectangular cross section, and has a key groove 48a formed on its upper surface. The key groove 48a consists of three stages in the arm axial direction; specifically, from the side closest to the small-diameter arc-shaped recess 47 (the left side in Figure 6), there are three key grooves 48a: a front stage, a middle stage, and a rear stage. When the support arm 48 is inserted into the arm through-holes 34d, 35d that pass through the large-diameter arc-shaped recesses 34, 35, the support arm 48 is positioned inside the pivot arms 32, 33, that is, as shown in the cross section of Figure 6, in the space S between the upper and lower arm plates, extending vertically to the fullest extent.

As can be seen in Figure 7, the arm through-holes 34d, 35d are aligned with the cross-sectional width (horizontal width) of the support arm 48, and relief grooves R are formed at the four corners. This allows the support arm 48 to move linearly within the space S by sliding the lower surface (sliding surface) 48c, with the side surface 48b slidably arranged along the side wall of the arm through-holes 34d, 35d, when moving the small-diameter arc-shaped recess 47 forward or backward.

As shown in Figures 6 and 8, the fixing means 49 consists of a key engagement that secures the support arm 48 by fitting the key plate 49a from above into the key groove 48a. The key plate 49a has a width corresponding to the cross-sectional width of the support arm 48 and a thickness corresponding to the groove width of the key groove 48a. As shown in Figure 9, the key plate 49a can be engaged with the key groove 48a of each stage by selecting one of the two key insertion holes 32d, 33d provided side by side on the arm-shaped upper plate of the pivot arms 32, 33. The key insertion holes 32d, 33d consist of two, front and rear, located in order from the side closest to the large-diameter arc-shaped recesses 34, 35 (the left side in Figure 6).

When the key plate 49a is fitted into the key groove 48a, the flange-shaped mounting plate 49b abuts against the arm-shaped upper plate, determining its vertical position, and achieving the required amount of overlap (lap) in the arm axial direction between it and the key groove 48a. Thus, when key engagement is achieved, each collar 39, 40, 41, 42 is fixed in the set position of the pivot arms 32, 33 by tightening the two mounting bolts 51 for the mounting plate 49b and the single pressing bolt 52, the tip of which contacts the upper surface of the support arm 48.

When installing the first steel pipe pile 71 (outer diameter 318.5 mm), the first set of retractable collars 39, 40, 41, and 42 thus formed are each attached to the anti-vibration member 22 by key engagement between the front key groove 48a and the rear key insertion holes 32d and 33d, as shown in Figures 5 and 6. As a result, in the closed state, the inner arc-shaped circumferential surface 47a of the small-diameter arc-shaped recess 47 and the outer circumferential surface of the steel pipe pile 71 are positioned at a substantially uniform radial distance, and a small-diameter opening 50 is provided in a predetermined shape on the pivot base side. Thus, the outer circumferential surface of the first steel pipe pile 71 abuts substantially the entire inner arc-shaped circumferential surface 47a of the small-diameter arc-shaped recess 47, thereby suppressing vibration due to rotation. Meanwhile, when extending the steel pipe pile 71, the small-diameter opening 50 ensures a smooth movement path for opening and closing the anti-vibration member 22. Additionally, by providing multiple key insertion holes 32d and 33d, the key grooves 48a can be spaced apart sufficiently, eliminating any strength issues with the support arm 48.

When installing the second steel pipe pile 72 (outer diameter 267.4 mm), as shown in Figures 10 and 11, the middle key groove 48a is reassembled into a key engagement with the rear key insertion holes 32d and 33d. As a result, in the closed position, the inner arc-shaped circumferential surface 47a of the small-diameter arc-shaped recess 47 and the outer circumferential surface of the steel pipe pile 72 are positioned with a slight gap G on one circumferential side toward the rotation end due to the difference in curvature between them, which is smaller in diameter than the first steel pipe pile 71. However, even with this uneven gap, a sufficient contact area is ensured to hold the steel pipe pile 72. A small-diameter opening 53 is provided in a predetermined shape on the rotation base side. Thus, the outer circumferential surface of the second steel pipe pile 72 abuts most of the inner arc-shaped circumferential surface 47a of the small-diameter arc-shaped recess 47, suppressing vibration due to rotation. On the other hand, when extending the steel pipe pile 72, the small diameter opening 53 ensures a clear path for opening and closing the pile.

When installing the third steel pipe pile 73 (outer diameter 216.3 mm), as shown in Figures 12 and 13, the rear key groove 48a is reassembled to key engagement with the rear key insertion holes 32d and 33d. In this case, the gap G between the inner arc-shaped circumferential surface 47a of the small-diameter arc-shaped recess 47 and the outer circumferential surface of the steel pipe pile 73 is larger because the diameter is even smaller than that of the second steel pipe pile 72, but a sufficient contact area is still ensured. A small-diameter opening 54 is provided in a predetermined shape on the pivot base side. In this way, the outer circumferential surface of the third steel pipe pile 73 abuts most of the inner arc-shaped circumferential surface 47a of the small-diameter arc-shaped recess 47, thereby suppressing vibration due to rotation. Meanwhile, when extending the steel pipe pile 73, the small-diameter opening 54 ensures a clear path for opening and closing the pile.

As mentioned above, the first set of retractable collars 39, 40, 41, 42 has an adjustment range that can accommodate the three types of steel pipe piles 71, 72, 73, which have relatively large outer diameters, out of the six types of small-diameter steel pipe piles 71-76. Therefore, the adjustment range is exceeded for the three types of steel pipe piles 74, 75, 76, which have smaller outer diameters, and they cannot be used as is. Therefore, a second set of retractable collars 43, 44, 45, 46 is provided for the anti-vibration member 22.

Figures 14 to 19 show the assembly state of the second set of retractable collars, which correspond to the fourth steel pipe pile 74, fifth steel pipe pile 75, and sixth steel pipe pile 76, which have relatively small outer diameters. The four collars 43, 44, 45, and 46 have the same shape as the first set of retractable collars but are different lengths. The main difference is that they have a small-diameter arc-shaped recess 55 that is shorter in the circumferential direction and a support arm 56 that is longer in the axial direction. The assembly method (key engagement, etc.) is the same as the first set of retractable collars, and although detailed explanations are omitted, the small-diameter arc-shaped recess 55 is concentrically located inside the large-diameter arc-shaped recess 34, 35, and the support arm 56 supports the small-diameter arc-shaped recess 55 so that it can be advanced and retreated relative to the arc center C of the large-diameter arc-shaped recess 34, 35, i.e., the axis of the steel pipe piles 74, 75, and 76.

When installing the fourth steel pipe pile 74 (outer diameter 190.7 mm), the second set of retractable collars 43, 44, 45, 46 formed in this manner are each assembled to the anti-vibration member 22 by key engagement between the middle key groove 56a and the rear key insertion holes 32d, 33d, as shown in Figures 14 and 15. As a result, in the closed state, the inner arc-shaped circumferential surface 55a of the small-diameter arc-shaped recess 55 and the outer circumferential surface of the steel pipe pile 74 are positioned at a substantially uniform radial distance, and a small-diameter opening 57 is formed in a predetermined shape on the pivot base side. Thus, the outer circumferential surface of the fourth steel pipe pile 74 abuts substantially the entire inner arc-shaped circumferential surface 55a of the small-diameter arc-shaped recess 55, suppressing vibration due to rotation. On the other hand, when extending the steel pipe pile 74, the small-diameter opening 57 ensures a smooth movement path for opening and closing the anti-vibration member 22. Furthermore, by providing multiple key insertion holes 32d, 33d, the key grooves 56a can be spaced sufficiently apart, eliminating any strength issues with the support arm 56.

When installing the fifth steel pipe pile 75 (outer diameter 165.2 mm), as shown in Figures 16 and 17, the front key groove 56a is reassembled into a key engagement with the front key insertion holes 32d and 33d. As a result, in the closed position, the inner arc-shaped circumferential surface 55a of the small-diameter arc-shaped recess 55 and the outer circumferential surface of the steel pipe pile 75 are positioned with a slight gap G on one circumferential side toward the rotation end due to the difference in curvature between them, which is smaller in diameter than the fourth steel pipe pile 74. However, even with this uneven gap, a sufficient contact area is ensured to hold the steel pipe pile 75. A small-diameter opening 58 is provided in a predetermined shape on the rotation base side. Thus, the outer circumferential surface of the fifth steel pipe pile 75 abuts most of the inner arc-shaped circumferential surface 55a of the small-diameter arc-shaped recess 55, suppressing vibration due to rotation. On the other hand, when extending the steel pipe pile 75, the small diameter opening 58 ensures a clear path for opening and closing the structure.

When installing the sixth steel pipe pile 76 (outer diameter 139.8 mm), as shown in Figures 18 and 19, the rear key groove 56a is reassembled to key engagement with the rear key insertion holes 32d and 33d. In this case, the inner arc-shaped circumferential surface 55a of the small-diameter arc-shaped recess 55 and the outer circumferential surface of the steel pipe pile 76 are positioned with a larger gap G due to the smaller diameter than the fifth steel pipe pile 75, but a sufficient contact area is still ensured. A small-diameter opening 59 is provided in a predetermined shape on the pivot base side. In this way, the outer circumferential surface of the sixth steel pipe pile 76 abuts most of the inner arc-shaped circumferential surface 55a of the small-diameter arc-shaped recess 55, thereby suppressing vibration due to rotation. Meanwhile, when extending the steel pipe pile 76, the small-diameter opening 59 ensures a clear path for opening and closing the pile.

As such, with the pile driver 11 of the present invention, the multiple collars 39-46 provided on the anti-vibration member 22 have small-diameter arc-shaped recesses 47, 55 that can move forward and backward relative to the arc center C of the large-diameter arc-shaped recesses 34, 35, making it possible to provide an adjustment range that can accommodate multiple pile diameters with the same type of collar. This reduces the number of types required compared to the conventional method, in which collars were prepared for each pile diameter, and minimizes the storage space for unused collars. Furthermore, simply by operating the fixing means 49, the collars 39-46 can be held in their new position, contributing to a reduction in the effort and time required for setup changes.

Furthermore, because the small-diameter arc-shaped recesses 47, 55 are eccentric to one side of the circumference toward the rotation end relative to the support arms 48, 56 that radially penetrate the large-diameter arc-shaped recesses 34, 35, it is possible to create openings 50, 53, 54, 57, 58, 59 between the small-diameter arc-shaped recesses 47, 55 that are similar to the opening 38 created between the large-diameter arc-shaped recesses 34, 35, eliminating unnecessary interference between the collars 39-46 and the steel pipe piles 71-76 when opening and closing the anti-vibration member 22. In particular, even in the closed state with openings created between the collars, the placement space for the support arms 48, 56 is not obstructed, and a well-balanced support state can be achieved with the four support arms 48, 56 spaced equally apart in the circumferential direction.

Furthermore, the large-diameter arc-shaped recesses 34, 35 have arm through-holes 34d, 35d that match the cross-sectional width of the support arms 48, 56, and key engagement is used as the fastening means 49 for the small-diameter arc-shaped recesses 47, 55. Therefore, of the impacts applied to the support arms 48, 56 by the rotating steel pipe piles 71-76, the rotational force is absorbed and mitigated by the walls of the arm through-holes 34d, 35d, limiting the direction of force transmission from the steel pipe piles 71-76 to the arm axial direction. This allows for stable key engagement through simple surface contact, despite the unique behavior of rotating piles, which are prone to fluctuations in force direction and magnitude. In particular, the structure uses multiple key grooves 48a, 56a into which the key plate 49a selectively fits, allowing for a wide range of pile diameters to be easily accommodated. In other words, a vibration-proof member 22 is achieved that maintains the connection state of the collars 39-46 while improving reassembly workability.

The present invention is not limited to the above-described example configuration. The retractable collars can be arbitrarily configured in shape and number as long as they can hold the pile with highly stable surface contact. They can be configured in sets of two or four, and other variations can be made to suit the specifications of the anti-vibration members. Furthermore, while the fixing means in the embodiment uses key engagement, simple pin connections can also be used.

11...pile driver, 12...lower running body, 13...upper rotating body, 14...base machine, 15...leader, 16...derailing cylinder, 17...leader support, 18...operator's cab, 19...equipment room, 20...top sheave, 21...steel pipe pile, 22...anti-vibration member, 23...guide pipe, 24...auger, 24a...guide gib, 25...adapter, 26...drive sprocket, 27...follower sprocket Rocket, 28...lifting chain, 29...bracket, 30...first pivot shaft, 31...second pivot shaft, 32...first pivot arm, 32a...first pivot base, 32b...first pile holding portion, 32c...first connecting portion, 32d...key insertion hole, 33...second pivot arm, 33a...second pivot base, 33b...second pile holding portion, 33c...second connecting portion, 33d...key insertion hole, 34...first large diameter circle Arc-shaped recess, 34a...one end, 34b...other end, 34c...inner arc-shaped circumferential surface, 34d...arm through-hole, 35...second large-diameter arc-shaped recess, 35a...one end, 35b...other end, 35c...inner arc-shaped circumferential surface, 35d...arm through-hole, 36...connecting pin, 37...fixing pin, 38...large-diameter opening, 39-46...collar, 47...small-diameter arc-shaped recess, 47a...inner arc-shaped circumferential surface, 47b...plate end, 48 ...Support arm, 48a...key groove, 48b...side surface, 48c...bottom surface, 49...fixing means, 49a...key plate, 49b...mounting plate, 50...small diameter opening, 51...mounting bolt, 52...pressure bolt, 53, 54...small diameter opening, 55...small diameter arc-shaped recess, 55a...inner arc circumferential surface, 56...support arm, 56a...key groove, 57, 58, 59...small diameter opening, 71-76...steel pipe pile

Claims (2)

A pile driver in which a working device is provided so as to be able to rise and fall along a leader erected at the front of a base machine, and a vibration-proof member is provided at the bottom of the leader to hold the outer peripheral surface of a steel pipe pile rotated by the working device,
The anti-vibration member is provided with a pair of pivot arms having a large-diameter arc-shaped recess that can abut against the outer peripheral surface of the steel pipe pile, and is formed to be rotatable around a pair of pivot axes provided at the bottom of the leader between a closed state in which the pivot ends of the pair of pivot arms are close to each other and an open state in which they are separated,
The pair of rotating arms are provided with a plurality of collars that are arranged opposite each other in the closed state and can be reassembled according to the outer diameter of the steel pipe pile,
the collar has a small-diameter arc-shaped recess provided concentrically inside the large-diameter arc-shaped recess, a support arm that radially penetrates the large-diameter arc-shaped recess and supports the small-diameter arc-shaped recess so that it can advance and retreat relative to the arc center of the large-diameter arc-shaped recess, and a fixing means that fixes the small-diameter arc-shaped recess at a moving position ,
The support arm is rod-shaped with a rectangular cross section, and a plurality of key grooves are formed on the upper surface thereof.
the large-diameter arc-shaped recess has an arm through-hole that matches the cross-sectional width of the support arm;
The pile driver is characterized in that the fixing means comprises a key engagement that is fixed by fitting a key plate into the key groove . In the closed state, the pair of pivot arms have an opening between the large-diameter arc-shaped recesses on the pivot base side,
2. The pile driver according to claim 1, wherein the position of the small-diameter arc-shaped recess relative to the support arm is offset toward one circumferential side toward the rotation end.