JP4566780B2 - Existing pile crusher - Google Patents

Description

  The present invention relates to an existing pile crusher.

  Conventionally, when a building is demolished due to aging or relocation of the building and a new building is constructed, it is necessary to construct a new foundation at a position corresponding to the new building. .

  At this time, existing piles left at the construction site, that is, cylindrical ready-made piles (precast piles) manufactured in advance in factories, etc., and forming vertical holes in the ground, and putting reinforcing rods in this vertical hole, It is necessary to remove the cast-in-place piles constructed by placing concrete by crushing or drawing out before starting the construction work of the building.

  For this purpose, a crushing device for crushing existing piles (for example, see Patent Document 1) and a drawing device for drawing out existing piles have been developed (for example, see Patent Document 2).

  That is, the crushing device comprises a cylindrical excavation body provided with a drilling blade at the lower peripheral edge and a drill head arranged in the cylindrical excavation body, and the cylindrical excavation body advances the digging at the outer peripheral position of the existing pile. At the same time, a crushing operation for crushing existing piles with a drill head is performed.

In addition, the pulling device is provided with a ribbon screw blade on the inner peripheral surface of a cylindrical excavation body provided with an excavating blade at the lower peripheral edge, and the excavation body is advanced at the outer peripheral position of the existing pile. The soil on the outer peripheral surface of the pile is discharged to the ground with a ribbon screw blade, and the friction resistance between the outer peripheral surface of the existing pile and the ground is weakened, and the existing pile can be easily pulled out in the same state I have to.
JP 2001-288746 A JP 2002-188145 A

  However, in the crushing apparatus described above, when the existing pile is a PC pile to which prestress is applied by the PC steel material, the PC steel material exposed along with the crushing is surrounded by the cylindrical excavated body. Furthermore, there is a problem that the drill head is entangled and obstructs the rotation of the drill head.

  For this reason, the drilling operation must be resumed after the drill head is pulled up to the ground to remove the PC steel material.

  Moreover, in such a crushing device, it is necessary to prepare a cylindrical excavation body having a diameter larger than the outer diameter of the existing pile and approximately equal to the length of the existing pile, and the cylindrical excavation body is driven to rotate. In order to secure the rotational driving force to make it happen, the crushing device itself becomes large, leading to an increase in construction costs.

  In order to maintain a large rotational force (torque) in the cylindrical excavated body, it is necessary to reduce the number of revolutions per unit time in inverse proportion to this. There is a defect that only leads to an increase in construction period.

  In addition, in the drawing device, it is necessary to prepare a cylindrical excavation body having a diameter larger than the outer diameter of the existing pile and approximately equal to the length of the existing pile, and to rotate the excavation body. In order to secure the rotational driving force, the pulling device itself becomes large, leading to an increase in construction cost.

  And, in order to keep the excavated body to have a large rotational force (torque), it is necessary to reduce the number of revolutions per unit time in inverse proportion to that, so the machining time increases, and the construction period is increased accordingly. There is a defect that leads to an increase in

  In addition, in such a drawing device, when the existing pile is a cast-in-place pile, for example, a large concrete structure having a diameter of 1000 mm to 2000 mm and a buried length of 40 m, the drawing work is difficult or impossible. There is.

Therefore, in the present invention, a crushing shaft body formed into a double shaft from an inner shaft and an outer shaft extending in the vertical direction, and the center portion of the existing pile while rotating by attaching to the lower end portion of the inner shaft of the crushing shaft body a central crushing member for crushing and provided with a peripheral edge crushing member for crushing the periphery of the existing pile while rotating attached to the lower end portion of the outer shaft of the crushing shaft, heart crushing member and the peripheral portion crushing The body was rotated in the opposite direction around the same axis via the crushing shaft body, and the peripheral crushing body was provided with a cutting portion for cutting the reinforcing bars and PC steel materials arranged in the existing piles. In the existing pile crushing device, the peripheral crush body is attached to the lower outer peripheral surface of the outer shaft with the base ends of the plurality of support arms spaced apart in the circumferential direction, and the distal end portion of each support arm is attached to the outer shaft. It protrudes in the radial direction, and the axis line between the tips of these support arms The upper edge of the cylindrical inner support piece and the outer support piece facing each other are attached to the inner and outer sides at regular intervals, and a plurality of crushing blade pieces are arranged in the circumferential direction between the peripheral surfaces of both inner and outer support pieces. An existing pile crushing device characterized by forming a cutting part for cutting a reinforcing bar or PC steel material arranged at the peripheral edge of an existing pile on a crushing blade piece with a certain interval between them. It is.

Further, according to the present invention, each crushing blade piece is inclined downward toward the rotation direction side of the outer shaft, the cutting edge is disposed substantially flush with the lower edge of the inner and outer support pieces, and the center of the cutting edge is arranged. The part is formed by cutting a cut part into a V shape so that the reinforcing bar and the PC steel material arranged on the peripheral part of the existing pile can be cut by the cut part .

In the present invention, the central part of the existing pile is crushed by the central part crushed body that rotates through the inner shaft of the crushed shaft body, and the peripheral edge of the existing pile by the peripheral part crushed body that rotates through the outer shaft of the crushed shaft body. The part can be crushed.

  At this time, since the center part and the peripheral part of the existing pile are crushed by the central part crushed body and the peripheral part crushed body individually rotated via the inner and outer shafts, The required torque can be applied to each of the peripheral crushed bodies, and the existing piles can be crushed quickly and reliably.

In particular, reinforcing bars and PC steel materials are arranged in the peripheral part of the existing pile, but these reinforcing bars and PC steel materials can be reliably cut by the peripheral part crushed body to which a large torque is applied. Pile crushing work can be performed efficiently.

And since the cutting part is provided in the peripheral part crushed body and the reinforcing bar and the PC steel material arranged in the cylindrical existing pile are cut by the same cutting part, the PC steel material is especially the peripheral part crushed body and the center. Generation | occurrence | production of the malfunction which becomes entangled in a part crushing body and becomes impossible for these crushing bodies to rotate can be prevented. As a result, it is possible to remarkably improve the crushing efficiency of existing piles by both crush bodies. Therefore, the existing pile can be efficiently crushed also from this point, and the construction period and the construction cost can be reduced.

  In addition, the crushing shaft rotates the inner shaft and the outer shaft in opposite directions, so that the center crushing body and the peripheral crushing body attached to each shaft rotate relatively reversely around the same axis. Therefore, it is possible to prevent the two crushed bodies from being deviated (displaced) from the shaft core (pile core) of the existing pile during the crushing operation, and the existing pile can be reliably crushed. As a result, the crushing work efficiency can be improved.

  A shown in FIG. 1 is an existing pile crusher equipped with an existing pile crusher M according to the present invention. The existing pile crusher A is detachably attached to the base machine 1 with the existing pile crusher M attached thereto. Yes.

  The base machine 1 is provided with a leader 3 extending in the vertical direction on a self-propelled base machine main body 2, and a drive motor 5 is suspended on the leader 3 via a lift wire 4 so that the lift position can be adjusted. An inner shaft rotating mechanism 6 is linked to the lower end of the driving motor 5 and the outer shaft rotating mechanism 8 is suspended from the inner shaft rotating mechanism 6 via a vertical position adjusting cylinder 7 serving as a vertical position adjusting means. The existing pile crushing device M as the first embodiment is attached to both the rotation mechanisms 6 and 8.

[Existing pile crusher as the first embodiment]
As shown in FIGS. 1 and 2 ((a) is a partially cutaway side view, (b) is a bottom view), the existing pile crushing device M as the first embodiment is provided in the above-described two rotation mechanisms 6 and 8. The upper end portion of the crushing shaft body 9 extending in the vertical direction is detachably attached, and the central portion crushing body 10 for crushing the center portion of the existing pile K and the peripheral portion of the existing pile K are crushed at the lower portion of the crushing shaft body 9. A peripheral edge crushed body 11 is provided. Reference numeral 12 denotes a guide / support for guiding and supporting the crushing shaft body 9 in the excavation direction.

  That is, as shown in FIGS. 1 to 3, the crushing shaft body 9 is extended in the vertical direction so as to surround the cylindrical inner shaft 20 formed by extending in the vertical direction and the outer periphery of the inner shaft 20. The inner shaft 20 is connected to the inner shaft rotating mechanism 6 at the upper end portion while the outer shaft 21 is rotated on the outer shaft. The upper end of the mechanism 8 is linked to the mechanism 8 so that the drive motor 5 can rotate in opposite directions around the same axis via both rotating mechanisms 6 and 8.

  And while attaching the central part crushed body 10 to the lower end part of the inner shaft 20, the peripheral part crushed body 11 is attached to the lower end part of the outer shaft 21, the central part crushed body 10 is more than the peripheral part crushed body 11 It is located below and the center part of the existing pile K is crushed ahead of the peripheral part crushed body 11.

  Further, as shown in FIG. 2 and FIG. 3, the center crushing body 10 is formed by providing a grid-like crushing tooth piece 23 on the lower surface of a support piece 22 formed in a disk shape, The center portion of the upper surface of the support piece 22 is connected to the lower end of the support piece 22, and the crushing tooth piece 23 provided on the lower surface of the support piece 22 is rotated around the axis of the inner shaft 20, while the crushing tooth piece 23 Is pressed against the central portion of the upper end surface of the existing pile K so that the central portion can be crushed.

  Here, a discharge part (not shown) that discharges liquid material and / or compressed air is provided at the center of the crushed body 10, and the liquid and / or compressed air supplied through the inner shaft 20 is the same. It can be discharged from the discharge section to remove slime in the vicinity of the central crushed body 10, reduce the degree of wear of the central crushed body 10, and further prevent seizure of the central crushed body 10 I can do it.

  As the liquid material, water or slurry can be used. From the discharge part, these liquid materials can be discharged alone, compressed air can be discharged alone, or the liquid material. It can also be discharged as a liquid material containing bubbles mixed with compressed air.

  As shown in FIG. 2 and FIG. 3, the peripheral edge crushed body 11 has a plurality of (four in the present embodiment) support arms 24 on the lower outer peripheral surface of the outer shaft 21 at regular intervals in the circumferential direction. A cylindrical inner support piece 25 with the tip of each support arm 24 projecting in the radial direction of the outer shaft 21 and with the axis line directed vertically between these support arms 24 and The upper edge of the outer support piece 26 is attached to the inner and outer sides with a certain interval, and a plurality of (eight in this embodiment) crushing blade pieces 27 are provided between the peripheral surfaces of the inner and outer support pieces 25 and 26. Are provided at regular intervals in the circumferential direction.

  Here, the inner support piece 25 is arranged above the peripheral edge of the support piece 22, while the outer support piece 26 is arranged above the outer side of the support piece 22, and the lower end edge of each support piece 25, 26. Tapered digging and crushing blade pieces 25a and 26a are formed in the part downward. The shape of the cutting and crushing blade pieces 25a, 26a is not limited to the present embodiment, and can be formed in a sawtooth shape, and a number of excavation bits can be arranged at regular intervals in the circumferential direction. It can also be opened and installed.

  Each crushing blade piece 27 is inclined downward toward the rotational direction of the outer shaft 21, and the cutting edge 27a is disposed substantially flush with the lower edge of the inner and outer support pieces 25, 26. A cutting portion 27b is formed in a V-shape in the central portion of 27a, and the reinforcing bars and PC steel materials t (see FIG. 1) arranged on the peripheral edge of the existing pile K are cut by the cutting portion 27b. To be able to.

  In addition, a seismic device 13 is attached to the upper outer peripheral surface of the outer shaft 21, and the seismic device 13 adds vibrations acting downward on the peripheral edge crush body 11 via the outer shaft 21. The crushing force by the peripheral crushed body 11 can be increased.

  The existing pile crushing apparatus M as 1st Embodiment is comprised as mentioned above, and demonstrates the existing pile crushing operation | work by the existing pile crushing apparatus M below.

  That is, in the existing pile crushing device M, as shown in FIG. 1, the ground G is excavated by the crushing tooth pieces 23 of the center crushing body 10 rotating through the inner shaft 20 of the crushing shaft body 9, and the existing pile While crushing the center part of K, while excavating the ground G with the crushing blade piece 27 of the peripheral part crushing body 11 rotating through the outer shaft 21 of the crushing shaft body 9, the peripheral part of the existing pile K is crushed. be able to. In FIG. 1, H is an excavation hole formed in the ground G, and W is a peripheral wall of the excavation hole H.

  At this time, the center part and the peripheral part of the existing pile K are crushed by the central part crushed body 10 and the peripheral part crushed body 11 that rotate individually via the inner and outer shafts 20, 21 respectively. The required torque can be applied to the center crushed body 10 and the peripheral crushed body 11, respectively, and the existing pile K can be crushed quickly and reliably.

  In particular, reinforcing bars and PC steel materials t are arranged on the peripheral edge of the existing pile K, but these reinforcing bars and PC steel materials t are surely secured by the cutting portion 27b of the peripheral crushed body 11 to which a large torque is applied. It can cut | disconnect and can perform the crushing operation | work of the existing pile K efficiently.

  Therefore, it is possible to prevent the occurrence of the problem that the PC steel material t is entangled with the central crushed body 10 and the peripheral crushed body 11 and the crushed bodies 10 and 11 cannot rotate.

  As a result, the crushing work efficiency of the existing pile K by these crush bodies 10 and 11 can be remarkably improved. Therefore, the existing pile K can be efficiently crushed also from this point, and the construction period and the construction cost can be reduced.

  Further, the crushing shaft body 9 rotates the inner shaft 20 and the outer shaft 21 in opposite directions, thereby allowing the central crushing body 10 and the peripheral crushing body 11 attached to the shafts 20 and 21 to be in the same axis. Since it can be rotated in the reverse direction around the center, both crushed bodies can be prevented from being displaced (displaced) from the shaft core (pile core) of the existing pile during crushing work. Can be reliably crushed. As a result, the crushing work efficiency can be improved.

  In the present embodiment, the center portion of the existing pile K is crushed by the center portion crushed body 10 in advance of the peripheral portion crushed body 11, and the center portion crushed body 10 receives a reaction force from the existing pile K. In this case, since the subsequent peripheral portion crushed body 11 is restrained from moving laterally by the peripheral wall W of the excavation hole H, the straight crushed property of the central portion crushed body 10 can be ensured satisfactorily.

  As a result, it is possible to prevent the center crushed body 10 from being displaced from the shaft center (so-called center misalignment), and reliably crush the center of the upper end of the existing pile K by the center crushed body 10. In addition, it is possible to reliably perform the crushing of the peripheral edge of the upper end of the existing pile K by the subsequent crushed part 11 and further the cutting of the reinforcing bars and the PC steel material t.

  And when the subsequent peripheral part crush body 11 crushes the peripheral part of the existing pile K, while the upper end center part of the existing pile K is crushed by the center part crush body 10 which precedes, the upper end peripheral part of the existing pile K Since the center portion 10 restricts the center portion 10 from being displaced from the axis (so-called misalignment), the peripheral edge portion of the existing pile K can be reliably broken by the subsequent peripheral portion crush body 11. .

  Further, the relative positional relationship between the center crushed body 10 and the peripheral crushed body 11 in the vertical direction can be appropriately adjusted by the above-described vertical position adjusting cylinder 7 as the vertical position adjusting means, and the geology of the ground G The existing pile crushing efficiency can be improved by adapting according to the difference in work conditions such as the form of the existing pile K (for example, ready-made pile, on-site pile, etc.).

[Existing pile crusher as the second embodiment]
As shown in FIG. 4 ((a) is a partially cutaway side view, (b) is a bottom view), the existing pile crushing apparatus M as the second embodiment is the basic structure as the first embodiment described above. Although it is the same as the existing pile crushing apparatus M, it differs in the structure of the peripheral part crushing body 11. FIG.

  That is, as shown in FIG. 4, the peripheral edge crush body 11 has a plurality of (three in this embodiment) support arms 30 on the outer peripheral surface of the outer shaft 21, and the base ends of the support arms 30 are spaced at regular intervals in the circumferential direction. At the same time, the tip of each support arm 30 is protruded in the radial direction of the outer shaft 21, and the outside of the outer shaft 21 is surrounded by the vertical line between the tips of the support arms 30. The upper end edge portion of the support cylinder piece 31 arranged in the state is attached, and a plurality of (this book) extends in the radial direction of the outer shaft 21 between the lower part of the inner peripheral surface of the support cylinder piece 31 and the outer peripheral surface of the outer shaft 21. In the embodiment, two support pieces 32, 32 are installed at point-symmetrical positions, and a lattice-shaped crushing tooth piece 33 is provided on the lower surface of each support piece 32, 32. 31a is a blade for excavation / crushing formed on the lower edge of the support cylinder piece 31.

  In this way, the above-described peripheral edge crushed body 11 also excavates the ground G and enables the peripheral edge of the existing pile K to be crushed. The rebar and the PC steel material t that are reinforced are also surely cut by the crushing tooth piece 33.

  Therefore, the existing pile crushing apparatus M as the second embodiment can efficiently crush the existing pile K as with the existing pile crushing apparatus M as the first embodiment.

[Existing pile crusher as a third embodiment]
As shown in FIG. 5 ((a) is a partially cutaway side view, (b) is a bottom view), the existing pile crushing apparatus M as the third embodiment is the first embodiment described above with the basic structure. Although it is the same as the existing pile crushing apparatus M, it differs in the structure of the peripheral part crushing body 11. FIG.

  That is, as shown in FIG. 5, the peripheral crush body 11 is attached to the lower outer peripheral surface of the outer shaft 21 with an inverted frustoconical support piece 35 that gradually increases in diameter from below to above. The crushing tooth pieces 36 are provided on the outer peripheral surface of the slab.

  Here, the support piece 35 is set such that the outer diameter of the lower peripheral edge portion 35a is set smaller than the outer diameter of the support piece 22 of the center fragment 10, and the outer diameter of the upper peripheral edge portion 35b is set to the outer shape of the support piece 22. It is set larger than that, and by providing the crushing tooth piece 36 on the entire outer peripheral surface of the support piece 35, the peripheral portion of the existing pile K left by crushing of the central crushing body 10, the reinforcing bars, and the PC steel t Can be crushed by the crushing tooth piece 36.

  In this way, the above-described peripheral edge crushed body 11 also excavates the ground G and enables the peripheral edge of the existing pile K to be crushed. The rebar and the PC steel material t that are reinforced are also surely cut by the crushing tooth piece 33.

  Therefore, also with the existing pile crushing apparatus M as the third embodiment, the crushing operation of the existing pile K can be performed efficiently, as with each of the existing pile crushing apparatuses M as the first and second embodiments described above. .

[Existing pile crusher as a fourth embodiment]
As shown in FIG. 6 ((a) is a partially cutaway side view, (b) is a bottom view), the existing pile crushing device M as the fourth embodiment is the basic structure as the third embodiment described above. Although it is the same as the existing pile crushing apparatus M, it differs in the structure of the center part crushing body 10. FIG.

  That is, as shown in FIG. 6, the crushed body 10 is attached to the lower end portion of the inner shaft 20 with an inverted conical support piece 37 that gradually increases in diameter from below to above. A crushing tooth piece 38 is provided on the surface.

  Here, the support piece 37 is formed so that the outer diameter of the upper end peripheral part 37a is substantially the same as the outer diameter of the lower end peripheral part 35a of the support piece 35 of the peripheral part crushed body 11, and the outer peripheral surfaces of both support pieces 35, 37 Is formed in a tapered surface that is continuous in the vertical direction, and crushing tooth pieces 38 are provided on the entire outer peripheral surface of the support piece 37 to crush the center portion of the existing pile K with the crushing tooth pieces 38. To be able to. a is the rotation direction of the center crush body 10, and b is the rotation direction of the peripheral crush body 11.

  In addition, the above-described peripheral edge crushed body 11 also excavates the ground G and allows the peripheral edge of the existing pile K to be crushed. Reinforcing steel bars and PC steel materials t can be reliably cut by the crushing tooth pieces 33.

  Therefore, also with the existing pile crushing apparatus M as the fourth embodiment, the crushing operation of the existing pile K can be efficiently performed as with the respective existing pile crushing apparatuses M as the first to third embodiments. .

[Existing pile crusher as a fifth embodiment]
The existing pile crushing apparatus M as the fifth embodiment has the same basic structure as the existing pile crushing apparatus M as the first embodiment as shown in FIG. However, it differs in that the peripheral portion of the existing pile K is crushed prior to the center crushed body 10.

  That is, the central fragment 10 is disposed in the inner support piece 25 of the peripheral fragment 11, and the crushing tooth piece of the central fragment 10 is more than the cutting edge 27a of the crushing tooth piece 27 of the peripheral fragment 11. The crushing tooth piece 27 precedes the crushing tooth piece 23 and crushes the peripheral portion of the existing pile K and cuts the reinforcing bar and the PC steel material t.

  Thus, when the subsequent center part crushing body 10 crushes the center part of the existing pile K by crushing the peripheral part of the existing pile K with the peripheral part crushing body 11 ahead of the center part crushing body 10 The ground G is excavated by the preceding peripheral crushed body 11 to form the excavation hole H, and the peripheral wall W of the excavation hole H regulates the lateral movement of the peripheral crushed body 11, Since the upper edge peripheral part of the existing pile K is crushed by the peripheral part crushed body 11, the straight crushed property of the center part crushed body 10 can be ensured satisfactorily.

  As a result, it is possible to prevent the center crushed body 10 from being displaced from the shaft center (so-called center misalignment), and reliably crush the center of the upper end of the existing pile K by the center crushed body 10. be able to.

[Existing pile crusher as a sixth embodiment]
The existing pile crushing apparatus M as the sixth embodiment has the same basic structure as the existing pile crushing apparatus M as the first embodiment as shown in FIG. And the peripheral crushed body 11 are different in that the upper end surface of the existing pile K is crushed simultaneously.

  That is, the center fragment 10 is disposed in the inner support piece 25 of the peripheral fragment 11 and the cutting edge 27a of the fragment 27 of the peripheral fragment 11 and the fragment 23 of the center fragment 10 are obtained. So that the crushing tooth piece 27 and the crushing tooth piece 23 crush the upper end surface of the existing pile K at the same time, and the crushing tooth piece 27 cuts the rebar and the PC steel t. I am doing it.

  Thus, when the center part crushing body 10 crushes the center part of the existing pile K by crushing the upper end surface of the existing pile K simultaneously with the center part crushing body 10 and the peripheral part crushing body 11, The ground G is excavated by the peripheral crushed body 11 to form an excavation hole H, and the peripheral wall W of the excavation hole H regulates the lateral movement of the peripheral crushed body 11. Since the upper-end peripheral part of the existing pile K is crushed, the straight crushed property of both the crushed bodies 10 and 11 can be ensured favorably.

  As a result, it is possible to prevent the center crushed body 10 from being displaced from the shaft center (so-called misalignment), and to efficiently crush the upper end surface of the existing pile K by the both crushed bodies 10 and 11. Can do.

Explanatory drawing of the existing pile crusher which comprises the existing pile crushing apparatus as 1st Embodiment which concerns on this invention. Explanatory drawing of the existing pile crushing apparatus. The perspective explanatory drawing of a center part crushed body and a peripheral part crushed body. Explanatory drawing of the existing pile crushing apparatus as 2nd Embodiment. Explanatory drawing of the existing pile crushing apparatus as 3rd Embodiment. Explanatory drawing of the existing pile crushing apparatus as 4th Embodiment. Explanatory drawing of the existing pile crushing apparatus as 5th Embodiment. Explanatory drawing of the existing pile crushing apparatus as 6th Embodiment.

Explanation of symbols

A Existing pile crusher M Existing pile crusher 1 Base machine 2 Base machine body 3 Leader 4 Lifting wire 5 Motor for driving 6 Inner shaft rotating mechanism 7 Vertical adjustment cylinder 8 Outer shaft rotating mechanism 9 Crushing shaft
10 Central fragment
11 Fragmented peripheral edge

Claims (2)

A crushing shaft formed into a double shaft from an inner shaft and an outer shaft extending in the vertical direction;
A central part crushing body that crushes the central part of the existing pile while rotating by attaching to the lower end part of the inner shaft of the crushing shaft,
A peripheral edge crushing body that crushes the peripheral edge of the existing pile while rotating by attaching to the lower end of the outer shaft of the crushing shaft ,
The center part crushed body and the peripheral part crushed body are rotated in the opposite direction around the same axis through the crushing shaft body,
The peripheral crushed body is an existing pile crushing device provided with a cutting part for cutting reinforcing bars and PC steel arranged in an existing pile,
The peripheral crush body is attached to the lower outer peripheral surface of the outer shaft with the base ends of the plurality of support arms spaced apart in the circumferential direction, and the distal end portion of each support arm projects in the radial direction of the outer shaft. A cylindrical inner support piece and an upper support edge of the outer support piece, which are axially oriented in the vertical direction, are attached to the inner and outer sides of the support arm with a certain distance between them, and the peripheral surfaces of both inner and outer support pieces A plurality of crushing blade pieces were interposed in the circumferential direction with a certain interval therebetween, and a cutting portion for cutting the reinforcing bars and PC steel materials arranged on the peripheral edge of the existing pile was formed in the crushing blade pieces. An existing pile crusher characterized by that. Each crushing blade piece is inclined downward toward the rotation direction side of the outer shaft, the cutting edge is arranged substantially flush with the lower edge of the inner and outer support pieces, and a cutting part is provided at the center of the cutting edge. The existing pile crusher according to claim 1, characterized in that it is formed by cutting into a V shape so that reinforcing bars and PC steel materials arranged on the peripheral edge of the existing pile can be cut by the cut portion. apparatus.

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