Attachment for forming crushed stone pile and crushed stone pile forming device comprising the same

Abstract

To enable opening of an opening / closing lid widely with relatively small force while suppressing damage on the opening / closing lid.SOLUTION: An attachment 10 comprises a n12 and an opening / closing lid 61 which closes a crushed stone charging hole 15. The opening / closing lid 61 comprises a 62 with its outer shape matching the crushed stone charging hole 15, a reinforcing cloth 63 arranged inside the cover main body 62, and a plurality of reinforcing plates 64 which are arranged at intervals along the axis direction in the cover main body 62 and extend in the width direction perpendicularly intersecting with the axis direction. The cover main body 62 comprises: a first peripheral portion 65 which extends along the axis direction and is fixed to the cylindrical portion 12; and a second peripheral portion 66 which extends along the axis direction, is positioned with spacing in the width direction, and is not fixed to the cylindrical portion 12. The cover main body 62 is switched between an open state with the crushed stone charging hole 15 being open and a closed state with the crushed stone charging hole 15 being closed by being bent with the first peripheral portion 65 as the supporting point. The reinforcing cloth 63 is partially arranged in the width direction of the cover main body 62.SELECTED DRAWING: Figure 5

Description

[Technical field]

[0001] The technology disclosed in this specification relates to an attachment for forming a crushed stone pile and a crushed stone pile forming device equipped with the attachment. [Background technology]

[0002] A method of forming crushed stone piles in the ground is used for ground improvement such as liquefaction countermeasures. As a method of forming crushed stone piles in the ground, an attachment is used that is inserted into the ground to form a space and forms a crushed stone pile in the space while rising from the ground. This type of attachment has a cylindrical part with a crushed stone input hole formed along the axial direction on its side, and a shaft that is rotatably arranged in the cylindrical part and rotates by a driving force from a driving device. The upper end side of the shaft and the output shaft side of the driving device are connected by a hollow joint rod. Therefore, when the driving device is driven, the rotational force is transmitted to the shaft side through the joint rod, and the shaft rotates. Then, the shaft rotates in the forward direction to insert the attachment into the ground and form a space in the ground. When the attachment is inserted into the ground, crushed stone is input into the internal space of the cylindrical part, and the shaft rotates in the reverse direction to pull out the attachment and form a crushed stone pile. For example, Patent Document 1 discloses an example of an attachment for forming crushed stone piles. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2010-248885 A Summary of the Invention [Problem to be solved by the invention]

[0004] This type of attachment is equipped with an openable lid for closing the crushed stone input hole of the cylindrical part. The openable lid includes a lid body having an external shape corresponding to the crushed stone input hole, a reinforcing cloth arranged generally within the lid body, and a plurality of reinforcing plates arranged at intervals in the axial direction of the attachment within the lid body and extending in the width direction perpendicular to the axial direction. When forming the crushed stone pile, it is necessary to open the openable lid at a location slightly above the ground surface, insert the tip of the chute part of the crushed stone input device into the opened location, and input crushed stone into the space in the cylindrical part.

[0005] That is, since the part of the opening and closing lid inserted in the ground remains closed, the insertion point of the chute part must be deformed significantly outward relative to the part inserted in the ground. In detail, the opening and closing lid must be opened by twisting a part slightly above the ground surface relative to the part inserted in the ground, and a force that tries to stretch in the axial direction acts on the twisted part of the opening and closing lid. However, if the reinforcing cloth is arranged entirely inside the lid body, the deformation of the lid body is suppressed, making it difficult to open and close the opening and closing lid. In addition, if the opening and closing lid cannot be opened widely, it becomes difficult to secure the width for putting in the crushed stone. In addition, if a large force is applied to the opening and closing lid to open it widely, a large force is applied from the opening and closing lid to the attachment, which results in the attachment rotating around its axis, and there is also a problem that the position of the crushed stone input hole (the position where the opening and closing lid is provided) changes during the formation of the crushed stone pile.

[0006] This specification discloses a technique that enables the opening and closing cover to be opened widely with a relatively small force while preventing damage to the opening and closing cover. [Means for solving the problem]

[0007] The attachment disclosed in this specification is a crushed stone pile forming attachment that is attached to a crushed stone pile forming device that forms a crushed stone pile in a space formed in the ground, is inserted into the ground to form a space, and forms a crushed stone pile in the space while rising from the ground. This attachment includes a cylindrical part having a crushed stone input hole extending along the axial direction formed on its side, and an openable / closable lid that closes the crushed stone input hole. The openable / closable lid includes a lid body having an outer shape corresponding to the crushed stone input hole, a reinforcing cloth arranged in the lid body, and a plurality of reinforcing plates arranged in the lid body at intervals in the axial direction and extending in a width direction perpendicular to the axial direction. The lid body includes a first edge portion that extends along the axial direction and is fixed to the cylindrical part, and a second edge portion that extends along the axial direction, is positioned at an interval in the width direction from the first edge portion, and is not fixed to the cylindrical part. The lid body is bent with the first edge portion as a fulcrum, so that it can be switched between an open state that opens the crushed stone input hole and a closed state that closes the crushed stone input hole. The reinforcing cloth is partially disposed in the width direction of the lid body.

[0008] With the above attachment, the reinforcing cloth is partially arranged in the width direction of the lid body, making the opening and closing lid more easily deformable. Therefore, when opening the opening and closing lid and inserting the chute, the opening and closing lid can be opened widely with less force than before. Meanwhile, the reinforcing cloth can be partially arranged in the part of the opening and closing lid that is easily damaged. As a result, the opening and closing lid can be opened widely with a relatively small force while preventing damage to the opening and closing lid.

[0009] This specification also discloses a crushed stone pile forming device including the above-mentioned attachment. That is, the crushed stone pile forming device disclosed in this specification includes the above-mentioned attachment and a drive device that generates rotational drive forces in the forward rotation direction and the reverse rotation direction to drive the attachment. [Brief description of the drawings]

[0010] [Figure 1] 1 is a diagram showing a schematic configuration of a crushed stone pile forming device 100 disclosed in this specification. [Diagram 2] FIG. 13 is a view of only the attachment from a different angle. [Diagram 3] This is a cross-sectional view taken along line AA in Figure 1 (in the closed state (when excavating underground) where the tip of the hopper is not inserted into the crushed stone inlet hole). [Figure 4] This is a cross-sectional view taken along line AA in Figure 1 (showing the open state with the tip of the hopper inserted into the crushed stone inlet (when the attachment is being pulled out of the ground)). [Diagram 5] 2 is a partially cutaway front view of an opening / closing lid of the crushed stone pile forming device 100. FIG. [Figure 6] 2 is a schematic cross-sectional view of an opening / closing lid of the crushed stone pile forming device 100. FIG. [Figure 7] FIG. 11 is a schematic cross-sectional view of an opening / closing cover according to a modified example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] (Feature 1) In the attachment disclosed in this specification, the lid body is fixed to the cylindrical portion by a fastener, and the reinforcing cloth may be positioned at least in the range from the position where the fastener is arranged to the end of the reinforcing plate on the first edge side.

[0012] The crushed stone pile forming device 100 disclosed in this specification will be described in detail below. As shown in Fig. 1, the crushed stone pile forming device 100 includes a ground improvement machine 40 as a construction machine, and an attachment 10 attached to the ground improvement machine 40. As shown in Fig. 1, the ground improvement machine 40 includes a ground improvement machine main body structure 1, a cabin 7 as a driver's seat, a crawler 6 which is an endless track capable of moving on uneven ground with low ground pressure, and an outrigger 5 which suppresses the shaking of the ground improvement machine 40 during construction.

[0013] The ground improvement machine 40 further includes, as components for operating the attachment 10, a drive unit 11 that supplies rotational driving force to the attachment 10 via an output shaft 27, a leader 4 having a lifting guide rail 9, a lifting platform 17 that raises and lowers the drive unit 11 and the attachment 10 along the lifting guide rail 9, a leader mounting base 2 for supporting the leader 4, a hydraulic cylinder 3 that controls the inclination of the leader 4, and an extension column 8 that is formed integrally with the leader 4 at the lower end of the leader 4.

[0014] As shown in Figures 1 and 2, the attachment 10 comprises a cylindrical portion 12 provided with fins 13, a core rod 22 (shown in Figures 3 and 4), a spiral portion 14, an enclosing frame 30 for preventing the cylindrical portion 12 from vibrating, a hanger stay 18 attached to the lifting platform 17, a top cover case 16, a crushed stone feeding device 32, a support plate 37 supporting the enclosing frame 30, a support arm 39 supporting the crushed stone feeding device 32, and a construction management device 41 for managing the construction status by the attachment 10.

[0015] The cylindrical portion 12 has a crushed stone input hole 15 formed in the axial direction on the side surface thereof. The crushed stone input hole 15 extends in the axial direction of the cylindrical portion 12 and is closed by an opening / closing lid 61. The opening / closing lid 61 will be described in detail later.

[0016] The crushed stone injection device 32 includes a hopper section 33 and a chute section 34 disposed below the hopper section 33. The crushed stone injection hole 15 is closed by an openable lid 61 when the attachment 10 excavates the ground. This prevents soil and sand from entering the cylindrical section 12 through the crushed stone injection hole 15. When the crushed stone is injected into the cylindrical section 12, the openable lid 61 is opened. This allows the crushed stone injected into the crushed stone injection device 32 to be injected into the cylindrical section 12 through the crushed stone injection hole 15. Furthermore, since the crushed stone injection hole 15 is provided as a long hole along the axial direction, the crushed stone can be injected into the cylindrical section 12 without changing the crushed stone injection position even if the cylindrical section 12 rises.

[0017] As shown in Figures 1 and 2, the helical portion 14 is located at the tip of the cylindrical portion 12, and is integrally formed with the core rod 22 (shown in Figures 3 and 4) and the rotation input shaft 31. The rotation input shaft 31 is connected to the motor output shaft 27 of the drive unit 11. The rotation input shaft 31 rotates according to the rotational driving force of the motor output shaft 27, and transmits the rotational driving force to the helical portion 14 via the core rod 22 integrally connected thereto. An excavation blade is provided at the tip of the helical portion 14. The excavation blade is formed in a helical shape whose diameter increases toward the tip of the helical portion 14. Almost the entirety of the excavation blade is disposed inside the cylindrical portion 12, and only a part of the tip of the excavation blade protrudes from the tip of the cylindrical portion 12.

[0018] The core rod 22 (shown in FIG. 3) is rotatably connected to the cylindrical portion 12 at a position not shown, and shares a common rotation axis with the cylindrical portion 12. The cylindrical portion 12 has a helical fin 13 around its periphery. The fin 13 has a helical shape in the same direction as the helix of the helical portion 14 (i.e., the excavation wing). That is, during excavation, the cylindrical portion 12 and the helical portion 14 rotate in the same direction. As a result, the excavated soil generated by the excavation of the helical portion 14 is transported to the ground surface by the fin 13.

[0019] The top cover case 16 is attached to the rear end of the cylindrical portion 12 and is integrated with the cylindrical portion 12. The core rod 22 penetrates the upper surface of the top cover case 16 and is rotatably supported by the top cover case 16. Therefore, even if the core rod 22 is rotationally driven, the cylindrical portion 12 does not rotate together with the core rod 22 and is kept in a free state.

[0020] The attachment 10 further includes a rotational drive force transmission unit and a reversal prevention unit, not shown. The rotational drive force transmission unit is a one-way clutch mechanism, and when the helical part 14 is driven in the rotation direction during excavation, it automatically rotates the helical part 14 and the cylindrical part 12 as a unit. This allows the soil excavated by the helical part 14 to be discharged to the ground by the fins 13 of the cylindrical part 12, as described above. On the other hand, when the rotational drive force transmission unit drives the helical part 14 in the direction opposite to the rotation direction during excavation, it applies pressure to the crushed stone by rotating the helical part 14 in the reverse direction, and also cuts off the power transmission from the helical part 14 to the cylindrical part 12 to stop the rotation of the cylindrical part 12. When the helical part 14 is driven in the direction opposite to the rotation direction during excavation, the reversal prevention unit restricts the rotation of the cylindrical part 12 so that the cylindrical part 12, whose rotation has been stopped, does not rotate in either the rotation direction during excavation or the reverse direction. Hereinafter, the direction in which the cylindrical portion 12 and the spiral portion 14 rotate in the same direction, i.e., the rotation direction during excavation, will be referred to as the "forward direction", and the direction in which they rotate in the opposite direction to the rotation direction during excavation, i.e., the rotation direction in which pressure is applied to the crushed stone by the spiral portion 14, will be referred to as the "reverse direction". In addition, the forward direction will be described as right rotation (clockwise) and the reverse direction will be described as left rotation (counterclockwise).

[0021] Here, the configuration of the opening / closing lid 61 provided on the cylindrical portion 12 will be described in detail with reference to Figs.

[0022] As shown in FIG. 5, the opening and closing lid 61 is a vertically long rectangular member for closing the crushed stone input hole 15 formed in the cylindrical portion 12. The opening and closing lid 61 includes a lid body 62, a reinforcing cloth 63, and a plurality of reinforcing plates 64. The lid body 62 has an outer shape corresponding to the crushed stone input hole 15. The lid body 62 is made of an elastically deformable rubber or resin material. The lid body 62 includes a first edge portion 65 and a second edge portion 66. The first edge portion 65 is an edge portion that extends along the axial direction and is fixed to the cylindrical portion 12. On the other hand, the second edge portion 66 is an edge portion that extends along the axial direction and is located at a distance in the width direction from the first edge portion 65 and is not fixed to the cylindrical portion 12. The lid body 62 is fixed to a first opening edge 68a of a door mounting plate 68 provided on the cylindrical portion 12 by a fastener 67. The fasteners 67 are, for example, bolts and nuts, and are provided at a plurality of locations along the axial direction at equal intervals.

[0023] The lid body 62 is bent about a first edge 65 as a fulcrum, so that it can be switched between an open state (see FIG. 4) in which the crushed stone input hole 15 is opened, and a closed state (see FIG. 3) in which the crushed stone input hole 15 is closed. In the open state, the second edge 66 of the lid body 62 is separated from the second opening edge 68b of the door mounting plate 68, connecting the internal area of ​​the cylindrical portion 12 with the external area. In the closed state, the second edge 66 of the lid body 62 abuts against the second opening edge 68b of the door mounting plate 68, blocking communication between the internal area of ​​the cylindrical portion 12 and the external area.

[0024] The reinforcing plates 64 are embedded in the cover body 62 to reinforce the opening / closing cover 61. The reinforcing plates 64 are installed to prevent the opening / closing cover 61 from bending due to soil pressure or water pressure in the ground, and are arranged at intervals in the axial direction (Z-axis direction in FIG. 5) in the cover body 62, and extend in the width direction (X-axis direction in FIG. 5) perpendicular to the axial direction. The reinforcing plates 64 are metal aggregates, and have a dimension slightly shorter than the length of the reinforcing plates 64 in the width direction. An end t2 on the second edge 66 side of the reinforcing plate 64 is arranged so as to reach the vicinity of the second edge 66 of the cover body 62. An end t1 on the first edge 65 side of the reinforcing plate 64 is not arranged in the vicinity of the first edge 65 of the cover body 62, and is arranged closer to the second edge 66 than the fastener 67. The ends t1 and t2 have rounded corners.

[0025] The reinforcing cloths 63a and 63b are disposed inside the lid body 62 to reinforce the opening / closing lid 61, and mainly prevent the lid body 62 from being torn by the reinforcing plate 64. The reinforcing cloth 63a is embedded in the lid body 62 on the rear side of the reinforcing plate 64 (i.e., the inner surface side of the lid body 62), and the reinforcing cloth 63b is embedded in the lid body 62 on the front side of the reinforcing plate 64 (i.e., the outer surface side of the lid body 62).

[0026] Further, the reinforcing cloths 63a, 63b are disposed almost entirely in the axial direction of the lid body 62, but are not disposed entirely in the width direction of the lid body 62, but are disposed partially. The reinforcing cloths 63a, 63b are disposed in a range including from the position P1 where the fastener 67 is disposed to the end t1 on the first edge 65 side of the reinforcing plate 64. Specifically, the reinforcing cloths 63a, 63b are disposed in a range from the first edge 65 to a position slightly closer to the second edge 66 than the end t1 on the first edge 65 side. In other words, the reinforcing cloths 63a, 63b are not disposed in a range from a position slightly closer to the second edge 66 than the end t1 on the first edge 65 side to the second edge 66.

[0027] Next, the operation of the crushed stone pile forming device 100 when the crushed stone pile forming device 100 forms a crushed stone pile will be described.

[0028] First, the attachment 10 is aligned. The attachment 10 is aligned by adjusting the position and direction of the ground improvement machine 40 by driving the crawler 6. After adjusting the position and direction of the ground improvement machine 40, the ground improvement machine 40 may be fixed to the ground by the outrigger 5. This makes it possible to suppress shaking and displacement of the ground improvement machine 40 during construction.

[0029] Next, the attachment 10 is inserted into the ground to excavate the ground. Specifically, after the ground improvement machine 40 is fixed to the ground, the attachment 10 is lowered while driving the drive unit 11. At this time, the drive unit 11 is driven to generate a rotational drive force in the forward direction. As described above, when the drive unit 11 generates a rotational drive force in the forward direction, the spiral part 14 and the cylindrical part 12 are rotated in the forward direction by the rotational drive force transmission part. This allows the attachment 10 to be inserted into the ground and excavate. The soil discharged by excavation in the ground is carried to the outer periphery of the cylindrical part 12 and discharged to the ground surface by the fins 13. When the attachment 10 reaches a predetermined depth, the drive unit 11 stops driving the forward rotation and ends excavation.

[0030] Next, the attachment 10 is raised, and a crushed stone pile is formed in the ground. The crushed stone pile is formed in the following procedure. First, as shown in FIG. 4, crushed stone is charged into the crushed stone charging device 32 with the opening and closing lid 61 open. The crushed stone charged into the crushed stone charging device 32 is charged into the cylindrical portion 12 through the crushed stone charging hole 15. Next, the driving device 11 is driven so as to generate a rotational driving force in the reverse direction. Then, the spiral portion 14 rotates in the reverse direction, and the crushed stone charged into the cylindrical portion 12 is discharged out of the cylindrical portion 12 while being pressed from the spiral portion 14. As a result, the attachment 10 is pushed out of the ground, and a crushed stone pile is formed in the space formed by the cylindrical portion 12. As described above, when the driving device 11 generates a rotational driving force in the reverse direction, only the spiral portion 14 rotates in the reverse direction by the rotational driving force transmission portion, and the cylindrical portion 12 is in a state where it does not rotate in either the normal direction or the reverse direction. This makes it possible to prevent the position of the crushed stone injection hole 15 provided in the cylindrical portion 12 from changing in the circumferential direction, and allows crushed stone to be injected into the cylindrical portion 12 without adjusting the position of the crushed stone injection device 32. Then, when the attachment 10 is pushed out to the ground surface, the driving of the driving device 11 in the reverse direction is stopped, and the formation of the crushed stone pile is completed.

[0031] Incidentally, when forming a crushed stone pile with this type of attachment 10, it is necessary to open a portion of the opening / closing lid 61 slightly above the ground surface, insert the tip of the chute section 34 of the crushed stone input device 32 into the open portion, and input crushed stone into the space of the cylindrical section 12. However, since the portion of the opening / closing lid 61 buried in the ground (hereinafter, sometimes referred to as the buried portion) remains closed, the chute section insertion portion must be largely deformed outward relative to the buried portion. In particular, since the first edge section 65 of the lid body 62 is fixed to the cylindrical section 12, the second edge section 66 side of the lid body 62 must be largely opened outward until the tip of the chute section 34 can be inserted. For this reason, the portion slightly above the ground surface is twisted relative to the portion inserted in the ground, and a force that tends to stretch in the axial direction acts on the twisted portion of the opening / closing lid 61 (particularly, the second edge section 66 side). As described above, in the opening and closing lid 61 of this embodiment, the reinforcing cloths 63a, 63b are not arranged in the range from the position slightly closer to the second edge 66 than the end t1 on the first edge 65 side to the second edge 66. Therefore, the opening and closing lid 61 is easily deformed in the range where the reinforcing cloths 63a, 63b are not arranged, and the second edge 66 side of the opening and closing lid 61 extends in the axial direction. Therefore, compared with the case where the reinforcing cloth is arranged over the entire opening and closing lid 61, the opening and closing lid 61 can be opened widely with a small force, and the tip of the chute part 34 of the crushed stone input device 32 can be inserted. In addition, since the force required to open the opening and closing lid 61 is reduced, the force acting from the opening and closing lid 61 to the cylindrical part 12 as a reaction (i.e., the force that tries to rotate the cylindrical part 12 around the axis) is also reduced. This makes it possible to suppress the position of the crushed stone input hole 15 (the position of the opening and closing lid 61) from changing during the formation of the crushed stone pile.

[0032] Meanwhile, the reinforcing cloths 63a, 63b are partially arranged in the width direction of the lid main body 62. More specifically, the reinforcing cloths 63a, 63b are arranged to include a range from the position P1 where the fastener 67 is arranged to the end t1 on the first edge 65 side of the reinforcing plate 64. This prevents the fastener 67 from tearing the opening / closing lid 61 and the end t1 of the reinforcing plate 64 from breaking through the opening / closing lid 61. As a result, it becomes possible to open the opening / closing lid 61 widely with a relatively small force while suppressing damage to the opening / closing lid 61.

[0033] In addition, in each of the above-mentioned examples, the reinforcing cloth 63 is embedded on both the front and rear sides of the reinforcing plate 64 in the lid main body 62, but this is not limited to this. For example, in another example, the reinforcing cloth 63 may be embedded on the front side of the reinforcing plate 64 in the lid main body 62, or the reinforcing cloth 63a may be embedded only on the rear side of the reinforcing plate 64 as shown in Fig. 7.

[0034] In the above-mentioned crushed stone pile forming device 100, the method of forming a crushed stone pile by pouring crushed stone into a space formed in the ground is performed by compacting the stone by reverse rotation of the screw of the attachment 10, but the present invention is not limited to this example. The technology disclosed in this specification can also be used in a crushed stone pile forming method that does not rely on compaction by reverse rotation of the screw of the attachment 10.

[0035] In addition, the above-mentioned crushed stone pile forming device 100 is an attachment 10 of a type that discharges excavated soil to the ground surface (so-called soil discharge type), but is not limited to such an example. The technology disclosed in this specification can also be used in, for example, a non-soil discharge type attachment.

[0036] Although specific examples of the technology disclosed in this specification have been described in detail above, these are merely examples and do not limit the scope of the claims. The technology described in the claims includes various modifications and changes of the specific examples exemplified above. For example, in the above embodiment, the earth and sand are excavated when the cylindrical part rotates clockwise, but the present invention is not limited to such an example, and the earth and sand are excavated when the cylindrical part rotates in the opposite direction to the above embodiment, and the fixing position of the opening and closing cover is reversed from the left to the right to the above embodiment, etc. are also within the scope of the present invention. In addition, the technical elements described in this specification or drawings exhibit technical usefulness alone or in various combinations, and are not limited to the combinations described in the claims at the time of filing. [Explanation of symbols]

[0037] 10: Attachment 12: Cylindrical section 15: Crushed stone injection hole 61: Opening and closing lid 62: Lid body 63: Reinforcement fabric 64: Reinforcement plate 65: First edge 66: Second edge 67: Fasteners 100: Crushed stone pile forming device P1: Position where the fastener is placed t1: End of the first edge t2: End of the second edge

Claims

1. A crushed stone pile forming attachment that is attached to a crushed stone pile forming device that forms a crushed stone pile in a space formed in the ground, is inserted into the ground to form the space, and forms a crushed stone pile in the space while rising from the ground, A cylindrical portion having a crushed stone injection hole extending along an axial direction on a side surface thereof; An opening and closing cover for closing the crushed stone input hole is provided. The opening and closing cover is A lid body having an outer shape corresponding to the crushed stone insertion hole; A reinforcing cloth disposed within the lid body; A plurality of reinforcing plates are disposed in the lid body at intervals in the axial direction and extend in a width direction perpendicular to the axial direction, The lid body is A first edge portion extending along the axial direction and fixed to the cylindrical portion; a second edge portion extending along the axial direction and spaced apart from the first edge portion in the width direction and not fixed to the cylindrical portion, The cover body is bent with the first edge portion as a fulcrum to be switched between an open state in which the crushed stone injection hole is opened and a closed state in which the crushed stone injection hole is closed, An attachment for forming crushed stone piles, wherein the reinforcing cloth is partially arranged in the width direction of the lid body.

2. The lid body is fixed to the cylindrical portion by a fastener, 2. The attachment for forming a crushed stone pile according to claim 1, wherein the reinforcing cloth is arranged at least in the range from the position where the fastener is arranged to the end of the reinforcing plate on the first edge side.

3. An attachment according to claim 1; A crushed stone pile forming device comprising: a drive device that generates rotational driving forces in a forward rotation direction and a reverse rotation direction to drive the attachment.

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