Deep foundation drilling machine

Abstract

To suppress interference between a rope to be detected for slackness and a slackness detection device.SOLUTION: A caisson type pile excavator 1 includes a first lifting sheave 19 and a first opening / closing sheave 21 that move in the length direction of an arm 10, a second lifting sheave 23 and a second opening / closing sheave 30, a lifting rope 38 wound around the first lifting sheave 19 and the second lifting sheave 23, an opening / closing rope 39 wound around the first opening / closing sheave 21 and the second opening / closing sheave 30, and slackness detection device 47 (62) that detects the slackness of the detected rope among the lifting rope 38 and the opening / closing rope 39. The slackness detection device 47 (62) is arranged inside a lifting rope path 38C formed by the lifting rope 38 wound around the first lifting sheave 19 and the second lifting sheave 23, and / or it is arranged inside an opening / closing rope path 39C formed by the opening / closing rope 39 wound around the first opening / closing sheave 21 and the second opening / closing sheave 30.SELECTED DRAWING: Figure 6

Description

TECHNICAL FIELD

[0001] The present disclosure relates to a deep foundation excavator suitably used for excavating shafts.

BACKGROUND ART

[0002] As a deep foundation excavator that excavates a shaft in the ground and lifts and discharges the excavated earth and sand, a deep foundation excavator has been proposed in which a clamshell bucket is attached to the tip of a cylindrical arm mounted to the boom tip of a hydraulic excavator via a hoisting rope and an opening / closing rope. This deep foundation excavator is provided with a bucket hoisting and opening / closing device on the arm, and excavates a shaft in the ground by performing the hoisting operation and the opening / closing operation of the clamshell bucket with the bucket hoisting and opening / closing device.

[0003] When excavating a shaft with a clamshell bucket, the hoisting rope and the opening / closing rope are paid out to lower the clamshell bucket and land it on the ground. Then, the clamshell bucket is closed while penetrating into the ground under its own weight, whereby earth and sand can be excavated. Thereafter, the hoisting rope and the opening / closing rope are wound up to raise the clamshell bucket, and the excavated earth and sand is discharged to the cargo bed of a dump truck or the like.

[0004] Here, if the hoisting rope and the opening / closing rope are excessively loosened when the clamshell bucket lands on the ground, time is wasted when the hoisting rope and the opening / closing rope are wound up to raise the clamshell bucket after excavating earth and sand. For this reason, it is necessary to detect the slack of the hoisting rope and the like to stop the lowering operation of the clamshell bucket and promptly shift to the raising operation. As a device for detecting such rope slack, a slack detection device has been proposed that includes a coil spring provided at the end of the rope to be detected, which expands and contracts according to the tension acting on the rope to be detected, and a sensor that detects the slack of the rope to be detected based on the displacement or the like of the end of the rope to be detected (Patent Documents 1 and 2).

PRIOR ART DOCUMENTS

PATENT DOCUMENTS

[0005] [Patent Document 1] Japanese Patent Publication No. 2004-176391 [Patent Document 2] Japanese Patent Application Publication No. 8-134878 [Overview of the project] [Problems that the invention aims to solve]

[0006] However, deep foundation drilling machines excavate shafts by lowering a clamshell bucket deep into the ground, so the lifting ropes and opening / closing ropes are each wound around multiple sheaves. Since the multiple sheaves are arranged adjacent to each other in the axial direction of the rotation center, the spacing between adjacent lifting ropes and opening / closing ropes wound around these multiple sheaves is very narrow.

[0007] In contrast, the loosening detection devices described in Patent Documents 1 and 2 have a shape larger than the diameter of the rope to be detected. Therefore, if the loosening detection devices described in Patent Documents 1 and 2 are installed at the end of the rope to be detected among the lifting ropes and opening / closing ropes mounted on a deep foundation excavator, there is a problem that the loosening detection device will interfere with the adjacent rope to be detected, causing damage to the rope to be detected.

[0008] The object of the present invention is to provide a deep foundation drilling machine that can suppress interference between the rope to be detected and the loosening detection device. [Means for solving the problem]

[0009] The present invention comprises an arm provided on a self-propelled vehicle body, a clamshell bucket provided on the arm so as to be able to move up and down, and a bucket lifting / opening device provided on the arm for lifting and lowering and opening and closing operations of the clamshell bucket, wherein the bucket lifting / opening device comprises a first lifting sheave and a first opening / closing sheave provided on the arm and moving in the longitudinal direction of the arm by a lifting cylinder,The aforementioned First lifting sheave and The aforementioned A deep foundation drilling machine comprising: a second lifting sheave and a second opening / closing sheave, each provided on the arm spaced apart from a first opening / closing sheave; a lifting rope wound around the first and second lifting sheaves, with one end attached to the arm and the other end attached to the clamshell bucket; an opening / closing rope wound around the first and second opening / closing sheaves, with one end attached to the arm and the other end attached to the clamshell bucket; and a looseness detection device provided at one end of the lifting rope and the opening / closing rope to be detected for detecting looseness in the rope to be detected, wherein the machine comprises: a second lifting sheave and a second opening / closing sheave, each provided on the arm spaced apart from a first opening / closing sheave; a lifting rope wound around the first and second lifting sheaves, with one end attached to the arm and the other end attached to the clamshell bucket; and a looseness detection device provided at one end of the lifting rope and the opening / closing rope to be detected for detecting looseness in the rope to be detected, The lifting rope is arranged on one side and the other side of the first lifting sheave and the second lifting sheave in a direction perpendicular to the longitudinal direction of the arm in the radial direction of the first lifting sheave and the second lifting sheave, respectively, and is wound around the first lifting sheave and the second lifting sheave in a ring shape, and the opening and closing rope is arranged on one side and the other side of the first opening and closing sheave and the second opening and closing sheave in a direction perpendicular to the longitudinal direction of the arm in the radial direction of the first opening and closing sheave and the second opening and closing sheave, respectively, and is wound around the first opening and closing sheave and the second opening and closing sheave in a ring shape, The slack detection device is located inside the annular lifting rope path formed by the lifting rope wound around the first lifting sheave and the second lifting sheave. And, of the portion of the lifting rope that is wound around the first lifting sheave and the second lifting sheave, between the portion on one side and the portion on the other side , and / or inside the annular opening / closing rope path formed by the opening / closing rope wound around the first opening / closing sheave and the second opening / closing sheave And, between the portion of the opening / closing rope that is wound around the first opening / closing sheave and the second opening / closing sheave, and the portion on one side and the portion on the other side. It is characterized by being arranged in a specific position. [Effects of the Invention]

[0010] According to the present invention, when the rope to be detected is a lifting rope, the looseness detection device can be placed inside the annular lifting rope path formed by the lifting rope. Therefore, even if a looseness detection device larger than the rope diameter is provided at one end of the lifting rope, interference between the looseness detection device and the lifting rope can be prevented. Similarly, when the rope to be detected is an opening / closing rope, the looseness detection device can be placed inside the annular opening / closing rope path formed by the opening / closing rope. Therefore, even if a looseness detection device larger than the rope diameter is provided at one end of the opening / closing rope, interference between the looseness detection device and the opening / closing rope can be prevented. [Brief explanation of the drawing]

[0011] [Figure 1] This is a left side view showing a deep foundation excavator according to an embodiment of the present invention. [Figure 2]This is a left side view showing the bucket lifting / lowering and opening / closing device. [Figure 3] This is a plan view showing the bucket lifting / lowering and opening / closing device. [Figure 4] This is a right side view showing the bucket lifting / lowering and opening / closing device. [Figure 5] This is an exploded view of the arm. [Figure 6] This is a perspective view showing the looseness detection device, the lifting rope, and the like. [Figure 7] This is an enlarged left side view showing the looseness detection device. [Figure 8] This is a bottom view of the looseness detection device as viewed in the direction of arrows VIII-VIII in Fig.7. [Figure 9] This is a cross-sectional view of the looseness detection device as viewed in the direction of arrows IX-IX in Fig.7. [Figure 10] This is a cross-sectional view of the looseness detection device as viewed in the direction of arrows X-X in Fig.8. [Figure 11] This is a right side view of the bucket lifting / lowering and opening / closing device showing a modified example in which no looseness detection device is provided at one end of the opening / closing rope. [Modes for Carrying Out the Invention]

[0012] Hereinafter, the deep foundation excavator according to the embodiment of the present invention will be described in detail with reference to the accompanying drawings. In the embodiment, description will be made with the length direction of the arm defined as the front-rear direction, and the direction orthogonal to the length direction of the arm defined as the left-right direction.

[0013] In Fig.1, the deep foundation excavator 1 is manufactured based on, for example, a crawler-type hydraulic excavator. The deep foundation excavator 1 is constituted by a self-propelled crawler-type lower traveling body 2, an upper revolving body 3 rotatably mounted on the lower traveling body 2, and a working device 5 which is provided on the upper revolving body 3 and will be described later. The lower traveling body 2 and the upper revolving body 3 constitute the vehicle body of the deep foundation excavator 1.

[0014] The cab 4 is provided on the left front side of the upper revolving structure 3. The cab 4 defines an operator's compartment, in which an operator who operates the deep foundation excavator 1 rides. Inside the cab 4, a driver's seat 4A on which the operator sits is provided, and around the driver's seat 4A, operating devices (not shown) for operating the traveling motion of the lower traveling structure 2, the revolving motion of the upper revolving structure 3, and the work device 5 are provided.

[0015] The work device 5 includes a boom 6 provided on the upper revolving structure 3 so as to be rotatable in the vertical direction, an arm 10 to be described later, a clamshell bucket 9, and a bucket lifting / lowering and opening / closing device 17. A boom cylinder 7 is provided between the upper revolving structure 3 and the boom 6, and the boom 6 rotates relative to the upper revolving structure 3 in accordance with the expansion and contraction operation of the boom cylinder 7. An arm cylinder 8 is provided between the boom 6 and the arm 10, and the arm 10 rotates relative to the boom 6 in accordance with the expansion and contraction operation of the arm cylinder 8.

[0016] The clamshell bucket 9 is suspended from the front end of the arm 10 so as to be able to move up and down by using a lifting rope 38 to be described later. The clamshell bucket 9 has a bucket support portion 9A, a pair of buckets 9B provided below the bucket support portion 9A so as to be openable and closable, a connection bracket 9C to which the pair of buckets 9B are rotatably connected, and a pair of opening / closing arms 9D that connect between the bucket support portion 9A and the pair of buckets 9B. The bucket support portion 9A is provided with a plurality of upper sheaves 9E, and the connection bracket 9C is provided with a plurality of lower sheaves 9F that face the upper sheaves 9E in the vertical direction.

[0017] The other end 38B of the lifting rope 38 is attached to the bucket support portion 9A of the clamshell bucket 9. An opening / closing rope 39 to be described later is alternately wound around the upper sheaves 9E and the lower sheaves 9F of the clamshell bucket 9, and the other end 39B of the opening / closing rope 39 is attached to the bucket support portion 9A of the clamshell bucket 9.

[0018] The arm 10 is rotatably mounted at the tip of the boom 6. As shown in Figure 5, the arm 10 is divisible, consisting of an arm body 11 formed of a hollow cylindrical body and extending in the front-rear direction, a pair of guide arms 12 and 13 detachably mounted on the rear side of the arm body 11, and a sheave mounting member 14 movably attached to the guide arms 12 and 13.

[0019] The arm body 11 is the base of the arm 10 and is formed as a rectangular tubular body with a rectangular cross-section. The arm body 11 is surrounded by a left side panel 11A and a right side panel 11B that are opposite each other in a direction perpendicular to the length direction (front-to-back direction) of the arm 10 (left-to-right direction), an upper panel 11C that connects the upper ends of the left side panel 11A and the right side panel 11B, and a lower panel 11D that connects the lower ends of the left side panel 11A and the right side panel 11B. Here, the left side panel 11A of the arm body 11 is positioned on the side of the driver's seat 4A located inside the cab 4 of the upper slewing body 3, and is a surface that is easy to see (highly visible) for the operator sitting in the driver's seat 4A.

[0020] The distance between the left side panel 11A and the right side panel 11B is set to be smaller than the distance between the top panel 11C and the bottom panel 11D. The front end 11E of the arm body 11 is closed, and the rear end 11F of the arm body 11 is an open end. On the top panel 11C of the arm body 11, a stepped surface 11G is formed in the part located in front of the center in the front-rear direction, which is lower in height (distance from the bottom panel 11D) than the part located behind the center. An intermediate guide sheave 37, which will be described later, is provided on the stepped surface 11G. The bottom panel 11D of the arm body 11 is provided with a boom mounting bracket 11H and a cylinder mounting bracket 11J. The boom mounting bracket 11H is rotatably connected to the tip of the boom 6 via a connecting pin 11K (see Figure 1). The cylinder mounting bracket 11J is pin-connected to the tip of the arm cylinder 8, whose base end is attached to the boom 6. Therefore, the arm body 11 rotates in the forward / backward or up / down direction around the connecting pin 11K in accordance with the extension / retraction movement of the arm cylinder 8.

[0021] The rear end 11F side of the left side panel 11A and the right side panel 11B each have two pin insertion holes 11L and 11M, spaced apart vertically and penetrating horizontally. Connecting pins 12B and 13B, described later, are inserted through these pin insertion holes 11L and 11M. A trunnion pin 18D, described later, is inserted in front of the pin insertion holes 11L and 11M on both the left side panel 11A and the right side panel 11B. On the other hand, a guide sheave support shaft 32, described later, is fixed to the front end 11E side of the left side panel 11A. A second lifting sheave shaft 24, described later, is fixed to the middle of the left side panel 11A in the front-to-back direction.

[0022] Guide arms 12 and 13 are detachably attached to the rear side of the arm body 11 in a pair in the vertical direction. Each guide arm 12 and 13 is formed as a rectangular tubular body with a rectangular cross-section and extends in the front-rear direction. Cylindrical portions 12A and 13A extending in the left-right direction are fixed to the front ends of each guide arm 12 and 13. A connecting pin 12B is inserted through the inner circumference of the cylindrical portion 12A of guide arm 12, and both ends of the connecting pin 12B are inserted through the pin insertion holes 11L of the arm body 11. A connecting pin 13B is inserted through the inner circumference of the cylindrical portion 13A of guide arm 13, and both ends of the connecting pin 13B are inserted through the pin insertion holes 11M of the arm body 11. On the other hand, the rear ends of guide arms 12 and 13 are connected via a connecting member 13C. As a result, the guide arms 12 and 13 extend rearward from the rear end 11F of the arm body 11 while maintaining a constant distance between them in the vertical direction.

[0023] The sheave mounting member 14 is movably attached to a pair of guide arms 12 and 13 and constitutes part of the arm 10. The sheave mounting member 14 moves in the front-rear direction along the guide arms 12 and 13 with the first lifting sheave 19 and the first opening / closing sheave 21, which will be described later, attached to it. The sheave mounting member 14 is formed as a cylindrical body having a rectangular cross-sectional shape equivalent to that of the arm body 11 and surrounds the guide arms 12 and 13 from the outside. That is, the sheave mounting member 14 is formed as a short cylindrical body (frame) surrounded by a left plate 14A, a right plate 14B, an upper plate 14C, and a lower plate 14D.

[0024] The front portions of the left plate 14A and the right plate 14B, which constitute the sheave mounting member 14, each have pin insertion holes 14E that penetrate in the left-right direction, formed concentrically. A rod mounting pin 18F, which will be described later, is inserted through these two pin insertion holes 14E. In the center of the left plate 14A, which constitutes the sheave mounting member 14, a left shaft mounting hole 14F that penetrates in the left-right direction is formed, and in the center of the right plate 14B, a right shaft mounting hole 14G that penetrates in the left-right direction is formed. The first lifting sheave shaft 20, which will be described later, is attached to the left shaft mounting hole 14F, and the first opening / closing sheave shaft 22, which will be described later, is attached to the right shaft mounting hole 14G.

[0025] Slide plates 15 are provided between the inner surfaces of the left plate 14A, right plate 14B, and upper plate 14C of the sheave mounting member 14 and the guide arm 12, and the slide plates 15 are in slidable contact with the guide arm 12. Slide plates 16 are provided between the inner surfaces of the left plate 14A, right plate 14B, and lower plate 14D of the sheave mounting member 14 and the guide arm 13, and the slide plates 16 are in slidable contact with the guide arm 13. These slide plates 15 and 16 are fixed to the sheave mounting member 14 using bolts or the like, and allow the sheave mounting member 14 to move (slide) smoothly relative to the guide arms 12 and 13.

[0026] Next, the bucket lifting and opening / closing device 17 used in this embodiment will be described.

[0027] The bucket lifting and opening / closing device 17 is installed on the arm 10. The bucket lifting and opening / closing device 17 performs various operations, including lifting and lowering and opening and closing operations of the clamshell bucket 9. The bucket lifting and opening / closing device 17 is composed of a lifting cylinder 18, a first lifting sheave 19, a first opening / closing sheave 21, a second lifting sheave 23, a second opening / closing sheave 30, an opening / closing cylinder 31, an intermediate guide sheave 37, a lifting rope 38, an opening / closing rope 39, a slack adjustment sheave 45, and a slack adjustment cylinder 46, which will be described later.

[0028] The lifting cylinder 18 is located within the arm body 11 that constitutes the arm 10, and extends along the length (front-to-back direction) of the arm body 11. The lifting cylinder 18 raises or lowers the clamshell bucket 9 by extending or retracting in response to the operation of an operating device located inside the cab 4. The lifting cylinder 18 has a tube 18A, a piston (not shown) inserted into the tube 18A, and a rod 18B whose base end is attached to the piston and whose tip protrudes from the tube 18A.

[0029] A mounting flange 18C is fixed to the tube 18A, and two trunnion pins 18D, which are inserted through the left side plate 11A and the right side plate 11B of the arm body 11, are fitted into the mounting flange 18C. As a result, the tube 18A of the lifting cylinder 18 is supported on the arm body 11 so as to be able to swing around the trunnion pins 18D. On the other hand, a cylindrical mounting eye 18E is provided at the tip of the rod 18B of the lifting cylinder 18, and a rod mounting pin 18F is inserted through the pin insertion hole 14E of the sheave mounting member 14 and the mounting eye 18E.

[0030] Thus, the tube 18A of the lifting cylinder 18 is attached to the arm body 11, and the rod 18B is attached to the sheave mounting member 14. Therefore, by extending and retracting the lifting cylinder 18, the sheave mounting member 14 moves in the front-rear direction along the guide arms 12 and 13.

[0031] The first lifting sheave 19 is attached to the outer surface of the left plate 14A, which constitutes the sheave mounting member 14, via the first lifting sheave shaft 20. The base end of the first lifting sheave shaft 20 is fixed to the left shaft mounting hole 14F of the sheave mounting member 14 (left plate 14A), and the tip protrudes to the left from the sheave mounting member 14. Multiple first lifting sheaves 19 are provided in a row (for example, 5) arranged in the axial direction of the first lifting sheave shaft 20, and are supported by the sheave mounting member 14 so as to be rotatable about the first lifting sheave shaft 20.

[0032] The first opening / closing sheave 21 is attached to the outer surface of the right side plate 14B, which constitutes the sheave mounting member 14, via the first opening / closing sheave shaft 22. The base end of the first opening / closing sheave shaft 22 is fixed to the right shaft mounting hole 14G of the sheave mounting member 14 (right side plate 14B), and the tip protrudes to the right from the sheave mounting member 14. Multiple first opening / closing sheaves 21 are provided in a row (for example, 5) arranged in the axial direction of the first opening / closing sheave shaft 22, and are rotatably supported on the sheave mounting member 14 about the first opening / closing sheave shaft 22.

[0033] The second lifting sheave 23 is provided on the arm body 11, spaced apart from the first lifting sheave 19. The second lifting sheave 23 is attached to the outer surface of the left side panel 11A of the arm body 11 via the second lifting sheave shaft 24. The base end of the second lifting sheave shaft 24 is fixed to the left side panel 11A of the arm body 11, and the tip protrudes to the left from the arm body 11. Multiple (for example, four) second lifting sheaves 23 are provided in the axial direction of the second lifting sheave shaft 24, and are rotatably supported on the arm body 11 about the second lifting sheave shaft 24. Therefore, as the sheave mounting member 14 moves in accordance with the extension and retraction operation of the lifting cylinder 18, the first lifting sheave 19 attached to the sheave mounting member 14 moves closer to and further away from the second lifting sheave 23. The first lifting sheave 19 and the second lifting sheave 23 are wound with a lifting rope 38.

[0034] The opening / closing sheave moving mechanism 25 is located in the middle of the arm body 11 in the front-rear direction and is provided on the right side panel 11B. The opening / closing sheave moving mechanism 25 supports the second opening / closing sheave 30 so that it can move in the front-rear direction. As shown in Figure 3, the opening / closing sheave moving mechanism 25 is composed of a guide rail 26, a pair of sliding members 27, a frame member 28, and a second opening / closing sheave shaft 29.

[0035] The guide rail 26 consists of a T-shaped block body extending in the front-rear direction and is fixed to the right side plate 11B of the arm body 11. A pair of slide members 27 are paired vertically on either side of the guide rail 26 and are slidably engaged with the guide rail 26. The frame member 28 is attached to the pair of slide members 27 using bolts or the like. A rod mounting pin 28A extending in the left-right direction is attached to the frame member 28, and a mounting eye 31D for the opening / closing cylinder 31, which will be described later, is attached to the rod mounting pin 28A. In addition, a second opening / closing sheave shaft 29 extending in the left-right direction is attached to the frame member 28 adjacent to the rod mounting pin 28A.

[0036] The second opening / closing sheave 30 is rotatably mounted on the second opening / closing sheave shaft 29 of the opening / closing sheave moving mechanism 25. That is, the second opening / closing sheave 30 is provided on the outer surface of the right side plate 11B that constitutes the arm body 11, so as to be movable in the front-rear direction via the opening / closing sheave moving mechanism 25. Multiple (for example, four) second opening / closing sheaves 30 are provided in the axial direction of the second opening / closing sheave shaft 29 provided on the opening / closing sheave moving mechanism 25, and are rotatably supported on the arm body 11 about the second opening / closing sheave shaft 29.

[0037] The opening / closing cylinder 31 is located on the rear side (rear end 11F side) of the arm body 11 and is mounted on the right side face plate 11B. The opening / closing cylinder 31 extends in the front-rear direction and moves the second opening / closing sheave 30 closer to and further away from the first opening / closing sheave 21. The opening / closing cylinder 31 has a tube 31A, a piston (not shown) inserted inside the tube 31A, and a rod 31B whose base end is attached to the piston and whose tip protrudes from the tube 31A. The bottom side of the tube 31A is attached to the rear end 11F side of the right side face plate 11B of the arm body 11 via a bracket 31C. A cylindrical mounting eye 31D is provided at the tip of the rod 31B, and the mounting eye 31D is attached to the frame member 28 of the opening / closing sheave moving mechanism 25 via a rod mounting pin 28A. Therefore, the second opening / closing sheave 30, which is attached to the opening / closing sheave moving mechanism 25, moves in the forward and backward directions in accordance with the extension and retraction operation of the opening / closing cylinder 31, and moves closer to and further away from the first opening / closing sheave 21.

[0038] The guide sheave support shaft 32 is provided on the left side panel 11A located on the front end 11E side of the arm body 11. The base end of the guide sheave support shaft 32 is fixed to the left side panel 11A, and the tip of the guide sheave support shaft 32 protrudes to the left from the left side panel 11A. The guide sheave support shaft 32 rotatably supports the lifting guide sheave 33 and the opening / closing guide sheave 34.

[0039] The lifting guide sheave 33 and the opening / closing guide sheave 34 are provided on the left side panel 11A of the arm body 11 via the guide sheave support shaft 32. The lifting guide sheave 33 and the opening / closing guide sheave 34 have the same diameter. The lifting guide sheave 33 guides the lifting rope 38, which is wound around the first lifting sheave 19 and the second lifting sheave 23, to the clamshell bucket 9. The opening / closing guide sheave 34 guides the opening / closing rope 39, which is wound around the first opening / closing sheave 21, the second opening / closing sheave 30, and the intermediate guide sheave 37 and the slack adjustment sheave 45 (described later), to the clamshell bucket 9. As a result, as shown in Figure 1, for example, with the arm 10 held horizontally to the ground, the clamshell bucket 9 can be raised and lowered vertically using the lifting rope 38 wound around the lifting guide sheave 33 located at the front end of the arm 10.

[0040] Here, the lifting guide sheave 33 and the opening / closing guide sheave 34 are positioned on the front end 11E side of the left side panel 11A of the arm body 11, which is highly visible to the operator seated in the driver's seat 4A. This allows the operator to operate the bucket lifting / opening / closing device 17 while visually confirming the status of the lifting rope 38 and opening / closing rope 39 attached to the clamshell bucket 9. Furthermore, by making the lifting guide sheave 33 and the opening / closing guide sheave 34 the same diameter, the front-to-back distance A between the lifting rope 38 and the opening / closing rope 39 near the front end 11E of the arm body 11 can be made as small as possible (see Figure 1). This creates a front-to-back distance A between the lifting rope 38 and the opening / closing rope 39, which prevents the clamshell bucket 9 from moving towards the upper slewing body 3, and allows for smooth lifting and lowering of the clamshell bucket 9.

[0041] The intermediate guide sheave shaft 35 is provided on the stepped surface 11G located on the front end 11E side of the arm body 11. A frame member 36, which is bent into a U-shape in cross-section, is fixed to the stepped surface 11G of the arm body 11. The intermediate guide sheave shaft 35 is attached to the stepped surface 11G at its base end and to the frame member 36 at its tip, and extends upward from the stepped surface 11G while slightly inclined toward the rear.

[0042] The intermediate guide sheave 37 is rotatably mounted on the stepped surface 11G of the arm body 11 via the intermediate guide sheave shaft 35. The intermediate guide sheave 37 is interposed between the opening / closing guide sheave 34 provided on the left side plate 11A of the arm body 11 and the looseness adjustment sheave 45 provided on the right side plate 11B of the arm body 11, and the opening / closing rope 39 extending from the looseness adjustment sheave 45 is wound around the intermediate guide sheave 37, guiding the opening / closing rope 39 to the opening / closing guide sheave 34.

[0043] Thus, even when the loosening adjustment sheave 45 and the opening / closing guide sheave 34 are positioned on opposite sides of the arm body 11, the opening / closing rope 39 can be smoothly guided from the loosening adjustment sheave 45 to the opening / closing guide sheave 34 via the intermediate guide sheave 37. Furthermore, the intermediate guide sheave 37 is positioned on a stepped surface 11G of the upper plate 11C of the arm body 11, where the gap between it and the lower plate 11D is low. This prevents the intermediate guide sheave 37 from protruding from the upper plate 11C of the arm body 11, and when the deep foundation excavator 1 excavates a shaft with the arm 10 held horizontally to the ground (as shown in Figure 1), the ground height of the deep foundation excavator 1 can be kept as low as possible.

[0044] The lifting rope 38 is provided between the arm 10 and the clamshell bucket 9, and supports the clamshell bucket 9 so that it can be raised and lowered. The lifting rope 38 is made of wire rope, and one end 38A of the lifting rope 38 is attached to the left side panel 11A of the arm body 11 via a loosening detection device 47, etc., which will be described later. The other end 38B of the lifting rope 38 is attached to the bucket support part 9A of the clamshell bucket 9 (see Figure 1). The middle section of the lifting rope 38 is alternately wound around multiple first lifting sheaves 19 and multiple second lifting sheaves 23.

[0045] The opening / closing rope 39 is provided between the arm 10 and the clamshell bucket 9 and opens and closes a pair of buckets 9B of the clamshell bucket 9. The opening / closing rope 39 is made of wire rope, and one end 39A of the opening / closing rope 39 is attached to the right side plate 11B of the arm body 11 via a loosening detection device 62, etc., which will be described later. The other end 39B of the opening / closing rope 39 is attached to the bucket support part 9A of the clamshell bucket 9 (see Figure 1). The middle section of the opening / closing rope 39 is alternately wound around multiple first opening / closing sheaves 21 and multiple second opening / closing sheaves 30. The other end 39B of the opening / closing rope 39 is alternately wound around multiple upper sheaves 9E and multiple lower sheaves 9F that make up the clamshell bucket 9.

[0046] The clamshell bucket 9 descends when the lifting cylinder 18 retracts, causing the first lifting sheave 19 to move closer to the second lifting sheave 23, and rises when the lifting cylinder 18 extends, causing the first lifting sheave 19 to move away from the second lifting sheave 23. Therefore, the descent distance (depth of the shaft) of the clamshell bucket 9 can be freely set by increasing the number of first and second lifting sheaves 19 and 23, or by changing the stroke of the lifting cylinder 18. On the other hand, the clamshell bucket 9 opens when the opening / closing cylinder 31 retracts, causing the second opening / closing sheave 30 to move closer to the first opening / closing sheave 21, and closes when the opening / closing cylinder 31 extends, causing the second opening / closing sheave 30 to move away from the first opening / closing sheave 21.

[0047] The loosening adjustment sheave moving mechanism 40 is located on the front end 11E side of the arm body 11 and is provided on the right side panel 11B (second opposing surface). The loosening adjustment sheave moving mechanism 40 supports the loosening adjustment sheave 45 so that it can move in the front-rear direction. As shown in Figures 3 and 12, the loosening adjustment sheave moving mechanism 40 is composed of a guide rail 41, a pair of sliding members 42, a frame member 43, and a loosening adjustment sheave shaft 44.

[0048] The guide rail 41 consists of a T-shaped block body extending in the front-rear direction and is fixed to the right side plate 11B of the arm body 11. A pair of slide members 42 are paired vertically on either side of the guide rail 41 and are slidably engaged with the guide rail 41. The frame member 43 is attached to the pair of slide members 42 using bolts or the like. A rod mounting pin 43A extending in the left-right direction is attached to the frame member 43, and the rod 46B of the loosening adjustment cylinder 46, which will be described later, is attached to the rod mounting pin 43A. In addition, a loosening adjustment sheave shaft 44 extending in the left-right direction is attached to the frame member 43 adjacent to the rod mounting pin 43A.

[0049] The loosening adjustment sheave 45 is rotatably mounted on the loosening adjustment sheave shaft 44 of the loosening adjustment sheave moving mechanism 40. That is, the loosening adjustment sheave 45 is provided on the right side plate 11B (second opposing surface) of the arm body 11 so as to be movable in the front-rear direction via the loosening adjustment sheave moving mechanism 40. The loosening adjustment sheave 45 consists of a single sheave and is rotatably supported on the arm body 11 around the loosening adjustment sheave shaft 44.

[0050] The opening / closing rope 39, wound around multiple first opening / closing sheaves 21 and multiple second opening / closing sheaves 30, is then sequentially wound around a slack adjustment sheave 45, an intermediate guide sheave 37, and an opening / closing guide sheave 34. The other end 39B of the opening / closing rope 39 wound around the opening / closing guide sheave 34 is then wound around the upper sheave 9E and lower sheave 9F of the clamshell bucket 9, and the other end 39B of the opening / closing rope 39 is attached to the bucket support 9A. In this way, the slack adjustment sheave 45, multiple second opening / closing sheaves 30, and multiple first opening / closing sheaves 21 around the opening / closing rope 39 are arranged in order from the front end 11E of the arm body 11.

[0051] The loosening adjustment cylinder 46 is located in front of the opening / closing sheave movement mechanism 25 and is provided on the right side panel 11B of the arm body 11. The loosening adjustment cylinder 46 extends in the front-rear direction and moves the loosening adjustment sheave 45 closer to or further away from the second opening / closing sheave 30. The loosening adjustment cylinder 46 has a tube 46A, a piston (not shown) inserted inside the tube 46A, and a rod 46B whose base end is attached to the piston and whose tip protrudes from the tube 46A. The bottom side of the tube 46A is attached to the right side panel 11B of the arm body 11 via a bracket 46C. The tip of the rod 46B is attached to the frame member 43 of the loosening adjustment sheave movement mechanism 40 via a pin or the like.

[0052] Therefore, the loosening adjustment sheave 45 attached to the loosening adjustment sheave moving mechanism 40 moves in the forward and backward direction in accordance with the extension and retraction operation of the loosening adjustment cylinder 46, moving closer to and further away from the second opening / closing sheave 30. As a result, for example, when excavating a shaft using the deep foundation drilling machine 1, when the clamshell bucket 9 lands on the ground and the opening / closing rope 39 is loosened, the loosening adjustment cylinder 46 can be extended to move the loosening adjustment sheave 45 away from the second opening / closing sheave 30, thereby removing the looseness from the opening / closing rope 39.

[0053] Next, the looseness detection devices 47 and 62 used in this embodiment will be described. The looseness detection device 47 for the lifting rope, which uses the lifting rope 38 as the rope to be detected, is installed between one end 38A of the lifting rope 38 and the left side panel 11A of the arm body 11, and detects looseness in the lifting rope 38. The looseness detection device 62 for the opening / closing rope, which uses the opening / closing rope 39 as the rope to be detected, is installed between one end 39A of the opening / closing rope 39 and the right side panel 11B of the arm body 11, and detects looseness in the opening / closing rope 39. Here, since the looseness detection device 47 for the lifting rope and the looseness detection device 62 for the opening / closing rope have similar configurations, the looseness detection device 47 will be described below, and the description of the looseness detection device 62 will be omitted.

[0054] As shown in Figure 2, the loosening detection device 47 is positioned inside the annular lifting rope path 38C formed by the lifting rope 38 wound around the first lifting sheave 19 and the second lifting sheave 23 (between the upper lifting rope 38 and the lower lifting rope 38). The loosening detection device 47 is provided between one end 38A of the lifting rope 38 and the left side panel 11A of the arm body 11, and detects loosening of the lifting rope 38. As shown in Figures 6 to 10, the loosening detection device 47 is composed of an arm-side swinging member 48, a rope-side movable member 53, a coil spring 57, and a limit switch 59.

[0055] The arm-side swinging member 48 is located behind the second lifting sheave 23 and is supported via a support pin 50 on a bracket 49 that protrudes from the left side panel 11A of the arm body 11. The bracket 49 has two base plates 49A that face each other vertically at a certain distance apart and extend to the left from the left side panel 11A of the arm body 11, and a pair of pin mounting plates 49B that are fixed between the two base plates 49A and face each other horizontally at a certain distance apart. These pair of pin mounting plates 49B protrude rearward from the base plates 49A, and a support pin 50 is attached between their protruding ends, extending in a direction perpendicular to the longitudinal direction of the arm 10 (arm body 11).

[0056] As shown in Figures 6 and 10, the arm-side swinging member 48 has a rectangular cylindrical body 51 with a square cross-section. The cylindrical body 51 is surrounded by a left pin mounting plate 51A and a right pin mounting plate 51B that are opposite each other in the left-right direction, and an upper plate 51C and a lower plate 51D that are opposite each other in the up-down direction, and houses the rope-side movable member 53, a coil spring 57, etc. One end of the cylindrical body 51 is an opening 51E for inserting the rope-side movable member 53, the coil spring 57, etc., and the other end of the cylindrical body 51 is closed by a rectangular lid 51F. A support pin 50 is attached to the left pin mounting plate 51A and the right pin mounting plate 51B that constitute the cylindrical body 51 on the side in front of the opening 51E, straddling the opening 51E. Therefore, the arm-side swinging member 48 can swing vertically around the support pin 50.

[0057] Here, the tip of the left pin mounting plate 51A that constitutes the cylindrical body 51 is a stopper 51G that extends forward from the support pin 50. The stopper 51G is positioned between the tips of the two base plates 49A of the bracket 49 and comes into contact with the base plates 49A when the arm-side swinging member 48 swings excessively around the support pin 50. As a result, the swing range of the arm-side swinging member 48 around the support pin 50 is limited by the stopper 51G. In addition, a trapezoidal notch 51H is formed at the edge of the lower plate 51D that constitutes the cylindrical body 51 on the side of the opening 51E, recessed toward the lid portion 51F (see Figure 8).

[0058] A stepped cylindrical guide member 52 is fixed to the center of the lid portion 51F that closes the other end of the cylindrical body 51. The guide member 52 has a large-diameter portion 52A located inside the cylindrical body 51 and a small-diameter portion 52B that protrudes rearward from the cylindrical body 51, and the inner circumference of the guide member 52 has a shaft insertion hole 52C that penetrates in the axial direction.

[0059] The rope-side movable member 53 is movably mounted on the guide member 52 that constitutes the arm-side swinging member 48, and one end 38A of the lifting rope 38 is attached to it. The rope-side movable member 53 has a stepped cylindrical shaft 54 ​​and a rope connecting member 55 that is detachably attached to the cylindrical shaft 54. The cylindrical shaft 54 ​​has a small-diameter shaft portion 54A that is axially movably inserted into the shaft insertion hole 52C of the guide member 52, and a large-diameter shaft portion 54B that is housed in a cylindrical body 51. A female thread 54C is formed on the inner circumferential surface of the small-diameter shaft portion 54A, and a disc-shaped flange portion 54D with a larger diameter than the large-diameter shaft portion 54B is provided on the tip side of the large-diameter shaft portion 54B.

[0060] The rope connecting member 55 has a long screw shaft 55A with male threads formed on its outer circumference, and a connecting plate 55B integrally formed at one end of the screw shaft 55A. The screw shaft 55A of the rope connecting member 55 is screwed into the female thread 54C of the cylindrical shaft 54 ​​(small diameter shaft portion 54A) and positioned by a nut 55C. A terminal fitting 56 attached to one end 38A of the lifting rope 38 is pin-connected to the connecting plate 55B of the rope connecting member 55 so as to be rotatable in the vertical direction. As a result, one end 38A of the lifting rope 38 is connected to the rope-side movable member 53 via the terminal fitting 56.

[0061] Here, one end 38A of the lifting rope 38 extends diagonally upward from the lower end of the first lifting sheave 19 and is connected to the loosening detection device 47 (rope connecting member 55) via the terminal fitting 56. Therefore, as shown in Figure 2, the angle θ between the lifting rope 38 extending from the lower end of the first lifting sheave 19 to the lower end of the second lifting sheave 23 and the lifting rope 38 extending from the lower end of the first lifting sheave 19 to the loosening detection device 47 changes in accordance with the movement of the first lifting sheave 19 due to the extension and retraction operation of the lifting cylinder 18. In contrast, the loosening detection device 47 has an arm-side swinging member 48 that is supported on a bracket 49 protruding from the left side panel 11A of the arm body 11 so as to be able to swing around a support pin 50 perpendicular to the longitudinal direction of the arm body 11, and a rope-side movable member 53 to which one end 38A of the lifting rope 38 is connected is movably attached to the arm-side swinging member 48. Therefore, even if the angle θ changes in accordance with the extension and retraction operation of the lifting cylinder 18, the arm-side swinging member 48 swings around the support pin 50 so that one end 38A of the lifting rope 38 can smoothly follow the change in angle θ without being subjected to excessive bending force.

[0062] The coil spring 57, acting as an elastic member, is provided between the guide member 52 of the arm-side oscillating member 48 and the cylindrical shaft 54 ​​of the rope-side movable member 53. The coil spring 57 is positioned on the outer circumference of the large-diameter shaft portion 54B of the cylindrical shaft 54 ​​that constitutes the rope-side movable member 53, and is provided so as to be expandable and contractible between the flange portion 54D of the cylindrical shaft 54 ​​and the large-diameter portion 52A of the guide member 52. The coil spring 57 is a compression spring and, against the tension acting on the lifting rope 38, biases the rope-side movable member 53 (the flange portion 54D of the cylindrical shaft 54) toward the support pin 50. Therefore, the flange portion 54D of the cylindrical shaft 54 ​​is displaced axially within the cylinder 51 in response to changes in the tension acting on the lifting rope 38, and when the lifting rope 38 loosens and the tension falls below a predetermined value, it is pressed by the coil spring 57 and approaches the support pin 50.

[0063] The cushioning material 58 is provided between the flange portion 54D of the cylindrical shaft 54 ​​that constitutes the rope-side movable member 53 and the support pin 50. The cushioning material 58 is formed in a cylindrical shape using an elastic material such as rubber and is supported by the support pin 50 inserted through its inner circumference. The cushioning material 58 prevents the flange portion 54D of the cylindrical shaft 54, which is biased by the coil spring 57, from directly colliding with the support pin 50, thereby protecting the support pin 50 and suppressing noise. Here, the distance between the flange portion 54D of the cylindrical shaft 54 ​​and the cushioning material 58 is set to a small dimension (for example, 10 mm or less). This makes it possible to reduce the length dimension of the loosening detection device 47.

[0064] Furthermore, the support pin 50, to which the cushioning material 58 is attached, is mounted on the tip sides of the left pin mounting plate 51A and the right pin mounting plate 51B of the cylindrical body 51, which houses the cylindrical shaft 54 ​​and the coil spring 57 inside, and is positioned to straddle the opening 51E of the cylindrical body 51. As a result, even if the lifting rope 38 is cut while the coil spring 57 is compressed, the cylindrical shaft 54, coil spring 57, etc. will collide with the support pin 50, preventing them from flying out of the cylindrical body 51.

[0065] The limit switch 59, acting as a sensor, is provided on the lower plate 51D of the cylindrical body 51 that constitutes the arm-side swinging member 48. As shown in Figures 7 and 9, the limit switch 59 has an actuator 59A that is rotatably mounted on the switch body. The limit switch 59 is attached to a spacer 60 that protrudes downward from the lower plate 51D of the cylindrical body 51 via a bracket 61 or the like, and is positioned outside the cylindrical body 51. The actuator 59A protrudes into the cylindrical body 51 through a notch 51H formed in the lower plate 51D and is positioned between the flange portion 54D of the cylindrical shaft 54 ​​and the support pin 50. Since the limit switch 59 is provided on the cylindrical body 51 of the arm-side swinging member 48, even if the lifting rope 38 loosens, it is possible to avoid contact between the limit switch 59 and the loosened lifting rope 38, thereby protecting the limit switch 59.

[0066] The actuator 59A of the limit switch 59 is operated by the flange portion 54D of the cylindrical shaft 54, which is pressed by the coil spring 57, when the lifting rope 38 becomes slack and its tension falls below a predetermined value. As a result, the limit switch 59 detects that the lifting rope 38 has become slack and its tension falls below a predetermined value and outputs a detection signal. In this way, the limit switch 59 detects whether the tension acting on the lifting rope 38 has fallen below a predetermined value based on the movement of the rope-side movable member 53 (cylindrical shaft 54). When the controller (not shown) that controls the operation of the bucket lifting / opening / closing device 17 determines, based on the detection signal from the limit switch 59, that the tension of the lifting rope 38 has fallen below a predetermined value and that the lifting rope 38 has become slack, it stops the payout operation of the lifting rope 38 by the lifting cylinder 18, for example.

[0067] The loosening detection device 62 for the opening / closing rope, which uses the opening / closing rope 39 as the rope to be detected, is installed between one end 39A of the opening / closing rope 39 and the right side panel 11B of the arm body 11. As shown in Figure 4, the loosening detection device 62 is positioned inside the annular opening / closing rope path 39C formed by the opening / closing rope 39 wound around the first opening / closing sheave 21 and the second opening / closing sheave 30 (between the upper opening / closing rope 39 and the lower opening / closing rope 39).

[0068] The looseness detection device 62 is configured similarly to the looseness detection device 47 for the lifting rope described above, and detects whether the tension acting on the opening / closing rope 39 has fallen below a predetermined value. When the opening / closing rope 39 loosens and the tension falls below the predetermined value, the controller (not shown) that controls the operation of the bucket lifting / closing device 17 removes the looseness of the opening / closing rope 39 by, for example, extending the looseness adjustment cylinder 46.

[0069] The deep foundation excavator 1 according to this embodiment has the configuration described above, and the operation of excavating a shaft using the deep foundation excavator 1 will be described below.

[0070] The operator, seated in cab 4, drives the deep foundation excavator 1 to the work site. Then, as shown in Figure 1, operates the boom cylinder 7 to lift the tip of the boom 6 upwards, and, for example, operates the arm cylinder 8 to hold the arm 10 in a horizontal position relative to the ground. The position of the arm 10 relative to the ground (the inclination of the arm 10) can be changed as appropriate according to the limitations on the working height. Next, with the clamshell bucket 9 closed, the machine is positioned above the ground where the shaft is to be excavated, and then the lifting cylinder 18 is retracted. As a result, the sheave mounting member 14 moves forward along the guide arms 12 and 13, the first lifting sheave 19 approaches the second lifting sheave 23, and the first opening / closing sheave 21 approaches the second opening / closing sheave 30. Consequently, the lifting rope 38 and the opening / closing rope 39 are unfurled from the arm 10, and the clamshell bucket 9 descends.

[0071] When the clamshell bucket 9 reaches a position several meters (for example, 2-3 meters) above the ground, the operator stops the downward movement of the clamshell bucket 9 by the lifting cylinder 18 and then retracts the opening / closing cylinder 31. This causes the second opening / closing sheave 30, attached to the opening / closing sheave moving mechanism 25, to approach the first opening / closing sheave 21. As a result, the opening / closing rope 39 is unfurled from the arm 10, and the pair of buckets 9B of the clamshell bucket 9 are fully opened. After the clamshell bucket 9 is fully open, the operator retracts the lifting cylinder 18 again. This causes the fully opened clamshell bucket 9 to descend, and the lower ends of the pair of buckets 9B touch the ground.

[0072] After the lower end of the clamshell bucket 9 touches the ground, the operator continues to retract the lifting cylinder 18, causing the clamshell bucket 9 to sink into the ground under its own weight. Next, before closing the clamshell bucket 9, the operator extends the slack adjustment cylinder 46, separating the slack adjustment sheave 45, which is attached to the slack adjustment sheave moving mechanism 40, from the second opening / closing sheave 30. As a result, the lifting rope 38 remains slack, while only the slack in the opening / closing rope 39 is removed.

[0073] Next, the operator extends the opening / closing cylinder 31 and separates the second opening / closing sheave 30, which is attached to the opening / closing sheave moving mechanism 25, from the first opening / closing sheave 21, thereby pulling the opening / closing rope 39 towards the arm 10. As a result, the clamshell bucket 9 closes while sinking into the ground under its own weight, allowing it to scoop up a large amount of soil. In this case, by extending the slack adjustment cylinder 46 before closing the clamshell bucket 9, the lifting rope 38 remains slack, while only the slack in the opening / closing rope 39 is removed. As a result, the clamshell bucket 9 can be closed simultaneously with the extension of the opening / closing cylinder 31, allowing for rapid excavation of soil.

[0074] After closing the clamshell bucket 9 and scooping up the soil, the operator extends the lifting cylinder 18. At this time, if the lifting rope 38 is loose after scooping up the soil, the operator extends the lifting cylinder 18 and simultaneously retracts the looseness adjustment cylinder 46. As a result, the first lifting sheave 19 attached to the sheave mounting member 14 separates from the second lifting sheave 23, and the lifting rope 38 is pulled up toward the arm 10, while the first opening / closing sheave 21 separates from the second opening / closing sheave 30, and the opening / closing rope 39 is pulled up toward the arm 10. As a result, the lifting rope 38 and the opening / closing rope 39 are pulled up toward the arm 10 together, and the clamshell bucket 9, holding the soil, is lifted and rises by the lifting rope 38 and the opening / closing rope 39.

[0075] After raising the clamshell bucket 9 to the outside of the shaft, the upper rotating body 3 is rotated, for example, to move the clamshell bucket 9 above the bed of a dump truck (not shown). In this state, the operator retracts the opening / closing cylinder 31, bringing the second opening / closing sheave 30, which is attached to the opening / closing sheave moving mechanism 25, closer to the first opening / closing sheave 21. As a result, the opening / closing rope 39 is pulled out from the arm 10, and the clamshell bucket 9 opens, allowing the excavated soil to be discharged onto the bed of the dump truck.

[0076] In this way, after dumping soil onto the bed of the dump truck, the upper rotating body 3 is rotated to move the clamshell bucket 9 above the shaft, and the shaft can be excavated by repeating the aforementioned work (operation).

[0077] As described above, during shaft excavation work using the deep foundation drilling machine 1, the clamshell bucket 9 can be lowered into the ground by its own weight by retracting the lifting cylinder 18 and extending the lifting rope 38, thereby excavating a large amount of soil. However, if the lifting rope 38 becomes looser than necessary to lower the clamshell bucket 9 into the ground, time will be wasted before the clamshell bucket 9, which is holding the soil, rises when the lifting cylinder 18 is extended, reducing the work efficiency of the excavation operation.

[0078] The loosening detection device 47 according to this embodiment detects whether the lifting rope 38 is loose based on whether the tension acting on the lifting rope 38 falls below a predetermined value. The operation of the loosening detection device 47 will be described below.

[0079] When the clamshell bucket 9 is suspended by the lifting rope 38, the lifting rope 38 is not slack, and a tension exceeding a predetermined value is acting on the lifting rope 38. In this state, the flange portion 54D of the cylindrical shaft 54 ​​moves toward the lid portion 51F of the cylindrical body 51 against the coil spring 57, and maintains a position separated from the limit switch 59. Therefore, the actuator 59A of the limit switch 59 is not operated by the flange portion 54D of the cylindrical shaft 54.

[0080] When the lifting cylinder 18 is retracted and the clamshell bucket 9 is submerged in the ground, the lifting rope 38 may become significantly slack. In this case, the tension acting on the lifting rope 38 falls below a predetermined value, and the flange portion 54D of the cylindrical shaft 54 ​​is pressed by the coil spring 57 and moves toward the support pin 50. As a result, the actuator 59A of the limit switch 59 is operated by the flange portion 54D, and the limit switch 59 outputs a detection signal to a controller (not shown) that controls the operation of the bucket lifting / opening / closing device 17. The controller determines from the detection signal from the limit switch 59 that a predetermined amount of slack has occurred in the lifting rope 38 and stops the retraction operation of the lifting cylinder 18 (the unwinding operation of the lifting rope 38).

[0081] In this way, the loosening detection device 47 can detect when the tension acting on the lifting rope 38 during shaft excavation falls below a predetermined value, thereby preventing excessive loosening of the lifting rope 38. As a result, after closing the clamshell bucket 9 and excavating soil, the lifting cylinder 18 can be extended to quickly reel in the lifting rope 38 and lift the clamshell bucket 9, thereby improving the work efficiency of the excavation operation.

[0082] Meanwhile, a looseness detection device 62, provided between one end 39A of the opening / closing rope 39 and the right side panel 11B of the arm body 11, detects looseness in the opening / closing rope 39 depending on whether the tension acting on the opening / closing rope 39 falls below a predetermined value. For example, when the clamshell bucket 9 lands on the ground, if a predetermined amount of looseness occurs in the opening / closing rope 39, a detection signal is output from the looseness detection device 62 to the controller. The controller determines that a predetermined amount of looseness has occurred in the opening / closing rope 39 based on the detection signal from the looseness detection device 62 and causes the looseness adjustment cylinder 46 to extend. As a result, the looseness in the opening / closing rope 39 is quickly removed, allowing the clamshell bucket 9 to be closed by the opening / closing cylinder 31 to excavate soil, thereby improving the work efficiency of the excavation operation.

[0083] In this embodiment, the looseness detection device 47 has a shape larger than the rope diameter of the lifting rope 38. On the other hand, since the lifting rope 38 is wound alternately around multiple first lifting sheaves 19 and second lifting sheaves 23, the spacing between adjacent lifting ropes 38 is narrow. Therefore, if the looseness adjustment device were to be placed adjacent to the lifting rope 38, there is a risk that the lifting rope 38 would come into contact with the looseness detection device and be damaged. In contrast, the looseness detection device 47 according to this embodiment is positioned inside the annular lifting rope path 38C formed by the lifting rope 38 wound around the first lifting sheaves 19 and second lifting sheaves 23. Since the sheave diameters of the first lifting sheaves 19 and second lifting sheaves 23 are larger than the looseness detection device 47, sufficient space can be secured around the looseness detection device 47. As a result, interference between the lifting rope 38 and the loosening detection device 47 can be reliably prevented, thereby protecting the lifting rope 38 and the like. The same applies to the loosening detection device 62 for the opening and closing rope.

[0084] Furthermore, the loosening detection device 47 includes an arm-side swinging member 48 that is pivotably supported on a bracket 49 protruding from the left side panel 11A of the arm body 11, with respect to a support pin 50 perpendicular to the longitudinal direction of the arm body 11, and a rope-side movable member 53 that is movable relative to the arm-side swinging member 48. One end 38A of the lifting rope 38 is attached to the rope-side movable member 53 (rope connecting member 55).

[0085] As a result, even if the angle θ between the lifting rope 38 extending from the lower end of the first lifting sheave 19 to the lower end of the second lifting sheave 23 and the lifting rope 38 extending from the lower end of the first lifting sheave 19 to the looseness detection device 47 changes in accordance with the extension and retraction operation of the lifting cylinder 18, the arm-side swinging member 48 swings around the support pin 50, thereby preventing excessive bending force from acting on one end 38A of the lifting rope 38. Moreover, compared to a rope tension detection device that rotates around a spherical contact surface as a fulcrum, such as in Patent Document 2, the looseness detection device 47 can limit the operation of the arm-side swinging member 48 to only vertical swinging around the support pin 50. As a result, the arm-side swinging member 48 can be prevented from colliding with the arm body 11, protecting the arm body 11, the looseness detection device 47, etc.

[0086] Furthermore, a stopper 51G is provided at the tip of the left pin mounting plate 51A that constitutes the cylindrical body 51 of the arm-side swinging member 48, extending forward from the support pin 50. The stopper 51G contacts the base plate 49A when the arm-side swinging member 48 swings excessively around the support pin 50, thereby limiting the range of swing of the arm-side swinging member 48 around the support pin 50. This prevents the arm-side swinging member 48 from swinging excessively around the support pin 50 when the lifting rope 38 loosens, and prevents one end 38A of the lifting rope 38 from bending significantly downward. As a result, damage to the lifting ropes 38 from contact with each other is suppressed, and the lifting ropes 38 can be protected.

[0087] Furthermore, the support pin 50, which pivotably supports the arm-side swinging member 48, is mounted between the left pin mounting plate 51A and the right pin mounting plate 51B of the cylindrical body 51 that constitutes the arm-side swinging member 48, and is positioned across the opening 51E for inserting the cylindrical shaft 54, coil spring 57, etc., into the cylindrical body 51. As a result, even if the lifting rope 38 is cut while the coil spring 57 housed inside the cylindrical body 51 is compressed, the cylindrical shaft 54, coil spring 57, etc. will collide with the support pin 50, preventing them from flying out of the cylindrical body 51.

[0088] Furthermore, a cushioning material 58 is provided between the flange portion 54D of the cylindrical shaft 54 ​​that constitutes the rope-side movable member 53 and the support pin 50. This prevents the flange portion 54D of the cylindrical shaft 54, which is biased by the coil spring 57, from directly colliding with the support pin 50, even if the lifting rope 38 becomes loose. As a result, the support pin 50 is protected, and noise generated by the collision between the flange portion 54D and the support pin 50 can be suppressed.

[0089] In this case, the distance between the flange portion 54D of the cylindrical shaft 54 ​​and the cushioning material 58 is set to the smallest possible dimension, thus shortening the overall length of the loosening detection device 47. As a result of shortening the loosening detection device 47, the first lifting sheave 19 can be brought closer to the second lifting sheave 23, and the rear end positions of the guide arms 12 and 13 provided on the arm body 11 can be positioned further forward. Consequently, the protruding length of the guide arms 12 and 13 from the rear end of the upper slewing body 3 can be reduced, thereby reducing the risk of the guide arms 12 and 13 interfering with surrounding obstacles when the upper slewing body 3 is slewing. Furthermore, by arranging the coil spring 57, cushioning material 58 and actuator 59A inside the cylindrical body 51, and the stopper 51G inside the bracket 49, the loosening detection device 47 is made even more compact in the length direction.

[0090] Furthermore, the limit switch 59, which detects slack in the lifting rope 38, is attached to the lower plate 51D of the cylindrical body 51 that constitutes the arm-side swinging member 48, and is positioned outside the cylindrical body 51. This prevents the limit switch 59 from coming into contact with the slackened lifting rope 38 even if the lifting rope 38 becomes loose, thus protecting the limit switch 59. Moreover, the actuator 59A of the limit switch 59 is positioned inside the cylindrical body 51 through a notch 51H formed in the lower plate 51D. This ensures that the limit switch 59 is attached to the cylindrical body 51 while maintaining its strength, and the actuator 59A is operated by the flange portion 54D of the cylindrical shaft 54 ​​inside the cylindrical body 51, thereby accurately detecting slack in the lifting rope 38.

[0091] Thus, in this embodiment, the bucket lifting and opening / closing device 17 includes a first lifting sheave 19 and a first opening / closing sheave 21 provided on the arm 10 and moving in the longitudinal direction of the arm 10 by a lifting cylinder 18, a second lifting sheave 23 and a second opening / closing sheave 30 provided on the arm 10 spaced apart from the first lifting sheave 19 and the first opening / closing sheave 21, a lifting rope 38 wound around the first lifting sheave 19 and the second lifting sheave 23, with one end 38A attached to the arm 10 and the other end 38B attached to the clamshell bucket 9, and a rope wound around the first opening / closing sheave 21 and the second opening / closing sheave 30, with one end 39A In a deep foundation excavator 1 comprising an opening / closing rope 39 attached to an arm and the other end 39B attached to a clamshell bucket 9, and a looseness detection device 47(62) provided at one end of the rope to be detected among the lifting rope 38 and the opening / closing rope 39 for detecting looseness in the rope to be detected, the looseness detection device 47(62) is positioned inside the annular lifting rope path 38C formed by the lifting rope 38 wound around the first lifting sheave 19 and the second lifting sheave 23, and / or inside the annular opening / closing rope path 39C formed by the opening / closing rope 39 wound around the first opening / closing sheave 21 and the second opening / closing sheave 30.

[0092] With this configuration, if the rope to be detected is a lifting rope 38, the looseness detection device 47 can be placed inside the lifting rope path 38C formed by the lifting rope 38. Therefore, even if a looseness detection device 47 larger than the rope diameter is provided at one end 38A of the lifting rope 38, interference between the looseness detection device 47 and the lifting rope 38 can be prevented. Also, if the rope to be detected is an opening / closing rope 39, the looseness detection device 62 can be placed inside the opening / closing rope path 39C formed by the opening / closing rope 39. Therefore, even if a looseness detection device 62 larger than the rope diameter is provided at one end 39A of the opening / closing rope 39, interference between the looseness detection device 62 and the opening / closing rope 39 can be prevented.

[0093] In this embodiment, the loosening detection device 47 includes an arm-side swinging member 48 that is pivotably mounted to the arm 10 around a support pin 50 that extends in a direction perpendicular to the longitudinal direction of the arm 10; a rope-side movable member 53 that is movable relative to the arm-side swinging member 48 and to which one end 38A of the lifting rope 38 is attached; a coil spring 57 that is extendable and retractable between the arm-side swinging member 48 and the rope-side movable member 53 and biases the rope-side movable member 53 toward the support pin 50 against the tension acting on the lifting rope 38; and a limit switch 59 provided on the arm-side swinging member 48 that detects whether the tension acting on the lifting rope 38 has fallen below a predetermined value based on the movement of the rope-side movable member 53.

[0094] In this configuration, when the lifting rope 38 loosens and its tension falls below a predetermined value, the coil spring 57 causes the rope-side movable member 53 to move toward the support pin 50. Therefore, by detecting the movement of the rope-side movable member 53 with the limit switch 59, the loosening of the lifting rope 38 can be detected. Here, the angle θ between the lifting rope 38 extending from the lower end of the first lifting sheave 19 to the lower end of the second lifting sheave 23 and the lifting rope 38 extending from the lower end of the first lifting sheave 19 to the loosening detection device 47 changes according to the extension and retraction operation of the lifting cylinder 18. However, by the arm-side swinging member 48 swinging around the support pin 50, excessive bending force acting on one end 38A of the lifting rope 38 can be suppressed, thereby extending the lifespan of the lifting rope 38. Furthermore, since the movement of the arm-side swinging member 48 is limited to vertical swinging around the support pin 50, it is possible to prevent the arm-side swinging member 48 from colliding with the arm body 11, thereby protecting the arm body 11, the loosening detection device 47, etc.

[0095] In this embodiment, the arm-side swinging member 48 is pivotably supported by a bracket 49 protruding from the outer surface of the arm body 11 via a support pin 50, and the arm-side swinging member 48 is provided with a stopper 51G that contacts the bracket 49 to limit the range of swing around the support pin 50. With this configuration, when the lifting rope 38 loosens, the arm-side swinging member 48 does not swing excessively around the support pin 50, preventing one end 38A of the lifting rope 38 from bending significantly downward. As a result, damage to the lifting ropes 38 from contact with each other is suppressed, and the lifting ropes 38 can be protected.

[0096] In this embodiment, a cushioning material 58 is provided between the support pin 50 and the rope-side movable member 53. With this configuration, even if the lifting rope 38 becomes loose, the cushioning material 58 prevents the rope-side movable member 53, which is biased by the coil spring 57, from directly colliding with the support pin 50. As a result, the support pin 50 is protected, and noise generated by the collision between the rope-side movable member 53 and the support pin 50 can be suppressed.

[0097] In this embodiment, the arm-side swinging member 48 has a cylindrical body 51 that houses the rope-side movable member 53 and the coil spring 57 inside, an opening 51E for inserting the rope-side movable member 53 and the coil spring 57 into the cylindrical body 51, and a left pin mounting plate 51A and a right pin mounting plate 51B facing each other across the opening 51E, and the support pin 50 is attached to the left pin mounting plate 51A and the right pin mounting plate 51B, straddling the opening 51E. With this configuration, even if the lifting rope 38 is cut while the coil spring 57 housed inside the cylindrical body 51 is compressed, the arm-side swinging member 48, the coil spring 57, etc. will collide with the support pin 50, so the support pin 50 can prevent them from flying out of the cylindrical body 51.

[0098] In this embodiment, the limit switch 59 has an actuator 59A that is operated by the rope-side movable member 53, the limit switch 59 is provided outside the cylindrical body 51 that constitutes the arm-side swinging member 48, and the actuator 59A is positioned inside the cylindrical body 51 through a notch 51H formed in the cylindrical body 51. With this configuration, even if the lifting rope 38 loosens, the limit switch 59 can avoid contact with the loosened lifting rope 38, thereby protecting the limit switch 59.

[0099] In this embodiment, a looseness detection device 47 is provided on one end 38A of the lifting rope 38, and a looseness detection device 62 is provided on one end 39A of the opening / closing rope 39. However, the present invention is not limited to this, and a looseness detection device may be provided on either the lifting rope or the opening / closing rope. For example, as shown in the modified example in Figure 11, one end 39A of the opening / closing rope 39 may be attached to a bracket 63 protruding from the right side panel 11B of the arm body 11, and a looseness detection device may be provided only on one end of the lifting rope. With this configuration, one end 39A of the opening / closing rope 39 can be positioned adjacent to the opening / closing rope 39 which is wound around a plurality of first opening / closing sheaves 21 and second opening / closing sheaves 30. In this case, looseness of the opening / closing rope 39 can be indirectly detected based on, for example, a change in the cylinder pressure of the lifting cylinder 18.

[0100] Furthermore, in the embodiment, a contact-type limit switch 59 is used as a sensor to detect whether or not the tension acting on the lifting rope 38 has fallen below a predetermined value. However, the present invention is not limited to this, and non-contact switches such as proximity switches or load cells may also be used. [Explanation of Symbols]

[0101] 1. Deep foundation drilling machine 2. Lower running body (vehicle body) 3. Upper rotating body (vehicle body) 9 Clamshell Bucket 10 Arms 17 Bucket lifting and opening / closing device 18 Lifting Cylinder 19. First lifting sheave 21. First opening / closing sheave 23. Second lifting sheave 30. Second opening / closing sheave 38 Lifting rope 38A,39A one end 38B,39B other end 38C Ascent / Descending Rope Route 39 Opening / Closing Rope 39C Opening / Closing Rope Route 47,62 Looseness detection device 48. Arm-side oscillating member 49 Bracket 50 support pins 51 Cylinder 51A Left pin mounting plate 51B Right-hand pin mounting plate 51E opening 51G Stopper 51H Notch 53 Rope-side movable member 57. Coil spring (elastic material) 59 Limit switch (sensor) 59A Actuator

Claims

1. It consists of an arm mounted on a self-propelled vehicle body, a clamshell bucket mounted on the arm so as to be able to move up and down, and a bucket lifting / opening device mounted on the arm that performs the lifting and lowering and opening / closing operations of the clamshell bucket, The bucket lifting and opening / closing device is A deep foundation drilling machine comprising: a first lifting sheave and a first opening / closing sheave provided on the arm and moving in the longitudinal direction of the arm by a lifting cylinder; a second lifting sheave and a second opening / closing sheave provided on the arm spaced apart from the first lifting sheave and the first opening / closing sheave; a lifting rope wound around the first lifting sheave and the second lifting sheave, with one end attached to the arm and the other end attached to the clamshell bucket; an opening / closing rope wound around the first opening / closing sheave and the second opening / closing sheave, with one end attached to the arm and the other end attached to the clamshell bucket; and a looseness detection device provided at one end of the rope to be detected among the lifting rope and the opening / closing rope for detecting looseness of the rope to be detected, wherein The lifting rope is arranged on one side and the other side of the first and second lifting sheaves in a direction perpendicular to the longitudinal direction of the arm in the radial direction of the first and second lifting sheaves, respectively, and is wound around the first and second lifting sheaves in a ring shape. The opening and closing ropes are arranged on one side and the other side of the first and second opening and closing sheaves, respectively, in a direction perpendicular to the longitudinal direction of the arm in the radial direction of the first and second opening and closing sheaves, and are wound around the first and second opening and closing sheaves in an annular manner. The loosening detection device is characterized in that it is positioned inside the annular lifting rope path formed by the lifting rope wound around the first lifting sheave and the second lifting sheave, between one portion and the other portion of the lifting rope wound around the first lifting sheave and the second lifting sheave, and / or inside the annular opening and closing rope path formed by the opening and closing rope wound around the first opening and closing sheave and the second opening and closing sheave, between one portion and the other portion of the opening and closing rope wound around the first opening and closing sheave and the second opening and closing sheave.

2. The loosening detection device is, An arm-side pivoting member is pivotably attached to the arm around a support pin that extends in a direction perpendicular to the longitudinal direction of the arm, A rope-side movable member is provided so as to be movable relative to the arm-side swinging member, and one end of the rope to be detected is attached to it. An elastic member is provided so as to be extendable and retractable between the arm-side swinging member and the rope-side movable member, and biases the rope-side movable member toward the support pin against the tension acting on the detected rope, The deep foundation drilling machine according to claim 1, further comprising a sensor provided on the arm-side swinging member for detecting whether or not the tension acting on the rope to be detected has fallen below a predetermined value based on the movement of the rope-side movable member.

3. The deep foundation excavator according to claim 2, further comprising a stopper that limits the range of oscillation of the arm-side oscillating member around the support pin.

4. The vehicle comprises an arm provided on a self-propelled vehicle body, a clamshell bucket provided on the arm so as to be able to move up and down, and a bucket lifting / opening device provided on the arm for lifting and lowering and opening and closing operations of the clamshell bucket, The bucket lifting and opening / closing device is A deep foundation drilling machine comprising: a first lifting sheave and a first opening / closing sheave provided on the arm and moving in the longitudinal direction of the arm by a lifting cylinder; a second lifting sheave and a second opening / closing sheave provided on the arm spaced apart from the first lifting sheave and the first opening / closing sheave; a lifting rope wound around the first lifting sheave and the second lifting sheave, with one end attached to the arm and the other end attached to the clamshell bucket; an opening / closing rope wound around the first opening / closing sheave and the second opening / closing sheave, with one end attached to the arm and the other end attached to the clamshell bucket; and a looseness detection device provided at one end of the rope to be detected among the lifting rope and the opening / closing rope for detecting looseness of the rope to be detected, wherein The loosening detection device is positioned inside the annular lifting rope path formed by the lifting rope wound around the first lifting sheave and the second lifting sheave, and / or inside the annular opening and closing rope path formed by the opening and closing rope wound around the first opening and closing sheave and the second opening and closing sheave. The loosening detection device is, An arm-side pivoting member is pivotably attached to the arm around a support pin that extends in a direction perpendicular to the longitudinal direction of the arm, A rope-side movable member is provided so as to be movable relative to the arm-side swinging member, and one end of the rope to be detected is attached to it. An elastic member is provided so as to be extendable and retractable between the arm-side swinging member and the rope-side movable member, and biases the rope-side movable member toward the support pin against the tension acting on the detected rope, The system includes a sensor provided on the arm-side swinging member that detects whether the tension acting on the rope to be detected has fallen below a predetermined value based on the movement of the rope-side movable member, A deep foundation excavator is characterized in that a buffer material is provided between the support pin and the rope-side movable member.

5. The arm-side swinging member has a cylindrical body that houses the rope-side movable member and the elastic member inside, an opening for inserting the rope-side movable member and the elastic member into the cylindrical body, and a pair of pin mounting plates facing each other on either side of the opening. The deep foundation excavator according to claim 2, characterized in that the support pin is attached to the pair of pin mounting plates, straddling the opening.

6. The deep foundation drilling machine according to claim 5, characterized in that the sensor is provided on the outside of the cylindrical body constituting the arm-side oscillating member.

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