Deep foundation excavator

Abstract

The cantilever (10) has a first pair of opposing surfaces (a left side panel (11A) of a cantilever main body (11) and a left side plate (14A) of a pulley mounting member (14)) and a second pair of opposing surfaces (a right side panel (11B) of the cantilever main body (11) and a right side plate (14B) of the pulley mounting member (14)) that oppose each other in a direction (left-right direction) orthogonal to a length direction (front-rear direction) of the cantilever (10). A first lifting pulley (19) is arranged on an outer side of the left side plate (14A) of the pulley mounting member (14), and a second lifting pulley (23) is arranged on an outer side of the left side panel (11A) of the cantilever main body (11). A first opening / closing pulley (21) is arranged on an outer side of the right side plate (14B) of the pulley mounting member (14), and a second opening / closing pulley (30) and an opening / closing cylinder (31) are arranged on an outer side of the right side panel (11B) of the cantilever main body (11).

Description

Technical Field

[0001] This disclosure relates to a deep foundation excavator suitable for digging vertical pits. Background Technology

[0002] In recent years, the demand for renovating high-rise buildings in Chinese cities has increased. To shorten the construction period of renovation projects and ensure stable construction when carrying out underground engineering on soft foundations, the demand for deep foundation excavators has risen. Since most high-rise building renovation projects are indoor on-site operations, the bucket cannot be raised too high during excavation. Deep foundation excavators are thus limited by their operating height when carrying out excavation operations.

[0003] As a deep foundation excavator used to dig vertical pits on the ground and unload the excavated sand and soil, a known deep foundation excavator is based on a hydraulic excavator and has a telescopic clamshell-shaped working device including a multi-stage telescopic boom and a clamshell bucket. However, deep foundation excavators with telescopic clamshell-shaped working devices are difficult to deploy in work sites where the working height is limited.

[0004] On the other hand, a deep foundation excavator is proposed, in which a clamshell bucket is installed at the front end of a cylindrical cantilever mounted on the front end of the boom of a hydraulic excavator via a wire rope (see Patent Document 1). This deep foundation excavator has a bucket lifting device and a bucket opening and closing device inside the cylindrical cantilever. By raising and lowering the clamshell bucket using the bucket lifting device and opening and closing the clamshell bucket using the bucket opening and closing device, a vertical pit is excavated on the ground.

[0005] Existing technical documents

[0006] Patent documents

[0007] Patent Document 1: Japanese Patent Application Publication No. 2003-147800 Summary of the Invention

[0008] Patent Document 1 describes a deep foundation excavator that houses the bucket lifting and opening / closing device, which performs the lifting and lowering and opening / closing actions of the bucket, within a cylindrical cantilever. This prevents the bucket lifting and opening / closing device from interfering with obstacles present around the deep foundation excavator and improves the aesthetic appearance of the deep foundation excavator.

[0009] However, the deep-foundation excavator in Patent Document 1 houses components such as hydraulic cylinders, wire ropes, and multiple pulleys that constitute the bucket lifting and opening / closing device within the boom. Therefore, there is a problem of reduced operability when performing regular replacement of the wire ropes or maintenance of the hydraulic cylinders or pulleys. Especially when the number of pulleys is increased to increase the digging depth, pulley maintenance becomes more complex, further reducing operability.

[0010] Furthermore, the deep foundation excavator in Patent Document 1 has a large boom due to the bucket lifting and opening / closing device being housed inside the boom, which reduces the operability (transportability) when transporting the deep foundation excavator to the work site. Moreover, since the bucket lifting and opening / closing device needs to be assembled inside the boom, there is also a problem that the operability is reduced during this assembly.

[0011] The purpose of this invention is to provide a deep foundation excavator that improves the workability of maintaining the bucket lifting and opening / closing device.

[0012] The deep foundation excavator of the present invention comprises a self-propelled vehicle body and a working device disposed on the vehicle body. The working device includes: a boom disposed on the vehicle body; a cantilever disposed at the front end of the boom; a bucket lifting and opening / closing device disposed on the cantilever; and a clamshell bucket, which is vertically mounted relative to the cantilever and excavates vertical pits through the lifting and opening / closing actions of the bucket lifting and opening / closing device. The bucket lifting and opening / closing device includes: a lifting cylinder disposed on the cantilever; a first lifting pulley and a first opening / closing pulley, which move along the length of the cantilever via the lifting cylinder; a second lifting pulley disposed on the cantilever away from the first lifting pulley; and a second opening / closing pulley disposed on the cantilever away from the first opening / closing pulley. The deep foundation excavator is characterized in that the cantilever has a first opposing surface and a second opposing surface facing each other in a direction orthogonal to the length direction of the cantilever; the first lifting pulley and the second lifting pulley are arranged on the outer surface of the first opposing surface; and the opening and closing cylinder is arranged on the outer surface of the second opposing surface.

[0013] According to the present invention, the first lifting pulley, the second lifting pulley, the first opening and closing pulley, the second opening and closing pulley, and the opening and closing cylinder are respectively disposed on the outer side of the cantilever. Therefore, a larger working space can be ensured when maintaining the components of these bucket lifting and opening / closing devices, thereby improving the operability of maintenance work. Attached Figure Description

[0014] Figure 1 This is a left-side view of a deep foundation excavator according to an embodiment of the present invention.

[0015] Figure 2 This is a left-side view showing the bucket lifting and opening / closing device.

[0016] Figure 3 This is a plan view showing the bucket lifting and opening / closing device.

[0017] Figure 4 This is a right-side view of the bucket lifting and opening / closing device.

[0018] Figure 5 This is an exploded view of the cantilever.

[0019] Figure 6 From Figure 2 The cross-sectional view of the connection between the cantilever body and the guide cantilever is viewed in the direction of arrow VI-VI.

[0020] Figure 7 From Figure 2 The cross-sectional view of the guide cantilever and pulley mounting components is viewed in the direction of arrow VII-VII.

[0021] Figure 8 From Figure 2 The cross-sectional view of the connection between the cantilever body and the lifting cylinder is viewed in the direction of arrow VIII-VIII.

[0022] Figure 9 It means from Figure 3 The cross-sectional view of the guide cantilever, pulley mounting components, first lifting pulley, and first opening and closing pulley is viewed in the direction of arrow IX-IX.

[0023] Figure 10 From Figure 3 The arrow XX points in the diagram, showing the cross-sectional view of the cantilever body, the opening and closing pulley moving mechanism, etc.

[0024] Figure 11 From Figure 3 The cross-sectional view of the cantilever body, the second lifting pulley, the second opening and closing pulley, etc., is viewed in the direction of arrow XI-XI.

[0025] Figure 12 From Figure 3 The cross-sectional view of the cantilever body, slack adjustment pulley, slack adjustment pulley moving mechanism, lifting guide pulley, opening and closing guide pulley, etc., is viewed in the direction of arrow XII-XII. Detailed Implementation

[0026] Hereinafter, a deep foundation excavator according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings. Furthermore, in this embodiment, the longitudinal direction of the cantilever is referred to as the front-rear direction, and the direction orthogonal to the longitudinal direction of the cantilever is referred to as the left-right direction.

[0027] exist Figure 1 In this case, the deep foundation excavator 1 is manufactured based on, for example, a tracked hydraulic excavator. The deep foundation excavator 1 consists of a self-propelled tracked lower traveling body 2, an upper rotating body 3 rotatably mounted on the lower traveling body 2, and a working device 5 (described later) provided on the upper rotating body 3. The lower traveling body 2 and the upper rotating body 3 constitute the vehicle body of the deep foundation excavator 1.

[0028] The cab 4 is located on the left front side of the upper slewing body 3. The cab 4 is divided into a working room for the operator to ride in the deep foundation excavator 1. Inside the cab 4 is a driver's seat 4A for the operator to sit on. Around the driver's seat 4A are operating devices (not shown) for operating the travel motion of the lower traveling body 2, the slewing motion of the upper slewing body 3, and the operating device 5.

[0029] The working device 5 is configured to include a lifting boom 6 rotatably mounted on the upper rotating body 3, a cantilever 10 (described later), a clamshell bucket 9, and a bucket lifting and opening / closing device 17. A lifting boom cylinder 7 is provided between the upper rotating body 3 and the lifting boom 6, and the lifting boom 6 rotates relative to the upper rotating body 3 according to the extension and retraction of the lifting boom cylinder 7. A cantilever cylinder 8 is provided between the lifting boom 6 and the cantilever 10, and the cantilever 10 rotates relative to the lifting boom 6 according to the extension and retraction of the cantilever cylinder 8.

[0030] The clamshell bucket 9 is suspended from the front end of the cantilever 10 using a lifting rope 38 described later. The clamshell bucket 9 has a bucket support 9A, a pair of buckets 9B, a connecting bracket 9C, and a pair of opening and closing cantilever 9D. The pair of buckets 9B are closable and located below the bucket support 9A. The pair of buckets 9B are rotatably connected to the connecting bracket 9C. The pair of opening and closing cantilever 9D connects the bucket support 9A and the pair of buckets 9B. The bucket support 9A is provided with a plurality of upper pulleys 9E, and the connecting bracket 9C is provided with a plurality of lower pulleys 9F opposite to the upper pulleys 9E in the vertical direction.

[0031] The other end 38B of the lifting rope 38 is installed on the bucket support part 9A of the clamshell bucket 9. The opening and closing rope 40, described later, is alternately wound on the upper pulley 9E and the lower pulley 9F of the clamshell bucket 9, and the other end 40B of the opening and closing rope 40 is installed on the bucket support part 9A of the clamshell bucket 9.

[0032] The cantilever 10 is rotatably mounted at the front end of the boom 6. For example... Figures 5 to 6 As shown, the cantilever 10 is divisibly composed of a cantilever body 11 formed through a hollow cylinder and extending in the front-rear direction, a pair of guide cantilever arms 12 and 13, and a pulley mounting component 14. The pair of guide cantilever arms 12 and 13 are detachably disposed on the rear side of the cantilever body 11. The pulley mounting component 14 is movably mounted on the guide cantilever arms 12 and 13.

[0033] The cantilever body 11 serves as the base for the cantilever 10 and is formed as a rectangular cylindrical body. The cantilever body 11 is surrounded by a left-side panel 11A, a right-side panel 11B, an upper panel 11C, and a lower panel 11D, which are opposed to each other in a direction orthogonal to the longitudinal direction (front-back direction) of the cantilever 10 (left-right direction). The upper panel 11C connects the upper ends of the left-side panel 11A and the right-side panel 11B. The lower panel 11D connects the lower ends of the left-side panel 11A and the right-side panel 11B. The first opposing surface of the cantilever body 11, namely the left-side panel 11A, is located on the side of the driver's seat 4A within the cab 4 of the upper rotating body 3, making it easily observable (high visual visibility) for the operator seated in the driver's seat 4A.

[0034] The distance between the left panel 11A and the right panel 11B is set smaller than the distance between the upper panel 11C and the lower panel 11D. The front end 11E of the cantilever body 11 is closed, and the rear end 11F of the cantilever body 11 is an open end. In the upper panel 11C of the cantilever body 11, a stepped surface 11G is formed at a position forward of the center in the front-rear direction, with a height (distance from the lower panel 11D) lower than that at a position backward of the center. An intermediate guide pulley 37, described later, is provided on the stepped surface 11G. A boom mounting bracket 11H and a cylinder mounting bracket 11J are provided on the lower panel 11D of the cantilever body 11. The boom mounting bracket 11H is rotatably connected to the front end of the boom 6 (see reference 11K) via a connecting pin 11K. Figure 1 The base end of the cylinder mounting bracket 11J is engaged with the front end pin of the cantilever cylinder 8 mounted on the boom 6. Therefore, the boom body 11 rotates about the connecting pin 11K in the front-back or up-down direction according to the extension and retraction of the cantilever cylinder 8.

[0035] Two pin insertion holes 11L and 11M, which are vertically separated and extend horizontally, are formed on the rear end 11F side of the left panel 11A and the right panel 11B, respectively. Connecting pins 12B and 13B (described later) are inserted into these pin insertion holes 11L and 11M. Additionally, trunnion pin insertion holes 11N, extending horizontally, are concentrically formed on the left panel 11A and the right panel 11B at positions forward of the pin insertion holes 11L and 11M (see [link to trunnion pin insertion hole]). Figure 8 The trunnion pin 18E, described later, is inserted into these two trunnion pin insertion holes 11N. On the other hand, a front shaft mounting hole 11P extending in the left-right direction is formed on the front end 11E side of the left side panel 11A (see reference). Figure 12 A guide pulley support shaft 32, described later, is fixed to the front shaft mounting hole 11P. A central shaft mounting hole 11Q, extending in the left-right direction, is formed in the middle of the left side panel 11A in the front-rear direction (see reference). Figure 11The second lifting pulley shaft 24, described later, is fixed in the intermediate shaft mounting hole 11Q.

[0036] Guide arms 12 and 13 are detachably mounted to the rear side of the cantilever body 11 in a pair in the vertical direction. Guide arms 12 and 13 are each formed as a rectangular cylindrical body extending in the front-rear direction. Cylindrical portions 12A and 13A extending in the left-right direction are fixed to the front ends of guide arms 12 and 13, respectively. A connecting pin 12B is inserted into the inner circumference of the cylindrical portion 12A of guide arm 12, with both ends of the connecting pin 12B inserted into pin insertion holes 11L in the cantilever body 11. A connecting pin 13B is inserted into the inner circumference of the cylindrical portion 13A of guide arm 13, with both ends of the connecting pin 13B inserted into pin insertion holes 11M in the cantilever body 11. Meanwhile, the rear ends of guide arms 12 and 13 are connected via a connecting member 13C. Thus, the guide arms 12 and 13 extend rearward from the rear end 11F of the cantilever body 11 with a constant interval in the vertical direction.

[0037] The pulley mounting component 14 is movably mounted on a pair of guide arms 12, 13 and forms part of the cantilever 10. With the first lifting pulley 19 and the first opening / closing pulley 21 (described later) installed, the pulley mounting component 14 moves along the guide arms 12, 13 in the front-to-back direction. Figure 7 as well as Figure 9 As shown, the pulley mounting component 14 is formed as a cylindrical body with a rectangular cross-sectional shape identical to that of the cantilever body 11, and surrounds the guide cantilever 12, 13 from the outside. That is, the pulley mounting component 14 is formed as a short cylindrical body (frame) surrounded by a left side plate 14A as the first opposing surface, a right side plate 14B as the second opposing surface, an upper plate 14C, and a lower plate 14D.

[0038] On the front sides of the left side plate 14A and the right side plate 14B constituting the pulley mounting component 14, there are concentric pin insertion holes 14E extending in the left-right direction. Rod mounting pins 18G (described later) are inserted into these two pin insertion holes 14E. A left shaft mounting hole 14F extending in the left-right direction is formed in the center of the left side plate 14A, and a right shaft mounting hole 14G extending in the left-right direction is formed in the center of the right side plate 14B. A first lifting pulley shaft 20 (described later) is installed in the left shaft mounting hole 14F, and a first opening / closing pulley shaft 22 (described later) is installed in the right shaft mounting hole 14G (see reference). Figure 9 ).

[0039] Slide plates 15 are respectively provided between the inner circumferential surfaces of the left side plate 14A, right side plate 14B, and upper plate 14C of the pulley mounting component 14 and the guide cantilever 12, and the slide plates 15 slidably abut against the guide cantilever 12. Slide plates 16 are respectively provided between the inner circumferential surfaces of the left side plate 14A, right side plate 14B, and lower plate 14D of the pulley mounting component 14 and the guide cantilever 13, and the slide plates 16 slidably abut against the guide cantilever 13. These slide plates 15 and 16 are fixed to the pulley mounting component 14 using bolts or the like, so that the pulley mounting component 14 can move (slide) smoothly relative to the guide cantilever 12 and 13.

[0040] Next, the bucket lifting and opening / closing device 17 used in this embodiment will be described.

[0041] The bucket lifting and opening / closing device 17 is installed on the boom 10. The bucket lifting and opening / closing device 17 performs various actions including lifting and opening / closing the clamshell bucket 9. The bucket lifting and opening / closing device 17 is configured to include, as described later, a lifting cylinder 18, a first lifting pulley 19, a first opening / closing pulley 21, a second lifting pulley 23, a second opening / closing pulley 30, an opening / closing cylinder 31, an intermediate guide pulley 37, a lifting rope 38, an opening / closing rope 40, a slack adjustment pulley 47, and a slack adjustment cylinder 48.

[0042] The lifting cylinder 18 is disposed within the cantilever body 11 constituting the cantilever 10 and extends along the length direction (front-to-back direction) of the cantilever body 11. The lifting cylinder 18 extends or retracts according to the operation of the operating device disposed in the cab 4, thereby raising or lowering the clamshell bucket 9. The lifting cylinder 18 has a tube 18A, a piston (not shown) inserted into the tube 18A, and a rod 18B with its base end mounted on the piston and its front end protruding from the tube 18A.

[0043] like Figure 8 As shown, a mounting flange 18C is fixed to the tube 18A, and two pin holes 18D are concentrically formed on the mounting flange 18C across the tube 18A. Two trunnion pins 18E, which are inserted into the trunnion pin insertion holes 11N of the cantilever body 11 (left panel 11A and right panel 11B), are fitted into these two pin holes 18D. Thus, the tube 18A of the lifting cylinder 18 is supported relative to the cantilever body 11 so that it can swing about the trunnion pins 18E. On the other hand, a cylindrical mounting ring 18F is provided at the front end of the rod 18B of the lifting cylinder 18, and a rod mounting pin 18G (see reference) is inserted into the pin insertion hole 14E of the pulley mounting component 14 and the mounting ring 18F. Figure 7 ).

[0044] Thus, the tube 18A of the lifting cylinder 18 is installed on the cantilever body 11, and the rod 18B is installed on the pulley mounting component 14. Therefore, by extending and retracting the lifting cylinder 18, the pulley mounting component 14 moves along the guide cantilever 12, 13 in the front-rear direction.

[0045] The first lifting pulley 19 is mounted on the outer side of the left side plate 14A (first opposing surface) constituting the pulley mounting member 14 via the first lifting pulley shaft 20. The base end of the first lifting pulley shaft 20 is fixed to the left shaft mounting hole 14F of the pulley mounting member 14 (left side plate 14A), and the front end protrudes to the left from the pulley mounting member 14. A plurality of first lifting pulleys 19 are arranged (e.g., five) along the axial direction of the first lifting pulley shaft 20, and are supported relative to the pulley mounting member 14 so as to be able to rotate about the first lifting pulley shaft 20.

[0046] The first opening and closing pulley 21 is mounted on the outer side of the right side plate 14B (second opposing surface) constituting the pulley mounting member 14 via the first opening and closing pulley shaft 22. The base end of the first opening and closing pulley shaft 22 is fixed to the right shaft mounting hole 14G of the pulley mounting member 14 (right side plate 14B), and the front end protrudes to the right from the pulley mounting member 14. A plurality of first opening and closing pulleys 21 are arranged axially along the first opening and closing pulley shaft 22 (e.g., five), and are supported relative to the pulley mounting member 14 so as to be able to rotate about the first opening and closing pulley shaft 22.

[0047] The second lifting pulley 23 is separately disposed from the first lifting pulley 19 on the cantilever body 11. The second lifting pulley 23 is mounted on the outer side of the left side panel 11A (first opposing surface) constituting the cantilever body 11 via the second lifting pulley shaft 24. The base end of the second lifting pulley shaft 24 is fixed to the intermediate shaft mounting hole 11Q of the cantilever body 11 (left side panel 11A), and the front end protrudes to the left from the cantilever body 11. Multiple (e.g., four) second lifting pulleys 23 are arranged axially along the second lifting pulley shaft 24, and can rotate about the second lifting pulley shaft 24 relative to the supported position of the cantilever body 11. Therefore, the first lifting pulley 19 mounted on the pulley mounting member 14 moves closer to or further away from the second lifting pulley 23 according to the extension and retraction of the lifting cylinder 18. A lifting rope 38 is wound around the first lifting pulley 19 and the second lifting pulley 23.

[0048] The opening and closing pulley moving mechanism 25 is located in the middle of the cantilever body 11 in the front-rear direction and is provided on the right side panel 11B (second opposing surface). The opening and closing pulley moving mechanism 25 supports the second opening and closing pulley 30 so that it can move in the front-rear direction. Figure 3 as well as Figure 10 As shown, the opening and closing pulley moving mechanism 25 is configured to include a guide rail 26, a pair of sliding parts 27, a frame part 28, and a second opening and closing pulley shaft 29.

[0049] The guide rail 26 is constructed from a T-shaped block extending in the front-to-back direction and is fixed to the right side panel 11B of the cantilever body 11. A pair of sliding members 27 clamp the guide rail 26 in a vertical direction and are slidably engaged with the guide rail 26. The frame member 28 is mounted to the pair of sliding members 27 using bolts or the like. A rod mounting pin 28A extending in the left-to-right direction is mounted on the frame member 28, and a mounting ring 31D of the opening / closing cylinder 31 (described later) is mounted on the rod mounting pin 28A. In addition, a second opening / closing pulley shaft 29 extending in the left-to-right direction is mounted adjacent to the rod mounting pin 28A on the frame member 28.

[0050] The second opening and closing pulley 30 is rotatably mounted on the second opening and closing pulley shaft 29 of the opening and closing pulley moving mechanism 25. That is, the second opening and closing pulley 30 is provided on the outer side of the right side panel 11B (second opposing surface) constituting the cantilever body 11, which is movable in the front-back direction via the opening and closing pulley moving mechanism 25. A plurality of second opening and closing pulleys 30 are arranged (for example, four) in the axial direction of the second opening and closing pulley shaft 29 provided on the opening and closing pulley moving mechanism 25, and are supported relative to the cantilever body 11 so as to be able to rotate about the second opening and closing pulley shaft 29.

[0051] The opening / closing cylinder 31 is located on the rear side (rear end 11F side) of the cantilever body 11 and is provided on the right side panel 11B. The opening / closing cylinder 31 extends in the front-rear direction, causing the second opening / closing pulley 30 to approach and move away from the first opening / closing pulley 21. The opening / closing cylinder 31 has a tube 31A, a piston (not shown) inserted into the tube 31A, and a rod 31B with its base end mounted on the piston and its front end protruding from the tube 31A. The bottom side of the tube 31A is mounted to the rear end 11F side of the right side panel 11B of the cantilever body 11 via a bracket 31C. A cylindrical mounting ring 31D is provided at the front end of the rod 31B, and the mounting ring 31D is mounted to the frame member 28 of the opening / closing pulley moving mechanism 25 via a rod mounting pin 28A. Therefore, the second opening / closing pulley 30 mounted on the opening / closing pulley moving mechanism 25 moves in the front-rear direction according to the extension and retraction of the opening / closing cylinder 31, approaching and moving away from the first opening / closing pulley 21.

[0052] The guide pulley support shaft 32 is located on the front end 11E side of the cantilever body 11 and is disposed on the left side panel 11A. For example... Figure 12 As shown, the base end of the guide pulley support shaft 32 is fixed to the front shaft mounting hole 11P of the left side panel 11A, and the front end of the guide pulley support shaft 32 protrudes to the left from the left side panel 11A. The guide pulley support shaft 32 rotatably supports the lifting guide pulley 33 and the opening and closing guide pulley 34.

[0053] The lifting guide pulley 33 and the opening / closing guide pulley 34 are mounted on the left side panel 11A (first opposing surface) of the cantilever body 11 via the guide pulley support shaft 32. The lifting guide pulley 33 and the opening / closing guide pulley 34 have the same diameter. The lifting guide pulley 33 guides the lifting rope 38 wound around the first lifting pulley 19 and the second lifting pulley 23 to the clamshell bucket 9. The opening / closing guide pulley 34 guides the opening / closing rope 40 wound around the first opening / closing pulley 21, the second opening / closing pulley 30, and the intermediate guide pulley 37 and the slack adjustment pulley 47 (described later) to the clamshell bucket 9. Thus, as... Figure 1 As shown, when the cantilever 10 is held horizontally relative to the ground, the clamshell bucket 9 can be raised and lowered in the vertical direction by using the lifting rope 38 wound around the lifting guide pulley 33 located at the front end of the cantilever 10.

[0054] Here, the lifting guide pulley 33 and the opening / closing guide pulley 34 are positioned on the front end 11E side of the left panel 11A of the boom body 11, which provides high visual visibility for the operator seated in the driver's seat 4A. This allows the operator to visually confirm the status of the lifting rope 38 and the opening / closing rope 40 installed on the clamshell bucket 9 while operating the bucket lifting / closing device 17. Furthermore, by making the lifting guide pulley 33 and the opening / closing guide pulley 34 the same diameter, the longitudinal distance A between the lifting rope 38 and the opening / closing rope 40 near the front end 11E of the boom body 11 can be minimized (see reference). Figure 1 Therefore, it is possible to suppress the front-to-back gap A between the lifting rope 38 and the opening and closing rope 40, so that the clamshell bucket 9 can move towards the upper rotating body 3 side, and the lifting and lowering action of the clamshell bucket 9 can be performed smoothly.

[0055] The intermediate guide pulley shaft 35 is located on the stepped surface 11G on the front end 11E side of the cantilever body 11. A frame member 36 bent into a U-shaped cross section is fixed to the stepped surface 11G of the cantilever body 11. The base end of the intermediate guide pulley shaft 35 is mounted on the stepped surface 11G, and the front end is mounted on the frame member 36, thereby extending upward from the stepped surface 11G at a slight rearward inclination.

[0056] The intermediate guide pulley 37 is rotatably mounted on the stepped surface 11G of the cantilever body 11 via the intermediate guide pulley shaft 35. The intermediate guide pulley 37 is located between the opening / closing guide pulley 34 provided on the left side panel 11A of the cantilever body 11 and the slack adjustment pulley 47 provided on the right side panel 11B of the cantilever body 11. The intermediate guide pulley 37 guides the opening / closing rope 40, which extends from the slack adjustment pulley 47, to the opening / closing guide pulley 34 by winding the opening / closing rope 40.

[0057] Thus, even when the slack adjustment pulley 47 and the opening / closing guide pulley 34 are arranged opposite each other across the cantilever body 11, the opening / closing rope 40 can be smoothly guided from the slack adjustment pulley 47 to the opening / closing guide pulley 34 via the intermediate guide pulley 37. Furthermore, the intermediate guide pulley 37 is disposed on the stepped surface 11G of the upper panel 11C of the cantilever body 11, which is at a lower distance from the lower panel 11D. This prevents the intermediate guide pulley 37 from protruding from the upper panel 11C of the cantilever body 11, thus preventing the cantilever 10 from being held horizontally relative to the ground in the deep foundation excavator 1. Figure 1 In the case of excavating a vertical pit under the condition of (the state of the deep foundation excavator), the ground height of the deep foundation excavator 1 should be kept as low as possible.

[0058] A lifting rope 38 is installed between the cantilever 10 and the clamshell bucket 9, providing liftable support for the clamshell bucket 9. The lifting rope 38 is made of steel wire rope, with one end 38A mounted to a left bracket 39 protruding from the left side panel 11A of the cantilever body 11. The other end 38B of the lifting rope 38 is mounted to the bucket support 9A of the clamshell bucket 9 (see reference). Figure 1 The middle portion of the lifting rope 38 is alternately wound around a plurality of first lifting pulleys 19 and a plurality of second lifting pulleys 23.

[0059] An opening / closing rope 40 is installed between the cantilever 10 and the clamshell bucket 9 to open and close the pair of buckets 9B of the clamshell bucket 9. The opening / closing rope 40 is made of steel wire rope, with one end 40A mounted to a right bracket 41 protruding from the right side panel 11B of the cantilever body 11. The other end 40B of the opening / closing rope 40 is mounted to the bucket support 9A of the clamshell bucket 9 (see reference). Figure 1 The middle portion of the opening and closing rope 40 is alternately wound around a plurality of first opening and closing pulleys 21 and a plurality of second opening and closing pulleys 30. In addition, the other end 40B of the opening and closing rope 40 is alternately wound around a plurality of upper pulleys 9E and a plurality of lower pulleys 9F constituting the clamshell hopper 9.

[0060] The lifting cylinder 18 shortens, bringing the first lifting pulley 19 closer to the second lifting pulley 23, thereby lowering the clamshell bucket 9. Conversely, the lifting cylinder 18 extends, moving the first lifting pulley 19 away from the second lifting pulley 23, thereby raising the clamshell bucket 9. Therefore, by increasing the number of the first lifting pulley 19 and the second lifting pulley 23, or by changing the stroke of the lifting cylinder 18, the descent distance (depth of the pit) of the clamshell bucket 9 can be freely set. On the other hand, the opening and closing cylinder 31 shortens, bringing the second opening and closing pulley 30 closer to the first opening and closing pulley 21, thereby opening the clamshell bucket 9. Conversely, the opening and closing cylinder 31 extends, moving the second opening and closing pulley 30 away from the first opening and closing pulley 21, thereby closing the clamshell bucket 9.

[0061] The slack adjustment pulley moving mechanism 42 is located on the front end 11E side of the cantilever body 11 and is disposed on the right side panel 11B (second opposing surface). The slack adjustment pulley moving mechanism 42 supports the slack adjustment pulley 47 in a movable manner in the front-back direction. Figure 3 as well as Figure 12 As shown, the slack adjustment pulley moving mechanism 42 is configured to include a guide rail 43, a pair of sliding parts 44, a frame part 45, and a slack adjustment pulley shaft 46.

[0062] The guide rail 43 is constructed from a T-shaped block extending in the front-to-back direction and is fixed to the right side panel 11B of the cantilever body 11. A pair of sliding members 44 clamp the guide rail 43 in a vertical direction and are slidably engaged with the guide rail 43. The frame member 45 is mounted to the pair of sliding members 44 using bolts or the like. A rod mounting pin 45A extending in the left-to-right direction is mounted on the frame member 45, and a rod 48B of the slack adjustment cylinder 48 (described later) is mounted on the rod mounting pin 45A. In addition, a slack adjustment pulley shaft 46 extending in the left-to-right direction is mounted adjacent to the rod mounting pin 45A on the frame member 45.

[0063] The slack adjustment pulley 47 is rotatably mounted on the slack adjustment pulley shaft 46 of the slack adjustment pulley moving mechanism 42. That is, the slack adjustment pulley 47 is provided on the right side panel 11B (second opposing surface) of the cantilever body 11 via the slack adjustment pulley moving mechanism 42 in the front-back direction. The slack adjustment pulley 47 is a single pulley and is supported relative to the cantilever body 11 so that it can rotate about the slack adjustment pulley shaft 46.

[0064] The opening and closing rope 40, wound around multiple first opening and closing pulleys 21 and multiple second opening and closing pulleys 30, is sequentially wound around a slack adjustment pulley 47, an intermediate guide pulley 37, and an opening and closing guide pulley 34. Furthermore, the other end 40B of the opening and closing rope 40 wound around the opening and closing guide pulley 34 is wound around the upper pulley 9E and the lower pulley 9F of the clamshell bucket 9. The other end 40B of the opening and closing rope 40 is installed on the bucket support 9A. Thus, the slack adjustment pulley 47 with the opening and closing rope 40 wound around it, the multiple second opening and closing pulleys 30, and the multiple first opening and closing pulleys 21 are arranged sequentially from the front end 11E of the cantilever body 11.

[0065] The slack adjustment cylinder 48 is located in front of the opening and closing pulley moving mechanism 25 and is disposed on the right side panel 11B of the cantilever body 11. The slack adjustment cylinder 48 extends in the front-rear direction, causing the slack adjustment pulley 47 to approach and move away from the second opening and closing pulley 30. The slack adjustment cylinder 48 has: a tube 48A; a piston (not shown) inserted into the tube 48A; and a rod 48B, the base of which is mounted to the piston and the front end of which protrudes from the tube 48A. The bottom side of the tube 48A is mounted to the right side panel 11B of the cantilever body 11 via a bracket 48C. The front end of the rod 48B is mounted to the frame member 45 of the slack adjustment pulley moving mechanism 42 via a pin or the like.

[0066] Therefore, the slack adjustment pulley 47, installed in the slack adjustment pulley moving mechanism 42, moves in the front-to-back direction according to the extension and retraction of the slack adjustment cylinder 48, approaching and moving away from the second opening and closing pulley 30. Thus, during excavation operations, for example, using a deep foundation excavator 1, when the clamshell bucket 9 reaches the ground and the opening and closing rope 40 is slack, the slack adjustment cylinder 48 is extended, causing the slack adjustment pulley 47 to move away from the second opening and closing pulley 30, thereby eliminating (removing) the slack of the opening and closing rope 40.

[0067] The deep foundation excavator 1 of this embodiment has the structure described above. Hereinafter, the operation of excavating a vertical pit using the deep foundation excavator 1 will be described.

[0068] After the operator in cab 4 drives the deep foundation excavator 1 to the work site, as follows: Figure 1 As shown, the boom cylinder 7 is operated to lift the front end of the boom 6 upwards, and the cantilever cylinder 8 is operated to keep the cantilever 10 in a horizontal position relative to the ground. Furthermore, the position of the cantilever 10 relative to the ground (the tilt of the cantilever 10) can be appropriately changed according to the limitations of the working height. Next, after the clamshell bucket 9 is positioned in a closed state above the ground where the pit to be excavated is to be dug, the lifting cylinder 18 is shortened. As a result, the pulley mounting component 14 moves forward along the guide cantilever arms 12 and 13, the first lifting pulley 19 approaches the second lifting pulley 23, and the first opening / closing pulley 21 approaches the second opening / closing pulley 30. Consequently, the lifting rope 38 and the opening / closing rope 40 are delivered from the cantilever 10, and the clamshell bucket 9 descends.

[0069] When the clamshell bucket 9 reaches a position several meters (e.g., 2-3 meters) above the ground, the operator stops the descent of the clamshell bucket 9 based on the lifting cylinder 18 and then shortens the opening / closing cylinder 31. This causes the second opening / closing pulley 30, mounted on the opening / closing pulley moving mechanism 25, to approach the first opening / closing pulley 21. As a result, the opening / closing rope 40 is sent from the cantilever 10, and the pair of buckets 9B of the clamshell bucket 9 are fully open. After the clamshell bucket 9 is fully open, the operator shortens the lifting cylinder 18 again, causing the fully open clamshell bucket 9 to descend, and the lower ends of the pair of buckets 9B reach the ground.

[0070] After the lower end of the clamshell bucket 9 reaches the ground, the operator continues to shorten the lifting cylinder 18 to extend the lifting rope 38, slackening it for the amount of descent of the clamshell bucket 9 into the ground when it closes. Then, before closing the clamshell bucket 9, the operator extends the slack adjustment cylinder 48, moving the slack adjustment pulley 47, mounted on the slack adjustment pulley moving mechanism 42, away from the second opening and closing pulley 30. As a result, while keeping the lifting rope 38 slack, only the slack in the opening and closing rope 40 is eliminated.

[0071] Next, the operator extends the opening / closing cylinder 31, causing the second opening / closing pulley 30, mounted on the opening / closing pulley moving mechanism 25, to move away from the first opening / closing pulley 21, thereby pulling the opening / closing rope 40 towards the cantilever 10. As a result, the clamshell bucket 9 closes while sinking into the ground due to its own weight, allowing for the retrieval of a large amount of sand. In this case, the slack adjustment cylinder 48 is extended in the initial stage before closing the clamshell bucket 9, thereby removing the slack only from the opening / closing rope 40 while keeping the lifting rope 38 slack. As a result, the clamshell bucket 9 can be closed simultaneously with the extension of the opening / closing cylinder 31, enabling rapid excavation of sand.

[0072] After closing the clamshell hopper 9 and scooping up the sand, the operator extends the lifting cylinder 18. At this time, while the lifting rope 38 is slackened after scooping up the sand, the slack adjustment cylinder 48 is simultaneously reduced while the lifting cylinder 18 is extended. As a result, the first lifting pulley 19, mounted on the pulley mounting component 14, moves away from the second lifting pulley 23, pulling the lifting rope 38 toward the cantilever 10 side, and the first opening and closing pulley 21 moves away from the second opening and closing pulley 30, pulling the opening and closing rope 40 toward the cantilever 10 side. As a result, the lifting rope 38 and the opening and closing rope 40 are lifted together toward the cantilever 10 side, and the clamshell hopper 9, while still containing sand, is lifted and raised by the lifting rope 38 and the opening and closing rope 40.

[0073] After the clamshell bucket 9 is raised to the outside of the pit, for example, the upper rotating body 3 is rotated to move the clamshell bucket 9 above the cargo box of the dump truck (not shown). In this state, the operator shortens the opening / closing cylinder 31, bringing the second opening / closing pulley 30, which is mounted on the opening / closing pulley moving mechanism 25, closer to the first opening / closing pulley 21. As a result, the opening / closing rope 40 is pulled out from the cantilever 10, the clamshell bucket 9 opens, and the excavated sand can be unloaded from the cargo box of the dump truck.

[0074] Here, the lifting rope 38 that raises and lowers the clamshell bucket 9 is installed on the clamshell bucket 9 via a lifting guide pulley 33 located on the left side panel 11A of the boom body 11. Similarly, the opening and closing rope 40 that opens and closes the clamshell bucket 9 is also installed on the clamshell bucket 9 via an opening and closing guide pulley 34 located on the left side panel 11A of the boom body 11. These lifting guide pulleys 33 and opening and closing guide pulleys 34 are located on the front end 11E side of the left side panel 11A within the boom body 11, providing high visual visibility for the operator seated in the driver's seat 4A. This allows the operator to check the status of the lifting rope 38 and opening and closing rope 40 installed on the clamshell bucket 9 while operating the bucket lifting and opening / closing device 17, improving operability.

[0075] In this way, after the sand is unloaded into the cargo box of the dump truck, the upper rotating body 3 is rotated, and the clamshell bucket 9 is moved to the top of the vertical pit. The above operation is repeated, thereby excavating the vertical pit.

[0076] In this embodiment, the cantilever 10 of the deep foundation excavator 1 is divisibly constructed from a cantilever body 11, a pair of guide cantilever arms 12 and 13, and a pulley mounting component 14. A first lifting pulley 19 is disposed on the outer side of the left side plate 14A (first opposing surface) of the pulley mounting component 14, and a second lifting pulley 23 is disposed on the outer side of the left side panel 11A (first opposing surface) of the cantilever body 11. Furthermore, a first opening and closing pulley 21 is disposed on the outer side of the right side plate 14B (second opposing surface) of the pulley mounting component 14, and a second opening and closing pulley 30 is disposed on the outer side of the right side panel 11B (second opposing surface) of the cantilever body 11.

[0077] Therefore, in this embodiment, when performing maintenance work on the bucket lifting and opening / closing device 17, such as periodic replacement of the lifting rope 38 and the opening / closing rope 40, and maintenance and inspection of the first lifting pulley 19, the second lifting pulley 23, the first opening / closing pulley 21, and the second opening / closing pulley 30, a large working space can be ensured outside the boom 10. Thus, compared to a structure that, for example, houses the bucket lifting and opening / closing device inside the cylindrical boom, the operability of maintenance work can be improved.

[0078] Furthermore, in this embodiment, workability during maintenance can be ensured, thus allowing for an increase in the number of the first lifting pulley 19, the second lifting pulley 23, the first opening and closing pulley 21, and the second opening and closing pulley 30. As a result, the excavation depth of the deep foundation excavator 1 can be increased.

[0079] Furthermore, the cantilever body 11, which serves as the base of the cantilever 10, is formed from a rectangular tube with a small cross-sectional area that can only accommodate the lifting cylinder 18 internally. The guide cantilever arms 12 and 13 are formed from rectangular tubes with a smaller cross-sectional area than the cantilever body 11, and the pulley mounting component 14 is formed from a rectangular tube shorter than the cantilever body 11. Therefore, compared to the cantilever of the prior art, which houses the bucket lifting and opening / closing device internally, the cantilever 10 of this embodiment can be significantly lighter, improving workability (transportability) when transporting it to the work site. Moreover, in this embodiment, components other than the lifting cylinder 18, such as the opening / closing cylinder 31 and the slack adjustment cylinder 48, of the bucket lifting and opening / closing device 17 are mounted externally on the cantilever 10. Therefore, compared to the structure of prior art deep-foundation excavators that house the bucket lifting and opening / closing device internally, the workability when assembling the bucket lifting and opening / closing device can be improved, and manufacturing costs can also be reduced.

[0080] Furthermore, the deep foundation excavator 1 is configured such that the boom 10, which is equipped with a bucket lifting and opening / closing device 17, is divisibly composed of a boom body 11, a pair of guide booms 12 and 13, and a pulley mounting component 14. Therefore, even in confined work sites such as indoor sites, where it is not possible to ensure the space required to move the deep foundation excavator 1 in, the boom 10 can be detached from the lifting boom 6, the detached boom 10 can be divided and loaded onto a relatively small transport vehicle and moved into the work site, and then the boom 10 can be assembled at the work site.

[0081] That is, for example, such as Figure 5 As shown, relative to the cantilever body 11, which is equipped with a lifting cylinder 18, a second lifting pulley 23, a second opening and closing pulley 30, a lifting guide pulley 33, an opening and closing guide pulley 34, an intermediate guide pulley 37, and a slack adjustment pulley 47, a guide cantilever 12 is assembled using a connecting pin 12B, and a guide cantilever 13 is assembled using a connecting pin 13B. Next, after assembling the pulley mounting component 14, which is equipped with the first lifting pulley 19 and the first opening and closing pulley 21, onto the guide cantilever 12 and 13, the mounting ring 18F of the rod 18B located on the lifting cylinder 18 is assembled onto the pulley mounting component 14 using a rod mounting pin 18G. After assembling the cantilever 10 in this way, the body of the deep foundation excavator 1 is moved into the work site, such as an indoor site, and the cantilever 10 is installed at the front end of the boom 6 of the deep foundation excavator 1, thereby enabling the excavation of vertical pits.

[0082] Furthermore, by changing the lengths of the guide arms 12 and 13 installed on the cantilever body 11, the overall length of the cantilever 10 can be appropriately set. Therefore, when the lengths of the guide arms 12 and 13 are increased, thereby increasing the overall length of the cantilever 10, the excavation depth of the vertical pit of the deep foundation excavator 1 can be increased; when the lengths of the guide arms 12 and 13 are reduced, thereby reducing the overall length of the cantilever 10, the cantilever 10 can be made lighter, and its transportability can be improved.

[0083] Thus, in the deep foundation excavator 1 of this embodiment, the bucket lifting and opening / closing device 17 includes: a lifting cylinder 18 disposed on the cantilever 10; a first lifting pulley 19 and a first opening / closing pulley 21, which move along the length (front-to-back direction) of the cantilever 10 via the lifting cylinder 18; a second lifting pulley 23 disposed on the cantilever 10 away from the first lifting pulley 19; and a second opening / closing pulley 30 disposed away from the first opening / closing pulley 21. The following components are provided: a cantilever 10; an opening / closing cylinder 31 that moves the second opening / closing pulley 30 relative to the first opening / closing pulley 21; a lifting rope 38, one end of which is installed on the cantilever 10 and the other end of which is installed on the clamshell 9, with the middle portion wound around the first lifting pulley 19 and the second lifting pulley 23; and an opening / closing rope 40, one end of which is installed on the cantilever 10 and the other end of which is installed on the clamshell 9, with the middle portion wound around the first opening / closing pulley 21 and the second opening / closing pulley 30. Furthermore, the cantilever 10 has a first opposing surface (the left side panel 11A of the cantilever body 11 and the left side plate 14A of the pulley mounting component 14) and a second opposing surface (the right side panel 11B of the cantilever body 11 and the right side plate 14B of the pulley mounting component 14) facing each other in a direction orthogonal to the length direction of the cantilever 10 (left-right direction). A first lifting pulley 19 is arranged on the outer side of the left side plate 14A of the pulley mounting component 14, and a second lifting pulley 23 is arranged on the outer side of the left side panel 11A of the cantilever body 11. A first opening and closing pulley 21 is arranged on the outer side of the right side plate 14B of the pulley mounting component 14, and a second opening and closing pulley 30 and an opening and closing cylinder 31 are arranged on the outer side of the right side panel 11B of the cantilever body 11.

[0084] According to this structure, the first lifting pulley 19, the second lifting pulley 23, the first opening and closing pulley 21, and the second opening and closing pulley 30 can be arranged across the cantilever 10 in a direction orthogonal to the length direction of the cantilever 10. Thus, the first lifting pulley 19, the second lifting pulley 23, the first opening and closing pulley 21, and the second opening and closing pulley 30 can be positioned on the outer side of the cantilever 10. As a result, maintenance work on the bucket lifting and opening / closing device 17, such as periodic replacement of the lifting rope 38 and the opening and closing rope 40, and maintenance and inspection of the first lifting pulley 19, the second lifting pulley 23, the first opening and closing pulley 21, and the second opening and closing pulley 30, can be performed in a larger working space on the outer side of the cantilever 10, thereby improving its operability.

[0085] In this embodiment, the cantilever 10 is equipped with a slack adjustment cylinder 48 for adjusting the slack of the opening and closing rope 40, and a slack adjustment pulley 47 installed in the slack adjustment cylinder 48 and wound around the middle part of the opening and closing rope 40. The slack adjustment pulley 47, the second opening and closing pulley 30, and the first opening and closing pulley 21 are arranged sequentially from the front side of the cantilever 10 (the front end 11E side of the cantilever body 11). In this way, by arranging the slack adjustment pulley 47, the second opening and closing pulley 30, and the first opening and closing pulley 21 sequentially from the front side of the cantilever 10, the winding distance of the opening and closing rope 40 between the pulleys can be shortened, thereby shortening the length of the opening and closing rope 40. As a result, the workability when the opening and closing rope 40 is wound around the slack adjustment pulley 47, the second opening and closing pulley 30, and the first opening and closing pulley 21 can be improved, and the weight of the bucket lifting and opening / closing device 17 can be reduced.

[0086] In this embodiment, the cantilever 10 is configured to include: a cantilever body 11, which is composed of a hollow cylinder; and a pair of guide arms 12 and 13, which are detachably disposed on the rear side of the cantilever body 11 and extend in the front-rear direction while facing each other across the lifting cylinder 18. Furthermore, a pulley mounting member 14, which moves in the front-rear direction via the lifting cylinder 18, is installed on the pair of guide arms 12 and 13. A first lifting pulley 19 and a first opening / closing pulley 21 are disposed opposite each other across the lifting cylinder 18 on the pulley mounting member 14. According to this structure, by changing the length of the guide arms 12 and 13 installed on the cantilever body 11, the overall length of the cantilever 10 can be appropriately set. For example, by increasing the length of the guide arms 12 and 13, thereby increasing the overall length of the cantilever 10, the excavation depth of the vertical pit of the deep foundation excavator 1 can be increased. On the other hand, by reducing the length of the guide arms 12 and 13 and thus reducing the overall length of the cantilever 10, the cantilever 10 can be made lighter, which can improve transportability.

[0087] In this embodiment, the lifting cylinder 18 is housed inside the boom body 11. With this structure, compared to a structure where the lifting cylinder 18 is positioned outside the boom 10, the bucket lifting and opening / closing device 17 can be miniaturized. Furthermore, the lifting cylinder 18 can be protected by the boom body 11.

[0088] In this embodiment, a lifting guide pulley 33 is provided on the left side panel 11A of the cantilever body 11 to guide the other end 38B of the lifting rope 38 to the clamshell bucket 9, and an opening and closing guide pulley 34 to guide the other end 40B of the opening and closing rope 40 to the clamshell bucket 9. The left side panel 11A of the cantilever body 11 is located on the driver's seat 4A side of the upper rotating body 3. According to this structure, it is possible to, for example... Figure 1 As shown, with the boom 10 held horizontally relative to the ground, the clamshell bucket 9 is raised and lowered vertically from the front end (front end 11E of the boom body 11) side of the boom 10 to excavate a vertical pit. As a result, even in work sites with height restrictions, such as indoors, the deep-ground excavator 1 can smoothly perform vertical pit excavation operations. Moreover, the operator seated in the cab 4A can visually monitor the status of the lifting guide pulley 33 and the opening / closing rope 40 extending to the clamshell bucket 9, as well as the lifting rope 38 and the opening / closing rope 40. As a result, the operability of operating the bucket lifting and opening / closing device 17 is improved.

[0089] In this embodiment, an opening / closing guide pulley 34 is provided on the left side panel 11A of the cantilever body 11 to guide the other end 40B of the opening / closing rope 40 to the clamshell hopper 9; a slack adjustment pulley 47 is provided on the right side panel 11B of the cantilever body 11; and an intermediate guide pulley 37 is provided on the cantilever 10 to guide the opening / closing rope 40 wound on the slack adjustment pulley 47 to the opening / closing guide pulley 34. With this structure, even when the slack adjustment pulley 47 and the opening / closing guide pulley 34 are arranged on opposite sides of each other across the cantilever body 11, the opening / closing rope 40 can be smoothly guided from the slack adjustment pulley 47 to the opening / closing guide pulley 34 via the intermediate guide pulley 37.

[0090] In this embodiment, the cantilever body 11 includes a left side panel 11A and a right side panel 11B facing each other in a direction orthogonal to the length direction of the cantilever 10; and an upper panel 11C connecting the upper ends of the left side panel 11A and the right side panel 11B. A stepped surface 11G is formed on the upper panel 11C at the front side of the cantilever 10, with a height lower than that of the portion of the upper panel 11C at the rear side of the cantilever 10. An intermediate guide pulley 37 is disposed on the stepped surface 11G. With this structure, the protrusion of the intermediate guide pulley 37 from the upper panel 11C of the cantilever body 11 can be suppressed, and when the deep foundation excavator 1 is digging a vertical pit while holding the cantilever 10 horizontally relative to the ground, the ground height of the deep foundation excavator 1 can be kept as low as possible.

[0091] Furthermore, in the embodiments, it is illustrated that the cantilever 10 is divisibly constructed from the cantilever body 11, a pair of guide cantilever arms 12 and 13, and a pulley mounting member 14. However, the present invention is not limited to this. For example, it may be constructed as a cantilever consisting of a single cylindrical body having a quadrilateral cross-sectional shape and having a first opposing surface and a second opposing surface facing each other in a direction orthogonal to the length direction. A first lifting pulley and a second lifting pulley are provided on the first opposing surface of the cantilever, and a first opening and closing pulley and a second opening and closing pulley are provided on the second opposing surface.

[0092] Furthermore, in the embodiments, the cantilever body 11 and the pulley mounting component 14 are illustrated as being constructed from a rectangular cylindrical body with a quadrilateral cross-sectional shape. However, the present invention is not limited to this; for example, cylindrical bodies with a polygonal or circular cross-sectional shape other than a quadrilateral may also be used to form the cantilever body and the pulley mounting component.

[0093] Furthermore, the embodiment illustrates a bucket lifting and opening / closing device 17 equipped with a slack adjustment pulley 47 for adjusting the slack of the opening and closing rope 40 and a slack adjustment cylinder 48. However, the present invention is not limited to this, and it may also be configured such that the slack adjustment pulley 47 and the slack adjustment cylinder 48 are removed from the bucket lifting and opening / closing device 17 provided on the cantilever 10.

[0094] Symbol Explanation

[0095] 1—Deep foundation excavator; 2—Lower traveling body (vehicle body); 3—Upper rotating body (vehicle body); 4A—Driver's seat; 5—Working device; 6—Lifting boom; 9—Clamshell bucket; 10—Cantilever; 11—Cantilever body; 11A—Left side panel (first opposing surface); 11B—Right side panel (second opposing surface); 11C—Top panel (upper surface); 11E—Front end; 11G—Step surface; 12, 13—Guide cantilever; 14—Pulley mounting component; 14A—Left side panel (first opposing surface) 14B—Right side plate (second opposing surface), 17—Bucket lifting and opening / closing device, 18—Lifting cylinder, 19—First lifting pulley, 21—First opening / closing pulley, 23—Second lifting pulley, 30—Second opening / closing pulley, 31—Opening / closing cylinder, 33—Lifting guide pulley, 37—Intermediate guide pulley, 38—Lifting rope, 38A, 40A—One end, 38B, 40B—The other end, 40—Opening / closing rope, 47—Relaxation adjustment pulley, 48—Relaxation adjustment cylinder.

Claims

1. A deep foundation excavator, comprising a self-propelled vehicle body and a working device disposed on the vehicle body, The working device includes: a lifting boom mounted on the vehicle body; a cantilever mounted at the front end of the lifting boom; a bucket lifting and opening / closing device mounted on the cantilever; and a clamshell bucket, which is vertically movably mounted relative to the cantilever and excavates vertical pits through the lifting and opening / closing actions of the bucket lifting and opening / closing device. The bucket lifting and opening / closing device includes: A lifting cylinder is mounted on the cantilever. The first lifting pulley and the first opening and closing pulley move along the length direction of the cantilever via the lifting cylinder. A second lifting pulley is disposed on the cantilever away from the first lifting pulley; A second opening and closing pulley is disposed on the cantilever away from the first opening and closing pulley; The cylinder is opened and closed, which causes the second opening and closing pulley to move relative to the first opening and closing pulley; A lifting rope, one end of which is attached to the cantilever, the other end of which is attached to the clamshell bucket, and the middle portion of which is wound around the first lifting pulley and the second lifting pulley; and The opening and closing rope has one end attached to the cantilever and the other end attached to the clamshell bucket, with its middle portion wound around the first and second opening and closing pulleys. The deep foundation excavator is characterized by the following features: The cantilever has a first opposing surface and a second opposing surface that are orthogonal to the length direction of the cantilever. The first lifting pulley and the second lifting pulley are disposed on the outer side of the first opposing surface. The first opening and closing pulley, the second opening and closing pulley, and the opening and closing cylinder are arranged on the outer side of the second opposing surface.

2. The deep foundation excavator according to claim 1, characterized in that, The cantilever is equipped with: a slack adjustment cylinder for adjusting the slack of the opening and closing rope; and a slack adjustment pulley installed in the slack adjustment cylinder and wound around the middle part of the opening and closing rope. The relaxation adjustment pulley, the second opening and closing pulley, and the first opening and closing pulley are arranged sequentially from the front side of the cantilever.

3. The deep foundation excavator according to claim 1, characterized in that, The cantilever is configured to include: a cantilever body, which is composed of a hollow cylinder; and a pair of guide cantilever arms, which are detachably disposed on the rear side of the cantilever body and extend in the front-rear direction while being opposite each other across the lifting cylinder.

4. The deep foundation excavator according to claim 3, characterized in that, A pulley mounting component that moves in the front-rear direction via the lifting cylinder is installed on the pair of guide cantilever arms. The first lifting pulley and the first opening and closing pulley are disposed opposite each other on the pulley mounting component across the lifting cylinder.

5. The deep foundation excavator according to claim 3, characterized in that, The lifting cylinder is housed inside the cantilever body.

6. The deep foundation excavator according to claim 1, characterized in that, The first opposing surface is provided with: a lifting guide pulley that guides the other end of the lifting rope to the clam shell bucket; and an opening and closing guide pulley that guides the other end of the opening and closing rope to the clam shell bucket. The first opposing surface is disposed on the driver's seat side of the vehicle body.

7. The deep foundation excavator according to claim 2, characterized in that, An opening and closing guide pulley is provided on the first opposing surface to guide the other end of the opening and closing rope to the clam shell hopper. The relaxation adjustment pulley is provided on the second opposing surface. The cantilever is provided with an intermediate guide pulley that guides the opening and closing rope wound around the slack adjustment pulley to the opening and closing guide pulley.

8. The deep foundation excavator according to claim 7, characterized in that, The cantilever has: a first opposing surface and a second opposing surface, which are opposed to each other in a direction orthogonal to the length direction of the cantilever; and an upper surface that connects the upper ends of the first opposing surface and the second opposing surface. A stepped surface is formed on the upper surface at the front side of the cantilever, with a height lower than that of the upper surface at the rear side of the cantilever. The intermediate guide pulley is disposed on the stepped surface.

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