Excavator

Abstract

To provide an excavator capable of adjusting the attitude of an excavation device with a simple configuration.SOLUTION: An excavator comprises a boom rotatable about an axis extending in a first direction intersecting a longitudinal direction and extendable in the longitudinal direction, an excavation device suspended from the boom, and a connecting shaft connecting the excavation device and the boom, rotatable about an axis extending in the first direction, and movable in a second direction intersecting the longitudinal direction and the first direction. Preferably, the excavator further comprises a first support device attached to one of the boom and the excavator and supporting the connecting shaft rotatably about the axis extending in the first direction and movable in the second direction, and a second support device attached to the other of the boom and the excavator and holding the connecting shaft rotatably about the axis extending in the first direction.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present technology relates to an excavator that embeds an excavation device in the ground for excavation.

Background Art

[0002] An earth auger in which a crane body and a leader are connected by a backstay and a support cylinder has been proposed. The leader supports a cylindrical outer shaft that extends vertically and is embedded in the ground and an inner shaft inserted inside the cylindrical outer shaft so as to be movable up and down (see Patent Document 1). The leader is supported by the backstay and the support cylinder, and the posture of the leader is adjusted.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] A hydraulic cylinder may be used for the support cylinder. The hydraulic cylinder tends to be complicated.

[0005] The present disclosure has been made in view of such circumstances, and an object thereof is to provide an excavator capable of adjusting the posture of an excavation device with a simple configuration.

Means for Solving the Problems

[0006] An excavator according to an embodiment of the present disclosure is rotatable about an axis extending in a first direction intersecting the longitudinal direction, a boom that is extendable and retractable in the longitudinal direction, an excavation device suspended from the boom, and the excavation device and the boom are connected, and a connecting shaft that is rotatable about an axis extending in the first direction and movable in a second direction intersecting the longitudinal direction and the first direction.

Effects of the Invention

[0007] In a excavator according to an embodiment of the present disclosure, the connecting shaft rotates or moves according to the rotation or telescopic movement of the boom, and can keep the excavation device in a desired posture, for example, a posture perpendicular to the ground.

Brief Description of the Drawings

[0008]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Embodiments for Carrying Out the Invention

[0009] Hereinafter, the present invention will be described based on the drawings showing the excavator 1. In the following description, the up, down, front, rear, left, and right shown in the drawings are used. Note that the up, down, front, rear, left, and right shown in the drawings are merely for facilitating the understanding of the invention and do not limit the scope of the rights. FIG. 1 is a schematic right side view of the excavator 1. The excavator 1 includes a vehicle body 2, a boom 3, an excavation device 5, and two connecting shafts 33. The boom 3 has a telescopic structure and is configured to be telescopically extendable in the longitudinal direction. The boom 3 has a first-stage boom 3a to a fourth-stage boom 3d. The first-stage boom 3a is the boom located at the bottom most, and the fourth-stage boom 3d is the boom located at the top most. A rotary shaft 4 having the left-right direction as the axial direction is provided at the rear part of the vehicle body 2, and the lower end of the first-stage boom 3a is connected to the rotary shaft 4. A fixture 11 is provided at the upper end of the second-stage boom 3b.

[0010] The excavating device 5 includes a leader 6, a drive unit 12, and a casing 14. The leader 6 has a frame 7 extending vertically, and a rail 8 extending vertically is provided on the front surface of the frame 7. A plurality of second support devices 9 are provided on the back surface of the frame 7. The second support devices 9 are provided in a pair on the left and right. In the present embodiment, three pairs of second support devices 9 are arranged vertically. The vertical positions of the second support devices 9 constituting the pair are substantially the same. The second support device 9 includes a pivot (not shown) with the left-right direction as the axial direction. A coupler 10 is provided at the upper end of the frame 7. The coupler 10 is connected to a fixture 11 via a pivot 10a with the left-right direction as the axial direction. The fixture 11 is provided at the upper end of the second boom 3b.

[0011] The drive unit 12 is attached to the rail 8 via a plurality of sliders 13. The slider 13 can slide on the rail 8. The casing 14 is disposed below the drive unit 12. The casing 14 is cylindrical and extends in the vertical direction. The lower end of the drive unit 12 is connected to the upper end of the casing 14. The connection between the casing 14 and the drive unit 12 can be released. A plurality of blades 15 are arranged side by side in the circumferential direction of the casing 14 at the lower edge of the casing 14. In FIG. 1, the casing 14 is disposed substantially directly above a predetermined position 51 on the ground 50. By driving the drive unit 12, the casing 14 can rotate in the circumferential direction. Further, the drive unit 12 and the casing 14 can move vertically along the rail 8 via the slider 13. The excavating device 5 is suspended from the second boom 3b via the fixture 11 and the coupler 10, and is suspended rotatably via the pivot 10a.

[0012] The first support device 20 is attached to the lower portion of the boom 3b in the second stage, below the fixture 11. Each of the two cylindrical connecting shafts 33 is supported by the first support device 20 and the second support device 9. In the present embodiment, one end of each of the two connecting shafts 33 is connected to the pivot shafts of the pair of second support devices 9 located at the uppermost position, and the middle portion of the two connecting shafts 33 is supported by the first support device 20. The connecting shaft 33 may be connected to the pair of second support devices 9 located at the lowermost position or the pair of second support devices 9 located at the vertical center. The second support device 9 rotatably supports the connecting shaft 33 about an axis extending in the left-right direction (the first direction intersecting the longitudinal direction of the boom 3).

[0013] A wire rope winding device is provided on the vehicle body 2 for the wire rope 16. The winding device includes a drum, and the wire rope 16 is wound around the drum. The wire rope 16 is guided from the drum to the upper end of the boom 3 via a plurality of pulleys. The wire rope 16 hangs down from the upper end of the boom 3, and a hook 17 is provided at the lower end of the wire rope 16. The hook 17 is hung on, for example, the upper end of the drive unit 12. By driving the winding device and adjusting the amount of winding of the wire rope 16, the drive unit 12 and the casing 14 can be moved up and down along the rail 8.

[0014] FIG. 2 is a partially enlarged right side view schematically showing the configuration of the first support device 20, FIG. 3 is a partially enlarged perspective view schematically showing the configuration of the first support device 20, and FIG. 4 is a partially enlarged rear cross-sectional view schematically showing the configuration of the first support device 20.

[0015] The first support device 20 includes a right fixing plate 21, a right mounting plate 22, a right support plate 23, and a right support cylinder 24. The right fixing plate 21 has a fixing plate portion 21a facing the right side surface of the second-stage boom 3b. The fixing plate portion 21a is fixed to the right side surface of the boom 3 by a fixing portion (not shown), such as bolts or welding. The fixing plate portion 21a has, for example, a rectangular shape when viewed from the right side. An upper plate portion 21c projects to the right from the upper edge of the fixing plate portion 21a. A lower plate portion 21b projects to the right from the lower edge of the fixing plate portion 21a.

[0016] A right mounting plate 22 is arranged on the right side of the right fixing plate 21. The right mounting plate 22 has a mounting plate portion 22a facing the fixing plate portion 21a. The mounting plate portion 22a is, for example, square-shaped when viewed from the right side. The upper edge of the mounting plate portion 22a is located above the upper edge of the fixing plate portion 21a. The lower edge of the mounting plate portion 22a is located below the lower edge of the fixing plate portion 21a. An upper plate portion 22c projects leftward from the upper edge of the mounting plate portion 22a. A lower plate portion 22b projects leftward from the lower edge of the mounting plate portion 22a. The upper plate portion 21c of the right fixing plate 21 and the upper plate portion 22c of the right mounting plate 22 are connected by bolts 35a and nuts 35b. The lower plate portion 21b of the right fixing plate 21 and the lower plate portion 22b of the right mounting plate 22 are connected by bolts 35a and nuts 35b. The right fixing plate 21 and the right mounting plate 22 may be connected by welding.

[0017] The front portion of the mounting plate portion 22a is curved so as to project forward and is located in front of the front edge of the fixing plate portion 21a. A concave portion (not shown) is formed on the right side surface of the front portion of the mounting plate portion 22a, and a bearing 29 with the left-right direction as the axial direction is fitted into the concave portion. A rotating shaft 29a projects rightward from the inner ring of the bearing 29.

[0018] A right support plate 23 is arranged on the right side of the right mounting plate 22. The right support plate 23 includes a right plate portion 23a facing the mounting plate portion 22a. The right plate portion 23a has a home base shape with a rounded tip when viewed from the right side. The tip portion of the right plate portion 23a is connected to the rotating shaft 29a of the bearing 29. A support plate portion 23b projects leftward from the bottom side (the side located on the opposite side of the tip, see FIG. 2) of the right plate portion 23a. A right support cylinder 24 is supported on the outer surface (the surface located on the opposite side of the rotating shaft 29a) of the support plate portion 23b. The right support cylinder 24 is fixed to the support plate portion 23b by welding, for example. The right fixing plate 21, the right mounting plate 22, the right support plate 23, and the bearing 29 constitute a support mechanism.

[0019] The first support device 20 includes a left fixing plate 25, a left mounting plate 26, a left support plate 27, and a left support cylinder 28. The left fixing plate 25 has a fixing plate portion 25a facing the left side surface of the second-stage boom 3b. The fixing plate portion 25a is fixed to the left side surface of the boom 3 by a fixing portion (not shown), such as bolts or welding. The fixing plate portion 25a has, for example, a rectangular shape when viewed from the left side. An upper plate portion 25c projects leftward from the upper edge of the fixing plate portion 25a. A lower plate portion 25b projects leftward from the lower edge of the fixing plate portion 25a.

[0020] The left mounting plate 26 is disposed on the left side of the left fixing plate 25. The left mounting plate 26 has a mounting plate portion 26a facing the fixing plate portion 25a. The mounting plate portion 26a has, for example, a rectangular shape when viewed from the left side. The upper edge of the mounting plate portion 26a is located above the upper edge of the fixing plate portion 25a. The lower edge of the mounting plate portion 26a is located below the lower edge of the fixing plate portion 25a. An upper plate portion 26c projects rightward from the upper edge of the mounting plate portion 26a. A lower plate portion 22b projects rightward from the lower edge of the mounting plate portion 26a. The upper plate portion 25c of the left fixing plate 25 and the upper plate portion 26c of the left mounting plate 26 are connected by bolts 35a and nuts 35b. The lower plate portion 25b of the left fixing plate 25 and the lower plate portion 26b of the left mounting plate 26 are connected by bolts 35a and nuts 35b. The left fixing plate 25 and the left mounting plate 26 may be connected by welding.

[0021] The front portion of the mounting plate portion 26a is curved so as to project forward and is located in front of the front edge of the fixing plate portion 25a. A concave portion (not shown) is formed on the left side surface of the front portion of the mounting plate portion 26a, and a bearing (not shown) having the left-right direction as the axial direction is fitted into the concave portion. A rotating shaft 30a projects leftward from the inner ring of the bearing.

[0022] A left support plate 27 is disposed on the left side of the left mounting plate 26. The left support plate 27 includes a left plate portion 27a facing the mounting plate portion 26a. The left plate portion 27a has a home base shape with a rounded tip when viewed from the left side. The tip portion of the left plate portion 27a is connected to the rotation axis 30a of the bearing. A support plate portion 27b projects rightward from the bottom side (the side located on the opposite side of the tip) of the left plate portion 27a. A left support cylinder 28 is supported on the outer surface (the surface located on the opposite side of the rotation axis 30a) of the support plate portion 27b. The left support cylinder 28 is fixed to the support plate portion 27b by, for example, welding. The left fixing plate 25, the left mounting plate 26, the left support plate 27, and the bearing constitute a support mechanism.

[0023] The rear end portions of the right mounting plate 22 and the left mounting plate 26 are connected by a rear plate 31. The right mounting plate 22, the left mounting plate 26, and the rear plate 31 are connected by bolts 35a and nuts 35b. The right mounting plate 22, the left mounting plate 26, and the rear plate 31 may be connected by welding.

[0024] The connecting shaft 33 is inserted into the right support cylinder 24 and the left support cylinder 28. The right support cylinder 24 and the left support cylinder 28 support the connecting shaft 33 movably in the axial direction (the second direction intersecting the longitudinal direction of the boom 3 and the first direction) of the right support cylinder 24 and the left support cylinder 28, and the right support plate 23, the left support plate 27, the bearing 29, etc. support the connecting shaft 33 rotatably about an axis extending in the left-right direction (the first direction). That is, the first support device supports the connecting shaft rotatably about an axis extending in the first direction and movably in the second direction.

[0025] In FIGS. 1 to 4, the right support plate 23 and the left support plate 27 with the right support cylinder 24 and the left support cylinder 28 located on the upper side are shown. FIGS. 1 to 4 show the state before the start of excavation. Before the start of excavation, the second-stage boom 3b is extended, and the third-stage boom 3c and the fourth-stage boom 3d are retracted.

[0026] FIG. 5 is a schematic right side view of the excavator 1 when excavating by the excavating device 5. When excavating, the boom 3 rotates about the rotation axis 4 so that the lower end of the casing 14 approaches the ground 50. As shown in FIG. 5, the second-stage boom 3b is contracted, and the lower end of the casing 14 contacts the predetermined position 51. By driving the drive unit 12, the casing 14 rotates, and the predetermined position 51 is excavated. As the excavation progresses, the feed amount of the wire rope 16 is increased to move the casing 14 downward for deeper excavation. Note that excavation may proceed only by the rotation and telescoping of the boom 3 without feeding the wire rope 16.

[0027] By shortening the second-stage boom 3b, the position of the casing 14 is adjusted so that the casing 14 approaches the ground 50 and is positioned substantially directly above the predetermined position 51. Although the position of the casing 14 deviates from substantially directly above the predetermined position 51 due to the rotation of the boom 3, it can be adjusted by shortening the second-stage boom 3b.

[0028] As shown in FIG. 5, due to the rotation of the boom 3 and the shortening of the second-stage boom 3b, the two connecting shafts 33 move inside the right support cylinder 24 and the left support cylinder 28 and also rotate about the axis of the bearing 29. The movement and rotation of the connecting shaft 33 prevent the casing 14 from swaying, and the casing 14 is more likely to maintain a substantially vertical posture with respect to the ground 50. That is, the connecting shaft 33 moves inside the right support cylinder 24 and the left support cylinder 28 and also rotates according to the rotation and telescoping of the boom 3.

[0029] In addition, when the upper end of the casing 14 is buried in the ground 50 and excavation continues, for example, the connection between the upper end of the casing 14 and the driving unit 12 is released, and the lower end of the new casing 14 and the upper end of the casing 14 buried in the ground 50 are joined by, for example, welding, and the upper end of the new casing 14 and the driving unit 12 are connected. Then, the plurality of connected casings 14 are rotated. For example, when removing a pile driven into the ground, a plurality of casings 14 are joined according to the length of the pile, and the periphery of the pile is excavated. Among the casings 14 buried in the ground 50, the part protruding above the ground 50 is cut, a new casing 14 is connected to the driving unit 12, and the cut portion of the casing 14 buried in the ground 50, that is, the upper end, and the lower end of the new casing 14 may be joined by, for example, welding.

[0030] In the excavator 1 according to the embodiment, the connecting shaft 33 rotates or moves according to the rotation or extension of the boom 3, and the excavating device 5 can be maintained in a desired posture, for example, a posture perpendicular to the ground 50.

[0031] Also, via the first support device 20 and the second support device 9, the connecting shaft 33 connects the boom 3 and the excavating device 5, and realizes maintaining the excavating device 5 in a desired posture. In the embodiment, the first support device 20 is provided on the boom 3 and the second support device 9 is provided on the excavating device 5, but the first support device 20 may be provided on the excavating device 5 and the second support device 9 may be provided on the boom 3.

[0032] Also, the movement of the connecting shaft 33 is realized by the right support cylinder 24 and the left support cylinder 28, and the rotation of the connecting shaft 33 is realized by the right support plate 23, the left support plate 27, the bearing 29, etc. (support mechanism).

[0033] (Modification example) FIG. 6 is a schematic right side view of the excavator 1 with a partially modified configuration. In the above-described embodiment, the hook 17 is hung on the upper end of the drive unit 12, and the hoisting device is driven to adjust the winding amount of the wire rope 16, thereby moving the drive unit 12 and the casing 14 up and down along the rail 8. However, in the modified example, a hoisting device for the wire rope 16a is provided on the vehicle body 2, and instead of the hook 17, a plurality of pulleys 17a are provided at the upper ends of the drive unit 12 and the boom 3, etc.

[0034] In the modified example, by driving the hoisting device and adjusting the winding amount of the wire rope 16a, the drive unit 12 and the casing 14 can be moved up and down along the rail 8. By using a plurality of pulleys 17a, the force required when winding up the wire rope 16a can be reduced.

[0035] The embodiments disclosed this time should be considered as illustrative in all respects and not restrictive. The scope of the present invention is intended to include all modifications within the scope of the claims and the scope equivalent to the claims. The matters described in each embodiment can be combined with each other. Also, the independent claims and dependent claims described in the claims can be combined with each other in all possible combinations regardless of the citation form. Furthermore, although the claims use a form (multi-claim form) of describing claims that cite two or more other claims, it is not limited to this. It may be described using a form of describing a multi-claim (multi-multi-claim) that cites at least one multi-claim.

Explanation of Reference Numerals

[0036] 1 Excavator 3 Boom 3a~3d First-stage boom~Fourth-stage boom 5 Excavating device 9 Second support device 20 First support device 24 Right support cylinder (support cylinder) 28 Left support cylinder (support cylinder) 21 Right fixed plate (support mechanism) 22 Right mounting plate (support mechanism) 23 Right support plate (support mechanism) 25 Left fixed plate (support mechanism) 26 Left mounting plate (support mechanism) 27 Left support plate (support mechanism) 29 Bearing (support mechanism) 33 Connecting shaft

Claims

1. A boom that is rotatable about an axis extending in a first direction intersecting the longitudinal direction and is telescopic in the longitudinal direction, An excavation device suspended from the boom, A connecting shaft that connects the excavation device and the boom, is rotatable about an axis extending in the first direction, and is movable in a second direction intersecting the longitudinal direction and the first direction An excavator comprising.

2. A first support device attached to one of the boom and the excavator, which supports the connecting shaft rotatably about an axis extending in the first direction and movably in the second direction, A second support device attached to the other of the boom and the excavator, which supports the connecting shaft rotatably about an axis extending in the first direction Comprising The excavator according to claim 1.

3. The first support device is A support cylinder into which the connecting shaft is inserted and which supports the connecting shaft movably in the second direction, A support mechanism that supports the support cylinder rotatably about an axis extending in the first direction Comprising The excavator according to claim 2.

Images