Cab support structure and construction machine

Abstract

To improve workability.SOLUTION: A cab support structure includes a mount device installed on a vehicle body frame and a connection mechanism which connects a cab installed above the vehicle body frame with the vehicle body frame through the mount device rotatably between a seating position and a tilt position. The connection mechanism includes: a connection shaft connected with the mount device and extending in the horizontal direction; a displacement allowance member connected with the vehicle body frame; and an interlock member connected with the cab and rotatable by interlocking with the rotation of the cab. The displacement allowance member includes a displacement allowance hole which allows a displacement of the connection shaft in the vertical direction and allows the rotation of the connection shaft between the seating position and the tilt position. The interlock member includes a displacement allowance section which allows the displacement of the connection shaft in the vertical direction at the seating position and a displacement regulation section which regulates the displacement of the connection shaft in the downward direction at the tilt position.SELECTED DRAWING: Figure 4

Description

Technical Field

[0001] The present invention relates to a cab support structure and a construction machine.

Background Art

[0002] As construction machines, work vehicles such as dump trucks and hydraulic excavators are known. For example, Patent Document 1 below discloses a dump truck having a body frame, a mounting device mounted on the body frame, and a cab rotatably (tilt up, tilt down) connected to the mounting device via a connecting pin. The body frame is provided with a stopper having an insertion hole through which the connecting pin is inserted. A gap is formed between the insertion hole of the stopper and the connecting pin to restrict a displacement amount of the connecting pin in the radial direction by a predetermined amount or more. The connecting pin is provided movably along the axial direction of the connecting pin. A gap filling member that is inserted into and removed from the gap with the movement of the connecting pin is integrally provided on the outer periphery of the connecting pin.

[0003] For example, Patent Document 2 below discloses a hydraulic excavator including a swing frame provided with a swing-type working device on the front side, a floor plate provided on the swing frame so as to be tiltable with the front side as a fulcrum and having an operator's cab, and a plurality of floor plate support mechanisms provided between the front position of the swing frame and the front position of the floor plate to support the floor plate tiltably. The plurality of floor plate support mechanisms are composed of a central floor plate support mechanism and left and right floor plate support mechanisms provided on the left and right sides of the central floor plate support mechanism. The central floor plate support mechanism is provided with a displacement restricting portion that allows the front position of the floor plate to be displaced in the vertical direction with respect to the swing frame when the floor plate is in the horizontal position and restricts the vertical displacement of the floor plate when the floor plate is in the tilted position. The left and right floor plate support mechanisms are provided with frame-side bearings. The frame-side bearings are provided with elastic members that elastically deform with a connecting pin attached to the floor plate-side bearing. The displacement restricting portion is composed of upper and lower notch grooves provided so as to notch the pin hole in the vertical direction with a width dimension smaller than the diameter dimension of the pin hole in the frame-side bearing, and a narrow shaft portion notched in parallel with a width dimension smaller than the width dimension of the notch groove at a position facing the notch groove in the connecting pin. The central floor plate support mechanism is provided with a tilt stopper that restricts the tilt operation of the floor plate at a predetermined angular position when the floor plate is tilted.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0005] In the case of Patent Document 1, when the cab is rotated in the tilt-up direction or the tilt-down direction, it is necessary to move the connecting pin together with the gap filling member and push the gap filling member into the insertion hole. On the other hand, when returning the connecting pin to its original position, it is necessary to pull out the gap filling member from the gap. Since operations such as pushing in and pulling out the gap filling member are required, there is room for improvement in workability. In the case of Patent Document 2, when the floor board is arranged in the horizontal position, the narrow-width shaft portion of the connecting pin can be displaced vertically within each notch groove of the frame-side bearing. When the narrow-width shaft portion of the connecting pin enters the notch groove, the rotation of the connecting pin is restricted. When rotating the connecting pin from the state where the narrow-width shaft portion of the connecting pin has entered the notch groove, an operation of aligning the rotation center of the connecting pin and the center of the pin hole is required, so there is room for improvement in workability.

[0006] Therefore, an object of the present invention is to provide a cab support structure and a construction machine that can improve workability.

Means for Solving the Problems

[0007] A cab support structure according to an aspect of the present invention includes a mounting device provided on a vehicle body frame, and a connecting mechanism that connects a cab provided above the vehicle body frame via the mounting device to the vehicle body frame so as to be rotatable between a seating position and a tilt position. The connecting mechanism includes a connecting shaft that is connected to the mounting device and extends in the horizontal direction, a displacement allowance member connected to the vehicle body frame, and an interlocking member connected to the cab and rotatable in conjunction with the rotation of the cab. The displacement allowance member has a displacement allowance hole that allows displacement of the connecting shaft in the vertical direction and allows rotation of the connecting shaft between the seating position and the tilt position. The interlocking member has a displacement allowance portion that allows displacement of the connecting shaft in the vertical direction when in the seating position, and a displacement restricting portion that restricts downward displacement of the connecting shaft when in the tilt position. Moreover, the interlocking member is arranged at a distance from the displacement tolerance member in the horizontal direction. 。

Effects of the Invention

[0008] According to the above aspect, workability can be improved.

Brief Description of the Drawings

[0009]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Mode for Carrying Out the Invention

[0010] Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the embodiment, a dump truck will be described as an example of a construction machine (work vehicle).

[0011] <Construction Machine> As shown in FIG. 1, a dump truck 1 as a construction machine includes a vehicle front part 10 and a vehicle rear part 20. Hereinafter, the forward direction, reverse direction, and vehicle width direction of the dump truck 1 are referred to as "vehicle front (one side of the vehicle longitudinal direction)", "vehicle rear (the other side of the vehicle longitudinal direction)", and "vehicle width direction", respectively. The vehicle width direction may also be referred to as "left side (one side of the vehicle width direction)" or "right side (the other side of the vehicle width direction)". The right hand with respect to the direction in which the dump truck 1 advances is called the right side, and the left hand with respect to the direction in which the dump truck 1 advances is called the left side. The vertical direction, upward, and downward in the state where the dump truck 1 is disposed on a horizontal plane are simply referred to as "vertical direction", "upward", and "downward", respectively.

[0012] The vehicle front part 10 includes a front frame 11 (vehicle body frame), front wheels 12, a bonnet 13, and a cab 14. The front frame 11 constitutes the frame of the vehicle front part 10. The bonnet 13 is attached to the front part of the front frame 11 so as to be openable and closable. The cab 14 is provided above the front frame 11. The cab 14 is a ROPS (Roll Over Protective System) cab having a safe structure to ensure the safety of the operator when the dump truck 1 overturns.

[0013] The vehicle rear part 20 includes a rear frame 21, rear front wheels 22, and rear rear wheels 23. The rear frame 21 constitutes the frame of the vehicle rear part 20. The vehicle rear part 20 is provided behind the vehicle front part 10. The rear frame 21 is connected to the front frame 11 so as to be bendable and swingable. A pair of left and right steering cylinders 24 are spanned between the front frame 11 and the rear frame 21. By expanding and contracting each steering cylinder 24, the rear frame 21 can be bent with respect to the front frame 11, enabling steering operation.

[0014] The rear part 20 of the vehicle includes a bed 25 and a lift cylinder 26. The bed 25 is provided above the rear frame 21. The bed 25 loads, for example, cargos such as earth and sand. The lift cylinder 26 is provided between the left and right sides of the front part of the bed 25 and the rear frame 21. The lower side of the rear part of the bed 25 is rotatably attached to the rear frame 21. The bed 25 rotates when the lift cylinder 26 expands and contracts.

[0015] A pair of front wheels 12 are provided on the front frame 11 spaced apart in the vehicle width direction. A pair of front rear wheels 22 are provided on the front part of the rear frame 21 spaced apart in the vehicle width direction. A pair of rear rear wheels 23 are provided on the rear part of the rear frame 21 spaced apart in the vehicle width direction. When the front wheels 12, the front rear wheels 22, and the rear rear wheels 23 are driven, the dump truck 1 moves forward or backward.

[0016] As shown in FIG. 2, the cab 14 is rotatable in the arrow TU direction (tilt-up direction) and the arrow TD direction (tilt-down direction) while being fixedly supported on the front frame 11 via a pair of rear side support structures 29B. In the space below the bonnet 13 and the cab 14, various devices 15 such as an engine, a torque converter, a transmission, and a hydraulic pump are provided.

[0017] Between the cab 14 and the front frame 11, a front-side support structure 29A and a rear-side support structure 29B are provided as a cab support structure. The front-side support structure 29A is provided in a pair spaced apart in the vehicle width direction between the front part of the cab 14 and the front frame 11. The rear-side support structure 29B is provided in a pair spaced apart in the vehicle width direction between the rear part of the cab 14 and the front frame 11. Hereinafter, the initial position before the cab 14 rotates in the direction of arrow TU is referred to as the "seating position" (see FIGS. 3, 4, 6, and 8). Hereinafter, the position where the cab 14 is rotated from the seating position by a predetermined rotation angle in the direction of arrow TU is referred to as the "tilt position" (see FIGS. 5, 7, and 9). In the seating position of the cab 14, the left and right sides of the front part and the left and right sides of the rear part of the cab 14 are supported by the cab support devices 29A and 29B.

[0018] For example, when inspecting and maintaining various devices 15, the operator opens the bonnet 13 and further disassembles the front-side support structure 29A. For example, by removing a connecting shaft (not shown) from each front-side support structure 29A, it is possible to release the support state by the mounting devices on the left and right sides of the front part of the cab 14. After the operator releases the support state, the operator rotates the cab 14 in the direction of arrow TU by using operating power such as a hydraulic cylinder or a crane. As a result, the upper side of the various devices 15 is exposed. With the cab 14 rotated, a support bar 28 is inserted between the cab 14 and the front frame 11 to hold the cab 14 at a predetermined rotation angle.

[0019] <Rear-side support structure> Hereinafter, the rear-side support structure 29B as a cab support structure will be described. As the rear-side support structure 29B, one of the pair of left and right rear-side support structures 29B will be described. Since the other rear-side support structure 29B has the same configuration as one rear-side support structure 29B, detailed description thereof will be omitted. As shown in FIG. 3, the rear-side support structure 29B includes a mounting device 30, a connecting mechanism 39, and a cover 90.

[0020] <Mounting device> The mounting device 30 is a device that supports the cab 14. The mounting device 30 is provided on the front frame 11. The mounting device 30 is fixed to the front frame 11 by fastening members such as bolts. Inside the mounting device 30, a viscous fluid (liquid) such as silicone oil is enclosed. The mounting device 30 is a liquid-filled mounting device 30. As shown in FIG. 8, the mounting device 30 includes a movable shaft 31, a cup 32, and a cushion rubber 33.

[0021] The movable shaft 31 is formed in a cylindrical shape. The movable shaft 31 extends in the vertical direction. The cup 32 is sealed in a liquid-tight state by the movable shaft 31 and the cushion rubber 33. The cushion rubber 33 is integrally provided on the outer periphery of the movable shaft 31. For example, when vibration occurs in the cab 14, the vibration is transmitted to the mounting device 30 via the connecting mechanism 39. The vibration transmitted to the mounting device 30 displaces the movable shaft 31. The displacement of the movable shaft 31 stirs the silicone oil. The vibration of the cab 14 is attenuated by the viscous resistance when the silicone oil is stirred.

[0022] <Connecting mechanism> The connecting mechanism 39 connects the cab 14 via the mounting device 30 to the front frame 11 so as to be rotatable between the seating position and the tilt position. The connecting mechanism 39 includes a mount-side bracket 40, a cab-side bracket 50 (connecting member), displacement allowance members 60A, 60B, a connecting shaft 69, and an interlocking member 80.

[0023] <Mount-side bracket> The mount-side bracket 40 is formed in a U shape by a bottom portion 41 and side portions 42. The bottom portion 41 is fixed to the movable shaft 31 of the mounting device 30 by a bolt 45. The side portions 42 project upward from both the left and right ends of the bottom portion 41 and are integrally formed. As shown in FIG. 8, mount-side attachment holes 43 to which the connecting shaft 69 is attached are provided in portions of the pair of side portions 42 that face each other. A boss portion 44 that projects inward is provided on the outer periphery of the mount-side attachment hole 43.

[0024] <Cab-side bracket> The cab-side bracket 50 includes a plate portion 51, a base portion 52, and a mounting portion 53. The plate portion 51 is formed in a plate shape along the mounting surface of the cab 14. The plate portion 51 is fixed to the mounting surface of the cab 14 by, for example, welding. The base portion 52 protrudes rearward from the plate portion 51. The base portion 52 is fixed to the plate portion 51 by, for example, welding. The mounting portion 53 is formed in a cylindrical shape that opens in the vehicle width direction. The mounting portion 53 is fixed to the rear end of the base portion 52 by, for example, welding.

[0025] As shown in FIG. 8, the mounting portion 53 has a cab-side mounting hole 54 (insertion hole) through which the connecting shaft 69 is inserted. The connecting shaft 69 is attached to the cab-side mounting hole 54 via metal bushes 55 inserted from both the left and right sides of the cab-side mounting hole 54. An annular shim 56 is provided between the bush 55 and the boss portion 44. As shown in FIG. 4, the mounting portion 53 is provided with a grease nipple 57 for supplying lubricating oil such as grease to the inside of the mounting portion 53.

[0026] As shown in FIG. 8, the mount-side mounting hole 43 and the cab-side mounting hole 54 are provided such that their centers are located on the same axis. The inner diameter dimension of the mount-side mounting hole 43 and the inner diameter dimension of the bush 55 are substantially equal to the outer diameter dimension of the connecting shaft 69. The outer diameter dimension of the bush 55 is substantially equal to the inner diameter dimension of the cab-side mounting hole 54. The cab 14 is supported by the mount device 30 with substantially no gap via the cab-side bracket 50, the connecting shaft 69, and the mount-side bracket 40.

[0027] <Displacement tolerance member> The displacement tolerance members 60A and 60B are provided in a pair. The pair of displacement tolerance members 60A and 60B are arranged at intervals in the vehicle width direction. The mounting device 30 is arranged between the pair of displacement tolerance members 60A and 60B in the vehicle width direction. The pair of displacement tolerance members 60A and 60B include a first displacement tolerance member 60A provided on the first end side in the axial direction of a connecting shaft 69 extending in the vehicle width direction (horizontal direction), and a second displacement tolerance member 60B provided on the second end side in the axial direction of the connecting shaft 69.

[0028] The first displacement tolerance member 60A includes a plate-shaped first vertical plate portion 61A extending in the vertical direction and a plate-shaped first horizontal plate portion 62A extending in the front-rear direction (horizontal direction). In the cross-sectional view of FIG. 8, the first displacement tolerance member 60A has an L-shaped cross-sectional shape.

[0029] The first vertical plate portion 61A has a first end side hole 63A (displacement tolerance hole) that opens in the axial direction of the connecting shaft 69. The first end side hole 63A allows displacement of the connecting shaft 69 in the vertical direction. The first end side hole 63A allows rotation of the connecting shaft 69 between the seating position and the tilt position. At the position of FIG. 8, the center of the first end side hole 63A is on the same axis as the mount side attachment hole 43 and the cab side attachment hole 54. The inner diameter dimension of the first end side hole 63A is larger than the outer diameter dimension of the connecting shaft 69 by a predetermined value (2×St).

[0030] The first horizontal plate portion 62A is fixed to the lower end of the first vertical plate portion 61A by, for example, welding. The lower end of the first vertical plate portion 61A is fixed to the inner portion (the portion closer to the mount side bracket 40) of the first horizontal plate portion 62A in the vehicle width direction. The first horizontal plate portion 62A is fixed to the front frame 11 by a fastening member such as a bolt 64. The first horizontal plate portion 62A has an upper surface 65A parallel to the horizontal direction.

[0031] The second displacement tolerance member 60B includes a plate-shaped second vertical plate portion 61B (vertical plate portion) extending in the vertical direction and a plate-shaped second horizontal plate portion 62B (horizontal plate portion) extending in the front-rear direction (horizontal direction). In the cross-sectional view of FIG. 8, the second displacement tolerance member 60B has an inverted T-shaped cross-sectional shape.

[0032] The second vertical plate portion 61B has a second end side hole 63B (displacement allowance hole) that opens in the axial direction of the connecting shaft 69. The second end side hole 63B allows displacement of the connecting shaft 69 in the vertical direction. The second end side hole 63B allows rotation of the connecting shaft 69 between the seating position and the tilt position. At the position shown in FIG. 8, the center of the second end side hole 63B is on the same axis as the mount side mounting hole 43 and the cab side mounting hole 54. The inner diameter dimension of the second end side hole 63B is larger than the outer diameter dimension of the connecting shaft 69 by a predetermined value (2×St). For example, the first vertical plate portion 61A and the second vertical plate portion 61B may be formed in the same shape as each other.

[0033] The second horizontal plate portion 62B is fixed to the lower end of the second vertical plate portion 61B by, for example, welding. The lower end of the second vertical plate portion 61B is fixed to the central portion of the second horizontal plate portion 62B in the vehicle width direction. The second horizontal plate portion 62B is fixed to the front frame 11 by a fastening member such as a bolt 64. The second horizontal plate portion 62B has an upper surface 65B that is parallel to the horizontal direction. For example, the first horizontal plate portion 62A and the second horizontal plate portion 62B may be formed in the same shape as each other.

[0034] Each displacement allowance member 60A, 60B is detachably connected to the front frame 11 via a fastening member such as a bolt 64. Each displacement allowance member 60A, 60B is formed of a material obtained by quenching metal. Each displacement allowance member 60A, 60B is formed of, for example, a member obtained by quenching a steel plate.

[0035] <Connecting shaft> The connecting shaft 69 is formed in a columnar shape extending in the vehicle width direction. The connecting shaft 69 is connected to an interlocking member 80 described later. Both ends of the connecting shaft 69 project outward in the vehicle width direction with respect to the first vertical plate portion 61A and the second vertical plate portion 61B, respectively. A space S having a radial dimension of St is formed between the outer peripheral surface of the connecting shaft 69 and the inner peripheral surfaces of the end side holes 63A, 63B. Due to the existence of this space S, the connecting shaft 69 is displaceable by a dimension of St in the radial direction (the vertical direction in FIG. 8). In other words, the displacement of the connecting shaft 69 by a displacement amount of St or more, which is a predetermined displacement amount, is restricted by each displacement allowance member 60A, 60B.

[0036] <Linkage member> The linkage member 80 is connected to the connecting shaft 69. The linkage member 80 is disposed between the mount side bracket 40 and the second displacement allowance member 60B. The linkage member 80 is disposed at an interval from the second vertical plate portion 61B of the second displacement allowance member 60B in the vehicle width direction. The linkage member 80 is formed in a plate shape extending parallel to the second vertical plate portion 61B.

[0037] The linkage member 80 has a connecting hole 81 through which the connecting shaft 69 is inserted. A boss portion 82 protruding inward is provided on the outer periphery of the connecting hole 81. The center of the connecting hole 81 is on the same axis as the mount side mounting hole 43 and the cab side mounting hole 54. The inner diameter dimension of the connecting hole 81 is substantially equal to the outer diameter dimension of the connecting shaft 69.

[0038] The linkage member 80 is connected to the cab side bracket 50 via the connecting shaft 69, the cylindrical member 77, and the bolt 78. The linkage member 80 is connected to the cab 14 via the cab side bracket 50. The linkage member 80 is made rotatable in conjunction with the rotation of the cab 14. A bolt insertion hole 83 that opens in the vehicle width direction is provided in the linkage member 80. The cylindrical member 77 is formed in a cylindrical shape extending in the vehicle width direction from the surface facing the upper portion of the linkage member 80 at the base portion 52 of the cab side bracket 50 toward the linkage member 80. The end portion of the cylindrical member 77 on the base portion 52 side is fixed to the base portion 52 by welding or the like. The portion of the cylindrical member 77 on the linkage member 80 side is fixed to the upper portion of the linkage member 80 by the bolt 78 through the bolt insertion hole 83.

[0039] The linkage member 80 is detachably connected to the cab 14 via the bolt 78 or the like. The linkage member 80 is formed of a quenched metal material. The linkage member 80 is formed of, for example, a quenched steel plate member. For example, the linkage member 80 may be formed of the same member as the displacement allowance members 60A and 60B.

[0040] As shown in FIG. 6, the interlocking member 80 includes a displacement allowance portion 85 that allows displacement of the connecting shaft 69 and a displacement restricting portion 86 that restricts displacement of the connecting shaft 69. The displacement allowance portion 85 and the displacement restricting portion 86 are continuous along the outer periphery of the interlocking member 80.

[0041] FIG. 6 is a view of the state when the cab 14 is in the seating position, as seen from the axial direction of the connecting shaft 69. The displacement allowance portion 85 allows vertical displacement of the connecting shaft 69 when in the seating position. When in the seating position, a gap G that allows vertical displacement of the connecting shaft 69 is provided between the displacement allowance portion 85 and the upper surface 65B of the second horizontal plate portion 62B. As shown in FIG. 8, when in the seating position, the vertical dimension Gt of the gap G is larger than the vertical dimension St of the space S (the distance between the inner surface of the displacement allowance hole and the connecting shaft 69). As shown in FIG. 6, the displacement allowance portion 85 has a first plane P1 that is parallel to the horizontal direction when in the seating position. When in the seating position, the first plane P1 is parallel to the upper surface 65B of the second horizontal plate portion 62B.

[0042] FIG. 7 is a view of the state when the cab 14 is in the tilt position, as seen from the axial direction of the connecting shaft 69. The displacement restricting portion 86 restricts downward displacement of the connecting shaft 69 when in the tilt position. When in the tilt position, the displacement restricting portion 86 contacts the upper surface 65B of the second horizontal plate portion 62B. The displacement restricting portion 86 has a second plane P2 (plane) that follows the upper surface 65B of the second horizontal plate portion 62B when in the tilt position.

[0043] FIG. 10 is a view showing the state when the interlocking member 80 in FIG. 7 is rotated from the tilt position to the lift-up position. The cab 14 is rotatable to a lift-up position that is more inclined than the tilt position. The displacement restricting portion 86 includes a first restricting portion 87 that contacts the upper surface 65B of the second horizontal plate portion 62B when in the tilt position and a second restricting portion 88 that contacts the upper surface 65B of the second horizontal plate portion 62B when in the lift-up position.

[0044] As shown in FIG. 7, the first restricting portion 87 has a second plane P2 (plane) along the upper surface 65B of the second horizontal plate portion 62B at the tilt position. As shown in FIG. 10, the second restricting portion 88 has an arcuate curved surface P3 that curves outward in the radial direction of the connecting shaft 69 when viewed from the axial direction along the connecting shaft 69. The first plane P1, the second plane P2, and the curved surface P3 are arranged in order in the rotation direction of the interlocking member 80.

[0045] <Cover> As shown in FIG. 3, the cover 90 is provided on the connecting mechanism 39. The cover 90 is formed of an elastic body such as rubber. The cover 90 covers the gap G. The cover 90 is detachably attached to the plate portion 51 of the cab side bracket 50 by an attachment pin 91 or the like.

[0046] The cover 90 extends downward from the plate portion 51 and covers the connecting mechanism 39 from above. The lower end of the cover 90 is in contact with the upper surfaces 65A and 65B of the respective horizontal plate portions 62A and 62B. The cover 90 extends so as to straddle the first vertical plate portion 61A of the first displacement allowance member 60A and the second vertical plate portion 61B of the second displacement allowance member 60B in the vehicle width direction.

[0047] <Rotation operation of the cab> Next, the operation when the cab 14 is rotated in the tilt-up direction from the state where the cab 14 is tilted down (the state in the seating position) will be described. When in the seating position, the cab 14 is supported by four cab support structures on both the left and right sides of the front and both the left and right sides of the rear of the cab 14. As shown in FIG. 6, when in the seating position, a gap G that allows vertical displacement of the connecting shaft 69 is provided between the displacement allowance portion 85 of the interlocking member 80 and the upper surface 65B of the second horizontal plate portion 62B of the second displacement allowance member 60B. As shown in FIG. 8, when in the seating position, the vertical dimension Gt of the gap G is larger than the vertical dimension St of the distance S between the inner surface of the displacement allowance hole and the connecting shaft 69. When in the seating position, the weight of the cab 14 acts on the mounting devices in the four cab support structures (the left and right front side support structures 29A and the left and right rear side support structures 29B) on both the left and right sides of the front and both the left and right sides of the rear of the cab 14.

[0048] For example, as shown in FIG. 2, when rotating the cab 14 in the tilt-up direction from the seating position, the support state by the mounting devices on both the left and right sides of the front of the cab 14 is released by removing the connecting shaft (not shown) from each front side support structure 29A. After releasing the support state, the cab 14 is rotated in the direction of arrow TU by using operating power such as a hydraulic cylinder or a crane.

[0049] When the cab 14 rotates in the direction of arrow TU, the interlocking member 80 rotates in conjunction with the rotation of the cab 14. As the interlocking member 80 rotates, the displacement restricting portion 86 of the interlocking member 80 approaches the upper surface 65B of the second horizontal plate portion 62B. As shown in FIG. 7, when in the tilt position, the displacement restricting portion 86 (the first restricting portion 87) of the interlocking member 80 contacts the upper surface 65B of the second horizontal plate portion 62B. When in the tilt position, the first restricting portion 87 of the interlocking member 80 abuts against the upper surface 65B of the second horizontal plate portion 62B with their planes in contact.

[0050] Hereinafter, when viewed from the axial direction of the connecting shaft 69, the angle formed by the upper surface 65B (horizontal plane) of the second horizontal plate portion 62B and the straight line along the displacement allowance portion 85 of the interlocking member 80 is referred to as the rotation angle. For example, in the tilt position, by inserting a support rod 28 (see FIG. 2) between the cab 14 and the front frame 11, the cab 14 is held at a predetermined rotation angle A1. For example, in the tilt position, the rotation angle A1 is about 27°.

[0051] As shown in FIG. 10, in order to insert the support rod 28 (see FIG. 2) between the cab 14 and the front frame 11, the cab 14 is first rotated to the lift-up position inclined more than the tilt position. In the lift-up position, the second restricting portion 88 of the interlocking member 80 contacts the upper surface 65B of the second horizontal plate portion 62B. In the example of FIG. 10, the portion of the second restricting portion 88 of the interlocking member 80 closer to the first restricting portion 87 contacts the upper surface 65B of the second horizontal plate portion 62B. For example, in the lift-up position, the rotation angle A2 is about 29°.

[0052] After inserting the support rod 28 (see FIG. 2) between the cab 14 and the front frame 11 in the lift-up position, the cab 14 is rotated (returned) from the lift-up position to the tilt position. In the tilt position, the weight of the cab 14 acts on the front frame 11 through the interlocking member 80 and the second horizontal plate portion 62B in the two cab support structures (left and right rear side support structures 29B) on the left and right sides of the rear portion of the cab 14.

[0053] Note that the displacement allowance holes 63A, 63B (see FIG. 8) allow the rotation of the connecting shaft 69 not only between the seating position and the tilt position but also between the tilt position and the lift-up position. That is, the displacement allowance holes 63A, 63B always allow the rotation of the connecting shaft 69 between the seating position and the lift-up position.

[0054] <Function and effect> As described above, the rear support structure 29B of the present embodiment includes a mounting device 30 provided on the front frame 11, and a coupling mechanism 39 that couples the cab 14 provided above the front frame 11 via the mounting device 30 to the front frame 11 so as to be rotatable between a seating position and a tilt position. The coupling mechanism 39 includes a coupling shaft 69 that is coupled to the mounting device 30 and extends in the horizontal direction, displacement allowance members 60A and 60B that are coupled to the front frame 11, and an interlocking member 80 that is coupled to the cab 14 and is rotatable in conjunction with the rotation of the cab 14. The displacement allowance members 60A and 60B have displacement allowance holes 63A and 63B that allow displacement of the coupling shaft 69 in the vertical direction and allow rotation of the coupling shaft 69 between the seating position and the tilt position. The interlocking member 80 has a displacement allowance portion 85 that allows displacement of the coupling shaft 69 in the vertical direction when in the seating position, and a displacement restricting portion 86 that restricts downward displacement of the coupling shaft 69 when in the tilt position. In the present embodiment, when in the seating position, the displacement allowance portion 85 of the interlocking member 80 allows displacement of the coupling shaft 69 in the vertical direction. On the other hand, when in the tilt position, the displacement restricting portion 86 of the interlocking member 80 restricts downward displacement of the coupling shaft 69. Therefore, it is not necessary to perform an operation of pushing in or pulling out a gap filling member with respect to the displacement allowance holes 63A and 63B of the displacement allowance members 60A and 60B. Further, in the present embodiment, since the displacement allowance holes 63A and 63B allow rotation of the coupling shaft 69 between the seating position and the tilt position, it is not necessary to align the rotation center of the coupling shaft 69 with the centers of the displacement allowance holes 63A and 63B. Therefore, workability can be improved.

[0055] In this embodiment, the displacement tolerance member 60B has a displacement tolerance hole 63B, and includes a plate-shaped vertical plate portion 61B that extends in the vertical direction, and a plate-shaped horizontal plate portion 62B that is coupled to the lower portion of the vertical plate portion 61B and is connected to the front frame 11 and extends in the horizontal direction. The interlocking member 80 is formed in a plate shape that extends parallel to the vertical plate portion 61B. The displacement tolerance portion 85 and the displacement restricting portion 86 are continuous along the outer periphery of the interlocking member 80. When in the seating position, a gap G that allows the vertical displacement of the connecting shaft 69 is provided between the displacement tolerance portion 85 and the upper surface 65B of the horizontal plate portion 62B. When in the tilt position, the displacement restricting portion 86 contacts the upper surface 65B of the horizontal plate portion 62B. As shown in FIG. 6, in this embodiment, the displacement tolerance portion 85 and the displacement restricting portion 86 are continuous along the outer periphery of the interlocking member 80. As shown in FIG. 8, when in the seating position, the gap G between the displacement tolerance portion 85 of the interlocking member 80 and the upper surface 65B of the horizontal plate portion 62B allows the vertical displacement of the connecting shaft 69. As shown in FIG. 9, when in the tilt position, the displacement restricting portion 86 of the interlocking member 80 contacts the upper surface 65B of the horizontal plate portion 62B, thereby restricting the downward displacement of the connecting shaft 69. Therefore, the displacement tolerance state and the displacement restricting state of the connecting shaft 69 can be smoothly switched by the rotation of the interlocking member 80.

[0056] In this embodiment, when in the seating position, the vertical dimension Gt of the gap G is larger than the vertical dimension St of the interval S between the inner surface of the displacement tolerance hole and the connecting shaft 69 (Gt>St). Therefore, even when an excessive load is applied to the connecting shaft 69, the connecting shaft 69 contacts the inner surface of the displacement tolerance hole. Therefore, the interlocking member 80 does not contact the upper surface 65B of the second horizontal plate portion 62B.

[0057] By the way, when the displacement restricting portion 86 has a curved surface that curves toward the upper surface 65B of the horizontal plate portion 62B when in the tilt position, there is a possibility that the pressure at the contact portion becomes excessive due to the point contact of the displacement restricting portion 86 with the upper surface 65B of the horizontal plate portion 62B. In contrast, in the present embodiment, as shown in FIG. 7, the displacement restricting portion 86 has a plane P2 along the upper surface 65B of the horizontal plate portion 62B at the tilt position. Therefore, at the tilt position, the displacement restricting portion 86 and the upper surface 65B of the horizontal plate portion 62B are in contact with each other as planes. Thus, it is possible to suppress the pressure at the contact portion from becoming excessive.

[0058] In the present embodiment, the cab 14 is rotatable to a lift-up position that is more inclined than the tilt position, and the displacement restricting portion 86 includes a first restricting portion 87 that contacts the upper surface 65B of the horizontal plate portion 62B at the tilt position, and a second restricting portion 88 that contacts the upper surface 65B of the horizontal plate portion 62B at the lift-up position. The second restricting portion 88 has an arcuate curved surface P3 that curves toward the outside in the radial direction of the connecting shaft 69 when viewed from the axial direction along the connecting shaft 69. Therefore, it is possible to smoothly switch from the tilt position to the lift-up position by the rotation of the interlocking member 80. By the way, when the second restricting portion 88 has an angular shape that protrudes toward the outside in the radial direction of the connecting shaft 69 when viewed from the axial direction, the connecting shaft 69 may be excessively displaced in the direction of the arrow F (upward) shown in FIG. 10, and an excessive load may be applied upward to the mounting device 30. In contrast, in the present embodiment, since the second restricting portion 88 has an arcuate curved surface P3 that curves toward the outside in the radial direction of the connecting shaft 69 when viewed from the axial direction, it is possible to suppress the connecting shaft 69 from being excessively displaced upward. Thus, it is possible to suppress an excessive load from being applied upward to the mounting device 30.

[0059] In the present embodiment, the rear side support structure 29B is provided in the connecting mechanism 39, and further includes a cover 90 that covers the gap G. Therefore, it is possible to suppress foreign matters such as gravel from entering the gap G.

[0060] In the present embodiment, the cover 90 is formed of an elastic body. Therefore, between the seating position and the tilt position, the cover 90 can be deformed following the rotation of the interlocking member 80. As a result, since it is not necessary to attach and detach the cover 90 to and from the connection mechanism 39, workability can be improved.

[0061] In the present embodiment, each of the displacement tolerance members 60A, 60B and the interlocking member 80 is formed of a quenched metal material. Therefore, compared with the case where at least one of the displacement tolerance members 60A, 60B and the interlocking member 80 is formed of a mere metal (a material not quenched), the strength of each of the displacement tolerance members 60A, 60B and the interlocking member 80 can be increased, and wear can be suppressed.

[0062] In the present embodiment, a pair of displacement tolerance members 60A, 60B are provided. The pair of displacement tolerance members 60A, 60B are a first displacement tolerance member 60A provided on the first end side in the axial direction of the connecting shaft 69, and a second displacement tolerance member 60B provided on the second end side in the axial direction of the connecting shaft 69. Therefore, even when an excessive load is applied to the connecting shaft 69, the connecting shaft 69 contacts the inner surfaces of the respective displacement tolerance holes 63A, 63B in the first displacement tolerance member 60A and the second displacement tolerance member 60B. Therefore, the interlocking member 80 does not contact the upper surface 65B of the second horizontal plate portion 62B. By the way, when connecting the displacement tolerance member to the front frame 11, it is necessary to lift the displacement tolerance member onto the front frame 11. If the displacement tolerance member is a single member, the weight of the displacement tolerance member is heavy, and it may be difficult to lift the displacement tolerance member. On the other hand, in the present embodiment, since a pair of displacement tolerance members 60A, 60B are provided, the weight can be shared by each of the displacement tolerance members 60A, 60B. Therefore, the work of lifting each of the displacement tolerance members 60A, 60B can be facilitated.

[0063] In this embodiment, the rear support structure 29B further includes a cab-side bracket 50 connected to the cab 14. The cab-side bracket 50 has a cab-side mounting hole 54 through which a connecting shaft 69 is inserted, and the interlocking member 80 is connected to the cab 14 via the cab-side bracket 50. Since the interlocking member 80 is connected to the cab 14 via the connecting shaft 69 and the cab-side bracket 50, the interlocking member 80 can be more firmly connected. Therefore, the interlocking member 80 can be rotated more smoothly in conjunction with the rotation of the cab 14.

[0064] <Other Embodiments> In the above-described embodiment, an example in which the displacement allowance portion 85 and the displacement restricting portion 86 are continuous along the outer periphery of the interlocking member 80 has been described, but the present invention is not limited to this. For example, the displacement allowance portion 85 and the displacement restricting portion 86 may not be continuous along the outer periphery of the interlocking member 80. For example, at least one of the displacement allowance portion 85 and the displacement restricting portion 86 may be provided at a site different from the outer periphery of the interlocking member 80. For example, the modes of the displacement allowance portion 85 and the displacement restricting portion 86 can be changed according to the required specifications.

[0065] In the above-described embodiment, an example in which a gap G for allowing the vertical displacement of the connecting shaft 69 is provided between the displacement allowance portion 85 of the interlocking member 80 and the upper surface 65B of the horizontal plate portion 62B at the seating position, and the displacement restricting portion 86 of the interlocking member 80 contacts the upper surface 65B of the horizontal plate portion 62B at the tilt position has been described, but the present invention is not limited to this. For example, a gap G for allowing the vertical displacement of the connecting shaft 69 may be provided between the displacement allowance portion 85 of the interlocking member 80 and the upper surface of the front frame 11 at the seating position, and the displacement restricting portion 86 of the interlocking member 80 may contact the upper surface of the front frame 11 at the tilt position. For example, the displacement allowance members 60A and 60B may not have the horizontal plate portions 62A and 62B. For example, the modes of the displacement allowance members 60A and 60B can be changed according to the required specifications.

[0066] In the above-described embodiments, an example where the vertical dimension Gt of the gap G is larger than the vertical dimension St of the distance S between the inner surface of the displacement tolerance hole and the connecting shaft 69 (Gt > St) when in the seating position has been described, but it is not limited to this. For example, when in the seating position, the vertical dimension Gt of the gap G may be less than or equal to the vertical dimension St of the distance S between the inner surface of the displacement tolerance hole and the connecting shaft 69 (Gt ≦ St).

[0067] In the above-described embodiments, an example where the displacement restricting portion 86 has the plane P2 along the upper surface 65B of the horizontal plate portion 62B when in the tilt position has been described, but it is not limited to this. For example, when in the tilt position, the displacement restricting portion 86 may have a curved surface that curves toward the upper surface 65B of the horizontal plate portion 62B or a convex portion that protrudes toward the upper surface 65B of the horizontal plate portion 62B. For example, the shape of the displacement restricting portion 86 can be changed according to the required specifications.

[0068] In the above-described embodiments, the cab 14 is rotatable to a lift-up position that is more inclined than the tilt position, and the displacement restricting portion 86 includes a first restricting portion 87 that contacts the upper surface 65B of the horizontal plate portion 62B when in the tilt position, and a second restricting portion 88 that contacts the upper surface 65B of the horizontal plate portion 62B when in the lift-up position. An example where the second restricting portion 88 has an arcuate curved surface P3 that curves radially outward of the connecting shaft 69 when viewed from the axial direction along the connecting shaft 69 has been described, but it is not limited to this. For example, the second restricting portion 88 may have an angular shape that protrudes radially outward of the connecting shaft 69 when viewed from the axial direction. For example, the shape of the second restricting portion 88 can be changed according to the required specifications.

[0069] In the above-described embodiments, an example where the rear-side support structure 29B further includes a cover 90 provided on the connecting mechanism 39 and covering the gap G has been described, but it is not limited to this. For example, the rear-side support structure 29B may not include the cover 90. For example, the gap G may be constantly exposed.

[0070] In the above-described embodiments, an example in which the cover 90 is formed of an elastic body has been described, but the present invention is not limited thereto. For example, the cover 90 may be formed of a material other than an elastic body. For example, the material for forming the cover 90 can be changed according to the requirements specification.

[0071] In the above-described embodiments, an example in which each of the displacement tolerance members 60A and 60B and the interlocking member 80 is formed of a quenched metal material has been described, but the present invention is not limited thereto. For example, at least one of the displacement tolerance members 60A and 60B and the interlocking member 80 may be formed of a mere metal (a material not quenched).

[0072] For example, when the displacement tolerance member 60B is detachably connected to the front frame 11 and the interlocking member 80 is detachably connected to the cab 14, only the interlocking member 80 of the displacement tolerance member 60B and the interlocking member 80 may be formed of a quenched metal material. In this case, the strength of the interlocking member 80 can be increased and wear can be suppressed. For example, when the displacement tolerance member 60B is easier to replace than the interlocking member 80, the replacement frequency of the interlocking member 80 can be reduced, and the replacement operation to a new displacement tolerance member can be facilitated when the displacement tolerance member 60B wears.

[0073] In the above-described embodiments, a pair of displacement tolerance members 60A and 60B have been described, and the pair of displacement tolerance members 60A and 60B include a first displacement tolerance member 60A provided on the first end side in the axial direction of the connecting shaft 69 and a second displacement tolerance member 60B provided on the second end side in the axial direction of the connecting shaft 69. However, the present invention is not limited thereto. For example, the displacement tolerance member may be a single member. For example, the form of the displacement tolerance member can be changed according to the requirements specification.

[0074] In this embodiment, the rear support structure 29B further includes a cab-side bracket 50 connected to the cab 14. The cab-side bracket 50 has a cab-side mounting hole 54 through which a connection shaft 69 is inserted. The interlocking member 80 is described by taking as an example the case where it is connected to the cab 14 via the cab-side bracket 50, but it is not limited thereto. For example, the rear support structure 29B may not include the cab-side bracket 50. For example, the interlocking member 80 may be connected to the cab 14 via the connection shaft 69 without passing through the cab-side bracket 50. For example, the connection mode of the interlocking member 80 can be changed according to the required specifications.

[0075] In the above-described embodiment, as an example of a construction machine (work vehicle), an articulated dump truck 1 in which a vehicle body frame is constituted by a front frame and a rear frame is described, but it is not limited thereto. For example, the present invention may be applied to a rigid frame type dump truck having a single vehicle body frame, or other work vehicles such as a hydraulic excavator and a bulldozer.

[0076] In the above-described embodiment, as an example of a mounting device, a liquid-filled mounting device is described, but it is not limited thereto. For example, the mounting device may be another type of mounting device using rubber, a spring, or the like. For example, the mode of the mounting device can be changed according to the required specifications.

[0077] The embodiments of the present invention have been described above, but the present invention is not limited thereto, and additions, omissions, substitutions, and other changes in the configuration are possible without departing from the spirit of the present invention, and it is also possible to appropriately combine the above-described embodiments.

Description of Reference Numerals

[0078] 1…Dump truck (construction machinery), 11…Front frame (vehicle body frame), 14…Cab, 29A…Front side cab support structure (cab support structure), 29B…Rear side support structure (cab support structure), 30…Mounting device, 39…Linking mechanism, 50…Cab side bracket (connecting member), 54…Cab side mounting hole (insertion hole), 60A…First displacement tolerance member (displacement tolerance member), 60B…Second displacement tolerance member (displacement tolerance member), 61B…Second vertical plate portion (vertical plate portion), 62B…Second horizontal plate portion (horizontal plate portion), 63B…Second end side hole (displacement tolerance hole), 65B…Upper surface, 69…Linking shaft, 80…Interlocking member, 85…Displacement tolerance portion, 86…Displacement restricting portion, 87…First restricting portion, 88…Second restricting portion, 90…Cover, G…Gap, Gt…Vertical dimension of the gap, P2…Second plane (plane), P3…Curved surface, S…Space (interval), St…Vertical dimension of the space (interval)

Claims

1. A mounting device provided on a vehicle body frame, and a connecting mechanism that connects a cab provided above the vehicle body frame via the mounting device to the vehicle body frame so as to be rotatable between a seating position and a tilt position. The connecting mechanism includes: a connecting shaft connected to the mounting device and extending in the horizontal direction; a displacement allowance member connected to the vehicle body frame; and an interlocking member connected to the cab and rotatable in conjunction with the rotation of the cab. The displacement allowance member has a displacement allowance hole that allows displacement of the connecting shaft in the vertical direction and allows rotation of the connecting shaft between the seating position and the tilt position. The interlocking member has: a displacement allowance portion that allows displacement of the connecting shaft in the vertical direction when in the seating position; and a displacement restricting portion that restricts downward displacement of the connecting shaft when in the tilt position. The interlocking member is arranged at a distance from the displacement allowance member in the horizontal direction. Cab support structure.

2. The displacement allowance member includes: a plate-shaped vertical plate portion having the displacement allowance hole and extending in the vertical direction; and a plate-shaped horizontal plate portion that is coupled to the lower portion of the vertical plate portion, connected to the vehicle body frame, and extends in the horizontal direction. The interlocking member is formed in a plate shape extending parallel to the vertical plate portion. The displacement allowance portion and the displacement restricting portion are continuous along the outer periphery of the interlocking member. When in the seating position, a gap is provided between the displacement allowance portion and the upper surface of the horizontal plate portion to allow displacement of the connecting shaft in the vertical direction. When in the tilt position, the displacement restricting portion contacts the upper surface of the horizontal plate portion. The cab support structure according to Claim 1.

3. When in the seating position, the vertical dimension of the gap is larger than the vertical dimension of the distance between the inner surface of the displacement allowance hole and the connecting shaft. The cab support structure according to Claim 2.

4. The displacement restricting portion has a plane that follows the upper surface of the horizontal plate portion when in the tilt position. The cab support structure according to Claim 2 or 3.

5. The cab is rotatable to a lift-up position that is more inclined than the tilt position. The displacement restricting portion includes: a first restricting portion that contacts the upper surface of the horizontal plate portion when in the tilt position; and a second restricting portion that contacts the upper surface of the horizontal plate portion when in the lift-up position. The second restricting portion has an arcuate curved surface that curves toward the outside in the radial direction of the connecting shaft when viewed from the axial direction along the connecting shaft. The cab support structure according to any one of claims 2 to 4.

6. Further comprising a cover provided in the connecting mechanism and covering the gap The cab support structure according to any one of claims 2 to 5.

7. The cover is formed of an elastic body. The cab support structure according to claim 6.

8. At least one of the displacement tolerance member and the interlocking member is formed of a quenched metal material. The cab support structure according to any one of claims 1 to 7.

9. The displacement tolerance member is detachably connected to the vehicle body frame, The interlocking member is detachably connected to the cab, Only the interlocking member of the displacement tolerance member and the interlocking member is formed of a quenched metal material. The cab support structure according to any one of claims 1 to 8.

10. A pair of the displacement tolerance members are provided, The pair of displacement tolerance members are A first displacement tolerance member provided on the first end side in the axial direction of the connecting shaft, and A second displacement tolerance member provided on the second end side in the axial direction of the connecting shaft. The cab support structure according to any one of claims 1 to 9.

11. Further comprising a connecting member connected to the cab, The connecting member has an insertion hole through which the connecting shaft is inserted, The interlocking member is connected to the cab via the connecting member. The cab support structure according to any one of claims 1 to 10.

12. A vehicle body frame, A cab provided above the vehicle body frame, And a cab support structure according to any one of claims 1 to 11 provided between the vehicle body frame and the cab. Construction machinery.

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