Work vehicle

Abstract

To provide a work vehicle whose wheel for travel is driven by a hydraulic motor in which a hydraulic hose from a hydraulic pump mounted on a vehicle body is connected to the hydraulic motor without damage.SOLUTION: A work vehicle comprises: a steering component 26; a wheel 19 and a hydraulic motor 27 supported by the steering component 26; and a first hydraulic hose 10 through which hydraulic fluid is supplied from a hydraulic pump to the hydraulic motor 27. The first hydraulic hose 10 includes: a first portion 11 which is fixed to a first stationary member 41 and extends from the first stationary member 41 along support arms 8, 9 in a direction opposite to the steering component 26; a second portion 12 which changes an extension direction from the first portion 11 to the reverse direction to extend along the support arms 8, 9 toward the steering component 26; and a third portion 13 which extends from the second portion 12 to the hydraulic motor 27, is fixed to a second stationary member 42, and connected with the hydraulic motor 27.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a work vehicle whose running wheels are driven by a hydraulic motor. [Background technology]

[0002] In the work vehicle disclosed in Patent Document 1, support arms are attached to multiple locations on the body on which the hydraulic pump is mounted, and wheels and hydraulic motors that drive the wheels are supported at the ends of the support arms. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2018-103681 Summary of the Invention [Problem to be solved by the invention]

[0004] In the above-mentioned work vehicle, it has been proposed to attach a steering member to the end of the support arm so that it can be steered about a steering axis along the vertical direction, and to attach wheels and a hydraulic motor to the steering member. By steering the steering member relative to the support arm, the direction of travel of the work vehicle can be changed. In this type of work vehicle, when connecting a hydraulic hose from a hydraulic pump mounted on the vehicle body to a hydraulic motor, it is necessary to reduce damage to the hydraulic hose.

[0005] The present invention aims to configure a work vehicle whose running wheels are driven by a hydraulic motor so that a hydraulic hose from a hydraulic pump mounted on the vehicle body can be connected to the hydraulic motor with minimal damage. [Means for solving the problem]

[0006] The work vehicle of the present invention comprises a body on which a hydraulic pump is mounted, support arms attached to a plurality of locations on the body, a steering member supported on the end of the support arm so as to be steerable about a steering axis along the vertical direction, wheels for travel supported on the steering member, a hydraulic motor supported on the steering member and capable of driving the wheels, a first hydraulic hose capable of supplying working oil from the hydraulic pump to the hydraulic motor, a first fixing member provided at an upper position relative to the support arm, and a second fixing member provided on the steering member, the first hydraulic hose having a first portion fixed to the first fixing member and extending from the first fixing member in a direction opposite to the steering member, a second portion which has the extension direction changed from the first portion of the first hydraulic hose to the opposite direction and extends along the support arm towards the steering member, and a third portion which extends from the second portion of the first hydraulic hose towards the hydraulic motor, is fixed to the second fixing member, and is connected to the hydraulic motor.

[0007] According to the present invention, a support arm is attached to a machine body on which a hydraulic pump is mounted, and a steering member is supported at an end of the support arm so as to be steerable about a steering axis along the vertical direction, and wheels and a hydraulic motor are supported on the steering member. A first fixing member is provided at a position above the support arm, and a second fixing member is provided on the steering member.

[0008] According to the present invention, the first hydraulic hose is fixed to the first fixed member and extends from the first fixed member toward the side opposite to the steering member (first portion of the first hydraulic hose). The extending direction of the first hydraulic hose is reversed from the first portion of the first hydraulic hose, and extends along the support arm toward the steering member (second portion of the first hydraulic hose). The first hydraulic hose extends from the second portion of the first hydraulic hose toward the hydraulic motor, is fixed to the second fixing member, and is connected to the hydraulic motor (third portion of the first hydraulic hose).

[0009] As a result, the second portion of the first hydraulic hose is configured to be long and extend from the vicinity of the end of the support arm on the opposite side from the steering member to the vicinity of the end of the support arm on the steering member side. By configuring the second portion of the first hydraulic hose to be long, even when the steering member is steered and the orientation of the second portion of the first hydraulic hose is changed along with the steering member, the deflection of the second portion of the first hydraulic hose (the deflection angle of the portion on the opposite side of the steering member) is small. By reducing the deflection of the second portion of the first hydraulic hose (the deflection angle of the portion opposite the steering member), there is less contact between the first hydraulic hose and other objects, and damage to the first hydraulic hose caused by repeated deflection is reduced, thereby improving the durability of the first hydraulic hose.

[0010] In the present invention, it is preferable that the second portion of the first hydraulic hose is provided below the first fixing member.

[0011] According to the present invention, the second portion of the first hydraulic hose has its extension direction changed downward from the first portion of the first hydraulic hose and then changed in the opposite direction, and extends downward from the first fixed member along the support arm toward the steering member. This allows the extension direction of the first hydraulic hose to be changed smoothly, and the first hydraulic hose to extend along the support arm toward the steering member, which is advantageous in terms of improving the durability of the first hydraulic hose.

[0012] In the present invention, it is preferable that a steering cylinder is provided that is attached across the support arm and the steering member and is capable of steering the steering member relative to the support arm, and a second hydraulic hose that is capable of supplying hydraulic oil from the hydraulic pump to the steering cylinder, and that the second hydraulic hose has a first portion that is fixed to the first fixing member and extends from the first fixing member toward the opposite side to the steering member, and a second portion that is changed so that the extension direction is reversed from the first portion of the second hydraulic hose and is connected to the steering cylinder.

[0013] According to the present invention, a steering cylinder is attached across the support arm and the steering member, and the steering member is steered by the steering cylinder. According to the present invention, in the above-described configuration, the second hydraulic hose is fixed to the first fixed member and extends from the first fixed member along the support arm toward the opposite side to the steering member (first portion of the second hydraulic hose). The extending direction of the second hydraulic hose is reversed from the first portion of the second hydraulic hose and connected to the steering cylinder (second portion of the second hydraulic hose).

[0014] According to the present invention, the second hydraulic hose is arranged along the first hydraulic hose, which reduces contact between the second hydraulic hose and other objects, thereby improving the durability of the second hydraulic hose.

[0015] In the present invention, it is preferable that the second portion of the second hydraulic hose is provided below the first fixing member.

[0016] According to the present invention, the second portion of the second hydraulic hose is provided below the first fixing member, with the extension direction thereof changed downward from the first portion of the second hydraulic hose and then changed in the opposite direction. This allows the extending direction of the second hydraulic hose to be changed smoothly and the second hydraulic hose to be connected to the steering cylinder, which is advantageous in terms of improving the durability of the second hydraulic hose.

[0017] In the present invention, it is preferable that the second portion of the first hydraulic hose and the second portion of the second hydraulic hose are provided below the first fixing member, and the first portion of the first hydraulic hose is fixed to a portion of the first fixing member below the first portion of the second hydraulic hose.

[0018] According to the present invention, the second portion of the first hydraulic hose has its extension direction changed downward from the first portion of the first hydraulic hose and then changed in the opposite direction, and extends downward from the first fixed member along the support arm toward the steering member. This allows the extension direction of the first hydraulic hose to be changed smoothly, and the first hydraulic hose to extend along the support arm toward the steering member, which is advantageous in terms of improving the durability of the first hydraulic hose.

[0019] According to the present invention, the second portion of the second hydraulic hose is provided below the first fixing member, with the extension direction thereof changed downward from the first portion of the second hydraulic hose and then changed in the opposite direction. This allows the extending direction of the second hydraulic hose to be changed smoothly and the second hydraulic hose to be connected to the steering cylinder, which is advantageous in terms of improving the durability of the second hydraulic hose.

[0020] According to the present invention, when the first hydraulic hose and the second hydraulic hose are fixed to the first fixing member as described above, the first portion of the first hydraulic hose is provided below the first portion of the second hydraulic hose in the first fixing member. This reduces the likelihood of the first hydraulic hose and the second hydraulic hose crossing each other in a side view, allows the second portion of the first hydraulic hose to extend smoothly along the support arm toward the steering member, and allows the second portion of the second hydraulic hose to be smoothly connected to the steering cylinder, which is advantageous in terms of improving the durability of the first hydraulic hose and the second hydraulic hose.

[0021] In the present invention, it is preferable that a support member supported on the aircraft body is provided, the end of the support arm opposite the steering member is supported on a lower part of the support member so as to be able to rise and fall around a horizontally extending lifting axis, a lifting cylinder is attached across the support member and the support arm and is able to raise and lower the support arm relative to the support member, and the first fixed member is provided on a lateral surface portion of the support member located above the steering cylinder.

[0022] According to the present invention, a support member is provided on the aircraft body, and an end of the support arm opposite to the steering member is supported on a lower part of the support member so as to be movable up and down about a horizontal lift axis. An elevator cylinder is attached across the support member and the support arm, and the height of the aircraft body from the ground can be changed by raising and lowering the support arm with the elevator cylinder.

[0023] According to the present invention, the first fixing member is provided on the lateral surface portion of the support member located above the steering cylinder. This allows the first portion of the second hydraulic hose to extend from the first fixing member in the direction opposite to the steering member, and when the second portion of the second hydraulic hose is connected to the steering cylinder with its extension direction reversed from the first portion of the second hydraulic hose, the second portion of the second hydraulic hose can be connected to the steering cylinder without any strain, which is advantageous in terms of improving the durability of the second hydraulic hose.

[0024] According to the present invention, the bent portion between the first and second portions of the first hydraulic hose and the bent portion between the first and second portions of the second hydraulic hose are located near the lifting axis of the support arm.

[0025] As a result, when the support arm is raised and lowered by the lifting cylinder, the degree of bending at the bent portion of the first hydraulic hose and the bent portion of the second hydraulic hose increases or decreases, allowing the lifting cylinder to raise and lower the support arm smoothly. When the support arm is raised and lowered by the lifting cylinder, the degree of bending of the first hydraulic hose and the second hydraulic hose changes, and the vibration of the first hydraulic hose and the second hydraulic hose is small, so there is less contact between the first hydraulic hose and the second hydraulic hose and other objects, which is advantageous in terms of improving the durability of the first hydraulic hose and the second hydraulic hose.

[0026] In the present invention, it is preferable that the lifting cylinder is provided along a lateral surface of the support member opposite to the lateral surface on which the first fixing member is provided.

[0027] According to the present invention, when the first fixing member is provided on a side surface portion of the support member located above the steering cylinder, a lifting cylinder for raising and lowering the support arm is provided along the side surface portion of the support member opposite to the side surface portion on which the first fixing member is provided. This reduces contact between the first hydraulic hose and the second hydraulic hose (first fixed member) and the lift cylinder, which is advantageous in terms of improving the durability of the first hydraulic hose and the second hydraulic hose.

[0028] In the present invention, it is preferable that the upper part of the support member is supported by the machine body so as to be swingable around a swing axis along a horizontal direction, and that a swing cylinder is attached across the machine body and the support member and is capable of swinging the support member relative to the machine body, and that a third fixed member is provided above the swing axis, and that the first hydraulic hose has a fourth portion that is fixed to the third fixed member, extends from the third fixed member towards the steering member, has an extension direction changed towards the first fixed member, is fixed to the first fixed member, and is connected to the first portion of the first hydraulic hose.

[0029] According to the present invention, the upper part of the support member is supported on the machine body so as to be swingable around a swing axis along the horizontal direction. A swing cylinder is attached across the machine body and the support member, and the support member is swung by the swing cylinder.

[0030] According to the present invention, the third fixed member is provided above the swing axis. The fourth portion of the first hydraulic hose is fixed to the third fixed member, extends from the third fixed member toward the steering member, changes its extending direction toward the first fixed member, is fixed to the first fixed member, and is connected to the first portion of the first hydraulic hose.

[0031] According to the present invention, the bent portion of the fourth section of the first hydraulic hose is located near the pivot axis of the support member. As a result, when the support member is swung by the swing cylinder, the degree of bending at the bent portion of the first hydraulic hose increases or decreases, and the swing operation of the support member by the swing cylinder is carried out smoothly. When the support member is swung by the oscillating cylinder, the degree of bending of the first hydraulic hose changes, and the vibration of the first hydraulic hose is small, so there is less contact between the first hydraulic hose and other objects, which is advantageous in terms of improving the durability of the first hydraulic hose.

[0032] In the present invention, it is preferable that the second hydraulic hose has a third portion that is fixed to the third fixed member, extends from the third fixed member toward the steering member, has an extending direction changed toward the first fixed member, is fixed to the first fixed member, and is connected to the first portion of the second hydraulic hose.

[0033] According to the present invention, the third portion of the second hydraulic hose is fixed to the third fixing member, extends from the third fixing member toward the steering member, changes the extension direction toward the first fixing member, is fixed to the first fixing member, and is connected to the first portion of the second hydraulic hose.

[0034] According to the present invention, the bent portion of the third section of the second hydraulic hose is located near the pivot axis of the support member. As a result, when the support member is swung by the swing cylinder, the degree of bending at the bent portion of the second hydraulic hose increases or decreases, and the swing operation of the support member by the swing cylinder is carried out smoothly. When the support member is swung by the oscillating cylinder, the degree of bending of the second hydraulic hose changes, and the vibration of the second hydraulic hose is small, so there is less contact between the second hydraulic hose and other objects, which is advantageous in terms of improving the durability of the second hydraulic hose. [Brief explanation of the drawings]

[0035] [Figure 1] FIG. [Figure 2] FIG. [Figure 3] FIG. 2 is a left side view of the vicinity of the first support arm, the second support arm, the steering member, etc., provided at the front right part of the aircraft body. [Figure 4] FIG. 2 is a rear view of the vicinity of the first support arm, second support arm, steering member, etc., provided at the front right part of the aircraft body. [Figure 5] FIG. 2 is a front view of the vicinity of the first support arm, the second support arm, the steering member, etc., provided at the front right part of the aircraft body. [Figure 6] FIG. 2 is a plan view of the vicinity of the first support arm, the second support arm, the steering member, etc., provided at the front right part of the aircraft body. DETAILED DESCRIPTION OF THE INVENTION

[0036] Figures 1 to 6 show remotely controlled and autonomously traveling work vehicles, and in Figures 1 to 6, F indicates the forward direction, B indicates the backward direction, U indicates the upward direction, D indicates the downward direction, R indicates the right direction, and L indicates the left direction.

[0037] (Overall configuration of the work vehicle) As shown in Figures 1 and 2, there is provided a machine body 1 formed by connecting frames (not shown) in a frame shape, and a loading platform 2 for placing cargo is provided on the upper part of the machine body 1. An engine 3 and a hydraulic pump 4 are provided on the lower front part of the machine body 1, and the hydraulic pump 4 is driven by the engine 3. Four control valve units 5 are provided on the right and left parts of the upper part of the machine body 1, and hydraulic oil from the hydraulic pump 4 is supplied to the control valve units 5.

[0038] Flat right and left covers 25 are provided on the right and left sides of the engine 3, along the front-to-back and up-to-down directions, across the front and rear ends of the aircraft body 1. The right and left lateral sides of the engine 3 and the right lateral side of the hydraulic pump 4 are covered by the covers 25.

[0039] Four pairs of first support arms 6, 7 (corresponding to support members) and second support arms 8, 9 (corresponding to support arms) are provided at the right front and left front and right rear and left rear of the machine body 1, and wheels 19 for traveling are supported at the ends of the second support arms 8, 9. The machine body 1 is supported by the four pairs of first support arms 6, 7 and second support arms 8, 9 and the wheels 19.

[0040] The right front first support arms 6, 7 and second support arms 8, 9 have a symmetrical configuration to the left front first support arms 6, 7 and second support arms 8, 9. The right rear first support arms 6, 7 and second support arms 8, 9 have a symmetrical configuration to the left rear first support arms 6, 7 and second support arms 8, 9.

[0041] The right front first support arms 6, 7 and second support arms 8, 9 and the right rear first support arms 6, 7 and second support arms 8, 9 have a front-to-back symmetrical configuration. The left front first support arms 6, 7 and second support arms 8, 9 and the left rear first support arms 6, 7 and second support arms 8, 9 have a front-to-back symmetrical configuration.

[0042] (Configuration of the first support arm) Of the four pairs of first support arms 6, 7 and second support arms 8, 9, the first support arms 6, 7 of the right front pair of first support arms 6, 7 and second support arms 8, 9 will be described below with reference to FIGS.

[0043] As shown in Figures 3 to 6, a pair of support brackets 15, 16 are connected to the right front portion of the upper part of the fuselage 1 and extend downward, and a fulcrum shaft 17 is connected along the left-right direction across the lower part of the support brackets 15, 16.

[0044] A pair of flat plate-shaped first support arms 6, 7 are provided, and a round pipe-shaped fulcrum portion 6a is connected across the upper parts of the first support arms 6, 7. The fulcrum portions 6a of the first support arms 6, 7 are rotatably attached to a fulcrum shaft 17, and the upper parts of the first support arms 6, 7 are supported so as to be swingable back and forth around an axis P1 (corresponding to the swing axis) along the left-right direction (corresponding to the horizontal direction).

[0045] A pair of brackets 18 are connected to the right and left portions of the fulcrum shaft 17 and extend rearward (toward the center between the front and rear of the aircraft body 1). A double-acting first hydraulic cylinder 31 (corresponding to a swing cylinder) is attached across the brackets 18 and the lower portions of the first support arms 6, 7, and is provided between the first support arms 6, 7 in plan and rear views.

[0046] When the first hydraulic cylinder 31 contracts, the first support arms 6, 7 are swung rearward (toward the center of the front and rear of the machine body 1) relative to the machine body 1. When the first hydraulic cylinder 31 extends, the first support arms 6, 7 are swung forward relative to the machine body 1.

[0047] With the above configuration, first support arms 6, 7 (support members) supported by the machine body 1 are provided as shown in FIGS. The upper portions of the first support arms 6, 7 (support members) are supported by the machine body 1 so as to be swingable about an axis P1 (swing axis) along the left-right direction (horizontal direction). A first hydraulic cylinder 31 (swing cylinder) is attached across the machine body 1 and the first support arms 6, 7 (support members) and is capable of swinging the first support arms 6, 7 (support members) relative to the machine body 1.

[0048] (Configuration of the second support arm) Of the four pairs of first support arms 6, 7 and second support arms 8, 9, the second support arms 8, 9 of the right front pair of first support arms 6, 7 and second support arms 8, 9 will be described below with reference to FIGS.

[0049] As shown in Figures 3 to 6, a pair of second support arms 8, 9 each shaped like a squashed round pipe are provided, and a fulcrum shaft 8a is connected to the rear of the second support arms 8, 9. A round pipe-shaped fulcrum portion 6b is connected to the lower portions of the first support arms 6, 7, and the fulcrum shaft 8a of the second support arms 8, 9 is rotatably attached to the fulcrum portions 6b of the first support arms 6, 7.

[0050] As a result, the rear portions of the second support arms 8, 9 are supported by the lower portions of the first support arms 6, 7 so as to be able to move up and down around an axis P2 (corresponding to the lift axis) along the left-right direction (corresponding to the horizontal direction), and the second support arms 8, 9 extend forward from the lower portions of the first support arms 6, 7. An auxiliary wheel 24 is supported on the fulcrum axis 8a of the second support arms 8, 9 at a portion laterally outward of the second support arm 9 so as to be able to rotate freely.

[0051] A fulcrum shaft 8b is connected across the rear portions of the second support arms 8, 9. A double-acting second hydraulic cylinder 32 (corresponding to a lifting cylinder) is attached across the front portions of the upper portions of the first support arms 6, 7 and the fulcrum shaft 8b of the second support arms 8, 9. The second hydraulic cylinder 32 is provided between the first support arms 6, 7 and between the second support arms 8, 9 in plan and front views, and is provided forward of the first hydraulic cylinder 31.

[0052] When the second hydraulic cylinder 32 contracts, the second support arms 8, 9 are swung upward relative to the first support arms 6, 7. When the second hydraulic cylinder 32 extends, the second support arms 8, 9 are swung downward relative to the first support arms 6, 7.

[0053] With the above-described configuration, as shown in FIGS. 3 to 6, the machine body 1 on which the hydraulic pump 4 is mounted, and the second support arms 8, 9 (support arms) attached to the machine body 1 at a plurality of locations are provided. The end of the second support arm 8, 9 (support arm) opposite the steering member 26 is supported by the lower part of the first support arm 6, 7 (support member) so as to be movable up and down around an axis P2 (lifting axis) along the left-right direction (horizontal direction). A second hydraulic cylinder 32 (lifting cylinder) is provided which is attached across the first support arms 6, 7 (support members) and the second support arms 8, 9 (support arms) and can raise and lower the second support arms 8, 9 (support arms) relative to the first support arms 6, 7 (support members).

[0054] (Configuration of steering member) Of the four pairs of first support arms 6, 7 and second support arms 8, 9, the steering member 26 attached to the second support arms 8, 9 of the right front pair of first support arms 6, 7 and second support arms 8, 9 will be described below with reference to Figures 3 to 6.

[0055] 3 to 6, a horizontal frame 8c is connected across the front portions of the second support arms 8, 9. A steering member 26 is supported on the horizontal frames 8c of the second support arms 8, 9 at a portion on the left-right center side of the aircraft body 1 so as to be steerable about an axis P3 along the vertical direction.

[0056] The wheels 19 are rotatably supported on the right outer lateral portion of the steering member 26. A hydraulic motor 27 is supported on the steering member 26 at a portion on the left-right center side of the machine body 1, and the hydraulic motor 27 drives and rotates the wheels 19 in the forward and reverse directions.

[0057] A bracket 8d is connected to the rear of the second support arm 8 at the center of the fuselage 1 in the lateral direction, and a bracket 26a is connected to the upper part of the steering member 26 at the center of the fuselage 1 in the lateral direction.

[0058] A double-acting third hydraulic cylinder 33 (corresponding to a steering cylinder) is attached across the bracket 26a of the steering member 26 and the bracket 8d of the second support arms 8, 9. The third hydraulic cylinder 33 is provided on the left-right central side of the machine body 1 with respect to the second support arm 8 in a plan view, and is provided along the second support arm 8. By operating the third hydraulic cylinder 33 to extend or retract, the steering member 26 is steered left and right with respect to the second support arms 8, 9.

[0059] With the above configuration, as shown in Figures 3 to 6, a steering member 26 is provided that is supported on the ends of the second support arms 8, 9 (support arms) so as to be steerable about an axis P3 (steering axis) that extends in the vertical direction. Wheels 19 for traveling are provided that are supported on the steering member 26. A hydraulic motor 27 that is supported on the steering member 26 and can drive the wheels 19 is provided. A third hydraulic cylinder 33 (steering cylinder) is provided which is attached across the second support arms 8, 9 (support arms) and the steering member 26 and is capable of steering the steering member 26 relative to the second support arms 8, 9 (support arms).

[0060] (Configuration of hydraulic hoses supplying hydraulic oil to the first hydraulic cylinder and the second hydraulic cylinder) Of the four sets of first support arms 6, 7 and second support arms 8, 9, the hydraulic hoses 28, 29 to the first hydraulic cylinder 31 and second hydraulic cylinder 32 of the right front first support arms 6, 7 and second support arms 8, 9 will be described below with reference to Figures 3 to 6.

[0061] As shown in Figures 3 to 6, the control valve unit 5 is provided rearward of the fulcrum shaft 17 (towards the center of the front and rear of the machine body 1) and at approximately the same height as the fulcrum shaft 17. A pair of flexible hydraulic hoses 28 extend forward from the lower part of the control valve unit 5 and are connected to the first hydraulic cylinder 31 while bending.

[0062] A third fixing member 43 is attached to the lateral surface of the support bracket 15 on the side of the support bracket 16. A pair of flexible hydraulic hoses 29 extend forward from the lower part of the control valve unit 5, extend upward and are fixed to the lower part of the third fixing member 43, and are provided between the support brackets 15 and 16.

[0063] The hydraulic hose 29 extends forward from the third fixing member 43, then extends downward, and is connected to the second hydraulic cylinder 32. A bent portion 29a of the hydraulic hose 29 is located in front of the fulcrum shaft 17 (axis center P1) and is located at approximately the same height as the fulcrum shaft 17 (axis center P1).

[0064] The hydraulic oil from the hydraulic pump 4 is supplied to the control valve unit 5, and is supplied and discharged from the control valve unit 5 to the first hydraulic cylinder 31 and the second hydraulic cylinder 32 via hydraulic hoses 28, 29, causing the first hydraulic cylinder 31 and the second hydraulic cylinder 32 to extend and retract.

[0065] (Configuration of hydraulic hoses that supply hydraulic oil to hydraulic motors) - 1 Of the four sets of first support arms 6, 7 and second support arms 8, 9, the hydraulic hose 10 (corresponding to the first hydraulic hose) to the hydraulic motor 27 of the right front first support arms 6, 7 and second support arms 8, 9 will be described below with reference to Figures 3 to 6.

[0066] 3 to 6, a first fixing member 41 is attached to the upper and lower middle portion of the lateral surface of the first support arm 6 at the left-right center of the machine body 1. A second fixing member 42 is attached to the front portion of the steering member 26. The second hydraulic cylinder 32 and the first fixing member 41 are located on the lateral surface on the opposite side of the first support arm 6, with the first support arm 6 sandwiched between them.

[0067] A pair of flexible hydraulic hoses 10 (fourth portion 14) extend forward from the lower portion of the control valve unit 5, extend upward, and are fixed to the upper portion of the third fixing member 43, and are provided between the support brackets 15 and 16.

[0068] The hydraulic hose 10 (fourth portion 14) extends forward from the third fixing member 43, then extends downward, and is fixed to the lower part of the first fixing member 41. The bent portion 14a of the hydraulic hose 10 (fourth portion 14) is located in front of the fulcrum shaft 17 (axis center P1) and is located at approximately the same height as the fulcrum shaft 17 (axis center P1).

[0069] The hydraulic hose 10 (first portion 11) extends from a position above the second support arm 8, from the fourth portion 14 of the hydraulic hose 10 and the first fixing member 41, toward the rear (toward the center of the front and rear of the aircraft body 1).

[0070] The hydraulic hose 10 (second portion 12) is changed so that the extension direction is reversed from the first portion 11 of the hydraulic hose 10 toward the front, and extends from a position above the second support arm 8 toward the front (steering member 26) along the second support arm 8. A bent portion 11a (the connection portion between the first portion 11 and the second portion 12) of the hydraulic hose 10 is located above the fulcrum shaft 8a (axis center P2) of the second support arms 8, 9.

[0071] The hydraulic hose 10 (third portion 13 ) extends downward from the second portion 12 of the hydraulic hose 10 toward the hydraulic motor 27 , is fixed to the second fixing member 42 , and is connected to the hydraulic motor 27 .

[0072] Hydraulic oil from the hydraulic pump 4 is supplied to the control valve unit 5, and is then supplied and discharged from the control valve unit 5 to the hydraulic motor 27 via the fourth part 14, the first part 11, the second part 12, and the third part 13 of the hydraulic hose 10, and the hydraulic motor 27 drives the wheels 19 to rotate forward and backward.

[0073] (Configuration of hydraulic hoses that supply hydraulic oil to hydraulic motors) - 2 With the above configuration, as shown in FIGS. 3 to 6, the hydraulic hose 10 (first hydraulic hose) capable of supplying hydraulic oil from the hydraulic pump 4 to the hydraulic motor 27 is provided.

[0074] A first fixing member 41 is provided at an upper position relative to the second support arm 8 (support arm). A second fixing member 42 is provided on the steering member 26. A third fixing member 43 is provided at an upper side relative to the axis P1 (oscillating axis).

[0075] A first fixing member 41 is provided on a lateral surface portion of the first support arm 6 (support member) located above the third hydraulic cylinder 33 (steering cylinder). A second hydraulic cylinder 32 (lifting cylinder) is provided along the side surface of the first support arm 6 (support member) opposite to the side surface on which the first fixing member 41 is provided.

[0076] The hydraulic hose 10 (first hydraulic hose) is fixed to the third fixing member 43, extends from the third fixing member 43 toward the steering member 26, changes its extension direction toward the first fixing member 41, and has a fourth portion 14 that is fixed to the first fixing member 41 and connected to the first portion 11.

[0077] The hydraulic hose 10 (first hydraulic hose) has a first portion 11 that is fixed to the first fixing member 41 and extends from the first fixing member 41 toward the opposite side from the steering member 26, a second portion 12 that extends from the first portion 11 of the hydraulic hose 10 (first hydraulic hose) in the opposite direction and extends along the second support arm 8 (support arm) toward the steering member 26, and a third portion 13 that extends from the second portion 12 of the hydraulic hose 10 (first hydraulic hose) toward the hydraulic motor 27, is fixed to the second fixing member 42, and is connected to the hydraulic motor 27. The second portion 12 of the hydraulic hose 10 (first hydraulic hose) is provided below the first fixing member 41.

[0078] (Configuration of hydraulic hose supplying hydraulic oil to the third hydraulic cylinder) - 1 Of the four sets of first support arms 6, 7 and second support arms 8, 9, the hydraulic hose 20 (corresponding to the second hydraulic hose) to the third hydraulic cylinder 33 of the right front first support arms 6, 7 and second support arms 8, 9 will be described below with reference to Figures 3 to 6.

[0079] As shown in Figures 3 to 6, a pair of flexible hydraulic hoses 20 (third portions 23) extend forward from the lower portion of the control valve unit 5, extend upward, and are fixed to the upper and lower middle portions of the third fixing member 43 (the portion between the fourth portion 14 of the hydraulic hose 10 and the hydraulic hose 29), and are provided between the support brackets 15 and 16.

[0080] The hydraulic hose 20 (third portion 23) extends forward from the third fixing member 43, then extends downward, and is fixed to an upper portion of the first fixing member 41. The bent portion 23a of the hydraulic hose 20 (third portion 23) is located in front of the fulcrum shaft 17 (axis center P1) and is located at approximately the same height as the fulcrum shaft 17 (axis center P1).

[0081] The hydraulic hose 20 (first portion 21) extends from a position above the second support arm 8, from the third portion 23 of the hydraulic hose 20 and the first fixing member 41, toward the rear (toward the center of the fore-and-aft direction of the aircraft body 1).

[0082] The hydraulic hose 20 (second portion 22) is changed so that its extending direction is reversed and faces forward from the first portion 21 of the hydraulic hose 20, and extends from a position above the second support arm 8 along the second support arm 8 toward the front (steering member 26) and is connected to the third hydraulic cylinder 33. A bent portion 21a (the connection portion between the first portion 21 and the second portion 22) of the hydraulic hose 20 is located above the fulcrum shaft 8a (axis center P2) of the second support arms 8, 9.

[0083] In the vicinity of the third fixing member 43, the third portion 23 of the hydraulic hose 20 is located below the fourth portion 14 of the hydraulic hose 10 in a side view. The hydraulic hose 29 is located below the third portion 23 of the hydraulic hose 20 in a side view.

[0084] The bent portion 23a of the hydraulic hose 20 (third portion 23) and the bent portion 29a of the hydraulic hose 29 are located rearward (toward the center of the fore-and-aft of the aircraft 1) of the bent portion 14a of the hydraulic hose 10 (fourth portion 14) in a side view.

[0085] In the vicinity of the first fixing member 41, the first portion 21 and the third portion 23 of the hydraulic hose 20 are positioned above the first portion 11 and the fourth portion 14 of the hydraulic hose 10 in a side view. The second portion 22 of the hydraulic hose 20 is positioned below the second portion 12 of the hydraulic hose 10 in a side view, and is positioned above the second support arm 8 and the third hydraulic cylinder 33.

[0086] The bent portion 21a (the connection portion between the first portion 21 and the second portion 22) of the hydraulic hose 20 is located rearward (toward the center of the fore-and-aft direction of the aircraft 1) of the bent portion 11a (the connection portion between the first portion 11 and the second portion 12) of the hydraulic hose 10 in a side view.

[0087] (Configuration of hydraulic hose supplying hydraulic oil to the third hydraulic cylinder) - 2 With the above configuration, as shown in FIGS. 3 to 6, the hydraulic hose 20 (second hydraulic hose) is provided which can supply hydraulic oil from the hydraulic pump 4 to the third hydraulic cylinder 33 (steering cylinder).

[0088] The hydraulic hose 20 (second hydraulic hose) is fixed to the third fixing member 43, extends from the third fixing member 43 toward the steering member 26, has an extension direction changed toward the first fixing member 41, and has a third portion 23 fixed to the first fixing member 41 and connected to the first portion 21 of the hydraulic hose 20 (second hydraulic hose).

[0089] The hydraulic hose 20 (second hydraulic hose) has a first portion 21 that is fixed to the first fixing member 41 and extends from the first fixing member 41 toward the opposite side of the steering member 26, and a second portion 22 that extends in the opposite direction from the first portion 21 of the hydraulic hose 20 (second hydraulic hose) and is connected to a third hydraulic cylinder 33 (steering cylinder).

[0090] The second portion 22 of the hydraulic hose 20 (second hydraulic hose) is provided below the first fixing member 41. The second portion 12 of the hydraulic hose 10 (first hydraulic hose) and the second portion 22 of the hydraulic hose 20 (second hydraulic hose) are provided below the first fixing member 41. The first portion 11 of the hydraulic hose 10 (first hydraulic hose) is fixed to a portion of the first fixing member 41 that is below the first portion 21 of the hydraulic hose 20 (second hydraulic hose).

[0091] (First Alternative Embodiment of the Invention) Instead of four pairs of first support arms 6, 7 and second support arms 8, 9, three pairs of first support arms 6, 7 and second support arms 8, 9 may be provided, or six pairs of first support arms 6, 7 and second support arms 8, 9 may be provided.

[0092] (Second Alternative Embodiment of the Invention) In the first support arms 6, 7 and the second support arms 8, 9, the first hydraulic cylinder 31 may be eliminated and the first support arms 6, 7 may be configured to be fixed to the machine body 1.

[0093] (Third Alternative Embodiment of the Invention) The engine 3 may be eliminated and the hydraulic pump 4 may be driven by an electric motor (corresponding to a drive unit) (not shown). [Industrial Applicability]

[0094] The present invention can be applied to work vehicles that are suitable for traveling on uneven or sloping work ground, and can also be applied to work vehicles that can accommodate a worker. [Explanation of symbols]

[0095] 1 aircraft 4 Hydraulic pump 6 First support arm (support member) 7 First support arm (support member) 8 Second support arm (support arm) 9 Second support arm (support arm) 10 Hydraulic hose (first hydraulic hose) 11 Part 1 12 Part 2 13 Part 3 14 Part 4 19 wheels 20 Hydraulic hose (second hydraulic hose) 21 Part 1 22 Part 2 23 Part 3 26 Steering member 27 Hydraulic motor 31 First hydraulic cylinder (swing cylinder) 32 Second hydraulic cylinder (lifting cylinder) 33 Third hydraulic cylinder (steering cylinder) 41 First fixing member 42 Second fixing member 43 Third fixing member P1 shaft center (oscillating shaft center) P2 shaft center (elevating shaft center) P3 axis (steering axis)

Claims

1. The aircraft is equipped with a hydraulic pump, support arms attached to a plurality of locations on the airframe; a steering member supported on an end of the support arm so as to be steerable about a steering axis along a vertical direction; a wheel for running supported by the steering member; a hydraulic motor supported by the steering member and capable of driving the wheels; a first hydraulic hose capable of supplying hydraulic oil from the hydraulic pump to the hydraulic motor; a first fixing member provided at an upper position relative to the support arm; a second fixing member provided on the steering member, The first hydraulic hose has: a first portion that is fixed to the first fixed member and extends from the first fixed member in a direction opposite to the steering member; a second portion that is changed to an extending direction opposite to the first portion of the first hydraulic hose and extends along the support arm toward the steering member; and a third portion that extends from the second portion of the first hydraulic hose toward the hydraulic motor, is fixed to the second fixed member, and is connected to the hydraulic motor.

2. The work vehicle according to claim 1 , wherein the second portion of the first hydraulic hose is provided below the first fixed member.

3. a steering cylinder attached across the support arm and the steering member and capable of steering the steering member relative to the support arm; a second hydraulic hose capable of supplying hydraulic oil from the hydraulic pump to the steering cylinder, 2. The work vehicle according to claim 1, wherein the second hydraulic hose has a first portion that is fixed to the first fixed member and extends from the first fixed member in a direction opposite to the steering member, and a second portion that extends in the opposite direction from the first portion of the second hydraulic hose and is connected to the steering cylinder.

4. The work vehicle according to claim 3 , wherein the second portion of the second hydraulic hose is provided below the first fixed member.

5. a second portion of the first hydraulic hose and a second portion of the second hydraulic hose are provided below the first fixing member, 4. The work vehicle according to claim 3, wherein the first portion of the first hydraulic hose is fixed to a portion of the first fixing member that is lower than the first portion of the second hydraulic hose.

6. a support member supported on the fuselage; an end portion of the support arm opposite to the steering member is supported by a lower portion of the support member so as to be able to rise and fall about an elevation axis along a horizontal direction; a lifting cylinder attached across the support member and the support arm and capable of lifting and lowering the support arm relative to the support member; 4. The work vehicle according to claim 3, wherein the first fixing member is provided on a lateral surface portion of the support member located above the steering cylinder.

7. 7. The work vehicle according to claim 6, wherein the lifting cylinder is provided along a side surface of the support member opposite to the side surface on which the first fixing member is provided.

8. an upper portion of the support member is supported by the aircraft body so as to be swingable around a swing axis along a horizontal direction; a swing cylinder attached across the machine body and the support member and capable of swinging the support member relative to the machine body; a third fixing member provided above the oscillation axis, 7. The work vehicle according to claim 6, wherein the first hydraulic hose has a fourth portion that is fixed to the third fixed member, extends from the third fixed member toward the steering member, has an extending direction changed toward the first fixed member, is fixed to the first fixed member, and is connected to the first portion of the first hydraulic hose.

9. 9. The work vehicle according to claim 8, wherein the second hydraulic hose has a third portion that is fixed to the third fixed member, extends from the third fixed member toward the steering member, has an extending direction changed toward the first fixed member, is fixed to the first fixed member, and is connected to the first portion of the second hydraulic hose.

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