Work vehicle

Abstract

Provided is a work vehicle capable of easily performing maintenance on a hydraulic machine. A work vehicle (1) comprises: a vehicle body (2); a structure (3) that can be connected to the vehicle body; a hydraulic actuator (62) that is mounted on the vehicle body or the structure; a hydraulic machine (101) that is mounted on the vehicle body or structure not provided with the hydraulic actuator, and that differs from the hydraulic actuator; and a movement mechanism (90) that moves the vehicle body or structure mounted with the hydraulic machine in the up-down direction together with the hydraulic machine.

Description

Work vehicles

[0001] The present invention relates to a work vehicle for performing work such as agricultural work.

[0002] A known work vehicle is disclosed in Patent Document 1. The work vehicle (tractor) disclosed in Patent Document 1 includes a gear pump that is operated by engine power to generate pressurized oil, a hydraulic cylinder (hydraulic actuator) for driving a lift arm, and a control valve (hydraulic device) that controls the supply of pressurized oil to the hydraulic cylinder.

[0003] A known work vehicle is disclosed in Patent Document 2. The work vehicle (backhoe) disclosed in Patent Document 2 includes left and right traveling devices including traveling frames, a swivel base that is disposed above the left and right traveling frames and rotates, and a hydraulic unit (control valves, etc.) that controls the operation of hydraulic equipment.

[0004] Japanese Patent Publication No. 2005-67327 and Japanese Patent Publication No. 2007-92380

[0005] In the work vehicle disclosed in Patent Document 1, the control valve (hydraulic device) is located between the left and right wheels (rear wheels), so the control valve (hydraulic device) cannot be accessed from the side, making it difficult to perform maintenance on the control valve (hydraulic device).

[0006] The present invention has been made in consideration of the above problems, and has an object to provide a work vehicle that allows for easy maintenance of hydraulic equipment.

[0007] In the work vehicle disclosed in Patent Document 2, the hydraulic unit that controls the operation of the hydraulic equipment is located on a swivel above the left and right traveling frames. As a result, the hydraulic unit is positioned above the left and right traveling frames, making it difficult to store and arrange the hydraulic unit compactly relative to the traveling frames.

[0008] The present invention has been made in consideration of the above problems, and has an object to provide a work vehicle in which a hydraulic unit can be housed and arranged in a compact manner.

[0009] A work vehicle according to one aspect of the present invention comprises a vehicle body, a structure connectable to the vehicle body, a hydraulic actuator mounted on either the vehicle body or the structure, hydraulic equipment mounted on the vehicle body or the structure on which the hydraulic actuator is not provided and separate from the hydraulic actuator, and a movement mechanism that moves either the vehicle body or the structure on which the hydraulic equipment is mounted in the vertical direction together with the hydraulic equipment.

[0010] The hydraulic device may be a hydraulic valve that controls the operation of the hydraulic actuator.

[0011] The hydraulic actuator may be disposed at a fixed position, and the movement mechanism may move the hydraulic device to change the position of the hydraulic device relative to the hydraulic actuator.

[0012] The hydraulic device may be moved relative to the structure together with the vehicle body by the movement mechanism.

[0013] The structure may be a running frame arranged on the side of the vehicle body and supporting the wheels, the moving mechanism may be a lifting mechanism that raises and lowers the vehicle body relative to the running frame, and the hydraulic equipment may be raised and lowered together with the vehicle body relative to the running frame by the lifting mechanism.

[0014] The hydraulic actuator may be fixed to the traveling frame, and the hydraulic device may rise and fall relative to the hydraulic actuator when the vehicle body rises and falls relative to the traveling frame.

[0015] The structure may be a running frame arranged on the side of the vehicle body and supporting the wheels, the hydraulic actuator may include a steering cylinder that steers the wheels, and the steering cylinder may be fixed to the structure.

[0016] A work vehicle according to one aspect of the present invention comprises a vehicle body, a traveling frame including a left traveling frame arranged on the left side of the vehicle body and supporting the left wheel, and a right traveling frame arranged on the right side of the vehicle body and supporting the right wheel, and a hydraulic unit arranged between the left traveling frame and the right traveling frame, which includes a hydraulic valve that controls the operation of hydraulic equipment mounted on the vehicle body or the traveling frame.

[0017] The hydraulic unit may be covered on the left side by the left traveling frame and on the right side by the right traveling frame.

[0018] The work vehicle may be equipped with a battery that stores electricity to be supplied to electrical equipment mounted on the vehicle body or the traveling frame, and the hydraulic unit and the battery may be arranged side by side in the front and rear between the left traveling frame and the right traveling frame.

[0019] The work vehicle may be equipped with a lifting mechanism that raises and lowers the vehicle body relative to the traveling frame, and the hydraulic unit may be covered on at least two sides when the vehicle body is lowered, and covered on at least one side when the vehicle body is raised.

[0020] The hydraulic unit may include the hydraulic valve, a hydraulic oil tank that stores hydraulic oil to be supplied to the hydraulic equipment, and a hydraulic pump that is driven by the hydraulic oil, and the hydraulic valve, the hydraulic pump, and the hydraulic oil tank may be concentrated at the rear of the vehicle body.

[0021] The vehicle body may have a main body and a body frame that supports the main body, the body frame supporting the main body between the left running frame and the right running frame and being capable of rising and falling together with the main body, and the hydraulic unit may be positioned so as not to protrude from the body frame at least in the left-right direction.

[0022] According to the work vehicle of the present invention, either the vehicle body or the structure on which the hydraulic equipment is mounted can be moved vertically together with the hydraulic equipment, making it easy to perform maintenance on the hydraulic equipment.

[0023] According to the work vehicle of the present invention, the hydraulic unit is disposed between the left traveling frame and the right traveling frame, so the hydraulic unit can be housed and disposed in a compact manner.

[0024] 1 is a perspective view showing an embodiment of a work vehicle; FIG. 2 is a left side view showing an embodiment of a work vehicle; FIG. 3 is a right side view showing an embodiment of a work vehicle; FIG. 4 is a front view showing an embodiment of a work vehicle; FIG. 5 is a rear view showing an embodiment of a work vehicle; FIG. 6 is a plan view showing an embodiment of a work vehicle; FIG. 7 is a block diagram showing an example of the overall configuration of a work vehicle; FIG. 8 is a perspective view of a frame structure; FIG. 9 is a perspective view of a body frame; FIG. 10 is a perspective view of a traveling frame; FIG. 11 is an exploded perspective view of a body frame; FIG. 12 is a plan view showing the frame structure in a state where the rods of the left and right cylinders are extended; FIG. 13 is a rear view showing the frame structure in a state where the body frame is lowered; FIG. 14 is a rear view showing the frame structure in a state where the body frame is raised; FIG. 15 is a front view showing a schematic of a work vehicle with the body lowered; FIG. 16 is a front view showing a schematic of a work vehicle with the body raised; FIG. 17 is a perspective view showing a work vehicle with the body raised; FIG. 18 is a left side view showing a work vehicle with the body raised; FIG. 19 is a right side view showing a work vehicle with the body raised; FIG. 20 is a front view showing a work vehicle with the body raised. 1 is a rear view showing a work vehicle in a raised state of the vehicle body. FIG. 2 is a schematic plan view showing an example of a work vehicle equipped with a position change mechanism. FIG. 3 is a schematic plan view showing another example of a work vehicle equipped with a position change mechanism. FIG. 4 is a view of the hydraulic unit as seen from the front left. FIG. 5 is a block diagram showing the relationship between the hydraulic unit and the hydraulic actuator. FIG. 6 is an enlarged plan view of the rear of the body frame of the work vehicle. FIG. 7 is a left side view showing a schematic change in the position of the hydraulic unit when the vehicle body is raised or lowered. FIG. 8 is a view showing an example (first embodiment) of a connection configuration of electrical wiring in a work vehicle. FIG. 9 is a front view showing movable parts and electrical wiring in a state where the vehicle body is lowered and the vehicle body and the traveling part are close to each other. FIG. 10 is a front view showing movable parts and electrical wiring in a state where the vehicle body is raised. FIG. 11 is a front view showing movable parts and electrical wiring in a state where the distance between the vehicle body and the traveling part is increased. FIG. 12 is a view showing an example (second embodiment) of a connection configuration of electrical wiring in a work vehicle. FIG. 13 is a view showing an example (third embodiment) of a connection configuration of electrical wiring in a work vehicle. FIG. 14 is a view showing an example (fourth embodiment) of a connection configuration of electrical wiring in a work vehicle. FIG. 15 is a view showing an example (fifth embodiment) of a connection configuration of electrical wiring in a work vehicle.FIG. 1 is a diagram showing an example (sixth embodiment) of a connection configuration of electrical wiring of a work vehicle. FIG. 2 is a diagram showing a first example of the operation of the height change mechanism based on the detection results of the tilt detection device. FIG. 3 is a diagram showing a second example of the operation of the height change mechanism based on the detection results of the tilt detection device. FIG. 4 is a diagram showing an example of the operation of the height change mechanism when the vehicle body frame is connected to the traveling frame without a mast mechanism. FIG. 5 is a diagram showing a third example of the operation of the height change mechanism based on the detection results of the tilt detection device. FIG. 6 is a flowchart showing an example of the operation of the height change mechanism based on the detection results of the tilt detection device. FIG. 7 is a flowchart showing another example of the operation of the height change mechanism based on the detection results of the tilt detection device. FIG. 8 is a diagram showing a first example of the operation of the distance change mechanism based on the detection results of the tilt detection device. FIG. 9 is a diagram showing a second example of the operation of the distance change mechanism based on the detection results of the tilt detection device. FIG. 10 is a flowchart showing an example of the operation of the distance change mechanism based on the detection results of the tilt detection device. FIG. 11 is a diagram showing a first example of the operation of the position change mechanism based on the detection results of the tilt detection device. FIG. 12 is a diagram showing a second example of the operation of the position change mechanism based on the detection results of the tilt detection device.

[0025] A preferred embodiment of a work vehicle 1 according to the present invention will now be described. Figures 1 to 7 are diagrams showing one embodiment of the work vehicle 1. Figure 1 is a perspective view of the work vehicle 1. Figure 2 is a left side view of the work vehicle 1. Figure 3 is a right side view of the work vehicle 1. Figure 4 is a front view of the work vehicle 1. Figure 5 is a rear view of the work vehicle 1. Figure 6 is a plan view of the work vehicle 1. Figure 7 is a block diagram showing the overall configuration of the work vehicle 1.

[0026] In the following description, the direction indicated by arrow X1 in the drawings is referred to as the forward direction, the direction indicated by arrow X2 as the backward direction, the direction indicated by arrow Y1 as the left direction, the direction indicated by arrow Y2 as the right direction, the direction indicated by arrow Z1 as the upward direction, and the direction indicated by arrow Z2 as the downward direction.

[0027] Examples of work performed by the work vehicle 1 include, but are not limited to, agricultural work, industrial (civil engineering, construction, etc.) work, and transportation work. In a preferred embodiment of the present invention, the work performed by the work vehicle 1 is agricultural work (farm work). In this case, the work vehicle 1 is an agricultural work vehicle.

[0028] As shown in Figures 1 to 6, the work vehicle 1 includes a vehicle body 2 and a structure 3 connectable to the vehicle body 2. The structure 3 includes a traveling section 4 disposed on the side of the vehicle body 2. The traveling section 4 includes a left traveling section 4L and a right traveling section 4R. The left traveling section 4L is disposed on the left side of the vehicle body 2. The right traveling section 4R is disposed on the right side of the vehicle body 2. Therefore, the vehicle body 2 is disposed between the left traveling section 4L and the right traveling section 4R.

[0029] The vehicle body 2 has a main body 5 and a body frame 21 that supports the main body 5. The main body 5 is formed in a box shape with an internal space. In the present embodiment, the main body 5 is formed in a substantially rectangular parallelepiped shape with an internal space. However, the shape of the main body 5 is not limited to a substantially rectangular parallelepiped shape. A first battery 12A, which will be described later, is housed in the internal space of the main body 5. In other words, the main body 5 functions as a case that houses the first battery 12A. Hereinafter, the main body 5 will also be referred to as the "main body case 5."

[0030] The body frame 21 supports the main body case 5 between a left traveling frame 8L and a right traveling frame 8R, which will be described later. The body frame 21 is a center frame located at the left-right center of the work vehicle 1. The body frame (center frame) 21 can be raised and lowered together with the main body case 5 by driving a height change mechanism (lifting mechanism) 90, which will be described later.

[0031] The body frame 21 includes a left body frame 23, a right body frame 24, and a central body frame 22. The central body frame 22 includes an upper body frame 25 and a lower body frame 26. The left body frame 23 is disposed to the left of the main body case 5. The right body frame 24 is disposed to the right of the main body case 5. The upper body frame 25 is disposed above the main body case 5. The lower body frame 26 is disposed below the main body case 5.

[0032] The traveling unit 4 includes wheels 7 and a traveling frame 8 that supports the wheels 7. The wheels 7 include a left front wheel 7LF, a left rear wheel 7LB, a right front wheel 7RF, and a right rear wheel 7RB. In the following description, the left front wheel 7LF and the left rear wheel 7LB will be collectively referred to as the "left wheels," and the right front wheel 7RF and the right rear wheel 7RB will be collectively referred to as the "right wheels." Furthermore, the left front wheel 7LF, the right front wheel 7RF, the left rear wheel 7LB, and the right rear wheel 7RB will be collectively referred to as the "wheels 7."

[0033] The wheels 7 (left front wheel 7LF, right front wheel 7RF, left rear wheel 7LB, and right rear wheel 7RB) are disposed on the sides of the vehicle body 2. The left wheels (left front wheel 7LF and left rear wheel 7LB) are disposed on the left side of the vehicle body 2. The right wheels (right front wheel 7RF and right rear wheel 7RB) are disposed on the right side of the vehicle body 2.

[0034] The traveling frame 8 is a structure 3 that can be connected to the vehicle body 2. In other words, the work vehicle 1 of this embodiment is equipped with the traveling frame 8 as the structure 3 that can be connected to the vehicle body 2. In the following explanation, the structure 3 that can be connected to the vehicle body 2 will be described as the traveling frame 8. However, the structure 3 that can be connected to the vehicle body 2 is not limited to the traveling frame 8. Therefore, the work vehicle 1 may be equipped with a structure that is different from the traveling frame 8 as the structure 3 that can be connected to the vehicle body 2.

[0035] The traveling frame 8 includes a left traveling frame 8L disposed on the left side of the vehicle body 2 and a right traveling frame 8R disposed on the right side of the vehicle body 2. The left traveling frame 8L supports the left wheels (left front wheel 7LF and left rear wheel 7LB). The right traveling frame 8R supports the right wheels (right front wheel 7RF and right rear wheel 7RB).

[0036] As shown in Figure 7, the work vehicle 1 is equipped with a power unit 9 for driving (rotating) the wheels 7. The power unit 9 generates power for driving the wheels 7, and the power is transmitted to the wheels 7. The power unit 9 includes a motor 10 and a battery 12. However, the power unit 9 may include an engine instead of the motor 10. The power unit 9 may also include a fuel cell.

[0037] The motor 10 is a traction motor that generates power to drive the wheels 7. The motor 10 is an electric motor that is driven by electricity. An inverter 13 is connected to the motor 10. The inverter 13 includes a plurality of inverters (first inverter 13A, second inverter 13B, third inverter 13C, fourth inverter 13D, and fifth inverter 13E) described below. The inverter 13 controls the rotation of the motor 10 based on a control signal from a control device 19 described below. The battery 12 stores the power supplied to the motor 10.

[0038] As shown in Figure 7, the work vehicle 1 is equipped with a motor 10, which is a traveling motor, as well as a motor 11, which is a work motor. The work motor generates power to drive devices and mechanisms other than the wheels 7. The motor 11 is an electric motor that is driven by power supplied from a battery 12. The rotation of the motor 11 can be controlled by an inverter 13.

[0039] Hereinafter, motor 10 may be referred to as the "traveling motor 10," and motor 11 may be referred to as the "working motor 11." Traveling motor 10 and working motor 11 can be driven independently of each other. Working motor 11 is a motor for driving a hydraulic pump that operates a hydraulic cylinder, which will be described later.

[0040] The work system motor 11 may be a hydraulic motor. The hydraulic motor is driven by hydraulic oil supplied from a hydraulic pump. In this case, for example, the hydraulic pump is driven by the traveling motor 10, the hydraulic oil supplied from the hydraulic pump drives the hydraulic motor (work system motor 11), and the external output shaft is driven by the hydraulic motor. Furthermore, the work vehicle 1 may be equipped with a work system motor 11 that is a hydraulic motor in addition to the work system motor 11 that is an electric motor.

[0041] Although not shown, the work vehicle 1 can be equipped with a mounting section (e.g., a three-point linkage mechanism) for mounting a work implement, and an output shaft that outputs power to drive the work implement mounted on the mounting section. The implement section and output shaft are provided, for example, at the rear or front of the vehicle body 2. The external output shaft can be driven by a work-related motor 11.

[0042] The battery 12 stores power to be supplied to electrical equipment mounted on the vehicle body 2 or the traveling frame 8. The electrical equipment mounted on the vehicle body 2 or the traveling frame 8 includes a traveling motor 10 and a working motor 11. The traveling motor 10 (motor 10LF, motor 10RF, motor 10LB, and motor 10RB, described below) is mounted on the traveling frame 8. The working motor 11 is mounted on the vehicle body 2.

[0043] As shown in Figure 6 and other figures, the battery 12 includes a first battery 12A and a second battery 12B. The first battery 12A stores the power supplied to the propulsion motor 10 and the work motor 11. The second battery 12B stores the power supplied to the propulsion motor 10 and the work motor 11. The first battery 12A is disposed in the vehicle body 2 (more specifically, the main body case 5). The second battery 12B is disposed in the traveling section 4 (more specifically, the left traveling frame 8L and the right traveling frame 8R).

[0044] The first battery 12A and the second battery 12B have the same function and the same structure or operating principle for performing that function. For example, the first battery 12A and the second battery 12B are lithium-ion batteries. Note that the work vehicle 1 may also be equipped with a battery (e.g., a lead battery) different from the first battery 12A and the second battery 12B.

[0045] As shown in Figure 7, the work vehicle 1 is equipped with a transmission 14. The transmission 14 is capable of switching the propulsive force of the travel device (travel motor 10) by changing gears. The transmission 14 is also capable of switching between forward and reverse travel of the work vehicle 1. The transmission 14 may be equipped with a speed change clutch that can switch between a four-wheel drive state (4WD) in which all four wheels (left front wheel 7LF, right front wheel 7RF, left rear wheel 7LB, right rear wheel 7RB) are driven, and a two-wheel drive state (2WD) in which only the rear wheels (left rear wheel 7LB, right rear wheel 7RB) or only the front wheels (left front wheel 7LF, right front wheel 7RF) are driven.

[0046] 7, the work vehicle 1 is equipped with a positioning device 15. The positioning device 15 is capable of detecting the position of the vehicle body 2 (positioning information including latitude and longitude) using a satellite positioning system (positioning satellite) such as D-GPS, GPS, GLONASS, Beidou, Galileo, or Michibiki. That is, the positioning device 15 receives satellite signals (position of the positioning satellite, transmission time, correction information, etc.) transmitted from the positioning satellites, and detects the position of the vehicle body 2 (for example, latitude and longitude) based on the satellite signals.

[0047] The positioning device 15 has a receiving device 16 and an inertial measurement unit (IMU) 17. The receiving device 16 has an antenna and the like and is a device that receives satellite signals transmitted from positioning satellites, and is attached to the vehicle body 2. The inertial measurement unit 17 has an acceleration sensor that detects acceleration, a gyro sensor that detects angular velocity, and the like. The inertial measurement unit 17 is attached to the vehicle body 2. The inertial measurement unit 17 can detect the roll angle, pitch angle, yaw angle, etc. of the vehicle body 2. Note that the yaw angle may be detected by installing multiple positioning devices 15.

[0048] As shown in FIG. 7 , the work vehicle 1 is equipped with a situation detection device 18. The situation detection device 18 detects the situation around the vehicle body 2. The situation detection device 18 detects, for example, road information, which is information about roads on which the work vehicle 1 can travel, as the situation around the vehicle body 2. The situation detection device 18 detects, for example, the width of the travel path as the road information. The width of the travel path detected by the situation detection device 18 is the width of an object that the work vehicle 1 is attempting to straddle between its left and right wheels. The situation detection device 18 detects, for example, the width of a ridge on the ground or the width of an obstacle on the ground that obstructs travel, as the width of the travel path.

[0049] As shown in FIG. 7 , the situation detection device 18 includes a camera (image capture device) 18a, a sensor 18b, and a calculation unit 18c. The camera 18a is mounted on the vehicle body 2 and captures images of the surroundings of the vehicle body 2 to generate image signals. The calculation unit 18c is composed of a computer or the like including a signal processing circuit that processes the generated image signals. The signal processing circuit detects the state of an object (presence or absence of an object, the position of the object, the type of object, the size of the object, etc.) based on the image signals output from the camera 18a. The sensor 18b is mounted on the vehicle body 2 and detects objects around the vehicle body 2. The sensor 18b is an optical sensor, and is composed of, for example, a LiDAR (Light Detection And Ranging) sensor.

[0050] As shown in Fig. 7, the work vehicle 1 is equipped with a control device 19. The control device 19 is a device that performs various controls of the work vehicle 1. The control device 19 is equipped with a calculation unit (CPU, etc.) and a storage unit (RAM, ROM, etc.). The storage unit may include an external memory provided outside the control device 19. The control device 19 is connected to the various devices and mechanisms shown in Fig. 7 and other figures via an in-vehicle LAN (on-board network) such as a CAN (Controller Area Network) or a communication line.

[0051] The control device 19 controls the operation of various devices and mechanisms communicably connected to the control device 19 by having the calculation unit execute various control programs stored in the memory unit. The functions of each control unit of the control device 19 (automatic driving control unit 19A, distance change control unit 19B, height change control unit 19C, position change control unit 19D) described below are realized by having the calculation unit execute predetermined control programs stored in the memory unit.

[0052] As shown in Fig. 7, the control device 19 includes an automatic driving control unit 19A. The automatic driving control unit 19A controls the automatic driving of the work vehicle 1. The automatic driving control unit 19A is capable of executing line-type automatic driving control and autonomous-type automatic driving control. In line-type automatic driving control, the automatic driving control unit 19A controls the operation of the steering mechanism 60, transmission 14, motor 10, etc., which will be described later, so that the work vehicle 1 (vehicle body 2) moves along a predetermined planned driving line.

[0053] In autonomous automatic driving control, the automatic driving control unit 19A sets the direction of travel (steering direction) and vehicle speed (velocity) of the vehicle body 2 based on the results of sensing (detecting objects) around the work vehicle 1 (vehicle body 2) using the positioning device 15, situation detection device 18, etc., and controls the operation of the steering mechanism 60, transmission 14, motor 10, etc. so that the set steering and vehicle speed are achieved.

[0054] Note that the line-type automatic driving control and the autonomous-type automatic driving control may be switchable by a switch or the like. Also, the automatic driving control unit 19A may be configured to be able to execute either the line-type automatic driving control or the autonomous-type automatic driving control. Note that the configuration of the automatic driving control unit 19A is not limited to the configuration described above.

[0055] The work vehicle 1 can perform automatic driving (unmanned driving) without an operator on board because the control device 19 includes the automatic driving control unit 19A. Therefore, the work vehicle 1 in the illustrated embodiment does not have a driver's seat where an operator sits. However, the work vehicle 1 may also be a vehicle that performs automatic driving with an operator on board. Alternatively, the work vehicle 1 may be a vehicle that an operator on board drives and drives. When the work vehicle 1 is a vehicle in which an operator rides, a driver's seat is provided in the vehicle body 2.

[0056] As shown in Fig. 1, the work vehicle 1 is equipped with a frame structure 20. The frame structure 20 forms the skeleton of the work vehicle 1. Fig. 8 is a perspective view showing the frame structure 20. The frame structure 20 is made up of a body frame 21 and a traveling frame 8. Fig. 9 is a perspective view showing the body frame 21. Fig. 10 is a perspective view showing the traveling frame 8. Fig. 11 is an exploded perspective view of the body frame 21.

[0057] 11 , the body frame 21 is configured by combining a central body frame 22, a left body frame 23, and a right body frame 24. The central body frame 22 has an upper body frame 25, a lower body frame 26, and a connecting frame 27.

[0058] The upper vehicle body frame 25 includes a first upper frame member 25a, a second upper frame member 25b, a first cylindrical body 25c, a second cylindrical body 25d, and a third cylindrical body 25e. The first upper frame member 25a and the second upper frame member 25b are arranged parallel to each other with a gap in the left-right direction and extend in the front-rear direction. The first cylindrical body 25c extends in the left-right direction and connects the front of the first upper frame member 25a to the front of the second upper frame member 25b. The second cylindrical body 25d extends in the left-right direction and connects the rear of the first upper frame member 25a to the rear of the second upper frame member 25b. The third cylindrical body 25e extends in the left-right direction and connects the center of the first upper frame member 25a to the center of the second upper frame member 25b.

[0059] The lower body frame 26 has a first lower frame member 26a, a second lower frame member 26b, a fourth cylindrical body 26c, and a fifth cylindrical body 26d. The first lower frame member 26a and the second lower frame member 26b are arranged parallel to each other with a gap in the left-right direction and extend in the front-rear direction. The fourth cylindrical body 26c extends in the left-right direction and connects the front portion of the first lower frame member 26a to the front portion of the second lower frame member 26b. The fifth cylindrical body 26d extends in the left-right direction and connects the rear portion of the first lower frame member 26a to the rear portion of the second lower frame member 26b.

[0060] The connecting frame 27 extends in the vertical direction and connects the upper vehicle body frame 25 and the lower vehicle body frame 26. The connecting frame 27 includes a first connecting frame member 27a, a second connecting frame member 27b, a third connecting frame member 27c, and a fourth connecting frame member 27d. The first connecting frame member 27a connects the front portion of the first upper frame member 25a to the front portion of the first lower frame member 26a. The second connecting frame member 27b connects the front portion of the second upper frame member 25b to the front portion of the second lower frame member 26b. The third connecting frame member 27c connects the rear portion of the first upper frame member 25a to the rear portion of the first lower frame member 26a. The fourth connecting frame member 27d connects the rear portion of the second upper frame member 25b to the rear portion of the second lower frame member 26b.

[0061] The length in the front-to-rear direction of the lower body frame 26 is smaller than the length in the front-to-rear direction of the upper body frame 25. The rear portion of the upper body frame 25 extends further rearward than the rear portion of the lower body frame 26. A first support body 28 is provided below the rear portion of the upper body frame 25 that extends further rearward than the rear portion of the lower body frame 26. The first support body 28 supports a hydraulic unit 100, which will be described later. The first support body 28 has a support plate 28a and the like that support the hydraulic unit 100, which will be described later.

[0062] The left body frame 23 has an upper left frame member 23a, a first vertical frame member 23b, a second vertical frame member 23c, and a third vertical frame member 23d. The upper left frame member 23a is located to the left of the first upper frame member 25a and extends in the front-to-rear direction. The first vertical frame member 23b extends downward from the front of the upper left frame member 23a. The second vertical frame member 23c extends downward from the upper left frame member 23a behind the first vertical frame member 23b. The third vertical frame member 23d extends downward from the upper left frame member 23a behind the second vertical frame member 23c.

[0063] The left vehicle body frame 23 has a first connecting member 23e, a second connecting member 23f, a third connecting member 23g, a fourth connecting member 23h, and a fifth connecting member 23i. The first connecting member 23e is connected to the front of the upper-left frame member 23a and extends to the right. The second connecting member 23f is connected to a midpoint in the fore-and-aft direction of the upper-left frame member 23a and extends to the right. The third connecting member 23g is connected to the rear of the upper-left frame member 23a and extends to the right. The fourth connecting member 23h is connected to the lower part of the first vertical frame member 23b and extends to the right. The fifth connecting member 23i is connected to the lower part of the third vertical frame member 23d and extends to the right.

[0064] The right vehicle body frame 24 has an upper right frame member 24a, a fourth vertical frame member 24b, a fifth vertical frame member 24c, and a sixth vertical frame member 24d. The upper right frame member 24a is located to the right of the second upper frame member 25b and extends in the front-to-rear direction. The fourth vertical frame member 24b extends downward from the front of the upper right frame member 24a. The fifth vertical frame member 24c extends downward from the upper right frame member 24a behind the fourth vertical frame member 24b. The sixth vertical frame member 24d extends downward from the upper right frame member 24a behind the fifth vertical frame member 24c.

[0065] The right body frame 24 has a sixth link member 24e, a seventh link member 24f, an eighth link member 24g, a ninth link member 24h, and a tenth link member 24i. The sixth link member 24e is connected to the front of the upper right frame member 24a and extends to the left. The seventh link member 24f is connected to the midpoint of the upper right frame member 24a in the fore-and-aft direction and extends to the left. The eighth link member 24g is connected to the rear of the upper right frame member 24a and extends to the left. The ninth link member 24h is connected to the lower part of the fourth vertical frame member 24b and extends to the left. The tenth link member 24i is connected to the lower part of the sixth vertical frame member 24d and extends to the left.

[0066] As shown by the arrows in Figure 11, the first connecting member 23e is inserted into the first cylindrical body 25c from the left. The second connecting member 23f is inserted into the third cylindrical body 25e from the left. The third connecting member 23g is inserted into the second cylindrical body 25d from the left. The fourth connecting member 23h is inserted into the fourth cylindrical body 26c from the left. The fifth connecting member 23i is inserted into the fifth cylindrical body 26d from the left. This connects the central body frame 22 and the left body frame 23.

[0067] The sixth connecting member 24e is inserted into the first cylindrical body 25c from the right. The seventh connecting member 24f is inserted into the third cylindrical body 25e from the right. The eighth connecting member 24g is inserted into the second cylindrical body 25d from the right. The ninth connecting member 24h is inserted into the fourth cylindrical body 26c from the right. The tenth connecting member 24i is inserted into the fifth cylindrical body 26d from the right. This connects the central body frame 22 and the right body frame 24.

[0068] The first connecting member 23e and the sixth connecting member 24e are movable in the left-right direction along the first cylindrical body 25c. The second connecting member 23f and the seventh connecting member 24f are movable in the left-right direction along the third cylindrical body 25e. The third connecting member 23g and the eighth connecting member 24g are movable in the left-right direction relative to the second cylindrical body 25d. The fourth connecting member 23h and the ninth connecting member 24h are movable in the left-right direction relative to the fourth cylindrical body 26c. The fifth connecting member 23i and the tenth connecting member 24i are movable in the left-right direction relative to the fifth cylindrical body 26d. This allows the left body frame 23 and the right body frame 24 to move in the left-right direction relative to the central body frame 22.

[0069] The left body frame 23 is connected to the left traveling frame 8L via a mast mechanism, which will be described later. Therefore, when the left body frame 23 moves left and right relative to the central body frame 22, the left traveling frame 8L can move left and right relative to the central body frame 22. This allows the left traveling unit 4L to move left and right relative to the body 2. A specific method for moving the left traveling unit 4L will be described in detail later.

[0070] The right body frame 24 is connected to the right traveling frame 8R via a mast mechanism, which will be described later. Therefore, when the right body frame 24 moves left and right relative to the central body frame 22, the right traveling frame 8R can move left and right relative to the central body frame 22. This allows the right traveling unit 4R to move left and right relative to the body 2. A specific method for moving the right traveling unit 4R will be described in detail later.

[0071] 10 , the left running frame 8L has a first upper-left frame member 8La and a second upper-left frame member 8Lb. The first upper-left frame member 8La extends in the front-to-rear direction and has a front portion 8La1, a rear portion 8La2, and a middle portion 8La3. The second upper-left frame member 8Lb has a first portion extending rearward and to the left from the front portion 8La1 of the first upper-left frame member 8La, a second portion extending leftward from the rear portion 8La2 of the first upper-left frame member 8La, and a third portion connecting the first and second portions.

[0072] The left running frame 8L includes a first left vertical frame member 8Lc, a second left vertical frame member 8Ld, a third left vertical frame member 8Le, a fourth left vertical frame member 8Lf, and a fifth left vertical frame member 8Lg. The first left vertical frame member 8Lc is connected to the front portion 8La1 of the first upper-left frame member 8La and extends downward. The second left vertical frame member 8Ld is connected to the front portion 8La1 and the middle portion 8La3 of the first upper-left frame member 8La and extends downward. The third left vertical frame member 8Le is connected to the rear portion 8La2 and the middle portion 8La3 of the first upper-left frame member 8La and extends downward. The fourth left vertical frame member 8Lf extends downward from the second upper-left frame member 8Lb to the left of the second left vertical frame member 8Ld. The fifth left vertical frame member 8Lg extends downward from the second upper left frame member 8Lb to the left of the third left vertical frame member 8Le.

[0073] The left running frame 8L has a first left connecting member 8Lh, a second left connecting member 8Li, a third left connecting member 8Lj, and a fourth left connecting member 8Lk. The first left connecting member 8Lh, the second left connecting member 8Li, the third left connecting member 8Lj, and the fourth left connecting member 8Lk are formed in an arch shape that protrudes upward. The first left connecting member 8Lh connects the front of the first upper-left frame member 8La to the front of the second upper-left frame member 8Lb. The second left connecting member 8Li connects the first upper-left frame member 8La to the second upper-left frame member 8Lb behind the first left connecting member 8Lh. The third left connecting member 8Lj connects the first upper-left frame member 8La to the second upper-left frame member 8Lb behind the second left connecting member 8Li. The fourth left connecting member 8Lk connects the first upper left frame member 8La and the second upper left frame member 8Lb behind the third left connecting member 8Lj.

[0074] The left portion of the first left connecting member 8Lh and the left portion of the second left connecting member 8Li are connected by a first anterior connecting member 8Lm. The left portion of the second left connecting member 8Li and the left portion of the third left connecting member 8Lj are connected by a first intermediate connecting member 8Ln. The right portion of the second left connecting member 8Li and the right portion of the third left connecting member 8Lj are connected by a second intermediate connecting member 8Lo. The left portion of the third left connecting member 8Lj and the left portion of the fourth left connecting member 8Lk are connected by a first posterior connecting member 8Lp.

[0075] The left running frame 8L has a second support body 29. The second support body 29 supports a second battery 12B (described later). The second support body 29 has the four left vertical frame members (the second left vertical frame member 8Ld, the third left vertical frame member 8Le, the fourth left vertical frame member 8Lf, and the fifth left vertical frame member 8Lg) described above, as well as a first lower left frame member 29a, a second lower left frame member 29b, a third lower left frame member 29c, and a fourth lower left frame member 29d.

[0076] The first lower left frame member 29a connects the second left vertical frame member 8Ld and the fourth left vertical frame member 8Lf. The second lower left frame member 29b connects the third left vertical frame member 8Le and the fifth left vertical frame member 8Lg. The third lower left frame member 29c connects the second left vertical frame member 8Ld and the third left vertical frame member 8Le. The fourth lower left frame member 29d connects the fourth left vertical frame member 8Lf and the fifth left vertical frame member 8Lg.

[0077] 10 , the right-traveling frame 8R has a first upper right frame member 8Ra and a second upper right frame member 8Rb. The first upper right frame member 8Ra extends in the front-to-rear direction and has a front portion 8Ra1, a rear portion 8Ra2, and a middle portion 8Ra3. The second upper right frame member 8Rb has a first portion extending rearward and to the right from the front portion 8Ra1 of the first upper right frame member 8Ra, a second portion extending rightward from the rear portion 8Ra2 of the first upper right frame member 8Ra, and a third portion connecting the first and second portions.

[0078] The right running frame 8R includes a first right vertical frame member 8Rc, a second right vertical frame member 8Rd, a third right vertical frame member 8Re, a fourth right vertical frame member 8Rf, and a fifth right vertical frame member 8Rg. The first right vertical frame member 8Rc is connected to the front portion 8Ra1 of the first right upper frame member 8Ra and extends downward. The second right vertical frame member 8Rd is connected to the front portion 8Ra1 and the middle portion 8Ra3 of the first right upper frame member 8Ra and extends downward. The third right vertical frame member 8Re is connected to the rear portion 8Ra2 and the middle portion 8Ra3 of the first right upper frame member 8Ra and extends downward. The fourth right vertical frame member 8Rf extends downward from the second right upper frame member 8Rb to the right of the second right vertical frame member 8Rd. The fifth right vertical frame member 8Rg extends downward from the second right upper frame member 8Rb to the right of the third right vertical frame member 8Re.

[0079] The right running frame 8R includes a first right connecting member 8Rh, a second right connecting member 8Ri, a third right connecting member 8Rj, and a fourth right connecting member 8Rk. The first right connecting member 8Rh, the second right connecting member 8Ri, the third right connecting member 8Rj, and the fourth right connecting member 8Rk are formed in an arch shape that protrudes upward. The first right connecting member 8Rh connects the front portion of the first right upper frame member 8Ra to the front portion of the second right upper frame member 8Rb. The second right connecting member 8Ri connects the first right upper frame member 8Ra to the second right upper frame member 8Rb behind the first right connecting member 8Rh. The third right connecting member 8Rj connects the first right upper frame member 8Ra to the second right upper frame member 8Rb behind the second right connecting member 8Ri. The fourth right connecting member 8Rk connects the first upper right frame member 8Ra and the second upper right frame member 8Rb behind the third right connecting member 8Rj.

[0080] The right portion of the first right connecting member 8Rh is connected to the right portion of the second right connecting member 8Ri by a first anterior connecting member 8Rm. The right portion of the second right connecting member 8Ri is connected to the right portion of the third right connecting member 8Rj by a first intermediate connecting member 8Rn. The left portion of the second right connecting member 8Ri is connected to the left portion of the third right connecting member 8Rj by a second intermediate connecting member 8Ro. The right portion of the third right connecting member 8Rj is connected to the right portion of the fourth right connecting member 8Rk by a first posterior connecting member 8Rp.

[0081] The right running frame 8R has a third support body 30. The third support body 30 supports a second battery 12B (described later). The third support body 30 has the four right vertical frame members (the second right vertical frame member 8Rd, the third right vertical frame member 8Re, the fourth right vertical frame member 8Rf, and the fifth right vertical frame member 8Rg) described above, as well as a first lower right frame member 30a, a second lower right frame member 30b, a third lower right frame member 30c, and a fourth lower right frame member 30d.

[0082] The first lower right frame member 30a connects the second right vertical frame member 8Rd and the fourth right vertical frame member 8Rf. The second lower right frame member 30b connects the third right vertical frame member 8Re and the fifth right vertical frame member 8Rg. The third lower right frame member 30c connects the second right vertical frame member 8Rd and the third right vertical frame member 8Re. The fourth lower right frame member 30d connects the fourth right vertical frame member 8Rf and the fifth right vertical frame member 8Rg.

[0083] The frame structure 20 includes a mast mechanism that supports the traveling frames (left traveling frame 8L, right traveling frame 8R) so that they can move up and down relative to the body frame 21. As shown in Figures 9, 10, 11, and 12, the mast mechanism includes a first member 31 attached to the traveling frames (left traveling frame 8L, right traveling frame 8R) and a second member 32 attached to the body frame 21. Note that in the drawings, the first member 31 is also shown in Figures 9 and 11, which are diagrams of the body frame 21, to show the positional relationship between the first member 31 and the second member 32.

[0084] The first member 31 and the second member 32 extend in the vertical direction. The second member 32 is connected to the first member 31 so as to be movable in the vertical direction. The second member 32 moves in the vertical direction along the first member 31, thereby allowing the body frame 21 to move in the vertical direction relative to the traveling frames (left traveling frame 8L, right traveling frame 8R).

[0085] 10, the first members 31 are attached to the left running frame 8L and the right running frame 8R. In the left running frame 8L, the first members 31 are attached to the first left vertical frame member 8Lc, the second left vertical frame member 8Ld, and the third left vertical frame member 8Le. In the right running frame 8R, the first members 31 are attached to the first right vertical frame member 8Rc, the second right vertical frame member 8Rd, and the third right vertical frame member 8Re.

[0086] 9 and 11, the second members 32 are attached to each of the left and right vehicle body frames 23, 24. In the left vehicle body frame 23, the second members 32 are attached to each of the first vertical frame member 23b, the second vertical frame member 23c, and the third vertical frame member 23d. In the right vehicle body frame 24, the second members 32 are attached to each of the fourth vertical frame member 24b, the fifth vertical frame member 24c, and the sixth vertical frame member 24d.

[0087] The first member 31 attached to the left traveling frame 8L is disposed opposite to and connected to the second member 32 attached to the left body frame 23 so as to be movable up and down. The first member 31 attached to the right traveling frame 8R is disposed opposite to and connected to the second member 32 attached to the right body frame 24 so as to be movable up and down.

[0088] The left body frame 23 moves up and down relative to the left running frame 8L, allowing the body 2 to move up and down relative to the left running section 4L. The right body frame 24 moves up and down relative to the right running frame 8R, allowing the body 2 to move up and down relative to the right running section 4R.

[0089] The configuration of the mast mechanism is not limited to the above-described configuration. For example, the mast mechanism may include a third member in addition to the first member 31 and the second member 32. In this case, the third member is disposed between the first member 31 and the second member 32. The third member is connected to the first member 31 so as to be movable in the up and down direction, and the second member 32 is connected to the third member so as to be movable in the up and down direction.

[0090] As shown in FIG. 7 , the work vehicle 1 is equipped with a drive unit 40 for driving the wheels (left front wheel 7LF, right front wheel 7RF, left rear wheel 7LB, and right rear wheel 7RB). The drive unit 40 includes a drive device 45 that generates power, a transmission mechanism 50 that transmits the power generated by the drive device 45 to the wheels, and a steering mechanism 60 that changes the direction of the wheels. In the present embodiment, the steering mechanism 60 is a mechanism that changes the direction of the front wheels (left front wheel 7LF, right front wheel 7RF) and the rear wheels (left rear wheel 7LB, right rear wheel 7RB). More specifically, the steering mechanism 60 is a mechanism that independently changes the direction of the left front wheel 7LF, right front wheel 7RF, left rear wheel 7LB, and right rear wheel 7RB. However, the steering mechanism 60 may be a mechanism that changes the direction of only the front wheels or only the rear wheels.

[0091] 2 and 3 , the drive unit 40 includes a first drive unit 41 for driving the left front wheel 7LF, a second drive unit 42 for driving the right front wheel 7RF, a third drive unit 43 for driving the left rear wheel 7LB, and a fourth drive unit 44 for driving the right rear wheel 7RB. The first drive unit 41, the second drive unit 42, the third drive unit 43, and the fourth drive unit 44 each have a drive device 45 and a transmission mechanism 50, which will be described later. The first drive unit 41 and the second drive unit 42 each have a steering mechanism 60, which will be described later. Each drive unit is attached to the frame structure 20.

[0092] In this embodiment, the drive device 45 is a motor. More specifically, the drive device 45 is the traveling motor 10 described above. In other words, the motor that constitutes the drive device 45 is the same as the motor included in the power unit 9 described above. As will be described below, the motors 10 that constitute the drive device 45 of the drive unit 40 include a motor 10LF, a motor 10RF, a motor 10LB, and a motor 10RB.

[0093] 2, the first drive unit 41 includes a motor 10LF and a transmission mechanism 50LF that transmits the power of the motor 10LF to the left front wheel 7LF. The transmission mechanism 50LF is composed of a gear mechanism including multiple gears. When the first drive unit 41 drives the motor 10LF, the power of the motor 10LF is transmitted to the left front wheel 7LF via the transmission mechanism 50LF.

[0094] 3, the second drive unit 42 includes a motor 10RF and a transmission mechanism 50RF that transmits the power of the motor 10RF to the right front wheel 7RF. The transmission mechanism 50RF is composed of a gear mechanism including multiple gears. When the second drive unit 42 drives the motor 10RF, the power of the motor 10RF is transmitted to the right front wheel 7RF via the transmission mechanism 50RF.

[0095] 2, the third drive unit 43 includes a motor 10LB and a transmission mechanism 50LB that transmits the power of the motor 10LB to the left rear wheel 7LB. The transmission mechanism 50LB is composed of a gear mechanism including multiple gears. When the third drive unit 43 drives the motor 10LB, the power of the motor 10LB is transmitted to the left rear wheel 7LB via the transmission mechanism 50LB.

[0096] 3, the fourth drive unit 44 includes a motor 10RB and a transmission mechanism 50RB that transmits the power of the motor 10RB to the right rear wheel 7RB. The transmission mechanism 50RB is composed of a gear mechanism including multiple gears. When the fourth drive unit 44 drives the motor 10RB, the power of the motor 10RB is transmitted to the right rear wheel 7RB via the transmission mechanism 50RB.

[0097] As shown in Fig. 7, the drive unit 40 has a steering mechanism 60 that changes the direction of the wheels. As shown in Fig. 2 and Fig. 3, the steering mechanism 60 includes a left steering mechanism 60L that changes the direction of the left front wheel 7LF and the left rear wheel 7LB, and a right steering mechanism 60R that changes the direction of the right front wheel 7RF and the right rear wheel 7RB.

[0098] As shown in FIG. 2 , the first drive unit 41 and the third drive unit 43 each include a left steering mechanism 60L. The left steering mechanism 60L includes steering cylinders 62LF and 62LB. The steering cylinder 62LF is a cylinder for steering the left front wheel 7LF. The steering cylinder 62LB is a cylinder for steering the left rear wheel 7LB. The rod 62a of the steering cylinder 62LF is connected to a connector 63A that is connected to the left front wheel 7LF and rotatable about an axis AX1. The rod 62a of the steering cylinder 62LB is connected to a connector 63B that is connected to the left rear wheel 7LB and rotatable about an axis AX2. The left steering mechanism 60L can rotate the left front wheel 7LF about the axis AX1 by driving the steering cylinder 62LF to extend or retract the rod 62a. The left steering mechanism 60L can rotate the left rear wheel 7LB about the axis AX2 by driving the steering cylinder 62LB to extend and retract the rod 62a.

[0099] As shown in FIG. 3 , the second drive unit 42 and the fourth drive unit 44 each include a right steering mechanism 60R. The right steering mechanism 60R includes steering cylinders 62RF and 62RB. The steering cylinder 62RF is a cylinder for steering the right front wheel 7RF. The steering cylinder 62RB is a cylinder for steering the right rear wheel 7RB. The rod 62a of the steering cylinder 62RF is connected to a connector 63C that is connected to the right front wheel 7RF and rotatable about an axis AX3. The rod 62a of the steering cylinder 62RB is connected to a connector 63D that is connected to the right rear wheel 7RB and rotatable about an axis AX4. The right steering mechanism 60R can rotate the right front wheel 7RF about the axis AX3 by driving the steering cylinder 62RF to extend or retract the rod 62a. The right steering mechanism 60R can rotate the right rear wheel 7RB about the axis AX4 by driving the steering cylinder 62RB to extend and retract the rod 62a.

[0100] In the following description, the steering cylinders 62LF, 62LB, 62RF, 62RB will be collectively referred to as the "steering cylinders 62." The work vehicle 1 can change its direction of travel by driving the steering cylinders 62 of the steering mechanism 60 to change the orientation of the left front wheel 7LF and / or the right front wheel 7RF.

[0101] As shown in Figures 2, 3, and 6, the steering cylinder 62 is fixed to the traveling frame 8, which is the structure 3 described above. Specifically, the steering cylinder 62LF is fixed to the front of the left traveling frame 8L. The steering cylinder 62LB is fixed to the rear of the left traveling frame 8L. The steering cylinder 62RF is fixed to the front of the right traveling frame 8R. The steering cylinder 62RF is fixed to the rear of the right traveling frame 8R. Note that the steering cylinder 62 is omitted in some figures (Figure 1, etc.).

[0102] The left traveling section 4L includes a first drive unit 41 and a third drive unit 43. Therefore, the left traveling section 4L includes a motor 10LF and a transmission mechanism 50LF, a motor 10LB and a transmission mechanism 50LB, and a left steering mechanism 60L. The right traveling section 4R includes a second drive unit 42 and a fourth drive unit 44. Therefore, the right traveling section 4R includes a motor 10RF and a transmission mechanism 50RF, a motor 10RB and a transmission mechanism 50RB, and a right steering mechanism 60R.

[0103] In another embodiment of the drive unit 45, the motor of the drive unit 45 may be an in-wheel motor. In this case, all of the left front wheel 7LF, the right front wheel 7RF, the left rear wheel 7LB, and the right rear wheel 7RB may be driven by the in-wheel motor, or only some of the wheels (for example, the left front wheel 7LF and the right front wheel 7RF, or the left rear wheel 7LB and the right rear wheel 7RB) may be driven by the in-wheel motor.

[0104] The drive unit 40 is equipped with brake cylinders (not shown) for stopping the drive of the wheels 7. The brake cylinders are hydraulic actuators that operate using hydraulic pressure. Operation of the brake cylinders moves brake pads to stop the rotation of the wheels. The brake cylinders may stop both the front wheels (left front wheel 7LF, right front wheel 7RF) and the rear wheels (left rear wheel 7LB, right rear wheel 7RB), only the front wheels, or only the rear wheels. The operation of the brake cylinders can be controlled by the control device 19.

[0105] As shown in Fig. 7, the work vehicle 1 is equipped with a distance change mechanism 80. The distance change mechanism 80 changes the distance between the left traveling section 4L and the right traveling section 4R. As shown in Fig. 6, the distance change mechanism 80 includes a left change mechanism 80L that changes the left-right position of the left traveling section 4L, and a right change mechanism 80R that changes the left-right position of the right traveling section 4R.

[0106] As shown in FIG. 6 , the left changing mechanism 80L has a left cylinder 81L that moves the left running unit 4L left or right. The left cylinder 81L moves the left running frame 8L left or right. The left front wheel 7LF and the left rear wheel 7LB are supported by the left running frame 8L. As a result, the left cylinder 81L moves the left running frame 8L left or right, thereby moving the left front wheel 7LF and the left rear wheel 7LB together left or right.

[0107] As shown in FIG. 6 , the right change mechanism 80R has a right cylinder 81R that moves the right running unit 4R left or right. The right cylinder 81R moves the right running frame 8R left or right. The right front wheel 7RF and the right rear wheel 7RB are supported by the right running frame 8R. As a result, the right cylinder 81R moves the right running frame 8R left or right, thereby moving the right front wheel 7RF and the right rear wheel 7RB together left or right.

[0108] The right cylinder 81R and the left cylinder 81L are composed of hydraulic cylinders, which are hydraulic actuators that operate using hydraulic pressure. Hereinafter, the right cylinder 81R and the left cylinder 81L may be collectively referred to as the "distance changing cylinders 81." The hydraulic cylinders (distance changing cylinders 81) that make up the right cylinder 81R and the left cylinder 81L operate (extend and retract) using hydraulic oil supplied from a hydraulic pump driven by the above-mentioned working motor 11.

[0109] The configurations of the left changing mechanism 80L and the right changing mechanism 80R will be described in more detail below. As shown in Figure 9, the left cylinder 81L has a cylinder tube 81La attached to the central body frame 22 and a rod 81Lb that protrudes from the cylinder tube 81La and extends leftward. The tip of the rod 81Lb of the left cylinder 81L is connected to the left body frame 23. The right cylinder 81R has a cylinder tube 81Ra attached to the central body frame 22 and a rod 81Rb that protrudes from the cylinder tube 81Ra and extends rightward. The tip of the rod 81Rb of the right cylinder 81R is connected to the right body frame 24.

[0110] As shown by arrow L1 in Fig. 12, when the rod 81Lb of the left cylinder 81L extends to the left, the left body frame 23 moves to the left. When the rod 81Lb of the left cylinder 81L contracts to the right, the left body frame 23 moves to the right. As shown by arrow R1 in Fig. 12, when the rod 81Rb of the right cylinder 81R extends to the right, the right body frame 24 moves to the right. When the rod 81Rb of the right cylinder 81R contracts to the left, the right body frame 24 moves to the left.

[0111] In this way, the left body frame 23 moves left and right relative to the central body frame 22 by operation (extension and contraction) of the left cylinder 81L. In other words, the left and right position of the left body frame 23 can be changed. Also, the right body frame 24 moves left and right relative to the central body frame 22 by operation (extension and contraction) of the right cylinder 81R. In other words, the left and right position of the right body frame 24 can be changed.

[0112] As described above, the left body frame 23 is connected to the left traveling frame 8L via a mast mechanism. Similarly, the right body frame 24 is connected to the right traveling frame 8R via a mast mechanism. Therefore, when the left body frame 23 moves left or right relative to the central body frame 22, the left traveling frame 8L moves left or right relative to the central body frame 22. Similarly, when the right body frame 24 moves left or right relative to the central body frame 22, the right traveling frame 8R moves left or right relative to the central body frame 22.

[0113] In this way, by moving the left traveling frame 8L and the right traveling frame 8R in the left-right direction relative to the central body frame 22, the left and right positions of the left traveling section 4L and the right traveling section 4R can be changed. Therefore, the distance between the left traveling section 4L and the right traveling section 4R can be changed. In addition, the distance between the left traveling section 4L and the body 2 and the distance between the right traveling section 4R and the body 2 can also be changed. These distances can be changed by operating one or both of the left cylinder 81L and the right cylinder 81R.

[0114] FIG. 6 shows a state in which the rods of the left cylinder 81L and the right cylinder 81R are retracted. In this state, the distance between the left running section 4L and the right running section 4R is short. The distances between the left running section 4L and the vehicle body 2 and between the right running section 4R and the vehicle body 2 are also short. By extending the rod 81Lb of the left cylinder 81L and the rod 81Rb of the right cylinder 81R from this state (see arrows L1 and R1 in FIG. 13 ), the left running section 4L and the right running section 4R move in opposite directions. This increases the distance between the left running section 4L and the right running section 4R, as shown in FIG. 13 . The distances between the left running section 4L and the vehicle body 2 and between the right running section 4R and the vehicle body 2 can also be increased.

[0115] The operation of the distance change mechanism 80 is controlled by the control device 19. Specifically, the operation of the left cylinder 81L and the right cylinder 81R of the distance change mechanism 80 is controlled by the control device 19. As shown in FIG. 7 , the control device 19 includes a distance change control unit 19B. The distance change operation by the distance change mechanism 80 is performed by the distance change control unit 19B controlling the distance change mechanism 80. The distance change mechanism 80 changes the left / right position of the left running unit 4L and / or the right running unit 4R, for example, based on the detection result by the tilt detection device 170, which will be described later.

[0116] The distance change mechanism 80 can individually operate the left change mechanism 80L and the right change mechanism 80R. That is, the distance change mechanism 80 can operate only the left change mechanism 80L, only the right change mechanism 80R, or both the left change mechanism 80L and the right change mechanism 80R. The distance change mechanism 80 can individually operate the left change mechanism 80L and the right change mechanism 80R based on the detection results of the tilt detection device 170, which will be described later.

[0117] As shown in Figure 7, the work vehicle 1 is equipped with a height change mechanism 90. The height change mechanism 90 is capable of changing the vertical position of the vehicle body 2 relative to the traveling section 4. By changing the vertical position of the vehicle body 2 relative to the traveling section 4, the height of the vehicle body 2 from the ground can be changed. The height change mechanism 90 raises and lowers the vehicle body 2 at a position between the left traveling section 4L and the right traveling section 4R in the width direction (left-right direction) of the vehicle body 2.

[0118] As shown in Figures 5, 8, etc., the height change mechanism 90 has a lifting cylinder 91. The lifting cylinder 91 raises and lowers the body frame 21 relative to the traveling frame 8. As the body frame 21 rises and lowers, the body 2 including the body frame 21 and the main body case 5 rises and lowers. Therefore, by driving the lifting cylinder 91, the body 2 can be raised and lowered relative to the traveling frame 8. In this way, the height change mechanism 90 is a mechanism that can raise and lower the body 2 (body frame 21) relative to the traveling frame 8. In the following description, the height change mechanism 90 may be referred to as the "lifting mechanism 90."

[0119] The lift cylinders 91 include a left lift cylinder 91L and a right lift cylinder 91R. The left lift cylinder 91L is disposed on the left side of the vehicle body 2. The right lift cylinder 91R is disposed on the right side of the vehicle body 2. The lift cylinders 91 are composed of hydraulic cylinders, which are hydraulic actuators operated by hydraulic pressure. The lift cylinders 91 have a rod 91a that extends and retracts in the vertical direction, and a cylinder tube 91b to which hydraulic oil is supplied to drive the rod 91a. The rod 91a extends downward from the cylinder tube 91b.

[0120] 8 and 9, the cylinder tube 91Lb of the left lift cylinder 91L is attached to a left bracket 51L fixed to the upper part (upper-left frame member 23a) of the left body frame 23. The cylinder tube 91Rb of the right lift cylinder 91R is attached to a bracket 51R fixed to the upper part (upper-left frame member 24a) of the right body frame 24.

[0121] As shown in Figures 8 and 10, the left traveling frame 8L is provided with a left connector 52L to which the rod of the left lifting cylinder 91L is connected. The left connector 52L is fixed to the lower part of the left traveling frame 8L (the third left lower frame member 29c). The rod of the left lifting cylinder 91L is connected to the left connector 52L. This allows the left body frame 23 to be raised and lowered relative to the left traveling frame 8L by extending and retracting the rod of the left lifting cylinder 91L.

[0122] As shown in Figures 8 and 10, the right traveling frame 8R is provided with a right connector 52R to which the rod of the right lift cylinder 91R is connected. The right connector 52R is fixed to the lower part of the right traveling frame 8R (the third lower right frame member 30c). The rod of the right lift cylinder 91R is connected to the right connector 52R. This allows the right body frame 24 to be raised and lowered relative to the right traveling frame 8R by extending and retracting the rod of the right lift cylinder 91R.

[0123] When the rod of the left lift cylinder 91L extends and retracts, the left body frame 23 rises and falls. When the rod of the right lift cylinder 91R extends and retracts, the right body frame 24 rises and falls. This allows the body frame 21 to be raised and lowered in accordance with the extension and contraction of the rods of the lift cylinders 91 (left lift cylinder 91L, right lift cylinder 91R). Figure 14 shows the body frame 21 in a lowered state, and Figure 15 shows the body frame 21 in a raised state.

[0124] Because the body case 5 (see FIGS. 1, 4, etc.) is supported on the body frame 21, the body 2 including the body frame 21 and the body case 5 can be raised and lowered as the rod of the lifting cylinder 91 extends and retracts. Because the battery 12 (a first battery 12A, described below) is housed in the body case 5, the battery 12 also rises and lowers as the body 2 rises and lowers. FIG. 16 schematically shows the body 2 in a lowered state, and FIG. 17 schematically shows the body 2 in a raised state. As shown in FIGS. 16 and 17 , the vertical position of the body 2 (and the battery 12) relative to the traveling unit 4 can be changed as the rod 91 a of the lifting cylinder 91 extends and retracts. FIGS. 18 to 22 show the work vehicle 1 in a state in which the rod 91 a of the lifting cylinder 91 is extended to raise the body 2.

[0125] The operation of the height change mechanism 90 is controlled by the control device 19. Specifically, the operation of the lifting cylinder 91 of the height change mechanism 90 is controlled by a height change control unit 19C. As shown in FIG. 7 , the control device 19 includes the height change control unit 19C. The height change control unit 19C transmits a control signal to the height change mechanism 90 by causing a calculation unit of the control device 19 to execute a program stored in a memory unit. The height change mechanism 90 is driven based on the control signal transmitted from the height change control unit 19C. In other words, the height change mechanism 90 changes the up-down position of the vehicle body 2 by being driven based on the control of the control device 19.

[0126] As shown in Fig. 7 , the work vehicle 1 is equipped with a position change mechanism 70. The position change mechanism 70 is capable of changing the position of the vehicle body 2 in the fore-and-aft direction relative to the traveling section 4. Fig. 23 is a schematic plan view showing an example of a work vehicle 1 equipped with the position change mechanism 70. The position change mechanism 70 shown in Fig. 23 has a guide rail 71 attached to the traveling frame 8 and extending in the fore-and-aft direction, and a slide member 72 attached to the vehicle body frame 21 and extending in the fore-and-aft direction. The slide member 72 is movable in the fore-and-aft direction along the guide rail 71.

[0127] The guide rails 71 are attached to the right side of the left traveling frame 8L and the left side of the right traveling frame 8R. The slide members 72 are attached to the left and right sides of the body frame 21. This allows the body frame 21 to move in the front-to-rear direction relative to the traveling frames 8 (left traveling frame 8L, right traveling frame 8R).

[0128] The position changing mechanism 70 is equipped with a position changing cylinder 73 that moves the vehicle body 2 in the longitudinal direction. The position changing cylinder 73 is composed of a hydraulic cylinder, which is a hydraulic actuator that operates by hydraulic pressure. The position changing cylinder 73 has a cylinder tube 73a attached to the traveling frame 8 and a rod 73b attached to the vehicle body frame 21. The cylinder tube 73a is attached to the traveling frame 8 via a first attachment member 74a. The tip of the rod 73b is attached to the vehicle body frame 21 via a second attachment member 74b.

[0129] By extending and retracting the rod 73b of the position changing cylinder 73, the body frame 21 can be moved in the front-to-rear direction relative to the running frame 8. This allows the body 2 to be moved in the front-to-rear direction relative to the running unit 4. The left part of Fig. 23 shows a state in which the body 2 is not moving in the front-to-rear direction relative to the running unit 4. The upper right part of Fig. 23 shows a state in which the body 2 is moving forward relative to the running unit 4 due to the extension of the rod 73b of the position changing cylinder 73. The lower right part of Fig. 23 shows a state in which the body 2 is moving backward relative to the running unit 4 due to the contraction of the rod 73b of the position changing cylinder 73.

[0130] 24 shows a modified example of the position change mechanism 70. The modified position change mechanism 70 is capable of changing the position of a portion of the vehicle body 2 in the front-to-rear direction. Specifically, the modified position change mechanism 70 is capable of changing the position of the main body case 5 of the vehicle body 2 in the front-to-rear direction. Specifically, the modified position change mechanism 70 is capable of changing the position of the main body case 5 relative to the vehicle body frame 21.

[0131] The position change mechanism 70 of the modified example has guide rails 71 attached to the upper part of the lower body frame 26 (first lower frame member 26a, second lower frame member 26b) (see FIGS. 9 and 11) and extending in the front-to-rear direction, and a slide member 72 attached to the lower part of the main body case 5 and extending in the front-to-rear direction. The slide member 72 is movable in the front-to-rear direction along the guide rails 71. This allows the main body case 5 to move in the front-to-rear direction relative to the lower body frame 26.

[0132] The position changing mechanism 70 of the modified example includes a position changing cylinder 73 that moves the main body case 5 in the front-to-rear direction. The position changing cylinder 73 is composed of a hydraulic cylinder, which is a hydraulic actuator that operates by hydraulic pressure. The position changing cylinder 73 has a cylinder tube 73a attached to the body frame 21 and a rod 73b attached to the main body case 5. The cylinder tube 73a is attached to the body frame 21 via a first attachment member 74a. The tip of the rod 73b is attached to the main body case 5 via a second attachment member 74b.

[0133] By extending and retracting the rod 73b of the position changing cylinder 73, the main body case 5 can be moved in the front-to-rear direction relative to the body frame 21. The left part of Fig. 24 shows a state in which the main body case 5 has not moved in the front-to-rear direction relative to the body frame 21. The upper right part of Fig. 24 shows a state in which the main body case 5 has moved forward relative to the body frame 21. The lower right part of Fig. 24 shows a state in which the main body case 5 has moved rearward relative to the body frame 21.

[0134] As described above, the battery 12 (first battery 12A) is housed in the main body case 5. Therefore, by moving the main body case 5 in the fore-and-aft direction relative to the lower body frame 26, the battery 12 (first battery 12A) can be moved in the fore-and-aft direction relative to the lower body frame 26. This allows the fore-and-aft position of the battery 12 (first battery 12A) relative to the traveling unit 4 to be changed.

[0135] The operation of the position change mechanism 70 is controlled by a position change control unit 19D of the control device 19. For example, when a situation arises in which the position of the center of gravity of the work vehicle 1 needs to be moved in the fore-and-aft direction while the work vehicle 1 is traveling (for example, when the wheels get stuck in mud or mire), the position change control unit 19D drives the position change mechanism 70 to change the fore-and-aft position of the vehicle body 2 or a part of the vehicle body 2 (main body case 5), thereby moving the position of the center of gravity of the work vehicle 1 in the fore-and-aft direction.

[0136] As shown in Figures 1, 5, 6, 7, etc., the work vehicle 1 is equipped with a hydraulic unit 100. As shown in Figure 25, the hydraulic unit 100 includes a hydraulic valve 101 that controls the flow of hydraulic oil. The hydraulic valve 101 controls the operation of hydraulic equipment mounted on the vehicle body 2 or the traveling frame 8 by controlling the flow of hydraulic oil. In addition to the hydraulic valve 101, the hydraulic unit 100 includes a hydraulic oil tank 102 that stores hydraulic oil to be supplied to the hydraulic equipment, and a hydraulic pump 103 that is driven by the hydraulic oil.

[0137] The hydraulic oil tank 102 is disposed above the hydraulic pump 103. The hydraulic oil tank 102 is disposed above the work-system motor 11 that drives the hydraulic pump 103. The hydraulic pump 103 and the work-system motor 11 are disposed side by side in the left-right direction. The hydraulic oil tank 102 is formed in an L-shape when viewed from the front. In other words, the hydraulic oil tank 102 is formed in a rectangular shape with the upper corners cut out when viewed from the front. The hydraulic valve 101 is disposed in the cut-out portion of the hydraulic oil tank 102 (upper right portion).

[0138] 1 , 5 , 6 , etc., the hydraulic unit 100 is disposed at the rear of the vehicle body 2. Therefore, the hydraulic valve 101, hydraulic pump 103, and hydraulic oil tank 102 included in the hydraulic unit 100 are disposed in a concentrated manner at the rear of the vehicle body 2. More specifically, the hydraulic unit 100 is disposed behind the main body case 5 of the vehicle body 2. Therefore, the hydraulic valve 101, hydraulic pump 103, and hydraulic oil tank 102 are disposed behind the main body case 5.

[0139] In this way, by concentrating the hydraulic valve 101, hydraulic pump 103, and hydraulic oil tank 102 at the rear of the vehicle body 2, oil leak checks and the like can be performed all at once during daily inspections of the hydraulic valve 101, hydraulic pump 103, and hydraulic oil tank 102, improving maintainability.

[0140] In this embodiment, the hydraulic equipment mounted on the vehicle body 2 or the traveling frame 8 is a hydraulic actuator that operates by hydraulic pressure. The hydraulic actuator is mounted on either the vehicle body 2 or the structure 3 that can be connected to the vehicle body 2 (in this embodiment, the traveling frame 8). In this embodiment, the work vehicle 1 is equipped with a steering cylinder 62, a lifting cylinder 91, a distance changing cylinder 81, a position changing cylinder 73, and a brake cylinder 46 as hydraulic actuators (see FIG. 26 ). That is, in this embodiment, the hydraulic actuators are hydraulic cylinders that operate by hydraulic pressure.

[0141] The steering cylinder 62 is provided on the traveling frame 8. The distance changing cylinder 81 is provided on the body frame 21. The lifting cylinder 91 and the position changing cylinder 73 connect the body frame 21 and the traveling frame 8. The brake cylinder 46 is provided on the traveling frame 8. In other words, of the hydraulic actuators, the steering cylinder 62 and the brake cylinder 46 are provided on the traveling frame 8, which is the structure 3 connectable to the body 2.

[0142] The work vehicle 1 is mounted on a vehicle body 2 or structure (traveling frame 8) that is not provided with a hydraulic actuator, and is equipped with hydraulic equipment separate from the hydraulic actuator. In this embodiment, the separate hydraulic equipment is a hydraulic valve 101 (see FIGS. 25 and 26 ) that controls the operation of the hydraulic actuator. In this embodiment, the hydraulic valve 101 is mounted on the vehicle body 2, but it may also be mounted on the structure (traveling frame 8).

[0143] The hydraulic valve 101 controls the flow of hydraulic oil supplied to hydraulic actuators and the like. As shown in FIG. 26 , the hydraulic valve 101 includes a plurality of valves (a first valve 101A, a second valve 101B, a third valve 101C, a fourth valve 101D, and a fifth valve 101E) that control the flow of hydraulic oil. The hydraulic valve 101 is configured, for example, by an electromagnetic valve. The operation of the hydraulic valve 101 is controlled by a control device 19. The plurality of valves that make up the hydraulic valve 101 are each connected to a hydraulic actuator and the like via hydraulic hoses. The control device 19 controls the operation of each of the plurality of hydraulic valves 101, thereby driving each of the plurality of hydraulic actuators.

[0144] As shown in Figure 26, the first valve 101A is connected to the steering cylinders 62 (62LF, 62LB, 62RF, 62RB) via a first hydraulic hose 105. The second valve 101B is connected to the lift cylinders 91 (left lift cylinder 91L, right lift cylinder 91R) via a second hydraulic hose 106. The third valve 101C is connected to the distance changing cylinders 81 (left cylinder 81L, right cylinder 81R) via a third hydraulic hose 107. The fourth valve 101D is connected to the position changing cylinder 73 via a fourth hydraulic hose 108. The fifth valve 101E is connected to the brake cylinder 46 via a fifth hydraulic hose 109.

[0145] The hydraulic valve 101 is connected to the hydraulic oil tank 102 via a sixth hydraulic hose 110. The hydraulic valve 101 is connected to the hydraulic pump 103 via a seventh hydraulic hose 111. The hydraulic pump 103 is connected to the hydraulic oil tank 102 via an eighth hydraulic hose 112. The hydraulic pump 103 is connected to the work system motor 11 and is driven by the work system motor 11.

[0146] The hydraulic valve 101 operates (opens and closes the flow path through which the hydraulic oil flows) based on a control signal sent from the control device 19, thereby controlling the flow of hydraulic oil supplied to the steering cylinder 62, the lifting cylinder 91, the distance changing cylinder 81, the position changing cylinder 73, and the brake cylinder 46. In this way, the operations of the steering cylinder 62, the lifting cylinder 91, the distance changing cylinder 81, the position changing cylinder 73, and the brake cylinder 46 are controlled.

[0147] As shown in Figures 5 and 6, the hydraulic unit 100 is disposed between the left traveling frame 8L and the right traveling frame 8R. The hydraulic unit 100 and the battery 12 (first battery 12A) are disposed side by side in the front-to-rear direction between the left traveling frame 8L and the right traveling frame 8R. The hydraulic unit 100 is disposed rearward of the battery 12 (first battery 12A). As shown in Figure 27, the hydraulic unit 100 is disposed so as not to protrude from the body frame (center frame) 21 at least in the left-to-right direction. Specifically, the hydraulic unit 100 is located between the left end of the left body frame 23 and the right end of the right body frame 24. More specifically, the hydraulic unit 100 is located between the left end and the right end of the central body frame 22.

[0148] The work vehicle 1 is equipped with a movement mechanism that moves either the vehicle body 2 or the structure 3, on which the above-mentioned separate hydraulic equipment is mounted, in the up and down direction together with the separate hydraulic equipment. In the present embodiment, the separate hydraulic equipment is a hydraulic valve 101, and the hydraulic valve 101, which is separate hydraulic equipment, is mounted on the vehicle body 2. However, the hydraulic valve 101, which is separate hydraulic equipment, may also be mounted on the structure 3. When the separate hydraulic equipment (hydraulic valve 101) is mounted on the vehicle body 2, the separate hydraulic equipment (hydraulic valve 101) is not mounted on the structure 3.

[0149] In this embodiment, the movement mechanism is a height change mechanism (lifting mechanism) 90 that raises and lowers the vehicle body 2 relative to the traveling frame 8. The height change mechanism 90, which is a movement mechanism, moves another hydraulic device (hydraulic valve 101) to change the position of the other hydraulic device (hydraulic valve 101) relative to the hydraulic actuator. Specifically, the height change mechanism 90 moves the hydraulic valve 101 in the vertical direction to change the vertical position of the hydraulic valve 101 relative to the hydraulic actuators (steering cylinder 62, brake cylinder 46).

[0150] As described above, the height changing mechanism 90 moves the vehicle body 2 relative to the structure (traveling frame 8). Therefore, the other hydraulic device (hydraulic valve 101) moves together with the vehicle body 2 relative to the structure (traveling frame 8) by the height changing mechanism 90.

[0151] On the other hand, the hydraulic actuators (steering cylinder 62, brake cylinder 46) are arranged at fixed positions. More specifically, the hydraulic actuators (steering cylinder 62, brake cylinder 46) are arranged at fixed positions in the up and down direction. Therefore, when the vehicle body 2 moves up and down relative to the traveling frame 8, the other hydraulic device (hydraulic valve 101) moves up and down relative to the hydraulic actuators (steering cylinder 62, brake cylinder).

[0152] In this way, the work vehicle 1 has the feature that the positions (vertical position) of the hydraulic actuators (steering cylinder 62, brake cylinder 46), which are the controlled equipment, are fixed, while the position (vertical position) of another hydraulic equipment (hydraulic valve 101), which is the controlling equipment, is variable. This improves accessibility to the controlling equipment (hydraulic valve 101), making maintenance easier.

[0153] When the vehicle body 2 is lowered, the hydraulic unit 100 is covered on at least two sides. In this embodiment, when the vehicle body 2 is lowered, the hydraulic unit 100 is covered on three sides (front, left, and right). As shown in FIGS. 2 to 6 , when the vehicle body 2 is lowered, the hydraulic unit 100 has the main body case 5 housing the first battery 12A disposed in front, the left running frame 8L disposed on the left, and the right running frame 8R disposed on the right. Therefore, when the vehicle body 2 is lowered, the front side of the hydraulic unit 100 is covered by the main body case 5, the left side is covered by the left running frame 8L, and the right side is covered by the right running frame 8R. Meanwhile, the rear side of the hydraulic unit 100 is exposed and uncovered. Thus, when the vehicle body 2 is lowered, only the rear side of the hydraulic unit 100 is exposed and uncovered.

[0154] When the vehicle body 2 is raised, the hydraulic unit 100 is covered in at least one direction. When the vehicle body 2 is raised, the hydraulic unit 100 is covered in fewer directions than when the vehicle body 2 is lowered. In this embodiment, when the vehicle body 2 is raised, the hydraulic unit 100 is covered in one direction (the front side). As shown in FIGS. 19 to 22 , when the vehicle body 2 is raised, the main body case 5 accommodating the first battery 12A is disposed in the front of the hydraulic unit 100. Therefore, when the vehicle body 2 is raised, the front side of the hydraulic unit 100 is covered by the main body case 5. On the other hand, the left, right, and rear sides of the hydraulic unit 100 are exposed and not covered. In this way, when the vehicle body 2 is raised, the left, right, and rear sides of the hydraulic unit 100 are exposed and not covered.

[0155] In this way, when the vehicle body 2 of the work vehicle 1 is in a lowered state, the left and right sides of the hydraulic unit 100 are covered, but when the vehicle body 2 is in a raised state, the left and right sides of the hydraulic unit 100 are not covered. Therefore, when the vehicle body 2 is in a raised state, it is possible to access the hydraulic unit 100 from the left and right sides, which was difficult to access when the vehicle body 2 was in a lowered state. This improves the maintainability of the hydraulic unit 100.

[0156] Note that when the vehicle body 2 is raised, only a portion (lower portion) of the left and right sides of the hydraulic unit 100 may be covered by the traveling frame 8. In this case, the area covered by the left and right sides of the hydraulic unit 100 when the vehicle body 2 is raised is significantly smaller than the area covered by the left and right sides of the hydraulic unit 100 when the vehicle body 2 is lowered. In other words, when the vehicle body 2 is raised, the exposed area of ​​the left and right sides of the hydraulic unit 100 increases significantly. This makes it easier to access the hydraulic unit 100 from the left and right sides, improving maintainability.

[0157] The upper part of the hydraulic unit 100 is exposed and uncovered whether the vehicle body 2 is lowered or raised. Therefore, the hydraulic unit 100 can be accessed from above whether the vehicle body 2 is lowered or raised. In particular, access from above is easy when the vehicle body 2 is lowered.

[0158] Figure 28 is a left side view that schematically shows the change in position of the hydraulic unit 100 when the vehicle body 2 is raised or lowered. The right side view is symmetrical to the left side view. As shown in the left view of Figure 28, when the vehicle body 2 is lowered, the entire hydraulic unit 100 overlaps with the traveling frame 8 in side view. Furthermore, when the vehicle body 2 is lowered, a portion of the hydraulic unit 100 overlaps with the rear wheels (left rear wheel 7LB, right rear wheel 7RB) in side view. Furthermore, when the vehicle body 2 is lowered, a portion of the hydraulic unit 100 overlaps with the second battery 12B in side view.

[0159] 28 , when the vehicle body 2 is raised, only a portion (lower portion) of the hydraulic unit 100 overlaps with the traveling frame 8 in a side view. Furthermore, when the vehicle body 2 is raised, the hydraulic unit 100 does not overlap with the rear wheels (left rear wheel 7LB, right rear wheel 7RB) in a side view. Furthermore, when the vehicle body 2 is raised, the hydraulic unit 100 does not overlap with the second battery 12B in a side view.

[0160] 28, the positional relationship between the hydraulic unit 100 and the second battery 12B changes as the vehicle body 2 is raised or lowered, but the positional relationship between the hydraulic unit 100 and the first battery 12A does not change. Whether the vehicle body 2 is lowered or raised, the hydraulic unit 100 and the first battery 12A overlap in the vertical direction.

[0161] The work-system motor 11, which operates the hydraulic pump 103 of the hydraulic unit 100, is located near the hydraulic unit 100 (see FIG. 25 ) and is operated by power supplied from the first battery 12A and the second battery 12B. Because the positional relationship between the hydraulic unit 100 and the first battery 12A does not change when the vehicle body 2 is raised or lowered, the electrical wiring connecting the first battery 12A and the work-system motor 11 can be shortened.

[0162] 28 , the positional relationship between the first battery 12A and the second battery 12B changes as the vehicle body 2 is raised or lowered. When the vehicle body 2 is lowered, the first battery 12A overlaps the second battery 12B in a side view. When the vehicle body 2 is raised, the first battery 12A does not overlap the second battery 12B in a side view. In this way, the positional relationship (overlapping relationship) between the first battery 12A and the second battery 12B changes as the vehicle body 2 is raised or lowered, in the same way as the positional relationship between the hydraulic unit 100 and the second battery 12B.

[0163] 13 , the work vehicle 1 can increase the distance between the left traveling section 4L and the vehicle body 2 and the distance between the right traveling section 4R and the vehicle body 2 by moving the left traveling section 4L and the right traveling section 4R in the left-right direction using the distance change mechanism 80. This makes it possible to expose the left and right sides of the hydraulic unit 100, allowing access to the hydraulic unit 100 from the left and right sides. This improves the ease of maintenance of the hydraulic unit 100.

[0164] 23 , the left and right sides of the hydraulic unit 100 can also be exposed by using the position change mechanism 70 to move the vehicle body 2 rearward so that the rear of the vehicle body 2 protrudes rearward beyond the running unit 4. This makes it possible to access the hydraulic unit 100 from the left and right sides, improving the ease of maintenance of the hydraulic unit 100.

[0165] 24, by moving the main body case 5 forward using the position change mechanism 70, it is possible to increase the distance between the front of the hydraulic unit 100 and the rear of the main body case 5. This makes it possible to access the hydraulic unit 100 from the front, improving the ease of maintenance of the hydraulic unit 100.

[0166] In this way, the work vehicle 1 can ensure easy access to the hydraulic unit 100 and improve maintainability of the hydraulic unit 100 not only by raising the vehicle body 2 with the height change mechanism 90, but also by moving the left traveling section 4L and the right traveling section 4R in the left-right direction with the distance change mechanism 80, by moving the vehicle body 2 rearward with the position change mechanism 70, and by moving the main body case 5 forward with the position change mechanism 70. The work vehicle 1 is configured to be able to perform at least one, preferably two or more, and more preferably three or more of these methods.

[0167] Fig. 29 is a diagram showing an example (first embodiment) of a connection configuration of electrical wiring in a work vehicle 1. As shown in Fig. 29 , the work vehicle 1 is equipped with a plurality of electrical devices 120. In the present embodiment, the plurality of electrical devices 120 includes a first electrical device 121 arranged in the vehicle body 2 and a second electrical device 122 arranged in the traveling section 4. Each of the plurality of electrical devices 120 includes at least one battery. In the present embodiment, the first electrical device 121 includes a first battery 12A, and the second electrical device 122 includes a second battery 12B. The first battery 12A and the second battery 12B are configured as a battery unit (battery pack) formed by combining a plurality of batteries.

[0168] The number of first batteries 12A may be one or more. The number of second batteries 12B may also be one or more. In this embodiment, the number of first batteries 12A is one, and the number of second batteries 12B is two.

[0169] The second electric device 122 includes electric devices different from the second battery 12B. Specifically, the second electric device 122 includes a left traveling motor (motor 10LF, motor 10LB) that drives the left wheels and a right traveling motor (motor 10RF, motor 10RB) that drives the right wheels. Therefore, the left traveling motor (motor 10LF, motor 10LB) that drives the left wheels is disposed in the left traveling section 4L as the second electric device 122. The right traveling section 4R is disposed a right traveling motor (motor 10RF, motor 10RB) that drives the right wheels as the second electric device 122.

[0170] As shown in Figure 29, the work vehicle 1 is equipped with multiple junction boxes 130. The junction boxes 130 relay and electrically connect one electrical wiring to another electrical wiring. The multiple junction boxes 130 include a main junction box 130A and a sub-junction box 130B. The work vehicle 1 is equipped with one main junction box 130A. The main junction box 130A is provided on at least either the vehicle body 2 or the structure 3. The sub-junction box 130B is provided on at least either the vehicle body 2 or the structure 3.

[0171] More specifically, the main junction box 130A is disposed in either the vehicle body 2 or the running section 4. When the main junction box 130A is disposed in the vehicle body 2, the sub-junction box 130B is disposed in the running section 4, and when the main junction box 130A is disposed in the running section 4, the sub-junction box 130B is disposed in the vehicle body 2. In this embodiment, the main junction box 130A is disposed in the vehicle body 2. The sub-junction boxes 130B are disposed in the running sections 4 (left running section 4L and right running section 4R).

[0172] At least one of the plurality of electric devices 120 is connected to the sub junction box 130B. At least one of the plurality of electric devices 120 is connected to the main junction box 130A, and the main junction box 130A is connected to an electric device 120 that is different from the electric device connected to the sub junction box 130B. The main junction box 130A is also connected to the sub junction box 130B.

[0173] The main junction box 130A is connected to at least one battery (first battery 12A, second battery 12B), the sub junction box 130B, and at least one electrical device other than the batteries. The sub junction box 130B is connected to the main junction box 130A and at least one electrical device other than the batteries.

[0174] The main junction box 130A is connected to the first electric device 121 when disposed in the vehicle body 2, and is connected to the second electric device 122 when disposed in the traveling section 4. The sub-junction box 130B is connected to the second electric device 122 when disposed in the traveling section 4, and is connected to the first electric device 121 when disposed in the vehicle body 2. In the present embodiment, the main junction box 130A is disposed in the vehicle body 2, and is therefore connected to the first battery 12A, which is the first electric device 121 disposed in the vehicle body 2. In addition, the sub-junction box 130B is disposed in the traveling section 4, and is therefore connected to the left traveling motor (motor 10LF, motor 10LB) or the right traveling motor (motor 10RF, motor 10RB), which is the second electric device 122, via the inverter 13.

[0175] The multiple junction boxes 130 include a first junction box 131 disposed on the vehicle body 2, a second junction box 132 disposed on the left traveling section 4L, and a third junction box 133 disposed on the right traveling section 4R. In this embodiment, the first junction box 131 is a main junction box 130A. The second junction box 132 and the third junction box 133 are sub-junction boxes 130B.

[0176] At least one battery (first battery 12A, second battery 12B) and at least one junction box (first junction box 131, second junction box 132, third junction box 133) are disposed in each of the vehicle body 2 and the traveling section 4. In this embodiment, the first battery 12A and the first junction box 131 are disposed in the vehicle body 2, and the second battery 12B, the second junction box 132, and the third junction box 133 are disposed in the traveling section 4. The second battery 12B and the second junction box 132 are disposed in the left traveling section 4L. The second battery 12B and the third junction box 133 are disposed in the right traveling section 4R.

[0177] In the following description, the second battery 12B arranged in the left running section 4L may be referred to as the "second battery 12BL," and the second battery 12B arranged in the right running section 4R may be referred to as the "second battery 12BR."

[0178] The first battery 12A is disposed inside the main body case 5 of the vehicle body 2 (see FIGS. 4 and 6). The second battery 12B is housed in a case 35 and disposed on the left traveling frame 8L and the right traveling frame 8R (see FIGS. 2, 3, and 6). Specifically, the second battery 12BL is disposed on the second support 29 of the left traveling frame 8L (see FIG. 2). The second battery 12BR is disposed on the third support 30 of the right traveling frame 8R (see FIG. 3).

[0179] The first junction box 131 (main junction box 130A) is disposed on the upper portion of the central body frame 22 of the body frame 21 (see FIGS. 1, 2, and 6). The second junction box 132 (sub-junction box 130B) is disposed on the second support body 29 of the left traveling frame 8L and is located above the second battery 12BL (see FIGS. 1, 2, and 6). The third junction box 133 (sub-junction box 130B) is disposed on the third support body 30 of the right traveling frame 8R and is located above the second battery 12BR (see FIGS. 1, 3, and 6).

[0180] The first battery 12A and the second battery 12B are connected directly or indirectly to the main junction box 130A. As shown in Fig. 29 , in this embodiment, the first battery 12A is connected directly (without going through any other device) to the main junction box 130A by a first electrical wiring 141. The second battery 12B is indirectly connected to the main junction box 130A via the first battery 12A.

[0181] Specifically, the second battery 12BL is connected to the first battery 12A by the second electrical wiring 142, and the first battery 12A is connected to the main junction box 130A by the first electrical wiring 141. The second battery 12BR is connected to the first battery 12A by the third electrical wiring 143, and the first battery 12A is connected to the main junction box 130A by the first electrical wiring 141.

[0182] As shown in Figure 29, in addition to the first battery 12A and main junction box 130A, the vehicle body 2 is also equipped with a first inverter 13A, the work-system motor 11, a DCDC converter 160, and an OBC / DCDC converter 161. The first inverter 13A is connected to the first battery 12A and the work-system motor 11. The first inverter 13A and the work-system motor 11 are disposed on a first support 28 (see Figure 11) that supports the hydraulic unit 100 behind the first battery 12A. More specifically, as shown in Figure 5, the first inverter 13A is disposed below the first support 28, and the work-system motor 11 is disposed above the first inverter 13A.

[0183] The DCDC converter 160 and the OBC / DCDC converter 161 are connected to the first battery 12A. The DCDC converter 160 transforms (steps down or steps up) the power supplied from the first battery 12A to supply it to other electrical devices. The OBC / DCDC converter 161 includes an OBC (on-board charger) and a DCDC converter. The OBC / DCDC converter 161 is connected to a charging port 162. The charging port 162 is provided on the vehicle body 2 and is connected to electrical wiring that is connected to an external power source installed at a charging station or the like. The OBC / DCDC converter 161 converts the AC voltage of the power supplied from the charging port 162 to a DC voltage and transforms (steps down or steps up) the converted DC voltage to a voltage required for the first battery 12A.

[0184] In addition to the second battery 12BL and the sub-junction box 130B (second junction box 132), the left traveling section 4L is also provided with the second inverter 13B, the third inverter 13C, and the left traveling motors (motors 10LF and 10LB). As shown in FIG. 2, the second inverter 13B and the third inverter 13C are supported by a second support 29. The second inverter 13B is disposed in front of the second battery 12BL. The third inverter 13C is disposed behind the second battery 12BL.

[0185] 29, the second inverter 13B is connected to the motor 10LF and the sub-junction box 130B (second junction box 132). The third inverter 13C is connected to the motor 10LB and the sub-junction box 130B (second junction box 132).

[0186] In addition to the second battery 12BR and the sub-junction box 130B (third junction box 133), the right traveling section 4R is also provided with a fourth inverter 13D, a fifth inverter 13E, and a right traveling motor (motor 10RF, motor 10RB). As shown in FIG. 3, the fourth inverter 13D and the fifth inverter 13E are supported by the third support 30. The fourth inverter 13D is disposed in front of the second battery 12BR. The fifth inverter 13E is disposed behind the second battery 12BR.

[0187] 29, the fourth inverter 13D is connected to the motor 10RF and the sub-junction box 130B (third junction box 133). The fifth inverter 13E is connected to the motor 10RB and the sub-junction box 130B (third junction box 133).

[0188] The main junction box 130A and the two sub-junction boxes 130B are connected by electrical wiring. Specifically, the main junction box 130A and one sub-junction box 130B (second junction box 132) (left running section 4L) are connected by a fourth electrical wiring 144. The main junction box 130A and the other sub-junction box 130B (third junction box 133) (right running section 4R) are connected by a fifth electrical wiring 145.

[0189] The second junction box 132 relays electrical wiring that connects from the main junction box 130A to the left traveling motors (motors 10LF and 10LB). Therefore, the power output from the first battery 12A and the second battery 12B is supplied to the left traveling motors (motors 10LF and 10LB) via the main junction box 130A and the second junction box 132.

[0190] The third junction box 133 relays electrical wiring that connects from the main junction box 130A to the right travel motors (motors 10RF and 10RB). Therefore, the power output from the first battery 12A and the second battery 12B is supplied to the right travel motors (motors 10RF and 10RB) via the main junction box 130A and the third junction box 133.

[0191] In this way, the sub-junction box 130B (second junction box 132, third junction box 133) relays electrical wiring connected to electrical equipment (left driving motors 10LF, 10LB, right driving motors 10RF, 10RB) other than the second battery 12B.

[0192] As described above, the vehicle body 2 can be moved up and down by driving the height change mechanism 90. Therefore, the main junction box 130A arranged on the vehicle body 2 can change its position in the up and down direction together with the vehicle body 2. In addition, the traveling unit 4 can be moved left and right by driving the distance change mechanism 80. Therefore, the sub junction box 130B arranged on the traveling unit 4 can change its position in the left and right direction together with the traveling unit 4. As a result, the positional relationship between the main junction box 130A and the sub junction box 130B can be changed in the up and down direction and the left and right direction.

[0193] 29 , the work vehicle 1 is provided with a movable part 150 that guides the connection wiring (fourth electrical wiring 144, fifth electrical wiring 145) that connects the main junction box 130A and the sub junction box 130B and moves in response to deformation of the connection wiring (fourth electrical wiring 144, fifth electrical wiring 145). The movable part 150 includes a first movable part 151 that guides the fourth electrical wiring 144 and moves in response to deformation of the fourth electrical wiring 144, and a second movable part 152 that guides the fifth electrical wiring 145 and moves in response to deformation of the fifth electrical wiring 145.

[0194] The movable part 150 is disposed along the electrical wiring and moves in response to deformation of the electrical wiring. For example, the movable part 150 may be configured by connecting a plurality of rigid members and allowing bending at the connecting parts. The movable part 150 accommodates or holds the electrical wiring, thereby supporting the electrical wiring while avoiding contact with the outside.

[0195] The movable part 150 is configured from, for example, a Cableveyor (registered trademark). In the following description, the movable part 150 is assumed to be the Cableveyor 150. The Cableveyor 150 is a member for supporting a movable cable (electrical wiring, etc.) and is also called a cable carrier, a cable chain, etc. The Cableveyor 150 is deformable to follow the cable. Therefore, by supporting (accommodating) the electrical wiring in the Cableveyor 150, the Cableveyor 150 can deform to follow the electrical wiring.

[0196] The electrical wiring (fourth electrical wiring 144, fifth electrical wiring 145) deforms while being supported (housed) in the cable bear 150, and the cable bear 150 follows this deformation. Therefore, it is possible to prevent malfunctions (twisting, tangling, damage) from occurring when the electrical wiring (fourth electrical wiring 144, fifth electrical wiring 145) deforms.

[0197] 30 and 31 are diagrams showing the movement of the movable parts (first movable part 151, second movable part 152) and the electrical wiring (fourth electrical wiring 144, fifth electrical wiring 145) when the vehicle body 2 is raised. As shown in Fig. 30, when the vehicle body 2 is lowered, the vertical distance between the main junction box 130A (first junction box 131) arranged on the vehicle body 2 and the sub-junction boxes 130B (second junction box 132, third junction box 133) arranged on the running parts 4 (left running part 4L, right running part 4R) is short.

[0198] 30 , the main junction box 130A (first junction box 131) disposed on the vehicle body 2 moves upward relative to the sub junction boxes 130B (second junction box 132, third junction box 133) disposed on the traveling sections 4 (left traveling section 4L, right traveling section 4R). As a result, the vertical distance between the main junction box 130A (first junction box 131) and the sub junction boxes 130B (second junction box 132, third junction box 133) increases (see FIG. 31 ).

[0199] As the vertical positional relationship between the main junction box 130A and the sub junction box 130B changes, the electrical wiring (fourth electrical wiring 144, fifth electrical wiring 145) connecting the main junction box 130A and the sub junction box 130B deforms, and the movable parts (first movable part 151, second movable part 152) also deform in response to this deformation (see Figure 31).

[0200] As described above, as the car body 2 rises, the electrical wiring (fourth electrical wiring 144, fifth electrical wiring 145) deforms, and the cable bear 150 also deforms in response to the deformation of the electrical wiring. This prevents malfunctions (twisting, tangling, damage) in the electrical wiring connecting the main junction box 130A and the sub junction box 130B caused by the rise of the car body 2.

[0201] 30 and 32 are diagrams illustrating the movement of the movable parts (first movable part 151, second movable part 152) and the electrical wiring (fourth electrical wiring 144, fifth electrical wiring 145) when the traveling parts (left traveling part 4L, right traveling part 4R) move in the left-right direction. As shown in FIG. 30 , when the vehicle body 2 and the traveling parts (left traveling part 4L, right traveling part 4R) are close to each other in the left-right direction, the left-right distance between the main junction box 130A (first junction box 131) disposed on the vehicle body 2 and the sub-junction boxes 130B (second junction box 132, third junction box 133) disposed on the traveling parts 4 (left traveling part 4L, right traveling part 4R) is short.

[0202] 30 , when the traveling units (left traveling unit 4L, right traveling unit 4R) move in a direction (left or right) away from the vehicle body 2, the main junction box 130A (first junction box 131) arranged on the vehicle body 2 moves in a direction (left or right) away from the sub junction box 130B (second junction box 132, third junction box 133) arranged on the traveling units 4 (left traveling unit 4L, right traveling unit 4R). As a result, the distance in the left-right direction between the main junction box 130A (first junction box 131) and the sub junction box 130B (second junction box 132, third junction box 133) increases (see FIG. 32 ).

[0203] As the left-right positional relationship between the main junction box 130A and the sub junction box 130B changes, the electrical wiring (fourth electrical wiring 144, fifth electrical wiring 145) connecting the main junction box 130A and the sub junction box 130B deforms, and the movable parts (first movable part 151, second movable part 152) also deform in response to this deformation (see Figure 32).

[0204] As described above, the electrical wiring (fourth electrical wiring 144, fifth electrical wiring 145) deforms as the traveling sections (left traveling section 4L, right traveling section 4R) move left and right, and the cable bear 150 also deforms in response to the deformation of the electrical wiring. This prevents malfunctions (twisting, tangling, damage) in the electrical wiring connecting the main junction box 130A and the sub-junction box 130B caused by the left and right movement of the traveling sections (left traveling section 4L, right traveling section 4R).

[0205] 29 , the movable part 150 includes a third movable part 153 and a fourth movable part 154. The third movable part 153 guides the connection wiring (second electrical wiring 142) connecting the first battery 12A and the second battery 12BL and moves in response to deformation of the connection wiring (second electrical wiring 142). The fourth movable part 154 guides the connection wiring (third electrical wiring 143) connecting the first battery 12A and the second battery 12BR and moves in response to deformation of the connection wiring (third electrical wiring 143).

[0206] 33 to 37 are diagrams showing other examples (second to sixth embodiments) of the connection configuration of the electrical wiring of the work vehicle 1. Below, for the second to sixth embodiments, differences from the first embodiment described above will be explained, and explanations of configurations common to the first embodiment will be omitted.

[0207] 33 is a diagram illustrating a second embodiment. In the second embodiment, the sub junction box 130B (second junction box 132) arranged in the left traveling section 4L and the sub junction box 130B (third junction box 133) arranged in the right traveling section 4R are connected by a sixth electrical wiring 146. That is, in the second embodiment, not only are the main junction box 130A and the sub junction box 130B connected, but the sub junction boxes 130B (second junction box 132 and third junction box 133) are also connected to each other.

[0208] In the second embodiment, the work vehicle 1 is provided with a fifth movable part 155 that guides the connection wiring (sixth electrical wiring 146) connecting the second junction box 132 and the third junction box 133 and moves in accordance with deformation of the connection wiring (sixth electrical wiring 146). In Fig. 33, the fifth movable part 155 is provided between the left traveling part 4L and the vehicle body 2 and between the right traveling part 4R and the vehicle body 2, but it may be provided on only one of them.

[0209] 34 is a diagram showing a third embodiment. In the third embodiment, a main junction box 130A is disposed in the left traveling section 4L, and sub-junction boxes 130B are disposed in the vehicle body 2 and the right traveling section 4R, respectively. The main junction box 130A disposed in the left traveling section 4L is connected to the first battery 12A and sub-junction box 130B disposed in the vehicle body 2, and the sub-junction box 130B disposed in the right traveling section 4R.

[0210] In the third embodiment, the work vehicle 1 is provided with a sixth movable part 156 that guides the connection wiring (first electrical wiring 141) that connects the main junction box 130A arranged on the left traveling section 4L and the first battery 12A arranged on the vehicle body 2 and moves in accordance with the deformation of the connection wiring (first electrical wiring 141).

[0211] 35 is a diagram showing a fourth embodiment. In the fourth embodiment, a main junction box 130A is disposed in the right traveling section 4R, and sub-junction boxes 130B are disposed in the vehicle body 2 and the left traveling section 4L, respectively. The main junction box 130A disposed in the right traveling section 4R is connected to the first battery 12A and sub-junction box 130B disposed in the vehicle body 2, and the sub-junction box 130B disposed in the left traveling section 4L.

[0212] In the fourth embodiment, the work vehicle 1 is provided with a sixth movable part 156 that guides the connection wiring (first electrical wiring 141) that connects the main junction box 130A arranged on the right running part 4R and the first battery 12A arranged on the vehicle body 2 and moves in accordance with the deformation of the connection wiring (first electrical wiring 141).

[0213] FIG. 36 illustrates a fifth embodiment. In the fifth embodiment, the sub-junction box 130B (second junction box 132) disposed in the left traveling section 4L is connected to the second battery 12BL via a sixth electrical wiring 146. The sub-junction box 130B (third junction box 133) disposed in the right traveling section 4R is connected to the second battery 12BR via a seventh electrical wiring 147. Similarly to the first embodiment, the main junction box 130A is connected to the first battery 12A. Thus, in the fifth embodiment, the battery 12 is directly connected to all of the junction boxes 130 (without going through other devices).

[0214] Figure 37 is a diagram showing a sixth embodiment. In Figure 37, the vehicle body 2 is divided into a main body case 5 of the vehicle body 2 in which the first battery 12A is disposed, and a portion 2B other than the main body case 5. A main junction box 130A and the like are disposed in the portion 2B other than the main body case 5. The main body case 5 is located in the front portion of the vehicle body 2, and the portion 2B other than the main body case 5 is located in the rear portion of the vehicle body 2. Hereinafter, the portion 2B other than the main body case 5 will be referred to as the "rear portion 2B of the vehicle body."

[0215] In the sixth embodiment, a seventh movable part 157 is provided which guides the connection wiring (first electrical wiring 141) connecting the first battery 12A and the main junction box 130A and moves in response to deformation of the connection wiring (first electrical wiring 141). The seventh movable part 157 is disposed between the main body case 5 and the rear vehicle body 2B.

[0216] The connection wiring (second electrical wiring 142) connecting the first battery 12A and the second battery 12BL runs from the first battery 12A arranged in the main body case 5 through the rear vehicle body 2B to the second battery 12BL arranged in the left traveling frame 8L. The connection wiring (third electrical wiring 143) connecting the first battery 12A and the second battery 12BR runs from the first battery 12A arranged in the main body case 5 through the rear vehicle body 2B to the second battery 12BR arranged in the right traveling frame 8R.

[0217] Two third movable parts 153 are provided to guide the connection wiring (second electrical wiring 142) connecting the first battery 12A and the second battery 12BL and move in response to deformation of the connection wiring (second electrical wiring 142). One of the third movable parts 153 is disposed between the main body case 5 and the rear vehicle body 2B. The other third movable part 153 is disposed between the left traveling frame 8L and the rear vehicle body 2B.

[0218] Two fourth movable parts 154 are also provided to guide the connection wiring (third electrical wiring 143) connecting the first battery 12A and the second battery 12BR and to move in response to deformation of the connection wiring (third electrical wiring 143). One of the fourth movable parts 154 is disposed between the main body case 5 and the rear vehicle body 2B. The other fourth movable part 154 is disposed between the right traveling frame 8R and the rear vehicle body 2B.

[0219] The sixth embodiment can be suitably applied, for example, to a work vehicle 1 having a configuration in which the main body case 5 is movable in the fore-and-aft direction (see FIG. 24 ). In this case, the main body case 5 is movable in the fore-and-aft direction relative to the rear vehicle body section 2B. In the sixth embodiment, movable parts (the third movable part 153, the fourth movable part 154, and the seventh movable part 157) are disposed between the main body case 5 and the rear vehicle body section 2B. This prevents malfunctions (twisting, tangling, damage) caused by movement of the main body case 5 in the fore-and-aft direction from occurring in the connection wiring (the second electrical wiring 142, the third electrical wiring 143) connecting the first battery 12A and the second batteries 12BL, 12BR and the connection wiring (the first electrical wiring 141) connecting the first battery 12A and the main junction box 130A.

[0220] As described above, the work vehicle 1 can change the positional relationship between the main junction box 130A and the sub junction box 130B. Specifically, the positional relationship between the main junction box 130A and the sub junction box 130B in the up-down direction, the left-right direction, and the front-rear direction can be changed. However, the work vehicle 1 does not need to be able to change all of the positional relationship in the up-down direction, the left-right direction, and the front-rear direction, but is able to change at least one positional relationship, and preferably at least two positional relationships.

[0221] Being able to change the relative positions of the main junction box 130A and the sub junction box 130B makes it possible to change the routing (positions through which the electrical wiring passes) of the electrical wiring connected to the main junction box 130A and the sub junction box 130B. Therefore, for example, when the type or number of electrical devices is changed, it becomes possible to flexibly change the routing of the electrical wiring in response to this change.

[0222] The movable part 150 is configured to guide the connection wiring connecting the main junction box 130A and the sub junction box 130B and move in accordance with the deformation of the connection wiring when at least one, and preferably two or more of the vertical positional relationship, horizontal positional relationship, and front-to-back positional relationship between the main junction box 130A and the sub junction box 130B is changed.

[0223] As shown in Figure 7, the work vehicle 1 is equipped with an inclination detection device 170. The inclination detection device 170 detects the inclination of the vehicle body 2. More specifically, the inclination detection device 170 detects the inclination angle of the vehicle body 2 with respect to the horizontal direction. For example, an inclination sensor, a load cell, a camera, or the like can be used as the inclination detection device 170. However, the type of the inclination detection device 170 is not particularly limited as long as it is a device that can detect the inclination of the vehicle body 2.

[0224] The tilt sensor may be, for example, a pendulum tilt sensor equipped with a detection unit such as a pendulum and a magnetic resistance element, a capacitance tilt sensor that detects the tilt of the liquid as a change in capacitance, a quartz tilt sensor that uses a quartz oscillator, etc. The tilt angle can be calculated based on the detected value of the sensor (such as the change in capacitance) by a calculation unit or the like included in the control device 19 or the tilt detection device 170.

[0225] When a load cell is used as the tilt detection device 170, a strain gauge included in the load cell detects the strain of the axle that occurs when the vehicle body tilts, and the tilt angle of the vehicle body 2 is calculated based on the strain value. The calculation of the tilt angle based on the detected strain value can be performed by a calculation unit or the like included in the control device 19 or the tilt detection device 170.

[0226] When a camera is used as the tilt detection device 170, for example, an image of the ground on which the work vehicle 1 is traveling is captured by a camera fixed to the vehicle body 2, and the tilt angle of the vehicle body 2 with respect to the ground is calculated based on the captured image. The calculation of the tilt angle based on the captured image can be performed by a calculation unit or the like included in the control device 19 or the tilt detection device 170. The camera 18a of the situation detection device 18 described above may be used as the camera.

[0227] As shown in Fig. 7 , the work vehicle 1 is equipped with a change mechanism 180 that changes the positional relationship between the vehicle body 2 and the traveling unit 4 based on the detection results of the tilt detection device 170. The change mechanism 180 includes the height change mechanism 90, distance change mechanism 80, and position change mechanism 70 described above. In the case of the present embodiment, the change mechanism 180 includes all of the height change mechanism 90, distance change mechanism 80, and position change mechanism 70. However, it is sufficient that the change mechanism 180 includes at least one (one or two) of the height change mechanism 90, distance change mechanism 80, and position change mechanism 70.

[0228] The change mechanism 180 is a mechanism for preventing the work vehicle 1 from tipping over. The operation of the change mechanism 180 is preferably performed particularly when the vehicle body 2 is in a raised position relative to the traveling section 4. The operation of raising the vehicle body 2 relative to the traveling section 4 is performed, for example, to avoid contact between the vehicle body 2 and an obstacle on the ground (for example, a ridge in a field or crops planted in the ridges). Therefore, when the work vehicle 1 travels in a field, a state in which the vehicle body 2 is in a raised position relative to the traveling section 4 may occur.

[0229] When the work vehicle 1 is traveling, a force may act in a direction that causes the work vehicle 1 to tip over due to strong winds, a slope of the ground, unevenness of the ground, turning motion of the work vehicle 1, etc. When the vehicle body 2 is in a raised position relative to the traveling section 4, the center of gravity of the work vehicle 1 is in a high position, making the work vehicle 1 prone to tipping over. In such a state, by operating the change mechanism 180, it is possible to prevent the work vehicle 1 from tipping over. The specific configuration and operation of the change mechanism 180 will be described below.

[0230] First, a case will be described in which the change mechanism 180 is the height change mechanism 90. In this case, the height change mechanism 90 changes the vertical position of the vehicle body 2 based on the detection result of the tilt detection device 170. The operation of this height change mechanism 90 is controlled by the height change control unit 19C. In other words, the height change control unit 19C controls the operation of the height change mechanism 90 based on the detection result of the tilt detection device 170.

[0231] 19 and 20 , the height change mechanism 90 includes a left height change mechanism 90L that changes the height of the left section of the vehicle body 2, and a right height change mechanism 90R that changes the height of the right section of the vehicle body 2. The left height change mechanism 90L has a left lift cylinder 91L. The right height change mechanism 90R has a right lift cylinder 91R. The height change mechanism 90 changes the height of the left section of the vehicle body 2 by driving the left lift cylinder 91L, and changes the height of the right section of the vehicle body 2 by driving the right lift cylinder 91R.

[0232] The height change mechanism 90 can make the height of the left section and the height of the right section of the vehicle body 2 different based on the detection result of the tilt detection device 170. In detail, when the tilt detection device 170 detects that the vehicle body 2 is tilted to the left by a predetermined amount or more, the height change mechanism 90 performs at least one of an operation to raise the left section of the vehicle body 2 and an operation to lower the right section of the vehicle body 2, and when the tilt detection device 170 detects that the vehicle body 2 is tilted to the right by a predetermined amount or more, the height change mechanism 90 performs at least one of an operation to raise the right section of the vehicle body 2 and an operation to lower the left section of the vehicle body 2.

[0233] As an example, the magnitude of the predetermined amount can be set in the range of 20 to 40 degrees with respect to the horizontal direction. However, the magnitude of the predetermined amount is not limited to this range, and can be changed and set as appropriate depending on the conditions of the location where the work vehicle 1 is traveling (ground inclination and unevenness), the vehicle height when the work vehicle 1 is traveling, the wind speed when traveling, etc. This also applies to the operation of the other change mechanisms (distance change mechanism 80, position change mechanism 70) described below.

[0234] Figure 38 is a diagram showing a first example of the operation of the height change mechanism 90. The left diagram in Figure 38 shows a state in which a force (see arrow F1) is acting on the work vehicle 1 to tip it over to the left. When this force F1 causes the vehicle body 2 to tilt to the left, the tilt detection device 170 detects the left tilt of the vehicle body 2. When the tilt detection device 170 detects that the vehicle body 2 has tilted to the left by more than a predetermined amount, the height change mechanism 90 performs at least one of an operation to raise the left section of the vehicle body 2 and an operation to lower the right section of the vehicle body 2.

[0235] As shown in the right diagram of Figure 38, the operation of raising the left section of the vehicle body 2 is performed by extending the rod 91a of the left lift cylinder 91L. The operation of lowering the right section of the vehicle body 2 is performed by shortening the rod 91a of the right lift cylinder 91R. This operation is performed by the height change control unit 19C controlling the left lift cylinder 91L and the right lift cylinder 91R.

[0236] The height change control unit 19C determines whether the vehicle body 2 is tilted to the left by a predetermined amount or more based on the detection result of the tilt detection device 170, and if it determines that the vehicle body 2 is tilted by the predetermined amount or more, drives the left lifting cylinder 91L and / or the right lifting cylinder 91R, thereby performing at least one of an operation to lift the left part of the vehicle body 2 and an operation to lower the right part of the vehicle body 2.

[0237] As described above, by performing at least one of the operations of raising the left section of the vehicle body 2 and lowering the right section of the vehicle body 2, a rightward moment (see arrow F2) acts on the vehicle body 2, as shown in the right diagram of Figure 38. This moment acts in a direction that counteracts the force (see arrow F1) that would cause the work vehicle 1 to tip over to the left, and therefore it is possible to prevent the vehicle body 2 from tipping over to the left.

[0238] Figure 39 is a diagram showing a second example of the operation of the height change mechanism 90. The left diagram in Figure 39 shows a state in which a force (see arrow F3) is acting on the work vehicle 1 to tip it to the right. When this force F3 causes the vehicle body 2 to tilt to the right, the tilt detection device 170 detects the right tilt of the vehicle body 2. When the tilt detection device 170 detects that the vehicle body 2 has tilted to the right by more than a predetermined amount, the height change mechanism 90 performs at least one of an operation to raise the right section of the vehicle body 2 and an operation to lower the left section of the vehicle body 2.

[0239] As shown in the right diagram of Figure 39, the operation of lifting the right section of the vehicle body 2 is performed by extending the rod 91a of the right lift cylinder 91R. The operation of lowering the left section of the vehicle body 2 is performed by shortening the rod 91a of the left lift cylinder 91L. This operation is performed by the height change control unit 19C controlling the left lift cylinder 91L and the right lift cylinder 91R. Based on the detection result of the tilt detection device 170, the height change control unit 19C determines whether the vehicle body 2 is tilted to the right by a predetermined amount or more, and if it determines that the vehicle body 2 is tilted by the predetermined amount or more, drives the left lift cylinder 91L and / or the right lift cylinder 91R. This performs at least one of the operation of lifting the right section of the vehicle body 2 and the operation of lowering the left section of the vehicle body 2.

[0240] As described above, by performing at least one of the operations of raising the right section of the vehicle body 2 and lowering the left section of the vehicle body 2, a leftward moment (see arrow F4) acts on the vehicle body 2, as shown in the right diagram of Figure 39. This moment acts in a direction that cancels out the force (see arrow F3) that would cause the work vehicle 1 to tip over to the right, and therefore it is possible to prevent the vehicle body 2 from tipping over to the right.

[0241] 40 , the body frame 21 may be connected to the traveling frame 8 without the mast mechanism described above. In other words, the work vehicle 1 may not be equipped with a mast mechanism. In this case, the body frame 21 is connected to the traveling frame 8 via the left lift cylinder 91L and the right lift cylinder 91R, without the mast mechanism. In this case, it is preferable to provide a plurality of left lift cylinders 91L and a plurality of right lift cylinders 91R spaced apart in the fore-and-aft direction. In this case, the upper ends of the cylinder tubes 91b of the left lift cylinder 91L and the right lift cylinder 91R are pivotally supported relative to the body frame 21 about a first shaft 55 extending in the fore-and-aft direction, and the lower ends of the rods 91a of the left lift cylinder 91L and the right lift cylinder 91R are pivotally supported relative to the traveling frame 8 about a second shaft 56 extending in the fore-and-aft direction.

[0242] With this configuration, the body frame 21 can easily swing left and right, which makes it easier for the body 2 to tilt left and right. Therefore, the left lift cylinder 91L and / or the right lift cylinder 91R can be driven smoothly to make the left and right parts of the body 2 different in height.

[0243] When the tilt detection device 170 detects that the vehicle body 2 is tilted by a predetermined amount or more, the height change mechanism 90 can lower the vehicle body 2. At this time, the height change mechanism 90 simultaneously lowers the left and right parts of the vehicle body 2. In addition, the height change mechanism 90 lowers the left and right parts of the vehicle body 2 by the same distance.

[0244] Figure 41 is a diagram showing a third example of the operation of the height change mechanism 90. Figure 41 shows a state in which a force that causes the work vehicle 1 to tip to the left (see arrow F5) or a force that causes the work vehicle 1 to tip to the right (see arrow F6) is acting on the work vehicle 1. When the force F5 or F6 causes the vehicle body 2 to tilt to the right or left, the tilt detection device 170 detects the tilt of the vehicle body 2. When the tilt detection device 170 detects that the vehicle body 2 has tilted to the right or left by more than a predetermined amount, the height change mechanism 90 lowers the vehicle body 2.

[0245] As shown in the right diagram of Figure 41, the operation of lowering the vehicle body 2 is performed by shortening the rods 91a of the right lift cylinder 91R and the left lift cylinder 91L. This operation is performed by the height change control unit 19C controlling the left lift cylinder 91L and the right lift cylinder 91R. Based on the detection result of the tilt detection device 170, the height change control unit 19C determines whether the vehicle body 2 is tilted by a predetermined amount or more, and if it determines that the vehicle body 2 is tilted by the predetermined amount or more, it drives the left lift cylinder 91L and the right lift cylinder 91R. In this way, the operation of lowering the vehicle body 2 is performed.

[0246] As described above, by lowering the vehicle body 2, as shown in the right diagram of Figure 41, the height of the vehicle body 2 is lowered, and the center of gravity of the work vehicle 1 is lowered. This makes it possible to prevent the work vehicle 1 from tipping over. When lowering the vehicle body 2, it is preferable to lower the height of the vehicle body 2 to the lowest height within the range of heights that can be changed by the height change mechanism 90. At this time, the first battery 12A, which is a heavy object mounted on the vehicle body 2, is positioned lower than the upper ends of the left traveling section 4L and the right traveling section 4R. This makes it possible to reliably prevent the work vehicle 1 from tipping over.

[0247] In the operations of the first and second examples described above, there is a limit to how much the difference in height between the left and right parts of the vehicle body 2 can be increased, making it difficult to increase the moment required to avoid tipping, which may reduce the effectiveness of avoiding tipping. In contrast, according to the operation of the third example, by lowering the vehicle body 2 and lowering the center of gravity of the work vehicle 1, it is possible to shorten the distance between the point of action (the point in contact with the ground) and the point of effort (the point at which a force acts to tip the vehicle), thereby more reliably preventing tipping.

[0248] The predetermined amount of inclination of the vehicle body 2 when performing the above-described operation of lowering the vehicle body 2 (second predetermined amount) may be the same as the predetermined amount of inclination of the vehicle body 2 when performing the above-described operation of changing the height of the left section and the height of the right section of the vehicle body 2 (first predetermined amount), or the first predetermined amount and the second predetermined amount may be different. By making the first predetermined amount and the second predetermined amount different, it is possible to change the height of the vehicle body 2 in an optimal manner depending on the magnitude of the inclination of the vehicle body 2, and prevent the work vehicle 1 from tipping over.

[0249] Preferably, the second predetermined amount is set to be greater than the first predetermined amount. By setting the second predetermined amount in this manner, the height change mechanism 90 can perform an operation to make the heights of the left and right parts of the vehicle body 2 different when the inclination of the vehicle body 2 detected by the inclination detection device 170 is small, and can perform an operation to lower the vehicle body 2 when the inclination of the vehicle body 2 detected by the inclination detection device 170 is large. This makes it possible to continue work without changing the height of the vehicle body 2 much when the inclination of the vehicle body 2 is small, and to lower the vehicle body 2 to reliably prevent the work vehicle 1 from tipping over when the inclination of the vehicle body 2 is large.

[0250] Fig. 42 is a flowchart showing an example of the operation of the height change mechanism 90. Below, an example of the operation of the height change mechanism 90 will be described with reference to Fig. 42. The operation of the height change mechanism 90 is executed based on the control of the height change control unit 19C.

[0251] While the work vehicle 1 is traveling, the tilt detection device 170 detects the left-right tilt of the vehicle body 2 (S1). The height change control unit 19C determines whether the amount of tilt detected by the tilt detection device 170 is equal to or greater than a first predetermined amount (S2). If it is determined that the amount of tilt is less than the first predetermined amount (S2: No), the height change control unit 19C continues the detection operation. If it is determined that the amount of tilt is equal to or greater than the first predetermined amount (S2: Yes), the height change control unit 19C determines whether the amount of tilt detected by the tilt detection device 170 is equal to or greater than a second predetermined amount (S3). If it is determined that the amount of tilt is equal to or greater than the second predetermined amount (S3: Yes), the height change mechanism 90 lowers the vehicle body 2 (S4). If it is determined that the amount of tilt is less than the second predetermined amount (S3: No), the height change control unit 19C determines whether the direction of tilt is to the left (S5). If it is determined that the tilt direction is to the left (S5: Yes), the height changing mechanism 90 performs at least one of an operation to raise the left part of the body 2 and an operation to lower the right part of the body 2 (S6). If it is determined that the tilt direction is to the right (S5: No), the height changing mechanism 90 performs at least one of an operation to raise the right part of the body 2 and an operation to lower the left part of the body 2 (S7).

[0252] 42 is an example of the operation of the height changing mechanism 90, and the operation of the height changing mechanism 90 is not limited to the flowchart of FIG. 42 and can be modified as needed. For example, the determinations of S2 and S3 may be performed simultaneously, or the order of the determinations of S3 and S5 may be reversed. Furthermore, in S5, it may be determined whether the tilt direction of the vehicle body 2 is to the right, or whether it is to the left or right.

[0253] The height change mechanism 90 can change the difference in height between the left and right parts of the vehicle body 2 in response to the amount (magnitude) of tilt detected by the tilt detection device 170. Specifically, the difference in height between the left and right parts of the vehicle body 2 can be increased as the tilt detected by the tilt detection device 170 increases. This allows the balance between the left and right heights of the vehicle body 2 to be appropriately adjusted in accordance with the risk of tipping over.

[0254] Fig. 43 is a flowchart showing another example of the operation of the height change mechanism 90. Hereinafter, with reference to Fig. 43, another example of the operation of the height change mechanism 90 will be described. This operation of the height change mechanism 90 is also executed based on the control by the height change control unit 19C.

[0255] While the work vehicle 1 is traveling, the tilt detection device 170 detects the left-right tilt of the vehicle body 2 (S1). The height change control unit 19C determines whether the amount of tilt detected by the tilt detection device 170 is equal to or greater than a first predetermined amount (S2). If it is determined that the amount of tilt is less than the first predetermined amount (S2: No), the height change control unit 19C continues the detection operation. If it is determined that the amount of tilt is equal to or greater than the first predetermined amount (S2: Yes), the height change control unit 19C determines whether the amount of tilt is equal to or greater than a second predetermined amount (S3). If it is determined that the amount of tilt is less than the second predetermined amount (S3: No), the height change control unit 19C determines whether the direction of tilt is to the left (S4). If it is determined that the direction of tilt is to the left (S4: Yes), the height change mechanism 90 performs at least one of an operation to raise the left section of the vehicle body 2 and an operation to lower the right section of the vehicle body 2 (S5). If it is determined that the tilt direction is to the right (S4: No), the height change mechanism 90 performs at least one of the following operations: raising the right part of the body 2 and lowering the left part of the body 2 (S6).

[0256] If it is determined that the amount of tilt is equal to or greater than the second predetermined amount (S3: Yes), it is determined whether the amount of tilt is equal to or greater than a third predetermined amount (S7). The magnitude relationship among the first predetermined amount, the second predetermined amount, and the third predetermined amount is first predetermined amount<second predetermined amount<third predetermined amount.

[0257] If it is determined that the amount of tilt is less than the third predetermined amount (S7: No), it is determined whether the direction of tilt is to the left (S8). If it is determined that the direction of tilt is to the left (S8: Yes), the height change mechanism 90 operates to lower the left and right sections of the vehicle body 2. At this time, the amount of lowering of the right section of the vehicle body 2 is made greater than the amount of lowering of the left section of the vehicle body 2 (S9). If it is determined that the direction of tilt is to the right (S8: No), the height change mechanism 90 operates to lower the left and right sections of the vehicle body 2. At this time, the amount of lowering of the left section of the vehicle body 2 is made greater than the amount of lowering of the right section of the vehicle body 2 (S10).

[0258] If it is determined that the amount of tilt is equal to or greater than the third predetermined amount (S7: Yes), the height changing mechanism 90 lowers the vehicle body 2 (S11). At this time, the amount of lowering of the right section of the vehicle body 2 is the same as the amount of lowering of the left section of the vehicle body 2. The amount of lowering of the left and right sections of the vehicle body 2 at this time is preferably the maximum amount of lowering that can be achieved by the height changing mechanism 90, but is at least equal to or greater than the amount of lowering of the right section of the vehicle body 2 in S9 and the amount of lowering of the left section of the vehicle body 2 in S10.

[0259] The operation of the height changing mechanism 90 shown in the flowchart of FIG. 43 can be modified as needed. For example, the determinations in S2, S3, and S7 may be performed simultaneously. Furthermore, in S4 and S8, it may be determined whether the tilt direction of the vehicle body 2 is to the right, or whether it is to the left or right. Furthermore, the positions of S5 and S9, and the positions of S6 and S10 may be reversed. That is, in step S4, if the answer is Yes, the operation described in S9 may be performed, and if the answer is No, the operation described in S10 may be performed. Furthermore, in step S8, if the answer is Yes, the operation described in S5 may be performed, and if the answer is No, the operation described in S6 may be performed.

[0260] In the operation of the height change mechanism 90 shown in the flowchart of Figure 43, when the amount of tilt of the vehicle body 2 is small (when the amount is equal to or greater than the first predetermined amount but less than the second predetermined amount and the third predetermined amount), the height change mechanism 90 raises one of the left and right sections of the vehicle body 2 and lowers the other. When the amount of tilt of the vehicle body 2 is moderate (when the amount is equal to or greater than the first predetermined amount and the second predetermined amount but less than the third predetermined amount), the height change mechanism 90 lowers one of the left and right sections of the vehicle body 2 and lowers the other section more than the other. When the amount of tilt of the vehicle body 2 is large (when the amount is equal to or greater than the first predetermined amount, the second predetermined amount, and the third predetermined amount), the height change mechanism 90 lowers the left and right sections of the vehicle body 2 by the same lowering amount.

[0261] By performing such operations, if the inclination of the vehicle body 2 is small, work can be continued without changing the height of the vehicle body 2 too much; if the inclination of the vehicle body 2 is moderate, the vehicle body 2 can be lowered slightly to reduce the risk of the work vehicle 1 tipping over; and if the inclination of the vehicle body 2 is large, the vehicle body 2 can be lowered significantly to reliably prevent the work vehicle 1 from tipping over.

[0262] Next, a case where the change mechanism 180 is the distance change mechanism 80 will be described. In this case, the distance change mechanism 80 changes the left-right distance of the traveling unit 4 relative to the vehicle body 2 based on the detection result of the tilt detection device 170. The operation of the distance change mechanism 80 is controlled by the distance change control unit 19B.

[0263] The distance change mechanism 80 includes a left distance change mechanism 80L that changes the lateral distance of the left traveling unit 4L relative to the vehicle body 2, and a right distance change mechanism 80R that changes the lateral distance of the right traveling unit 4R relative to the vehicle body 2 (see FIG. 6 ). The left distance change mechanism 80L is the left change mechanism 80L described above and includes a left cylinder 81L. The right distance change mechanism 80R is the right change mechanism 80R described above and includes a right cylinder 81R. The distance change mechanism 80 changes the lateral distance of the left traveling unit 4L relative to the vehicle body 2 by driving the left cylinder 81L, and changes the lateral distance of the right traveling unit 4R relative to the vehicle body 2 by driving the right cylinder 81R.

[0264] The distance change mechanism 80 can change the distance between the left traveling section 4L and the vehicle body 2 and the distance between the right traveling section 4R and the vehicle body 2 based on the detection result of the tilt detection device 170. In detail, the distance change mechanism 80 increases the distance between the left traveling section 4L and the vehicle body 2 when the tilt detection device 170 detects that the vehicle body 2 is tilted to the left by a predetermined amount or more, and increases the distance between the right traveling section 4R and the vehicle body 2 when the tilt detection device 170 detects that the vehicle body 2 is tilted to the right by a predetermined amount or more.

[0265] Figure 44 is a diagram showing a first example of the operation of the distance change mechanism 80. The left diagram in Figure 44 shows a state in which a force (see arrow F7) is acting on the work vehicle 1 to tip it to the left. When this force F7 causes the vehicle body 2 to tilt to the left, the tilt detection device 170 detects the leftward tilt of the vehicle body 2. When the tilt detection device 170 detects that the vehicle body 2 has tilted to the left by more than a predetermined amount, the distance change mechanism 80 operates to increase the lateral distance between the left running section 4L and the vehicle body 2.

[0266] As shown in the right diagram of Figure 44, the operation of increasing the distance between the left running unit 4L and the vehicle body 2 is performed by extending the rod 81a of the left cylinder 81L. This operation is performed by the distance change control unit 19B controlling the left cylinder 81L. Based on the detection result of the tilt detection device 170, the distance change control unit 19B determines whether the vehicle body 2 is tilted to the left by more than a predetermined amount, and if it determines that the vehicle body 2 is tilted by more than the predetermined amount, it drives the left cylinder 81L to extend the rod 81a. This causes the left running unit 4L to move in a direction away from the vehicle body 2 (to the left) (see arrow L2), increasing the distance between the left running unit 4L and the vehicle body 2.

[0267] As described above, by performing the operation to increase the distance between the left running section 4L and the body 2, the left wheels (front left wheel 7LF, rear left wheel 7LB) contact the ground at a position further to the left from the body 2 than before the operation, as shown in the right diagram of Figure 44. This makes it possible to prevent the body 2 from tipping over to the left.

[0268] Figure 45 is a diagram showing a second example of the operation of the distance change mechanism 80. The left diagram in Figure 45 shows a state in which a force (see arrow F8) is acting on the work vehicle 1 to tip it to the right. When this force F8 causes the vehicle body 2 to tilt to the right, the tilt detection device 170 detects the rightward tilt of the vehicle body 2. When the tilt detection device 170 detects that the vehicle body 2 has tilted to the right by more than a predetermined amount, the distance change mechanism 80 operates to increase the lateral distance between the right running section 4R and the vehicle body 2.

[0269] As shown in the right diagram of Figure 45, the operation of increasing the distance between the right running unit 4R and the vehicle body 2 is performed by extending the rod 81a of the right cylinder 81R. This operation is performed by the distance change control unit 19B controlling the right cylinder 81R. Based on the detection result of the tilt detection device 170, the distance change control unit 19B determines whether the vehicle body 2 is tilted to the right by more than a predetermined amount, and if it determines that the vehicle body 2 is tilted by more than the predetermined amount, it drives the right cylinder 81R to extend the rod 81a. This causes the right running unit 4R to move in a direction away from the vehicle body 2 (to the right) (see arrow R2), increasing the distance between the right running unit 4R and the vehicle body 2.

[0270] As described above, by performing the operation to increase the distance between the right running section 4R and the body 2, the right wheels (right front wheel 7RF, right rear wheel 7RB) contact the ground at a position farther to the right from the body 2 than before the operation, as shown in the right diagram of Figure 45. This makes it possible to prevent the body 2 from tipping over to the right.

[0271] Note that the distance change mechanism 80 may perform both an operation to increase the distance between the left running unit 4L and the vehicle body 2 and an operation to increase the distance between the right running unit 4R and the vehicle body 2 as an operation to make the distance between the left running unit 4L and the vehicle body 2 different from the distance between the right running unit 4R and the vehicle body 2. In this case, by making the extension amount of the rod 81 a of the left cylinder 81L different from the extension amount of the rod 81 a of the right cylinder 81R, the distance between the running unit 4L and the vehicle body 2 can be made different from the distance between the right running unit 4R and the vehicle body 2.

[0272] When the tilt detection device 170 detects tilt of the vehicle body 2 while the left and right running sections 4L and 4R are positioned at a certain distance from the vehicle body 2 (when the distance between the left and right running sections 4L and 4R and the vehicle body 2 is equal to or greater than a predetermined distance), the distance change mechanism 80 may increase the distance between one of the left and right running sections 4L and 4R and the vehicle body 2, and decrease the distance between the other running section and the vehicle body 2. In this case, by extending the rod of one of the left and right cylinders 81L and 81R and shortening the other, the extension amount of the rod of the left cylinder 81L and the extension amount of the rod of the right cylinder 81R can be made different, thereby making the distance of the left running section 4L from the vehicle body 2 different from the distance of the right running section 4R from the vehicle body 2.

[0273] Figure 46 is a flowchart showing an example of the operation of the distance change mechanism 80. Below, an example of the operation of the distance change mechanism 80 will be described with reference to Figure 46. The operation of the distance change mechanism 80 is executed based on the control of the distance change control unit 19B.

[0274] While the work vehicle 1 is traveling, the tilt detection device 170 detects the left-right tilt of the vehicle body 2 (S1). The distance change control unit 19B determines whether the amount of tilt detected by the tilt detection device 170 is equal to or greater than a predetermined amount (S2). If it determines that the amount of tilt is less than the predetermined amount (S2: No), the distance change control unit 19B continues the detection operation. If it determines that the amount of tilt is equal to or greater than the predetermined amount (S2: Yes), it determines whether the direction of tilt is to the left (S3). If it determines that the direction of tilt is to the left (S3: Yes), the distance change mechanism 80 operates to increase the distance between the left traveling unit 4L and the vehicle body 2 (S4). If it determines that the direction of tilt is to the right (S3: No), the distance change mechanism 80 operates to increase the distance between the right traveling unit 4R and the vehicle body 2 (S5).

[0275] The flowchart shown in Figure 46 is an example of the operation of the distance change mechanism 80, and the operation of the distance change mechanism 80 is not limited to the flowchart in Figure 46 and can be modified appropriately as necessary. For example, the determinations in S2 and S3 may be performed simultaneously, or the order of the determinations in S2 and S3 may be reversed. Furthermore, in S3, it may be determined whether the tilt direction of the vehicle body 2 is to the right, or whether it is to the left or right.

[0276] The distance change mechanism 80 can change the lateral distance between the vehicle body 2 and the traveling units 4 (left traveling unit 4L, right traveling unit 4R) in accordance with the amount (magnitude) of tilt detected by the tilt detection device 170. Specifically, the lateral distance between the vehicle body 2 and the traveling units 4 can be increased as the tilt detected by the tilt detection device 170 increases. This allows the lateral distance between the vehicle body 2 and the traveling units 4 to be appropriately adjusted in accordance with the risk of tipping over.

[0277] Next, a case where the change mechanism 180 is the position change mechanism 70 will be described. In this case, the position change mechanism 70 changes the longitudinal position of the vehicle body 2 based on the detection result of the tilt detection device 170. The operation of this position change mechanism 70 is controlled by the position change control unit 19D. As described above, the position change mechanism 70 has a position change cylinder 73. The position change mechanism 70 changes the longitudinal position of the vehicle body 2 by driving the position change cylinder 73.

[0278] The position change mechanism 70 moves the vehicle body 2 backward relative to the running part 4 when the tilt detection device 170 detects that the vehicle body 2 is tilted forward by a predetermined amount or more, and moves the vehicle body 2 forward relative to the running part 4 when the tilt detection device 170 detects that the vehicle body 2 is tilted backward by a predetermined amount or more.

[0279] Figure 47 is a diagram showing a first example of the operation of the position change mechanism 70. The left diagram in Figure 47 shows a state in which a force (see arrow F9) is acting on the work vehicle 1 to tip it forward. When this force F9 causes the vehicle body 2 to tilt forward, the tilt detection device 170 detects the forward tilt of the vehicle body 2. When the tilt detection device 170 detects that the vehicle body 2 has tilted forward by more than a predetermined amount, the position change mechanism 70 performs an operation to move the vehicle body 2 rearward (see arrow A1 in Figure 47).

[0280] The operation of moving the vehicle body 2 rearward is performed by extending or retracting the rod 73b of the position changing cylinder 73 (see FIG. 23). This operation is performed by the position change control unit 19D controlling the position changing cylinder 73. Based on the detection result of the tilt detection device 170, the position change control unit 19D determines whether the vehicle body 2 is tilted forward by more than a predetermined amount, and if it determines that the vehicle body 2 is tilted by more than the predetermined amount, it drives the position change cylinder 73 to retract the rod 73b. This causes the vehicle body 2 to move rearward.

[0281] As described above, by performing the operation of moving the vehicle body 2 rearward, the vehicle body 2 moves rearward relative to the traveling unit 4, as shown in the right diagram of Figure 47. This moves the center of gravity of the work vehicle 1 rearward, making it possible to prevent the vehicle body 2 from tipping forward.

[0282] Figure 48 is a diagram showing a second example of the operation of the position change mechanism 70. The left diagram in Figure 48 shows a state in which a force (see arrow F10) is acting on the work vehicle 1 to cause it to tip backward. When this force F10 causes the vehicle body 2 to tilt backward, the tilt detection device 170 detects the rearward tilt of the vehicle body 2. When the tilt detection device 170 detects that the vehicle body 2 has tilted rearward by more than a predetermined amount, the position change mechanism 70 performs an operation to move the vehicle body 2 forward (see arrow A2 in Figure 48).

[0283] The operation of moving the vehicle body 2 forward is performed by extending or retracting the rod 73b of the position changing cylinder 73 (see FIG. 23). This operation is performed by the position change control unit 19D controlling the position changing cylinder. Based on the detection result of the tilt detection device 170, the position change control unit 19D determines whether the vehicle body 2 is tilted rearward by more than a predetermined amount, and if it determines that the vehicle body 2 is tilted by more than the predetermined amount, it drives the position change cylinder to extend the rod 73b. This causes the vehicle body 2 to move forward.

[0284] As described above, by performing the operation of moving the vehicle body 2 forward, the vehicle body 2 moves forward relative to the traveling unit 4, as shown in the right diagram of Figure 48. This moves the center of gravity of the work vehicle 1 forward, making it possible to prevent the vehicle body 2 from tipping over backward.

[0285] Fig. 49 is a flowchart showing an example of the operation of the position changing mechanism 70. Below, an example of the operation of the position changing mechanism 70 will be described with reference to Fig. 49. The operation of the position changing mechanism 70 is executed based on the control of the position change control unit 19D.

[0286] While the work vehicle 1 is traveling, the tilt detection device 170 detects the tilt of the vehicle body 2 in the fore-and-aft direction (S1). The position change control unit 19D determines whether the amount of tilt detected by the tilt detection device 170 is equal to or greater than a predetermined amount (S2). If it is determined that the amount of tilt is less than the predetermined amount (S2: No), the position change control unit 19D continues to perform the detection operation. If it is determined that the amount of tilt is equal to or greater than the predetermined amount (S2: Yes), it determines whether the direction of tilt is forward (S3). If it is determined that the direction of tilt is forward (S3: Yes), the position change mechanism 70 performs an operation to move the vehicle body 2 rearward relative to the traveling unit 4 (S4). If it is determined that the direction of tilt is rearward (S3: No), the position change mechanism 70 performs an operation to move the vehicle body 2 forward relative to the traveling unit 4 (S5).

[0287] The flowchart shown in Figure 49 is an example of the operation of the position change mechanism 70, and the operation of the position change mechanism 70 is not limited to the flowchart in Figure 49 and can be modified appropriately as necessary. For example, the determinations in S2 and S3 may be performed simultaneously, or the order of the determinations in S2 and S3 may be reversed. Furthermore, in S3, it may be determined whether the tilt direction of the vehicle body 2 is rearward, or whether it is forward or rearward.

[0288] The position change mechanism 70 can change the amount of forward or backward movement of the vehicle body 2 in response to the amount (magnitude) of tilt detected by the tilt detection device 170. Specifically, the amount of forward or backward movement of the vehicle body 2 can be increased as the tilt detected by the tilt detection device 170 increases. This makes it possible to appropriately adjust the longitudinal position of the vehicle body 2 relative to the running unit 4 in accordance with the risk of tipping over.

[0289] The position change mechanism 70 may change the longitudinal position of a portion of the vehicle body 2 based on the detection result of the tilt detection device 170. In this case, a modified position change mechanism 70 shown in FIG. 24 is used as the position change mechanism 70. In this case, the position change mechanism 70 changes the longitudinal position of the main body case 5 that houses the first battery 12A by driving the position change cylinder 73 based on the detection result of the tilt detection device 170. Specifically, the position change mechanism 70 moves the main body case 5 rearward relative to the vehicle body frame 21 when the tilt detection device 170 detects that the vehicle body 2 is tilted forward by more than a predetermined amount, and moves the main body case 5 forward relative to the vehicle body frame 21 when the tilt detection device 170 detects that the vehicle body 2 is tilted rearward by more than the predetermined amount. This moves the center of gravity of the work vehicle 1 in the direction opposite to the direction of tilt, thereby preventing the work vehicle 1 from tipping over.

[0290] A preferred embodiment of the present invention provides a work vehicle 1 as described in the following items.

[0291] (Item A1) A work vehicle 1 comprising a vehicle body 2, a structure 3 connectable to the vehicle body 2, a plurality of junction boxes 130 including a main junction box 130A provided on at least either the vehicle body 2 or the structure 3, and a sub-junction box 130B provided on at least either the vehicle body 2 or the structure 3, and a plurality of electrical devices 120, wherein at least one electrical device 120 of the plurality of electrical devices 120 is connected to the sub-junction box 130B, and at least one electrical device 120 of the plurality of electrical devices 120 that is different from the electrical device 120 connected to the sub-junction box 130B is connected to the main junction box 130A, and the sub-junction box 130B is connected to the work vehicle 1.

[0292] The work vehicle 1 according to item A1 can prevent the electrical wiring connecting the multiple junction boxes 130 and the multiple electrical devices 120 from becoming complicated. Furthermore, because the electrical wiring can be connected to the main junction box 130A via the sub-junction box 130B, the number of electrical wiring can be reduced. Therefore, even if a part of the work vehicle 1 is deformed (moved), the electrical wiring is less likely to become tangled.

[0293] (Item A2) The structure 3 includes a running section 4 arranged on the side of the vehicle body 2, the main junction box 130A is arranged on either the vehicle body 2 or the running section 4, and the sub-junction box 130B is arranged on the running section 4 when the main junction box 130A is arranged on the vehicle body 2, and is arranged on the vehicle body 2 when the main junction box 130A is arranged on the running section 4.

[0294] According to the work vehicle 1 relating to item A2, the main junction box 130A and the sub junction box 130B are arranged separately in the vehicle body 2 and the structure 3, so that the arrangement of the electrical equipment 120 arranged in the vehicle body 2 and the structure 3 can be simplified and easily carried out.

[0295] (Item A3) The plurality of electrical devices 120 include a first electrical device 121 arranged on the vehicle body 2 and a second electrical device 122 arranged on the traveling section 4, the main junction box 130A is connected to the first electrical device 121 when arranged on the vehicle body 2, and is connected to the second electrical device 122 when arranged on the traveling section 4, and the sub junction box 130B is connected to the second electrical device 122 when arranged on the traveling section 4, and is connected to the first electrical device 121 when arranged on the vehicle body 2. This is the work vehicle 1 described in Item A2.

[0296] According to the work vehicle 1 relating to item A3, the main junction box 130A and the sub junction box 130B can be positioned nearby to easily connect both the first electrical device 121 arranged on the vehicle body 2 and the second electrical device 122 arranged on the running part 4.

[0297] (Item A4) The running unit 4 includes a left running unit 4L arranged on the left side of the vehicle body 2 and a right running unit 4R arranged on the right side of the vehicle body 2, the main junction box 130A is arranged on the vehicle body 2, and the sub junction box 130B is arranged on the left running unit 4L and the right running unit 4R, a work vehicle 1 described in Item A2.

[0298] According to the work vehicle 1 relating to item A4, the main junction box 130A can be placed nearby and connected to the electrical equipment 120 arranged on the vehicle body 2, and the sub-junction box 130B can be placed nearby and connected to the electrical equipment 120 arranged on the left running section 4L and the right running section 4R.

[0299] (Item A5) The first electrical device 121 includes a first battery 12A, the second electrical device 122 includes a second battery 12B, and the first battery 12A and the second battery 12B are directly or indirectly connected to the main junction box 130A.

[0300] According to the work vehicle 1 relating to item A5, power can be supplied from the first battery 12A and the second battery 12B to the electrical equipment 120 via the main junction box 130A, making it easy to arrange the electrical wiring.

[0301] (Item A6) The work vehicle 1 described in Item A5, wherein the second electrical device 122 includes an electrical device 120 different from the second battery 12B, and the sub-junction box 130B relays electrical wiring connected to the electrical device 120 different from the second battery 12B.

[0302] According to the work vehicle 1 according to item A6, it is possible to easily arrange electrical wiring connected to an electrical device 120 different from the second battery 12B.

[0303] (Item A7) A work vehicle 1 described in any of items A1 to A6, which is provided with a movable part 150 that guides connection wiring connecting the main junction box 130A and the sub junction box 130B and moves in accordance with deformation of the connection wiring.

[0304] According to the work vehicle 1 relating to item A7, when the positional relationship between the main junction box 130A and the sub junction box 130B changes, it is possible to prevent malfunctions (twisting, tangling, damage) from occurring in the connection wiring connecting the main junction box 130A and the sub junction box 130B.

[0305] (Item A8) The work vehicle 1 according to any one of items A1 to A7, wherein the main junction box 130A is disposed on the vehicle body 2 and is capable of changing its vertical position together with the vehicle body 2.

[0306] According to the work vehicle 1 relating to item A8, the main junction box 130A can be changed in its vertical position together with the vehicle body 2, thereby preventing malfunctions in the electrical wiring connected to the main junction box 130A when the vertical position of the vehicle body 2 changes.

[0307] (Item A9) The work vehicle 1 according to Item A2, wherein the sub-junction box 130B is disposed on the traveling section 4 and is capable of changing its position in the left-right direction together with the traveling section 4.

[0308] According to the work vehicle 1 according to item A9, it is possible to prevent malfunctions from occurring in the electrical wiring connected to the sub-junction box 130B when the position of the traveling section 4 in the left-right direction changes.

[0309] (Item A10) A work vehicle 1 described in Item A2, in which the plurality of electrical devices 120 each include at least one battery 12, and at least one battery 12 and one junction box 130 are arranged on the vehicle body 2 and the traveling section 4, respectively.

[0310] According to the work vehicle 1 relating to item A10, the battery 12 and junction box 130 arranged on the vehicle body 2 and the running section 4 make it easy to arrange electrical wiring to the electrical equipment 120 arranged on the vehicle body 2 and the running section 4 without complicating the layout.

[0311] (Item A11) The running section 4 includes a left running section 4L arranged on the left side of the vehicle body 2 and a right running section 4R arranged on the right side of the vehicle body 2, and the multiple junction boxes 130 include a first junction box 131 arranged on the vehicle body 2, a second junction box 132 arranged on the left running section 4L, and a third junction box 133 arranged on the right running section 4R.

[0312] According to the work vehicle 1 relating to item A11, a junction box 130 is arranged on each of the vehicle body 2, the left running section 4L, and the right running section 4R, so that various electrical wiring arrangements for electrical equipment arranged on the vehicle body 2, the left running section 4L, and the right running section 4R can be easily carried out without complicating the arrangements.

[0313] (Item A12) The plurality of electrical devices 120 include a first electrical device 121 arranged on the vehicle body 2 and a second electrical device 122 arranged on the traveling section 4, and the left traveling section 4L is provided with a left traveling motor (motor 10LF, motor 10LB) that drives the left wheels as the second electrical device 122, and the right traveling section 4R is provided with a right traveling motor (motor 10RF, motor 10RB) that drives the right wheels as the second electrical device 122, and the second junction box 132 relays electrical wiring that is connected to the left traveling motor (motor 10LF, motor 10LB), and the third junction box 133 relays electrical wiring that is connected to the right traveling motor (motor 10RF, motor 10RB). This is the work vehicle 1 described in Item A11.

[0314] According to the work vehicle 1 relating to item A12, the electrical wiring for the left driving motor (motor 10LF, motor 10LB) that drives the left wheels and the right driving motor (motor 10RF, motor 10RB) that drives the right wheels can be easily performed without complicating the wiring.

[0315] (Item B1) A work vehicle 1 comprising a vehicle body 2, a traveling frame 8 including a left traveling frame 8L arranged on the left side of the vehicle body 2 and supporting the left wheel, and a right traveling frame 8R arranged on the right side of the vehicle body 2 and supporting the right wheel, and a hydraulic unit 100 arranged between the left traveling frame 8L and the right traveling frame 8R, and including a hydraulic valve 101 that controls the operation of hydraulic equipment mounted on the vehicle body 2 or the traveling frame 8.

[0316] According to the work vehicle 1 according to item B1, the hydraulic unit 100 is disposed between the left traveling frame 8L and the right traveling frame 8R, so that the hydraulic unit 100 can be disposed compactly in the left-right direction.

[0317] (Item B2) The work vehicle 1 according to Item B1, wherein the hydraulic unit 100 is covered on the left side by the left traveling frame 8L and on the right side by the right traveling frame 8R.

[0318] According to the work vehicle 1 according to item B2, both the left and right sides of the hydraulic unit 100 can be protected by the traveling frame 8.

[0319] (Item B3) A work vehicle 1 described in Item B1 or B2, which is provided with a battery 12 that stores electricity to be supplied to electrical equipment mounted on the vehicle body 2 or the traveling frame 8, and the hydraulic unit 100 and the battery 12 are arranged side by side in the front and rear between the left traveling frame 8L and the right traveling frame 8R.

[0320] According to the work vehicle 1 according to item B3, the hydraulic unit 100 and the battery 12 can be arranged in a compact manner in the left-right direction. Furthermore, the front or rear of the hydraulic unit 100 can be protected by the battery 12, and the front or rear of the battery 12 can also be protected by the hydraulic unit 100.

[0321] (Item B4) A work vehicle 1 described in any of Items B1 to B3, which is equipped with a lifting mechanism 90 that raises and lowers the vehicle body 2 relative to the traveling frame 8, and in which the hydraulic unit 100 is covered in at least two directions when the vehicle body 2 is lowered and in at least one direction when the vehicle body 2 is raised.

[0322] According to the work vehicle 1 relating to item B4, when the vehicle body 2 is raised, there are more directions from which the hydraulic unit 100 can be accessed compared to when the vehicle body 2 is lowered, thereby improving the maintainability of the hydraulic unit 100.

[0323] (Item B5) The hydraulic unit 100 includes the hydraulic valve 101, a hydraulic oil tank 102 that stores hydraulic oil to be supplied to the hydraulic equipment, and a hydraulic pump 103 that is driven by the hydraulic oil, and the hydraulic valve 101, the hydraulic pump 103, and the hydraulic oil tank 102 are concentrated at the rear of the vehicle body 2. A work vehicle 1 described in any of Items B1 to B4.

[0324] According to the work vehicle 1 relating to item B5, the hydraulic valve 101, hydraulic pump 103, and hydraulic oil tank 102 are concentrated at the rear of the vehicle body 2, so that oil leak checks and the like can be performed all at once when inspecting the hydraulic valve 101, hydraulic pump 103, and hydraulic oil tank 102, making it easy to maintain.

[0325] (Item B6) The work vehicle 1 described in Item B4, in which the vehicle body 2 has a main body 5 and a body frame 21 that supports the main body 5, the body frame 21 supports the main body 5 between the left running frame 8L and the right running frame 8R and is capable of rising and falling together with the main body 5, and the hydraulic unit 100 is positioned so as not to protrude from the body frame 21 at least in the left-right direction.

[0326] According to the work vehicle 1 according to item B6, interference between the hydraulic unit 100 and the traveling frame 8 can be avoided when the body frame 21 is raised or lowered.

[0327] (Item C1) A work vehicle 1 comprising a vehicle body 2, a structure 3 connectable to the vehicle body 2, a hydraulic actuator mounted on either the vehicle body 2 or the structure 3, hydraulic equipment mounted on the vehicle body 2 or the structure 3 on which the hydraulic actuator is not provided and separate from the hydraulic actuator, and a movement mechanism that moves either the vehicle body 2 or the structure 3 on which the hydraulic equipment is mounted, together with the hydraulic equipment, in the vertical direction.

[0328] According to the work vehicle 1 of this item C1, either the vehicle body 2 or the structure 3 on which the hydraulic equipment is mounted can be moved up and down together with the hydraulic equipment, making it easy to perform maintenance on the hydraulic equipment. Specifically, by moving the hydraulic equipment up and down, it becomes possible to easily access the hydraulic equipment, and maintenance of the hydraulic equipment can be easily performed.

[0329] (Item C2) The work vehicle 1 according to Item C1, wherein the hydraulic device is a hydraulic valve 101 that controls the operation of the hydraulic actuator.

[0330] According to the work vehicle 1 relating to item C2, maintenance of the hydraulic valve 101 that controls the operation of the hydraulic actuator can be easily performed.

[0331] (Item C3) A work vehicle 1 described in Item C1 or C2, wherein the hydraulic actuator is arranged at a fixed position, and the movement mechanism moves the hydraulic equipment to change the position of the hydraulic equipment relative to the hydraulic actuator.

[0332] According to the work vehicle 1 according to item C3, the position of the hydraulic equipment can be changed without moving the hydraulic actuator, thereby facilitating maintenance of the hydraulic equipment.

[0333] (Item C4) The work vehicle 1 according to any one of Items C1 to C3, wherein the hydraulic equipment is moved relative to the structure 3 together with the vehicle body 2 by the movement mechanism.

[0334] According to the work vehicle 1 according to item C4, the hydraulic equipment moves together with the vehicle body 2 relative to the structure 3, making it possible to access the hydraulic equipment without it being obstructed by the structure 3.

[0335] (Item C5) The structure 3 is a running frame 8 that is arranged on the side of the vehicle body 2 and supports the wheels, the moving mechanism is a lifting mechanism 90 that raises and lowers the vehicle body 2 relative to the running frame 8, and the hydraulic equipment is raised and lowered together with the vehicle body 2 relative to the running frame 8 by the lifting mechanism 90. A work vehicle 1 as described in Item C4.

[0336] According to the work vehicle 1 according to item C5, the hydraulic equipment moves together with the vehicle body 2 relative to the traveling frame 83, making it possible to access the hydraulic equipment without it being obstructed by the traveling frame 83.

[0337] (Item C6) The work vehicle 1 described in Item C5, wherein the hydraulic actuator is fixed to the traveling frame 8, and the hydraulic equipment rises and falls relative to the hydraulic actuator when the vehicle body 2 rises and falls relative to the traveling frame 8.

[0338] According to the work vehicle 1 according to item C6, the position of the hydraulic equipment can be changed without moving the hydraulic actuator and the traveling frame 8, thereby facilitating maintenance of the hydraulic equipment.

[0339] (Item C7) A work vehicle 1 described in Item C5 or C6, in which the structure 3 is a running frame 8 arranged on the side of the vehicle body 2 and supporting the wheels, the hydraulic actuator includes a steering cylinder 62 that steers the wheels, and the steering cylinder 62 is fixed to the structure 3.

[0340] According to the work vehicle 1 according to item C7, the position of the hydraulic equipment can be changed without moving the steering cylinder 62 and the structure 3, thereby facilitating maintenance of the hydraulic equipment.

[0341] (Item D1) A work vehicle 1 comprising a vehicle body 2, a running section 4 including a left running section 4L arranged on the left side of the vehicle body 2 and a right running section 4R arranged on the right side of the vehicle body 2, an inclination detection device 170 that detects the inclination of the vehicle body 2, and a change mechanism 180 that changes the positional relationship between the vehicle body 2 and the running section 4 based on the detection results of the inclination detection device 170.

[0342] According to the work vehicle 1 relating to this item D1, it is possible to prevent the work vehicle 1 from tipping over by changing the positional relationship between the vehicle body 2 and the running part 4 based on the detection results of the tilt detection device 170.

[0343] (Item D2) The change mechanism 180 includes a height change mechanism 90 that can change the vertical position of the vehicle body 2 relative to the running unit 4, and the height change mechanism 90 changes the vertical position of the vehicle body 2 based on the detection results of the tilt detection device 170. A work vehicle 1 as described in Item D1.

[0344] According to the work vehicle 1 relating to item D2, it is possible to lower the center of gravity of the work vehicle 1 based on the detection results of the tilt detection device 170, thereby preventing the work vehicle 1 from tipping over.

[0345] (Item D3) The change mechanism 180 includes a distance change mechanism 80 that can change the left-right distance of the running unit 4 relative to the vehicle body 2, and the distance change mechanism 80 changes the left-right distance of the running unit 4 relative to the vehicle body 2 based on the detection results of the tilt detection device 170.A work vehicle 1 described in item D1 or D2.

[0346] According to the work vehicle 1 relating to item D3, it is possible to increase the left-right distance of the running part 4 relative to the vehicle body 2 based on the detection results of the tilt detection device 170, thereby preventing the work vehicle 1 from tipping over.

[0347] (Item D4) The height change mechanism 90 includes a left height change mechanism 90L that changes the height of the left part of the vehicle body 2, and a right height change mechanism 90R that changes the height of the right part of the vehicle body 2, and the work vehicle 1 described in Item D2 makes the height of the left part and the height of the right part of the vehicle body 2 different based on the detection results of the tilt detection device 170.

[0348] According to the work vehicle 1 according to item D4, by raising the vehicle body on the side opposite to the side where the vehicle body 2 is tilted, a moment can be applied in a direction that prevents the work vehicle 1 from tipping over. This makes it possible to prevent the work vehicle 1 from tipping over.

[0349] (Item D5) The height change mechanism 90 performs at least one of the following operations: raising the left part of the vehicle body 2 and lowering the right part of the vehicle body 2 when the tilt detection device 170 detects that the vehicle body 2 is tilted to the left by a predetermined amount or more; and performs at least one of the following operations: raising the right part of the vehicle body 2 and lowering the left part of the vehicle body 2 when the tilt detection device 170 detects that the vehicle body 2 is tilted to the right by a predetermined amount or more. This is the work vehicle 1 described in Item D4.

[0350] According to the work vehicle 1 relating to item D5, a moment can be applied to the vehicle body 2 in a direction that prevents tipping over based on the detection results of the tilt detection device 170, thereby preventing the work vehicle 1 from tipping over.

[0351] (Item D6) The work vehicle 1 described in Item D2, wherein the height change mechanism 90 lowers the vehicle body 2 when the tilt detection device 170 detects that the vehicle body 2 is tilted by a predetermined amount or more.

[0352] According to the work vehicle 1 relating to item D6, when the vehicle body 2 is tilted significantly, the vehicle body 2 is lowered to lower the center of gravity of the work vehicle 1, thereby preventing the work vehicle 1 from tipping over.

[0353] (Item D7) The distance change mechanism 80 includes a left distance change mechanism 80L that changes the left-right distance of the left running unit 4L relative to the vehicle body 2, and a right distance change mechanism 80R that changes the left-right distance of the right running unit 4R relative to the vehicle body 2, and the work vehicle 1 described in Item D3 makes the distance of the left running unit 4L from the vehicle body 2 and the distance of the right running unit 4R from the vehicle body 2 different based on the detection results of the tilt detection device 170.

[0354] According to the work vehicle 1 relating to item D7, the work vehicle 1 can be prevented from tipping over by increasing the left-right distance from the vehicle body 2 of the running section 4 on the side where the vehicle body 2 is tilted.

[0355] (Item D8) The distance change mechanism 80 of the work vehicle 1 described in Item D7 increases the distance between the left running section 4L and the vehicle body 2 when the tilt detection device 170 detects that the vehicle body 2 is tilted to the left by more than a predetermined amount, and increases the distance between the right running section 4R and the vehicle body 2 when the tilt detection device 170 detects that the vehicle body 2 is tilted to the right by more than a predetermined amount.

[0356] According to the work vehicle 1 relating to item D8, the work vehicle 1 can be prevented from tipping over by increasing the left-right distance from the vehicle body 2 of the running section 4 on the side where the vehicle body 2 is tilted based on the detection results of the tilt detection device 170.

[0357] (Item D9) A work vehicle 1 described in any of items D1 to D8, wherein the change mechanism 180 includes a position change mechanism 70 that can change the fore-and-aft position of the vehicle body 2 relative to the running unit 4, and the position change mechanism 70 changes the fore-and-aft position of the vehicle body 2 based on the detection results of the tilt detection device 170.

[0358] According to the work vehicle 1 relating to item D9, by changing the position of the vehicle body 2 in the forward / backward direction on the side opposite to the side on which the vehicle body 2 is tilted, it is possible to prevent the work vehicle 1 from tipping over.

[0359] (Item D10) The position change mechanism 70 moves the vehicle body 2 rearward relative to the running unit 4 when the tilt detection device 170 detects that the vehicle body 2 is tilted forward by more than a predetermined amount, and moves the vehicle body 2 forward relative to the running unit 4 when the tilt detection device 170 detects that the vehicle body 2 is tilted backward by more than a predetermined amount. This is the work vehicle 1 described in Item D9.

[0360] According to the work vehicle 1 relating to item D10, the position of the vehicle body 2 can be changed in the forward / backward direction on the side opposite to the side on which the vehicle body 2 is tilted based on the detection results of the tilt detection device 170, thereby preventing the work vehicle 1 from tipping over.

[0361] Although the embodiments of the present invention have been described above, the embodiments disclosed herein should be considered to be illustrative in all respects and not restrictive. The scope of the present invention is defined by the claims, not by the above description, and is intended to include all modifications within the meaning and scope of the claims.

[0362] REFERENCE SIGNS LIST 1 Work vehicle 2 Vehicle body 3 Structure 8 Traveling frame 8L Left traveling frame 8R Right traveling frame 12 Battery 21 Center frame (vehicle body frame) 62 Steering cylinder (hydraulic actuator) 90 Lifting mechanism (movement mechanism) 100 Hydraulic unit 101 Hydraulic valve (hydraulic equipment) 102 Hydraulic oil tank 103 Hydraulic pump

Claims

1. A work vehicle comprising a vehicle body, a structure connectable to the vehicle body, a hydraulic actuator mounted on either the vehicle body or the structure, a hydraulic device mounted on the vehicle body or the structure where the hydraulic actuator is not provided and different from the hydraulic actuator, and a moving mechanism for moving either the vehicle body or the structure on which the hydraulic device is mounted in the vertical direction together with the hydraulic device.

2. The work vehicle according to claim 1, wherein the hydraulic device is a hydraulic valve that controls the operation of the hydraulic actuator.

3. The work vehicle according to claim 1 or 2, wherein the hydraulic actuator is arranged with a fixed position, and the moving mechanism moves the hydraulic device to change the position of the hydraulic device relative to the hydraulic actuator.

4. The work vehicle according to claim 1 or 2, wherein the hydraulic device moves with the vehicle body relative to the structure by the moving mechanism.

5. The structure is a traveling frame arranged on the side of the vehicle body and supporting wheels. The moving mechanism is a lifting mechanism for lifting and lowering the vehicle body relative to the traveling frame. The work vehicle according to claim 4, wherein the hydraulic device is lifted and lowered with the vehicle body relative to the traveling frame by the lifting mechanism.

6. The work vehicle according to claim 5, wherein the hydraulic actuator is fixed to the traveling frame, and the hydraulic device moves up and down relative to the hydraulic actuator when the vehicle body moves up and down relative to the traveling frame.

7. The structure is a traveling frame arranged on the side of the vehicle body and supporting wheels. The hydraulic actuator includes a steering cylinder for steering the wheels. The work vehicle according to claim 1 or 2, wherein the steering cylinder is fixed to the structure.

8. A work vehicle comprising a vehicle body, a traveling frame including a left traveling frame arranged on the left side of the vehicle body and supporting left wheels and a right traveling frame arranged on the right side of the vehicle body and supporting right wheels, and a hydraulic unit arranged between the left traveling frame and the right traveling frame, the hydraulic unit including a hydraulic valve for controlling the operation of a hydraulic device mounted on the vehicle body or the traveling frame.

9. The work vehicle according to claim 8, wherein the hydraulic unit is covered on the left side by the left traveling frame and on the right side by the right traveling frame.

10. The work vehicle according to claim 8 or 9, further comprising a battery for storing electric power supplied to electrical equipment mounted on the vehicle body or the traveling frame, wherein the hydraulic unit and the battery are arranged side by side in the front-rear direction between the left traveling frame and the right traveling frame.

11. The work vehicle according to claim 8 or 9, further comprising a lifting mechanism for lifting and lowering the vehicle body with respect to the traveling frame, wherein at least two directions of the hydraulic unit are covered when the vehicle body is in the lowered state, and at least one direction of the hydraulic unit is covered when the vehicle body is in the raised state.

12. The work vehicle according to claim 8 or 9, wherein the hydraulic unit includes the hydraulic valve, a hydraulic oil tank for storing hydraulic oil supplied to the hydraulic equipment, and a hydraulic pump driven by the hydraulic oil, and the hydraulic valve, the hydraulic pump, and the hydraulic oil tank are centrally arranged at the rear part of the vehicle body.

13. The vehicle body has a main body and a vehicle body frame for supporting the main body, the vehicle body frame supports the main body between the left traveling frame and the right traveling frame and is capable of lifting and lowering together with the main body, and the hydraulic unit is arranged so as not to protrude from the vehicle body frame at least in the left-right direction. The work vehicle according to claim 11.

Images