Work vehicle

Abstract

To provide a work vehicle comprising hydraulic equipment and enabling the hydraulic equipment to be easily maintained.SOLUTION: A work vehicle comprises: a vehicle body; a structure connectable to the vehicle body; a hydraulic actuator mounted either on the vehicle body or the structure; hydraulic equipment which is mounted on the vehicle body where no hydraulic actuator is provided or on the structure and is different from the above hydraulic actuator; and a movement mechanism vertically moving either the vehicle body mounted with the hydraulic equipment or the structure, together with the hydraulic equipment.SELECTED DRAWING: Figure 22

Description

Technical Field

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

Background Art

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

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the above-described work vehicle, since the control valve (hydraulic device) is arranged between the left and right wheels (rear wheels), it is impossible to access the control valve (hydraulic device) from the side. Therefore, it was impossible to easily perform maintenance on the control valve (hydraulic device).

[0005] The present invention has been made in view of the above problems, and an object thereof is to provide a work vehicle capable of easily performing maintenance on a hydraulic device.

Means for Solving the Problems

[0006] A work vehicle according to an embodiment of the present invention includes 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.

[0007] The hydraulic device may be a hydraulic valve that controls the operation of the hydraulic actuator.

[0008] The hydraulic actuator may be fixedly arranged, and the moving mechanism may move the hydraulic device to change the position of the hydraulic device relative to the hydraulic actuator.

[0009] The hydraulic device may move relative to the structure together with the vehicle body by the moving mechanism.

[0010] 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, and the hydraulic device may be lifted and lowered relative to the traveling frame together with the vehicle body by the lifting mechanism.

[0011] The hydraulic actuator is fixed to the traveling frame, and the hydraulic device may be lifted and lowered relative to the hydraulic actuator when the hydraulic device is lifted and lowered relative to the traveling frame together with the vehicle body.

[0012] 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, and the steering cylinder may be fixed to the structure.

Advantages of the Invention

[0013] According to the work vehicle of the present invention, since either the vehicle body or the structure on which the hydraulic equipment is mounted can be moved vertically together with the hydraulic equipment, the maintenance of the hydraulic equipment can be easily performed.

Brief Description of the Drawings

[0014]

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Embodiments for Carrying Out the Invention

[0015] Hereinafter, a preferred embodiment of the work vehicle 1 according to the present invention will be described. FIGS. 1 to 7 are views showing an embodiment of the work vehicle 1. FIG. 1 is a perspective view of the work vehicle 1. FIG. 2 is a left side view of the work vehicle 1. FIG. 3 is a right side view of the work vehicle 1. FIG. 4 is a front view of the work vehicle 1. FIG. 5 is a rear view of the work vehicle 1. FIG. 6 is a plan view of the work vehicle 1. FIG. 7 is a block diagram showing the overall configuration of the work vehicle 1.

[0016] In the following description, the direction indicated by the arrow X1 in the drawings is the front, the direction indicated by the arrow X2 is the rear, the direction indicated by the arrow Y1 is the left, the direction indicated by the arrow Y2 is the right, the direction indicated by the arrow Z1 is the upper, and the direction indicated by the arrow Z2 is the lower.

[0017] Examples of the work performed by the work vehicle 1 include, but are not limited to, work related to agriculture, work related to industry (such as civil engineering and construction), work related to transportation, etc. In the case of the preferred embodiment of the present invention, the work performed by the work vehicle 1 is work related to agriculture (farming work). In this case, the work vehicle 1 is an agricultural work vehicle.

[0018] As shown in FIGS. 1 to 6, the work vehicle 1 includes a vehicle body 2 and a structure 3 that can be connected to the vehicle body 2. The structure 3 includes a traveling unit 4 disposed on the side of the vehicle body 2. The traveling unit 4 includes a left traveling unit 4L and a right traveling unit 4R. The left traveling unit 4L is disposed on the left side of the vehicle body 2. The right traveling unit 4R is disposed on the right side of the vehicle body 2. Therefore, the vehicle body 2 is disposed between the left traveling unit 4L and the right traveling unit 4R.

[0019] The vehicle body 2 has a main body 5 and a vehicle body frame 21 that supports the main body 5. The main body 5 is formed in a box shape having an internal space. In the case of the present embodiment, the main body 5 is formed in a substantially rectangular parallelepiped shape having an internal space. However, the shape of the main body 5 is not limited to the substantially rectangular parallelepiped shape. A first battery 12A described later is accommodated in the internal space of the main body 5. That is, the main body 5 has a function of a case for accommodating the first battery 12A. Hereinafter, the main body 5 will also be referred to as the "main body case 5".

[0020] The vehicle body frame 21 supports the main body case 5 between the left traveling frame 8L and the right traveling frame 8R, which will be described later. The vehicle body frame 21 is a center frame disposed at the center in the left-right direction of the work vehicle 1. The vehicle body frame (center frame) 21 can be lifted and lowered together with the main body case 5 by the drive of a height changing mechanism (lifting mechanism) 90, which will be described later.

[0021] The vehicle body frame 21 includes a left vehicle body frame 23, a right vehicle body frame 24, and a central vehicle body frame 22. The central vehicle body frame 22 includes an upper vehicle body frame 25 and a lower vehicle body frame 26. The left vehicle body frame 23 is disposed to the left of the main body case 5. The right vehicle body frame 24 is disposed to the right of the main body case 5. The upper vehicle body frame 25 is disposed above the main body case 5. The lower vehicle body frame 26 is disposed below the main body case 5.

[0022] 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 are collectively referred to as "left wheels", and the right front wheel 7RF and the right rear wheel 7RB are collectively referred to as "right wheels". Also, the left front wheel 7LF, the right front wheel 7RF, the left rear wheel 7LB, and the right rear wheel 7RB are collectively denoted as "wheels 7".

[0023] The wheels 7 (left front wheel 7LF, right front wheel 7RF, left rear wheel 7LB, right rear wheel 7RB) are disposed on the side of the vehicle body 2. The left wheels (left front wheel 7LF and left rear wheel 7LB) are disposed to the left of the vehicle body 2. The right wheels (right front wheel 7RF and right rear wheel 7RB) are disposed to the right of the vehicle body 2.

[0024] The traveling frame 8 is a structure 3 connectable to the vehicle body 2. That is, the work vehicle 1 of the present embodiment includes the traveling frame 8 as a structure 3 connectable to the vehicle body 2. In the following description, it will be described assuming that the structure 3 connectable to the vehicle body 2 is the traveling frame 8. However, the structure 3 connectable to the vehicle body 2 is not limited to the traveling frame 8. Therefore, the work vehicle 1 may include a structure different from the traveling frame 8 as the structure 3 connectable to the vehicle body 2.

[0025] 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).

[0026] As shown in FIG. 7, the work vehicle 1 includes a power device 9 for driving (rotating) the wheels 7. The power device 9 generates power for driving the wheels 7, and the power is transmitted to the wheels 7. The power device 9 includes a motor 10 and a battery 12. However, the power device 9 may include an engine instead of the motor 10. Further, the power device 9 may include a fuel cell.

[0027] The motor 10 is a traveling system motor that generates power for driving the wheels 7. The motor 10 is an electric motor 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, fifth inverter 13E) described later. The inverter 13 controls the rotation of the motor 10 based on a control signal from a control device 19 described later. The battery 12 stores the power supplied to the motor 10.

[0028] As shown in FIG. 7, the work vehicle 1 includes a motor 11 which is a work system motor in addition to a motor 10 which is a traveling system motor. The work system motor generates power to drive a device or mechanism different from the wheels 7. The motor 11 is an electric motor driven by electric power supplied from a battery 12. The rotation of the motor 11 can be controlled by an inverter 13.

[0029] Hereinafter, the motor 10 may be referred to as the "traveling system motor 10", and the motor 11 may be referred to as the "work system motor 11". The traveling system motor 10 and the work system motor 11 can be driven independently of each other. The work system motor 11 is a motor for driving a hydraulic pump that operates a hydraulic cylinder described later.

[0030] 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 system motor 10, the hydraulic motor (work system motor 11) is driven by the hydraulic oil supplied from the hydraulic pump, and the external output shaft is driven by the drive of the hydraulic motor. Further, the work vehicle 1 may include a work system motor 11 that is a hydraulic motor separately from the work system motor 11 that is an electric motor.

[0031] Although not shown, the work vehicle 1 can include a mounting portion (for example, a three-point link mechanism or the like) for mounting a work device (implement), and an output shaft that outputs power for driving the work device mounted on the mounting portion. The device portion and the output shaft are provided, for example, at the rear or front of the vehicle body 2. The external output shaft can be driven by the work system motor 11.

[0032] The battery 12 stores electric power 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 the traveling system motor 10 and the work system motor 11. The traveling system motor 10 (motor 10LF, motor 10RF, motor 10LB, motor 10RB described later) is mounted on the traveling frame 8. The work system motor 11 is mounted on the vehicle body 2.

[0033] As shown in FIG. 6 and the like, the battery 12 includes a first battery 12A and a second battery 12B. The first battery 12A stores the electric power supplied to the traveling system motor 10 and the working system motor 11. The second battery 12B stores the electric power supplied to the traveling system motor 10 and the working system motor 11. The first battery 12A is disposed on the vehicle body 2 (specifically, the main body case 5). The second battery 12B is disposed on the traveling unit 4 (specifically, the left traveling frame 8L and the right traveling frame 8R).

[0034] The first battery 12A and the second battery 12B are batteries having the same function and the same structure or operating principle for exerting the function. For example, the first battery 12A and the second battery 12B are lithium-ion batteries. Note that the work vehicle 1 may be provided with a battery (for example, a lead battery) different from the first battery 12A and the second battery 12B.

[0035] As shown in FIG. 7, the work vehicle 1 includes a transmission 14. The transmission 14 can switch the driving force of the traveling device (traveling system motor 10) by shifting gears. Further, the transmission 14 can switch the forward and reverse of the work vehicle 1. The transmission 14 may be provided with a shift clutch capable of switching 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.

[0036] As shown in FIG. 7, the work vehicle 1 includes a positioning device 15. The positioning device 15 can detect the position of the vehicle body 2 (positioning information including latitude and longitude) by a satellite positioning system (positioning satellite) such as D-GPS, GPS, GLONASS, Beidou, Galileo, or Michibiki. That is, the positioning device 15 receives a satellite signal (position of the positioning satellite, transmission time, correction information, etc.) transmitted from the positioning satellite, and detects the position of the vehicle body 2 (for example, latitude and longitude) based on the satellite signal.

[0037] The positioning device 15 includes a receiving device 16 and an inertial measurement unit (IMU) 17. The receiving device 16 has an antenna or 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 includes 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. Incidentally, the yaw angle may be detected by installing a plurality of positioning devices 15.

[0038] As shown in FIG. 7, the work vehicle 1 includes a situation detection device 18. The situation detection device 18 detects the situation around the vehicle body 2. The situation detection device 18 detects, as the situation around the vehicle body 2, for example, road information which is information regarding a road on which the work vehicle 1 can travel. The situation detection device 18 detects, as the road information, for example, the width of the traveling road. The width of the traveling road detected by the situation detection device 18 is the width of an object that the work vehicle 1 attempts to straddle between the left and right wheels and travel over. The situation detection device 18 detects, as the width of the traveling road, for example, the width of ridges provided on the ground, the width of obstacles that impede travel existing on the ground, and the like.

[0039] As shown in FIG. 7, the situation detection device 18 includes a camera (imaging device) 18a, a sensor 18b, and a calculation unit 18c. The camera 18a is mounted on the vehicle body 2 and captures the surroundings of the vehicle body 2 to generate an image signal. The calculation unit 18c is composed of a computer or the like including a signal processing circuit that processes the generated image signal. The signal processing circuit detects the state of the object (presence or absence of the object, position of the object, type of the object, size of the object, etc.) based on the image signal 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).

[0040] As shown in FIG. 7, the work vehicle 1 is provided with a control device 19. The control device 19 is a device that performs various controls on the work vehicle 1. The control device 19 includes an arithmetic unit (such as a CPU) and a storage unit (such as a RAM and a ROM). The storage unit may include an external memory provided outside the control device 19. The control device 19 is connected to various devices and mechanisms shown in FIG. 7 etc. via an in-vehicle LAN (in-vehicle network) such as a CAN (Controller Area Network) or a communication line.

[0041] The control device 19 controls the operations of various devices and mechanisms communicably connected to the control device 19 by the arithmetic unit executing various control programs stored in the storage unit. The functions of each control unit (the automatic driving control unit 19A, the distance change control unit 19B, the height change control unit 19C, the position change control unit 19D) of the control device 19 described later are realized by the arithmetic unit executing a predetermined control program stored in the storage unit.

[0042] 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 automatic driving control. In the line-type automatic driving control, the automatic driving control unit 19A controls the operations of a steering mechanism 60, a transmission 14, a motor 10, etc. described later so that the work vehicle 1 (the vehicle body 2) moves along a preset travel planned line.

[0043] In the autonomous automatic driving control, the automatic driving control unit 19A sets the traveling direction (steering direction) and vehicle speed (speed) of the vehicle body 2 etc. based on the result of sensing (detecting an object) the surroundings of the work vehicle 1 (the vehicle body 2) by a positioning device 15, a situation detection device 18, etc., and controls the operations of the steering mechanism 60, the transmission 14, and the motor 10 etc. so as to achieve the set steering and vehicle speed.

[0044] Note that the line-type automatic driving control and the autonomous-type automatic driving control may be switchable by a switch or the like. Further, the automatic driving control unit 19A may be configured to be capable of executing either one of the line-type automatic driving control and the autonomous-type automatic driving control. Note that the configuration of the automatic driving control unit 19A is not limited to the above-described configuration.

[0045] The work vehicle 1 can perform automatic driving (driverless driving) without the operator boarding because the control device 19 includes the automatic driving control unit 19A. Therefore, the work vehicle 1 of the illustrated embodiment does not have a driver's seat on which the operator sits. However, the work vehicle 1 may be a vehicle on which the operator boards and performs automatic driving. Alternatively, the work vehicle 1 may be a vehicle on which the operator boards and drives to travel. When the work vehicle 1 is a vehicle on which the operator boards, the vehicle body 2 is provided with a driver's seat.

[0046] As shown in FIG. 1, the work vehicle 1 includes a frame structure 20. The frame structure 20 constitutes the skeleton of the work vehicle 1. FIG. 8 is a perspective view showing the frame structure 20. The frame structure 20 is composed of a vehicle body frame 21 and a traveling frame 8. FIG. 9 is a perspective view showing the vehicle body frame 21. FIG. 10 is a perspective view showing the traveling frame 8. FIG. 11 is an exploded perspective view of the vehicle body frame 21.

[0047] As shown in FIG. 11, the vehicle body frame 21 is configured by combining a central vehicle body frame 22, a left vehicle body frame 23, and a right vehicle body frame 24. The central vehicle body frame 22 has an upper vehicle body frame 25, a lower vehicle body frame 26, and a connection frame 27.

[0048] The upper body frame 25 has 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 space therebetween 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 portion of the first upper frame member 25a and the front portion of the second upper frame member 25b. The second cylindrical body 25d extends in the left-right direction and connects the rear portion of the first upper frame member 25a and the rear portion of the second upper frame member 25b. The third cylindrical body 25e extends in the left-right direction and connects the central portion of the first upper frame member 25a and the central portion of the second upper frame member 25b.

[0049] 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 space therebetween 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 and 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 and the rear portion of the second lower frame member 26b.

[0050] The connection frame 27 extends in the vertical direction and connects the upper body frame 25 and the lower body frame 26. The connection frame 27 includes a first connection frame member 27a, a second connection frame member 27b, a third connection frame member 27c, and a fourth connection frame member 27d. The first connection frame member 27a connects the front portion of the first upper frame member 25a and the front portion of the first lower frame member 26a. The second connection frame member 27b connects the front portion of the second upper frame member 25b and the front portion of the second lower frame member 26b. The third connection frame member 27c connects the rear portion of the first upper frame member 25a and the rear portion of the first lower frame member 26a. The fourth connection frame member 27d connects the rear portion of the second upper frame member 25b and the rear portion of the second lower frame member 26b.

[0051] The length of the lower body frame 26 in the front-rear direction is smaller than the length of the upper body frame 25 in the front-rear direction. The rear part of the upper body frame 25 extends further rearward than the rear part of the lower body frame 26. Below the rear part of the upper body frame 25 that extends further rearward than the rear part of the lower body frame 26, a first support 28 is provided. The first support 28 supports a hydraulic unit 100 described later. The first support 28 has a support plate 28a and the like that support the hydraulic unit 100 described later.

[0052] The left body frame 23 has an upper left frame member 23a, a first longitudinal frame member 23b, a second longitudinal frame member 23c, and a third longitudinal frame member 23d. The upper left frame member 23a is disposed to the left of the first upper frame member 25a and extends in the front-rear direction. The first longitudinal frame member 23b extends downward from the front part of the upper left frame member 23a. The second longitudinal frame member 23c extends downward from the upper left frame member 23a behind the first longitudinal frame member 23b. The third longitudinal frame member 23d extends downward from the upper left frame member 23a behind the second longitudinal frame member 23c.

[0053] The left 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 part of the upper left frame member 23a and extends rightward. The second connecting member 23f is connected to the middle part in the front-rear direction of the upper left frame member 23a and extends rightward. The third connecting member 23g is connected to the rear part of the upper left frame member 23a and extends rightward. The fourth connecting member 23h is connected to the lower part of the first longitudinal frame member 23b and extends rightward. The fifth connecting member 23i is connected to the lower part of the third longitudinal frame member 23d and extends rightward.

[0054] The right vehicle body frame 24 has an upper right frame member 24a, a fourth longitudinal frame member 24b, a fifth longitudinal frame member 24c, and a sixth longitudinal frame member 24d. The upper right frame member 24a is disposed to the right of the second upper frame member 25b and extends in the front-rear direction. The fourth longitudinal frame member 24b extends downward from the front portion of the upper right frame member 24a. The fifth longitudinal frame member 24c extends downward from the upper right frame member 24a behind the fourth longitudinal frame member 24b. The sixth longitudinal frame member 24d extends downward from the upper right frame member 24a behind the fifth longitudinal frame member 24c.

[0055] The right vehicle body frame 24 has a sixth connecting member 24e, a seventh connecting member 24f, an eighth connecting member 24g, a ninth connecting member 24h, and a tenth connecting member 24i. The sixth connecting member 24e is connected to the front portion of the upper right frame member 24a and extends leftward. The seventh connecting member 24f is connected to the middle portion in the front-rear direction of the upper right frame member 24a and extends leftward. The eighth connecting member 24g is connected to the rear portion of the upper right frame member 24a and extends leftward. The ninth connecting member 24h is connected to the lower portion of the fourth longitudinal frame member 24b and extends leftward. The tenth connecting member 24i is connected to the lower portion of the sixth longitudinal frame member 24d and extends leftward.

[0056] As shown by the arrows in FIG. 11, the first connecting member 23e is inserted into the inside of the first cylindrical body 25c from the left. The second connecting member 23f is inserted into the inside of the third cylindrical body 25e from the left. The third connecting member 23g is inserted into the inside of the second cylindrical body 25d from the left. The fourth connecting member 23h is inserted into the inside of the fourth cylindrical body 26c from the left. The fifth connecting member 23i is inserted into the inside of the fifth cylindrical body 26d from the left. Thereby, the central vehicle body frame 22 and the left vehicle body frame 23 are connected.

[0057] The sixth connecting member 24e is inserted into the interior of the first cylindrical body 25c from the right. The seventh connecting member 24f is inserted into the interior of the third cylindrical body 25e from the right. The eighth connecting member 24g is inserted into the interior of the second cylindrical body 25d from the right. The ninth connecting member 24h is inserted into the interior of the fourth cylindrical body 26c from the right. The tenth connecting member 24i is inserted into the interior of the fifth cylindrical body 26d from the right. Thereby, the central vehicle body frame 22 and the right vehicle body frame 24 are connected.

[0058] 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 with respect to the second cylindrical body 25d. The fourth connecting member 23h and the ninth connecting member 24h are movable in the left - right direction with respect to the fourth cylindrical body 26c. The fifth connecting member 23i and the tenth connecting member 24i are movable in the left - right direction with respect to the fifth cylindrical body 26d. Thereby, the left vehicle body frame 23 and the right vehicle body frame 24 are movable in the left - right direction with respect to the central vehicle body frame 22.

[0059] The left vehicle body frame 23 is connected to the left traveling frame 8L via a mast mechanism described later. Therefore, when the left vehicle body frame 23 moves in the left - right direction with respect to the central vehicle body frame 22, the left traveling frame 8L can move in the left - right direction with respect to the central vehicle body frame 22. Thereby, the left traveling unit 4L can move in the left - right direction with respect to the vehicle body 2. A specific method for moving the left traveling unit 4L will be described in detail later.

[0060] The right vehicle body frame 24 is connected to the right traveling frame 8R via a mast mechanism described later. Therefore, when the right vehicle body frame 24 moves in the left - right direction with respect to the central vehicle body frame 22, the right traveling frame 8R can move in the left - right direction with respect to the central vehicle body frame 22. Thereby, the right traveling unit 4R can move in the left - right direction with respect to the vehicle body 2. A specific method for moving the right traveling unit 4R will be described in detail later.

[0061] As shown in FIG. 10, the left traveling 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-rear direction and has a front portion 8La1, a rear portion 8La2, and an intermediate portion 8La3. The second upper left frame member 8Lb has a first portion extending left-rearward 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 portion and the second portion.

[0062] The left traveling frame 8L has 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 intermediate 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 intermediate 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.

[0063] The left traveling 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 protruding upward. The first left connecting member 8Lh connects the front part of the first upper left frame member 8La and the front part of the second upper left frame member 8Lb. The second left connecting member 8Li connects the first upper left frame member 8La and 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 and 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.

[0064] The left part of the first left connecting member 8Lh and the left part of the second left connecting member 8Li are connected by a first front connecting member 8Lm. The left part of the second left connecting member 8Li and the left part of the third left connecting member 8Lj are connected by a first intermediate connecting member 8Ln. The right part of the second left connecting member 8Li and the right part of the third left connecting member 8Lj are connected by a second intermediate connecting member 8Lo. The left part of the third left connecting member 8Lj and the left part of the fourth left connecting member 8Lk are connected by a first rear connecting member 8Lp.

[0065] The left traveling frame 8L has a second support 29. The second support 29 supports a second battery 12B to be described later. The second support 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, the fifth left vertical frame member 8Lg) described above, and 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.

[0066] 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.

[0067] As shown in FIG. 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-rear direction and has a front portion 8Ra1, a rear portion 8Ra2, and an intermediate portion 8Ra3. The second upper right frame member 8Rb has a first portion extending right-rearward 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 portion and the second portion.

[0068] The right traveling frame 8R has 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 upper right frame member 8Ra and extends downward. The second right vertical frame member 8Rd is connected to the front portion 8Ra1 and the intermediate portion 8Ra3 of the first upper right frame member 8Ra and extends downward. The third right vertical frame member 8Re is connected to the rear portion 8Ra2 and the intermediate portion 8Ra3 of the first upper right frame member 8Ra and extends downward. The fourth right vertical frame member 8Rf extends downward from the second upper right 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 upper right frame member 8Rb to the right of the third right vertical frame member 8Re.

[0069] The right running frame 8R has 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 protruding upward. The first right connecting member 8Rh connects the front part of the first upper right frame member 8Ra and the front part of the second upper right frame member 8Rb. The second right connecting member 8Ri connects the first upper right frame member 8Ra and the second upper right frame member 8Rb behind the first right connecting member 8Rh. The third right connecting member 8Rj connects the first upper right frame member 8Ra and the second upper right 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.

[0070] The right part of the first right connecting member 8Rh and the right part of the second right connecting member 8Ri are connected by a first front connecting member 8Rm. The right part of the second right connecting member 8Ri and the right part of the third right connecting member 8Rj are connected by a first intermediate connecting member 8Rn. The left part of the second right connecting member 8Ri and the left part of the third right connecting member 8Rj are connected by a second intermediate connecting member 8Ro. The right part of the third right connecting member 8Rj and the right part of the fourth right connecting member 8Rk are connected by a first rear connecting member 8Rp.

[0071] The right running frame 8R has a third support 30. The third support 30 supports a second battery 12B described later. The third support 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, the fifth right vertical frame member 8Rg) described above, and 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.

[0072] 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.

[0073] The frame structure 20 includes a mast mechanism that supports the running frames (left running frame 8L, right running frame 8R) so as to be vertically movable with respect to the vehicle body frame 21. As shown in FIGS. 9, 10, 11, and 12, the mast mechanism includes a first member 31 attached to the running frames (left running frame 8L, right running frame 8R) and a second member 32 attached to the vehicle body frame 21. In the drawings, the first member 31 is also shown in FIGS. 9 and 11, which are views of the vehicle body frame 21, in order to show the positional relationship between the first member 31 and the second member 32.

[0074] 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 vertically movable. By moving the second member 32 vertically along the first member 31, the vehicle body frame 21 can be moved vertically with respect to the running frames (left running frame 8L, right running frame 8R).

[0075] As shown in FIG. 10, the first member 31 is attached to the left running frame 8L and the right running frame 8R, respectively. In the left running frame 8L, the first member 31 is attached to the first left vertical frame member 8Lc, the second left vertical frame member 8Ld, and the third left vertical frame member 8Le, respectively. In the right running frame 8R, the first member 31 is attached to the first right vertical frame member 8Rc, the second right vertical frame member 8Rd, and the third right vertical frame member 8Re, respectively.

[0076] As shown in FIGS. 9 and 11, the second member 32 is attached to the left body frame 23 and the right body frame 24, respectively. In the left body frame 23, the second member 32 is attached to the first longitudinal frame member 23b, the second longitudinal frame member 23c, and the third longitudinal frame member 23d, respectively. In the right body frame 24, the second member 32 is attached to the fourth longitudinal frame member 24b, the fifth longitudinal frame member 24c, and the sixth longitudinal frame member 24d, respectively.

[0077] The first member 31 attached to the left traveling frame 8L is disposed opposite to the second member 32 attached to the left body frame 23 and is connected thereto so as to be movable in the vertical direction. The first member 31 attached to the right traveling frame 8R is disposed opposite to the second member 32 attached to the right body frame 24 and is connected thereto so as to be movable in the vertical direction.

[0078] When the left body frame 23 moves in the vertical direction with respect to the left traveling frame 8L, the vehicle body 2 can move in the vertical direction with respect to the left traveling part 4L. When the right body frame 24 moves in the vertical direction with respect to the right traveling frame 8R, the vehicle body 2 can move in the vertical direction with respect to the right traveling part 4R.

[0079] Note that 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 vertical direction, and the second member 32 is connected to the third member so as to be movable in the vertical direction.

[0080] As shown in Fig. 7, the work vehicle 1 includes a drive unit 40 for driving wheels (left front wheel 7LF, right front wheel 7RF, left rear wheel 7LB, right rear wheel 7RB). The drive unit 40 has 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 case of this embodiment, the steering mechanism 60 is a mechanism that changes the directions of the front wheels (left front wheel 7LF, right front wheel 7RF) and the rear wheels (left rear wheel 7LB, right rear wheel 7RB). Specifically, the steering mechanism 60 is a mechanism that independently changes the directions of the left front wheel 7LF, the right front wheel 7RF, the left rear wheel 7LB, and the 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.

[0081] As shown in Figs. 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.

[0082] In the case of this embodiment, the drive device 45 is a motor. Specifically, the drive device 45 is the traveling system motor 10 described above. That is, the motor that constitutes the drive device 45 is the same as the motor included in the power device 9 described above. As will be described below, the motor 10 that constitutes the drive device 45 of the drive unit 40 includes a motor 10LF, a motor 10RF, a motor 10LB, and a motor 10RB.

[0083] As shown in FIG. 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 a plurality of gears. When the motor 10LF is driven, the power of the motor 10LF is transmitted to the left front wheel 7LF through the transmission mechanism 50LF.

[0084] As shown in FIG. 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 a plurality of gears. When the motor 10RF is driven, the power of the motor 10RF is transmitted to the right front wheel 7RF through the transmission mechanism 50RF.

[0085] As shown in FIG. 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 a plurality of gears. When the motor 10LB is driven, the power of the motor 10LB is transmitted to the left rear wheel 7LB through the transmission mechanism 50LB.

[0086] As shown in FIG. 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 a plurality of gears. When the motor 10RB is driven, the power of the motor 10RB is transmitted to the right rear wheel 7RB through the transmission mechanism 50RB.

[0087] As shown in FIG. 7, the drive unit 40 has a steering mechanism 60 that changes the direction of the wheels. As shown in FIGS. 2 and 3, the steering mechanism 60 includes a left steering mechanism 60L that changes the directions of the left front wheel 7LF and the left rear wheel 7LB, and a right steering mechanism 60R that changes the directions of the right front wheel 7RF and the right rear wheel 7RB.

[0088] As shown in FIG. 2, the first drive unit 41 and the third drive unit 43 are provided with 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 connecting body 63A that is connected to the left front wheel 7LF and is rotatable around the axis AX1. The rod 62a of the steering cylinder 62LB is connected to a connecting body 63B that is connected to the left rear wheel 7LB and is rotatable around the axis AX2. The left steering mechanism 60L can rotate the left front wheel 7LF around the axis AX1 by driving the steering cylinder 62LF to expand and contract the rod 62a. The left steering mechanism 60L can rotate the left rear wheel 7LB around the axis AX2 by driving the steering cylinder 62LB to expand and contract the rod 62a.

[0089] As shown in FIG. 3, the second drive unit 42 and the fourth drive unit 44 are provided with 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 connecting body 63C that is connected to the right front wheel 7RF and is rotatable around the axis AX3. The rod 62a of the steering cylinder 62RB is connected to a connecting body 63D that is connected to the right rear wheel 7RB and is rotatable around the axis AX4. The right steering mechanism 60R can rotate the right front wheel 7RF around the axis AX3 by driving the steering cylinder 62RF to expand and contract the rod 62a. The right steering mechanism 60R can rotate the right rear wheel 7RB around the axis AX4 by driving the steering cylinder 62RB to expand and contract the rod 62a.

[0090] In the following description, the steering cylinders 62LF, 62LB, 62RF, and 62RB are collectively referred to as "steering cylinder 62". The work vehicle 1 can change the traveling direction by driving the steering cylinder 62 of the steering mechanism 60 to change the direction of the left front wheel 7LF and / or the right front wheel 7RF.

[0091] As shown in FIGS. 2, 3, and 6, the steering cylinder 62 is fixed to the traveling frame 8 which is the above-described structure 3. Specifically, the steering cylinder 62LF is fixed to the front part of the left traveling frame 8L. The steering cylinder 62LB is fixed to the rear part of the left traveling frame 8L. The steering cylinder 62RF is fixed to the front part of the right traveling frame 8R. The steering cylinder 62RF is fixed to the rear part of the right traveling frame 8R. Note that in some drawings (such as FIG. 1), the steering cylinder 62 is omitted.

[0092] The left traveling part 4L includes a first drive unit 41 and a third drive unit 43. Therefore, the left traveling part 4L includes the motor 10LF and the transmission mechanism 50LF, the motor 10LB and the transmission mechanism 50LB, and the left steering mechanism 60L. The right traveling part 4R includes a second drive unit 42 and a fourth drive unit 44. Therefore, the right traveling part 4R includes the motor 10RF and the transmission mechanism 50RF, the motor 10RB and the transmission mechanism 50RB, and the right steering mechanism 60R.

[0093] Note that as a different embodiment of the drive device 45, the motor of the drive device 45 may be a hub 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 hub motor, or a part thereof (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 hub motor.

[0094] The drive unit 40 is provided with a brake cylinder (not shown) for stopping the drive of the wheel 7. The brake cylinder is a hydraulic actuator that operates by hydraulic pressure. By the operation of the brake cylinder, the brake pads can move to stop the rotation of the wheel. The brake cylinder 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), or only the front wheels, or only the rear wheels. The operation of the brake cylinder can be controlled by the control device 19.

[0095] As shown in FIG. 7, the work vehicle 1 is provided with a distance changing mechanism 80. The distance changing mechanism 80 changes the distance between the left traveling unit 4L and the right traveling unit 4R. As shown in FIG. 6, the distance changing mechanism 80 includes a left changing mechanism 80L that changes the left - right position of the left traveling unit 4L and a right changing mechanism 80R that changes the left - right position of the right traveling unit 4R.

[0096] As shown in FIG. 6, the left changing mechanism 80L has a left cylinder 81L that moves the left traveling unit 4L to the left or right. The left cylinder 81L moves the left traveling frame 8L to the left or right. The left front wheel 7LF and the left rear wheel 7LB are supported by the left traveling frame 8L. Thus, the left cylinder 81L can integrally move the left front wheel 7LF and the left rear wheel 7LB to the left or right by moving the left traveling frame 8L to the left or right.

[0097] As shown in FIG. 6, the right changing mechanism 80R has a right cylinder 81R that moves the right traveling unit 4R to the left or right. The right cylinder 81R moves the right traveling frame 8R to the left or right. The right front wheel 7RF and the right rear wheel 7RB are supported by the right traveling frame 8R. Thus, the right cylinder 81R can integrally move the right front wheel 7RF and the right rear wheel 7RB to the left or right by moving the right traveling frame 8R to the left or right.

[0098] The right cylinder 81R and the left cylinder 81L are composed of hydraulic cylinders which are hydraulic actuators actuated by hydraulic pressure. Hereinafter, the right cylinder 81R and the left cylinder 81L may be collectively referred to as the "distance changing cylinder 81". The hydraulic cylinders (distance changing cylinder 81) constituting the right cylinder 81R and the left cylinder 81L are actuated (extended and contracted) by the hydraulic oil supplied from a hydraulic pump driven by the above-described working system motor 11.

[0099] Hereinafter, the configurations of the left change mechanism 80L and the right change mechanism 80R will be described in more detail. As shown in FIG. 9, the left cylinder 81L has a cylinder tube 81La attached to the central vehicle body frame 22 and a rod 81Lb protruding from the cylinder tube 81La and extending leftward. The tip of the rod 81Lb of the left cylinder 81L is connected to the left vehicle body frame 23. The right cylinder 81R has a cylinder tube 81Ra attached to the central vehicle body frame 22 and a rod 81Rb protruding from the cylinder tube 81Ra and extending rightward. The tip of the rod 81Rb of the right cylinder 81R is connected to the right vehicle body frame 24.

[0100] As shown by the arrow L1 in FIG. 12, when the rod 81Lb of the left cylinder 81L extends leftward, the left vehicle body frame 23 moves leftward. When the rod 81Lb of the left cylinder 81L contracts rightward, the left vehicle body frame 23 moves rightward. As shown by the arrow R1 in FIG. 12, when the rod 81Rb of the right cylinder 81R extends rightward, the right vehicle body frame 24 moves rightward. When the rod 81Rb of the right cylinder 81R contracts leftward, the right vehicle body frame 24 moves leftward.

[0101] In this way, by the actuation (extension and contraction) of the left cylinder 81L, the left vehicle body frame 23 moves in the left-right direction with respect to the central vehicle body frame 22. That is, the left-right position of the left vehicle body frame 23 can be changed. Also, by the actuation (extension and contraction) of the right cylinder 81R, the right vehicle body frame 24 moves in the left-right direction with respect to the central vehicle body frame 22. That is, the left-right position of the right vehicle body frame 24 can be changed.

[0102] As described above, the left body frame 23 is connected to the left traveling frame 8L via the mast mechanism. Also, the right body frame 24 is connected to the right traveling frame 8R via the mast mechanism. Therefore, when the left body frame 23 moves in the left - right direction with respect to the central body frame 22, the left traveling frame 8L moves in the left - right direction with respect to the central body frame 22. Also, when the right body frame 24 moves in the left - right direction with respect to the central body frame 22, the right traveling frame 8R moves in the left - right direction with respect to the central body frame 22.

[0103] In this way, by moving the left traveling frame 8L and the right traveling frame 8R in the left - right direction with respect to the central body frame 22, the left - right positions of the left traveling unit 4L and the right traveling unit 4R can be changed. Therefore, the distance between the left traveling unit 4L and the right traveling unit 4R can be changed. Also, the distance between the left traveling unit 4L and the vehicle body 2, and the distance between the right traveling unit 4R and the vehicle body 2 can also be changed. These distance changes can be performed by operating one or both of the left cylinder 81L and the right cylinder 81R.

[0104] FIG. 6 shows a state in which the rods of the left cylinder 81L and the right cylinder 81R are shortened. In this state, the distance between the left traveling unit 4L and the right traveling unit 4R is short. Also, the distance between the left traveling unit 4L and the vehicle body 2, and the distance between the right traveling unit 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 the arrows L1, R1 in FIG. 13), the left traveling unit 4L and the right traveling unit 4R move in opposite directions. As a result, as shown in FIG. 13, the distance between the left traveling unit 4L and the right traveling unit 4R can be increased. Also, the distance between the left traveling unit 4L and the vehicle body 2, and the distance between the right traveling unit 4R and the vehicle body 2 can also be increased.

[0105] The operation of the distance changing mechanism 80 is controlled by the control device 19. Specifically, the operations of the left cylinder 81L and the right cylinder 81R of the distance changing mechanism 80 are controlled by the control device 19. As shown in FIG. 7, the control device 19 includes a distance change control unit 19B. The change operation by the distance changing mechanism 80 is performed by the distance change control unit 19B controlling the distance changing mechanism 80. The distance changing mechanism 80 changes the left - right positions of the left traveling unit 4L and / or the right traveling unit 4R based on, for example, the detection result by the inclination detection device 170 described later.

[0106] The distance changing mechanism 80 can operate the left changing mechanism 80L and the right changing mechanism 80R individually. That is, the distance changing mechanism 80 can operate only the left changing mechanism 80L, can operate only the right changing mechanism 80R, or can operate both the left changing mechanism 80L and the right changing mechanism 80R. The distance changing mechanism 80 can operate the left changing mechanism 80L and the right changing mechanism 80R individually based on the detection result by the inclination detection device 170 described later.

[0107] As shown in FIG. 7, the work vehicle 1 is provided with a height changing mechanism 90. The height changing mechanism 90 can change the vertical position of the vehicle body 2 with respect to the traveling unit 4. By changing the vertical position of the vehicle body 2 with respect to the traveling unit 4, the height of the vehicle body 2 from the ground can be changed. The height changing mechanism 90 raises and lowers the vehicle body 2 at a position between the left traveling unit 4L and the right traveling unit 4R in the width direction (left - right direction) of the vehicle body 2.

[0108] As shown in FIGS. 5, 8, etc., the height changing mechanism 90 has a lifting cylinder 91. The lifting cylinder 91 raises and lowers the vehicle body frame 21 with respect to the traveling frame 8. When the vehicle body frame 21 is raised and lowered, the vehicle body 2 including the vehicle body frame 21 and the main body case 5 is raised and lowered. Therefore, by driving the lifting cylinder 91, the vehicle body 2 can be raised and lowered with respect to the traveling frame 8. In this way, the height changing mechanism 90 is a mechanism that can raise and lower the vehicle body 2 (vehicle body frame 21) with respect to the traveling frame 8. In the following description, the height changing mechanism 90 may be referred to as the "lifting mechanism 90".

[0109] The lifting cylinder 91 includes a left lifting cylinder 91L and a right lifting cylinder 91R. The left lifting cylinder 91L is disposed on the left part of the vehicle body 2. The right lifting cylinder 91R is disposed on the right part of the vehicle body 2. The lifting cylinder 91 is composed of a hydraulic cylinder which is a hydraulic actuator operated by hydraulic pressure. The lifting cylinder 91 has a rod 91a that expands and contracts in the vertical direction, and a cylinder tube 91b to which hydraulic oil for driving the rod 91a is supplied. The rod 91a extends downward from the cylinder tube 91b.

[0110] As shown in FIGS. 8 and 9, the cylinder tube 91Lb of the left lifting cylinder 91L is attached to a left bracket 51L fixed to the upper part (the upper left frame member 23a) of the left vehicle body frame 23. The cylinder tube 91Rb of the right lifting cylinder 91R is attached to a bracket 51R fixed to the upper part (the upper right frame member 24a) of the right vehicle body frame 24.

[0111] As shown in FIGS. 8 and 10, the left traveling frame 8L is provided with a left connecting portion 52L for connecting the rod of the left lifting cylinder 91L. The left connecting portion 52L is fixed to the lower part (the third lower left frame member 29c) of the left traveling frame 8L. The rod of the left lifting cylinder 91L is connected to the left connecting portion 52L. Thereby, the left vehicle body frame 23 can be lifted and lowered with respect to the left traveling frame 8L by the expansion and contraction of the rod of the left lifting cylinder 91L.

[0112] As shown in FIGS. 8 and 10, the right traveling frame 8R is provided with a right connecting portion 52R for connecting the rod of the right lifting cylinder 91R. The right connecting portion 52R is fixed to the lower part (the third lower right frame member 30c) of the right traveling frame 8R. The rod of the right lifting cylinder 91R is connected to the right connecting portion 52R. Thereby, the right vehicle body frame 24 can be lifted and lowered with respect to the right traveling frame 8R by the expansion and contraction of the rod of the right lifting cylinder 91R.

[0113] When the rod of the left lifting cylinder 91L expands and contracts, the left body frame 23 moves up and down. When the rod of the right lifting cylinder 91R expands and contracts, the right body frame 24 moves up and down. Accordingly, the body frame 21 can be moved up and down as the rod of the lifting cylinder 91 (left lifting cylinder 91L, right lifting cylinder 91R) expands and contracts. FIG. 14 shows the state where the body frame 21 has descended, and FIG. 15 shows the state where the body frame 21 has ascended.

[0114] Since the main body case 5 (see FIGS. 1, 4, etc.) is supported by the body frame 21, the body 2 including the body frame 21 and the main body case 5 can be moved up and down as the rod of the lifting cylinder 91 expands and contracts. Since the battery 12 (first battery 12A described later) is housed in the main body case 5, the battery 12 also moves up and down as the body 2 moves up and down. FIG. 16 schematically shows the state where the body 2 has descended, and FIG. 17 schematically shows the state where the body 2 has ascended. As shown in FIGS. 16 and 17, the vertical position of the body 2 (and the battery 12) with respect to the traveling unit 4 can be changed as the rod 91a of the lifting cylinder 91 expands and contracts. FIGS. 18 to 22 show the work vehicle 1 in a state where the rod 91a of the lifting cylinder 91 is extended to raise the body 2.

[0115] The operation of the height changing mechanism 90 is controlled by the control device 19. Specifically, the operation of the lifting cylinder 91 of the height changing mechanism 90 is controlled by the 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 changing mechanism 90 by executing a program stored in the storage unit by the arithmetic unit of the control device 19. The height changing mechanism 90 is driven based on the control signal transmitted from the height change control unit 19C. That is, the height changing mechanism 90 changes the vertical position of the body 2 by being driven based on the control by the control device 19.

[0116] As shown in FIG. 7, the work vehicle 1 is provided with a position changing mechanism 70. The position changing mechanism 70 can change the position of the vehicle body 2 in the front-rear direction with respect to the traveling unit 4. FIG. 23 is a schematic plan view showing an example of the work vehicle 1 provided with the position changing mechanism 70. The position changing mechanism 70 shown in FIG. 23 has a guide rail 71 attached to the traveling frame 8 and extending in the front-rear direction, and a slide member 72 attached to the vehicle body frame 21 and extending in the front-rear direction. The slide member 72 is movable in the front-rear direction along the guide rail 71.

[0117] The guide rail 71 is attached to the right part of the left traveling frame 8L and the left part of the right traveling frame 8R. The slide member 72 is attached to the left and right parts of the vehicle body frame 21. Thereby, the vehicle body frame 21 is movable in the front-rear direction with respect to the traveling frame 8 (left traveling frame 8L, right traveling frame 8R).

[0118] The position changing mechanism 70 is provided with a position changing cylinder 73 for moving the vehicle body 2 in the front-rear direction. The position changing cylinder 73 is composed of a hydraulic cylinder which is a hydraulic actuator operated 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.

[0119] By expanding and contracting the rod 73b of the position changing cylinder 73, the vehicle body frame 21 can be moved in the longitudinal direction with respect to the traveling frame 8. As a result, the vehicle body 2 can be moved in the longitudinal direction with respect to the traveling unit 4. The left part of FIG. 23 shows a state where the vehicle body 2 has not moved in the longitudinal direction with respect to the traveling unit 4. The upper right part of FIG. 23 shows a state where the vehicle body 2 has moved forward with respect to the traveling unit 4 due to the expansion of the rod 73b of the position changing cylinder 73. The lower right part of FIG. 23 shows a state where the vehicle body 2 has moved backward with respect to the traveling unit 4 due to the contraction of the rod 73b of the position changing cylinder 73.

[0120] FIG. 24 shows a modified example of the position changing mechanism 70. The position changing mechanism 70 of the modified example can change the longitudinal position of a part of the vehicle body 2. Specifically, the position changing mechanism 70 of the modified example can change the longitudinal position of the main body case 5 of the vehicle body 2. Specifically, the position changing mechanism 70 of the modified example can change the position of the main body case 5 with respect to the vehicle body frame 21.

[0121] The position changing mechanism 70 of the modified example has a guide rail 71 that is attached to the upper part of the lower vehicle body frame 26 (the first lower frame member 26a, the second lower frame member 26b) (see FIGS. 9 and 11) and extends in the longitudinal direction, and a slide member 72 that is attached to the lower part of the main body case 5 and extends in the longitudinal direction. The slide member 72 is movable in the longitudinal direction along the guide rail 71. As a result, the main body case 5 is movable in the longitudinal direction with respect to the lower vehicle body frame 26.

[0122] The position changing mechanism 70 of the modified example includes a position changing cylinder 73 that moves the main body case 5 in the longitudinal direction. The position changing cylinder 73 is composed of a hydraulic cylinder that is a hydraulic actuator operated by hydraulic pressure. The position changing cylinder 73 has a cylinder tube 73a attached to the vehicle body frame 21 and a rod 73b attached to the main body case 5. The cylinder tube 73a is attached to the vehicle 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.

[0123] By expanding and contracting the rod 73b of the position changing cylinder 73, the main body case 5 can be moved in the front-rear direction with respect to the vehicle body frame 21. The left part of FIG. 24 shows a state where the main body case 5 is not moving in the front-rear direction with respect to the vehicle body frame 21. The upper right part of FIG. 24 shows a state where the main body case 5 is moving forward with respect to the vehicle body frame 21. The lower right part of FIG. 24 shows a state where the main body case 5 is moving rearward with respect to the vehicle body frame 21.

[0124] As described above, the battery 12 (the first battery 12A) is housed in the main body case 5. Therefore, by moving the main body case 5 in the front-rear direction with respect to the lower vehicle body frame 26, the battery 12 (the first battery 12A) can be moved in the front-rear direction with respect to the lower vehicle body frame 26. Thereby, the front-rear position of the battery 12 (the first battery 12A) with respect to the traveling unit 4 can be changed.

[0125] The operation of the position changing mechanism 70 is controlled by the position changing control unit 19D of the control device 19. For example, when it is necessary to move the center of gravity position of the work vehicle 1 in the front-rear direction during the traveling of the work vehicle 1 (for example, when the wheels are stuck in mud or soft ground and stacked), the position changing control unit 19D drives the position changing mechanism 70 to change the front-rear position of the vehicle body 2 or a part of the vehicle body 2 (the main body case 5), thereby moving the center of gravity position of the work vehicle 1 in the front-rear direction.

[0126] As shown in FIGS. 1, 5, 6, 7, etc., the work vehicle 1 is provided with a hydraulic unit 100. As shown in FIG. 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 in which the hydraulic oil supplied to the hydraulic equipment is stored, and a hydraulic pump 103 driven by the hydraulic oil.

[0127] The hydraulic oil tank 102 is disposed above the hydraulic pump 103. The hydraulic oil tank 102 is disposed above the working system motor 11 that drives the hydraulic pump 103. The hydraulic pump 103 and the working system motor 11 are arranged 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 shape with the upper - corner part of a rectangle cut off when viewed from the front. The hydraulic valve 101 is disposed at the part (upper - right part) where the hydraulic oil tank 102 is cut off.

[0128] As shown in FIGS. 1, 5, 6, etc., the hydraulic unit 100 is disposed at the rear part of the vehicle body 2. Therefore, the hydraulic valve 101, the hydraulic pump 103, and the hydraulic oil tank 102 included in the hydraulic unit 100 are concentratedly disposed at the rear part of the vehicle body 2. Specifically, the hydraulic unit 100 is disposed behind the main body case 5 of the vehicle body 2. Therefore, the hydraulic valve 101, the hydraulic pump 103, and the hydraulic oil tank 102 are disposed behind the main body case 5.

[0129] In this way, since the hydraulic valve 101, the hydraulic pump 103, and the hydraulic oil tank 102 are concentratedly disposed at the rear part of the vehicle body 2, it is possible to collectively perform oil leakage checks and the like during daily inspections of the hydraulic valve 101, the hydraulic pump 103, and the hydraulic oil tank 102, so the maintainability is improved.

[0130] In the case of 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 a structure 3 (in the case of this embodiment, the traveling frame 8) that can be connected to the vehicle body 2. In the case of this embodiment, the work vehicle 1 includes 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 the case of this embodiment, the hydraulic actuator is a hydraulic cylinder that operates by hydraulic pressure.

[0131] The steering cylinder 62 is provided on the traveling frame 8. The distance changing cylinder 81 is provided on the vehicle body frame 21. The lifting cylinder 91 and the position changing cylinder 73 connect the vehicle body frame 21 and the traveling frame 8. The brake cylinder 46 is provided on the traveling frame 8. That is, among 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 vehicle body 2.

[0132] The work vehicle 1 is mounted on the vehicle body 2 or the structure (traveling frame 8) on which no hydraulic actuator is provided, and is provided with hydraulic equipment different from the hydraulic actuator. In the case of this embodiment, the different hydraulic equipment is the hydraulic valve 101 (see FIGS. 25 and 26) that controls the operation of the hydraulic actuator. In the case of this embodiment, the hydraulic valve 101 is mounted on the vehicle body 2, but may be mounted on the structure (traveling frame 8).

[0133] The hydraulic valve 101 controls the flow of the hydraulic oil supplied to the hydraulic actuator and the like. As shown in FIG. 26, the hydraulic valve 101 includes a plurality of valves (first valve 101A, second valve 101B, third valve 101C, fourth valve 101D, fifth valve 101E) that control the flow of the hydraulic oil. The hydraulic valve 101 is composed of, for example, an electromagnetic valve. The operation of the hydraulic valve 101 is controlled by the control device 19. The plurality of valves constituting the hydraulic valve 101 are respectively connected to the hydraulic actuator and the like via hydraulic hoses. By the control device 19 controlling the operations of the plurality of hydraulic valves 101 respectively, the plurality of hydraulic actuators are respectively driven.

[0134] As shown in FIG. 26, the first valve 101A is connected to the steering cylinder 62 (62LF, 62LB, 62RF, 62RB) via the first hydraulic hose 105. The second valve 101B is connected to the lifting cylinder 91 (left lifting cylinder 91L, right lifting cylinder 91R) via the second hydraulic hose 106. The third valve 101C is connected to the distance changing cylinder 81 (left cylinder 81L, right cylinder 81R) via the third hydraulic hose 107. The fourth valve 101D is connected to the position changing cylinder 73 via the fourth hydraulic hose 108. The fifth valve 101E is connected to the brake cylinder 46 via the fifth hydraulic hose 109.

[0135] The hydraulic valve 101 is connected to the hydraulic oil tank 102 via the sixth hydraulic hose 110. The hydraulic valve 101 is connected to the hydraulic pump 103 via the seventh hydraulic hose 111. The hydraulic pump 103 is connected to the hydraulic oil tank 102 via the 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.

[0136] The hydraulic valve 101 operates (opens and closes the flow path through which the hydraulic oil flows) based on the control signal transmitted from the control device 19, thereby controlling the flow of the 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. Thereby, 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.

[0137] As shown in FIGS. 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 (the first battery 12A) are arranged side by side in the front-rear direction between the left traveling frame 8L and the right traveling frame 8R. The hydraulic unit 100 is disposed behind the battery 12 (the first battery 12A). As shown in FIG. 27, the hydraulic unit 100 is arranged so as not to protrude from the vehicle body frame (center frame) 21 at least in the left-right direction. Specifically, the hydraulic unit 100 is located between the left end of the left vehicle body frame 23 and the right end of the right vehicle body frame 24. More specifically, the hydraulic unit 100 is located between the left end and the right end of the center vehicle body frame 22.

[0138] The work vehicle 1 is provided with a moving mechanism that moves either the vehicle body 2 or the structure 3, which is equipped with the above-described other hydraulic equipment, in the vertical direction together with the other hydraulic equipment. In the case of the present embodiment, the other hydraulic equipment is the hydraulic valve 101, and the hydraulic valve 101, which is the other hydraulic equipment, is mounted on the vehicle body 2. However, the hydraulic valve 101, which is the other hydraulic equipment, may be mounted on the structure 3. When the other hydraulic equipment (hydraulic valve 101) is mounted on the vehicle body 2, the structure 3 is not equipped with the other hydraulic equipment (hydraulic valve 101).

[0139] In the case of the present embodiment, the moving mechanism is a height changing mechanism (lifting mechanism) 90 that raises and lowers the vehicle body 2 with respect to the traveling frame 8. The height changing mechanism 90, which is the moving mechanism, moves the other hydraulic equipment (hydraulic valve 101) to change the position of the other hydraulic equipment (hydraulic valve 101) with respect to the hydraulic actuator. Specifically, the height changing mechanism 90 moves the hydraulic valve 101 in the vertical direction to change the vertical position of the hydraulic valve 101 with respect to the hydraulic actuators (steering cylinder 62, brake cylinder 46).

[0140] As described above, the height changing mechanism 90 moves the vehicle body 2 relative to the structure (traveling frame 8). Therefore, another hydraulic device (hydraulic valve 101) moves relative to the structure (traveling frame 8) together with the vehicle body 2 by the height changing mechanism 90.

[0141] On the other hand, the hydraulic actuators (steering cylinder 62, brake cylinder 46) are arranged with their positions fixed. Specifically, the hydraulic actuators (steering cylinder 62, brake cylinder 46) are arranged with their vertical positions fixed. Therefore, when the vehicle body 2 moves up and down relative to the traveling frame 8, another hydraulic device (hydraulic valve 101) moves up and down relative to the hydraulic actuators (steering cylinder 62, brake cylinder).

[0142] In this way, the work vehicle 1 has the characteristic that the positions (vertical positions) of the hydraulic actuators (steering cylinder 62, brake cylinder 46), which are the devices on the controlled side, are fixed, and the position (vertical position) of another hydraulic device (hydraulic valve 101), which is the device on the controlling side, changes. Thereby, the accessibility to the device (hydraulic valve 101) on the controlling side can be improved, and maintenance can be easily performed.

[0143] The hydraulic unit 100 is covered at least in two directions when the vehicle body 2 is in the lowered state. In the case of this embodiment, the hydraulic unit 100 is covered in three directions (front side, left side, right side) when the vehicle body 2 is in the lowered state. As shown in FIGS. 2 to 6, when the vehicle body 2 is in the lowered state, the main body case 5 storing the first battery 12A is arranged in front of the hydraulic unit 100, the left traveling frame 8L is arranged on the left side, and the right traveling frame 8R is arranged on the right side. Therefore, when the vehicle body 2 is in the lowered state, the front side of the hydraulic unit 100 is covered by the main body case 5, the left side is covered by the left traveling frame 8L, and the right side is covered by the right traveling frame 8R. On the other hand, the rear of the hydraulic unit 100 is exposed without being covered. In this way, when the vehicle body 2 is in the lowered state, only the rear side among the front, rear, left, and right sides of the hydraulic unit 100 is exposed without being covered.

[0144] The hydraulic unit 100 is covered in at least one direction when the vehicle body 2 is in the raised state. The hydraulic unit 100 is covered in fewer directions when the vehicle body 2 is in the raised state than when the vehicle body 2 is in the lowered state. In the case of this embodiment, the hydraulic unit 100 is covered in one direction (front side) when the vehicle body 2 is in the raised state. As shown in FIGS. 19 to 22, the main body case 5 that houses the first battery 12A is arranged in the front when the vehicle body 2 is in the raised state for the hydraulic unit 100. Therefore, the front side of the hydraulic unit 100 is covered by the main body case 5 when the vehicle body 2 is in the raised state. On the other hand, the left side, the right side, and the rear side of the hydraulic unit 100 are exposed without being covered. Thus, the left side, the right side, and the rear side among the front, rear, left, and right of the hydraulic unit 100 are exposed without being covered when the vehicle body 2 is in the raised state.

[0145] In this way, for the work vehicle 1, the left and right sides of the hydraulic unit 100 are covered when the vehicle body 2 is in the lowered state, but the left and right sides of the hydraulic unit 100 are not covered when the vehicle body 2 is in the raised state. Therefore, in the state where the vehicle body 2 is in the raised state, access from the left and right sides, which was difficult when the vehicle body 2 was in the lowered state, becomes possible. Therefore, the maintainability of the hydraulic unit 100 is improved.

[0146] Incidentally, in the state where the vehicle body 2 is in the raised state, only a part (lower part) of the left side and the right side of the hydraulic unit 100 may be covered by the traveling frame 8. In this case, the range in which the left side and the right side of the hydraulic unit 100 are covered when the vehicle body 2 is in the raised state is significantly smaller than the range in which the left side and the right side of the hydraulic unit 100 are covered when the vehicle body 2 is in the lowered state. That is, when the vehicle body 2 rises, the range in which the left side and the right side of the hydraulic unit 100 are exposed increases significantly. Therefore, access to the hydraulic unit 100 from the left and right sides becomes easy, and the maintainability is improved.

[0147] Above the hydraulic unit 100 is exposed without being covered in either the state where the vehicle body 2 has descended or the state where it has ascended. Therefore, it is possible to access the hydraulic unit 100 from above in either the state where the vehicle body 2 has descended or the state where it has ascended. In particular, when the vehicle body 2 is in the descended state, access from above is easy.

[0148] FIG. 28 is a left side view schematically showing the change in the position of the hydraulic unit 100 when the vehicle body 2 is raised and lowered. The right side view appears symmetrically with the left side view. As shown in the left figure of FIG. 28, when the vehicle body 2 is in the descended state, in a side view, the entire hydraulic unit 100 overlaps with the running frame 8. Also, when the vehicle body 2 is in the descended state, in a side view, a part of the hydraulic unit 100 overlaps with the rear wheels (left rear wheel 7LB, right rear wheel 7RB). Also, when the vehicle body 2 is in the descended state, in a side view, a part of the hydraulic unit 100 overlaps with the second battery 12B.

[0149] As shown in the right figure of FIG. 28, when the vehicle body 2 is in the ascended state, in a side view, only a part (lower part) of the hydraulic unit 100 overlaps with the running frame 8. Also, when the vehicle body 2 is in the ascended state, in a side view, the hydraulic unit 100 does not overlap with the rear wheels (left rear wheel 7LB, right rear wheel 7RB). Also, when the vehicle body 2 is in the ascended state, in a side view, the hydraulic unit 100 does not overlap with the second battery 12B.

[0150] Also, as shown in FIG. 28, although the positional relationship between the hydraulic unit 100 and the second battery 12B changes due to the raising and lowering of the vehicle body 2, the positional relationship between the hydraulic unit 100 and the first battery 12A does not change. In either the state where the vehicle body 2 has descended or the state where it has ascended, the vertical positions of the hydraulic unit 100 and the first battery 12A overlap.

[0151] The working system motor 11 that operates the hydraulic pump 103 of the hydraulic unit 100 is arranged near the hydraulic unit 100 (see Fig. 25) and operates by the electric power supplied from the first battery 12A and the second battery 12B. Since the positional relationship between the hydraulic unit 100 and the first battery 12A does not change due to the elevation of the vehicle body 2, the electrical wiring connecting the first battery 12A and the working system motor 11 can be shortened.

[0152] Also, as shown in Fig. 28, the positional relationship between the first battery 12A and the second battery 12B changes due to the elevation of the vehicle body 2. In the state where the vehicle body 2 has descended, in a side view, the first battery 12A overlaps the second battery 12B. Also, in the state where the vehicle body 2 has ascended, in a side view, the first battery 12A does not overlap the second battery 12B. Thus, due to the elevation of the vehicle body 2, the positional relationship (overlapping relationship) between the first battery 12A and the second battery 12B changes in the same manner as the positional relationship between the hydraulic unit 100 and the second battery 12B.

[0153] Also, as shown in Fig. 13, the work vehicle 1 can increase the distance between the left traveling unit 4L and the vehicle body 2, and the distance between the right traveling unit 4R and the vehicle body 2 by moving the left traveling unit 4L and the right traveling unit 4R in the left - right direction by the distance changing mechanism 80. Thereby, the left side and the right side of the hydraulic unit 100 can be exposed, and access to the hydraulic unit 100 from the left and right sides becomes possible. Therefore, the maintainability of the hydraulic unit 100 is improved.

[0154] Also, as shown in the lower right figure of Fig. 23, by moving the vehicle body 2 rearward by the position changing mechanism 70 and protruding the rear part of the vehicle body 2 rearward from the traveling unit 4, the left side and the right side of the hydraulic unit 100 can also be exposed. Thereby, access to the hydraulic unit 100 from the left and right sides becomes possible, and the maintainability of the hydraulic unit 100 is improved.

[0155] Also, as shown in the upper right figure of FIG. 24, by moving the main body case 5 forward by the position changing mechanism 70, the distance between the front part of the hydraulic unit 100 and the rear part of the main body case 5 can be increased. Thereby, access to the hydraulic unit 100 from the front becomes possible, and the maintainability of the hydraulic unit 100 is improved.

[0156] In this way, the work vehicle 1 can ensure easy access to the hydraulic unit 100 and improve the maintainability of the hydraulic unit 100 not only by the method of raising the vehicle body 2 by the height changing mechanism 90, but also by the method of moving the left traveling part 4L and the right traveling part 4R in the left-right direction by the distance changing mechanism 80, the method of moving the vehicle body 2 backward by the position changing mechanism 70, and the method of moving the main body case 5 forward by the position changing mechanism 70. The work vehicle 1 is configured to be able to execute at least one of these methods, preferably two or more, more preferably three or more.

[0157] FIG. 29 is a diagram showing an example (first embodiment) of the connection form of the electrical wiring of the work vehicle 1. As shown in FIG. 29, the work vehicle 1 includes a plurality of electrical devices 120. In the case of this embodiment, the plurality of electrical devices 120 includes a first electrical device 121 disposed on the vehicle body 2 and a second electrical device 122 disposed on the traveling part 4. Each of the plurality of electrical devices 120 includes at least one battery. In the case of this 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 composed of a battery unit (battery pack) formed by combining a plurality of batteries.

[0158] The number of the first batteries 12A may be one or more. The number of the second batteries 12B may also be one or more. In the case of this embodiment, the number of the first batteries 12A is one, and the number of the second batteries 12B is two.

[0159] The second electrical device 122 includes an electrical device different from the second battery 12B. Specifically, the second electrical device 122 includes a left traveling motor (motor 10LF, motor 10LB) that drives the left wheel and a right traveling motor (motor 10RF, motor 10RB) that drives the right wheel. Therefore, as the second electrical device 122, a left traveling motor (motor 10LF, motor 10LB) that drives the left wheel is arranged in the left traveling unit 4L. As the second electrical device 122, a right traveling motor (motor 10RF, motor 10RB) that drives the right wheel is arranged in the right traveling unit 4R.

[0160] As shown in FIG. 29, the work vehicle 1 includes a plurality of junction boxes 130. The junction box 130 relays and electrically connects one electrical wiring and another electrical wiring. The plurality of junction boxes 130 includes a main junction box 130A and a sub-junction box 130B. The number of main junction boxes 130A included in the work vehicle 1 is one. The main junction box 130A is provided in at least one of the vehicle body 2 and the structure 3. The sub-junction box 130B is provided in at least one of the vehicle body 2 and the structure 3.

[0161] Specifically, the main junction box 130A is arranged in either the vehicle body 2 or the traveling unit 4. The sub-junction box 130B is arranged in the traveling unit 4 when the main junction box 130A is arranged in the vehicle body 2, and is arranged in the vehicle body 2 when the main junction box 130A is arranged in the traveling unit 4. In the case of this embodiment, the main junction box 130A is arranged in the vehicle body 2. The sub-junction box 130B is arranged in the traveling unit 4 (left traveling unit 4L and right traveling unit 4R).

[0162] At least one of the plurality of electrical devices 120 is connected to the sub-junction box 130B. The main junction box 130A has connected to it electrical devices 120 that are different from at least the electrical devices connected to the sub-junction box 130B among the plurality of electrical devices 120. Also, the main junction box 130A has the sub-junction box 130B connected to it.

[0163] At least one battery (the first battery 12A, the second battery 12B), the sub-junction box 130B, and at least one electrical device other than the battery are connected to the main junction box 130A. At least one electrical device other than the main junction box 130A and at least one battery are connected to the sub-junction box 130B.

[0164] When the main junction box 130A is disposed on the vehicle body 2, it is connected to the first electrical device 121, and when it is disposed on the running unit 4, it is connected to the second electrical device 122. When the sub-junction box 130B is disposed on the running unit 4, it is connected to the second electrical device 122, and when it is disposed on the vehicle body 2, it is connected to the first electrical device 121. In the case of the present embodiment, since the main junction box 130A is disposed on the vehicle body 2, it is connected to the first battery 12A, which is the first electrical device 121 disposed on the vehicle body 2. Also, since the sub-junction box 130B is disposed on the running unit 4, it is connected via the inverter 13 to the left running motor (motor 10LF, motor 10LB) or the right running motor (motor 10RF, motor 10RB), which is the second electrical device 122.

[0165] The plurality of junction boxes 130 includes 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 the case of this embodiment, the first junction box 131 is the main junction box 130A. The second junction box 132 and the third junction box 133 are sub-junction boxes 130B.

[0166] The battery (the first battery 12A and the second battery 12B) and the junction boxes (the first junction box 131, the second junction box 132, and the third junction box 133) are each disposed at least one on the vehicle body 2 and the traveling section 4. In the case of this embodiment, the first battery 12A and the first junction box 131 are disposed on the vehicle body 2, and the second battery 12B, the second junction box 132, and the third junction box 133 are disposed on the traveling section 4. The second battery 12B and the second junction box 132 are disposed on the left traveling section 4L. The second battery 12B and the third junction box 133 are disposed on the right traveling section 4R.

[0167] In the following description, the second battery 12B disposed on the left traveling section 4L may be referred to as "the second battery 12BL", and the second battery 12B disposed on the right traveling section 4R may be referred to as "the second battery 12BR".

[0168] 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 disposed on the left traveling frame 8L and the right traveling frame 8R in a state of being housed in the case 35 (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).

[0169] The first junction box 131 (main junction box 130A) is disposed above the central body frame 22 of the vehicle body frame 21 (see FIGS. 1, 2, and 6). The second junction box 132 (sub-junction box 130B) is disposed on the second support 29 of the left running 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 30 of the right running frame 8R and is located above the second battery 12BR (see FIGS. 1, 3, and 6).

[0170] The first battery 12A and the second battery 12B are directly or indirectly connected to the main junction box 130A. As shown in FIG. 29, in the case of this embodiment, the first battery 12A is directly connected to the main junction box 130A by the first electrical wiring 141 (without passing through other devices). The second battery 12B is indirectly connected to the main junction box 130A via the first battery 12A.

[0171] 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.

[0172] As shown in FIG. 29, in addition to the first battery 12A and the main junction box 130A, a first inverter 13A, a work motor 11, a DCDC converter 160, and an OBC / DCDC converter 161 are arranged on the vehicle body 2. The first inverter 13A is connected to the first battery 12A and the work motor 11. The first inverter 13A and the work motor 11 are arranged on a first support 28 (see FIG. 11) that supports the hydraulic unit 100 behind the first battery 12A. Specifically, as shown in FIG. 5, the first inverter 13A is arranged at the lower part of the first support 28, and the work motor 11 is arranged above the first inverter 13A.

[0173] The DCDC converter 160 and the OBC / DCDC converter 161 are connected to the first battery 12A. The DCDC converter 160 transforms (step-down or step-up) the electric power supplied from the first battery 12A to supply other electrical devices. The OBC / DCDC converter 161 includes an OBC (ON-BORD CHARGER) and a DCDC converter. The OBC / DCDC converter 161 is connected to the charging port 162. The charging port 162 is provided on the vehicle body 2 and is connected to an electrical wiring that is connected to an external power source arranged on a charging stand or the like. The OBC / DCDC converter 161 converts the AC voltage of the electric power supplied from the charging port 162 into a DC voltage, and transforms (step-down or step-up) the converted DC voltage to the voltage required for the first battery 12A.

[0174] In addition to the second battery 12BL and the sub-junction box 130B (second junction box 132), a second inverter 13B, a third inverter 13C, and left travel motors (motor 10LF, motor 10LB) are arranged on the left travel unit 4L. As shown in FIG. 2, the second inverter 13B and the third inverter 13C are supported by the second support 29. The second inverter 13B is arranged in front of the second battery 12BL. The third inverter 13C is arranged behind the second battery 12BL.

[0175] As shown in FIG. 29, the second inverter 13B is connected to the motor 10LF and the sub-junction box 130B (the second junction box 132). The third inverter 13C is connected to the motor 10LB and the sub-junction box 130B (the second junction box 132).

[0176] In the right traveling unit 4R, in addition to the second battery 12BR and the sub-junction box 130B (the third junction box 133), the fourth inverter 13D and the fifth inverter 13E and the right traveling motors (motor 10RF, motor 10RB) are arranged. 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 arranged in front of the second battery 12BR. The fifth inverter 13E is arranged behind the second battery 12BR.

[0177] As shown in FIG. 29, the fourth inverter 13D is connected to the motor 10RF and the sub-junction box 130B (the third junction box 133). The fifth inverter 13E is connected to the motor 10RB and the sub-junction box 130B (the third junction box 133).

[0178] The main junction box 130A and the two sub-junction boxes 130B are connected by electrical wiring. Specifically, the main junction box 130A and the sub-junction box 130B (the second junction box 132) on one side (the left traveling unit 4L) are connected by the fourth electrical wiring 144. The main junction box 130A and the sub-junction box 130B (the third junction box 133) on the other side (the right traveling unit 4R) are connected by the fifth electrical wiring 145.

[0179] The second junction box 132 relays the electrical wiring connected from the main junction box 130A to the left traveling motors (motor 10LF, motor 10LB). Therefore, the power output from the first battery 12A and the second battery 12B is supplied to the left traveling motors (motor 10LF, motor 10LB) via the main junction box 130A and the second junction box 132.

[0180] The third junction box 133 relays the electrical wiring connected from the main junction box 130A to the right traveling motors (motor 10RF, motor 10RB). Therefore, the power output from the first battery 12A and the second battery 12B is supplied to the right traveling motors (motor 10RF, motor 10RB) via the main junction box 130A and the third junction box 133.

[0181] In this way, the sub-junction box 130B (the second junction box 132, the third junction box 133) relays the electrical wiring connected to electrical devices (left traveling motors 10LF, 10LB, right traveling motors 10RF, 10RB) different from the second battery 12B.

[0182] As described above, the vehicle body 2 can move vertically by driving the height changing mechanism 90. Therefore, the main junction box 130A arranged on the vehicle body 2 can change its vertical position together with the vehicle body 2. Also, the traveling unit 4 can move horizontally by driving the distance changing mechanism 80. Therefore, the sub-junction box 130B arranged on the traveling unit 4 can change its horizontal position together with the traveling unit 4. Thereby, the positional relationship between the main junction box 130A and the sub-junction box 130B in the vertical and horizontal directions can be changed.

[0183] As shown in FIG. 29, the work vehicle 1 includes a movable part 150 that guides connection wiring (fourth electrical wiring 144 and fifth electrical wiring 145) connecting the main junction box 130A and the sub-junction box 130B and moves following the deformation of the connection wiring (fourth electrical wiring 144 and fifth electrical wiring 145). The movable part 150 includes a first movable part 151 that guides the fourth electrical wiring 144 and moves following the deformation of the fourth electrical wiring 144, and a second movable part 152 that guides the fifth electrical wiring 145 and moves following the deformation of the fifth electrical wiring 145.

[0184] The movable part 150 is arranged along the electrical wiring and moves following the deformation of the electrical wiring. As the movable part 150, for example, a configuration in which a plurality of rigid members are connected and can be bent at the connection parts can be used. The movable part 150 can support the electrical wiring by housing or holding it, avoiding contact with the outside.

[0185] The movable part 150 is, for example, composed of a cable carrier (registered trademark). Hereinafter, it will be described assuming that the movable part 150 is the cable carrier 150. The cable carrier 150 is a member for supporting a movable cable (such as electrical wiring), and is also called a cable carrier or a cable chain. The cable carrier 150 can be deformed following the cable. Therefore, by supporting (housing) the electrical wiring in the cable carrier 150, the cable carrier 150 can be deformed following the electrical wiring.

[0186] The electrical wiring (fourth electrical wiring 144 and fifth electrical wiring 145) deforms while being supported (housed) by the cable carrier 150, and the cable carrier 150 follows this deformation. Therefore, when the electrical wiring (fourth electrical wiring 144 and fifth electrical wiring 145) deforms, it is possible to prevent problems (twisting, entanglement, damage) from occurring.

[0187] Figures 30 and 31 are diagrams showing the movement of the movable parts (the first movable part 151 and the second movable part 152) and the electrical wiring (the fourth electrical wiring 144 and the fifth electrical wiring 145) when the vehicle body 2 rises. As shown in Figure 30, in the state where the vehicle body 2 is descending, the vertical distance between the main junction box 130A (the first junction box 131) arranged on the vehicle body 2 and the sub-junction boxes 130B (the second junction box 132 and the third junction box 133) arranged on the traveling part 4 (the left traveling part 4L and the right traveling part 4R) is short.

[0188] When the vehicle body 2 rises from the state shown in Figure 30, the main junction box 130A (the first junction box 131) arranged on the vehicle body 2 moves upward with respect to the sub-junction boxes 130B (the second junction box 132 and the third junction box 133) arranged on the traveling part 4 (the left traveling part 4L and the right traveling part 4R). As a result, the vertical distance between the main junction box 130A (the first junction box 131) and the sub-junction boxes 130B (the second junction box 132 and the third junction box 133) becomes longer (see Figure 31).

[0189] Along with the change in the vertical positional relationship between the main junction box 130A and the sub-junction box 130B, the electrical wiring (the fourth electrical wiring 144 and the fifth electrical wiring 145) connecting the main junction box 130A and the sub-junction box 130B is deformed, and following this deformation, the movable parts (the first movable part 151 and the second movable part 152) are also deformed (see Figure 31).

[0190] As described above, when the vehicle body 2 rises, the electrical wiring (the fourth electrical wiring 144 and the fifth electrical wiring 145) is deformed, and following the deformation of the electrical wiring, the cable bear 150 is also deformed. As a result, it is possible to prevent defects (twisting, entanglement, damage) from occurring in the electrical wiring connecting the main junction box 130A and the sub-junction box 130B due to the rise of the vehicle body 2.

[0191] Figures 30 and 32 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 traveling part (left traveling part 4L, right traveling part 4R) moves in the left - right direction. As shown in Figure 30, in a state where the vehicle body 2 and the traveling part (left traveling part 4L, right traveling part 4R) are approaching each other in the left - right direction, the lateral 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 traveling part 4 (left traveling part 4L, right traveling part 4R) is short.

[0192] When the traveling part (left traveling part 4L, right traveling part 4R) moves in a direction (left or right) away from the vehicle body 2 from the state shown in Figure 30, 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 boxes 130B (second junction box 132, third junction box 133) arranged on the traveling part 4. As a result, the lateral 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) becomes longer (see Figure 32).

[0193] Along with the change in the lateral positional relationship between this main junction box 130A and the sub - junction box 130B, the electrical wiring (fourth electrical wiring 144, fifth electrical wiring 145) connecting the main junction box 130A and the sub - junction box 130B is deformed, and following this deformation, the movable parts (first movable part 151, second movable part 152) are also deformed (see Figure 32).

[0194] As described above, as the traveling units (left traveling unit 4L and right traveling unit 4R) move in the left-right direction, the electrical wirings (fourth electrical wiring 144 and fifth electrical wiring 145) are deformed, and the cable bear 150 is also deformed following the deformation of the electrical wirings. Thereby, it is possible to prevent problems (twisting, entanglement, damage) from occurring in the electrical wiring connecting the main junction box 130A and the sub-junction box 130B due to the left-right movement of the traveling units (left traveling unit 4L and right traveling unit 4R).

[0195] As shown in FIG. 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 following the 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 following the deformation of the connection wiring (third electrical wiring 143).

[0196] FIGS. 33 to 37 are diagrams showing another example (second to sixth embodiments) of the connection form of the electrical wiring of the work vehicle 1. Hereinafter, the differences from the above-described first embodiment in the second to sixth embodiments will be described, and the description of the configurations common to the first embodiment will be omitted.

[0197] FIG. 33 is a diagram showing the second embodiment. In the case of the second embodiment, the sub-junction box 130B (second junction box 132) arranged in the left traveling unit 4L and the sub-junction box 130B (third junction box 133) arranged in the right traveling unit 4R are connected by the sixth electrical wiring 146. That is, in the case of the second embodiment, not only the main junction box 130A and the sub-junction box 130B are connected, but also the sub-junction boxes 130B (second junction box 132 and third junction box 133) are connected to each other.

[0198] In the case of the second embodiment, the work vehicle 1 includes a fifth movable part 155 that guides a connection wiring (sixth electrical wiring 146) connecting the second junction box 132 and the third junction box 133 and moves following the 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.

[0199] FIG. 34 is a diagram showing a third embodiment. In the case of the third embodiment, the main junction box 130A is arranged in the left traveling part 4L, and the sub-junction boxes 130B are arranged in the vehicle body 2 and the right traveling part 4R, respectively. The main junction box 130A arranged in the left traveling part 4L is connected to the first battery 12A and the sub-junction box 130B arranged in the vehicle body 2 and the sub-junction box 130B arranged in the right traveling part 4R.

[0200] In the case of the third embodiment, the work vehicle 1 includes a sixth movable part 156 that guides a connection wiring (first electrical wiring 141) connecting the main junction box 130A arranged in the left traveling part 4L and the first battery 12A arranged in the vehicle body 2 and moves following the deformation of the connection wiring (first electrical wiring 141).

[0201] FIG. 35 is a diagram showing a fourth embodiment. In the case of the fourth embodiment, the main junction box 130A is arranged in the right traveling part 4R, and the sub-junction boxes 130B are arranged in the vehicle body 2 and the left traveling part 4L, respectively. The main junction box 130A arranged in the right traveling part 4R is connected to the first battery 12A and the sub-junction box 130B arranged in the vehicle body 2 and the sub-junction box 130B arranged in the left traveling part 4L.

[0202] In the case of the fourth embodiment, the work vehicle 1 includes a connection wiring (first electrical wiring 141) that guides a connection between the main junction box 130A disposed in the right traveling unit 4R and the first battery 12A disposed in the vehicle body 2, and a sixth movable portion 156 that moves following deformation of the connection wiring (first electrical wiring 141).

[0203] FIG. 36 is a diagram showing a fifth embodiment. In the case of the fifth embodiment, the sub-junction box 130B (second junction box 132) disposed in the left traveling unit 4L is connected to the second battery 12BL via the sixth electrical wiring 146. Further, the sub-junction box 130B (third junction box 133) disposed in the right traveling unit 4R is connected to the second battery 12BR via the seventh electrical wiring 147. Also, similar to the first embodiment, the main junction box 130A is connected to the first battery 12A. Thus, in the case of the fifth embodiment, the battery 12 is directly connected to all the junction boxes 130 (without passing through other devices).

[0204] FIG. 37 is a diagram showing a sixth embodiment. In FIG. 37, the vehicle body 2 is depicted as being divided into the main body case 5 of the vehicle body 2 where the first battery 12A is disposed and a portion 2B other than the main body case 5. In the portion 2B other than the main body case 5, the main junction box 130A and the like are disposed. The main body case 5 is at the front of the vehicle body 2, and the portion 2B other than the main body case 5 is at the rear of the vehicle body 2. Hereinafter, the portion 2B other than the main body case 5 is referred to as the "rear vehicle body 2B".

[0205] In the case of the sixth embodiment, the work vehicle 1 includes a seventh movable portion 157 that guides a connection wiring (first electrical wiring 141) that connects the first battery 12A and the main junction box 130A and moves following deformation of the connection wiring (first electrical wiring 141). The seventh movable portion 157 is disposed between the main body case 5 and the rear vehicle body 2B.

[0206] The connection wiring (second electrical wiring 142) that connects the first battery 12A and the second battery 12BL is connected to the second battery 12BL disposed on the left traveling frame 8L via the rear part 2B of the vehicle body from the first battery 12A disposed in the main body case 5. The connection wiring (third electrical wiring 143) that connects the first battery 12A and the second battery 12BR is connected to the second battery 12BR disposed on the right traveling frame 8R via the rear part 2B of the vehicle body from the first battery 12A disposed in the main body case 5.

[0207] Two third movable parts 153 are provided that guide the connection wiring (second electrical wiring 142) that connects the first battery 12A and the second battery 12BL and move following the 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 part 2B of the vehicle body. The other of the third movable parts 153 is disposed between the left traveling frame 8L and the rear part 2B of the vehicle body.

[0208] Two fourth movable parts 154 are also provided that guide the connection wiring (third electrical wiring 143) that connects the first battery 12A and the second battery 12BR and move following the 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 part 2B of the vehicle body. The other of the fourth movable parts 154 is disposed between the right traveling frame 8R and the rear part 2B of the vehicle body.

[0209] The sixth embodiment can be suitably applied to a work vehicle 1 having a configuration in which the main body case 5 is movable in the front-rear direction (see FIG. 24). In this case, the main body case 5 is movable in the front-rear direction with respect to the rear part 2B of the vehicle body. In the case of the sixth embodiment, since movable parts (third movable part 153, fourth movable part 154, seventh movable part 157) are arranged between the main body case 5 and the rear part 2B of the vehicle body, due to the movement of the main body case 5 in the front-rear direction, connection wirings (second electrical wiring 142, third electrical wiring 143) connecting the first battery 12A and the second batteries 12BL, 12BR, and a connection wiring (first electrical wiring 141) connecting the first battery 12A and the main junction box 130A can be prevented from having problems (twisting, entanglement, damage).

[0210] 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 vertical positional relationship, the left-right positional relationship, and the front-rear positional relationship between the main junction box 130A and the sub-junction box 130B can be changed. However, the work vehicle 1 does not necessarily need to be able to change all of the vertical positional relationship, the left-right positional relationship, and the front-rear positional relationship, and is configured to be able to change at least one positional relationship, preferably at least two positional relationships.

[0211] By being able to change the positional relationship between the main junction box 130A and the sub-junction box 130B, it becomes possible to change the routing path (the position 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 types or numbers of electrical devices are changed, it becomes possible to flexibly change the routing path of the electrical wiring in response to this change.

[0212] 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 following the deformation of the connection wiring when at least one, preferably two or more, of the vertical, horizontal, and front-rear positional relationships between the main junction box 130A and the sub-junction box 130B are changed.

[0213] As shown in FIG. 7, the work vehicle 1 is provided with an inclination detection device 170. The inclination detection device 170 detects the inclination of the vehicle body 2. Specifically, the inclination detection device 170 detects the inclination angle of the vehicle body 2 with respect to the horizontal direction. As the inclination detection device 170, for example, an inclination sensor, a load cell, a camera, etc. can be used. However, the inclination detection device 170 may be any device that can detect the inclination of the vehicle body 2, and its type is not particularly limited.

[0214] As the inclination sensor, for example, a pendulum type inclination sensor provided with a detection unit such as a pendulum and a magnetoresistive element, an electrostatic capacitance type inclination sensor that detects the inclination of a liquid as a change amount of electrostatic capacitance, a crystal type inclination sensor using a crystal oscillator, etc. can be used. The calculation of the inclination angle based on the detection value of the sensor (such as the change amount of electrostatic capacitance) can be performed by an arithmetic unit or the like included in the control device 19 or the inclination detection device 170.

[0215] When a load cell is used as the inclination detection device 170, the strain of the axle generated when the vehicle body inclines is detected by a strain gauge included in the load cell, and the inclination angle of the vehicle body 2 is calculated based on the strain value. The calculation of the inclination angle based on the detected strain value can be performed by an arithmetic unit or the like included in the control device 19 or the inclination detection device 170.

[0216] When a camera is used as the inclination detection device 170, for example, the camera fixed to the vehicle body 2 photographs the ground on which the work vehicle 1 is traveling, and calculates the inclination angle of the vehicle body 2 with respect to the ground based on the photographed image. The calculation of the inclination angle based on the photographed image can be performed by an arithmetic unit or the like included in the control device 19 or the inclination detection device 170. As the camera, the camera 18a of the situation detection device 18 described above may be used.

[0217] As shown in FIG. 7, the work vehicle 1 includes a change mechanism 180 that changes the positional relationship between the vehicle body 2 and the traveling unit 4 based on the detection result of the inclination detection device 170. The change mechanism 180 includes the height change mechanism 90, the distance change mechanism 80, and the 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, the distance change mechanism 80, and the position change mechanism 70. However, the change mechanism 180 may include at least one (one or two) of the height change mechanism 90, the distance change mechanism 80, and the position change mechanism 70.

[0218] The change mechanism 180 is a mechanism for preventing the work vehicle 1 from tipping over. The operation of the change mechanism 180 is particularly preferably executed when the vehicle body 2 is in a raised position with respect to the traveling unit 4. The operation of raising the vehicle body 2 with respect to the traveling unit 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 a crop planted on the ridge). Therefore, when the work vehicle 1 travels in the field, a state may occur in which the vehicle body 2 is in a raised position with respect to the traveling unit 4.

[0219] 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, the inclination of the ground, the unevenness of the ground, the turning operation of the work vehicle 1, or the like. When the vehicle body 2 is in a raised position with respect to the traveling unit 4, the center of gravity of the work vehicle 1 is at a high position, so the work vehicle 1 is in a state where it is likely to tip over. In such a state, by operating the change mechanism 180, it is possible to avoid the tipping over of the work vehicle 1. Hereinafter, the specific configuration and operation of the change mechanism 180 will be described.

[0220] First, a case where the changing mechanism 180 is the height changing mechanism 90 will be described. In this case, the height changing mechanism 90 changes the vertical position of the vehicle body 2 based on the detection result of the inclination detection device 170. The operation of this height changing mechanism 90 is controlled by the height change control unit 19C. That is, the height change control unit 19C controls the operation of the height changing mechanism 90 based on the detection result of the inclination detection device 170.

[0221] As shown in FIGS. 19 and 20, the height changing mechanism 90 includes a left height changing mechanism 90L that changes the height of the left part of the vehicle body 2 and a right height changing mechanism 90R that changes the height of the right part of the vehicle body 2. The left height changing mechanism 90L has a left lifting cylinder 91L. The right height changing mechanism 90R has a right lifting cylinder 91R. The height changing mechanism 90 changes the height of the left part of the vehicle body 2 by driving the left lifting cylinder 91L and changes the height of the right part of the vehicle body 2 by driving the right lifting cylinder 91R.

[0222] Based on the detection result of the inclination detection device 170, the height changing mechanism 90 can make the height of the left part and the right part of the vehicle body 2 different. Specifically, when the inclination detection device 170 detects that the vehicle body 2 is inclined to the left by a predetermined amount or more, the height changing mechanism 90 performs at least one of the operations of raising the left part of the vehicle body 2 and lowering the right part of the vehicle body 2. When it detects that the vehicle body 2 is inclined to the right by a predetermined amount or more, it performs at least one of the operations of raising the right part of the vehicle body 2 and lowering the left part of the vehicle body 2.

[0223] 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 appropriately changed and set according to the situation of the place where the work vehicle 1 travels (such as the inclination and unevenness of the ground), the vehicle height during the travel of the work vehicle 1, the wind speed during the travel, etc. This is the same for the operations of other changing mechanisms (distance changing mechanism 80, position changing mechanism 70) described later.

[0224] FIG. 38 is a diagram showing a first example of the operation of the height changing mechanism 90. The left diagram in FIG. 38 shows a state in which a force (see arrow F1) for tilting the work vehicle 1 to the left acts. When a leftward tilt occurs in the vehicle body 2 due to this force F1, 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 is tilted leftward by a predetermined amount or more, the height changing mechanism 90 performs at least one of an operation of raising the left part of the vehicle body 2 and an operation of lowering the right part of the vehicle body 2.

[0225] As shown in the right diagram of FIG. 38, the operation of raising the left part of the vehicle body 2 is performed by extending the rod 91a of the left lifting cylinder 91L. The operation of lowering the right part of the vehicle body 2 is performed by shortening the rod 91a of the right lifting cylinder 91R. This operation is performed by the height change control unit 19C controlling the left lifting cylinder 91L and the right lifting cylinder 91R.

[0226] 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 leftward by a predetermined amount or more. If it is determined that the vehicle body 2 is tilted by a predetermined amount or more, the left lifting cylinder 91L and / or the right lifting cylinder 91R is driven. Thereby, at least one of an operation of raising the left part of the vehicle body 2 and an operation of lowering the right part of the vehicle body 2 is performed.

[0227] As described above, by performing at least one of an operation of raising the left part of the vehicle body 2 and an operation of lowering the right part of the vehicle body 2, as shown in the right diagram of FIG. 38, a moment in the right direction (see arrow F2) acts on the vehicle body 2. Since this moment acts in a direction to cancel the force (see arrow F1) for tilting the work vehicle 1 to the left, it is possible to avoid the vehicle body 2 from tilting to the left.

[0228] FIG. 39 is a diagram showing a second example of the operation of the height changing mechanism 90. The left diagram of FIG. 39 shows a state in which a force (see arrow F3) for tilting the work vehicle 1 to the right acts on the work vehicle 1. When a rightward tilt occurs in the vehicle body 2 due to this force F3, 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 is tilted to the right by a predetermined amount or more, the height changing mechanism 90 performs at least one of an operation of raising the right part of the vehicle body 2 and an operation of lowering the left part of the vehicle body 2.

[0229] As shown in the right diagram of FIG. 39, the operation of raising the right part of the vehicle body 2 is performed by extending the rod 91a of the right elevating cylinder 91R. The operation of lowering the left part of the vehicle body 2 is performed by shortening the rod 91a of the left elevating cylinder 91L. This operation is performed by the height change control unit 19C controlling the left elevating cylinder 91L and the right elevating cylinder 91R. The height change control unit 19C determines whether the vehicle body 2 is tilted to the right 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 a predetermined amount or more, it drives the left elevating cylinder 91L and / or the right elevating cylinder 91R. Thereby, at least one of an operation of raising the right part of the vehicle body 2 and an operation of lowering the left part of the vehicle body 2 is performed.

[0230] As described above, by performing at least one of an operation of raising the right part of the vehicle body 2 and an operation of lowering the left part of the vehicle body 2, as shown in the right diagram of FIG. 39, a moment in the left direction (see arrow F4) acts on the vehicle body 2. Since this moment acts in a direction to cancel the force (see arrow F3) for tilting the work vehicle 1 to the right, it is possible to avoid the vehicle body 2 from tilting to the right.

[0231] Furthermore, as shown in FIG. 40, the vehicle body frame 21 may be connected to the traveling frame 8 without passing through the mast mechanism described above. That is, the work vehicle 1 may not be provided with the mast mechanism. In this case, the vehicle body frame 21 is connected to the traveling frame 8 via the left lifting cylinder 91L and the right lifting cylinder 91R without passing through the mast mechanism. In this case, it is preferable to provide a plurality of left lifting cylinders 91L and right lifting cylinders 91R at intervals in the front-rear direction. Also, in this case, the upper ends of the cylinder tubes 91b of the left lifting cylinder 91L and the right lifting cylinder 91R are pivotally supported so as to be rotatable about a first axis 55 extending in the front-rear direction with respect to the vehicle body frame 21, and the lower ends of the rods 91a of the left lifting cylinder 91L and the right lifting cylinder 91R are pivotally supported so as to be rotatable about a second axis 56 in the front-rear direction with respect to the traveling frame 8.

[0232] According to this configuration, since the vehicle body frame 21 is likely to swing in the left-right direction, the vehicle body 2 is likely to tilt in the left-right direction. Therefore, the operation of driving the left lifting cylinder 91L and / or the right lifting cylinder 91R to make the heights of the left and right portions of the vehicle body 2 different can be performed smoothly.

[0233] 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 portions of the vehicle body 2. Also, the height change mechanism 90 lowers the left and right portions of the vehicle body 2 by the same distance.

[0234] FIG. 41 is a diagram showing a third example of the operation of the height change mechanism 90. FIG. 41 shows a state in which a force (see arrow F5) for tilting the work vehicle 1 to the left or a force (see arrow F6) for tilting it to the right acts. When a tilt in the right or left direction occurs in the vehicle body 2 due to this force F5 or F6, 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 is tilted to the right or left by a predetermined amount or more, the height change mechanism 90 lowers the vehicle body 2.

[0235] As shown in the right figure of FIG. 41, the operation of lowering the vehicle body 2 is performed by shortening the rods 91a of the right lifting cylinder 91R and the left lifting cylinder 91L. This operation is performed by the height change control unit 19C controlling the left lifting cylinder 91L and the right lifting cylinder 91R. The height change control unit 19C determines whether the vehicle body 2 is tilted by a predetermined amount or more based on the detection result of the tilt detection device 170. If it is determined that the vehicle body 2 is tilted by a predetermined amount or more, the left lifting cylinder 91L and the right lifting cylinder 91R are driven. Thereby, the operation of lowering the vehicle body 2 is performed.

[0236] As described above, by performing the operation of lowering the vehicle body 2, as shown in the right figure of FIG. 41, the height of the vehicle body 2 decreases, so the center of gravity position of the work vehicle 1 drops. Thereby, it is possible to avoid the work vehicle 1 from tipping over. When performing the operation of 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 at a position lower than the upper ends of the left traveling unit 4L and the right traveling unit 4R. Thereby, it is possible to surely avoid the work vehicle 1 from tipping over.

[0237] In the case of the operations of the above-described first example and second example, there is a limit to increasing the height difference between the left and right parts of the vehicle body 2, and it is difficult to increase the moment for avoiding tipping over, so the effect of avoiding tipping over may be reduced. On the other hand, according to the operation of the third example, by lowering the vehicle body 2 to lower the center of gravity position of the work vehicle 1, the distance between the action point (the point in contact with the ground) and the force point (the point where the force trying to tip over the vehicle acts) can be shortened, so tipping over can be more surely avoided.

[0238] When performing the operation of lowering the vehicle body 2 described above, the predetermined amount (second predetermined amount) of the inclination of the vehicle body 2 may be the same as the predetermined amount (first predetermined amount) of the inclination of the vehicle body 2 when performing the operation of making the height of the left part and the right part of the vehicle body 2 different from each other described above, but the first predetermined amount and the second predetermined amount may be made different from each other. By making the first predetermined amount and the second predetermined amount different from each other, it becomes possible to avoid the work vehicle 1 from tipping over by changing the height of the vehicle body 2 in an optimal manner according to the magnitude of the inclination of the vehicle body 2.

[0239] Preferably, the second predetermined amount is set to be larger than the first predetermined amount. By setting it in this way, when the inclination of the vehicle body 2 detected by the inclination detection device 170 is small, the height changing mechanism 90 performs an operation of making the height of the left part and the right part of the vehicle body 2 different from each other, and when the inclination of the vehicle body 2 detected by the inclination detection device 170 is large, the height changing mechanism 90 can perform an operation of lowering the vehicle body 2. As a result, when the inclination of the vehicle body 2 is small, the work can be continued without changing the height of the vehicle body 2 very much, and when the inclination of the vehicle body 2 is large, it is possible to surely avoid the work vehicle 1 from tipping over by lowering the vehicle body 2.

[0240] FIG. 42 is a flowchart showing an example of the operation of the height changing mechanism 90. Hereinafter, an example of the operation of the height changing mechanism 90 will be described based on FIG. 42. The operation of the height changing mechanism 90 is executed based on the control by the height change control unit 19C.

[0241] When the work vehicle 1 is running, the inclination detection device 170 detects the inclination of the vehicle body 2 in the left-right direction (S1). The height change control unit 19C determines whether the amount of inclination detected by the inclination detection device 170 is equal to or greater than a first predetermined amount (S2). If it is determined that the amount of inclination is less than the first predetermined amount (S2: No), the detection operation is continuously executed. If it is determined that the amount of inclination is equal to or greater than the first predetermined amount (S2: Yes), it is determined whether the amount of inclination detected by the inclination detection device 170 is equal to or greater than a second predetermined amount (S3). If it is determined that the amount of inclination 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 inclination is less than the second predetermined amount (S3: No), it is determined whether the direction of inclination is to the left side (S5). If it is determined that the direction of inclination is to the left side (S5: Yes), the height change mechanism 90 performs at least one of the operation of raising the left part of the vehicle body 2 and the operation of lowering the right part of the vehicle body 2 (S6). If it is determined that the direction of inclination is to the right side (S5: No), the height change mechanism 90 performs at least one of the operation of raising the right part of the vehicle body 2 and the operation of lowering the left part of the vehicle body 2 (S7).

[0242] Note that the flowchart shown in FIG. 42 is an example of the operation of the height change mechanism 90, and the operation of the height change mechanism 90 is not limited to the flowchart of FIG. 42 and can be appropriately changed as necessary. 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. Also, in S5, it may be determined whether the direction of inclination of the vehicle body 2 is to the right side, or it may be determined whether it is to the left side or the right side.

[0243] The height change mechanism 90 can change the difference in height between the left part and the right part of the vehicle body 2 corresponding to the amount (magnitude) of inclination detected by the inclination detection device 170. Specifically, as the inclination detected by the inclination detection device 170 increases, the difference in height between the left part and the right part of the vehicle body 2 can be increased. Thereby, the left-right height balance of the vehicle body 2 can be appropriately adjusted according to the risk of tipping.

[0244] FIG. 43 is a flowchart showing another example of the operation of the height changing mechanism 90. Hereinafter, based on FIG. 43, another example of the operation of the height changing mechanism 90 will be described. The operation of this height changing mechanism 90 is also executed based on the control by the height change control unit 19C.

[0245] When the work vehicle 1 is traveling, the inclination detection device 170 detects the inclination of the vehicle body 2 in the left-right direction (S1). The height change control unit 19C determines whether or not the amount of inclination detected by the inclination detection device 170 is equal to or greater than a first predetermined amount (S2). If it is determined that the amount of inclination is less than the first predetermined amount (S2: No), the detection operation is continuously executed. If it is determined that the amount of inclination is equal to or greater than the first predetermined amount (S2: Yes), it is determined whether or not the amount of inclination is equal to or greater than a second predetermined amount (S3). If it is determined that the amount of inclination is less than the second predetermined amount (S3: No), it is determined whether or not the direction of inclination is to the left (S4). If it is determined that the direction of inclination is to the left (S4: Yes), the height changing mechanism 90 performs at least one of the operation of raising the left part of the vehicle body 2 and the operation of lowering the right part of the vehicle body 2 (S5). If it is determined that the direction of inclination is to the right (S4: No), the height changing mechanism 90 performs at least one of the operation of raising the right part of the vehicle body 2 and the operation of lowering the left part of the vehicle body 2 (S6).

[0246] If it is determined that the amount of inclination is equal to or greater than the second predetermined amount (S3: Yes), it is determined whether or not the amount of inclination 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 the first predetermined amount < the second predetermined amount < the third predetermined amount.

[0247] When it is determined that the amount of inclination is less than the third predetermined amount (S7: No), it is determined whether the direction of inclination is to the left (S8). When it is determined that the direction of inclination is to the left (S8: Yes), the height changing mechanism 90 performs an operation of lowering the left and right portions of the vehicle body 2. At this time, the amount of descent of the right portion of the vehicle body 2 is made larger than the amount of descent of the left portion of the vehicle body 2 (S9). When it is determined that the direction of inclination is to the right (S8: No), the height changing mechanism 90 performs an operation of lowering the left and right portions of the vehicle body 2. At this time, the amount of descent of the left portion of the vehicle body 2 is made larger than the amount of descent of the right portion of the vehicle body 2 (S10).

[0248] When it is determined that the amount of inclination is equal to or more than the third predetermined amount (S7: Yes), the height changing mechanism 90 lowers the vehicle body 2 (S11). At this time, the amount of descent of the right portion of the vehicle body 2 and the amount of descent of the left portion of the vehicle body 2 are the same. The amount of descent of the left and right portions of the vehicle body 2 at this time is preferably the maximum amount of descent that can be implemented by the height changing mechanism 90, but is set to be equal to or exceed at least the amount of descent of the right portion of the vehicle body 2 in S9 and the amount of descent of the left portion of the vehicle body 2 in S10.

[0249] Incidentally, the operation of the height changing mechanism 90 shown in the flowchart of FIG. 43 can be appropriately changed as needed. For example, the determinations in S2, S3, and S7 may be performed simultaneously. Also, in S4 and S8, it may be determined whether the direction of inclination of the vehicle body 2 is to the right, or it may be determined whether it is to the left or the right. Further, the positions of S5 and S9, and the positions of S6 and S10 may be reversed. That is, in the step of S4, if Yes, the operation described in S9 is performed, and if No, the operation described in S10 is performed. In the step of S8, if Yes, the operation described in S5 is performed, and if No, the operation described in S6 may be performed.

[0250] In the operation of the height change mechanism 90 shown in the flowchart of FIG. 43, when the amount of inclination of the vehicle body 2 is small (when it is equal to or greater than the first predetermined amount, but less than the second predetermined amount and less than the third predetermined amount), the height change mechanism 90 raises one of the left and right portions of the vehicle body 2 and lowers the other. When the amount of inclination of the vehicle body 2 is moderate (when it is equal to or greater than the first predetermined amount and equal to or greater than the second predetermined amount, but less than the third predetermined amount), the height change mechanism 90 lowers one of the left and right portions of the vehicle body 2 and lowers the other by more than the one. When the amount of inclination of the vehicle body 2 is large (when it is equal to or greater than the first predetermined amount, equal to or greater than the second predetermined amount, and equal to or greater than the third predetermined amount), the height change mechanism 90 lowers the left and right portions of the vehicle body 2 by the same amount of descent.

[0251] By performing such an operation, when the inclination of the vehicle body 2 is small, the operation can be continued without significantly changing the height of the vehicle body 2. When 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. When the inclination of the vehicle body 2 is large, the vehicle body 2 can be lowered significantly to surely avoid the work vehicle 1 from tipping over.

[0252] Next, the 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 direction distance of the traveling unit 4 with respect to the vehicle body 2 based on the detection result of the inclination detection device 170. The operation of the distance change mechanism 80 is controlled by the distance change control unit 19B.

[0253] The distance change mechanism 80 includes a left - hand distance change mechanism 80L that changes the left - right direction distance of the left traveling unit 4L with respect to the vehicle body 2, and a right - hand distance change mechanism 80R that changes the left - right direction distance of the right traveling unit 4R with respect to the vehicle body 2 (see FIG. 6). The left - hand distance change mechanism 80L is the above - described left - hand change mechanism 80L and has a left cylinder 81L. The right - hand distance change mechanism 80R is the above - described right - hand change mechanism 80R and has a right cylinder 81R. The distance change mechanism 80 changes the left - right direction distance of the left traveling unit 4L with respect to the vehicle body 2 by driving the left cylinder 81L, and changes the left - right direction distance of the right traveling unit 4R with respect to the vehicle body 2 by driving the right cylinder 81R.

[0254] The distance changing mechanism 80 can make the distance between the left traveling unit 4L and the vehicle body 2 different from the distance between the right traveling unit 4R and the vehicle body 2 based on the detection result of the inclination detection device 170. Specifically, when the inclination detection device 170 detects that the vehicle body 2 is inclined to the left by a predetermined amount or more, the distance changing mechanism 80 increases the distance between the left traveling unit 4L and the vehicle body 2, and when it detects that the vehicle body 2 is inclined to the right by a predetermined amount or more, it increases the distance between the right traveling unit 4R and the vehicle body 2.

[0255] FIG. 44 is a diagram showing a first example of the operation of the distance changing mechanism 80. The left diagram in FIG. 44 shows a state in which a force (see arrow F7) for tilting the work vehicle 1 to the left acts. When a leftward tilt occurs in the vehicle body 2 due to this force F7, the inclination detection device 170 detects the leftward tilt of the vehicle body 2. When the inclination detection device 170 detects that the vehicle body 2 is inclined to the left by a predetermined amount or more, the distance changing mechanism 80 performs an operation of increasing the left - right direction distance between the left traveling unit 4L and the vehicle body 2.

[0256] As shown in the right diagram of FIG. 44, the operation of increasing the distance between the left traveling 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. The distance change control unit 19B determines based on the detection result of the inclination detection device 170 whether the vehicle body 2 is inclined to the left by a predetermined amount or more, and if it determines that it is inclined by a predetermined amount or more, it drives the left cylinder 81L to extend the rod 81a. As a result, the left traveling unit 4L moves in the direction away from the vehicle body 2 (leftward) (see arrow L2), and the distance between the left traveling unit 4L and the vehicle body 2 increases.

[0257] As described above, by performing the operation of increasing the distance between the left traveling unit 4L and the vehicle body 2, as shown in the right diagram of FIG. 44, the left wheels (left front wheel 7LF, left rear wheel 7LB) contact the ground at a position farther to the left from the vehicle body 2 than before the operation. Thereby, it is possible to avoid the vehicle body 2 from tilting to the left.

[0258] FIG. 45 is a diagram showing a second example of the operation of the distance changing mechanism 80. The left diagram of FIG. 45 shows a state in which a force (see arrow F8) for tilting the work vehicle 1 to the right acts. When a rightward tilt occurs in the vehicle body 2 due to this force F8, 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 is tilted to the right by a predetermined amount or more, the distance changing mechanism 80 performs an operation of increasing the left-right distance between the right traveling unit 4R and the vehicle body 2.

[0259] As shown in the right diagram of FIG. 45, the operation of increasing the distance between the right traveling 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 a predetermined amount or more. If it is determined that the vehicle body 2 is tilted by a predetermined amount or more, the right cylinder 81R is driven to extend the rod 81a. As a result, the right traveling unit 4R moves in a direction away from the vehicle body 2 (rightward) (see arrow R2), and the distance between the right traveling unit 4R and the vehicle body 2 increases.

[0260] As described above, by performing the operation of increasing the distance between the right traveling unit 4R and the vehicle body 2, as shown in the right diagram of FIG. 45, the right wheels (right front wheel 7RF, right rear wheel 7RB) contact the ground at a position farther to the right from the vehicle body 2 than before the operation. Thereby, it is possible to avoid the vehicle body 2 from tilting to the right.

[0261] In addition, as an operation of making the distance between the left traveling unit 4L and the vehicle body 2 different from the distance between the right traveling unit 4R and the vehicle body 2, the distance changing mechanism 80 may perform both an operation of increasing the distance between the left traveling unit 4L and the vehicle body 2 and an operation of increasing the distance between the right traveling unit 4R and the vehicle body 2. In this case, by making the extension amount of the rod 81a of the left cylinder 81L different from the extension amount of the rod 81a of the right cylinder 81R, the distance between the traveling unit 4L and the vehicle body 2 and the distance between the right traveling unit 4R and the vehicle body 2 can be made different.

[0262] When the tilt detection device 170 detects the tilt of the vehicle body 2 in a state where the left traveling unit 4L and the right traveling unit 4R are at a position separated from the vehicle body 2 by a certain distance (a state where the distance between the left traveling unit 4L and the right traveling unit 4R and the vehicle body 2 is equal to or greater than a predetermined distance), the distance changing mechanism 80 may perform an operation of increasing the distance between one of the left traveling unit 4L and the right traveling unit 4R and the vehicle body 2 and decreasing the distance between the other traveling unit and the vehicle body 2. In this case, by extending one rod of the left cylinder 81L and the right cylinder 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, and the distance between the left traveling unit 4L and the vehicle body 2 and the distance between the right traveling unit 4R and the vehicle body 2 can be made different.

[0263] FIG. 46 is a flowchart showing an example of the operation of the distance changing mechanism 80. Hereinafter, an example of the operation of the distance changing mechanism 80 will be described with reference to FIG. 46. The operation of the distance changing mechanism 80 is executed based on the control by the distance change control unit 19B.

[0264] When 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 or not 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 detection operation is continuously executed. If it is determined that the amount of tilt is equal to or greater than the predetermined amount (S2: Yes), it is determined whether or not the direction of tilt is to the left (S3). If it is determined that the direction of tilt is to the left (S3: Yes), the distance changing mechanism 80 performs an operation of increasing the distance between the left traveling unit 4L and the vehicle body 2 (S4). If it is determined that the direction of tilt is to the right (S3: No), the distance changing mechanism 80 performs an operation of increasing the distance between the right traveling unit 4R and the vehicle body 2 (S5).

[0265] The flowchart shown in FIG. 46 is an example of the operation of the distance changing mechanism 80. The operation of the distance changing mechanism 80 is not limited to the flowchart of FIG. 46 and can be appropriately changed as necessary. For example, the determinations of S2 and S3 may be performed simultaneously, or the order of the determinations of S2 and S3 may be reversed. Also, in S3, it may be determined whether the direction of the inclination of the vehicle body 2 is to the right, or it may be determined whether it is to the left or the right.

[0266] The distance changing mechanism 80 can change the magnitude of the left - right direction distance between the vehicle body 2 and the traveling unit 4 (left traveling unit 4L, right traveling unit 4R) corresponding to the amount (magnitude) of the inclination detected by the inclination detection device 170. Specifically, as the inclination detected by the inclination detection device 170 increases, the left - right direction distance between the vehicle body 2 and the traveling unit 4 can be increased. Thereby, the left - right direction distance between the vehicle body 2 and the traveling unit 4 can be appropriately adjusted according to the risk of tipping over.

[0267] Next, the case where the change mechanism 180 is the position changing mechanism 70 will be described. In this case, the position changing mechanism 70 changes the position of the vehicle body 2 in the front - rear direction based on the detection result of the inclination detection device 170. The operation of this position changing mechanism 70 is controlled by the position change control unit 19D. As described above, the position changing mechanism 70 has a position change cylinder 73. The position changing mechanism 70 changes the position of the vehicle body 2 in the front - rear direction by driving the position change cylinder 73.

[0268] When the inclination detection device 170 detects that the vehicle body 2 is inclined forward by a predetermined amount or more, the position changing mechanism 70 moves the vehicle body 2 backward with respect to the traveling unit 4. When the inclination detection device 170 detects that the vehicle body 2 is inclined backward by a predetermined amount or more, the position changing mechanism 70 moves the vehicle body 2 forward with respect to the traveling unit 4.

[0269] FIG. 47 is a diagram showing a first example of the operation of the position changing mechanism 70. The left diagram of FIG. 47 shows a state in which a force (see arrow F9) for tilting forward with respect to the work vehicle 1 acts. When a forward tilt occurs in the vehicle body 2 due to this force F9, 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 is tilted forward by a predetermined amount or more, the position changing mechanism 70 performs an operation of moving the vehicle body 2 rearward (see arrow A1 in FIG. 47).

[0270] The operation of moving the vehicle body 2 rearward is performed by extending or shortening the rod 73b of the position changing cylinder 73 (see FIG. 23). This operation is performed by the position changing control unit 19D controlling the position changing cylinder 73. Based on the detection result of the tilt detection device 170, the position changing control unit 19D determines whether the vehicle body 2 is tilted forward by a predetermined amount or more. If it is determined that the vehicle body 2 is tilted forward by a predetermined amount or more, the position changing control unit 19D drives the position changing cylinder 73 to shorten the rod 73b. As a result, the vehicle body 2 moves rearward.

[0271] As described above, by performing the operation of moving the vehicle body 2 rearward, as shown in the right diagram of FIG. 47, the vehicle body 2 moves rearward with respect to the traveling unit 4. As a result, since the center of gravity position of the work vehicle 1 moves rearward, it is possible to avoid the vehicle body 2 from tilting forward.

[0272] FIG. 48 is a diagram showing a second example of the operation of the position changing mechanism 70. The left diagram of FIG. 48 shows a state in which a force (see arrow F10) for tilting backward with respect to the work vehicle 1 acts. When a backward tilt occurs in the vehicle body 2 due to this force F10, the tilt detection device 170 detects the backward tilt of the vehicle body 2. When the tilt detection device 170 detects that the vehicle body 2 is tilted backward by a predetermined amount or more, the position changing mechanism 70 performs an operation of moving the vehicle body 2 forward (see arrow A2 in FIG. 48).

[0273] The operation of moving the vehicle body 2 forward is performed by extending or shortening the rod 73b of the position changing cylinder 73 (see FIG. 23). This operation is performed by the position changing control unit 19D controlling the position changing cylinder. Based on the detection result of the inclination detection device 170, the position changing control unit 19D determines whether the vehicle body 2 is inclined rearward by a predetermined amount or more. When it is determined that the inclination is by a predetermined amount or more, the position changing cylinder is driven to extend the rod 73b. As a result, the vehicle body 2 moves forward.

[0274] As described above, by performing the operation of moving the vehicle body 2 forward, as shown in the right figure of FIG. 48, the vehicle body 2 moves forward with respect to the traveling unit 4. As a result, since the center of gravity position of the work vehicle 1 moves forward, it is possible to avoid the vehicle body 2 from tipping backward.

[0275] FIG. 49 is a flowchart showing an example of the operation of the position changing mechanism 70. Hereinafter, an example of the operation of the position changing mechanism 70 will be described based on FIG. 49. The operation of the position changing mechanism 70 is executed based on the control by the position changing control unit 19D.

[0276] When the work vehicle 1 is traveling, the inclination detection device 170 detects the inclination of the vehicle body 2 in the front-rear direction (S1). The position changing control unit 19D determines whether the amount of inclination detected by the inclination detection device 170 is equal to or greater than a predetermined amount (S2). If it is determined that the amount of inclination is less than the predetermined amount (S2: No), the detection operation is continuously executed. If it is determined that the amount of inclination is equal to or greater than the predetermined amount (S2: Yes), it is determined whether the direction of inclination is the front side (S3). If it is determined that the direction of inclination is the front side (S3: Yes), the position changing mechanism 70 performs an operation of moving the vehicle body 2 backward with respect to the traveling unit 4 (S4). If it is determined that the direction of inclination is the rear side (S3: No), the position changing mechanism 70 performs an operation of moving the vehicle body 2 forward with respect to the traveling unit 4 (S5).

[0277] The flowchart shown in FIG. 49 is an example of the operation of the position changing mechanism 70, and the operation of the position changing mechanism 70 is not limited to the flowchart of FIG. 49 and can be appropriately changed 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. Further, in S3, it may be determined whether the direction of the inclination of the vehicle body 2 is the rear side, or it may be determined whether it is the front side or the rear side.

[0278] The position changing mechanism 70 can change the amount of movement of the vehicle body 2 forward or backward corresponding to the amount (magnitude) of the inclination detected by the inclination detection device 170. Specifically, as the inclination detected by the inclination detection device 170 increases, the amount of movement of the vehicle body 2 forward or backward can be increased. Thereby, the position of the vehicle body 2 in the front-rear direction with respect to the traveling unit 4 can be appropriately adjusted according to the risk of tipping over.

[0279] Incidentally, the position changing mechanism 70 may change the position of a part of the vehicle body 2 in the front-rear direction based on the detection result of the inclination detection device 170. In this case, as the position changing mechanism 70, the position changing mechanism 70 of the modified example shown in FIG. 24 is used. In this case, the position changing mechanism 70 drives the position changing cylinder 73 based on the detection result of the inclination detection device 170 to change the position of the main body case 5 that houses the first battery 12A in the front-rear direction. Specifically, when the inclination detection device 170 detects that the vehicle body 2 is inclined forward by a predetermined amount or more, the position changing mechanism 70 moves the main body case 5 backward with respect to the vehicle body frame 21, and when it detects that the vehicle body 2 is inclined backward by a predetermined amount or more, the position changing mechanism 70 moves the main body case 5 forward with respect to the vehicle body frame 21. Thereby, since the center of gravity position of the work vehicle 1 moves in the direction opposite to the direction of inclination, it is possible to avoid the work vehicle 1 from tipping over.

[0280] A preferred embodiment of the present invention provides the work vehicle 1 described in the following items.

[0281] (Item A1) A vehicle body 2, a structure 3 connectable to the vehicle body 2, a main junction box 130A provided at least on either the vehicle body 2 or the structure 3, and a sub-junction box 130B provided at least on either the vehicle body 2 or the structure 3, a plurality of junction boxes 130 including these, and a plurality of electrical devices 120. The sub-junction box 130B has at least one of the plurality of electrical devices 120 connected thereto, and the main junction box 130A has an electrical device 120 different from the electrical device 120 connected to the sub-junction box 130B among the plurality of electrical devices 120 connected thereto, and the work vehicle 1 to which the sub-junction box 130B is connected.

[0282] According to the work vehicle 1 according to this Item A1, it is possible to prevent the routing of the electrical wiring connecting the plurality of junction boxes 130 and the plurality of electrical devices 120 from becoming complicated. Further, since 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 when a part of the work vehicle 1 is deformed (moved), the electrical wiring is less likely to get entangled.

[0283] (Item A2) The structure 3 includes a traveling unit 4 disposed on the side of the vehicle body 2. The main junction box 130A is disposed on either the vehicle body 2 or the traveling unit 4. When the main junction box 130A is disposed on the vehicle body 2, the sub-junction box 130B is disposed on the traveling unit 4. When the main junction box 130A is disposed on the traveling unit 4, the work vehicle 1 according to Item A1 disposed on the vehicle body 2.

[0284] According to the work vehicle 1 related to this item A2, since the main junction box 130A and the sub-junction box 130B are separately arranged on the vehicle body 2 and the structure 3, it is possible to simplify and easily perform the routing of the electrical equipment 120 arranged on the vehicle body 2 and the structure 3.

[0285] (Item A3) The plurality of electrical equipment 120 includes a first electrical equipment 121 arranged on the vehicle body 2 and a second electrical equipment 122 arranged on the traveling unit 4. When the main junction box 130A is arranged on the vehicle body 2, it is connected to the first electrical equipment 121, and when it is arranged on the traveling unit 4, it is connected to the second electrical equipment 122. The sub-junction box 130B is connected to the second electrical equipment 122 when arranged on the traveling unit 4 and is connected to the first electrical equipment 121 when arranged on the vehicle body 2. The work vehicle 1 according to item A2.

[0286] According to the work vehicle 1 related to this item A3, it is possible to easily connect the main junction box 130A and the sub-junction box 130B in the vicinity of both the first electrical equipment 121 arranged on the vehicle body 2 and the second electrical equipment 122 arranged on the traveling unit 4.

[0287] (Item A4) The traveling unit 4 includes a left traveling unit 4L arranged on the left side of the vehicle body 2 and a right traveling 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 traveling unit 4L and the right traveling unit 4R. The work vehicle 1 according to item A2.

[0288] According to the work vehicle 1 related to this item A4, the main junction box 130A can be arranged and connected in the vicinity of the electrical equipment 120 arranged on the vehicle body 2, and the sub-junction box 130B can be arranged and connected in the vicinity of the electrical equipment 120 arranged on the left traveling unit 4L and the right traveling unit 4R.

[0289] (Item A5) The first electrical device 121 includes the first battery 12A, the second electrical device 122 includes the second battery 12B, and the first battery 12A and the second battery 12B are directly or indirectly connected to the main junction box 130A. The work vehicle 1 described in Item A3.

[0290] According to the work vehicle 1 according to this Item A5, since the power supply from the first battery 12A and the second battery 12B to the electrical device 120 can be performed via the main junction box 130A, the routing of the electrical wiring can be easily performed.

[0291] (Item A6) The second electrical device 122 includes an electrical device 120 different from the second battery 12B, and the sub-junction box 130B relays the electrical wiring connected to the electrical device 120 different from the second battery 12B. The work vehicle 1 described in Item A5.

[0292] According to the work vehicle 1 according to this Item A6, the routing of the electrical wiring connected to the electrical device 120 different from the second battery 12B can be easily performed.

[0293] (Item A7) The work vehicle 1 according to any one of Items A1 to A6, which includes a movable part 150 that guides the connection wiring connecting the main junction box 130A and the sub-junction box 130B and moves following the deformation of the connection wiring.

[0294] According to the work vehicle 1 according to this Item A7, when the positional relationship between the main junction box 130A and the sub-junction box 130B changes, it is possible to prevent problems (twisting, entanglement, damage) from occurring in the connection wiring connecting the main junction box 130A and the sub-junction box 130B.

[0295] (Item A8) The main junction box 130A is disposed on the vehicle body 2, and the work vehicle 1 according to any one of Items A1 to A7, which can change the vertical position together with the vehicle body 2.

[0296] According to the work vehicle 1 according to this Item A8, since the main junction box 130A can change the vertical position together with the vehicle body 2, it is possible to prevent a problem from occurring in the electrical wiring connected to the main junction box 130A when the vertical position of the vehicle body 2 changes.

[0297] (Item A9) The sub-junction box 130B is disposed on the traveling unit 4, and the work vehicle 1 according to Item A2, which can change the horizontal position together with the traveling unit 4.

[0298] According to the work vehicle 1 according to this Item A9, it is possible to prevent a problem from occurring in the electrical wiring connected to the sub-junction box 130B when the horizontal position of the traveling unit 4 changes.

[0299] (Item A10) Each of the plurality of electrical devices 120 includes at least one battery 12, and the work vehicle 1 according to Item A2, in which at least one of the battery 12 and the junction box 130 is disposed on each of the vehicle body 2 and the traveling unit 4.

[0300] According to the work vehicle 1 according to this Item A10, by the battery 12 and the junction box 130 disposed on the vehicle body 2 and the traveling unit 4, the routing of the electrical wiring to the electrical devices 120 disposed on the vehicle body 2 and the traveling unit 4 can be easily performed without complicating the routing.

[0301] (Item A11) The traveling unit 4 includes a left traveling unit 4L disposed on the left side of the vehicle body 2 and a right traveling unit 4R disposed on the right side of the vehicle body 2. The plurality of 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 unit 4L, and a third junction box 133 disposed on the right traveling unit 4R. The work vehicle 1 according to Item A2.

[0302] According to the work vehicle 1 according to this Item A11, since the junction boxes 130 are arranged on the vehicle body 2, the left traveling unit 4L, and the right traveling unit 4R respectively, various arrangements of electrical wiring for the electrical equipment arranged on the vehicle body 2, the left traveling unit 4L, and the right traveling unit 4R can be easily carried out without complicating them.

[0303] (Item A12) The plurality of electrical devices 120 include a first electrical device 121 disposed on the vehicle body 2 and a second electrical device 122 disposed on the traveling unit 4. In the left traveling unit 4L, as the second electrical device 122, left traveling motors (motors 10LF, 10LB) for driving the left wheels are arranged. In the right traveling unit 4R, as the second electrical device 122, right traveling motors (motors 10RF, 10RB) for driving the right wheels are arranged. The second junction box 132 relays the electrical wiring connected to the left traveling motors (motors 10LF, 10LB), and the third junction box 133 relays the electrical wiring connected to the right traveling motors (motors 10RF, 10RB). The work vehicle 1 according to Item A11.

[0304] According to the work vehicle 1 according to this Item A12, the electrical wiring for the left traveling motors (motors 10LF, 10LB) for driving the left wheels and the right traveling motors (motors 10RF, 10RB) for driving the right wheels can be easily carried out without complicating them.

[0305] (Item B1) A working vehicle 1 comprising a vehicle body 2, a left traveling frame 8L disposed on the left side of the vehicle body 2 and supporting a left wheel, and a right traveling frame 8R disposed on the right side of the vehicle body 2 and supporting a right wheel, a hydraulic unit 100 disposed between the left traveling frame 8L and the right traveling frame 8R, and a hydraulic valve 101 for controlling the operation of hydraulic equipment mounted on the vehicle body 2 or the traveling frame 8.

[0306] According to the working vehicle 1 according to this Item B1, since the hydraulic unit 100 is disposed between the left traveling frame 8L and the right traveling frame 8R, the hydraulic unit 100 can be disposed in a compact manner in the left - right direction.

[0307] (Item B2) The working vehicle 1 according to Item B1, wherein the left side of the hydraulic unit 100 is covered by the left traveling frame 8L and the right side is covered by the right traveling frame 8R.

[0308] According to the working vehicle 1 according to this Item B2, both the left and right sides of the hydraulic unit 100 can be protected by the traveling frame 8.

[0309] (Item B3) The working vehicle 1 according to Item B1 or B2, further comprising a battery 12 for storing electric power supplied to electrical equipment mounted on the vehicle body 2 or the traveling frame 8, wherein the hydraulic unit 100 and the battery 12 are arranged side - by - side in the front - rear direction between the left traveling frame 8L and the right traveling frame 8R.

[0310] According to the working vehicle 1 according to this Item B3, the hydraulic unit 100 and the battery 12 can be disposed in a compact manner in the left - right direction. Also, 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 be protected by the hydraulic unit 100.

[0311] Item B4: The work vehicle 1 according to any one of Items B1 to B3, comprising a lifting mechanism 90 for lifting and lowering the vehicle body 2 with respect to the traveling frame 8, wherein the hydraulic unit 100 is covered in at least two directions when the vehicle body 2 is in the lowered state and is covered in at least one direction when the vehicle body 2 is in the raised state.

[0312] According to the work vehicle 1 according to this Item B4, when the vehicle body 2 is in the raised state, the number of directions accessible to the hydraulic unit 100 increases compared to when the vehicle body 2 is in the lowered state, so the maintainability of the hydraulic unit 100 is improved.

[0313] Item B5: The work vehicle 1 according to any one of Items B1 to B4, wherein the hydraulic unit 100 includes the hydraulic valve 101, a hydraulic oil tank 102 for storing the hydraulic oil supplied to the hydraulic equipment, and a hydraulic pump 103 driven by the hydraulic oil, and the hydraulic valve 101, the hydraulic pump 103, and the hydraulic oil tank 102 are centrally arranged at the rear of the vehicle body 2.

[0314] According to the work vehicle 1 according to this Item B5, since the hydraulic valve 101, the hydraulic pump 103, and the hydraulic oil tank 102 are centrally arranged at the rear of the vehicle body 2, it is possible to collectively perform oil leakage checks etc. when inspecting the hydraulic valve 101, the hydraulic pump 103, and the hydraulic oil tank 102, and it has excellent maintainability.

[0315] Item B6: The work vehicle 1 according to Item B4, wherein the vehicle body 2 has a main body 5 and a vehicle body frame 21 for supporting the main body 5, the vehicle body frame 21 supports the main body 5 between the left traveling frame 8L and the right traveling frame 8R and is capable of lifting and lowering together with the main body 5, and the hydraulic unit 100 is arranged so as not to protrude from the vehicle body frame 21 at least in the left - right direction.

[0316] According to the work vehicle 1 according to this Item B6, interference between the hydraulic unit 100 and the traveling frame 8 can be avoided when the vehicle body frame 21 is lifted and lowered.

[0317] (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, a hydraulic device mounted on the vehicle body 2 or the structure 3 where the hydraulic actuator is not provided and different from the hydraulic actuator, and a moving mechanism for moving either the vehicle body 2 or the structure 3 on which the hydraulic device is mounted in the vertical direction together with the hydraulic device.

[0318] According to the work vehicle 1 according to this Item C1, since either the vehicle body 2 or the structure 3 on which the hydraulic device is mounted can be moved in the vertical direction together with the hydraulic device, the maintenance of the hydraulic device can be easily performed. Specifically, by moving the hydraulic device in the vertical direction, it becomes possible to facilitate access to the hydraulic device, and the maintenance of the hydraulic device can be easily performed.

[0319] (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.

[0320] According to the work vehicle 1 according to this Item C2, the maintenance of the hydraulic valve 101 that controls the operation of the hydraulic actuator can be easily performed.

[0321] (Item C3) The work vehicle 1 according to Item C1 or C2, wherein the hydraulic actuator is fixedly arranged, and the moving mechanism changes the position of the hydraulic device relative to the hydraulic actuator by moving the hydraulic device.

[0322] According to the work vehicle 1 according to this Item C3, it is possible to realize the facilitation of the maintenance of the hydraulic device by changing the position of the hydraulic device without moving the hydraulic actuator.

[0323] (Item C4) The work vehicle 1 according to any one of Items C1 to C3, wherein the hydraulic device moves relative to the structure 3 together with the vehicle body 2 by the moving mechanism.

[0324] According to the work vehicle 1 related to this item C4, by moving the hydraulic equipment together with the vehicle body 2 with respect to the structure 3, it is possible to access the hydraulic equipment without being blocked by the structure 3.

[0325] (Item C5) The structure 3 is a traveling frame 8 disposed on the side of the vehicle body 2 and supporting wheels, the moving mechanism is a lifting mechanism 90 that raises and lowers the vehicle body 2 with respect to the traveling frame 8, and the hydraulic equipment is the work vehicle 1 according to item C4 that is raised and lowered with the vehicle body 2 with respect to the traveling frame 8 by the lifting mechanism 90.

[0326] According to the work vehicle 1 related to this item C5, by moving the hydraulic equipment together with the vehicle body 2 with respect to the traveling frame 8, it is possible to access the hydraulic equipment without being blocked by the traveling frame 83.

[0327] (Item C6) The hydraulic actuator is fixed to the traveling frame 8, and the hydraulic equipment is the work vehicle 1 according to item C5 that is raised and lowered with respect to the hydraulic actuator when the vehicle body 2 is raised and lowered with respect to the traveling frame 8.

[0328] According to the work vehicle 1 related to this item C6, it is possible to realize the facilitation of maintenance of the hydraulic equipment by changing the position of the hydraulic equipment without moving the hydraulic actuator and the traveling frame 8.

[0329] (Item C7) The structure 3 is a traveling frame 8 disposed on the side of the vehicle body 2 and supporting wheels, the hydraulic actuator includes a steering cylinder 62 that steers the wheels, and the steering cylinder 62 is fixed to the structure 3, and the work vehicle 1 according to item C5 or C6.

[0330] According to the work vehicle 1 related to this item C7, it is possible to realize the facilitation of maintenance of the hydraulic equipment by changing the position of the hydraulic equipment without moving the steering cylinder 62 and the structure 3.

[0331] (Item D1) A work vehicle 1 including a vehicle body 2, a left traveling unit 4L disposed on the left side of the vehicle body 2, and a right traveling unit 4R disposed 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 traveling unit 4 based on the detection result of the inclination detection device 170.

[0332] According to the work vehicle 1 according to this Item D1, it is possible to avoid the overturning of the work vehicle 1 by changing the positional relationship between the vehicle body 2 and the traveling unit 4 based on the detection result of the inclination detection device 170.

[0333] (Item D2) The change mechanism 180 includes a height change mechanism 90 that can change the vertical position of the vehicle body 2 with respect to the traveling unit 4. The height change mechanism 90 changes the vertical position of the vehicle body 2 based on the detection result of the inclination detection device 170. The work vehicle 1 according to Item D1.

[0334] According to the work vehicle 1 according to this Item D2, it is possible to lower the center of gravity of the work vehicle 1 based on the detection result of the inclination detection device 170, so that the overturning of the work vehicle 1 can be avoided.

[0335] (Item D3) The change mechanism 180 includes a distance change mechanism 80 that can change the lateral distance between the traveling unit 4 and the vehicle body 2. The distance change mechanism 80 changes the lateral distance between the traveling unit 4 and the vehicle body 2 based on the detection result of the inclination detection device 170. The work vehicle 1 according to Item D1 or D2.

[0336] According to the work vehicle 1 according to this Item D3, it is possible to increase the lateral distance between the traveling unit 4 and the vehicle body 2 based on the detection result of the inclination detection device 170, so that the overturning of the work vehicle 1 can be avoided.

[0337] (Item D4) The height changing mechanism 90 includes a left height changing mechanism 90L that changes the height of the left part of the vehicle body 2 and a right height changing mechanism 90R that changes the height of the right part of the vehicle body 2. Based on the detection result of the inclination detection device 170, the working vehicle 1 described in Item D2 that makes the height of the left part of the vehicle body 2 different from the height of the right part of the vehicle body 2.

[0338] According to the working vehicle 1 according to this Item D4, by raising the vehicle body on the side opposite to the side where the vehicle body 2 is tilted, a moment in the direction of preventing tipping can be applied. Thereby, it is possible to avoid the working vehicle 1 from tipping over.

[0339] (Item D5) The height changing mechanism 90 performs at least one of an operation of raising the left part of the vehicle body 2 and an operation of lowering the right part of the vehicle body 2 when the inclination 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 an operation of raising the right part of the vehicle body 2 and an operation of lowering the left part of the vehicle body 2 when the inclination detection device 170 detects that the vehicle body 2 is tilted to the right by a predetermined amount or more. The working vehicle 1 described in Item D4.

[0340] According to the working vehicle 1 according to this Item D5, based on the detection result of the inclination detection device 170, a moment in the direction of preventing tipping can be applied to the vehicle body 2, so that it is possible to avoid the working vehicle 1 from tipping over.

[0341] (Item D6) The height changing mechanism 90 is the working vehicle 1 described in Item D2 that lowers the vehicle body 2 when the inclination detection device 170 detects that the vehicle body 2 is tilted by a predetermined amount or more.

[0342] According to the working vehicle 1 according to this Item D6, when the inclination of the vehicle body 2 is large, by lowering the vehicle body 2 to lower the center of gravity position of the working vehicle 1, it is possible to avoid the working vehicle 1 from tipping over.

[0343] (Item D7) The distance changing mechanism 80 includes a left distance changing mechanism 80L that changes the left-right direction distance of the left traveling unit 4L with respect to the vehicle body 2, and a right distance changing mechanism 80R that changes the left-right direction distance of the right traveling unit 4R with respect to the vehicle body 2. Based on the detection result of the inclination detection device 170, the working vehicle 1 according to Item D3 that makes the distance from the vehicle body 2 of the left traveling unit 4L different from the distance from the vehicle body 2 of the right traveling unit 4R.

[0344] According to the working vehicle 1 according to this Item D7, by increasing the left-right direction distance of the traveling unit 4 on the side where the vehicle body 2 is tilted from the vehicle body 2, it is possible to avoid the working vehicle 1 from tipping over.

[0345] (Item D8) The distance changing mechanism 80 is the working vehicle 1 according to Item D7 that increases the distance between the left traveling unit 4L and the vehicle body 2 when the inclination 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 unit 4R and the vehicle body 2 when the inclination detection device 170 detects that the vehicle body 2 is tilted to the right by a predetermined amount or more.

[0346] According to the working vehicle 1 according to this Item D8, based on the detection result of the inclination detection device 170, by increasing the left-right direction distance of the traveling unit 4 on the side where the vehicle body 2 is tilted from the vehicle body 2, it is possible to avoid the working vehicle 1 from tipping over.

[0347] (Item D9) The changing mechanism 180 includes a position changing mechanism 70 that can change the front-rear direction position of the vehicle body 2 with respect to the traveling unit 4. The position changing mechanism 70 changes the front-rear direction position of the vehicle body 2 based on the detection result of the inclination detection device 170. The working vehicle 1 according to any one of Items D1 to D8.

[0348] According to the working vehicle 1 according to this Item D9, by changing the position of the vehicle body 2 in the front-rear direction on the side opposite to the side where the vehicle body 2 is tilted, it is possible to avoid the working vehicle 1 from tipping over.

[0349] (Item D10) In the work vehicle 1 according to Item D9, when the inclination detection device 170 detects that the vehicle body 2 is inclined forward by a predetermined amount or more, the position changing mechanism 70 moves the vehicle body 2 backward with respect to the traveling unit 4, and when the inclination detection device 170 detects that the vehicle body 2 is inclined backward by a predetermined amount or more, the position changing mechanism 70 moves the vehicle body 2 forward with respect to the traveling unit 4.

[0350] According to the work vehicle 1 according to this Item D10, based on the detection result of the inclination detection device 170, by changing the position of the vehicle body 2 in the front-rear direction on the side opposite to the side where the vehicle body 2 is inclined, it is possible to avoid the work vehicle 1 from tipping over.

[0351] As described above, the embodiments of the present invention have been described. However, it should be considered that the disclosed embodiments are illustrative in all respects and not restrictive. The scope of the present invention is indicated by the claims rather than the above description, and it is intended that all modifications within the meaning and scope equivalent to the claims are included.

Explanation of Reference Numerals

[0352] 1 Work vehicle 2 Vehicle body 3 Structure 8 Traveling frame 62 Steering cylinder (hydraulic actuator) 90 Lifting mechanism (moving mechanism) 101 Hydraulic valve (hydraulic device)

Claims

1. 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, 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, A work vehicle comprising the above.

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 hydraulic actuator is fixedly arranged, The work vehicle according to Claim 1 or 2, wherein 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 relative to the traveling frame together with the vehicle body by the lifting mechanism.

6. The hydraulic actuator is fixed to the traveling frame, The work vehicle according to Claim 5, wherein when the hydraulic device is lifted and lowered relative to the traveling frame together with the vehicle body, it is lifted and lowered relative to the hydraulic actuator.

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.

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