Work vehicle

Abstract

To provide a work vehicle desired to be able to take measures even when an operation error occurs in any portion of a vehicle and after the operation error.SOLUTION: A work vehicle includes: a plurality of vehicle body support portions respectively supporting a plurality of travel devices such that the positions of the travel devices can be changed with respect to a vehicle body; and a control device C configured to control operation of a plurality of actuators 4 for running and a plurality of actuators 6, 7 for changing the orientation. The control device C includes a main control unit 11, a sub control unit 21 for running configured to control the operation of the plurality of actuators 4 for running, and a sub control unit 22 for supporting the vehicle body configured to control the operation of the plurality of actuators 6, 7 for changing the orientation. The main control unit 11 can be switched between a normal operation state where each of the plurality of actuators 4 for running and the plurality of actuators 6, 7 for changing the orientation is operated and an emergency operation state where the operation of the actuators for running and / or the actuators for changing the orientation are all stopped.SELECTED DRAWING: Figure 7

Description

[Technical Field]

[0001] The present invention relates to a work vehicle suitable for moving over uneven terrain. [Background technology]

[0002] A conventional work vehicle as described above has four running wheels driven by hydraulic motors as running actuators supported on the vehicle body via an articulating link mechanism that can be extended and retracted by operating hydraulic cylinders as attitude-changing actuators, and by changing the height of the running wheels, the vehicle body can be run while maintaining its attitude even on uneven terrain (see, for example, Patent Document 1). This work vehicle is equipped with a control device that controls the operation of the hydraulic cylinders and hydraulic motors, and the control device is configured to stop the operation of all hydraulic cylinders and hydraulic motors if an operational abnormality occurs in the vehicle. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2020-1440 A Summary of the Invention [Problem to be solved by the invention]

[0004] The above-mentioned work vehicle is sometimes used in a work mode in which it travels with a load loaded on top of the vehicle body by maintaining the vehicle body in a horizontal position. However, with the above-mentioned conventional configuration, if an operational abnormality occurs, such as when traveling on uneven, sloping ground, the operation of all hydraulic cylinders and hydraulic motors is stopped, which causes the vehicle body to be unable to be maintained in a horizontal position, and the load may fall off, or the vehicle may become stuck and unable to move, with no subsequent measures being able to be taken.

[0005] Therefore, in this type of work vehicle, it has been desired to be able to take measures after an operational abnormality occurs anywhere in the vehicle. [Means for solving the problem]

[0006] A characteristic configuration of a work vehicle according to the present invention comprises a vehicle body, a plurality of traveling devices located at the front and rear on both the left and right sides of the vehicle body, a plurality of vehicle body support sections that support the plurality of traveling devices so that their positions can be changed independently relative to the vehicle body, traveling actuators that drive the traveling devices, a plurality of attitude-changing actuators that drive the vehicle body support sections, and a control device that controls the operation of the plurality of traveling actuators and the plurality of attitude-changing actuators, wherein the control device has a main control section that manages the operating state of the entire vehicle, a traveling sub-control section that manages the operation of the plurality of traveling actuators based on control information from the main control section, and a vehicle body support sub-control section that manages the operation of the plurality of attitude-changing actuators based on control information from the main control section, and the main control section is configured to be switchable between a normal operating state in which the plurality of traveling actuators and the plurality of attitude-changing actuators are each operated, and an emergency operating state in which operation of either the plurality of traveling actuators or the plurality of attitude-changing actuators is stopped, The vehicle is provided with a plurality of travelling drive units that drive the travelling actuators in response to control signals from the main control unit, and a plurality of attitude change drive units that drive the attitude change actuators in response to control signals from the main control unit, the travelling sub-control unit having a switching element that stops the operation of the travelling drive units by the switching element when the main control unit stops the operation of all of the travelling actuators in the emergency driving state, and the vehicle body support sub-control unit having a switching element that stops the operation of the attitude change drive units by the switching element when the main control unit stops the operation of all of the attitude change actuators in the emergency driving state. It's at the point.

[0007] According to the present invention, when an operational abnormality occurs in any of the plurality of travel actuators, the main control unit switches to an emergency operation state in which the operation of all of the plurality of travel actuators is stopped, while the operation of the attitude change actuators that are not experiencing an operational abnormality continues.

[0008] As a result, for example, if the vehicle is used in a work mode in which it travels with cargo loaded on top of the vehicle body by maintaining the vehicle body in a horizontal position, the vehicle's position can be maintained continuously. Although the travel actuator cannot be driven, measures can be taken such as moving the vehicle body using another cart while maintaining its position, or using auxiliary wheels to move it to a location where repair work can be performed.

[0009] If any of the attitude change actuators has an operational abnormality, the main control unit switches to an emergency operation state in which all of the attitude change actuators are stopped, while the running actuators that are not experiencing an operational abnormality continue to operate.

[0010] As a result, although it is not possible to continue maintaining the vehicle's posture, it is possible to move the vehicle using the travel actuators, and measures can be taken such as moving the vehicle to a location where repair work can be performed.

[0011] Therefore, even if an operational abnormality occurs anywhere in the vehicle, it is possible to take measures afterwards.

[0012] In the present invention, The aforementioned It is preferable that the attitude change sub-control unit is configured to allow the transmission of control signals from the main control unit to the plurality of attitude change drive units in the normal operating state, and to stop operation of the plurality of attitude change drive units in the emergency operating state.

[0013] According to this configuration, in normal operation, the main control unit transmits control signals to the plurality of attitude change drive units, and the plurality of attitude change actuators are individually controlled to perform the desired attitude change operations. On the other hand, when an operational abnormality occurs, the main control unit switches to the emergency operation state, and the attitude change sub-control unit stops the operation of all of the plurality of attitude change drive units.

[0014] In this way, in the event of an operational abnormality, the attitude change sub-controller stops multiple attitude change drive units using a single signal, so there is no need for complicated control and it can be handled with simple control.

[0015] In the present invention, it is preferable that the vehicle body support section is composed of a bending link mechanism in which a plurality of links are pivotally connected, the attitude change actuator is composed of a hydraulic cylinder that can change the attitude of the plurality of links, and the attitude change drive section includes a hydraulic control valve that supplies and discharges hydraulic oil to and from the hydraulic cylinder, and a drive circuit that switches and operates the hydraulic control valve according to a control signal from the main control section.

[0016] According to this configuration, the drive circuit operates in response to a control signal from the main control unit to switch the hydraulic control valve, which in turn causes the hydraulic cylinder to expand and contract, changing the position of the link, and the bending link mechanism allows the travel device to change its position relative to the vehicle body.

[0017] In an emergency operating state, the attitude change sub-controller can stop the operation of the plurality of attitude change drive units by stopping the operation of the plurality of drive circuits collectively.

[0018] In the present invention, The aforementioned The sub-controller for traveling allows transmission of control signals from the main controller to the plurality of traveling drive units in the normal driving state, and When the main control unit stops the operation of all of the traveling actuators, configured to deactivate the plurality of travel drives; When the main control unit stops the operation of all of the traveling actuators in the emergency driving state, the vehicle body support sub-control unit allows the main control unit to transmit control signals to the plurality of attitude change drive units, and maintains a state in which the plurality of attitude change drive units are controlled so that the vehicle body is in a horizontal attitude. It is suitable.

[0019] According to this configuration, in normal operation, the main control unit transmits control signals to the plurality of travel drive units, and the plurality of travel actuators are individually controlled to perform desired operations. On the other hand, when an operational abnormality occurs, the main control unit switches to an emergency operation state, and the travel sub-control unit stops the operation of all of the plurality of travel drive units.

[0020] In this way, in the event of an operational abnormality, the sub-travel control unit stops the multiple travel drive units through centralized management using a single signal, eliminating the hassle of control and allowing for simple control.

[0021] In the present invention, it is preferable that the traveling actuator is configured by a hydraulic motor capable of rotationally driving the traveling device, and the traveling drive unit is equipped with a hydraulic control valve that supplies and discharges hydraulic oil to and from the hydraulic motor, and a drive circuit that switches and operates the hydraulic control valve based on a control signal from the main control unit.

[0022] According to this configuration, the drive circuit is operated by a control signal from the main control unit to switch the hydraulic control valve, thereby operating the hydraulic motor to drive the traveling device.

[0023] In an emergency driving state, the traveling sub-controller can stop the operation of the plurality of traveling drive units by collectively stopping the operation of the plurality of drive circuits. [Brief explanation of the drawings]

[0024] [Figure 1] FIG. [Figure 2] FIG. [Figure 3] FIG. [Figure 4] FIG. [Figure 5] FIG. [Figure 6] FIG. [Figure 7] FIG. 2 is a block diagram of an operating system that drives the hydraulic device. DETAILED DESCRIPTION OF THE INVENTION

[0025] An embodiment of the present invention will be described with reference to the drawings. In the following description, the direction of the arrow FW shown in the drawings will be referred to as "front," the direction of the arrow BK as "rear," the direction of the arrow RH as "right," the direction of the arrow LH as "left," the direction of the arrow UP as "up," and the direction of the arrow DW as "down."

[0026] As shown in Figures 1 to 3, the work vehicle is equipped with a vehicle body 1 that is approximately rectangular in plan view and supports the entire vehicle, a plurality of running wheels 2 that serve as running devices that support the vehicle body 1, a plurality of auxiliary wheels 3 that are provided corresponding to each of the plurality of running wheels 2, a support mechanism A that supports the plurality of running wheels 2 so that their positions can be changed relative to the vehicle body 1, and a plurality of hydraulic motors 4 that serve as running actuators that individually drive the plurality of running wheels 2.

[0027] The traveling wheels 2 are located at the front and rear of both the left and right sides of the vehicle body 1. In this embodiment, the work vehicle is equipped with four traveling wheels 2, located at the left front, right front, left rear, and right rear. It also has four support mechanisms A, located at the left front, right front, left rear, and right rear. The support mechanisms A include a bending link mechanism 5 as a vehicle body support part, and a plurality of hydraulic cylinders 6, 7 as attitude changing actuators that can individually change the attitude of the bending link mechanism 5.

[0028] The vehicle body 1 is generally rectangular in plan view, and is provided on the upper surface of the vehicle body 1 with a flat loading section 8 on which cargo can be loaded. The loading section 8 is a generally rectangular section in plan view, and extends from the right end to the left end of the vehicle body 1. The loading section 8 is configured so that cargo can be placed on it. Examples of cargo that can be placed on the loading section 8 include agricultural machinery, agricultural supplies such as fertilizer and chemicals, harvested crops and harvest baskets, and pallets on which these are placed.

[0029] The vehicle body 1 is provided with a hydraulic supply source 9 below the loading section 8 that sends hydraulic oil to the hydraulic cylinders 6, 7 and the hydraulic motor 4, a control device C that adjusts the supply of hydraulic oil from the hydraulic supply source 9 to control the operation of the hydraulic cylinders 6, 7 and the hydraulic motor 4, and a battery 12 for power supply. The hydraulic supply source 9 is provided with a hydraulic pump 9b driven by an engine 9a. The hydraulic supply source 9 also includes a hydraulic oil tank 9c, a radiator 9d, etc. The hydraulic supply source 9 is supported by an underframe 10. A fuel tank 9e is provided at a high position on the rear side of the vehicle body 1. The battery 12 is charged by a generator driven by power from the engine 9a. Reference numeral 13 in the figure denotes an operating handle that can be gripped and operated by an operator.

[0030] [Support mechanism] As described above, the support mechanism A includes the articulating link mechanism 5 and a plurality of hydraulic cylinders 6, 7. As shown in Fig. 1, a plurality of (specifically, four) traveling wheels 2 are supported via the articulating link mechanism 5 with respect to the vehicle body 1 so as to be able to move up and down individually.

[0031] As shown in Figures 4 and 5, the bending link mechanism 5 includes a base end portion 14 supported by the vehicle body 1, a first link 15 having an upper end portion supported on the lower portion of the base end portion 14 so as to be rotatable about a horizontal axis X1, and a second link 16 having one end portion supported on the lower end portion of the first link 15 so as to be rotatable about a horizontal axis X2 and having the running wheel 2 supported on the other end portion.

[0032] A support bracket 17 that supports the traveling wheel 2 is supported by a boss portion 18 provided at the swing side end of the second link 16 so as to be swingable around the vertical axis Y. A hydraulic cylinder 20 for swing operation (hereinafter referred to as a swing cylinder) is provided across a bracket 19 on one end side of the second link 16 and an arm portion 17a provided on the support bracket 17.

[0033] A plurality of hydraulic cylinders 6, 7 are provided corresponding to the plurality of articulating link mechanisms 5, respectively, and capable of individually changing the posture of the articulating link mechanisms 5. That is, a first hydraulic cylinder 6 is provided that can change the swing posture of the first link 15 relative to the vehicle body 1, and a second hydraulic cylinder 7 is provided that can change the swing posture of the second link 16 relative to the first link 15.

[0034] When the first hydraulic cylinder 6 is extended or retracted with the operation of the second hydraulic cylinder 7 stopped, the first link 15, the second link 16, and the traveling wheel 2 swing together around the horizontal axis X1 of the pivotal connection point with respect to the base end 14 while maintaining a constant relative posture. When the second hydraulic cylinder 7 is extended or retracted with the operation of the first hydraulic cylinder 6 stopped, the second link 16 and the traveling wheel 2 swing together around the horizontal axis X2 of the connection point between the first link 15 and the second link 16 while maintaining a constant posture of the first link 15.

[0035] An auxiliary wheel 3 is rotatably supported at an intermediate bending portion of each of the plurality of bending link mechanisms 5. The auxiliary wheels 3 are configured as wheels with approximately the same outer diameter as the running wheels 2. A support shaft that pivotally connects the first link 15 and the second link 16 is formed to extend so as to protrude outward in the width direction of the vehicle body, and the auxiliary wheels 3 are rotatably supported at the extended protruding portion of the support shaft.

[0036] By operating the turning cylinder 20, the traveling wheel 2 can be turned around the vertical axis Y relative to the articulating link mechanism 5, thereby enabling the vehicle to be turned.

[0037] The hydraulic control valve 25 corresponding to the hydraulic motor 4 adjusts the flow rate of the hydraulic oil, so that the rotation speed of the hydraulic motor 4, that is, the rotation speed of the traveling wheels 2, can be changed.

[0038] [Sensor] This work vehicle is equipped with various sensors. As shown in Fig. 6, each of the four second hydraulic cylinders 7 is provided with a head-side pressure sensor S1 and a cap-side pressure sensor S2. The head-side pressure sensor S1 detects the internal pressure of the oil chamber in the head-side chamber of the second hydraulic cylinder 7. The cap-side pressure sensor S2 detects the internal pressure of the oil chamber in the cap-side chamber of the second hydraulic cylinder 7.

[0039] A plurality of stroke sensors S3 capable of detecting the amount of extension / contraction operation are provided for each of the four first hydraulic cylinders 6 and the four second hydraulic cylinders 7. The amount of extension / contraction operation of each hydraulic cylinder 6, 7 is a detected value corresponding to the swing position of the first link 15 and second link 16, which are the objects of operation.

[0040] The vehicle body 1 is provided with an inclination sensor S4 for detecting the inclination state of the vehicle body. The inclination sensor S4 is an inertial measurement unit (IMS) having a well-known configuration. The IMU has a three-axis acceleration sensor and a gyro sensor, and can detect changes in the attitude of the vehicle body 1, specifically, tilt in the front-rear and left-right directions.

[0041] A rotation sensor S5 is provided near the traveling wheels 2 to detect the rotation speed of the traveling wheels 2 driven by the hydraulic motor 4. Based on the rotation speed of the traveling wheels 2 detected by the rotation sensor S5, the supply of hydraulic oil to the hydraulic motor 4 is controlled so that the rotation speed of the traveling wheels 2 becomes a target value. A pressure sensor S6 is provided to detect the pressure of the hydraulic oil supplied to the hydraulic motor 4. Based on the pressure of the hydraulic oil detected by the pressure sensor S6, the supply (pressure) of hydraulic oil to the hydraulic motor 4 is controlled so that the drive torque of the traveling wheels 2 becomes a target value. A stroke sensor S7 capable of detecting the extension / retraction operation amount is provided for each of the four swing cylinders 20.

[0042] [Control device] As shown in Fig. 6, the vehicle is equipped with an ECU 11 (Electronic Control Unit) as a main control unit that controls the overall driving state of the vehicle. The ECU 11 is equipped with a microcomputer and is capable of executing various controls according to a control program. The ECU 11 includes a non-volatile memory (not shown) that stores programs corresponding to the functional units described below, and a CPU (not shown) that executes the programs. The programs are executed by the CPU, thereby realizing the functions of the functional units.

[0043] The ECU 11 includes a posture control unit 100 and a running control unit 101 as functional units. When the vehicle is traveling with the four running wheels 2 in contact with the ground, the traveling control unit 101 controls the operation of the hydraulic motor 4 for each of the four running wheels 2 so that the rotational speed of the running wheels 2 detected by the rotation sensor S5 becomes the target speed and the drive torque detected by the pressure sensor S6 becomes the target value.

[0044] When the vehicle body is moving, the posture control unit 100 executes horizontal control, which controls the operation of the support mechanism A so that the loading section 8 of the vehicle body 1 is in a horizontal posture, based on the detection information of the inclination sensor S4. In the horizontal control, the posture control unit 100 controls the operation of the four first hydraulic cylinders 6 and the four second hydraulic cylinders 7 so that the tilt angles in the front-to-rear direction and the left-to-right direction from the horizontal posture of the vehicle body 1 become values ​​corresponding to the horizontal posture, based on the detection information of the inclination sensor S4 and the detection information of the stroke sensor S3.

[0045] To explain further, the target operating amounts of the four first hydraulic cylinders 6 and the four second hydraulic cylinders 7 required to bring the loading section 8 to a horizontal position are calculated from the inclined position of the loading section 8 detected by the inclination sensor S4, and the operation of the four first hydraulic cylinders 6 and the four second hydraulic cylinders 7 is controlled so that the actual operating amounts detected by the stroke sensor S3 become the target operating amounts.

[0046] As shown in Figure 7, in addition to the ECU 11, the control device is equipped with a driving management unit 21 as a driving sub-control unit that manages the operation of the four hydraulic motors 4 based on control information from the ECU 11, a vehicle body support management unit 22 as a vehicle body support sub-control unit that manages the operation of the multiple hydraulic cylinders 6, 7 (four first hydraulic cylinders 6 and four second hydraulic cylinders 7) based on control information from the ECU 11, multiple attitude change drive units 23 that drive the multiple hydraulic cylinders 6, 7 based on control signals from the ECU 11, and multiple driving units 24 that drive the hydraulic motors based on control signals from the ECU 11.

[0047] The ECU 11 is configured to be switchable between a normal operating state and an emergency operating state. In the normal operating state, the ECU 11 activates each of the four hydraulic motors 4 and the plurality of position-changing hydraulic cylinders (the four first hydraulic cylinders 6 and the four second hydraulic cylinders 7). In the emergency operating state, the ECU 11 stops the operation of all of the four hydraulic motors 4 and either of the plurality of position-changing hydraulic cylinders 6, 7.

[0048] The position change drive unit 23 includes a hydraulic control valve 25 and a drive circuit 26. The hydraulic control valve 25 supplies and discharges hydraulic oil to the position change hydraulic cylinders 6, 7. The drive circuit 26 switches the hydraulic control valve 25 based on a control signal from the ECU 11. A separate position change drive unit 23 is provided for each of the multiple position change hydraulic cylinders 6, 7.

[0049] Similarly, the traveling drive unit 24 includes a hydraulic control valve 25 and a drive circuit 27. The hydraulic control valve 25 supplies and discharges hydraulic oil to and from the hydraulic motor 4. The drive circuit 27 switches the hydraulic control valve 25 based on a control signal from the ECU 11. A separate traveling drive unit 24 is provided for each of the multiple hydraulic motors 4.

[0050] Although not shown, the hydraulic control valve 25 is operated by electromagnetic force. operation This electromagnetically operated valve shifts the spool to control the supply and discharge of hydraulic oil. Formula oilThe drive circuits 26 and 27 include switching elements such as transistors, and are configured to switch the hydraulic control valve 25 based on control signals from the ECU 11.

[0051] The vehicle body support management unit 22 is configured to allow transmission of control signals from the ECU 11 to the plurality of attitude change drive units 23 in the normal operating state, and to stop operation of the plurality of attitude change drive units 23 in the emergency operating state. The traveling management unit 21 is configured to allow transmission of control signals from the ECU 11 to the plurality of traveling drive units 24 in the normal operating state, and to stop operation of the plurality of traveling drive units 24 in the emergency operating state.

[0052] The vehicle body support management unit 22 includes switching elements such as transistors (not shown), and is configured to switch each of the multiple attitude change drive units 23 to an inactive state based on a control signal from the ECU 11 during an emergency operating state.

[0053] The driving management unit 21 includes switching elements such as transistors (not shown), and is configured to switch each of the multiple driving units 24 to a non-operating state based on a control signal from the ECU 11 during an emergency operating state.

[0054] The ECU 11 is always set to a normal operating state when the entire vehicle is operating normally. However, if an abnormality occurs somewhere during operation, for example, if the sensors that detect the operating status of the hydraulic cylinders 6, 6 or the hydraulic motor 4 fail and prevent proper operation, or if the hydraulic cylinders 6, 7 or the hydraulic motor 4 fail, the ECU 11 can be switched to an emergency operating state.

[0055] Various configurations can be adopted to switch the ECU 11 to the emergency operating state, such as a configuration in which the switching is performed by operating a manually operated switching device, or a configuration in which the ECU 11 determines an operational abnormality such as that described above through self-diagnosis and, as a result, automatically switches to the emergency operating state.

[0056] When the ECU 11 switches to an emergency operation state, some kind of response can be taken by switching to either a state in which the operation of all the position-changing hydraulic cylinders 6, 7 is stopped but the operation of all the traveling hydraulic motors 4 is enabled, or a state in which the operation of all the traveling hydraulic motors 4 is stopped but the operation of all the position-changing hydraulic cylinders 6, 7 is enabled.

[0057] If any of the multiple attitude changing hydraulic cylinders 6, 7 or any of the multiple stroke sensors S3 fails, the ECU 11 sends an emergency signal to the vehicle body support management unit 22. The vehicle body support management unit 22 stops the operation of all attitude changing drive units 23. At this time, the traveling management unit 21 maintains a state that allows the transmission of control signals from the ECU 11 to the multiple traveling drive units 24. In this state, although the vehicle body cannot maintain its attitude, the traveling wheels 2 can be driven, so the vehicle can be moved to a safe location and subsequent measures can be taken.

[0058] If any of the multiple travel motors 4 or any of the multiple pressure sensors S6 fails, the ECU 11 sends an emergency signal to the travel management unit 21. The travel management unit 21 stops the operation of all travel drives 24. At this time, the vehicle body support management unit 22 maintains a state that allows the ECU 11 to transmit control signals to the multiple attitude change drives 23. In this state, the hydraulic motors 4 cannot drive the travel wheels 2, but the vehicle body 1 can be maintained in a horizontal position, preventing the loaded cargo from scattering outward. At this time, it is possible to take measures such as moving the vehicle in an inchworm-like motion by bending the links 15, 16 of the articulating link mechanism 5. Furthermore, by bending the articulating link mechanism 5 so that the auxiliary wheels 3 contact the ground, the vehicle can also be moved manually.

[0059]

[0060]

[0061] [Another embodiment] ( 1 The vehicle body support management unit 22 may be configured to include a non-volatile memory that stores a program dedicated to vehicle body support, and a CPU that executes the program.

[0062] ( 2 ) The travel management unit 21 may be configured to include a non-volatile memory that stores a program dedicated to travel and driving, and a CPU that executes the program.

[0063] ( 3 ) An electric motor may be used as the traveling actuator.

[0064] ( 4 ) An electric cylinder, an electric motor, etc. may be used as the attitude changing actuator.

[0065] ( 5 ) The bending link mechanism 5 may be a mechanism having one link or three or more links. [Industrial Applicability]

[0066] The present invention can be applied to a work vehicle that is suitable for moving over uneven terrain. [Explanation of symbols]

[0067] 1 Vehicle body 2 Running gear 4 Travel actuator 5 Body support 6,7 Hydraulic cylinder 11 Main control unit 15,16 Link 21 Sub-controller for driving 22 Sub-controller for vehicle support 23 Posture change drive unit 24 Travel drive unit 25 Hydraulic control valve 26,27 Drive circuit C Control device

Claims

1. The vehicle body, a plurality of travel devices located at the front and rear of each of the left and right sides of the vehicle body; a plurality of vehicle body support sections that support the plurality of traveling devices so that their positions can be changed independently relative to the vehicle body; a traveling actuator that drives the traveling device; a plurality of attitude-changing actuators that drive the vehicle body support parts; a control device that controls the operation of the plurality of traveling actuators and the plurality of attitude changing actuators, The control device a main control unit that manages the operating state of the entire vehicle; a sub-controller for traveling that manages the operation of the plurality of actuators for traveling based on control information from the main controller; a vehicle body support sub-controller that manages the operation of the plurality of attitude change actuators based on control information from the main control unit, the main control unit is configured to be switchable between a normal operation state in which the plurality of traveling actuators and the plurality of attitude-changing actuators are activated, and an emergency operation state in which all of either the plurality of traveling actuators or the plurality of attitude-changing actuators are stopped from operating, a plurality of travel drive units that drive the travel actuators in response to control signals from the main control unit; a plurality of attitude-changing drive units that drive the attitude-changing actuators in response to control signals from the main control unit, the traveling sub-control unit includes a switching element, and when the main control unit stops operation of all of the traveling actuators in the emergency operating state, the switching element stops operation of the traveling drive unit; The vehicle body support sub-control unit is equipped with a switching element, and when the main control unit stops operation of all of the attitude change actuators in the emergency operating state, the switching element stops operation of the attitude change drive unit.

2. A work vehicle as described in Claim 1, wherein the vehicle body support sub-control unit is configured to allow control signals to be transmitted from the main control unit to multiple attitude change drive units in the normal operating state, and to stop operation of multiple attitude change drive units in the emergency operating state.

3. The vehicle body support portion is configured with a bending link mechanism in which a plurality of links are pivotally connected, the attitude-changing actuator is configured with a hydraulic cylinder capable of changing the attitudes of the plurality of links, 3. The work vehicle according to claim 2, wherein the attitude changing drive unit includes a hydraulic control valve that supplies and discharges hydraulic oil to and from the hydraulic cylinder, and a drive circuit that switches and operates the hydraulic control valve in response to a control signal from the main control unit.

4. The driving sub-controller is configured to allow transmission of control signals from the main controller to the plurality of driving drive units in the normal driving state, and to stop operation of the plurality of driving drive units when the main controller stops operation of all of the driving actuators in the emergency driving state; 4. A work vehicle as described in any one of claims 1 to 3, wherein when the main control unit stops operation of all of the driving actuators in the emergency operating state, the vehicle body support sub-control unit allows the main control unit to transmit control signals to the plurality of attitude change drive units, and maintains a state in which the plurality of attitude change drive units are controlled so that the vehicle body is in a horizontal position.

5. the traveling actuator is configured by a hydraulic motor capable of rotationally driving the traveling device, 5. The work vehicle according to claim 4, wherein the traveling drive unit includes a hydraulic control valve that supplies and discharges hydraulic oil to and from the hydraulic motor, and a drive circuit that switches and operates the hydraulic control valve in response to a control signal from the main control unit.

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