Work vehicle

Abstract

To provide a working vehicle capable of saving labor in transshipping work of crops.SOLUTION: The work vehicle 10 includes a vehicle body 11 having a load-carrying platform 22, a plurality of wheels 12 located on both left and right sides of the vehicle body 11, and a support mechanism 13 capable of changing a distance between a ground contact surface of the wheel 12 and the vehicle body 11. In the vehicle 10 of the above embodiment, the support mechanism 13 can change the inclination of the load-carrying platform 22 to horizontal when the traveling surface of the wheels 12 is an inclined surface, and can change the inclination of the load-carrying platform 22 to an angle inclined with respect to the horizontal surface when the traveling surface of the wheels 12 is a horizontal surface.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a work vehicle. [Background technology]

[0002] Patent Document 1 discloses a work vehicle for use in orchards, etc. The conventional work vehicle disclosed in Patent Document 1 etc. is a vehicle intended to be used mainly for transporting harvested fruit, and is effective in reducing the labor required for transporting fruit. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Utility Model Application Publication No. 7-028320 Summary of the Invention [Problem to be solved by the invention]

[0004] Harvested fruits are transported by a work vehicle and then transferred onto the truck bed or a sorting table. With conventional work vehicles, the work of transferring harvested fruits requires workers to drag or lift baskets containing fruit and other items across the bed, which places a heavy physical burden on the workers. For this reason, there is a demand for a work vehicle that can reduce the labor required not only for transporting harvested fruits but also for transferring them.

[0005] Therefore, an object of the present disclosure is to provide a work vehicle that can reduce the labor required for transshipping harvested products. [Means for solving the problem]

[0006] The work vehicle of the present disclosure comprises a vehicle body having a loading platform, a plurality of wheels located at the front and rear of both the left and right sides of the vehicle body, and a support mechanism capable of changing the distance between the contact surfaces of the wheels and the vehicle body, and the support mechanism is capable of changing the inclination of the loading platform to a horizontal position when the running surface of the wheels is an inclined surface, and is capable of changing the inclination of the loading platform to an angle inclined relative to the horizontal surface when the running surface of the wheels is a horizontal surface. [Effects of the Invention]

[0007] The work vehicle of the present disclosure can reduce the labor required for transferring harvested products. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a side view of a work vehicle according to a first embodiment. [Figure 2] FIG. 2 is a plan view of the work vehicle shown in FIG. [Figure 3] FIG. 3 is an explanatory diagram of a support mechanism at the right front portion of the work vehicle according to the first embodiment. [Figure 4] FIG. 4 is a schematic diagram illustrating the operation of the work vehicle according to the first embodiment. [Figure 5] FIG. 5 is a front view of a work vehicle according to the second embodiment. [Figure 6] FIG. 6 is a control block diagram of the work vehicle. [Figure 7] FIG. 7 is a plan view of a work vehicle according to the third embodiment. [Figure 8] FIG. 8 is a plan view of a work vehicle according to the fourth embodiment. [Figure 9] FIG. 9 is an explanatory diagram of the rotational positions of the fence. [Figure 10] FIG. 10 is a plan view of a work vehicle according to the fifth embodiment. [Figure 11] FIG. 11 is a plan view of the work vehicle according to the fifth embodiment (when the turntable is rotating). DETAILED DESCRIPTION OF THE INVENTION

[0009] <Summary of Embodiments of the Present Disclosure> Below, an outline of the embodiments of the present disclosure will be listed and described. (1) A work vehicle disclosed herein includes a vehicle body having a loading platform, a plurality of wheels positioned at the front and rear of both the left and right sides of the vehicle body, and a support mechanism that can change the distance between the ground contact surfaces of the wheels and the vehicle body. The support mechanism can change the inclination of the loading platform to a horizontal position when the running surface of the wheels is an inclined surface, and can change the inclination of the loading platform to an angle inclined relative to the horizontal surface when the running surface of the wheels is a horizontal surface.

[0010] According to the above configuration, in a work vehicle having a vehicle body capable of controlling the level of the loading platform, the loading platform can be tilted when the traveling surface is horizontal. In this case, the loading platform can be tilted when transferring harvested products from the loading platform to a truck. Therefore, the work vehicle of the present disclosure can reduce the labor required for transferring harvested products.

[0011] (2) The work vehicle of the present disclosure includes a vehicle body having a loading platform, wheels for propelling the vehicle body, and a loading platform changing mechanism for changing the inclination of the loading platform. The loading platform changing mechanism can change the inclination of the loading platform to a horizontal position when the running surface of the wheels is an inclined surface, and can change the inclination of the loading platform to an angle inclined relative to the horizontal position when the running surface of the wheels is a horizontal surface. According to the above configuration, in a work vehicle having a vehicle body capable of controlling the level of the loading platform, the loading platform can be tilted when the traveling surface is horizontal. In this case, the loading platform can be tilted when transferring harvested products from the loading platform to a truck. Therefore, the work vehicle of the present disclosure can reduce the labor required for transferring harvested products.

[0012] (3) It is preferable that the work vehicle according to the aspect (1) or (2) of the present disclosure further comprises a first conveyor arranged on the loading surface of the loading platform. In the work vehicle having the above configuration, when the harvested products are transferred from the loading platform to the truck, the first conveyor can facilitate the movement of the harvested products on the loading platform. Therefore, the work vehicle of the present disclosure can reduce the labor required for transferring the harvested products.

[0013] (4) The work vehicle of the aspect (3) of the present disclosure further comprises a fence installed at at least one of the front, rear, left and right outer edges of the loading platform, and it is preferable that the fence be rotatable between a first position where the angle between the extension line of the fence in the height direction and the loading surface of the loading platform is 90 degrees, and a second position where the angle is an obtuse angle. According to the above configuration, by providing a fence in a work vehicle equipped with a first conveyor, it is possible to prevent harvested products from falling off the loading platform.

[0014] (5) In the work vehicle of the aspect (4) of the present disclosure, it is preferable that the fence be capable of retaining its rotational position at a third position between the first position and the second position. According to the above configuration, the inclination angle of the fence can be adjusted to match the height of the truck, etc. Therefore, with the work vehicle of the present disclosure, the fence can be placed across the work vehicle regardless of the height of the truck, etc.

[0015] (6) In the work vehicle of the aspect (4) of the present disclosure, it is preferable that a second conveyor be provided on the fence so as to be connected to the first conveyor. The work vehicle having the above configuration can easily move the cargo on the loading platform by using the first and second conveyors by placing a fence across the truck or the like. Therefore, the work vehicle of the present disclosure can reduce the labor required for transferring harvested products.

[0016] (7) It is preferable that the work vehicle according to the aspect (3) or (4) of the present disclosure further comprises a turntable disposed on the loading platform, and the first conveyor is provided on the turntable. The work vehicle having the above configuration can change the direction of the first conveyor using the turntable, thereby enabling the direction of harvest product transfer to be selected as desired. Therefore, the work vehicle of the present disclosure can reduce the labor required for the work of transferring harvest products.

[0017] <Details of the embodiment of the present disclosure> Hereinafter, details of embodiments of the present disclosure will be described with reference to the drawings. Note that at least some of the embodiments described below may be combined in any manner.

[0018] [Overall configuration of the work vehicle] FIG. 1 is a side view of a work vehicle according to the first embodiment. FIG. 2 is a plan view of the work vehicle shown in FIG. 1. FIG. 3 is an explanatory diagram of a support mechanism at the right front of the work vehicle according to the first embodiment. The work vehicle 10 shown in FIGS. 1 to 3 is a vehicle that can travel on uneven road surfaces (uneven ground). The work vehicle 10 shown in FIGS. 1 to 3 is the work vehicle 10 according to the first embodiment, and will also be referred to as work vehicle 10A. In the following description, when simply referring to "work vehicle 10," the description is of configurations that are common to work vehicle 10A and work vehicles 10B to 10E according to other embodiments that will be described later.

[0019] In the following explanation, the direction of the arrow FW shown in the figure is the "front" of the work vehicle 10, which is the straight-ahead direction of the work vehicle 10. The direction of the arrow BK is the "rear" of the work vehicle 10, which is opposite to the straight-ahead direction. The direction of the arrow RH is the "right" of the work vehicle 10 moving straight, and the direction of the arrow LH is the "left" of the work vehicle 10 moving straight. The direction of the arrow DW is the "bottom" of the work vehicle 10, which is the road surface side, and the direction of the arrow UP is the "top" of the work vehicle 10, which is the opposite side to the road surface.

[0020] The work vehicle 10 has a vehicle body 11, a plurality of wheels 12, a plurality of support mechanisms 13, and a control device 17. The work vehicle 10 of this embodiment has four wheels 12 and the same number (four) of support mechanisms 13 as the wheels 12. The wheels 12 are traveling devices that support the vehicle body 11 so that it can travel. The wheels 12 are located at the front and rear of each of the left and right sides of the vehicle body 11. In other words, the work vehicle 10 has four wheels 12: a left front wheel, a right front wheel, a left rear wheel, and a right rear wheel. The support mechanisms 13 connect the vehicle body 11 and the wheels 12.

[0021] The vehicle body 11 has a frame 21. The vehicle body 11 has a loading platform 22 (loading platform) on top of the frame 21, on which cargo can be loaded. The loading platform 22 has a flat loading surface 221 on its upper surface. The loading surface 221 has a substantially rectangular shape in a plan view (see FIG. 2). The loading surface 221 is provided so as to extend in the left-right and front-rear directions. The cargo to be loaded is, for example, agricultural equipment, agricultural materials such as fertilizer and chemicals, harvested crops or harvesting baskets, or pallets on which these are placed.

[0022] The support mechanisms 13 are located at the left front, right front, left rear, and right rear of the vehicle body 11. The support mechanisms 13 are attached to the vehicle body 11 (part of the frame 21) and support the wheels 12 so that their positions can be changed relative to the vehicle body 11. The support mechanisms 13 have articulating link mechanisms 30 as operating parts that are operable to change the positions of the wheels 12. The wheels 12 are attached to the articulating link mechanisms 30. The support mechanisms 13 have actuators 14 that drive the articulating link mechanisms 30.

[0023] The actuator 14 operates the articulating link mechanism 30 to change the posture of the articulating link mechanism 30. The actuator 14 has a first hydraulic cylinder 36 and a second cylinder 37. The specific configurations of the support mechanism 13 and the actuator 14 will be described later. The work vehicle 10 has multiple hydraulic motors 15. The hydraulic motors 15 are provided at the ends of the articulating linkages 30 together with the wheels 12. The hydraulic motors 15 are travel actuators that drive the wheels 12 to rotate.

[0024] The wheels 12 are driven wheels that are rotated by hydraulic motors 15. The rotation of the wheels 12 causes the work vehicle 10 to move. The work vehicle 10 has a plurality of training wheels 16. The training wheels 16 are attached midway along the articulating link mechanism 30. The training wheels 16 are attached to the connecting parts (joint parts) between a first link 31 and a second link 32, which will be described later and which make up the articulating link mechanism 30. The training wheels 16 are driven wheels that can rotate freely.

[0025] The work vehicle 10 has a hydraulic unit (hydraulic pressure supply source) 51, a battery 52, and an engine 53. The hydraulic unit 51 supplies hydraulic oil to the hydraulic motor 15, the first hydraulic cylinder 36, the second hydraulic cylinder 37, and a swing hydraulic cylinder 38 (described later). The hydraulic unit 51 has a hydraulic pump 54 driven by the engine 53, multiple hydraulic control valves 55, and a hydraulic oil tank 56.

[0026] A hydraulic control valve 55 is connected to each of the hydraulic motor 15 and the hydraulic cylinders 36, 37, 38. The hydraulic control valve 55 is an electromagnetic valve and has the function of supplying, stopping the supply of hydraulic oil from the hydraulic pump 54, and adjusting the supply flow rate. The control device 17 adjusts the supply state (supply amount) of hydraulic oil from the hydraulic unit 51 by controlling the hydraulic control valve 55. In other words, the control device 17 controls the operations of the hydraulic motor 15 and the hydraulic cylinders 36, 37, and 38.

[0027] The hydraulic unit 51, the battery 52, and the control device 17 are mounted on the vehicle body 11 (frame 21), and are located under the loading platform 22 in this embodiment (see FIG. 1). The battery 52 supplies power to the control device 17, the hydraulic unit 51, and a number of sensors, which will be described later. The work vehicle 10 has an operating handle 18 that is gripped by an operator. The operating handle 18 is attached to a frame 21.

[0028] [Support mechanism 13 and actuator 14] The left front support mechanism 13 and the right front support mechanism 13 are "front support mechanisms 13f" located at the front of the vehicle body 11. The left rear support mechanism 13 and the right rear support mechanism 13 are "rear support mechanisms 13b" located at the rear of the vehicle body 11. On the left and right sides of the work vehicle 10, the front support mechanisms 13f and the rear support mechanisms 13b are attached in different directions, but have the same configuration. The front support mechanisms 13f and the rear support mechanisms 13b are collectively referred to as "support mechanisms 13" and the support mechanisms 13 will be described below.

[0029] The support mechanism 13 supports the wheels 12 so that they can be raised and lowered individually relative to the vehicle body 11. To this end, the support mechanism 13 has a bending link mechanism 30. As shown in FIG. 3 , the bending link mechanism 30 has a first link 31 and a second link 32. The first link 31 and the second link 32 are each a linear member. A fixed bracket 23 is fixed to a part of a frame 21 of the vehicle body 11. A first end 311 on one side, which is the upper side of the first link 31, is supported by the fixed bracket 23 so as to be swingable around a first horizontal axis X1 in the left-right direction.

[0030] A first end 321 on one side of the second link 32 is supported by a second end 312 on the other side, which is below the first link 31, so as to be swingable about a second horizontal axis X2 in the left-right direction. A support bracket 33 is attached to the second end 322 on the other side, which is the tip side of the second link 32. The wheel 12 is supported by the support bracket 33.

[0031] A set of actuators 14 is provided for one bending link mechanism 30 having a first link 31 and a second link 32. Each set of actuators 14 has one first hydraulic cylinder 36 and one second hydraulic cylinder 37. The first hydraulic cylinder 36 swings the first link 31 around the first horizontal axis X1 by extending and retracting. The first hydraulic cylinder 36 changes the swinging posture of the first link 31 relative to the vehicle body 11. The second hydraulic cylinder 37 swings the second link 32 around the second horizontal axis X2 by extending and retracting. The second hydraulic cylinder 37 changes the swinging posture of the second link 32 relative to the first link 31.

[0032] The hydraulic control valve 55 connected to the first hydraulic cylinder 36 and the hydraulic control valve 55 connected to the second hydraulic cylinder 37 are separate valves (see FIG. 6), and the first hydraulic cylinder 36 and the second hydraulic cylinder 37 operate to extend and retract independently. The extension and retraction of the first hydraulic cylinder 36 and the second hydraulic cylinder 37 causes the articulating link mechanism 30 to bend and extend.

[0033] 3, for example, when the first hydraulic cylinder 36 extends or retracts while the second hydraulic cylinder 37 is stopped, the first link 31, the second link 32, and the wheel 12 swing together around the first horizontal axis X1 while maintaining a constant relative positional relationship. When the second hydraulic cylinder 37 extends or retracts while the first hydraulic cylinder 36 is stopped, the second link 32 and the wheel 12 swing together around the second horizontal axis X2 while maintaining a constant attitude of the first link 31 relative to the vehicle body 11.

[0034] A support bracket 33 that supports the wheel 12 is attached to the second link 32. The hydraulic motor 15 is mounted on the support bracket 33. The support bracket 33 is attached to the other end of the second link 32 so that it can swing around a vertical axis Y in the up-and-down direction. The work vehicle 10 has a hydraulic cylinder 38 for swinging (hereinafter referred to as a swing cylinder 38) to change the rolling direction of the wheel 12. The swing cylinder 38 is attached between a part of the second link 32 and the support bracket 33. When the swing cylinder 38 extends and retracts, the support bracket 33 and the wheel 12 swing around the vertical axis Y. The movement of the swing cylinder 38 changes the traveling direction of the work vehicle 10.

[0035] The work vehicle 10 of this embodiment has four support mechanisms 13, and each support mechanism 13 is provided with a set of actuators 14. One set of actuators 14 provided on one support mechanism 13 and another set of actuators 14 provided on another support mechanism 13 are separate actuators, and each actuator 14 operates independently. As described above, the four wheels 12 can be raised and lowered individually relative to the vehicle body 11. Furthermore, the positions of the four wheels 12 relative to the vehicle body 11 can be varied. The support mechanisms 13 make it possible to change the distance, particularly the vertical distance, between the ground contact surface of each wheel 12 and the vehicle body 11. Note that the "distance" referred to here refers to the vertical distance (distance L shown in FIG. 1) between the lower surface (ground contact surface) of the wheels 12 and the loading surface 221 of the vehicle body 11 (the upper end of the loading platform 22).

[0036] [Sensor] The work vehicle 10 is equipped with multiple sensors. A head-side pressure sensor S1 and a rod-side pressure sensor S2 are connected to the second hydraulic cylinder 37. The head-side pressure sensor S1 detects the internal pressure of the head-side oil chamber of the second hydraulic cylinder 37. The rod-side pressure sensor S2 detects the internal pressure of the rod-side oil chamber of the second hydraulic cylinder 37. The control device 17 acquires the detection signals of the sensors S1 and S2.

[0037] A stroke sensor S3 that detects the amount of extension / contraction is provided to each of the first hydraulic cylinder 36 and the second hydraulic cylinder 37. The amount of extension / contraction of each of the first hydraulic cylinder 36 and the second hydraulic cylinder 37 is related to the swing position of each of the first link 31 and the second link 32. Therefore, the detection value of the stroke sensor S3 is correlated with the swing position of each of the first link 31 and the second link 32. As a result, the stroke sensor S3 can uniquely detect the position of the wheel 12 relative to the vehicle body 11. The control device 17 acquires the detection signal of the stroke sensor S3 and detects the position of the wheel 12 (detection by calculation).

[0038] The vehicle body 11 is equipped with an inclination sensor S4 that detects the inclination state of the vehicle body 11. The inclination sensor S4 is configured using an inertial measurement unit (IMU), which is a well-known configuration. The IMU of this embodiment has a three-axis acceleration sensor and a gyro sensor, and detects changes in the attitude of the vehicle body 11, specifically, tilt in the front-rear and left-right directions. The control device 17 acquires the detection signal of the inclination sensor S4.

[0039] The wheel 12 is provided with a rotation sensor S5 located near the wheel 12 for detecting the rotation speed of the wheel 12. The control device 17 acquires a detection signal from the rotation sensor S5. Based on the detection value of the rotation sensor S5, the control device 17 controls the supply of hydraulic oil to the hydraulic motor 15 so that the rotation speed of the wheel 12 reaches a target value.

[0040] The work vehicle 10 has a pressure sensor S6 that detects the pressure of the hydraulic oil supplied to the hydraulic motor 15. The control device 17 acquires the detection signal of the pressure sensor S6. Based on the pressure of the hydraulic oil detected by the pressure sensor S6, the control device 17 controls the supply (pressure) of hydraulic oil to the hydraulic motor 15 so that the drive torque of the wheels 12 becomes a target value. Each of the four swing cylinders 38 is equipped with a stroke sensor S7 that can detect the amount of extension / retraction operation. The control device 17 acquires the detection signal of the stroke sensor S7. This allows the work vehicle to control its traveling direction.

[0041] [Control device] Figure 6 is a control block diagram of the work vehicle. As shown in Figures 1 and 6, the work vehicle 10 is equipped with a control device 17. As shown in Figure 6, the control device 17 has an ECU 170 (Electronic Control Unit) that functions as a main control unit that controls the operation of the work vehicle 10. The ECU 170 has a microcomputer and executes various controls according to a control program. The ECU 170 has a non-volatile memory that stores programs corresponding to the functional units that execute the various controls, and a CPU that executes the programs. The functions (control) of each functional unit are realized by the CPU executing the programs.

[0042] The ECU 170 has, as the functional units, a driving control unit 171 and an attitude control unit 172. When the vehicle is traveling with all four wheels 12 in contact with the ground, the driving control unit 171 controls the operation of the hydraulic motor 15 for each of the four wheels 12 so that the rotational speed of the wheel 12 detected by the rotation sensor S5 becomes a target speed and the drive torque detected by the pressure sensor S6 becomes a target value. The attitude control unit 172 executes horizontal control and center-of-gravity position control, which will be described below.

[0043] (Selector switch) The work vehicle 10 of the present disclosure further includes a changeover switch 41 located near the operating handle 18 (see FIG. 1). The changeover switch 41 is a switch that selects the control mode of the work vehicle. The changeover switch 41 can select one of three control modes. When the changeover switch 41 is switched to the first mode, the control device 17 executes "horizontal control" which will be described below. When the changeover switch 41 is switched to the second mode, the control device 17 executes "parallel control" which will be described below. When the changeover switch 41 is switched to the third mode, the control device 17 executes "tilt mode" which will be described below.

[0044] (Horizontal Control) The posture control unit 172 performs horizontal control based on the detection signal from the inclination sensor S4 when the work vehicle 10 is traveling. Horizontal control is a control that operates the support mechanism 13 so that the vehicle body 11 is horizontal, in other words, so that the loading surface 221 of the loading platform 22 is horizontal. The posture control unit 172 determines the tilt angles in the front-to-rear direction and the left-to-right direction from a reference position in which the vehicle body 11 (loading platform 22) is in a horizontal position, based on the detection signal from the inclination sensor S4 and the detection signal from the stroke sensor S3. The posture control unit 172 controls the operation of the four first hydraulic cylinders 36 and the four second hydraulic cylinders 37 so that these tilt angles become values ​​corresponding to the horizontal position (i.e., the tilt angles are zero).

[0045] For example, when the work vehicle 10 travels on a traveling surface that slopes downward to the left, the support mechanisms 13 provided at the front and rear of the left side of the vehicle body 11 are located at the bottom of the slope, and the support mechanisms 13 provided at the front and rear of the right side of the vehicle body 11 are located at the top of the slope. In this case, the operation of the four support mechanisms 13 is controlled so that the distance between the ground contact surfaces of the wheels 12 provided at the front and rear of the left side of the vehicle body 11 and the vehicle body 11 is greater than the distance between the ground contact surfaces of the wheels 12 provided at the front and rear of the right side of the vehicle body 11 and the vehicle body 11. Also, for example, when the work vehicle 10 travels on a traveling surface that slopes downward to the front, the support mechanisms 13 provided at the front left and right of the vehicle body 11 are located at the front of the slope, and the support mechanisms 13 provided at the rear left and right of the vehicle body 11 are located at the top of the slope. In this case, the operation of the four support mechanisms 13 is controlled so that the distance between the ground contact surfaces of the wheels 12 provided on the left and right sides of the front of the vehicle body 11 and the vehicle body 11 is greater than the distance between the ground contact surfaces of the wheels 12 provided on the left and right sides of the rear of the vehicle body 11 and the vehicle body 11. In this way, the work vehicle 10 can control the level of the vehicle body 11 (loading platform 22).

[0046] To further explain the horizontal control, the ECU 170 calculates the target operation amounts of the four first hydraulic cylinders 36 and the four second hydraulic cylinders 37 required to bring the loading platform 22 to a horizontal position, based on the inclination position (tilt angle) of the loading platform 22 detected by the inclination sensor S4. The ECU 170 controls the operation of the four first hydraulic cylinders 36 and the four second hydraulic cylinders 37 so that the actual operation amounts detected by the stroke sensor S3 become the target operation amounts.

[0047] (Tilt mode) The work vehicle 10 of the present disclosure is capable of selecting a "tilt mode." The "tilt mode" is a mode suitable for, for example, unloading cargo from the loading platform 22. When the "tilt mode" is selected, the work vehicle 10 can change the angle between the loading surface 221 of the loading platform 22 and the travel surface to any angle. The work vehicle 10 of the present disclosure is equipped with an operating lever 42 provided near the operating handle 18 (see FIGS. 1 and 2), for example. The operating lever 42 is a lever used by the worker to instruct the travel direction when the work vehicle 10 is traveling. When the "tilt mode" is selected in the work vehicle 10 of this embodiment, the operating lever 42 can be used to instruct the tilt angle of the loading platform 22. Note that the work vehicle 10 may be configured to have a separate operating lever dedicated to instructing the tilt angle of the loading platform 22 when the "tilt mode" is selected.

[0048] When the worker operates the control lever 42 in the "tilt mode," the control device 17 activates the support mechanisms 13 provided on the front, rear, left, and right sides of the vehicle body 11 according to the direction and amount of operation. This allows the work vehicle 10 of the present disclosure to tilt the placing surface 221 to any angle.

[0049] Specifically, when unloading from the work vehicle 10, if the "tilt mode" is selected, the worker can tilt the loading platform 22 so that the loading surface 221 slopes downward toward the unloading destination. In this case, the worker can slide the load from the loading platform 22 to the unloading destination, making it easier to move the load.

[0050] 4 is a schematic diagram illustrating the operation of the work vehicle according to the first embodiment. When the "tilt mode" is selected and the running surface of the wheels 12 is horizontal, the worker can change the tilt angle of the platform 22 by operating the control lever 42 so that the loading surface 221 is inclined relative to the running surface (horizontal).

[0051] As shown in the upper figure of FIG. 4, for the work vehicle 10A, for example, when the running surface of the wheels 12 is a horizontal plane and unloading is performed from the loading platform 22 to the left side, the distance La between the ground contact surface of the wheels 12 provided at the front and rear on the left side of the vehicle body 11 and the vehicle body 11 is smaller than the distance Lb between the ground contact surface of the wheels 12 provided at the front and rear on the right side of the vehicle body 11 and the vehicle body 11 (La < Lb), and the operations of the four support mechanisms 13 are controlled. Thereby, when the running surface is a horizontal plane, the work vehicle 10A can incline the vehicle body 11 (loading platform 22) downward to the left. Here, although the case of inclining the vehicle body 11 in the left-right direction is illustrated, the work vehicle 10A can also incline the vehicle body 11 in the front-rear direction, and thereby the loading platform 22 can be inclined downward to the front (or downward to the rear).

[0052] Further, when the "incline mode" is selected in a state where the running surface of the wheels 12 of the work vehicle 10 of the present disclosure is an inclined surface, the inclination angle of the loading platform 22 can be changed so that the placement surface 221 becomes horizontal by operating the operation lever 42 by the operator.

[0053] As shown in the lower figure of FIG. 4, for the work vehicle 10A, for example, when the running surface of the wheels 12 is an inclined surface that slopes downward to the left, the distance La between the ground contact surface of the wheels 12 provided at the front and rear on the left side of the vehicle body 11 and the vehicle body 11 is larger than the distance Lb between the ground contact surface of the wheels 12 provided at the front and rear on the right side of the vehicle body 11 and the vehicle body 11 (La > Lb), and the operations of the four support mechanisms 13 are controlled. Thereby, the work vehicle 10A can horizontally control the vehicle body 11 (loading platform 22) when the running surface is an inclined surface.

[0054] In other words, when the running surface of the wheels 12 is an inclined surface, the work vehicle 10A can operate the support mechanism 13 by operating the operation lever 42 to change the inclination of the placement surface 221 to horizontal, and when the running surface of the wheels 12 is a horizontal plane, the work vehicle 10A can operate the support mechanism 13 by operating the operation lever 42 to change the inclination of the placement surface 221 to an angle inclined with respect to the horizontal plane.

[0055] As described above, the work vehicle 10A according to the first embodiment of the present disclosure includes a vehicle body 11 having a loading platform 22, a plurality of wheels 12 positioned at the front and rear of both the left and right sides of the vehicle body 11, and a support mechanism 13 capable of changing the distance between the contact surfaces of the wheels 12 and the vehicle body 11. In the work vehicle 10A, the support mechanism 13 can change the inclination of the loading platform 22 to a horizontal position when the running surface of the wheels 12 is an inclined surface, and can change the inclination of the loading platform 22 to an angle inclined relative to the horizontal surface when the running surface of the wheels 12 is a horizontal surface. According to the work vehicle 10A having such a configuration, the vehicle body 11 can control the horizontal position of the loading platform 22, and the loading platform 22 can be tilted when the running surface is a horizontal surface. In this case, the loading platform 22 can be tilted when transferring harvested produce from the loading platform 22 to a truck or the like. This reduces the labor required for transferring harvested produce from the work vehicle 10A.

[0056] When the running surface of the wheels 12 is an inclined surface, the work vehicle 10A according to the first embodiment can travel while controlling the level of the vehicle body 11 by operating the support mechanism 13, and can stop the vehicle body 11 at a certain point while controlling the level. Furthermore, by operating the support mechanism 13 (first hydraulic cylinder 36 and second hydraulic cylinder 37) from this stopped state while controlling the level, the work vehicle 10A can tilt the loading surface 221 of the platform 22 relative to the horizontal. The work vehicle 10A configured in this way can unload harvested crops by tilting the platform 22 as needed, even if the running surface of the wheels 12 is an inclined surface.

[0057] (Center of gravity control) The posture control unit 172 is capable of performing center of gravity position control, which determines the center of gravity position G of the vehicle body 11 based on the detection information of the inclination sensor S4 and the stroke sensor S3, and controls the operation of the support mechanism 13 so that the center of gravity position G is located in the center of multiple (four) wheels 12 in a planar view.

[0058] The center of gravity position control will be further explained. The tilt state of the vehicle body 11 is detected by the output of the tilt sensor S4. The posture control unit 172 obtains the tilt angle in the front-to-rear direction and the tilt angle in the left-to-right direction from the horizontal posture of the vehicle body 11 from the detection signal of the tilt sensor S4. The state of the support mechanism 13 (the angle of the first link 31 relative to the vehicle body 11, and the angle of the second link 32 relative to the first link 31) is detected from the detection results of the extension / contraction amounts of the first hydraulic cylinder 36 and the second hydraulic cylinder 37 detected by the multiple stroke sensors S3.

[0059] As a result, the attitude control unit 172 can obtain, through calculation, what attitude (inclined state) the vehicle body 11 is in as a whole and what position the center of gravity G of the vehicle body 11 is in relative to the ground contact positions of the four wheels 12. The attitude control unit 172 operates the first hydraulic cylinder 36 and the second hydraulic cylinder 37 so that the center of gravity G obtained in this manner becomes the target attitude in which it is located in the center of the multiple (four) wheels 12 in a plan view.

[0060] As a variation of the center of gravity position control, the posture control unit 172 does not determine the center of gravity position of the vehicle body 11, but determines the ground contact pressure of multiple (four) wheels 12. The ground contact pressure is determined based on detection signals from pressure sensors S1 and S2. In this case, the posture control unit 172 controls the operation of the support mechanism 13 so that the ground contact pressure of the wheels 12 on the lower side of the incline and the ground contact pressure of the wheels 12 on the upper side of the incline are equal.

[0061] In this way, center of gravity position control is a control that adjusts the pressure (force) supporting the vehicle body 11 so that the center of gravity of the vehicle body 11 converges to the target center of gravity on any road surface. By controlling the center of gravity position, it becomes possible to generate driving force by moving the wheels 12 along the uneven shape of the road surface.

[0062] By performing horizontal control and center of gravity position control, the posture control unit 172 can operate the support mechanism 13 so that the posture of the loading platform 22 (loading surface 221) is horizontal and so that all wheels 12 generate driving force in accordance with the uneven shape of the road surface.

[0063] (Load-carrying platform change mechanism) Figure 5 is a front view of a work vehicle according to the second embodiment. Figure 5 shows a work vehicle 10 according to the second embodiment of the present disclosure (hereinafter also referred to as work vehicle 10B). As shown in Figure 5, work vehicle 10B differs from the work vehicle 10A (see Figures 1 to 3) described above in that it is equipped with a platform changing mechanism 60. Other than being equipped with the platform changing mechanism 60, work vehicle 10B has the same configuration as work vehicle 10A.

[0064] 5, the loading platform changing mechanism 60 is a mechanism that can change the inclination angle of the loading surface 221 of the loading platform 22 independently of the inclination angle of the vehicle body 11 with respect to the traveling surface. The loading platform changing mechanism 60 includes a joint part 61 that rotatably supports the loading platform 22, and an actuator 62.

[0065] In the work vehicle 10B, the actuator 62, which is a hydraulic cylinder, has a rod whose tip is rotatably connected to the loading platform 22 via a joint 61. The head side end of the actuator 62 is rotatably supported relative to the frame 21. Note that although the joint 61 in this embodiment has a rotation axis that is parallel to the fore-and-aft direction of the vehicle body 11, it may also be a ball joint. In this case, it is preferable that the head side end of the actuator 62 be rotatably supported relative to the frame 21 via a ball joint.

[0066] In the work vehicle 10B, a platform conversion mechanism 60 is provided at the front and rear of each of the left and right sides of the platform 22. That is, in the work vehicle 10B, a total of four platform conversion mechanisms 60 are provided, one at each of the four corners of the platform 22. Therefore, when the front and rear actuators 62 on the left side are extended, the platform 22 is tilted downward to the right, and when the front and rear actuators 62 on the right side are extended, the platform 22 is tilted downward to the left. In the work vehicle 10B, the platform conversion mechanism 60 can also tilt the platform 22 downward to the front or rear. Note that in the work vehicle 10 of the present disclosure, the platform conversion mechanism 60 may be provided at the front and rear of each of the left and right sides of the platform 22. That is, in the work vehicle 10B, a total of two platform conversion mechanisms 60 may be provided at two adjacent corners of the platform 22. In this case, the platform 22 of the work vehicle 10 can be tilted downward to either the right or left side, or the front or rear side.

[0067] A work vehicle 10B equipped with a platform changing mechanism 60 is further equipped with the following sensors. Note that the following sensors are omitted in a work vehicle 10 (the work vehicle 10A described above) that does not have a platform changing mechanism 60. As shown in Figures 5 and 6, the actuator 62, which is a hydraulic cylinder, is provided with a head-side pressure sensor S8 on its head side and a rod-side pressure sensor S9 on its rod side. The head-side pressure sensor S8 detects the internal pressure of an oil chamber on the head side of the actuator 62. The rod-side pressure sensor S9 detects the internal pressure of an oil chamber on the rod side of the actuator 62. The control device 17 acquires the detection signals of sensors S8 and S9.

[0068] The actuator 62 is further provided with a stroke sensor S10 that detects the amount of expansion and contraction. The amount of expansion and contraction of the actuator 62 is related to the rotational position of the loading platform 22 around the axis of the joint part 61. As a result, the stroke sensor S10 can uniquely detect the rotational position of the loading platform 22 relative to the vehicle body 11. The control device 17 acquires the detection signal of the stroke sensor S10 and detects (by calculation) the rotational position of the loading platform 22.

[0069] The work vehicle 10B equipped with the platform changing mechanism 60 can adjust the tilt angle of the platform 22 when the "tilt mode" is selected using the platform changing mechanism 60. When the "tilt mode" is selected, the operator can change the angle between the loading surface 221 of the platform 22 and the travel surface to any angle by operating the operation lever 42 located near the operation handle 18 (see FIGS. 1 and 2). The control device 17 controls the extension and contraction amounts of the actuators 62 located on the front, rear, left, and right sides of the platform 22 in response to the operator's operation of the operation lever 42. This allows the loading surface 221 of the work vehicle 10 to be tilted to a desired angle. In the work vehicle 10B configured as described above, when the tilt mode is selected during unloading, the operator can tilt the platform 22 so that the loading surface 221 slopes downward toward the unloading destination. The work vehicle 10B configured as described above makes it easy to unload cargo from the platform 22.

[0070] For example, when unloading a load at a location where the running surface of the wheels 12 is horizontal, the work vehicle 10B can use the loading platform changing mechanism 60 to tilt the loading platform 22 downward in the desired direction. Also, for example, when the running surface of the wheels 12 is inclined, the work vehicle 10B can use the loading platform changing mechanism 60 to control the placing surface 221 of the loading platform 22 to be horizontal. Note that when the running surface of the wheels 12 is inclined, the work vehicle 10B can also use the loading platform changing mechanism 60 to tilt the placing surface 221 of the loading platform 22 relative to the horizontal direction.

[0071] In other words, when the running surface of the wheels 12 of the work vehicle 10B is an inclined surface, the loading platform change mechanism 60 can be operated by operating the operating lever 42 to change the inclination of the loading surface 221 to a horizontal surface, and when the running surface of the wheels 12 is a horizontal surface, the loading platform change mechanism 60 can be operated by operating the operating lever 42 to change the inclination of the loading surface 221 to an angle inclined relative to the horizontal surface.

[0072] As described above, the work vehicle 10B according to the second embodiment of the present disclosure includes a vehicle body 11 having a bed 22, wheels 12 for propelling the vehicle body 11, and a bed changing mechanism 60 for changing the inclination of the bed 22. In the work vehicle 10B, the bed changing mechanism 60 can change the inclination of the bed 22 to horizontal when the running surface of the wheels 12 is an inclined surface, and can change the inclination of the bed 22 to an angle inclined relative to the horizontal when the running surface of the wheels 12 is a horizontal surface. The work vehicle 10B configured in this manner can tilt the bed 22 when the running surface is a horizontal surface. In this case, the bed can be tilted when transferring harvested produce from the bed 22 to a truck. Therefore, the work vehicle 10B can reduce the labor required for transferring harvested produce from the work vehicle 10B.

[0073] Note that when the "tilt mode" is selected, the work vehicle 10B equipped with the platform changing mechanism 60 may tilt the vehicle body 11 with respect to the running surface of the wheels 12 by operating the support mechanism 13, and may also tilt the platform 22 by operating the platform changing mechanism 60. In other words, the work vehicle 10 of the present disclosure may have a configuration that combines the configurations of both the work vehicle 10A according to the first embodiment and the work vehicle 10B according to the second embodiment.

[0074] Furthermore, in a work vehicle 10 having a configuration combining the configurations of both the work vehicle 10A according to the first embodiment and the work vehicle 10B according to the second embodiment, when the running surface of the wheels 12 is inclined, the support mechanism 13 is operated to control the vehicle body 11 to be horizontal, and the loading surface 221 of the loading platform 22 can also be tilted relative to the horizontal direction by operating the loading platform changing mechanism 60. With a work vehicle 10 configured in this way, even if the running surface of the wheels 12 is inclined, the loading platform 22 can be tilted as necessary to unload harvested crops.

[0075] (Third embodiment of the work vehicle) FIG. 7 is a plan view of a work vehicle according to a third embodiment. FIG. 7 shows a third embodiment of a work vehicle 10 according to the present disclosure. In the following description, the work vehicle 10 according to the third embodiment will also be referred to as work vehicle 10C. As shown in FIG. 7, the work vehicle 10C according to the third embodiment is equipped with a conveyor device 70 (hereinafter also referred to as a first conveyor device 70A). The conveyor device 70 exemplified in this embodiment uses a roller conveyor including multiple rollers, but may also be a belt conveyor including an endless belt. Furthermore, in the conveyor device 70 exemplified in this embodiment, each roller rotates passively, but each roller (or belt) of the conveyor device 70 may also be configured to be rotationally driven by a drive source.

[0076] In the work vehicle 10C, the first conveyor device 70A includes a first conveyor 71 disposed on the loading surface 221 of the loading platform 22. With the work vehicle 10C configured in this manner, when the harvest basket C containing harvested products is transferred from the loading platform 22 to a truck or the like, the first conveyor 71 makes it easy to move the harvest basket C on the loading platform 22. This reduces the labor required to transfer the harvest basket C from the work vehicle 10C.

[0077] (Fourth embodiment of the work vehicle) FIG. 8 is a plan view of a work vehicle according to a fourth embodiment. FIG. 9 is an explanatory diagram of the rotational position of the fence. FIG. 8 shows a fourth embodiment of a work vehicle 10 according to the present disclosure. In the following description, the work vehicle 10 according to the fourth embodiment will also be referred to as work vehicle 10D. As shown in FIG. 8, the work vehicle 10D is equipped with a conveyor device 70 (hereinafter also referred to as a second conveyor device 70B). The work vehicle 10D is equipped with fences 19 installed on the front, rear, left, and right outer edges of the loading platform 22. The fences 19 include a movable fence 19a and a fixed fence 19b. In the work vehicle 10D, the movable fence 19a is provided only in one location on the left side of the outer periphery of the loading platform 22, but it may be provided in two or more locations. Furthermore, the fence 19 does not have to include the fixed fence 19b, and may be entirely composed of movable fences 19a. Alternatively, the fence 19 does not have to include the movable fence 19a, and may be entirely composed of fixed fences 19b.

[0078] As shown in Figures 8 and 9, the second conveyor device 70B includes a first conveyor 71 and a second conveyor 72 attached to the fence 19 so as to connect to the first conveyor 71. A work vehicle 10D configured in this manner can span a movable fence 19a across a transfer destination Z, such as the bed of a truck. With the movable fence 19a spanned across the transfer destination Z, the first conveyor 71 and the second conveyor 72 are arranged in a straight line in a plan view. By spanning the movable fence 19a across the transfer destination Z, the work vehicle 10D can easily move the harvest basket C on the bed 22 to the transfer destination Z using the first conveyor 71 and the second conveyor 72. Therefore, the work vehicle 10C can reduce the labor required to transfer the harvest basket C from the work vehicle 10D.

[0079] As shown in FIG. 9 , in the work vehicle 10D, the fence 19 (movable fence 19a) can rotate between a first position P1 where an extension line L of the movable fence 19a in the height direction intersects perpendicularly with an imaginary plane FS including the loading surface 221 of the loading platform 22 (the angle θ between the extension line L and the imaginary plane FS is 90 degrees), and a second position P2 where the angle θ is an obtuse angle. The angle θ at the first position P1 is also referred to as θ1, and the angle θ at the second position P2 is also referred to as θ2. The work vehicle 10D equipped with this first conveyor 71 can prevent the harvested products on the loading platform 22 from falling off by providing the fence 19. The angle θ is defined as 0 degrees when the movable fence 19a is tilted inward of the loading platform 22 and the extension line L is parallel to the loading surface 221. In this description, the term "obtuse angle" includes angles greater than 180 degrees.

[0080] Furthermore, in the work vehicle 10D, the fence 19 (movable fence 19a) can maintain a rotational position at a third position P3 between the first position P1 and the second position P2. The angle θ at the third position P3 is also referred to as θ3. The magnitude relationship between the angles θ1, θ2, and θ3 is θ1 (=90°)<θ3<θ2. The work vehicle 10D configured in this manner can adjust the angle θ of the fence 19 to match the height of the transfer destination Z, which may be the bed of a truck, for example. Therefore, the work vehicle 10D can span the fence 19 across the transfer destination Z regardless of the height of the transfer destination Z.

[0081] (Fifth embodiment of the work vehicle) FIG. 10 is a side view of a work vehicle according to a fifth embodiment. FIG. 11 is a plan view of the work vehicle according to the fifth embodiment (when the turntable is rotating). FIGS. 10 and 11 show a fifth embodiment of a work vehicle 10 according to the present disclosure. In the following description, the work vehicle 10 according to the fifth embodiment will also be referred to as a work vehicle 10E. As shown in FIGS. 10 and 11, the work vehicle 10E is equipped with a conveyor device 70 according to a third embodiment (hereinafter also referred to as a third conveyor device 70C). In the work vehicle 10E, the third conveyor device 70C is equipped with a turntable 73 arranged on the loading platform 22. In the third conveyor device 70C, the first conveyor 71 is provided on the turntable 73. The third conveyor device 70C may further include a first conveyor 71 arranged on the loading surface 221 outside the turntable 73.

[0082] As shown in Figures 8 and 9, the work vehicle 10E can change the conveying direction of the first conveyor 71 by rotating the turntable 73, and the first conveyor 71 can transport the harvest basket C in any direction, including the left-right and front-rear directions of the vehicle body 11. The work vehicle 10E configured in this way can freely select the transfer direction of the harvest basket C by changing the direction of the first conveyor 71 using the turntable 73. Therefore, the work vehicle 10E can reduce the labor required to transfer the harvest basket C from the work vehicle 10E.

[0083] The above-described embodiments are illustrative in all respects and are not limiting. The scope of the present invention is defined by the claims rather than the above-described embodiments, and includes all modifications within the scope equivalent to the configurations described in the claims. [Explanation of symbols]

[0084] 10, 10A, 10B, 10C, 10D Work vehicle 11 Vehicle body 12 wheels 13 Support mechanism 19 Fence 22 Cargo bed 60 Cargo platform change mechanism 71 First Conveyor 72 Second Conveyor 73 Turntable 221 Placement surface P1 first position P2 2nd position P3 third position θ angle

Claims

1. a vehicle body having a loading platform; a plurality of wheels located at the front and rear of both the left and right sides of the vehicle body; a support mechanism that can change the distance between the ground contact surface of the wheel and the vehicle body, The support mechanism includes: When the running surface of the wheels is an inclined surface, the inclination of the loading platform can be changed to a horizontal position; and, When the running surface of the wheels is a horizontal plane, the inclination of the loading platform can be changed to an angle inclined relative to the horizontal plane.

2. a vehicle body having a loading platform; wheels for driving the vehicle body; a loading platform changing mechanism that changes the inclination of the loading platform, The loading platform changing mechanism is When the running surface of the wheels is an inclined surface, the inclination of the loading platform can be changed to a horizontal position; and, When the running surface of the wheels is a horizontal plane, the inclination of the loading platform can be changed to an angle inclined relative to the horizontal plane.

3. The work vehicle according to claim 1 or 2, further comprising a first conveyor disposed on the loading surface of the loading platform.

4. The vehicle further includes a fence installed at at least one of the front, rear, left, and right outer edges of the loading platform, The work vehicle of claim 3, wherein the fence is rotatable between a first position in which the angle formed between the extension line of the fence in the height direction and the loading surface of the loading platform is 90 degrees, and a second position in which the angle is an obtuse angle.

5. The fence is: The work vehicle according to claim 4 , wherein the pivot position can be held at a third position between the first position and the second position.

6. The work vehicle according to claim 4 , further comprising a second conveyor provided on the fence so as to be connected to the first conveyor.

7. Further, a turntable is disposed on the loading platform, The work vehicle according to claim 3 , wherein the first conveyor is provided on the turntable.

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