Work vehicle

Abstract

A work vehicle 10 according to the present disclosure comprises: a vehicle body 11 having a load-carrying platform 22, a seat 19, and support members 24 for supporting the seat 19; a plurality of wheels 12 positioned to the front and rear on both left and right sides of the vehicle body 11; and support mechanisms 13 capable of changing the distances between the ground-contacting surfaces of the wheels 12 and the vehicle body 11. The support mechanisms 13 can horizontally control the vehicle body 11, the support members 24 attached to the horizontally controllable vehicle body 11 have seat support parts 25 positioned below the load-carrying platform 22, and the seat 19 is attached to the seat support parts 25.

Description

Work vehicle

[0001] This application claims priority to Japanese Patent Application No. 2024-103480, filed on June 27, 2024, and incorporates by reference all of the contents of said Japanese application.

[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.

[0003] Japanese Utility Model Application Laid-Open Publication No. 7-028320

[0004] A work vehicle according to one aspect of the present disclosure comprises a vehicle body having a loading platform, a seat, and a support member supporting the seat, 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, wherein the support mechanism is capable of controlling the vehicle body to be horizontal, and the support member attached to the horizontally controllable vehicle body has a seat support portion located below the loading platform, and the seat is attached to the seat support portion.

[0005] According to the present disclosure, it is possible to reduce the labor required not only for fruit harvesting but also for tasks such as flower thinning and fruit thinning.

[0006] FIG. 1 is a side view of a work vehicle equipped with a seat according to a 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 shown in FIG. 1. FIG. 4 is a front view of the work vehicle shown in FIG. 1. FIG. 5 is a control block diagram of the work vehicle. FIG. 6 is a front view of a work vehicle equipped with a seat according to a second embodiment. FIG. 7 is a front view of a work vehicle equipped with a seat according to a third embodiment. FIG. 8 is a schematic diagram illustrating the operation of tilting the seat. FIG. 9 is a side view of a work vehicle equipped with a seat according to a fourth embodiment. FIG. 10 is a plan view of a work vehicle equipped with a seat according to the fourth embodiment.

[0007] <Problem to be Solved by the Invention> Work carried out in orchards and the like includes not only fruit harvesting but also flower thinning, fruit thinning, and other such work. Flower thinning and fruit thinning require workers to carefully assess the condition of each flower bud and fruit to be thinned, making it difficult to reduce the labor required. Furthermore, flower thinning and fruit thinning require workers to maintain a posture of looking up for long periods of time, placing a great physical burden on the workers. For this reason, there is a demand for a work vehicle that enables labor-saving not only for fruit harvesting but also for flower thinning, fruit thinning, and other such work. The present disclosure aims to provide a work vehicle that enables labor-saving not only for fruit harvesting but also for flower thinning, fruit thinning, and other such work.

[0008] <Effects of the Invention> The work vehicle of the present disclosure can reduce the labor required not only for fruit harvesting but also for flower and fruit thinning and other tasks.

[0009] <Outline of Embodiments of the Present Disclosure> The following is a list and description of outlines of embodiments of the present disclosure. (1) A work vehicle of the present disclosure includes a vehicle body having a loading platform, a seat, and a support member supporting the seat, 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 capable of changing the distance between the contact surfaces of the wheels and the vehicle body, the support mechanism being capable of controlling the vehicle body to be horizontal, the support member attached to the horizontally controllable vehicle body having a seat support portion positioned below the loading platform, and the seat being attached to the seat support portion.

[0010] In the work vehicle having the above configuration, the seat is attached to a support member that is part of the vehicle body that can be controlled to be level, so that the seat surface can be kept horizontal even when the wheel contact surface is inclined. Therefore, with the work vehicle of the present disclosure, it is easy to perform work that requires facing upward, such as fruit harvesting, flower thinning, and fruit picking, while sitting in the seat on sloping ground. This allows for labor savings in work such as fruit harvesting, flower thinning, and fruit picking.

[0011] (2) In the work vehicle of the aspect (1) of the present disclosure, it is preferable that the seat is located to the side of the loading platform. With the work vehicle of the above configuration, when working while sitting in the seat, it is easy to put harvested products into the harvest basket on the loading platform. Therefore, the work vehicle of the present disclosure can reduce the labor required for fruit harvesting work.

[0012] (3) In the work vehicle according to the above aspect (1) or (2) of the present disclosure, it is preferable that the seat surface of the seat is located below the loading platform. The work vehicle having the above configuration can use the side of the vehicle body as a backrest. Therefore, with the work vehicle according to the present disclosure, when working while sitting in the seat, the worker can lean their weight against the vehicle body, making it easier to maintain an upright posture.

[0013] (4) In the work vehicle according to any one of the aspects (1) to (3) of the present disclosure, it is preferable that the seat has a backrest, and at least a portion of the backrest is located below the loading platform. In the work vehicle having the above configuration, the occupant can rest their weight on the backrest when working while sitting in the seat. Therefore, the work vehicle according to the present disclosure makes it easier to maintain an upward posture.

[0014] (5) In the work vehicle according to any one of the aspects (1) to (4) of the present disclosure, it is preferable that the seat support portion is provided so as to extend to the side of the vehicle body. This configuration of the work vehicle allows the seat to be positioned to the side of the loading platform. This makes it easy to load harvested produce into a harvest basket on the loading platform.

[0015] (6) In the work vehicle according to any one of the aspects (1) to (5) of the present disclosure, the seat is preferably a bench extending in the left-right or front-rear direction of the vehicle body. In a work vehicle having the above configuration, the worker can work while moving within the range of the seat, thereby expanding the range in which the worker can work while the work vehicle is stopped. Therefore, the work vehicle according to the present disclosure can reduce the effort required to move the work vehicle and improve the work efficiency of harvesting work using the work vehicle.

[0016] (7) In the work vehicle according to any one of the aspects (1) to (6) of the present disclosure, it is preferable that the seat can be installed in at least two directions from the front, rear, left, and right sides of the vehicle body. In a work vehicle with the above configuration, the worker can select a seat position that is appropriate for the work location and the work content, depending on the slope of the work location, the presence or absence of obstacles, etc. Therefore, the work vehicle according to the present disclosure can improve the work efficiency of harvesting work using the work vehicle.

[0017] (8) In the work vehicle according to any one of the aspects (1) to (7) of the present disclosure, it is preferable that the seat support portion is detachable from the support member. In the work vehicle having the above configuration, the operator can attach or detach the seat depending on the slope of the work site, the presence or absence of obstacles, etc. Therefore, the work vehicle according to the present disclosure can improve the work efficiency of harvesting work using the work vehicle.

[0018] (9) In the work vehicle according to any one of the aspects (1) to (8) of the present disclosure, it is preferable that the seat be adjustable in angle between a first imaginary plane including the seat surface of the seat and a second imaginary plane including the side of the vehicle body. In a work vehicle with the above configuration, the worker can adjust the angle of the seat surface depending on the slope of the work site, the worker's body shape, preferences, etc. As a result, the work vehicle according to the present disclosure can improve the work efficiency of harvesting work using the work vehicle.

[0019] <Details of the embodiments of the present disclosure> Hereinafter, the details of the 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.

[0020] [Overall configuration of work vehicle] Fig. 1 is a side view of a work vehicle equipped with a seat 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 shown in Fig. 1. Fig. 4 is a front view of the work vehicle shown in Fig. 1. The work vehicle 10 shown in Figs. 1 to 4 is a vehicle capable of traveling on uneven road surfaces (uneven ground). The work vehicle 10 shown in Figs. 1 to 4 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 a configuration that is common to work vehicle 10A and work vehicles 10B to 10D according to other embodiments that will be described later.

[0021] In the following description, 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 "down" of the work vehicle 10, which is the road surface side, and the direction of the arrow UP is the "up" of the work vehicle 10, which is the opposite side to the road surface.

[0022] 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.

[0023] The vehicle body 11 has a frame 21. The vehicle body 11 has, on top of the frame 21, a loading platform 22 on which cargo can be loaded. The loading platform 22 has a flat loading surface 221 on its upper surface. The loading surface 221 is generally rectangular in plan view (see FIG. 2 ). The loading surface 221 is provided to extend in the left-right and front-rear directions. Loads to be loaded include, for example, agricultural equipment, agricultural materials such as fertilizer and chemicals, harvested crops and harvest baskets, or pallets on which these are placed. The work vehicle 10 further has covers 26 that cover the left and right side surfaces 11 a of the vehicle body 11.

[0024] 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 a frame 21 that is a part of the vehicle body 11, 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.

[0025] 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 hydraulic cylinder 37. Specific configurations of the support mechanism 13 and the actuator 14 will be described later.

[0026] The work vehicle 10 has a plurality of 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.

[0027] 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 portions (joint portions) of 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.

[0028] 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.

[0029] A hydraulic control valve 55 is connected to each of the hydraulic motor 15 and the hydraulic cylinders 36, 37, and 38. The hydraulic control valve 55 is an electromagnetic valve and has the function of supplying, stopping the supply, and adjusting the supply flow rate of hydraulic oil from the hydraulic pump 54. The control device 17 controls the hydraulic control valve 55 to adjust the supply state (supply amount) of hydraulic oil from the hydraulic unit 51. In other words, the control device 17 controls the operation of the hydraulic motor 15 and the hydraulic cylinders 36, 37, and 38.

[0030] The hydraulic unit 51, battery 52, and control device 17 are mounted on the vehicle body 11 (frame 21), and in this embodiment (see FIG. 1 ), are located under the loading platform 22. The battery 52 supplies power to the control device 17, hydraulic unit 51, and multiple sensors, which will be described later. The work vehicle 10 has an operating handle 18 that is gripped by the worker. The operating handle 18 is attached to the frame 21.

[0031] [Support mechanisms 13 and actuators 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. The front support mechanisms 13f and the rear support mechanisms 13b are attached in different directions on the left and right sides of the work vehicle 10, 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.

[0032] The support mechanism 13 supports the wheels 12 so that they can be individually raised and lowered 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 about a first horizontal axis X1 in the left-right direction.

[0033] 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.

[0034] A set of actuators 14 is provided for one articulating 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 extends and retracts to swing the first link 31 around the first horizontal axis X1. 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 extends and retracts to swing the second link 32 around the second horizontal axis X2. The second hydraulic cylinder 37 changes the swinging posture of the second link 32 relative to the first link 31.

[0035] Figure 5 is a control block diagram of the work vehicle. 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 Figure 5), 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.

[0036] 3, for example, when the first hydraulic cylinder 36 extends and 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 and 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.

[0037] 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) for changing 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 traveling direction of the work vehicle 10 is changed by the operation of the swing cylinder 38.

[0038] The work vehicle 10 of this embodiment has four support mechanisms 13, with each support mechanism 13 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 allow the distance, particularly the vertical distance, between the ground contact surface of each wheel 12 and the vehicle body 11 to be changed. Note that the "distance" referred to here refers to the vertical distance (distance L shown in FIG. 1 ) between the bottom surface (ground contact surface) of the wheels 12 and the loading surface 221 (the upper end of the loading platform 22) of the vehicle body 11.

[0039] (Regarding the seat) As shown in Figures 1 to 4, the work vehicle 10 is equipped with a seat 19. The seat 19 is a portion where a user who performs work using the work vehicle 10 can sit while working. The seat 19 has a seat portion 191. The seat portion 191 has a seat surface 192 on its upper surface. The seat portion 191 is positioned below the loading platform 22, and the seat surface 192 is located below the loading platform 22. The seat portion 191 is also positioned above the upper ends of the training wheels 16.

[0040] (Regarding the Support Member) The work vehicle 10 further includes a support member 24 that supports the seat 19. The support member 24 is attached to a frame 21, which is part of the vehicle body 11. The support members 24 are provided in a total of four locations, arranged front and rear on the left and right sides of the vehicle body 11. The support member 24 is made of a flat steel plate and extends downward from the lower end of the frame 21. The support member 24 includes an insertion hole 24a formed below the loading platform 22. The insertion hole 24a is a substantially cylindrical recess with an axis parallel to the left-right direction. Note that the insertion hole 24a may be a through-hole that passes through the support member 24 in the left-right direction. The vehicle body 11 is horizontally controllable, as will be described later. That is, in the work vehicle 10, the support member 24 is attached to a vehicle body 11 that is horizontally controllable.

[0041] (Regarding the Seat Support Portion) The support member 24 further includes a seat support portion 25. The seat support portion 25 is a part of the support member 24. The seat support portion 25 is formed of a tubular or cylindrical member and is inserted into the insertion hole 24a. Therefore, the seat support portion 25 is positioned below the loading platform 22. Specifically, the seat support portion 25 is positioned below the lower end of the cover 26. The seat support portion 25 is also positioned above the upper ends of the training wheels 16. The seat support portion 25 extends to the side of the vehicle body 11. The seat support portion 25 of the support member 24 is configured to be detachably attached to the insertion hole 24a. In the work vehicle 10 of this embodiment, the insertion hole 24a has a female thread, and the seat support portion 25 has a male thread at its axial end. The seat support portion 25 is detachably attached to the support member 24 by screwing the male thread into the female thread of the insertion hole 24a. In the work vehicle 10, the support member 24 may be a member shared with the fixed bracket 23 described above. In the work vehicle 10, the seat support portion 25 may be provided extending to the front and rear sides of the vehicle body 11. In this case, it is preferable to arrange the seat 19 in two locations, one on the front side and one on the rear side of the loading platform 22. In the work vehicle 10, the seat 19 may also be arranged in a total of two locations, one on either the left or right side of the loading platform 22 and one on either the front or rear side.

[0042] The seat 19 is attached to the seat support part 25 by fixing members (bolts, nuts, etc.) not shown. In the work vehicle 10, the seat 19 is located to the side of the loading platform 22. The seat surface 192 is located below the loading platform 22. In the work vehicle 10 of this embodiment, the seat surface 192 is parallel to the loading surface 221 of the loading platform 22. In addition, in the work vehicle 10, the seat support part 25 is provided to extend to the side of the vehicle body 11. Furthermore, in the work vehicle 10, the seat support part 25 is configured to be detachable from the support member 24. In other words, the seat 19 is detachable in the work vehicle 10.

[0043] [Sensors] 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.

[0044] 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).

[0045] 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 triaxial 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.

[0046] The wheels 12 are provided with rotation sensors S5 in the vicinity thereof that detect the rotation speed of the wheels 12. The control device 17 acquires the detection signal of 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 wheels 12 reaches a target value.

[0047] 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 hydraulic oil pressure 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 extension / retraction operation amount. The control device 17 acquires the detection signal of the stroke sensor S7. This allows the work vehicle to control its traveling direction.

[0048] [Control Device] Figure 5 is a control block diagram of the work vehicle. As shown in Figures 1 and 5, the work vehicle 10 is equipped with a control device 17. As shown in Figure 5, 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.

[0049] The ECU 170 has, as its 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.

[0050] (Horizontal Control) When the work vehicle 10 is traveling, the posture control unit 172 performs horizontal control based on the detection signal from the inclination sensor S4. Horizontal control is 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).

[0051] 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 vehicle body 11 and the ground contact surfaces of the wheels 12 provided on the left and right sides of the front of the vehicle body 11 is greater than the distance between the vehicle body 11 and the ground contact surfaces of the wheels 12 provided on the left and right sides of the rear of the vehicle body 11. In this way, the work vehicle 10 can control the level of the vehicle body 11 (loading platform 22).

[0052] 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 tilt position (tilt angle) of the loading platform 22 detected by the tilt 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.

[0053] (Center of gravity position 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.

[0054] 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 determines the tilt angle in the front-to-rear direction and the left-to-right direction from the horizontal posture of the vehicle body 11 based on 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 based on 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.

[0055] As a result, the attitude control unit 172 can obtain, through calculation, the overall attitude (inclined state) of the vehicle body 11 and the position of the center of gravity G of the vehicle body 11 in relation 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.

[0056] 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 rather determines the ground contact pressure of multiple (four) wheels 12. The ground contact pressure is determined based on detection signals from the 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 slope and the ground contact pressure of the running wheels 12 on the upper side of the slope are equal.

[0057] 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. Center of gravity position control makes it possible to generate driving force by aligning the wheels 12 with the uneven shape of the road surface.

[0058] By performing horizontal control and center of gravity position control, the posture control unit 172 is able to 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.

[0059] (Regarding the First Embodiment of the Seat) Figures 1 to 4 show a work vehicle 10A according to the first embodiment. The work vehicle 10A is equipped with a seat 19 according to the first embodiment (hereinafter referred to as seat 19A). As shown in Figures 1 to 4, the seat 19A is equipped with a seat portion 191. In other words, the seat 19A is equipped only with the seat portion 191 and does not have a backrest portion.

[0060] 1 to 4, the seat surface 192 of the seat 19A is located below the loading platform 22. With this configuration of the vehicle 10A, the cover 26 covering the side surface 11a of the vehicle body 11 can be used as a backrest, and when working while sitting in the seat 19A, the worker can rest their weight on the vehicle body 11. This makes it easier for the worker to maintain an upward posture when working while sitting in the seat 19A of the vehicle 10A.

[0061] 1 to 4, the seat 19A is a bench extending in the fore-and-aft direction of the vehicle body 11. In a vehicle 10A configured in this manner, the worker can move around within the area of ​​the seat 192 while sitting in the seat 19A, thereby expanding the area in which the worker can work while the vehicle 10 is parked. Therefore, the vehicle 10A can reduce the effort required to move the vehicle 10A, improving work efficiency. Note that in the vehicle 10A, the seat 19A may be located at the front or rear of the vehicle body 11, and in this case, the seat 19A may be a bench extending in the left-and-right direction of the vehicle body 11.

[0062] (Second embodiment of seat) Fig. 6 is a schematic diagram showing a work vehicle equipped with a seat according to a second embodiment. Fig. 6 shows a work vehicle 10 according to the second embodiment (hereinafter also referred to as work vehicle 10B). As shown in Fig. 6, the work vehicle 10B differs from the work vehicle 10A described above in that it is equipped with a seat 19 according to the second embodiment (hereinafter also referred to as seat 19B). As shown in Fig. 6, the seat 19B provided on the work vehicle 10B is equipped with a backrest 193. The seat 19B differs from the previously described seat 19A (see Fig. 1) in that it is equipped with the backrest 193, but the rest of the configuration is the same as that of the seat 19A. The work vehicle 10 of the present disclosure may be configured to include the seat 19B.

[0063] The seat 19B is a bench that extends in the front-to-rear direction of the vehicle body 11 and can be installed on either the left or right side (two directions) of the vehicle body 11.

[0064] As shown in Figure 6, the seat 19B includes a seat portion 191 and a backrest portion 193. In the work vehicle 10B, the seat surface 192 of the seat portion 191 is located below the loading platform 22. In the seat 19B, the backrest portion 193 is located to the side of the loading platform 22, and at least a portion of the backrest portion 193 is located below the loading platform 22. In this case, a worker performing work using the work vehicle 10B can lean their weight on the backrest portion 193 when sitting in the seat 19B to perform work, making it easier to maintain an upward posture.

[0065] It is more preferable that at least one of the height and width of the backrest 193 of the seat 19B is adjustable. In this case, the operator can adjust the height and / or width of the backrest 193 according to the conditions of the work area, the operator's body shape, preferences, etc. This improves the efficiency of harvesting work using the work vehicle 10B.

[0066] It is more preferable that the angle of the backrest 193 of the seat 19B relative to the side surface 11a of the vehicle body 11 is adjustable. In this case, the worker can adjust the angle of the backrest 193 depending on the conditions of the work area, the worker's body shape, preferences, etc. This improves the efficiency of harvesting work using the work vehicle 10B.

[0067] (Third embodiment of seat) Fig. 7 is a schematic diagram showing a work vehicle equipped with a seat according to a third embodiment. Fig. 7 shows a work vehicle 10 according to a third embodiment (hereinafter also referred to as work vehicle 10C). As shown in Fig. 7, the work vehicle 10C differs from the work vehicle 10B described above in that it includes a seat 19 according to a third embodiment (hereinafter also referred to as seat 19C). As shown in Fig. 7, the seat 19C provided on the work vehicle 10C differs from the seat 19B (see Fig. 6) described above in that the angle of the seat surface 192 is adjustable, but the rest of the configuration is the same as that of the seat 19B. The work vehicle 10 of the present disclosure may be configured to include the seat 19C.

[0068] In the work vehicle 10C, the seat surface 192 of the seat portion 191 is located below the loading platform 22. The seat 19C is a bench that extends in the front-to-rear direction of the vehicle body 11 and can be installed on either the left or right side of the vehicle body 11 (two directions).

[0069] 7, the seat 19C is configured to allow adjustment of the angle θ formed between a first imaginary plane FS1 including the seat surface 192 and a second imaginary plane FS2 including the side surface 11a of the vehicle body 11. With a work vehicle 10C configured in this way, the operator can adjust the angle θ of the seat surface 192 depending on the slope of the work location, the operator's body shape, preferences, etc. This can improve the efficiency of harvesting work using the work vehicle 10C.

[0070] FIG. 8 is a schematic diagram illustrating the operation of tilting the seat. Here, a method for adjusting the angle of the seat 192 relative to the horizontal direction will be described for a configuration that does not include a mechanism for adjusting the angle of the seat 192, such as the aforementioned work vehicles 10A and 10B. Here, using the work vehicle 10A as an example, a case will be described in which the angle of the left seat 192 is adjusted so that the left side of the seat 192 is tilted downward when the running surface of the wheels 12 is horizontal. In this case, as shown in FIG. 8 , the operation of the four support mechanisms 13 is controlled so that the distance La 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 smaller than the distance Lb 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 (La < Lb). This tilts the vehicle body 11 (cargo bed 22) relative to the running surface (horizontal plane), allowing the seat 192 of the seat 19A to be tilted relative to the running surface (horizontal plane). In this case, the angle of the right side of the seat 192 is tilted upward to the right. Here, an example is given of tilting the vehicle body 11 in the left-right direction, but the work vehicle 10 can also tilt the vehicle body 11 in the front-to-rear direction, in which case the seat surface 192 of the seat 19 can be tilted in the front-to-rear direction.

[0071] (Fourth embodiment of seat) Fig. 9 is a side view showing a work vehicle equipped with a seat according to a fourth embodiment. Fig. 10 is a plan view showing a work vehicle equipped with a seat according to the fourth embodiment. Figs. 9 and 10 show a work vehicle 10 according to the fourth embodiment (hereinafter also referred to as work vehicle 10D). As shown in Figs. 9 and 10, the work vehicle 10D differs from the work vehicles 10A to 10C described above in that it is equipped with a seat 19 according to the fourth embodiment (hereinafter also referred to as seat 19D). The work vehicle 10 of the present disclosure may be configured to include seat 19D.

[0072] 9 and 10 , the seat 19D is a so-called swivel chair and includes a seat portion 191, a backrest portion 193, and a rotation axis 194. The work vehicle 10D further includes a support case 200 for supporting the seat 19D from the seat support portion 25. The support case 200 includes a first portion 201 for supporting the support case 200 from the seat support portion 25, a second portion 202 for supporting the support case 200 from the loading platform 22, and a third portion 203 for supporting the seat 19D by the support case 200.

[0073] The first portion 201 has a support hole 204 for inserting the seat support portion 25. The support case 200 is fixed to the vehicle body 11 by inserting the seat support portion 25 into the support hole 204 and fixing the second portion 202 to the cargo bed 22 with fastening members (bolts) 205. With the support case 200 fixed to the vehicle body 11, the third portion 203 is provided extending toward the rear of the vehicle body 11. The third portion 203 rotatably supports the rotation shaft 194 of the seat 19D. In the work vehicle 10D, the seat 19D is provided on the left rear side of the vehicle body 11.

[0074] In this way, in the work vehicle 10D, the seat 19D is attached to the seat support part 25 via the support case 200. In the work vehicle 10D, the seat surface 192 of the seat 19D is located below the loading platform 22. Note that, if the support case 200 is used, the seat 19D can be installed on either the left or right side (two directions) of the vehicle body 11.

[0075] As described above, the work vehicles 10A to 10D of the present embodiment are equipped with a vehicle body 11 having a loading platform 22, a seat 19, and a support member 24 that supports the seat 19, a plurality of wheels 12 located at the front and rear of both the left and right sides of the vehicle body 11, and a support mechanism 13 that can change the distance between the ground contact surface of the wheels 12 and the vehicle body 11. The support mechanism 13 is capable of controlling the level of the vehicle body 11. In the work vehicles 10A to 10D of the above embodiments, the support member 24 attached to the level-controllable vehicle body 11 has a seat support portion 25 that is located below the loading platform 22. In the work vehicles 10A to 10D of the above embodiments, the seats 19A to 19D are attached to the seat support portion 25.

[0076] In work vehicles 10A to 10D configured as described above, by attaching the seat 19 to support member 24, which is part of the vehicle body 11 that can be controlled to be horizontal, the seat surface 192 of the seat 19 can be kept horizontal even when the contact surface of the wheels 12 is inclined. Therefore, with work vehicles 10A to 10D, it is easy to perform work that requires facing upward, such as harvesting fruit, picking flowers, and thinning fruit, while sitting in seat 19 on sloping ground, and this can reduce the labor required for work such as harvesting fruit, picking flowers, and thinning fruit.

[0077] 1 to 4, the seat 19 is located to the side of the loading platform 22. With the work vehicle 10 configured in this way, when an operator sits in the seat 19 to perform work, it is easy to load harvested produce into the harvest basket on the loading platform 22.

[0078] Furthermore, in the work vehicles 10A to 10D, the seat support portions 25 are provided to extend to the left and right sides of the vehicle body 11. Therefore, in the work vehicles 10A to 10D, the seats 19A to 19D can be positioned in two locations, on the left and right sides of the loading platform 22. In work vehicles 10A to 10D configured in this way, the worker can select a seat position that is appropriate for the work location and type of work, depending on the slope of the work location, the presence or absence of obstacles, etc., thereby improving the work efficiency of work using the work vehicles 10A to 10D.

[0079] 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.

[0080] REFERENCE SIGNS LIST 10 Work vehicle 10A Work vehicle 10B Work vehicle 10C Work vehicle 10D Work vehicle 11 Vehicle body 12 Wheel 13 Support mechanism 19 Seat 19A Seat 19B Seat 19C Seat 19D Seat 22 Cargo bed 24 Support member 25 Seat support portion 192 Seat surface 193 Backrest portion FS1 First imaginary plane FS2 Second imaginary plane θ Angle

Claims

1. A work vehicle comprising: a vehicle body having a loading platform, a seat, and a support member that supports the seat; 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 that can change the distance between the contact surface of the wheels and the vehicle body, wherein the support mechanism can control the horizontal position of the vehicle body; the support member attached to the horizontally controllable vehicle body has a seat support part located below the loading platform, and the seat is attached to the seat support part.

2. The work vehicle according to claim 1, wherein the seat is located on the side of the loading platform.

3. A work vehicle according to claim 1 or 2, wherein the seat surface of the seat is positioned below the loading platform.

4. The work vehicle according to claim 2, wherein the seat has a backrest, and at least a portion of the backrest is positioned below the loading platform.

5. A work vehicle according to claim 1 or 2, wherein the seat support portion is provided extending to the side of the vehicle body.

6. A work vehicle according to claim 1 or claim 2, wherein the seat is a bench extending in the left-right direction or the front-rear direction of the vehicle body.

7. A work vehicle as set forth in claim 1 or claim 2, wherein the seats can be installed in at least two directions from the front, rear, left and right sides of the vehicle body.

8. A work vehicle according to claim 1 or claim 2, wherein the seat support portion is detachable from the support member.

9. A work vehicle as described in claim 1 or claim 2, wherein the seat is capable of adjusting the angle formed by a first imaginary plane including the seat surface of the seat and a second imaginary plane including the side of the vehicle body.

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