JP7595560B2 - Work vehicle - Google Patents

Description

The present invention relates to a work vehicle.

Patent Document 1 discloses a work vehicle equipped with four running wheels. This work vehicle is suitable for traveling on rough ground, and is equipped with a bending link mechanism that supports each running wheel so that it can be raised and lowered independently.

JP 2020-001444 A

In the work vehicle described in Patent Document 1, the hydraulic control valve and the control device are mounted on the upper side of the vehicle frame. In addition, an exterior frame for protecting these objects is placed on the upper side of the vehicle frame. Therefore, the top surface of the work vehicle is not flat, making it difficult to load cargo onto the work vehicle.

The objective of this invention is to create a work vehicle that is easy to load onto.

As a means for solving the above-mentioned problems, the work vehicle of the present invention has:
A vehicle body, a plurality of running wheels located at the front and rear of each of the left and right sides of the vehicle body,
The vehicle body is provided with a support mechanism that is supported by the vehicle body and supports the multiple running wheels in a state where their positions relative to the vehicle body can be individually changed, and a loading platform portion that is provided on the upper surface of the vehicle body and is capable of placing luggage, wherein the top surface of the loading platform portion is located higher than any other portion of the upper part of the vehicle body other than the loading platform portion, the vehicle body is provided with side frames extending in the fore-and-aft direction at both left and right end portions, and a center frame extending in the left-and-right direction at a central portion in the fore-and-aft direction between the side frames at both left and right end portions, the side frames at both left and right end portions are provided in a state where the front ends of the side frames are separated from each other and the rear ends of the side frames are separated from each other, and the loading platform portion is supported by the side frames at both left and right end portions and the center frame .

According to the above-mentioned features, the loading platform allows cargo to be placed on the work vehicle. In addition, since the top surface of the loading platform is located higher than the other parts, even if the cargo extends beyond the loading platform, contact between the cargo and the other parts is suppressed, improving the stability of the cargo. In other words, according to the above-mentioned features, a work vehicle that is easy to load cargo on can be realized.
In the present invention, the vehicle body is provided with a mounting frame that is positioned between the front-to-rear ends of the side frames at both left and right end portions, protruding toward the cargo bed portion and positioned lower than the top surface of the cargo bed portion, and it is preferable that the mounting frame is capable of mounting a handle that is gripped by an operator.

In the present invention, it is preferable that the loading platform portion extends from the right end to the left end of the vehicle body.

The above features allow the loading platform to be enlarged in the left-right direction of the aircraft, making it even easier to load luggage.

In the present invention, the loading platform portion preferably includes a plurality of top plate members extending in the front-rear direction, and the top plate members are preferably arranged side-by-side with some of them overlapping each other.

The above features improve the strength of the loading platform, making it easier to load luggage. In addition, the loading platform is made up of multiple top plate members, making it easier to maintain.

In the present invention, it is preferable that the vehicle further includes a plurality of connection mechanisms to which a sling can be connected, the connection mechanisms being located in front of and behind the loading platform on the top surface of the vehicle body.

The above features allow the lifting device to be positioned on the top surface of the vehicle body with good front-to-rear balance. This makes it easy to use the lifting device to lift the work vehicle.

In the present invention, it is preferable that the vehicle further includes a hydraulic motor that drives the traveling wheels, a pump that supplies hydraulic oil to the hydraulic motor, and an engine that drives the pump, and that the pump and the engine are located below the loading platform.

According to the above features, the pump and engine, which are heavy objects, are located below the loading platform, so the center of gravity of the vehicle body is relatively low. In addition, even if the amount or position of the cargo placed on the loading platform changes, the fluctuation in the center of gravity position is small. This is therefore preferable as it stabilizes the driving performance of the work vehicle.

In the present invention, it is preferable that the vehicle further includes a hydraulic oil tank for storing the hydraulic oil and a fuel tank for storing fuel for the engine, and that the hydraulic oil tank and the fuel tank are located below the loading platform.

According to the above features, the hydraulic oil tank and fuel tank, which are heavy objects, are located below the loading platform, so the center of gravity of the vehicle body is relatively low. In addition, even if the amount or position of the luggage placed on the loading platform changes, the fluctuation in the center of gravity position is small. This is therefore preferable as it stabilizes the driving performance of the work vehicle.

In the present invention, it is preferable that the vehicle further includes a valve for adjusting the amount of hydraulic oil supplied to the hydraulic motor, the valve being located below the loading platform and to the right and/or left of the engine in a plan view.

The above features allow the valves to be located under the loading platform and on the left and right sides of the engine, making it possible to make the vertical size of the vehicle body relatively small.

In the present invention, it is preferable that the vehicle further comprises a switch that accepts manual operation for an emergency stop, the switch being located on one side of the vehicle body in the fore-and-aft direction relative to the loading platform, facing upward and below the top surface of the loading platform.

The above feature is preferable because it reduces the risk of erroneous switch operation when loading luggage onto the loading platform.

FIG. FIG. FIG. FIG. 2 is a plan view showing each frame of the vehicle body. FIG. FIG. FIG.

The following describes an embodiment of a work vehicle according to the present invention with reference to the drawings. Note that the present invention is not limited to the following embodiment, and various modifications are possible without departing from the spirit of the invention.

In the following explanation, the direction of the arrow FW shown in the figure is referred to as "forward", the direction of the arrow BK is referred to as "backward", the direction of the arrow RH is referred to as "right", the direction of the arrow LH is referred to as "left", the direction of the arrow UP is referred to as "up", and the direction of the arrow DW is referred to as "down".

As shown in Figure 1-3, the work vehicle includes a vehicle body 1 that is substantially rectangular in plan view, multiple running wheels 2 that serve as running devices supporting the vehicle body 1, multiple auxiliary wheels 3 that correspond to each of the multiple running wheels 2, a support mechanism A that supports the multiple running wheels 2 in a state in which their positions relative to the vehicle body 1 can be individually changed, and multiple hydraulic motors 4 that drive the running wheels 2.

The running wheels 2 are located at the front and rear of both the left and right sides of the vehicle body 1. In this embodiment, the work vehicle is equipped with four running wheels 2: the front left, front right, rear left, and rear right.

The support mechanism A is supported by the vehicle body 1. In this embodiment, the work vehicle is equipped with four support mechanisms A, one each at the left front, right front, left rear, and right rear, corresponding to the four traveling wheels 2. The support mechanism A is equipped with a bending link mechanism 5 and a number of hydraulic cylinders 6, 7 that can individually change the position of the bending link mechanism 5.

The structures of the running wheels 2, auxiliary wheels 3, and support mechanism A of the work vehicle in this embodiment are symmetrical front to rear, and the work vehicle can travel in both the forward and backward directions defined in the figure.

The vehicle body 1 is equipped with a loading platform 8 on which luggage can be placed. The loading platform 8 is provided on the top surface of the vehicle body 1.

The vehicle body 1 is equipped with a hydraulic supply source 9, an ECU 11, a battery 12, and a hydraulic control valve 13 (an example of a valve) that adjusts the amount of hydraulic oil supplied to the hydraulic motor 4 and hydraulic cylinders 6, 7. The hydraulic control valve 13 and the ECU 11 constitute a control device C that controls the work vehicle.

Details of the vehicle body 1 will be described later.

[Support mechanism]
As described above, the support mechanism A includes the articulating link mechanism 5 and the plurality of hydraulic cylinders 6, 7. As shown in Fig. 1, the plurality of (specifically, four) running wheels 2 are supported via the articulating link mechanism 5 in a state in which their positions can be changed individually relative to the vehicle body 1.

As shown in Figures 5 and 6, the bending link mechanism 5 is provided with a base end 14 supported by the vehicle body 1, a first link 15 whose upper end is supported on the lower part of the base end 14 so as to be rotatable about the horizontal axis X1, and a second link 16 whose one end is supported on the lower end of the first link 15 so as to be rotatable about the horizontal axis X2 and whose other end supports the running wheel 2.

As shown in FIG. 5, the support bracket 17 that supports the running wheel 2 is supported by a boss portion 18 provided at the swinging end of the second link 16 so that it can swing about the vertical axis Y. A hydraulic cylinder for swing operation (hereinafter referred to as a swing cylinder 20) is provided between a bracket 19 on one end side of the second link 16 and an arm portion 17a provided on the support bracket 17.

A plurality of hydraulic cylinders 6, 7 capable of individually changing the posture of each of the bending link mechanisms 5 are provided corresponding to each of the bending link mechanisms 5. That is, a first hydraulic cylinder 6 capable of changing the swing posture of the first link 15 relative to the vehicle body 1, and a second hydraulic cylinder 7 capable of changing the swing posture of the second link 16 relative to the first link 15 are provided.

When the first hydraulic cylinder 6 is extended or retracted with the second hydraulic cylinder 7 stopped, the first link 15, the second link 16, and the running wheel 2 each oscillate together around the horizontal axis X1 of the pivot connection point to the base end 14 while maintaining a constant relative posture. When the second hydraulic cylinder 7 is extended or retracted with the first hydraulic cylinder 6 stopped, the second link 16 and the running wheel 2 oscillate together around the horizontal axis X2 of the connection point between the first link 15 and the second link 16 while maintaining a constant posture of the first link 15.

The auxiliary wheels 3 are rotatably supported at intermediate bent portions of each of the plurality of bent link mechanisms 5 .
The auxiliary wheel 3 is configured as a wheel having approximately the same outer diameter as the running wheel 2. A support shaft that pivotally connects the first link 15 and the second link 16 is extended so as to protrude outward in the vehicle body width direction, and the auxiliary wheel 3 is rotatably supported at the extended protruding portion of the support shaft.

By operating the turning cylinder 20, the running wheel 2 can be rotated around the vertical axis Y relative to the bending link mechanism 5.

The hydraulic control valve 13 corresponding to the hydraulic motor 4 adjusts the flow rate of the hydraulic oil, thereby changing the rotation speed of the hydraulic motor 4, i.e., the rotation speed of the traveling wheels 2.

[Sensor]
As shown in FIG. 7, the work vehicle is equipped with various sensors.

The work vehicle is equipped with a head-side pressure sensor S1 and a cap-side pressure sensor S2 for each of the four second hydraulic cylinders 7. The head-side pressure sensor S1 detects the hydraulic pressure in the head-side chamber of the second hydraulic cylinder 7. The cap-side pressure sensor S2 detects the hydraulic pressure in the cap-side chamber of the second hydraulic cylinder 7.

The work vehicle is equipped with multiple stroke sensors S3 capable of detecting the amount of extension and retraction operation for each of the four first hydraulic cylinders 6 and the four second hydraulic cylinders 7. The amount of extension and retraction operation for each hydraulic cylinder 6, 7 is a detection value that corresponds to the swing position of the first link 15 and second link 16 that are the objects of operation.

The vehicle body 1 is equipped with a tilt sensor S4 that detects the tilt state of the vehicle body. The tilt sensor S4 is configured using an inertial measurement unit (IMU). The IMU has a three-axis acceleration sensor and a gyro sensor, and can detect changes in the attitude of the vehicle body 1, specifically, tilt in the forward/backward and left/right directions.

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

[ECU]
The ECU 11 (Electronic Control Unit) includes a memory (such as a HDD or non-volatile RAM, not shown) that stores programs corresponding to the functional units described below, and a CPU (not shown) that executes the programs. The functions of the functional units are realized by the CPU executing the programs. In other words, the ECU 11 includes a non-transitory recording medium that stores the programs.

The ECU 11 has an attitude control unit 100 and a driving control unit 101 as functional units.

When the vehicle is traveling with the four running wheels 2 in contact with the ground, the travel control unit 101 controls the hydraulic control valve 13 to control the operation of the hydraulic motor 4 so that the rotation speed of each of the four running wheels 2 detected by the rotation sensor S5 becomes the target speed and the drive torque detected by the pressure sensor S6 becomes the target value.

When the vehicle body is moving, the posture control unit 100 performs horizontal control to control the operation of the support mechanism A so that the vehicle body 1 is in a horizontal posture based on the detection information of the inclination sensor S4.

In horizontal control, the posture control unit 100 controls the hydraulic control valve 13 to control the operation of the four first hydraulic cylinders 6 and the four second hydraulic cylinders 7 so that the tilt angles in the front-to-rear direction and the left-to-right direction from the horizontal posture of the vehicle body 1 become values corresponding to the horizontal posture based on the detection information of the tilt sensor S4.

[Vehicle body, loading platform]
As described above, the vehicle body 1 has a generally rectangular shape in a plan view. In this embodiment, the vehicle body 1 has a cargo bed 8, a front cover 31, and a rear cover 32 arranged on its upper surface.

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

The loading platform 8 is equipped with multiple top plate members 8a that extend in the front-rear direction. The top plate members 8a are plate-shaped members that are approximately rectangular in plan view. The top plate members 8a have multiple rib portions 8b that protrude upward. The rib portions 8b are formed by bending the top plate members so that their cross sections are trapezoidal, and extend in the front-rear direction and are lined up in the left-right direction.

The tabletop members 8a are arranged side by side, with some overlapping. In this embodiment, three tabletop members 8a are arranged side by side. The central tabletop member 8a overlaps the right end of the left tabletop member 8a and the left end of the right tabletop member 8a. The rib portion 8b at the left end of the central tabletop member 8a overlaps the rib portion 8b at the right end of the left tabletop member 8a. The rib portion 8b at the right end of the central tabletop member 8a overlaps the rib portion 8b at the left end of the right tabletop member 8a.

The front cover 31 is a plate-shaped member with a flat upper surface. The front cover 31 is positioned in front of the loading platform 8 with its normal line aligned in the vertical direction.

The rear cover 32 is a plate-shaped member with a flat upper surface. The rear cover 32 is positioned behind the loading platform 8 with its normal line aligned in the vertical direction.

The uppermost surface of the loading platform 8 is the upper surface of the rib portion 8b of the top plate member 8a. As shown in Figures 1 and 2, the upper surface of the rib portion 8b is located above the parts of the upper part of the vehicle body 1 other than the loading platform 8, i.e., above the front cover 31 and the rear cover 32.

[Vehicle body frame]
As shown in Figures 1-4, the vehicle body 1 includes structures supporting each component and device, such as a main frame 41, left and right outer side frames 42 (side frames) , left and right inner side frames 43, front and rear mounting frames 44, an underframe 45, and a center frame 46.

As shown in FIG. 4, the main frame 41 has left and right vertical frames 41a that are rod-shaped and extend forward and backward, and five horizontal frames 41b that connect the vertical frames 41a. The four base ends 14 of the bending link mechanism 5 are supported by the main frame 41.

The outer side frame 42 is a member formed by bending a round pipe. The outer side frame 42 is supported by the main frame 41. The outer side frame 42 extends in the front-rear direction at the right and left ends of the vehicle body 1, and is bent inward in the left-right direction at the front and rear ends of the vehicle body 1.

The inner side frame 43 is composed of a member formed by bending a round pipe and a flat plate-shaped member. The inner side frame 43 is disposed between the main frame 41 and the outer side frame 42. The inner side frame 43 is supported by the base end portion 14 of the bending link mechanism 5 and the main frame 41.

The mount frame 44 is a member that protrudes in the front-rear direction from the front and rear ends of the main frame 41. A handle or the like that is held by the operator can be attached to the mount frame 44.

The underframe 45 is composed of a U-shaped member that protrudes downward from the underside of the mainframe 41 and a rod-shaped member that extends in the front-rear direction below the mainframe 41.

The center frame 46 is a hollow rod-shaped member that is arranged in the center of the vehicle body 1 and extends in the left-right direction. The center frame 46 is supported by the main frame 41.

The loading platform 8 is supported by the main frame 41 via the outer side frames 42 and the center frame 46. More specifically, the front-to-rear center of the top plate member 8a of the loading platform 8 is supported by the center frame 46. The front and rear ends of the top plate member 8a are supported by portions of the outer side frames 42 that extend in the left-right direction. The top plate member 8a is detachable from the outer side frames 42 and the center frame 46.

[Vehicle body devices]
The vehicle body 1 includes a hydraulic supply source 9, an ECU 11, a battery 12, and a hydraulic control valve 13 (an example of a valve) as devices for supplying hydraulic oil to the hydraulic motor 4 and the hydraulic cylinders 6, 7.

The hydraulic supply source 9 is composed of a pump 9a, an engine 9b (an example of a drive source), a radiator 9c, a hydraulic oil tank 9d, and a fuel tank 9e.

The pump 9a supplies hydraulic oil to the hydraulic motor 4 and hydraulic cylinders 6 and 7 via the hydraulic control valve 13. The engine 9b drives the pump 9a. The radiator 9c cools the cooling water for the engine 9b. The hydraulic oil tank 9d stores hydraulic oil. The fuel tank 9e stores fuel for the engine 9b.

As shown in FIG. 1-3, the devices constituting the hydraulic supply source 9 described above are located below the loading platform 8. The hydraulic supply source 9 is supported by an underframe 45. The left and right sides of the hydraulic supply source 9 are covered by side covers 45a. The side covers 45a are supported by the underframe 45.

As shown in FIG. 4, the hydraulic supply source 9 is located between the left and right vertical frames 41a of the main frame 41 in a plan view. In particular, the hydraulic oil tank 9d and the fuel tank 9e are located below the top plate member 8a in the center of the loading platform 8. Therefore, the hydraulic oil tank 9d and the fuel tank 9e can be easily accessed by removing the top plate member 8a.

The ECU 11 is powered by the battery 12 and controls the hydraulic supply source 9 and the hydraulic control valve 13. The ECU 11 is located below the loading platform 8. The ECU 11 is supported by the inner side frame 43. The ECU 11 is disposed to the right and/or left of the engine 9b in a plan view. In other words, the ECU 11 is disposed outside the engine 9b in the left-right direction in a plan view.

The battery 12 is located below the loading platform 8. The battery 12 is supported by the underframe 45.

The hydraulic control valve 13 is located below the loading platform 8. The hydraulic control valve 13 is supported by the inner side frame 43. The hydraulic control valve 13 is disposed to the right and/or left of the engine 9b in a plan view. In other words, the hydraulic control valve 13 is disposed outside the engine 9b in the left-right direction in a plan view.

The work vehicle further includes a plurality of connection mechanisms 51 to which a hoisting tool can be connected. A hoisting tool is a tool used when suspending the work vehicle with a crane or the like, such as an eye bolt (a bolt with a loop attached to the head). In this embodiment, the connection mechanism 51 is a screw hole into which the eye bolt can be screwed, and is provided in the main frame 41.

In this embodiment, the connection mechanisms 51 are located in front of and behind the loading platform 8 on the top surface of the vehicle body 1. More specifically, four connection mechanisms 51 are arranged at positions toward the right and left of the front of the vehicle body 1, and at positions toward the right and left of the rear of the vehicle body 1. Note that long holes 31a are formed in the front cover 31 at positions corresponding to the connection mechanisms 51. Long holes 32a are formed in the rear cover 32 at positions corresponding to the connection mechanisms 51.

The work vehicle further includes a switch 52 that accepts manual operation for an emergency stop. The switch 52 is connected to the ECU 11. When the switch 52 is operated, the driving control unit 101 stops the work vehicle from traveling, and the ECU 11 stops the engine 9b.

In this embodiment, as shown in Figures 1 and 2, the switch 52 is located below the top surface of the loading platform 8 (the upper surface of the rib portion 8b of the top plate member 8a). The switch 52 is located on the upper surface of the rear mounting frame 44.

[Another embodiment]
(1) The shape of the loading platform portion 8 is not limited to the above example. For example, the loading platform portion 8 may be the entire upper surface of the vehicle body 1. The loading platform portion 8 may be formed of a single top plate member 8a. The top plate members 8a may be arranged side by side in the front-to-rear direction. The top plate members 8a do not have to overlap each other. The top plate members 8a may be in contact with each other, or there may be a gap between the top plate members 8a. The rib portion 8b may extend in the left-right direction. The upper surface of the loading platform portion 8 may be flat.

(2) The driving source of the work vehicle is not limited to an engine and hydraulics. Instead of the engine 9b and fuel tank 9e, the work vehicle may be equipped with an electric motor (an example of a driving source) that drives the pump 9a and a battery that supplies power to the electric motor. The traveling wheels 2 and the support mechanism A may be driven by an electric actuator.

(3) The ECU 11 may be disposed only to the right or only to the left of the engine 9b in a plan view.
The hydraulic control valve 13 may be disposed only to the right or only to the left of the engine 9b in a plan view.

The present invention can be applied to a work vehicle that is suitable for traveling on rough terrain. This work vehicle can be used in mountainous areas, forests, farm fields and their surrounding areas, around rivers, construction sites, etc.

1: Vehicle body 2: Traveling wheels 4: Hydraulic motor 8: Cargo platform 8a: Top plate member 9a: Pump 9b: Engine (drive source)
9d: hydraulic oil tank 9e: fuel tank 13: hydraulic control valve
42 : Outer side frame (side frame)
44 : Mount frame
46 : Center frame
51: Connection mechanism 52: Switch A: Support mechanism

Claims (9)

A vehicle body,
A plurality of running wheels located at the front and rear of each of the left and right sides of the vehicle body;
a support mechanism that is supported by the vehicle body and supports the plurality of traveling wheels in a state in which the positions of the traveling wheels with respect to the vehicle body can be individually changed;
a loading platform provided on an upper surface of the vehicle body and capable of carrying luggage;
The uppermost surface of the loading platform is located above a portion of the upper portion of the vehicle body other than the loading platform,
The vehicle body includes side frames extending along a front-rear direction at both left and right end portions, and a center frame extending along a left-right direction at a central portion in the front-rear direction between the side frames at the left and right end portions,
The side frames at both left and right ends are provided in a state in which the front ends of the side frames are spaced apart from each other and the rear ends of the side frames are spaced apart from each other,
A work vehicle in which the loading platform is supported by side frames at both left and right ends and the center frame . a mount frame is provided on the vehicle body, the mount frame being positioned between one end of the side frames at the left and right ends in the front-rear direction and protruding relative to the loading platform and positioned lower than the top surface of the loading platform;
2. The work vehicle according to claim 1, wherein the mount frame is capable of mounting a handle that is gripped by an operator . 3. The work vehicle according to claim 1, wherein the loading platform extends from the right end to the left end of the vehicle body. The loading platform portion includes a plurality of top plate members extending in a front-rear direction,
4. The work vehicle according to claim 1, wherein the top plate members are arranged side by side on the left and right with some of the top plate members overlapping each other. Further comprising a plurality of connection mechanisms to which the slings can be connected,
5. The work vehicle according to claim 1, wherein the connection mechanisms are located on the top surface of the vehicle body, in front of and behind the loading platform. A hydraulic motor that drives the traveling wheels;
a pump for supplying hydraulic oil to the hydraulic motor;
A drive source that drives the pump,
6. The work vehicle according to claim 1, wherein the pump and the driving source are positioned below the loading platform. A hydraulic oil tank that stores the hydraulic oil;
A fuel tank that stores fuel for the engine provided as the driving source,
7. The work vehicle according to claim 6 , wherein the hydraulic oil tank and the fuel tank are located below the loading platform. The hydraulic motor further includes a valve for adjusting the amount of hydraulic oil supplied to the hydraulic motor.
8. The work vehicle according to claim 6 , wherein the valve is located below the platform and to the right and/or left of the drive source in a plan view. Further provided with a switch for accepting manual operation of an emergency stop,
9. The work vehicle according to claim 1, wherein the switch is located facing upward and below the top surface of the loading platform on one side of the loading platform in the front-rear direction of the vehicle body .

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