JP7624917B2 - Work vehicle - Google Patents

Description

The present invention relates to a work vehicle that is suitable for traveling on uneven ground such as uneven surfaces or mountainous areas.

Conventionally, the above-mentioned work vehicle has four running wheels supported on the vehicle body via a bending link mechanism in a support mechanism, and the height of the running wheels relative to the vehicle body can be changed so that the running wheels can rotate while following the ground even if the ground is uneven (for example, see Patent Document 1).

JP 2019-111985 A

With the above configuration, even when traveling on uneven ground such as uneven surfaces or mountainous areas (hereinafter simply referred to as uneven ground), it is possible to travel while maintaining the vehicle body in a predetermined position, such as a horizontal position, with multiple running wheels in contact with the ground.

Work carried out in mountainous areas where this type of work vehicle is used includes, for example, fruit growing and harvesting. When carrying out such work, not only is the harvested crop transported by the work vehicle, but the crops are also sprayed with water and chemicals. Conventionally, when carrying out such spraying work, a dedicated liquid spraying machine with a drive source had to be prepared, which was costly and had disadvantages such as the hassle of transporting multiple pieces of equipment.

Therefore, there was a demand for a work vehicle that can travel on rough terrain and that can perform tasks that require a drive source with a simple configuration.

The characteristic configuration of the work vehicle of the present invention is that it comprises a vehicle body, a plurality of traveling devices located at the front and rear on both the left and right sides of the vehicle body, a plurality of traveling drive devices which drive each of the plurality of traveling devices separately, and a support mechanism which supports the plurality of traveling devices on the vehicle body so that they can be raised and lowered separately, and each of the traveling devices which can be raised and lowered separately is provided with a towing support section which is provided separately from the vehicle body and which supports a mobile trolley so that it can be towed, and a power take-off section which can take out the rotational power of the traveling drive devices to the outside of the vehicle body.

According to the present invention, since the multiple traveling devices can be raised and lowered separately by the support mechanism, any one or more of the multiple traveling devices can be raised above the traveling surface. Furthermore, since each of the multiple traveling devices can be driven by a traveling drive device separately, the raised traveling devices can also be driven to rotate by the traveling drive device. Furthermore, by providing a power take-off section, it becomes possible to take power from the traveling drive device that is raised above the traveling surface to the outside of the vehicle body.

As a result, even when work that requires a drive source is required, the traveling drive device can be used, and work can be performed with a simple configuration without the hassle of having to prepare a dedicated work machine with a drive source.

As a result, it has become possible to perform work that requires a drive source with a simple configuration in a work vehicle that can travel on rough ground. In addition, because the rotational power of the travel drive devices on the front, rear, left and right sides of the vehicle body can be controlled separately, different power sources can be extracted simultaneously from one vehicle. In addition, by controlling the travel drive devices, a variety of power extraction methods can be realized according to the application, such as extracting rotational power with infinite rotation, extracting rotational power by rotating by a fixed angle, or extracting rotational power by rotating with an arbitrary torque.

In the present invention, it is preferable that the traveling device includes a swivel cylinder, and the swivel cylinder swings the traction support part left and right.

In the present invention, it is preferable that the support mechanism is provided with a bending link mechanism, the bending link mechanism is provided with a first link, one end of which is supported so as to be swingable about a horizontal axis relative to the vehicle body, and a second link, one end of which is supported so as to be swingable about a horizontal axis on the other end of the first link, the running device is supported on the other end of the second link, and an auxiliary wheel is supported at the connection point between the first link and the second link.

With this configuration, the support mechanism can stably support the vehicle body with a wide contact width in the fore-and-aft direction using the running gear and the auxiliary wheels, and by changing the swing posture of the first link relative to the vehicle body, the running gear and the auxiliary wheels can be raised and lowered relative to the vehicle body.
Furthermore, by fixing the swinging attitude of the first link relative to the vehicle body and changing the swinging attitude of the second link relative to the first link, the traveling device can be raised and lowered with the auxiliary wheels fixed in position.

As a result, it is possible to lift the running gear with the auxiliary wheels on the ground, and power can be extracted from the running drive gear with the vehicle body stably supported on the ground using the auxiliary wheels.

In the present invention, it is preferable that the power take-off section is provided with an attachment section to which a power take-off attachment can be attached while being positioned on the side of the traveling device.

This configuration makes it possible to drive an external working device via a power extraction attachment attached to the mounting portion, without the need for troublesome tasks such as removing the traveling device from the support mechanism.

FIG. FIG. FIG. FIG. FIG. FIG. FIG. 2 is an overall side view of the movable dolly being towed; FIG. 11 is a plan view of a support mechanism according to another embodiment. FIG. 4 is an overall side view of the movable dolly being towed; FIG. 2 is a plan view of the traction support. FIG. 2 is a plan view of the traction support.

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

[Reference embodiment]
As shown in Figures 1 and 2, the work vehicle is equipped with a vehicle body 1 which is approximately rectangular in plan view and supports the entire vehicle, a plurality of running wheels 2 which serve as running devices supporting the vehicle body 1, a plurality of auxiliary wheels 3 which correspond to each of the plurality of running wheels 2, a support mechanism A which supports the plurality of running wheels 2 so that their position can be changed relative to the vehicle body 1, and a plurality of hydraulic motors 4 which serve as running drive devices which drive each of the plurality of 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 has four running wheels 2, located at the left front, right front, left rear, and right rear. It also has four support mechanisms A, located at the left front, right front, left rear, and right rear. The support mechanisms A include a bending link mechanism 5 and multiple hydraulic cylinders 6, 7 that can individually change the position of the bending link mechanism 5.

A flat loading section 8 capable of carrying luggage is provided on the top of the vehicle body 1. For example, luggage such as containers for storing harvested crops can be loaded and supported on top of this loading section 8.

The vehicle body 1 is provided with a hydraulic supply source 9 that sends hydraulic oil to the hydraulic cylinders 6, 7 and hydraulic motor 4 under the loading section 8, a valve mechanism 10 that adjusts the supply state of hydraulic oil from the hydraulic supply source 9, and an ECU (Electronic Control Unit) 11 that controls the operation of the valve mechanism 10. The hydraulic supply source 9 has a hydraulic pump driven by the engine. The ECU 11 has a microcomputer and is capable of performing various controls according to a control program. The valve mechanism 10 has multiple hydraulic control valves 13 that supply and discharge hydraulic oil or adjust the flow rate. The hydraulic control valves 13 and the ECU 11 constitute the control device C.

[Support mechanism]
As described above, the support mechanism A includes the bending link mechanism 5 and the multiple hydraulic cylinders 6, 7. As shown in Figures 3 and 4, the bending link mechanism 5 includes a base end portion 14 supported by the vehicle body 1, a first link 15 having an upper end portion supported on a lower portion of the base end portion 14 so as to be rotatable about a horizontal axis X1, and a second link 16 having one end portion supported on a lower end portion of the first link 15 so as to be rotatable about a horizontal axis X2 and having the running wheel 2 supported on the other end portion.

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 around the vertical axis Y. A hydraulic cylinder 20 for swing operation (hereinafter referred to as a swing cylinder) 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 four bending link mechanisms 5 are provided. 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 the intermediate bent portions of each of the four bent link mechanisms 5. The auxiliary wheels 3 are composed of wheels with approximately the same outer diameter as the running wheels 2. The support shaft that pivotally connects the first link 15 and the second link 16 is extended so as to protrude outward in the vehicle width direction, and the auxiliary wheels 3 are 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 each hydraulic motor 4 adjusts the flow rate of the hydraulic oil, so that the rotational speed of each hydraulic motor 4, i.e., the rotational speed of each running wheel 2, can be changed individually.

[Sensor]
This work vehicle is equipped with various sensors.
5 , a head side pressure sensor S1 and a cap side pressure sensor S2 are provided 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.

Each of the four first hydraulic cylinders 6 and the four second hydraulic cylinders 7 is equipped with a plurality of stroke sensors S3 capable of detecting the amount of extension/retraction operation. The amount of extension/retraction operation of each hydraulic cylinder 6, 7 is a detection value corresponding 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), which is a well-known configuration. The IMU has a three-axis acceleration sensor and a gyro sensor, and can detect changes in the attitude of the vehicle body 1, specifically, tilt in the 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 includes a posture control unit 100 and a driving control unit 101. When the vehicle is traveling with the four traveling wheels 2 in contact with the ground, the driving control unit 101 controls the operation of the hydraulic motor 4 for each of the four traveling wheels 2 so that the rotation speed of the traveling wheels 2 detected by the rotation sensor S5 becomes a target speed and the drive torque detected by the pressure sensor S6 becomes a 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 operation of the four first hydraulic cylinders 6 and the four second hydraulic cylinders 7 based on the detection information of the tilt sensor S4 so that the tilt angles in the front-to-rear direction and the left-to-right direction from the horizontal position of the vehicle body 1 become values corresponding to the horizontal position.

[Traction support part]
1 and 2, a towing support section 22 that supports the movable dolly ID so that it can be towed is provided in the center of the left and right direction on both the front and rear sides of the vehicle body 1. The tip of a connecting arm 23 extended from the movable dolly ID is connected to the towing support section 22, so that the movable dolly ID can be towed and pulled as the work vehicle moves and travels.

The towing support part 22 is fixed to the end of the support part 24 that extends from the vehicle body 1, and is formed in a circular ring shape in a plan view. The tip of the connecting arm 23 of the mobile dolly ID is provided with a hook member 25 that engages with the towing support part 22. Therefore, the connecting arm 23 is connected to the towing support part 22 so that it can swing up and down and left and right. The connecting arm 23 is connected to the mobile dolly ID so that it can swing up and down and left and right. The mobile dolly ID is towed by the work vehicle while following the ground and smoothly rotating.

[Power take-off section]
The vehicle is provided with a power take-off unit TO capable of taking off the rotational power of the hydraulic motor 4 to the outside of the vehicle body. That is, as shown in Figures 2 and 3, the power take-off unit TO is provided with an attachment portion 27 on the side of any one of the four running wheels 2, more specifically, on the same axis as the drive shaft of the running wheel 2, to which a power relay device 26 as an attachment for taking off power can be attached.

The mounting portion 27 is provided with a power transmission shaft 28 that is driven to rotate by the hydraulic motor 4 and protrudes laterally. The power transmission shaft 28 is configured, for example, as a splined shaft or hexagonal shaft, into which the inserted driven shaft fits to transmit torque, or into a shape that rotates integrally with the driven shaft via a connecting pin that penetrates radially. In short, any configuration that allows the transmission of rotational power to the driven shaft will suffice.

When driving the external work device GS using the mounting part 27, first, as shown in FIG. 6, the posture of the bending link mechanism 5 is adjusted so that the running wheel 2 equipped with the mounting part 27 is lifted off the ground. At this time, the grounding posture of the entire work vehicle is stabilized by grounding the auxiliary wheel 3 corresponding to the running wheel 2. It is also possible to support the work vehicle on the ground by the remaining three running wheels 2 without grounding the auxiliary wheel 3.

Then, as shown in FIG. 3, the connecting portion 26A of the power relay device 26 is connected to the mounting portion 27. The power relay device 26 is configured to transmit rotational power to the power input portion 29 of the external work device GS. When the hydraulic motor 4 is driven with the power relay device 26 attached, the power of the hydraulic motor 4 is transmitted to the external work device GS via the power relay device 26, and work is performed. Various types of work devices can be used as the external work device GS. For example, there is a watering pump that draws up water and sprays it on crops.

[Embodiment]
In the above-described reference embodiment, the towing support part 22 is provided on the vehicle body 1, but instead of this configuration, the towing support part 22 may be provided on the bending link mechanism 5. As shown in Fig. 9, a tip end of a connecting arm 23 extended from the movable dolly ID is integrally connected to a support bracket 17 of any one of the four traveling wheels 2. A rear end of the connecting arm 23 is connected to the movable dolly ID so as to be swingable in the up-down and left-right directions.
In this configuration, the movable carriage ID is pulled with the target traveling wheel 2 raised, as shown in Fig. 9. When the turning cylinder is operated, the connecting arm 23 swings left and right via the support bracket 17, as shown in Fig. 10 and Fig. 11, so that the movable carriage ID can be pulled so as to avoid, for example, protrusions and recesses on the ground.
[Another embodiment]
(1) In the above embodiment, the power take-off unit TO is configured to include a mounting portion 27 on the side of the running wheel 2 to which a power take-off attachment can be attached, but instead of this configuration, as shown in Fig. 8, the running wheel 2 may be removed from the support mechanism A, and the wheel mounting portion 30 remaining after the running wheel 2 is removed may be used as the power take-off unit TO, and a power take-off attachment may be connected to the wheel mounting portion 30 to take off power. Also, the power take-off attachment may be connected to a position other than the drive shaft of the running wheel 2 via a gear or the like.

(2) In the above embodiment, the power take-off unit (mounting portion 27) can be provided for any one of the four running wheels 2, but it is also possible to provide a power take-off unit for two or more running wheels 2.

( 3 ) In the above embodiment, the traveling drive device is configured with a hydraulic motor 4. However, an electric motor may be used instead of the hydraulic motor 4, and the power of the engine may be transmitted via a transmission mechanism provided separately for each traveling wheel 2.

( 4 ) In the above-described conventional configuration, the support mechanism A is configured to include the flexural link mechanism 5 and the hydraulic cylinders 6, 7. However, instead of this configuration, a hydraulic motor may be provided at the fulcrum of the swinging of the flexural link mechanism 5, and the posture of the flexural link mechanism 5 may be changed by the hydraulic motor.

( 5 ) In the above embodiment, the support mechanism A is provided with a bending link mechanism 5. However, instead of this configuration, for example, a configuration in which the running wheels 2 are supported using a robot arm that can bend in any direction may be used. In short, it is sufficient that the running wheels 2 are supported individually so that their height positions can be freely changed relative to the vehicle body 1, and that the vehicle body 1 is supported so that its posture can be maintained. The configuration of the support mechanism A can be modified in various ways.

The present invention can be applied to work vehicles that are suitable for traveling on rough terrain.

Reference Signs List 1 Vehicle body 2 Traveling wheel 3 Auxiliary wheel 4 Traveling drive device 5 Articulated link mechanism 15 First link 16 Second link
20 Swivel cylinder
22 Traction support part
26 Attachment 27 Mounting portion A Support mechanism
ID Mobile Cart
TO Power take-off section X1 First horizontal axis

Claims (4)

A vehicle body,
A plurality of traveling devices located at the front and rear of each of the left and right sides of the vehicle body;
A plurality of travel drive devices each for driving the plurality of travel devices separately;
a support mechanism that supports the plurality of traveling devices on the vehicle body so that each traveling device can be raised and lowered separately ;
The traveling devices, which can be raised and lowered separately,
a towing support section provided separately from the vehicle body and configured to support the movable carriage so as to be towable;
and a power take-off section capable of taking out the rotational power of the traveling drive device to the outside of the vehicle body. The traveling device includes a swivel cylinder,
2. The work vehicle according to claim 1, wherein the swivel cylinder swings the towing support part left and right. The support mechanism is provided with an articulated link mechanism,
The bending link mechanism includes a first link having one end supported to be swingable about a horizontal axis with respect to the vehicle body, and a second link having one end supported to be swingable about the horizontal axis on the other end of the first link,
3. The work vehicle according to claim 1, wherein the traveling device is supported on the other end of the second link, and an auxiliary wheel is supported at a connection point between the first link and the second link. A work vehicle according to any one of claims 1 to 3, in which the power take-off section is provided with a mounting section to which a power take-off attachment can be attached while being positioned on the side of the traveling device.

Images