Work vehicle

Abstract

Provided is a work vehicle comprising a vehicle body, a travel device attached to the vehicle body, a work machine, and a work hitch device that connects the vehicle body and the work machine. The work vehicle also comprises a first prime mover that drives the travel device and a second prime mover that drives the work machine, and further comprises a first motive power source dedicated to the first prime mover, and a second motive power source dedicated to the second prime mover, whereby the time over which the motive power sources operate is extended.

Description

Work vehicle

[0001] The present invention relates to a work vehicle equipped with a working machine such as a tiller and performing various operations.

[0002] Conventionally, there is known a work vehicle that is an electric working machine driven by electric power from a battery, and includes a work unit (tilling unit) having a working device (tilling shaft, tilling claw) and a working electric motor that drives the working device, a traveling device (axle, traveling wheel), and a traveling unit having a traveling electric motor that drives the traveling device, and a body unit having a control device and an operation unit that control the power supply to the working electric motor and the traveling electric motor (see Patent Document 1).

[0003] Japanese Patent Application Laid-Open No. 2012-175923

[0004] However, in such a work vehicle, since two motors are driven by one power source, there is a problem that the duration of the power source becomes short.

[0005] In the present invention, in consideration of the problems of such conventional work vehicles, an object is to provide a work vehicle having a long power source duration.

[0006] The invention according to claim 1 includes a vehicle body, a traveling device attached to the vehicle body, a working machine, and a work hitch device that connects the vehicle body and the working machine, and includes a first prime mover that drives the traveling device and a second prime mover that drives the working machine, and a first power source dedicated to the first prime mover and a second power source dedicated to the second prime mover. A work vehicle characterized by comprising.

[0007] By providing the work vehicle with independent power sources and prime movers respectively, the problem of the short duration of the power source can be solved.

[0008] The invention according to claim 2 is the work vehicle according to claim 1, characterized in that the first prime mover is an electric motor, the first power source is a battery, the second prime mover is an engine, and the second power source is fuel.

[0009] As a result, workability is improved by having the internal combustion engine handle the heavier load.

[0010] The invention described in claim 3 is a work vehicle according to claim 2, wherein the traveling device has a left traveling section and a right traveling section, and the first prime mover is composed of a left motor section that drives the left traveling section and a right motor section that drives the right traveling section.

[0011] This allows for independent left and right drive, improving operability.

[0012] The invention described in claim 4 is a work vehicle according to claim 3, comprising a work machine that rotates up and down by a lift mechanism, characterized in that, within the working range of the vertical movement of the work machine during operation, the change in the forward and backward tilt posture of the work machine is small within the working range, and large in the area above the working range.

[0013] This causes the upper part of the work equipment to move towards the vehicle body, making the front-to-rear width of the machine more compact and easier to turn.

[0014] The invention described in claim 5 is a work vehicle according to claim 4, characterized in that, within the working range of vertical movement of the work machine during operation, the rotational speed of the work machine is slower than the rotational speed above the working range.

[0015] As a result, the rotation speed of the implement during tilling is slower than the rotation speed in the working range, which follows a trajectory similar to an ascent or descent, and slower than the rotation speed in the upward direction, which follows a trajectory similar to a turn, allowing for precise adjustment of the tilling depth.

[0016] The invention described in claim 6 is a work vehicle according to any one of claims 1 to 5, wherein, in addition to the first power source, another battery is provided to serve as a power source other than the running gear.

[0017] This reduces the power consumption of the battery, which is the primary power source, and extends the usable time.

[0018] The invention described in claim 7 is a work vehicle according to claim 6, wherein the first power source is located at the front of the vehicle body and the work machine is located at the rear of the first power source.

[0019] This allows the first power source to be positioned towards the front of the vehicle, and the work equipment to be located adjacent to the rear of the first power source, thereby securing space for mounting the work equipment and its internal combustion engine.

[0020] The invention described in claim 8 is a work vehicle according to claim 7, wherein the traveling device and the work machine are configured to be remotely controllable, the traveling device is provided with an emergency stop mechanism that allows it to be stopped by remote control, and in addition to the remote emergency stop mechanism, an emergency stop mechanism for the traveling device is also provided on the vehicle body.

[0021] This makes it convenient to operate remotely, and since both the remote control device and the vehicle itself are equipped with an emergency stop mechanism, safety is also improved.

[0022] The invention described in claim 9 is a work vehicle according to claim 1, characterized in that a remote controller is used for remote operation, and the remote controller includes at least an operating device for emergency stop operation and travel speed adjustment operation of the travel device, and for raising and lowering operation of the work machine.

[0023] Using an easy-to-operate remote controller enables comfortable work, and since the travel speed and the raising and lowering of the work equipment can be controlled remotely, work efficiency and safety are improved.

[0024] The invention described in claim 10 is the work vehicle described in claim 1, wherein the running device is a running device that utilizes an endless track belt.

[0025] This ensures stable driving even on rough roads, allowing for comfortable work operations.

[0026] Perspective view of a work vehicle according to an embodiment of the present invention Left side view of the work vehicle Right side view of the work vehicle Front view of the work vehicle Rear view of the work vehicle Plan view of the work vehicle Enlarged perspective view of the front of the work vehicle Enlarged perspective view of the link components of the work vehicle Plan view of the link components of the work vehicle Side view of the work vehicle with the work machine at its highest position Perspective view of the work hitch device of the work vehicle Perspective view of the work machine of the work vehicle Enlarged side view of part of the work machine of the work vehicle Enlarged perspective view of part of the work machine of the work vehicle Perspective view of the hitch mounting bracket of the work vehicle Perspective view of the gear case of the work vehicle Cross-sectional view of the gear case of the work vehicle Perspective view of the coupling case of the work vehicle Perspective view of the pivot of the work machine of the work vehicle Perspective view of the central axis of the work vehicle Front view of the control panel of the remote controller for the work vehicle Left side view of the work vehicle (lowest position) Perspective view of the link components of the work vehicle Rear view of the link components (A), (B), (C) Schematic diagrams illustrating the operation of the link components Rear perspective view of the link components in the state shown in Figure 26 Plan view of the link components Left side view of the work vehicle (upper limit of working range) Perspective view of the link components in the state shown in Figure 26 Rear perspective view of the link components in the state shown in Figure 26 (highest position) Perspective view of the link components in the state shown in Figure 29 viewed from below Perspective view of the link components in the state shown in Figure 29 viewed from below Perspective view of the link components in the state shown in Figure 29 viewed from above Perspective view of the link components in the state shown in Figure 29 (A), (B), (C) Schematic diagrams illustrating the operation of the link components Rear perspective view of the work vehicle with the cargo bed attached Lower perspective view of the work vehicle with the cargo bed attached Left side view of the work vehicle Left side view of the work vehicle Partial enlargement view from above with the cargo bed tilted to the rear Left side view of the work vehicle without the cargo bed attached Perspective view centered on the link components in the state shown in Figure 40

[0027] The embodiments of the present invention will be described in detail below with reference to the drawings.

[0028] Figure 1 is a perspective view from the upper left of a tilling work vehicle, which is an example of a work vehicle according to an embodiment of the present invention. Figure 2 is the left side of the same work vehicle. Figure 3 is the right side of the same work vehicle. Figure 4 is the front view of the same work vehicle. Figure 5 is the rear view of the same work vehicle. Figure 6 is the top view of the same work vehicle. Hereafter, the direction of travel of the vehicle body will be used as the reference point for the front-rear direction and the left-right direction.

[0029] As shown in Figures 1 to 6, a vehicle body 1 is mounted on a crawler-type running gear 2, and a tiller, which is an example of a work implement 3, is positioned behind the vehicle body 1. A work hitch device 4 connects the vehicle body 1 and the work implement 3. A detailed explanation follows.

[0030] Figure 40 is a side view of the work hitch device 4 in a state where no work equipment or other devices are attached.

[0031] This work vehicle is an electrically powered, remotely controlled vehicle that has a main frame 5 and features different front and rear orientations depending on the type of work. A front hitch 6 is provided at the very front of the main frame 5, where various work implements, as well as various components such as bumpers, weights, and steps, can be attached.

[0032] As shown in Figure 7, a battery box 7 is provided in front of the main frame 5, behind the mounting hole for the front hitch 6, to which the main battery (first power source) 7a is mounted. The outlet for the main battery 7a is located on the side of the aircraft, so that heavy objects are not inserted or removed in the direction of the aircraft's movement. Hereinafter, the first power source in the claims will also be referred to as the main battery.

[0033] A curved plate 8 is provided on top of the battery box 7 to act as a sunshade to protect the main battery 7a from direct sunlight, and to secure switches, control components, and harnesses. The control device 9 is positioned on the plate 8, above the battery box 7. The control components are arranged around the battery box 7, minimizing the length of the harnesses.

[0034] A monitor 10 for displaying information about the main battery 7a, a power button 11 for control-related functions, an emergency stop switch 12, and a key switch 13 for high voltages of the motor and main battery 7a are provided in front of the battery box 7 on plate 8.

[0035] The device is powered on by the power button 11 and can be operated by the key switch 13. Pressing the emergency stop switch 12 will cause an emergency stop, but power will remain on and subsequent operations will be possible. Turning the key switch 13 off will also cause an emergency stop, but power will remain on and subsequent operations will need to be resumed by turning the key switch 13 on again.

[0036] The power button 11, emergency stop switch 12, and key switch 13 are fixed in place, and a cover 14 is provided to cover the monitor 10 and fuse box. The monitor 10 has an opening and is provided with a sunshade.

[0037] The main frame 5 is configured to allow the attachment of running frames to both sides. Fixed wheels are mounted on the running frames at the rear of the machine, and movable wheels are mounted at the front of the machine. Crawlers 15 are then attached to these running frames.

[0038] Behind the main battery 7a, as shown in Figure 6, is a plate 16 for body grounding and on which a relay switch can be mounted, and a space 17 for passing a harness is provided in the center of the aircraft.

[0039] As shown in Figure 4, an electric double-acting or cylinder 18 is provided at the lower part of the main frame 5, which is attached to the main frame 5 and used to raise and lower the work machine 3.

[0040] Behind the plate 16, sub-batteries 19 (different from both the first and second power sources) are provided on the left and right sides of the aircraft, which are power sources for control equipment and for starting the main battery 7a, etc., and a space 17 is provided in the center of the aircraft through which a harness can be passed. Behind the sub-batteries 19, a left motor unit 2a that drives the left-side running gear and a right motor unit 2b that drives the right-side running gear are provided on the left and right sides, respectively.

[0041] As shown in Figures 6 and 8, a link component 20 that forms the lifting track for the work equipment 3 is provided behind the motor sections 2a and 2b for travel. Figure 8 is an enlarged perspective view of the link component 20. A work hitch device 4 is provided at the rear end of the link component 20, allowing the work equipment 3 and other equipment to be attached.

[0042] An independent power source that operates independently, which will be described later, is provided at the upper part of the working machine 3 attached to the working hitch device 4.

[0043] Insertion and removal of the battery, startup operation of the power source of the working machine 3, operation switching lever of the working machine 3, etc. are all centralized on the left side of the machine body. Also, as described above, a space 17 through which a harness can pass is provided at the center of the machine body from the front to the rear of the machine body.

[0044] All parts behind the main battery 7a are configured to be within 150 mm in height from the outer peripheral surface of the crawler 15, and a layout is provided with a space where other components can be mounted for use in transport carts, harvesting work vehicles, etc.

[0045] The positional relationship of the front hitch 6 is the position that first touches the ground when the machine body tilts forward and backward, and when a bumper is attached, it is the position that first collides when the machine body collides with something. Also, a tail wheel can be attached to the front hitch 6, and even when traveling on a sloping road with the tail wheel attached to the working machine 3, by grounding the tail wheel, a stable running configuration is achieved even on slopes. The control device 9 is arranged at the position farthest from the engine and motor that generate noise.

[0046] The working hitch device 4 can mount a rotary working machine, a ridge forming machine, a control machine, a transplanter, a seeder, a harvester, a weeding machine, a transport cart, etc.

[0047] The working machine 3 that moves up and down, for example, a tiller, has an independent power (internal combustion engine) provided therein, and as shown in FIG. 2, it touches the ground in a rearwardly tilted state (10 degrees) in the lowest state, and as shown in FIG. 10, it is attached so as to be in a forwardly tilted state (31.4 degrees) in the highest state.

[0048] The link component 20 on the vehicle body 1 side is composed of a lift arm 20c, a lift link 20d, a lower link 20b, and a top link 20a. When viewed from the outside of the machine body, the lift arm 20c and the lower link 20b are on the same plane, the lift link 20d is arranged inside thereof, and the top link 20a is arranged further inside.

[0049] As described above, the center of gravity will differ depending on the work equipment 3 attached, but by adding balance weights, etc., the center of gravity is located below the drive motor and above the two fixed road wheels, with the left and right sides in the center of the machine body.

[0050] Figure 11 is a drawing of the work hitch device 4.

[0051] As described above, the vehicle body 1 is equipped with a link component 20 consisting of a top link 20a and a lower link 20b that can rotate up and down, but the work hitch device 4 has a hitch body 4a with a U-shaped cross-section, a top link shaft 4b attached to the upper part of the hitch body 4a, and a lower link shaft 4c attached to the lower part of the hitch body 4a.

[0052] The work hitch device 4 is configured to be vertically rotatable, with the top link 20a connected to the top link shaft 4b and the lower link 20b connected to the lower link shaft 4c.

[0053] The hitch body 4a, which has a U-shaped cross-section, has a bracket 4d with a U-shaped vertical cross-section on its rear side, and a bearing piece 4e is erected on the upper part of the bracket 4d. In addition, a hole 4d1 is drilled in the lower part of the bracket 4d, and the work hitch device 4 is attached to a predetermined location on the main body of the work machine 3 using this hole.

[0054] As shown in Figures 12 to 14, the work machine 3 is provided with a hitch mounting device 21 for fixing an independent prime mover. The hitch mounting device 21 is connected to the work hitch device 4 using a hole 4f provided in the upper part of the work hitch device 4. The hitch mounting device 21 is provided with a top plate 21a (see Figure 15) for fixing the prime mover. The top plate 21a is provided with four elongated holes 21a1, which allow for adjustment of assembly errors of the power source and the tension of the belt, which will be described later.

[0055] In Figures 12 to 14, the work hitch device 4 is depicted on the work implement 3 side for illustrative purposes, but as shown in Figure 8, it is mounted on the vehicle body 1 side via a link component 20. As shown in Figures 8, 11, and 14, the left insertion pin 3hL and the right insertion pin 3hR formed on the work implement 3 side are inserted into and connected to the left receiving portion 4hL and the right receiving portion 4hR formed on the work hitch device 4 side. The work implement 3 is connected to the bracket 4d, which is configured on the work hitch device 4 side, by inserting a kingpin (not shown) from above and below.

[0056] Furthermore, a rear bracket 21b is provided at the lower rear of the top plate 21a for fixing to the hole position on the rotary 22 side. Two holes 21b1 for mounting the Z rotary are provided in each of the rear brackets 21b, and a reinforcing plate 21b2 is provided between the rear brackets 21b for reinforcement in the left-right direction. A gap S is provided in the reinforcing plate 21b2 between it and the top plate 21a for fingers or tools to enter. The lower end of the reinforcing plate 21b2 is positioned above the position of the holes 21b1.

[0057] Front brackets 21c are provided on the left and right sides of the top plate 21a, below the front and in front of the rear bracket 21b, for attachment to the work hitch device 4. The front brackets 21c are provided with elongated holes 21c1 for attachment via pins to holes 4f provided in the upper part of the work hitch device 4, allowing adjustment of the mounting position and distance between the axes of the power source. The front brackets 21c are also provided with a circular cutout shape 21c2 to match the shape of the upper end of the gear case 23 of the rotary 22, which will be described later. Reinforcing plates 21c3 are provided between the front brackets 21c for lateral reinforcement.

[0058] A gear case 23 is provided that transmits power from a power source located on the top plate 21a of the hitch mounting fixture 21 via a belt 27, reverses the direction of rotation, reduces the rotational speed, and transmits power to the rotary 22.

[0059] As shown in Figures 16 and 17, the gear case 23 is provided with two symmetrical gear case parts 23-1 and 23-2 made of the same material. In part 23-1, an oil supply hole 23a for both oil supply and oil inspection is provided at the top of the center of the case. Below the oil supply hole 23a, a bearing receiving part 23b and an oil seal receiving part for fixing the shaft gear 23c for the rotary shaft are provided. Below the fixing part of the shaft gear 23c, a bearing receiving part 23f for receiving power from the power source and an oil seal receiving part, and a hole 23g for the output shaft of the shaft gear 23e are provided. Below the fixing part of the shaft gear 23e, a hole 23d for an oil drain is provided.

[0060] In the gear case component 23-2, a bearing receiving portion and an oil seal receiving portion for fixing the rotary shaft shaft gear (output shaft) 23c are provided below the groove for the oil fill port and oil inspection port at the top of the center of the case, and a hole is provided through which the shaft gear 23c passes. Below the fixing portion of the shaft gear 23c, a bearing receiving portion is provided to receive the shaft gear (input shaft) 23e that receives power from the power source.

[0061] Next, the shaft gear 23e is provided with a square shaft portion 23j to which a pulley for receiving power from a power source is attached. The shaft gear 23e is provided with a gear portion with fewer teeth than the gear portion of the shaft gear 23c. The gear portion provided in the shaft gear 23e is provided with bearing receiving steps on both sides.

[0062] As shown in Figure 18, a connecting case 24 is provided to connect the gear case 23 and an engine 26, which is an example of an internal combustion engine 26 (see Figures 13 and 14). The connecting case 24 serves as both an axis gauge for the gear case 23 and a lateral gauge for the engine 26.

[0063] Flange portions 24a and 24b are provided on both sides to provide strength for fixing the engine 26 and the gear case 23. Power is transmitted from the engine 26 to the gear case 23 by a belt 27, and a hole 24c for attaching a tension spring device that can adjust the tension of the belt 27 is provided in one of the flange portions 24b.

[0064] The upper part of the connecting case 24 is provided with a recess 24d shaped to accommodate the engine output shaft, and two holes 24e, 24e for engine mounting. Furthermore, a hole 24f is provided in the center, sized so as not to interfere with the engine oil drain bolt.

[0065] Furthermore, a hole 24g is provided at the bottom for attachment to a recessed portion of the gear case 23, and a notch 24h is provided that follows the outer shape of the gear case 23. A reinforcing flange 24i is provided on the back side for reinforcement in the opposite direction to the flange direction.

[0066] As shown in Figures 13 and 14, a central shaft 29 is passed through holes in both the gear case 23 and the connecting case 24, and the two are fastened together, with this point serving as the pivot point to realize a tension mechanism that applies tension to the drive belt. Figure 19 shows the components of this tension mechanism. A tube 28a for rotation is provided at the bottom, and a pin 28b for attaching a pulley that applies tension to the belt 27 is provided at the top. Furthermore, two grooves 28b1 are provided for attaching retaining rings that fix the position of the pulley on the pin 28b.

[0067] Furthermore, a plate 28c is provided with a hole for attaching a clutch spring or the like when connecting the tube 28a and the pin 28b and applying tension. The portion of the plate 28c to which the tube 28a is attached is cut out in an arc shape, 28c1. The portion to which the pin 28b is attached is provided with a hole 28c2, and the holes in the cutout 28c1 and 28c2 are on the same center line.

[0068] When fastening the tube 28a together with the central shaft 29, the central shaft 29 is provided with a stepped portion that is longer than the tube 28a, as shown in Figure 20.

[0069] On the other hand, the tension of the spring 31 can be adjusted by placing the spring 31 through a hole 28c3 formed near the center of the plate 28c and attaching the spring 31 to the hole 24c of the flange of the connecting case 24 using an I-bolt 30.

[0070] As described above, the work vehicle according to the embodiment of the present invention is equipped with a first prime mover (specifically an electric motor) and a second prime mover (specifically an internal combustion engine), and is equipped with a first power source (main battery) dedicated to the first prime mover and a second power source (fuel tank 32) dedicated to the second prime mover. With this configuration, it is possible to operate for a long time.

[0071] Figure 21 shows a configuration in the operation program of a work vehicle that is operated by the remote controller R. This allows for reduced fatigue through remote operation, making it possible to easily perform work even in hard-to-reach places such as under trees in orchards.

[0072] Specifically, the remote controller R is equipped with LEDs that light up in multiple colors. Main transmission D1 is assigned to button R1, and pressing button R1 at any time during operation changes the travel speed to the work speed, which is set to 0.5 km / h. Main transmission D2 is assigned to button R2, and pressing button R2 at any time during operation changes the travel speed to the work speed, which is set to 1 km / h. Main transmission D3 is assigned to button R3, and pressing button R3 at any time during operation changes the travel speed to the work speed, which is set to 2.3 km / h. Main transmission D4 is assigned to button R4, and pressing button R4 at any time during operation changes the travel speed to the work speed, which is set to 4.6 km / h.

[0073] In normal mode, pressing button R5 moves the aircraft forward, and releasing button R5 stops the aircraft. Pressing button R6 moves the aircraft backward, and releasing button R6 stops the aircraft. Pressing button R7 performs a pivot turn to the left, using the aircraft's center as the axis, and releasing button R7 stops the aircraft. Pressing button R8 performs a pivot turn to the right, using the aircraft's center as the axis, and releasing button R8 stops the aircraft. Pressing button R5 and button R7 simultaneously causes the aircraft to move forward while turning left using the left running section as the pivot point, and releasing either or both buttons stops the aircraft. Pressing button R5 and button R8 simultaneously causes the aircraft to move forward while turning right using the right running section as the pivot point, and releasing either or both buttons stops the aircraft. By pressing button R6 and then button R7, the aircraft will move backward while simultaneously turning left using the left track as a pivot point. Releasing either or both buttons will stop the aircraft. In normal mode, by pressing button R6 and then button R8, the aircraft will move backward while simultaneously turning right using the right track as a pivot point. Releasing either or both buttons will stop the aircraft.

[0074] Furthermore, the operation mode can be changed by pressing button R9, and the LED light on the remote controller R will flash. Pressing button R9 switches the operation method only for buttons R5 and R6, and the operation continues even after releasing buttons R5 and R6 respectively.

[0075] The operation mode can be changed by pressing button R10, and the LED on the remote controller R will light up. Pressing button R10 switches the operation method only for buttons R5 and R6, and the operation stops when you release your hand after pressing buttons R5 and R6 respectively.

[0076] Pressing button R11 resets the main transmission to zero and also engages parking. Pressing button R11 also resets the data for each communication, allowing you to return to normal operation if you notice any issues with the system's sensitivity or other malfunctions.

[0077] Pressing button R12 allows you to pair and unpair the controller with this device.

[0078] 1. Each of the four main gear buttons has a predetermined speed, such as the optimal speed for tilling work. These buttons are used when you need to adjust the speed arbitrarily, such as in important locations or when you want to switch speeds instantly.

[0079] 2. Regarding the variable speed lever L2, the speed increases while the lever is raised and decreases while the lever is lowered relative to the current speed.

[0080] 3. Sharing is a method for pairing the controller with this device. For the initial connection only, it resets the controller's pairing history and searches for a pairing target.

[0081] 4. Mode Change (C): The (C) stands for CLICK, and this mode allows the device to continue the previously instructed action even after you release the button once. This is useful in situations where you don't need to press buttons often, such as during long-distance travel. In other words, once you press the mode (c) button, the device will move when you operate other buttons or levers, and it will continue moving even after you stop operating the buttons or levers.

[0082] 5. Mode Change (P): The (P) stands for PUSH, and the action corresponding to the button is performed only while the button is pressed. The aircraft automatically stops when you release the button, making it a very safe mode. In other words, once you press mode (p), the aircraft will only move while you are operating other buttons or levers, and will stop when you stop operating the buttons or levers.

[0083] 6. The reset button instantly returns the aircraft to its initial startup state in cases such as when the set flight speed is lost, a communication problem occurs, or an alert is issued. However, in the case of an alert that has a significant impact on the aircraft, the reset button cannot be used to return to the initial state. The same applies to emergency stops.

[0084] 7. To unpair, disconnect the connection between this unit and the controller and turn off the controller's power. Turning off this unit's power will also unpair the devices, but the controller will remain powered on for a while to search for the lost communication signal and will not immediately turn off.

[0085] As described above, a remote controller R is provided for remotely operating the traveling device 2 and the work implement 3. The remote operation includes at least emergency stop operation and travel speed adjustment operation of the traveling device 2, and lifting and lowering operation of the work implement 3. An emergency stop mechanism for emergency stop operation of the traveling device 2 is also provided on the vehicle body 1.

[0086] The following describes the detailed configuration of vehicle body 1 and the operation of work implement 3.

[0087] Figures 23 and 24 are perspective views of the work vehicle in the lowest position according to an embodiment of the present invention, viewed from the link component 20, and Figure 25 is a plan view. Here, by pulling the rod 18a of the cylinder 18 as far forward as possible and pulling the U-shaped bracket 20f forward, the horizontal shaft 20e is rotated, which in turn rotates the lift arm 20c and the lift link 20d, thereby lowering the lower link 20b to its lowest position, and consequently the top link 20a is also lowered to its lowest position, resulting in the work hitch device 4 being in its lowest position.

[0088] Here, the method for determining the length and position of the lower link 20b and the top link 20a will be explained based on Figure 24.

[0089] Let (A) be the pivot point where the lower link 20b supports the work hitch device 4, (B) be the pivot point of the lower link 20b, (C) be the pivot point where the top link 20a supports the work hitch device 4, and (D) be the pivot point of the top link 20a.

[0090] With the work implement in the lowest position (lowest position) within the above working range, the length of the lower link 20b and the positions of the pivot point (A) on the vehicle body 1 side and the pivot point (B) on the work hitch device 4 side of the lower link 20b are determined. Furthermore, the size, position, and orientation of the work hitch device 4 are determined, and the top link 20a is set parallel to the lower link 20b, and the pivot point (C) of the top link 20a on the work hitch device 4 side is determined. Furthermore, the pivot point (D) of the top link 20a on the vehicle body side is determined at a position where the length of the top link 20a is shorter than the length of the lower link 20b. The position of the pivot point (D) is then appropriately determined according to the distance from the lowest position to the upper position within the working range.

[0091] Figure 26 is a left side view of the work vehicle with the tiller 3 of the embodiment of the present invention in the upper limit position of the working range, Figure 27 is a perspective view of the same state, looking up from below with the link component 20 as the center, and Figure 28 is a perspective view of the same from the rear and above. Here, the working range refers to the range from the lowest position of the tiller 3 in Figure 22 (lower limit position of the working range) to the tilling position just before it approaches the ground in Figure 26.

[0092] By extending the rod 18a of the cylinder 18 a predetermined amount backward and moving the U-shaped bracket 20f a predetermined amount backward, the horizontal shaft 20e is rotated, causing the lift arm 20c and lift link 20d to rotate, which brings the lower link 20b to a nearly horizontal position, and consequently the top link 20a to a slightly inclined position, resulting in the work hitch device 4 being raised to a middle position.

[0093] Figure 29 is a left side view of the work vehicle with the tiller 3 of the embodiment of the present invention in its highest position, Figure 30 is a perspective view looking up from below with the link component 20 as the center in that state, Figure 32 is a perspective view looking up from the rear above, and Figure 33 is a further enlarged view.Here, by extending the rod 18a of the cylinder 18 as far rear as possible and moving the lower end of the U-shaped bracket 20f as far rear as possible, the horizontal shaft 20e is rotated greatly, causing the lift arm 20c and lift link 20d to rotate, which puts the lower link 20b in an upward diagonal rearward position, and consequently the top link 20a rotates greatly to become almost vertical, resulting in the work hitch device 4 and work implement 3 being in a state where they are raised to their maximum height and rotated.

[0094] Figure 34 is a schematic diagram showing the movement of the lower link 20b and the top link 20a. Figure 34(A) shows the positional relationship between the lower link 20b and the top link 20a when the tiller 3 is at the lower limit position in the working range. Figure 34(B) shows the positional relationship between the lower link 20b and the top link 20a when the tiller 3 is at the upper limit position in the working range. Figure 34(C) shows the positional relationship between the lower link 20b and the top link 20a when the tiller 3 is at the highest position above the working range.

[0095] As is clear from the diagram, the tiller 3 moves almost vertically up and down within the working range, and when it leaves the working range and comes above, it makes a large turn, the lower end of the tiller 3 rises rapidly, and its upper end approaches the vehicle body 1 quickly, making the entire work vehicle compact and stabilizing the center of gravity, so that the lower end of the tiller 3 does not hit the ridge or other obstacles during high-speed turns, and it quickly becomes suitable for turning on ridges and other obstacles.

[0096] Furthermore, since the lifting speed of the implement 3 during tilling is slower than the speed at which the implement 3 moves out of the working range and rotates upward, the tilling depth can be adjusted with precision.

[0097] The following describes an embodiment in which the work equipment 3 attached to the rear of the vehicle body 1 is a cargo bed device 3N.

[0098] As shown in Figures 35 and 36, a vehicle body 1 is mounted on a crawler-type running gear 2, a cargo bed device 3N is positioned behind the vehicle body 1, and a work hitch device 4 connects the vehicle body 1 and the cargo bed device 3N.

[0099] This work vehicle is an electrically operated, radio-controlled vehicle, and is configured to transport containers, soil, harvested produce, etc., by connecting a cargo bed device 3N to a lifting work hitch device 4 that can be raised and lowered.

[0100] The link components 20 on the vehicle body 1 side consist of a lift arm 20c, a lift link 20d, a lower link 20b, and a top link 20a. In a plan view of the vehicle body, the lift arm 20c and the lower link 20b are on the same plane, with the lift link 20d positioned inside them, and the top link 20a positioned further inside.

[0101] The length of the top link 20a is shorter than the length of the lower link 20b, and the tilt position of the cargo bed device 3N can be changed by the vertical rotation of the work hitch device 4. This allows the cargo bed device 3N to change from a horizontal position to a rearward tilt position. The base of the top link 20a and the base of the lower link 20b (rotation pivot point 20b1) are positioned relative to the front-rear direction, with the base of the top link 20a being shifted rearward compared to the base of the lower link 20b (rotation pivot point 20b1), making it easier for the cargo bed device 3N to assume a horizontal position when raised. The connection pivot point 20a2 on the work hitch device 4 side of the top link 20a is indicated by 20a2, and the connection pivot point 20b2 on the work hitch device 4 side of the lower link 20b is indicated by 20b2. The connection pivot point 20a2 on the work hitch device 4 side of the top link 20a is the top link shaft 4b shown in Figure 41. The connecting pivot point 20b2 on the working hitch device 4 side of the lower link 20b is the lower link shaft 4c shown in Figure 41.

[0102] Furthermore, because the loading platform 3N is tilted abruptly when changed from a horizontal position to an inclined position, the soil and other materials loaded on the loading platform 3N can be discharged quickly.

[0103] The top link 20a and the lower link 20b can be rotated vertically using a cylinder 18 or the like. A hydraulic cylinder may be used instead of the cylinder 18.

[0104] In this way, with the work hitch device 4 in its highest position, the cargo bed device 3N of the work vehicle becomes horizontal to the machine body. The work hitch device 4 is originally configured to also be able to accommodate a tiller 3. When a tiller 3 is attached to the work hitch device 4, raising the work hitch device 4 to its highest position causes the tiller 3 to be in a non-working position and at its highest raised position, as shown in Figure 37. This makes it easier to mount the cargo bed device 3N by configuring it so that the cargo bed device 3N can be attached to the vehicle body 1 in a nearly horizontal position when the tiller 3 is at its highest raised position.

[0105] When the work hitch device 4 is lowered to its lowest position, the tiller 3 is in the working position, which is its maximum lowered position (maximum tilling depth position).

[0106] When the rod 18a of the cylinder 18 is pulled in the P direction while it is in the highest position, the U-shaped plate moves in the P direction with the U-shaped pivot axis 40a as the pivot point. As a result, the pivot axis 40a rotates, and the lower link 20b, top link 20a, and work hitch device 4 move via the lift arm 20c and lift link 20d to the lowest position.

[0107] As shown above, when the trailer is in the state of the tilling device shown in Figure 10 (maximum height), attaching the cargo bed device 3N to the work hitch device 4 results in the position of the cargo bed device 3N shown in Figure 37. This makes it easier to mount the cargo bed device 3N horizontally. Furthermore, when the trailer is in the state of the tilling device shown in Figure 22 (lowest position), attaching the cargo bed device 3N to the hitch device results in the position of the cargo bed device 3N shown in Figure 38.

[0108] The cargo bed device 3N tilts backward relative to the machine body as the work hitch device 4 moves from its highest to lowest position. As will be described later, the rear door 3Nb opens automatically, providing a dumping function.

[0109] The cargo bed 3N is positioned behind the battery box 7. The top plate 3Na of the cargo bed 3N is positioned below the top surface 7b of the battery box 7 in the transport state (see Figure 37). The top plate 3Na of the cargo bed 3N is positioned above the motor and sub-battery in the transport state, and the center of gravity is positioned as low as possible on the underside of the aircraft. In Figure 39, the running gear 2 has a left running section and a right running section, and the electric motor consists of a left motor section 2a that drives the left running section and a right motor section 2b that drives the right running section. 19 is the sub-battery box.

[0110] The cargo bed device 3N is broadly composed of various parts, each of which can be easily fixed and assembled by inserting a pin.

[0111] Since this invention provides a work vehicle with a longer power supply duration, it is ideal for work vehicles equipped with implements such as cultivators that perform various tasks.

Claims

1. A work vehicle comprising a vehicle body, a running gear attached to the vehicle body, a work implement, and a work hitch device connecting the vehicle body and the work implement; a first prime mover for driving the running gear and a second prime mover for driving the work implement; and a first power source dedicated to the first prime mover and a second power source dedicated to the second prime mover.

2. The work vehicle according to claim 1, characterized in that the first prime mover is an electric motor, the first power source is a battery, the second prime mover is an engine, and the second power source is fuel.

3. The work vehicle according to claim 2, wherein the traveling device has a left traveling section and a right traveling section, and the first prime mover is composed of a left motor section that drives the left traveling section and a right motor section that drives the right traveling section.

4. The work vehicle according to claim 3, comprising a work machine that rotates up and down by a lift mechanism, characterized in that, within the working range of vertical movement of the work machine during operation, the change in the forward and backward tilt posture of the work machine is small within the working range, and large in the area above the working range.

5. The work vehicle according to claim 4, characterized in that, within the working range of vertical movement of the work machine during operation, the rotational speed of the work machine is slower than the rotational speed above the working range.

6. The work vehicle according to any one of claims 1 to 5, wherein, in addition to the first power source, another battery is provided to serve as a power source other than the running gear.

7. The work vehicle according to claim 6, wherein the first power source is located at the front of the vehicle body, and the work machine is located at the rear of the first power source.

8. The work vehicle according to claim 7, wherein the traveling device and the work machine are configured to be remotely controllable, and the traveling device is provided with an emergency stop mechanism that allows it to be stopped remotely, and in addition to the remote emergency stop mechanism, an emergency stop mechanism for the traveling device is also provided on the vehicle body.

9. The work vehicle according to claim 1, wherein a remote controller is used for remote operation, and the remote controller includes at least an operating device for emergency stop operation and travel speed adjustment operation of the travel device, and for raising and lowering operation of the work machine.

10. The work vehicle according to claim 1, wherein the running gear is a running gear that utilizes an endless track belt.

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