Work vehicle

Abstract

To solve the problem that crawler type travel parts are greatly inclined in the front and rear directions relative to unevenness of a field because they are long in the front and rear direction, and the inclination in the right and left directions causes not only inclination of a vehicle body but also twisting, the position of a work machine is not located at a target position, an unplowed land is generated in plowing work, and crops cannot be recovered in harvesting work.SOLUTION: A work vehicle includes travel parts which are independent on the right and left sides, absorbs vibration and twisting in unevenness of a field by a rocker link mechanism, and reduces influence on a body frame.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a travel configuration for an unmanned work vehicle having a crawler travel section that travels while reducing vibrations caused by unevenness in a farm field. [Background technology]

[0002] There is a work vehicle in which the left and right track frames are divided into front and rear halves, and the front and rear track frames are able to move up and down independently with their midpoints in the front and rear as fulcrums. (Patent Document 1) [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 9-193850 Summary of the Invention [Problem to be solved by the invention]

[0004] In the prior art, there is a vibration reduction technology in which the left and right track frames are divided into front and rear halves, and the front and rear track frames are made movable up and down independently with their midpoints at the front and rear as fulcrums.

[0005] However, simply dividing the track frame into front and rear halves and configuring them to be able to move up and down independently prioritizes contact with the field, so even if vibrations to the main body of the work vehicle are reduced, it cannot be said that it is sufficient to deal with tilting or twisting of the main frame.

[0006] An object of the present invention is to provide a work vehicle that is configured to respond to tilting and twisting throughout the entire work vehicle and also supports vibration reduction. [Means for solving the problem]

[0007] The first aspect of the present invention is achieved by the following technical means.

[0008] A rocker link mechanism 20 that connects the left crawler ASSY 30 and the right crawler ASSY 50 is provided above the independent running parts of the left crawler ASSY 30 and the right crawler ASSY 50, and the rocker link mechanism 20 is rotatable on both plane B that is parallel to the ground and plane A that is perpendicular to the ground. Above the rocker link mechanism 20, the main body frame 10 of the work vehicle is fixedly connected to the center of the front part in the running direction, and the left crawler ASSY 30 and the right crawler ASSY 50 are driven by independent electric motors for running.

[0009] The second invention is solved by the following technical means.

[0010] A gauge wheel 110 is attached to the center of the rear part in the running direction of the main body frame 10 of the work vehicle, and the length of the gauge wheel 110 is automatically changed by a damper mechanism to automatically follow the running posture of the main body frame 10.

[0011] The third aspect of the invention is solved by the following technical means.

[0012] The cage wheel 120 is attached to a connecting arm 131 of a working machine 130 of a work vehicle, and is connected to the center of the rear part of the main body frame 10 in the traveling direction. [Effects of the Invention]

[0013] The first invention configures the running section with independent power sources on the left and right, allowing the left and right sides to respond independently to changes in the unevenness of the field, while the rocker link mechanism absorbs vibrations and twists, reducing the impact on the main frame.

[0014] According to the second aspect of the present invention, it is possible to reduce vibrations when the amount of deformation of the main body frame is large and it is difficult for the rocker link mechanism to absorb the vibrations.

[0015] According to the third aspect of the present invention, when a work implement is attached, it is possible to reduce the vibration of the work implement and also reduce the influence of vibration of the work vehicle body. [Brief explanation of the drawings]

[0016] [Figure 1] FIG. 1 is an overall perspective view of a work vehicle according to the present invention, seen from the left front; [Figure 2] FIG. 1 is a perspective view of the overall construction vehicle of the present invention, seen from the front left and above; [Figure 3] FIG. 1 is an overall perspective view of a work vehicle according to the present invention, seen from the left rear; [Figure 4] Left side view of the work vehicle of the present invention [Figure 5] FIG. 1 is a perspective view of a work vehicle of the present invention equipped with a gauge wheel and a front work device. [Figure 6] FIG. 1 is a perspective view of a working machine according to the present invention with a gauge wheel attached thereto; [Figure 7] 1 is a top perspective view of a work vehicle of the present invention equipped with a work implement having gauge wheels; [Figure 8] FIG. 1 is a perspective view showing the internal structure of a crawler portion of a work vehicle according to the present invention; DETAILED DESCRIPTION OF THE INVENTION

[0017] The present invention will be described below with reference to the embodiments shown in the drawings.

[0018] The work vehicle shown in FIGS. 1 to 8 shows an example of this embodiment.

[0019] The background and configuration of the work vehicle of the present invention will be described.

[0020] This is a general-purpose electric unmanned vehicle, also known as a robotic work vehicle, used in field farming. Field farming does not become muddy like paddy fields, but the soil is often ridged and soft to make it easier for root vegetables to grow. Because it contains a lot of moisture, wheels can slip when traveling on wheels, so a crawler-type vehicle is preferred.

[0021] However, because the crawler-type running gear is long from front to back, it can tilt significantly forward and backward when the field is uneven. The left-right tilting also causes not only the vehicle body to tilt but also twisting, which can cause the implement to miss its target position, resulting in uncultivated land during tilling work and the inability to retrieve crops during harvesting work. Twisting of the main frame also weakens the vehicle's durability.

[0022] To address these issues, a rocker link mechanism that absorbs vibrations and twists between the running unit and the main frame, additional gauge wheels that support the vehicle, and gauge wheels on the work equipment itself are installed.

[0023] The configuration of the crawler assembly and rocker link mechanism of the traveling portion of the work vehicle of the present invention will be described with reference to Figs.

[0024] The left crawler assembly 30 and right crawler assembly 50 are configured as separate left and right units. In the left crawler assembly 30, the left swing arm 21 and left link rod 22 are connected to a boss hole 23A on the left side of the rocker arm 23. In the left crawler assembly 50, the right swing arm 27 and right link rod 28 are connected to a boss hole 23B on the right side of the rocker arm 23. Bearings are fitted into the left and right boss holes, allowing the left link rod 22 and right link rod 28 to rotate relative to the rocker arm 23 on plane B parallel to the ground. In this way, the left and right crawler assemblies twist via the left and right link rods and left and right rocker arms to form a crawler travelling body that ensures ground contact.

[0025] At the centre of rocker arm 23, on plane A perpendicular to plane B parallel to the ground, there is a boss hole 23C on the side facing the direction of travel of the work vehicle, and there is a bearing inside, into which shaft 24A extending from one end of connecting link plate 24 is inserted, allowing link plate 24 to rotate on plane A perpendicular to the ground. The other end of link plate 24 is joined to main body frame 10 of work vehicle 1, and link plate 24 can rotate main body frame 10 on plane B parallel to the ground.

[0026] The left swing arm 21, left link rod 22, rocker arm 23, right link rod 28, and swing arm 27 are arranged in a series that can move freely in both horizontal and vertical directions relative to the ground surface. As a result, the left crawler assembly 30 and the right crawler assembly 50 can move freely in both horizontal and vertical directions independently relative to the ground surface, allowing them to twist to accommodate vibrations while maintaining contact with the ground in response to unevenness in the field.

[0027] Each joint is a bearing mechanism, but it may be one that reduces rotational resistance to an absolute minimum, and by providing a certain degree of rotational load, it is possible to absorb and mitigate minute movements, thereby achieving an anti-vibration effect.

[0028] Of these, by applying a rotational load to each bearing section, the left swing arm 21, left link rod 22, rocker arm 23, right link rod 28, and swing arm 27 are configured in series to form a link mechanism that can be used as a power transmission configuration, a frame configuration for the work vehicle itself, and a vibration reduction configuration; this is also a rocker link mechanism or rocker bogie mechanism, and in the present invention is referred to as rocker link mechanism 20.

[0029] Rocker link mechanism 20 rotates about boss hole 23C relative to plane A, which is perpendicular to the ground surface, and rotates about boss holes 23A and 23B relative to plane B. If plane C is defined as a plane that follows the side of the work vehicle and intersects planes A and B perpendicularly, the joint between left swing arm 21 and left link rod 22 is joined by a universal joint, and can rotate in multiple directions by joint ball 22A. The joint between right swing arm 27 and right link rod 28 is also joined by a universal joint, and can rotate in multiple directions by joint ball 28A. This universal joint can be used to tilt work vehicle 1 forward or backward, and can also be used to adjust vehicle height.

[0030] A working mechanism 60 is connected to the center of the main body frame 10. A parallel frame 62 is placed between a left support frame 61 and a right support frame 63, forming a portal frame. The left and right support frames are mechanisms that rotate within a predetermined range with respect to plane C at joints 61A and 63A.

[0031] A slide rail 64 is provided in front of the parallel frame 62. Although not shown in the figure, the slide rail 64 is a mechanism that can rotate at the center of the parallel frame 62, and is a mechanism that allows the work vehicle 1 to face horizontally relative to the ground even if it tilts in the rotation direction on plane A.

[0032] As shown in Figure 3, a forward-facing working machine 70 is attached to the slide rail 64. The working machine 70 is a robotic hand, but it can also be a harvesting device with a reaping section, and various working machines can be attached, and by moving it in line with the slide rail 64 inside the working mechanism 60, which is a gate-shaped frame, it is possible to perform optimal work.

[0033] Figure 4 is a side view of the work vehicle 1 as seen from the left side. The rocker link mechanism 20 is sandwiched vertically between the left crawler ASSY 30, which is the running part, and the main body frame 10. Because of this mechanism, the rocker link mechanism 20 absorbs the effects of the field on the left and right crawler ASSY, which are the running parts, making it less likely to be affected by the main body frame 10.

[0034] Although this configuration is designed to reduce vibrations, if the left and right crawler assemblies change significantly when they move in a way that perfectly follows the amount of change, it will take time for them to return to their original positions, and not only will they not be able to follow the next change, but the amount of change may be so large that it could actually increase vibrations. Therefore, it is necessary to set a limit on the amount of change in order to follow it.

[0035] This limiting function is built into the structure of the rocker link mechanism 20. The maximum amount of change in torsion between the left crawler assembly 30 and the right crawler assembly 50 is limited to the maximum range of movement by joint ball 22A and joint ball 28A. This is addressed by providing a fixed claw on the outer periphery of the range of movement within the universal joint, preventing further movement. This prevents any movement that would eliminate twist more than necessary.

[0036] The left swing arm 21 and the right swing arm 27 are located midway between the left and right crawler units in the front-to-rear direction. Therefore, the angle change when climbing is the same whether moving forward or backward, and the structure is such that shaking due to changes in the ground surface is minimized. This structure is also a measure to minimize the amount of change.

[0037] The configuration for controlling the working posture of the main body frame 10 of the work vehicle 1 will now be described.

[0038] This control is achieved by a structure that tilts the rocker link mechanism 20 and main body frame 10, as shown in Figures 1 and 2. In the rocker link mechanism 20, a pitching cylinder 25 is connected between the left link rod 22 and the left crawler assembly 30. The pitching cylinder 25 is configured hydraulically or the like, and the internal cylinder extends and retracts to adjust its overall length, allowing the main body frame 10 of the work vehicle 1 to be tilted forward or backward, as explained above. A similar mechanism is used to connect the pitching cylinder 26 between the right link rod 28 and the right crawler assembly 50, allowing different movements to occur left and right.

[0039] The attitude control during driving will be explained.

[0040] During normal running, the twisting action of the rocker link mechanism 20 allows the vehicle to follow the ground, and the pitching cylinders 25 and 26 control the forward and backward tilt of the vehicle body, making it possible to change the working height of the work vehicle.

[0041] This section explains how to install and remove the crawler assembly and how to maintain it.

[0042] The left and right crawler assemblies can be attached and detached using the left and right swing arms. The right crawler assembly 50 will be explained in Figure 3. There is a connecting shaft 29 below the right swing arm 27, and by removing this shaft, the right crawler assembly 50 can be removed from the work vehicle 1.

[0043] Crawler assemblies come in different shapes, and it is possible to change the vehicle height, the front-to-rear length, the width of the crawler assemblies, etc. Also, by changing the basic assembly angle of the left and right crawler assemblies relative to the left and right swing arms, it is possible to change the basic posture of the vehicle.

[0044] The electric motor for driving will be explained with reference to Figs. 1, 2 and 3.

[0045] Mounting plate 32 for travel motor 31, which provides the driving force for left crawler assembly 30, is located inside work vehicle 1, and transmits power to axle 34 via belt 33. Axle 34 rotates drive wheels 35, which in turn rotates lug belt 36 to provide driving power. Travel motor 31 is located above lug belt 36.

[0046] Similarly, a mounting plate 52 for a traveling motor 51 that provides the driving force for the right crawler assembly 50 is located inside the work vehicle 1, and power is transmitted to an axle 54 by a belt 53. The axle 54 rotates a driving wheel 55, which in turn rotates a lug belt 56 to provide traveling power. The traveling motor 51 is located above the lug belt 56.

[0047] In this way, the left and right travel motors are arranged on the left and right lug belts, so they do not get in the way when work equipment is placed inside the rear of the work vehicle 1. Conversely, if the left and right motors are placed outside the work vehicle 1, they will be outside the width of the vehicle body, so there will be no problem of them interfering with work.

[0048] The left and right travel motors are powered by battery power. The battery 81, together with a battery management system 82, which is a CPU that controls the power, is housed in a control case 80 that is dust-proof and water-proof. The control case 80 is provided at the rear of the main body frame 10.

[0049] As shown in Figure 2, area 90 in front of control case 80 is a location that can be used as a platform for cases of harvested crops. In each figure, the platform is not shown so that the interior can be seen, but by providing a platform in area 90, harvesting work can be done efficiently with the front implement 70, and by placing the weight of the harvested crops on area 90, it is possible to easily balance the weight with the rear control case 80.

[0050] As described above, the first invention has a crawler assembly with independent left and right running parts on the ground. Because these parts are powered independently by electric motors, it is possible to change the left and right rotation speeds and reverse the direction of rotation. Furthermore, they can also be tilted, twisted, and adjusted in height independently, allowing the crawler assembly to adapt to the unevenness of the field. However, if these independent running parts were the only option, the main body frame would twist and cause significant vibration. In this invention, a rocker link mechanism that can rotate both parallel and perpendicular to the ground is placed on top of the independent running parts, and the main body frame is placed above that. This allows the running parts to be in close contact with the field surface, while reducing vibration of the main body.

[0051] The gauge wheel configuration for stabilizing the running of a work vehicle according to the present invention will be explained with reference to FIG.

[0052] In order to make the running of the work vehicle 1 of the present invention even more stable, a gauge wheel 110 is provided in the center of the vehicle body, at the rear of the vehicle body, in the position forward where the rear work equipment is attached. The gauge wheel 110 has wheels 111 that rotate and come into contact with the field, and above these are dampers 112 and 113 that absorb vibrations. Further above, a link mechanism 114 that rotates while connecting dampers 112 and 113 is provided, and this link mechanism is joined to the main body frame 10. When the gauge wheel 110 is in contact with the ground, twisting of the crawler is suppressed, reducing twisting caused by slight unevenness or increases or decreases in drive torque.

[0053] The mounting position of the gauge wheel 110 can be adjusted as desired, and by adjusting the positions of the left and right crawler assemblies and the gauge wheel 110, it is possible to travel while moving away from the planting position of the crops.

[0054] When the gauge wheel 110 is placed on the ground during work, twisting of the left and right crawler assemblies is suppressed, but because it does not protrude excessively from the rear end position of the crawler, it does not interfere with the pitching of the entire running part.

[0055] It is also possible to provide a plurality of gauge wheels 110. For example, if gauge wheels are provided on the left and right, stable running is possible even when tilted.

[0056] A configuration in which the gauge wheel 120 is disposed on the work machine side will be described with reference to FIGS.

[0057] A gauge wheel 120 is positioned forward from the main machine connection part of the work implement 130 and is connected to the work vehicle 1 by a connecting arm 131. The connection position of the gauge wheel 120 to the work vehicle 1 can be moved as desired for connection.

[0058] It is also possible to install a rotary encoder inside the gauge wheel 120 to obtain wheel odometry and obtain the actual working distance.

[0059] With this function, if a gauge wheel is provided on the work equipment side, it becomes less susceptible to the pitching motion of the work vehicle 1.

[0060] In the second and third inventions, both involve the installation of gauge wheels equipped with dampers, but they are not simply wheels that are in contact with the left and right crawlers, but are positioned to actively reduce vibration. In other words, these work vehicles are equipped with work equipment at the rear or front of the vehicle. When traction is particularly required, the work equipment is attached to the rear of the vehicle, so the overall length of the vehicle including the work equipment should be considered. In this case, the position of the gauge wheels in the second and third inventions is near the center of the overall length of the work vehicle equipped with the work equipment. Placing the gauge wheels in this position can be extremely effective, and wheel marks left by the gauge wheels can sometimes be erased by the work equipment at the rear, making this an essential placement location.

[0061] The configuration of the crawler assembly will be explained.

[0062] As explained above, the left and right crawler units can be removed by pulling them outward on the left and right from the connecting shafts of the left and right swing arms. Because the running part can be removed without disassembling the rocker link mechanism 20, the standard vibration response mechanism is utilized. If the rocker link mechanism were disassembled to remove the running part, adjustments would have to be made each time the running part was attached, which would result in poor maintainability.

[0063] Figure 8 shows the main parts of the internal mechanism of the crawler assembly. This is characterized by the fact that, while it has a crawler structure, the longitudinal lug belts move differently front and rear to improve ground contact with uneven ground. This will be explained using the left crawler assembly 30.

[0064] Using crawler frame 40 as a reference, rear equalizer shaft 41B is provided with rollers 43 as pivot points 41A, allowing equalizer plate 41 to rotate. Similarly, front equalizer shaft 42B is provided with rollers 43 as pivot points 42A, allowing equalizer plate 42 to rotate. Equalizer plates 41 and 42 are connected at the pivot points by subframes 45 and 47, and are fixed to crawler frame 40 by pivot points 46.

[0065] With this configuration, equalizer plates 41 and 42 can freely rotate using fulcrum shaft 46 and pivot points 41A and 42A, allowing for different movements, and enabling roller 43 to adjust to the unevenness of the field. In this embodiment, the front driven wheel 44 is movable to accommodate the tension of the lug belt. Fixed rollers are also provided in some locations, but are not shown in the drawings of this embodiment.

[0066] A feature of this left crawler assembly 30 is that although the bending shape of the lug belt changes depending on the front and rear equalizers, the change in the basic positions of the driven wheels 44 and drive wheels 35 is small, so the tension of the lug belt is maintained within the range of the automatic tension. The right crawler assembly 50 has a similar configuration, with the left and right sides moving independently. [Explanation of symbols]

[0067] 1 Work vehicle 10 Main frame 20 Rocker link mechanism 30 Left crawler assembly 50 Right crawler assembly 60 Working mechanism 80 Control Case

Claims

1. A rocker link mechanism (20) is provided above the independent running parts of the left crawler ASSY (30) and the right crawler ASSY (50) to connect the left crawler ASSY (30) and the right crawler ASSY (50), The rocker link mechanism (20) is rotatable on both a plane (B) parallel to the ground and a plane (A) perpendicular to the ground, The vehicle body frame (10) is fixedly connected to the center of the front portion in the traveling direction of the vehicle body frame (10) above the rocker link mechanism (20), The left crawler assembly (30) and the right crawler assembly (50) are driven by independent electric motors, and the work vehicle moves.

2. A gauge wheel (110) is attached to the center of the rear portion of the main body frame (10) of the work vehicle in the traveling direction, The gauge wheel (110) automatically changes its length using a damper mechanism.

2. A work vehicle according to claim 1, which automatically follows the traveling posture of the main body frame (10).

3. 2. A work vehicle according to claim 1, wherein the cage wheel (120) is attached to a connecting arm (131) of the work implement (130) of the work vehicle and connected to the center of the rear part in the traveling direction of the main frame (10).

Images