Vehicle platform

Abstract

The present invention provides a platform for a vehicle. The platform includes: a first wheel and a second wheel; and a first orientation maintaining mechanism for moving the first wheel in the vehicle width direction and maintaining the orientation of the first wheel relative to the vehicle's longitudinal direction before and after the first wheel moves. The first orientation maintaining mechanism includes: a first central member disposed between the first wheel and the second wheel; a first wheel arm rotatably connected to the first central member and mounted on the first central member and supporting the first wheel; and a first rotation actuator for rotating the first wheel arm relative to the first central member to move the first wheel closer to or further away from the first central member.

Description

[0001] Cross-references to related applications

[0002] This application claims priority based on Japanese Patent Application No. 2022-007966 and Japanese Patent Application No. 2022-007984, filed on January 21, 2022, the entire contents of which are incorporated herein by reference. Technical Field

[0003] This invention relates to a vehicle platform constituting a self-propelled vehicle capable of transporting goods or moving people. Background Technology

[0004] As is known in the past, vehicle platforms constituting self-propelled vehicles include platforms capable of widening and narrowing the wheelbase. Here, "wheelbase" refers to the distance between the left and right wheels. For example, Japanese Patent Application Publication No. 2014-221612 discloses a vehicle frame device configured such that the wheelbase can be widened or narrowed by sliding annular members on the wheel sides on a main rotating shaft extending in the vehicle width direction.

[0005] However, the frame device described in Japanese Patent Application Publication No. 2014-221612 has the following problem: the vehicle cannot be driven when the distance between the left and right wheels (wheel track) is reduced, thus limiting the vehicle's use.

[0006] The present invention was made to solve the above-mentioned problems, and its object is to provide a vehicle platform that enables the vehicle to move even when the wheel spacing is reduced. Summary of the Invention

[0007] The vehicle platform of the present invention comprises: a first wheel disposed on one side of the vehicle width direction; a second wheel disposed on the other side of the vehicle width direction; a prime mover for driving the first wheel and the second wheel; and a first orientation maintaining mechanism for moving the first wheel in the vehicle width direction and maintaining the orientation of the first wheel relative to the longitudinal direction of the vehicle before and after the first wheel moves. The first orientation maintaining mechanism comprises: a central member disposed between the first wheel and the second wheel and supported by the first wheel and the second wheel; a first wheel arm mounted on the central member and the first wheel in a state of being rotatably connected to the central member and supporting the first wheel; and a first rotation actuator for rotating the first wheel arm relative to the central member to move the first wheel closer to or further away from the central member.

[0008] According to the vehicle platform of the present invention, the first rotation actuator of the first orientation maintaining mechanism rotates the first wheel arm relative to the center member, thereby bringing the first wheel closer to or further away from the center member. This allows the vehicle to move by widening or narrowing the gap (wheelbase) between the first wheel and the second wheel. Furthermore, since the first orientation maintaining mechanism maintains the orientation of the first wheel relative to the vehicle's longitudinal direction before and after the first wheel moves, the vehicle can be moved while maintaining the orientation of the first wheel even if the aforementioned gap changes.

[0009] According to a preferred embodiment of the present invention, the vehicle platform includes a second orientation maintaining mechanism that moves the second wheel in the vehicle width direction and maintains the orientation of the second wheel relative to the vehicle's longitudinal direction before and after the second wheel moves. The second orientation maintaining mechanism includes: a second wheel arm that is rotatably connected to the central member and mounted on the central member and the second wheel to support the second wheel; and a second rotation actuator that rotates the second wheel arm relative to the central member to move the second wheel closer to or further away from the central member.

[0010] According to the above method, the second rotation actuator of the second orientation maintaining mechanism rotates the second wheel arm relative to the center member, so that the second wheel approaches or moves away from the center member. This allows the vehicle to move by widening or narrowing the gap (wheelbase) between the first and second wheels. Furthermore, since the second orientation maintaining mechanism maintains the orientation of the second wheel relative to the vehicle's longitudinal direction before and after the second wheel moves, the vehicle can move while maintaining the orientation of the second wheel even if the aforementioned gap changes.

[0011] According to a preferred embodiment of the invention, the first orientation maintaining mechanism includes a first support shaft disposed on the central member and extending in a vertical direction, and providing rotatable support for the first wheel arm.

[0012] According to the above method, the first wheel arm can be easily rotated relative to the central component with the first support shaft as the center.

[0013] According to a preferred embodiment of the invention, the second orientation maintaining mechanism includes a second support shaft disposed on the central member and extending in a vertical direction, and providing rotatable support for the second wheel arm.

[0014] According to the above method, the second wheel arm can be easily rotated relative to the central component with the second support shaft as the center.

[0015] According to a preferred embodiment of the present invention, the first orientation maintaining mechanism comprises: a first support shaft disposed on the central component and extending vertically, and rotatably supporting the first wheel arm; and a first wheel support member rotatably connected to the first wheel arm and providing the first wheel; the second orientation maintaining mechanism comprises: a second support shaft disposed on the central component and extending vertically, and rotatably supporting the second wheel arm; and a second wheel support member rotatably connected to the second wheel arm and providing the second wheel; the first rotation actuator and the second rotation actuator cause the first wheel arm to rotate about the first support shaft, thereby rotating the first wheel support member, and cause the second wheel arm to rotate about the second support shaft, thereby rotating the second wheel support member, thereby causing the first wheel and the second wheel to reciprocate in the vehicle width direction respectively.

[0016] According to the above method, by rotating the first wheel support member with the first wheel and the second wheel support member with the second wheel relative to the central member, the first wheel and the second wheel can be easily moved back and forth in the vehicle width direction.

[0017] According to a preferred embodiment of the present invention, the first wheel comprises a first front wheel and a first rear wheel arranged in the longitudinal direction of the vehicle, the second wheel comprises a second front wheel and a second rear wheel arranged in the longitudinal direction of the vehicle, and the central component comprises: a front central component disposed between the first front wheel and the second front wheel and supported by the first front wheel and the second front wheel; and a rear central component disposed between the first rear wheel and the second rear wheel and supported by the first rear wheel and the second rear wheel, wherein the first rotation actuator and the second rotation actuator move the first support shaft of the front central component and the first support shaft of the rear central component in a direction approaching or moving away from each other in the longitudinal direction of the vehicle, and move the second support shaft of the front central component and the second support shaft of the rear central component in a direction approaching or moving away from each other in the longitudinal direction of the vehicle.

[0018] According to the above method, by using the first rotation actuator and the second rotation actuator, the first support shaft and the second support shaft of the front center component and the first support shaft and the second support shaft of the rear center component can be moved in a direction that approaches or moves away from each other along the longitudinal direction of the vehicle, thereby widening or narrowing the gap between the first wheel and the second wheel.

[0019] According to a preferred embodiment of the present invention, the driving prime mover comprises: a first wheel driving prime mover for driving the first wheel; and a second wheel driving prime mover for driving the second wheel.

[0020] According to the above method, the first wheel and the second wheel can be driven independently.

[0021] According to a preferred embodiment of the present invention, the first and second rotary actuators are driven during vehicle travel to bring the first and second wheels closer to or further away from the central component, respectively.

[0022] According to the above method, the distance between the first wheel and the second wheel can be changed during vehicle operation.

[0023] Other vehicle platforms involved in this invention are vehicle platforms constituting a vehicle, characterized by comprising: a first wheel disposed on one side in the vehicle width direction; a second wheel disposed on the other side in the vehicle width direction; a prime mover for driving the first wheel, driving the first wheel; a prime mover for driving the second wheel, driving the second wheel; and a variable mechanism for changing the distance between the first wheel and the second wheel in the vehicle width direction, the variable mechanism comprising: a first wheel support member supporting the first wheel and the first wheel drive prime mover; and a second wheel support member supporting the second wheel and the second wheel drive prime mover, the variable mechanism being configured to change the distance between the first wheel and the second wheel in the vehicle width direction. At least one of the wheel support member and the second wheel support member moves closer to or further away from the other, thereby changing the distance between the first wheel and the second wheel. The first wheel drive prime mover and the second wheel drive prime mover are positioned at different locations in at least one of the vehicle's longitudinal direction and the vehicle's vertical direction when the first wheel and the second wheel are at their furthest apart in the vehicle width direction. The variable mechanism brings the first wheel support member and the second wheel support member closer to each other so that at least a portion of the first wheel drive prime mover and the second wheel drive prime mover are in the same position in the vehicle width direction when viewed from the front of the vehicle.

[0024] According to other vehicle platforms of the present invention, when the first wheel and the second wheel are at their furthest apart in the vehicle width direction, the prime mover for driving the first wheel and the prime mover for driving the second wheel are positioned at different locations in at least one of the vehicle's longitudinal direction and vertical direction. A variable mechanism is used to bring the first wheel support member and the second wheel support member closer together so that at least a portion of the first wheel support member and the second wheel support member are in the same position in the vehicle width direction when viewed from the front of the vehicle. As described above, when the first wheel and the second wheel are at their furthest apart in the vehicle width direction, the first wheel support member and the second wheel support member are positioned at different locations in at least one of the vehicle's longitudinal direction and vertical direction. Therefore, even when the first wheel support member and the second wheel support member are close together, contact (i.e., interference) between the first wheel support member and the second wheel support member can be suppressed, and a narrower wheelbase (track) can be achieved.

[0025] According to a preferred embodiment of the present invention, when viewed from the front of the vehicle, the prime mover for driving the first wheel and the prime mover for driving the second wheel are configured at different positions in the vehicle width direction when the first wheel and the second wheel are at their furthest apart in the vehicle width direction.

[0026] The above method allows for a narrower gap between the first and second wheels.

[0027] According to a preferred embodiment of the present invention, when the first wheel and the second wheel are at their furthest apart in the vehicle width direction, the prime mover for driving the first wheel is disposed in the vehicle width direction between the centerline of the vehicle extending in the longitudinal direction and the first wheel, and the prime mover for driving the second wheel is disposed in the vehicle width direction between the centerline of the vehicle extending in the longitudinal direction and the second wheel.

[0028] According to the above method, since the first vehicle drive prime mover and the second wheel drive prime mover can be configured in a balanced and good manner in the vehicle width direction, the driving stability of the vehicle platform can be improved.

[0029] According to a preferred embodiment of the present invention, the first wheel drive prime mover and the second wheel drive prime mover are arranged at the same height in the vertical direction of the vehicle.

[0030] The above method improves the driving stability of the vehicle platform.

[0031] According to a preferred embodiment of the present invention, the first wheel drive prime mover and the second wheel drive prime mover are located at their closest points in the vehicle width direction, which overlap with the center line when viewed from above.

[0032] According to the above method, when the prime mover for driving the first wheel and the prime mover for driving the second wheel are closest in the vehicle width direction, the center of gravity of the vehicle platform is located at the center or periphery in the vehicle width direction, thus improving the driving stability of the vehicle platform.

[0033] According to the present invention, a vehicle platform is provided that enables the vehicle to move even when the wheel spacing is reduced. Attached Figure Description

[0034] Figure 1 This is a perspective view showing the general structure of the vehicle platform according to the first embodiment.

[0035] Figure 2 It is a schematic representation Figure 1 The diagram shows a schematic top view of the exterior structure of the vehicle platform.

[0036] Figure 3 It is a schematic representation Figure 1 The diagram shows a schematic bottom view of the exterior structure of the vehicle platform.

[0037] Figure 4 It means Figure 1 The diagram shown is a schematic block diagram of the control system for the vehicle platform.

[0038] Figure 5 It is a schematic representation Figure 1 The diagram shows a schematic top view of the exterior structure of the vehicle platform with a reduced wheelbase.

[0039] Figure 6 It is a schematic representation Figure 1 The image shown is a schematic bottom view of the exterior structure of the vehicle platform with a reduced wheelbase.

[0040] Figure 7A This is a front view that schematically represents the state of widened wheelbase.

[0041] Figure 7B This is a front view that schematically represents the state of a reduced wheelbase.

[0042] Figure 8 It's a state where some components have been removed. Figure 5 The diagram shows a schematic top view of the vehicle platform.

[0043] Figure 9This is a schematic top view showing the general appearance structure of the vehicle platform according to the first variation of the first embodiment.

[0044] Figure 10 This is a schematic top view illustrating the general appearance structure of the vehicle platform according to the second variation of the first embodiment.

[0045] Figure 11 This is a schematic top view showing the general appearance structure of the vehicle platform according to the third variation of the first embodiment.

[0046] Figure 12 This is a schematic top view showing the general appearance structure of the vehicle platform according to the fourth variation of the first embodiment.

[0047] Figure 13A This is a front view that schematically represents the state of widened wheelbase.

[0048] Figure 13B This is a front view that schematically represents the state of a reduced wheelbase.

[0049] Figure 14 This is a schematic top view showing the general appearance structure of the vehicle platform according to the second embodiment.

[0050] Figure 15 It is a schematic representation Figure 14 The diagram shows a schematic front view of the exterior structure of the vehicle platform.

[0051] Figure 16 It means Figure 14 The diagram shown is a schematic block diagram of the control system for the vehicle platform.

[0052] Figure 17 It is a schematic representation Figure 14 The diagram shows a schematic top view of the exterior structure of the vehicle platform with a reduced wheelbase.

[0053] Figure 18 It is a schematic top view showing the general appearance structure of the vehicle platform involved in the modified example. Detailed Implementation

[0054] Hereinafter, an embodiment of the vehicle platform according to the present invention will be described with reference to the accompanying drawings.

[0055] <First Implementation>

[0056] The vehicle platform 100 according to the first embodiment of the present invention will be described. Figure 1 This is a schematic perspective view showing the overall structure of the vehicle platform 100 that constitutes the vehicle. Additionally, Figure 2 It is a schematic representation Figure 1 This is a schematic top view of the exterior structure of the vehicle platform 100 in the expanded wheelbase state (the state where the first wheel 112 and the second wheel 122 are furthest apart). Additionally, Figure 3 It is a schematic representation Figure 1 A schematic bottom view of the exterior structure of the vehicle platform 100 shown. Figure 4 It means Figure 1 The diagram shown is a schematic block diagram of the control system for the vehicle platform 100. Additionally, Figure 5 It is a schematic representation Figure 1 This is a schematic top view of the exterior structure of the vehicle platform 100 in a reduced wheelbase state (the state where the first wheel 112 and the second wheel 122 are closest). Additionally, Figure 6 It is a schematic representation Figure 1 This is a schematic bottom view of the exterior structure of the vehicle platform 100 with its wheelbase reduced. Furthermore, the longitudinal direction (the direction of travel of the vehicle platform 100) is defined as the X-axis, the vehicle width direction orthogonal to this X-axis in a top view is defined as the Y-axis, and the vertical direction orthogonal to these X-axis and Y-axis directions is defined as the Z-axis.

[0057] The vehicle, consisting of platform 100, is the main component of a self-propelled work vehicle (not shown) that travels on uneven ground such as farms or gardens through remote operation by the operator for the purpose of transporting goods.

[0058] (Structure of vehicle platform 100)

[0059] like Figure 1 As shown, the vehicle platform 100 includes a first wheel support member 110 with a first wheel 112 and a second wheel support member 120 with a second wheel 122. The first wheel support member 110 and the second wheel support member 120 form the left and right sidewalls of the vehicle platform 100 and are components on which the main components of the vehicle platform 100 are mounted. The vehicle platform 100 includes a prime mover for driving the first wheel 112 and the second wheel 122. The prime mover includes a first wheel drive prime mover 111 and a second wheel drive prime mover 121.

[0060] Specifically, a first wheel drive prime mover 111, a first wheel 112, and a first drive force transmission mechanism 113 are mounted on the first wheel support member 110. A first center member 115 and a second center member 125 are connected to the first wheel support member 110 via a first wheel arm 117. On the other hand, a second wheel drive prime mover 121, a second wheel 122, and a second drive force transmission mechanism 123 are mounted on the second wheel support member 120. The first center member 115 and the second center member 125 are connected to the second wheel support member 120 via a second wheel arm 127. The first center member 115 is an example of a front center member. The second center member 125 is an example of a rear center member. The first center member 115 is disposed between the first front wheel 112F and the second front wheel 122F (described later). The second center member 125 is disposed between the first rear wheel 112R and the second rear wheel 122R (described later).

[0061] The first wheel support member 110 and the second wheel support member 120 are formed of metal or resin. The first wheel support member 110 and the second wheel support member 120 are formed as plates extending and erected along the travel direction of the vehicle platform 100. The length of the first wheel support member 110 and the second wheel support member 120 in the X-axis direction is shorter than the combined length in the X-axis direction of the first rotary actuator 114 and the second rotary actuator 124 (described later) when they are retracted and arranged in a straight line in the X-axis direction. The first wheel support member 110 and the second wheel support member 120 are separated and opposite each other in the vehicle width direction (Y-axis direction).

[0062] In addition, the first wheel support component 110 and the second wheel support component 120 are equipped with cargo platforms, machinery, appliances or devices for enabling the vehicle platform 100 to function as a self-propelled work vehicle, but since they are not directly related to the present invention, their description is omitted.

[0063] The prime mover 111 for driving the first wheel is a drive source for rotating the first wheel 112. The prime mover 121 for driving the second wheel is a drive source for rotating the second wheel 122. Both the prime mover 111 and the prime mover 121 are composed of synchronous motors whose operation is controlled by the control device 130 described later. Alternatively, the prime mover 111 and the prime mover 121 may also be composed of DC motors.

[0064] The first wheel drive prime mover 111 and the second wheel drive prime mover 121 are mounted on the opposing inner surfaces of the first wheel support member 110 and the second wheel support member 120. Specifically, the first wheel drive prime mover 111 is mounted on the inner surface of the first wheel support member 110 on the side located in the X-axis direction where the first rear wheel 112R is disposed (see reference). Figure 2 The prime mover 121 for driving the second wheel is mounted on the inner side of the second wheel support member 120 on the side opposite to the X-axis where the second front wheel 122F is located (see reference). Figure 2 ).

[0065] The first wheel drive prime mover 111 and the second wheel drive prime mover 121 are positioned at different locations in the longitudinal direction of the vehicle platform 100, which is orthogonal to the vehicle width direction, so that they are not opposite to each other in the vehicle width direction. When the first wheel 112 and the second wheel 122 are at their furthest apart in the vehicle width direction, the first wheel drive prime mover 111 and the second wheel drive prime mover 121 are positioned at at least one of the longitudinal direction and the vertical direction of the vehicle. Here, "vehicle longitudinal direction" refers to the longitudinal direction of the vehicle platform 100, and "vehicle vertical direction" refers to the vertical direction of the vehicle platform 100. In this embodiment, when the first wheel 112 and the second wheel 122 are at their furthest apart in the vehicle width direction, the first wheel drive prime mover 111 and the second wheel drive prime mover 121 are positioned at different locations in the vehicle width direction when viewed from the front of the vehicle. With the first wheel 112 and the second wheel 122 closest to each other in the vehicle width direction, the prime mover 111 for driving the first wheel and the prime mover 121 for driving the second wheel are arranged adjacent to each other at the center of the vehicle platform 100 in the longitudinal direction. Figure 2As shown, in the state where the first wheel 112 and the second wheel 122 are at their furthest apart in the vehicle width direction, the prime mover 111 for driving the first wheel and the prime mover 121 for driving the second wheel are symmetrical with respect to the center point in both the longitudinal and width directions of the vehicle platform 100. In the state where the first wheel 112 and the second wheel 122 are at their furthest apart, the prime mover 111 is positioned in the vehicle width direction between the centerline LC of the vehicle extending in the longitudinal direction and the first wheel 112. In the state where the first wheel 112 and the second wheel 122 are at their furthest apart, the centerline LC1 of the prime mover 111, extending in the longitudinal direction, is positioned in the vehicle width direction between the centerline LC of the vehicle extending in the longitudinal direction and the second wheel 122. When the first wheel 112 and the second wheel 122 are at their furthest apart, the centerline LC2 of the prime mover 121 for driving the second wheel, extending in the longitudinal direction, is positioned between the centerline LC and the second wheel 122 in the vehicle width direction. On the other hand, as... Figure 5 As shown, in the state where the first wheel 112 and the second wheel 122 are closest, the centerline LC1 is positioned between the centerline LC and the second wheel 122 in the vehicle width direction. Furthermore, in the state where the first wheel 112 and the second wheel 122 are closest, the centerline LC2 is positioned between the centerline LC and the first wheel 112 in the vehicle width direction. Alternatively, in the state where the first wheel 112 and the second wheel 122 are closest, the centerlines LC1 and LC2 may overlap. Additionally, as... Figure 7A and Figure 7B As shown, the straight line LC3 extending along the vehicle width direction intersects the center line LC1 and the center line LC2. The straight line LC3 is a horizontal line.

[0066] In addition, such as Figure 7A , Figure 7B As shown, the first wheel drive prime mover 111 and the second wheel drive prime mover 121 are positioned at the same height in the vertical direction (Z-axis direction). Viewed from the Y-axis direction, the first wheel drive prime mover 111 is located between the upper second rotation actuator 124a and the lower second rotation actuator 124b, and the second wheel drive prime mover 121 is located between the upper first rotation actuator 114a and the lower first rotation actuator 114b. Alternatively, the first wheel drive prime mover 111 and the second wheel drive prime mover 121 may be positioned at different heights in the vertical direction (Z-axis direction). Furthermore, in Figure 7A , Figure 7BIn order to clarify the positional relationship between the prime mover 111 for driving the first wheel and the prime mover 121 for driving the second wheel, only one of the first wheel support component 110, the first wheel prime mover 111, the first wheel 112, the first driving force transmission mechanism 113 (reduction mechanism 113a, belt transmission mechanism 113b), the second wheel support component 120, the second wheel prime mover 121, the second wheel 122, and the second driving force transmission mechanism 123 (reduction mechanism 123a, belt transmission mechanism 123b) are shown.

[0067] The first wheel 112 and the second wheel 122 are a pair of left and right components that roll on the road surface to allow the vehicle to move forward or backward using the platform 100. The first wheel 112 and the second wheel 122 are made of metal and have rubber tires mounted on their outer circumference. The first wheel 112 is positioned on one side in the vehicle width direction (…). Figure 2 (The lower side). The second wheel 122 is positioned on the other side in the vehicle width direction ( Figure 2 (on the upper side). The first wheel 112 and the second wheel 122 are two wheels arranged in a row in the direction of travel (X-axis direction) of the vehicle platform 100.

[0068] One of the two wheels, the first wheel 112 and the second wheel 122, functions as the front wheel, and the other as the rear wheel. The first wheel 112 and the second wheel 122, each consisting of two wheels, are respectively mounted on the outer surfaces of the first wheel support member 110 and the second wheel support member 120 via the first drive force transmission mechanism 113 and the second drive force transmission mechanism 123. Here, as... Figure 2 As shown, the first wheel 112 includes a first front wheel 112F and a first rear wheel 112R arranged in the longitudinal direction of the vehicle, and the second wheel 122 includes a second front wheel 122F and a second rear wheel 122R arranged in the longitudinal direction of the vehicle.

[0069] The first drive force transmission mechanism 113 and the second drive force transmission mechanism 123 are devices for transmitting the driving forces generated by the prime mover 111 for driving the first wheel and the prime mover 121 for driving the second wheel to the first wheel 112 and the second wheel 122, respectively. Specifically, the first drive force transmission mechanism 113 and the second drive force transmission mechanism 123 respectively include reduction mechanisms 113a and 123a and belt transmission mechanisms 113b and 123b.

[0070] The reduction mechanisms 113a and 123a are composed of gear trains (not shown) that reduce the driving force generated by the prime mover 111 for driving the first wheel and the prime mover 121 for driving the second wheel, respectively. In addition, the belt transmission mechanisms 113b and 123b are each equipped with a V-belt (not shown) and a pulley (not shown) for transmitting the driving force reduced by the reduction mechanisms 113a and 123a to each of the two wheels constituting the first wheel 112 and the second wheel 122.

[0071] Furthermore, the first driving force transmission mechanism 113 and the second driving force transmission mechanism 123 can also be replaced by a chain transmission mechanism or a gear transmission mechanism instead of belt transmission mechanisms 113b and 123b. Additionally, since the reduction mechanisms 113a and 123a and the belt transmission mechanisms 113b and 123b are known structures, therefore... Figures 1-3 Only the outer housings that house the deceleration mechanisms 113a and 123a and the belt transmission mechanisms 113b and 123b are shown.

[0072] The first drive force transmission mechanism 113 and the second drive force transmission mechanism 123 are disposed at the center of the first wheel support member 110 and the second wheel support member 120 in the X-axis direction. The first drive force transmission mechanism 113 and the second drive force transmission mechanism 123 are respectively disposed through the first wheel support member 110 and the second wheel support member 120. Specifically, the first drive force transmission mechanism 113 and the second drive force transmission mechanism 123 are respectively disposed through the first wheel support member 110 and the second wheel support member 120 in a state in which the reduction mechanisms 113a and 123a are respectively connected to the output shafts (not shown) of the first wheel drive prime mover 111 and the second wheel drive prime mover 121 on the inner side surfaces of the first wheel support member 110 and the second wheel support member 120, respectively, so that they can transmit power.

[0073] In addition, belt transmission mechanisms 113b and 123b are respectively disposed on the outer surfaces of the first wheel support member 110 and the second wheel support member 120. The input side of the driving force of belt transmission mechanisms 113b and 123b is connected to the reduction mechanisms 113a and 123a in a power-transmitting manner, and the output side of the driving force is connected to the two wheels constituting the first wheel 112 and the second wheel 122 in a power-transmitting manner.

[0074] Between the first wheel support component 110 and the second wheel support component 120, a first rotation actuator 114, a second rotation actuator 124, a first center component 115, a second center component 125, an intermediate component 116, a first wheel arm 117, and a second wheel arm 127 are respectively provided.

[0075] The first rotation actuator 114 and the second rotation actuator 124 are drive sources for generating driving force to displace the first wheel 112 and the second wheel 122 in directions of separation and proximity (i.e., reciprocating in the vehicle width direction). The first rotation actuator 114 is configured to rotate the first wheel arm 117 relative to the first center member 115 and the second center member 125, so that the first wheel 112 approaches or moves away from the first center member 115 and the second center member 125. The second rotation actuator 124 is configured to rotate the second wheel arm 127 relative to the first center member 115 and the second center member 125, so that the second wheel 122 approaches or moves away from the first center member 115 and the second center member 125. The first rotation actuator 114 and the second rotation actuator 124 rotate the first wheel support member 110 by rotating the first wheel arm 117 about the first support shaft 171, and rotate the second wheel support member 120 by rotating the second wheel arm 127 about the second support shaft 172, thereby causing the first wheel 112 and the second wheel 122 to move back and forth in the vehicle width direction. The first rotation actuator 114 and the second rotation actuator 124 move the first support shaft 171 of the first center member 115 and the first support shaft 171 of the second center member 125 in a direction that approaches or moves away from each other in the longitudinal direction of the vehicle, and move the second support shaft 172 of the first center member 115 and the second support shaft 172 of the second center member 125 in a direction that approaches or moves away from each other in the longitudinal direction of the vehicle. The first rotary actuator 114 and the second rotary actuator 124 are driven during vehicle operation to bring the first wheel 112 and the second wheel 122 closer to or further away from the first central component 115 and the second central component 125, respectively. The first rotary actuator 114 and the second rotary actuator 124 are composed of electric linear motion cylinders, each consisting of a piston rod that moves linearly within the cylinder driven by an electric motor. In this embodiment, the first rotary actuator 114 and the second rotary actuator 124 are each composed of four electric linear motion cylinders.

[0076] Of the four electric direct-acting cylinders constituting the first rotary actuator 114, two are upper first rotary actuator 114a located on the upper side within the vehicle platform 100, and the remaining two are lower first rotary actuator 114b located below the upper first rotary actuator 114a. Similarly, of the four electric direct-acting cylinders constituting the second rotary actuator 124, two are upper second rotary actuator 124a located on the upper side within the vehicle platform 100, and the remaining two are lower second rotary actuator 124b located below the upper second rotary actuator 124a. The first rotary actuator 114 and the second rotary actuator 124 are respectively controlled by the control device 130.

[0077] A first central component 115 and a second central component 125 are disposed between a first wheel 112 and a second wheel 122. The first central component 115 and the second central component 125 are supported on the first wheel 112 and the second wheel 122 respectively via a first wheel support component 110, a second wheel support component 120, a first wheel arm 117, and a second wheel arm 127. The first central component 115 supports an upper first rotating actuator 114a and a lower first rotating actuator 114b. The second central component 125 supports an upper second rotating actuator 124a and a lower second rotating actuator 124b.

[0078] The first central component 115 and the second central component 125 are formed of a metallic material or a resin material. The first central component 115 and the second central component 125 are formed as blocks extending along the Z-axis direction. The first central component 115 and the second central component 125 are symmetrical about an axis of symmetry extending along the Y-axis direction (see reference). Figure 2 and Figure 3 Therefore, the first central component 115 will be described in detail. The first central component 115 consists of one outer first central component 115a and two inner first central components 115b.

[0079] The outer first central component 115a supports the rear ends of the two upper first rotating actuators 114a and the two lower first rotating actuators 114b, respectively. The outer first central component 115a is a plate-shaped body that is roughly U-shaped when viewed from above.

[0080] Regarding the two inner first central components 115b, one inner first central component 115b supports the front ends of each of the two upper first rotating actuators 114a, and the other inner first central component 115b supports the front ends of each of the two lower first rotating actuators 114b. The inner first central component 115b is formed as a block through which the upper first rotating actuators 114a and the lower first rotating actuators 114b respectively pass. That is, one of the two inner first central components 115b is disposed on the upper side within the vehicle platform 100, and the other inner first central component 115b is disposed on the lower side within the vehicle platform 100.

[0081] Furthermore, the second center component 125, like the first center component 115, is composed of one outer second center component 125a and two inner second center components 125b. The outer second center component 125a supports the rear ends of the two upper second rotation actuators 124a and the two lower second rotation actuators 124b in the same manner as the outer first center component 115a supports the rear ends of the two upper first rotation actuators 114a and the two lower first rotation actuators 114b; therefore, detailed description is omitted. Similarly, the two inner second center components 125b support the front ends of the upper second rotation actuators 124a and the lower second rotation actuators 124b in the same manner as the two inner first center components 115b supports the front ends of the upper first rotation actuators 114a and the lower first rotation actuators 114b; therefore, detailed description is omitted.

[0082] The first rotary actuator 114 and the second rotary actuator 124 are held by the first central member 115 and the second central member 125 respectively, with the front ends of the four piston rods of the first rotary actuator 114 facing each other in the X-axis direction. Furthermore, an intermediate member 116 is disposed between the first central member 115 and the second central member 125.

[0083] The intermediate component 116, with its corresponding front ends facing each other in the X-axis direction, receives the front ends of the four piston rods of the first rotary actuator 114 and the four piston rods of the second rotary actuator 124. The intermediate component 116 is constructed by forming a block of metal or resin material. The first rotary actuator 114 and the second rotary actuator 124 are configured such that the four piston rods of the first rotary actuator 114 and the four piston rods of the second rotary actuator 124 press against each other via the intermediate component 116. The intermediate component 116 is supported at the center of the vehicle platform 100 in the direction of travel by the first rotary actuator 114 and the second rotary actuator 124.

[0084] The first wheel arm 117 and the second wheel arm 127 are components for movably connecting the first wheel support member 110 and the second wheel support member 120 relative to the first center member 115 and the second center member 125, respectively. When the first wheel arm 117 is rotatably connected to the first center member 115 and the second center member 125, two of the first wheel arms 117 extend between the first center member 115 and the first front wheel 112F to support the first front wheel 112F, and the remaining two of the first wheel arms 117 extend between the second center member 125 and the first rear wheel 112R to support the first rear wheel 112R. With the second wheel arm 127 rotatably connected to both the first center component 115 and the second center component 125, two of the second wheel arms 127 extend between the first center component 115 and the second front wheel 122F to support the second front wheel 122F, and the remaining two of the second wheel arms 127 extend between the second center component 125 and the second rear wheel 122R to support the second rear wheel 122R. The first wheel arm 117 and the second wheel arm 127 are made of metal or resin. The first wheel arm 117 and the second wheel arm 127 are symmetrical about the centerline LC extending along the X-axis (see reference). Figure 2 and Figure 3 Therefore, the description will mainly focus on the first wheel arm 117. The first wheel arm 117 consists of two outer first wheel arms 117a and three sets of inner first wheel arms 117b.

[0085] Two outer first wheel arms 117a are components for movably connecting the first wheel support member 110 relative to the outer first central member 115a and the outer second central member 125a. The outer first wheel arms 117a are plate-like bodies extending along the Z-axis. One of the two outer first wheel arms 117a is disposed on the front surface side of the vehicle platform 100, and the other of the two outer first wheel arms 117a is disposed on the rear surface side of the vehicle platform 100. One of the two outer first wheel arms 117a is rotatably connected to the first wheel support member 110 and the outer first central member 115a via a hinge structure, and the other of the two outer first wheel arms 117a is rotatably connected to the first wheel support member 110 and the outer second central member 125a via a hinge structure. One of the two outer first wheel arms 117a is supported by a first support shaft 171 of an outer first central member 115a, and the other of the two outer first wheel arms 117a is supported by a first support shaft 171 of an outer second central member 125a. The first support shafts 171 of the outer first central member 115a and the outer second central member 125a extend vertically. The first support shafts 171 of the outer first central member 115a and the outer second central member 125a support the outer first wheel arm 117a in a rotatable manner.

[0086] The three sets of inner first wheel arms 117b are components for movably connecting the first wheel support component 110 relative to the inner first center component 115b and the inner second center component 125b. Each set of inner first wheel arms 117b consists of two rod-shaped bodies extending on a plane formed by the X-axis and the Y-axis.

[0087] The three sets of inner first wheel arms 117b include a first set of inner first wheel arms 117b, a second set of inner first wheel arms 117b, and a third set of inner first wheel arms 117b. The first set of inner first wheel arms 117b is rotatably connected to the upper inner first center member 115b and the first wheel support member 110 of the upper first rotating actuator 114a via hinge structures. The first set of inner first wheel arms 117b is supported by the first support shaft 171 of the upper inner first center member 115b. The first support shaft 171 of the upper inner first center member 115b supports the first set of inner first wheel arms 117b in a rotatable manner. In addition, another set (second set) of the three sets of inner first wheel arms 117b is rotatably connected to the inner first center component 115b and the first wheel support component 110 on the lower side of the supporting lower first rotating actuator 114b via a hinge structure.

[0088] Furthermore, the remaining one (third group) of the three sets of inner first wheel arms 117b is rotatably connected to the upper inner second center member 125b supporting the upper second rotating actuator 124a and the first wheel support member 110 via hinge structures. These three sets of inner first wheel arms 117b are in the state where the first wheel 112 and the second wheel 122 are furthest apart (refer to...). Figure 2 and Figure 3 When viewed from above, the vehicle platform 100 is tilted relative to the X-axis.

[0089] Furthermore, the inner first wheel arm 117b is not located between the inner second center member 125b and the first wheel support member 110 on the lower side of the supporting second rotating actuator 124b. This is to avoid physical interference with the prime mover 111 for driving the first wheel. However, if such physical interference can be avoided, the inner first wheel arm 117b can also be located between the lower inner second center member 125b and the first wheel support member 110.

[0090] The second wheel arm 127, like the first wheel arm 117 described above, is composed of two outer second wheel arms 127a and three sets of inner second wheel arms 127b. The outer second wheel arms 127a and the three sets of inner second wheel arms 127b are also constructed in the same way as the two outer first wheel arms 117a and the three sets of inner first wheel arms 117b described above, therefore their description is omitted. One of the two outer second wheel arms 127a is supported by the second support shaft 172 of the outer first central member 115a, and the other of the two outer second wheel arms 127a is supported by the second support shaft 172 of the outer second central member 125a. The second support shafts 172 of the outer first central member 115a and the outer second central member 125a extend vertically. The second support shafts 172 of the outer first central member 115a and the outer second central member 125a support the outer second wheel arm 127a in a rotatable manner. The three sets of inner second wheel arms 127b are supported by the second support shaft 172 of the upper inner first center component 115b and the second support shaft 172 of the upper and lower inner second center components 125b. The second support shaft 172 of the upper inner first center component 115b and the second support shaft 172 of the upper and lower inner second center components 125b support the three sets of inner second wheel arms 127b in a rotatable manner.

[0091] The control device 130 is composed of a microcomputer, which includes a CPU, ROM, RAM, etc. The control device 130 comprehensively controls the movement of the vehicle platform 100 and, more specifically, the self-propelled work vehicle as a whole. Specifically, based on instructions from the operating element 131, the control device 130 executes a control program pre-stored in a storage device such as ROM to control the movements of the first wheel drive prime mover 111 and the second wheel drive prime mover 121, thereby causing the vehicle platform 100 to move, stop, or turn.

[0092] Based on instructions from the operating element 131, the control device 130 controls the actions of the first rotary actuator 114 and the second rotary actuator 124 by executing a control program to increase or decrease the distance (wheelbase) between the first wheel 112 and the second wheel 122. When the device mounted on the vehicle platform 100 includes an electric machine, appliance, or device, the control device 130 also controls the operation of that electric machine, appliance, or device.

[0093] The operating element 131 is an input device for inputting instructions from the operator of the self-propelled work vehicle into the control device 130. The operating element 131 can be a joystick, toggle switch, button, or dial that is manually operated by the operator. The operating element 131 is directly mounted on the self-propelled work vehicle, including the vehicle platform 100. Alternatively, the operating element 131 can be physically separated from the self-propelled work vehicle and installed independently. The control device 130 and the operating element 131 are connected via wired or wireless means. Furthermore, the vehicle platform 100 includes a battery that stores electricity supplied to the first wheel drive prime mover 111, the second wheel drive prime mover 121, the first rotation actuator 114, the second rotation actuator 124, and the control device 130.

[0094] (The actions of platform 100 for vehicles)

[0095] Next, the operation of the vehicle platform 100 will be described. As described above, the vehicle platform 100 is included in a self-propelled work vehicle used for transporting crops in farms or gardens. Therefore, in this embodiment, a car for loading, storing, and unloading crops is envisioned as the load mounted on the vehicle platform 100. In addition, as an initial state, the vehicle platform 100 is in a state where the distance between the first wheel 112 and the second wheel 122 (wheelbase) is expanded to its maximum width.

[0096] First, the operator operates the control unit 131 to turn on the power to the control device 130 and start the self-propelled work vehicle. Next, the operator operates the control unit 131 to instruct the control device 130 to move the vehicle platform 100. In response to this instruction, the control device 130 can start the movement of the vehicle platform 100 by driving the first wheel drive prime mover 111 and the second wheel drive prime mover 121 respectively. In this case, the control device 130 appropriately adjusts the rotation direction and / or the rotation speed of the first wheel drive prime mover 111 and the second wheel drive prime mover 121 according to the operator's operation of the control unit 131, thereby enabling right or left turns in addition to moving straight or backward.

[0097] Next, when the vehicle platform 100 approaches a location with a narrow road, the operator can reduce the distance (wheelbase) between the first wheel 112 and the second wheel 122. Specifically, the operator operates the operating element 131 to instruct the control device 130 to reduce the distance (wheelbase) between the first wheel 112 and the second wheel 122. In response to this instruction, the control device 130 drives the first rotary actuator 114 and the second rotary actuator 124 respectively. Specifically, the control device 130 extends the piston rods of the first rotary actuator 114 and the second rotary actuator 124 respectively.

[0098] As the piston rod extends, the first central component 115 and the second central component 125 separate from the intermediate component 116, thereby separating the first central component 115 and the second central component 125 from each other. Here, the first wheel arm 117 and the second wheel arm 127 are rotatably connected to the first central component 115 and the second central component 125, respectively, and these first wheel arms 117 and second wheel arms 127 are rotatably connected to the first wheel support component 110 and the second wheel support component 120, respectively. Therefore, the first wheel support component 110 and the second wheel support component 120 simultaneously displace toward the first central component 115 side and the second central component 125 side, respectively, as the piston rods of the first rotary actuator 114 and the second rotary actuator 124 extend.

[0099] By displacing the first wheel support member 110 and the second wheel support member 120 toward the first center member 115 and the second center member 125, respectively, the first wheel 112 and the second wheel 122 approach the center of the vehicle platform 100 in the vehicle width direction. Thus, as... Figure 5As shown, the first wheel 112 and the second wheel 122 approach each other, resulting in a reduction in the distance (wheelbase) between them. At this time, the positions where the prime mover 111 for driving the first wheel and the prime mover 121 for driving the second wheel are closest to each other in the vehicle width direction overlap with the center line LC when viewed from above. Since the first center component 115 and the second center component 125 maintain an orientation displacement parallel to the travel direction of the vehicle platform 100, each wheel also maintains its orientation displacement.

[0100] The vehicle platform 100 is equipped with a first orientation maintaining mechanism 181 (see reference). Figure 2 The first orientation maintaining mechanism 181 includes a first wheel support member 110, a first center member 115, a second center member 125, a first support shaft 171, an intermediate member 116, and a first wheel arm 117. The first orientation maintaining mechanism 181 moves the first wheel 112 in the vehicle width direction and maintains the orientation of the first wheel 112 relative to the vehicle's longitudinal direction during this movement. Furthermore, in this embodiment, the first orientation maintaining mechanism 181 includes a first rotation actuator 114 and a second rotation actuator 124. The first rotation actuator 114 and the second rotation actuator 124 integrally connect the outer first center member 115a and the inner first center member 115b, and integrally connect the outer second center member 125a and the inner second center member 125b. The first parallel linkage mechanism is constituted by a portion of the first wheel support member 110 included in the first orientation maintaining mechanism 181, two of the first wheel arms 117 (the first wheel arms 117 on the side of the first front wheel 112F), the first center member 115, and the first rotation actuator 114. For example, when the two first wheel arms 117 of the first parallel linkage mechanism rotate clockwise by a predetermined angle in plan view, the first orientation maintaining mechanism 181 causes the first wheel support member 110 to rotate counterclockwise relative to the two first wheel arms 117 by the same angle, thus maintaining the orientation of the first front wheel 112F provided on the first wheel support member 110. The second parallel linkage mechanism is constituted by a portion of the first wheel support member 110 included in the first orientation maintaining mechanism 181, the remaining two of the first wheel arms 117 (the first wheel arms 117 on the side of the first rear wheel 112R), the second center member 125, and the second rotation actuator 124. For example, when the two first wheel arms 117 of the second parallel linkage mechanism rotate clockwise by a predetermined angle in top view, the first orientation maintaining mechanism 181 causes the first wheel support member 110 to rotate counterclockwise relative to the two first wheel arms 117 by the same angle, thus maintaining the orientation of the first rear wheel 112R provided on the first wheel support member 110.

[0101] In addition, the vehicle platform 100 is equipped with a second orientation maintaining mechanism 182 (see reference). Figure 2 The second orientation maintaining mechanism 182 includes a second wheel support member 120, a first center member 115, a second center member 125, a second support shaft 172, an intermediate member 116, and a second wheel arm 127. The second orientation maintaining mechanism 182 moves the second wheel 122 in the vehicle width direction and maintains the orientation of the second wheel 122 relative to the vehicle's longitudinal direction during this movement. Furthermore, in this embodiment, the second orientation maintaining mechanism 182 includes a first rotation actuator 114 and a second rotation actuator 124. The first rotation actuator 114 and the second rotation actuator 124 integrally connect the outer first center member 115a and the inner first center member 115b, and integrally connect the outer second center member 125a and the inner second center member 125b. The third parallel linkage mechanism is constituted by a portion of the second wheel support member 120 included in the second orientation maintaining mechanism 182, two of the second wheel arms 127 (the second wheel arms 127 on the side of the second front wheel 122F), the first center member 115, and the first rotation actuator 114. For example, when the two second wheel arms 127 of the third parallel linkage mechanism rotate clockwise by a predetermined angle in plan view, the second orientation maintaining mechanism 182 causes the second wheel support member 120 to rotate counterclockwise relative to the two second wheel arms 127 by the same angle, thus maintaining the orientation of the second front wheel 122F provided on the second wheel support member 120. Furthermore, the fourth parallel linkage mechanism is constituted by a portion of the second wheel support member 120 included in the second orientation maintaining mechanism 182, the remaining two of the second wheel arms 127 (the second wheel arms 127 on the side of the second rear wheel 122R), the second center member 125, and the second rotation actuator 124. For example, when the two second wheel arms 127 of the fourth parallel linkage rotate clockwise by a predetermined angle in plan view, the second orientation maintaining mechanism 182 causes the second wheel support member 120 to rotate counterclockwise relative to the two second wheel arms 127 by the same angle, thus maintaining the orientation of the second rear wheel 122R disposed on the second wheel support member 120. The first orientation maintaining mechanism 181 and the second orientation maintaining mechanism 182 are examples of variable mechanisms. That is, the first orientation maintaining mechanism 181 and the second orientation maintaining mechanism 182 are configured to change the distance (wheelbase) between the first wheel 112 and the second wheel 122 in the vehicle width direction. The first orientation maintaining mechanism 181 and the second orientation maintaining mechanism 182 are configured to change the distance between the first wheel 112 and the second wheel 122 in the vehicle width direction by bringing at least one of the first wheel support member 110 and the second wheel support member 120 closer to or further away from the other.

[0102] In addition, the first wheel drive prime mover 111 and the second wheel drive prime mover 121, which are respectively provided on the inner sides of the first wheel support member 110 and the second wheel support member 120, are staggered in different positions in the X-axis direction so that they are not opposite each other in the Y-axis direction. Therefore, even if the first wheel support member 110 and the second wheel support member 120 are close to each other, they will not come into contact with each other.

[0103] Therefore, the control device 130 can displace the first wheel support member 110 and the second wheel support member 120 to positions where at least a portion of the first wheel drive prime mover 111 and the second wheel drive prime mover 121 overlap each other when viewed from the front-rear direction (X-axis direction) of the vehicle platform 100. In this embodiment, as... Figure 8 As shown, the control device 130 displaces the first wheel support member 110 to a position where the first wheel drive prime mover 111 is adjacent to the inner side of the second wheel support member 120 with a small gap S1, and displaces the second wheel support member 120 to a position where the second wheel drive prime mover 121 is adjacent to the inner side of the first wheel support member 110 with a small gap S2. As a result, the first wheel 112 and the second wheel 122 approach each other near the center of the vehicle platform 100 in the vehicle width direction, thereby reducing the wheelbase.

[0104] In addition, Figure 8 In order to clarify the positional relationship between the prime mover 111 for driving the first wheel and the prime mover 121 for driving the second wheel, the illustrations of the upper first rotating actuator 114a, the lower first rotating actuator 114b, the inner first central component 115b, the intermediate component 116, the inner first wheel arm 117b, the upper second rotating actuator 124a, the lower second rotating actuator 124b, the inner second central component 125b, and the inner second wheel arm 127b are omitted.

[0105] Next, when the road width increases, the operator can operate the control unit 131 to instruct the control device 130 to increase the distance (wheelbase) between the first wheel 112 and the second wheel 122. In this case, the control device 130 causes the piston rods of the first rotary actuator 114 and the second rotary actuator 124 to shorten.

[0106] As the piston rod shortens, the first central component 115 and the second central component 125 approach the intermediate component 116, resulting in the first central component 115 and the second central component 125 moving closer to each other. Therefore, the first wheel support component 110 and the second wheel support component 120 simultaneously displace in directions away from the first central component 115 and the second central component 125, respectively, as the piston rods of the first rotary actuator 114 and the second rotary actuator 124 shorten.

[0107] As a result, the first wheel 112 and the second wheel 122 separate outward in the vehicle width direction, thereby widening the gap (wheelbase). Since the first center component 115 and the second center component 125 maintain an orientation parallel to the travel direction of the vehicle platform 100, each wheel also moves while maintaining its orientation.

[0108] The control device 130 can increase or decrease the wheel track of the first wheel 112 and the second wheel 122 only during the operation of the operating component 131 by the operator, or it can increase or decrease the wheel track of the first wheel 112 and the second wheel 122 by a predetermined amount each time the operator operates the operating component 131. Moreover, the operator can operate the operating component 131 to increase or decrease the wheel track of the first wheel 112 and the second wheel 122 not only while the vehicle platform 100 is moving, but also while the vehicle platform 100 is stationary.

[0109] As can be seen from the above description of this embodiment, the first wheel arm 117 connected to the first front wheel 112F rotates relative to the first center member 115, the first wheel arm 117 connected to the first rear wheel 112R rotates relative to the second center member 125, the second wheel arm 127 connected to the second front wheel 122F rotates relative to the first center member 115, and the second wheel arm 127 connected to the second rear wheel 122R rotates relative to the second center member 125. Through the rotation of the first wheel arm 117 and the second wheel arm 127, the first wheel 112 and the second wheel 122 approach or move away from the first center member 115 and the second center member 125. Therefore, even when the distance (wheelbase) between the first wheel 112 and the second wheel 122 is reduced, the vehicle can still move.

[0110] According to this embodiment, the first wheel drive prime mover 111 and the second wheel drive prime mover 121 are respectively mounted on the first wheel support member 110 and the second wheel support member 120, and are arranged at different positions in the vehicle's longitudinal direction (travel direction). The first wheel support member 110 and the second wheel support member 120 are able to approach each other in such a way that the first wheel drive prime mover 111 and the second wheel drive prime mover 121 overlap when viewed from the longitudinal direction of the vehicle platform 100. Since the first wheel drive prime mover 111 and the second wheel drive prime mover 121 are arranged differently when the first wheel support member 110 and the second wheel support member 120 are at their furthest apart, the first wheel drive prime mover 111 and the second wheel drive prime mover 121 will not contact each other even when the first wheel support member 110 and the second wheel support member 120 are close to each other, and the distance (wheelbase) between the first wheel 112 and the second wheel 122 can be sufficiently varied. Furthermore, the first orientation maintaining mechanism 181 and the second orientation maintaining mechanism 182 are configured such that at least a portion of the first wheel drive prime mover 111 and the second wheel drive prime mover 121 are in the same position in the vehicle width direction when viewed from the front of the vehicle, so that the first wheel support member 110 and the second wheel support member 120 are close to each other.

[0111] This invention is not limited to the first embodiment described above, and various modifications can be made without departing from the purpose of this invention. Furthermore, in the various modifications shown below, the same reference numerals are used to denote components identical to those in the vehicle platform 100 of the above embodiment, and their descriptions are omitted.

[0112] For example, in the above embodiment, two first wheels 112 are mounted on the first wheel support member 110. However, it is sufficient to mount at least one first wheel 112 on the first wheel support member 110. Similarly, for the second wheel support member 120, it is sufficient to mount at least one second wheel 122, just like with the first wheel support member 110.

[0113] Furthermore, in the above embodiment, the first drive force transmission mechanism 113 is configured to drive two first wheels 112. However, the first drive force transmission mechanism 113 only needs to drive at least one first wheel 112. Therefore, by transmitting drive force only to one of the two first wheels 112, the first drive force transmission mechanism 113 can drive only that one first wheel 112. Similarly, the second drive force transmission mechanism 123, like the first drive force transmission mechanism 113, can drive only that one second wheel 122 by transmitting drive force only to one of the two second wheels 122.

[0114] Furthermore, in the above embodiment, the first center component 115 is composed of an outer first center component 115a and an inner first center component 115b. However, the first center component 115 only needs to be configured to be disposed between the first wheel 112 and the second wheel 122 and supported by the first wheel 112 and the second wheel 122. Therefore, the first center component 115 may also be composed of at least one of the outer first center component 115a and the inner first center component 115b. It is not necessary to provide both the upper and lower inner first center components 115b on the vehicle platform 100. Either the upper or lower inner first center component 115b may be provided on the vehicle platform 100. In addition, the second center component 125, like the first center component 115, may also be composed of at least one of the outer second center component 125a and the inner second center component 125b.

[0115] Furthermore, in the above embodiment, the vehicle platform 100 is configured such that the first wheel 112 and the second wheel 122 are respectively reciprocated in the vehicle width direction. However, the vehicle platform 100 may also be configured such that either the first wheel 112 or the second wheel 122 is reciprocated in the vehicle width direction. Figure 9 As shown, the vehicle platform 100 according to the first variation of the first embodiment is a structure in which the intermediate component 116 and the first wheel support component 110 are formed as one piece and the first wheel arm 117 is not present. Therefore, the vehicle platform 100 can move only the second wheel support component 120 backward in the vehicle width direction and only the second wheel 122 backward in the vehicle width direction according to the extension and retraction of the piston rods of the first rotation actuator 114 and the second rotation actuator 124. In this case, the first rotation actuator 114 is an actuator for rotating the second wheel arm 127, and essentially functions as the second rotation actuator 124, but for ease of explanation, in Figure 9 The first rotary actuator 114 and the second rotary actuator 124 are shown in the figure.

[0116] Furthermore, in the above embodiment, the vehicle platform 100 is configured such that the first wheel support member 110 and the second wheel support member 120 are moved backward and forward respectively in the vehicle width direction using the first rotation actuator 114 and the second rotation actuator 124. However, the vehicle platform 100 may also be configured such that either the first rotation actuator 114 or the second rotation actuator 124 is used to move the first wheel support member 110 and the second wheel support member 120 backward and forward respectively in the vehicle width direction. Figure 10As shown, in the second variation of the first embodiment, the vehicle platform 100 includes a piston cylinder 140 instead of the first rotary actuator 114. The piston cylinder 140 includes a piston, a cylinder, and a piston rod that slides freely within the cylinder and engages with the piston. Therefore, the vehicle platform 100 of the second variation of the first embodiment can retract the first wheel support member 110 and the second wheel support member 120 in the vehicle width direction according to the extension and retraction of the piston cylinder 140 and the piston rod of the second rotary actuator 124, and can retract the first wheel 112 and the second wheel 122 in the vehicle width direction.

[0117] Furthermore, in the above embodiment, the first rotary actuator 114 and the second rotary actuator 124 are each composed of four electric direct-acting cylinders. However, the first rotary actuator 114 and the second rotary actuator 124 may be composed of at least one electric direct-acting cylinder. Additionally, the first rotary actuator 114 and the second rotary actuator 124 may be composed of components other than electric direct-acting cylinders, such as hydraulic cylinders, pneumatic cylinders, or feed screw mechanisms.

[0118] Furthermore, in the above embodiment, the prime mover 111 for driving the first wheel is mounted on the inner side of the first wheel support member 110. However, the prime mover 111 for driving the first wheel may also be mounted on the outer side of the first wheel support member 110. Additionally, the vehicle platform 100 may also employ a so-called in-wheel motor structure in which the prime mover 111 for driving the first wheel is housed inside one of the first wheels 112. Furthermore, the prime mover 121 for driving the second wheel, like the prime mover 111 for driving the first wheel, may be mounted on the outer side of the second wheel support member 120, or it may be housed inside one of the second wheels 122.

[0119] Furthermore, in the above embodiment, the first wheel drive prime mover 111 and the second wheel drive prime mover 121 are arranged at different positions in the X-axis direction and are respectively mounted on the inner sides of the first wheel support member 110 and the second wheel support member 120 in a non-opposite manner in the vehicle width direction. Therefore, the vehicle platform 100 can avoid physical interference between the first wheel drive prime mover 111 and the second wheel drive prime mover 121, and can further reduce the distance (wheelbase) between the first wheel 112 and the second wheel 122. However, the first wheel drive prime mover 111 and the second wheel drive prime mover 121 can also be arranged at the same position in the X-axis direction and respectively mounted on the inner sides of the first wheel support member 110 and the second wheel support member 120 in a non-opposite manner in the vehicle width direction. Alternatively, the prime mover 111 for driving the first wheel and the prime mover 121 for driving the second wheel may have one of them disposed on the inner side of the first wheel support member 110 or the second wheel support member 120, and the other disposed on the outer side of the first wheel support member 110 or the second wheel support member 120.

[0120] Furthermore, in the above embodiment, the vehicle platform 100 is a four-wheel platform having four wheels, consisting of two first wheels 112 and two second wheels 122. However, the vehicle platform 100 only needs to be configured to have at least one pair of left and right first wheels 112 and second wheels 122. Figure 11 As shown, the vehicle platform 100 in the third variation of the first embodiment may also be a three-wheel platform having a first wheel 112 mounted on the first wheel support member 110, a second wheel 122 mounted on the second wheel support member 120, and a third wheel 150 mounted on the lower end of the outer first center member 115a.

[0121] Furthermore, in the above embodiment, the control device 130 displaces the first wheel support member 110 to a position where the first wheel drive prime mover 111 is adjacent to the inner side of the second wheel support member 120 through a small gap S1, and displaces the second wheel support member 120 to a position where the second wheel drive prime mover 121 is adjacent to the inner side of the first wheel support member 110 through a small gap S2. The gaps S1 and S2 can be the same size or different sizes. However, the control device 130 only needs to displace the first wheel support member 110 and the second wheel support member 120 to positions where at least a portion of the first wheel drive prime mover 111 and the second wheel drive prime mover 121 overlap when viewed from the front-rear direction of the vehicle platform 100.

[0122] Alternatively, the first wheel support member 110 can be moved to a position where the prime mover 111 for driving the first wheel contacts the inner side of the second wheel support member 120, and the second wheel support member 120 can be moved to a position where the prime mover 121 for driving the second wheel contacts the inner side of the first wheel support member 110. For example... Figure 12 As shown, the control device 130 of the vehicle platform 100 according to the fourth variation of the first embodiment can also displace the first wheel support member 110 and the second wheel support member 120 to a degree that, when viewed from the front-rear direction of the vehicle platform 100, the end of the first wheel drive prime mover 111 on the side of the second wheel support member 120 and the end of the second wheel drive prime mover 121 on the side of the first wheel support member 110 slightly overlap.

[0123] Furthermore, in the above embodiment, the vehicle platform 100 sets the first wheel drive prime mover 111 and the second wheel drive prime mover 121 at the same height. This improves the driving stability of the vehicle platform 100. However, the vehicle platform 100 may also set the first wheel drive prime mover 111 and the second wheel drive prime mover 121 at different heights.

[0124] Furthermore, in the above embodiment, the vehicle platform 100 has the first wheel drive prime mover 111 and the second wheel drive prime mover 121 positioned at different locations in the longitudinal direction of the vehicle. This prevents the vehicle platform 100 from increasing in height and improves driving stability. However, the vehicle platform 100 only needs to be positioned at different locations in at least one of the longitudinal direction and the vertical direction.

[0125] like Figure 13A and Figure 13B As shown, the vehicle platform 100 according to the fifth modification of the first embodiment includes a first wheel drive prime mover 111 and a second wheel drive prime mover 121 arranged at different positions in the vertical direction of the vehicle. Furthermore, in Figure 13A , Figure 13B In order to clarify the positional relationship between the prime mover 111 for driving the first wheel and the prime mover 121 for driving the second wheel, only one of the following components is shown: the first wheel support component 110, the first wheel prime mover 111, the first wheel 112, the first driving force transmission mechanism 113 (reduction mechanism 113a, belt transmission mechanism 113b), the second wheel support component 120, the second wheel prime mover 121, the second wheel 122, and the second driving force transmission mechanism 123 (reduction mechanism 123a, belt transmission mechanism 123b).

[0126] In the first embodiment, the vehicle platform 100 is configured such that, when the first wheel 112 and the second wheel 122 are closest in the vehicle width direction, the prime mover 111 for driving the first wheel and the prime mover 121 for driving the second wheel are adjacent at the center in the longitudinal direction of the vehicle platform 100. This makes it easier for the center of gravity of the vehicle platform 100 to be located at or around the center in the longitudinal and width directions, thereby improving the driving stability of the vehicle platform 100. However, the vehicle platform 100 can also be configured such that, when the first wheel 112 and the second wheel 122 are closest in the vehicle width direction, the prime mover 111 for driving the first wheel and the prime mover 121 for driving the second wheel are positioned separately in the longitudinal or vertical direction of the vehicle.

[0127] <Second Implementation>

[0128] (Structure of vehicle platform 200)

[0129] Next, use them respectively Figures 14 to 17 A second embodiment of the vehicle platform will be described. In this description, the differences from the first embodiment will be primarily explained, while common aspects will be omitted as appropriate.

[0130] like Figure 14 As shown, the vehicle platform 200 includes a central component 201. The central component 201 is disposed between the first wheels 210 and 220 and the second wheels 230 and 240. The central component 201 is supported on the first wheels 210 and 220 and the second wheels 230 and 240 respectively via the first wheel arms 212 and 222 and the second wheel arms 232 and 242.

[0131] The central component 201 supports the first rotary actuators 215 and 225 and the second rotary actuators 235 and 245, respectively. Additionally, the central component 201 is equipped with a cargo platform, machinery, implements, or devices to enable the vehicle platform 200 to function as a self-propelled work vehicle. The central component 201 is formed of metal or resin material and is shaped as a flat plate extending in the XY-axis plane.

[0132] A first wheel 210 and a second wheel 230 are arranged in pairs and roll on the road surface to move the vehicle platform 200 forward or backward. Both the first wheel 210 and the second wheel 230 are made of metal and have rubber tires mounted on their outer circumference. A first wheel drive prime mover 211, consisting of an electric motor for rotating the first wheel 210, is installed inside the first wheel 210. That is, the first wheel 210 is a so-called in-wheel electric motor. A second wheel drive prime mover 231 is installed inside the second wheel 230. The second wheel drive prime mover 231 is an electric motor for rotating the second wheel 230. That is, the second wheel 230 has a so-called in-wheel electric motor. The operation of the first wheel drive prime mover 211 and the second wheel drive prime mover 231 is controlled by a control device 250.

[0133] The first wheel arm 212 is a component for movably connecting the first wheel support component 213 relative to the central component 201, and is formed of a metal or resin material. The first wheel arm 212 is formed as an elongated plate. One end of the first wheel arm 212 is rotatably connected to the lower surface of the central component 201, and the other end is rotatably connected to the lower surface of the first wheel support component 213.

[0134] The first wheel support component 213 connects the first wheel 210 and the first wheel arm 212. The first wheel support component 213 is made of metal or resin. The first wheel support component 213 is formed as an elongated block extending from the center of the first wheel 210 toward the axis of rotation. The first wheel support component 213 is integrally assembled to the first wheel 210.

[0135] like Figure 14 As shown, a first orientation maintaining mechanism 214 is provided between one end of the first wheel arm 212 and the first wheel support member 213. The first orientation maintaining mechanism 214 is a device for maintaining the orientation of the first wheel 210 in the traveling direction (X-axis direction) of the vehicle platform 200. The first orientation maintaining mechanism 214 includes a body-side gear 214a, a wheel-side gear 214b, and a chain 214c.

[0136] The body-side gear 214a passes through the central component 201 and is integrally mounted to one end of the first wheel arm 212, thereby rotating integrally with the first wheel arm 212. The wheel-side gear 214b is integrally mounted to the first wheel support component 213. The chain 214c is a ring-shaped component made of metal that is mounted between the body-side gear 214a and the wheel-side gear 214b to transmit the rotation of the body-side gear 214a to the wheel-side gear 214b.

[0137] That is, the body-side gear 214a of the first orientation maintaining mechanism 214 rotates integrally with the first wheel arm 212, while the wheel-side gear 214b rotates relative to the first wheel arm 212. Thus, the first orientation maintaining mechanism 214 rotates the body-side gear 214a by rotating the first wheel arm 212, thereby maintaining the orientation of the first wheel 210 in the travel direction (X-axis direction) of the vehicle platform 200. Specifically, the number of teeth on the body-side gear 214a and the wheel-side gear 214b is set such that even if the rotation angle of the first wheel arm 212 changes, the first orientation maintaining mechanism 214 will always maintain the orientation of the first wheel 210 in the travel direction (X-axis direction) of the vehicle platform 200.

[0138] The first rotary actuator 215 is a drive source for generating a driving force to reciprocate the first wheel 210 in the vehicle width direction. Specifically, the first rotary actuator 215 is composed of an electric direct-acting cylinder, which consists of a piston rod that moves linearly within the cylinder using an electric motor as a drive source. One end of the piston rod of the first rotary actuator 215 is connected to the first wheel arm 212, and the other end of the piston rod is rotatably mounted relative to the lower surface of the central member 201. The operation of the first rotary actuator 215 is controlled by a control device 250.

[0139] The vehicle platform 200 includes first wheels 220 arranged in a row with the first wheels 210 in the X-axis direction. The first wheels 220 function as either front or rear wheels depending on the direction of travel of the vehicle platform 200. The first wheels 220 function in the same way as the first wheel 210 through the first wheel drive prime mover 221, first wheel arm 222, first wheel support member 223, first orientation maintenance mechanism 224 (body side gear 224a, wheel side gear 224b, chain 224c) and first rotation actuator 225, which are configured in the same way as the first wheel drive prime mover 211, first wheel arm 222, first wheel support member 223, first orientation maintenance mechanism 224 (body side gear 224a, wheel side gear 224b, chain 224c) and first rotation actuator 225.

[0140] The first wheel 220, the prime mover 221 for driving the first wheel, the first wheel arm 222, the first wheel support component 223, the first orientation maintaining mechanism 224 (body-side gear 224a, wheel-side gear 224b, chain 224c), and the first rotation actuator 225 are symmetrical with respect to the plane extending along the Y-axis and passing through the center of the vehicle platform 200 (see reference). Figure 14 and Figure 17 For example, when the first wheel arm 212 rotates counterclockwise by a predetermined angle in a top view, the first orientation maintaining mechanism 214 causes the first wheel 210 to rotate clockwise relative to the first wheel arm 212 by the same angle, thus maintaining the orientation of the first wheel 210. Similarly, when the first wheel arm 222 rotates counterclockwise by a predetermined angle in a top view, the first orientation maintaining mechanism 224 causes the first wheel 220 to rotate clockwise relative to the first wheel arm 222 by the same angle, thus maintaining the orientation of the first wheel 220.

[0141] Additionally, the vehicle platform 200 includes second wheels 230 and 240, which are symmetrical with respect to the surfaces extending along the X-axis and passing through the center of the vehicle platform 200 with respect to the first wheels 210 and 220 (see reference). Figure 14 and Figure 17 The second wheels 230 and 240 are wheels that form a pair with the first wheels 210 and 220. Specifically, the second wheel drive prime mover 231, second wheel arm 232, second wheel support member 233, second orientation maintenance mechanism 234 (body side gear 234a, wheel side gear 234b, chain 234c) and second rotation actuator 235, which are configured in the same way as the first wheel drive prime mover 211, first wheel arm 212, first wheel support member 213, first orientation maintenance mechanism 214 (body side gear 214a, wheel side gear 214b, chain 214c) and first rotation actuator 215, enable the second wheel 230 to function in the same way as the first wheel 210.

[0142] The second wheel 230, the prime mover 231 for driving the second wheel, the second wheel arm 232, the second wheel support component 233, the second orientation maintenance mechanism 234 (body-side gear 234a, wheel-side gear 234b, chain 234c), and the second rotation actuator 235 are symmetrical with respect to the plane extending along the X-axis and passing through the center of the vehicle platform 200 (see reference). Figure 14 and Figure 17 ).

[0143] Furthermore, the second wheel 240 functions in the same way as the first wheel 220 through the second wheel drive prime mover 241, second wheel arm 242, second wheel support member 243, second orientation maintenance mechanism 244 (body side gear 224a, wheel side gear 224b, chain 224c) and second rotation actuator 245, which are configured in the same way as the first wheel drive prime mover 221, first wheel arm 222, first wheel support member 223, first orientation maintenance mechanism 224 (body side gear 244a, wheel side gear 244b, chain 244c) and second rotation actuator 245.

[0144] The second wheel 240, the prime mover 241 for driving the second wheel, the second wheel arm 242, the second wheel support component 243, the second orientation maintaining mechanism 244 (body-side gear 244a, wheel-side gear 244b, chain 244c), and the second rotation actuator 245 are symmetrical with respect to the plane extending along the X-axis and passing through the center of the vehicle platform 200 (see reference). Figure 14 and Figure 17 For example, when the second wheel arm 232 rotates counterclockwise by a predetermined angle in a top view, the second orientation maintaining mechanism 234 causes the second wheel 230 to rotate clockwise relative to the second wheel arm 232 by the same angle, thus maintaining the orientation of the second wheel 230. Similarly, when the second wheel arm 242 rotates counterclockwise by a predetermined angle in a top view, the second orientation maintaining mechanism 244 causes the second wheel 240 to rotate clockwise relative to the second wheel arm 242 by the same angle, thus maintaining the orientation of the second wheel 240.

[0145] The control device 250 is composed of a microcomputer, which includes a CPU, ROM, RAM, etc. The control device 250 comprehensively controls the movements of the vehicle platform 200 and, consequently, the entire self-propelled work vehicle. Specifically, as... Figure 16 As shown, the control device 250, based on instructions from the operating element 251, executes a control program pre-stored in a storage device such as a ROM to control the actions of the prime movers 211 and 221 for the first wheel drive and the prime movers 231 and 241 for the second wheel drive, thereby causing the vehicle platform 200 to move, stop, or turn.

[0146] Based on instructions from the operating element 251, the control device 250 controls the actions of the first rotary actuators 215 and 225 and the second rotary actuators 235 and 245 by executing a control program, thereby increasing or decreasing the distance (wheel track) between the first wheels 210 and 220 and the second wheels 230 and 240. When the device mounted on the vehicle platform 200 includes an electric machine, appliance, or device, the control device 250 also controls the operation of that electric machine, appliance, or device.

[0147] The operating component 251 is the same as the operating component 131 in the first embodiment described above, so its description is omitted. In addition, the vehicle platform 200 includes a battery that stores electricity supplied to the first wheel drive prime movers 211 and 221, the second wheel drive prime movers 231 and 241, the first rotation actuators 215 and 225, the second rotation actuators 235 and 245, and the control device 250.

[0148] (The actions of vehicle platform 200)

[0149] Next, the operation of the vehicle platform 200 will be explained. Like the vehicle platform 100, the vehicle platform 200 is included in a self-propelled work vehicle used for transporting crops in farms or gardens. Therefore, in this embodiment, a car for loading, storing, and unloading crops is envisioned as the load mounted on the vehicle platform 200. Furthermore, in its initial state, the vehicle platform 200 is in a state where the distance (wheelbase) between the first wheels 210, 220 and the second wheels 230, 240 is maximized.

[0150] First, the operator operates the control unit 251 to turn on the power to the control device 250, starting the self-propelled work vehicle. Next, the operator operates the control unit 251 to instruct the control device 250 to move the vehicle platform 200. In response to this instruction, the control device 250 starts the movement of the vehicle platform 200 by driving the first wheel drive prime movers 211, 221 and the second wheel drive prime movers 231, 241 respectively. In this case, the control device 130 adjusts the rotation direction and / or the rotation speed of the first wheel drive prime movers 211, 221 and the second wheel drive prime movers 231, 241 appropriately according to the operator's operation of the control unit 251, thereby enabling right or left turns in addition to moving straight or backward.

[0151] Next, when the vehicle platform 200 approaches a location with a narrow road, the operator can reduce the distance (wheelbase) between the first wheels 210, 220 and the second wheels 230, 240. Specifically, the operator operates the operating element 251 to instruct the control device 250 to reduce the distance (wheelbase) between the first wheels 210, 220 and the second wheels 230, 240. In response to this instruction, the control device 250 drives the first rotary actuators 215, 225 and the second rotary actuators 235, 245, respectively. Specifically, the control device 250 extends the piston rods of the first rotary actuators 215, 225 and the second rotary actuators 235, 245, respectively.

[0152] like Figure 14 and Figure 17 As shown, by extending the piston rod, the first wheel arm 212 and the second wheel arm 242 rotate counterclockwise around their connection with the central member 201, and the first wheel arm 222 and the second wheel arm 232 rotate clockwise around their connection with the central member 201. Therefore, the first wheels 210 and 220 and the second wheels 230 and 240 approach the center of the vehicle platform 200 in the vehicle width direction. As a result, the first wheels 210 and 230 approach each other, and the first wheels 220 and 240 approach each other. Consequently, the distance (wheelbase) between the first wheels 210 and 220 and the second wheels 230 and 240 decreases. In this case, the first wheels 210 and 220 and the second wheels 230 and 240 are displaced while maintaining an orientation parallel to the travel direction of the vehicle platform 200 by the first orientation maintaining mechanisms 214 and 224 and the second orientation maintaining mechanisms 234 and 244.

[0153] Next, the operator can operate the control unit 251 to instruct the control device 250 to increase the distance (wheelbase) between the first wheels 210, 220 and the second wheels 230, 240, when the road width is increased. In this case, the control device 250 causes the piston rods of the first rotary actuators 215, 225 and the second rotary actuators 235, 245 to shorten.

[0154] like Figure 14 and Figure 17 As shown, by shortening the piston rod, the first wheel arm 212 and the second wheel arm 242 rotate clockwise around their connection with the central member 201, and the first wheel arm 222 and the second wheel arm 232 rotate counterclockwise around their connection with the central member 201. Therefore, the first wheels 210, 220 and the second wheels 230, 240 move away from the center of the vehicle platform 200 in the vehicle width direction. As a result, the first wheels 210 and 230 separate from each other, and the first wheels 220 and 240 separate from each other. Consequently, the distance (wheelbase) between the first wheels 210, 220 and the second wheels 230, 240 increases. In this case, the first wheels 210, 220 and the second wheels 230, 240 are displaced while maintaining an orientation parallel to the travel direction of the vehicle platform 200 by the first orientation maintaining mechanisms 214, 224 and the second orientation maintaining mechanisms 234, 244.

[0155] The control device 250 can also widen or narrow the distance (wheelbase) between the first wheels 210, 220 and the second wheels 230, 240 only during the operator's operation of the operating component 251. The control device 250 can also widen or narrow the wheelbase between the first wheels 210, 220 and the second wheels 230, 240 by a predetermined distance each time the operator operates the operating component 251. Furthermore, the operator can widen or narrow the distance (wheelbase) between the first wheels 210, 220 and the second wheels 230, 240 not only while the vehicle platform 200 is moving, but also while the vehicle platform 200 is stationary.

[0156] Alternatively, the operator can operate the operating component 251 to activate only the first rotary actuator 215 and the second rotary actuator 235, thereby only widening or narrowing the distance (wheelbase) between the first wheel 210 and the second wheel 230. Alternatively, the operator can operate the operating component 251 to activate only the first rotary actuator 225 and the second rotary actuator 245, thereby only widening or narrowing the distance (wheelbase) between the first wheel 220 and the second wheel 240. Alternatively, the operator can operate the operating component 251 to activate only the first rotary actuator 215 and the first rotary actuator 225, thereby only widening or narrowing the distance (wheelbase) between the first wheels 210, 220 and the second wheels 230, 240. Alternatively, the operator can operate the operating component 251 to activate only the second rotary actuator 235 and the second rotary actuator 245, thereby only widening or narrowing the distance (wheelbase) between the first wheels 210, 220 and the second wheels 230, 240.

[0157] As can be seen from the above description of the second embodiment, the vehicle platform 200 rotates relative to the central member 201 by means of the first wheel arms 212 and 222, which are respectively connected to the first wheels 210 and 220, and the second wheel arms 232 and 242, which are respectively connected to the second wheels 230 and 240, rotating relative to the central member 201. This causes the first wheels 210 and 220 and the second wheels 230 and 240 to move closer to or further away from the central member 201. Therefore, even when the distance (wheelbase) between the first wheels 210 and 220 and the second wheels 230 and 240 is reduced, the vehicle can still move.

[0158] In the second embodiment described above, the vehicle platform 200 is configured to move all four wheels of the first wheels 210 and 220 and the second wheels 230 and 240 backward in the vehicle width direction. However, by configuring the vehicle platform 200 to move at least one of the four wheels of the first wheels 210 and 220 and the second wheels 230 and 240 backward in the vehicle width direction, the wheelbase can be increased or decreased.

[0159] Furthermore, in the second embodiment described above, the vehicle platform 200 is a four-wheel platform having four wheels: first wheels 210 and 220, and second wheels 230 and 240. However, the vehicle platform 200 only needs to be configured to have at least one pair of left and right first wheels 210 (or first wheels 220) and second wheels 230 (or second wheels 240). Figure 18 As shown, the vehicle platform 200 involved in the variation of the second embodiment is a three-wheel platform having a first wheel 220, a second wheel 240 and a third wheel 260. The third wheel 260 is located in the center of the vehicle width direction in the central component 201 and is mounted on a portion separated from the first wheel 220 and the second wheel 240.

[0160] Furthermore, in the first and second embodiments described above, the vehicle platforms 100 and 200 constitute self-propelled agricultural work vehicles. However, the vehicle platforms involved in this invention can also be configured as various work vehicles for civil engineering, disaster prevention, rescue, industrial, or medical purposes, and of course, they can also be configured as various vehicles for passenger use.

Claims

1. A vehicle platform constituting a vehicle, characterized in that, The vehicle platform has the following features: The first wheel is positioned on one side in the width direction of the vehicle; The second wheel is positioned on the opposite side of the vehicle width direction; The first wheel is driven by a prime mover. The second wheel is driven by a prime mover; and A variable mechanism that changes the distance between the first wheel and the second wheel in the vehicle width direction. The variable mechanism has the following features: A first wheel support component supports the first wheel and extends along the travel direction of the vehicle platform, i.e., the fore-and-aft direction; and The second wheel support component supports the second wheel and extends along the longitudinal direction. The first wheel support component and the second wheel support component are separated in the vehicle width direction and are opposite to each other. Between the first wheel support component and the second wheel support component, a first rotation actuator, a second rotation actuator, a first center component, a second center component, an intermediate component, a first wheel arm, and a second wheel arm are respectively provided. The first wheel arm and the second wheel arm are components for movably connecting the first wheel support component and the second wheel support component relative to the first center component and the second center component, respectively. The first central component and the second central component are formed to extend along vertical directions orthogonal to the front-rear direction and the vehicle width direction, respectively, and are symmetrical to each other with respect to an axis of symmetry extending along the vehicle width direction. The variable mechanism is configured such that, By extending the piston rods of the first and second rotary actuators, the first and second central components separate from each other in the longitudinal direction, and the first and second wheel support components simultaneously shift towards the first and second central components respectively in the vehicle width direction, thereby reducing the gap between the first and second wheels. By shortening the piston rods of the first and second rotary actuators, the first and second central components approach each other in the longitudinal direction, and the first and second wheel support components simultaneously move away from the first and second central components in the vehicle width direction, thereby increasing the distance between the first and second wheels.

2. The vehicle platform according to claim 1, characterized in that, With the first wheel and the second wheel at their furthest apart in the vehicle width direction, the prime mover for driving the first wheel and the prime mover for driving the second wheel are positioned at different locations in at least one of the vehicle's longitudinal direction and its vertical direction. The variable mechanism brings the first wheel support member and the second wheel support member closer together so that, when viewed from the front of the vehicle, at least a portion of the first wheel drive prime mover and the second wheel drive prime mover are in the same position in the vehicle width direction.

3. The vehicle platform according to claim 2, wherein, When the first wheel and the second wheel are at their furthest apart in the vehicle width direction, the prime mover for driving the first wheel and the prime mover for driving the second wheel are positioned at different locations in the vehicle width direction when viewed from the front of the vehicle.

4. The vehicle platform according to claim 3, wherein, When the first wheel and the second wheel are at their furthest apart in the vehicle width direction, the prime mover for driving the first wheel is positioned between the centerline of the vehicle extending in the longitudinal direction and the first wheel in the vehicle width direction, and the prime mover for driving the second wheel is positioned between the centerline of the vehicle extending in the longitudinal direction and the second wheel in the vehicle width direction.

5. The vehicle platform according to claim 4, characterized in that, The first wheel drive prime mover and the second wheel drive prime mover are positioned at the same height in the vertical direction of the vehicle.

6. The vehicle platform according to claim 4, characterized in that, The positions where the first wheel drive prime mover and the second wheel drive prime mover are closest to each other in the vehicle width direction overlap with the center line when viewed from above.

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