Vehicle

Abstract

To realize stable travel performance by surely contacting a road surface and a driving wheel when using a wheel having respectively rotatably arranged plural free wheels on the outer periphery of a main wheel.SOLUTION: A vehicle 1 has a vehicle body part 2, a plurality of driving wheels 10, and a plurality of suspensions 50, and respective ones of the plurality of driving wheels 10 have a power source 40, a main wheel 101 driven by the power source 40 and a plurality of free wheels inclinedly arranged to a rotary shaft 101s of the main wheel 101 so as to be juxtaposed in the circumferential direction on the outer periphery of the main wheel 101, and the suspension 50 has a first plate part 51 extendedly arranged so as to cross in the vertical direction U and fixed to a vehicle body part 2, a second plate part 52 fixed on the corresponding driving wheels 10, mutually movably arranged to the first plate part 51 so as to move a driving wheel 10 in the vertical direction U while maintaining an attitude, and an elastic member 55 arranged between the first plate part 51 and the second plate part 52.SELECTED DRAWING: Figure 11

Description

[Technical field]

[0001] The present invention relates to a vehicle. [Background technology]

[0002] 2. Description of the Related Art Various vehicles are used for the purpose of performing tasks such as transporting goods within a facility, such as transport vehicles that transport materials within a factory, and robots that handle goods in an automated warehouse. Consider a case where such a vehicle is configured, for example, like a general passenger car, with rubber tires as the front and rear wheels, and only the front wheels are steering wheels that can change the running direction of the vehicle. In such a vehicle, the running direction can be changed by moving forward and turning right or left while operating the steering wheel, turning around a point located on the outside side of the vehicle as a center. Therefore, when changing the running direction, a certain size of area is required on the running road. Therefore, for example, when the running road is narrow, it may not be possible to freely change the running direction. For this reason, the above-mentioned vehicle may be configured to change the running direction while maintaining its posture.

[0003] In this regard, for example, Patent Document 1 discloses a rocker bogie car with a total of six wheels, in which a pair of front, middle, and rear wheels are provided on the left and right sides as driving wheels. This rocker bogie car includes a bogie link on which the front and middle wheels are supported, a rocker link on which the rear wheels are supported, and a main body connected to the rocker link. The bogie link is supported on the main body or the rocker link and can rotate freely or dynamically, and the rocker link is fixed to the main body. The front and rear wheels of such a rocker bogie car are Mecanum Wheels (registered trademark) that are rotatably supported on the outer periphery of the main wheel at an inclination of 45° with respect to the axle and have a structure having a plurality of free wheels arranged in the circumferential direction. In addition, the middle wheel is an Omniwheel (registered trademark) that is rotatably supported on the outer periphery of the main wheel at an inclination of 90° with respect to the axle and has a structure having a plurality of free wheels arranged in the circumferential direction.

[0004] As described above, in Patent Document 1, a plurality of wheels, such as a Mecanum wheel or an Omni wheel, are used as driving wheels, which include a main wheel and a plurality of free wheels arranged circumferentially around the outer periphery of the main wheel, each of which is rotatable, and the rotation axis of each of the free wheels is inclined at the same angle to the rotation axis of the main wheel so as to follow the outer periphery of the main wheel. For example, in a Mecanum wheel, when the main wheel is driven and rotates, a frictional force acts between the free wheels arranged on the outer periphery of the main wheel and the road surface in association with this rotation, and the free wheels tend to rotate due to this frictional force. Here, since the rotation axis of the free wheels is inclined at the same angle of 45° to the rotation axis of the main wheel, the torque of the main wheel is converted from the rotation direction of the main wheel to a direction according to the inclination of the rotation axis of the free wheels. In this way, the vehicle's traveling direction can be changed while maintaining the vehicle's attitude unchanged.

[0005] In this way, in a vehicle using wheels such as Mecanum wheels or omni wheels as drive wheels, in order to appropriately change the running direction of the vehicle as intended, it is necessary for each drive wheel to always be in good contact with the road surface and to maintain a constant frictional force between the drive wheels and the road surface. For this reason, it is desirable to provide a suspension that allows the drive wheels to move up and down in response to the unevenness of the road surface.

[0006] Here, for example, in the case of using an independent suspension used in a general passenger car, the inclination of the rotation axis of the wheel with respect to the road surface changes when the suspension expands and contracts. Then, even if the suspension is configured so that the entire widthwise area of ​​the outer circumference of the wheel is in contact with the road surface when the suspension is in a neutral state without expanding and contracting, the suspension operates and the rotation axis of the wheel inclines, so that a part of the widthwise direction of the wheel is separated from the road surface. In this way, the contact area between the wheel and the road surface changes, and the frictional force acting between the wheel and the road surface changes. As a result, in a configuration using a wheel whose running direction is changed by the frictional force with the road surface as described above, it may be difficult to run the vehicle in the intended direction. When a wheel having a plurality of swivel wheels, each of which is freely rotatable, attached to the outer periphery of a main wheel is used as a drive wheel, it is desirable to ensure that the drive wheel comes into contact with the road surface to achieve stable driving performance. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] JP 2023-6068 A Summary of the Invention [Problem to be solved by the invention]

[0008] The problem that the present invention aims to solve is to provide a vehicle that can ensure reliable contact between the road surface and the drive wheels, thereby achieving stable driving performance, when the drive wheels are wheels that have a number of swivel wheels, each of which is freely rotatable, attached to the outer periphery of the main wheels. [Means for solving the problem]

[0009] In order to solve the above problems, the present invention employs the following means. That is, the vehicle of the present invention comprises a vehicle body section, a plurality of drive wheels, and a plurality of suspensions, each of the plurality of drive wheels comprising a power source, a main wheel driven by the power source, and a plurality of swivel wheels each rotatably arranged in a circumferential line around the outer periphery of the main wheel, and in each of the plurality of drive wheels, the rotation axis of each of the plurality of swivel wheels is arranged along the outer periphery of the main wheel and inclined at the same angle with respect to the rotation axis of the main wheel, and each of the plurality of suspensions is provided corresponding to each of the plurality of drive wheels, and comprises a first plate section provided to intersect in the vertical direction and fixed to the vehicle body section, a second plate section fixed to the corresponding drive wheel, and provided below the first plate section at a position spaced from the first plate section, intersecting in the vertical direction and movable relative to the first plate section so as to allow the drive wheel to move in the vertical direction while maintaining its posture, and an elastic member provided between the first plate section and the second plate section. In the above configuration, the vehicle is provided with a plurality of drive wheels. Each of the plurality of drive wheels includes a power source, a main wheel driven by the power source, and a plurality of free wheels that are arranged circumferentially on the outer periphery of the main wheel and are each rotatable. In each of the plurality of drive wheels, the rotation axis of each of the plurality of free wheels is inclined at the same angle with respect to the rotation axis of the main wheel so as to follow the outer periphery of the main wheel. In this configuration, when the main wheel is driven and rotates, a frictional force acts between the free wheel provided on the outer periphery of the main wheel and the road surface in association with this rotation, and the free wheel tries to rotate due to this frictional force. Here, since the rotation axis of the free wheel is inclined at the same angle with respect to the rotation axis of the main wheel, the torque of the main wheel is converted from the rotation direction of the main wheel to a direction according to the inclination of the rotation axis of the free wheel. In this way, the traveling direction of the vehicle can be changed while maintaining the attitude of the vehicle unchanged. Regarding such a drive wheel, the vehicle is provided with a plurality of suspensions. Each of the plurality of suspensions is provided corresponding to each of the plurality of drive wheels. Each of the plurality of suspensions includes a first plate portion provided to cross vertically and fixed to the vehicle body portion, a second plate portion provided to cross vertically below the first plate portion and spaced apart from the first plate portion, and an elastic member provided between the first plate portion and the second plate portion. In such a configuration, when there are irregularities on the road surface during travel, the drive wheel tries to move vertically in accordance with the condition of the road surface. Here, the second plate portion is provided to be movable relative to the first plate portion so as to allow the drive wheel to move vertically, so that the drive wheel and the second plate portion to which the drive wheel is fixed move vertically relative to the first plate portion. In addition, an elastic member is provided between the first plate portion and the second plate portion. Therefore, when there is a recess in the road surface, the elastic member stretches and the second member and the drive wheel are urged against the road surface. Furthermore, when there is a bump on the road surface, the elastic member contracts to absorb the rise of the drive wheel and the second member. Here, the second plate portion is provided with respect to the first plate portion so that the corresponding drive wheel can move up and down while maintaining its posture, so that when the suspension absorbs the relative movement of the drive wheel with respect to the vehicle body portion, the angle and posture of the rotation axis of the main wheel with respect to the road surface are maintained. Therefore, even if the drive wheel moves up and down in response to unevenness in the road surface, the inclination and posture of the drive wheel do not change, and the contact area between the drive wheel and the road surface is also unlikely to change, so the frictional force acting between the drive wheel and the road surface is also unlikely to change. Therefore, the torque acting on the drive wheel is appropriately transmitted to the road surface via the swivel wheel, and as a result, the vehicle can be driven in the intended direction. In this way, when a wheel having a plurality of swivel wheels, each of which is freely rotatable, attached to the outer periphery of the main wheel is used as a drive wheel, it is possible to provide a vehicle that can ensure reliable contact between the road surface and the drive wheel, thereby realizing stable driving performance.

[0010] In one aspect of the present invention, in each of the multiple suspensions, the second plate portion faces the first plate portion and is freely swingable in the vertical direction relative to the first plate portion around a rotation axis provided along an end edge of the second plate portion, and the end edge of the second plate portion on which the rotation axis is provided is located at the front or rear in the fore-and-aft direction of the vehicle body portion. According to this configuration, the first plate portion and the second plate portion are firmly connected to each other so as to be able to swing up and down relative to the first plate portion about a rotation axis provided along an end side of the second plate portion, which makes it possible to prevent the drive wheel and the second plate portion from being displaced in directions other than the up and down direction when they swing up and down relative to the first plate portion. In addition, if the end edge of the second plate part on which the rotation axis is provided is located, for example, on the right side, rather than on the front or rear side of the second plate part in the front-rear direction of the vehicle body part, the rotation axis of the second plate part will be in a state of extending in the front-rear direction on the right side of the vehicle body part. This direction is perpendicular to the left-right direction (vehicle width direction) in which the rotation axis of the main wheel of the drive wheel fixed to the second plate part extends. Therefore, when the second plate part swings around the rotation axis relative to the first plate part, the left side of the second plate part moves up and down relative to the right side, causing the second plate part to tilt left and right, and accordingly, the angle of the rotation axis of the main wheel of the drive wheel fixed to the second plate part with respect to the road surface changes. This changes the inclination and attitude of the drive wheel with respect to the road surface, and the contact area between the drive wheel and the road surface changes, which may also change the frictional force acting between the drive wheel and the road surface. In contrast, in the above-mentioned configuration, the end edge of the second plate part on which the rotation axis is provided is located on the front or rear side in the front-rear direction of the vehicle body part, so that the rotation axis of the second plate part extends in the left-right direction (vehicle width direction) of the vehicle body part, that is, in a direction parallel to the rotation axis of the main wheel of the drive wheel fixed to the second plate part, and the second plate part extends in the front-rear direction of the vehicle body part from the end edge on which the rotation axis is provided. In this configuration, when the second plate part swings around the rotation axis relative to the first plate part, the side opposite to the rotation axis of the second plate part moves up and down relative to the rotation axis side, so that the second plate part itself tilts forward and backward, but this tilting does not change the inclination of the rotation axis of the main wheel of the drive wheel, which is provided parallel to the second plate part, relative to the road surface. For this reason, the attitude of the drive wheel and the contact area with the road surface do not change, and therefore the frictional force acting between the drive wheel and the road surface is also unlikely to change. In this way, even if a suspension is provided, the torque acting on the drive wheels is appropriately transmitted to the road surface via the swivel wheels, and as a result, the vehicle can be made to travel in the intended direction.

[0011] In another aspect of the present invention, in each of the plurality of suspensions, a protrusion is provided on each of the opposing surfaces of the first plate portion and the second plate portion so as to protrude from the surfaces, the protrusions of the first plate portion and the second plate portion are arranged so as to overlap each other when viewed from the side, and the rotation axis of the second plate portion is arranged so as to pass through the overlapping portions of the protrusions of the first plate portion and the second plate portion. According to this configuration, the rotating shaft penetrates the protruding portion of the first plate portion and the protruding portion of the second plate portion, so that both the first plate portion and the second plate portion are firmly connected to be freely swingable around the rotating shaft. This makes it possible to more firmly prevent the drive wheel and the second plate portion from being displaced in directions other than the up-down direction when they swing up and down relative to the first plate portion. In addition, since the protruding portion of the first plate portion and the protruding portion of the second plate portion overlap each other when viewed from the side, when the first plate portion and the second plate portion try to move relatively in the direction in which the rotating shaft extends, the protruding portion of the first plate portion and the protruding portion of the second plate portion come into contact with each other. This makes it possible to prevent the drive wheel and the second plate portion from being displaced in the direction in which the rotating shaft extends relative to the first plate portion when they swing up and down relative to the first plate portion.

[0012] In another aspect of the present invention, each of the multiple suspensions is provided with a relative movement direction regulating member between the first plate portion and the second plate portion that regulates the direction of movement of the drive wheel only in the up and down direction. According to this configuration, the drive wheels are moved only in the up-down direction by the relative movement direction regulating member, which makes it possible to prevent the drive wheels from being displaced in directions other than the up-down direction, such as the vehicle width direction or the front-rear direction.

[0013] In another aspect of the present invention, in each of the plurality of suspensions, the elastic member is any one of a coil spring, rubber, and a leaf spring. According to this configuration, by using any one of a coil spring, rubber, and a leaf spring as the elastic member, the elastic member can be formed with a simple structure. Effect of the Invention

[0014] According to the present invention, when the drive wheels are wheels that have multiple swivel wheels, each of which is freely rotatable, attached to the outer periphery of the main wheel, it is possible to provide a vehicle that can ensure contact between the drive wheels and the road surface, thereby achieving stable driving performance. [Brief description of the drawings]

[0015] [Figure 1] 1 is a side view showing a configuration of a vehicle according to an embodiment of the present invention. [Diagram 2] FIG. 2 is a plan view showing the configuration of the vehicle in FIG. [Diagram 3] FIG. 2 is a view of the front and rear wheels from the front-to-rear direction. [Figure 4] FIG. 2 is a view of the front and rear wheels from the left and right direction. [Diagram 5] This is a view of the center wheel from the front to rear. [Figure 6] This is a view of the center wheel from the left and right. [Figure 7] 3 is a schematic diagram showing the rotation direction of each drive wheel and the magnitude of drive force when the vehicle moves forward. FIG. [Figure 8] 4 is a schematic diagram showing the rotation direction of each drive wheel and the magnitude of drive force when the vehicle is traversed to the right. FIG. [Figure 9] 4 is a schematic diagram showing the rotation direction of each drive wheel and the magnitude of drive force when the vehicle is moved obliquely backward to the right; FIG. [Figure 10] 4 is a schematic diagram showing the rotation direction of each drive wheel and the magnitude of drive force when the vehicle is turned clockwise. FIG. [Figure 11] FIG. 4 is a diagram showing a mounting structure of the suspension for each drive wheel. [Figure 12] FIG. 2 is a perspective view showing a configuration of a suspension. [Figure 13] FIG. 4 is a perspective view showing a suspension provided on a vehicle according to a first modified example of the present embodiment. [Figure 14] FIG. 11 is a perspective view showing a suspension provided on a vehicle according to a second modified example of the present embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment of a vehicle according to the present invention will be described with reference to the accompanying drawings. Fig. 1 shows a side view of a vehicle according to an embodiment of the present invention. Fig. 2 is a plan view of the vehicle. In Fig. 1, the left side of the paper is the front side in the longitudinal direction of the vehicle 1, and the right side is the rear side. In Fig. 2, the upper side of the paper is the front side in the longitudinal direction of the vehicle 1, and the lower side is the rear side. As shown in FIGS. 1 and 2, a vehicle 1 includes a vehicle body 2, a plurality of drive wheels 10, and a plurality of suspensions 50.

[0017] In this embodiment, the vehicle 1 is a rocker bogie vehicle. The vehicle body 2 includes a housing 5, a bogie link 20, and a rocker link 30. The housing 5 has, for example, a rectangular shape when viewed from above. For example, various devices, a battery, a control device, etc. are housed inside the housing 5. Note that the configuration of the housing 5 is not limited to the configuration shown here, and can be changed to other configurations as appropriate.

[0018] As shown in FIG. 2, a pair of bogie links 20 are provided on the left and right sides of the vehicle 1 in the vehicle width direction W. The pair of bogie links 20 includes a right bogie link 20R provided on the right side and a left bogie link 20L provided on the left side. The right bogie link 20R and the left bogie link 20L have a symmetrical configuration. In the following description, except when it is necessary to distinguish between the right bogie link 20R and the left bogie link 20L, each of the right bogie link 20R and the left bogie link 20L will be simply referred to as the bogie link 20.

[0019] The bogie link 20 supports each of the front wheels 11 and middle wheels 12 (described later) so as to be freely rotatable about an axis extending in the left-right direction. The bogie link 20 extends in the front-rear direction F of the vehicle body 2. The front wheels 11 are rotatably supported at a front end 20f of the bogie link 20. The middle wheels 12 are rotatably supported at a rear end 20r of the bogie link 20. In this manner, the bogie link 20 axially supports each of the front wheels 11 and the middle wheels 12 and connects them together.

[0020] A pair of rocker links 30 are provided on the left and right sides of the vehicle body 2 in the vehicle width direction W. The pair of rocker links 30 are provided on the left and right sides of the vehicle 1. The pair of rocker links 30 includes a right rocker link 30R provided on the right side and a left rocker link 30L provided on the left side. The right rocker link 30R and the left rocker link 30L are configured symmetrically. In the following description, except where it is necessary to distinguish between the right rocker link 30R and the left rocker link 30L, each of the right rocker link 30R and the left rocker link 30L will be simply referred to as the rocker link 30.

[0021] As shown in Figs. 1 and 2, the rocker link 30 extends in the front-rear direction F. An intermediate portion 30c of the rocker link 30 in the front-rear direction F is rotatably supported by the housing 5 around the rocker link shaft 31 extending in the left-right direction (vehicle width direction W). The rocker link 30 extends obliquely downward from the intermediate portion 30c in the front-rear direction F. A front end portion 30f of the rocker link 30 is rotatably supported by the intermediate portion 20c of the bogie link 20 in the front-rear direction F around the central axis of the drive shaft 35 extending in the left-right direction. This allows the bogie link 20 to swing around the drive shaft 35 relative to the rocker link 30. A rear wheel 13 is rotatably supported by a rear end portion 30r of the rocker link 30. In this manner, the rocker link 30 axially supports and connects the intermediate portion 20c between the front wheel 11 and the center wheel 12 of the bogie link 20 and the rear wheel 13 described below.

[0022] The bogie link 20 (right bogie link 20R, left bogie link 20L) is driven by the bogie link control motor 37 to rotate relatively around the central axis of the drive shaft 35 with respect to the rocker link 30 (right rocker link 30R, left rocker link 30L). In other words, the bogie link 20 is dynamically rotatable with respect to the rocker link 30 by the bogie link control motor 37. The relative angle between the bogie link 20 and the rocker link 30 around the drive shaft 35 is controllable. In addition, the bogie link 20 and the rocker link 30 are placed in a state in which they can freely rotate around the drive shaft 35 by turning off the drive by the bogie link control motor 37. Such a bogie link control motor 37 can be realized by an actuator that can freely control the rotational drive force, for example, a torque motor or a Harmonic Drive (registered trademark), etc.

[0023] Since the car body 2 has such bogie link 20 and rocker link 30, for example, the bogie link 20 can be rotated by the bogie link control motor 37 as appropriate to raise or lower the front wheel 11 as desired, thereby changing the height of the front wheel 11. This allows the car body 2 to traverse a step. For example, when climbing a step, the front wheel 11 is raised to the height of the step to move the car body 2 forward, the front wheel 11 is placed on the step, and then the bogie link 20 is rotated so as to apply a load to the front wheel 11 to raise the middle wheel 12, the middle wheel 12 is raised to the same height as the front wheel 11 to move the car body 2 forward, and the middle wheel 12 is placed on the step. The same procedure can be followed when descending a step. Furthermore, when the drive by the bogie link control motor 37 is turned off and the bogie link 20 is allowed to freely rotate around the drive shaft 35, the bogie link 20 moves in accordance with the shape of the road surface. Therefore, even on uneven ground with an uneven road surface, the front wheels 11, middle wheels 12, and rear wheels 13 are prevented from coming off the road surface.

[0024] The multiple drive wheels 10 are provided in pairs on the left and right sides of the vehicle 1 in the vehicle width direction W. The multiple drive wheels 10 include front wheels 11, center wheels 12, and rear wheels 13, each provided in a pair on the left and right. The multiple drive wheels 10 are provided on the housing 5 via a bogie link 20 and a rocker link 30.

[0025] A pair of front wheels 11 are provided on the left and right at the front end of the vehicle 1. The pair of front wheels 11 includes a right front wheel 11R provided on the right side and a left front wheel 11L provided on the left side. The middle wheels 12 are provided as a pair on the left and right in the middle of the vehicle 1 in the front-rear direction F. The pair of middle wheels 12 includes a right middle wheel 12R provided on the right side and a left middle wheel 12L provided on the left side. A pair of rear wheels 13 are provided on the left and right at the rear end of the vehicle 1. The pair of rear wheels 13 includes a right rear wheel 13R provided on the right side and a left rear wheel 13L provided on the left side.

[0026] Fig. 3 is a view of the front and rear wheels as viewed from the front-rear direction, and Fig. 4 is a view of the front and rear wheels as viewed from the left-right direction. 3 and 4, each of the front wheels 11 (right front wheel 11R, left front wheel 11L) and the rear wheels 13 (right rear wheel 13R, right rear wheel 13R) is a Mecanum wheel (registered trademark) 100. Each of the front wheels 11 and the rear wheels 13 has a main wheel 101 and a plurality of swivel wheels 102 provided on the outer periphery of the main wheel 101. The main wheel 101 is driven by a power source 40, which will be described later, and is provided rotatably about a rotation axis 101s extending in the left-right direction.

[0027] A plurality of swivel wheels 102 are arranged in a line in the circumferential direction on the outer periphery of the main wheel 101. Each swivel wheel 102 is a so-called barrel-shaped free wheel, and is supported so as to be freely rotatable around a rotation axis 102s. The rotation axis 102s of each swivel wheel 102 is arranged so as to follow the outer periphery of the main wheel 101. The rotation axis 102s of each swivel wheel 102 is inclined so that the inclination angle θ1 with respect to the rotation axis 101s of the main wheel 101 is 45°. The diagonal lines in the right front wheel 11R, the left front wheel 11L, the right rear wheel 13R, and the left rear wheel 13L shown in FIG. 2 indicate the direction in which the rotation shaft 102s of the swivel wheel 102 extends when viewed from above. As shown in Fig. 2, in the right front wheel 11R and the left front wheel 11L, the rotation shaft 102s of each of the multiple swivel wheels 102 is inclined at an angle of 45° so as to gradually move forward in the rotation direction of the main wheel 101 as it moves from the inside to the outside in the vehicle width direction (left-right direction) W. Also, as shown in Fig. 2 as well, in the right rear wheel 13R and the left rear wheel 13L, the rotation shaft 102s of each of the multiple swivel wheels 102 is inclined at an angle of 45° so as to gradually move backward in the rotation direction of the main wheel 101 as it moves from the inside to the outside in the vehicle width direction (left-right direction) W. In this way, in each of the drive wheels 10, that is, the front wheels 11 (right front wheel 11R, left front wheel 11L) and the rear wheels 13 (right rear wheel 13R, right rear wheel 13R), the rotation axis 102s of each of the multiple swivel wheels 102 is inclined at the same angle (45°) relative to the rotation axis 101s of the main wheel 101 so as to follow the outer periphery of the main wheel 101.

[0028] In the Mecanum wheel 100 configured as described above, when the main wheel 101 is driven to rotate, a frictional force acts between the swivel wheel 102 provided on the outer periphery of the main wheel 101 and the road surface R (see FIG. 1) in association with this rotation, and the swivel wheel 102 tries to rotate due to this frictional force. Here, since the rotation axis 102s of the swivel wheel 102 is inclined at the same angle with respect to the rotation axis 101s of the main wheel 101, the torque of the main wheel 101 is converted from the rotation direction of the main wheel 101 to a direction according to the inclination of the rotation axis 102s of the swivel wheel 102. In this way, the traveling direction of the vehicle 1 can be changed while maintaining the attitude of the vehicle 1 unchanged.

[0029] Fig. 5 is a view of the middle wheel as seen from the front-rear direction, and Fig. 6 is a view of the middle wheel as seen from the left-right direction. 5 and 6, the middle wheels 12 (right middle wheel 12R, left middle wheel 12L) are Omniwheels (registered trademark) 200. The middle wheels 12 include a main wheel 201 and a plurality of swivel wheels 202 provided on the outer periphery of the main wheel 201. The main wheel 201 is driven by a power source 40, which will be described later, and is provided rotatably about a rotation shaft 201s extending in the left-right direction.

[0030] The multiple swivel wheels 202 are arranged in a line in the circumferential direction on the outer periphery of the main wheel 201. Each swivel wheel 202 is a so-called barrel-shaped free wheel, and is supported so as to be freely rotatable around a rotation axis 202s. The rotation axis 202s of each swivel wheel 202 is provided along the outer periphery of the main wheel 201. The rotation axis 202s of each swivel wheel 202 is provided to extend in the rotation direction of the main wheel 201 so that the inclination angle θ2 with respect to the rotation axis 201s of the main wheel 201 is 90°. The vertical lines in the right middle wheel 12R and the left middle wheel 12L shown in FIG. 2 indicate the direction in which the rotation shaft 202s of the swivel wheel 202 extends when viewed from above. In this way, in each of the middle wheels 12 (right middle wheel 12R, left middle wheel 12L) which are the driving wheels 10, the rotation axis 202s of each of the multiple swivel wheels 202 is arranged on the outer periphery of the main wheel 201 and inclined at the same angle (90°) relative to the rotation axis 201s of the main wheel 201.

[0031] In the omni-wheel 200 configured as above, when the main wheel 201 is driven to rotate, a frictional force acts between the swivel wheels 202 provided on the outer periphery of the main wheel 201 and the road surface R (see FIG. 1) in association with this rotation. Here, in the omni-wheel 200, each of the multiple swivel wheels 202 is provided so that the rotation axis 202s is inclined at the same angle (90°) with respect to the rotation axis 201s of the main wheel 201 so as to follow the outer periphery of the main wheel 201, i.e., along the rotation direction of the main wheel 201. For this reason, the rotation of the swivel wheels 202 is suppressed and the rotation of the main wheel 201 is directly transmitted to the road surface R, and the vehicle 1 can be moved forward in the rotation direction of the main wheel 201. Also, for example, when the vehicle 1 is caused to move laterally to the right or left while maintaining its posture, if the omni-wheel 200 is stopped, the swivel wheel 202 that is in contact with the road surface R in that state will rotate. Therefore, the omni-wheel 200 will not impede the vehicle 1 from moving laterally.

[0032] 2, each drive wheel 10 is rotated by a corresponding power source 40. The power source 40 is a motor. The vehicle 1 is equipped with power sources 40, which include power sources 41R, 41L, 42R, 42L, 43R, and 43L. The main wheel 101 of the right front wheel 11R is driven to rotate by the power source 41R. The main wheel 101 of the left front wheel 11L is driven to rotate by the power source 41L. The main wheel 201 of the right center wheel 12R is driven to rotate by the power source 42R. The main wheel 201 of the left center wheel 12L is driven to rotate by the power source 42L. The main wheel 101 of the right rear wheel 13R is driven to rotate by the power source 43R. The main wheel 101 of the left rear wheel 13L is driven by the power source 43L. These power sources 41R, 41L, 42R, 42L, 43R, and 43L are motors that can be controlled independently. In other words, the front wheel 11, the center wheel 12, and the rear wheel 13 can be controlled to drive independently.

[0033] In such a vehicle 1, the front wheels 11 (right front wheel 11R, left front wheel 11L), middle wheels 12 (right middle wheel 12R, left middle wheel 12L), and rear wheels 13 (right rear wheel 13R, right rear wheel 13R) are controlled to rotate in a forward or backward direction independently of one another. This allows the vehicle 1 to travel forward, backward, sideways, diagonally, or make spin turns. A specific example of such rotation of the front right wheel 11R, front left wheel 11L, center right wheel 12R, center left wheel 12L, rear right wheel 13R and rear left wheel 13L and the behavior of the vehicle 1 will now be described.

[0034] Fig. 7 is a schematic diagram showing the rotation direction of each drive wheel and the magnitude of the drive force when the vehicle moves forward. Note that in Fig. 7 and Figs. 8 to 10 described later, the diagonal lines of the Mecanum wheel 100 indicate the direction in which the rotation shaft 102s of the free wheel 102 extends when viewed from above, but the direction in which the rotation shaft 102s of the free wheel 102 extends is perpendicular to the diagonal lines when viewed from the road surface R side. As shown in FIG. 7, when the front right wheel 11R, the front left wheel 11L, the center right wheel 12R, the center left wheel 12L, the rear right wheel 13R and the rear left wheel 13L are all rotated forward (normally), the vehicle 1 moves forward. Contrary to FIG. 7, when the front right wheel 11R, the front left wheel 11L, the center right wheel 12R, the center left wheel 12L, the rear right wheel 13R and the rear left wheel 13L are all rotated backward (inverted), the vehicle 1 moves backward.

[0035] FIG. 8 is a schematic diagram showing the rotation direction of each drive wheel and the magnitude of the drive force when the vehicle is traversed to the right. 8, when the left front wheel 11L and the right rear wheel 13R are rotated forward and the right front wheel 11R and the left rear wheel 13L are rotated backward, the vehicle 1 moves parallel to the right (right lateral movement). In this case, the right middle wheel 12R and the left middle wheel 12L are not driven, and the swivel wheel 202 that is in contact with the ground rotates freely according to the traveling direction of the vehicle 1. 8, when the left front wheel 11L and the right rear wheel 13R are rotated backward and the right front wheel 11R and the left rear wheel 13L are rotated forward, the vehicle 1 moves parallel to the left (left lateral movement). In this case, the right middle wheel 12R and the left middle wheel 12L are not driven, and the swivel wheel 202 that is in contact with the ground rotates freely according to the traveling direction of the vehicle 1.

[0036] FIG. 9 is a schematic diagram showing the rotation direction of each drive wheel and the magnitude of the drive force when the vehicle is moved obliquely backward to the right. As shown in Fig. 9, when the right front wheel 11R and the left rear wheel 13L are rotated backward and the right middle wheel 12R and the left middle wheel 12L are rotated backward at a rotation speed slower than that of the right front wheel 11R and the left rear wheel 13L, the vehicle 1 moves diagonally backward to the right (backward right diagonal movement). Alternatively, for example, the bogie link 20 may be rotated by the bogie link control motor 37 to raise the right middle wheel 12R and the left middle wheel 12L above and away from the road surface R, and the right front wheel 11R and the left rear wheel 13L may be rotated backward. In either case, the left front wheel 11L and the right rear wheel 13R are not driven, and the swivel wheel 102 on the ground is in a state of freely rotating according to the traveling direction of the vehicle 1. Even when the vehicle 1 is caused to slant in another direction, it can be controlled in the same manner as in FIG.

[0037] FIG. 10 is a schematic diagram showing the rotation direction of each drive wheel and the magnitude of the drive force when the vehicle is turned clockwise. As shown in FIG. 10, when the right front wheel 11R, the right middle wheel 12R, and the right rear wheel 13R are rotated backward and the left front wheel 11L, the left middle wheel 12L, and the left rear wheel 13L are rotated forward, the vehicle 1 turns clockwise (right spin turn). Contrary to FIG. 10, when the right front wheel 11R, the right middle wheel 12R, and the right rear wheel 13R are rotated forward and the left front wheel 11L, the left middle wheel 12L, and the left rear wheel 13L are rotated backward, the vehicle 1 turns counterclockwise (left spin turn).

[0038] In this way, by using Mecanum wheels and Omni wheels as the front wheels 11, middle wheels 12, and rear wheels 13, the vehicle 1 is configured to be able to travel in all directions of 360° while maintaining its posture.

[0039] Each of the multiple suspensions 50 is provided corresponding to each of the multiple driving wheels 10. The suspension 50F corresponding to the front wheel 11 is provided between the front end portion 20f of the bogie link 20 and the front wheel 11. The suspension 50M corresponding to the middle wheel 12 is provided between the rear end portion 20r of the bogie link 20 and the middle wheel 12. The suspension 50R corresponding to the rear wheel 13 is provided between the rear end portion 30r of the rocker link 30 and the rear wheel 13.

[0040] Fig. 11 is a diagram showing the mounting structure of the suspension for each drive wheel. Fig. 12 is a perspective view showing the configuration of the suspension. In this embodiment, the left side of the paper in Fig. 11 is the front side in the fore-and-aft direction F of the vehicle 1, and the right side is the rear side. In Fig. 12, the right side of the paper is the front side in the fore-and-aft direction F of the vehicle 1, and the left side is the rear side. Here, the mounting structure of the suspension 50 is the same for each of the front wheels 11, the middle wheels 12, and the rear wheels 13. For this reason, in the following description, the front wheels 11, the middle wheels 12, and the rear wheels 13 will be referred to simply as drive wheels 10, and the power sources 41R, 41L, 42R, 42L, 43R, and 43L will be referred to as power source 40.

[0041] As shown in FIGS. 11 and 12, the suspension 50 includes a first plate portion 51, a second plate portion 52, and an elastic member 55. The first plate portion 51 and the second plate portion 52 are made of a plastic material. The first plate portion 51 is a plate-shaped member, and is provided along a plane intersecting with the up-down direction U. The first plate portion 51 is provided so that its long side direction is along the front-rear direction F and its short side direction is along the vehicle width direction W. In this embodiment, the first plate portion 51 is provided so as to be horizontal when the vehicle 1 is placed on a horizontal road surface R. The first plate portion 51 is fixed to the lower end surfaces of the front end portion 20f, the rear end portion 20r of the bogie link 20, and the rear end portion 30r of the rocker link 30, which are parts of the vehicle body portion 2.

[0042] The second plate portion 52 is provided below the first plate portion 51 at a position spaced from the first plate portion 51 so as to face the first plate portion 51. The second plate portion 52 is a plate-shaped member and is provided along a plane intersecting the up-down direction U. The second plate portion 52 is provided so that the long side direction is along the front-rear direction F and the short side direction is along the vehicle width direction W. In this embodiment, as shown in FIG. 1, when the load of the vehicle body portion 2 acts on the elastic member 55 described later and the elastic member 55 is appropriately contracted, the second plate portion 52 is provided so as to be parallel to the first plate portion. In this embodiment, when the vehicle 1 is provided on a horizontal road surface R, the second plate portion 52 is provided so as to be horizontal. The second plate portion 52 is provided so as to overlap the first plate portion 51 when viewed from above. A support member 18 is fixed to the underside of the second plate portion 52, which supports the rotating shafts 101s, 201s of the main wheels 101, 201 of the drive wheel 10 and a power source 40 that corresponds to the drive wheel 10 and drives the drive wheel 10.

[0043] The first plate portion 51 and the second plate portion 52 have respective protruding portions 51b, 52b on their opposing surfaces 51f, 52f. In the first plate portion 51, an end side 51s on one side in the front-rear direction F is wider in the left-right direction than an end side 51t on the other side in the front-rear direction F. In this manner, an enlarged width portion 51w is formed on the end side 51s. The enlarged width portion 51w is formed wider in the left-right direction than an end side 52s located on the same side in the front-rear direction F of the second plate portion 52. The protruding portions 51b are provided in pairs so as to protrude downward from each of the end portions on both left and right sides of the enlarged width portion 51w. The protruding portion 52b of the second plate portion 52 protrudes upward from an end side 52s on one side in the front-rear direction F and is inserted between the left and right protruding portions 51b. As a result, the protruding portion 51b of the first plate portion 51 and the protruding portion 52b of the second plate portion 52 are provided so as to overlap each other when viewed from the side in the left-right direction.

[0044] The rotation shaft 53 extends in the left-right direction and is provided so as to penetrate the overlapping portion of the protrusion 51b of the first plate portion 51 and the protrusion 52b of the second plate portion 52. As a result, the second plate portion 52 is provided so that its other end side 52t, which is opposite to the end side 52s, can swing freely in the up-down direction U relative to the first plate portion 51, centered on the rotation shaft 53 provided along the end side 52s.

[0045] With this configuration, the second plate portion 52 is provided so as to be movable relative to the first plate portion 51 so as to enable the drive wheel 10 to move in the up-down direction U while maintaining its posture. That is, when the drive wheel 10 fixed to the underside of the second plate portion 52 attempts to move up and down in response to unevenness in the road surface R, it swings in the up-down direction U together with the second plate portion 52 around the rotation axis 53. Even if the second plate portion 52 swings in the up-down direction U in this manner, the first plate portion 51 basically does not move in the up-down direction U within a range in which this swing is permitted as an operation of the suspension 50. In addition, the rotation shaft 53 of the second plate portion 52 extends in the left-right direction of the vehicle body portion 2 parallel to the rotation shafts 101s, 201s of the main wheels 101, 201 of the driving wheels 10 fixed to the second plate portion 52. Therefore, when the second plate portion 52 swings around the rotation shaft 53 relative to the first plate portion 51, the side opposite to the rotation shaft 53 of the second plate portion 52 (rear side) moves up and down relative to the rotation shaft 53 side (front side), so that the second plate portion 52 itself tilts slightly forward and backward. However, this tilting does not change the inclination of the rotation shafts 101s, 201s of the main wheels 101, 201 of the driving wheels 10, which are provided in parallel with the second plate portion 52, with respect to the road surface R. Therefore, the attitude of the driving wheel 10 and the contact area with the road surface R do not change, and therefore the frictional force acting between the driving wheel 10 and the road surface R is also unlikely to change. In this embodiment, the end side 52s of the second plate portion 52 on which the rotating shaft 53 is provided is located on the front side of the vehicle 1 as shown in Fig. 1. The end side 52s of the second plate portion 52 on which the rotating shaft 53 is provided may be located on the rear side of the vehicle 1.

[0046] The elastic member 55 is provided between the first plate portion 51 and the second plate portion 52. In this embodiment, the elastic member 55 is provided between the surfaces 51f, 52f of the first plate portion 51 and the second plate portion 52, which face each other, on the opposite side of the rotation shaft 53 in the front-rear direction F. In this embodiment, the elastic member 55 is a coil spring 56. The coil spring 56 as the elastic member 55 absorbs the displacement energy of the second plate portion 52 that swings around the rotation shaft 53 when the drive wheel 10 moves up and down in accordance with the unevenness of the road surface R.

[0047] Furthermore, in this embodiment, each suspension 50 is provided between the first plate portion 51 and the second plate portion 52 with a relative movement direction regulating member 57 that regulates the direction of movement of the drive wheel 10 only in the up-down direction U. When the second plate portion 52 oscillates relative to the first plate portion 51 about the rotation shaft 53, the relative movement direction regulating member 57 regulates the direction of the oscillation only in the up-down direction U so as not to deviate in the left-right direction of the vehicle body portion 2 (vehicle width direction W). The relative movement direction regulating member 57 is, for example, a guide rod extending in the up-down direction U, and is inserted into a through hole (not shown) formed in the second plate portion 52. This through hole is formed with a clearance between the guide rod and the second plate portion 52 so that the guide rod does not interfere with the second plate portion 52 when the second plate portion 52 swings around the rotation shaft 53. Furthermore, the suspension 50 may include a damper (shock absorber) that attenuates the displacement energy of the second plate portion 52 relative to the first plate portion 51. In this case, the damper may function as a relative movement direction regulating member 57.

[0048] In such a suspension 50, when the road surface R during travel is uneven, the driving wheel 10 and the second plate portion 52 fixed thereto attempt to move in the vertical direction U in accordance with the condition of the road surface R. Here, the second plate portion 52 is provided so as to be movable relative to the first plate portion 51 so as to enable the driving wheel 10 to move in the vertical direction U while maintaining its posture, and therefore the movement of the driving wheel 10 and the second plate portion 52 in the vertical direction U is performed relative to the first plate portion 51. In addition, an elastic member 55 is provided between the first plate portion 51 and the second plate portion 52. Therefore, when the road surface R has a recess, the elastic member 55 expands and the second member and the driving wheel 10 are biased against the road surface R. In addition, when the road surface R has a projection, the elastic member 55 contracts and absorbs the rise of the driving wheel 10 and the second member.

[0049] According to the vehicle 1 as described above, the vehicle 1 includes a vehicle body 2, a plurality of drive wheels 10, and a plurality of suspensions 50. Each of the plurality of drive wheels 10 includes a power source 40, a main wheel 101, 201 driven by the power source 40, and a plurality of swivel wheels 102, 202 each rotatably provided on the outer periphery of the main wheels 101, 201 so as to be aligned in the circumferential direction. In each of the plurality of drive wheels 10, the rotation axes 102s, 202s of the plurality of swivel wheels 102, 202 are aligned with respect to the rotation axes 101s, 201s of the main wheels 101, 201 so as to be aligned along the outer periphery of the main wheels 101, 201. The multiple suspensions 50 are arranged at the same angle, and each of the multiple suspensions 50 corresponds to each of the multiple drive wheels 10, and is arranged so as to intersect in the vertical direction U and is fixed to the vehicle body portion 2, a second plate portion 52 is fixed to the corresponding drive wheel 10 and is arranged below the first plate portion 51, at a position spaced from the first plate portion 51, so as to intersect in the vertical direction U and be movable relative to the first plate portion 51 so as to allow the drive wheel 10 to move in the vertical direction U while maintaining its posture, and an elastic member 55 is provided between the first plate portion 51 and the second plate portion 52. In the above-mentioned configuration, the vehicle 1 includes a plurality of drive wheels 10. Each of the plurality of drive wheels 10 includes a power source 40, a main wheel 101, 201 driven by the power source 40, and a plurality of swivel wheels 102, 202 that are rotatably arranged in a line around the outer periphery of the main wheel 101, 201. In each of the plurality of drive wheels 10, the rotation axes 102s, 202s of the plurality of swivel wheels 102, 202 are inclined at the same angle with respect to the rotation axes 101s, 201s of the main wheels 101, 201 so as to follow the outer periphery of the main wheel 101, 201. In this configuration, when the main wheel 101, 201 is driven to rotate, a frictional force acts between the swivel wheels 102, 202 that are arranged around the outer periphery of the main wheel 101, 201 and the road surface R, and the swivel wheels 102, 202 tend to rotate due to this frictional force. Here, the rotation axes 102s, 202s of the swivel wheels 102, 202 are inclined at the same angle with respect to the rotation axes 101s, 201s of the main wheels 101, 201, so the torque of the main wheels 101, 201 is converted from the rotation direction of the main wheels 101, 201 to a direction according to the inclination of the rotation axes 102s, 202s of the swivel wheels 102, 202. In this way, the traveling direction of the vehicle 1 can be changed while maintaining the attitude of the vehicle 1 unchanged. For such a driving wheel 10, the vehicle 1 is provided with a plurality of suspensions 50. Each of the plurality of suspensions 50 is provided corresponding to each of the plurality of driving wheels 10. Each of the plurality of suspensions 50 includes a first plate portion 51 fixed to the vehicle body portion 2 so as to intersect with the vertical direction U, a second plate portion 52 fixed to the corresponding driving wheel 10 and provided below the first plate portion 51 at a position spaced apart from the first plate portion 51 so as to intersect with the vertical direction U, and an elastic member 55 provided between the first plate portion 51 and the second plate portion 52. In this configuration, when the road surface R during traveling has unevenness or the like, the driving wheel 10 tries to move in the vertical direction U following the condition of the road surface R. Here, the second plate portion 52 is provided so as to be movable relative to the first plate portion 51 so as to allow the drive wheel 10 to move in the up-down direction U, and therefore the drive wheel 10 and the second plate portion 52 to which the drive wheel 10 is fixed move in the up-down direction U relative to the first plate portion 51. In addition, an elastic member 55 is provided between the first plate portion 51 and the second plate portion 52. Therefore, when there is a recess in the road surface R, the elastic member 55 expands and biases the second member and the drive wheel 10 against the road surface R. In addition, when there is a protrusion in the road surface R, the elastic member 55 contracts and absorbs the rise of the drive wheel 10 and the second member. Here, the second plate portion 52 is provided with respect to the first plate portion 51 so as to allow the corresponding driving wheel 10 to move in the up-down direction U while maintaining its posture, so that when the suspension 50 absorbs the relative movement of the driving wheel 10 with respect to the body portion 2, the angle and posture of the rotation shafts 101s, 201s of the main wheels 101, 201 with respect to the road surface R are maintained. Therefore, even if the driving wheel 10 moves up and down in response to the unevenness of the road surface R, the inclination and posture of the driving wheel 10 do not change, and the contact area between the driving wheel 10 and the road surface R is also unlikely to change, so that the frictional force acting between the driving wheel 10 and the road surface R is also unlikely to change. Therefore, the torque acting on the driving wheel 10 is appropriately transmitted to the road surface R via the swivel wheels 102, 202, and as a result, the vehicle 1 can be made to travel in the intended direction. In this way, when the driving wheel 10 is a wheel having a plurality of swivel wheels 102, 202, each of which is freely rotatable, attached to the outer periphery of the main wheels 101, 201, it is possible to provide a vehicle 1 that can ensure reliable contact between the road surface R and the driving wheel 10, thereby realizing stable driving performance.

[0050] In addition, in each of the multiple suspensions 50, the second plate portion 52 faces the first plate portion 51 and is freely swingable in the vertical direction U relative to the first plate portion 51, centered on a rotating shaft 53 provided along an end edge 52s of the second plate portion 52, and the end edge 52s of the second plate portion 52 on which the rotating shaft 53 is provided is located at the front or rear side in the fore-and-aft direction F of the vehicle body portion 2. According to this configuration, the first plate portion 51 and the second plate portion 52 are firmly connected to each other so as to be able to swing freely in the vertical direction U relative to the first plate portion 51, centered on the rotation shaft 53 provided along the end side 52s of the second plate portion 52. This makes it possible to prevent the drive wheel 10 and the second plate portion 52 from being displaced in directions other than the vertical direction U when they swing in the vertical direction U relative to the first plate portion 51. In addition, if the end side 52s of the second plate portion 52 on which the rotation shaft 53 is provided is located, for example, on the right side, not on the front or rear side of the second plate portion in the front-rear direction F of the vehicle body portion 2, the rotation shaft 53 of the second plate portion 52 will be in a state of extending in the front-rear direction F on the right side of the vehicle body portion 2. This direction is a direction perpendicular to the left-right direction (vehicle width direction W) in which the rotation shafts 101s, 201s of the main wheels 101, 201 of the drive wheels 10 fixed to the second plate portion 52 extend. Therefore, when the second plate portion 52 swings around the rotation shaft 53 relative to the first plate portion 51, the left side of the second plate portion 52 moves up and down relative to the right side, so that the second plate portion 52 tilts left and right, and accordingly, the angle of the rotation shafts 101s, 201s of the main wheels 101, 201 of the drive wheels 10 fixed to the second plate portion with respect to the road surface R changes. This may change the inclination and posture of the drive wheel 10 relative to the road surface R, changing the contact area between the drive wheel 10 and the road surface R, and potentially changing the frictional force acting between the drive wheel 10 and the road surface R. In contrast, in the above-mentioned configuration, the end edge 52s of the second plate portion on which the rotating shaft 53 is provided is located at the front or rear in the fore-and-aft direction F of the vehicle body portion 2, so that the rotating shaft 53 of the second plate portion 52 extends in the left-right direction (vehicle width direction W) of the vehicle body portion 2, i.e., in a direction parallel to the rotating shafts 101s, 201s of the main wheels 101, 201 of the driving wheel 10 fixed to the second plate portion 52, and the second plate portion 52 extends in the fore-and-aft direction F of the vehicle body portion 2 from the end edge 52s on which the rotating shaft 53 is provided. In this configuration, when the second plate portion 52 swings around the rotation shaft 53 relative to the first plate portion 51, the side of the second plate portion 52 opposite the rotation shaft 53 moves up and down relative to the rotation shaft 53 side, causing the second plate portion 52 itself to tilt forward and backward, but this tilt does not change the inclination of the rotation shafts 101s, 201s of the main wheels 101, 201 of the drive wheel 10, which are provided parallel to the second plate portion 52, with respect to the road surface R. For this reason, the attitude of the drive wheel 10 and the contact area with the road surface R do not change, and therefore the frictional force acting between the drive wheel 10 and the road surface R is also unlikely to change. In this way, even if a suspension is provided, the torque acting on the drive wheels 10 is appropriately transmitted to the road surface via the swivel wheels 102, 202, and as a result, the vehicle 1 can be made to travel in the intended direction.

[0051] In addition, in each of the multiple suspensions 50, the opposing surfaces 51f, 52f of the first plate portion 51 and the second plate portion 52 are each provided with a protrusion 51b, 52b that protrudes from the surface 51f, 52f, the protrusions 51b, 52b of the first plate portion 51 and the second plate portion 52 are arranged to overlap each other when viewed from the side, and the rotation axis 53 of the second plate portion 52 is arranged to pass through the overlapping portions of the protrusions 51b, 52b of the first plate portion 51 and the second plate portion 52. According to this configuration, the rotating shaft 53 penetrates the protruding portion 51b of the first plate portion 51 and the protruding portion 52b of the second plate portion 52, so that both the first plate portion 51 and the second plate portion 52 are firmly connected to each other so as to be freely swingable about the rotating shaft 53. This makes it possible to more firmly prevent the driving wheel 10 and the second plate portion 52 from being displaced in any direction other than the vertical direction U when they swing in the vertical direction U relative to the first plate portion 51. In addition, since the protruding portion 51b of the first plate portion 51 and the protruding portion 52b of the second plate portion 52 overlap each other when viewed from the side, when the first plate portion 51 and the second plate portion 52 try to move relatively in the left-right direction in which the rotating shaft 53 extends, the protruding portion 51b of the first plate portion 51 and the protruding portion 52b of the second plate portion 52 come into contact with each other. As a result, when the drive wheel 10 and the second plate portion 52 swing in the up-down direction U relative to the first plate portion 51, positional deviation in the left-right direction relative to the first plate portion 51 is suppressed.

[0052] Further, each of the plurality of suspensions 50 includes a relative movement direction regulating member 57 between the first plate portion 51 and the second plate portion 52, which regulates the direction of movement of the drive wheel 10 only in the up-down direction U. According to this configuration, the relative movement direction regulating member 57 causes the drive wheel 10 to move only in the up-down direction U. This makes it possible to prevent the drive wheel 10 from being displaced in directions other than the up-down direction U, such as the vehicle width direction or the front-rear direction F of the vehicle.

[0053] In each of the suspensions 50 , the elastic member 55 is a coil spring 56 . According to this configuration, by using the coil spring 56 as the elastic member 55, the elastic member 55 can be formed with a simple structure.

[0054] (First Modification of the Embodiment) The vehicle of the present invention is not limited to the embodiment described above with reference to the drawings, and various modifications are possible within the technical scope of the vehicle. For example, in the above embodiment, the coil spring 56 is provided as the elastic member 55 of the suspension 50 provided in the vehicle 1, but the present invention is not limited to this. FIG. 13 is a perspective view showing a suspension provided on a vehicle according to a first modified example of the present embodiment. As shown in Fig. 13, the suspension 50B provided in the vehicle 1 according to this modification includes a block-shaped rubber 58 as the elastic member 55. The rubber 58 as the elastic member 55 is provided between the first plate portion 51 and the second plate portion 52. In this embodiment, the elastic member 55 is provided between the surfaces 51f, 52f facing each other at a position on the opposite side of the rotation shaft 53 in the front-rear direction F of the first plate portion 51 and the second plate portion 52. The rubber 58 as the elastic member 55 absorbs the displacement energy of the second plate portion 52 swinging around the rotation shaft 53 when the drive wheel 10 moves up and down in accordance with the unevenness of the road surface R.

[0055] According to this configuration, by using rubber 58 as elastic member 55, elastic member 55 can be formed with a simple structure. By providing a suspension 50B having such a configuration, as in the above embodiment, when the driving wheel 10 is a wheel having a plurality of swivel wheels 102, 202, each of which is freely rotatable, attached to the outer periphery of the main wheels 101, 201, it is possible to provide a vehicle 1 that can ensure reliable contact between the road surface R and the driving wheel 10, thereby achieving stable driving performance.

[0056] (Second Modification of the Embodiment) FIG. 14 is a perspective view showing a suspension provided on a vehicle according to a second modification of the present embodiment. As shown in FIG. 14, the suspension 50C provided in the vehicle 1 according to this modification includes a leaf spring 59 as the elastic member 55. The leaf spring 59 as the elastic member 55 is provided between the first plate portion 51 and the second plate portion 52. The leaf spring 59 has both ends in the up-down direction U connected to the first plate portion 51 and the second plate portion 52. The leaf spring 59 has a bent portion 59c bent in the front-rear direction F in the middle portion in the up-down direction U. In this embodiment, the elastic member 55 is provided between the surfaces 51f and 52f facing each other at a position on the opposite side of the rotation shaft 53 in the front-rear direction F of the first plate portion 51 and the second plate portion 52. When the drive wheel 10 moves up and down due to the unevenness of the road surface R, the leaf spring 59 as the elastic member 55 elastically deforms in the up-down direction U to absorb the displacement energy of the second plate portion 52 swinging around the rotation shaft 53.

[0057] According to this configuration, by using the leaf spring 59 as the elastic member 55, the elastic member 55 can be formed with a simple structure. By providing a suspension 50C having such a configuration, as in the above embodiment, when the driving wheel 10 is a wheel having a plurality of swivel wheels 102, 202, each of which is freely rotatable, attached to the outer periphery of the main wheels 101, 201, it is possible to provide a vehicle 1 that can ensure reliable contact between the road surface R and the driving wheel 10, thereby achieving stable driving performance.

[0058] (Third Modification of the Embodiment) In the above embodiment and each modified example, the rotation shaft 53 is provided on one side, for example, the front side, of the first plate portion 51 and the second plate portion 52 in the front-rear direction F, and the elastic member 55 is provided on the other side, for example, the rear side. Instead of this, as shown in Fig. 12, a combination of a coil spring 56 as the elastic member 55 and a guide rod as a relative movement direction regulating member 57 may be provided on both the front and rear sides in the front-rear direction F, and the rotation shaft 53 may not be provided on either the front or rear side. In this case, the second plate portion 52 does not move in the up-down direction U by swinging relative to the first plate portion 51, but moves relatively in the up-down direction U so that the second plate portion 52 moves toward or away from the first plate portion 51 as a whole. In this case, it is desirable to provide a parallel movement mechanism between the first plate portion 51 and the second plate portion 52 such that the relative movement of the second plate portion 52 in the up-down direction U with respect to the first plate portion becomes a parallel movement with respect to the first plate portion, so that the posture of the drive wheel 10 is maintained even if the drive wheel 10 moves in the up-down direction U. Such a parallel movement mechanism may be configured, for example, such that a pair of link members are provided parallel and obliquely between the side surfaces of the first plate portion 51 and the second plate portion 52 on each of the side surfaces on both sides of the first plate portion 51 and the second plate portion 52 in the left-right direction (vehicle width direction W) of the vehicle body portion 2, so that a parallelogram is formed by the first plate portion 51, the second plate portion 52 and the pair of link members, and when the second plate portion 52 moves relatively to the first plate portion 51, each of the pair of link members simultaneously changes the inclination angle while maintaining the overall shape of the parallelogram, so that the second plate portion 52 moves parallel to the first plate portion 51. Even in such a case, a configuration can be realized in which each of the multiple suspensions 50 is provided corresponding to each of the multiple drive wheels 10, and includes a first plate portion 51 fixed to the vehicle body portion 2, a second plate portion 52 fixed to the corresponding drive wheel 10, and disposed below the first plate portion 51 and spaced from the first plate portion 51, so as to intersect with the vertical direction U and be movable relative to the first plate portion 51 so as to enable the drive wheel 10 to move in the vertical direction U while maintaining its posture, and an elastic member 55 provided between the first plate portion 51 and the second plate portion 52.

[0059] In addition, the configurations described in the above embodiments can be selected or changed as appropriate without departing from the spirit of the present invention. For example, in the above first and second modified examples, the suspensions 50B, 50C may be configured to have a relative movement direction determining member 57 such as a guide rod, in addition to the rubber 58 or leaf spring 59 as the elastic member 55, as in the embodiment. [Explanation of symbols]

[0060] 1 vehicle 2 Body 10 Drive wheels 40, 41L, 41R, 42L, 42R, 43L, 43R power source 50, 50B, 50C, 50F, 50M, 50R Suspension 51 1st plate part 51b Protrusion 51f surface 52 2nd plate part 52b Protrusion 52f surface 52s edge 53 Rotation axis 55 Elastic member 56 Coil spring 57 Relative movement direction control member 58 Rubber (relative movement direction control member) 59 Leaf spring (relative movement direction control member) 101 Main wheel 101s Rotation Axis 102 Free wheel 102s Rotation axis 201 Main wheel 201s Rotation axis 202 Free wheel 202s Rotation axis F Front and back direction U vertical direction

Claims

1. A vehicle body part, A plurality of drive wheels; Multiple suspensions and Equipped with Each of the plurality of drive wheels includes a power source, a main wheel driven by the power source, and a plurality of free wheels each rotatably arranged to be aligned in a circumferential direction on an outer periphery of the main wheel, and in each of the plurality of drive wheels, the rotation axis of each of the plurality of free wheels is inclined at the same angle with respect to the rotation axis of the main wheel so as to be aligned along the outer periphery of the main wheel, Each of the plurality of suspensions is provided corresponding to each of the plurality of drive wheels, A first plate portion provided so as to intersect in the vertical direction and fixed to the vehicle body portion; a second plate portion fixed to the corresponding driving wheel, disposed below the first plate portion and spaced from the first plate portion, so as to intersect with the up-down direction and to be movable relative to the first plate portion so as to allow the driving wheel to move in the up-down direction while maintaining its posture; An elastic member provided between the first plate portion and the second plate portion; A vehicle comprising:

2. 2. The vehicle described in claim 1, wherein in each of the plurality of suspensions, the second plate portion faces the first plate portion and is freely swingable in the up-down direction relative to the first plate portion around a rotation axis provided along an end edge of the second plate portion, and the end edge of the second plate portion on which the rotation axis is provided is located at the front or rear in the fore-and-aft direction of the vehicle body portion.

3. In each of the plurality of suspensions, a protrusion is provided on each of the mutually opposing surfaces of the first plate portion and the second plate portion so as to protrude from the corresponding surface, The protruding portions of the first plate portion and the second plate portion are provided so as to overlap each other when viewed from a side, The vehicle according to claim 2 , wherein the rotation shaft of the second plate portion is provided to pass through overlapping portions of the protruding portions of the first plate portion and the second plate portion.

4. 4. The vehicle according to claim 1, wherein each of the plurality of suspensions is provided with a relative movement direction regulating member between the first plate portion and the second plate portion, which regulating the direction of movement of the drive wheel only in the up-down direction.

5. 4. The vehicle according to claim 1, wherein in each of the plurality of suspensions, the elastic member is any one of a coil spring, rubber, and a leaf spring.

Images