JPH0764205B2 - Steering mechanism for omnidirectional vehicles - Google Patents

Description

Description: TECHNICAL FIELD OF THE INVENTION The present invention relates to a steering mechanism for an omnidirectional vehicle having four wheels and traveling by turning each wheel in an arbitrary direction.

BACKGROUND OF THE INVENTION Generally, there are two types of vehicles, one is a vehicle type vehicle that steers the front wheels to change the direction of the vehicle body while the other is a vehicle type vehicle that changes the direction of all the wheels. There is an omnidirectional vehicle that moves in all the front-back, left-right, and diagonal directions without changing the direction, but the above-mentioned vehicle-type vehicle has a large turning radius when changing the traveling direction. It is unsuitable as a moving vehicle that moves while changing direction even in a narrow space between desks, a moving vehicle that follows a specified complicated movement pattern, or a vehicle that requires a sharp turning direction. is there. Therefore, an omnidirectional vehicle that uses all the wheels to move in all directions without changing the direction of the vehicle body is used.

[First Prior Art] As a steering mechanism for an omnidirectional vehicle as described above, there is a conventional steering mechanism configured as shown in FIGS. 13 (A) and 13 (B). That is, in this type of steering mechanism, four steering shafts 2 ... Are vertically provided on a vehicle body 1, and the vehicle bearings 3 ... At the lower end of the steering shafts 2 ... Wheels 4 ... Are rotatably provided, and pulleys 5 ... Are provided above the respective steering shafts 2 ..., and one belt 6 is wound around the pulleys 5 ... By rotating the steering shafts 2 by a drive device (not shown), all the steering shafts 2 ...
The direction of the car is changed to change the traveling direction.
In this case, the wheels 4, ... Are driven by a drive motor (not shown) to drive the omnidirectional vehicle.

However, in such a steering mechanism,
Since the rotation of one steering shaft 2 is transmitted to each steering shaft 2 by a belt 6 and all the wheels 4 are turned in the same direction, it is shown in FIG. 14 (A). Such an omnidirectional mode (a function of running straight in front, rear, left and right and diagonal directions) is possible, but a car mode (a function of turning an automobile) as shown in FIG.
Alternatively, the rotation mode (function of rotating the pivot) as shown in FIG. 7C cannot be performed.

[Second Prior Art] In addition to the steering mechanism as described above,
As shown in FIGS. (A) and (B), the front unit 7 and the rear unit 8 are arranged so that the wheels 4 operate separately on the front side (right side in the figure) and the rear side (left side in the figure). There is one divided into. That is, of these units 7, 8, the front unit 7 is the drive unit 9 provided on the lower surface of the vehicle body 1.
Each driving shaft 9a of the above is projected to the upper side of the vehicle body 1 and is rotatably attached to the vehicle body 1 through a bearing 9b, and a driving pulley 10 is provided on each of the driving shafts 9a projecting upward. A drive pulley which is formed by winding a belt 11 for transmitting the rotation to each pulley 5a, 5a of the right steering shaft 2a, 2a, and which is normally or reversely rotated by a drive device 9.
The front (right) steering shafts 2a, 2a are appropriately rotated by 10 to change the direction of the wheels 4a, 4a to a predetermined direction. On the other hand, similarly to the front unit 7 described above, the rear unit 8 also includes the drive device 12, the drive pulley 13 provided on the driving shaft 12a, and the rotation of the drive device 12, the pulleys 5b and 5b of the left steering shafts 2b and 2b. And a belt 14 which is transmitted to the steering wheel 2b and 2b on the rear side (left side) by a drive pulley 13 which is normally rotated and reversely rotated by a drive device 12, so that the wheels 4b and 4b are oriented in a predetermined direction. It is designed to change to.

However, in such a steering mechanism, since the front unit 7 and the rear unit 8 move independently, the omnidirectional mode shown in FIG. 14 (A) and the car mode shown in FIG. 14 (B) are different from each other. Possible, but two wheels 4a, 4a of the front unit 7 or two of the rear unit 8
Since the four wheels 4b and 4b always move in synchronization, the rotation mode shown in FIG. 7C cannot be performed. Moreover, in the car mode, as shown in FIGS. 16 (A) and 16 (B), a large angle difference is generated between the rolling direction of the wheels 4a, 4a and 4b, 4b and the actual traveling direction during a small radius turning. . Therefore, there is a problem that resistance increases during traveling, a braking phenomenon occurs, a practical turning radius cannot be reduced, and a small turn cannot be performed.

[Object of the Invention] The present invention has been made in view of the above circumstances. The object of the present invention is to provide a wide variety of omnidirectional modes, car modes, rotation modes, etc. with a relatively simple structure. Another object of the present invention is to provide a steering mechanism for an omnidirectional vehicle that has a direction-changing function as well as is capable of traveling satisfactorily and has a very high degree of freedom of direction change.

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention has two steering wheels (hereinafter, two front steering wheels) rotatably provided at two locations on one side of a vehicle body. At the same time, two other steering wheels (hereinafter, also referred to as two rear steering wheels) are rotatably provided at two locations on the opposite side of the vehicle body facing each other, and wheels are respectively rotated on these four steering wheels. In a steering mechanism of an omnidirectional vehicle that is freely mounted and rotates each steering wheel as needed to change the direction of each wheel to travel, four driven pulleys are provided above each steering shaft of four steering wheels. , Alignment direction of front and rear steering on the vehicle body between the front and rear steering A moving driving means having a slider that moves along is provided, and the slider of the moving driving means passes through substantially the centers of the four steering wheels in accordance with the movement of the slider by the moving driving means, and the arrangement direction of the front and rear steering wheels A pair of control pulleys that move along the first belt is wound around one of the pair of control pulleys and the driven pulleys of the two front steering wheels, and the other of the pair of control pulleys. A second belt is wound around the driven pulleys of the two rear steering wheels, and the first and second tension adjusting means provided on the vehicle body respectively form the first and second belts as the control pulley moves. It is designed to give a constant tension.

Therefore, according to the present invention, one set of control pulleys is arranged substantially at the center of the four steering wheels by the movement driving means, and when one set of control pulleys rotates in this state,
The four driven pulleys all rotate in the same direction and the same angle through the first and second belts, and the four steering wheels operate in the same way, so that all four wheels rotate in the same direction and at the same angle. As a result, the vehicle is in an omnidirectional mode in which it travels straight in all directions.

Further, when the set of control pulleys is moved by a predetermined distance along the arrangement direction of the front and rear steering wheels by the movement driving means, the two driven pulleys around which the first belt is wound are Although the driven pulleys rotate in the same direction, the driven pulley on the approaching side of the control pulley is smaller than the driven pulley on the separating side of the control pulley, and the two driven pulleys around which the second belt is wound are The two driven pulleys rotate in the opposite direction, and the rotation angle of the driven pulley on the approaching side of the control pulley is smaller than that of the driven pulley on the separating side of the control pulley. , The wheels rotate in the directions corresponding to the rotations of the driven pulleys, respectively, whereby the car mode in which the vehicle travels in a curved line is obtained.

Furthermore, the set of control pulleys is moved further by the movement driving means than in the car mode, and the four driven pulleys are further rotated as in the car mode, respectively, and four wheels are formed around one of them. When facing the tangential direction of the circle, it becomes the rotation mode in which the pivot rotation is performed at that location.

[Structure of Embodiment] An embodiment of the present invention will be described below with reference to FIGS. 1 to 8.

1A to 1C show an omnidirectional vehicle. Four steering shafts 21a to 21d are rotatably provided near the four corners of a vehicle body 20 of the omnidirectional vehicle via bearings 22 ... Each of the steering shafts 21a to 21d has a cylindrical shape, a car bearing 23 ... Is provided at a lower end thereof, and driven pulleys 24a to 24d are provided at an upper portion thereof. The axle bearings 23 ... Rotate together with the steering shafts 21a to 21d, and the axle shafts 25 are provided inside thereof.
... are rotatably mounted via bearings 26, and wheels 27a to 27d are attached to the respective axles 25.
Are provided, and bevel gears 28 are provided. This bevel gear 28 ... has steering shafts 21a-2
A bevel gear 31 ... that rotates integrally with drive shafts 30a to 30d rotatably provided in 1d via bearings 29 ... meshes with the drive shafts 30a to 30d, which will be described later. When driven by 32, bevel gears 28 ... Rotate via bevel gears 31 ..., This rotation is transmitted to the axles 25 ..., and the wheels 27a to 27d rotate.

A drive pulley (control pulley) 33 is provided in the center of the vehicle body 20.
A movement drive device (movement drive means) 34 for sliding and rotating a and 33b is provided. That is, the drive pulley 33
The a and 33b are attached to the upper part of one support shaft 35. The movement drive device 34 includes a slider 36 on which a support shaft 35 of the drive pulleys 33a and 33b is rotatably erected, a pulley drive device 37 for rotating the support shaft 35, a movement mechanism 38 for sliding the slider 36, and this movement. Drive device for slider for driving mechanism 38
It consists of 39 and. The slider 36 is an opening in the center of the vehicle body 20.
Two guide shafts 40, which are suspended in 20a, sleeve 40 on 40
It is provided slidably via 1 and 41, and a support shaft 35 is rotatably attached to the center thereof via a bearing 35a. The pulley drive device 37 includes a speed reducer 37a, a motor 37b, an encoder 37c, etc., is provided under the slider 36, and the lower end of the support shaft 35 is connected to its output shaft. The moving mechanism 38 includes a pinion shaft 38b rotatably provided on the slider 36 via a bearing 38a, and a pinion 38c provided at an upper end of the pinion shaft 38b and integrally rotated.
And a rack 38d which is provided on the vehicle body 20 in parallel with the guide shafts 40, 40 and meshes with the pinion 38c.
The slider 36 is moved in the directions of arrows X and X '(the width direction of the vehicle body 20) as the rack 38d meshes with the rack 38d and rolls. The slider drive device 39 includes a speed reducer 39a, a motor 39b, an encoder 39c, etc., and is provided below the slider 36.
The lower end of the pinion shaft 38b is connected to the output shaft.
Therefore, the drive pulleys 33a and 33b are driven by the pulley drive device 37.
The slider drive device 39 drives the pinion shaft 38c of the moving mechanism 38 while the slider 36 rotates.
Is moved along the guide shafts 40, 40, the arrow X,
Move in the X'direction.

On the other hand, the first and second belts 41 and 42 are wound around the drive pulleys 33a and 33b and the driven pulleys 24a to 24d. That is,
The first belt 41 includes a drive pulley 33a and driven pulleys 24a and 24b.
And the steering shafts 21a and 21b of the front unit (right side in FIG. 1A) are rotated to change the direction of the wheels 27a and 27b. On the contrary, the second belt
42 is wound around a drive pulley 33b and driven pulleys 24c and 24d, and each steering shaft 21 of the rear unit (left side in the figure).
The directions of the wheels 27c and 27d are changed by rotating c and 21d. In this case, drive pulleys 33a, 33b and wheels
27a to 27d all have the same diameter and are set to the same size.

Further, the belts 41 and 42 are adjusted by the first and second tension adjusting devices 43 and 43 so that the tensions thereof are always constant. The tension adjusting devices 43, 43 are the same, and here the first tension adjusting device of the front unit is used.
43 will be described. The tension adjusting device 43 is a rotating arm 43a rotatably attached to the steering shaft 21b.
A shaft 43b provided at the tip of the rotating arm 43a, a tension roller 43d rotatably provided on the shaft 43b via a bearing 43c, and a rotating arm 43a always indicated by an arrow Y,
The coil spring 43e biases in the Y'direction, and the coil spring 43e pulls the coil spring 43e toward the rotating arm 43a.
The tension roller 43d is elastically contacted with the belt 41.

The drive device 32 for traveling that drives the wheels 27a to 27d is
As shown in FIGS. 2A and 2B, the speed reducer 32a, the motor 3
2b, encoder 32c, drive shaft 30 in each steering shaft 21a-21d via differential unit 45
The wheels a to d are rotated by rotating a to 30d. That is, the drive shafts 30a to 30d rotatably provided in the steering shafts 21a to 21d respectively include pulleys 46a to 4d at the portions protruding above the steering shafts 21a to 21d.
6d is provided for each drive shaft 30a, 3 on the front unit side.
Bevel gears 47, 47 are provided at the upper end of 0b, respectively.
The bevel gears 47, 47 are meshed with the bevel gears 48, 48 provided at the tips of the output shafts 45a, 45a of the differential unit 45, whereby the drive shafts 30a, 30b of the front unit are engaged.
Rotates, and the wheels 27 are rotated through the bevel gears 31 and 28 at the lower end thereof.
Rotate a and 27b. On the other hand, each drive shaft 30 of the rear unit
c and 30d are driven by two transmission belts 49 and 49 wound around the pulleys 46c and 46d on the upper side and the pulleys 46a and 46b on the front side unit, respectively, and the wheels via the bevel gears 31 and 28 at the lower end. It is designed to rotate 27c and 27d.

[Operation of Embodiment] Next, the operation of the steering mechanism of the omnidirectional vehicle configured as described above will be described with reference to FIGS. 3 to 8.

First, the case of the omnidirectional mode will be described. In this case, as shown in FIG. 3 (A), the drive pulleys 33a and 33b are arranged at the center of the vehicle body 20, that is, at the position where the diagonal lines connecting the steering shafts 21a to 21d intersect each other, and It is fixed by the drive device 39. In this state, the pulley drive device 37 moves the drive pulleys 33a, 3a through the support shaft 35.
When 3b is rotated, the driven pulleys 24a to 24d of all the steering shafts 21a to 21d are rotated by the respective belts 41 and 42 in the same direction by the same amount as the drive pulleys 33a and 33b. That is, when the drive pulleys 33a and 33b rotate by a predetermined angle θ, the driven pulleys
24a to 24d also rotate by θ. Driven pulley 24a like this
When .about.24d is turned, each steering shaft 21a.about.21d is also turned, and as shown in FIG. 4, all wheels 27a.about.27d are turned by .theta. In the same direction. As a result, the traveling direction of the omnidirectional vehicle is switched. Then, the driving device 32 for traveling is used for each wheel.
When 27a to 27d are driven, the omnidirectional vehicle travels in the set direction. In this case, the wheels 27a to 27d are
Since the steering shafts 21a to 21d turn 360 degrees, the omnidirectional vehicle can travel in all the front, rear, left, and right directions. In addition, the drive pulleys 33a, 3
The rotation angle θ of 3b is determined by the encoder 37c of the pulley drive device 37.
Is detected and controlled based on this detection signal, the directions of the wheels 27a to 27d can be accurately set.

Next, the case of the car mode will be described. In this case, the drive pulleys 33a and 33b are moved by a predetermined amount (distance) W _{1 in the} arrow X direction as shown in FIG. 3 (B). That is, by rotating the pinion 38c of the moving mechanism 38 with the slider driving device 39 and rolling the pinion 38c in the state of being engaged with the rack 38d, the slider 36 moves in the arrow X direction,
The drive pulleys 33a and 33b are moved in the same direction. In this case, the movement amount (distance) of the drive pulleys 33a and 33b is determined by the encoder 39c of the slider drive device 39 and the rotation amount (rotation speed) of the pinion 38c.
Is detected, and the amount of rotation is controlled based on this detection signal, so that it can be set accurately. Further, when the drive pulleys 33a and 33b move, they are fixed by the pulley drive device 37, so that the drive pulleys 33a and 33b move without rotating. When the drive pulleys 33a and 33b move in this way, the belts 41 and 42 move in accordance with this movement, and the driven pulleys 24a to 24d rotate as follows. That is, in the front unit on the right side, the belt 41 moves in the direction of the arrow Z ₁ in accordance with the movement of the drive pulley 33a and rotates the driven pulleys 24a and 24b in the same direction (clockwise), but the driven pulleys 24a and 24b.
Of the driven pulley 24a is different from the rotation angle θ of the driven pulley 24a.
_a is small, and the rotation angle θ _b of the driven pulley 24b is large. This is because the moving length of the belt 41 between the drive pulley 33a and the driven pulley 24a is short, and conversely, the drive pulley 33a
This is because the moving length of the belt 41 between the a and the driven pulley 24b is long, and the relationship is as shown in FIG. That is, in FIG. 7, among the steering shafts 21a to 21d, the length in the front-rear direction of the omnidirectional vehicle is L, and the length in the width direction is W. When L / W is 2.0, the horizontal axis is driven. Pulley 33
The movement amount W _x of a and 33b is obtained by taking the rotation angle θ _x of the driven pulleys 24a and 24b on the vertical axis, and the rotation angle θ _a of the driven pulleys 24a and 24b along with the movement of the drive pulleys 33a and 33b. , theta _b but gradually increases, the rotational angle than the rotational angle theta _a theta _b
Indicates that the change is larger. On the other hand, the shortest distance around which the drive pulley 33a and the driven pulleys 24a and 24b are wound is longer after the movement (the state of FIG. 3B) than before the movement (the state of FIG. 3A). Therefore, the tension roller 43d of the tension adjusting device 43 moves in the arrow Y'direction on the opposite side against the elastic force of the coil spring 43e. Similarly, in the rear unit, rotation of the drive pulley 33b causes the belt 42 to move in the direction of arrow Z ₂ opposite to that described above, so that each driven pulley
Rotate 24c and 24d in the same direction (counterclockwise). Also in this case, the driven pulley 24c and the driven pulley 24d have different rotation amounts, and the rotation angle θ _c of the driven pulley 24c becomes smaller than the rotation angle θ _d of the driven pulley 24d. Moreover, the rotation angle θ _c of the driven pulley 24c is the rotation angle θ of the driven pulley 24a of the front unit.
_{Although the} direction is opposite to that of a, the absolute value is the same, and the rotation angle θ _d of the driven pulley 24d is also the same as the rotation angle θ of the driven pulley 24b.
_The absolute value is the same as _b .

When the driven pulleys 24a to 24d rotate in this manner, the steering shafts 21a to 21d also rotate in the same manner as described above, and as shown in FIG. 5, the wheel 27a of the front unit has the same rotation angle as the driven pulley 24a. The wheel 27b turns downward by θ _a , and the wheel 27b turns downward by the same rotation angle θ _b as the driven pulley 24b. Each of the wheels 27a and 27b thus rotated is located on a tangent to a circle centered on the turning center P of the omnidirectional vehicle.
Similarly, the wheel 27c of the rear unit is rotated leftward by the same rotation angle θ _c (−θ _a ) as the driven pulley 24c, and the wheel 27d is rotated.
Rotates leftward downward by the same rotation angle θ _d (−θ _b ) as the driven pulley 24d, and is located on each tangent to a circle centered on the turning center P of the omnidirectional vehicle. Therefore, all the wheels 27a to 27d roll smoothly during turning of the omnidirectional vehicle, and roll smoothly even if the turning radius is small. This is clear from FIG. That is, FIG. 8 shows the steering shaft.
When the L / W between 21a to 21d is 2.0, the turning radius R is on the horizontal axis,
The vertical axis represents the angles of the wheels 27a and 27b. As the turning radius becomes smaller, the angles of the wheels 27a and 27b become larger, and the ideal curve shown by the dotted curves Q _a and Q _b becomes _a solid line Q ₁ , Q ₂ of this embodiment is approaching, and the one-dot chain line Q _x shows the conventional one, and the dotted curve
It is far from the ideal one shown by Q _a and Q _b . On the other hand, the wheels 27a, 27c and the wheels 27b, 27d corresponding to the front and rear roll on the same turning locus, so that the omnidirectional vehicle can travel more smoothly. In the case described above, the drive pulleys 33a and 33b are moved to the upper side as shown in FIG. 3 (B) to turn the omnidirectional vehicle to the right.
The drive pulleys 33a and 33b may be moved downward to turn the omnidirectional vehicle to the left.

Further, the case of rotation mode will be described.
In this case, as shown in FIG. 3 (C), the drive pulley 33
Similar to the car mode described above, a and 33b are further moved in the arrow X direction. That is, the slider driving device 39 is used as a moving mechanism.
Rotate the 38 pinion 38c and rack this pinion 38c
By rolling in the state of meshing with 38d, the slider 36 is moved by a predetermined amount (distance) W _{2 in the} direction of arrow X, and the drive pulleys 33a, 33b are moved in the same direction. This amount of movement (distance) W ₂
Is a length for rotating the driven pulleys 24a to 24d so that the wheels 27a to 27d located on the diagonal line face each other,
The encoder 39c of the slider driving device 39 detects the rotation amount of the pinion 38c on the basis of the detection signal, so that the pinion 38c can be set accurately. When the drive pulleys 33a and 33b move in this way, the belts 41 and 42 move in accordance with this movement, and the driven pulleys 24a to 24d rotate in the same manner as in the car mode described above. Therefore, the driven pulleys 24a and 24b of the front unit on the right side rotate by larger angles of rotation θ ₁ and θ ₂ than in the car mode. Also, the tension roller 43d of the tension adjusting device 43
Similarly, the coil spring 43e moves in the arrow Y'direction against the elastic force. On the other hand, similarly in the rear unit, the driven pulleys 24c and 24d are rotated by the rotational angles θ ₃ and θ ₃ more than in the car mode.
₄ rotates a lot. Also in this case, the rotation angle θ ₃ of the driven pulley 24c is the rotation angle θ ₃ of the driven pulley 24a of the front unit.
Although ₁ and orientation is reversed, the absolute value is the same, the rotation angle theta ₄ of the driven pulley 24d is the rotation angle theta ₂ to the absolute value of the driven pulley 24b are the same.

When the driven pulleys 24a to 24d rotate in this manner, the steering shafts 21a to 21d also rotate in the same manner as described above, and as shown in FIG. 6, all the wheels 27a to 27d have different angles in different directions. Rotate. That is, the wheel 27a of the front unit rotates right downward by the same rotation angle θ ₁ as the driven pulley 24a, and the wheel 27b rotates right downward by the same rotation angle θ ₂ as the driven pulley 24b. Similarly, the wheel 27c of the rear unit turns leftward by the same rotation angle θ ₃ (−θ ₁ ) as the driven pulley 24c, and the wheel 27d rotates the same rotation angle θ as the driven pulley 24d.
It rotates leftward by ₄ (-θ ₂ ). Each of the wheels 27a to 27d thus rotated is located on the tangent of one circle centered on the pivot rotation center (center of the omnidirectional vehicle) O of the omnidirectional vehicle, and on each diagonal. Wheels 27a-27d
Face each other. Therefore, the omnidirectional vehicle pivots about its center point O at that location. At this time, since all the wheels 27a to 27d are positioned on the tangent to the circle centered on the center point O, the wheels can roll smoothly and the omnidirectional vehicle can be rotated well.

The present invention is not limited to the above-described embodiment, but may be the ninth embodiment, for example.
As shown in FIG. 12 to FIG. 12, various modifications are possible. That is, FIGS. 9 (A) and 9 (B) show modifications of the mounting structure of the drive pulleys 33a and 33b. The drive pulleys 33a and 33b are provided above two rotary shafts 51 and 51 which are rotatably attached to sliders 36 which are guided by the guide shafts 40 and 40 and slide via bearings 50 and 50, respectively. There is. The rotary shafts 51, 51 are provided with driven gears 52, 52, respectively, and the driven gears 52, 52 are provided with a pulley drive device 37.
One drive gear 53 provided at the upper end of the output shaft of the above meshes with each other. Therefore, due to the meshing of the drive gear 53 and the driven gears 52, 52, each of the rotary shafts 51,
The drive pulleys 33a and 33b can be rotated by driving 51.

10 (A) and (B) show a modification of the tension adjusting device. The tension adjusting devices 60a and 60b adjust the tension of the belts 41 and 42 by moving the tension rollers 61a and 61b according to the movement of the drive pulleys 33a and 33b, and sandwiching the drive pulleys 33a and 33b on both sides. Each is provided. The tension adjusting device 60a is located on the rear side (left side in the figure) of the vehicle body 20 and adjusts the tension of the belt 42 of the rear unit. That is, the body 20 has two guide shafts 62, 62 in a direction orthogonal to the moving directions of the drive pulleys 33a, 33b.
The guide shafts 62, 62 are provided with a first slider 63 slidably via a sleeve. One end of a rotating arm 66 that rotates about a shaft 65 is rotatably attached to the side surface of the first slider 63, and the other end of the rotating arm 66 is a side surface of the second slider 67. Is rotatably attached to. The second slider 67 is slidably provided on guide shafts 69, 69 suspended between support plates 68, 68 standing on the vehicle body 20. This second
A support pillar 70 is erected on the upper surface of the slider 67, and a tension roller 61a is rotatably provided on the support pillar 70. A connecting pillar 71 is hung on the lower surface of the first slider 63, and one end of an interlocking arm 72 is rotatably attached to the lower portion of the connecting pillar 71. The other end of the interlocking arm 72 is rotatably connected to the shaft of a pulley drive device 37 that drives the drive pulleys 33a and 33b. Then, when the slider 36 of the drive pulleys 33a and 33b moves from the center of the vehicle body 20 to the side thereof, the interlocking arm 72 pulls the first slider 63 along the guide shafts 62 and 62. Then, the pivot arm 66 pivots about the shaft 65 to move the second slider 67 along the guide shafts 69, 69 in the opposite direction (the drive pulley 33.
Move away from a, 33b). Along with this, the tension roller 61a moves in the same direction, and the tension of the belt 42 is adjusted according to the amount of movement of the drive pulleys 33a and 33b.

On the other hand, the tension adjusting device 60b on the opposite side is arranged on the front side (right side in the drawing) of the vehicle body 20 and adjusts the tension of the belt 41 of the front unit. That is, as in the above, the vehicle body 20 is provided with the two guide shafts 73, 73, and the front slider 74 is slidably provided on the guide shafts 73, 73 via the sleeve 74a. A support column 75 is erected on the upper surface of the front slider 74, and a tension roller 61b is rotatably attached to the upper part of the support column 75 via a bearing 76. A connecting column 77 is hung on the lower surface of the front slider 74, and one end of a connecting arm 78 is rotatably attached to the lower end of the connecting column 77. The connecting arm 78 moves the front slider 74 in conjunction with the first slider 63 of the rear unit, and the other end thereof is rotatably attached to the lower end of the connecting column 71 of the first slider 63. There is. Then, in the tension adjusting device 60b of the front unit, when the first slider 63 of the rear unit is pulled, the connecting arm 78 moves the front slider.
74 is pushed to the front side (right side in the figure), and the front slider 74 is moved away from the drive pulleys 33a and 33b. This allows
The tension roller 61b also moves in the same direction, and the tension of the belt 41 is adjusted according to the amount of movement of the drive pulleys 33a and 33b. Therefore, also in such tension adjusting devices 60a and 60b, the tensions of the good belts 41 and 42 can be adjusted, and the driven pulleys 24a to 24d and the wheels 27a to 27d can be accurately rotated.

FIG. 11 shows a modification of the slider mechanism. That is, the slider mechanism 80 is provided on the vehicle body 20 for a slider drive device (not shown).
The output shaft 81 of the slider drive device is provided with a rotary arm 82 that rotates integrally with the output shaft 81. One end of a connecting arm 83 is rotatably attached to the tip of the rotary arm 82 with a pin 84. The other end is rotatably connected to the slider 36 by a pin 85, and when the rotating arm 82 is rotated by the slider driving device, the connecting arm is accompanied by this rotation.
83 is adapted to move the slider 36 along the guide shafts 40, 40 in the direction of the arrow. However, according to such a slider mechanism 80, the structure of the slider mechanism is simpler, and the slider 36 can be moved more accurately and satisfactorily than in the above-described embodiment.

FIG. 12 shows an omnidirectional vehicle that performs only two modes, an omnidirectional mode and a rotation mode. That is, in this omnidirectional vehicle, the slider 36 moves only from the center of the vehicle body 20 to one side. Therefore, although the omnidirectional mode and the rotation mode are performed as in the above-described embodiment, the car mode performs only one-sided turning. That is, in the figure, since the slider 36 moves upward from the center, only the right turn is performed. However, if the slider 36 is moved downward from the center, it is possible to make a left turn.

[Effects of the Invention] As described above, according to the steering mechanism for an omnidirectional vehicle according to the present invention, one set of control pulleys is arranged substantially at the center of four wheels by the movement drive means, and in this state, By rotating the set of control pulleys or moving one set of control pulleys from that position for a predetermined distance,
Since it can switch to omnidirectional mode, car mode, rotation mode, etc., it has a relatively simple structure and can have various kinds of direction changing functions such as omnidirectional mode, car mode, rotation mode, etc. It is possible to drive the vehicle satisfactorily and to obtain a vehicle with a very high degree of freedom in turning.

[Brief description of drawings]

1 to 8 show an embodiment of the present invention, FIG. 1 (A) is a plan view of the omnidirectional vehicle, FIG. 1 (B) is a side view of the main part broken, FIG. (C) is a cross-sectional view taken along the line A-A, second
FIG. 2A is a plan view showing a driving device for traveling, and FIG. 2B.
Is a sectional view taken along line BB, FIG. 3 (A) is a view showing a state of an omnidirectional mode, FIG. 3 (B) is a view showing a state of a car mode, and FIG. 3 (C) is a view of a rotation mode. FIG. 4 shows the state of the wheels in the omnidirectional mode, FIG. 4 shows the orientation of the wheels in the car mode, and FIG. 6 shows the orientation of the wheels in the rotation mode. FIG. 7 is a diagram showing the relationship between the sliding amount of the drive pulley and the rotation angle of the driven pulley, and FIG. 8 is a diagram showing the relationship between the turning radius of the omnidirectional vehicle and the wheel rotation angle in the car mode. FIG. 9 (A) is a plan view of an essential part showing a modified example of the drive mechanism of the drive pulley, FIG. 9 (B) is a sectional view taken along the line CC, and FIG. 10 (A) is a modified example of the tension adjusting device. FIG. 10 (B) is a sectional view taken along the line DD of FIG. 10, FIG. 11 is a plan view of a main part of the slider mechanism, and FIG. Fig. 13 to Fig. 16 show a conventional example, Fig. 13 (A) shows a plan view showing the first conventional example, and Fig. 13 (B) shows its E. -E sectional view, FIG. 14 (A) shows the omnidirectional mode, FIG. 14 (B) shows the car mode, and FIG. 14 (C).
Shows a rotation mode, FIG. 15 (A) is a plan view showing a second conventional example, FIG. 15 (B) is its FF sectional view, and FIG. 16 (A) is a car mode. FIG. 16 (B) is an enlarged view showing the direction of the wheels. 20 ... Body, 21a-21d ... Steering shaft, 24a-24d ...
... Driven pulleys, 27a to 27d ... Wheels, 33a, 33b ... Drive pulleys, 34 ... Moving drive device, 36 ... Slider, 37 ... Pulley drive device, 39 ... Slider drive device, 41, 42 …
… Belt, 43, 60a, 60b… Tension adjusting device, 80…
… Slider mechanism.

Claims (1)

[Claims] 1. Two steerings are rotatably provided at two positions on one side of a vehicle body, and two steering wheels are respectively rotated at two positions on the opposite side of the vehicle body facing the two steerings. The wheels are rotatably attached to these four steering wheels, and by appropriately rotating the steering wheels,
In a steering mechanism of an omnidirectional vehicle that travels by changing the direction of each wheel, four driven pulleys respectively provided above the respective steering shafts of the four steering wheels, and two steering wheels on one side of the vehicle body. And a drive unit provided on the vehicle body at a position between the other two steerings on the opposite side and having a slider that moves along the arrangement direction of each of the two steerings; A pair of control pulleys rotatably provided on the slider and moving along the arrangement direction of the two steering wheels through substantially the centers of the four steering wheels as the slider is moved by the movement driving means; One of a pair of control pulleys and two provided on each steering shaft of the two steerings on one side of the vehicle body A first belt that is wound around a driven pulley of the control pulley to transmit the rotation of the control pulley to the two driven pulleys, the other of the pair of control pulleys, and the other of the other opposite side of the vehicle body. A second winding which is wound around two driven pulleys provided on each steering shaft of the two steering wheels and which transmits the rotation of the control pulley to the other two driven pulleys.
And a second tension adjusting means that is provided on the vehicle body and that applies constant tensions to the first and second belts in accordance with the movement of the control pulley. Steering mechanism for mobile vehicles.