JPS61200003A - Driven wheel or transporting car - Google Patents

Abstract

PURPOSE:To prevent slippage between a wheel and a running surface when changing the direction of running, and improve a load withstanding performance by providing plural wheels each independently rotatably on a wheel shaft which is inclinedly provided on a supporting shaft which is perpendicular to said running surface. CONSTITUTION:A hollow and conical wheel 25 and a small wheel 26 which is housed in the wheel 25, are independently rotatably installed on a wheel shaft 23 which is inclinedly provided at a certain angle to a supporting shaft 15 having an axis perpendicular to a running surface L. By this construction, difference between the rotating direction of the supporting shaft 15 and the rotating direction of the wheels 25, 26 centering around the wheel shaft 23 when a vehicle body 11 changes its direction, can be made smaller than when the wheel shaft 23 is horizontally provided, preventing the slippage of the wheels 25, 26, deviation from the track of the vehicle body 11, and the generation of dust due to the wear of wheels, and enabling the use of a carrying vehicle in a clean room.

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to a transport vehicle that is mounted on a support shaft rotatably provided on a vehicle body and that rotates about the support shaft in accordance with the traveling direction of the vehicle body. Regarding the driven wheel of.

[Technical background of the invention and its problems]

For example, in a factory, when parts are transported from a parts warehouse to an assembly process, the driven wheels change direction according to the change in the running direction of an intangible body that travels through the factory while changing direction based on a predetermined command. It's starting to change.

Conventionally, the driven wheels have been constructed as shown in FIGS. 4 and 5. That is, a bearing 2 is attached to the lower surface of the vehicle body 1, and a support shaft 3 is rotatably provided on the bearing 2 with its axis perpendicular to the running surface. One end of an arm 4 is fixed to the lower end of this support shaft 3, and a wheel shaft 5 whose axis is parallel to the running surface is rotatably provided at the other end of this arm 4. A wheel 6 as a driven wheel is attached to the shaft 5. The wheels 6 are made of an elastic material such as rubber so as not to damage the running surface. According to such a structure, when the vehicle body 1 changes the traveling direction from the arrow a to the opposite direction, the arm 4 moves to the fifth position with the support shaft 3 as a fulcrum.
Rotate in the direction indicated by the arrow in the figure. However, since the rotation of the arm 4 in the direction indicated by the arrow is significantly different from the direction of rotation of the wheel 6 with the wheel shaft 5 as a fulcrum, the wheel 6 attempts to rotate in the direction indicated by the arrow while avoiding the running surface. .

As a result, the vehicle body 1 receives a force in a direction perpendicular to the traveling direction, resulting in a drawback that the trajectory of the vehicle body 1 is largely deviated. In other words, the support shaft 3 and the wheel axle 5 are 9
Since it forms a large angle of 0 degrees, the above-mentioned problem occurs.

In order to solve this problem, as shown in FIG. It has been considered to provide a rotatable wheel 8 consisting of a body. According to such a structure, it is true that the support shaft 3 and the wheel shaft 5
Since the angle formed by the two becomes smaller, the lateral force that the vehicle body 1 receives when changing the running direction is reduced. In other words, when the bracket 7 attempts to rotate 90 degrees together with the support shaft 3, the wheels 8 can rotate around the wheel shaft 5, so that the bracket 7 can smoothly rotate 90 degrees. However, if the curvature of the wheels 8 is increased so that they can withstand a large load, the contact area with the running surface increases, so that slipping occurs against the running surface when changing direction, and the trajectory of the vehicle body 1 is changed. Sometimes things shift.

In other words, since the wheels 6 cannot be shaped to have a large contact area with the running surface, there is a drawback that performance against loads cannot be improved.

Furthermore, since the wheels 8 are made of an elastic body, they are elastically deformed, which also increases the contact area of the wheels 8 with the running surface, causing slippage when changing the running direction.

Further, when the wheels 8 are worn out due to slipping, dust is generated, and therefore, it may not be possible to use the wheel 8 in a clean room where dust is averse.

[Purpose of the invention]

The present invention provides a follower for a transport vehicle that prevents slippage between the wheels and the running surface when the vehicle body changes the running direction, and also allows the wheels to withstand large loads. The purpose is to provide the driving wheel.

[Summary of the invention]

This invention provides a rotatable support shaft with an axis perpendicular to the running surface on the vehicle body, and a wheel axle with the axis inclined at a predetermined angle with respect to the running surface on the support shaft.
This is a driven wheel of a conveyance vehicle in which a plurality of wheels each of which is formed of an elastic body at least in a portion contacting the running surface and rotates independently is provided on the wheel shaft.

[Embodiments of the invention]

Hereinafter, a first example in which an embodiment of the present invention is applied to an automatic guided vehicle will be described.
This will be explained with reference to FIG. The automatic guided vehicle shown in FIG. 1 includes a vehicle body 11. A pair of driving wheels (not shown) are provided at one end of the lower surface of the vehicle body 11, and a pair of driven wheels 12 (only one of which is shown) is provided at the other end. This driven wheel 12 is constructed as follows. That is, one end of the mounting body 13 is fixed to the lower surface of the vehicle body 11 with a screw. A bearing body 14 is connected and fixed to the lower end of this mounting body 13. One end of a support shaft 15 whose axis is perpendicular to the running surface is rotatably supported by a bearing 16 on the bearing body 14 . A mounting hole 17 whose axis is parallel to the running surface is formed at the lower end of the support shaft 15, and a mounting shaft 18 is rotatably provided in the mounting hole 17 via a sleeve 19. One end portion of this mounting shaft 18 protrudes from one end of the mounting hole 17, and the center portion of a bracket 20 having a substantially reversed shape is fixed to this projecting end. A pair of support holes 21 are bored symmetrically about the axis of the support shaft 15 at both ends of the bracket 20 which are inclined at a predetermined angle with respect to the running surface. Each support hole 21 has a flange 22 formed in the middle of the wheel axle 2.
3 is fitted and fixed with a screw 24.

That is, the pair of wheel shafts 23 are symmetrical about the axis of the support shaft 15 and inclined at a predetermined angle with respect to the running surface. Each wheel shaft 23 has a first wheel 25 in the shape of a hollow truncated cone, and a second wheel 26 smaller than the first wheel 25 and housed inside the wheel, each rotatable by a bearing 27. It is set in. That is, each wheel 25.
26 are provided coaxially with the wheel shaft 23, and each can rotate independently. Also,
An elastic body 28 made of rubber, synthetic resin, or the like is attached to the lower end of the peripheral wall of each wheel 25, 26 over its entire length, and this elastic body 28 is in contact with the ground on the running surface. Therefore, the elastic body 28 prevents the running surface from being damaged.

According to the driven wheel 12 having such a structure, since the wheel shaft 23 is provided inclined at a predetermined angle with respect to the support shaft 15, the rotation of the support shaft 15 when the vehicle body 11 changes the running direction is prevented. The difference between the direction and the direction of rotation of the wheels 25, 26 about the wheel axle 23 is smaller than when the wheel axle 23 is provided horizontally. Therefore, large slippage is less likely to occur between the wheels 25, 26 and the running surface, so that the trajectory of the vehicle body 11 is less likely to shift. Furthermore, a first wheel 25 and a second wheel 26 are provided on the wheel shaft 23 so as to be able to rotate independently.

Therefore, even if the distance A from the axis of the support shaft 15 to the first wheel 25 and the distance B from the second wheel 26 differ when changing the running direction, these wheels 25 and 26 rotate at different speeds. Since it rotates, slippage does not occur due to the difference between the distances A and 8 mentioned above. In other words, even if a plurality of wheels are provided to increase the contact area with the running surface and to withstand a large load, this will not cause slippage to occur when changing the running direction.

Further, the pair of wheel shafts 23 are provided on the rotatable mounting shaft 18 via a bracket 20, symmetrically with respect to the axis of the support shaft 15. Therefore, even if the running surface is inclined,
The mounting shaft 18 rotates in accordance with this inclination, and each wheel provided on the pair of wheel axles 23 reliably touches the ground on the running surface, thereby stabilizing the running of the vehicle body 11.

In the above embodiment, each wheel axle is provided with a pair of wheels, but the number of wheels provided on each wheel axle is not limited to two, and may be three or more. Further, the number of wheel axles provided on the bracket is not limited to two, and may be one if the wheel axle is tilted in a direction perpendicular to the plane of the paper in FIG. 1, for example.

FIG. 3 shows another embodiment of the present invention, in which a wheel body 31 is rotatably provided on a wheel shaft 23 by a bearing 32, and a recess 33 is formed in one end of the wheel body 31. A support shaft 34 is installed in this recess 33 in parallel with the running surface, and a plurality of wheels 35 are respectively provided on this support shaft 34 so as to be freely rotatable by bearings 36. Even in such a structure, not only is slippage less likely to occur when changing the traveling direction, but also the durability against large loads can be improved by having a plurality of wheels 35, as in the above-mentioned embodiment.

〔Effect of the invention〕

As described above, the present invention provides a wheel axle whose axis is inclined at a predetermined angle with respect to the running surface on a support shaft provided on the vehicle body with the axis perpendicular to the running surface, and the wheel A plurality of wheels, each of which rotates independently, is provided on the shaft, at least a portion of which contacts the running surface made of an elastic body. Therefore, the wheel axle is not parallel to the running surface as in the conventional case, but is inclined at a predetermined angle, and each wheel rotates independently. It becomes difficult to slip. In other words, the trajectory of the vehicle body is less likely to shift when changing the running direction. Furthermore, since the vehicle has a plurality of wheels, the contact area with the running surface is increased, which has the advantage of improving load resistance.

[Brief explanation of drawings]

Fig. 1 is a side view of a driven wheel showing one embodiment of this invention, Fig. 2 is a sectional view taken along the line - - in Fig. 1, and Fig. 3 is a sectional view of a wheel showing another embodiment of this invention. , FIG. 4 is a side view showing a conventional driven wheel, FIG. 5 is a sectional view taken along the line V-V$ll in FIG. 4, and FIG. 6 is a sectional view showing the structure of another conventional wheel. 1... Vehicle body, 15... Support shaft, 18... Mounting shaft, 2
3... Wheel axle, 25... First wheel, 26... Second wheel, 28... Elastic body, 31... Wheel body, 3
5...wheels. Applicant's agent Patent attorney Takehiko Suzue Figure 1 n Figure 2 Figure 6

Claims (5)

[Claims] (1) A vehicle body, a support shaft rotatably provided on the vehicle body with its axis perpendicular to the running surface, and a support shaft provided on the support shaft with its axis inclined at a predetermined angle with respect to the running surface. and a plurality of wheels, each of which is independently rotatably provided on the wheel axle and whose at least the portion that contacts the running surface is made of an elastic body. Driving wheels. (2) The wheel axle is attached to a mounting shaft rotatably provided on the support shaft with its axis parallel to the running surface. driven wheels of transport vehicles. (3) The carrier vehicle according to claim 2, wherein a pair of wheel axles each having a plurality of wheels are provided on the mounting shaft symmetrically with respect to the axis of the support shaft. driven wheel. (4) The driven wheel of the carrier vehicle according to claim 1, wherein the wheel has a hollow truncated cone shape, and the elastic body is attached to the lower end of the peripheral wall of the wheel. . (5) The driven wheel of a transport vehicle according to claim 1, wherein the wheel comprises a wheel body and a plurality of wheels rotatably provided on the wheel body.