JP2003237304A - Caster - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a caster which can smoothly perform the inversion travel of a carrier of an unmanned carrying vehicle and a carrying truck by a small force. <P>SOLUTION: The caster 30 mainly comprises a bracket 34 which is rotatably fitted to a lower side of a holder 31 via a bearing 33 with a shaft 35 as a turning shaft, and a tire 36 which is disposed on the inner side of the bracket 34 via a shaft 40. Bearings 41 are provided on both sides of the shaft 40, and the bearings 41 are located in oblong guide holes 42 formed on both sides of the bracket 34. Racks 43 are respectively provided above the guide holes 42 on both sides, and pinions 44 engaged with the racks 43 are respectively fixed to both ends of the shaft 40. In the case of the inversion travel of the carrier, the shaft 40 is moved parallel to the longitudinal direction via the racks 43 and the pinions 44 by the eccentricity of the tire 36. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a caster used as a wheel of a carrier device such as an unmanned carrier or a carrier for carrying luggage.

[0002]

2. Description of the Related Art FIG. 5 is a schematic block diagram of a three-dimensional automated warehouse, in which a rack 1 provided with a large number of load shelves for storing loads is provided with a traveling path 2.
The rail 3 is laid on the traveling path 2. A stacker crane 4 is arranged on the rail 3 so that the stacker crane 4 can travel freely on the rail 3, and the stacker crane 4 can load and unload loads in the rack 1. A loading / unloading station 5 is provided on each end of the rack 1. The loading / unloading station 5 is a loading / unloading station 5a into which a load is loaded.
And a delivery station 5b that carries out a load.

Rails 6 and 7 for circling the unmanned transport vehicle 10 are laid on the side of the loading / unloading station 5 in a substantially rectangular shape, and the unmanned transport is carried out to the outside on the side opposite to the loading / unloading station 5 side. An entrance station 11 and an exit station 12 for loading and unloading a load with the vehicle 10 are provided respectively.

Then, the automatic guided vehicle 10 receives the load at the receiving station 11, travels on the rails 6 and 7 to reach the predetermined receiving station 5a on the rack 1 side, and loads the automatic guided vehicle 10 to the receiving station 5a. Unload the load. The stacker crane 4 moves to the storage station 5a and carries the load into a predetermined rack of the rack 1. Further, when carrying out the load of the rack 1, the stacker crane 4 goes to the load rack to pick up the load, and the delivery station 5b.
Transport the load to. At the delivery station 5b, a load is mounted on the automated guided vehicle 10, and the automated guided vehicle 10 travels to the delivery station 12 to unload the loaded station 12.

FIG. 6 is a schematic block diagram of the automatic guided vehicle 10 described above. On one side of the lower surface of the base 13 of the automatic guided vehicle 10, a driving wheel 15 having a motor 14 and driven wheels 16 are provided. It is provided. Casters 20 are provided on the other side of the lower surface of the base 13, and the drive wheels 15 and the driven wheels 16 roll on the rails 6, and the casters 20 are wider than the rails 6 and roll on the rails 7, respectively. The automated guided vehicle 10 travels on the rails 6 and 7.

FIG. 7 shows a perspective view of the caster 20.
The caster 20 has a well-known structure, and includes a flat plate-shaped base 21 directly attached to the lower surface of the base 13 of the automatic guided vehicle 10, and a lower surface of the base 21 via a bearing (not shown). 21, a shaft 22 rotatably mounted on the shaft 21, a bracket 23 having a substantially U-shape mounted on the lower surface of the shaft 22, and a tire 2 rotatably mounted on a lower portion of the bracket 23 by a pin 24.
It is composed of 5 and 5.

FIG. 8 shows a layout of the casters 20 and the like when the base 13 is viewed from above. The drive wheels 15 and the driven wheels 16 each have four guide rollers 17, and these guide rollers 17 are provided. Rollers 17 are located on the left and right of the rail 6 to guide the drive wheels 15 and the driven wheels 16.

[0008]

By the way, after the automatic guided vehicle 10 travels in the direction indicated by the arrow A in FIG. 5 and unloads the cargo at the receiving station 5a, the adjacent delivering station 5b (the upper delivering station in FIG. 5) is unloaded. When receiving a load at the station 5b), it may be possible to receive the load around the rails 6 and 7, but from the viewpoint of work efficiency, the automated guided vehicle 10 is reversed to the reverse as shown by the arrow B. The load will be received at the station 5b.

In such a case, as shown in FIG. 8, when the automatic guided vehicle 10 is reversed from forward (arrow A in FIG. 5) to reverse (arrow B in FIG. 5), the caster 20 is laterally displaced by the amount of eccentricity. It is necessary to change the direction while generating. Since the other driving wheel 15 and the driven wheel 16 are constrained by the rail 6 by four guide rollers 17, the lateral displacement of the caster 20 is dealt with by the movement of the tire 25 and the rail 7 due to friction. The moving force at this time requires a large force of about 0.6 in comparison with the usual rolling resistance of 0.01.
There is a problem that 0 cannot be smoothly reversed, and at the same time, there is a problem that a motor or the like having a large driving force is required for the drive wheels 15.

The present invention has been made in view of the above-mentioned problems, and provides a caster intended to smoothly perform the reverse running of a carrier device such as an automatic guided vehicle or a carrier vehicle with a small force. It is a thing.

[0011]

Therefore, in the caster according to claim 1 of the present invention, the caster is provided on the lower surface of the transporting device for transporting the load, and the wheels are rollable in the traveling direction and swivel on the horizontal plane. A possible caster is characterized in that guide means for guiding the rotary shaft in the front-rear direction is provided on both sides of a bracket that supports both sides of the rotary shaft of the wheel.

With this configuration, when the transport device is reversed, the rotation shaft of the wheel is moved forward and backward by the amount of eccentricity between the rotation shaft and the turning shaft through the guide means. It does not require a large force for the reversing operation, and the transport device can be smoothly reversed.

In the caster according to a second aspect of the present invention, the guide means is composed of an elongated hole formed in the bracket in the front-rear direction and a bearing mounted in the rotary shaft by rolling in the elongated hole. It has a feature. As a result, the reversal can be performed with a small force, and the guide means for moving the wheels forward and backward can be configured at low cost.

In the caster according to the present invention, racks having the same length as the front and rear direction of the elongated hole are arranged on both side surfaces of the bracket, and pinions that mesh with the racks are provided on both sides of the rotary shaft. The feature is that each is provided. With this, the rotation axis of the wheel does not become oblique with respect to the bracket, but moves on the same line as the front-rear direction,
Therefore, the end surface of the wheel does not come into contact with the inner surface of the bracket, and the rotating shaft can be moved smoothly.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a caster 3 of the present invention.
0 is an exploded perspective view of FIG. 2, and FIG. 2 is a base 1 of the automatic guided vehicle 10.
3 is a sectional view of the caster 30 attached to the lower surface of the caster 3, and FIG. 3 is a side view of the caster 30. Further, FIG. 4 is a view taken along the line AA of FIG.

The caster 30 of the present invention is constructed as follows. A hole 32 is vertically penetrated through a central portion of a flat plate-shaped holder 31 bolted to the lower surface of the base 13 of the automatic guided vehicle 10. A bracket 34 is rotatably supported on the lower surface of the holder 31 on a horizontal plane, that is, pivotally supported by a bearing 33. A shaft 35 protruding from the upper surface of the bracket 34 is inserted into the bearing 33 and the hole 32 of the holder 31. The shaft 35 is the bearing 3
It is rotatably attached to 3.

A bracket 34 formed in a substantially U-shape
The tire 36 is arranged inside, the shaft 40 is inserted into the shaft hole 37 of the tire 36, and the bearings 41 are attached to both sides of the shaft 40. Further, on both sides of the bracket 34, oblong hole-shaped guide holes 42 are formed respectively in the horizontal direction, and the bearings 41 are rotatably arranged in the guide holes 42. Further, above the guide hole 42, a rack 43 having a length substantially equal to the horizontal length dimension of the guide hole 42.
And a pinion 44 meshing with the rack 43 is fixed to both ends of the shaft 40. Further, a substantially U-shaped cover 45 is screwed into a screw hole 47 in which a bolt 46 is threaded on the side surface of the bracket 34 so that the shaft 40 having the bearing 41 and the pinion 44 does not drop leftward or rightward from the guide hole 42 of the bracket 34. It is attached by wearing it.

FIG. 2 is a sectional view of the above-mentioned members mounted on the bracket 34. The bearing 41 mounted on the shaft 40 is located in the guide hole 42 of the bracket 34, and the bearing 41 is located in the guide hole 42. Can be moved while rolling in the horizontal direction of the longitudinal direction. Also,
The lower portion of the tire 36 projects from the lower surface of the bracket 34 and rotates in the traveling direction with the shaft 40 as the rotation axis. Further, the tooth portions of the pinion 44 fixed to both ends of the shaft 40 mesh with the tooth portions of the rack 43.

In FIG. 3, assuming that the automated guided vehicle 10 is moving forward on the rails 6 and 7 (see FIG. 5), the shaft 40, which is the rotating shaft of the tire 36, is rearward (left in FIG. 3). Since the bearing 41 mounted on the shaft 40 moves rearward in the guide hole 42 of the bracket 34, it moves to the rear end portion (left end portion in FIG. 3) of the guide hole 42. To do. At this position, the distance between the shaft 40 and the shaft 35 of the bracket 34, which is the turning axis of the tire 36, becomes the amount of eccentricity of the tire 36, and stable traveling is possible.

Here, when the automatic guided vehicle 10 travels and moves backward after the predetermined work is completed, when the automatic guided vehicle 10 is reversely driven by the above-described drive wheels 15, the base 13 and the bracket 34 are rotated. Moves backwards. As the bracket 34 moves backward (to the left in FIG. 3), the rack 43 fixed to the bracket 34 also moves backward, so that the pinion 44 meshing with the rack 43 rotates. Therefore, the bearing 41 in the guide hole 42 rolls and moves to the front end portion (the right end portion in FIG. 3) of the guide hole 42. Also, when the bearing 41 moves, that is, when the shaft 40 moves in the horizontal direction,
Since the pinions 44 fixed to both ends of the shaft 40 move while rotating at the same time, the shaft 40 is fixed to the shaft 4.
It moves without being twisted with respect to the moving direction of 0. That is, the tire 36 can be translated in the reverse direction without being twisted.

When reversing the traveling of the automatic guided vehicle 10 in this manner, the shaft 40, which is the traveling axis (rotational axis) of the tire 36, is displaced back and forth by the amount of eccentricity with respect to the shaft 35 which is the turning axis. Therefore, the front and rear reversing operation does not require a large force, and the caster 30 can be smoothly reversed without turning. That is, the caster 30
Since the vehicle is moved in parallel in the reversing direction without turning, the automated guided vehicle 10 can be reversed without requiring a large force. In particular, the rack 43 and the pinion 44 prevent the shaft 40 from moving obliquely with respect to the bracket 34,
Since the tire 36 moves on the same line as the reversing direction, the end surface of the tire 36 and the inner surface of the bracket 34 do not come into contact with each other, and the tire 36 can be moved smoothly. The rack 43 and the pinion 44 may be omitted, but the rack 43 and the pinion 44
Is a preferable example. Further, since the shaft 40 is moved back and forth by the guide hole 42 of the bracket 34 and the bearing 41, the shaft 40 can be inverted with a small force, and the cost can be reduced.

When the automatic guided vehicle 10 is reversed from forward to reverse, the automatic guided vehicle 10 can be rotated around the rails 6 and 7 in the reverse state, and the rails 6 and 7 as shown in FIG. At the corner of the caster 30,
Since it can be turned around the center, the automated guided vehicle 1
0 can run smoothly in the corner.

Further, in the above embodiment, an unmanned guided vehicle was described as an example of the carrier device in which the casters according to the present invention are used. The present invention can be applied to general transporting devices for carrying and transporting the above-mentioned luggage. Of course, the present invention can be applied to a general transfer device that does not travel on rails.

[0024]

According to the caster of claim 1 of the present invention, when the transport device is reversed, the rotating shaft of the wheel is eccentric to the rotating shaft via the guide means. Since it is simply moved back and forth, a large force is not required for the front and rear reversing operation, and the conveyor device can be smoothly reversed and run.

According to the caster of the second aspect, the guide means is composed of a longitudinal hole formed in the bracket in the front-rear direction, and a bearing which rolls in the elongated hole and is attached to the rotary shaft. Therefore, the reversal can be performed with a small force, and the guide means for moving the wheel forward and backward can be constructed at low cost.

According to the caster of the third aspect, racks each having a length substantially equal to the front-rear direction of the elongated hole are provided on both side surfaces of the bracket, and pinions that mesh with the racks are connected to the rotary shaft. Since it is provided on both sides, the wheel rotation axis does not tilt with respect to the bracket but moves on the same line as the front-rear direction, so that the end surface of the wheel and the inner surface of the bracket do not contact and rotate. The axis can be moved smoothly.

[Brief description of drawings]

FIG. 1 is an exploded perspective view of a caster according to an embodiment of the present invention.

FIG. 2 is a sectional view of a caster according to the embodiment of the present invention.

FIG. 3 is a side view of the caster according to the embodiment of the present invention.

FIG. 4 is a view on arrow AA of FIG. 3 in the exemplary embodiment of the present invention.

FIG. 5 is a schematic configuration diagram of a three-dimensional automatic warehouse.

FIG. 6 is a schematic configuration diagram of an automated guided vehicle equipped with casters of a conventional example.

FIG. 7 is a perspective view of a conventional caster.

FIG. 8 is a layout configuration diagram of casters in a conventional automated guided vehicle.

[Explanation of symbols]

30 casters 34 Bearing 35 axes 36 tires 40 shaft 41 bearing 42 Guide hole 43 racks 44 pinion

Claims (3)

[Claims] 1. A lower surface of a transfer device for transferring a load,
In a caster in which wheels can roll in the traveling direction and can swivel on a horizontal plane, guide means for guiding the rotary shaft in the front-rear direction are provided on both sides of a bracket that supports both sides of the rotary shaft of the wheel. Casters characterized by. 2. The guide means is constituted by an elongated hole formed in the bracket in the front-rear direction and a bearing mounted on the rotary shaft by rolling in the elongated hole. The casters listed. 3. A rack having a length about the same as the front-back direction of the elongated hole is provided on each side surface of the bracket, and pinions meshing with the rack are provided on both sides of the rotary shaft, respectively. The caster according to claim 2, which is characterized in that: