JP2000118629A - Travelling position detection device of movable carriage in automatic warehouse - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve detection precision of a travelling position of a movable carriage. SOLUTION: An elevating type bracket 31 pressed downward by a spring 35 is installed on a fixed bracket 30 provided on a movable carriage, and an oscillating bracket 36 to revolve in a seesaw way is installed on an elevating type bracket 31. A pair of front and back side rollers 38 is provided on the oscillating bracket 36, and an interlocking shaft 41 to synchronously rotate with both of the rollers 38 through gears 40, 41 is connected to a rotor of a rotary encoder. Even when a rail 4 has irregularities and deflected deformation, as at least either one of the rollers 38 makes contact with the rail 4, detection precision of a travelling position is remarkably improved.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for detecting a traveling position of a mobile trolley in an automatic warehouse.

[0002]

2. Description of the Related Art In an automatic warehouse, a detecting device provided with a rotary encoder is provided in order to detect a traveling position of a movable cart. In this case, the simplest structure is that a movable roller is provided with a detection roller that rolls on the rail as the vehicle travels, and the rotation of this roller is counted as minute pulses by a rotary encoder. Is calculated.

[0003] However, the rollers may be separated from the rails due to the unevenness or bending deformation of the rails or the swinging of the movable cart. In some cases, it could not be detected accurately. Therefore, a device has been devised so that the position of the movable carriage can be accurately detected irrespective of the unevenness or the bending deformation of the rail. For example, JP-A-57-23501 and JP-A-61-1
JP-A-203008, JP-A-63-148691, and the like describe that a roller is pressed against a rail by a spring so that the rotation of the roller follows irregularities on the rail.

In Japanese Utility Model Laid-Open Publication No. 2-37109, a roller chain is provided on a member arranged in parallel along a rail, and a sprocket meshing with the roller chain is provided on a movable carriage, and the rotation of the sprocket is provided. Is detected by a rotary encoder.

[0005]

SUMMARY OF THE INVENTION Among the above prior arts, Japanese Patent Application Laid-Open No. 57-23501 and Japanese Patent Application Laid-Open No. 61-203008,
According to the structure in which the roller for detection is pressed against the rail with a spring as in JP63-148691, etc., the detection accuracy can be improved to some extent, but the phenomenon occurs in which the roller momentarily separates from the rail due to expansion and contraction of the spring. Because of this, it was difficult to say that it was perfect.

On the other hand, a roller chain and a sprocket as disclosed in Japanese Utility Model Laid-Open Publication No. 2-37109 are perfect in terms of accuracy because the sprocket is securely engaged with the chain. Not only does this increase the cost due to the necessity, but also causes a problem that a large load is applied to the connection (coupling) connecting the sprocket and the rotary encoder, so that the connection is easily damaged and the durability is low.

SUMMARY OF THE INVENTION An object of the present invention is to provide an apparatus having a significantly improved detection accuracy without complicating the structure.

[0008]

SUMMARY OF THE INVENTION A traveling position detecting device according to the present invention comprises a plurality of rollers which are rotatably abutted on the rail at positions separated along the traveling direction of a movable trolley, and are synchronized with the rollers. A rotary encoder that detects the rotation of an interlocking shaft that rotates by rotating the rollers, and the rollers are non-fixedly mounted on a movable trolley so as to be able to move following the unevenness of a rail or the like. have.

Further, according to the present invention, as described in claim 2, the movable carriage can pivot in a seesaw shape when viewed from a direction perpendicular to a rail and is urged downward by a spring. Are provided on both sides of the pivot axis of the swing bracket, the rollers being rotatably abutted on the rail, and further, the swing bracket is rotated in synchronization with the two rollers via gears. The configuration also includes an interlocking shaft and a rotary encoder that detects rotation of the interlocking shaft.

[0010]

[Function / Effect] With this configuration, even if one of the plurality of rollers is separated from the rail, the other roller can be brought into contact with the rail, and the rotation of each roller is rotated via the interlocking shaft. Since the signal is transmitted to the encoder, it is possible to significantly improve the detection accuracy by eliminating the influence of unevenness and bending of the rail, etc., even though the detection device is only provided on the movable carriage.

In particular, when a roller is attached to the seesaw-shaped swing bracket as in claim 2, when one roller separates from the rail and becomes free, the other roller is pressed against the rail and becomes free. One of the rollers is always in contact with the rail, so that the detection accuracy is more reliably improved.

[0012]

Next, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a schematic perspective view of one end of an automatic warehouse, and FIG. 2 is a partial schematic perspective view of the automatic warehouse. The automatic warehouse includes a hangar 1 and a loading / unloading unit 2 provided near one end of the hangar 1. And

The hangar 1 includes a large number of shelves 3 arranged in multiple stages on both sides of the passage, a large number of pairs of rails 4 arranged horizontally corresponding to the shelf plates 3 in each stage, and a plurality of rails 4. And a traveling trolley 5 for traveling. Each shelf board 3 is supported by an inner vertical frame 6 located on the passage side, an outer vertical frame 7 located on the outer side, and a horizontal rear frame 8 fixed between the adjacent outer vertical frames 6.

The rail 4 is fixed to the inner vertical frame 6, and the inner vertical frame 6 of each step and the shelf 3 are set at the same height. Adjacent outer vertical frames 7 are reinforced with braces 9. The loading / unloading section 2 includes a shelf conveyor 10 arranged in a state of being extended from the shelf 3 of each stage, and a support 11.
And a pair of lift conveyors 12 that freely move up and down along the line. Each lift conveyor 12 is a shelf conveyor in plan view.
It is arranged to extend in a straight line with 10.

In the vicinity of the loading / unloading section 2, there is provided a loading / unloading transport conveyor 13 extending in series with each of the lift conveyors 12 in plan view. As shown by a dashed line in FIG. 1, an upper conveyor 14 may be provided. The symbol W indicates a load. FIG. 3 is a plan view of the movable cart 5. As shown in this figure, the movable carriage 5 includes a main body frame 16 formed of a mold steel or the like and having a rectangular shape in plan view, a pair of front and rear wheels 18 connected by an axle 17, a motor 19 for driving one of the wheels 18, Fixed and movable picking devices 20, 21 extending in a direction perpendicular to the running direction
And the movable picking device 21 and the fixed picking device
A motor 22 for adjusting the movement toward 20 is provided.
The motors 19 and 22 are mounted on the upper plate 23.

Each of the picking devices 20 and 21 has a built-in reciprocating moving arm (not shown) that can move freely toward the shelf 3. A picker 24 for horizontal rotation is attached.
Each of the picking devices 20 and 21 has a mounting plate 25 on which a load W is loaded, and the mounting plates 25 partially overlap each other. Furthermore,
A position detecting device 27 according to the present invention is provided near one wheel 18 of the movable carriage 5. This will be described with reference to FIGS. FIG. 4 is a plan view, and FIG.
FIG. 6 is a sectional view taken along line VI-VI of FIG. 5, FIG. 7 is a sectional view taken along line VII-VII of FIG. 5, and FIG.

The position detecting device 27 is provided on the body frame 16 of the mobile trolley 5.
A fixed bracket 30 attached to the base plate via a base plate 28 and a support plate 29, and a downwardly open U-shaped elevating bracket 31 disposed below the fixed bracket 30. As shown in FIG.
The elevating bracket 31 is attached to the fixed bracket 30 via a pair of front and rear rods 32 so as to be able to move up and down.A bush 33 having an external thread formed on the outer periphery of the rod 32 is fitted. Screwed into. The bush 33 is provided with a lock nut. A spring 35 is fitted between the lifting bracket 31 and the bush 33 of the rod 32.

Accordingly, the lifting bracket 31 is pushed downward by the spring 35, and the spring force can be adjusted by rotating the bush 33 to change its height. A pair of right and left oscillating brackets 36 formed in an inverted T-shape in side view are attached to the elevating bracket 31 by a pair of hollow shafts 37 so as to rotate in a seesaw shape about the front and rear central portions thereof. Have been.

A pair of rollers abutting on the rail 4 are provided on the left and right swing bracket 36 on both front and rear sides of the rotation center.
38 is rotatably mounted by a shaft 39. Both rollers
The drive gear 38 is provided integrally with a driven gear 40, while the interlocking shaft 41 rotatably fitted into the hollow shaft 37 is provided integrally with a driven gear 42 meshing with the gear 40 (see FIG. 7). Although not shown in the figure, a rubber layer is provided on the outer peripheral surface of the roller to increase friction.

Further, a bracket 43 having a U-shape in plan view is provided on the liftable bracket 31 so as to project toward the movable carriage 5.
The rotary encoder 44 is attached to the bracket 44, and the rotor 44a of the rotary encoder 44 and the interlocking shaft 41 are connected by a coupling (coupling) 45. In the above configuration, the front and rear rollers 38 move upside down,
Further, since the roller 35 is pressed downward by the spring 35, as shown in an exaggerated manner in FIG. 8, even if one of the rollers 38 floats from the rail 4 due to, for example, the rail 4 being dented or bent and deformed, the other The roller 38 is pressed against the rail 4 in reverse, so that at least one of the rollers 38 is in contact with the rail 4. For this reason,
The traveling position of the mobile trolley 5 can be accurately detected.

By the way, since the wheels 18 of the movable trolley 5 always contact the rails 4, it can be said that the relative height relationship between the wheels 18 and the rails 4 is constant regardless of the bending deformation of the rails 4. For this reason, when the detection device 27 is arranged near the wheel 18 as in the embodiment, the relative height between the detection device 27 and the rail 4 can be made substantially constant.
The state in which the roller 38 is in contact with the rail 4 is more reliably held, and the detection accuracy can be further improved.

Since the rail 4 is less likely to bend and deform at a portion closer to the shelf 3, it is preferable that the roller 38 of the detecting device 27 is also brought into contact with the rail 4 at a portion as close to the shelf 3 as possible.
The interlocking means for synchronously rotating the plurality of rollers and the interlocking shaft is not limited to using a gear as in the embodiment, but may use another interlocking member such as a timing belt (however, a gear may be used). Is advantageous in that the structure is simple and rotation can be accurately transmitted.)

Further, the roller is not limited to contact with the upper surface of the rail, but may contact with the side surface or the inner surface.
Further, the interlocking shaft and the rotor of the rotary encoder may be integrated. Note that the mobile trolley is not limited to the one shown in the figure, but generally refers to one that travels for loading and unloading, and thus includes a stacker crane and the like.

[Brief description of the drawings]

FIG. 1 is a schematic perspective view of one end of an automatic warehouse.

FIG. 2 is a cutaway perspective view schematically showing a hangar.

FIG. 3 is a plan view of the movable cart.

FIG. 4 is a plan view of the detection device.

FIG. 5 is a VV view of FIG. 4;

FIG. 6 is a sectional view taken along line VI-VI of FIG.

FIG. 7 is a sectional view taken along line VII-VII of FIG.

FIG. 8 is a diagram showing an operation.

[Description of Signs] 1 Hangar 2 Entry / Exit Section 4 Rail 5 Moving Cart 27 Detector 30 Fixed Bracket 31 Elevating Bracket 32 Rod 35 Spring 36 Swing Bracket 38 Roller 41 Interlocking Shaft 44 Rotary Encoder

Claims (2)

[Claims] 1. A device provided on a mobile trolley for detecting a position of the mobile trolley traveling on a rail, wherein the device is rotatably abutted on the rail at a position separated along a traveling direction of the mobile trolley. A plurality of rollers and a rotary encoder that detects the rotation of an interlocking shaft that rotates in synchronization with these rollers are provided, and each of the rollers is mounted on a movable carriage so as to be able to move following irregularities on a rail or the like. A traveling position detecting device for a mobile trolley in an automatic warehouse, wherein the traveling position detecting device is mounted non-fixed to the automatic warehouse. 2. A swinging bracket, which is rotatable in a seesaw shape as viewed from a direction perpendicular to a rail and is urged downward by a spring, is provided on the movable trolley. Rollers are provided on both sides of the clamp so as to rollably contact the rails. Further, the swing bracket is provided with an interlocking shaft that rotates in synchronization with the two rollers via gears, and a rotary encoder that detects rotation of the interlocking shaft. The traveling position detecting device for a mobile trolley in an automatic warehouse according to claim 1, wherein: