JPS59152046A - Centering apparatus - Google Patents

Abstract

PURPOSE:To obtain a centering apparatus suitable for FMS by transmitting a control signal for driving an X-Y-theta table into said table from an arithmetic control part and correcting the position from a certain predetermined point in the table. CONSTITUTION:An X-Y-theta table 5 is loaded onto a base board 4. Said table 5 is constituted of an X-table 7, Y-table 9, and theta-table 11. Stays 14 and 15 are installed onto the side part of the base board 4. A differential transformer type position detector 16 is installed onto the stay 14, and position detectors 17 and 18 in the same type are installed onto the stay 15. Said position detectors 16-18 are electrically connected with an arithmetic control part 13. Thus, the control signal for driving the table 5 is output into the table 5 from the control part 13, and the position from a certain predetermined point in the table is corrected, and thus a centering apparatus suitable for FMS is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a centering device in an automatic production system.

[Technical background of the invention and its problems]

Recently, flexible manufacturing systems (FMS) have become popular.

A major feature of this system is that it is flexible enough to easily accommodate line changes and nine setup changes due to product changes. For example, F
In an MS, multiple automatic machine tools such as machining centers are arranged in a line and an automatic setup device is installed. contact us by any means,
Automatic machine tools, automatic setup devices, and conveyance means are now centrally managed and controlled. By the way, the automatic setup device described above performs setup work for holding and fixing a workpiece at a predetermined position on a plate that can be attached to a machine tool. The workpiece is stored at a predetermined position in an automated warehouse, and is gripped by a transport robot at a timely basis and placed on a centering device (1) as shown in FIG. The L-shaped positioning jig (2), which is provided in the centering device (1) so as to be freely removable, is moved in two orthogonal directions (directions of arrows (3a) and (3b) in Fig. 1). The positioning of the workpiece (W) is completed by contacting the side surface of the determining jig (2), and the positional deviation that occurs when the workpiece (W) is gripped by a transfer robot in an automated warehouse is eliminated. Ru. The workpiece (W) thus positioned by the centering device is gripped by the transfer robot again, and
It is conveyed to the automatic setup device and required setup work is performed.

However, the centering device (1) shown in FIG. 1 has various drawbacks. That is, every time there is a change in the shape, dimensions, weight, etc. of the workpiece (W), the positioning jig (2) or the suppression device may need to be replaced, resulting in an extremely complicated handling. Furthermore, the shape of the workpiece (W) pressed by the positioning jig (2) is not limited to any shape, and is limited to a shape that allows stable positioning. Trench positioning jig (2)
Since pressing against the workpiece (W) depends on the coefficient of static friction between the bottom surface of the workpiece (W) and the table, very high pressing accuracy cannot be expected. In view of the above, it is difficult for the conventional centering device (1) to be operated unmanned as a device constituting an FMS.

[Purpose of the invention]

The present invention has been made in consideration of the above circumstances, and is based on the FMS
The purpose is to provide a centering device that is suitable for

[Summary of the invention]

A workpiece is placed on the x-y-θ table, and a position detector is used to detect the position of a pre-registered specific surface of the workpiece, and the above is performed based on the output signal from this position detector. The amount of positional deviation of the workpiece on the x-y-θ table is calculated, and in order to eliminate the calculated amount of positional deviation, a control signal for driving the x-y-〇 table is sent from the arithmetic control unit to the x-y-θ table. The data is output to a y-θ table, and the position from a predetermined fixed point (origin) in the table is corrected.

[Embodiments of the invention]

Hereinafter, one embodiment of the present invention will be described in detail with reference to the drawings.

FIGS. 2 and 3 show a plan view and a front view, respectively, of the centering device of this embodiment. , on the base (4),
An x-y-θ table (5) is mounted.

This x-y-theta table (5) is placed on the X-table (7) provided at the bottom and movable in the direction of the arrow (6) in the figure. ) direction (perpendicular to the paper in Figure 3).
), and a θ table circle which is rotatably provided on the X table of and in the direction of arrow (10) in FIG. The xy-theta tape /I/(5) is driven by a stepping motor (not shown).

The stepping motor is connected to an arithmetic control unit 09 such as a microcomputer via a driver α. On the other hand, a first support column 04J and a second support column α4 are attached to the side surface of the base (4).

A differential transformer type first position detector α0 is protruded from this first pillar (1). The axis of the detector (16a), which is the core, is set to be parallel to the top surface of the θ table circle. position detector αD
, αυ is provided protrudingly. In these second and third position detectors α, the axes of the detectors (17a) and (18a), which are cylindrical cores provided movably in 18, are as follows:
The θ tables 0υ are provided parallel to the upper surface and parallel to each other. However, the above 1st and 2nd. The third Ijjaku detector αflj, (171, θ group is electrically connected to the calculation control unit (13).

Next, the operation of the centering device having the above configuration will be explained at 70 in FIG.
- Explain based on the chart. First, a cuboid-shaped workpiece (1) stored at a predetermined position in the automated warehouse is grasped by the transport robot and placed on the θ table α (
Figure 4 block (a)). At this time, the workpiece α■ on the θ table circle is deviated from the predetermined normal position mainly due to positioning errors and transportation errors in the storage position in the automated warehouse. Thus, the tip of the first position detector (IQ detector (16a) is placed on the side surface (19'a) of the workpiece α9, and the second and third position detectors α7), (ISO detector ( 17a),
The tip of (18a) is brought into contact with the side surface (19b) of workpiece a. Then, at this time, the first. Second. Based on the position detection signal output from the third position detector αe, α force, (1→), the position of the workpiece (11) is measured by the arithmetic control unit (l) (block 0υ in Fig. 4).Furthermore, , arithmetic control section α
In the fog, the processed material (
Reference position information and block when 19 is in the normal position (
The amount of positional deviation from the normal position is calculated by comparing the position information obtained at 2υ (block 0 in FIG. 4). In other words, the first position detector (IO) detects the positional deviation in the direction of arrow (8), and the second and third position detectors αη, α mark detect the positional deviation in the direction of arrow (6). The deviation and rotational position deviation in the direction of arrow QQ1 are detected.Thus,
The arithmetic control unit 03) outputs a control signal to the driver (12) in order to eliminate the determined positional deviation, and the driver inputting this control signal converts the X-y-θ table (5) into a control signal. (block (to) in FIG. 4). Next, block (2
The position of the workpiece α after the positional deviation has been corrected is measured in the same manner as in I) (block (24) in FIG. 4). If the positional deviation has been resolved, the centering work is completed. However, if the positional deviation remains, the positional deviation amount is calculated again in the same way as block (221). The process of calculating the amount of positional deviation and correcting the positional deviation is repeated until the workpiece α0 reaches the normal position.The workpiece α9 that has reached the normal position is then automatically transferred by the transfer robot. The workpiece is transported to the setup device and placed in a predetermined position.At this time, the workpiece has already been positioned by the centering device, so there is no need to perform new positioning by the automatic setup device. Setup 9 work can be done quickly.

In this way, the centering device of this embodiment can cope with changes in the shape, dimensions, and weight of the workpiece by storing the reference position information of the workpiece in advance on the arithmetic and control unit side. . Moreover, rather than moving the workpiece itself, the table side on which the workpiece is placed is moved, which reduces inaccuracies in the amount of movement due to the magnitude of the friction coefficient due to the weight of the workpiece. be done. Furthermore, if the side surface of the workpiece is uneven or curved, problems may occur when centering the workpiece by pressing it against a positioning jig. However, since the table side itself moves slowly, the centering accuracy does not deteriorate depending on the shape of the workpiece. Therefore, the centering device of this embodiment has improved 7 flexibility due to the above-mentioned effects, and is suitable for FMS.

In the above embodiment, a differential transformer type position detector is used as the position detector, but a potentiometer type position detector may also be used. Furthermore, the detection of positional deviation is
'V camera, CCD (Char7e Couple
This may be done using a visual sensor such as dl)evice). Furthermore, although three position detectors are used in this embodiment, three position detectors are used, from the viewpoint of the function of this device, and three or more position detectors are used. It is expected that centering accuracy will be significantly improved. Further, the procedure for position measurement and its correction may be the procedure described below. That is, in FIG. Third position detector (17
), (positional deviation of the workpiece (W) in the θ direction by IE9 (
After performing the correction of 101, the positional deviation (6) of the first to third detectors a6), αW, αWNyo) is performed.

Perform the correction in (8).

〔Effect of the invention〕

The centering device of the present invention can perform centering work quickly and with high precision regardless of the weight, weight, size, and shape of the workpiece. Therefore, since it has great flexibility, it becomes a device suitable for FMS.

[Brief explanation of the drawing]

Fig. 1 is a plan view of a conventional centering method, Figs. 2 and 3 are a plan view and a front view of a centering device according to an embodiment of the present invention, and Fig. 4 shows a procedure for centering work. It is a flowchart. (5): x-y-θ table (table), a: driver (drive mechanism), Q3): calculation control unit, Q6),
(17), Q8): Detector, Q9: Workpiece, 09a), 09b): Sum (Specific 8.)
. Agent/patent attorney Kensuke Norichika (and 1 other person)'f 1 Figure 4

Claims (1)

[Claims] A table on which an object is placed and which is rotatable along the object placement surface and movable in parallel in mutually intersecting directions; A position detector to detect, a drive mechanism to drive the table, and a positional shift amount of the object is calculated based on the position detection signal output from the position detector, and the drive mechanism corrects the position shift of the object. 1. A centering device, comprising: an arithmetic control section that outputs a control signal for stopping.