JPH05285776A - Grasping device of circular work - Google Patents

Abstract

PURPOSE:To correct a position slippage and to grasp in the correct condition by providing a work rotating means to receive the angle data to correct from a correction angle operation means, and to rotate a circular work grasped by a grasping tool at the angle to correct. CONSTITUTION:A circular work W which has a sigular point 20 at the position separated from the center of the circle is grasped by a grasping tool. The position of the sigular point 20 is detected by a position detecting means 31 under such a condition. The detected position in the peripheral direction is compared with the position in the peripheral direction of the sigular point 20 obtained beforehand under the standard grasping condition of the circular work W by the grasping tool, and the difference is calculated. At the same time, the angle to correct the circular work W in the peripheral direction is calculated from the difference by correction angle operation means 37 and 38. The circular work W is rotated at the angle to correct by a work rotating means.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention refers to a circular work (in the present specification, a work having a substantially circular shape when viewed from a specific direction. For example, a work having a perfect circular planar shape.
As another example, a polygonal work having a large number of surfaces on the periphery may be used. ) For holding or processing the same).

[0002]

2. Description of the Related Art When a circular work as described above is gripped for machining or assembling, the circular work is conveyed with respect to the center of the circular work in the process of transporting the circular work to a gripping position at the work place. There may be a positional deviation in the circumferential direction (for example, about 5 °). In this case, the above deviation is detected and corrected by visual inspection by a skilled worker.

[0003]

This conventional technique requires a specialized worker for detecting and correcting the above deviation, which is a problem that hinders automation of the continuous production line. ..

The present invention has been made in order to solve the above-mentioned problems (technical problems) of the prior art. When a circular work which is displaced in the circumferential direction with respect to the circular center is gripped, the circular work is held. It is an object of the present invention to provide a gripping device for a circular workpiece in which the above-mentioned misalignment is rotated by an angle for correcting the misalignment so that the misalignment is corrected to achieve a correct gripping state.

[0005]

In order to achieve the above object, a circular work gripping device according to the present invention comprises a gripping tool for gripping a circular work having a singular point at a position away from the center of the circle. Position detection means for detecting the circumferential position of the singular point in the circular workpiece gripped by the gripping tool, and the circumferential position of the singular point detected by the position sensing means as the reference gripping state of the circular workpiece by the gripping tool. A correction angle for calculating the difference by comparing with the circumferential position of the singular point obtained in advance and calculating the angle at which the circular workpiece gripped by the gripping tool should be corrected in the circumferential direction from the difference. Calculation means and work rotation means for receiving the data of the angle to be corrected from the correction angle calculation means and rotating the circular work held by the gripping tool by the angle to be corrected. It is as it has.

[0006]

The circular work having a singular point at a position away from the center of the circular shape is gripped by the gripping tool. In that state, the position of the singular point in the circumferential direction is detected by the position detecting means. The detected circumferential position is calculated by comparing the circumferential position of a singular point previously obtained in the reference gripping state of the circular work by the gripping tool, and the circular work is circumferentially calculated from the difference. The angle to be corrected is calculated. The circular work is rotated by the work rotating means by the angle to be corrected.

[0007]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows, as an example of a gripping device for a circular work, a device for superposing an upper mold having a circular planar shape on a lower mold in a pair of upper and lower sand molds for casting. Reference numeral 1 denotes a multi-joint mechanism that constitutes a mechanical main part of the apparatus, and as one example, a well-known multi-joint industrial robot is used. As shown in FIG. 2, the mechanism 1 is composed of portions indicated by reference numerals 2 to 8, and each portion is adapted to move as indicated by arrows a, b, c, d, h and f, respectively. .. Reference numeral 10 denotes a gripping tool for a circular work, which is configured as shown in FIG.
Reference numeral 11 denotes a main body of the grasping tool 10, which is attached to the acting portion 8 of the multi-joint mechanism 1 by an integrally provided attachment piece 12. 13
Indicates the center of rotation of the movement indicated by the arrow. Reference numeral 14 denotes an advancing / retreating rod which is provided on the main body 11 so as to freely move back and forth in the direction of the arrow. The shape of the work contact portion 17 of the gripping piece 16 is set to a shape suitable for the shape of the circular work to be handled.

Next, W shown in FIGS. 1 and 2 is a circular work, for example, the upper die. Reference numeral 20 shown in FIG. 2 denotes a singular point, which is a point at which the circular work W is provided at a position distant from the center of the circle (point indicated by the symbol C in FIG. 8). For example, it is a convex portion provided on the lower surface as shown in FIG. The singularity 20 may be a recess or a flat pattern. Reference numeral 21 in FIG. 1 indicates a gripping position of the circular work. Reference numeral 22 denotes a conveyor, which is used to convey a circular work to a gripping position as shown by an arrow 23. Reference numeral 24 indicates a working position of the circular work holding device. In this example, the position where the work for superposing the upper mold on the lower mold is performed is shown. The gripping device for the circular work is shown in FIG. 1 from the gripping position 21 to the working position 24.
Move it like an arc arrow. The arrow 28 indicates the loading direction of the lower mold toward the working position 24, and 29 indicates the unloading direction of the superposed lower mold and upper mold. These carry-in and carry-out are carried out by using any well-known carrying means. Reference numeral 30 indicates a standby position of the gripping device. Next, 31 is a singularity sensor, which is for detecting passage of the singularity 20 in the circular work when the circular work is moved along the above-mentioned path, by a pair of projector 32 and light receiver 33. It is arranged so that the singular point 20 passes between the light emitter 32 and the light receiver 33 to temporarily block the light from the light emitter 32 to the light receiver 33. As this sensor, a sensor according to the form of the singular point may be used.

Next, FIG. 4 showing a control system of the multi-joint mechanism 1 will be described. Reference numeral 35 denotes a position detecting means for detecting the circumferential position of the singular point 20 on the work W, and the current position detecting means provided in the singular point sensor 31 and the articulated mechanism 1 as well known. It consists of 36 and. 37 is a CPU, 38 is a memory, and these have a function of a correction angle calculation means as one of the functions. Reference numeral 40 denotes a transfer control means, which is a means for controlling the movement of the articulated mechanism 1 for transferring the work in the horizontal direction. Reference numeral 41 is a gripper rotation control means, which is a means for controlling the movement of the multi-joint mechanism 1 so that the circular workpiece W rotates around its circular center C.
42 is a gripper lifting control means.

Next, the outline of the operation of superposing the upper die and the lower die by the above apparatus is as follows. The upper die (circular work W) is conveyed by the conveyor 22 in the direction of arrow 23 and reaches the gripping position 21. The upper mold is gripped by the gripping tool 10,
It is transported to the work position 24. At the lower position of the working position 24, the lower mold conveyed in the direction of the arrow 28 is prepared in advance. The upper mold carried to the working position 24 is corrected for the circumferential deviation with respect to the center of the circle, and then is superimposed on the lower mold. The polymerized upper and lower molds are carried out in the direction of arrow 29.

Next, the above operation will be described in detail with reference to FIGS. 6 to 9. First, in the reference gripping state of the circular work W by the gripping tool 10, the data of the circumferential position of the singular point 20 is shown in FIG.
, And as shown in FIG.
When the program starts, in step S1,
The gripping tool 10 is moved from the standby position 30 to the gripping position 21 by the operation control of the multi-joint mechanism 1 by the transfer control means 40 and the gripping tool lifting control means 42. Next, in step S2, the circular work W is in the reference state, that is, the circular work W has its circular center C.
Grip in the correct position in the circumferential direction. In this case, the circular work W is prepared in advance in such a state. Next, in step S3, the circular work W is moved to its singular point by the control of the control means 40, 42.
The arc is moved as indicated by arrow 25 in FIG. 8 until 20 reaches the position immediately before the detection of the singular point. This movement is performed by the movement of the multi-joint mechanism 1 indicated by the arrow a. Then step S4
In the above, the circular work W is controlled by the control means 40.
Is moved linearly as indicated by an arrow 26 in FIG. 8 until the singular point 20 reaches the singular point detection position by the singular point sensor 31. This movement is performed by a combination of the movements indicated by a, b, c, h, and f in FIG. Next, in step S5, the reading of the current position P0 of the current position detecting means 36 at the time when the singular point 20 is detected by the singular point sensor 31 is input as data on the circumferential position of the singular point 20 in the reference grip state. And stores it in the memory 38. Next, in step S6, the circular work W is moved to the working position 24 in an arc as indicated by an arrow 27 in FIG. Next, in step S7, by the control of the control means 42,
The work W is lowered to the position above the lower mold which is prepared in the correct position in advance. Next, in step S8, the circular work W is released and polymerized on the lower mold. Next, in step S9, the control means 40 moves the gripping tool 10 to the standby position 30, and the program ends.

After the data of the circumferential position of the singular point in the reference gripping state of the circular work pieces is obtained as described above, the operation of superposing the ordinary circular work pieces W will be described hereafter. As shown in FIG. When the program starts, steps S11 to S15 are performed in the same manner as steps S1 to S5. However, in step S12, the circular work W is gripped in a state where the circular work W is still positioned at the grip position 21. In step S15, the reading of the current position P1 of the current position detecting means 36 at the time when the singular point sensor 31 detects the singular point 20 is input as the data of the circumferential position of the singular point 20 on the circular work W. To do. Next, in step S16, a difference d between the current position P1 and the previously obtained current position P0 is calculated. Next, in step S17, the difference is set to d, the distance from the center C of the circle in the circular work W to the position of the singular point 20 is set to R0, and θ =
From tan ⁻¹ (d / R0), an angle θ for correcting the circular work W with respect to the circular center C in the circumferential direction is calculated. When the angle θ is small, the calculation may be performed by calculating θ = d / R0. Next, step S18 is performed in the same manner as step S6. Next, in step S19, the multi-joint mechanism 1 is caused to function as the work rotating means by the operation control of the multi-joint mechanism 1 by the gripper rotation control means 41, and the circular work W is rotated by the angle θ to the circular center C thereof. It is rotated around as shown by arrow 44 in FIG. By this rotation, the position of the circular work (upper die) W in the circumferential direction with respect to the circular center C correctly corresponds to the lower die that is correctly prepared in advance thereunder. Next, step S20 to step S2
2 is performed in the same manner as steps S7 to S9.
The above operation is repeated every time the circular work W reaches the gripping position 21.

Next, regarding the preparation of the lower mold for the working position 24, the lower mold is prepared with the circumferential position being correct by another gripping device similar to the case of the upper mold. Good to do. Alternatively, by using the one gripping device, preparing the lower mold in a correct circumferential position,
Both the lower mold and the upper mold may be polymerized in a correct positional relationship. Further, the above-mentioned gripping device is a drill for drilling a circular work such as a circular metal plate or a non-metal plate when performing a drilling or other processing at a predetermined position such as an asymmetrical position. Or for other machining tools,
It can also be used for positioning in the correct positional relationship (spatial positional relationship and circumferential positional relationship with respect to the circular center).

[0014]

As described above, according to the present invention, when the circular work W that is displaced in the circumferential direction with respect to the circular center C is gripped, the magnitude of the deviation is determined to determine the circular work. W is an angle θ with respect to the circular center C for correcting the above deviation
It has the feature that it can be gripped in the correct state with the misalignment corrected by just turning. This means that, for example, a gripped circular workpiece W
Is one of a pair of mating molds, it is possible to face it with the other mold in a predetermined rotation angle state, it is possible to precisely polymerize both molds by just matching the molds, Further, when the circular work W is a workpiece, it can be held at a predetermined rotation angle state with respect to the processing machine, and it is possible to perform processing at an accurate position by advancing the processing operation as it is, It is possible to eliminate the detection and correction work of the shift by the worker as in the prior art,
It is useful to enable automation of continuous production lines.

[Brief description of drawings]

FIG. 1 is a plan view of a gripping device for a circular workpiece.

FIG. 2 is a side view of an articulated mechanism.

FIG. 3 is a plan view of a gripping tool.

FIG. 4 is a block diagram showing a configuration of a control system in a gripping device for a circular workpiece.

FIG. 5 is a partially cutaway perspective view showing the relationship between a circular work and a singularity sensor.

FIG. 6 is a flowchart showing an operation procedure for detecting a circumferential position of a singular point in a reference grip state.

FIG. 7 is a flowchart showing an operation procedure of a normal circular work.

FIG. 8 is a plan view showing the movement of the work in the case of detecting the circumferential position of the singular point in the reference gripping state.

FIG. 9 is a plan view showing movement of a work when a normal circular work is operated.

[Explanation of symbols]

 W circular work 1 Multi-joint mechanism 10 Grasping tool 20 Singular point 31 Singular point sensor

Claims (1)

[Claims] 1. A gripping tool for gripping a circular work having a singular point at a position distant from the center of the circle, and a position for detecting a circumferential position of the singular point in the circular work gripped by the gripping tool. The detecting means and the circumferential position of the singular point detected by the position detecting means are compared with the circumferential position of the singular point previously obtained in the reference gripping state of the circular workpiece by the gripping tool, and the difference is calculated. From the difference, a correction angle calculation means for calculating an angle for correcting the circular work gripped by the gripping tool in the circumferential direction, and data of the angle to be corrected from the correction angle calculation means, A circular workpiece gripping device for rotating a circular workpiece gripped by a gripping tool by the workpiece rotating means for rotating the circular workpiece by the angle to be corrected.