JPH06254698A - Work holding device - Google Patents

Abstract

PURPOSE:To suitably make a simultaneous production of a multi kind, to shorten a working time and to improve a working precision by increasing a number of a changable work holding jig and comparatively freely changing an attitude of the work holding jig. CONSTITUTION:A rotary shaft 4 is supported rotatively around a horizontal axis through bearing members 2, 3 on a base board 1, and a servo motor 5 driving with rotating the rotary shaft 4 is provided. Central parts of a pair of arm members 6, 6 are respectively fixed on both end parts of the rotary shaft 4 as one body of the rotation. Two of almost rectangular shape flat like rotary tables 7, 7 are arranged between the mutual end parts of both arm members 6, 6, both ends of each rotary table 7 are supported rotatively around the horizontal axis on the end parts of each arm member 6. Two servo motors 8, 9 respectively driving with rotating both rotary tables 7, 7 are provided. Four numbers of the work holding jigs 11-14 which are able to hold a mutually different kind of works are attached on both surfaces of each rotary table 7.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a work holding device for holding a work during automatic welding or the like, and more particularly to a work holding device capable of holding different kinds of works.

[0002]

2. Description of the Related Art Generally, when automatically welding a work such as a sheet metal, the work is held by a jig.
This jig is different for each size and shape of the work. Therefore, when flowing different kinds of works to one production line, it is necessary to prepare work holding jigs corresponding to the number of kinds of works and replace the work holding jigs according to the kinds of works. .

Conventionally, as a device for automatically exchanging a work holding jig, both ends of a rectangular flat plate-shaped rotary table are rotatably supported around a horizontal axis via bearing members, respectively, and Two work holding jigs capable of holding different kinds of works are attached to both sides of the rotary table, and the rotary table is rotated 180 degrees according to the kind of the work so that the work holding jig to be used is on the upper side. It is known to do so.

[0004]

However, in the above-mentioned prior art, since only two kinds of work holding jigs can be exchanged, three or more kinds of works cannot be flown into one production line. . In addition, the work holding jig can change its posture only by rotating the rotary table around the horizontal axis. Therefore, when performing work with a tool such as a welding gun on the work held by this jig, the work side However, there is a problem in that the posture can hardly be changed, the work time is accordingly long, and the work accuracy is deteriorated.

The present invention has been made in view of the above points, and an object thereof is to increase the number of replaceable work holding jigs and to relatively freely change the postures of the work holding jigs. By doing so, it is an object of the present invention to provide a work holding device which is suitable for simultaneous production of many kinds and can shorten the working time and improve the working accuracy.

[0006]

In order to achieve the above-mentioned object, the invention according to claim 1 is a work holding device, comprising a rotating shaft rotatably supported around a horizontal axis on a base through a bearing member. A first driving means for rotationally driving the rotating shaft, a pair of arm members having central portions fixed to both ends of the rotating shaft so as to rotate integrally, and arranged between end portions of the both arm members. And two substantially rectangular flat plate-shaped rotary tables each having both ends rotatably supported by the ends of the arm members about a horizontal axis, and two second drive means for rotationally driving the rotary tables, respectively. It is configured to include four work holding jigs that are attached to both surfaces of each of the above rotary tables and that can hold works of different types.

The invention described in claim 2 is dependent on the invention described in claim 1, and both the first and second driving means, which are the constituent elements thereof, are constituted by servomotors.

[0008]

With the above construction, in the work holding apparatus according to the invention as set forth in claim 1, even when four kinds of works are made to flow in one production line, the arm member serves as the first driving means in accordance with the kind of works. The rotary table at the end of the arm member is rotated by the operation of the second drive means while being rotated integrally with the rotary shaft by the operation, whereby the work holding jig to be used is above the rotary table and the welding gun. It becomes possible to perform work such as holding of the work and eventually welding on the work, because the work is located closer to the work tool. Moreover, since the work holding jig can change its posture by rotating the arm member (rotating shaft) and the rotary table, the posture of the work held by this jig can be changed relatively freely. You can

According to the second aspect of the present invention, since the first and second driving means are both servo motors, it is possible to appropriately change the posture of the work holding jig or the work.

[0010]

Embodiments of the present invention will be described below with reference to the drawings.

1 to 3 show a work holding device according to an embodiment of the present invention, in which 1 is a rectangular flat plate-shaped base, and 2 and 3.
Is a pair of bearing members erected on both sides of the base 1 in the longitudinal direction, and the upper ends of the bearing members 2 and 3 have both ends of a rotary shaft 4 whose axis extends in the horizontal direction around the axis, that is, around the horizontal axis. It is rotatably supported by. In one bearing member 2,
A servo motor 5 is attached as a first drive means for rotating the rotary shaft 4.

Bearing members 2, 3 are provided at both ends of the rotary shaft 4, respectively.
The central portions of the pair of arm members 6 and 6 are rotationally and integrally fitted to a position on the inner side. Two substantially rectangular flat plate-shaped rotary tables 7, 7 are provided between the ends of the arm members 6, 6.
And both ends of each rotary table 7 are rotatably supported by the end of each arm member 6 about a horizontal axis, and the rotation centers of both rotary tables 7, 7 are
The axis of the rotary shaft 4 is set as a pole so as to be polar symmetrical (see FIG. 3). Two servo motors 8 and 9 in total are attached to both ends of one arm member 6 as second drive means for rotationally driving the corresponding rotary table 7.

One work holding jig 11, 12, 13 or 14 is attached to both sides of each rotary table 7 via a mounting plate 15. These four work holding jigs 11 to 14 in total can hold four types of works (for example, sheet metal) having different sizes and shapes, and as shown in an enlarged detail in FIG. 1
6 and a plurality of holding members 17, 17 for holding a work between the receiving table 16 and a plurality of cylinders 18, 1 for moving each holding member 17 between a holding position and a standby position.
8 and so on.

In FIG. 2, reference numeral 21 is a controller for controlling the operation of the three servo motors 5, 8 and 9. Although not shown, each servo motor 5, 8, 9
An encoder that detects the rotation angle of the rotary shaft 4 or the rotary table 7 that is a driven body based on the rotation of the rotary shaft is incorporated, and the detection signals of these encoders are input to the controller 21, and the controller 21 outputs the detected signals. It is used for feedback control of the servomotors 5, 8 and 9.

Next, to explain the operation and effect of the above-mentioned embodiment, even when four kinds of works are flown into one production line, in the work holding device, the control of the control 21 is performed according to the kind of works. Below, servo motor 5
Is operated to rotate the arm member 6 integrally with the rotary shaft 4 about its axis (horizontal axis) about every 180 degrees, and at least one of the servomotors 8 and 9 is operated to rotate the rotary table 7 around the horizontal axis. It rotates about every 180 degrees. As a result, one of the four work holding jigs 11 to 14 to be used is located on the upper side of the rotary table 7 and on the side closer to the work tool such as the welding gun.
It is possible to hold the work and then perform work such as welding on the work.

Moreover, each of the above work holding jigs 11 to 14
At the time of use, the posture can be changed by rotating the arm member 6 and the rotating table 7. For example, one work holding jig 11 used for rotating the arm member 6 is positioned at a predetermined height. After that, by rotating the rotary table 7 to change the orientation of the work holding jig 11 around the horizontal axis, the posture of the held work can be changed relatively freely. Therefore, the work such as automatic welding can be quickly and reliably performed on the work, and the work time can be shortened and the work accuracy can be improved. Also, the arm member 6 is rotated by approximately 180 degrees to rotate the work holding jigs 11 to 14
When changing the use of, the posture can be changed by rotating the rotary table 7 so that the work holding jigs 11 to 14 rotate within the minimum radius of gyration about the axis of the rotary shaft 4. It is possible to reduce the height dimension of the bearing members 2 and 3 as much as possible while avoiding the interference of 1), and it is possible to reduce the size of the device.

Further, in the case of the present embodiment, since the rotary shaft 4 and the rotary table 7 are driven by the servomotors 5, 8 and 9, respectively, the work holding jigs 11 to 1 are particularly used.
4) The posture of the work can be changed quickly and accurately, and the work time can be further shortened.

[0018]

As described above, according to the work holding device of the invention as set forth in claim 1, even when four kinds of works are flown into one production line, the work holding jig corresponding to the kind of works can be provided. By rotating the arm member and rotating table to move it to the upper side of the rotating table and to the side closer to the work tool, it is possible to hold the work and then work on the work, which is suitable for multiple types of simultaneous production. Is. Moreover, since the posture of the work held by the jig can be changed relatively freely, the working time can be shortened and the working accuracy can be improved.

Further, according to the second aspect of the present invention, by configuring the rotation driving means by the servo motor, it is possible to appropriately change the posture of the work holding jig or the work, and shorten the work time. Can be improved.

[Brief description of drawings]

FIG. 1 is a perspective view of a work holding device according to an embodiment of the present invention.

FIG. 2 is a front view of the same.

FIG. 3 is a side view of the same.

FIG. 4 is a perspective view of a work holding jig.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Base 2,3 Bearing member 4 Rotating shaft 5 Servo motor (1st drive means) 6 Arm member 7 Rotary table 8,9 Servo motor (2nd drive means) 11-14 Work holding jig

Claims (2)

[Claims] 1. A rotary shaft rotatably supported on a base plate via a bearing member about a horizontal axis, a first drive means for rotationally driving the rotary shaft, and a center at each end of the rotary shaft. A pair of arm members whose parts are rotationally fixed to each other, and two substantially two arms which are respectively disposed between the ends of the arm members and whose both ends are rotatably supported by the ends of the arm members around a horizontal axis. A rectangular flat plate-shaped rotary table, two second drive means for rotationally driving both rotary tables, and four work holders mounted on both surfaces of each rotary table and capable of holding different kinds of works. A work holding device comprising a jig. 2. The work holding device according to claim 1, wherein the first and second driving means are both servo motors.