JPS6217174Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a welding device in which a welding gun can be indexed along straight lines and arcs by a single drive device.

As shown in FIG. 1, this type of conventional welding equipment moves electrode tips a and b of a welding gun along a straight line l and an arc r of a workpiece W to weld each welding point _P1.
~ When performing spot welding in P ₄ , a holding table holding a welding gun is installed on a movable table that can be moved in a straight line so that it can rotate, and the movable table is operated by a linear cylinder and the holding table is operated by another rotating cylinder. was.
That is, since the welding gun was indexed along a straight line and a circular arc using two driving devices, the welding apparatus had the drawback of becoming complicated and large.

Therefore, the present invention aims to simplify and downsize the welding device by configuring the welding gun to be indexed along straight lines and arcs by a single drive device, thereby solving the drawbacks of the conventional devices described above. The purpose is to

Embodiments of the present invention will be described below with reference to the accompanying drawings. As shown in FIGS. 2 and 3, a movable base 2 is mounted on a fixed base 1 so as to be slidable along two pilot bars 5 installed between supports 3 and 4. A holding table 7 is supported on the movable table 2 so as to be rotatable about a rotating shaft 6. Above the holding table 7 is a support block 13.
A welding gun 12 is held through the welding gun 12 (FIG. 4), and the welding gun 12 has a pair of rotary tips attached to the distal end thereof and pivoted so as to be openable and closable. Movable arms 10, 11 are provided. The centers of the electrode tips 8 and 9 are offset from the center of the rotating shaft 6 by the arc radius of the workpiece W to be welded.

Further, at the lower ends of the pair of rotating arms 10 and 11, the tip ends of the pressure cylinder 14 and the piston rod 16 are attached to pins 10a and 11a, respectively.
It is pivoted by. A hydraulic chamber (not shown) is formed in the cylinder 14, and by sending hydraulic pressure to the hydraulic chamber, the piston 16 and the cylinder 14 are
Since these move relative to each other in the axial direction, the rotating arms 10 and 11 rotate in opposite directions about the axes of the pins 15a and 15b, respectively, thereby opening and closing the electrode tips 8 and 9.

At the end of the fixed base 1, as shown in FIGS. 2 and 3, one end of a drive cylinder 17, which is a single drive device, is swingably supported on a support bracket 18. A piston (not shown) is built into the drive cylinder 17 so as to be able to slide freely in the axial direction, and the tip of the piston rod 19, which is integrally fixed to the piston, is connected to the holding base 7 via a connecting rod 20 and a pin 21. It is pivoted at a position offset from the center of rotation.

The fixed base 1 also includes the drive cylinder 17.
A guide member 22 is fixed to restrain the pivoting movement of the holding base 7 during operation. and the guide member 2
2 is formed with a linear long groove 22a parallel to the pilot bar 5 and open at one end, and a roller 23 pivotally supported by the holding table 7 is brought into sliding contact with the long groove 22a. In addition, the movable base 2 has a restraint link 2.
4 is pivotally supported at its rear end by a pin 25,
A claw portion 24a (FIG. 3) is formed at the front end, and a cam member 26 fixed to the holding base 7 is provided approximately at the center of the claw portion 24a (FIG. 3).
A roller 27 that comes into contact with is pivotally supported.

On the other hand, a spring holding stand 28 is fixed to the movable stand 2, and a presser 30 biased by a spring 29 is attached to the holding stand 28. Since the end face of the restraining link 24 is pressed while receiving the biasing force, the roller 27 receives a biasing force in the direction of contacting the cam surface of the cam member 26.

As shown in FIG. 3, a stopper 31 is fixed on the movable table 2, and when the holding table 7 rotates as shown in FIG. The pivoting movement of the holding table 7 is restricted by this. Further, an engagement block 32 is fixed to the support 3 fixed to one end of the base 1, and a claw portion 32a (Fig. 3) is formed at the end of the block 32 as shown in Fig. 5. When the holding base 7 is activated, it engages with the previously described claw portion 24a.

In the above configuration, in order to weld from the "in-place state" shown in FIGS. 2 and 3, when hydraulic pressure is sent into the drive cylinder 17 to move the piston rod 19 in the direction c (FIG. 2), the piston rod 19 is held. Since the turning movement of the table 7 is restrained by the engagement between the roller 23 and the long groove 22a of the guide member 22, the movable table 2 is moved in the a direction (the direction a) by the traction force of the piston rod 19 transmitted via the holding table 7. Move in a straight line to Figure 2).

Then, the drive device 17 is stopped while the first welding point _P1 of the straight line portion l of the workpiece W shown in FIG. 1 is detected by a limit switch not shown, and the welding gun 12 is moved to the first welding point _P1. Position. At this position, the rotating arms 10 and 11 operated by the hydraulic pressure in the pressure cylinder (Fig. 4) are operated to close, and the electrode tips 8 and 9 approach each other to pinch the workpiece W to a predetermined position. Spot welding is performed at _point P by applying current for a certain period of time. When welding at that location is completed, the electrode tips 8 and 9 are released in a direction that separates them from each other. Next, as the movable table 2 moves linearly, the second welding point P2 is similarly detected and welded.

When the drive device 17 operates again and the piston rod 19 moves in the direction c, the movable base 2 further moves in the direction a, reaching the end of the movement as shown in FIG. As soon as this end is reached, the roller 23 is disengaged from the long groove 22a of the guide member 22, and the holder 7 is still subjected to the force from the piston rod 19, so that the holder 7 begins to pivot counterclockwise in FIG.

Due to this rotation of the holding table 7, the third welding point P ₃ and the fourth welding point P ₄ of the circular arc portion r of the workpiece W are moved in the same manner as the first and second welding points P ₁ and P ₂ of the straight line portion l. Detected and welded.

When the holding base 7 reaches the end of rotation, the restraint link 2
The roller 27 on the movable base 2 is disengaged from the cam surface of the cam member 26 of the holding base 7, and the claw portion 24a engages with the claw portion 32a of the engagement block 32 due to the biasing force of the spring 29, and the movement of the movable base 2 is restrained. (the state shown in FIG. 5), and at the same time, the protrusion 7a of the holding base 7 is pressed against the stopper 31.
The turning movement is restrained by contacting the
Welding point P ₄ is welded.

In this manner, when the welding gun 12 on the holding table 7 moves along the straight line portion l and the circular arc portion r of the workpiece W, welding is performed at the welding points P ₁ to P ₄ . Then, by the reverse operation of the drive device 17, the holding base 7 turns clockwise from the state shown in FIG. 24 swings around the axis of the pin 25, both claws 24a,
32a is disengaged. By this disengagement, the movable base 2 becomes in a state where it can move in direction b (FIG. 2), and after the rotation of the holding base 7 is prevented, the movable base 2 is moved to the holding base 7 by the pressing action of the piston rod 19. It then moves linearly in the b direction together with the above-mentioned "original position state".

In this way, the present invention comprises: a movable table supported on a fixed base for linear movement; a holding table rotatably supported on the movable table and holding a welding gun having a pair of electrode tips; a single drive device connected to the fixed base; and a single drive device installed on the fixed base, which restrains the rotational movement of the holding stand when the drive device moves forward, and allows the movable stand to linearly move a certain distance integrally with the holding stand. and a guide member that allows rotation of the holding base at the sliding end of the movable base, and a guide member that restrains the linear movement of the movable base when the drive unit moves back, and restrains the movable base at the rotating end of the holding base. Since the welding device is constructed by a restraint link that releases the welding device, it has the effect of being simpler and smaller than a conventional welding device consisting of two drive devices.

[Brief explanation of the drawing]

Fig. 1 is an explanatory diagram of welding a workpiece W according to the device of the present invention, Fig. 2 is a front view of the device of the present invention, and Fig. 3 is a
A sectional view taken along the - line in the figure, Fig. 4 is a - of Fig. 2.
FIG. 5 is an enlarged sectional view taken along the line and is an explanatory diagram of the operating state. DESCRIPTION OF SYMBOLS 1... Fixed base, 2... Movable stand, 7... Holding stand, 12... Welding gun, 17... Drive device, 22
...Guide member, 24...Restriction link.

Claims (1)

[Scope of utility model registration request] a movable base supported on a fixed base for linear movement; a holding base rotatably supported on the movable base and holding a welding gun having a pair of electrode tips;
a single drive device connected to the holding base; and a single drive unit installed on the fixed base, which restrains the rotational movement of the holding base when the drive unit moves forward, and moves the movable base integrally with the holding base by a certain distance. a guide member that causes the movable base to move linearly and releases the restraint of the holding base at the sliding end of the movable base; and a guide member that restrains the linear motion of the movable base when the drive unit moves back and at the turning end of the retaining base; A welding device comprising: a restraint link for releasing the restraint of the welding device.