JPH0248147Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a C-type spot welding gun (hereinafter referred to as a C-gun), and more specifically, to an improvement of an equalization device for a C-gun.

1 and 2 show a conventional type of equalizing device for a C gun, and FIG. 3 shows an equalizing device according to the present invention.

In the figure, the C gun 1 literally has a C-shaped yoke 2 fixed to the gun cylinder body 3, and the tip of the yoke and the tip of the piston rod 4 of the gun cylinder body are connected to each other.
Chip holders 5 and 6 are fixed respectively, and a pair of positive and negative electrode chips 7 and 8 are attached to the chip holders 5 and 6.
It is fitted with.

On the other hand, an equalizer 10 supporting the C gun 1
In addition to being equipped with a so-called floating mechanism that utilizes the reaction force during welding pressure to uniformly press the workpiece (not shown) between the electrode tips from both sides to prevent the workpiece from deforming, Although not shown in FIG. 3, a spring 17, an air cylinder, or the like is usually provided as an electrode stroke regulating means (stopper) and a return means when the electrode is opened as shown in FIG. Now, when spot welding is carried out continuously using an industrial robot while freely changing the posture of a C gun attached via an equalizing device, the electrode tip is applied approximately at right angles to the welding point position of the workpiece. In order to do this, the necessary movements are taught while appropriately correcting the posture and angle of the C-gun, but during this teaching, the gun is often pressurized with an inappropriate posture and angle. Furthermore, even during continuous welding after teaching, excessive force such as twisting may be applied to the C gun depending on the shape of the workpiece and the set position. If gun pressure is applied in such an inappropriate condition, not only will the bearing of the equalizer be abnormally worn, as will be explained later, but the increase in the amount of wear on the bearing will also be caused by the tip of the electrode tip shifting from the point of impact on the flange. or touching the rising part of the flange, which may cause the dot position to shift.
It will have a negative effect on the welding results.

That is, in the conventional equalizing device 10 shown in FIG. 1, both ends of two parallel guide rods 11, 11 are fixed to end plates 12a, 12b of a fixed bracket 12, and the positions are fixed at the front and rear of the gun cylinder body 3. The guide rods 11, 11 are passed through the bearings 14 of the two slide plates 13, 13, respectively, so that the entire C gun can be movably supported inside the fixed bracket 12.

However, with the conventional type shown in Figure 1,
Since the structure is such that it moves inside the fixed bracket 12, the distance l between the bearings 14 between the slide plates 13 is
Since the bearing 14 is small, the electrode tip is likely to be misaligned due to early wear and tear of the bearing 14 as described above.
Therefore, in order to solve this problem, it is necessary to increase the distance l between the bearings, but this results in a problem that the equalizing device becomes larger and its weight increases.

On the other hand, in the conventional type equalizing device 10 shown in FIG. 2, a through hole for a guide rod is provided in a fixed support block 15, and bearings 14 are fitted into both ends of the through hole. Two guide rods 1 fixed between two fixed plates 13'
1 and 11 pass through the C gun so that the entire C gun can be moved outside the support block 15 together with the two guide rods.

However, the distance l between the bearings 14 of the support block 15 is small in the one shown in FIG. 2 as well as in the one shown in FIG. Distance l
Since it is necessary to increase the size of the support block 15, the structure and weight of the support block 15 become large, which is not preferable for the C gun to be operated easily by the robot.

Therefore, the present invention is an attempt to improve the above-mentioned conventional type of equalizing device in order to eliminate its drawbacks.The specific technical means is as shown in Fig. 3. In order to absorb reaction force during pressurization and prevent changes in the welded object, an equalizing device includes a rod-side slide plate 13 and a head-side slide plate fixed to the gun cylinder body 3 of the welding gun at an appropriate distance. A fixed support block 15 is interposed between the support block 15 and the plate 13, and on both sides of the support block facing each slide plate, there are parallel grooves having a required length in a direction substantially perpendicular to the mounting surface. The two guide rods 11, 11 are integrally fixed, and the guide rods pass through bearings 14 provided on each slide plate to make the cylinder body movable.

According to this configuration, the distance l between the bearings can be greatly increased with the simplest structure, regardless of the support bracket 12 and the support block 15, which are the heaviest parts of the equalizer, and without adding any other parts. As a result, even when unreasonable force such as twisting is applied, it is possible to hold on with sufficient force to cope with that force, reducing wear and tear on the bearing and preventing the electrode tip from shifting its position, extending the life of the bearing. It can contribute to maintaining and improving welding quality.

Hereinafter, the equalizing device according to the present invention will be explained based on the embodiment shown in the drawing of FIG.

In this case, the support block 15 is fixed to a movable member 18 such as a robot arm, and on both left and right sides of the support block 15 there are two parallel blocks having a required length in a direction perpendicular to the mounting surface.
Book guide rods 11, 11 are fixed in position.

The slide plates 13, 13 are fixed in position at a predetermined interval on the rod side and head side of the gun cylinder body 3, and these two slide plates 13, 13
Bearings 14 of the guide rods are inserted and fixed into the through holes provided in each of the guide rods. Guide rods 11, 11 are inserted into the lever bearing 14,
The C gun main body is slidably supported by the guide rod 11 having such a configuration. Between the slide plate 13 on the head side of the gun cylinder body 3 and the support block 15, a return means is fixed to the slide plate 13 for applying a pressing force in the direction of opening the electrode tip 7 on the yoke side. A spring 17 is wound around the outer circumference of the bolt 16.

Thus, in the conventional type shown in FIGS. 1 and 2, as is clear from the figures, the fixed positions A and B of the guide rod are on the outside of each bearing 14, and in both cases, the distance l between the bearings is set at a certain level or more. Although it cannot be expanded greatly, in the case of the type shown in FIG. It can take a long time.

As described above, according to the present invention, in an equalizing device for absorbing reaction force during welding pressurization of a C-type spot welding gun and preventing deformation of a workpiece, guide rods are fixed at both sides of a fixed support block. is passed through the bearing of the slide plate fixed at a predetermined position in the C-type spot welding gun body, and the distance l between the bearings of the slide plate, that is, the span can be increased, making it easy to use during teaching or welding work with a spot welding robot. Even if the gun is pressurized with an incorrect posture or angle, if the distance between the bearings is wide, the pressure reaction force against the bearings will be small and the bearings will be It is possible to reduce wear and tear, prevent the electrode tip from shifting, extend the life of the bearing, and maintain and improve welding quality.

[Brief explanation of drawings]

Fig. 1 is a side view of a conventional type equalizing device for a C-type spot welding gun, Fig. 2 is a side view of another conventional type equalizing device, and Fig. 3 is a side view showing an embodiment of the equalizing device according to the present invention. figure. Explanation of symbols, 1...C-type spot welding gun, 1
0...Equalizer, 11...Guide rod, 13
...Slide plate, 14...Bearing, 15...Support block.

Claims (1)

[Scope of utility model registration request] In an equalizing device for absorbing reaction force during welding pressurization of a C-type spot welding gun to prevent changes in the welded object, the rod side is fixed at an appropriate interval on the gun cylinder body 3 of the welding gun. A fixed support block 15 is interposed between the slide plate 13 and the slide plate 13 on the head side, and a support block 15 is provided on both sides facing each slide plate in a direction substantially perpendicular to the mounting surface thereof. Two parallel guide rods 11, 11 having a required length are integrally fixed, and the guide rods penetrate through bearings 14 provided on each slide plate to movably support the cylinder body. Equalizing device for C-type spot welding gun.