JPS6016874B2 - spot welding equipment - Google Patents

Description

[Detailed description of the invention] The present invention relates to a spot welding device.

As a conventional spot welding device, there is one shown in FIG. 1, for example.

Such a spot welding device has a guide plate 1 which is a welding gun support fixed to a frame (not shown).
The guide plate 1 has a groove 2 having a T-shaped cross section. A slide plate 3 is slidably inserted into the groove 2, and one or more spot welding guns 5 are fixed to the lower surface of the slide plate 3 via a bracket 4 so as to hang therefrom. Each spot welding gun 5 has a welding tip 6 at its lower end. Further, a cable 7 from a transmission line is connected to each welding gun 5. 8 is a cylinder fixed to the frame, and a piston rod (not shown) of this cylinder 8 is connected to the slide plate 3.

Then, after spot welding is performed at multiple points by squeezing and energizing the workpiece with the welding tip 6 and a buzz electrode (not shown), the cylinder 8 is actuated to move the welding gun 5 together with the slide plate 3. It is moved along groove 2 to perform spot welding of the next welding section. However, in such a conventional spot welding device, since the welding gun 5 is fixed to the slide plate 3, the melt point of the workpiece may be displaced in a straight line, or
Alternatively, it can be applied if the welding points of each bale section have the same pattern. There is a problem in that spot welding cannot be performed at all when the welding point is located on a curve or when the pitch between welding points changes. This invention was made by focusing on these conventional problems.
In a spot welding device, a welding gun support that supports multiple welding guns has a plurality of arms each having a welding gun attached to one end, a cam follower attached to the other end of each arm, and a welding gun support that is fixed to the welding gun support. A guide shaft rotatably supports each arm, and a cam foundation is formed which is rotatably provided to the welding gun support portion and into which each of the cam followers is carried, and the cam groove is formed so that the cam groove rotates in the sliding direction. The method includes a cam plate having a two-dimensional shape with respect to a direction, and an actuator that drives the cam plate according to the welding displacement, and each welding gun is relatively displaced in a different direction by sliding of the cam plate. The purpose is to solve the above problems.

The present invention will be explained below based on the drawings.

3, 4 and 5 are diagrams showing embodiments of the present invention.
First, the configuration will be described. In FIG. 3, 15 is a bed, and a shield 16 is fixed on the bed 15. A slider 17 is slidably supported on the rail 16, and a plurality of back fin pole holders 18a, 18b are attached to the slider 17. A plurality of back electrodes 19 are fixed to each of the back electrode holders 18a and 18b with different considerations, and each back electrode 19 has a war-torn workpiece 20 on it.
It is hidden so that it is located directly below the welding point. A cylinder 22 is fixed on the bed 15 via a bracket 21, and the tip of a piston rod 23 of this cylinder 22 is connected to the slider 17. Reference numeral 24 denotes a frame of the spot welding device, and a guide 25 disposed directly above the back magnetic pole holder 18 is fixed to the lower surface of the frame 24.

A slider 26 is freely supported on the guide 24,
A bracket 27 is fixed to the lower surface of the slider 26. 28 is a cylinder fixed to the frame 24, and the tip of a piston rod 29 of this cylinder 28 is connected to the slider 26.

As shown in FIG. 4, a support plate 30 serving as a welding gun support is attached to the lower end of the bracket 27.
A cam plate guide 31 is attached to this support plate 30. A cam plate 32 is supported on the cam plate guide 31 so as to be slidable.
2 has a plurality of (
In this embodiment, four cam guides 33 are formed, and the inner surface of each cam adjacent 33 is a cam having a different shape two-dimensionally with respect to the sliding direction of the cam plate 32, as shown in FIGS. 4 and 5. form a surface. Support plate 301 Support plate 3
A plurality of vertical guide balls 34 (four in this embodiment) passing through the guide shaft 34 are fixed with nuts 36 via washers 35, and an arm 37 is rotatably supported on each guide shaft 34. An arm 37 is attached to one end of each arm 37.
A vertical threaded shaft 38 passing through the cam plate 32 is fixed by a nut 39, and a cam follower 40, which is fitted with iron into the cam groove 33 of the cam plate 32 and engages with the cam surface, is rotatable at the lower end of each shaft 38. is supported by A thrust plate 41 is interposed between the other end of each arm 37 and the support plate 30. Further, a gun plate 42 is fixed to the lower surface of the other end of each arm 37, and a spot welding gun 43 is fixed to each gun plate 42 so as to hang therefrom. Each spot welding gun 43 has a welding tip 4 at its lower end.
It has 4. Further, a cable 45 from a power source is connected to each welding gun 43 via a bolt 46 and a nut 47. A plate 48 is fixed to the bracket 27,
A cylinder 50 as an actuator is attached to this plate 48 via a bracket 49. The tip of the piston rod 51 of the cylinder 50 has a clevis 52
The cam plate 32 is connected to the cam plate 32 via the cam plate 32. Next, the effect will be explained.

It is now assumed that the piston rod 51 of the cylinder 50 is at the position shown by the solid line in FIG. 5, and therefore the left end of the cam plate 32 in the figure is at the position pupil A shown by the solid line in the figure.

At this time, since the cam follower 40 is located approximately at the center of the cam groove 33, the rotational position of each arm 37 is regulated as shown by the solid line in the figure. Therefore, the spot welding gun 43 attached to each arm 37 is positioned vertically as shown by the broken line in the figure, and the center of the welding point is located at the point x. At this time, the back fin pole 19 on the electrode holder 18a is located directly below and apart from the welding tip 44 of each spot welding gun 43, and the workpiece 20, for example, the second The back door 9 shown in the figure is being used. Next, after the welding tip 44 and the back electrode 19 pinch the object 20 to be welded, the cable 45 is passed through to perform spot welding at a predetermined location. At this time, the thrust plate 41 receives the reaction force acting on the spot welding gun 43. When spot welding at a predetermined location is completed, the power supply is cut off, the clamping pressure is released, and the cylinder 22 (Fig. 3) is operated to retract the piston rod 23, and the slider 17, back electrode 19, and workpiece 20 are integrally welded. to the next welding section in the direction of arrow S. As a result, the back electrode 19 on the electrode holder 18a and the back electrode 19 on the electrode holder 18b, which are arranged differently, move to below the spot welding gun 43. Simultaneously with the actuation of the cylinder 22, the cylinder 50 is also actuated, for example to retract its piston rod 51. As a result, cam plate 3
2 is guided by the cam plate guide 31, and its end portion moves to position B shown by the imaginary line in FIG. Therefore, the cam follower 40' engages with the cam register 33 at a different location than in the above case, and the arm 37 is slightly extended around the guide shaft 34. As a result, each spot welding gun 43 is slightly displaced in different directions, as shown in FIG. In this way, the spot welding gun 43
The welding point of the welding tip 44 attached to the tip of the cam is changed to a position determined by the shape of the cam and the bar ratio. At this time, the center of the welding point moves from point x to point Y, and the back fin pole 19 on the electrode holder 18b is located directly below this welding point. Next, spot welding is performed in the same manner as described above. If the length of the welding area is very long and the cylinder 22 alone is not sufficient, the cylinder 28 (Fig. 3) is operated to protrude the piston rod 29 and the slider 26 and spot welding gun 43 are integrated. Just move it to the next weld section. In this case, the position of the welding point will change further, so the sill 50 is operated to move the cam plate 32, for example, to position C shown by the imaginary line in FIG. 5, and move the center of the welding point to point Z. In addition, when the back electrodes 19 are not provided individually as shown in the figure and are formed, for example, from a single flat plate, the fin pole holder 1
The same shaped back fin pole can be used for both 8a and 18b.

As explained above, according to the present invention, the welding gun support section is provided with a means for adjusting the relative positional relationship between the plurality of spot welding guns, so that each spot welding gun can be displaced in different directions. Therefore, even if the arrangement of welding points in each welding section is different, for example, even if the welding points are arranged on a curve or the pitch between welding points is different, the cam shape and arm length can be adjusted. By setting appropriately, spot welding can be easily and quickly performed.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of a secondary spot welding device, FIG. 2 is a front view of a back door of an automobile, and FIG. 3 is a schematic front view showing an embodiment of a spot welding machine according to the present invention. 4
The figure is a perspective view of the support plate and the vicinity of the spot welding gun, and FIG. 5 is a sectional view taken along the line V-V in FIG. 4. 30... Support plate, 32... Cam plate, 34...
Guide shaft, 37... Arm, 40... Cam follower, 43
...Spot welding gun, 50...Cylinder (actuator). Figure 1 Figure 2 Figure 3 Figure 4 Figure 5

Claims (1)

[Claims] 1. A welding gun support section that supports a plurality of welding guns includes a plurality of arms to which each welding gun is attached at one end, a cam follower attached to the other end of each arm, and a welding gun support section that is fixed to the welding gun support section and supports each arm. A guide shaft is rotatably supported, and a cam groove is formed to be slidable with respect to the welding gun support part and into which each of the cam followers is fitted, and the cam groove is arranged in the sliding direction. It is characterized by comprising a cam plate having a two-dimensional shape and an actuator that drives the cam plate according to the welding position, and each welding gun is relatively displaced in different directions by sliding of the cam plate. spot welding equipment.