JPS6049877A - Multispot welding machine - Google Patents

Abstract

PURPOSE:To reduce cost and to improve workability such as exchange of parts and maintenance as well as working efficiency by providing plural welding electrodes to one welding gun. CONSTITUTION:Welding electrodes 11, 12 are attached via a pin 16 to a welding gun 14 and are held in a prescribed position by means of a leaf spring 17. A cable connector 13 inclines by overcoming the force of the spring 17 if the space between the electrodes 11, 12 and materials 31 to be welded is not specified when the electrodes 11, 12 are brought into press contact with the materials 31. Uniform welding is thus accomplished while the electrodes 11, 12 are always brought into press contact with the materials under substantially the same pressing forc. Since the two electrodes 11, 12 are attached to one welding gun 14, the total number of the gun 14 and the connector 13 is reduced by half and the cost is considerably reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a multi-spot welding machine that uses a welding gun to press a welding electrode against an object to be welded, energizes the object, and welds the object at multiple points using Joule heat. Regarding.

car bodies, household appliances such as refrigerators and washing machines,
Alternatively, multi-spot welding machines are widely used to weld steel plate structures such as office desks. A multi-spot welding machine usually performs 8 to 40 C-spot welds with one welding machine, but conventionally, the configuration was complicated because it required as many welding guns as the number of spots.

Figure 1 shows a conventional multi-spot welding machine.
1 is a pair of welding electrodes, 2 is a cable connector attached to each welding electrode 1, a cable 3 is connected to each cable connector 2, and the end of each cable 3 is connected to a transformer 4.
is connected to. The welding electrode 1 and cable connector 2 are moved forward and backward by the welding gun 5, and the workpiece 7 is held under pressure between each welding electrode 1 and the other electrode 6,
Spot welding can be performed using the current from the transformer 4 above.
It is now possible to do this.

As can be understood from the above two configurations, in the past, each welding electrode l required a dedicated cable connector 2 and a welding gun 5, which increased the number of parts and increased costs. In addition, especially when it is necessary to weld at multiple points, it may become impossible to arrange the welding guns. At the same time, the welding gun is moved within the welding machine to perform a predetermined number of spot welds, which not only makes the welding machine expensive, but also complicates maintenance, inspection, and repair.

In view of such circumstances, the present invention provides a multi-spot welding machine in which the number of welding guns can be reduced to less than half of the conventional one by providing a plurality of welding electrodes in one welding gun. It is.

The invention will now be described with reference to the illustrated embodiment. In FIG. It is swingably connected to a fixed U-shaped bracket 15 via a pin 18. The bracket 15 is attached to the top of a chevron-shaped plate spring 17, and by bringing both ends of the spring into elastic contact with the cable connector 13, the axes of the welding electrodes 11 and 12 are normally adjusted to move forward and backward by the welding gun 14. The direction is parallel to the direction.

3 to 5 are diagrams showing the cable connector 13 and the bracket 15 in detail, and the L cable connector 13 is formed into a U-shape in the vertical plane, and at the same time, from the lower part to the horizontal plane. Formed into a U-shape inside,
Attach the two ends of the U-shaped ridges on the horizontal surface to the cable attachment part 2.
It is set at 0.21. Then, a through hole 23 for passing the cable attachment port 22 (Fig. 2) is drilled in each of the connecting parts 20.21, and as shown in Fig. 2, the transformation voltage is A cable 25 from the device 24 is connected.

Furthermore, tapped holes 26 and 27 for attaching the welding electrodes 11 and 12 are respectively formed on the lower end surface of the U-shaped portion in the vertical plane of the cable connector 13, and
Each screw hole 28.27 communicates with the welding electrode 11.12.
Screw hole 2 for connecting a conduit (not shown) that supplies cooling water to
8.29 is formed. The holes 28 and 29 communicate with each other through a communication hole 30 through which cooling water flows.

In this embodiment having the above configuration, each welding electrode 1
1.12 is attached to the welding gun 14 via the pin 16 and held in place by the leaf spring 17, so that when each welding electrode 11.12 is pressed against the workpiece 31, If the distance between the welding electrode 11.12 and the workpiece 31 is not constant, the cable connector 13 will be inclined against the leaf spring 17, and this will always keep the rewelding electrode 11.12 close to the workpiece. 31 with substantially the same pressing force to achieve uniform welding.

Also, one welding gun 14 has two welding electrodes 11 and 12.
Since it is installed, the total number of welding guns 14 and cable connectors 13 can be halved compared to the conventional one.
It will be possible to achieve significant cost reductions. Furthermore, if the total number of welding guns 14 and cable connectors 13 can be reduced, it will be easier to replace and maintain these parts, and repairs can be done quickly, resulting in an improvement in the operating rate of the welding machine. There is also.

Furthermore, even in places where two welding guns cannot be installed side by side, one welding gun 14 can perform spot welding at two points, making it possible to use two welding machines or move the welding gun unlike conventional methods. In such a case, it is possible to further reduce costs.

Next, FIG. 6 shows another embodiment of the present invention. In this embodiment, a cable connector 35 having substantially the same shape as the above embodiment is constructed from two members 35A and 35B. The members 35A and 35B are integrally connected through an insulating material 36 in an electrically insulated state.
Cable attachment portions 37 and 38 are formed at A and 35B, and cables from the transformer are connected to each of the connecting portions 37 and 38, respectively. The rest of the structure is the same as that of the above-described embodiment, and the same parts are denoted by the same reference numerals.

It is clear that even in such a configuration, the same effects as those of the above embodiment can be obtained.

As shown in Figure 1-L, the present invention provides a single welding gun with a plurality of welding electrodes, so it is possible to significantly reduce costs by reducing the number of welding guns to less than half that of conventional equipment. The effect is that it is possible to improve the workability of parts replacement and maintenance work, and to improve the operating rate of the welding machine. Furthermore, even in places where it is not possible to install two welding guns in parallel, multiple points can be welded with one welding gun 14, making it possible to use two welding machines or move the welding gun, unlike conventional methods. There is no need to do this, and there is also the advantage that it is possible to further reduce costs.

[Brief explanation of drawings]

Figure 1 is a perspective view showing a conventional multi-spot welding machine.
Fig. 2 is a perspective view showing one embodiment of the present invention, and Fig. 3 is a perspective view showing an embodiment of the present invention.
4 is a right side view of FIG. 3, FIG. 5 is a plan view of FIG. 3, and FIG. 6 is a perspective view of another embodiment of the present invention. . 11.12... Welding electrode 13.35... Cable connector 14... Welding gun 15... Bracket 16
... Pin 17 ... Leaf spring 25 ... Cable 31 ... Welded object 6 / 401- Fig. 2 Fig. 3 (!!ff Fig. 4 Fig. 6 Fig. 402-

Claims (1)

[Claims] In a multi-spot welding machine that is equipped with a cable that supplies current to a welding electrode and a welding gun that brings the welding electrode into pressure contact with a workpiece, and that welds at multiple points, a single welding gun is equipped with a plurality of welding electrodes. A multi-spot welding machine characterized by: