JPS61206577A - Resistance welding method - Google Patents

Abstract

PURPOSE:To fix with supporting a welding object over the whole surface on a fixed electrode and to eliminate the thermal deflection and plastic deflection by making the lower part electrode a plate like fixed electrode and the upper part electrode a mobile bar electrode. CONSTITUTION:The welding object 11 of which deflection is to be prevented out of a pair of welding objects 11, 12 is directly fixed with placing on a fixed electrode 10 and the another welding object 12 is fixed in the state of being placed on the welding object 11. The gun cylinder 13 of the mobile electrode is then arranged on the tip of the piston shaft 13b which is slidably provided inside the cylinder body 13a directed for the lower part and which is made movable to the welding object 12 on the upper part of another welding object 12. Both welding objects 11, 12 are welded by applying DC voltage on the electrodes with pressing and touching the electrode part of the gun cylinder 13 from the upper part of the upper part welding object 12.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a resistance welding method in which the workpiece is welded by applying current between the upper and lower electrodes when the workpiece is pressed and held between the upper and lower electrodes, and in particular the above-mentioned method. This invention relates to a resistance welding method in which welding distortion can be further reduced by using a plate-shaped fixed electrode as the lower electrode.

[Prior art] This type of conventional resistance welding method, as shown in Fig. 7,
Since both the upper and lower electrodes 1 and 2 are rod-shaped, 1 when welding
There is a problem in that considerable thermal strain and plastic strain occur in both objects 3 and 4 to be welded, and concave welding marks 5 are formed on both surfaces as shown in FIG.

[Purpose of the invention] The second invention was made in view of the above-mentioned circumstances, and its purpose is to apply current between the upper and lower electrodes to prevent the welding object from being welded when the object to be welded is pressed and held between the upper and lower electrodes facing each other. A resistance welding method for welding, in which the lower electrode is a plate-shaped fixed electrode that supports the entire lower part of the welding object, and the upper electrode advances and retreats from the welding object. One welding object on the side where welding distortion is to be prevented is fixed on the fixed electrode, and the other welding object is placed on top of this one welding object. The conventional technology It is an object of the present invention to provide a resistance welding method capable of solving the above problems and reducing thermal strain, plastic strain, and welding marks.

[Example 1] An example of the present invention will be described below based on the attached drawings.

Figure 1 is a schematic cross-sectional view showing the resistance welding method of this invention.
In the drawing, reference numeral 10 denotes a fixed electrode that can support almost the entire lower surface of the welding object 11 below and is a negative electrode made of an electrode material such as chrome steel. One of the pair of welding objects 1.1.12 whose distortion should be prevented] 1 is directly placed and fixed, and the other welding object 12 is the welding object 1.
It is fixed while being placed on top of 1. A positive electrode is integrally attached to the tip of a piston shaft 13b that is slidably disposed in the cylinder body 3a facing downward on the upper part of the upper welding target 12 and is movable toward and away from the welding target 12. A gun cylinder 13, which is a movable electrode fixed to the gun cylinder, is disposed. The two welding objects 11 and 12 are welded by applying a DC voltage to both electrodes while pressing the electrode portion at the tip of the gun cylinder 13 into contact with the upper welding object 12 from above.

FIG. 3 shows a welding device using the resistance welding method of the present invention. In one drawing, 10 is the plate-shaped fixed electrode, and the fixed electrode 10 is a jig 16 comprising legs 14 and a plate-shaped support plate 15. It is arranged almost horizontally on the floor 17.

On the fixed electrode 10, first, a welding object 11 to be welded to prevent distortion as much as possible is placed and fixed in contact with the surface using a vice or the like.Next, the other welding object 12 to be welded to this welding object 11 is placed and fixed. Place them from above and fix them in the same way.

A moving device [20] comprising a vertically moving cylinder 18 and a horizontally moving section 19 movable in the horizontal direction in the drawing by a servo motor or the like is disposed above the upper welding object 12. . At the lower end of the vertically moving cylinder 18 of the moving device 20, a pair of gun cylinders 13' similar to the gun cylinder 13, each having an electrode section attached to the lower end, are provided.
13'' is mounted. The electrode portions of the gun cylinders 13' and 13'' can press and contact the upper welding object 12 so that it can move forward and backward from above. At this time, the pair of gun cylinders 13' and 13'' are used to supply electricity to the fixed electrode (negative electrode) 10. through the object to be welded.

The moving device i20 includes a support member 2 in which a plurality of columns 21 are erected in two rows so as to face the floor 17, and horizontal members 22 are respectively installed between the upper ends of the columns 21 facing each other.
It is possible to move via wheels 25 in a direction perpendicular to one sheet of paper along a rail member 24 installed in the column direction in the middle part of 3.

In addition, the apparatus using the resistance welding method of this invention is as follows.

As shown in FIG. 4, a conventional spot welding device is used to supply electricity to the fixed electrode 10! It is also possible to use the lower electrode 27 of the spot welding device 26, in which case the moving electrode of the gun cylinder 13 is connected to the upper electrode 2 of the spot welding device 26.
It is considered to be 8. Further, as shown in FIG. 5, the negative electrode of a transformer is directly connected to the fixed electrode 10, and as shown in FIG. Attach the tip to the object to be welded 11.
It is also possible to connect without going through 12.

[Effects of the Invention] As described above, the resistance welding method according to the present invention has the following effects.

(1) Since the lower electrode is a plate-shaped fixed electrode, the object to be welded can be fixed on the fixed electrode while supporting the entire lower surface of the object, thereby preventing thermal strain and plastic strain during welding of the object to be welded. can be made smaller.

(2) Since the plate-shaped fixed electrode is used as the lower electrode as described above, welding marks 5 on the lower surface of the welding object can be made smaller as shown in the second figure.

(3) Since the plate-shaped fixed electrode is used, one welding object can be placed on the fixed electrode, and the other welding object can be placed on top of it, and the welding object below can be fixed to a certain extent. It is possible to simplify the fixing of the lower welding object, and since both welding objects can be supported and fixed over the entire surface in a stacked state on the fixed electrode, more appropriate fixation can be achieved.

[Brief explanation of drawings]

Figures 1 and 2 are a schematic cross-sectional view showing the resistance welding method according to the present invention and a schematic view showing welding marks when the resistance welding method is used, and Figure 3 is a schematic diagram showing a welding device using the resistance welding method. 4, 5 and 6 are schematic diagrams showing different embodiments of the same resistance welding method, and FIGS. 7 and 8 are schematic diagrams showing the conventional resistance welding method. In addition, in the drawing. 10 Fixed electrode 11.12 Welding object 13, 13', 13'' Gun cylinder (moving electrode) 16 Jig 17 Floor 20 Moving device 23 Supporting member. Patent applicant Tokyu Vehicle Manufacturing Co., Ltd. Figure 1 Figure 4 Figure 5Figure 3

Claims (1)

[Claims] This is a resistance welding method in which the object to be welded is pressed and held between the upper and lower electrodes, and current is passed between the upper and lower electrodes to weld the object. It is a plate-shaped fixed electrode that can be supported by
The electrode located above is a rod-shaped movable electrode that can move forward and backward toward the welding object, one welding object on the side where welding distortion is to be prevented is fixed on the fixed electrode, and this one welding object is fixed on the fixed electrode. The other welding target is fixed on top of the object, and when the movable electrode is pressed into contact with the upper part of the upper welding target, both electrodes are energized, thereby welding both the welding targets. A resistance welding method characterized by welding objects together.