JPS6356366A - Lap welding method - Google Patents

Abstract

PURPOSE:To weld both metal plates to the satisfactory surface without deviation of the metal plates and a welding dent by forming a weld recessed zone lapping the metal plate of the other side on a bent part with different levels of the metal plate and spot-welding the abutting end face of the metal plate of the other side and afterward, overlay-welding the weld recessed zone. CONSTITUTION:The metal plate 2 of the other side is lapped on the bent part with the different levels of the metal plate 1 to form the weld recessed zone 3. The abutting end face 2a part of the metal plate 2 of the other side is subjected to the indirect spot welding 6 to join both the metal plates. Next, the weld recessed zone 3 is overlay-welded 11 to make it to the gentle surface. Both the metal plates 1 and 2 are welded without the deviation of the metal plates and the welding dent and made in the satisfactory surface condition. Furthermore, if this overlay part is smoothened by a grinder, etc., the finishing is improved much more.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a lap welding method, which welds two plate members without leaving any welding marks during welding. This invention relates to a lap welding method for joining.

[Prior art] Conventionally, as a method for overlapping thin plates welding, for example, one plate member bent in the opposite direction is stacked on top of the other plate member, and the difference between the stepped portion and the end face of the other plate member is Overlay welding is performed in the weld recess formed between the two. 7 like this
In the B welding method 6, it is necessary to keep the plate members forming the four welded parts in a fixed state during welding, so temporary attachment is performed by welding and spot welding. For example, when attaching a roof to the fender of an automobile, as shown in FIG.
A welding section 3 is formed between the Then, the movable electrode 16 presses the vicinity of the welding recess 3 of the roof panel 2 against the roof panel 2 to perform spot welding 2, and then build-up welding as shown by the -1 dot chain line. Overlay 11 was applied.

[Problem that the invention seeks to solve]

In such a conventional lap welding method, the roof panel 2 is attached to the fender by the movable electrode 16 during spot welding.
Due to the strong pressure applied to the panel 1, a circular concave dent 17 remains on the roof panel 2 side. Therefore, after welding was completed, it was necessary to erase the dents 17 from the viewpoint of appearance, and for this purpose, it took a considerable amount of time to fill the recesses with filler material.

In addition, in the figure, 18 is a fixed electrode, l 9 &;
− is.

The present invention has been made in consideration of such circumstances, and an object of the present invention is to provide a lap welding method for joining two plate members without leaving welding marks during tack welding.

[Means for solving problems]

In order to achieve the above object, the present invention has four welded parts by stacking the other plate member on top of one plate member bent at different levels, and welding the other plate member. A movable electrode is brought into contact with the end face of the concave portion and pressure is applied to perform indirect welding, and then overlay welding is performed on the welding concave portion described in I-.

[For production]

On one plate member 67B bent at different levels, the other plate member is superimposed to form four welded parts a).

A movable electrode is brought into contact and pressurized with the end face on the side of the welding recess, and 1
-The other plate member is in-die reflex to one plate member) 1
8 times.

Thereafter, build-up welding is performed on the four welded parts to firmly join the other plate member and one plate member, and the weld ('ν) The weld dents formed are repaired by weld overlay,
Appearance is erased.

〔Effect of the invention〕

1F of the present invention! The snap welding method involves overlapping one plate member bent at different levels and the other plate member.
A welding recess; 13 is formed, a movable electrode is brought into contact and pressure is applied to the α1) 1 surface of the other plate member described in -11 on the welding recess side, and indirect welding is performed, and then overlay welding is performed in the welding recess. Therefore, two plate members can be joined together without leaving any welding marks during tacking. Furthermore, since the force applied to the workpiece by the movable electrode in indirect welding is small, displacement of the workpiece can be prevented.

〔Example〕

In the following, the present invention will be explained in detail based on its embodiments.

The overlap welding method shown in this embodiment is for joining thin plates together, and as shown in FIG. 1, for example, one plate member 1, a fender panel, is bent at different levels.
- A welding section 3 for overlay welding is formed between the end surface 2a of the roof panel which is the other plate member 2 overlapped with the roof panel 2, and the movable electrode 4 is brought into contact with the end surface 2a of the roof panel 2 to make an indirect spot. weld, and then the welding recess 3
This is a joining method that performs overlay welding.

The indirect spot welding adopted in this example is
As shown in the figure, the fixed electrode 5 is clamped to the bottom panel L which is distant from the welding recess 3, and the roof panel 2 is
Electricity is applied from the movable electrode 4 that presses the end surface 2a toward the fender panel 1 to form an oval welded part called a nugget 6 between the fender panel l and the roof panel 2. This is spot welding. The movable electrode 4 is a cylinder 7 for pressurizing the roof panel l which is the base material to be welded.
) The end face 2a is pressed and driven, but the pressing force is considerably lower than that of normal spot welding. Note that each time a switch 9 provided on the handle 8 is operated, a welding current is supplied from the transformer 10 to the movable electrode 4.

In the present invention, (this indirect welding) welding is used only for tack welding, and the necessary welding strength is ensured by the subsequent overlay welding. As shown in Fig. 3, welding is performed at a predetermined interval at a point where the lower end surface 2a of the roof panel 2 arranged horizontally and laterally overlaps with one end edge of the roof panel 1. Although some dents remain on the inclined end surface 2a due to the pressing force of the movable electrode 4, as shown in FIGS.
completely obscured by Also, as mentioned above,
Although not shown because the pressing force of the movable electrode 4 is not large,
The position of the roof panel 2, which is previously fixed in a predetermined position relative to the fender panel 1 by the clamping device, will not shift due to indirect spot welding.

Overlay welding performed after indirect spot welding is performed using the MTG welding method. MIG welding method is the fifth
As shown in the figure, an inert gas 13 is quickly formed in a welded part by a gas nozzle 12 so as to surround a metal electrode 14, which is a welding filler. This is a method of connecting at t7' like 1 ha. In addition, since the fender panel 1 and the roof panel 2 are made of thin plates, a cooling metal fitting 15 is placed near the welding recess 3 to perform welding while dissipating heat appropriately in order to prevent melt dripping. . When the build-up welding is completed, finishing processing is performed using a grinder or the like so that the welding surface becomes flat.

[Brief explanation of the drawing]

Fig. 1 is an explanatory diagram of the lap welding method shown in the embodiment of the present invention, Fig. 2 is an explanatory diagram of indirect spot welding, and Fig. 3 is an explanatory diagram of the overlap welding method shown in the embodiment of the present invention.
The figure is a front view showing the fender panel core and roof panel temporarily attached by indirect spot welding.
No. 41 1 is M I (", an external view showing the state in which art materials are joined by overlay welding between the fender panel and roof panel using the welding method. Figure 5 is an explanatory diagram of the MIG welding method.
Fig. 1 is an explanatory diagram of the conventional vehicle welding method. , 2a-surface, 3-welding recess, 4-movable electrode, 11-welding overlay. Patent applicant Mazda Co., Ltd. agent Patent attorney Katsutoshi Yoshiso (one idiot) Figure 1 Figure 2 Figure 5 High School Figure 6

Claims (1)

[Claims] (1) Overlap the other plate member on top of one plate member bent at different levels to form a welding recess, and a movable electrode is brought into contact and pressurized with the end face of the other plate member on the side of the welding recess. A lap welding method, characterized in that indirect welding is performed using the welding method, and overlay welding is performed in the welding recess.