JPH0263685A - Welding method - Google Patents

Abstract

PURPOSE:To simplify a jig for positioning by forming a projection on material to be welded in advance, executing positioning in a state with the projection directed to base material, generating an arc between the projection and the base metal and pressing the projection against the base metal to weld both together. CONSTITUTION:A robot 16 holds a part 2 by a work holding tool 17 and takes out it from a part feeder and conveys it up to the position of a forming device 19. When the part 2 is positioned by the robot 16, the projection is formed on the part 2 by operation of the forming device 19. The robot 16 then positions the part 2 on the prescribed position on the base metal 1 based on moving information taught in advance and electricity is supplied to a gun 18 and the arc is generated between the projection and the base metal 17. The pressurizing force is then actuated on the part 2 which is pressed on the base metal 1, by which both are welded together. By this method, since the part 2 is tack-welded to the base metal 1, afterward, spot welding of each spot is performed successively by a gun 6 for spot welding.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a welding method applying the principle of stud welding.

(Prior Art) As is well known, when resistance welding is performed, a large pressing force is applied to the object to be welded via a welding gun, so it is necessary to firmly position the object to be welded. .

That is, for example, parts 2, 3, . . . are attached to a base material 1 shown in FIG.
46 and 5, a high pressure of about 200 kg is applied to the welding gun 6 of the welding machine. therefore,
In this case, it is necessary to firmly position each of the parts 2 to 5 using dedicated positioning jigs 7 to 10, respectively.

Incidentally, in FIG. 5, the spot welding points for each of the parts 2 to 5 are indicated by X marks.

[Problems to be Solved by the Invention] As mentioned above, resistance welding requires a dedicated positioning jig with strong clamping force, which is disadvantageous when performing high-mix, low-volume production, and also reduces equipment costs. It has the disadvantage of being bulky.

SUMMARY OF THE INVENTION In view of these conventional problems, an object of the present invention is to provide a welding method that can simplify the positioning jig.

[Means to solve the problem]

Welding method C according to the present invention includes a step of forming a projection on a workpiece in advance, a step of positioning the workpiece in such a manner that the projection is directed toward a base metal, and a step of aligning the workpiece with the base metal. 2) The process of generating an arc between the culms and the process of pressing the protrusions onto the base material are carried out in a large box.

[Effect]

According to the present invention, the projection functions as a tip of a stud in arc stud welding, and the object to be welded and the base metal are welded at the projection.

〔Example] Hereinafter, embodiments of the present invention will be described in detail without reference to the drawings.

First, regarding arc stud welding applied to the present invention, C
Explain easily.

This arc stud welding is performed by stud 11 shown in FIG.
It is applied when welding to the base material 12.

This stud contact C causes an arc to be generated between the substantially arrow-shaped tip of the stud 11 and the base material 12, and the arc heats both. Then, when both are heated appropriately, the stud 11 is pressed against the base material 12 to weld them together.

The advantage of this arc stud welding is that the pressure required during welding is as low as several kilograms of kneading.

The present invention focuses on this advantage and applies the principle of arc stud welding. That is, in the present invention, as shown in FIG. 3(a), a protrusion 14 having a shape similar to the tip end shape of the stud 11 is formed in advance on the workpiece 13.

During welding, the protrusion 14 is directed toward the base metal 15, and an arc is generated between the two. Then, similarly to arc stud welding, the workpiece 13 is pressurized while the protrusion 14 and the base metal 15 are heated to an appropriate temperature, as shown in FIG. 3(b).
As shown in FIG.
Welded to 5.

FIG. 1 illustrates one embodiment of the invention.

In this figure, the same elements as those shown in FIG. 4 are given the same reference numerals.

The welding robot 16 shown in FIG.
7, a welding gun 18, and a pressurizing means (not shown) that applies pressurizing force to the workpiece, and is automatically operated by a robot controller (not shown).

Note that the welding gun 18 is made of, for example, a copper-based material, and has a tip shape that makes surface contact with the object to be welded. Further, the workpiece holding jig 17 uses holding means such as a magnetic force type or a vacuum type.

The molding device 19 shown in FIG. 1 has an upper arm 20, a lower arm 21, and a pressurizing cylinder 22 interposed between the proximal ends of these arms, and the tip of the arm 20 is equipped with a punch. The object to be welded is sandwiched between the part and the tip of the arm 21 to which the die is attached, and the
) functions to form a protrusion 14 as exemplified in FIG.

The robot 16 picks up parts 2, 3, 46 and 5, which are objects to be welded, arranged in a parts feeder (not shown).
First, the part 2 is held by the workpiece holder 17 and taken out from the parts feeder. Then, this part 2 is transported to the position of the molding device 19.

When the part 2 is positioned by the robot 16, the molding machine 19 is operated to form the protrusion 14 on the part 2. The molding position of the protrusion 14 in this part 2 is set at the temporary attachment position indicated by the black mark in FIG.

Next, the robot 16 positions the part 2 at a predetermined position on the base material 1 based on the movement information taught in advance, and after that positioning, the robot 16 supplies power to the gun 18 and the protrusion 14 (
Not shown in FIG. ) and the base material 17. Next, a pressurizing force is applied to the part 2 to press the part 2 to the base material 1, thereby welding the two together.

As a result, part 2 is temporarily attached to base material 1, so from now on,
The spot welding gun 6 described above sequentially performs spot welding at each point indicated by an X in FIG. Since the component 2 is strongly fixed to the base material 1 by the above-mentioned temporary attachment, a fixing jig is not required when performing spot welding.

The other parts 3 to 5 are tack welded to the base material 1 in a similar manner, and in FIG. 5, the positions of these parts tack welded are indicated by black marks.

As described above, according to this embodiment, a simple holding jig such as a magnetic type, a vacuum type, a hook type, etc. can be used as a positioning jig, so that a jig dedicated to each component is not required.

(Effects of the Invention) As described above, according to the present invention, it is possible to simplify the positioning shell.Therefore, the equipment cost can be significantly reduced, and the production of other varieties and small shells can be carried out efficiently. Another advantage is that it becomes possible to perform positional welding work using a light and portable l''bot.

[Brief explanation of the drawing]

Figure 1 is a perspective view showing an embodiment of the welding method according to the present invention, Figure 2 is an explanatory diagram of arc stud welding, and Figure 3 (a
) and (b) respectively show an example of a protrusion and a state in which a workpiece to be welded is welded to a base metal.
...Molding equipment.

Claims (1)

[Claims] A step of forming a projection in advance on a part to be welded, a step of positioning the object to be welded in such a manner that the projection is directed toward the base material, and generating an arc between the projection and the base material. A welding method comprising: a step of pressing the protrusion against a base material.