JPS60238092A - Resistance welding method of hinge piece - Google Patents

Abstract

PURPOSE:To execute satisfactorily resistance welding of a hinge piece for an automobile, etc. without cracking a weld zone by forming preliminarily projections to the rounded end of a sheet metal forming a shaft insertion part or the section of the sheet metal with which said end contacts. CONSTITUTION:The plural projecting lines 6 are formed at prescribed intervals to the terminal (a) of the part where the shaft insertion part 5 is formed by rounding the sheet metal 4 for forming the hinge piece. The part 5 where the round end (a) contacts with the metal 4 or comes in proximity thereto is formed when the part for forming said part 5 is rounded. The projections 6 contact locally with the metal 4 and exhibit large contact resistance when the part 5 is inserted between electrodes 7, 8 and electricity is conducted thereto. The projections 6 and the contact points thereof generate consequently heat to melt and the part 5 is resistance-welded under the pressure exerted by the electrodes 7, 8. Said part is similarly resistance-welded even if the projections are formed on the surface of the metal 4 with which the end (a) contacts. Cracking of the weld zone is prevented and the trouble in the stage of opening and closing a door is eliminated by the above-mentioned method.

Description

[Detailed description of the invention] A method of resistance welding hinge pieces.

As a hinge part of a conventional automobile door hinge, a sheet metal 1 is rolled up to form a shaft insertion part 2, and the rounded end a is arc welded 3 to the sheet metal 1, as shown in FIGS. 1 and 2. is publicly known.

However, arc welding in this manner has the problem of causing cracks in the welded area.

The present invention was made to solve this problem.
This enables resistance welding of rounded edges and sheet metal, eliminating the occurrence of cracks in the weld.

Therefore, the technical means of the present invention is to form a shaft insertion part by rolling a sheet metal, and in a hinge part whose rounded end is welded to the sheet metal, a protrusion is formed in advance at the rounded end or at the part of the sheet metal that the rounded end comes into contact with. After rounding, the rounded end and the sheet metal are brought into contact with each other through the projections, and resistance welding is performed.

Therefore, according to this method, when the shaft insertion part is sandwiched between the electrodes and energized, contact resistance occurs in the protrusion part, and local heat generation increases Joule heat in this part, melting the protrusion and its contact part. By applying pressure to the shaft insertion part, the sheet metal and the rounded end can be resistance welded.

Next, an example of a method related to the present invention will be described.

Actual eaves example/When punching the sheet metal 4 at the end (hereinafter referred to as the rounded end) a of the part where the shaft insertion part 5 is formed by rolling the sheet metal 4 forming the hinge piece, as shown in FIG. When a plurality of protrusions 6 are formed at predetermined intervals and the part forming the shaft insertion portion is rounded as shown in Fig. Since a portion 5b is formed, when this shaft insertion portion 5 is sandwiched between electrodes 7 and 8 and energized, the protrusion 6 provided on the rounded end a comes into contact with the sheet metal 4 at the pole part and exhibits a larger contact resistance than other parts. , the protrusion 6 and its contact point generate heat, and the electrical resistance increases accordingly, generating Joule heat, which melts the protrusion 6 and its contact point, and the electrode 7.8 causes (3
) The shaft insertion part 5 is resistance welded because it is fused and integrated on the added side.

Embodiment 2 A shaft insertion part 5 is formed by rolling the sheet metal 4 forming the hinge piece.
When forming the sheet metal 4, when punching the sheet metal 4, extrusion is performed from the back side as shown in Fig. g of the drawing on the part where the rounded end a comes into contact with, as shown in Fig. g of the drawing. Since the protrusion 6 is formed, after the protrusion 6 is formed, when the end of the sheet metal 4 is rounded to form the shaft insertion part 5, the rounded end a comes into contact with or approaches the protrusion 6 of the sheet metal 4. In this state, when the shaft insertion part 5 is sandwiched between the electrodes 7 and 8 and energized, the protrusion 6 and its contact point are heated and melted.
It is also resistance welded.

As mentioned above, the method according to the present invention involves: forming a hinge piece in which a shaft insertion part is formed by rounding a sheet metal (4), providing a protrusion at the rounded end of the shaft insertion part or a corresponding part of the sheet metal; Since welding heat is generated due to the contact resistance of 1, and has the unique effect of eliminating troubles caused by this when opening and closing the door.

[Brief explanation of the drawing]

FIG. 7 is a front view showing a conventional door hinge. Figure 2 is the same plan view. FIG. 3 is a front view showing an example of a hinge piece in a door hinge resistance welded by the method according to the present invention. FIG. 7 is a partial side view showing a state of resistance welding similar to the above. FIG. S is a perspective view showing a state in which the protrusions are formed. FIG. 3 is a front view showing another example of a hinge piece in a door hinge resistance welded by the method according to the present invention. FIG. 7 is a side view showing the same resistance welding state as above. gth
The figure is a sectional view showing a state in which the protrusions are formed. In the figure, 4 is a sheet metal, 5 is a shaft insertion part, a is a rounded end, 6 rod early

Claims (1)

[Claims] In a hinge piece in which a shaft insertion part is formed by rolling a sheet metal and the rounded end is welded to the sheet metal, a protrusion is formed in advance on the rounded end or the part of the sheet metal that this will come into contact with, and after the rounding process, the rounded end is welded to the sheet metal. A method of resistance welding a hinge piece, characterized in that resistance welding is performed by bringing a sheet metal into extreme contact with the projection.