JPS58156711A - Structure of projection welded bolt - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to the structure of a metal panel III [I] for use as a metal panel III [I].

As is well known, a welding bolt used for welding to, for example, an automobile body panel has a structure as shown in FIG. 1. That is, *sib<tt of the bolt 3 into which the hole in the metal panel 1] aK screw part jla is inserted, a plurality of welding protrusions 2c are formed on the surface of the metal panel, and the welding protrusions With the tip of 8C pressed against the surface of metal panel l, the welding protrusion jlc is welded to metal panel K by applying current 1111 between projection welding port 3 and metal panel l.

However, 1! In the actual welding process, there may be cases where there is a paris a on the inner surface of the hole 1a, or the projection weld bolt field may be installed offset to the metal panel L&C as shown in the virtual summary, and such machining errors and positioning may occur. If there is an error, a current as shown in the virtual embroidery will flow during welding, causing S
*The current density at the protrusion position becomes smaller. For this reason, the welding force of the welding protrusion me deteriorates, and thermal distortion occurs at the root of the threaded portion 1a in contact with the hole 1aK and a part of the metal panel l, resulting in a decrease in the reliability of the welded structure.

The purpose of the present invention is to prevent electricity from flowing from a position other than the above-mentioned S* protrusion, and to provide electrical insulation for the hole into which the threaded part of a projection welding bolt is inserted or the root of the threaded part. It is proposed to cover the #I rich current with a material to stop the formation of the IIi path type acid.

Details of embodiments of the present invention will be explained below with reference to FIGS.

Figure 3 is the eleventh example of the present invention! This figure corresponds to figure W4141 of the embodiment, and the same reference numerals are given to the same structural parts as in FIG. 1. 11th! The feature of this example is a sleeve 8 made of an electrically insulating material that is fitted into the base of the threaded part 3a of the welding bolt 3a, and this sleeve 1 is applied to the surface 1111 facing the metal panel l. It is composed of a flange 8a, and a body part 8b that is continuously molded into the seven-flange hole 1 and covers the shoulder surface of the root of the screw la that is inserted into the hole 1aK.

Therefore, when welding the Groziexic S connection bolt 8 with such a sleeve 8 attached to the metal pad #1, there is a gap between the root of the screw l11m and the inner surface of the hole 1a of the metal panel 1 as shown in the figure. Since sleeve 1 is interposed,
hole] There is a hole on the edge of a, or the projector ii
Even if the ys* port l is installed with the piece I facing the hole 'f la & C, the S* current will not be coupled to the metal panel IK from the root position of the threaded portion 1a.

FIG. 8 shows a metal panel 1 instead of the sleeve 8 described above.
This is the Sth embodiment of the present invention in which the sleeve 1 is fitted into the hole 1aK. That is, the steps 1) and 4 are as follows.

The flange 4aK, which is made of an electrically insulating material like the sleeve 8 described with reference to FIG. There is.

Therefore, the body 4b of the sleeve 1 is inserted into the hole 1 as shown in the figure.
If it is set in a, it is possible to prevent the welding current from being supplied as in the case shown in figure S.

In the above embodiment, the sleeve 8 is formed separately from the projection welding bolt field or the metal panel 1.
．． In the present invention, Gloziection Expo W! The root of the threaded portion of the melt 8 or the hole 1aK of the metal panel l may be formed with an edge coating.

As is clear from the above description, according to the present invention, it is possible to completely prevent the welding current from flowing from a position other than the welding protrusion position. It is possible to prevent deterioration and hardening of the material.

[Brief explanation of the drawing]

Fig. 1 is a cross-sectional tm diagram of the conventional Proziexy fII bolt structure, the WtS diagram is a diagram corresponding to Fig. 1 of the first actual example of the present invention, and Figure 8 is the IIS of the first actual example of the present invention. It is a figure equivalent figure. 1... Metal panel, 1a... Hole, 8... Groziection welding bolt, la... Screw catch, sb... iI 1 part, lc... Welding butt, 8.4
···sleeve. 66-

Claims (1)

[Claims] l) In a projection welding bolt structure in which a threaded portion of a projection welding bolt is inserted into a hole in a metal panel, and a welding protrusion formed protrudingly formed on the surface of a portion III of the welding bolt is welded to the surface of the metal panel, the hole or the screw hole is A projection weld bolt structure in which electricity is prevented from flowing around the hole by covering the base of the hole with an electrically insulating material.