JPS597550B2 - Nut welding method to thin plate - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a welding method for welding a nut to a thin plate member to be attached.

Generally, when attaching a member to a thin plate member, for example, when attaching a radiator (not shown) to a radiator shroud b at the front end of the vehicle body a in the front part of an automobile body as shown in FIG. A structure is adopted in which a nut d is welded to the groove-shaped member c of the radiator shroud b, and a bolt (not shown) for attaching the radiator is screwed into the nut d.

Conventionally, as a welding method for welding the nut d to the groove-shaped member c, as shown in FIG. After that, the flat plate e is placed at the position of the bolt through hole g of the groove-shaped member c, and both c and e are fixed by spot welding. However, the conventional welding method described above requires a flat plate e that is separate from the nut d, and also requires a through hole f to be provided in the flat plate e, as well as an operation for welding the flat plate e and the nut d. Therefore, there is a problem that the number of parts and the number of work steps are increased, and the cost is also high, and it is also difficult to position the flat plate e with respect to the groove-shaped member c.

Therefore, in order to deal with this problem, as shown in FIG.
, and a flange part i2 are integrally formed, and a welding protrusion j having a height equivalent to the plate thickness of the groove-shaped member c is provided on the lower surface of the flange part i2 of the nut i, and the above-mentioned fitting hole is provided in the lower part of the nut i. A guide having a diameter slightly smaller than that of the groove and having a height higher than the height of the protrusion j (that is, the plate thickness of the groove-shaped member c) is provided, and the guide is fitted into the fitting hole to tighten the nut. A method has been proposed in which, after positioning the groove-shaped member c and the nut i, a welding gun is used to weld the groove-shaped member c and the nut i by applying pressure. Since the height of the protrusion j needs to be larger than the thickness of the groove-shaped member c, when welding, a part of the guide protrudes from the outer surface of the groove-shaped member c, as shown in Fig. 4. Depending on the shape of the mounting member to be attached with bolts, attachment may become impossible.

The present invention has been made in view of these points, and includes forming a fitting hole with a protruding peripheral edge in a thin plate member to be attached.
A guide having a diameter slightly smaller than the diameter of the fitting hole and a height equal to or less than the plate thickness of the member to be attached, and a nut having a welding protrusion protruding from the guide mounting surface side, After arranging the nut on the side of the protruding part of the member to be mounted, and positioning the nut by fitting the guide into the fitting hole, the member to be mounted and the nut are welded together by applying pressure to the nut using a welding gun. An object of the present invention is to provide a method for welding a nut to a thin plate by reducing the number of parts and man-hours, thereby simplifying the work and reducing costs, and which enables attachment of attachment members with bolts regardless of their shape. It is.

Hereinafter, the present invention will be explained in detail with reference to the drawings. First, as shown in FIG. 5a, a fitting hole 2 is punched in the thin plate member 1 to be attached, and a peripheral edge protruding diagonally upward is formed on the periphery of the fitting hole 2 by burring. A protrusion 2a is formed. Further, as shown in FIG. 8, for a nut 3 integrally formed with a circular head 3a and a flange 3b protruding outward from the lower part of the outer peripheral surface of the head 3a, the lower part of the head 3a is A guide 4 having a diameter slightly smaller than the diameter of the fitting hole 2 and a height less than the thickness of the member 1 to be attached is formed, and a guide 4 having a height approximately equal to the thickness of the member 1 to be attached to the flange 3b is formed. For example, two welding protrusions 5, 5 are formed which protrude downward, that is, are higher than the guide 4. Next, as shown in FIG. 5b, the nut 3 is placed on the side of the protrusion 2a of the member 1 to be attached, and the guide 4 of the nut 3 is fitted into the fitting hole 2, so that the nut 3 is attached to the member 1 to be attached.
positioning.

Here, although the height of the guide 4 is lower than the welding protrusion 5, since the periphery of the fitting hole 2 protrudes obliquely upward,
As shown in detail in FIG. 6, the guide 4 and the fitting hole 2 are fitted together before the welding protrusion 5 comes into contact with the periphery of the fitting hole 2 of the attached member 1. Positioning can be performed easily. After that, the positioned nut 3
When the attached member 1 and the flange portion 3b of the nut 3 are pressed together with the welding gun 6 and energized, as shown in FIG.
As shown in FIG. 2, the welding protrusion 5 is heated and melted and crimped onto the attached member 1, and the protrusion 2a of the fitting hole 2 is heated.
The mounted member 1 and the nut 3 are welded together in a flat state by applying pressure.

Since the height of the guide 4 of the nut 3 welded in this way is smaller than the plate thickness of the attached member 1, the guide 4 is used to guide the attachment of the attached member 1 to which the attachment member is attached, as shown in detail in FIG. It does not protrude from the surface (lower surface in the figure), so even when mounting a mounting member having a flat mounting surface, the mounting member can be mounted in close contact with the mounting surface of the member to be mounted 1. circumference, in the above embodiment, the head 3a
A guide 4 is attached to a nut 3 formed integrally with a flange portion 3b and a flange portion 3b.
However, in the present invention, a guide l is formed on the lower surface of the hexagonal nut 7 as shown in FIGS. 9 and 10.
For example, three welding protrusions 5', 5', and 5' may be formed, and the same effect can be achieved. In addition, in the above embodiment, the height of the guide 4 is set to the height of the attached member 1.
Although the plate thickness is set to be equal to or less than , it goes without saying that the plate thickness may be made equal to the plate thickness of the attached member 1.

As explained above, according to the method for welding a nut to a thin plate of the present invention, a fitting hole with a protruding peripheral edge is formed in a thin plate to be attached, and the fitting hole has a diameter slightly smaller than the diameter of the fitting hole and is attached to a thin plate. A nut having a guide with a height equal to or less than the plate thickness of the mounting member and a welding protrusion protruding from the guide mounting surface side is provided, and the nut is arranged on the protrusion side of the mounting member. After fitting the nut guide into the fitting hole and positioning it, the workpiece is welded to the workpiece by applying pressure to the nut using a welding gun. Even if there is a problem, the nut can be easily positioned, the number of parts and work hours can be reduced, work can be simplified and costs can be reduced, and the mounting parts can be reliably installed. It has several advantages.

[Brief explanation of the drawing]

Figures 1 to 4 show conventional examples, where Figure 1 is a perspective view of the front part of an automobile body, Figure 2 is a sectional view taken along the line of Figure 1, Figure 3 is a cross-sectional view, and Figures 4 and 4 are other examples. 2 and 5 to 10 illustrate the embodiment of the present invention, and FIGS. 5 a to 5 c are welding process diagrams, and FIGS. 6 and 7 respectively. Fig. 5 is an enlarged sectional view of the main part during steps b and c, Fig. 8 is a perspective view of the nut, Figs. 9 and 10 show modified examples, and Fig. 9 is a perspective view of the nut. , FIG. 10 is a diagram corresponding to FIG. 6. DESCRIPTION OF SYMBOLS 1... Attached member, 2... Fitting hole, 2a... Peripheral protrusion, 3... Nut, 3a... Head, 3b...
Flange portion, 4, 4'...Guide, 5, 5'...Protrusion for welding, 6...Welding gun, 7...Hexagonal nut.

Claims (1)

[Claims] 1 A fitting hole with a protruding peripheral edge is formed in a thin plate member to be attached, and a guide having a diameter slightly smaller than the diameter of the fitting hole and a height equal to or less than the plate thickness of the member to be attached; , a nut having a welding protrusion protruding from the guide mounting surface is provided, the nut is placed on the protrusion side of the attached member, and the guide of the nut is fitted into the fitting hole for positioning; A method for welding a nut to a thin plate, characterized by welding a member to be attached and a nut by applying pressure and applying electricity using a welding gun.