JPS6017531Y2 - Weld nut mounting structure - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a weld nut mounting structure that is fixed to a plate or panel having bolt insertion holes.

In this specification, sheet metal members such as floors or various plates constituting an automobile body will be collectively referred to as panels hereinafter.

In general, weld nuts have a square or hexagonal shape, as shown in FIGS.
It is a formalized form of

The weld nut 1 is attached to the panel by pressing and clamping the weld nut together with the panel between a pair of electrodes, melting the small projections 3 by applying electricity to the electrodes, and fixing the weld nut 1 using the molten metal. .

In this case, unless the bolt insertion hole on the panel side and the threaded hole of the nut are aligned, it will be impossible to screw the bolt together after attaching the weld nut.

Therefore, conventionally, various positioning means shown in FIG. 2 At Bt C have been used.

The one shown in FIG. 2A uses a locating pin 4 to position a bolt insertion hole 6 drilled in a panel 5 and a screw hole 7 of a nut 1 in a state where they are aligned.

The nut 1 shown in FIG.
is fitted into the bolt insertion hole 6 and positioned.

However, in all of these, the locating pin 4 or protrusion 8 is inserted into the bolt insertion hole 6 to determine the position, so the gap that is naturally required between the bolt insertion hole 6 and the locating pin etc. is the cause of the nut being misaligned. There was a limit to the ability to create accurate alignment.

Further, in the one shown in FIG. 2C, the nut 1 is set in a predetermined position using a conductive member 9 having a recess 9a for positioning the outer periphery of the nut 1. In addition to positional deviation due to the gap between 9a and the outer periphery of the nut, positioning of the member 9 is required, which is not practical.

The present invention was made to eliminate the above-mentioned defects, and includes aligning the bolt insertion hole of the panel and the screw hole of the weld nut approximately concentrically, and bringing the welding small protrusion of the weld nut into contact with the panel. In a weld nut mounting structure in which the panel and the weld nut are welded by melting the small protrusion by applying electricity between the panel and the weld nut, the entrance periphery of the screw hole of the weld nut is inclined downward toward the center of the screw hole. By forming the weld nut on an inclined surface, providing an emboss on the edge of the bolt insertion hole of the panel, and engaging the inclined surface of the weld nut with the emboss on the panel, alignment can be easily and reliably performed with high precision. An object of the present invention is to provide a weld nut mounting structure that can perform welding.

An embodiment of the present invention will be described below with reference to the drawings.

FIG. 3 shows a weld nut 10 according to the present invention in panel 1.
FIG. 1 is a vertical cross-sectional view showing a state immediately before being fixed to 1. FIG.

This weld nut 10 has a screw hole 12 in the center and a small protrusion 14 on the outer peripheral corner of the seat surface 13 that contacts the waist panel 11.
It is equipped with...

In particular, in the present invention, the periphery of the entrance portion of the screw hole 12 is cut out in a conical shape concentric with the screw hole 12, and an inclined surface 15 that slopes downward toward the center of the screw hole 12 is formed here. There is.

On the other hand, a bolt insertion hole 16 is punched in the panel 11 to which the nut 10 is fixed.
6 with a truncated conical embossing 17 concentric with the insertion hole 16.
The embossing 17 and the inclined surface 15 are fitted into each other.

With this configuration, by simply engaging the inclined surface 15 of the weld nut 10 with the mouth edge of the bolt insertion hole 16 of the panel 11, the conical inner circumferential surface of the inclined surface 15 can form the conical embossment. The screw hole of the weld nut 10 is partially abutted on the outer circumferential surface of the weld nut 17, and then the inner circumferential surface slides against the outer circumferential surface due to the engagement force and guides the weld nut 10, and the two sides are completely fitted, thereby opening the screw hole of the weld nut 10. The so-called self-locating between the bolt insertion hole 12 and the bolt insertion hole 16 is completed.

That is, it is aligned with the nut 10 and bolt insertion hole 16.

In order to attach the weld nut 10 to the panel 11, the panel 11 is first positioned by a locating pin 20 integrally combined with a welding machine having electrodes 18, 19.

Next, place the weld nut 10 on the lower electrode 18,
This lower electrode 18 is raised.

As a result, the inner peripheral surface of the inclined surface 15 of the nut 10 and the bolt insertion hole 16 come into contact with the outer peripheral surface of the embossing 17, and the above-mentioned self-locating is performed, so that the nut 10 is centered accurately with respect to the bolt insertion hole 16 of the panel 11. Matched.

With this alignment, the upper electrode 19 is lowered, and the nut 10 and the plate 11 are pressed by both electrodes 18 and 19, and current is applied in this pressed state.

Due to this energization, the small protrusion 14 where the current is concentrated melts,
As shown in FIG. 4, this molten metal flows into the gap between the nut 10 and the panel 11 (specifically, the outer peripheral area of the embossing 17), and when it solidifies, the nut 10 is fixed to the panel 11. Become.

Therefore, even when the small protrusion 14 is melted, the nut 10 is aligned and held with respect to the panel 11 by the engagement between the embossing 17 and the recess 15, and is always attached at an accurate position. It turns out.

Although the current may spread to some extent due to the fitting between the embossing 17 on the plate side and the inclined surface 15 of the nut 10, there is no problem in practical terms with the fusion bonding.

In the embodiment described above, the outer circumferential surface of the embossing 17 and the inner circumferential surface of the inclined surface 15 of the nut 10 were formed approximately parallel to each other. The fitting force for fitting the inner peripheral surface to the embossing 17 (
In order to strengthen the so-called biting surface pressure), the inclination angle θ of the emboss 17 (Fig. 5) may be formed in advance to be larger than the inclination angle θ2 of the inclined surface and inner circumferential surface, taking into account the deformation of the emboss due to the pressing force. can.

Further, the small protrusion 14 can be replaced with a protrusion or a protruding ring that surrounds the edge of the bolt insertion hole 16, but in this case, the amount of melting of the protrusion or protruding ring becomes large. It is preferable to increase the inclination angle in the direction opposite to the welding distortion in consideration of the welding distortion on the panel side.

Furthermore, the bell-shaped inclined surface and the conical embossment may be shaped into a bowl shape, a dish shape, or the like, as long as alignment can be achieved properly.

Next, the tolerance of the fixing position of the weld nut 10 to the panel 11 in the above-described embodiment will be described.

When the conventional weld nut 1 shown in FIG. 2A is used instead of the weld nut 10 according to the present invention shown in FIG. However, when the weld nut 10 of the present invention was used, the accuracy of alignment between the bolt insertion hole 16 and the weld nut 10 was improved, and as a result, the difference in pitch P could be reduced to ±0.5.

As is clear from the above explanation, according to the present invention, the slope surface formed concentrically with the threaded hole of the weld nut and the embossment formed concentrically with the bolt insertion hole of the panel are engaged and then welded. The accuracy of alignment between the screw hole and the panel can be improved, and as a result, the position of welding the weld nut to the panel can be made more accurate, so the bolt can be installed reliably, and overall the assembly accuracy of the car body etc. can be improved. This results in extremely excellent effects, such as greatly contributing to the improvement of

[Brief Description of the Drawings] Figure 1 is a perspective view of a conventional weld nut, Figure 2 is an explanatory diagram schematically showing various methods of aligning the nut with the bolt insertion hole of the plate, and Figure 3 is a diagram of the present invention. FIG. 4 is a longitudinal cross-sectional view showing how the weld nut of the present invention is attached, and FIG. 5 is a vertical cross-sectional view of the essential parts of the weld nut and panel. 10... Weld nut, 11... Panel, 12... Screw hole, 13... Seat surface, 14... Small protrusion, 15... ...slanted surface,
16...Bolt insertion hole, 17...Conical emboss, 18.19...Electrode, 20...
...locate pin.

Claims (1)

[Scope of utility model registration request] The bolt insertion hole of the panel and the screw hole of the weld nut are aligned approximately concentrically, the small protrusion for welding of the weld nut is brought into contact with the panel, and the small protrusion is melted by applying current between the panel and the weld nut. In the weld nut mounting structure for welding the panel and the weld nut, the periphery of the entrance of the screw hole of the weld nut is shaped into an inclined surface that slopes downward toward the center of the screw hole, and the opening of the bolt insertion hole of the panel is formed. A mounting structure for a weld nut, in which a pot-shaped embossing is provided on the edge, and an inclined surface of the weld nut and the embossing on the panel are engaged with each other.