JPS6234023Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a screw attachment part, and more specifically, to an improvement of a screw attachment part in a thin plate.

In a conventional screw mounting part, when drilling and threading a pilot hole in a thin plate in which two or more threads cannot be obtained, as an example, as shown in Fig. Burring processing, that is, a process in which a punch is driven into a small hole to enlarge the hole diameter and to form a flange 2 protruding to one side on the hole edge, as shown in Figure 1b, the inner peripheral surface of the hole and the flange are Three to four threads are tapped by tap-cutting screws 3 on the inner circumferential surface, and a member 4 to be mounted, such as a terminal board, is mounted with mounting screws 5, as shown in Fig. 1c. . Even in this case, if the plate thickness is thin, the screws will only be able to cut at most two to two and a half threads, as shown in Figure 1b.
Moreover, in the case of a relatively soft metal such as a copper plate, the screws tend to become loose, which is a problem when connecting both conductors as part of an electric circuit, as this can cause an accident. In order to eliminate these defects, we use a thick plate and reduce the thickness of the plate in the area other than the area where the screw hole is drilled, that is, the contact area of the conductor, by cutting, or weld small pieces of the same material to reduce the thickness of this area. Although attempts have been made to increase the thickness, there are disadvantages in that materials are wasted and processing is time-consuming, making it difficult to mass-produce.

The purpose of this invention is to eliminate the above-mentioned drawbacks, and its feature is that the thin plate in which the screw hole is to be formed is folded with another plate interposed, and the folded part is To provide a screw mounting part which makes it possible to cut several threads on a thin plate where only one or two threads can be threaded by making a flanged hole for the lower part of the screw and tapping this hole. This invention will be described in detail below with reference to embodiments shown in the drawings.

As shown in FIG. 2a, from the end 12 of the band-shaped thin sheet metal member 11, such as a copper plate used for electrical wiring, etc., fold the inside by a dimension corresponding to the position where the screw hole is to be provided and the size of the screw, etc. The bent part 13 up to the bending position is folded back 180 degrees through another plate 11A in the middle and overlapped to form a screw hole installation part 14, and then as shown in FIG. 2b, the screw hole installation part 14 is As in the conventional method, a pilot hole 15 having a hole diameter equal to that of the screw pilot hole and an annular collar 16 having the same diameter as the pilot hole 15 are formed at one edge of the hole. Furthermore, as shown in FIGS. 2c and 3b, by threading the pilot hole 15 with a tap, it is possible to cut a thread 17 with three and a half threads.

Figures 2 d and 3 c show a state in which a member 19 to be attached, such as a terminal board, is attached to the screw attachment part 18 processed as described above with the attachment screw 20. The elasticity due to the half number of screw threads and the bent portion 13 acts on the mounting screw 20, making it difficult for the mounting screw to loosen even without using a spring washer.

As mentioned above, this idea involves folding the thin plate in which a screw hole is to be formed by interposing another plate, making a hole with a flange for lowering the screw in this folded part, and tapping into this hole. As a result, the number of threads that can be cut in the thickness of the thin plate can be increased compared to the conventional case, and the thread pitch that is cut by bending due to elasticity tends to expand in some parts. Therefore, the mounting screws are less likely to come loose, and there is no need to use a spring washer, making it easier to tighten the screws on the parts to be mounted.As there is no need for welding, processing is easy and inexpensive. have

[Brief explanation of the drawing]

1A to 1C are cross-sectional views according to the conventional processing order of the screw attachment part, and FIGS. 2A to 3D and 3A to 3C are each an embodiment of the present invention. 3A to 3D are cross-sectional views according to the processing order, and FIGS. 3A to 3C are perspective views. DESCRIPTION OF SYMBOLS 11... Band-shaped thin plate metal member, 11A... Other plate, 12... End part, 13... Bent part, 14...
Screw hole installation part, 15... Pilot hole, 16... Tsuba, 17
...screw, 18...screw attachment part, 19...mounted member, 20...mounting screw.

Claims (1)

[Scope of utility model registration request] A screw characterized in that the thin plate in which the screw hole is to be formed is folded with another plate interposed therebetween, a flanged hole for lowering the screw is formed in the folded portion, and this hole is tapped. Mounting part.