JPS6234024Y2 - - Google Patents

Description

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

[Prior Art] In a conventional screw mounting section, when a pilot hole is drilled and threaded in a thin plate where two or more threads cannot be removed, the pilot hole is first drilled in the thin plate 1, as shown in Fig. 1a, as an example. A burring process is performed to have a hole diameter equal to , 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. By tapping screws 3 on the inner circumferential surface of the terminal, three to four threads are tapped, and a member 4 to be mounted, such as a terminal board, is mounted with mounting screws 5, as shown in Fig. 1c. There is.

[Problems to be solved by the invention] In this case, if the thickness of the plate is thin, only two to two and a half threads can be threaded at most, 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, and when connecting two conductors as part of an electric circuit, this causes problems such as connection failures and other accidents. In order to eliminate these defects, we use a thick plate and reduce the thickness of the plate by cutting the area other than the area where the screw hole is drilled, that is, the contact area of the conductor, or weld small pieces of the same material to thicken the plate thickness in this area. However, the drawbacks are that materials are wasted, processing is time-consuming, and mass production is not possible.

[Means for Solving the Problems] This invention aims to eliminate the above-mentioned drawbacks, and its feature is that a thin plate 11 having some elasticity is folded while maintaining a predetermined gap 9. By turning it back, a folded part 13 is formed, and in this folded part 13, a screw hole 1 having a dish-shaped concave upper part is formed.
5 and 15 are opened while maintaining the gap 9, and a flange 16 made of the thin plate 11 is formed around the lower screw hole 15 of each of these screw holes 15, 15. The screw holes 17, 17 are formed by tapping the screw holes 15 while maintaining the gap 9, thereby preventing loosening of the screws.

[Function] The gap 9 provided between the thin plate 11 and the folded portion 13 acts as a spring washer to prevent the male screw from loosening.

[Example] Hereinafter, an example of this invention shown in the drawings will be described in detail.

As shown in Fig. 2a, for example, from the end 12 of a thin plate 11 such as a copper plate used for electrical wiring, etc., fold it back to the inside bending position by a distance corresponding to the position where a screw hole is to be provided and the size of the screw, etc. The portions 13 are folded 180 degrees through the spacer 10 and arranged in parallel with a predetermined gap 9 maintained, a screw hole installation portion 14 is made and the spacer 10 is removed. A screw pilot hole 15 whose hole diameter is equal to the screw pilot hole by burring processing and this screw pilot hole 15
An annular flange 16 having a screw hole with the same diameter is formed, and a gap is formed between the thin plate 11 and the end portion 12 in the screw hole 15 as shown in FIGS. 2c and 3a. If you cut the thread with a tap while holding 9, you will be able to cut approximately three and a half threads.

2d and 3b show an egg lug terminal plate 19a attached to the screw mounting portion 18 processed as described above.
This figure shows a state in which a mounted member 19 such as the one shown in FIG.
In this way, the number of threads is about three and a half, and the folded part is 1.
3 acts on the mounting screw 20, making it difficult for the mounting screw to loosen even without using a spring washer.

4a and 4b show a modification of this invention, in which the gap 9a of the folded portion 13 of the thin plate 11 is shown.
The gap between the end portions is increased by slanting the end portion, and portions with the same reference numerals as in FIGS. 1a to 3b indicate portions having the same effect as the aforementioned portions.

[Effects of the invention] As described above, in this invention, the thin plate on which the screw hole is to be formed is folded back, a pre-screw hole is provided with a predetermined gap, and this pre-screw hole is tapped. The number of threads that can be cut into a thin plate can be increased compared to the conventional method, and the thin plate has a spring washer effect due to its elasticity, and the thread pitch that has been cut due to bending tends to expand in some areas. The mounting screws are less likely to come loose,
Since there is no need to use a spring washer, it is easy to screw the attached member, and there is no need for welding, so the process is simple and inexpensive.

[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. Figures a to d are cross-sectional views according to the processing order, the third
FIGS. 4a and 4b are perspective views, and FIGS. 4a and 4b are sectional views according to a processing sequence that is a modification of this invention. 9, 9a...Gap, 10...Spacer, 11...
... Thin plate, 12 ... End part, 13 ... Turned part, 14
...Screw hole installation part, 15...Screw pilot hole, 16...
Tsuba, 17...Screw hole, 18...Screw mounting part, 19
... Attached member, 20... Mounting screw.

Claims (1)

[Scope of utility model registration request] A thin plate 11 having some elasticity is inserted into a predetermined gap 9.
A folded part 13 is formed by folding the
In this folded portion 13, screw holes 15, 15 having a dish-shaped upper part are formed while keeping the gap 9 open. Tsuba 16 made of the thin plate 11
, and the threaded holes 17, 17 are formed by tapping each of the threaded pilot holes 15, 15 while maintaining the gap 9.