JPS59202119A - Bending method of metallic sheet - Google Patents

Abstract

PURPOSE:To bend a metallic sheet to a small radius of bending without cracking, etc. by providing a properly sized hole in the position deviated from a centerline for bending and bending the sheet in the same direction as the direction of the roll grain. CONSTITUTION:A properly sized hole 3 having a centerline B is provided in the position slightly deviated from a centerline A for bending a metallic sheet 1 and the sheet is bent at the centerline A. The direction of the roll grain 2 near the bend is changed toward the center of the hole 3 by the above-mentioned method, by which a product having a required bending characteristic with a small inside diameter R is obtd. This bending method is applicable to fabrication of the metallic sheet to a terminal of a variable resistor, etc.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a method of bending a metal plate used for processing terminals of variable resistors and the like.

Conventional structure and its problems Conventionally, when bending terminals made from metal materials constituting a variable resistor, the inner radius R of bending is generally equal to the thickness of the metal plate 1, as shown in Fig. 1. In particular, for springs such as shin bronze and nickel silver, an R of 1.5 to 3 times the material thickness is required. On the other hand, in recent years, as the demand for smaller size, higher precision, and higher density of component parts has increased, it has become desirable to reduce the radius R of bending by 2゜. Hoop processing of parts (for example, terminals, etc.) has become common, but in order to remove the material, roll number 2 is used as shown in Figure 1.
There have been cases where the bending direction and the bending direction have to match. In such a case, if the radius of bending Ri is made too small, cracks may occur at the bent portion, or the bent portion may become brittle, resulting in an open circuit.

Purpose of the Invention The present invention has been made in view of such conventional problems, and is a method of reducing the radius of bending without causing cracks in the bent portion where the direction of the roll grain and the bending direction almost coincide with each other. The purpose of this paper is to provide a method for bending paulownia wood plates.

Structure of the Invention In order to achieve the above object, the metal plate bending method of the present invention is such that when bending is performed in substantially the same direction as the roll grain direction, the bending process is performed at a position slightly shifted from the center position of the bending process. By forming a hole of an appropriate size with the center and performing the bending process, it is possible to reduce the bending radius of the 3-base bending process.

DESCRIPTION OF EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. 2 and 3. In the present invention, as shown in FIG.
A hole 3 of an appropriate size with the center line B is provided at a position slightly shifted from the center line B of the bending process, as shown in Fig. I have to. By bending the metal plate 1 in this way using the bending center line operator, it can be seen that the two directions of the roll marks near the bending are changing toward the center of the hole 3, as shown in Figure 3. Ta.

This is thought to be because the degree of elongation of the material during bending is different due to the holes 3.

Figure 4 shows the relationship between the material thickness and the inner radius R of bending to obtain the required properties by the method of the present invention and the conventional method. It is explained that the necessary bending characteristics can be obtained by adjusting the inner diameter R.

This Figure 4 shows the characteristics of phosphor bronze for springs.

Effects of the Invention As described above, the metal plate bending method of the present invention is structured such that a hole of an appropriate size having a center line is provided at a position slightly shifted from the center line of the bending process. By bending in almost the same direction as the roll grain direction, sufficient bending properties can be obtained even with the inner radius of bending that is equivalent to the material thickness. In the parts field, its practicality is the key.

[Brief explanation of the drawing]

Fig. 1 is a perspective view showing the bending state of a metal plate by the conventional processing method, Fig. 2 is a top view of the metal plate explaining the present invention in detail, and Fig. 3 is a bending of the metal plate by the processing method of the present invention. Fig. 4 is a perspective view showing the state, and is a diagram showing the relationship between the material thickness and the inner radius of bending to obtain the necessary characteristics by the method of the present invention and the conventional method. ...Roll number, 3...hole, A5-, -" ...The song is the center line of processing, B...
- Center line of the hole. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
Figure 2 Figure 3

Claims (1)

[Claims] A bending process for a metal plate characterized by bending a metal plate having a hole at the center of the dowel, using a line in the direction of the roll grain that is slightly deviated from the line formed between the center position and the direction of the roll grain as a center line. Law.