JPS6231980A - Molding of bus bar type electric connection metal - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a method for forming a busbar type electrical connection fitting, specifically, a method for forming a busbar type electrical connection fitting by punching and bending a metal substrate. The present invention relates to a molding method for improving the strength of a bent piece constituting an electrical contact part.

(Prior art) Conventionally, in order to form a busbar type electrical connection fitting from a metal substrate, first, a metal substrate (hereinafter simply referred to as the substrate) of an appropriate thickness is punched into a predetermined shape, and then the electrical contact portions are formed. This is done by bending the portion to be formed using a press die or the like.

That is, FIG. 2 shows an example of a bus bar type electrical connection fitting molded by a conventional molding method, in which (a) is a perspective view thereof, (b) is a plan view thereof, and (C1 is a side view thereof. A bent piece 2 constituting an electrical connection portion 2a is formed upright by bending on the outer edge of a substrate 1 punched into a predetermined shape via a bent portion 2b. Board 1 as a terminal for connection with the circuit of
Not only when the electrical connection part 2a' is formed to have the same thickness as the board 1 as shown in FIG. 2
C is formed into a thin concave portion having a step from the edge 1a of the substrate 1 by a press die 3 used for bending.

Note that the bent portion 2b is generally rounded (R) and processed to disperse stress concentration due to bending so that the bent portion 2b does not easily break when an external force is applied to the electrical connection portion 2a.

However, a drawback of the bus bar type electrical connection fitting molded by this molding method is that when an external force such as vibration is applied to the bending piece 2, the boundary 2d between the thin board part 2c and the board 1
The mechanical strength of the boundary portion 2d is weak, and this portion is prone to breakage and stress corrosion cracking in a corrosive environment, resulting in poor conduction of the circuit via the electrical connection portion 2a. There were problems such as vibration causing chattering and heat generation, and molten titanium generated in the vicinity.

(Problems to be Solved by the Invention) The present invention has been made by focusing on the above-mentioned problems associated with the conventional method of forming a hub bar type electrical connection fitting. It is an object of the present invention to provide a method for forming a bus bar type electrical connection fitting which eliminates the above-mentioned drawbacks by improving the mechanical strength of the boundary part 2d between the substrate part 2C and the substrate 1, and which provides low reliability of electrical connection. purpose.

(Means for Solving the Problems) The present inventor has proposed a thin substrate portion 2 on which an electrical connection portion 2a is formed.
As a result of various studies on the causes of weakening of the mechanical strength of the boundary part 2d between the board 1 and the board 1, we found that the residual stress when the bending piece 2 including the electrical connection part 2a is bent by the press die 3 is Boundary area 2 where the plate thickness changes depending on the mold
d, but we have discovered that this boundary portion 2d is caused by the fact that it coincides with the line of stress action in the A-A' direction when an external force is applied to the bent piece 2, leading to the present invention. Ta.

That is, the present invention provides a method for forming a busbar type electrical connection fitting by punching and bending a substrate, in which a thin substrate portion, on which a bent piece constituting an electrical connection portion is formed, is formed by a press die or the like at the edge of the substrate. This is a molding method that extends from the inside of the substrate.

The present invention will be described below with respect to a bus bar type electrical connection fitting illustrated in FIG. In FIG. 1, (al indicates a perspective view thereof, fb) a plan view thereof, and fc) a side view thereof.

In the figure, when an electrical connection portion 2a is bent and formed on the outer edge of a substrate 1 punched into a predetermined shape using a press die 4,
In the molding method of the present invention, the thin substrate portion 2c, which is pressed by the press mold 4 to form the rounded bent portion 2b, extends from the edge portion 1a of the substrate 1 to the inner position lb of the substrate 1. Therefore, the thin substrate portion 2c and the substrate 1
The boundary portion 2e between the substrate 1 and the substrate 1 is also formed to be shifted to the inner position of the substrate 1. This extension of the thin substrate portion 2c can be easily achieved by increasing the thickness t of the press die 4.

(Function) According to the method for forming an electrical connection fitting of the present invention, the thin substrate portion 2c on which the bent piece 2 is formed by the press die 4 extends to the inner side 1b of the substrate 1, as shown in FIG. Since the thin substrate portion 2c is formed by press processing,
The residual stress generated is concentrated at the inner boundary 2e of the substrate 1,
The concentrated position is shifted by a distance 111d from the line AA', which corresponds to the conventional boundary part 2d, to the line B-B', which corresponds to the boundary part 2e in the case of the present invention. Therefore, the bent piece 2
The position of the thin substrate portion 2c along the line A-A', which is the line of stress action when an external force is applied to A
'Breakage of the thin substrate portion 2c at a position along the line is prevented.

(Effects of the Invention) As explained in detail above, according to the molding method of the present invention, even if an external force acts on the bent piece constituting the electrical connection part, the position where stress is applied to the bent piece due to the external force is Since the position differs from the accumulation position of residual stress generated during processing, the strength of the bent piece against external forces is increased, and stress corrosion cracking in a corrosive environment is also prevented by dispersing residual stress due to processing. Therefore, according to the present invention, the thickness of the bent piece constituting the electrical connection portion can be intentionally made thinner. From the above, it is possible to significantly improve the reliability of electrical connections using bus bar type electrical connection fittings.

[Brief explanation of the drawing]

FIG. 1 al is a perspective view showing an example of a hash bar type electrical connection fitting molded according to the present invention, FIG. 1 (bl is the same plan view, FIG. 1 fcl is the same side view, and FIG. FIG. 2 is a perspective view showing an example of a hash bar type electrical connection fitting molded by (bl is a plan view of the same, FIG. 2 fcl is a side view of the same, and FIG. 3 is a side view of an example of the same location. 1 ...Substrate, 2...Bending piece, 2a...Electrical connection part, 2b...Bending part, 2C...Thin board part, 2d,
'le...Kyobobe, 3,4...Press type. Patent applicant Yazaki Sogyo Co., Ltd. Figure 1 (b)

Claims (1)

[Claims] In a method of forming a busbar type electrical connection fitting by punching and bending a metal substrate, a thin substrate portion on which a bent piece constituting an electrical contact portion is formed is formed from the edge of the substrate using a press die or the like. A method for forming a bus bar type electrical connection fitting, which comprises extending inward of the substrate.