| 摘要 |
<p>Multi-gauge strips are mainly used as materials for terminals of lead frames, relays, connectors, etc. of power transistors. The objective of the present invention is to provide a method of producing multi-gauge strips by means of forming copper, a copper alloy, or a metal strip which can undergo plastic work in such a manner that its two sides in the widthwise direction are thinner than the center portion. In order to achieve the objective therein, the present invention provides a method producing multi-gauge strips, which comprises the following steps of: forming a flat strip into semi-circular and 'U' shapes by means of a press and metal molds while sequentially feeding the material thereto; and then stretching the 'U' shape into a flat sheet so that the center portion of the strip in the widthwise direction is thicker, and the two sides from the center are made comparatively thinner. In this manner, the present invention enables stretch-forming with an ordinary press in the widthwise direction of a material, which is a rather difficult process even with high-priced special-purpose equipment of the prior art. Consequently, the present invention provides, among others, economical efficiency by way of using inexpensive general-purpose equipment; reduction in production cost due to its easy workability and enhancement of productivity; and efficiently coping with the small-lot production of a variety of types.</p> |
