| 摘要 |
PROBLEM TO BE SOLVED: To provide a yoke 1 improved in radiation performance and a method for manufacturing the yoke 1. SOLUTION: The yoke 1 is tubularly formed by rounding a steel plate (e.g., Zn-Al-Mg plated steel plate) subjected beforehand to anticorrosion treatment into a cylindrical shape and mechanically joining together its both ends. In the outer circumferential surface of the yoke 1, there are formed multiple streak-like grooves 4 extended in the axial direction. These grooves are arranged at equal intervals throughout the entire perimeter of the yoke 1. The grooves 4 are simultaneously formed when the steel plate is rounded. Since the yoke 1 is tubularly formed using the steel plate subjected beforehand to anticorrosion treatment, it is unnecessary to thereafter apply coating, plating, or the like, and the grooves 4 are prevented from being filled with coating or plating material. As a result, the surface area of the yoke 1 is increased and radiation performance is enhanced. The Zn-Al-Mg plated steel plate is silver in surface color. Therefore, it does not absorb radiant heat from an engine, and the effect of suppressing temperature rise in the yoke 1 can also be brought about. COPYRIGHT: (C)2007,JPO&INPIT |
