| 摘要 |
<p>PROBLEM TO BE SOLVED: To stabilize the electrical characteristics by previously making an insertion hole smaller than a desired size and stripping the inner surface of the insertion hole tubularly through machining after integration thereby removing a protrusion at the rising part of interface between an insulating part and a semiconductive part. SOLUTION: An insulating part 4a principally comprising ethylene propylene rubber is formed by taping. Inside diameter of an insertion hole 7 is set smaller than a desired value. A semiconductive part 4b principally comprising ethylene propylene rubber is then formed by taping on the outside of the insulating part 4a and integrated therewith. Subsequently, a rubber stress cone thus obtained is fixed to a lathe and a grinding wheel is inserted, while turning, reversely into the insertion hole 7 from one end thereof in order to grind the inner surface thereof and to remove a part 4E therefrom thus finishing the inner surface of the insertion hole 7. According to the method, an electrically stabilized rubber stress cone having a high breakdown voltage can be obtained.</p> |
