摘要 |
PROBLEM TO BE SOLVED: To reduce the cost of molding dies. SOLUTION: Because a rear seal crest 16 and a rear end surface 18 in this rubber plug are continued through a sharp edge part 19, it is unnecessary to smoothly continue molding surfaces 25A, 26A of peripheral surface molding die 25 and a rear end surface molding die 26 in the edge part 19. Accordingly, high precision is not required when machining the dies 25, 26, to reduce a die cost. |