| 摘要 |
PROBLEM TO BE SOLVED: To simplify a cap screw in constitution in such a way that the thread of its shaft part is to be threadedly engaged therewith, and an opening part is to be blocked by the cap part of its head part, and prevent sealing performance from being degraded. SOLUTION: In this cap screw, a ring shaped thermal plastic elastomer (e) is projected out of the fastening seat surface (f) of a resinous cap part 1c for an oil level gauge to be mounted to an oil inspection hole 3 by means of two- tone color molding, and it is so designed that the elastomer (e) is fitted in the inside of a fitting recessed part 3p when a thread part (n) of a shaft part 1j is threadedly engaged with a screw hole 3i so as to be fastened, in this case, even if foreign matters such as refuse come in the fitting recessed part 3p, since the foreign matters are removed out while the elastomer (e) is also rotated together when the cap part 1c is rotated so as to be fastened, no foreign matter will be held in between the elastomer (e) and the fitting recessed part 3p, and sealing performance is thereby prevented from being degraded. |
