HERMETICALLY SEALING DEVICE

摘要

In a hermetically sealing device provided by fitting and mounting a seal member on an annular member, fitting strength between the annular member and the seal member is reduced. A seal member (7) is provided with a reinforcing ring (7b), a contact part (72), which is integrally provided with the reinforcing ring (7b) and contacts a first outer circumference skirt part (13a) when it is fitted in the first outer circumference skirt part (13a) of a piston member (11), and a seal main body (7a) which has a seal lip (71) which hermetically contacts a circumference plane of a piston inserting hole (5).