To prevent the twisting of a gasket, to improve the identifiability of the twist, further, to maintain sealability and to reduce torque at the time of tightening by using the gasket having a flat sectional shape in an axial direction.
A case 5 is installed on an engine seat face and has a housing part of a cap 4 consisting of a cylindrical wall 8 and a base part 9. The gasket 7 having the flat sectional shape in the axial direction is used. The twist of the gasket 7 is substantially prevented by using the gasket 7 having the flat sectional shape. Even in the case of the twisted gasket, the twist is identifiable by a change in its appearance and the correction thereof is made easy. The contact area of the cap 4 and the case with the sealing surface increases and the sealability improves. Further, the compression margin in the diametral direction of the gasket 7 is decreased and therefore, the tightening torque at the time of coupling the cap 4 to the case 5 in the state of mounting the gasket 7 at the cap 4 may be reduced.
TOMITA MASAHIRO
ODA SHOGO
