| 摘要 |
<p>A projection for holding 10 is formed in an installation space 4b. A wall face 7a is formed in the installation space 4b on an arrow A side rather than the projection for holding 10. A main body 15a is provided so as to be linearly inserted in and pulled from the installation space 4b in a direction of an axial center P1. An abutting end face 16b is formed at the main body 15a so as to abut the abutting end face 16b on the wall face 7a in the direction as shown by the arrow A. A rib for holding 11 is annularly formed at the main body 15a along a plane perpendicular to the axis center P1. An engagement groove 25 is provided with the main body 15a so as to engage a piston 39. When the main body 15a is installed in the installation space 4b, the rib for holding 11 can be abutted on and engaged with the projection for holding 10 and the wall face 7a can be abutted on and engaged with the abutting end face 16b such that the main body 15a between the rib for holding 11 and the abutting end face 16b receives a predetermined compressive stress from the projection for holding 10 and the wall face 7a, and positions MQ1, MQ2 which are seal portions formed between the rib for holding 11 and the projection for holding 10 are formed with a width W3 smaller than any of a width W2 of the rib for holding and a width W1 of the projection for holding 10 in the direction as shown by the arrows A and B. <IMAGE></p> |
