| 摘要 |
<P>PROBLEM TO BE SOLVED: To prevent an outer circumferential surface of a pressure block from smashing into an inner circumferential surface of a cylinder, and thereby to improve durability. <P>SOLUTION: On an inside end surface of a lid 22a, a small-diameter part 27 is formed having a cylindrical outer circumferential surface concentric with the lid 22a and an outer diameter smaller than a part close to an outside end. The small-diameter part 27 is inserted, so that a pressure block 21a is displaced axially with respect to the lid 22a, into a recess 24a formed on the outside end surface of the pressure block 21a and having a cylindrical inner circumferential surface concentric with the pressure block 21a. A difference between the outer diameter r<SB POS="POST">27</SB>of the small-diameter part 27 of the lid 22a and the inner diameter R<SB POS="POST">24a</SB>of the recess 24a is smaller than the difference between the outer diameter r<SB POS="POST">21a</SB>of the pressure block 21a and the inner diameter R<SB POS="POST">20</SB>of the cylinder 20. <P>COPYRIGHT: (C)2013,JPO&INPIT |
