| 摘要 |
<p>A packing mounting groove 14 consisting of a wide portion 14a and a narrow portion 14b is formed in a seal land 13 in a spool. In addition, a packing 11 includes on both sides of its second portion 11b, which is fitted on the narrow portion 14b, a seal lip 18 that contacts the groove wall of the narrow portion 14b in a gas-tight manner such that air is prevented from flowing into the groove bottom. Furthermore, a lip width (f) representing the distance between both seal lips 18 and 18 under a non-seal condition is set the same as or smaller than the width (a) of the wide portion 14a of the mounting groove 14. Air resistance which occurs when a packing is mounted in the mounting groove of a spool is reduced. Reducing this air resistance facilitates the mounting operation and prevents compressed air from being contained in a groove bottom space, and thus prevents the packing from floating. <IMAGE></p> |
