| 摘要 |
<p>A holding means for holding a slide valve (60) at a predetermined front position includes a locking member (64) assembled to a power piston (30) so as to be capable of moving linearly in the radial direction, and a gutter spring (65) that impels the locking member (64) inward in the radial direction. The locking member (64) is provided with a hook (64a) that can be engaged to and disengaged from a hook (60b) provided to the slide valve (60) and forms the holding means with the gutter spring (65) or the like. When a plunger (41) advances with respect to the power piston (30) to an extent greater than a predetermined value, a pressed slope surface (64c) of the locking member (64) is pressed outward in the radial direction by a pressing slope surface (41d) of the plunger (41), and the hook (64a) of the locking member (64) is detached from the hook (60b) of the slide valve (60). A relief part (30m) is provided in the power piston (30), corresponding to the key member (63). Thereby, it is possible to solve the problems associated with defects due to bending deformation of the key member without causing new problems (increase in costs, increase in axial dimensions or the like).</p> |
