| 摘要 |
<P>PROBLEM TO BE SOLVED: To improve durability of a negative pressure boosting device that has a simple and compact configuration and has a stable threshold when an emergency braking characteristic is obtained. <P>SOLUTION: A holding mechanism for holding a slide valve 60 at a front predetermined position includes a locking member 64 incorporated to a power piston 30 to be movable linearly in the radial direction, and a garter spring 65 for biasing it radially inward thereof. The locking member 64 is provided with a projection 64f engaged with the power piston 30 to regulate the radial outward movement of the locking member 64, and a locking side hook 64a capable of being engaged/released with/from a valve side hook 60b provided in the slide valve 60 and constituting the holding mechanism by the garter spring 65 or the like. If a plunger 41 is advanced with respect to the power piston 30 to exceed a predetermined value, a pushing slope 41d of the plunger 41 pushes a passive slope 64c of the locking member 64 to the front and radial outward side, so that the locking side hook 64a is removed from the valve side hook 60b. <P>COPYRIGHT: (C)2012,JPO&INPIT |
