| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an inexpensive negative pressure booster capable of effectively reducing a flowing sound of the air after passing through a breather valve, even if dimensions are not managed at such a high level. <P>SOLUTION: A small annular ring-shaped projection part 10b is formed in an outer peripheral edge part of a flange 10a of a valve plunger 10 provided with a breather valve seat 14. This annular ring-shaped projection part 10b is opposed to an annular ring-shaped recessed part 12h of a breather valve part 12d. The air passing through the breather valve 16 strikes on the annular ring-shaped projection part 10b. Thus, a flow of the air is disturbed a little by receiving resistance by the annular ring-shaped projection part 10b, and a flow speed reduces a little. Thus, generation of the flowing sound is restrained when the air passing through the breather valve 16 changes to a flow in the axial direction of a valve body 4 from a flow in the radial direction, by reducing the flow speed of the air. <P>COPYRIGHT: (C)2009,JPO&INPIT |
