| 摘要 |
PROBLEM TO BE SOLVED: To provide a negative pressure booster achieving weight saving of which is achieved and which is suppressed in noise: and to provide a brake system using the negative pressure booster.SOLUTION: The negative pressure booster includes: a valve body 4 arranged to be freely moved backward and forward to a rear shell 3; a power piston 5 partitioning a space between a front shell 2 and the rear shell 3 into a constant pressure chamber 8 where negative pressure is introduced, and a voltage transformation chamber 9 where atmosphere is introduced in operating time; an output shaft 20 which is connected to the valve body 4 and outputs output power generated by the power piston 5 to boost the input; a valve plunger 10 connected to the input axis 11 and also arranged inside the valve body 4 to freely slide; a negative pressure valve 13 controlling connection or interruption between the constant pressure chamber 8 and the transformation chamber 9 by operation of the valve plunger 10; an atmosphere valve 14 controlling interruption or connection between the transformation chamber 9 and at least atmosphere; and a cover member 30 attachable to at least part of the outer periphery of a cylinder part 3a covering the valve body 4 of the rear shell 3. |
