| 摘要 |
In the negative pressure booster equipment 1 according to the present invention, a groove 27 is provided on the inner peripheral beads 14a and 16a of the diaphragms 14 and 16, fixed on the valve body 8 and forming the power pistons in order to communicate the variable pressure chambers 5b and 7b divided by the diaphragms 14 and 16 with the passages 26 and 28 corresponding to the variable pressure chambers 5b and 7b. Accordingly, the air passages are opened to the variable pressure chambers 5b and 7b through the groove 27 formed on the beads 14a and 16a of the diaphragms 14 and 16. According to this invention, therefore, there is no need to provide wide gap between the fixed portion of the beads and the center plate in order to open the air passages to the variable pressure chambers. This makes it possible to shorten overall length of the negative pressure booster equipment 1. |
