| 摘要 |
PURPOSE: To furthermore make the device simple in structure, and reduce its cost much while the pressure changing chamber of the brake booster is being released to atmospheric pressure at a stretch. CONSTITUTION: At the time of abrupt braking, by the quick footing of a brake pedal, a valve plunger 20 is quickly advanced so as to be brought into contact with the shaft section of a first piston 33, and thereby the first piston 33 is quickly advanced. This constitution thereby allows the tip end of a second cup seal 39 to pass through the opening end close to the first piston 33 of a first fluid flow path 31 before an output shaft 32 is outputted, namely, before pressure is built up in a first fluid chamber in which fluid is to be filled. As a result, the first fluid chamber 36 is communicated with a second fluid chamber 37 by way of a first and a second fluid flow paths 31 and 34, and fluid in the first fluid chamber 36 flows in the second fluid chamber 37. This constitution thereby allows a reaction mechanism by the pressure of the first fluid chamber 36 to be temporarily suspended, and also allows the output of the brake boostor to be raised up to its full loading at a stretch. |
