| 摘要 |
The device has a silencer (27) disposed in a passage for leading an atmospheric air to an atmosphere valve. A secondary passage (53) is formed between an internal surface of a valve piston (8) and an external surface of the silencer to communicate directly with the atmosphere. A communication unit (60) varies its path area depending on an advance amount of an input rod (23) when the rod is moved beyond a preset distance relative to the valve piston, so that the air from the passage is led via the communication unit to a variable pressure chamber, when a brake pedal is stepped on strongly. |
