| 摘要 |
PURPOSE:To enable improvement in stable brake property and durability by engaging a first valve portion with a poppet seal, steadily seating a second valve portion onto the seal, and opening/closing an orifice so as to give a driver preferable braking feeling with relief. CONSTITUTION:When the stopping-on of a brake pedal is stopped at the middle load state, an input shaft 20 is stopped and a valve body 18 is advanced so that the first valve portion 28 of a plunger 19 is engaged with the inner circumference of a poppet seal 23. Thereat, a second valve portion 29 isn't steadily seated onto the front end surface of the seal 23, so that atmospheric air is gradually introduced into a variable pressure chamber 14 through the orifice 30 of the seal 23 so as to rise only output. Therefore, the output rise gives a driver preferable braking feeling with safety. And moreover, the advance of the body 18 steadily seated the valve portion 29 onto the front end surface of the seal 23 so as to completely cut off the communication between the variable pressure chamber 14 and the atmospheric air, thereby stopping the advance of the body 18, And next, restepping-on of the brake pedal advances the plunger 19 so as to introduce the atmospheric air into the variable pressure chamber 14, thereby transmitting boost power to an output shaft 21. |
