| 摘要 |
PURPOSE:To make a decelerating rate constant for a fixed stepping-in force even when the carried load is varied, by regulating the vacuum pressure of a vacuum booster through utilizing a fluid pressure to be varied with the weight of a vehicle. CONSTITUTION:A stepped cylinder 4 consisting of a large diameter part 2 and a small diameter part 3 is provided in the interior of a casing 1. The large diameter part 2 is provided with a valve chamber 6 connected to a vacuum chamber 14, to which an input part 7 for the vacuum pressure is communicated. The large diameter part 2 is provided also with an output part 8, to which the vacuum booster S is connected. On the other hand, the small diameter part 3 is provided with an intake port 9 for the fluid pressure, and a fluid pressure source varied in accordance with the load is connected to the port 9. Further, a stepped piston 10 consisting of a large are part 11 slidded within the large diameter part 2 and a small are part 12 slidden within the small diameter part 3 is provided in the cylinder 4. The valve chamber 6 is provided with the first valve means 15 for communicating the input port 7 and the vacuum chamber 14 to each other and interrupting the communication therebetween, and a piston 10 is provided also with a communicating hole 16 for the vacuum chamber 14 and the atmosphere, which hole 16 is opened and closed by the second valve means 17. |
