| 摘要 |
A two-stage brake valve, has a pair of stages with different effective areas which become effective in succession upon an actuation of the valve, including a larger area fill chamber and a smaller area pressure chamber. A fill stage pressure relief valve is connected between the fill chamber and a reservoir. The relief valve includes a valve element, which is exposed to the pressure in the reservoir and spring force, and which is exposed to pressure in the fill chamber, so that it opens upon a pre-set brake pressure existing in the fill chamber. The relief valve also includes a pressure relief piston which can be exposed to the pressure in the fill chamber, and which can be exposed to the pressure in the pressure chamber. The piston has a free end which engages the valve element, and forces the valve element in its opening direction with increasing pressure difference between the pressure chamber and the fill chamber.
|
