| 摘要 |
<p>A vehicle brake pressure proportioning valve has a stepped proportioning plunger movable by brake pressure against a loading spring. A control plunger subject to pressure from an inlet port co-operates with a metering valve associated with the proportioning plunger. For low inlet pressures both plungers move together and there is no significant pressure drop through the valve but at a particular vehicle deceleration a control mass moves to hydraulically lock the control plunger and allow full operation of the metering valve. A control spring acts on the control mass with a force which, at the time of hydraulic locking, varies according to the distance moved by the control plunger and, by inference, the weight of the vehicle.</p> |
