PNEUMATIC BRAKE ACTUATOR WITH FLOW RATE NO-REACTION TWO-WAY CONTROL VALVE

摘要

PROBLEM TO BE SOLVED: To improve a pneumatic brake actuator with a flow rate no-reaction two-way control valve.SOLUTION: A pneumatic brake actuator includes: a spring brake actuator with a spring chamber and a spring brake pressure chamber; and a service brake actuator with a service brake pressure chamber and a pushrod chamber. A control valve for regulating a fluid flow between the spring chamber and the service brake pressure chamber includes a seal that is moveable between an open position which is a position where fluid is permitted to flow between the spring chamber and the service brake pressure chamber and a closed position which is a position where the fluid is blocked to flow between the spring chamber and the service brake pressure chamber. A first surface of the seal is connected in fluid communication with the service brake pressure chamber. A second surface of the seal is connected in fluid communication with a valve chamber, that is not connected in fluid communication with the spring chamber or the service brake pressure chamber. The seal moves between the open position and the closed position on the basis of pressure in the service brake pressure chamber. This movement is not dependent on flow rate of fluid and pressure difference between the spring chamber and the service brake pressure chamber.SELECTED DRAWING: Figure 1