Electro-magnetic drive control valve

摘要

An electro-magnetic drive control valve having a housing defining valve seats 54 and 66, and valve members 68 and 70 arranged so as to face the valve seat 64 and 66, respectively. The valve members 68 and 70 are formed on a valve rod 67, which is mechanically connected to a solenoid actuator 46. First and second diaphragm members 88 and 96 are provided for connecting the valve rod 67 to the housing and for sealing a flow passageway in the housing, while the valve rod 67 is axially moved by the solenoid actuator 46. The first diaphragm 88 is for sealing the flow passageway to the space 104 inside the solenoid actuator 46. The second diaphragm 96 forms a second chamber 107 on one side thereof remote from the flow passageway. An axial opening 67-2 is formed in the valve rod 67 for creating a communication passageway for connecting the chambers 104 and 106 with each other for equalizing the pressure therein. The pressure equalization allows the solenoid 46 to move in response to a small force generated in the solenoid actuator 46.