초록 ▼

A solenoid operated valve is connected in series with a resistor and a PTC thermistor. Upon coil energization, the armature moves to close the valve member against a valve seat and further armature movement to close an air gap with a pole piece is absorbed by a spring between the armature and valve

A solenoid operated valve is connected in series with a resistor and a PTC thermistor. Upon coil energization, the armature moves to close the valve member against a valve seat and further armature movement to close an air gap with a pole piece is absorbed by a spring between the armature and valve member. Upon closure of the air gap, the magnetic reluctance between the armature and pole piece is decreased such that significantly less current is required in the coil to hold the valve closed. Upon heating of the thermistor, the resistance is increased sufficiently to reduce the current to the hold-close level and less power is required thereafter to maintain the valve closed. The valve is applied to on-board vehicle diagnostic procedures performed after engine shut-down where current must be minimized to prevent battery drain to a level preventing re-start.

대표청구항 ▼

1. A diagnostic system for a motor vehicle fuel vapor management system comprising:(a) a fuel vapor storage canister connected to receive fuel vapor through a conduit from the vehicle fuel tank and atmospheric air; (b) means for controlling flow of vapor from said canister to the air inlet of the ve

1. A diagnostic system for a motor vehicle fuel vapor management system comprising:(a) a fuel vapor storage canister connected to receive fuel vapor through a conduit from the vehicle fuel tank and atmospheric air; (b) means for controlling flow of vapor from said canister to the air inlet of the vehicle motor; (c) an electrically operated valve disposed for controlling venting of atmospheric air to said canister; and, (d) a PTC resistor electrically in circuit with said electrically operated valve, said resistor operative to reduce the current flow in said valve after a predetermined time interval, wherein said valve has a solenoid operator with an armature connected to a valve element moveable between an open and closed position wherein said armature continues movement with respect to said valve element for closing a working air gap with a pole piece when said valve element is in the closed position.