TWO-STAGE HIGH FLOW PURGE VALVE

摘要

A two-stage high flow purge valve for an evaporative emission system of a vehicle. The valve body contains two valves for controlling fluid flow through s eparate parallel flow paths in the valve body. A fast-acting, pulse width modulated sole noid valve responsive to an electrical control signal from the engine control compute r precisely controls flow through a low flow path, and a vacuum-responsive valve c ontrols flow through a high flow path in accordance with the level of manifold vacuum at the engine intake. A third valve member is provided to block flow through the high flow path when the engine is off and the manifold vacuum is zero. Means for calibrati ng both the solenoid valve and the vacuum-responsive valves are also provided.