Patent ID: 6390078
Filing Date: 2002-05-21
Classification: F02M

Abstract:
An EGR valve for controlling exhaust gas recirculation flow in an engine, said valve comprising;a housing enclosing an actuator reciprocable in the housing on an axis; a valve body connected with the housing and defining a valve chamber including axially spaced inlet and outlet openings and a first valve seat between the openings; first and second pintle valves mounted in the valve body and reciprocable on said axis; said first valve engagable with the first valve seat in the first valve closed position, the first valve including a second valve seat connecting through an internal low flow passage with a connecting opening to the valve chamber; said second valve extending concentrically within the first valve and engagable with the second valve seat in a second valve closed position; and first and second biasing means respectively biasing the first and second valves toward their valve closed positions; said actuator being controllably movable over a total stroke including consecutive first and second stages, the actuator being operative to controllably open the second valve in the first stage of the stroke to allow EGR flow between the valve body inlet and outlet openings only through the low flow passage in the first valve and to controllably open the first valve in the second stage of the stroke to allow flow between the valve body inlet and outlet openings through the valve chamber of the valve body.