Time delay apparatus for an exhaust gas recirculation controller

Claim 1

In a motor vehicle with an internal combustion engine having a controller valve for controlling the recirculation of exhaust gases from the exhaust manifold of the engine to the intake manifold thereof, the valve being of the type operated by a vacuum signal transmitted from a source within the engine through a flow conduit to the controller, a vacuum delay valve installed in the flow conduit intermediate the controller and the vacuum source for delaying the transmittal of the vacuum signal to the controller during the starting of the engine, the vacuum delay valve comprising: A. vacuum relay valve means having; 1. housing means defining an outlet port fluidly connected to said vacuum source and an inlet port fluidly connected to the controller; 2. valve means disposed fluidly intermediate said inlet and outlet ports and moveable between a closed position preventing flow therebetween and an open position permitting flow; 3. a signal conduit having a downstream end in fluid communication with said engine intake manifold and an upstream end; 4. pressure responsive actuator means in fluid communication with said signal conduit upstream end for moving said valve means from said closed position to said open position in response to an increase in engine intake manifold vacuum above a predetermined level; and B. vacuum signal delay means comprising orifice means disposed in said signal conduit intermediate said engine intake manifold and said actuator means whereby movement of said valve means between said closed and open position is delayed a predetermined length of time.