Automotive exhaust gas recirculation valve

Abstract From the Canadian patent

Abstract of the Disclosure, An exhaust gas recirculation valve for installation in the recirculation flow path between the exhaust and intake manifolds of an internal combustion engine. A metering control in the form of an axially displaceable pintle is operative in the flow path of a throat body to form an annular convergent-divergent nozzle. Pintle movement is responsive to predetermined engine variables to vary the throat flow area for continuously maintaining sonic gas flow therethrough. By the pintle being disposed toward closing the throat in a direction counter to the direction of incoming gas flow, sonic flow can be maintained at high efficiency throughout the full range flow …