Power mode air switching diverter valve

Abstract

In a system for delivering secondary air from an air pump selectively, as a function of engine operation, to either the exhaust manifold at a location closely adjacent to the exhaust ports of the engine, or either to a converter in the exhaust system downstream of the exhaust manifold or to the atmosphere, as preselected, an integral air switching diverter valve assembly having an inlet connected to the air pump, a primary outlet for discharge of air to the exhaust manifold and a secondary outlet, for delivery of air either to the converter or to the atmosphere, as preselected, a valve being mounted in the assembly for movement between a first position to which it is normally biased to allow secondary air flow and through the secondary outlet while blocking secondary air flow through the first outlet to the exhaust manifold and a second position to allow secondary air flow to the exhaust manifold while blocking air flow out through the second outlet, the assembly including a differential pressure operated switching diaphragm assembly used to effect movement of the valve between the port and converter modes, an engine manifold vacuum actuated divert timing assembly operative to control operation of the switching diaphragm assembly, the valve further including a pressure relief outlet which is operative for pressure relief of excess secondary air above a predetermined pressure to the atmosphere.