US Patent 11255243 Dual purpose doser spring

An injection assembly for a vehicle exhaust system includes a housing defining a fluid cavity, a doser mounted to the housing and configured to inject a fluid into the fluid cavity, and a valve to control flow of the fluid. The valve is moveable between an open position and a closed position. A resilient member is configured with a biasing force to bias the valve to the closed position. The biasing force is overcome when fluid is heated downstream of the valve and exceeds a predetermined pressure level to allow backflow into the fluid cavity.