Thermal throttle actuator

摘要

A thermal throttle actuator adapted to be mounted in an opening of a throttle body of an internal combustion engine wherein the fuel system is electronically controlled. The thermal throttle actuator comprises a housing in which a plunger is mounted for reciprocating movement and is adapted to contact a spring loaded throttle plate in the throttle body. The plunger is yieldingly urged toward the throttle plate by a bias spring. A shape memory alloy in the shape of a helical spring is provided to produce a force on the plunger in a direction opposite to that of the bias spring when the shape memory alloy is heated to a temperature above a predetermined temperature. When the temperature is below the predetermined temperature, the shape memory alloy spring is readily deformable, the bias spring functions to provide a force on the throttle plate which maintains the throttle plate in an open position to enhance performance during cold starting of the engine.