Throttle control unit for induction system of internal combustion engine

摘要

A single torsion spring is provided to both close the throttle during normal operation and to permit the engine to run at part-power under emergency conditions, e.g. failure of throttle control system. The throttle valve is mounted on a spindle which has a quadrant gear (4) and throttle opening is controlled a stepper motor gear (4) through reduction gearing (8,9). When the outer end (12) of the throttle spring is against a fixed stop (13), and no torque is being applied to the throttle spindle gear (4) by the motor gear (7) the throttle is partly open. The motor operates a cam (10) attached to the reduction gear (8,9) to move the spring end away from the stop to fully close so the throttle.