Patent ID: 7302931
Filing Date: 2007-12-04
Classification: F02D

Abstract:
1. A motor-driven throttle valve control device for an internal combustion engine comprising a throttle shaft, a throttle valve fixed to the throttle shaft, and a motor, wherein a torque of the motor is transmitted to the throttle shaft, the throttle valve control device further comprising: a default stopper provided at a specified opening position from a minimum opening position of the throttle valve; a default spring which exerting its spring force on the throttle shaft toward a default stopper position in a valve opening direction; and a return spring which acts independently of the default spring to exert its spring force on the throttle shaft in a valve closing direction between the default stopper position and a full open position of the throttle valve, wherein the default spring and the return spring have mutually different coil diameters and are integrated with each other by a double coil spring arrangement in which those springs are formed continuously in a length of spring wire and arranged with overlapped structure in an axial direction so that at least part of one spring with a smaller coil diameter is located inside another with a larger coil diameter.