Abstract: A transmitting case includes a first case half integrally formed on one side of a throttle body, and a second case half coupled to the first case half. A first assembly is constructed by disposing a final gear inside the first case half and securing it to one end of a valve shaft. A second assembly is constructed by mounting on the second case half an electric motor and an intermediate gear of a speed reduction device for transmitting the rotation of an output shaft of the electric motor to the final gear. Upon coupling of the first case half and the second case half, the intermediate gear and the final gear are meshed with each other. Thus, there is provided an engine intake control system having an excellent assemblability and an improved accuracy of throttle valve opening degree.

Abstract: An apparatus for controlling an opening degree of a throttle valve of an internal combustion engine using a DC motor, in which a real opening degree of the throttle valve is detected, a target opening degree of the throttle valve is set in accordance with an operation state of the internal combustion engine, an output voltage of a DC power source is boosted, and one voltage of the boosted voltage and the output voltage of the DC power source is selected in accordance with an opening degree difference between the real opening degree and the target opening degree to apply the selected one voltage to the DC motor.

Abstract: A transmitting case includes a first case half integrally formed on one side of a throttle body, and a second case half coupled to the first case half. A first assembly is constructed by disposing a final gear inside the first case half and securing it to one end of a valve shaft. A second assembly is constructed by mounting on the second case half an electric motor and an intermediate gear of a speed reduction device for transmitting the rotation of an output shaft of the electric motor to the final gear. Upon coupling of the first case half and the second case half, the intermediate gear and the final gear are meshed with each other. Thus, there is provided an engine intake control system having an excellent assemblability and an improved accuracy of throttle valve opening degree.

Abstract: An apparatus for controlling an opening degree of a throttle valve of an internal combustion engine using a DC motor, in which a real opening degree of the throttle valve is detected, a target opening degree of the throttle valve is set in accordance with an operation state of the internal combustion engine, an output voltage of a DC power source is boosted, and one voltage of the boosted voltage and the output voltage of the DC power source is selected in accordance with an opening degree difference between the real opening degree and the target opening degree to apply the selected one voltage to the DC motor.