Throttle valve control for internal combustion engine

A throttle valve control apparatus for controlling a degree of opening of a throttle valve disposed in an intake system of an internal combustion engine, comprising:

• accelerator actuation detection means for developing an output in response to an actuation position of an accelerator pedal;
• opening degree setting means for setting a target degree of opening of the throttle valve based on the actuation position of the accelerator pedal thus detected, thereby generating an output which expresses the target degree of opening;
• throttle valve opening degree detection means for developing an output in response to an actual degree of opening of the throttle valve;
• drive speed setting means for setting a speed for driving the throttle valve in response to running conditions of the internal combustion engine;
• and
• drive means for driving the throttle valve at said speed which has been set, so as to reduce deviations between said target degree of opening which are obtained from the opening degree setting means;
• wherein said opening degree setting means derives a reference degree of opening of the throttle valve in response to the actuation position of the accelerator pedal, and corrects said reference degree of opening in response to the running conditions, thereby establishing said target degree of opening, and moreover, an upper limit degree of opening and a lower limit degree of opening of the throttle valve are respectively derived with respect to the actuation position of the accelerator pedal and an output is generated which expresses said target degree of opening as said upper limit degree of opening when said target degree of opening is greater than said upper limit degree of opening, and furthermore an output is generated which expresses said target degree of opening as said lower limit degree of opening when said target degree of opening is less than said lower limit degree of opening.