Patent ID: 7210451

Claim:
A throttle control device comprising: a throttle body defining an intake air channel; a throttle shaft having a rotational axis: a throttle valve mounted to the throttle shaft and disposed within the intake air channel; a motor coupled to the throttle shaft, wherein the motor drives the throttle valve to rotate to incrementally open and close the intake air channel so as to control a flow rate of intake air through the intake air channel: and a detection device arranged and constructed to detect a rotational position of the throttle valve, the detection device comprising: a magnet support having an inner surface and an outer surface; at least two magnets mounted to the throttle shaft via the inner surface of the magnet support and positioned to oppose each other across the rotational axis so as to produce a magnetic field wherein the magnets are made of ferrite-based magnetic materials and have opposite end portions in a circumferential direction about the center of rotation, and wherein the magnets are spaced from each other in the circumferential direction by gaps; wherein there is no magnetic material along an inner peripheral surface of the at least two magnets, and wherein said at least two magnets are not continuous in a circumferential direction; a sensor mounted to the throttle body and arranged and constructed to detect a direction of the magnetic field produced by the magnets, so that the sensor outputs a signal representing the rotational position of the throttle valve.