Rear wheel toe angle control device
A rear wheel toe angle control device that ensures a stable steering performance even when the cornering powers of laterally opposing rear wheels are different from each other. When a reduction in the cornering power of one of the rear wheels owing to a drop in the tire pressure or a temporary tire is determined, a control unit changes the toe angle of the other rear wheel in a direction to increase the slip angle of thereof, and additionally changes the toe angle of the one rear wheel in a direction to decrease the slip angle of thereof. The combined cornering power of the two rear wheels is maintained at a normal level, and the steering performance of the turning vehicle remains the same. This also contributes to a stable running performance of the vehicle, and a maximization of the total available cornering power of the rear wheels.
1. A rear wheel toe angle control device for a vehicle including a pair of rear wheels, comprising:
a toe angle actuator for changing a toe angle of each rear wheel;
a cornering power detecting unit for determining a cornering power of each rear wheel; and
a control unit for controlling the toe angle actuator;
wherein, when a reduction in the cornering power of one of the rear wheels is determined by the cornering power detecting unit, the control unit changes the toe angle of the other rear wheel in a direction to increase a slip angle of the other rear wheel.
2. The rear wheel toe angle control device according to claim 1 , wherein, when a reduction in the cornering power of one of the rear wheels is determined by the cornering power detecting unit, the control unit additionally changes the toe angle of the one rear wheel in a direction to decrease the slip angle of the one rear wheel.
3. The rear wheel toe angle control device according to claim 1 , wherein the cornering power detecting unit comprises at least a member of a group consisting of an air pressure sensor for detecting an air pressure of a pneumatic tire of each rear wheel and a tire kind determining unit for determining a kind of a tire fitted to each of the rear wheels.