Four-wheel drive system with deceleration-responsive center differential control
AssigneeNissan Motor Co., Ltd.
InventorKunihiko Suzuki
Life of this patent
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Abstract
A four-wheel drive system has a center differential between front and rear wheels, and differential restraining or locking means for restraining or locking the center differential. The four-wheel drive system is equipped with an automatic control system for automatically locking the center differential in accordance with the deceleration of the vehicle. The control system may have means for determining a coefficient of friction between the tire and road surface in order to lock the center differential at a low vehicle deceleration when the sensed coefficient of friction is low.
Claims13
A four-wheel drive vehicle having front and rear wheels and an engine, said vehicle comprising;
- (a) a four-wheel drive system for transmitting power from the engine to the front wheels and the rear wheels, said four-wheel drive system comprising;
- (i) a center differential connected between the front wheels and the rear wheels for absorbing a rotational speed difference between the front wheels and the rear wheels, and
- (ii) differential restraining means capable of bringing said center differential into a restrained condition in which the function of said center differential is restrained, and
- (b) a control system comprising
- (i) deceleration sensing means for sensing the deceleration of the vehicle,
- (ii) condition sensing means for detecting whether said center differential is in or out of said restrained condition, and
- (iii) control means, connected with said deceleration sensing means and said condition sensing means, for controlling said center differential by actuating said differential restraining means in accordance with signals of said deceleration and condition sensing means, said control means being arranged to actuate said differential restraining means to bring said center differential into said restrained condition if the sensed deceleration of the vehicle is equal to or higher than a predetermined value, and at the same time said center differential is out of said restrained condition.
Dependencies are inferred from the claim text.