Patent ID: 6145614
Filing Date: 2000-11-14
Classification: B60K

Abstract:
A four-wheel drive vehicle comprising:a first differential mechanism for distributing engine drive force to front drive wheels and rear drive wheels, either the front drive wheels or the rear drive wheels being used as main drive wheels and the other drive wheels being used as slave drive wheels;a second differential mechanism for distributing the engine drive force that has been distributed by the first differential mechanism to left and right main drive wheels, the main drive wheels get more drive force than the slave drive wheels;first differential-limiting means for operating differential-limiting control of the first differential mechanism;second differential-limiting means for operating differential-limiting control of the second differential mechanism;rotational speed detection means for detecting rotational speed of each drive wheel;turn direction detection means for detecting the direction of a turn that the vehicle is making; andcontrol means for, based on detection signals from the rotational speed detection means and the turn direction detection means, controlling differential-limiting force provided by the second differential-limiting means according to a difference between the rotational speed of the left main drive wheel and that of the right main drive wheel, determining front and rear drive wheels on the outer side in the turn direction by comparing an absolute value of an output from the turn direction detection means with a predetermined threshold value and determining the turn direction according to plus/minus of the output, and controlling differential-limiting force provided by the first differential-limiting means according to a rotational speed difference between the front and rear drive wheels on the outer side in the turn direction.