Patent ID: 6580994
Filing Date: 2003-06-17
Classification: B60K,B60W,F16D,Y10T

Abstract:
A driving force controlling apparatus for a four-wheel drive vehicle, comprising:a front-and-rear wheel driving force distribution control system including a clutch disposed in a midway of an engine driving system of the vehicle through front and rear road wheels of the vehicle, the front-and-rear wheel driving force distribution control system executing a control to modify a driving force distribution ratio between the front and rear road wheels toward an equal-distribution ratio as a clutch engagement force of the clutch becomes stronger; a road wheel velocity detecting section that detects a road wheel velocity of each of the front and rear road wheels of the vehicle; a clutch input torque detecting section that detects a clutch input torque inputted from the engine driving system to the clutch; a clutch transmission torque detecting section that detects a clutch transmission torque which the clutch is enabled to transmit to an output portion of the clutch; and a clutch force reduction controlling section that outputs a command to the front-and-rear wheel driving force distribution control system to reduce the clutch engagement force of the clutch when a subtraction value of a detected value of the clutch transmission torque from that of the clutch input torque is smaller than a predetermined value and detected wheel velocities of both of left and right road wheels of the vehicle are substantially equal to each other.