Apparatus for controlling the distribution of drive power for four-wheel-drive motor vehicles

Claim 1

An apparatus for controlling the distribution of drive power in a four-wheel-drive motor vehicle which has a drive power transmitting system, a drive power source for applying the drive power to the drive power transmitting system, and main drive wheels and auxiliary drive wheels which are coupled to the drive power transmitting system, said apparatus comprising: drive power distributing means for independently regulating drive power transmitted through the drive power transmitting system to left and right auxiliary drive wheels, and for variably distributing the drive power between said left and right auxiliary drive wheels and the drive power between said main and auxiliary drive wheels; and control means for controlling said drive power distributing means to distribute drive power between said left and right auxiliary drive wheels while maintaining the ratio of drive power between said main and auxiliary drive wheels at an appropriate value, output torque detecting means for detecting an output torque (T) from said drive power source; and lateral acceleration detecting means for detecting a lateral acceleration (Y) exerted to the motor vehicle; said control means comprising means for calculating target drive powers (TL, TR) to be transmitted to said left and right auxiliary drive wheels based on the detected output torque and the detected lateral acceleration according to the following equations: TL=T×η×(1+k×Y) TR=T×η×(1-k×Y) where η is an initial value for the drive power distribution ratio for one of the left and right auxiliary drive wheels, the initial value being determined on the basis of the specification of the motor vehicle, and k is a conversion coefficient for matching various values, and for controlling said drive power distributing means according to the calculated target drive power.

Claim 2

An apparatus for controlling the distribution of drive power in a four-wheel-drive motor vehicle which has a drive power transmitting system, a drive power source for applying the drive power to the drive power transmitting system, and main drive wheels and auxiliary drive wheels which are coupled to the drive power transmitting system, said apparatus comprising: drive power distributing means for independently regulating drive power transmitted through the drive power transmitting system to left and right auxiliary drive wheels, and for variably distributing the drive power between said left and right auxiliary drive wheels and the drive power between said main and auxiliary drive wheels; and control means for controlling said drive power distributing means to distribute drive power between said left and right auxiliary drive wheels while maintaining the ratio of drive power between said main and auxiliary drive wheels at an appropriate value, output torque detecting means for detecting an output torque (T) from said drive power source; and lateral acceleration detecting means for detecting a lateral acceleration (Y) exerted to the motor vehicle; said control means comprising means for calculating target drive powers (TL, TR) to be transmitted to said left and right auxiliary drive wheels based on the detected output torque and the detected lateral acceleration according to the following equations: TL=T×η×(1+k×Y) TR=T×η×(1-k×Y) where η is an initial value for the drive power distribution ratio for one of the left and right auxiliary drive wheels, the initial value being determined on the basis of the specification of the motor vehicle, and k is a conversion coefficient for matching various values, and for controlling said drive power distributing means according to the calculated target drive power.