Control method for controlling a vehicle four-wheel drive system including a torque distribution control apparatus and method for controlling the torque distribution device including a clutch means which can selectively engage

摘要

PURPOSE: To prevent generation of excessive relative slip between front and rear wheels by selectively-engaging a clutch fitted at a torque distributor between the front and rear wheels if a difference in the number of pulses indicating the rotational amount of the front and rear wheels. CONSTITUTION: The speed of a front output shaft 27 is detected by a speed sensor 44 disposed, adjacent to a front output gear 37, and the speed of a rear output shaft 26 is detected by a speed sensor 46 in the same way, each of which is inputted into an electronic controller 24 as a pulse signal respectively. The electronic controller 24 compares the number of pulses inputted, and a slip condition is detected between both the output shafts 26, 27. If excessive slip is detected, the controller 24 outputs a clutch engagement signal to a clutch coil 42 to operate an electromagnetic clutch 29. As a result, clutch plates 39, 41 make frictional engagement, so that a sun gear 34 and a loop gear 38 links with each other. It is thus possible to prevent generation of excessive slip condition between the front and rear wheels.