Driving force control device for four-wheel drive vehicle

摘要

A driving force control device for a four-wheel drive vehicle including one pair of front or rear driven wheels (WF) which are driven directly by a prime mover (E) and another pair of front or rear driven wheels (WR) which are driven via a hydraulic clutch (C), a first hydraulic pump (PF) which is driven by being operatively connected to the one pair of driven wheels (WF), and a second hydraulic pump (PR) which is driven by being operatively connected to the other pair of driven wheels (WR). The engagement force of the hydraulic clutch (C) is controllable based on the difference in rotation of the first and second hydraulic pumps (PF,PR). The torque transmission to the other pair of the front or rear driven wheels (WR) can thus be controlled according to the driving conditions of the vehicle. The engagement force of the hydraulic clutch (C) is controlled by an engagement force control unit (57) by selecting from multiple engagement characteristics, in which the responsiveness of the torque transmitted by the hydraulic clutch (C) is varied, according to the driving conditions of the vehicle. <IMAGE>