REAR WHEEL STEERING DEVICE FOR FRONT AND REAR WHEEL STEERING VEHICLE

PURPOSE:To make it possible to optimumly set the steering angle of rear wheels by coupling a conical crank shaft to a rotary shaft associated with front wheel steering operation so that the synergism between the inclined angle of an inclined pin part of the crank shaft and the axial displacement of the crank shaft causes rear wheel steering operation rods to be driven. CONSTITUTION:In a coupling mechanism A having an input shaft 41 connected to a rotary shaft associated with front wheel steering operation, for moving rear wheel steering operation rods in the axial direction, the front end of a conical crank shaft 42 is rotatably and slidably coupled into a rear cylindrical section 41a at the other end of the crank shaft 42. The rear end 42b of the crank shaft 42 is journalled to a housing H through the intermediary of a shaft feed mechanism D which is composed of a ball and screw mechanism D1 and a motor M so as to the shaft 42 is fed by a predetermined feed amount corresponding to the speed of the vehicle during rotation of the crank shaft 42. Further, the rotation of a coupling member 43 assembled to a pin part 42a of the crank shaft 42 allows the axial displacement of the operation rod 30 through a rotor 44 and the like.