STEERING GEAR RATIO CHANGING DEVICE

摘要

PURPOSE:To simplify a structure by utilizing the front power steering pressure as the steering reaction force and performing the gear ratio variable control with the generated pressure by a phase control valve in a steering ratio changing device changing the car steering angle against the handle steering angle. CONSTITUTION:A column shaft 16 is connected to the input shaft 7a of a rotary valve communicated to a pinion serving as the input shaft of a steering gear assembly 9 and a torsion bar 8 via a steering gear ratio changing device 14, and the changing device 14 is constituted of two sets of planetary gear mechanisms 21 and 22 and a ring gear displacing mechanism 23. The ring gear displacing mechanism 23 is inserted with a piston 53 into a valve chamber 52 formed on a slender valve main body 51, the generated pressure by a phase control valve is guided into pressure receiving chambers 55a and 55b formed between the piston end and the end wall of the valve chamber 52, and the front power steering pressure is guided into pressure receiving chambers 60a and 60b on both sides of a piston large-diameter section 57.