Vehicular power steering having steering effort control system

摘要

A vehicular power steering system is provided with a steering effort control system which controls the degree of power assistance by controlling the supply of hydraulic fluid to the hydraulic power actuator unit. The steering effort control system monitors the speed of the vehicle and the angular velocity of the steering wheel, and controls the quantity of the fluid supply in accordance with the monitored variables. The fluid supply quantity is determined so as to satisfy the following three conditions: (1) The steering must become heavier as the vehicle speed increases; (2) however, a sufficient amount of the fluid must be supplied even when the steering wheel is turned rapidly; and (3) the driver must be given a feel about the lateral acceleration of the vehicle during a turn.