US 5,097,918 A · Motor-driven power steering apparatus

Abstract

The electric power steering apparatus of the invention is provided with a rotary detector for detecting a rotational position of a motor, a torque sensor for detecting a steering torque, and when the steering torque is within a dead zone, by increasing flow current to a motor for assisting steering force correspondingly to increase of a steering angle decided on the basis of the rotational position of the motor, the steering assisting force corresponding to the steering angle can be gained at the time of returning the steering wheel steered by mostly using by the steering torque being in the dead zone, and the proper steering assisting force can also be gained by making flow quantity corresponding to the steering angle to be minimum within a predetermined speed range and by increasing it at lower or higher speed than the predetermined speed range when the steering wheel is returned during a time of running at a low speed (such as a time of slowing down).

Claims13

Dependent claims

A power steering apparatus comprising,

a steering mechanism for converting rotations of a steering wheel into a movement for steering a vehicle to right or left direction;
a steering angle detecting means for detecting a steering angle of said steering mechanism;
a torque sensor for detecting a steering torque exerted on said steering wheel;
a motor for assisting steering force;
a first electric current control means for controlling a driving current of said motor corresponding to said steering torque, when a detected steering torque is outside a dead zone;
and
a second electric current control means for alternately controlling a driving current of said motor corresponding to said steering angle, when a detected steering torque is within said dead zone.

4 more elements

A power steering apparatus comprising,

a steering mechanism for converting rotations of a steering wheel into a movement for steering a vehicle to right or left direction;
a steering angle detecting means for detecting a steering angle of said steering mechanism;
a torque sensor for detecting a steering torque exerted on said steering wheel;
a motor for assisting steering force;
a first electric current control means for controlling a driving current of said motor corresponding to said steering torque when a detected steering torque is outside a dead zone, wherein said first electric current control means increases said driving current corresponding to the increase of said steering torque;
and
a second electric current control means for alternately controlling a driving current of said motor corresponding to said steering angle when a detected steering torque is within said dead zone, wherein said second electric current control means increases said driving current corresponding to the increase of said steering angle.

4 more elements

Dependencies are inferred from the claim text.

Motor-driven power steering apparatus

Life of this patent

Motor-driven power steering apparatus

Life of this patent

Abstract

Claims13