US 7,882,925 B2 · Vehicle steering apparatus

Abstract

A vehicle steering apparatus utilizing SBW capable of downsizing an expensive turning-power motor, in which a steering mechanism 20 provided with a steering wheel 21 maneuvered by a driver is mechanically separated from a turning mechanism 30 for turning road wheels 35, 35. A turning-power motor 45 of the turning mechanism 30 turns the road wheels 35, 35 based on a turning angle-steering angle ratio determined by a control portion 66 of a controller 61 in accordance with a vehicle speed of the vehicle. The turning angle-steering angle ratio increases with increasing vehicle speed until the vehicle speed reaches a predetermined value from zero; while when the vehicle speed is higher than the predetermined value, the turning angle-steering angle ratio decreases with increasing vehicle speed.

Claims7

Dependent claims

A vehicle steering apparatus having a steering mechanism provided with a steering wheel maneuvered by a driver and a turning mechanism for turning a road wheel, the steering mechanism and the turning mechanism being mechanically separated from each other, comprising:

a control means for changing a turning angle-steering angle ratio of a turning angle of the road wheel to a steering angle of the steering wheel in accordance with vehicle speed;
and
a turning-power motor for turning the road wheel based on the turning angle-steering angle ratio determined by the control means,
wherein the turning angle-steering angle ratio increases with increasing vehicle speed until a vehicle speed reaches a predetermined value from zero and decreases with increasing vehicle speed when the vehicle speed is larger than the predetermined value,
wherein an average value of absolute values of a rate of change of the turning angle-steering angle ratio when the turning angle-steering angle ratio decreases is smaller than an average value of absolute values of a rate of change of the turning angle-steering angle ratio when the turning angle-steering angle ratio increases, and
wherein the predetermined value is set to less than 50 km/h.

3 more elements

a control means for changing a turning angle-steering angle ratio of a turning angle of the road wheel to a steering angle of the steering wheel in accordance with vehicle speed;
and
a turning-power motor for turning the road wheel based on the turning angle-steering angle ratio determined by the control means,
wherein the turning angle-steering angle ratio increases for at least a portion of a low speed region, where the vehicle speed is equal to or lower than a predetermined vehicle speed, and decreases for at least a portion of a high speed region, where the vehicle speed is equal to or higher than the predetermined vehicle speed.

1 more element

Dependencies are inferred from the claim text.

Vehicle steering apparatus

Life of this patent

Vehicle steering apparatus

Life of this patent

Abstract

Claims7