US 7,124,577 B2 · Vehicular steering control device

Abstract

The present invention lowers energy loss while at the same time enhancing the responsiveness of a steering control system. When a steering controller is operated rapidly, the aperture area of a steering flow control valve 4 rapidly increases, and the differential pressure (Pp′-PL) across the steering flow control valve 4 rapidly decreases. When the differential pressure (Pp′-PL) across the steering flow control valve 4 rapidly decreases, a flow control valve 6 is biased by the spring force of a spring 6f and quickly moves to the side of a valve position 6b to increase the differential pressure (Pp′-PL) and make it correspond to a set pressure. Thus, the pressure oil of a surplus flow α, which up to this point has been flowing to a discharge oil line 7, is quickly supplied from the flow control valve 6 to a steering hydraulic cylinder 5 via the steering flow control valve 4. Thus, an output Q′ starts quickly relative to an input St.

Claims2

Dependent claims

A vehicular steering control device for driving vehicular steering by supplying pressure oil from a variable capacity-type hydraulic pump to a hydraulic actuator for steering through pressure oil supply lines in response to a steering drive command signal, said vehicular steering control device comprising:

a steering flow control valve, which is disposed on said pressure oil supply lines, and which operates such that pressure oil of a flow corresponding to said steering drive command signal is supplied to said steering hydraulic actuator;
a flow control valve, which is disposed on said pressure oil supply line between said variable capacity-type hydraulic pump and said steering flow control valve, and which discharges pressure oil from said variable capacity-type hydraulic pump to a tank via a discharge oil line so that a differential pressure across said steering flow control valve constitutes a set value;
a restrictor disposed on said discharge oil line;
and
capacity control means for controlling a capacity of said variable capacity-type hydraulic pump such that a differential pressure across said restrictor becomes a set value.

2 more elements

Dependencies are inferred from the claim text.

Vehicular steering control device

Life of this patent

Vehicular steering control device

Life of this patent

Abstract

Claims2