JPS6422676A - Hydraulic control valve - Google Patents

Abstract

PURPOSE:To aim at increasing steering assist force upon running at a low speed by using the function of a cut-out part formed in one corner section between an elongated groove formed in a valve element and the outer peripheral surface of the valve element so as to change the feed amount of hydraulic oil in accordance with the relative displacement between a casing and the valve element. CONSTITUTION:In the circumferential direction of a valve element 2, there are formed a first cut-out section 8 having an arcuated cross-section having a radius R, which is formed in one corner section between an elongated groove 6 formed in the valve element 2 and the outer peripheral surface of the valve element 2, a part having a linear axially cross-sectional shape and a second cut-out section 9 whose axially cross-sectional shape has an inclined angle alpha with respect to a line tangential to the outer peripheral circle of the valve element 2. As a result, a first edge E1 is formed between one side wall of the elongated groove 6 and the first cut-out section 8, and also a second edge E2 between the first cut-out section 8 and the intermediate part of the second cut-out section, and a third edge E3 between the second cut-out section 9 and the valve member are formed. When a steering force is applied upon steering, and the valve member 2 is rotated in the circumferential direction, the area of the oil passage is changed by the edges, thereby it is possible to obtain a large assist force during running at a low speed.