| 摘要 |
PROBLEM TO BE SOLVED: To provide a flow rate control device of working fluid for power steering capable of obtaining a linear flow rate characteristic also in a pump rotation frequency range in which control flow rate changes when a flow rate difference between control flow rate at the time of a constant flow rate control and control flow rate at the time of a drooping control is small. SOLUTION: A flow rate control device 1 is provided with a bypass reflux mechanism constituted of a spool valve 9 performing a control action (constant flow rate control) to fixed flow rate by sliding by front and rear differential pressure of a throttle passage 16 and regulating opening to a bypass passage 5 and a drooping mechanism constituted of a fixed throttle 10, a sub-spool valve 15 and the like. In the sub-spool valve 15, a cylindrical part 15c reducing opening area of the throttle passage 16 is formed. In an orifice forming member 14, a groove 17 is provided. Within the groove 17, an auxiliary throttle passage 18 is formed. When opening area of the throttle passage 16 is restricted at the cylindrical part 15c, hydraulic fluid flows in the auxiliary throttle passage 18. |
