| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a solenoid proportional control valve capable of easily stabilizing a spool operation.SOLUTION: A solenoid proportional control valve 100 including a spool 40 driven by a solenoid 70, and capable of controlling a pressure or a flow rate of water as a working fluid according to an axial position of the spool, further includes a cylindrical sleeve 30 slidably accommodating the spool, static pressure bearing mechanisms 50, 60 respectively disposed on both ends of the sleeve, having throttles 53, 63 for bearings, and supplying the water passing through the throttles 53, 63 for bearings between an inner peripheral face of the sleeve and an outer peripheral face of the end of the spool, back pressure chambers 23, 24 which are disposed while facing both ends of the spool, and in which the water from the corresponding static pressure bearing mechanisms flows, and tank passages 8, 9 having throttles 8A, 9A for attenuation, and communicating each of the back pressure chambers with a tank 2. The throttles for bearings and the throttles for attenuation are constituted to satisfy a formula (1): 0.69≤D2/D1≤1.6 in which D1 is an equivalent diameter calculated on the basis of a cross sectional area of the throttle for bearing, and D2 is an equivalent diameter calculated on the basis of a cross-sectional area of the throttle for attenuation.</p> |
