| 摘要 |
<p>PURPOSE:To obtain a compact size and a low cost structure by providing relief valves for bypass in parallel to a fixed orifice provided in a communication passage between liquid chambers at both ends of a spool, in a fluid pressure control device suitable particularly for an automobile brake and the like. CONSTITUTION:The passing flow of a fixed orifice is determined by the differential pressure before and behind the fixed orifice 15, and the differential pressure is determined by the difference between the output of a power/force converter 20 and the force of a spring 18. A spool 12 is moved automatically to maintain the fluid pressure difference between liquid chambers A and B so as to regulate the opening of a variable orifice formed between a surface passage 14 and an input port 13 or an exhaust port 17. In relief valves 33 and 34, the relief pressures are set at a value a little smaller than a limit differential pressure. As a result, when a differential pressure responding to a demanded flow exceeds the set relief pressure, the relief valves 33 and 34 are opened to open a bypass passage 31 or 32, and the fluid pressure at the output side comes to rise rapidly or to fall suddenly.</p> |
