STEERING CONTROL VALVE HAVING FLOW CLEARANCE HAVING DIFFERENT SIZE

摘要

PROBLEM TO BE SOLVED: To improve the flow control of a liquid pressure fluid by forming flow gaps having the minimum flow cross section areas formed by surface segments, with the minimum flow cross section area of a gradually tapered flow gap made larger than the minimum flow cross section area of a gradually expanded flow gap for controlling a valve noise. SOLUTION: Flow limiting gaps, or passages 232, are provided for a liquid pressure fluid flowing from a channel 116 to a channel 110. Each flow gap 232 has a cross section area formed by one end surface 202 of each land 200 and one chamfering portion 226 of each land 222. The cross section area of the flow gap 232 for the liquid pressure fluid to flow from the channel 116 to the channel 110 is gradually reduced to the minimum cross section area A right close to the channel 110. The flow gap 232 is called a gradually tapered flow gap. The cross section area of each flow gap 234 for the liquid pressure fluid to flow from a channel 98 to a channel 122 is gradually increased from the minimum cross section area B right close to the channel 98. The flow gap 234 is called a gradually expended flow gap.