Patent ID: 6675823
Filing Date: 2004-01-13
Classification: F04C,F16K,Y10T

Abstract:
A flowrate control valve which controls the flowrate supplied from a pump to a load circuit comprising a relief valve, the relief valve comprising:a valve seat having a seat hole; a ball which opens and closes the seat hole from a downstream side; a movable member which supports the ball from the downstream side, the movable member having an outer circumferential surface; a housing part which houses the movable member, the housing part having an inner circumferential surface; and a vibration damping orifice formed downstream of the seat hole which damps vibration of the movable member and suppresses chattering by restricting an oil flow, wherein: the movable member slides on the inner circumferential surface of the housing part; the vibration damping orifice is grooves formed on either one of the outer circumferential surface of the movable member, and the inner circumferential surface of the housing part; and the relief valve opens when pressure on the load circuit side thereof rises, and part of the fluid from the pump is discharged to a tank port.