Abstract: A housing (22) is provided with a valve body mounting hole 22A one end of which opens to an outside thereof and that extends in the axis line (O1-O1) direction. A valve body (25) having an oil chamber (26) formed inside thereof is mounted in the valve body mounting hole (22A). The valve body (25) is provided with throttle holes (27) that establish communication between an inflow part (23) and the oil chamber (26) of the housing (22) and restrict the oil flowing into the oil chamber (26), and communicating holes (28) that establish communication between an outflow part (24) and the oil chamber (26) of the housing (22). When a total oil passage cross-sectional area of the throttle holes (27) is indicated at A, and a minimum oil passage cross-sectional area of the oil chamber (26) is indicated at B, a relation of A<B is set.