| 摘要 |
PURPOSE:To improve the discharge capacity of a discharging device for residual working fluid and to smoothen a closing of a valve hole by means of a check ball, by forming a check ball cylinder in the shape which is gradually widened in the direction of a working liquid chamber. CONSTITUTION:When a liquid pressure in a working fluid chamber 3 is removed, a check ball 13 is released from a state to close a valve hole 12 shown by a two-dotted line, a centrifugal force, simultaneously, is exerted on the check ball 13 by a rotating clutch piston 4 to move the check ball 13 in a direction of the increased diameter of the tapered check ball cylinder 11a, and is brought to a stop in a condition to abut on a projection 14. In case a liquid pressure is fed to a working fluid chamber 3, the check ball 13 moves in the direction of the valve hole 12 along a tapered surface. Less difference in a step S between the check ball cylinder 11a and the valve hole 12 causes smoothening of a closing and expediting of a clutch coupling reaction. |
