| 摘要 |
<p>PROBLEM TO BE SOLVED: To relieve a kick-back phenomenon to a pedal caused by torque reversal generated immediately after the stop of a vehicle. SOLUTION: This wheel cylinder for a drum brake device is provided with a control piston 70 displaceable according to anchor reaction transmitted through a primary piston 61 or a secondary piston 64 when braking, and an opening/ closing valve mechanism 80 for closing a communicating passage 71 when anchor reaction reaches a specified multiplying factor and the displacement of the control piston 70 reaches the specified quantity, the stop the supply of hydraulic pressure to a primary cylinder part 62 and a secondary cylinder part 66. In this case, a hydraulic pressure lead-in cylinder part 68 is equipped with a bypass passage 102 communicating with the primary cylinder part 62, and a cutoff valve 104 for closing the bypass passage 102 when the displacement toward the brake shoe side, of the primary piston 61 for pressing a primary shoe reaches the specified quantity.</p> |
