| 摘要 |
PURPOSE:To make ease of maintenance and inspection for a solenoid on-off valve by installing the on-off valve in an exhaust passage exhausting pressure oil led into a power room formed in one end of a power piston, to a reservoir, and making this on-off valve so as to be closed when vehicle's stoppage retaining condictions are effected. CONSTITUTION:When a brake pedal is operated and an input shaft 6 is made going to the left, the tip of a ring pin 23 comes into contact with a valve disc 26 of a check valve 22 whereby an exhaust passage 51 is interrupted, and this valve disc 26 separates from a valve seat 27 due to left movement of the successive input shaft 6, opening a feed passage 50, and thereby pressure oil is led into a power room 8. If so, a power piston 3 is made going to the left, and thus brake action is displayed. When a vehicle is stopped, and materialization of stoppage retaining condictions that such a vehicle stopped state as an accelerator pedal is not operated has continued as long as the specified time is judged by a control means 61 from each output of a car speed detector 62 and an accelerator detector 63, a solenoid on-off valve 46 is closed, so that a continued braking state is made so as to be secured even if operation on the brake pedal is released. |
