| 摘要 |
PURPOSE:To make an engine brake appliable without fail even if there is trouble in an electric signal system for actuating a valve body to its closing position in time of idle running of a car or admixture of dust into oil, by closing a creep preventing valve with signal pressure proportionate to a car speed. CONSTITUTION:Holding a manual valve Vm at a first speed holding position I, when an engine brake is going to be applied, even if a transistor 140 is internally short-circuited whereby such trouble that a solenoid 101 is being left excited intact happens there, governor pressure Pg proportioned to the square of a car speed works in an upper oil chamber 87 so that a valve body 85 is held at a closing position. Therefore, the engine brake is surely secured. Likewise, even when dust is mixed in hydraulic fluid and thereby it fails to move the valve body 85 downward with only spring force of a return spring 89, the valve body 85 is surely shifted to the closing position by the help of hydraulic power from an accumulator 72. |
