| 摘要 |
PURPOSE:To secure a braking action of the engine of a vehicle in a favorable condition while preventing the driving condition of the vehicle from getting worse by a method wherein the velocity at which a throttle valve is gradually closed after the valve is held opened is varied in proportion to the opening degree of the valve prior to the closing of the valve. CONSTITUTION:In case where a check valve 20, a temperature sensitive valve 28 and a pressure reducing valve 30 are all closed after the completion of heating of the engine and the engine is in a high load operation condition with the throttle valve 3 opened wide and in case where the valve 3 is choked to a predetermined second opening degree B so as to reduce the velocity of the engine, the top end of an arm 13 comes into contact with the top end of a rod 12. In this case, the negative pressure of sucked air increases and as a first diaphragm 6 turns to the right gradually due to the action of a thottle 19, the valve 13 is closed gradually. Next, when the valve 3 is choked further to have a predetermined first opening degree A, the diaphragm 6 comes into contact with a stopper 14. |
