| 摘要 |
PURPOSE:To provide accurate opening/closing operational property by which a compact size and prevention of chattering, etc., can be secured in the case where the exhaust control value of a secondary turbo supercharger is constituted in a downstream opening type, in an engine provided with a sequential turbo type supercharger. CONSTITUTION:An exhaust control valve 55 of the downstream opening type provided on the turbine side of a secondary turbo supercharger 50 is closed by a force equivalent to the sum of the negative pressure of an actuator 56 and spring force, and maintained in its closed condition without generation any chattering by exhaust inpulse, etc., and then it is opened by a force equivalent to the sum of the negative pressure of the actuator 56 and positive force and constituted to be surely maintained in its opened condition. |
