| 摘要 |
PURPOSE:To efficiently carry out purification of CO and HC at cold starting of an engine without increasing the fuel cost by increasing the quantity of secondary air to be supplied to an exhaust system at the cold starting move than that at warmed up starting. CONSTITUTION:In a secondary air inlet pipe 16, air provided at least one reed valve 22 and secondary air forcibly feeding means 18 such as an electrically driven blower or the like, a controller 28 which is supplied with a signal from an O2 sensor 30 or the like which increases the amount of secondary air by actuating the means 18 in a period of time in which a large amount of secondary air is required, and is provided in an exhaust pipe 8. At the time of cold starting of the engine, the amount of secondary air supplied to the exhaust system is increased and the time is detected by control means consisting of the sensor 30 or the like and the controller 28 to operate the means 18 and charge a large amount of secondary air into the exhaust pipe 8 through the reed valve 22 or the like. By this procedure, CO and HC within the exhaust gas can be purified without using an air pump having a large drive loss. |
