| 摘要 |
PURPOSE:To improve the operating performance and to decrease the amount of harmful components in the exhaust when an engine is at low temperature by detecting the engine temperature and introducting the secondary air into an exhaust pipe located upstream from a ternary catalst. CONSTITUTION:When engine cooling water temperature is lower than the prescribed temperature, a water temperature switch 8 is closed, and a designated signal is sent to a solenoid 3a through a control unit 14, which has been informed of the cooling water temperature. With this procedure, the air fuel ratio in an electronic control carburettor 3 is duty-controlled to a ''rich'' side depending on a choke valve 3b, a solenoid 11 is energized to open a valve 11, the negative pressure in an intake pipe 2 is introduced into a diaphragm unit 12a to open a cut valve 12, and the secondary air is supplied to the upstream side an exhaust pipe 5 from an air cleaner 4 via a pipe 9. |
