| 摘要 |
PURPOSE:To make exhaust gas emission control performable so favorably even at the time of engine cold, by performing a secondary air supply in a port air injection system at the time of engine cold, while constituting this secondary air to be supplied in a manifold air injection system after warming-up completion. CONSTITUTION:A first secondary air supply port 15 opened to an exhaust port 5 is installed in an internal-combustion engine 1, while secondary air is led into the said port 15 from an air cleaner 42 via an air control valve 25 and a reed valve 17. In addition, a second secondary air supply port 20 is installed in an exhaust manifold 10, while the secondary air is led into the said port 20 from the air cleaner 42 via an air control valve 30 and a reed valve 22. Each of these air control valves 25 and 30 is formed into a diaphragm operating system being opened at a time when suction pressure of more than the specified value is fed to suction pressure chambers 26 and 31 from conduits 35 and 39, and temperature sensitive valves 36 and 40, connecting a part (a) to a suction pressure port (b) in the case where each cooling water temperature is, for example, less than 45 deg.C and more than 35 deg.C, are installed in each of these conduits 35 and 39 side by side.
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