| 摘要 |
<p>An internal combustion engine which is provided with an exhaust gas treatment system, such as thermal or catalytic reactors, includes a primary regulating system for admitting fresh air to the exhaust system for the chemical processes taking place in the reactors. This fresh air regulation depends on the engine rpm and on the induction tube pressure. There is also provided a secondary air control system, including a three-way valve and an electronic controller and an oxygen probe, located in the exhaust manifold. The probe supplies the controller with a signal related to the oxygen concentration in the exhaust gas and the controller uses this signal to actuate the three-way valve which admits either induction tube pressure or, alternatively, exhaust system pressure, to a control chamber in the primary regulating system, thereby influencing the quantity of fresh air supplied to the exhaust manifold of the engine.</p> |
