| 摘要 |
PROBLEM TO BE SOLVED: To activate a catalyst in a short time by a method in which the quantity of fuel to be supplied is set up corresponding to the operation condition of an engine, the quantity of fuel is increased and corrected corresponding to the degree of deterioration of an exhaust gas purifying catalyst, and the quantity of secondary air to be introduced is set up on the basis of these data so that an air-fuel ratio of exhaust gas flowing into the catalyst is adjusted to be a prescribed value. SOLUTION: A pulse signal is generated at every prescribed angle synchronously with the rotation of an engine 1, and a crank angle sensor 3 for detecting a crank position and an engine rotation speed and a water temperature sensor 4 for detecting a cooling water temperature in a cooling jacket are installed. An exhaust gas purifying catalyst 8 is set in an exhaust gas passage, an air-fuel ratio sensor for detecting the air-fuel ratio of exhaust gas is installed on the upstream side, and an air-fuel ratio sensor 9 is installed on the downstream side. A secondary air pump 13 is installed in a secondary air introduction pipe 10, and a flow rate is calculated by a control unit 5 to control operation. In this way, the control of emission by the introduction of secondary air and the activation of the exhaust gas purifying catalyst in a short time can be attained at a high level. |
