| 摘要 |
<p>PURPOSE:To prevent the reliability of a catalyst from deteriorating, and appropriate by carry out the heating control in an electrical catalyst during increase of exhaust pressure by providing heating restraining means for restraining the control of heating by secondary air hearing means in association with the operation of engine control means toward the exhaust increasing side. CONSTITUTION:A heater 11 for heating secondary air is located between a secondary air feed pump 8 provided in an exhaust system and air passages 9, 10. A control unit 12 controls the air pump 8 and the heater 11 in accordance with a controlled condition of a variable silencer 6. When the air pump 8 feeds secondary air which is then heated by the heater 11 after a start of an engine, the silencer 6 is changed over into the exhaust pressure increasing side. In association with the change-over of the silencer 6, the heating value of the heater 11 is decreased while the supply volume of the secondary air from the air pump 8 is increased. Thereby it is possible to prevent the reliability of the secondary air heating means and a catalyst from deteriorating.</p> |
