CONTROL DEVICE FOR ELECTRICALLY HEATED CATALYST

摘要

A purpose of the present invention is to prevent a PM-caused short circuit between a heating element and a case in an electrically heated catalyst. The electrically heated catalyst is provided in an exhaust gas passage of an internal combustion engine the air-fuel ratio of which is controlled at a ratio near a theoretical air-fuel ratio at an operation time. The electrically heated catalyst includes a heating element that generates heat through electric conduction, a case that stores the heating element therein, and an insulating member sandwiched between the heating element and the case. According to the present invention, the heating element is electrically conducted after the operation of the internal combustion engine is stopped.

主权项

1. A control device for an electrically heated catalyst provided in an exhaust gas passage of an internal combustion engine, an air-fuel ratio of the internal combustion engine being controlled at a ratio near a theoretical air-fuel ratio at an operation time, the electrically heated catalyst including a heating element that is heated by electric conduction to heat the catalyst by the heating, a case that stores the heating element therein and an insulating member provided between the heating element and the case to insulate electricity,
the control device for an electrically heated catalyst comprising: an electric conduction control unit configured to electrically conduct the heating element after an operation of the internal combustion engine is stopped and when a temperature of the electrically heated catalyst or a temperature of an exhaust gas correlated with the temperature of the electrically heated catalyst when the operation of the internal combustion engine is stopped is equal to or higher than a first predetermined temperature, the electric conduction control unit configured to either inhibit electric conduction to the heating element or electrically conduct the heating element after a predetermined electric conduction stop period elapses from when the operation of the internal combustion engine is stopped.