Electrically heated exhaust gas control apparatus

Abstract

An electrically heated exhaust gas control apparatus includes: a hollow base member that has electroconductivity; a first insulation member that is disposed within the base member and that divides a vertically upper space and a vertically lower space from each other; a honeycomb catalyst formed in each of the vertically upper space and the vertically lower space; a pair of upper electrodes that heat the honeycomb catalyst in the vertically upper space and a pair of lower electrodes that heat the honeycomb catalyst in the vertically lower space; and a control portion that is able to stop electrifying the lower electrodes while continuing to electrify the upper electrodes.

1 . An electrically heated exhaust gas control apparatus comprising:
 a hollow base member that has electroconductivity;   a first insulation member that is disposed within the base member and that divides an upper space and a lower space from each other;   a honeycomb catalyst formed in each of the upper space and the lower space;   a pair of upper electrodes that heat the honeycomb catalyst in the upper space;   a pair of lower electrodes that heat the honeycomb catalyst in the lower space; and   a control portion that is able to stop electrifying the lower electrodes while continuing to electrify the upper electrodes.   
     
     
         2 . The electrically heated exhaust gas control apparatus according to  claim 1 , wherein the first insulation member is made of one of a ceramic material, a cement, a thermosetting resin, and a thermoplastic resin. 
     
     
         3 . The electrically heated exhaust gas control apparatus according to  claim 1 , wherein the first insulation member is disposed at a middle position in the base member. 
     
     
         4 . The electrically heated exhaust gas control apparatus according to  claim 1 , wherein the first insulation member is disposed above a horizontal center of the base member. 
     
     
         5 . The electrically heated exhaust gas control apparatus according to  claim 1 , wherein the first insulation member is disposed below a horizontal center of the base member. 
     
     
         6 . The electrically heated exhaust gas control apparatus according to  claim 1 , further comprising:
 a second insulation member that is disposed at least in the lower space and divides the lower space into a plurality of divided spaces; and   a honeycomb catalyst and a pair of divided electrodes that are provided specifically for each of the divided spaces.   
     
     
         7 . The electrically heated exhaust gas control apparatus according to  claim 6 , wherein the second insulation member is disposed in both the upper space and the lower space. 
     
     
         8 . The electrically heated exhaust gas control apparatus according to  claim 1 , further comprising a sensor that measures a value of current that flows between the lower electrodes,
 wherein the control portion receives a measured datum from the sensor, and if the measured datum exceeds a predetermined threshold current value, the control portion performs an OFF control of stopping electrifying the lower electrodes that correspond to the measured datum, and continues electrifying at least the upper electrodes.   
     
     
         9 . The electrically heated exhaust gas control apparatus according to  claim 6 , further comprising a sensor that measures a value of current that flows between the divided-space electrodes of each divided space of the lower space,
 wherein the control portion receives measured data from the sensor, and if a measured datum of the measured data from the sensor exceeds a predetermined threshold current value, the control portion performs an OFF control of stopping electrifying the divided-space electrodes that correspond to the measured datum, and continues electrifying at least the upper electrodes.   
     
     
         10 . The electrically heated exhaust gas control apparatus according to  claim 1 , further comprising a thermocouple that is disposed in an exhaust control apparatus main body and that periodically measures base member temperature in the lower space of the base member, and sends the base member temperature to the control portion,
 wherein the control portion determines whether or not the base member temperature in the lower space is higher than or equal to a threshold value, and if the base member temperature is higher than or equal to the threshold temperature value, the control portion ends electrification of the lower electrodes, and if the base member temperature is lower than the threshold temperature value, the control portion continues electrifying the upper electrodes and the lower electrodes.   
     
     
         11 . The electrically heated exhaust gas control apparatus according to  claim 6 , further comprising a thermocouple that is disposed in an exhaust control apparatus main body and that periodically measures base member temperature in the lower space of the base member, and sends the base member temperature to the control portion,
 wherein the control portion determines whether or not the base member temperature in the lower space is higher than or equal to a threshold value, and if the base member temperature is higher than or equal to the threshold temperature value, the control portion ends electrification of the lower electrodes, and if the base member temperature is lower than the threshold temperature value, the control portion continues electrifying the upper electrodes and the lower electrodes.   
     
     
         12 . The electrically heated exhaust gas control apparatus according to  claim 8 , further comprising a thermocouple that is disposed in an exhaust control apparatus main body and that periodically measures base member temperature in the lower space of the base member, and sends the base member temperature to the control portion,
 wherein the control portion determines whether or not the base member temperature in the lower space is higher than or equal to a threshold value, and if the base member temperature is higher than or equal to the threshold temperature value, the control portion ends electrification of the lower electrodes, and if the base member temperature is lower than the threshold temperature value, the control portion continues electrifying the upper electrodes and the lower electrodes.