Exhaust purifying apparatus for internal combustion engine

Abstract

Degradation of ignition means due to combustion of foreign objects attached to the ignition means is suppressed. There are provided a fuel supplying apparatus for supplying fuel into an exhaust passage in an internal combustion engine, a heating apparatus for burning the supplied fuel, and a controller. The controller, in a case where unburned components of an exhaust gas are deposited in the heating apparatus, burns the deposited unburned components by the heating apparatus for removal before increasing a temperature of the exhaust gas by igniting the fuel supplied from the fuel supplying apparatus by the heating apparatus.

1 . An exhaust purifying apparatus for an internal combustion engine comprising:
 a fuel supplying apparatus for supplying fuel into an exhaust passage in an internal combustion engine:   a heating apparatus which is capable of being heated to burn the fuel supplied from the fuel supplying apparatus; and   a controller for controlling the fuel supplying apparatus and the heating apparatus, wherein   the controller suppresses a supply quantity of the fuel from the fuel supplying apparatus under a predetermined condition while having a heating operation of the heating apparatus executed, said condition is at least one of:   that a suppression time has not elapsed following a start of a heating operation of said heating apparatus, said suppression time being predetermined so that, even if supply of fuel b said fuel supplying apparatus and heating by said heating apparatus are executed after the suppression time elapsed, the temperature of the heating apparatus would be lower than an upper limit temperature which would not degrade the heating apparatus: and   that a temperature of the heating apparatus is not lower than an upper limit temperature, said upper limit temperature being predetermined so that, even if supply of fuel by the fuel supplying apparatus and heating by the heating apparatus are executed when the temperature is lower than said upper limit temperature, the temperature of the heating apparatus would be lower than an upper limit temperature which would not degrade the heating apparatus.   
     
     
         2 . (canceled) 
     
     
         3 . (canceled) 
     
     
         4 . An exhaust purifying apparatus for an internal combustion engine according to  claim 1 , wherein:
 the controller shortens the execution time of the fuel supplying apparatus and the heating apparatus as the temperature of the exhaust passage is higher.   
     
     
         5 . An exhaust purifying apparatus for an internal combustion engine according to  claim 1 , wherein:
 the controller shortens the execution time of fuel supplying apparatus and of the heating apparatus as the fuel supply quantity is larger.   
     
     
         6 . (canceled)