Apparatus and method for regenerating particulate filter that removes particulates out of exhaust gas for internal combustion engine

An apparatus for regenerating a particulate filter in an exhaust passage for an internal combustion engine, the particulate filter removing particulates out of an exhaust gas therein comprising:

• first estimation means for estimating a particulate deposit amount on the particulate filter during a usual period other than a regeneration period of the particulate filter;
• judging means for judging that it is time to regenerate the particulate filter when the estimated particulate deposit amount goes beyond a first predetermined value;
• burning means for burning particulates deposited on the particulate filter when it is time to regenerate the particulate filter;
• setting means for setting a particulate deposit amount at judgment time of regeneration period start as a first amount at a starting point of the regeneration period;
• second estimation means for estimating a particulate deposit amount during the regeneration period of the particulate filter based upon the first amount;
• and
• regeneration ending means for ending with the regeneration period when the estimated particulate deposit amount during the regeneration period decreases to a second predetermined value.

A method for regenerating a particulate filter that removes particulates out of an exhaust gas for an internal combustion engine comprising:

• estimating a particulate deposit amount on the particulate filter during a usual period other than a regeneration period of the particulate filter;
• judging that it is time to regenerate the particulate filter when the estimated particulate deposit goes beyond a first predetermined value during the usual period;
• burning particulates deposited on the particulate filter when it is time to regenerate the particulate filter, as well as setting a particulate deposit amount at judgment time of regeneration period start as a first amount at a starting point of the regeneration period;
• estimating a particulate deposit amount during the regeneration period based upon the first amount;
• and
• ending with the regeneration period when the estimated particulate deposit amount during the regeneration period decreases to a second predetermined value.