Regeneration controller for exhaust purification apparatus of internal combustion engine

A method for eliminating particulate matter accumulated in an exhaust purification apparatus arranged in an exhaust system of an internal combustion engine, the method comprising:

• estimating the amount of particulate matter accumulated in the exhaust purification apparatus to obtain an estimated accumulation amount;
• determining whether the estimated accumulation amount is greater than a reference accumulation amount;
• starting a normal heating mode for continuously keeping the air-fuel ratio in the exhaust system low by continuously adding fuel to exhaust when the estimated accumulation amount is greater than the reference accumulation amount;
• determining whether the estimated accumulation amount is less than or equal to a determination value, which is less than the reference accumulation amount;
• and
• starting a burn-up heating mode for intermittently lowering the air-fuel ratio in the exhaust system by intermittently adding fuel to the exhaust when the estimated accumulation amount is within a mode change range set in accordance with a state in which a great part of the accumulated particulate matter is eliminated from the exhaust purification apparatus and less than or equal to the determination value so that a temperature of a catalyst bed is elevated so that the temperature of the catalyst bed is higher in the burn-up heating mode than in the normal heating mode, wherein in the burn-up heating mode, the amount of fuel repeatedly added, the period of fuel addition, and the period when fuel is not added are set so as to realize activated oxygen state and exhaust temperatures at upstream and downstream sides of the exhaust purification apparatus capable of burning up the particulate matter accumulated in the exhaust purification apparatus.

A regeneration controller for eliminating particulate matter accumulated in an exhaust purification apparatus that is arranged in an exhaust system of an internal combustion engine, the regeneration controller comprising:

• a heating section for heating the exhaust purification apparatus to eliminate the particulate matter accumulated in the exhaust purification apparatus when an estimated accumulation amount is greater than a reference accumulation amount, wherein the heating section obtains the estimated accumulation amount by estimating the amount of particulate matter accumulated in the exhaust purification apparatus;
• and
• a mode change section for changing exhaust purification apparatus heating modes when heating the purification apparatus if the estimated accumulation amount is within a mode change range, wherein:
• an exhaust having an air-fuel ratio flows the exhaust system;
• the mode change range is set in accordance with a state in which a great part of the accumulated particulate matter is eliminated from the exhaust purification apparatus;
• and
• the mode change section changes the heating mode when the estimated accumulation amount is within the mode change range and less than or equal to a normal burn-up start determination value, which is slightly greater than an end determination value, from a normal heating mode, for heating the exhaust purification apparatus by continuously keeping the air-fuel ratio in the exhaust system low, to a burn-up heating mode, for burning up the particulate matter by intermittently lowering the air-fuel ratio in the exhaust system so that a temperature of a catalyst bed is elevated so that the temperature of the catalyst bed is higher in the burn-up heating mode than in the normal heating mode.

A regeneration controller for eliminating particulate matter accumulated in an exhaust purification apparatus that is arranged in an exhaust system of an internal combustion engine, the regeneration controller comprising:

• a heating section for heating the exhaust purification apparatus to eliminate the particulate matter accumulated in the exhaust purification apparatus when an estimated accumulation amount is greater than a reference accumulation amount, wherein the heating section obtains the estimated accumulation amount by estimating the amount of particulate matter accumulated in the exhaust purification apparatus;
• and
• a mode change section for changing exhaust purification apparatus heating modes when heating the purification apparatus if the estimated accumulation amount is within a mode change range, wherein:
• an exhaust having an air-fuel ratio flows the exhaust system;
• the mode change range is set in accordance with a state in which a great part of the accumulated particulate matter is eliminated from the exhaust purification apparatus;
• and
• the mode change section changes the heating mode when the estimated accumulation amount is within the mode change range from a normal heating mode, for heating the exhaust purification apparatus by continuously keeping the air-fuel ratio in the exhaust system low, to a burn-up heating mode, for burning up the particulate matter by intermittently lowering the air-fuel ratio in the exhaust system so that a temperature of a catalyst bed is elevated so that the temperature of the catalyst bed is higher in the burn-up heating mode than in the normal heating mode;
• in the burn-up heating mode, the amount of fuel repeatedly added, the period of fuel addition, and the period when fuel is not added are set so as to realize activated oxygen state and exhaust temperatures at upstream and downstream sides of the exhaust purification apparatus capable of burning up the particulate matter accumulated in the exhaust purification apparatus.