Patent ID: 7600373
Filing Date: 2009-10-13
Classification: F01N,F02B,F02D,Y02T

Abstract:
1. A regeneration controller for an exhaust purification apparatus that is arranged in an exhaust system of an internal combustion engine, wherein the regeneration controller burns particulate matter in the exhaust purification apparatus by intermittently adding fuel to the exhaust system or by intermittently increasing the amount of fuel added to the exhaust system, the regeneration controller comprising: a first heating control and a second heating control adapted for execution by the regeneration controller, the first heating control generates an oxygen-rich, fuel-lean, environment while increasing temperature of the catalyst bed, the second heating control intermittently generates a fuel-rich environment and an oxygen-rich, fuel lean, environment while increasing temperature of the catalyst bed; an exhaust temperature detector for detecting exhaust temperature at a location downstream from the exhaust purification apparatus; a stop timing determination section for determining a timing for stopping the fuel addition to the exhaust system or the increase of fuel addition to the exhaust system executed by the second heating control based on the exhaust temperature detected by the exhaust temperature detector and an elapsed time of the fuel addition to the exhaust system or the increase of fuel addition to the exhaust system; and a start timing determination section for determining a timing for starting the fuel addition to the exhaust system or the increase of fuel addition to the exhaust system based on the exhaust temperature detected by the exhaust temperature detector and an elapsed time in which there is no fuel addition to the exhaust system or in which there is no increase of fuel addition to the exhaust system; wherein the stop timing determination section stops the fuel addition to the exhaust system or the increase of fuel addition to the exhaust system when at least one of the exhaust temperature detected by at least one of the exhaust temperature detector is greater than a stop determination reference temperature or when the elapsed time of the fuel addition to the exhaust system or the increase of fuel addition to the exhaust system is longer than a stop determination reference period, wherein the start timing determination section staffs the fuel addition to the exhaust system or the increase of fuel addition to the exhaust system when each of at least one of the exhaust temperature detected by at least one of the exhaust temperature detector is less than a start determination reference temperature and the elapsed time of the fuel addition to the exhaust system or the increase of fuel addition to the exhaust system is longer than a start determination reference period, wherein both the exhaust temperature and the elapsed time are monitored to control the stop timing determination section and the staff timing section under the second heating control, and wherein the temperature of a NOx storage reduction catalyst under the burn-up is higher than the temperature of the catalyst before performing the burn-up.