Patent ID: 7340884

Claim:
An exhaust purifying apparatus for an internal combustion engine, the apparatus performing PM elimination control in which an unburned fuel component is supplied to a catalyst located in an exhaust system of the internal combustion engine so that the temperature of the catalyst is increased and particulate matter trapped at the catalyst is burned, the apparatus comprising: execution unit, wherein, when an accumulation amount of particulate matter at the catalyst becomes less than a first determination value after the PM elimination control is started, the execution unit executes burn-up control in which performance and stopping of concentrated intermittent fuel addition to a section of the exhaust system that is upstream of the catalyst are repeated a predetermined number of times; stopping unit that stops the PM elimination control based on an end of the burn-up control; and forcibly ending unit that forcibly ends the burn-up control when, after the burn-up control is started, time elapsed since the accumulation amount of particulate matter at the catalyst has dropped to a second determination value reaches a predetermined time, the second determination value being less than the first determination value, wherein the predetermined time is longer than a time required for consecutively repeating the performance and stopping of the concentrated intermittent fuel addition of the burn-up control the predetermined number of times, and is sufficiently short for preventing deterioration of fuel economy due to the performance of the PM elimination control in the predetermined time.