Patent ID: 7454897

Claim:
An exhaust purifier for a diesel engine having an exhaust passage and an intake passage, the exhaust purifier comprising: a filter arrangeable in the exhaust passage of the diesel engine; a first detector for detecting atmospheric pressure; a controller for controlling the engine speed of the diesel engine; a second detector for detecting the engine speed of the diesel engine; a throttle valve arrangeable in the intake passage of the diesel engine; and an EGR valve for opening and closing a fluid communication path between the intake passage and the exhaust passage; wherein the diesel engine includes a fuel injection valve, and the controller is further configured to: perform idle-up by increasing the amount of fuel injected from the fuel injection valve of the diesel engine, compare an intake air amount, which is based on the atmospheric pressure detected by the first detector and the engine speed detected by the second detector, with a reference air amount during regeneration of the filter; perform idle-up for increasing the idle speed of the diesel engine when the intake air amount is less than the reference air amount; and increase the fuel injection amount if the intake air amount, which is based on the atmospheric pressure detected by the first detector and the engine speed detected by the second detector, is less than the reference air amount when the throttle valve is completely open and the EGR valve is completely closed during the regeneration of the filter.