Patent ID: 7600374

Claim:
An exhaust gas filter regeneration control device used together with a diesel engine comprising: a fuel injector which injects fuel into the engine, an exhaust gas filter which is provided in an exhaust passage of the engine, and which traps particulate matter contained in an exhaust gas of the engine to prevent the particulate matter from being discharged into the atmosphere, and a catalyst which is provided in the exhaust passage upstream of the exhaust gas filter, and which raises an exhaust gas temperature through a catalytic reaction with components of a post-injected fuel when the exhaust gas filter is to be regenerated, the device comprising a programmable controller programmed to: determine whether or not the engine is decelerating during the regeneration of the exhaust gas filter; determine whether or not the catalyst is active when the engine is decelerating; determine whether the engine is decelerating gently or decelerating rapidly when the catalyst is active; cause the fuel injector to perform a post-injection following a main fuel injection when the engine is decelerating gently; and cause the fuel injector to perform the main fuel injection but not to perform the post-injection when the engine is decelerating rapidly.