Method for manually regenerating particulate filter

Abstract

Related is a method for regeneration of a particulate filter 6 wherein manual regeneration of the particulate filter 6 started with a vehicle being stopped causes an exhaust brake 14 to throttle an exhaust passage. This increases an engine load and a fuel injection amount to elevate in temperature an exhaust gas 3; then, fuel addition is started by post injection with a fuel injection device 10, and the particulate filter 6 is regenerated by heat of an oxidation reaction of the added fuel on an oxidation catalyst 5 . After the starting of the manual regeneration, whether a fuel injection amount exceeds a reference value or not is judged. Only if the judgment is affirmative, throttling of the exhaust passage by the exhaust brake 14 is released provided exhaust temperature exceeds a reference temperature on an entry side of the particulate filter 6.

1 . A method for manually regenerating a particulate filter, said particulate filter being incorporated in an exhaust pipe and having an oxidation catalyst preceding the same, fuel addition means being arranged upstream of said oxidation catalyst for addition of fuel to exhaust gas, exhaust throttling means being arranged for throttling of an exhaust passage from an engine, manual regeneration of said particulate filter being started with a vehicle being stopped to throttle the exhaust passage by said exhaust throttling means and thus increase an engine load, fuel addition by said fuel addition means being started after an fuel injection amount is increased to increase temperature of the exhaust gas, captured particulates being burned off by heat from an oxidation reaction of the added fuel on said oxidation catalyst, thereby regenerating said particulate filter, which comprises determining whether the fuel injection amount exceeds a reference value after the starting of the manual regeneration of the particulate filter, and releasing the throttling of the exhaust passage by said exhaust throttling means provided exhaust temperature on an entry side of the particulate filter exceeds a reference temperature and only if said fuel injection amount exceeds the reference value. 
     
     
         2 . The method for manually regenerating the particulate filter as claimed in  claim 1 , wherein a fuel injection device for the engine is employed as fuel addition means, the fuel addition being carried out such that main injection of fuel near a compression top dead center is followed by post injection at non-ignition timing after the compression top dead center.