US 6,981,370 B2
Method and apparatus for PM filter regeneration
Cornelius N. Opris, Peoria, Ill. (US); and Maarten Verkiel, Metamora, Ill. (US)
Assigned to Caterpillar Inc, Peoria, Ill. (US)
Filed on Dec. 03, 2002, as Appl. No. 10/308,969.
Prior Publication US 2004/0103648 A1, Jun. 03, 2004
Int. Cl. F01N 3/02 (2006.01)
U.S. Cl. 60—311 28 Claims
OG exemplary drawing
 
1. A method for initiating regeneration of a particulate matter (PM) filter in an exhaust system in an internal combustion engine, including the steps of:
determining a change in pressure of exhaust gases passing through the PM filter; and
extending an open duration of an intake valve in fluid communication with a combustion chamber beyond a normal duratio in response to the change in pressure to increase a temperature of the exhaust gases passing through the PM filter.