Patent Number: 6,253,545

Title: Internal combustion engine having lean NOx catalyst

Abstract: An engine having in an exhaust system a lean NOx catalyst for purifying nitrogen oxide in an oxygen excessive exhaust gas by using a reducing agent, includes an intake air quantity decreasing device for decreasing a quantity of intake air flowing through an intake system when the nitrogen oxide needs to be purified by the lean NOx catalyst, and a combustion heater provided separately from the internal combustion engine also serves as a CO.sub.2 adding device for adding carbon dioxide to the intake air when a flowing quantity in the intake system decreases by operating the intake air quantity decreasing device. With this arrangement the reducing agent such as hydro carbon and the like can be supplied even when eliminating an auxiliary injection hitherto needed in the internal combustion engine having the lean NOx catalyst.

Inventors: Suzuki; Makoto (Mishima, JP)

Assignee: Toyota Jidosha Kabushiki Kaisha

International Classification: F01N 3/08 (20060101); F01N 3/20 (20060101); F02D 21/06 (20060101); F02D 21/00 (20060101); F02M 31/02 (20060101); F02M 31/04 (20060101); F02B 3/00 (20060101); F02B 3/06 (20060101); F02M 025/06 ()

Expiration Date: 07/03/2018