Patent ID: 8341939
Filing Date: 2013-01-01
Classification: F01N,F02M,Y02T

Abstract:
1. A purification system for variable post injection in LP EGR, the system comprising: a turbo charger disposed downstream of a diesel engine; a DPF (diesel particulate filter) disposed downstream of the turbo charger; a NOx reduction apparatus disposed upstream or downstream of the DPF; a bypass line diverged from the DPF for mixing exhaust gas and air inflowing the turbo charger; an exhaust gas control portion disposed downstream of the DPF for controlling flowing of the exhaust gas; and a lean/rich controlling portion for controlling a lean/rich state of the exhaust gas wherein the lean/rich controlling portion comprising: a post injector disposed upstream of the NOx reduction apparatus; and an injector control portion that determines injecting timing of the post injector according to NOx concentration and amount of the NOx and modulates fuel injection patterns according to engine driving conditions, wherein the exhaust as control ortion comprises: a first throttle flap that controls flowing of the exhaust gas flowing to the NOx reduction apparatus; and a second throttle flap that controls flowing of the exhaust gas flowing to the bypass line, wherein the first throttle flap is fixed to the second throttle flap and the first throttle flap and the second throttle flap are vertically disposed to each other, wherein the exhaust gas control portion further comprises a DC motor and the DC motor controls openings of the first throttle flap and the second throttle flap simultaneously.