发明名称 |
Control device for internal combustion engine |
摘要 |
A device includes: downstream air-fuel ratio feedback control unit that performs feedback control of an upstream target air-fuel ratio so that a downstream air-fuel ratio detected by a downstream air-fuel ratio detecting unit coincides with a downstream target air-fuel ratio; a target air-fuel ratio varying unit that varies the upstream target air-fuel ratio at the time of diagnosing degradation of a ternary catalyst; and a catalyst degradation judging unit that judges catalyst degradation from the behavior of the downstream air-fuel ratio at the time of diagnosing degradation of the ternary catalyst. When diagnosing degradation of the ternary catalyst, the downstream air-fuel ratio feedback control unit is stopped or its control constant is set at a smaller value. Thus, when varying the air-fuel ratio for diagnosing catalyst degradation, interference between downstream air-fuel ratio feedback and upstream air-fuel ratio feedback is prevented and catalyst degradation is accurately diagnosed.
|
申请公布号 |
US7293404(B2) |
申请公布日期 |
2007.11.13 |
申请号 |
US20060326403 |
申请日期 |
2006.01.06 |
申请人 |
MITSUBISHI DENKI KABUSHIKI KAISHA |
发明人 |
ENOKI KEIICHI;YEHLIU KUEN |
分类号 |
F01N3/00;F02D41/04;F02D41/14;F02D41/20;F02D43/00;F02D45/00 |
主分类号 |
F01N3/00 |
代理机构 |
|
代理人 |
|
主权项 |
|
地址 |
|