Catalyst deterioration detection device for internal combustion engine

Abstract

Abstract Translated from Japanese (57)【要約】 【目的】 複数の気筒群を有する、例えばＶ型、水平対 向型等の内燃機関の排気通路に配置した触媒コンバータ の劣化検出を、各気筒群の空燃比制御タイミングを強制 的に同期させることなく行う。 【構成】 各気筒群の排気系に配置した上流側Ｏ 2 セン サ１３Ａ，１３Ｂ、排気集合部下流に配置した触媒コン バータ１６、下流側Ｏ 2 センサ１７、制御回路１０で構 成する。制御回路１０は、各気筒群の空燃比をそれぞれ の上流側Ｏ 2 センサ出力に基づいて個別に制御すると共 に、特別な操作を行うことなく運転中に各気筒群の空燃 比変化が同期した場合にのみ触媒劣化検出を実施する。 各気筒群の空燃比制御タイミングを強制的に同期させる 操作を行わないので、一時的制御特性の悪化や排気エミ ッションの過渡的悪化が生じない。 (57) [Abstract] [Purpose] Deterioration detection of a catalytic converter arranged in the exhaust passage of an internal combustion engine having a plurality of cylinder groups, such as a V-type or a horizontally opposed type, is forced by the air-fuel ratio control timing of each cylinder group. Without syncing. [Structure] The upstream side O 2 sensors 13A and 13B arranged in the exhaust system of each cylinder group, the catalytic converter 16 arranged downstream of the exhaust collecting section, the downstream O 2 sensor 17, and the control circuit 10. The control circuit 10 individually controls the air-fuel ratio of each cylinder group based on the output of the upstream O 2 sensor, and when the air-fuel ratio change of each cylinder group is synchronized during operation without performing a special operation. The catalyst deterioration detection is carried out only on. Since the operation of forcibly synchronizing the air-fuel ratio control timing of each cylinder group is not performed, temporary deterioration of control characteristics and transient deterioration of exhaust emission do not occur.

Inventors

• 👤 Yasuhiro Shimizu
• 👤 康弘 清水

Bibliographic Details