公开(公告)号：US10082480B2

公开(公告)日：2018-09-25

申请号：US15597826

申请日：2017-05-17

Applicant: NGK SPARK PLUG CO., LTD.

Inventor： Satoru Abe ,  Tomonori Uemura ,  Tetsuya Ito ,  Satoshi Teramoto

IPC: G01N27/409 ,  G01N27/407 ,  G01N33/00

CPC classification number: G01N27/409 ,  F02D41/1446 ,  F02D41/1456 ,  G01N27/4073 ,  G01N33/0036

Abstract: A gas concentration detection device for detecting a gas concentration using a limiting current type gas concentration sensor. In an application voltage line set to pass through a plurality of limiting current regions for different values of gas concentration, a ratio for lean is set as a ratio of change in current with respect to a change in voltage when an air/fuel ratio corresponding to the gas concentration is lean, and a ratio of rich different from the ratio for lean is set when the air/fuel ratio is rich.

公开(公告)号：US11174808B2

公开(公告)日：2021-11-16

申请号：US17039778

申请日：2020-09-30

Applicant: NGK SPARK PLUG CO., LTD.

Inventor： Tetsuya Ito ,  Yuki Saito

IPC: F02D41/14 ,  F01N3/10

Abstract: An air-fuel ratio control system (1) including an air-fuel ratio control section (3) for controlling the air-fuel ratio λ of an air-fuel mixture, an exhaust gas purifier (4); an air-fuel ratio sensor (5) whose output changes sharply when λ in the exhaust gas changes between rich and lean sides about a stoichiometric air-fuel ratio; a heater (6); and a temperature control section (7). The air-fuel ratio control section (3) controls λ based on the output of the air-fuel ratio sensor (5) using, as a target air-fuel ratio, a predetermined air-fuel ratio such that 0.980≤λ