公开(公告)号：US10247694B2

公开(公告)日：2019-04-02

申请号：US15023446

申请日：2014-09-25

Applicant: DENSO CORPORATION

Inventor： Takao Mishima ,  Shingo Nakata ,  Mikiyasu Matsuoka ,  Tomoo Kawase ,  Yuuji Yamada

IPC: G01N27/407 ,  G01N27/406 ,  F02D41/14 ,  F02D41/24 ,  G01N27/41 ,  F02D41/06 ,  F02D41/12

Abstract: An O2 sensor includes a sensor element using a solid electrolyte layer and a pair of electrodes placed at a position to interpose the solid electrolyte layer, detects an exhaust gas from an internal combustion engine as an object of a detection, and outputs an electromotive force signal depending on an air-fuel ratio of the exhaust gas. The sensor element is connected with a constant current circuit supplying a constant current that is prescribed. A microcomputer calculates an element resistance, determines whether the air-fuel ratio is at least rich, lean, or stoichiometric, on the basis of a comparison between an electromotive force output of the electrogenic cell and a prescribed threshold. Further, the microcomputer controls the constant current supplied by the constant current circuit on the basis of the element resistance.