Control system of internal combustion engine

Patent metadata

Field	Value
Publication number	US-10473049-B2
Application number	US-201314763566-A
Country	US
Kind code	B2
Filing date	Jan 29, 2013
Priority date	Jan 29, 2013
Publication date	Nov 12, 2019
Grant date	Nov 12, 2019

Abstract

This control device for an internal combustion engine is equipped with: an air/fuel ratio sensor; and an engine control device that controls the internal combustion engine according to the output of the air/fuel ratio sensor. The air/fuel ratio sensor is configured so that the applied voltage at which the output current reaches zero varies according to the exhaust air/fuel ratio, and the output current increases if the applied voltage is increased at the air/fuel ratio sensor when the exhaust air/fuel ratio is the stoichiometric air/fuel ratio. When the air/fuel ratio of exhaust gas is to be detected by the air/fuel ratio sensor, the applied voltage at the air/fuel ratio sensor is fixed at a constant voltage, said constant voltage being different to the voltage at which the output current reaches zero when the exhaust air/fuel ratio is the stoichiometric air/fuel ratio, and being the voltage at which the output current reaches zero when the exhaust air/fuel ratio is different to the stoichiometric air/fuel ratio. Thus provided is a control device for an internal combustion engine that uses an air/fuel ratio sensor capable of detecting an absolute value for the air/fuel ratio of exhaust gas even if the air/fuel ratio of the exhaust gas is not the stoichiometric air/fuel ratio.

First claim

The invention claimed is:

1. A control system of an internal combustion engine comprising: an air-fuel ratio sensor which is provided in an exhaust passage of the internal combustion engine and configured to detect an exhaust air-fuel ratio; and an electronic control unit (ECU) including a computer and a processor for executing programs stored in memory of the computer, the ECU configured to control the internal combustion engine in accordance with an output of said air-fuel ratio sensor,
wherein said air-fuel ratio sensor is configured so that an applied voltage, when an output current becomes zero, changes in accordance with the exhaust air-fuel ratio, and the ECU is further configured so that when the exhaust air-fuel ratio is a stoichiometric air-fuel ratio, in response to the applied voltage increasing at said air-fuel ratio sensor, the output current of the air-fuel ratio sensor increases, and
wherein the ECU is further configured to fix the voltage applied to said air-fuel ratio sensor to a constant voltage when said air-fuel ratio sensor detects the air-fuel ratio of the exhaust gas, and wherein said constant voltage is a voltage which is different from the voltage whereby the output current of the air-fuel ration sensor becomes zero when the exhaust air-fuel ratio is the stoichiometric air-fuel ratio, and is the voltage whereby the output current becomes zero when the exhaust air-fuel ratio is an air-fuel ratio which is different from the stoichiometric air-fuel ratio.

2. The control system of the internal combustion engine according to claim 1 , wherein said engine control system judges ECU is configured to judge that the exhaust air-fuel ratio is a predetermined air-fuel ratio which is different from the stoichiometric air-fuel ratio, when the output current of said air-fuel ratio sensor becomes 0.

Assignees

• Hayashita Go
• Aoki Keiichiro
• Toyota Motor Co Ltd

Inventors

• Hayashita Go
• Aoki Keiichiro

Classifications

• G01N27/4065

  Circuit arrangements specially adapted therefor · CPC title

• F02D41/1441 Primary

  Plural sensors · CPC title

• G01N27/4076

  Reference electrodes or reference mixtures · CPC title

• F02D41/1401

  characterised by the control or regulation method (F02D41/1473, F02D41/1477 take precedence) · CPC title

• G01N27/403

  Cells and electrode assemblies · CPC title