Method and apparatus for controlling internal combustion engine

Patent metadata

Field	Value
Publication number	US-2016290267-A1
Application number	US-201615058272-A
Country	US
Kind code	A1
Filing date	Mar 2, 2016
Priority date	Mar 30, 2015
Publication date	Oct 6, 2016
Grant date	—

Abstract

In automatic stopping of the internal combustion engine, an electronic control unit controls a heater so that an element temperature of the air-fuel ratio sensor becomes a first temperature. The first temperature is a temperature that is below an activation temperature range in which the air-fuel ratio sensor is activated, and is also below a desorption temperature range in which HC components adsorbed on the air-fuel ratio sensor desorb therefrom. In a case where, after the element temperature of the air-fuel ratio sensor becomes the first temperature, it is estimated that the amount of HC components adsorbed on the air-fuel ratio sensor increases to exceed a first predetermined amount, the electronic control unit controls the heater so that the element temperature of the air-fuel ratio sensor becomes a second temperature. The second temperature is a temperature included in the desorption temperature range.

First claim

1 . A method for controlling an internal combustion engine in which an air-fuel ratio sensor having a built-in heater is provided in an exhaust passage, comprising:
executing a first processing in automatic stopping of the internal combustion engine, the first processing configured to control the heater so that an element temperature of the air-fuel ratio sensor becomes a first temperature that is below an activation temperature range in which the air-fuel ratio sensor is activated and is also below a desorption temperature range in which HC components that are adsorbed on the air-fuel ratio sensor desorb therefrom; and executing a second processing in a case where, after the element temperature of the air-fuel ratio sensor becomes the first temperature, it is estimated that an amount of HC components adsorbed on the air-fuel ratio sensor increases to exceed a first predetermined amount, the second processing configured to control the heater so that the element temperature of the air-fuel ratio sensor becomes a second temperature that is included in the desorption temperature range.

2 . The method according to claim 1 , wherein the second temperature is below the activation temperature range.

3 . The method according to claim 1 , further comprising:
executing a third processing in a case where, after the element temperature of the air-fuel ratio sensor becomes the second temperature, it is estimated that an amount of HC components adsorbed on the air-fuel ratio sensor decreases to less than a second predetermined amount, the third processing configured to control the heater so that the element temperature of the air-fuel ratio sensor becomes a third temperature that is below the activation temperature range and is also below the desorption temperature range.

4 . The method according to claim 3 , further comprising:
executing a fourth processing until restarting of the internal combustion engine after the element temperature of the air-fuel ratio sensor becomes the third temperature, the fourth processing configured to control the heater so that the element temperature of the air-fuel ratio sensor is maintained at a temperature that is below the desorption temperature range.

5 . An apparatus for controlling an internal combustion engine in which an air-fuel ratio sensor having a built-in heater is provided in an exhaust passage, comprising:
at least one processor; and at least one memory including at least one computer program, the at least one memory and the at least one computer program configured, with the at least one processor, to cause the apparatus at least to execute a first processing in automatic stopping of the internal combustion engine, the first processing configured to control the heater so that an element temperature of the air-fuel ratio sensor becomes a first temperature that is below an activation temperature range in which the air-fuel ratio sensor is activated and is also below a desorption temperature range in which HC components that are adsorbed on the air-fuel ratio sensor desorb therefrom, and execute a second processing in a case where, after the element temperature of the air-fuel ratio sensor becomes the first temperature, it is estimated that an amount of HC components adsorbed on the air-fuel ratio sensor increases to exceed a first predetermined amount, the second processing configured to control the heater so that the element temperature of the air-fuel ratio sensor becomes a second temperature that is included in the desorption temperature range.

6 . The apparatus according to claim 5 , wherein the second temperature is below the activation temperature range.

7 . The apparatus according to claim 5 , wherein the apparatus is further caused to execute a third processing in a case where, after the element temperature of the air-fuel ratio sensor becomes the second temperature, it is estimated that an amount of HC components adsorbed on the air-fuel ratio sensor decreases to less than a second predetermined amount, the third processing configured to control the heater so that the element temperature of the air-fuel ratio sensor becomes a third temperature that is below the activation temperature range and is also below the desorption temperature range.

8 . The apparatus according to claim 7 , wherein the apparatus is further caused to execute a fourth processing until restarting of the internal combustion engine after the element temperature of the air-fuel ratio sensor becomes the third temperature, the fourth processing configured to control the heater so that the element temperature of the air-fuel ratio sensor is maintained at a temperature that is below the desorption temperature range.

9 . An internal combustion engine in which an air-fuel ratio sensor having a built-in heater is provided in an exhaust passage, comprising:
an electronic control unit in communication with the air-fuel ratio sensor, the electronic control unit configured to execute a first processing in automatic stopping of the internal combustion engine, the first processing configured to control the heater so that an element temperature of the air-fuel ratio sensor becomes a first temperature that is below an activation temperature range in which the air-fuel ratio sensor is activated and is also below a desorption temperature range in which HC components that are adsorbed on the air-fuel ratio sensor desorb therefrom, and execute a second processing in a case where, after the element temperature of the air-fuel ratio sensor becomes the first temperature, it is estimated that an amount of HC components adsorbed on the air-fuel ratio sensor increases to exceed a first predetermined amount, the second processing configured to control the heater so that the element temperature of the air-fuel ratio sensor becomes a second temperature that is included in the desorption temperature range.

10 . The internal combustion engine according to claim 9 , wherein the second temperature is below the activation temperature range.

11 . The internal combustion engine according to claim 9 , wherein the electronic control unit is further configured to execute a third processing in a case where, after the element temperature of the air-fuel ratio sensor becomes the second temperature, it is estimated that an amount of HC components adsorbed on the air-fuel ratio sensor decreases to less than a second predetermined amount, the third processing configured to control the heater so that the element temperature of the air-fuel ratio sensor becomes a third temperature that is below the activation temperature range and is also below the desorption temperature range.

12 . The internal combustion engine according to claim 11 , wherein the electronic control unit is further configured to execute a fourth processing until restarting of the internal combustion engine after the element temperature of the air-fuel ratio sensor becomes the third temperature, the fourth processing configured to control the heater so that the element temperature of the air-fuel ratio sensor is maintained at a temperature that is below the desorption temperature range.

Assignees

• Toyota Motor Co Ltd

Inventors

• Ide Koji
• Aoki Keiichiro
• Hayashita Go

Classifications

• F02D41/2403

  using essentially up/down counters · CPC title

• F02D41/1494 Primary

  Control of sensor heater · CPC title

• F02D41/1495

  Detection of abnormalities in the air/fuel ratio feedback system · CPC title

• F02D41/401

  Controlling injection timing (F02D41/402 takes precedence) · CPC title

• F02B77/086

  Sensor arrangements in the exhaust, e.g. for temperature, misfire, air/fuel ratio, oxygen sensors · CPC title