Internal combustion engine control apparatus

Patent metadata

Field	Value
Publication number	US-9528458-B2
Application number	US-201213440750-A
Country	US
Kind code	B2
Filing date	Apr 5, 2012
Priority date	May 30, 2011
Publication date	Dec 27, 2016
Grant date	Dec 27, 2016

Abstract

An internal combustion engine control apparatus includes a first period in which the target heater applied effective voltage is set to a first target voltage with which the temperature of an exhaust gas sensor becomes a target temperature at a time when the internal combustion engine is being operated; a second control period in which after the automatic stop mode of the engine has started, the target heater applied effective voltage is set to a second target voltage lower than the first target voltage; and a third period in which after the second period, the target heater applied effective voltage is controlled to a third target voltage higher than the second target voltage and with which the temperature of an exhaust gas sensor becomes a target temperature at a time when the engine is in the automatic stop mode.

First claim

What is claimed is:

1. An internal combustion engine control apparatus of a vehicle, said internal combustion engine control apparatus comprising:
an automatic stop/automatic start device, for an internal combustion engine, that automatically stops the internal combustion engine when a stopping condition for the internal combustion engine is established and automatically starts the internal combustion engine when a starting condition for the internal combustion engine is established;
an exhaust gas sensor that is provided in an exhaust path of the internal combustion engine and detects at least one of the air-fuel ratio in an exhaust gas and the rich/lean tendency of the exhaust gas with respect to the theoretical air-fuel ratio;
a heater that heats the exhaust gas sensor; and
a heater control device that controls an applied effective voltage for the heater in such a way that the applied effective voltage becomes equal to a target heater applied effective voltage, wherein the heater control device includes a first control period in which the target heater applied effective voltage is set to a first target applied effective voltage with which a sensor element temperature of the exhaust gas sensor becomes equal to a sensor element target temperature at a time when the internal combustion engine is being operated; a second control period in which after the automatic stop mode of the internal combustion engine has started, the target heater applied effective voltage is set to a second target applied effective voltage that is lower than the first target applied effective voltage; a second control period end determiner that determines, during the second control period, the end of the second control period; and a third control period in which after determination of the end of the second control period, the target heater applied effective voltage is controlled to be a third target applied effective voltage that is higher than the second target applied effective voltage and with which the sensor element temperature of the exhaust gas sensor becomes equal to a sensor element target temperature at a time when the internal combustion engine is in the automatic stop mode after being operated, and just prior to being restarted,
wherein the heater control device includes an automatic stop mode elapsed time measurer that measures an elapsed time from the start of the automatic stop mode of the internal combustion engine; and the second control period end determiner determines that the second control period has ended, when the elapsed time from the start of the automatic stop mode, measured by the automatic stop mode elapsed time measurer, expands as wide as a second control period end duration.

2. The internal combustion engine control apparatus according to claim 1 , further including a fuel injection amount corrector that corrects the amount of fuel injected into the internal combustion engine, in accordance with a detection value of the exhaust gas sensor, wherein the heater control device includes a fourth control period in which after the internal combustion engine has automatically started, the target heater applied effective voltage is set to a fourth target applied effective voltage, which is the same as or higher than the first target applied effective voltage, until the sensor element temperature becomes equal to the sensor element target temperature at a time when the internal combustion engine is being operated; the fourth control period is set in such a way as to end by the time the fuel injection amount corrector starts the operation thereof after the internal combustion engine has automatically started; and the sensor element target temperature at a time when the internal combustion engine is in the automatic stop mode is set in such a way that the sum of the heater power consumption amounts in the second control period, the third control period, and the fourth control period becomes minimum.

3. The internal combustion engine control apparatus according to claim 1 , wherein the second control period end duration is set to a period from a time point when the automatic stop mode of the internal combustion engine starts to a time point when the sensor element temperature of the exhaust gas sensor reaches the sensor element target temperature at a time when the internal combustion engine is in the automatic stop mode.

4. The internal combustion engine control apparatus according to claim 1 , wherein the heater control device includes an automatic stop/automatic start continuity determiner that determines whether or not the automatic stop/automatic start of the internal combustion engine continues; and in the case where the automatic stop/automatic start continuity determiner determines that the automatic stop/automatic start is continuing, the second control period end duration is corrected to become shorter.

5. The internal combustion engine control apparatus according to claim 1 , wherein the heater control device includes the automatic stop/automatic start continuity determiner that determines whether or not the automatic stop/automatic start of the internal combustion engine continues; and in the case where the automatic stop/automatic start continuity determiner determines that the automatic stop/automatic start is continuing, the third target applied effective voltage is corrected to become higher.

6. The internal combustion engine control apparatus according to claim 4 , wherein the state where the automatic stop/automatic start continues is a state where after the internal combustion engine has started, the automatic stop mode of the internal combustion engine is started again before the exhaust gas sensor is activated.

7. The internal combustion engine control apparatus according to claim 1 , wherein the heater control device includes an impedance measurer that measures an sensor element impedance of the exhaust gas sensor, and an applied effective voltage setter that sets an applied effective voltage for the heater in such a way that the sensor element impedance measured by the impedance measurer becomes equal to a target impedance; in the first control period, the applied effective voltage setter sets the first target applied effective voltage in such a manner that the sensor element impedance becomes equal to a first target impedance related to the sensor element target temperature at a time when the internal combustion engine is being operated; in the second control period after the start of the automatic stop mode of the internal combustion engine, the applied effective voltage setter sets the second target applied effective voltage in such a manner that the sensor element impedance becomes equal to a second target impedance that is higher than the first target impedance; and after the second control period end determiner determines that the second control period has ended, the applied effective voltage setter sets the third target applied effective voltage in such a manner that in the third control period, the sensor element impedance becomes equal to a third target impedance related to the sensor element target temperature at a time when the internal combustion engine is in the automatic stop mode.

8. The internal combustion engine control apparatus according to claim 7 , wherein in the second control period after the start of the automatic stop mode of the internal combustion engine, the second control period end determiner determines that the second control period has ended, when the sensor element impedance reaches the third target impedance in the second control period.

9. The internal combustion engine control apparatus according to claim 7 , wherein in the second control period after the start of the automatic stop mode of the internal combus

Assignees

• Date Toshiaki
• Wachi Satoshi
• Mitsubishi Electric Corp

Inventors

• Date Toshiaki
• Wachi Satoshi

Classifications

• F02D41/1494

  Control of sensor heater · CPC title

• F01N2560/025

  for measuring or detecting O2, e.g. lambda sensors · CPC title

• F02D41/1456

  with sensor output signal being linear or quasi-linear with the concentration of oxygen · CPC title

• F02N11/0814

  comprising means for controlling automatic idle-start-stop · CPC title

• F02D41/042 Primary

  for stopping the engine · CPC title