CONTROL APPARATUS AND CONTROL METHOD FOR INTERNAL COMBUSTION ENGINE

• US 20130116911A1
• Filed: 11/06/2012
• Published: 05/09/2013
• Est. Priority Date: 11/07/2011
• Status: Active Grant

• Current Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Original Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Inventors: Suzuki, Takashi
• Granted Patent: US 9,032,942 B2
• Time in Patent Office: Days
• US Class Current: 701/103
• CPC Class Codes: F02D 2200/0802 Temperature of the exhaust gas treatment apparatus
• CPC Class Codes: F02D 41/008 Controlling each cylinder individually
• CPC Class Codes: F02D 41/024 to increase temperature of the exhaust gas treating apparatus
• CPC Class Codes: Y02T 10/12 Improving ICE efficiencies

Abstract

A control apparatus for an internal combustion engine including a plurality of combustion chambers and a catalyst that cleans exhaust gases includes a controller configured to execute individual air-fuel ratio control in which an air-fuel ratio of an air-fuel mixture generated in at least one non-specific combustion chamber is controlled such that an average air-fuel ratio of the engine matches a target air-fuel ratio, based on an air-fuel ratio of an air-fuel mixture generated in at least one specific combustion chamber, the controller being configured to execute catalyst temperature increase control in which a temperature of the catalyst is increased, and the controller being configured to prohibit execution of the individual air-fuel ratio control when the catalyst temperature increase control is executed.

Claims

1. A control apparatus for an internal combustion engine including a plurality of combustion chambers and a catalyst that cleans exhaust gases, the control apparatus comprising:

a controller configured to execute individual air-fuel ratio control in which an air-fuel ratio of an air-fuel mixture generated in at least one non-specific combustion chamber is controlled such that an average air-fuel ratio of the internal combustion engine matches a target air-fuel ratio, based on an air-fuel ratio of an air-fuel mixture generated in at least one specific combustion chamber, the at least one specific combustion chamber being at least one of the plurality of combustion chambers, the at least one non-specific combustion chamber including the plurality of combustion chambers except the at least one specific combustion chamber, the controller being configured to execute catalyst temperature increase control in which a temperature of the catalyst is increased, and the controller being configured to prohibit execution of the individual air-fuel ratio control when the catalyst temperature increase control is executed.

2. The control apparatus according to claim 1, wherein:

the internal combustion engine further includes an exhaust passage common to all of the combustion chambers, and an air-fuel ratio detection portion that detects an air-fuel ratio of the exhaust gas in the exhaust passage; and

the controller is configured to use, as the specific combustion chamber, the combustion chamber that discharges a highest sensitivity exhaust gas that is the exhaust gas whose air-fuel ratio is detected by the air-fuel ratio detection portion with the highest detection sensitivity among the exhaust gases discharged from the plurality of combustion chambers, and the controller is configured to use the air-fuel ratio of the exhaust gas discharged from the specific combustion chamber detected by the air-fuel ratio detection portion as the air-fuel ratio of the air-fuel mixture generated in the specific combustion chamber in the individual air-fuel ratio control.

3. The control apparatus according to claim 1, wherein the internal combustion engine further includes a plurality of fuel supply portions that supply fuel to the corresponding combustion chambers, and the controller is configured to control the air-fuel ratio of the air-fuel mixture generated in the at least one non-specific combustion chamber by controlling an amount of the fuel supplied to the at least one non-specific combustion chamber from at least one of the fuel supply portions, which corresponds to the at least one non-specific combustion chamber.

4. A control method for an internal combustion engine including a plurality of combustion chambers and a catalyst that cleans exhaust gases, comprising:

determining whether or not catalyst temperature increase control in which a temperature of the catalyst is increased is executed; and

prohibiting, when it is determined that the catalyst temperature increase control is executed, execution of individual air-fuel ratio control in which an air-fuel ratio of an air-fuel mixture generated in at least one non-specific combustion chamber is controlled such that an average air-fuel ratio of the internal combustion engine matches a target air-fuel ratio, based on an air-fuel ratio of an air-fuel mixture generated in at least one specific combustion chamber, the at least one specific combustion chamber being at least one of the plurality of combustion chambers, and the at least one non-specific combustion chamber including the plurality of combustion chambers except the at least one specific combustion chamber.