JP2011226490A5

JP2011226490A5 -

Info

Publication number: JP2011226490A5
Application number: JP2011177462A
Authority: JP
Filing date: 2011-08-15
Publication date: 2011-12-22
Anticipated expiration: 2028-01-11

Description

そのため請求項１記載の発明では、燃料カット状態から燃料供給が再開されるときに空燃比をリッチ化すると共に、そのときの吸入空気量が多いほど速い速度でリッチ化が小さくなる方向に変化させると共に、内燃機関の実際の空燃比と目標空燃比とを比較して空燃比操作量を出力する空燃比制御における目標空燃比を、前記リッチ化に応じて補正するようにした。 Therefore, according to the first aspect of the invention, the air-fuel ratio is enriched when the fuel supply is resumed from the fuel cut state, and the enrichment is changed at a faster speed as the intake air amount at that time increases. At the same time, the actual air-fuel ratio of the internal combustion engine is compared with the target air-fuel ratio, and the target air-fuel ratio in the air-fuel ratio control for outputting the air-fuel ratio manipulated variable is corrected according to the enrichment.

Claims

An air-fuel ratio control device applied to an internal combustion engine having an exhaust purification catalyst in an exhaust pipe,
Enrichment means for enriching the air-fuel ratio when fuel supply is resumed from the fuel cut state, and changing the enrichment at a faster speed as the amount of intake air at that time increases,
An air-fuel ratio control means for comparing an actual air-fuel ratio of the internal combustion engine with a target air-fuel ratio and outputting an air-fuel ratio manipulated variable;
Target air-fuel ratio correction means for correcting a target air-fuel ratio in the air-fuel ratio control means in response to enrichment by the enrichment means;
An air-fuel ratio control apparatus for an internal combustion engine, comprising:

The internal combustion engine air conditioner according to claim 1, further comprising enrichment setting means for setting the enrichment in the enrichment means to a larger value as the amount of oxygen stored in the exhaust purification catalyst during the fuel cut increases. Fuel ratio control device.

The enrichment setting means estimates the amount of oxygen stored in the exhaust purification catalyst during the fuel cut based on the integrated value of the intake air amount of the internal combustion engine during the fuel cut, and based on the oxygen storage amount The air-fuel ratio control apparatus for an internal combustion engine according to claim 2, wherein the enrichment is set .

The air-fuel ratio control means performs output control of the air-fuel ratio manipulated variable on the condition that an actual air-fuel ratio of the internal combustion engine is less than a determination value. An air-fuel ratio control apparatus for an internal combustion engine.

The air-fuel ratio control apparatus for an internal combustion engine according to claim 3 , wherein the enrichment setting means estimates the oxygen storage amount using a value near a preset minimum amount as an initial value.

The air-fuel ratio control apparatus for an internal combustion engine according to claim 3 or 5 , wherein the enrichment setting means limits the estimated value of the oxygen storage amount to a predetermined upper limit value or less.