Control Device for an Internal Combustion Engine
First Claim
1. A control device for an internal combustion engine comprising:
- an evaporative fuel gas adsorption unit which adsorbs evaporative fuel gas from a fuel tank;
an evaporative fuel gas purging unit which is internally provided with an opening-adjustable purge control valve and which purges evaporative fuel gas adsorbed by the evaporative fuel gas adsorption unit into an intake passage of the internal combustion engine;
a fuel correction unit which feedback controls, based on an air-fuel ratio detected by an air-fuel ratio detection unit, an air-fuel ratio of an air-fuel mixture to be fed to the internal combustion engine to a prescribed value;
a purge control valve opening control unit which performs control to open the purge control valve under a prescribed condition;
a purge quantity calculation unit which, with the purge control valve open under the prescribed condition, calculates a quantity of purged evaporative fuel gas based on a fuel correction value determined by the fuel correction unit engaged in fuel correction calculation for realizing a prescribed air-fuel ratio;
an adsorption quantity estimation unit which determines, based on a quantity of purged evaporative fuel gas calculated by the purge quantity calculation unit, a quantity of evaporative fuel gas adsorbed by the evaporative fuel gas adsorption unit;
an adsorption quantity change calculation unit which changes, according to a condition of the internal combustion engine and vehicle, a quantity of evaporative fuel gas determined by the adsorption quantity estimation unit;
an adsorption quantity correction unit which corrects, according to a condition of the fuel correction unit, a change value calculated by the adsorption quantity change calculation unit; and
a fuel correction value calculation unit which calculates a fuel correction value based on an adsorption quantity change calculated by the adsorption quantity change calculation unit.
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Accused Products
Abstract
A control device for an internal combustion engine can quickly control, regardless of variation of the quantity of evaporative fuel gas adsorbed in a canister of the engine, the air-fuel ratio to a target value by performing air-fuel ratio feedback compensation control so as not to cause the emission performance of the engine to deteriorate. For the first canister purge performed after the engine is started up, a purge valve is driven for a prescribed period at a prescribed purge flow rate. During the period, the quantity of purged fuel is calculated using an air-fuel ratio feedback factor. Based on the fuel quantity thus calculated, an adsorption quantity estimation section estimates the quantity of evaporative fuel gas adsorbed in the canister. At the same time, a fuel evaporation quantity calculation section calculates the quantity of fuel evaporating from a fuel tank according to the condition of the engine and vehicle, and the quantity of fuel in the canister is estimated based on the balance between the quantities of fuel charged to and purged from the canister.
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Citations
9 Claims
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1. A control device for an internal combustion engine comprising:
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an evaporative fuel gas adsorption unit which adsorbs evaporative fuel gas from a fuel tank; an evaporative fuel gas purging unit which is internally provided with an opening-adjustable purge control valve and which purges evaporative fuel gas adsorbed by the evaporative fuel gas adsorption unit into an intake passage of the internal combustion engine; a fuel correction unit which feedback controls, based on an air-fuel ratio detected by an air-fuel ratio detection unit, an air-fuel ratio of an air-fuel mixture to be fed to the internal combustion engine to a prescribed value; a purge control valve opening control unit which performs control to open the purge control valve under a prescribed condition; a purge quantity calculation unit which, with the purge control valve open under the prescribed condition, calculates a quantity of purged evaporative fuel gas based on a fuel correction value determined by the fuel correction unit engaged in fuel correction calculation for realizing a prescribed air-fuel ratio; an adsorption quantity estimation unit which determines, based on a quantity of purged evaporative fuel gas calculated by the purge quantity calculation unit, a quantity of evaporative fuel gas adsorbed by the evaporative fuel gas adsorption unit; an adsorption quantity change calculation unit which changes, according to a condition of the internal combustion engine and vehicle, a quantity of evaporative fuel gas determined by the adsorption quantity estimation unit; an adsorption quantity correction unit which corrects, according to a condition of the fuel correction unit, a change value calculated by the adsorption quantity change calculation unit; and a fuel correction value calculation unit which calculates a fuel correction value based on an adsorption quantity change calculated by the adsorption quantity change calculation unit. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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Specification