Cylinder-by-cylinder intake air quantity detecting apparatus for internal combustion engine
First Claim
1. A cylinder-by-cylinder intake air quantity detecting apparatus for an internal combustion engine having a plurality of cylinders, the cylinder-by-cylinder intake air quantity detecting apparatus comprising:
- a detecting unit including at least one of an airflow meter for detecting an intake air quantity flowing in an intake pipe, a pressure sensor for detecting intake pipe pressure in the intake pipe, and an in-cylinder pressure sensor for detecting in-cylinder pressure;
an area calculating unit for calculating the area of the intake air quantity of the output waveform from the detecting unit for a predetermined period for one of every intake stroke and every compression stroke of each cylinder;
a cylinder-to-cylinder intake air quantity variations calculating unit for calculating the rate of cylinder-to-cylinder variations in intake air quantity or the cylinder-by-cylinder intake air quantities according to the area of the intake air quantity for the predetermined period of each cylinder.
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Accused Products
Abstract
A rate of cylinder-to-cylinder variations in an intake air quantity is calculated, and learned as a learning value based on an output from an airflow meter when a predetermined condition is met. The predetermined condition is set at a preferable condition for learning the rate of cylinder-to-cylinder variations. Subsequently, the rate of cylinder-to-cylinder variations is estimated based on the learning value when the predetermined condition is not met. Thus, cylinder-to-cylinder variations of an engine are accurately obtained in almost all the operating ranges, so that the measurement of the cylinder-by-cylinder intake air quantity with high degree of accuracy is achieved.
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Citations
11 Claims
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1. A cylinder-by-cylinder intake air quantity detecting apparatus for an internal combustion engine having a plurality of cylinders, the cylinder-by-cylinder intake air quantity detecting apparatus comprising:
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a detecting unit including at least one of an airflow meter for detecting an intake air quantity flowing in an intake pipe, a pressure sensor for detecting intake pipe pressure in the intake pipe, and an in-cylinder pressure sensor for detecting in-cylinder pressure;
an area calculating unit for calculating the area of the intake air quantity of the output waveform from the detecting unit for a predetermined period for one of every intake stroke and every compression stroke of each cylinder;
a cylinder-to-cylinder intake air quantity variations calculating unit for calculating the rate of cylinder-to-cylinder variations in intake air quantity or the cylinder-by-cylinder intake air quantities according to the area of the intake air quantity for the predetermined period of each cylinder. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
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Specification