Combustion state-detecting system for internal combustion engines
AssigneeHonda Giken Kogyo Kabushiki Kaisha
InventorsShigetaka Kuroda, Yuichi Shimasaki
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Abstract
A combustion state-detecting system for an internal combustion engine comprises a rotational speed sensor for detecting a value of the rotational speed of the engine with a predetermined repetition period shorter than the firing period of the spark plug whenever the crankshaft rotates through a predetermined angle, and an ECU which calculates a difference amount between a value of the detected rotational speed of the engine and a value of the detected rotational speed of the engine a predetermined number of firing periods earlier. A combustion state of the engine is detected based on the calculated difference amount.
Claims6
A combustion state-detecting system for an internal combustion engine having at least one spark plug, and a crankshaft, comprising:
- rotational speed-detecting means for detecting a value of rotational speed of said engine with a predetermined repetition period shorter than a firing period of said spark plug whenever said crankshaft rotates through a predetermined angle;
- difference amount-calculating means for calculating a difference amount between a value of said rotational speed of said engine detected by said rotational speed-detecting means and a value of said rotational speed of said engine detected by said rotational speed-detecting means a predetermined number of firing periods earlier;
- combustion state-detecting means for detecting a combustion state of said engine, based on said difference amount calculated by said difference amount-calculating means;
- engine braking state-detecting means for detecting an engine braking state of said engine;
- and
- difference amount-storing means for storing said difference amount calculated by said difference amount-calculating means when said engine braking state of said engine is detected by said engine braking state-detecting means,
- wherein said combustion state-detecting means compares said difference amount detected by said difference amount-detecting means with said difference amount stored by said difference amount-storing means when said engine braking state of said engine is detected, and detects said combustion state of said engine, based on a result of said comparison.
A combustion state-detecting system for an internal combustion engine having at least one spark plug, and a crankshaft, comprising:
- rotational speed-detecting means for detecting a value of rotational speed of said engine with a predetermined repetition period shorter than a firing period of said spark plug whenever said crankshaft rotates through a predetermined angle;
- averaging means for continuously averaging values of said rotational speed of said engine detected by said rotational speed-detecting means, over a period of one rotation of said crankshaft, to obtain an average value;
- first difference amount-calculating means for calculating a first difference amount between a value of said average value calculated by said averaging means and a value of said average value calculated by said averaging means a predetermined number of firing periods earlier;
- second difference mount-calculating means for calculating a second difference amount between a value of said rotational speed of said engine detected by said rotational speed-detecting means and a value of said rotational speed of said engine detected by said rotational speed-detecting means a predetermined number of firing periods earlier;
- and
- combustion state-detecting means for detecting a combustion state of said engine based on said first difference amount calculated by said first difference amount-calculating means when said rotational speed of said engine detected by said rotational speed-detecting means is higher than a predetermined value, and based on said second difference amount calculated by said second difference amount-calculating means when said rotational speed of said engine detected by said rotational speed-detecting means is lower than said predetermined value.
Dependencies are inferred from the claim text.