Cylinder-specific spark ignition control system for direct fuel injected two-stroke engine
First Claim
1. A multi-cylinder, two-stroke internal combustion engine comprising:
- a plurality of engine cylinders each coextensive with a respective combustion chamber;
a cylinder spark ignition system for each cylinder, each cylinder spark ignition system having a spark plug mounted to the engine so that a spark plug ignition electrode is exposed within the respective combustion chamber;
an engine speed sensor that monitors an engine revolution rate and generates an engine speed signal in response thereto; and
an electronic control unit that inputs the engine speed signal and generates a cylinder-specific spark ignition timing control signal that is transmitted to each cylinder spark ignition system to control spark timing for the respective spark plug electrode, wherein the electronic control unit contains a set of spark ignition timing control parameters pre-calibrated for each respective cylinder and determines spark timing for each respective spark plug electrode based at least in part on the spark ignition timing control parameters which are pre-calibrated for the respective cylinder.
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Accused Products
Abstract
A direct fuel injected two-stroke engine controls spark ignition timing and/or ignition coil dwell time on a cylinder-specific basis. The engine also preferably controls fuel injection timing and amount and injection/delivery duration on a cylinder-specific basis. Cylinder-specific customization of spark ignition and fuel injection allows better coordination of spark with fuel injection which results in better running quality, lower emissions, etc. Memory in the electronic control unit for the engine preferably includes a high resolution global look-up table that determines global values for spark ignition and fuel injection control based on engine load (e.g. throttle position, manifold air pressure, etc.) and engine speed. Memory in the electronic control unit also includes a plurality of low resolution, cylinder-specific offset value look-up tables from which cylinder-specific offset values for spark ignition and fuel injection can be determined, preferably depending on engine load and engine speed. The offset values are combined with the global values to generate cylinder-specific control signals for spark ignition and fuel injection.
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Citations
32 Claims
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1. A multi-cylinder, two-stroke internal combustion engine comprising:
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a plurality of engine cylinders each coextensive with a respective combustion chamber; a cylinder spark ignition system for each cylinder, each cylinder spark ignition system having a spark plug mounted to the engine so that a spark plug ignition electrode is exposed within the respective combustion chamber; an engine speed sensor that monitors an engine revolution rate and generates an engine speed signal in response thereto; and an electronic control unit that inputs the engine speed signal and generates a cylinder-specific spark ignition timing control signal that is transmitted to each cylinder spark ignition system to control spark timing for the respective spark plug electrode, wherein the electronic control unit contains a set of spark ignition timing control parameters pre-calibrated for each respective cylinder and determines spark timing for each respective spark plug electrode based at least in part on the spark ignition timing control parameters which are pre-calibrated for the respective cylinder. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
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12. A multi-cylinder, two-stroke internal combustion engine comprising:
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a plurality of engine cylinders each coextensive with a respective combustion chamber; a cylinder spark ignition system for each cylinder, each cylinder spark ignition system having a spark plug mounted to the engine so that a spark plug ignition electrode is exposed within the respective combustion chamber and a dedicated ignition coil and electronic driver for each spark plug; an engine rpm sensor that monitors an engine revolution rate and generates an engine rpm signal in response thereto; and an electronic control unit that inputs the rpm signal and generates a cylinder-specific ignition coil dwell time control signal that is transmitted to the respective electronic driver to control ignition coil dwell time for the respective ignition coil, wherein the electronic control unit contains a set of ignition coil dwell time control parameters pre-calibrated for each cylinder and determines ignition coil dwell time for each respective ignition coil based at least in part on the ignition coil dwell time control parameters which are pre-calibrated for the respective cylinder. - View Dependent Claims (13, 14)
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15. In multi-cylinder, fuel injected two-cycle internal combustion engine, a method of contemporaneously controlling spark ignition and fuel injection, the method comprising the steps of:
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monitoring engine revolution rate and generating an engine speed signal in response thereto; sensing engine load and generating an engine load signal in response thereto; determining a global value for cylinder spark advance timing from the value of the engine load signal and the value of the engine rpm signal; determining cylinder-specific spark advance timing offset values for each cylinder based on cylinder-specific characteristics; combining the global value for the cylinder-specific spark advance timing with each respective cylinder-specific offset spark advance timing value to generate a separate cylinder-specific spark advance timing control signal; transmitting the cylinder-specific spark advance timing control signals to a cylinder spark ignition system for each respective cylinder; determining a global value for cylinder fuel injection timing from the value of the engine load signal and the value of the engine rpm signal; determining cylinder-specific fuel injection timing offset values for each cylinder based on cylinder-specific characteristics; combining the global value for cylinder fuel injection timing with each respective cylinder-specific offset fuel injection timing value to generate a separate cylinder-specific fuel injection timing control signal; and transmitting the cylinder-specific fuel injection timing control signals to a fuel injection mechanism for each respective cylinder. - View Dependent Claims (16, 17, 18, 19, 20, 21)
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22. A multi-cylinder, two-stroke internal combustion engine comprising:
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a plurality of engine cylinders each coextensive with a respective combustion chamber; a cylinder spark ignition system for each cylinder, each cylinder spark ignition system having a spark plug mounted to the engine so that a spark plug ignition electrode is exposed within the respective combustion chamber; an engine load sensor that monitors the engine load and generates an engine load signal in response thereto; an engine speed sensor that monitors an engine revolution rate and generates an engine speed signal in response thereto; and an electronic control unit that inputs the engine speed signal and the engine load signal and generates a cylinder-specific spark ignition timing control signal that is transmitted to each cylinder spark ignition system to control spark timing for the respective spark plug electrode, wherein the electronic control unit determines spark timing for each respective spark plug electrode based on cylinder-specific characteristics; and
whereinthe electronic control unit contains; a global spark ignition timing matrix from which a global value for cylinder spark timing is determined from the value of the engine load signal and the value of the engine speed signal; a plurality of pre-calibrated cylinder offset spark ignition timing matrices from which cylinder-specific offset values for adjusting spark timing from the global value are determined; and means for combining the global value with the cylinder-specific offset values to generate the cylinder-specific ignition timing control signals. - View Dependent Claims (23, 24, 25, 26, 27, 28, 29, 30)
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31. A multi-cylinder, two-stroke internal combustion engine comprising:
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a plurality of engine cylinders each coextensive with a respective combustion chamber; a cylinder spark ignition system for each cylinder, each cylinder spark ignition system having a spark plug mounted to the engine so that a spark plug ignition electrode is exposed within the respective combustion chamber and a dedicated ignition coil and electronic driver for each spark plug; an engine load sensor that monitors engine load and generates an engine load signal in response thereto; an engine rpm sensor that monitors an engine revolution rate and generates an engine rpm signal in response thereto; and an electronic control unit that inputs the rpm signal and the engine load signal and generates a cylinder-specific ignition coil dwell time control signal that is transmitted to the respective electronic driver to control ignition coil dwell time for the respective ignition coil, wherein the electronic control unit determines ignition coil dwell time for each respective ignition coil based on cylinder-specific characteristics; and
whereinthe electronic control unit contains; a global ignition coil dwell time matrix from which a global value for ignition coil dwell time is determined from the value of the engine load signal and the value of the engine speed signal; a plurality of pre-calibrated cylinder offset ignition coil dwell time matrices from which cylinder-specific offset values for adjusting ignition coil dwell times from the global value are determined; and means for combining the global value with the cylinder-specific offset values to generate cylinder-specific ignition coil dwell time control signals. - View Dependent Claims (32)
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Specification