Method for operating engine in intermittent combustion mode and engine control device
AssigneeToyota Jidosha Kabushiki Kaisha
InventorTomohiro Nakano
Life of this patent
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Abstract
An intermittent combustion mode is executed while cyclically switching an intermittent firing pattern in such a manner that the skipped-cylinder interval is changed by one cylinder at a time. Furthermore, the intermittent firing pattern is switched in such a manner that the fired cylinder ratio in one cycle of switching of the intermittent firing pattern becomes equal to a target fired cylinder ratio. This suppresses the occurrence of vibration and noise having low frequencies that tend to disturb the occupant while limiting an increase in the rotational fluctuation of the engine.
Claims16
A method for operating an engine in an intermittent combustion mode in such a manner that a fired cylinder ratio of an engine becomes equal to a target fired cylinder ratio set based on an operating state of the engine by repeating an intermittent firing pattern in which n cylinders are successively fired, and then m cylinders are successively skipped, where n and m are variables of natural numbers, the method comprising:
- switching the intermittent firing pattern in such a manner that
- one of n and m is set to a value equal to the value before switching the intermittent firing pattern,
- the other one of n and m is changed by only 1 from the value before switching the intermittent firing pattern,
- the switching of the intermittent firing pattern is performed cyclically so that, each time the switching of the intermittent firing pattern is performed a predetermined number of times, the intermittent firing pattern that is the same as the previous intermittent firing pattern appears, and
- the fired cylinder ratio in one cycle of switching of the intermittent firing pattern becomes equal to the target fired cylinder ratio.
An engine control device, comprising:
- a target fired-cylinder-ratio setting section, which sets a target fired cylinder ratio based on an operating state of an engine;
- and
- an intermittent combustion command section, which outputs a command signal that commands whether to fire or skip cylinders that are entering a combustion stroke, wherein the intermittent combustion command section outputs the command signal by repeating an output pattern in which the combustion command section commands to successively fire n cylinders and then commands to successively skip firing in m cylinders, where n and m are variables of natural numbers,
- wherein the intermittent combustion command section switches the intermittent firing pattern in such a manner that
- one of n and m is set to a value equal to the value before switching the intermittent firing pattern,
- the other one of n and m is changed by only 1 from the value before switching the intermittent firing pattern,
- the switching of the output pattern is performed cyclically so that, each time the switching of the output pattern is performed a predetermined number of times, the output pattern that is the same as the previous output pattern appears, and
- a fired cylinder ratio in one cycle of switching of the output pattern becomes equal to the target fired cylinder ratio.
Dependencies are inferred from the claim text.