MULTI-CYLINDER ENGINE
First Claim
1. A multi-cylinder engine capable of performing a selected cylinder operation in which combustion is stopped in some cylinders, the multi-cylinder engine comprising:
- an ignition-timing adjustment section configured such that, when the engine is in a second state in which the number of operating cylinders is smaller than that in a first state, the ignition-timing adjustment section retards ignition timing of each operating cylinder from that in the first state.
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Accused Products
Abstract
A multi-cylinder engine is configured to be able to perform a selected cylinder operation in which combustion is stopped in some cylinders. The multi-cylinder engine includes an ignition-timing adjustment section. This ignition-timing adjustment section retards ignition timing of each operating cylinder when the number of operating cylinders is small or when the engine operates in a selected cylinder operation mode in which explosion occurs at irregular intervals. In such a case, the peak of cylinder internal pressure is lowered by ignition timing retard. Thus, vibration and noise can be suppressed effectively.
54 Citations
24 Claims
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1. A multi-cylinder engine capable of performing a selected cylinder operation in which combustion is stopped in some cylinders, the multi-cylinder engine comprising:
an ignition-timing adjustment section configured such that, when the engine is in a second state in which the number of operating cylinders is smaller than that in a first state, the ignition-timing adjustment section retards ignition timing of each operating cylinder from that in the first state. - View Dependent Claims (2, 3, 4, 5)
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6. A multi-cylinder engine comprising a first-bank cylinder group including a first-bank first cylinder, a first-bank second cylinder, and a first-bank third cylinder which are arranged in a row along a cylinder arrangement direction to be in parallel with one another;
- and a second-bank cylinder group including a second-bank first cylinder, a second-bank second cylinder, and a second-bank third cylinder, which have center axes forming an angle greater than 0 degrees but not greater 180 degrees in relation to center axes of the first-bank first to third cylinders and are arranged in a row along the cylinder arrangement direction to be in parallel with one another,
the multi-cylinder engine being capable of switching its operation among a full-cylinder operation mode in which all the cylinders are operated;
a two-cylinder operation mode in which one cylinder of the first-bank cylinder group and one cylinder of the second-bank cylinder group are operated;
a three-cylinder operation mode in which three cylinders of the first-bank cylinder group or the second-bank cylinder group are operated; and
a four-cylinder operation mode in which one cylinder of the first-bank cylinder group and one cylinder of the second-bank cylinder group are stopped,wherein the multi-cylinder engine comprises an ignition-timing adjustment section which retards ignition timing of each operating cylinder in such a manner that the smaller the number of operating cylinders, the greater the amount by which the ignition timing of each operating cylinder is retarded. - View Dependent Claims (7, 8, 9, 10, 11, 12)
- and a second-bank cylinder group including a second-bank first cylinder, a second-bank second cylinder, and a second-bank third cylinder, which have center axes forming an angle greater than 0 degrees but not greater 180 degrees in relation to center axes of the first-bank first to third cylinders and are arranged in a row along the cylinder arrangement direction to be in parallel with one another,
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13. A multi-cylinder engine comprising a first-bank cylinder group including a first-bank first cylinder, a first-bank second cylinder, and a first-bank third cylinder which are arranged in a row along a cylinder arrangement direction to be in parallel with one another;
- and a second-bank cylinder group including a second-bank first cylinder, a second-bank second cylinder, and a second-bank third cylinder, which have center axes forming an angle greater than 0 degrees but not greater 180 degrees in relation to center axes of the first-bank first to third cylinders and are arranged in a row along the cylinder arrangement direction to be in parallel with one another,
the multi-cylinder engine being capable of switching its operation among a full-cylinder operation mode in which all the cylinders are operated;
a two-cylinder operation mode in which one cylinder of the first-bank cylinder group and one cylinder of the second-bank cylinder group are operated;
a three-cylinder operation mode in which three cylinders of the first-bank cylinder group or the second-bank cylinder group are operated; and
a four-cylinder operation mode in which one cylinder of the first-bank cylinder group and one cylinder of the second-bank cylinder group are stopped,wherein the multi-cylinder engine comprises an ignition-timing adjustment section which retards ignition timing of each operating cylinder in the four-cylinder operation mode from that in the full-cylinder operation mode. - View Dependent Claims (14, 15, 16, 17, 18, 19)
- and a second-bank cylinder group including a second-bank first cylinder, a second-bank second cylinder, and a second-bank third cylinder, which have center axes forming an angle greater than 0 degrees but not greater 180 degrees in relation to center axes of the first-bank first to third cylinders and are arranged in a row along the cylinder arrangement direction to be in parallel with one another,
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20. A multi-cylinder engine capable of performing a selected cylinder operation in which combustion is stopped in some cylinders, the multi-cylinder engine comprising:
an ignition-timing adjustment section which retards ignition timing of each operating cylinder when ignition intervals of a plurality of operating cylinders become irregular during the selected cylinder operation. - View Dependent Claims (21, 22, 23, 24)
Specification