METHOD AND SYSTEM FOR REDUCING UNBURNED FUEL AND OIL FROM EXHAUST MANIFOLDS
First Claim
1. A method for operating an internal combustion engine having an exhaust system and a plurality of cylinders that utilize fuel and/or oil for combustion and engine lubrication purposes, the method comprising:
- while the engine is operating in a low-load mode or an idle mode, successively operating distinct subsets of said cylinders at a cylinder load sufficient to increase an exhaust temperature for burning unburned fuel and/or oil deposited in the cylinders or engine exhaust system;
wherein each successively operated subset comprises at least one but fewer than all of the plurality of cylinders; and
wherein cylinders that are not currently being operated in a subset are operated in a low- or no-fuel mode.
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Accused Products
Abstract
Methods and systems are provided for operating an internal combustion engine having an exhaust system and a plurality of cylinders that utilize fuel and/or oil for combustion and engine lubrication purposes. In one example, a method comprises, while the engine is operating in a low-load mode or an idle mode, successively operating distinct subsets of said cylinders at a cylinder load sufficient to increase an exhaust temperature for burning unburned fuel and/or oil deposited in the cylinders or engine exhaust system. Herein, each successively operated subset comprises at least one but fewer than all of the plurality of cylinders, and the cylinders that are not currently being operated in a subset are operated in a low- or no-fuel mode.
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Citations
22 Claims
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1. A method for operating an internal combustion engine having an exhaust system and a plurality of cylinders that utilize fuel and/or oil for combustion and engine lubrication purposes, the method comprising:
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while the engine is operating in a low-load mode or an idle mode, successively operating distinct subsets of said cylinders at a cylinder load sufficient to increase an exhaust temperature for burning unburned fuel and/or oil deposited in the cylinders or engine exhaust system; wherein each successively operated subset comprises at least one but fewer than all of the plurality of cylinders; and wherein cylinders that are not currently being operated in a subset are operated in a low- or no-fuel mode. - View Dependent Claims (2, 3, 4, 5, 6)
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7. A method for operating an internal combustion engine with a plurality of cylinders, the cylinders operating in at least two modes, a first mode with a lower fuel injection amount, and a second mode with a higher fuel injection amount, the method comprising:
after a designated amount of low-load engine operation, and during low-load engine operation, operating at least one of the cylinders of the engine in the second mode while at least another cylinder operates in the first mode to increase exhaust temperature at least of the at least one cylinder in the second mode. - View Dependent Claims (8, 9, 10, 11, 12, 13, 14, 15, 16)
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17. A system for a vehicle comprising,
an internal combustion engine with a plurality of cylinders; -
a lubrication system coupled to the engine, the lubrication system configured to provide sufficient oil for high-load engine operation and to provide more than sufficient oil for low-load engine operation; a control system configured to adjust a cylinder operating mode among at least a first mode and a second mode, the first mode being a low cylinder load and the second mode being a high cylinder load, where, during engine idling, the control system is further configured to;
monitor a duration of idle time, and when the monitored idle duration reaches a threshold idle time, initiate a port heating operation including operating one engine cylinder in the second mode while remaining cylinders operate in the first mode, and successively operating different cylinders in the second mode of the port heating operation. - View Dependent Claims (18, 19, 20, 21, 22)
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Specification