Method of controlling knocking in an internal combustion engine equipped with a device for controlling the opening of inlet valves
AssigneeMagneti Marelli S.p.A.
InventorsNicola Garagnani, Fabio Sensi, Filippo Cavanna, Stefano Sgatti
Life of this patent
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Abstract
A method of controlling knocking in an internal combustion engine equipped with a device for controlling the opening of inlet valves; the control method includes the phases of: determining the occurrence of an excessive knocking in the cylinder of the internal combustion engine; and decreasing the mass of air sucked into the cylinder in which an excessive knocking has occurred by acting on the control device controlling the inlet valves of the cylinder.
Claims13
A method of controlling knocking in an internal-combustion engine (1) equipped with a plurality of cylinders (2), a plurality of inlet valves (6) of the cylinders (2), and a device (11) to control opening of the inlet valves (6), wherein the method comprises steps of:
- calculating, for each combustion of each of the cylinders (2), a knocking index (IKN) representing a level of knocking of the combustion;
- comparing the knocking index (IKN) with a first threshold value (S1) that indicates a maximum acceptable knocking;
- determining presence of knocking in the cylinders (2) when the knocking index (IKN) exceeds the first threshold value (S1);
- comparing the knocking index (IKN) with a second threshold value (S2) that indicates presence of “megaknock” events;
- determining the presence of the “megaknock” events in the cylinders (2) when the knocking index (IKN) exceeds the second threshold value (S2);
- reducing a mass of air sucked into the cylinder (2) in which the knocking occurs by acting on the device (11) for the control of the opening of valves that controls the inlet valves (6) while reducing an ignition advance in the cylinder (2) in which the knocking occurs;
- and
- making, in the cylinder (2) in which the “megaknock” occurs, a decrease in an amount of the air sucked by acting on the device (11) for the control of the opening of the valves that controls the inlet valves (6) without carrying out any work on the ignition advance.
Dependencies are inferred from the claim text.