Method and device for operating a multi-cylinder internal combustion engine
AssigneeSchaeffler Technologies AG & Co. KG
InventorsHartmut Faust, Thomas Winkler
Life of this patent
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Abstract
A method for operating a multi-cylinder internal combustion engine in which every active cylinder operates in a four-stroke mode and every deactivated cylinder filled with an approximately completed gas filling is compressed and expanded during the four-stroke operation of the activated cylinder. In a method in which excitations of a crankshaft speed are minimized, a limited number of even-numbered cylinders of a multi-cylinder internal combustion engine (2) having a maximum even number of cylinders (20, 21, 22, 23, 24, 25) are deactivated sequentially, the limited even number of cylinders being smaller than the maximum even number of cylinders (20, 21, 22, 23, 24, 25) of the multi-cylinder internal combustion engine (2).
Claims17
A method for operating a multi-cylinder internal combustion engine in which every active cylinder operates in a four-stroke mode and every deactivated cylinder filled with an approximately completed gas filling is compressed and expanded during the four-stroke mode of the activated cylinder, the method comprising, of the multi-cylinder internal combustion engine having a maximum even number of cylinders,
- operating the multi-cylinder internal combustion engine in a full-load mode with all of the cylinders activated, each of the cylinders having a respective power stroke timing during the full-load mode;
- deactivating sequentially a limited even number of cylinders, the limited even number of cylinders being smaller than the maximum even number of cylinders of the multi-cylinder internal combustion engine, each of the deactivated cylinders being operated to have dummy expansions that correspond to respective power stroke timing during the full-load mode,
- wherein the dummy expansions are performed when none of the activated cylinders is performing a power stroke.
A device for operating a multi-cylinder internal combustion engine which activates or deactivates cylinders of the multi-cylinder internal combustion engine, the multi-cylinder internal combustion engine being operable in a full-load mode with all of the cylinders activated, each of the cylinders having a respective power stroke timing during the full-load mode, the device comprising:
- a deactivator to sequentially deactivate a limited even number of cylinders of a maximum even number of cylinders of the multi-cylinder internal combustion engine, the limited even number of cylinders being smaller than the maximum even number of cylinders of the multi-cylinder internal combustion engine, the deactivator configured to operate the deactivated cylinders to have dummy expansions that correspond to a respective power stroke timing during the full-load mode,
- wherein the deactivated cylinders include a first deactivated cylinder and a second deactivated cylinder, the deactivator being configured such that the sequential deactivation of the limited even number of cylinders by the deactivator includes the deactivator operating the first deactivated cylinder and the second deactivated cylinder to perform a dummy expansion simultaneously.
A drivetrain of a motor vehicle, the drivetrain comprising:
- a multi-cylinder internal combustion engine connected to a control device operating the internal combustion engine in a full mode with all cylinders activated or in a cylinder deactivation mode with only a specified number of cylinders activated, each of the cylinders having a respective power stroke timing during the full mode, the cylinders being connected to a crankshaft, the control device configured to operate deactivated cylinders to have dummy expansions that correspond to a respective power stroke timing during the full-load mode;
- and
- a centrifugal pendulum positioned on the crankshaft to absorb an occurring excitation of a crankshaft rotation speed, the centrifugal pendulum having an oscillation frequency or order matched to the excitation of the crankshaft rotation speed by the cylinders,
- wherein the deactivated cylinders include a first deactivated cylinder, a second deactivated cylinder, a third deactivated cylinder and a fourth deactivated cylinder, the control device being configured such that a sequential deactivation of the limited even number of cylinders by a deactivator includes the deactivator operating the first deactivated cylinder and the third deactivated cylinder to perform a dummy expansion simultaneously and the deactivator operating the second deactivated cylinder and the fourth deactivated cylinder to perform a dummy expansion simultaneously.
Dependencies are inferred from the claim text.