Variable valve operating mechanism for an internal combustion engine
AssigneeBayerische Motoren Werke Aktiengesellschaft
InventorsMichael Bidlingmaier, Gert Fischer, Stefan Foester
Life of this patent
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Abstract
For a variable valve operating mechanism for an internal-combustion engine having variable valve lifts, which can be achieved at constant opening angles, variable valve opening angles are achieved in the case of particularly small valve lifts. To do so, the rocker axis of a valve lever, which is essentially parallel to the axis of rotation of the camshaft, can be dynamically displaced relative to a camshaft along a path in a controlled manner such that, when the rocker axis is displaced, the valve lever is activated for the valve operation by way of a roller which is controlled only approximately from the starting area to the end area of a cam tip of a radial cam on the camshaft.
Claims20
Variable valve operating mechanism for an internal-combustion engine, comprising:
- a lifting valve operated by a radial cam of a camshaft via a valve actuating lever, said valve actuating lever interacting with the radial cam by way of a cam plate arranged in an end area away from the valve and by way of a roller which is displaceable in a controlled manner;
- wherein the roller, which is discontinuously displaceable transversely to a camshaft axis of rotation against, and in, a rotating direction of the radial cam, is used for changing opening and closing points in time of the lifting valve for constant opening angles in combination with variable valve lifts because of a change of roller-caused valve actuating lever transmission ratios;
- and
- wherein a rocker axis of the valve actuating lever which is substantially parallel to the camshaft axis of rotation, is dynamically displaceable relative to the camshaft along a path in a controlled manner such that, when the rocker axis is displaced along the path extending transversely to a straight line connecting a center of the roller and a valve lever support on a shaft end of the lifting valve, the valve actuating lever is activated for the valve operation by way of the roller which is controlled only approximately from a starting area to an end area of a cam tip of the radial cam.
Dependencies are inferred from the claim text.