Control cam for a valve-controlled internal combustion engine
AssigneeBayerische Motoren Werke Aktiengesellschaft
InventorsClaus-Otto Griebel, Juergen Thams
Life of this patent
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Abstract
For a peripheral cam for a valve-controlled internal-combustion engine, having a cam contour which generates at least one positive acceleration course in the valve opening area, the gas dynamics, are advantageously influenced in that the peripheral cam has an opening flank with a contour causing a delayed opening acceleration course. The opening acceleration course is generated with acceleration curves with relatively high acceleration peak values of different amounts spaced by way of an intermediate curve of relatively low positive acceleration values. A first acceleration curve has a peak value of approximately 40 to 60% of a peak value of an adjacent acceleration curve set at 100%.
Claims12
Peripheral cam for a valve-controlled internal-combustion engine, comprising
- an opening flank with a cam contour configured to generate at least one positive acceleration course in a valve opening area, with an opening acceleration course having first and second acceleration curves with acceleration peak values of different amounts spaced by way of an intermediate curve of positive acceleration lower than the first and second acceleration curves,
- wherein
- the first acceleration curve has a peak value of approximately 40 to 60% of a peak value of the adjacent second acceleration curve set at 100%,
- an ascending curve section of the first acceleration curve and a descending curve section of the second acceleration curve each respectively intersecting with a zero acceleration line, and
- a distance between respective connection points of the descending curve section of the first acceleration curve and of the ascending curve section of the second acceleration curve with the intermediate curve corresponding to an amount of about 10 to 15% of the distance between the intersections at the zero acceleration line of the first and second acceleration curves.
Method of using a peripheral cam, comprising
- an opening flank of the peripheral cam having a cam contour configured to generate at least one positive acceleration course in a valve opening area, with an opening acceleration course having first and second acceleration curves with acceleration peak values of different amounts spaced by way of an intermediate curve of positive acceleration lower than the first and second acceleration curve
- wherein
- the first acceleration curve has a peak value of approximately 40 to 60% of a peak value of the adjacent second acceleration curve set at 100%,
- an ascending curve section of the first acceleration curve and a descending curve section of the second acceleration curve each respectively intersecting with a zero acceleration line, and
- a distance between respective connection points of the descending curve section of the first acceleration curve and of the ascending curve section of the second acceleration curve with the intermediate curve corresponding to an amount of about 10 to 15% of the distance between the intersections of the first and second acceleration curves at the zero acceleration line,
- comprising the step of using the peripheral cam as a cam for actuating one of an inlet valve and an outlet valve.
Dependencies are inferred from the claim text.