Valve-actuating device for varying the valve lift
AssigneeAVL List GmbH
InventorsGyula TOTH, Michael GROEGER
Life of this patent
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Abstract
The invention relates to a valve-actuating device (1) for actuating at least one first valve of a reciprocating piston machine, in particular an internal combustion engine, which valve-actuating device can be used in particular for engine braking and comprises a first rocker arm part (2), a second rocker arm part (3), and a first switching element (6) for changing the valve stroke (H) of the at least one first valve (5), wherein the first rocker arm part (2) and the second rocker arm part (3) are pivotably supported and are arranged in such a way that at least one first valve control motion of a first camshaft (4) can be transmitted to the at least one first valve (5) by means of the first rocker arm part (2) and the second rocker arm part (3).
Claims84
A valve-actuating device for actuating at least one first valve of a reciprocating piston engine, particularly an internal combustion engine, wherein the valve-actuating device is particularly suitable for engine braking, comprising:
- a first rocker arm part,
- a second rocker arm part, and
- a first switching element for varying the valve lift (H) of the at least one first valve, wherein the first rocker arm part and the second rocker arm part are pivotably mounted and arranged such that at least one first valve control motion is transmittable from a first camshaft via the first rocker arm part and the second rocker arm part to the at least one first valve.
A valve-actuating device for actuating at least one of two first valves of a reciprocating piston engine, particularly an internal combustion engine, wherein the valve-actuating device is particularly suitable for engine braking, comprising:
- a pivotable first rocker arm part,
- a pivotable second rocker arm part,
- a valve bridge arranged between the at least two first valves, and
- a second switching element for varying a valve lift (H) of the at least one of the two first valves, its effective direction being substantially parallel to the direction of the valve lift (H) motion,
- wherein the second rocker arm part and the valve bridge are arranged such that at least one first valve control motion can be transmitted from a first camshaft to the at least one of the two first valves,
- wherein the second rocker arm part comprises a first stop and a second stop and the first stop engages the valve bridge substantially above the one of the at least two first valves and the second stop engages the valve bridge substantially centrically and is actuatable by the second switching element.
A valve control method, particularly of an internal combustion engine, during different operating modes, particularly an engine operation and a engine braking mode, for selectively providing valve actuation using motion able to be transmitted from at least one camshaft to at least one valve by means of a valve-actuating device, wherein the valve-actuating device comprises a first rocker arm part, a second rocker arm part and a third switching element, the method comprising the following steps:
- tapping a first motion on the camshaft by the first rocker arm part;
- providing a control pulse, particularly by means of control fluid;
- selectively feeding the control pulse to the first switching element, particularly a first cylinder, to control the valve lift (H), wherein the position of the first switching element, particularly a first piston, depends on the magnitude and/or length of the control pulse, particularly the pressure and duration of the control fluid feed;
- transmitting the first motion to at least one first valve via the second rocker arm part as a function of the position of the first switching element.
A valve actuation method, particularly for decompression braking by a reciprocating piston engine or an internal combustion engine, comprising the following steps in the decompression braking mode:
- firstly opening at least one first valve of the reciprocating piston engine in a first phase at an approximate 660° KW to 30° KW, preferentially an approximate 680° KW to 10° KW, and particularly preferentially an approximate 690° KW to 0° KW, and/or at a valve lift (H) of approximately 50% to 100%, preferentially approximately 60% to 90%, particularly preferentially approximately 70% to 80%, and most preferentially approximately 75% of the maximum valve lift (H);
- and
- secondly opening the at least one first valve of the reciprocating piston engine in a second phase at an approximate 300° KW to 360° KW, preferentially an approximate 320° KW to 340° KW, and particularly preferentially an approximate 330° KW, and/or at a valve lift (H) of approximately 5% to 25%, preferentially approximately 10% to 20%, and particularly preferentially approximately 15% of the maximum valve lift (H).
Dependencies are inferred from the claim text.