EP1608851B1 - Device for the variable actuation of the gas exchange valves of internal combustion engines, and method for operating one such device - Google Patents

Abstract

The invention relates to a device for the variable actuation of gas exchange valves for internal combustion engines, wherein at least one cam ( 2 ) pertaining to a camshaft ( 1 ) mounted in a housing rotates according to the engine speed. The cam ( 2 ) first drives an intermediate member ( 4 ) which performs a clear oscillating, rotary movement and has a rotational axis ( 7 ) that can be displaced in the housing parallel to itself along a curve of displacement ( 8 ), said intermediate member comprising a control cam ( 5 ) having a lifting region ( 5 b) and actuating an output member ( 11 ) that, in turn, actuates at least one valve ( 13 ). The aim of the invention is to enable one such device to be reliably controlled. To this end, the control cam ( 5 ) has a catch region ( 5 a), and the intermediate member ( 4 ) is mounted on a bearing having an axis which corresponds to the rotational axis ( 7 ), said bearing being arranged in such a way that it is guided in a forced manner and can be displaced parallel to the curve of displacement ( 8, 28, 35 ), by means of an articulation ( 16, 24, 26 ) connected to the cylinder head or the housing or by a slide ( 34 ) that is guided in the housing in a positively locking manner. The invention also relates to a method for operating an internal combustion engine comprising a plurality of cylinders using at least one of the inventive devices.

Description

The invention relates to a device for the variable actuation of the gas exchange valves of internal combustion engines according to the preamble of claim 1.

Such devices serve to make the control of gas exchange valves so that it is possible to operate reciprocating engines without the usual throttle.

Such a device is for example from the DE 101 23 186 A1 known. In this device, a rotating cam first drives an intermediate member, which performs an oscillating, pure rotary motion and carries a control cam, which is composed of a latching area and a stroke area. The control cam transmits the necessary for actuation of the valve lift curve on the role of a drag lever-like output member, which in turn actuates the valve. The desired different Ventilhubkurven be generated by the fact that the center of rotation of the intermediate member is displaced on a circular arc-shaped path which is concentric with the role of the driven member in its position with the valve closed. The center of rotation is formed by a roller provided on the intermediate member, which is non-positively supported on a circular arc-shaped track in the housing, which is also concentric with the role of the output member, ie forms an equidistant to the orbit of the center of rotation and which is referred to as a backdrop. In addition, the roller mounted on the intermediate member is supported on a cam whose angular position determines the position of the center of rotation on its arcuate path. The device according to the prior art, however, still adhere to some disadvantages.

First, the mounted on the intermediate member role in the scenery only if the gas and inertial forces of the valve train are directed accordingly and the role actually supported on the backdrop. If this is not the case, which can happen at overspeed, for example, the traction is lost and there is a lifting, which can lead to noises and even damage when re-putting on. In addition, there is the relatively difficult processing of the scenes as segments of an inner cylinder, which can not be processed consistently and the insufficient hardness of common housing materials for the role-backdrop contact. With regard to the assembly, there is a disadvantage in that the control housing can not be completely pre-mounted on the cylinder head.

There are other devices of the generic type become known, in which the center of rotation of the intermediate elements driven by the cam is to be adjusted on a circular path ( OS 195 32 334 A1 ; EP 0717 174 A1 ; DE 101 64 493 A1 ). However, the prior publications contain no teaching for constructive realization of such an adjustment.

All known devices have the common drawback that, due to tolerances, the valve strokes for the individual cylinders are becoming relatively more variable, the farther they are reduced for the purpose of load control.

From the EP 1 255 027 A1 is a mechanically controllable Ventilhubverstelleinrichtung known for an internal combustion engine. This known Ventilhubverstelleinrichtung has a means in the form of a driven bar, which is slidably mounted in the housing of the internal combustion engine. With this slidably mounted, driven bar a lifting lever is moved along a slotted guide and thereby the valve lift is adjusted.

In the DE 101 23 186 A1 is a valve drive device for variable stroke adjustment of a gas exchange valve of an internal combustion engine disclosed. In this device, the pivot lever for adjusting the valve lift is adjusted by a cam of an adjusting device along a circular slide track. Likewise is from the DE 101 36 612 A1 a device for controlling the valve lift in internal combustion engines known. To adjust the valve lift here an angle lever is adjusted via a formed on the angle lever circular toothing, which is in engagement with a likewise having a toothing control shaft. This solution is due to the working with gear adjustment manufacturing costly.

Finally, out of the US 3,261,338 a device for changing the valve lift in internal combustion engines, in which a rectangular frame designed as a four-bar linkage is used as adjusting mechanism. An adjustment of the bearing axis 14 of the adjusting element 13 on a circular arc or nearly circular arc-shaped Verstellkurve can not be achieved with this known rectangular four-bar linkage.

The object underlying the present invention is to develop a device for variable actuation of gas exchange valves for internal combustion engines according to the preamble of claim 1 such that a safe adjustment takes place along a Verstellkurve that comes close to a circular arc shape.

This object is achieved with the features of claim 1. Advantageous embodiments and further developments are described in claims 2 to 15 and 19. A method for operating a multi-cylinder internal combustion engine using one or more devices according to the invention is set forth in claims 16 to 18.

The centers of rotation of the intermediate links driven by the cam are guided according to the invention by positive guides, thus in a form-locking manner on the adjustment cam. This ensures that the center of rotation of an intermediate link can not leave the Verstellkurve, so noises and damage that would be due to a leaving avoided. This feature is preferably realized structurally in that one or more intermediate links are mounted on a cylindrical bolt, on whose axis the centers of rotation lie, and that the axis of the bolt is guided on the Verstellkurve inevitably. If the active surface on the output member, to which the control cam of the intermediate member transmits its movement, is circular cylindrical, thus e.g. is formed by a roller, is assumed to be a circular arc-shaped Verstellkurve whose center coincides with the center of the circular cylindrical active surface or the roller.

Such a Verstellkurve is realized by a presently not claimed proposal by pendulum supports, which are connected via their respective first joint with the cylinder head and the control housing and with their respective second joint with the bolt. In this case, the axis common to the cylinder head side axis coincides with the axis of said, cylindrical active surfaces on the output member, the bolt-side joints with the Pin axis. In this way, it is achieved that the power flow extends exclusively over two-dimensional contact points on the shortest path from the bolt to the cylinder head and the control housing. In particular, no forces are transmitted via Hertzian pressure on the cylinder head or control housing.

According to the claimed solution according to the invention, the bolt or its axis according to the invention will also be forcibly guided on the adjustment curve with four-bar linkages formed from pendulum supports. The adjustment curve that can be realized in this way comes close to the circular arc shape and fulfills it exactly at the design point when the system lines meet at the center of the circular arc. The deviations outside the design point are absorbed by hydraulic lash adjusters, which are to be provided on the drag lever-like or even straight driven members. The claimed solution has the advantage that it can be used if between the output members of adjacent valves, be it designed like a drag lever or straight, not enough space for the above-mentioned, unclaimed solution is available.

According to a third, not claimed embodiment of the device, the leadership of the bolt is provided by a linearly adjustable in the control housing slide. With this embodiment, further, special space requirements can be met. There are relatively large contact surfaces between slide and control housing to realize so that the strength properties of the housing material sufficient in any case. The adjustment curve is a straight line whose deviations from the circular arc shape are also absorbed by the clearance compensation elements.

In all three embodiments, the position of the bolt or its axis on the respective Verstellkurve is preferably determined by the direct or indirect contact with one or more cams, which are rotatably mounted on one or more adjustment shafts. In a further embodiment, the cams are mounted on an axially displaceable adjustment axis. The adjustment or the adjustment can in turn be rotated or displaced by a suitable gear or a connecting element of an adjusting means, such as an adjusting motor. Of course, the adjustment can also be done by hydraulic elements. In the case of the leadership of the bolt by a linearly adjustable slide, the adjustment of the adjusting motor can also be done directly via a spindle provided with movement thread.

Furthermore, all embodiments have in common that the intermediate links or their cam rollers must be held by special springs with the cam in contact. This is immediately apparent from the zero stroke situation that occurs with cylinder deactivation.

A particularly advantageous in terms of space and variety of parts variant of the three embodiments is to simultaneously form the bolt on which the intermediate members are mounted as adjusting by provided with cams, rotatably mounted in the pendulum supports, the four-bar linkage or the slide and an adjusting means , For example, an adjusting motor, according to the desired Ventilhubkurve is rotated. In this variant, sliders must be provided for the cams made of a material of increased strength in the control housing. Since the adjusting motor will usually be arranged fixed to the housing, but the bolt or the control shaft but displaced parallel to itself during the adjustment, must be arranged between the two a connecting element, which allows this shift. This can be a PTO shaft, a Schmidt clutch, an Oldham clutch or even a gear or chain transmission depending on space requirements. With hydraulic actuation also offers a lever mechanism.

The device according to the invention can be provided separately for each valve of an engine, including an adjusting motor or an adjusting device, so that any desired combinations of valve lifts or opening angles the individual valves of an engine are possible, including the shutdown of individual cylinders. In general, however, you will provide a common adjustment of several valves. This applies in particular to multi-valve engines for the intake and exhaust valves of a cylinder. For example, two intake valves can be actuated by a cam via an intermediate member, which has a control cam for each valve. Since only one link and only one bolt is present, both valves are adjusted together and similar. According to the invention, however, two different cams can be provided on the common intermediate member with the result of different lifting curves on both valves despite common adjustment. This variant opens up the possibility of opening only one of the two valves, especially in the lowest load range. The particular advantage of this option is that very small cross-sections have to be released in the lowest load range and can be adhered to more precisely if they are only released by a valve. In addition, it is possible to generate a twist of the cylinder charge through the opening of only one of the intake valves. The possibilities of generating different valve lift curves for two intake or exhaust valves of a cylinder are inventively extended by the fact that two different cams and two intermediate links are used with different cams. Nevertheless, both valves can be adjusted together, since the two intermediate links can be mounted on a common bolt.

It is also possible to adjust the intermediate links of a larger number of parallel valves together by an adjusting motor or mechanism, in particular when they are mounted on a common bolt.

Since it is for the acceptance of a variable valve timing, including the device according to the invention is of great importance to keep the adjustment low and because it is higher in the loaded state of the device or their joints and joints than in the power-free state at closed valve is largely present, an adjustment is provided according to the invention essentially during the common rest periods of all valves to be adjusted together. These are derived from the signal of the crankshaft and the camshaft and are getting shorter, the more valves are adjusted together. Their number is therefore limited.

The common adjustment of the inlet and outlet valves of only one cylinder give long, easy adjustment rest periods. But it also allows an individual load control of the individual cylinders with an adjustment strategy according to the invention such that the torques of the individual cylinders are controlled for each load condition of the entire engine. This is essential, especially in the lower load range, for smooth engine operation, since the valve lifts normally do not match sufficiently due to tolerances. The signals required for this adjustment strategy are also supplied by the rotary encoder of the crankshaft and assigned to the individual cylinders by the rotary encoder of the camshaft.

The largely independent adjustment of the inlet and outlet valves offers the possibility to switch off selected valves by means of a continuous adjusting shaft, that is to say no longer open or at least to set a smaller valve lift. For this purpose, portions of the cams described the adjusting shaft are formed in the non-shutdown valves as a catch. The latching area is a contour, which is formed from a concentric to the center of rotation of the adjusting circular arc. Upon rotation of the adjusting the valve lift of the cams with locking controlled units within the range of action of the detent is not changed, while the valve lift of the cams controlled without rest units is changed. This change can be carried out until the valve is completely closed. If all intake valves and / or exhaust valves of the same cylinder are activated in this way, the charge cycle for selected cylinders is suspended. Of course it will achieved by using a straight guided wedge with corresponding cam contour, the same function. The latching area is then a contour which is formed from a direction parallel to the sliding direction of the drawing wedge.

The inventive solution was advantageous found an exact, low-wear adjustment for gas exchange valves, which also works with great accuracy.

Fig. 1

die in den Kraftfluss von der Nockenwelle zum Ventil eingeschalteten, beweglichen Teile einer nicht beanspruchten Vorrichtung

Fig. 2

einen Querschnitt unter Verwendung der in Fig.1 dargestellten Teile mit Pendelstütze und Verstellwelle

Fig. 3

eine perspektivische Darstellung der nicht beanspruchten Vorrichtung nach Fig. 2 mit Pendelstütze und dem Bolzen als Verstellwelle

Fig. 4

einen Querschnitt durch die erfindungsgemäße Vorrichtung mit Gelenkviereck und Verstellwelle

Fig. 5

eine perspektivische Darstellung der erfindungsgemäßen Vorrichtung nach Fig. 4

Fig. 6

einen Querschnitt durch eine nicht beanspruchte Vorrichtung mit Schieber, Verstellwelle und Verstellmotor

Fig. 7

schematisch das Zusammenwirken von Motormanagement, Gaspedal, Drehwinkelgeber, Verstellmotoren und Batterie.

The invention will be explained in more detail with reference to drawings. It shows

Fig. 1

the switched in the power flow from the camshaft to the valve, moving parts of an unclaimed device

Fig. 2

a cross section using the in Fig.1 Parts shown with pendulum support and adjusting shaft

Fig. 3

a perspective view of the unclaimed device according to Fig. 2 with pendulum support and the bolt as adjusting shaft

Fig. 4

a cross section through the device according to the invention with four-bar linkage and adjusting shaft

Fig. 5

a perspective view of the device according to the invention Fig. 4

Fig. 6

a cross section through an unclaimed device with slide, adjusting and adjusting motor

Fig. 7

schematically the interaction of engine management, accelerator pedal, rotary encoder, adjusting motors and battery.

Fig. 1 shows a camshaft 1, which carries a cam 2. This moves the roller 3 in the end region of the intermediate member 4. The intermediate member 4 has a control cam 5, which is composed of a latching region 5a and a lifting portion 5b. The intermediate member 4 is mounted on a pin 6, the axis 7 is guided on a circular arc-shaped Verstellkurve 8. The center of the arcuate Verstellkurve 8 lies on the axis 9 of the roller 10 of the output member 11, which is supported via a hinge 12 in the housing, not shown, and the valve 13 is actuated. It is clear that an adjustment of the axis 7 on the Verstellkurve 8 in the direction of arrow 14 has a reduction of the opening angle and stroke of the valve 13 result.

Fig. 2 shows an unclaimed solution in which the bolt 6 and its axis 7 is guided by a pendulum support 15 positively on the circular arc-shaped Verstellkurve 8. The cylinder-head-side joint 16 of the pendulum support 15 or its axis coincides with the axis 9 of the roller 10 of the output member 11 together. The adjusting shaft 17 carries cams 18 which determine the position of the bolt 6 and its axis 7 on the Verstellkurve 8 via plunger 18 a. An adjustment of the axis 7 on the Verstellkurve 8, as shown by the directional arrow 14, is caused by a rotation of the cam 18 and the adjusting shaft 17 corresponding to the direction arrow 14a. The adjusting movement described has a reduction of stroke and opening angle of the valve 13 result.

Fig. 3 shows a perspective view of the unclaimed solution similar Fig. 2 with pendulum support 15 for intake valve 19 and exhaust valve 20 of a cylinder, picked out from a number of cylinders or valves. Good to see is the cylinder head side hinge 16 of the pendulum support 15, whose axis coincides with the axis 9 of the rollers 10 of the output members 11, so that the pin 6 is forcibly guided on a circular arc-shaped adjustment curve. Unlike the embodiment according to Fig. 2 takes over here Bolt 6 at the same time the function of the adjusting shaft. He wears the cams 18, which are supported on mounted in the housing, hardened sliders 21 and is rotatable in the pendulum support. About a suitable connecting element of the bolt 6 is connected to the housing-fixed adjusting motor 23. In the present example, a propeller shaft 22 serves as a connecting element. This embodiment offers considerable advantages in terms of variety of parts, but also space in the area of the actual valve control. As well as drive shafts, other connecting elements, such as Schmitt couplings, Oldham couplings, toothed and chain drive come into question, a certain flexibility for the accommodation of the adjusting motor 23 is given.

Fig. 4 shows an embodiment of the invention for a valve or cylinder arrangement as in Fig. 3 in cross section. Here, the pin 6 is positively guided by four-bar linkages (24, 25, 26, 27) on a Verstellkurve 28, which comes close to a circular arc shape. Meet the system lines 29 and 30 on the axis 9 of the roller 10 of the output member 11, the instantaneous pole of the bolt is even there. The deviations in the remaining area must be absorbed by the clearance compensation element 31. Again, the bolt 6 could take over the function of an adjusting, as in Fig. 3 shown. But it can also, as shown, a separate adjusting 17 are used with cams 18. The embodiment shown is particularly suitable for pre-assembly of valves including springs, levers and clearance compensation elements in the cylinder head as a lower housing part and a complete pre-assembly of all other parts in the control housing as the upper part. In this regard, it is advantageous that the bearing blocks 32 for the joints 24 and 26 can be screwed in the same plane as the cover 33 of the camshaft bearing.

Fig. 5 shows a perspective view of the device according to the invention Fig. 4 , It can be better seen inlet valve 19 and exhaust valve 20 of the cylinder picked out, as well as the direct actuation of the bolt 6 by the cams 18. It can be clearly seen that not only the bolt 6 and the camshaft 1 in the upper housing part, the control housing can be pre-assembled, but also the adjusting shaft 17th

Fig. 6 shows a cross section through an unclaimed solution using a slide 34, which can be used separately for each valve or valve pair. Due to the separate application, the longest possible resting periods or common resting phases result, so that an adjustment is easily possible only during the rest periods. For the control of the individual cylinders, the separate arrangement is even necessary. The bolt 6 is guided in this embodiment by the slide 34 positively in the housing, so that its axis 7 along the Verstellkurve 35, a straight line, is performed. This straight line approximates a circular arc about the axis 9 of the roller 10 of the stationary output member 11 only more or less well. In the Fig. 6 the deviation is exaggerated. Turns now driven by the adjusting motor 23 threaded spindle 36 and moves the rack 37 by the amount shown by the arrow 38a, the adjusting shaft 17 and the cam 18 rotates according to the arrow 38b and slide 34 together with bolt 6 in the direction 38c. Due to the deviation of the line 35 from the circular arc shape, the clearance compensation element 31 must sink by a certain amount, which is represented by the arrow 38 d.

Fig. 7 schematically shows the interaction of accelerator pedal 40, adjusting motors 23, rotation angle sensor 42 on the flywheel and rotation angle sensor 43 on the camshaft with the engine management 44. A signal from the accelerator pedal 40 and a sensor for its position signal from the engine management 44 in a signal to the adjustment 23rd converted to increase or decrease the valve lifts. After reaching the desired load condition for the entire engine, the engine management system 44 evaluates the signals of the high-resolution rotation angle sensor 42 on the flywheel. These will with the help of the low-resolution rotation angle sensor 43 on the camshaft or at another, running at half crankshaft speed shaft, the individual cylinders. With this information, signals are sent to the individual servomotors 23 for leveling the torque peaks or the crankshaft speed, in which the valve strokes of the cylinders are corrected upwards with smaller torques and those of the cylinders with larger torques downwards. According to the invention, an adjustment takes place, with or without compensation, during the common rest phases of the valves operated by an adjusting motor. Its phase position takes the engine management 44 the sensor 43 on the camshaft by the way.

LIST OF REFERENCE NUMBERS

1

camshaft

2

cam

3

role

4

intermediary

5

cam

5a

Rest area

5b

Stroke range

6

bolt

7

axis

8th

adjustment curve

9

axis

10

role

11

driven member

12

joint

13

Valve

14

arrow

14a

arrow

15

Stabilizer

16

joint

17

adjusting

18

cam

18a

tappet

19

intake valve

20

outlet valve

21

slide

22

propeller shaft

23

adjusting

24

bar linkage

25

bar linkage

26

bar linkage

27

bar linkage

28

adjustment curve

29

system line

30

system line

31

Lash adjuster

32

bearing block

33

cover

34

pusher

35

adjustment curve

36

screw

37

rack

38a

arrow

38b

arrow

38c

direction

38d

arrow

40

accelerator

42

Rotation angle sensor

43

Rotation angle sensor

44

engine management

Claims (19)

1. Device for the variable actuation of gas exchange valves for internal combustion engines, including the following features:

   a) one or several cams (2) of a camshaft (1) mounted in a housing rotates/rotate in dependence upon the engine rotational speed,

   b) the cam (2) drives a connecting link (4) which is mounted on a bolt (6) having an axis (7) and performs an oscillating, purely rotational movement about the axis (7),

   c) the bolt (6) of the connecting link (4) is forcibly guided in the housing and can be displaced in parallel with itself along an adjustment curve (28),

   d) the connecting link (4) comprises a radial cam (5) with a stop region (5a) and a lift region (5b) and actuates, via this radial cam (5), a driven member (11) which for its part actuates at least one valve (13),

   characterised in that
   an articulation square is provided for the purpose of the forced guidance of the bolt (6), which square is connected to the cylinder head or to the housing and comprises first (24, 26) and second (25, 27) articulation points and in which the two first articulation points (24, 26) are disposed in a stationary manner at a first spaced disposition with respect to each other and each of the two second articulation points (25, 27) is disposed so as to be able to pivot about one of the first articulation points (24, 26), wherein the spaced disposition between the second articulation points (25, 27) is smaller than the first spaced disposition between the two first articulation points (24, 26) so that the bolt (6) is guided on an approximately circular arc-like adjustment curve (28).
2. Device as claimed in Claim 1, characterised in that a hydraulic clearance-compensation element (31) is disposed on the driven member (11).
3. Device as claimed in Claim 1 or 2, characterised in that the position of the bolt (6) or its axis (7) is directly or indirectly adjusted on the adjustment curve (8, 28, 35) by means of at least one cam disc (18) or a cam, and the bolt (6) or its axis (7) is supported in relation to the adjustment curve (8, 28, 35) substantially in the tangential direction with respect to the housing.
4. Device as claimed in Claim 1 or 2, characterised in that a hydraulic unit directly or indirectly provides the bolt (6) or its axis (7) with the position on the adjustment curve (8, 28, 35) which is required in each case and supports it in relation to the adjustment curve (8, 28, 35) in the tangential direction with respect to the housing.
5. Device as claimed in Claim 3, characterised in that the cam discs (18) to be rotated are disposed on an adjusting shaft (17) which is adjusted via an adjusting motor (23) and, if necessary, a gear system.
6. Internal combustion engine including several devices as claimed in any one or several of Claims 1 to 5, wherein one of the devices is separately allocated to each engine valve.
7. Internal combustion engine including at least one device as claimed in any one or several of Claims 1 to 5, wherein one device is separately allocated to every two adjacent, parallel valves of a cylinder.
8. Device as claimed in Claim 7, characterised by a common connecting link (4) having two different radial cams for the two valves.
9. Device as claimed in Claim 7, characterised by two different cams (2) and two connecting links (4) having different radial cams for the two valves.
10. Device as claimed in any one or several of Claims 1 to 9, characterised in that the gear system members are designed such that there is at least one adjustment position for the displaceable connecting link (4), in which position at least one valve (13) remains closed during rotation of the cam (2).
11. Device as claimed in any one or several of Claims 1 to 10, characterised by the common, combined actuation of the valves of several cylinders and a common, through-going bolt (6) for all the connecting links (4) of these valves.
12. Device as claimed in any one or several of Claims 3 to 11, characterised in that the bolt (6) is freely rotatable on the side of its guide, in that it supports one or several of the cam discs (18) in a rotationally-fixed manner, and in that it can be rotated by an adjusting motor (23) via a suitable connecting element and the cam discs (18) are supported with respect to the housing.
13. Device as claimed in Claim 12, characterised in that the cam discs (18) are supported on sliding blocks (21) which are provided in the housing and consist of a material having an increased hardness.
14. Internal combustion engine including several devices as claimed in any one or several of Claims 1 to 5 or 8 to 13, characterised by a common adjusting shaft (17) which comprises at least one cam disc (18) per device and the cam disc (18) for at least one device comprises a section in which the position of this device does not change during rotation of the adjusting shaft (17) and the cam disc (18) in at least one other device effects a change in the position of this other device during this rotation of the adjusting shaft (17).
15. Internal combustion engine including several devices as claimed in any one or several of Claims 1 to 5 or 8 to 13, characterised by a common adjusting shaft (17) which comprises at least one cam per device and the cam contour for at least one device comprises a section in which the position of this device does not change during displacement of the adjusting shaft (17) and the cam contour in at least one other device effects a change in the position of this other device during this displacement of the adjusting shaft (17).
16. Method for operating an internal combustion engine having several cylinders using one or several devices as claimed in any one or several of Claims I to 5 or 8 to 13, characterised in that after a desired load state for the entire engine has been achieved

    a) rotational angle signals from the crankshaft are received by means of a first rotational angle sensor (42) on the flywheel and are evaluated by an engine management system (44) in order to detect rotational irregularities in the crankshaft and/or torque peaks,

    b) these are allocated to the individual cylinders using a second rotational angle sensor (43) disposed on the camshaft or on another shaft running at half the crankshaft rotational speed, and

    c) signals are produced using this information which are fed to individual drives for equalising the torque peaks and/or the crankshaft rotational speed, wherein equalisation is achieved in that the valve strokes of the cylinders with the lower torques are corrected upwards and the valve strokes of the cylinders with the higher torques are corrected downwards.
17. Method for operating an internal combustion engine having several cylinders using one or several devices as claimed in any one or several of Claims 1 to 5 or 8 to 13, characterised in that

    a) a separate device and a drive for actuating the device are allocated to each cylinder,

    b) the phase position of the rest phases of the individual valves operated by a drive is determined, and

    c) the adjustment movements of the respective devices are performed during the common rest phases of the valves operated by the respective drive.
18. Method as claimed in Claim 17, characterised in that the phase position of the rest phases of the individual valves operated by a drive is determined by an engine management system (44) using the signal from a rotational angle sensor (43) disposed on the camshaft.
19. Device as claimed in Claim 1, characterised in that the articulation points (24, 25, 26, 27) are disposed with respect to each other such that in the design point the straight lines (29, 30) as system lines, which connect two articulation points (24, 25; 26, 27) to each other in each case, intersect each other in the centre point of a roller (10) provided on the driven member (11).

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