DE102018101937A1 - Engine for an internal combustion engine, method for operating a motor, control device - Google Patents

Abstract

The invention relates to an engine (300) for an internal combustion engine (400), in particular an internal combustion engine having an engine (300), the engine (300) comprising: a number of cylinders (11, 12, 13, 14), a cylinder (11 , 12, 13, 14) of the number comprises at least one gas exchange valve (141-144), one about a cam axis (AN) rotatably mounted camshaft (101) adapted to drive the gas exchange valve (141-144), wherein the camshaft (101) axially displaceable in the direction of the cam axis (AN), wherein the gas exchange valve (141-144) is spaced from an adjacent gas exchange valve (141-144) in the direction of the cam axis (AN) corresponding to a total number of valve levels (VE1-4), - the camshaft (101) has a plurality of cam groups (111-114) arranged along the cam axis (AN), wherein one cam group (111-114) is associated with a gas exchange valve (141-144), each cam group (111-114) has a plurality of Sequentially arranged cam tracks (121A -C, 122A-C, 123A-C, 124A-C), wherein the gas exchange valve (141-144) is operable over the plurality of cam tracks (121A-C, 122A-C, 123A-C, 124A-C) ,

Description

The invention relates to an engine for an internal combustion engine, in particular an internal combustion engine with an engine, wherein the engine comprises: a number of cylinders, wherein a cylinder of the number comprises at least one gas exchange valve, a cam shaft rotatably mounted about a cam shaft, adapted for driving the gas exchange valve, wherein the Camshaft is axially displaceable in the direction of the cam axis, wherein the gas exchange valve is spaced from an adjacent gas exchange valve in the direction of the cam axis corresponding to a total number of valve planes, the camshaft having a plurality of arranged along the cam axis cam groups, wherein a cam group is associated with a gas exchange valve, each cam group a plurality of sequentially arranged cam tracks, wherein the gas exchange valve is actuated via the plurality of cam tracks.

Motors with adjustable camshafts, in particular axially adjustable camshafts, are well known.

The DE 10 2011 054218 A1 discloses an internal combustion engine having a plurality of cylinders, wherein for actuating gas exchange valves of a plurality of cylinders of a cylinder group at least one rotatably mounted camshaft is provided on which a sliding cam is arranged axially displaceable for each cylinder, wherein to effect an axial displacement of the respective camshaft mounted axially displaceable Sliding cam for the sliding cam a common actuator is provided.

Despite the fundamentally advantageous axial adjustability of a camshaft, the abovementioned approach can still be improved, in particular with regard to a reliable and stable switching operation. It is therefore desirable to improve an engine in that the function of switching cam tracks is improved, in particular made more reliable.

At this point, the invention is based, whose task is to provide an engine that allows an improved, in particular more reliable, switching cam tracks to adjust the opening behavior of a gas exchange valve.

The object relating to the engine is solved by the invention with an engine of claim 1. The invention relates to an engine for an internal combustion engine, in particular an internal combustion engine with an engine, wherein the engine comprises: a number of cylinders, one cylinder of the number having at least one gas exchange valve, a camshaft rotatably mounted about a cam axis and configured to drive the gas exchange valve, wherein the camshaft is axially displaceable in the direction of the cam axis, wherein the gas exchange valve is spaced from an adjacent gas exchange valve in the direction of the cam axis corresponding to a total number of valve planes, the camshaft has a plurality of cam groups arranged along the cam axis, one cam group being respectively associated with a gas exchange valve, each cam group has a plurality of sequentially arranged cam tracks, wherein the gas exchange valve is operable over the plurality of cam tracks.

According to the invention it is provided in the engine that in a first cam group and a second cam group in each case a sequentially arranged corresponding cam path merges with an axially adjacent respectively sequentially arranged cam track, wherein a corresponding first transition in the first cam group and a corresponding second transition in the second Cam group is spaced apart in a change plane distance, such that there is a number of transitions of such kind compared to a number of gas exchange valves of the number of cylinders, wherein the axial displacement is always only a single transition of such kind to one of the gas exchange valves or axial displacement always the number Transitions of this kind compared to a number of gas exchange valves is less than the total number of valve levels.

The invention is based on the consideration that a common actuation of a plurality of gas exchange valves via a camshaft, in particular a single camshaft with a plurality of cam groups, is fundamentally advantageous.

The invention is based on the further consideration that an adaptability of the opening behavior of a gas exchange valve, in particular for adapting the engine to different operating conditions, is fundamentally advantageous.

The invention has recognized that, when changing a cam track to adapt the opening behavior of a gas exchange valve, in particular by displacing a camshaft, in particular due to a step-like transition between two cam tracks, the displacement movement can be impeded. Such obstruction may be present in particular in the form of blocking, because during the relative movement between the valve tappet and the camshaft, the valve tappet can not overcome the step-like transition between two cam tracks.

The invention has further recognized that this risk of jamming is significantly increased, in particular when several gas exchange valves are actuated via a single camshaft having a plurality of cam groups. This is due in particular to the fact that the cam track change of several valve tappets takes place almost simultaneously when the camshaft is displaced.

The invention therefore provides for the axial distances between the transitions of two cam tracks to be determined in such a way that - in particular with an axial displacement of the camshaft - there is always only one gas exchange valve with respect to a transition. This means that due to the geometry of the camshaft at a time always only one transition can be located in a valve plane of a gas exchange valve. A valve plane in this case represents a plane in which the gas exchange valve, in particular the longitudinal axis of the valve stem, is located and which runs perpendicular to the cam axis. As a result of such an advantageous effect of an offset cam lane change, in particular the opening behavior of a plurality of gas exchange valves can be switched one after the other, in particular immediately one after the other, and the danger of blockage can thus advantageously be reduced, in particular in contrast to simultaneous switching.

According to the concept of the invention, it is also possible that not only is there always a single transition to a gas exchange valve, but a limited number of transitions, but this number of transitions is less than the total number of gas exchange valves of an engine. In such developments, the advantage is also achieved that not all gas exchange valves, which are assigned to a camshaft, simultaneously perform a cam track change, and thus minimizes the risk of blocking or at least particularly advantageous reduced.

The invention also relates to a method for operating an engine and a control device for a motor.

With regard to the method of operating an engine for an internal combustion engine according to any one of the preceding claims, the engine comprises: a number of cylinders, wherein a cylinder of the number comprises at least one gas exchange valve, a camshaft rotatably mounted about a cam axis and configured to drive the gas exchange valve the camshaft is axially displaceable in the direction of the cam axis, wherein a gas exchange valve is in each case spaced from a neighboring gas exchange valve in the direction of the cam axis by one valve plane distance, the camshaft has a plurality of cam groups arranged along the cam axis, one cam group being associated with a gas exchange valve, each Cam group having a plurality of cam tracks, wherein the gas exchange valve is actuated via the plurality of cam tracks, and a cam track to an axially adjacent cam track - with transitions spaced in each case at a spacing plane distance-- Transitioning comprising the steps of: operating an engine in a first axial position of the camshaft, axially adjusting the camshaft toward the cam axis to a second axial position operating an engine in the second axial position of the camshaft. According to the invention, it is provided in the method that there is always only a single transition with respect to a gas exchange valve during the axial adjustment of the camshaft.

In the method according to the invention for operating an engine for an internal combustion engine, the advantages of the device, in particular the advantageous effect of an offset cam track change, are advantageously utilized.

In a development of the method, it is provided that in the axial adjustment of the camshaft, a number of transitions at a time is practically in coincidence with a number of valve levels, the number being less than the total number of valve levels. This may in particular mean that in the axial adjustment not only is there always a single transition with respect to a gas exchange valve, but a limited number of transitions, but this number of transitions is less than the total number of gas exchange valves of an engine. In such developments, the advantage is also achieved that not all gas exchange valves, which are assigned to a camshaft, simultaneously perform a cam track change, and thus minimizes the risk of blocking or at least particularly advantageous reduced.

The invention also leads to the solution of the problem to a control device for an engine of an internal combustion engine according to the concept of the invention for carrying out a method according to the concept of the invention. Such a control device can be formed as an independent unit, for example as an electronic control unit (ECU), or as part of another, in particular superordinate, control.

Advantageous developments of the invention can be found in the dependent claims and specify in particular advantageous ways to realize the above-described concept within the scope of the problem and with regard to further advantages.

A further development of the method further comprises the steps of determining the angular position of the camshaft and / or crankshaft, determining a switching time with which the axial displacement of the camshaft begins. In such a refinement, an optimum point in time for the cam track change can advantageously be determined, in particular a point in time at which the camshaft is rotated about the cam axis in such a way that the valve tappet is in or on the change surface when the camshaft is displaced axially. It can also be avoided in such a development of the method that a detrimental operating state occurs, in particular the risk of a collision of a gas exchange valve with a piston located in a cylinder can be minimized.

In a development of the device it is provided that the number of transitions at a time during operation of the engine is practically in coincidence with this number of valve levels, the number being less than the total number of valve levels. Specifically, this may specifically mean that the transitions between the cam tracks and thus the cam change planes are arranged such that two gas exchange valves simultaneously change the cam track during an axial adjustment of the camshaft, that is, at the same time pass through a transition. For example, in one embodiment, the first and third interplanar spacing may be equal to the respective associated interplanar spacing, and the second interplanar spacing may be different than the associated interplanar spacing. In this way it is achieved that the first and second gas exchange valve simultaneously change the cam track, and the third and fourth gas exchange valve also simultaneously - but at a different time than the first and second gas exchange valve - change the cam. In such a development, the advantage is also achieved that not all gas exchange valves, which are assigned to a camshaft, simultaneously perform a cam track change, and thus the risk of blocking is minimized.

In particular, it is provided that the exchange plane distance between two adjacent cam groups is different from the valve plane distance between the two associated valve planes. In this case, the exchange plane distance refers in particular to the distance between two alternating planes of two adjacent cam groups, wherein the two alternating planes are each arranged between a cam track of a first cam class and a cam track of a second cam class. This results in advantageous that with an axial adjustment of the camshaft always only a gas exchange valve, that is, in particular only a valve stem of this gas exchange valve, a transition happens.

In a further development, it is provided that each cam group is spaced from each other by a cam group spacing, each cam group spacing being different. This means, in particular, that the reference plane of a respective cam group is spaced apart by a cam group spacing to a reference plane of an adjacent cam group. In such a development is achieved particularly advantageous that each deviating from the valve plane intervals interplanar spacing, which lead according to the concept of the invention to the advantageous effect of a staggered cam lane change, not necessarily on different width cam tracks must be implemented, but on irregular, in particular of the Valve plane distances deviating, cam group distances. Thus, the cam groups, in particular the widths of the respective cam tracks of all cam groups, can be made the same, and thus the design and manufacture of a camshaft can be advantageously simplified.

In a further development, it is provided that sequentially correspondingly arranged cam tracks of different cam groups are cam tracks of a cam class and the cam tracks of a cam class have mutually different widths. In such a development, in particular different cam group spacings may be formed equal to each other and / or equal to the respectively associated valve plane spacings. In this case, the deviation between the alternating plane distance and the plane of the valve plane - to achieve the offset switching according to the concept of the invention - is achieved in that the individual cam tracks, in particular the cam tracks of a cam class, have different widths.

A further development is characterized by a number of alternating plane spacings corresponding to a plurality of sequentially arranged cam tracks of each cam group, wherein the change plane distance between the first transition in the first cam group and the second transition in the second cam group is different from all other cam level distances associated with a cam class, in particular all other interplanar spacing is different. In this case, two exchange plane distances are considered to be assigned to a cam class, if both designate respectively the distance between two change planes and in both cases both change planes are each arranged between a cam track of a first cam class and a cam track of a second cam class. This is the case, for example, for two exchange plane distances, each of which is the distance between two change planes between the first one and second sequentially arranged cam track of a cam group. By all Wechselebenenabstände are different from each other, and further in particular all alternating plane distances are different from all valve plane intervals, is advantageously achieved that there is always only a single gas exchange valve with respect to a transition of cam tracks, that is in a plane of change.

Advantageously, it is provided that the motor has a displacement drive for axially adjusting the camshaft. Such a displacement drive can in particular be designed mechanically, for example in the form of a pin-and-link pairing, electromechanically, for example in the form of a ball screw drive with an electric motor, or hydraulically. The displacement drive can be designed either as a direct drive, or in the sense of a transmission, the rotary (main) drive movement for the camshaft, in particular the transmitted to the camshaft drive movement of the crankshaft, for generating an axial movement of the camshaft, convert into a translational movement. For the latter, in particular a pin-and-link pairing comes into question, which can be brought into controllable manner with each other in order to convert the existing drive rotary motion in a defined displacement movement. In this way, the dependence on an additional direct drive, and thus in particular of an additional energy source can be reduced.

It is advantageously provided that the engine has a crankshaft position sensor. By means of a crankshaft position sensor can advantageously be read out the instantaneous angular position of the crankshaft and based on this information, the axial position of the camshaft for setting a cam track in turn be made for selective adjustment of the opening behavior of a gas exchange valve. By adjusting the axial position of the camshaft as a function of the angular position of the crankshaft, in particular the opening behavior of the gas exchange valves can be adapted to the operating state of the engine and in particular the state within the cylinder. In addition, the risk of a damaging operating state, in particular the risk of a collision of a gas exchange valve with a piston located in a cylinder, can be advantageously minimized.

In particular, it is provided that at least two, in particular all, adjacent cam tracks of a cam group have an alternating surface on which a cam track in the direction of the cam axis continuously, in particular flat, merges into the adjacent cam track. About such a change surface, the camshaft - in an axial displacement for changing the cam track - slide advantageous over the valve lifter. In particular, the change surface may be such that the common cam radius is a respective minimum cam radius of the cam tracks. Specifically, this means in particular that the change surface is arranged at the angular position at which several or all tracks have their respective minimum radius. This can lead to the advantage that when changing the pressure of the valve tappet on the change surface and the respective cam path is as low as possible, since the gas exchange valve, which is usually opened against a spring force, is deflected only to a relatively small extent.

• 1 eine ausschnittsweise Darstellung eines Motors gemäß dem Konzept der Erfindung mit einer Nockenwelle, vier Gaswechselventilen und entsprechend vier Nockengruppen,
• 2 eine Darstellung des Ablauf eines Wechsels der Nockenbahn in vier Nockengruppen gemäß dem Konzept der Erfindung,
• 3A, B jeweils eine Ansicht einer Nockengruppe in zwei unterschiedlichen Perspektiven,
• 4A-D jeweils eine Darstellung unterschiedlicher, mit verschiedenen Nockenbahnen zu erreichender Ventilhübe,
• 5A-E eine Darstellung des Ablauf eines Wechsels der Nockenbahn.

Embodiments of the invention will now be described below with reference to the drawing in comparison with the prior art, which is also partly shown. This is not necessarily to scale the embodiments, but the drawing, where appropriate for explanation, executed in a schematized and / or slightly distorted form. With regard to additions to the teachings directly recognizable from the drawing reference is made to the relevant prior art. It should be noted that various modifications and changes may be made in the form and detail of an embodiment without departing from the general idea of the invention. The disclosed in the description, in the drawing and in the claims features of the invention may be essential both individually and in any combination for the development of the invention. In addition, all combinations of at least two of the features disclosed in the description, the drawings and / or the claims fall within the scope of the invention. The general idea of the invention is not limited to the exact form or detail of the preferred embodiment shown and described below or limited to an article that would be limited in comparison with the subject matter claimed in the claims. For the given design ranges, values within the stated limits should also be disclosed as limit values and be arbitrarily usable and claimable. Further advantages, features and details of the invention will become apparent from the following description of the preferred embodiments and from the drawing; this shows in:

• 1 a partial representation of an engine according to the concept of the invention with a camshaft, four gas exchange valves and corresponding four cam groups,
• 2 a representation of the process of a change of the cam track in four cam groups according to the concept of the invention,
• 3A, B each a view of a cam group in two different perspectives,
• 4A-D an illustration of different, with different cam tracks to be reached valve lifts,
• 5A-E a representation of the course of a change of the cam track.

1 shows a partial view of an engine 300 according to the concept of the invention with a camshaft 101 , four gas exchange valves 141 . 142 . 143 . 144 and accordingly four cam groups 111 . 112 . 113 . 114 , In each case, there is a first gas exchange valve 141 a first cylinder 11 , a second gas exchange valve 142 a second cylinder 12 , a third gas exchange valves 143 a third cylinder 13 and a fourth gas exchange valve 144 a fourth cylinder 14 assigned.

The camshaft 101 is about a cam axis ON rotatably mounted and according to the concept of the invention along the cam axis ON formed axially movable. About a displacement drive 171 can be an axial movement BA be generated and thus the camshaft 101 along the cam axis ON be moved.

For the sake of illustration, all cam groups 111 - 114 shown upwardly to represent the maximum radial extent of each cam. In reality, the individual cam groups 111 - 114 angular offset from each other about the cam axis ON on the camshaft 101 arranged. Nevertheless, within the scope of the concept of the invention, other associations between gas exchange valve and cylinder may be possible, for example such that two or more gas exchange valves are assigned to one cylinder.

In the present case, according to the concept of the invention, each gas exchange valve 141 - 144 a cam group 111 - 114 assigned, ie a first gas exchange valve 141 is a first cam group 111 , a second gas exchange valve 142 is a second cam group 112 , a third gas exchange valve 143 is a third cam group 113 and a fourth gas exchange valve 144 is a fourth cam group 114 assigned. The arrangement of the camshaft 101 and the gas exchange valves 141 - 144 is formed such that in each case a cam track 121A - C the first cam group 111 with a pestle 141.1 of the first gas exchange valve 141 come into contact and thus the first gas exchange valve 141 can open. Similarly, in each case a cam track 122A - C the second cam group 112 with a pestle 142.1 of the second gas exchange valve 142 come into contact, in each case a cam track 123A - C the third cam group 113 with a pestle 143.1 the third gas exchange valve 143 come into contact and in each case a cam track 124A - C the fourth cam group 114 with a pestle 144.1 the fourth gas exchange valve 144 get in touch. In this way, the respective gas exchange valves 141 - 144 be opened and closed. The camshaft 101 is doing by a camshaft rotation BN rotationally driven. Such a drive, shown here in simplified form, can take place via a direct drive or, as shown here, by transmitting a rotational drive movement from a crankshaft 430 of the motor 300 respectively. The transmission of the rotary drive rotary motion can in particular via gears, a chain drive or - as shown here - a belt drive 180 respectively. In the present case, the belt drive 180 a drive pulley 190 , a pulley 169 as well as a belt 167 on, the drive pulley 190 and pulley 169 for the purpose of transmitting a rotational drive motion from the crankshaft 430 on the camshaft 101 combines. Here, the pulley points 169 a pulley width 169.1 on, which is transmitting the rotary motion through the belt 167 even with an axial displacement of the camshaft 101 - And thus an axial displacement of the pulley 169 - allows.

Furthermore, it is also possible that a driving of the camshaft via a direct drive takes place, for example, a structural unit with the displacement drive 171 forms. The displacement drive 171 is further with a control device 500 signal leading connected. About the controller 500 can be a selective control of the displacement drive and thus a selective axial positioning of the camshaft 101 respectively.

In this way, according to the concept of the invention, the opening behavior of one or more gas exchange valves 141 - 144 be adjusted. The control device 500 is in the present case further with a crankshaft position sensor 420 signal leading connected. About the crankshaft position sensor 420 In particular, an angular position of the crankshaft can be measured and the axial position AP the camshaft 101 as a function of the current angular position of a crankshaft - here only shown in a very simplified manner 430 be set. By adjusting the axial position AP the camshaft 101 Depending on the angular position of the crankshaft, in particular the opening behavior of the gas exchange valves 141 - 144 to the operating condition of the engine 300 and in particular the state within the cylinder 11 - 14 be adjusted. In addition, advantageously, the risk of a harmful operating condition, in particular the risk of collision of a gas exchange valve 141 - 144 with one in a cylinder 11 - 14 located piston to be minimized.

According to the concept of the invention, by axial displacement BA the camshaft 101 the cam track 121 a - C be changed, dealing with the gas exchange valve 141 in contact. This is particularly advantageous in order to change the opening behavior of a gas exchange valve and thus the gas exchange behavior of a cylinder, in particular to adapt to prevailing ambient and operating conditions. In the present case is every gas exchange valve 141 - 144 each in a valve plane VE-4 arranged. The first valve level VE1 is a first valve plane distance VA1 from the second valve level V2 spaced. The second valve level VE2 is corresponding to a second valve plane distance VA2 from the third valve level VE 3 spaced, and the third valve plane VE 3 by a third valve plane distance VA3 from the fourth valve level VE 4 spaced. In the present case, all three valve plane distances VA1-3 equal in terms of amount; However, this is not mandatory in the context of the invention.

The individual cam groups 111 - 114 are each a cam group spacing NGa1 - 3 from each other along the cam axis ON spaced. The cam group spacing NGa1 - 3 extends here from a first reference plane 111.1 a first cam group 111 up to a second reference level 112.1 an adjacent, second cam group 112 , Analogously, the respective cam group spacing results NGa2 . NGA3 from the references between the second reference plane 112.1 , a third reference plane 113.1 and a fourth reference plane 114.1 , In the present case are the cam group distances NGa1 - 3 equal in terms of amount; However, this is not mandatory in the context of the invention.

In the present case are the cam group distances NGa1 - 3 equal to the valve plane distances VA1 - 3 , In particular, the first cam group spacing NGa1 equal to the first valve plane distance VA1 , the second cam group spacing NGa2 equal to the second valve plane distance VA2 and the third cam group pitch NGA3 equal to the third valve plane distance VA3 ,

Each cam group 111 - 114 in the present case has three cam tracks each 121A - C . 122A - C . 123A - C . 124A - C each with different radial expression. In the present case, the respective first cam track 121A . 122A . 123A . 124A a cam group 111 - 114 an equal radial extent, in particular a first maximum cam radius RA on. These cam tracks 121A . 122A . 123A . 124A form a first cam class NK1 , Analogously, each have the second cam tracks 121B . 122B . 123B . 124B as a second cam class NK2 an equal radial extent, in particular a second maximum cam radius RB and the respective third cam tracks 121C . 122C . 123C . 124C as the third cam class NK3 an equal radial extent, in particular a third maximum cam radius RC on. The cam tracks 121A - C . 122A - C . 123A - C . 124A - C are presently arranged sequentially in each cam group, here with a decreasing radial extent of the cam tracks 121A - C . 122A - C . 123A - C . 124A - C , in particular with a decreasing maximum cam radius of the - in each cam group - first to the third cam track.

According to the concept of the invention, the cam tracks 121A - C . 122A - C . 123A - C . 124A - C different axial characteristics, ie widths on. For example, the first cam track 121 a the first cam group 111 a width B11 on, the second cam 121B the first cam group 111 a second width B12 and the third cam track 121C the first cam group 111 a third width B13 , For the other cam tracks 122A - C . 123A - C . 124A - C the remaining cam groups 112 - 114 analogous designations apply. Although the individual widths are different, in the present case the total width of each cam group, ie the cumulative width of the respective first to third cam track of a cam group, is the same. Although not required by the invention, a uniform width of each cam group may be beneficial to the manufacture and construction of the engine. The entire width of a cam group extends from the reference plane 111.1 . 112.1 . 113.1 . 114.1 up to a final level 111.2 . 112.2 . 113.2 . 114.2 a respective cam group 111 - 114 ,

Between two adjacent cam tracks 121A - C . 122A - C . 123A - C . 124A - C is located at a cam change plane NW1AB . NW1BC . NW2AB . NW2BC . NW3AB . NW3BC . NW4AB . NW4BC one each - in particular stepped - transition U11 . U12 . U21 . U22 . U31 . U32 . U41 . U42 , For example, goes the first cam 121A the first cam group 111 at a first transition U11 in a first cam change plane NW1AB stepped in the second cam 121B over and the second cam track 121B at a second transition U12 in a second cam change plane NW1BC stepped in the third cam 121C about. For the other transitions U21 . U22 . U31 . U32 . U41 . U42 and the other cam change planes NW2AB . NW2BC . NW3AB . NW3BC . NW4AB . NW4BC the remaining cam groups 112 - 114 analogous designations apply. In the present case are all cam tracks 121A - C . 122A - C . 123A - C . 124A - C arranged so that sequentially corresponding transitions U11 . U12 . U21 . U22 . U31 . U32 . U41 . U42 In particular, in each case all transitions from a cam track of a first cam class to a cam track of a second cam class occur in the same order in a respective cam group.

Due to the different widths B11 - 13 . B21 - 23 . B31 - 33 . B41 - 43 the cam tracks 121A - C . 122A - C . 123A - C . 124A - C , especially through the different widths B11 - 13 . B21 - 23 . B31 - 33 . B41 - 43 of cam tracks 121A - C . 122A - C . 123A - C . 124A - C a cam class NK1 - 3 , Is achieved in the present advantageous that during an axial displacement of the camshaft 101 always only a single or a limited number of cam change planes NW1AB . NW1BC . NW2AB . NW2BC . NW3AB . NW3BC . NW4AB . NW4BC a valve plane V1 - 4 passes. This means, in particular, that only one gas exchange valve at a time 141 - 144 or a limited number of gas exchange valves 141 - 144 the cam track 121A - C . 122A - C . 123A - C . 124A - C replaced.

The advantageous effect of an offset cam track change, ie in particular a non-simultaneous change of cam tracks of a cam class NK1 - 3 in another cam class NK1 - 3 , is achieved in particular by the fact that a distance between the intersections AB1 - 3 . BC1 - 3 from its associated valve plane distance VA1 - 3 is different. This means, for example, that the interplanar distances AB1 . BC1 between the first cam group 111 and the second cam group 112 namely the change plane distance AB1 between the first cam change plane NW1AB the first cam group 111 and the first cam change plane NW2AB the second cam group 112 , as well as the exchange plane distance BC1 between the second cam change plane NW1BC the first cam group 111 and the second cam change plane NW2BC the second cam group 112 - Each of the valve plane spacing VA1 between the gas exchange valves associated with these cam groups - namely the first gas exchange valve 141 and the second gas exchange valve 142 - are different.

In addition to the training shown here with different width cam tracks 121A - C . 122A - C . 123A - C . 124A - C can also be used to achieve different exchange plane distances AB1 - 3 . BC1 - 3 - And thus to achieve the advantageous effect of an offset cam track change - the cam group intervals NGa1 - 3 deviating from the respectively associated valve plane distances VA1 - 3 be formed - at the same time, the cam tracks 121A - C . 122A - C . 123A - C . 124A - C , In particular, the cam tracks of a cam class, be made the same width. In such a development, in particular the effect of an offset cam track change can be achieved and still advantageously the same geometry for each cam group 111 - 114 be used, and thus in particular the production of the camshaft 101 be simplified.

2 shows an example of a sequence a change of the gas exchange valves 141 - 144 from the cam tracks 121A . 122A . 123A . 124A the first cam class NK1 on the cam tracks 121B . 122B . 123B . 124B the second cam class NK2 , The camshaft 101 This is from a first axial position AP1 in a second axial position AP2 postponed. For this purpose, five different relative positions between the camshaft 101 and the four gas exchange valves 141 - 144 in five states I . II . III . IV . V shown. Although present the gas exchange valves 141 - 144 are each represented in a shifted position, in reality performs the camshaft by an axial movement BA a shift.

In a first position I is the camshaft 101 so relative to the gas exchange valves 141 -144 arranged that the first valve plane VE1 on the first cam track 121A located. At the same time, the other valve levels are also located VE-2 - 4 on the respective cam tracks 122A . 123A . 124A the first cam class NK1 ie the second valve level VE2 is located on the first cam track 122A the second cam group 112 , the third valve level VE 3 is located on the first cam track 123A the third cam group 113 and the fourth valve level VE 4 is located on the first cam track 124A the fourth cam group 114 ,

In the following, the process is shown, in which all gas exchange valves 141 - 144 successively from contact with a cam track 121A . 122A . 123A . 124A the first cam class NK1 on contact with a cam track 121B . 122B . 123B . 124B the second cam class NK2 be converted. First, the camshaft moves 101 in a first axial movement BA1 so along the cam axis ON in that, relatively speaking, the first valve plane V1 from the first cam track 121A through the first cam change plane NW1AB - and thus at the first transition U11 over - on the second cam 121B emotional.

Such a change is particularly advantageous at a time when the camshaft 101 in such a rotational position, ie angular position WP is located at the first cam track 121A and the second cam track 121 B an identical, in particular minimal, radial expression, ie a minimum cam radius R MIN . to have. This is in particular, as shown here, on the respective lower side of the cam groups 111 - 114 the case where all the cam tracks 121A - C . 122A - C . 123A - C . 124A - C , a cam group 111 - 114 the same, minimum cam radius R MIN have and thus at this point a change surface 131 . 132 . 133 . 134 form.

In a state II is therefore the first gas exchange valve 141 now in contact with the second cam track 121B , At the same time, the other gas exchange valves are located 142 . 143 . 144 , still in contact with the cam tracks 122A . 123A . 124A the first cam class NK1 ,

In a second axial movement BA2 the arrangement shown changes by a further axial displacement of the camshaft 101 from the state II in the state III , Here now also changes the second gas exchange valve 142 the cam track, namely from the first cam track 122A on the second cam track 122B the second cam group 112 , In relative terms, the second valve plane thus moves VE2 from the first cam track 122A the second cam group 112 through the first cam change plane NW2AB the second cam group 112 on the second cam track 122B the second cam group 112 ,

In condition III are therefore the first two gas exchange valves 141 . 142 each in contact with cam tracks 121B . 122B the second cam class NK2 and the two gas exchange valves 143 . 144 in contact with cam tracks 123A . 124A the first cam class NK1 ,

In a third axial movement BA3 becomes the camshaft 101 from the state III in the state IV shifted, so that now also the third gas exchange valve 143 the cam track changes, namely from the first cam track 123A the third cam group 113 on the second cam track 123B the third cam group 113 , This moves - relatively considered - the third valve level VE 3 from the first cam track 123A through the first cam change plane NW3AB the third cam group 113 on the second cam track 123B ,

Finally, the illustrated arrangement goes from the state IV in the state V over, by the camshaft 101 in a fourth axial movement BA4 so along the cam axis ON is moved that the contact of the fourth gas exchange valve 144 from the first cam track 124A the fourth cam group 114 on the second cam track 124B the fourth cam group 114 replaced. This moves - relatively considered - the fourth valve level VE 4 from the first cam track 124A through the first cam change plane NW4AB the fourth cam group 114 on the second cam track 124B ,

In condition V are now all gas exchange valves 141 - 144 each in contact with a cam track 121B . 122B . 123B . 124B the second cam class NK2 , Analogously, in particular, a change of the gas exchange valve 141 - 144 on the respective cam tracks 121C . 122C . 123C . 124C the third cam class NK3 , or back to the cam tracks 121A . 122A . 123A . 124A the first cam class NK1 to be performed.

It is particularly important that - as explained in the example - the cam tracks 121A - C . 122A - C . 123A - C . 124A - C not be changed at the same time, but in particular individually, one after the other. This is achieved in particular advantageous that the risk of blocking the camshaft 101 during the axial movement BA , which can occur in particular with a simultaneous change of the cam track of several gas exchange valves, is reduced or even minimized. In the present case, the respective first cam tracks 121A . 122A . 123A . 124A ascending cam groups 111 - 114 each a larger width B11 . B21 . B31 . B41 on, which causes a change from the first cam 121A . 122A . 123A . 124A on the second cam track 121B . 122B . 123B . 124B first at the first cam group 111 , then at the second cam group 112 , then at the third cam group 113 and finally the fourth cam group 114 is done.

Of course, by a corresponding, different choice of the widths of the cam tracks and / or by a different arrangement of the cam change planes, the advantageous effect - in particular the beneficial effect of non-simultaneous change of the cam tracks, d. H. an offset cam track change - be achieved.

In particular, for example, in a further development of the invention, the camshaft 101 be formed such that all cam tracks 121A - 124A . 121B - 124B . 121C - 124C a cam class NK1-3 have the same width and the beneficial effect of an offset cam track change by deviating cam group intervals NGa1 - 3 , in particular by each of the associated valve plane spacing VA1-3 different cam group distances NGa1 - 3 , is achieved. In such a development can advantageously the same geometry for each cam group 111 - 114 be used, and thus the production of the camshaft 101 be simplified.

Generally, it is advantageous, in particular required, that initially all cam tracks 121A - 124A . 121B - 124B . 121C - 124C a cam class NK1-3 were completely changed before switching to cam tracks 121A - 124A . 121B - 124B . 121C - 124C a next cam class NK1-3 is started.

3A shows a view of a cam group 111 a camshaft 101 in one on the front side of the camshaft 101 directed perspective. You can see the three stepped sections of the three cam tracks 121A - C and their respective different radial expression, that is their radius variable over their circumference. All three cam tracks 121A - C have at an angular position WP = 0 °, ie in the drawn view at the respective upper point of the respective cam track 121A - C , their maximum radial extent, that is their maximum radius RA . RB . RC on. From this respective maximum radius RA . RB . RC this results in the valve lift to be reached via the respective cam track VH ,

Next point all three cam tracks 121A - C at an angular position WP = 180 °, ie in the drawn view at the respective lower point of the respective cam track 121A - C , their respective minimum radial extent, a minimum cam radius R MIN on, which for all cam tracks 121A - C is equal to. This angular position WP is also called the common angular position WPG designated. The common cam radius RAG not necessarily the minimum radius R MIN However, in the present example this is the case.

In 3B is the same cam group 111 in a 90 ° rotated view, in which the cam axis ON horizontally in the drawing plane. In this view, in particular, a continuous change surface 131 recognizable, which is characterized by the amount and angular position WP identical minimum diameter R MIN all three cam tracks 121A-C results. When changing the cam track, the cam group 111 advantageous, in particular without having to overcome an obstacle in the form of a transition, on a particular continuous surface in the axial direction along the change surface 131 via a valve stem, not shown here 141.1 to be moved.

The 4A-D each show a representation of different, with different cam tracks 121A - C maximum achievable valve lifts VHA . VHB and VHC ,

4A shows a cam group 111 a camshaft 101 in an initial position in which the angular position WP is 0 °. In this position there is a plunger contact SK - That is a contact between a valve lifter 141.1 and the cam group 111 - on the changing surface 131 in which the radius of all three cam tracks 121A - C , and in the present case with the valve lifter 141.1 in contact with the first cam track 121A , is minimal.

In 4B is the camshaft 101 and thus also the cam group 111 180 ° around the cam axis ON rotated, hence the angular position WP 180 °. The plunger contact SK is thus at the maximum radial extent RA the first cam track 121A , Consequently, the valve stem becomes 141.1 of the gas exchange valve 141 around the first maximum valve lift VHA from the camshaft 101 pushed away. This first maximum valve lift VHA is given by: VHA = RA-RMIN.

In 4C the angular position WP is also 180 °. However, the plunger contact is located SK not on the first cam 121A but on the second cam track 121B , Consequently, the valve stem becomes 141.1 and thus the gas exchange valve 141 by a larger amount, namely the second maximum valve lift VHB , distracted. This second maximum valve lift VHB is given by: VHA = RB-RMIN.

In 4D the angular position WP is also 180 °. In the present case is the plunger contact SK on the third cam 121C , Consequently, the valve stem becomes 141.1 and thus the gas exchange valve 141 in turn, a larger amount, namely the third maximum valve lift VHC , distracted. This third maximum valve lift VHC is given by: VHC = RC-RMIN.

The 5A-E show schematically the course of a change of a cam track 121A - C , namely a change of the plunger contact SK from the first cam track 121A on the second cam track 121B ,

In 5A is the plunger contact SK on the first cam track 121A the first cam group 111 a camshaft 101 , The angular position WP is 0 °, ie WP = 0 °. The valve lifter 141.1 and thus the gas exchange valve 141 are located, along with the first cam track 121A in a common valve plane VE1 passing through a plane perpendicular to the cam axis ON is formed. That means that the gas exchange valve 141 opposite the first cam track 121A located. In 5B is this configuration, ie the arrangement of the gas exchange valve 141 in the valve plane VE1 with the first cam track 121A , again shown in an angular position WP = 180 °. In this case, therefore, the valve stem 141.1 around the maximum first valve lift VHA deflected.

In 5C is shown as the angular position WP after another half turn is zero again, ie WP = 0 °. The plunger contact SK is thus again at the minimum radial extent of the first cam track 121A , and thus on the changing surface 131 , For changing the opening behavior of the gas exchange valve 114 Now the camshaft 101 and thus the cam group 111 translationally in the axial direction, that is along the cam axis ON , by an axial movement BA by a displacement drive, not shown here 171 postponed.

As a result, as in 5D shown that the second cam 121B in the valve plane VE1 emotional. The change surface glides 131 over the valve lifter 141.1 , the ram contact SK shifts so in the axial direction of the first cam 121A on the second cam track 121B ,

The changing surface 131 this can - depending on the radial expression of the individual cam tracks 121A - C - Be different in size, in particular a different size tangential propagation on the surface of the cam tracks 121A - D respectively. If the radii of all cam tracks 121A - C only at a common angular position WPG match - as it is in 3A with the radius R MIN is shown for the angular position WP = 180 ° - results in a nearly line-shaped alternating surface 131 , If, however, a contiguous range of common angular positions WPG is present, increases the area in the multiple cam tracks 121A - C have the same radius. Consequently, the changing surface increases 131 on which the valve tappet 141.1 from one of the cam tracks 121A - C can be moved to the next, without having to slip over an obstacle, especially a step-changing surface.

It is also possible that a change surface 131 not over all cam tracks 121A - C extends, but only two or more directly adjacent cam tracks 121A - C have a common area of change. Thus, the common cam radius RAG for different pairs or groups of cam tracks 121A - C lie at different angular positions WP. Such a distribution can, for example, be advantageous for the smallest possible imbalance of the camshaft 101 or for an improved change of the cam track 121A - C by an axial displacement of the cam group 111 during operation of the engine.

In 5E is shown how the second cam 121B in the valve plane VE1 located, and the camshaft 101 in an angular position WP = 180 °. In this case, therefore, the valve stem 141.1 around the maximum second valve lift VHB deflected.

Moving to the cam track 121C in the valve plane VE1 is possible analogously to the procedure shown here. Furthermore, it is also possible not only between two adjacent cam tracks 121A - C but also between two more distant cam tracks 121A - C on a camshaft 101 to change, for example, from the first cam 121A directly on the third cam 121C ,

LIST OF REFERENCE NUMBERS

11, 12, 13, 14

Cylinder, first to fourth cylinder

101

camshaft

111, 112, 113, 114

Cam group, first to fourth cam group

111.1, 112.1, 113.1,

First to fourth reference plane, reference plane of the first to fourth

114.1

cam group

111.2, 112.2, 113.2,

First to fourth level of completion, final level of the first to fourth

114.2

cam group

121A-C

First to third cam track of the first cam group

122A-C

First to third cam track of the second cam group

123A-C

First to third cam track of the third cam group

124A-C

First to third cam track of the fourth cam group

131, 132, 133, 134

First to fourth change surface

141, 142, 143, 144

Gas exchange valve, first to fourth gas exchange valve

141.1, 142.1, 143.1,

Plunger of the gas exchange valve, plunger of the first to fourth

144.1

Gas exchange valve

167

belt

169

pulley

169.1

Pulley width

171

displacement drive

180

belt drive

190

Drive pulley

300

engine

400

Internal combustion engine

420

Crankshaft position sensor

430

crankshaft

500

control device

AD

Number of cam change planes

AG

Total number of valve levels

ON

cam axis

AB1-3,

Interchangeable plane distance between the respective first cam switching planes of the first to third cam group

BC1-3

Interchangeable plane distance between the respective second cam switching planes of the first to third cam group

AP1, AP2

First, second axial position of the camshaft

B11, B12, B13

Width of the first to third cam tracks of the first cam group

B21, B22, B23

Width of the first to third cam tracks of the second cam group

B31, B32, B33

Width of the first to third cam tracks of the third cam group

B41, B42, B43

Width of the first to third cam tracks of the fourth cam group

BA

axial movement

BA1, BA2, BA3, BA4

First to fourth axial movement

BN

Camshaft rotational movement

NGA 1, NGA 2, NGA 3

Cam group distance 1 - 3

NK1-3

First to third cam class

NW1AB, NW2AB,

Cam change plane of the first transition of the first to fourth

NW3AB, NW4AB

cam group

NW1BC, NW2BC,

Cam change plane of the second transition of the first to fourth

NW3BC, NW4BC

cam group

RA, RB, RC

First to third maximum cam radius

RAG

Common camshaft radius

R MIN

Minimum camshaft radius

SK

follower contact

U11, U12

First and second transition of the first cam group

U21, U22

First and second transition of the second cam group

U31, U32

First and second transition of the third cam group

U41, U42

First and second transition of the fourth cam group

VA1-3

Valve spacing

VE1-4

Valve level, first to fourth valve level

VH

valve

VHA, VHB, VHC

First to third maximum valve lift

WPG

Common angular position

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 102011054218 A1 [0003]

Claims (13)

Engine (300) for an internal combustion engine (400), in particular an internal combustion engine with an engine (300), the engine (300) comprising: - a number of cylinders (11, 12, 13, 14), wherein a cylinder (11, 12, 13, 14) 13, 14) of the number comprises at least one gas exchange valve (141-144), - about a cam axis (AN) rotatably mounted camshaft (101), adapted for driving the gas exchange valve (141-144), wherein the camshaft (101) in the direction the cam axis (AN) is axially displaceable, wherein - the gas exchange valve (141-144) from an adjacent gas exchange valve (141-144) in the direction of the cam axis (AN) corresponding to a total number of valve levels (VE1-4) is spaced, - the camshaft ( 101) has a plurality of cam groups (111-114) arranged along the cam axis (AN), one cam group (111-114) being associated with a gas exchange valve (141-144), each cam group (111-114) having a plurality of sequentially arranged cam tracks (121A-C, 122A-C, 123A-C, 124A-C), wherein - the gas exchange valve (141-144) is operable over the plurality of cam tracks (121A-C, 122A-C, 123A-C, 124A-C), characterized in that - in a first cam group and a second cam group each have a sequentially correspondingly arranged cam track (121A-C, 122A-C, 123A-C, 124A-C) to an axially adjacent respectively sequentially correspondingly arranged cam track (121A-C, 122A-C, 123A-C, 124A-C). C), wherein a corresponding first transition in the first cam group and a corresponding second transition in the second cam group (U11, U12, U21, U22, U31, U32, U41, U42) in a change plane distance (AB1-3, BC1-3 ), such that - a number (AD) of transitions (U11, U12, U21, U22, U31, U32, U41, U42) of such kind are opposite a number of gas exchange valves (141-144) of the number of cylinders (11, 12, 13, 14) can be located, wherein - at the axial displacement always only a single transition (U11, U12, U21, U22, U31, U32, U41, U42) of such kind with respect to one of the gas exchange valves (141-144) or during axial displacement always the number (AD) at transitions (U11, U12, U21, U22, U31, U32, U41 , U42) of such kind compared to a number of gas exchange valves (141-144) is less than the total number (AG) at valve levels (VE1-4). Motor (300) to Claim 1 , characterized in that the number (AD) at transitions (U11, U12, U21, U22, U31, U32, U41, U42) at a time during operation of the engine is practically in coincidence with a number of valve levels (VE1-4) wherein the number (AD) is less than the total number (AG) at valve levels (VE1-4). Motor (300) to Claim 1 or 2 , characterized in that the interplanar spacing (AB1-3, BC1-3) between two adjacent cam groups (111-114) is different from the valve plane spacing (VA1-3) between the two associated valve planes (VE1-4). Motor (300) according to one of the preceding claims, characterized in that each cam group (111-114) is spaced from each other by a cam group pitch (NGA1-3), each cam group pitch (NGA1-3) being different. Motor (300) according to one of the preceding claims, characterized in that sequentially correspondingly arranged cam tracks (121A-C, 122A-C, 123A-C, 124A-C) of different cam groups (111-114) comprise cam tracks (121A-C, 122A-C). C, 123A-C, 124A-C) of a cam class (NK1-3) and the cam tracks (121A-C, 122A-C, 123A-C, 124A-C) of a cam class (NK1-3) are different from each other (B11 -43). Motor (300) to Claim 5 characterized by a plurality of interplanar spacing (AB1-3, BC1-3) corresponding to a plurality of sequentially arranged cam tracks (121A-C, 122A-C, 123A-C, 124A-C) of each cam group (111-114), the interplanar spacing (AB1-3, BC1-3) between the first transition in the first cam group and the second transition in the second cam group (U11, U12, U21, U22, U31, U32, U41, U42) of all the others of a cam class (NK1- 3) associated alternating plane distances (AB1-3, BC1-3) is different, in particular from all other alternating plane distances (AB1-3, BC1-3) is different. Motor (300) according to one of the preceding claims, characterized in that the motor (300) has a displacement drive (171) for the axial adjustment of the camshaft (101). Engine (300) according to one of the preceding claims, characterized in that the engine (300) comprises a crankshaft position sensor (420). Motor (300) according to one of the preceding claims, characterized in that at least two, in particular all, adjacent cam tracks (121A-C, 122A-C, 123A-C, 124A-C) of a cam group (111-114) have an alternating surface (131 -134), on which a cam track (121A-C, 122A-C, 123A-C, 124A-C) in the direction of the cam axis (AN) is continuous, in particular flat, in the adjacent cam track (121A-C, 122A-C, 123A-C, 124A-C). A method of operating an engine (300) for an internal combustion engine (400) according to any one of the preceding claims, wherein the engine (300) comprises: - a number of cylinders (11, 12, 13, 14), wherein a cylinder (11, 12, 13, 14) 13, 14) of the number comprises at least one gas exchange valve (141-144), - about a cam axis (AN) rotatably mounted camshaft (101), adapted for driving the gas exchange valve (141-144), wherein the camshaft (101) in the direction the cam axis (AN) is axially displaceable, wherein - a gas exchange valve (141-144) in each case from an adjacent gas exchange valve (141-144) in the direction of the cam axis (AN) by a valve plane spacing (VA1-3) is spaced, - the camshaft ( 101) has a plurality of cam groups (111-114) arranged along the cam axis (AN), one cam group (111-114) being associated with a gas exchange valve (141-144), each cam group (111-114) having a plurality of Cam tracks (121A-C, 122A-C, 123A-C, 124A-C) where wherein the gas exchange valve (141-144) is operable over the plurality of cam tracks (121A-C, 122A-C, 123A-C, 124A-C), and a cam track (121A-C, 122A-C, 123A-C, 124A-C) to an axially adjacent cam track (121A-C, 122A-C, 123A-C, 124A-C) - with junctions (U11, U12, U21, U22, U31, U32, U41, U42) each in one Spacing distance (AB1-3, BC1-3) passes over, comprising the steps: - operating a motor (300) in a first axial position (AP1) of the camshaft (101), - axially adjusting the camshaft (101) in the direction of the cam axis ( AN) into a second axial position (AP2) - operating an engine (300) in the second axial position (AP2) of the camshaft (101), characterized in that - in the axial adjustment of the camshaft (101) always only a single transition ( U11, U12, U21, U22, U31, U32, U41, U42) with respect to a gas exchange valve (141-144) is located. Method according to Claim 10 , characterized in that in the axial displacement of the camshaft (101) a number (AD) at transitions (U11, U12, U21, U22, U31, U32, U41, U42) at a time practically coinciding with a number of valve levels ( VE1-4), the number (AD) being less than the total number (AG) at valve levels (VE1-4). Method according to Claim 10 or 11 , further comprising the steps of: - determining the angular position (WP) of the camshaft (101) and / or crankshaft (430), - determining a changeover point (UZ), with which the axial displacement of the camshaft (101) begins. Control device (500) for an engine (300) of an internal combustion engine (400) according to one of Claims 1 to 9 to carry out a method according to one of Claims 10 to 12 ,

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