EP1375832A2 - Method for adjusting the actuators linked to valve drive in an internal combustion engine - Google Patents

Abstract

The engine (10) may have a cylinder bank (11) with two camshafts (13) in the cylinder head (12). Each camshaft has a phase adjuster (14) fed with oil via control valves (19). The oil pump (15) and the valves are controlled by a computer (16) with a ROM (Read Only Memory 18) and a calculating circuit (17). A pressure sensor (20) is attached to the oil pump.

Description

The present invention relates to a method for adjusting the valve train actuators assigned to an internal combustion engine, a storage device with a Computer program for performing such a method and a motor vehicle with an internal combustion engine.

The valve train of internal combustion engines includes camshafts for actuating the Valves of the combustion chambers. It is also known the opening and closing times of the Valves and sometimes also the valve lift to be changed by camshaft adjusters. Each adjustable camshaft is assigned a camshaft adjuster. has an internal combustion engine several cylinder banks - in V-engines there are two - on, so groups of camshaft adjusters can be formed, which the each other summarize the corresponding valve actuating camshafts. Groups of Camshaft adjusters will be the same to be controlled by the camshaft adjuster Setpoint specified. The valve lift of valves can also be done separately Valve lift actuator, if necessary also separately for intake and exhaust valves, be adjustable. Actuators of the valve train are, in particular, camshaft actuators and valve lift actuators.

It is also known that internal combustion engines for actuating the valves Cylinder bank can have two camshafts, one of the two Actuation of the intake valves and the other is used to actuate the exhaust valves. Both camshafts can be adjustable, but it is also possible that only one of the is adjustable by means of a camshaft adjuster. It can for independent camshaft adjusters can be provided for each camshaft of a cylinder bank.

It is also possible to use one of the two camshafts depending on the other Adjust camshaft.

By means of the actuators of the valve train, one is determined in a control device predefined setpoint for the position of the elements of the valve train. For this the actuators carry out adjustment processes. The required for the actuation of an actuator Energy is provided by an external power source. Often the required Energy is supplied in the form of a pressurized fluid, such as engine oil. The Fluid pressure is generated by a pressure pump, which is also the Oil pressure of the engine oil circuit producing oil pressure pump can act. Also one electrical actuation of the actuator is conceivable, in this case the external power source is the Battery or the generator of the vehicle circuit.

Operating states can occur during the operation of the internal combustion engine which, on the one hand, control processes are carried out simultaneously on several actuators On the other hand, the external power source should only deliver a small amount of energy can, which is not sufficient to carry out all adjusting operations.

In the case of actuators whose external power source is the oil pressure pump of the engine circuit such a situation is, for example, the engine start. When starting the engine must first once the oil pressure in the oil circuit of the internal combustion engine can be built up. Of At this point in time there may be actuating operations on all actuators come because the camshafts from the reference position, which when turning off the Engine has been started, should be moved to other target positions and if necessary the valve stroke is to be changed at the same time. However, this is what is required Oil pressure not available. The same is higher in situations, for example Oil temperature and in the event of unfavorable load changes (e.g. rapid transition to Idle mode) the case. The high oil temperature leads to low viscosity of the Engine oil, at low engine speeds, this can lead to a brief drop in the Oil pressure at the outlet of the oil pressure pump. This is for the operation of the Internal combustion engine with its oil circuit is not disturbing, but can then Available oil pressure may no longer be sufficient, several To supply camshaft adjusters with the energy required for actuating processes.

Breaks the power supply required to perform multiple operations on, the adjustment processes cannot be carried out at all or not in a controlled manner become. Unwanted operating conditions of the internal combustion engine can occur occur.

Even with external power sources independent of the engine oil circuit, such Situations operating conditions occur in which the required energy is not is absolutely available. For example, when the outside temperature is low Vehicle started so the on-board electrical system voltage can be insufficient Battery charge and high load decrease. This can be exacerbated if at the same time other strong consumers, such as seat heating, electrical Window heaters and headlights are in operation.

The object of the invention is therefore to carry out a controlled operation to enable the actuator assigned to the valve train even when the Available energy not for the required, simultaneous Execution of all adjustment processes is sufficient.

This object is achieved by an inventive method for adjusting actuators the valve train of an internal combustion engine, by means of an inventive Storage device and solved in a motor vehicle according to the invention.

An inventive method for adjusting actuators of the valve train Internal combustion engine with at least two actuators, in particular takes place at Internal combustion engines of motor vehicles use. The adjustable elements one actuator is assigned to the valve train. This is used to carry out Actuating processes powered by an external power source. The actuating processes are used to control a predetermined target position with respect to a reference position. According to the invention, the energy provided by the external power source is detected. If several adjustment processes are to be carried out at the same time, it is checked whether the provided energy is sufficient, the actuating processes simultaneously, that is parallel to each other perform. If this is not the case, then adjustment processes become according to the invention deferred for later execution.

Resetting the execution of actuating processes according to the invention has the advantage that no collapse in the supply of energy from the external power source he follows. The actuators do not perform the adjusting movements to the desired extent in parallel, i.e. at the same time. Still, to a limited extent Adjusting movements are carried out. Undesired or undefined operating states the internal combustion engine are avoided. The target position of the actuator by the Adjustment processes should be achieved, despite the partially delayed Carrying out safer and achieved earlier, like when a temporary Collapse in the supply of energy from the external power source in purchase is taken.

A quick adjustability of the actuator is particularly the cold start of the Internal combustion engine of interest. Especially when cold starting, for example Optimization of exhaust gas conditioning and the function of the exhaust gas cleaning system Adjustments of the actuators of the valve train required. These are especially camshaft actuators and preferably also valve lift actuators. The Starting position, meaning a defined idle position must be left. Here The external energy is not only used to carry out the adjustment processes but also under Under certain circumstances also needed to release locking members. On the other hand is in the oil circuit the internal combustion engine the oil pressure has not yet built up, so that the Oil pressure pump of the oil circuit does not yet have the required oil pressure or required volume flow for pressure-free supply of the actuators stands. This is all the more true the greater the number of actuators and their energy requirements. In in this case it is then also for the operation of the internal combustion engine in the sense of a better conditioning of the exhaust gases cheaper if the actuators are actuated be carried out with a time delay.

According to an advantageous embodiment of the invention, the parallel to be carried out, the required energy is determined, wherein Adjustments are carried out in parallel, as far as the sum of the required Energy that does not exceed the energy provided. More to do Adjustments are then postponed for later execution. Through this Measure operations are carried out in parallel, due to the availability Amount of energy can be run in parallel. Further adjusting operations will be initially deferred. This can also become a fully or partially sequential Execution of actuating operations.

It is possible with this procedure that the External power source successively further, previously intended for later execution Actuating processes can be included one after the other in the parallel version. This In the end, they are only started with a time lag, but still partially executed in parallel to previously started actuating processes. Even if part of the parallel executed actuating operations is complete, actuating operations that were previously used later execution were planned, parallel to others still in the execution realized adjustment processes are carried out, insofar as the energy provided is sufficient for this. In this way, adjusting operations are advantageously carried out as far as necessary but no more than staggered in time. An optimized utilization the available energy of the external power source is reached.

According to an embodiment of the invention, such adjustment processes are preferred executed in parallel, which lead to the adjustment of camshaft adjusters, which actuating corresponding valves of different cylinder banks Camshafts are assigned.

According to the invention, it is also possible for control processes to be broken down into sub-processes become. Sub-operations of several actuating operations that are used to actuate different Camshaft adjusters can be combined cyclically into adjustment processes sequentially. In particular, such Adjustment processes are broken down into sub-processes, which relate to camshaft actuators, which actuating corresponding valves of different cylinder banks Camshafts are assigned. By breaking down these operations into Sub-processes and their cyclical (alternating with two camshaft actuators) In spite of the staggered execution, execution becomes a certain synchronization of this Camshafts reached. This promotes a smooth, smooth operation of one Internal combustion engine with several cylinder banks.

The parallel execution of actuating processes and the division into sub-processes can alternatively or in addition. For example, it is possible to carry out two adjustment processes in parallel, each of which is one represents sequential, cyclical execution of sub-operations of two actuating operations. So can, for example, in the case of a V-engine with two adjustable intake and Exhaust camshafts simultaneously adjusting the intake camshafts and the Exhaust camshafts take place, with a sequence of in both adjustment processes Sub-operations of the adjusting operations of the two corresponding valves of the two Camshafts actuating cylinder banks (the two intake and the two Exhaust camshafts). Thus, at any point in time the two Two camshaft adjusters are always actuated in parallel. It however, two camshaft actuators are actuated alternately with each adjustment process, between which a certain synchronization of the actuating movements is maintained. It there are always two actuating processes taking place in parallel and sequentially, this being the case required energy, which is provided by the external power source, does not exceed any Time for the adjustment of a camshaft adjuster of an intake valve and of a camshaft actuator of an exhaust valve, that is half of the energy Energy that is required to carry out all four actuating processes in parallel.

It is also possible that the actuating processes started first, for example the Adjustment of the intake camshafts, broken down into sub-operations while the Adjustment of the two exhaust camshafts, initially reset, later, if necessary but still parallel to the execution of the sub-processes, but also to each other in parallel. This can be done if the Energy provided by an external power source initially only the actuation of one Camshaft actuator of an intake valve actuating camshaft, for later At the same time, actuation of the two associated with the exhaust valves is also carried out Camshaft adjuster allowed.

According to the invention it can also be provided that groups of Camshaft actuators are formed, an actuation process the actuation of all Group camshaft adjusters. In this way, an actuation of Camshaft adjusters only carried out when the available energy of the External power source enables the actuation of all camshaft actuators in the group. A Delayed execution of camshaft adjusters and thus strongly different different positions of the camshaft adjuster of the group with each other avoided. In particular, the camshaft adjusters can form a group are summarized, the corresponding valves different Cylinder banks actuating camshafts are assigned.

According to an advantageous embodiment, the adjustment processes are different Categories divided. The assignment of the actuating processes in the different Categories determines which actuation processes are not carried out for all Adjustments of sufficient energy provided are carried out first. It can it can be provided in an advantageous manner that adjustment processes are the same Category broken down into sub-operations and carried out cyclically sequentially, as far as not the one required to carry out all the adjustment operations in the category Amount of energy is available.

The assignment of the adjustment processes in different categories can one after the actuated by the actuator element of the valve train. That's the way it is possible, the first category all valve lifters, the second category all Camshaft adjusters of the exhaust camshafts and the third category all Assign camshaft adjusters to the intake camshafts.

a) Vergrößerung des Ventilhubes der Ventile

b) Vergrößerung der Überschneidung der Ventilöffnung

c) Verringerung der Überschneidung der Ventilöffnung

d) Vergrößerung der Ventilöffnung der Einlassventile

erfolgen, wobei die Kategorien in der Reihenfolge absteigender Priorität geordnet sind. Es werden also zuerst die Stellvorgänge der Kategorie a) und zuletzt die Stellvorgänge der Kategorie d) ausgeführt. Dabei dienen die Verstellungen der Steller in den Kategorien a) und b) im wesentlichen der Abgaskonditionierung. So wird eine Vergrößerung der Überschneidung der Ventilöffnungen insbesondere vorgenommen um eine innere Abgasrückführung und eine schnellere Aufheizung von Katalysatoren im Abgasstrang zu bewirken. Betätigungen nach dem Kriterium c) dienen der Bereitstellung der vollen Leistung der Brennkraftmaschine, während Betätigungen der Steller nach Kriterium d) vor allem der Reduzierung des Verbrauchs der Brennkraftmaschine dienen.However, the categories can also be ordered according to the effect caused by the actuation of the camshaft adjuster. This makes it possible to choose the sequence of execution of the adjustment processes not according to the actuated actuator, but according to other optimization criteria. A division into categories can, for example, according to the criteria:

a) Increasing the valve stroke of the valves

b) enlarging the overlap of the valve opening

c) reducing the overlap of the valve opening

d) enlarging the valve opening of the intake valves

The categories are arranged in order of descending priority. The actuating processes of category a) are then carried out first and finally the actuating processes of category d). The adjustments of the actuators in categories a) and b) are mainly used for exhaust gas conditioning. Thus, the overlap of the valve openings is increased in particular in order to bring about an internal exhaust gas recirculation and a faster heating of catalysts in the exhaust system. Actuations according to criterion c) serve to provide the full power of the internal combustion engine, while actuations according to criterion d) primarily serve to reduce the consumption of the internal combustion engine.

Within the category b), in which the actuating processes an increase in the If necessary, overlap of the valve opening may result first Adjustments of the camshaft adjusters that actuate the exhaust valves Camshafts are assigned to be performed.

In the case of actuating operations in category c), actuating operations can be carried out first if necessary have performed a greater reduction in the overlap of the Result in valve opening. In this case it is from the current position of the Depending on the camshafts and their actuators as well as the available travel ranges, whether first the camshaft adjusters, the camshafts actuating the intake valves are assigned, or the camshaft actuators that actuate the exhaust valves Camshafts are assigned to be executed.

A method according to the invention can in particular be carried out on a computer, such as a microprocessor, executable computer program that run on a Storage device, such as a read-only memory (ROM) is.

Methods according to the invention are found in particular in internal combustion engines from Motor vehicles use at least two actuators for running Actuate movements of elements of the valve train of the internal combustion engine. at the actuators are in particular camshaft actuators and valve lift actuators. It is a source of external power to provide for the implementation of Adjustments of the actuator required energy provided. The actuating processes can partially in accordance with the energy provided for executing actuating processes be deferred. The external power source is in particular a Oil pressure pump, the actuators being hydraulic actuators. The oil pressure pump is preferably the oil pressure pump feeding the oil circuit of the internal combustion engine.

Fig. 1:

die schematische Darstellung einer erfindungsgemäßen Brennkraftmaschine;

Fig. 2:

die bereitgestellte Energie über die Zeit und die verzögerte Ausführung von Stellvorgängen;

Fig. 3:

die bereitgestellte Energie über die Zeit und die verzögerte Ausführung von Verstellungen, die jeweils aus einer zyklisch sequenziellen Abfolge von Teilvorgänge bestehen; und

Fig. 4:

das Blockschaltbild eines erfindungsgemäßen Verfahrens.

Otherwise, the invention is also explained in more detail with reference to the exemplary embodiments shown in the drawing, in which:

Fig. 1:

the schematic representation of an internal combustion engine according to the invention;

Fig. 2:

the energy provided over time and the delayed execution of actuating operations;

Fig. 3:

the energy provided over time and the delayed execution of adjustments, each consisting of a cyclically sequential sequence of sub-operations; and

Fig. 4:

the block diagram of a method according to the invention.

1 is a schematic representation of a design according to the invention Internal combustion engine 10 with the necessary elements to carry out a shown inventive method. Figures 2 to 4 show in different Forms of representation the sequence of inventive methods.

The internal combustion engine 10 has a cylinder block 11 and a cylinder block placed thereon Cylinder head 12 in which the valve train is arranged. The valve train includes the two camshafts 13, each of the two camshafts being a camshaft adjuster 14 is assigned. It is also possible for the valve stroke to be adjusted via the camshafts 13 and the associated camshaft adjusters or separate ones Valve lift actuator takes place. The oil pressure pump 15, which also serves as the external power source Supply of the internal combustion engine 10 with the oil pressure required for its operation performs. The oil pressure pump 15, like the camshafts 13 in particular via a timing chain through the crankshaft of the internal combustion engine 11 driven.

The control device 16 is used to control the control valves 19 via the supply the camshaft adjuster 14 with energy, namely pressurized engine oil. Due to the controlled supply of engine oil, adjustment processes of the Camshaft adjuster 14 generated. The control unit includes a computer 17 for Execution of programs stored on the memory device 18, a ROM. The programs are used to control the actuators, in particular the control valves 19 are thereby actuated. To capture the from the Oil pressure pump provided energy (pressure) is used by the pressure sensor 20, whose signals are fed to the control unit 16 and processed there. The control unit 20 can further signals are fed in, which are necessary for the control processes Setpoint determination of the control process and the control of the actuators used become.

FIG. 2 shows the execution of a time diagram inventive method. The dash-dotted line shows that of the External power source for the adjustment of the actuator provided energy E in the course of Time. Performed operations are shown as bars, the width of the Bar represents the energy required to perform the adjustment process. The length of the bars shows the time required to carry out the adjustment process on.

Up to the point in time t1, the energy E provided is not sufficient for an actuating process perform. There are actuating requirements for performing actuating processes Actuating operations cannot be carried out and therefore become a later one Execution postponed. At time t1 it is found that due to the now available energy an adjustment process 1, namely the setting process belongs to the highest category, for example adjusting the valve stroke via a corresponding valve lift actuator can be performed. This setting process is started, further actuation processes are deferred.

At time t2, the amount of energy provided is sufficient, parallel to the setting process 1 an actuating process 2, for example by adjusting the exhaust camshafts assigned camshaft adjuster 14 to perform. The two adjustment processes are therefore from this point on, executed at the same time. Further adjustment processes remain reset. At time t3, due to the then available Energy also the parallel execution of a third actuating process 3, for example adjustment of the intake camshafts possible. Now there are three operations executed at the same time. The first actuating process is completed at time t4. On any fourth, still deferred actuating process 4 can then be carried out. Its energy requirement demands the energy requirement of the completed first Setting process 1.

FIG. 3 shows the time diagram of a further method according to the invention. Also here the energy provided is shown as a dash-dotted line. The Adjustment processes 1,2 are shown as bars, the width of the bars shows theirs Energy demand. The adjustment processes 1, 2 are each periodically cyclical Sequence of sub-processes 1a, 1b or 2a, 2b of two actuating processes.

At time t1 it is determined that an adjustment process can be carried out. Further adjustment operations or adjustment operations must be carried out later be deferred. The adjustment process 1 is based on its priority or Belonging to a category that precedes the category of other adjustment processes ranked, selected. The adjustment process 1 can be the adjustment of the two camshaft adjusters, which actuate the camshafts two cylinder banks of the internal combustion engine are assigned act. In doing so the actuating processes are divided into sub-processes 1a, 1b. Sub-operations 1a can So it is a sub-process of an actuating process of the left camshaft actuator Cylinder bank and in the sub-processes 1b by a sub-process of an actuating process of the camshaft adjuster on the right cylinder bank. So that a synchronization between the camshaft adjustment of the camshaft actuating the intake valves of the two cylinder banks is guaranteed, the sub-processes are alternating carried out. First, a sub-process 1a for a time interval tz, then for a Time interval tz a sub-operation 1b, then again a sub-operation 1a and so on. The sequence of sub-processes 1a, 1b can be continued until both Adjustments are finished.

The alternating execution of the two actuating processes increases compared to one parallel execution of the actuating processes the time required until both actuators Have reached the target position. A parallel execution of the two adjustment processes can but can not be carried out at time t1, so that therefore the alternating Execution of sub-operations 1a, 1b is advantageous.

At time t2, it is then due to the energy available External power source possible, another, second adjustment 2 in parallel perform. Corresponding to the adjustment process 1, a can be used in the adjustment process 2 Adjustment of the two camshaft actuators that actuate the exhaust valves Camshafts are assigned to two cylinder banks of the internal combustion engine. The actuating processes are divided into sub-processes 2a, 2b. Sub-operations 2a are So a sub-processes of an actuating process of the camshaft actuator, which of the the exhaust valve actuating camshaft is assigned to the left cylinder bank, and in the sub-processes 2b by a sub-process of a setting process of the Camshaft actuator, which of the camshaft actuating the exhaust valves right cylinder bank is assigned. So that a certain synchronization between the Camshaft adjustment of the camshafts of the two actuating the exhaust valves Cylinder banks is guaranteed, the sub-operations 2a, 2b alternate carried out. First a sub-operation 2a for a time interval tz, then for a Time interval tz performed a sub-operation 2b. The sequence of sub-operations 2a, 2b can be continued until both actuating processes have ended.

So two adjustment processes are carried out parallel to each other, each of the two adjustment processes the sequential execution of two adjustment processes in Partial operations by operating two actuators. It will be at any time but only two actuators are actuated, so that the amount of energy required at any time is half as large as when all four adjustment processes are carried out simultaneously.

At time t3, the first time interval begins, due to the provided Energy can be carried out not only two operations, but in which in addition to the second adjustment process with the sub-processes 2a, 2b also the sub-processes 1a and 1b can be carried out in parallel. This leads to the fact that Sub-operations 1a finished the cyclical processing and both actuating operations now be carried out continuously and in parallel. At time t4 they are two actuating processes ended with sub-processes 1a, 1b of the first adjusting process, the corresponding setpoint on the actuators was set. The change between the sequential and parallel execution of the actuating processes reduces the required actuating time to carry out the actuating processes, insofar as that of the Energy provided by an external power source makes this possible. The second adjustment process with The sub-operations 2a, 2b of the associated actuating operations are carried out at time t5 completed.

FIG. 4 shows the block diagram of a method according to the invention Actuation of 3 digits. The procedure carried out largely corresponds to that with respect to Fig. 2. The first actuator St_1 can for a valve lift actuator, for the second actuators St_2 for the camshaft actuators, the assigned to the camshafts actuating the exhaust valves, and to the third Set St_3 around the camshaft adjusters that actuate the intake valves Camshafts are assigned to act.

Initially, none of the actuators St_1 to St_3 is active, there is no request for one Actuating process Stellanf_1 bis Stellanf_3 before. A supply of energy E the Auxiliary source is available. All actuators are initially on the Output switch AS 1 to AS3 deactivated.

Now there are several adjustment requests Verstellanf_1 bis Verstellanf_3 for the actuator St_1 to St_3, the energy E of the offer is initially provided with that for the energy B1 required for the first setting operation is compared in the comparator V1. Is this Supply of energy E greater than the requirement B1 is done by the flip-flop FF1 Permission signal passed to the output switch AS1. With the presence of the The adjustment request Verstellanf_1 for the adjustment process of the Actuator 1 forwarded to the control unit, which controls the setpoint at actuator St_1 performs. The actuator St_1 is activated.

By switching the switch S1 through the subtractor 31, the energy supply E reduced by the energy requirement B1 of the actuator St_1. Then in the comparator V2 checks whether the energy E-B1 still available is greater than that Energy requirement B2 for adjusting the second actuator St_2 in the second Adjustment request Verstellanf_2. If this is not the case, the flip-flop FF2 does not generate a permission signal, the output switch AS2 blocks the activation of the Stellers St_2. The adjustment request Verstellanf_2 is reset. Only when one sufficient supply of energy (E-B1> B2) is available through the Comparator V2 and the flip-flop the permission signal to the output switch AS 2 forwarded. With the presence of the permission signal, the adjustment request Verstellanf_2 forwarded to the control unit for the adjustment process of the actuator St_2, which controls the setpoint through the actuator St_2. The actuator is St_2 activated.

By switching the switch S2, the adder 32 and the subtractor 31 the energy supply E around the energy requirement B1 of the actuator St_1 and the energy requirement B2 of actuator St_2 reduced. Then it is checked in comparator V3 whether it is still available Available energy E-B1-B2 is greater than the energy requirement B2 for that Adjusting the third actuator St_3 based on the third adjustment request Verstellanf_3. If this is not the case, then no permission signal is generated by the flip-flop FF3 Output switch AS3 blocks the activation of the actuator St_3. The adjustment request Verstellanf_3 is reset. Only when there is a sufficient supply of energy (E-B1-B2> B3) is available, is by the comparator V3 and the flip-flop FF3 the permission signal is forwarded to the output switch AS3. With the presence of the The adjustment request Verstellanf_3 for the adjustment process of the Steller St_3 forwarded to the control unit, which sends the setpoint control to the Performs St_3. The actuator St_3 is activated.

By switching the switch S3 is now through the adders 32, 33 and the subtractor 31 the energy supply E around the energy requirement B1 of the actuator St_1, the energy requirement B2 of actuator St_2 and the energy requirement B3 of actuator St_3 are reduced. This serves checking whether the energy requirement is parallel even during the execution of the three performed actuation remains sufficient. Otherwise, the flip-flops would FF1 to FF3 actuation processes interrupted by resetting permission signals, the actuators St_3 are deactivated first.

A hierarchically stepped actuation of the actuators St_1 to St_3 becomes dependent of the available energy is reached, with insufficient energy Operations are deferred.

Claims (11)

Method for adjusting the valve train of an internal combustion engine, in particular in a motor vehicle, associated actuators, which are assigned to the adjustable elements of the valve train, by means of which a predetermined desired position of the actuator with respect to a reference position is controlled during actuating processes, the actuators for carrying out the actuating processes from a External power source are supplied with energy, at least two adjustable camshafts being provided, characterized in that it is detected whether the energy (E) provided by the external power source (15) is sufficient to simultaneously carry out a plurality of actuating processes (1, 2, 3) to be carried out in parallel and if the energy (E) provided is insufficient, actuating processes (1,2,3) are postponed for later execution. Method according to Claim 1, characterized in that the energy (E) required for the actuating process (1, 2, 3) to be carried out is determined for the individual actuators (14, St_1, St_2, St_3), part of the actuating processes (1 , 2, 3) is carried out in parallel insofar as the sum of the energy required for these actuating processes (1; 1, 2) is less than the energy provided (E), while further actuating processes (2, 3; 3) to be carried out later Execution be postponed. Method according to claim 2, characterized in that at least some of the actuators (14, St_1, St_2, St_3) are camshaft actuators (14) and preferably such actuating processes (1, 2, 3) are carried out in parallel that are carried out by camshaft actuators (14) are assigned to each other corresponding valves of different cylinder banks actuating camshafts (13). Method according to one of claims 1 to 3, characterized in that actuating processes are broken down into sub-processes (1a, 1b, 2a, 2b), with sub-processes (1a, 1b, 2a, 2b) of several actuating processes (1, 2) leading to actuating processes (1, 2) different actuators (14, St_1, St_2, St_3) belong to one adjustment process and within which cyclical sequential executions are carried out, in particular those control processes (1a, 1b, 2a, 2b) being combined to make adjustment processes that by camshaft actuators (14) which are assigned to each other corresponding valves of different cylinder banks actuating camshafts (13). Method according to one of the preceding claims, characterized in that at least some of the actuators (14, St_1, St_2, St_3) are camshaft actuators (14) and that groups of the camshaft actuators (14) have camshafts (13) which actuate corresponding valves of different cylinder banks ) are assigned, are formed, an actuating process (1, 2, 3) comprising the actuation of all camshaft actuators (14) in the group. Method according to one of the preceding claims, characterized in that a distinction is made between categories of actuating processes (1, 2, 3), the determination of the sequence of actuating processes (1, 2, 3) to be carried out first based on the category of the actuating processes (1, 2 , 3) is determined. A method according to claim 6, characterized in that the categories of actuating processes (1, 2, 3), the a) an increase in the valve lift of the valves, b) an increase in the overlap of the valve opening, c) a reduction in the overlap of the valve opening, and the d) an increase in the opening of the intake valve effect, are formed, the first-mentioned categories of actuating processes (1, 2, 3) being carried out first. A method according to claim 7, characterized in that at least some of the actuators (14, St_1, St_2, St_3) are camshaft actuators (14) and in the case of actuating processes (1, 2, 3) which cause an increase in the overlap of the valve opening, first the actuating processes (1, 2, 3) of the camshaft adjusters (14) are carried out, which are assigned to the camshafts actuating exhaust valves, and that for actuating processes (1, 2, 3) which reduce the overlap of the valve opening, the actuating processes of the Camshaft adjusters can be performed, which can bring about the greater reduction in the overlap, Storage device (18), in particular ROM, with a computer program that on a computer (17), such as a microprocessor, is executable, the Computer program for performing a method according to one of the previous claims is suitable. Motor vehicle with an internal combustion engine (10) and a valve train, the at least two with a respective camshaft adjuster (14) Reference position adjustable camshafts (13) and preferably also Has valve lift actuator for changing the valve lift, with an external power source (15), the energy (E) for carrying out adjusting operations (1, 2, 3) of the Provides camshaft adjuster (14) and possibly the valve lift actuator, and with a Control unit (16) for controlling the actuating processes of the camshaft adjuster (14) and optionally the valve lift actuator according to a method according to one of claims 1 to 8. Motor vehicle according to claim 10, characterized in that the external power source (15) includes an oil pressure pump, and a sensor (20) for detecting the oil pressure generated by the oil pressure pump is provided as a measure of the energy (E) provided, it being the oil pressure pump is preferably the oil pressure pump (15) feeding the oil circuit of the internal combustion engine.

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