DE10029858A1 - Method for operating an internal combustion engine - Google Patents

Abstract

The invention relates to an internal combustion engine (1), especially for an automobile, in which the fuel can be directly injected into a combustion chamber (4) in at least two operating modes and in which the gas can be delivered to said combustion chamber (4). Said gas can be caused to move in a predetermined manner (22, 23) inside the combustion chamber (4). A control device (18) for eliminating the knocking of the internal combustion engine (1) by regulation is provided. The gas can be moved once in the predetermined manner (22, 23) and once in a manner other than said predetermined manner (22, 23) inside the combustion chamber (4), in the same operating mode. The control device (18) provides a means of checking whether, when the knocking of the internal combustion engine (1) has been eliminated by regulation, the ignition angle with the predetermined gas movement (22, 23) differs significantly from the ignition angle without the predetermined gas movement (22, 23).

Description

State of the art

The invention is based on a method for operating an internal combustion engine, in particular a motor vehicle, with the fuel in at least two operating modes directly is injected into a combustion chamber, where the gas Combustion chamber is supplied, the gas within the Combustion chamber can be set in a predetermined movement can, and in which a knock of the internal combustion engine is settled. The invention also relates to a corresponding internal combustion engine and a control unit for such an internal combustion engine.

Such a method, such an internal combustion engine and such a control device are, for example, from a so-called. Gasoline direct injection known. There is fuel in a homogeneous operation during the intake phase or in one Shift operation during the compression phase in the Combustion chamber of the internal combustion engine injected. The Homogeneous operation is preferred for full load operation Internal combustion engine provided during shift operation is suitable for idling and part-load operation.

Depending on the operating parameters of the internal combustion engine is switched between the above operating modes. This can be done, for example, by a control unit of the  Internal combustion engine using an operating mode map be performed.

Furthermore, the control device is provided for a possible knocking of the internal combustion engine by a adjust the corresponding knock control. The Internal combustion engine is therefore essentially at their Knock limit operated.

For shift operation it is necessary that the injected fuel in the area of the spark plug arrives to be ignited by the spark plug. To for this purpose it is known to have a charge movement flap in the Provide intake pipe of the internal combustion engine with which Gas that is fed to the combustion chamber of the internal combustion engine a given movement can be given. For example. it is possible with such Charge movement flap the gas supplied to the combustion chamber within the combustion chamber in a roller-like movement offset. This roller-like movement then also the one injected into the combustion chamber by the injection valve Fuel carried along and ultimately the spark plug fed.

In homogeneous operation, especially in full load operation the internal combustion engine is the charge movement flap however not necessary, but rather a hindrance. Out for this reason the position of the Charge movement flap can be changed. This results in the risk that the cargo movement door due to a Defect is clamped, for example, and thereby the position the charge movement flap can no longer be changed can. This can cause the entire system to malfunction Lead internal combustion engine.  

Object and advantages of the invention

The object of the invention is to provide a method with a defect such as the Charge movement flap can be recognized.

This task is initiated in a procedure mentioned type according to the invention solved in that one and the same operating mode the gas inside the combustion chamber once in the specified movement and once not in the predetermined movement is offset and that is checked whether the knock is regulated in each case Internal combustion engine, that is, when the Internal combustion engine at the knock limit, the ignition angle at Existing predetermined movement of the gas differs from that Firing angle when there is no predetermined movement of the Gases differs significantly. At a Internal combustion engine and a control unit of the entry mentioned type, the task according to the invention solved.

The invention is based on the knowledge that the Homogeneous operation of the internal combustion engine in both positions the cargo movement door can be executed. at This mode of operation of the internal combustion engine can therefore be the gas within the combustion chamber in the specified movement be transferred or not. As I said, both can Possibilities of homogeneous operation can be carried out. The There is a difference between these two options however u. a. in that for optimal Combustion process set different ignition angles Need to become. Is the default within the combustion chamber If there is movement of the gas, the ignition angle must be adjusted be set late. However, is the default Movement within the combustion chamber of the internal combustion engine not available, the firing angle must be early  can be set. This difference is according to the invention exploited the functionality of the Check cargo movement door. Is namely with the the two possibilities mentioned the difference explained the respective ignition angle does not exist, so means this is that the charge movement flap has a defect having. However, the difference mentioned is the respective ignition angle available, this means that the Charge movement flap is OK at least in so far.

The invention thus makes it simple, but still extremely effective process provided with the functionality of the charge movement flap can be reliably recognized. It is for that method according to the invention no additional hardware Effort required. Instead, the invention Process completely through appropriate software will be realized.

Furthermore, the method according to the invention has the advantage on that there is no adverse effect on the Operation of the internal combustion engine has. In particular, is by the method according to the invention does not deteriorate Exhaust emissions or driving comfort. Instead remains the execution of the for the driver of the motor vehicle inventive method unnoticed.

It is particularly advantageous if approximately the same Ignition angles are concluded that a defect in the With regard to the generation of the predetermined movement of the Gas is present within the combustion chamber. Still is it is advantageous if at significantly different Firing angles suggest that the gas is inside the combustion chamber in the correct manner into the specified one Movement can be set.  

In an advantageous embodiment of the invention, if the gas inside the combustion chamber is within the given Movement is offset, the ignition angle is late set and it will when the gas is inside the Combustion chamber is not set in the specified movement, the ignition angle is set early and it is checked whether this ignition angle due to knocking of the Internal combustion engine can be changed significantly.

In this case, the different setting the firing angle if there is one or none Movement of the gas within the combustion chamber is active performed. As a result, there is no knocking in itself the internal combustion engine may arise. However, it is not the case, the internal combustion engine points out below a knock on it may indicate a defect in the Charge movement flap to be closed.

It is particularly advantageous if one substantial change in one of the two ignition angles on it it is concluded that a defect with regard to the Generation of the predetermined movement of the gas within the Combustion chamber is present, and if at minor Changes in the firing angle suggest that the gas inside the combustion chamber in the correct way predetermined movement can be offset.

In advantageous developments of the invention, the adjusted after knocking out Checked ignition angle, or it will be the one Correction of a knock caused corrections of the Checked ignition angle. With the second option The advantage here is that the corrections of the Ignition angle can be compared with a threshold value which is independent of the operating point in which the Internal combustion engine is currently operated.  

In a further advantageous embodiment, the gas within the combustion chamber in the specified movement offset, and it becomes the gas at the same ignition angle not set in motion within the combustion chamber, and it is checked whether the ignition angle is due to a Knocking the engine is changed significantly.

With this possibility of realizing the The method according to the invention is specifically a faulty one Setting the ignition angle. This incorrect setting is then from the knock control corrected. The presence of this correction can then used to determine whether the Charge movement flap is defective or not.

The realization of the inventive method in the form of a Computer program for the control unit of the Internal combustion engine is provided. The computer program is executable on a computer of the control unit and for Execution of the method according to the invention is suitable. In In this case, the invention is Computer program realized so this Computer program in the same way represents the invention like the procedure to carry out the Computer program is suitable. The computer program can preferably stored on a flash memory. A microprocessor can preferably be present as a computer his.

Other features, applications and advantages of the Invention result from the following description of embodiments of the invention shown in the figures the drawing are shown. Thereby everyone described or illustrated features for themselves or in any combination the subject of the invention,  regardless of their summary in the Patent claims or their relationship and independently from their formulation or representation in the description or in the drawing.

Embodiments of the invention

Fig. 1 shows a schematic block diagram of an embodiment of an internal combustion engine according to the invention, and

FIG. 2 shows a schematic block diagram of an exemplary embodiment of a method according to the invention for operating the internal combustion engine of FIG. 1.

In FIG. 1, an internal combustion engine 1 is shown a motor vehicle, in which a piston 2 reciprocating in a cylinder 3 and is movable. The cylinder 3 is provided with a combustion chamber 4 , which is delimited inter alia by the piston 2 , an inlet valve 5 and an outlet valve 6 . An intake pipe 7 is coupled to the inlet valve 5 and an exhaust pipe 8 is coupled to the exhaust valve 6 .

In the area of the intake valve 5 and the exhaust valve 6, an injection valve 9 and a spark plug 10 protrude into the combustion chamber 4 . Fuel can be injected into the combustion chamber 4 via the injection valve 9 . The fuel in the combustion chamber 4 can be ignited with the spark plug 10 .

In the intake pipe 7 , a rotatable throttle valve 11 is accommodated, via which air can be fed to the intake pipe 7 . The amount of air supplied is dependent on the angular position of the throttle valve 11 . A catalytic converter 12 is accommodated in the exhaust pipe 8 and serves to clean the exhaust gases resulting from the combustion of the fuel.

An exhaust gas recirculation pipe 13 leads from the exhaust pipe 8 back to the intake pipe 7 . An exhaust gas recirculation valve 14 is accommodated in the exhaust gas recirculation pipe 13 , with which the amount of the exhaust gas recirculated into the intake pipe 7 can be adjusted. The exhaust gas recirculation pipe 13 and the exhaust gas recirculation valve 14 form a so-called exhaust gas recirculation.

A tank ventilation line 16 leads from a fuel tank 15 to the intake pipe 7 . In the tank ventilation line 16 , a tank ventilation valve 17 is accommodated, with which the amount of fuel vapor supplied to the intake pipe 7 from the fuel tank 15 can be adjusted. The tank ventilation line 16 and the tank ventilation valve 17 form a so-called tank ventilation.

The combustion of the fuel in the combustion chamber 4 causes the piston 2 to move back and forth, which is transmitted to a crankshaft (not shown) and exerts a torque thereon.

A control device 18 is acted upon by input signals 19 , which represent operating variables of the internal combustion engine 1 measured by sensors. For example, control unit 18 is connected to an air mass sensor, a lambda sensor, a speed sensor and the like. Furthermore, the control unit 18 is connected to an accelerator pedal sensor, which generates a signal that indicates the position of an accelerator pedal that can be actuated by a driver and thus the requested torque. The control unit 18 generates output signals 20 with which the behavior of the internal combustion engine 1 can be influenced via actuators or actuators. For example, the control unit 18 is connected to the injection valve 9 , the spark plug 10 and the throttle valve 11 and the like and generates the signals required to control them.

Among other things, the control unit 18 is provided to control and / or regulate the operating variables of the internal combustion engine 1 . For example, the fuel mass injected into the combustion chamber 4 by the injection valve 9 is controlled and / or regulated by the control unit 18, in particular with regard to low fuel consumption and / or low pollutant development. For this purpose, the control unit 18 is provided with a microprocessor, which has stored a program in a storage medium, in particular in a flash memory, which is suitable for carrying out the control and / or regulation mentioned.

The internal combustion engine 1 of FIG. 1 can be operated in a plurality of operating modes. It is thus possible to operate the internal combustion engine 1 in a homogeneous operation, a stratified operation, a homogeneous lean operation, a stratified operation with a homogeneous basic charge and the like.

In homogeneous operation, the fuel is injected from the injection valve 9 directly into the combustion chamber 4 of the internal combustion engine 1 during the intake phase. As a result, the fuel is largely swirled until it is ignited, so that an essentially homogeneous fuel / air mixture is produced in the combustion chamber 4 . The torque to be generated is essentially set by the control unit 18 via the position of the throttle valve 11 . In homogeneous operation, the operating variables of internal combustion engine 1 are controlled and / or regulated in such a way that lambda is equal to one. Homogeneous operation is used particularly at full load.

The homogeneous lean operation largely corresponds to that Homogeneous operation, however, the lambda becomes one value set greater than one.

In stratified operation, the fuel is injected from the injection valve 9 directly into the combustion chamber 4 of the internal combustion engine 1 during the compression phase, and preferably into the area of the spark plug 10 . Thus, when the spark plug 10 is ignited, there is no homogeneous mixture in the combustion chamber 4 , but rather a fuel stratification. The throttle valve 11 can, apart from requirements such. B. the exhaust gas recirculation and / or the tank ventilation, fully opened and the engine 1 can be operated dethrottled. The torque to be generated is largely set via the fuel mass in shift operation. With stratified operation, the internal combustion engine 1 can be operated, in particular, when idling and at partial load.

It is possible to switch back and forth between the above-mentioned operating modes of the internal combustion engine 1 as a function of the operating variables of the internal combustion engine 1 . Such switching operations are carried out by the control unit 18 . For this purpose, an operating mode map is provided in the control unit 18 , in which an associated operating mode is stored for each operating point of the internal combustion engine 1 .

As has been explained, the fuel is injected into the area of the spark plug 10 as far as possible in stratified operation. This is supported in accordance with FIG. 1 in that a pivotable charge movement flap 21 is present in the intake pipe 7 . The charge movement door 21 can be in an open and a closed state. In FIG. 1, the closed state of charge movement flap 21 is shown. The opened state can be achieved in that the charge movement flap 21 is pivoted in the direction of the arrow.

In the closed state of the charge movement flap 21 shown, no air or gas can get into the combustion chamber 4 of the internal combustion engine 1 in the lower region of the intake pipe 7 shown in FIG. 1 when the inlet valve 5 is open. Instead, the gas can only get into the combustion chamber 4 via the upper region of the intake pipe 7 past the inlet valve 5 in accordance with the arrow 22 indicated in FIG. 1.

The gas flowing into the combustion chamber 4 according to the arrow 22 performs a roller-like or swirl-like movement within the combustion chamber 4 . This is indicated by the arrow 23 in FIG. 1. The roller-shaped movement is supported by a corresponding recess 24 in the piston 2 of the internal combustion engine 1 .

If the fuel is injected via the injection valve 9 , this fuel is entrained by the inflowing gas. The gas with the fuel performs the roller-like or swirl-like movement and finally arrives directly at the spark plug 10 . By correspondingly controlling the spark plug 10 , it can be ignited at precisely the point in time at which the gas and the fuel arrive at the spark plug 10 . It is thus possible to transport the fuel injected from the injection valve 9 to the spark plug 10 and ignite it there.

If, on the other hand, the charge movement flap 21 is open, ie it is in the state not shown in FIG. 1, there is no roller-like or swirl-like movement of the gas flowing into the combustion chamber 4 . This results from the fact that when the charge movement flap 21 is open, the gas can flow from the intake pipe 7 over the entire cross section past the inlet valve 5 into the combustion chamber 4 . The inflowing gas no longer has any particular flow direction, so that there is no particular movement, in particular no roller-like movement, within the combustion chamber 4 of the internal combustion engine 1 .

At this point it is pointed out that the charge movement flap 21 can be used in internal combustion engines with one intake valve per cylinder, but in the same way also in internal combustion engines with two intake valves per cylinder. Furthermore, it is pointed out that the charge movement flap 21 can be replaced by opening only one of these two intake valves in an internal combustion engine with two intake valves per cylinder. In this case, the second inlet valve, which remains closed, gives the gas flowing into the combustion chamber an approximately swirling movement within the combustion chamber.

As has been mentioned, the charge movement flap 21 of FIG. 1 is used in particular in shift operation of the internal combustion engine 1 . In this shift operation, the charge movement flap 21 is closed as shown in FIG. 1. In contrast, in homogeneous operation it is necessary to supply as much gas as possible to the combustion chamber 4 of the internal combustion engine 1 . The charge movement flap 21 is therefore opened in homogeneous operation, so that there is no specific movement of the gas within the combustion chamber 4 . Alternatively, however, it is also possible to leave the charge movement flap 21 in the closed state shown in FIG. 1 in homogeneous operation of the internal combustion engine 1 .

If homogeneous operation of the internal combustion engine 1 is carried out with the charge movement flap 21 open, this has the consequence that there is no specific movement of the gas flowing into the combustion chamber 4 . It is therefore a conventional homogeneous operation in which the fuel injected via the injection valve 9 is distributed essentially uniformly within the combustion chamber 4 . This results in an essentially homogeneous mixture within the combustion chamber 4 , which is then ignited by means of the spark plug 10 . The effluent in the combustion chamber 4 due to the combustion is not present charge motion within the combustion chamber relatively slowly. 4 As a result, the ignition angle for the ignition of the spark plug 10 must be set relatively early.

If, however, the homogeneous operation carried out with a closed charge movement flap 21, this has the consequence that the air flowing into the combustion chamber 4. Gas performs a specific motion within the combustion chamber. 4 As a result of this movement, the combustion within the combustion chamber 4 runs much faster. To avoid knocking of the internal combustion engine 1 , it is therefore necessary for the ignition angle to be set relatively late.

The difference between a homogeneous operation with open charge movement flap 21 and a homogeneous operation closed charge movement flap 21 consists in the fact that in the closed charge movement flap 21 of the firing angle for the ignition of the spark plug must be adjusted by 10 late.

This difference in the aforementioned two options for carrying out the homogeneous operation is used to check the functionality of the charge movement flap 21 . For this purpose, generally speaking, the homogeneous operation is carried out in succession with the charge movement flap 21 open and closed. As has been mentioned, this can only be carried out by adjusting the ignition angle accordingly. If the charge movement flap 21 is defective, for example it is clamped in the open or in the closed state, this has the consequence that the internal combustion engine 1 begins to knock as a result of the change in the ignition angle. This knocking can be detected in order to then conclude that the charge movement flap 21 is defective.

A method with which a defect of the charge movement flap 21 can be recognized is explained below with reference to FIG. 2. For this purpose, the internal combustion engine 1 is switched to homogeneous operation in a step 25 .

The charge movement flap 21 is then opened in a step 26 , so that there is no specific movement of the gas flowing into the combustion chamber 4 within the combustion chamber 4 of the internal combustion engine 1 . The charge movement flap 21 is thus in the state not shown in FIG. 1.

In a step 27 , the ignition angle for the spark plug 10 is set in accordance with an existing map. Due to the lack of charge movement, the ignition angle is set relatively early. Then, in the same step 27, an existing knock control system corrects the ignition angle in such a way that the internal combustion engine 1 is then operated at its knock limit.

In a step 28 , the charge movement flap 21 is brought into its closed state. This results in a targeted movement of the gas flowing into the combustion chamber 4 .

In a step 29 , the ignition angle for the spark plug 10 is then set in accordance with an existing map. Due to the closed charge movement flap 21 , this ignition angle is set relatively late.

Furthermore, in this step 29, a knock control system corrects the ignition angle in such a way that the internal combustion engine 1 is then operated at its knock limit.

In a subsequent step 30 , the correction value with which the knock control has corrected the ignition angle in step 27 is compared with the correction value with which the knock control has corrected the ignition angle in step 29 . In the simplest case, this comparison can be carried out by forming a difference.

In a step 31 , the comparison result is compared with a threshold value. If the comparison result is greater than the threshold value, a defect in the charge movement flap 21 is concluded in a step 32 . If, on the other hand, the comparison result is less than the threshold value, the charge movement flap 21 is diagnosed as functional.

In a step 34 , the charge movement flap 21 is brought back into its open state, and the ignition angle is set in accordance with this opened state. The internal combustion engine 1 continues to operate in its homogeneous operation.

If the charge movement flap 21 is intact, the firing angles taken from the maps are essentially correct for homogeneous operation with the charge movement flap open and for homogeneous operation with the charge movement flap 21 closed. The knock control therefore only needs to make minor corrections to these ignition angles, if at all. Furthermore, these corrections, if available, are usually to be carried out in the same way for both possibilities of homogeneous operation. The result of this is that when the step 30 is compared, the two correction values essentially cancel each other out, so that the comparison result in any case remains less than the threshold value. As stated, the charge movement flap 21 is thus diagnosed as functional.

However, if the charge movement flap 21 is defective, the consequence of this is that, in one of the two possibilities for carrying out homogeneous operation, the ignition angle taken from the respective characteristic diagram is incorrect. If, for example, the charge movement flap 21 is clamped in its open state and the homogeneous operation is to be carried out in the manner in which the charge movement flap has to be closed, the subsequent retardation of the ignition angle has the consequence that - due to the non-existent Charge movement within the combustion chamber 4 - the internal combustion engine 1 begins to knock. This is recognized by the knock control and the ignition angle is corrected accordingly. The correction of the ignition angle is of considerable extent, so that in the subsequent comparison in step 30 a comparison result is produced which is in any case greater than the predefined threshold value. As a result, the charge movement flap 21 is recognized as defective.

It is pointed out that the method shown in FIG. 2 can also be carried out differently. For example, it is possible not to compare the correction values of the knock control with one another, but to compare the actual ignition angles with the two possibilities for homogeneous operation. If these actual firing angles are essentially the same in both possibilities of homogeneous operation, then a defect in the charge movement flap 21 must be concluded. However, if the two firing angles are different, this means, according to the previous statements, that the charge movement flap 21 has assumed its open or closed state in the correct manner.

Another possibility for executing the method according to FIG. 2 is that the charge movement flap 21 is transferred from its open to its closed state in homogeneous operation of the internal combustion engine 1 without the ignition angle being corrected. As a result, the knock control detects knocking of the internal combustion engine 1 and carries out a corresponding correction of the ignition angle. This correction can then be used to recognize that the charge movement flap 21 is functioning correctly.

Claims (13)

1. Method for operating an internal combustion engine ( 1 ), in particular a motor vehicle, in which fuel is injected directly into a combustion chamber ( 4 ) in at least two operating modes, in which gas is supplied to the combustion chamber ( 4 ), the gas being in the combustion chamber ( 4 ) can be set in a predetermined movement ( 22 , 23 ), and in which knocking of the internal combustion engine ( 1 ) is corrected, characterized in that in one and the same operating mode the gas inside the combustion chamber ( 4 ) once in the predetermined movement ( 22 , 23 ) and once not in the predetermined movement ( 22 , 23 ), and that it is checked whether the knocking angle of the internal combustion engine ( 1 ) is regulated with a given predetermined movement ( 22 , 23 ) of the gas from each existing significantly differentiates the ignition angle when there is no predetermined movement ( 22 , 23 ) of the gas. 2. The method according to claim 1, characterized in that at approximately the same ignition angles it is concluded that a defect with regard to the generation of the predetermined movement ( 22 , 23 ) of the gas within the combustion chamber ( 4 ) is present. 3. The method according to claim 1 or 2, characterized in that at substantially different ignition angles it is concluded that the gas within the combustion chamber ( 4 ) can be set in the correct manner in the predetermined movement ( 22 , 23 ). 4. The method according to any one of the preceding claims, characterized in that when the gas inside the combustion chamber ( 4 ) is set in the predetermined movement ( 22 , 23 ), the ignition angle is set late that when the gas inside the combustion chamber ( 4 ) is not set in the predetermined movement ( 22 , 23 ), the ignition angle is set early, and it is checked whether these ignition angles are changed significantly due to knocking of the internal combustion engine ( 1 ). 5. The method according to claim 4, characterized in that in the event of a substantial change in one of the two ignition angles, it is concluded that a defect with regard to the generation of the predetermined movement ( 22 , 23 ) of the gas is present within the combustion chamber ( 4 ), and that in the event of slight changes in the ignition angle, it is concluded that the gas within the combustion chamber ( 4 ) can be set in the correct manner in the specified movement ( 22 , 23 ). 6. The method according to any one of claims 4 or 5, characterized characterized that the after a leveling one Knocking set ignition angle can be checked. 7. The method according to any one of claims 4 or 5, characterized characterized by a knock out Corrections caused the ignition angle checked become. 8. The method according to any one of the preceding claims, characterized in that the gas within the combustion chamber ( 4 ) is set in the predetermined movement ( 22 , 23 ), that with the same ignition angle, the gas within the combustion chamber ( 4 ) is not in the movement ( 22 , 23 ) is offset, and that it is checked whether the ignition angle is changed significantly due to knocking of the internal combustion engine ( 1 ). 9. The method according to claim 8, characterized in that in the event of only a slight change in the ignition angle, it is concluded that there is a defect with regard to the generation of the predetermined movement ( 22 , 23 ) of the gas within the combustion chamber ( 4 ), and in the event of a significant change in the ignition angle, it is concluded that the gas within the combustion chamber ( 4 ) can be set in the correct manner in the predetermined movement ( 22 , 23 ). 10. Computer program, characterized in that it is used for Implementation of the method according to one of claims 1 to 9 is suitable when running out on a computer becomes. 11. Computer program according to claim 10, characterized marked that it is stored on a memory is, especially on a flash memory. 12.Control device ( 18 ) for an internal combustion engine ( 1 ), in particular of a motor vehicle, wherein in the internal combustion engine ( 1 ) fuel can be injected directly into a combustion chamber ( 4 ) in at least two operating modes, gas being able to be fed to the combustion chamber ( 4 ), the Gas can be set in a predetermined movement ( 22 , 23 ) within the combustion chamber ( 4 ), and knocking of the internal combustion engine ( 1 ) can be regulated by the control device ( 18 ), characterized in that in one and the same operating mode the gas within the combustion chamber ( 4 ) once in the specified movement ( 22 , 23 ) and once not in the specified movement ( 22 , 23 ), and that the control unit ( 18 ) can be used to check whether the knocking is regulated in each case Internal combustion engine ( 1 ) the ignition angle when there is a predetermined movement ( 22 , 23 ) of the gas from the ignition angle when there is no predetermined movement ( 22 , 23 ) of the gas differs significantly. 13. Internal combustion engine ( 1 ), in particular for a motor vehicle, in which fuel can be injected directly into a combustion chamber ( 4 ) in at least two operating modes, and in which gas can be supplied to the combustion chamber ( 4 ), the gas inside the combustion chamber ( 4 ) in a predetermined movement ( 22 , 23 ) can be offset with a control device ( 18 ) for regulating knocking of the internal combustion engine ( 1 ), characterized in that in one and the same operating mode the gas inside the combustion chamber ( 4 ) once into the predetermined one Movement ( 22 , 23 ) and once not in the predetermined movement ( 22 , 23 ) can be set, and that can be checked by the control unit ( 18 ) whether the knocking of the internal combustion engine ( 1 ) is regulated in each case the ignition angle with existing predetermined movement ( 22 , 23 ) of the gas differs significantly from the ignition angle in the absence of a predetermined movement ( 22 , 23 ) of the gas.