EP0591469B1 - Process for controlling a static ignition distribution system - Google Patents

Abstract

The invention relates to a process for controlling a static ignition distribution system in an internal combustion engine with a gear wheel allocated to a crankshaft and at least two ignition coils, in which the sequence of making and ignition occurrences in the ignition coils is determined dependently upon revolution speed ranges determinable by transmission tooth increment thresholds.

Description

State of the art

The invention relates to a method for controlling a stationary high-voltage distribution in an internal combustion engine. From WO-A-9 007 057 a method for controlling a static high-voltage distribution in an internal combustion engine with a sensor wheel connected to a crankshaft and at least two ignition coils is known, ignition and closing events occurring in each crankshaft revolution and the closing angles of different ignition coils overlap some speed ranges of the crankshaft. A counter for triggering an event is set to a predetermined value and counted as a function of a crank signal which is dependent on the crank angle. Here, the value of a first counter is changed to trigger the ignition on a spark plug and the value of a second counter is changed by means of the crankshaft-dependent clock signal to determine the start of charging of an ignition coil.

GB-A-2,087,477 describes an ignition system with a rotating distribution, an optimum closing time being calculated regardless of the speed. This is done in that there is a means for predicting the ignition event as a function of periodically occurring pulses and in that there is a means for predicting each closing event based on each ignition input and the duration of the charging process.

Advantages of the invention

The method according to the invention as claimed has the advantage that a very precise control of the ignition is possible with a relatively simple control effort short program run times and the memory requirement is low. The fact that the sequence of the closing and ignition events of the ignition coils is determined as a function of speed ranges, which are determined by encoder tooth increment thresholds, makes it possible to determine the events with relatively little effort.

It is advantageous that the selection of the triggered ignition coil also takes place as a function of encoder tooth increments. In this way, the existing ignition coils can be controlled easily, that is, the program run times for such control are relatively short.

Advantageous embodiments of the invention are specified in the dependent claims.

A preferred embodiment of the method is characterized in that at least one of the encoder tooth increments is variable. This ensures that flexible adaptation to current operating conditions is possible with little technical effort.

In addition, a method is preferred in which the encoder tooth increment thresholds occur as a function of electrical properties of the ignition coil or as a function of the current level of the supply voltage. It is thus possible to adapt the ignition distribution method to specific circumstances of the controlled internal combustion engine and its voltage supply.

It is advantageous that the closing angle is dependent It is determined from the closing time and the speed of the internal combustion engine that, based on an ignition event of an ignition coil, the segment of the associated closing event is determined as a function of the encoder tooth increment thresholds already determined. With this method, the segment of the closing event is relatively easy to determine, so that short program run times are guaranteed.

drawing

Figur 1a

die Schließ- und Zündereignisse von drei Zündspulen einer Brennkraftmaschine wäh rend eines ersten Betriebszustands niedriger Drehzahl;

Figur 1b

die Schließ- und Zündereignisse von drei Zündspulen einer Brennkraftmaschine nach Überschreiten einer ersten Drehzahl schwelle,

Figuren 1c und 1d

die Schließ- und Zündereignisse von drei Zündspulen einer Brennkraftma schine nach Überschreiten einer zweiten und dritten Geberzahninkrementschwelle mit Schließwinkelüberlappung;

Figur 2

drei Kreisdiagramme zur Verdeutlichung der Festlegung des Schließereignisses einer Zündspule;

Figur 3a

Aufladephasen von drei Zündspulen bei einer Drehzahl von 1000 U/min der Brennkraftmaschine;

Figur 3b

Aufladephasen von drei Zündspulen bei einer Drehzahl von 3000 U/min der Brennkraftmaschine;

Figur 3c

Aufladephasen von drei Zündspulen bei einer Drehzahl von 5000 U/min der Brennkraftmaschine;

Figur 3d

Aufladephasen von drei Zündspulen bei einer Drehzahl von 6000 U/min der Brennkraftmaschine;

Figur 4

Aufladephasen von drei Zündspulen in einem dynamischen Betriebszustand der Brennkraftmaschine und

Figur 5

eine Prinzipskizze einer Steuerung einer Brennkraftmaschine mit sechs Zylindern und mit Einzelzündspulen.

The invention is explained below with reference to the drawing. Show it:

Figure 1a

the closing and ignition events of three ignition coils of an internal combustion engine during a first low-speed operating state;

Figure 1b

the closing and ignition events of three ignition coils of an internal combustion engine threshold after exceeding a first speed,

Figures 1c and 1d

the closing and ignition events of three ignition coils of an internal combustion engine after exceeding a second and third encoder tooth increment threshold with closing angle overlap;

Figure 2

three pie charts to illustrate the determination of the closing event of an ignition coil;

Figure 3a

Charging phases of three ignition coils at a speed of 1000 rpm of the internal combustion engine;

Figure 3b

Charging phases of three ignition coils at a speed of 3000 rpm of the internal combustion engine;

Figure 3c

Charging phases of three ignition coils at a speed of 5000 rpm of the internal combustion engine;

Figure 3d

Charging phases of three ignition coils at a speed of 6000 rpm of the internal combustion engine;

Figure 4

Charging phases of three ignition coils in a dynamic operating state of the internal combustion engine and

Figure 5

a schematic diagram of a control system of an internal combustion engine with six cylinders and with individual ignition coils.

Description of the embodiments

In FIGS. 1a to 1d, the closing and ignition events of three ignition coils are one above the other shown in the uppermost diagram, the ignition coil 1, including the ignition coil 2 and finally the bottom, the third ignition coil 3 is shown. The abscissa denotes the crank angle or the time. The closing event or ignition event of the respective ignition coils are identified by the large letters S and Z, the closing / ignition events of the ignition coils 1 to 3 being designated by the indices. The triggering of the ignition spark is also indicated by a lightning symbol. Different lines of time or angles are distinguished by vertical lines marked with tr1, tr2, tr3. It can be seen that two crankshaft revolutions are to be indicated here in FIGS. 1a to 1d.

The closing and ignition events of the three ignition coils in these figures are shown for four different speed ranges of the associated internal combustion engine, the speed increasing from Figure 1a to Figure 1d. Between the individual representation of the associated speed ranges there are encoder tooth increment thresholds, the definition of which is discussed in more detail below. The operating state in FIG. 1 a is to be distinguished from that shown in FIG. 1 b by a first encoder tooth increment threshold, a second encoder tooth increment threshold lies between the operating states shown in FIG. 1 b and FIG. 1 c, and finally a third threshold is defined between the operating states according to FIGS. 1 c and 1 d .

It can be seen from the illustration according to FIG. 1 a that the speed of the internal combustion engine is so low that the closing and ignition event of one and the same spark plug lies within a segment. This means that the ignition coil's closing event is in the segment in which its energy is to be released by ignition. The respective ignition coil is closed according to the corresponding tr mark. In the operating state shown in FIG. 1a, the internal combustion engine rotates at a low speed n.

It can be seen from the illustration according to FIG. 1a that a certain time or a certain angle of rotation elapses after the ignition process of a spark plug before a closing event takes place in another ignition coil.

In the first segment according to FIG. 1a, it is made clear by S2 that the closing event of the coil 2 is located here. Z2 indicates that the ignition event of this second ignition coil is also in this segment.

The closing event S3 and the ignition event Z3 of the third coil are in the second segment according to FIG. 1a, and both the closing event S1 and the ignition event Z1 of the first coil are in the subsequent segment. The events mentioned then repeat themselves cyclically.

The case identified in FIG. 1a is also identified by a large A standing in a circle.

It can be seen from FIG. 1b, which is also identified as case B, that the closing and ignition events of one and the same spark plug fall into two separate, successive segments. It can be seen that a closing event of one ignition coil coincides with the ignition event of another ignition coil. Thus, in the first segment according to FIG. 1b, the ignition event Z2 of the ignition coil 2 coincides with the closing event S3 of the ignition coil 3. In segment 2, the ignition event Z3 of the ignition coil 3 and the closing event S1 of the ignition coil 1 also take place at the same time. The following third segment contains the ignition event Z1 of the first coil and the closing event S2 of the second coil, etc. The closing events are again identified with S and the corresponding index, the ignition events with Z and the associated index of the ignition coil concerned.

The ratios shown in FIG. 1b change as a result of a further increase in the speed of the internal combustion engine: according to FIGS. 1c and 1d, there are overlapping closing angles. It should be said that a closing angle of an ignition coil is given by the period of time or the angle of rotation distance between the closing event and the ignition event.

While in case A -Figure 1a- the closing angle is smaller than the length of a segment, in case C, which is shown in FIG. 1c, it can be seen that the closing angle of the ignition coils overlaps extends an area that is longer than a segment.

From Figure 1c it can be seen that the closing event S3 of the coil 3 is in the first segment and that the associated ignition event Z3 is in the second segment. While the ignition coil 3 is being charged, the ignition coil 1 is also being charged. Their closing event S1 is at the beginning of the second segment, the associated ignition event Z1 is in the third segment. While the ignition coil 1 is being charged, the ignition coil 3 is being discharged. Shortly thereafter, the ignition coil 2 is loaded in the third segment, its closing event S2 is at the beginning of the third segment.

It should be noted that the closing event of one coil falls in the period in which another coil is already being charged. This results in the closing angle overlaps mentioned. However, the speed in case C is still so low that, for example, there is a brief pause between the ignition event Z1 of the ignition coil 1 and the closing event Z3 of the ignition coil 3.

When the next, third encoder tooth increment threshold is exceeded, the ignition method switches to the next operating state, which is shown in FIG. 1d and identified as case D. The closing angle overlap increases so that the ignition event of a coil, here the ignition event Z1 of the coil 1, coincides with the closing event of another coil, here the closing event S3 of the ignition coil 3. Both events take place while the second ignition coil is still charging.

In each segment there are again two events: in the first segment the ignition event Z2 of coil 2 and the closing event S1 in coil 1. Accordingly, in the second segment the ignition event Z3 in coil 3 and the closing event S2 in coil 2. The corresponding events result from the other segments.

In case D, the closing angle, that is the distance between a closing and an ignition event, becomes so large that it extends over two tr marks. After the ignition of one coil, the next but one is charged. It can be seen from FIG. 1d that the closing angle thus covers three segments.

The largest possible closing angles in the respective speed ranges are shown in FIGS. 1b to 1d. If the closing angle is increased further, the next case is reached. The closing angle can reach a maximum of 240 ° KW in the method shown here.

If a closing angle of more than 240 ° KW is to be achieved, a residual open angle monitoring must be carried out to ensure the necessary discharge duration of the ignition coil.

FIG. 2 again shows the four cases A to D different in FIG. 1, the following being shown: In the uppermost pie chart according to FIG. 2 it is made clear for case A that the closing and ignition event fall into a single segment.

It can be seen from the second pie chart in FIG. 2 that for cases B and C the ignition event takes place in one segment, while the associated closing event is shifted by one segment.

Finally, it can be seen from the lowest pie chart in FIG. 2 that the closing event of a coil is shifted by two segments compared to the ignition event.

The more precise relationships between the ignition and closing events will be discussed below.

In the diagrams according to FIG. 3, the charging phases of the individual ignition coils, which are limited by the closing and ignition event, are shown above the crank angle, which is given in degrees. The abscissa extends over a range of 1800 ° KW. The charging phases of the ignition coil 1, 2 and 3 are shown one above the other, the diagram of the ignition coil 1 below, that of the ignition coil 2 in the middle and that of the ignition coil 3 above.

The representations according to FIGS. 3a to 3d show example cases. They differ in different speed ranges. While a speed n of 1000 rpm is selected in FIG. 3a, the illustration according to FIG. 3b relates to a speed of 3000 rpm, that of 3c n = 5000 rpm and that of FIG. 3d a speed n of 6000 rpm. min.

It is readily apparent that the charging phases always increase with increasing speed to achieve the necessary energy within the ignition coil become longer, so that - as already described with reference to FIGS. 1a to 1d - a first closing angle overlap takes place from FIG. 3c, which takes on its maximum value in FIG. 3d. In contrast, it is clear that in Figure 3a there is a visible angular distance between the ignition event of the one coil and the closing event of the ignition coil controlled thereafter. This distance is reduced to zero in FIG. 3b, that is to say the ignition event, for example of ignition coil 2, coincides with the closing event of ignition coil 3, while its ignition event coincides with the closing event of ignition coil 1.

FIG. 4 shows the closing and ignition events of three ignition coils one above the other, the crank angle in degrees being plotted along the abscissa and the speed n in rpm being plotted on the ordinate. The speed is quasi triangular above the charging phases shown in dashed lines with a solid line. It is clear from the diagram that the speed increases during a freely selected range of a total of 10 revolutions from approx. 2500 rpm to almost 4000 rpm and then drops back to the initial value.

The dynamic behavior of the ignition control is to be explained on the basis of this representation:

In the lowest area of the increasing speed curve, approximately up to 720 ° KW, a distance between the ignition event of the one ignition coil and the closing event of the next ignition coil can be seen. In the subsequent range between 720 ° KW to about Almost 1400 ° KW, the ignition event of an ignition coil and the closing event of the subsequently controlled ignition coil coincide.

Due to the increasing speed, the associated encoder tooth increment threshold between case B and case C shown in FIGS. 1 and 3 is finally exceeded, so that a closing angle overlap finally occurs, which is approximately between 1400 ° KW and approximately 2000 ° KW. That is, the overlapping charging phases of the various ignition coils are: First, the charging phase of the ignition coil 1 with that of the ignition coil 3; the charging phase of the ignition coil 2 falls later in the charging phase of the ignition coil 3. While this is being charged, the closing event of the ignition coil 1 is finally initiated. The closing angle overlaps result more clearly from FIGS. 1c and 1d and 3c and 3d. According to FIG. 4, the area of the closing angle overlap with decreasing rotational speed is in turn followed by an area in which the charging phases of the various ignition coils directly adjoin one another. Finally, there is a clear gap between the individual charging phases when the engine speed has dropped further.

From the representations in the figures it is readily apparent that the control of the individual ignition coils takes place as a function of the speed, the sequence of the closing and ignition events of the individual ignition coils being determined as a function of specific speed ranges. These are differentiated by encoder tooth increment thresholds, as explained with reference to the figures.

The various speed ranges are selected so that a closing angle is set so large that the energy required to generate the ignition spark is fed into the ignition coil. To ensure this, the encoder tooth increment thresholds are designed to be variable, in particular they are determined as a function of the electrical parameters of the individual ignition coils. Depending on the ignition coil, a larger or smaller closing angle can be specified.

In addition, it is also possible to influence the encoder tooth increment thresholds and thus the predetermined speed ranges as a function of the supply voltage of the internal combustion engine. If the battery voltage drops, the closing angle is extended due to the present method so that sufficient energy is fed into the ignition coils.

From the previous explanations it is clear that the ignition and closing events of the ignition coils can fall into different segments depending on the specific speed ranges. Figures la to ld show that the ignition event of an ignition coil is close to a tr mark, which are shown in figures la to ld. In Figure 2, the numbers 1, 2 and 3 are chosen to designate these brands.

Depending on the speed and the parameters mentioned (coil data and battery voltage) To ensure the necessary ignition energy, the associated closing event of the corresponding coil must be predetermined for an ignition event of a coil.

This can be done in two different ways: firstly, a rough definition of the segment in which the closing event falls can be made, while the position of the closing event within this segment is then specified more precisely. It is also possible to determine in a suitable manner the number of teeth of a gearwheel assigned to the crankshaft which must be counted during the charging phase of an ignition coil, that is to say that the closing angle of an ignition coil is defined by the number of teeth counted.

In the former method, the control of the closing angle is carried out with the aid of an ignition counter IZX, an ignition coil counter IZS and an ignition control counter ZZ. The counter reading given in the ignition counter IZX determines which of the ignition coils 1, 2 or 3 is to be discharged in a specific segment. The status of the ignition coil counter IZS indicates the ignition coil 1, 2 or 3 that is to be loaded in this segment. The ignition control counter ZZ controls these events in a conventional manner, so that a more detailed description is dispensed with. The ignition coil to be charged is selected according to the following equation: $$\text{IZS = IZX + ILX}$$

ILX is the speed range-dependent offset that indicates the number of segments that must lie between the ignition event of an ignition coil and its closing event.

It can be seen from FIG. 2 that for case A the speed range-dependent offset ILX assumes the value 0 because the ignition coil, the ignition event of which is in a segment, is to be loaded in the same segment; its closing event therefore falls in the segment in which the ignition event is located.

For cases B and C explained with reference to FIG. 1, the speed range-dependent offset ILX according to FIG. 2 (central pie chart) assumes the value 1. It follows from this that the ignition coil to be charged is ignited in the next segment, that is to say the closing event and the ignition event of an ignition coil fall into two successive different segments.

Finally, in the bottom diagram of FIG. 2, the speed range-dependent offset ILX with the value 2 indicates that the ignition coil to be charged is ignited in the next but one segment, that is to say that, as shown in FIG. 1d, the closing event and ignition event of one and the same ignition coil are not in successive ones Segments fall, but that there is a segment in between. In other words, the closing angle of the ignition coil is so large that the closing event of this coil falls into one segment and its ignition event falls into the next but one segment.

From the above-mentioned equation (1) it follows that an ignition coil is skipped when the closing event passes over a tr mark without additional measures. This affects the transitions on the one hand between case A and case B and on the other hand between case C and case D.

In case A, ILX = 0 and in case B, ILX = 1. A Δ ILX = 1 is thus obtained. ILX = 1 also applies to case C and ILX = 2 applies to case D. Here, too, there is a difference of Δ ILX = 1. The count of the ignition counter IZX changes in each segment according to FIG. 2, so that the value IZS resulting from equation (1) changes by the value 2 during the transition from A to B or C to D. The transition from case A to case B should be illustrated using the following numbers for two successive ignition processes:

Ignition process n - 1 for case A: IZX = 2; ILX = 0. Therefore, the following applies to IZS: IZS = 2.

Ignition process n for case B: IZX = 3; ILX = 1; Therefore, the status of the ignition coil counter IZS is: IZS = 1. The value IZS = 3 was omitted. If the count of the ignition coil counter IZS assumes a value of> 3, this counter is set to the value 1 because after the 3rd ignition coil the first should be loaded again.

It can be seen that ILX changes at the transition to a tr mark. The reason for this is that the closing, like the ignition, is controlled from the beginning of the segment in accordance with the tr brands, specifically for the current segment. In case B the closing should have happened through the transition at the end of the last segment, which is not possible in principle. For this reason, the ignition coil in question is positively closed when a corresponding transition is detected at the tr mark. This measure has no external impact. The additional closing is therefore not noticeable. However, it is ensured that the closing process functions properly and dynamically.

Within the speed ranges defined by the encoder tooth increment thresholds, the closing angle is set more precisely using the ignition control counter ZZ.

The closing process is controlled in the following ways:

The ignition control counter ZZ is loaded with the number of encoder increments which, calculated from the tr mark, must still occur before the closing process can be initiated, ie before the associated coil can be closed.

For example, there is a requirement that 36 ° KW should be closed after the tr mark. This value of the crank angle is divided by the encoder tooth width of, for example, 6 °. This means that the value 36/6, ie the number "6", must be loaded into the ignition control counter ZZ. In the numerical example chosen here, it was assumed that a toothed disc with 60 teeth was selected as the encoder wheel, which is rigidly connected to the crankshaft. From this it can be deduced that a single increment tooth extends over 6 ° KW. This value is also referred to as L _Z.

The encoder tooth increments Z are calculated using the following formula $$\text{Z =}\frac{{\text{360}}^{\text{O}}{\text{· N}}_{\text{ms}}\text{· SZ}}{{\text{L}}_{\text{Z.}}}$$

In addition to the known names, the following information is used here: SZ denotes the closing time (measured in ms) and N _ms the number of crankshaft revolutions per millisecond.

It is noted in more detail below that the size of the tooth increment thresholds depends on the ignition angle.

The value loaded into the ignition control counter ZZ is then calculated by starting from a lower encoder increment threshold Z 'and by reducing the number of teeth per segment by the lower encoder increment threshold Z' as the value to be loaded into the ignition control counter ZZ.

It is particularly advantageous that the closing angle can be controlled to 6 ° to 3 ° KW in this way even without the use of a timer.

Since the speed ranges are determined by the variable encoder tooth increment thresholds, the current battery voltage with the coil data is included in the calculation of the respective charging time. The encoder tooth increment thresholds are corresponding to the Percentage change in loading time postponed. In this way, these methods dispense with the use of a map for the closing angle.

The distinction between the four cases A to D ensures that the control functions of the ignition control counter ZZ do not come into conflict with one another, because both ignition and closing are controlled via this counter.

In order to avoid malfunctions of the process, additional coercive measures can be integrated into the process: In addition to the positive ignition after the top dead center of a piston, depending on the speed range, before the ignition - this applies to cases A and C- or after the tr- Brand - this applies to cases B and D- if the closing event of an ignition coil in this or in the previous segment has not been initiated by the given time.

According to the other method, the closing angle which results from the closing time and the rotational speed is determined on the basis of the number of teeth counted of a gear wheel of the internal combustion engine assigned to the crankshaft, the desired closing angle also being reached when a predetermined number of teeth is reached. In this method, the closing angle is set based on the number of tooth increments over which an ignition coil must be closed.

$$\text{28 ≥ Z > 20 \hspace{1em}\hspace{1em}\hspace{1em}Bereich C}$$

$$\text{20 ≥ Z > 8 \hspace{1em}\hspace{1em}\hspace{1em}Bereich B}$$

$$\text{8 ≥ Z > 0 \hspace{1em}\hspace{1em}\hspace{1em}Bereich A}$$

In this method, the selection of the control range with which the closing angle is determined is based on the tooth increments Z. For example sweeps a segment, as defined in Figure 1 for a six-cylinder engine, 20 tooth increments. The number of tooth increments, according to which the ignition is triggered - calculated from the tr mark (beginning of the segment) - should be 8, for example. This results in the following division of areas by the encoder tooth increment thresholds: $$\text{40 ≥ Z> 28 area D}$$

$$\text{28 ≥ Z> 20 <figure-callout id="20" label="area C" filenames="imgf0011.png" state="{{state}}">area C</figure-callout>}$$

$$\text{20 ≥ Z> 8 area B}$$

$$\text{8 ≥ Z> 0 area A}$$

In the start area with Z = 0, in which the closing angle cannot be controlled with these methods, the closing angle is controlled with the aid of a timer control.

It is particularly advantageous that a direct coupling of the start of closing to the ignition of the coil is possible with this method. In particular, a transition from one control area to the adjacent can be brought about solely by changing the ignition angle, which depends on the respective operating state of the internal combustion engine. In principle, dynamic changes in the ignition angle after the ignition coil is closed continue to shorten or extend the closing time.

The size of the individual control areas is determined by the respective firing angle and the position of the tr mark.

With this method, the closing time is controlled correctly regardless of these parameters. The program duration is shortened in each individual segment.

Another advantage of this method is that the actual closing time of an ignition coil as a function of the battery voltage is stored as a characteristic. This allows the desired closing time for a given battery voltage to be entered directly.

It can be seen from FIG. 4 that the method described here can be used not only for static operating states of the internal combustion engine, but also when its speed changes.

For this purpose, an additional control mechanism is provided, in which a special activation of the ignition coils takes place during a transition via an encoder tooth increment threshold: If an encoder tooth increment threshold is exceeded from bottom to top, the control method can determine that the ignition timing of an ignition coil has already come so close, that the remaining charging time is no longer sufficient to achieve the required ignition energy. If a sensor tooth increment threshold is exceeded with increasing speed, the problem arises that during the lower speed a late closing event to achieve the desired ignition energy would have been enough. Now, after the speed had increased, an earlier closing event should have been initiated to ensure a sufficient charging phase. This is no longer possible retrospectively.

In the opposite case, if the encoder tooth increment threshold is exceeded from top to bottom, no further measures are required. During the high speed, the corresponding ignition coil was closed earlier to ensure the required ignition energy. Now, after the speed has been reduced, a later start of the charging phase, i.e. a later closing event, would be sufficient. In this case, a new closing event is initiated only for the ignition coil.

Ultimately, if a encoder tooth increment threshold was exceeded with increasing speed, the speed range-dependent offset ILX would increase. This means that there should be an additional segment between the ignition event and the closing event. Since such control is subsequently no longer possible, in this case, as shown above, care is taken to ensure that the ignition coil in question is positively closed at the upcoming tr mark as a compulsory measure.

These coercive measures are due to the software structure. Only the correct closing and ignition control appears to the outside.

The change in the control of the ignition coils visible in a dynamic operating state of the internal combustion engine can be seen from FIG. 4. This illustration shows a dynamic transition from case B to case C.

The method can be used for any number of ignition coils, with no additional memory or RAM cell requirement in the memories being required. In particular, individual ignition coils can also be used. It should also be pointed out that this method is characterized in that z-1 ignition coils can be closed simultaneously in the case of ignition coils of an internal combustion engine.

The described method can be reproduced again with the aid of FIG. 5. In this illustration, a control unit is shown which carries out the calculations described above. There are corresponding control signals to the ignition coils 1, 2, 3, 4, 5 and 6 of an internal combustion engine with six cylinders, which are only indicated here. The individual ignition coils 1, 2, 3, 4, 5 and 6 are assigned to cylinders 1 to 6.

A sensor wheel 20 is rigidly connected to the crankshaft of the internal combustion engine, not shown here, and individual teeth 22 are indicated on the circumferential surface thereof. Furthermore, a gap 24 can be recognized as a reference mark.

A master tooth increment, as mentioned above, is defined by the flanks of two teeth 22 immediately following one another. For clarification such a tooth increment Z was drawn in FIG. With the aid of a first sensor 26, the outer lateral surface of the sensor wheel 20 is scanned. The signals from the sensor 26 are forwarded to the control device 10 and processed by the latter.

In addition, a phase sensor wheel 40 is also shown here, which is rigidly connected to the camshaft of the internal combustion engine and has a tooth 42 on its outer surface. The phase sensor wheel 40 is scanned or the appearance of the tooth 42 is detected by a second sensor 44. The output signals of the second sensor 44 are also forwarded to the control unit 10.

The ignition events of the ignition coils 1, 2, 3, 4, 5 and 6 are controlled by the control unit 10 taking into account the signals emitted by the sensors 26 and 44, as was made clear above on the basis of the explanation of the method.

The phase signal is only required for single ignition coils for which the method can be applied in an analogous manner.

The method also allows the refined setting of the closing angle to be the specified 3 ° or 6 ° without eliminating the advantages of the program run step. In addition, the use of different ignition coils for the individual cylinders of an engine is conceivable and can be realized with this method.

Claims (4)

1. Method for controlling static high-voltage distribution in an internal combustion engine, having a sensor wheel (20) which is connected to a crankshaft, having at least two ignition coils (1,2,3,4,5,6), a plurality of events, namely ignition events and dwell events occurring in each rotation of the crankshaft, the dwell angles of the different ignition coils (1,2,3,4,5 and 6) overlapping in many revolution-speed ranges of the crankshafts, having the steps,

   -1.) that a revolution of the crankshaft is divided into angular segments, two events occurring in each angular segment,

   -2.) that starting from a reference mark (24), marks (trl, tr2, tr3) which each coincide with the start of an angular segment are provided on the sensor wheel (20),

   -3.) that the entire revolution-speed range of the crankshaft is divided into a plurality of working ranges (A,B,C,D) and the type and sequence of the events to be triggered in each angular segment is predetermined by each working range (A,B,C,D), the assignment of each event to the respective ignition coils (1,2,3,4,5,6) being predetermined by the working range (A,B,C,D),

   -4.) that a value (2) which is dependent on the revolution speed is calculated as a function of the particular revolution speed of the crankshaft at that time and a particular working range (A,B,C,D) at that time is selected as a function of this value (2) which is dependent on the revolution speed,

   -5.) that in each case a value is calculated in advance for the events to be triggered in each angular segment,

   -6.) that the triggering of the events is controlled over the entire revolution-speed range of the crankshaft, in particular the range with overlapping dwell angles using only one event counter (ZZ), the event counter (ZZ) being loaded with the previously calculated values after the occurrence of the respective mark,

   -7.) that the event counter (ZZ) is counted as a function of a clock signal which is triggered by the sensor wheel (20) and is dependent on the crankshaft angle and when the counter state corresponds to a predetermined value, in particular the value zero, the respective event is triggered.
2. Method according to Claim 1, characterized in that the working ranges (A, B, C, D) are specified as a function of electrical properties of the ignition coil or of the voltage supply.
3. Method according to one of the preceding claims, characterized in that the selection of the ignition coil to be charged takes place in such a way that a working range-dependent offset (ILX) is added to an ignition counter (IZX), the offset (ILX) indicating the number of segments which are located between the ignition event of an ignition coil and its dwell event.
4. Method according to Claim 3, characterized in that the working range-dependent offset values (ILX) are different for the individual working ranges (A,B,C,D).

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