Device for controlling a multiple spark operation of an internal combustion engine, and related method

Abstract

The invention relates to a device for controlling a multiple spark operation of an internal combustion engine, wherein an ignition transformer can be switched off and back on again for delivering or interrupting an ignition spark energy based on at least one current threshold. The invention proposes that the at least one current threshold be programmable.

Claims

1. A control unit for regulating a multiple spark operation of a combustion engine, comprising an ignition transformer that is switched on and off for releasing or interrupting an ignition spark current by a regulator electronic circuit for actuating the ignition transformer with the aid of at least one programmed current threshold, wherein the control unit is configured to transmit a first control signal and a second control signal to the regulator electronic circuit, the first and second control signals being separated from each other in time such that a value for a follow-up current threshold is defined by a variable pulse pause between a termination of the first control signal and a beginning of the second control signal when the first control signal and the second control signal are not being transmitted; wherein the control unit is configured to store a plurality of thresholds that correspond to a plurality of operating statuses of the combustion engine, wherein the first and second control signals are supplied to the regulator electronic circuit for defining the follow-up current threshold and for actuating the ignition transformer, wherein the first and second control signals are communicated from the control unit to the regulator electronic circuit over a single-wire interface, wherein the first control signal provides a loading time and an ignition time of a conventional ignition, and wherein the second control signal provides a duration of a multiple spark phase, wherein the variable pulse pause is an encoded interval, and wherein the value for the follow-up current threshold is transmitted over the single-wire interface via the encoded interval between the first control signal and the second control signal.

2. The control unit according to claim 1, wherein the release or interruption of the ignition spark current takes place depending on a comparison of the follow-up current threshold and a measurable transformer current, wherein the measurable transformer current is a secondary current.

3. The control unit according to claim 1, wherein a transmission of the value for the follow-up current threshold takes place depending on a duration of the variable pulse pause in combination with a further value of a related follow-up current threshold, wherein the related follow-up current threshold is a primary current switch-off threshold.

4. The control unit according to claim 3, wherein the transmission of the value for the follow-up current threshold value and/or a transmission of a further value for the follow-up current threshold takes place with the aid of a protocol which contains correlations between a duration of the variable pulse pause and the follow-up current threshold values.

5. The control unit according to claim 1, wherein a transmission of the value for the follow-up current threshold value takes place in connection with a current threshold difference value over a duration of the variable pulse pause.

6. The control unit according to claim 1, wherein a bidirectional interface is provided between the control unit and the ignition transformer, the bidirectional interface being used for transmitting a spark burning time.

7. The control unit according to claim 1, wherein a transmission of a value of a secondary current switch-off threshold over a duration of the variable pulse pause takes place during the detection of an amplitude value of a first primary current pulse for adjusting a primary current switch-off threshold.

8. The control unit according to claim 1, wherein a transmission of a combination of a secondary current switch-off threshold and a primary current switch-off threshold takes place with an amplitude of a first primary current pulse.

9. A regulator electronic circuit for an ignition transformer and for regulating a multiple spark operation of a combustion engine, comprising the ignition transformer, the ignition transformer being switched on and off for releasing or interrupting an ignition spark current by the regulator electronic circuit with the aid of at least one programmed current threshold, wherein the regulator electronic circuit is configured to receive a first control signal and a second control signal from a control unit, the first and second control signals being separated from each other in time such that a value for a follow-up current threshold is defined by a variable pulse pause between a termination of the first control signal and a beginning of the second control signal when the first control signal and the second control signal are not being transmitted; wherein the control unit is configured to associate a duration of the variable pulse pause with the follow-up current threshold, wherein the first and second control signals are supplied to the regulator electronic circuit for defining the follow-up current threshold and for actuating the ignition transformer, wherein the first and second control signals are communicated from the control unit to the regulator electronic circuit over a single-wire interface, wherein the first control signal provides a loading time and an ignition time of a conventional ignition, and wherein the second control signal provides a duration of a multiple spark phase, wherein the variable pulse pause is an encoded interval, and wherein the value for the follow-up current threshold is transmitted over the single-wire interface via the encoded interval between the first control signal and the second control signal.

10. The regulator electronic circuit according to claim 9, wherein the release or interruption of the ignition spark current takes place depending on a comparison of the follow-up current threshold and a measurable transformer current, wherein the measurable transformer current is a secondary current.

11. The regulator electronic circuit according to claim 9, wherein a transmission of the value for the follow-up current threshold takes place depending on the duration of the variable pulse pause in combination with a further value of a related follow-up current threshold, wherein the related follow-up current threshold is a primary current switch-off threshold.

12. The regulator electronic circuit according to claim 11, wherein the transmission of the value for the follow-up current threshold value and/or a transmission of a further value of the related follow-up current threshold takes place with the aid of a protocol which contains correlations between the duration of the variable pulse pause and the follow-up current threshold values.

13. The regulator electronic circuit according to claim 9, wherein a transmission of the value for the follow-up current threshold value takes place in connection with a current threshold difference value over the duration of the variable pulse pause.

14. The regulator electronic circuit according to claim 9, wherein a bidirectional interface is provided between the control unit and the ignition transformer, the bidirectional interface being used for transmitting a spark burning time.

15. The regulator electronic circuit according to claim 9, wherein a transmission of the value for the follow-up current threshold value of a secondary current switch-off threshold over a duration of the variable pulse pause takes place during the detection of an amplitude value of a first primary current pulse for adjusting a primary current switch-off threshold.

16. The regulator electronic circuit according to claim 9, wherein a transmission of a combination of a secondary current switch-off threshold and a primary current switch-off threshold takes place with an amplitude of a first primary current pulse.

17. A procedure for regulating a multiple spark operation of a combustion engine, comprising: switching an ignition transformer off and on for releasing or interrupting an ignition spark current by a regulator electronic circuit for actuating the ignition transformer with the aid of at least one current threshold, transmitting a first control signal and a second control signal to the regulator electronic circuit from a control unit, the first and second control signals being separated from each other in time, and defining a value for a follow-up current threshold using a duration of a variable pulse pause between a termination of the first control signal and a beginning of the second control signal when the first control signal and the second control signal are not being transmitted, wherein the first and second control signals are supplied to the regulator electronic circuit for defining the follow-up current threshold and for actuating the ignition transformer, wherein the first and second control signals are communicated from the control unit to the regulator electronic circuit over a single-wire interface, wherein the first control signal provides a loading time and an ignition time of a conventional ignition, and wherein the second control signal provides a duration of a multiple spark phase, wherein the variable pulse pause is an encoded interval, and wherein the value for the follow-up current threshold is transmitted over the single-wire interface via the encoded interval between the first control signal and the second control signal.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The invention as well as advantageous embodiments according to the characteristics of the further claims are subsequently further explained with the aid of the embodiments that are illustrated in the drawings, without a limitation of the invention; it comprises furthermore all variations, changes and equivalents, which are possible within the scope of the claims. It is shown in:

(2) FIG. 1 a diagram with a control signal course, in particular the course of a control voltage, as well as with a primary current course and with a secondary current course, at which the adjustment of the secondary current switch-off threshold takes place over a short pulse pause;

(3) FIG. 2 a further diagram with a control signal course, in particular the course of a control voltage, as well as with a primary current course and with a secondary current course, at which the adjustment of the secondary current switch-off threshold takes place over a long pulse pause;

(4) FIG. 3 a diagram with a control signal course, in particular a course of a control voltage, and with a course of a control current as well as with a primary current course and with a secondary current course, at which a change of the control current takes place by a regulator electronic of an ignition transformers depending on the operating status of the transformer (reloading=20 mA and unloading (ignition spark)=10 mA);

(5) FIG. 4 a diagram with a control signal course, in particular a course of a control voltage, as well as with a primary current course and with a secondary current course, at which the adjustment of a primary and secondary current switch-off threshold, in particular with the aid of a switch-off threshold value pair takes place over a short pulse pause;

(6) FIG. 5 a further diagram with a control signal course, in particular a course of a control voltage, as well as with a primary current course and with a secondary current course, at which the adjustment of a primary and secondary current switch-off threshold, in particular with the aid of a switch-off threshold value pair takes place over a long pulse pause; and

(7) FIG. 6 a diagram with a control signal course, in particular a course of a control voltage, as well as with a primary current course and with a secondary current course, at which an information transmission takes place for adjusting the current switch-off thresholds during a multiple spark phase.

(8) FIG. 7 shows an ignition control unit 78 connected to a control unit 80, a primary side coil 72 connected to the ignition control unit 78 and also to a power supply 70, and a secondary side coil 76 connected to a spark plug 74.

DETAILED DESCRIPTION

(9) FIG. 1 shows a diagram 10, which comprises the course of a control voltage 11, the course of a primary current 12 as well as the course of a secondary current 13. At a multiple spark system of the present type a control unit typically sends out a first pulse 14 and a second pulse 15 at the use of a single-wire interface in an ignition cycle. The first pulse 14 corresponds with a conventional transistor coil ignition, whereby the control unit provides a loading time as well as an ignition time. The second pulse 15 provides the duration of a multiple spark phase. There is a pulse pause 16 or also an interval between the two pulses 14, 15—also called control signals, which is relatively short according to FIG. 1 and which serves for programming at least one of the current thresholds. As long as the pause time 16 is encoded between the two pulses 14, 15 that are sent out by the control unit, information or data values, such as values of a secondary current threshold 17, can be transmitted over the pulse pause 16 to the ignition transformer, in particular ignition coil. The encoding can thereby take place by different variants.

(10) According to FIG. 1 a transmission of values of the secondary current switch-off threshold 17 takes place over the duration or length of the pulse pause 16. In the present embodiment the pulse pause 16 has a value of 10 μs and corresponds therefore with a secondary current switch-off threshold 17 of 80 mA, which is equivalent to a high switch-off current. Besides the secondary current switch-off threshold 17 there is a primary current switch-off threshold 18. At additional pairs of values the pulse duration 16 provides values of 30 μs, 60 μs, 100 μs or 160 μs, while the secondary current switch-off threshold 17 is set to values of 70 mA, 60 mA, 50 mA or 40 mA. According to FIG. 2 or according to a corresponding diagram 20 the secondary current switch-off threshold 17 corresponds with the lastly mentioned value of 40 mA of the pulse pause 16 at 160 μs, which mirrors a low switch-off current at a comparably long pulse pause. Apart from that the diagram according to FIG. 2 corresponds with the diagram according to FIG. 1 and provides also the course of the control signal 11, the course of the primary current 12 with a corresponding primary current switch-off threshold 18 as well as the course of the secondary current 13.

(11) FIG. 3 shows a diagram 30, which describes the course of the control voltage 11, the course of the control current 19 as well as the course of the primary current 12 and the course of the secondary current 13. A current threshold difference value or also a value delta is thereby transmitted over the pulse pause 16. A long pulse pause means in that context a sinking of the current threshold by 10 mA. A short pulse pause causes an increase of the current threshold by 10 mA. In order to avoid an erroneous interpretation of present pulse pauses, in particular at the transmission of current threshold difference values, a bidirectional interface can be provided between the control unit and ignition transformer. A feedback of information of the ignition transformer can thereby take place by a switchover of a control current. The control current 19 can for example correspond with a value 21 of 20 mA during a spark burning time and with a value 22 of 10 mA during a reloading phase. The control unit is able to determine the spark burning time over the current and increases or reduces the secondary current threshold depending on the required spark burning time. It is thereby ensured that the information in the control unit and in the ignition transformer do always correspond with each other, whereby an error is not carried along into every further ignition cycle.

(12) FIG. 4 shows a diagram 40, which illustrates the course of the control voltage 11, the course of the primary current 12 as well as the course of the secondary current 13. Thereby a combination of values from the secondary current switch-off threshold 17 and the primary current switch-off threshold 18 are transmitted over the duration of the pulse pause 16. The duration of the pulse pause 16 of 160 μs corresponds thereby with 50 mA for the secondary current switch-off threshold 17, and 17A for the primary current switch-off threshold 18. According to FIG. 5, whose diagram 50 also provides the course of the control current 11, the course of the primary current 12 and the course of the secondary current 13, the duration of the pulse pause is 100 μs, so that a value of 50 mA is associated to the secondary current switch-off threshold 17 and a value of 15 A to the primary current switch-off threshold 18. Further associations provide a current threshold relation of 70 mA to 17 A for a pulse pause of 60 μs and a current threshold relation of 70 mA to 15 A at a pulse pause of 30 μs for the secondary current switch-off threshold 17 or for the primary current switch-off threshold 18.

(13) FIG. 6 shows a diagram 60, which comprises the course of the control voltage 11 as well as the course of the primary current 12 and the course of the secondary current 13. The transmission of the information about the current thresholds takes thereby place during the multiple spark phase, thus during the second pulse 15. For the transmission of the information and values a protocol can be used that is suitable for single-wire interfaces. The multiple spark phase or its signal course are thereby the basis for a programming of the current thresholds. Alternatively also a pulse width modulated signal can be used. In order to avoid an undesired switching on or switching off of the ignition transformer due to the information transmission during the multiple spark phase, preferably very short pulses 15.1 to 15.4 are used, which can be filtered for a standard function. The sent information are processed for that case not unit the next ignition cycle, since the multiple spark phase or its signals themselves serve as information carriers.