JP2012122348A - Ignition device for internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ignition device for an internal combustion engine, which can exhibit original performance to be expected for a lap discharge type ignition device by suppressing the disturbance of superposed discharge energy wave form generated in an ignition coil secondary winding.SOLUTION: When a high voltage is generated in the secondary winding 7b of an ignition coil 7 by discharge energy of a capacity discharge type ignition circuit 4, a capacitor 3i for trigger signal generation of a self-exciting thyristor series inverter type ignition circuit 3 is charged by a voltage generated in a feedback winding 7c disposed on the ignition coil 7, and by a discharge current from the capacitor 3i for trigger signal generation in a procedure where the voltage in the feedback winding 7c falls, the thyristor 3c is triggered and the self-exciting thyristor serial inverter type ignition circuit 3 is started.

Description

  TECHNICAL FIELD The present invention relates to an ignition device for an internal combustion engine mounted on a motor vehicle, and more particularly, a capacitive discharge in which a plurality of self-excited thyristor series inverter ignition circuits are generated in succession in a capacity discharge energy generated by a capacity discharge ignition circuit. The present invention relates to an improvement of an overdischarge type internal combustion engine ignition device that superimposes energy.

  In recent years, a so-called lean burn engine (lean burn engine) in which the air-fuel ratio is set extremely thin has been adopted as an internal combustion engine mounted on a vehicle. Since this type of engine is not very efficient in ignition, a high energy type ignition device is required. Therefore, as previously disclosed in Patent Document 1 below, a multiple discharge ignition device has been proposed in which the high-voltage output of the DC-DC converter is superimposed on the secondary output of the ignition coil generated by the classic current interruption principle. It had been.

  That is, after the primary current of the ignition coil is cut off, a high voltage of several KV generated on the secondary side causes discharge breakdown in the discharge gap of the spark plug, and after the discharge current starts to flow from the secondary side of the ignition coil The DC-DC converter keeps the DC voltage (usually about 500V or more) higher than the discharge maintenance voltage that can maintain the discharge state, while adding the output current from the DC-DC converter to the ignition coil discharge current. Superimpose. In fact, according to such a system, a large amount of discharge energy can be obtained in the spark plug for a relatively long time, so that the ignitability of the fuel is improved and, consequently, the fuel efficiency is also improved.

  However, combustion in each cylinder combustion chamber of an internal combustion engine proceeds in sequence from initial discharge sparks to the spark plug to initial combustion, medium-term combustion, and main combustion. A sudden change in the airflow occurs, and the discharge spark generated in the gap between the discharge electrodes of the spark plug is blown out, despite the fact that a superimposed discharge current is supplied by the DC-DC converter. "Phenomenon" may occur. When such a blowout phenomenon occurs, the discharge is interrupted without being extended to a predetermined duration, and the intended combustion energy cannot be obtained.

  Therefore, in order to solve this problem, as disclosed in the following Patent Document 2 which is the hand of the present applicant, first, a capacitive discharge type ignition circuit having an initial ignition performance superior to that of the current interrupting circuit is used, and the capacity discharge energy is adjusted. On the other hand, as the superimposed energy, high-speed repeated discharge (generation of multiple discharge sparks) is possible, and even if a “blown out phenomenon” occurs, it is possible to re-discharge by repeating the discharge after that. Proposals have been made to use the capacity discharge energy generated by the self-excited thyristor series inverter ignition circuit.

  FIG. 2 shows a configuration example of an internal combustion engine ignition device constructed according to the technique disclosed in Patent Document 2. Explaining first, in the capacity discharge type ignition circuit 4, energy storage for capacity discharge is performed from the high voltage output terminal 2a of the DC-DC converter 2 operated by the power source 1 which is a battery mounted on the vehicle via the diode 4a and the resistor 4b. The capacitor 4c is charged. On the other hand, the line through the resistor 4d, the trigger element 4e, and the resistor 4f is connected to the gate of the thyristor 4g, and an appropriate circuit device for informing the ignition timing, nowadays from the engine control computer (ECU) at the ignition timing. The trigger element 4e that has received the trigger signal PC2 output from the trigger signal generator 5 in response to the generated ignition signal 5i is turned on, so that a trigger current flows through the thyristor 4g.

  As a result, when the thyristor 4g is turned on, the charge stored in the energy storage capacitor 4c is discharged to the primary winding 7a of the ignition coil 7 with the polarities (+) and (-) shown in the figure through the thyristor 4g. Thus, a high voltage is generated in the secondary winding 7b of the ignition coil 7, and a discharge spark is generated in the discharge gap Gp of the spark plug connected thereto, and the fuel in the internal combustion engine is ignited.

  On the other hand, the self-excited thyristor series inverter type ignition circuit 3 is a trigger signal dedicated to startup from the high voltage output terminal 2b of the DC-DC converter 2 via the resistors 3a and 6a before the ignition signal 5i is generated. The generating capacitor 6b is charged. The capacitor 6b is connected to the gate of the thyristor 3c via the trigger element 6c and the resistor 3b. The trigger element 6c receives the trigger signal PC1 output from the trigger signal generator 5 in response to the ignition signal 5i from the ECU. As a result, the discharge current from the start-up trigger signal generating capacitor 6b is supplied to the thyristor 3c as the start-up trigger signal, and the thyristor 3c is turned on.

  That is, in the circuit configuration of this conventional example, the resistor 6a, the start trigger signal generating capacitor 6b, and the trigger element 6c constitute a dedicated start circuit 6, and the start of discharge is a trigger signal given to the start circuit 6. It can be determined at any time by PC1. Of course, since the self-excited thyristor series inverter type ignition circuit 3 performs self-excited oscillation operation, the trigger signal PC1 is only necessary at the start of discharge and is not necessary for continuing the subsequent discharge, and is necessary for turning on the thyristor 3c. In addition, the pulse shape is sufficiently short, and the turn-off state is set after the turn-on.

  When the thyristor 3c is turned on and the self-excited thyristor series inverter ignition circuit 3 is activated, an oscillating current is generated by resonance of the resonant inductor 3d and the resonant capacitor 3e, and the current of the thyristor 3c is reversed when the resonant capacitor charging current is reversed. As a result, the thyristor 3c is turned off. Then, the charged charge of the resonance capacitor 3e, which is also an energy storage capacitor, is discharged through the other primary winding 7d of the ignition coil 7, and a high voltage is generated in the secondary winding 7b. Discharge energy that gives a plurality of sparks is applied to the discharge energy generated by the capacitive discharge ignition circuit 4 in a superimposed manner.

  At this time, a voltage having a polarity opposite to the polarities (+) and (−) shown in the figure is also generated in the feedback winding 7c provided in the ignition coil 7. Since the voltage polarity causes a short circuit with the Zener diode 3f in the forward direction, the gate of the thyristor 3c is not affected.

  Next, when the resonance current is reversed due to resonance between the resonance capacitor (energy storage capacitor) 3e and the primary winding 7d, a high voltage is generated in the secondary winding 7b at this time, and the discharge gap Gp of the spark plug is generated. Spark discharge occurs. At the same time, a voltage is generated in the feedback winding 7c wound around the ignition coil 7 with the polarities (+) and (-) shown in the figure, so that the current flows through the path of the diode 3h, the capacitor 3i, and the resistor 3g. When the capacitor 3i is charged and the voltage of the feedback winding 7c gradually decreases, the accumulated charge of the capacitor 3i flows up to the gate of the thyristor 3c through the resistor 3b and turns on. Let That is, after startup, the capacitor 3i becomes a trigger signal generating capacitor for oscillating operation continuation of the thyristor 3c. Thereafter, the above-described resonance operation is repeated, and a plurality of sparks continuous in time series are obtained in the discharge gap Gp.

  However, since the power source 1 by the battery mounted on the vehicle is of course a direct current, if nothing is done, the oscillation operation of the self-excited thyristor series inverter type ignition circuit 3 does not stop and the discharge is continued. Therefore, in order to terminate this at a predetermined timing, a stop switching element 3j is provided in parallel with the Zener diode 3f, and a stop signal PC3 generated from the trigger signal generator 5 that receives the stop signal 5s from the ECU is provided. Accordingly, the switching element 3j for stopping is turned on to cancel the voltage generated in the feedback winding 7c and invalidate the operation of the feedback winding 7c, so that the capacitor 3i for turning on the thyristor 3c again is turned on. Stop charging and stop discharging.

JP-A-8-68372 JP 2010-151069 A

  In the case of the overlap discharge type ignition device using the capacitive discharge type ignition circuit 4 and the self-excited thyristor series inverter type ignition circuit 3 as described above, the self-excited thyristor series inverter type ignition circuit 3 is activated by the capacitive discharge type ignition circuit. In principle, it is optimal that the discharge is started at the same time as the discharge at 4. However, it is extremely difficult to strictly control the ignition signal 5i from the ECU.

  Therefore, at present, the capacity discharge ignition circuit 4 is activated by the ignition signal 5i from the ECU, and at the same time, the activation circuit 6 of the self-excited thyristor series inverter type ignition circuit 3 is activated by the trigger signal PC1, and the self-excited thyristor series inverter type is activated. Although the ignition circuit 3 is activated, the circuit constants (capacitor capacity, primary winding inductance, etc.) are different between the circuits 3 and 4, and there are differences in the waveform rise and vibration frequency from the time of activation. The voltage waveforms applied to the primary windings 7a and 7d from 3 and 4 are not phase-matched, and when the combined waveform appears on the secondary winding 7b as a secondary high voltage waveform, The secondary high voltage waveform is easily distorted, and depending on how it overlaps, the rise of the secondary high voltage may become dull or even a low region may occur. There was a possibility that interruption of electricity occurred.

  The present invention has been made in view of this point, and suppresses the disturbance of the superimposed discharge energy waveform generated in the secondary winding of the ignition coil, and intends to demonstrate the original performance expected of the multiple discharge ignition device. It is.

  In order to achieve the above object, the present invention has obtained a new idea. The start circuit 6 of the self-excited thyristor series inverter type ignition circuit 3 required in the conventional circuit as shown in FIG. 2, that is, the operation timing of the capacity discharge type ignition circuit and the self-excited thyristor series inverter type ignition circuit. Without using the starting circuit 6 for simultaneous starting timing, the discharge spark generated on the basis of the capacity discharge energy of the capacitive discharge type ignition circuit exceeds the energy peak, and in a sense, at the timing when it is used. If the discharge spark based on the discharge energy generated by the excited thyristor series inverter type ignition circuit is generated so as to succeed the latter, the ignition coil secondary side high-voltage waveform that generates the discharge spark will not be disturbed, Self-excited thyristor series inverter ignition circuit Having to overcome the blow-off phenomenon of a plurality spark temporally consecutive, it is possible to both fully exhibit the characteristic of being able to obtain a substantially longer discharge time, is that.

Based on such an idea, the present invention
Based on the ignition signal, the discharge energy of the capacitive discharge type ignition circuit that discharges the energy stored in the energy storage capacitor to the primary side of the ignition coil generates a high voltage for generating a discharge spark in the discharge gap of the spark plug in the secondary winding of the ignition coil. In addition, once the thyristor is triggered, the multiple spark discharge energy from the self-excited thyristor series inverter ignition circuit that repeatedly generates multiple spark discharge energy on the primary side of the ignition coil until a stop signal is received, A multiple discharge internal combustion engine ignition device for obtaining a high voltage for a plurality of spark discharges in a discharge gap of an ignition plug in an ignition coil secondary winding;
When a high voltage is generated in the secondary winding of the ignition coil due to the discharge energy of the capacitive discharge ignition circuit, the voltage generated in the feedback winding provided in the ignition coil triggers the self-excited thyristor series inverter ignition circuit. Charging the signal generating capacitor and triggering the thyristor by the discharge current from the trigger signal generating capacitor in the process of falling the voltage of the feedback winding to activate the self-excited thyristor series inverter ignition circuit;
An internal combustion engine ignition device is proposed.

  In the present invention, as a result of the above configuration, the high voltage peak of the ignition coil secondary winding obtained based on the operation of the capacity discharge ignition circuit and the operation of the self-excited thyristor series inverter ignition circuit are obtained. Self-excited thyristor series inverter does not overlap with the high voltage peak of the ignition coil secondary winding, but at the timing when the ignition coil secondary high voltage generated based on the operation of the capacitive discharge type ignition circuit decreases from the peak Since the secondary voltage on the secondary side of the ignition coil rises based on the operation of the ignition circuit, and a plurality of sparks continue to be generated thereafter, the primary winding for the discharge of the capacitive discharge ignition circuit on the primary side of the ignition coil So that at least part or all of the wire is also the primary winding for the self-excited thyristor series inverter ignition circuit to provide multiple spark discharge energy , It is also possible to sharing of the primary winding.

  ADVANTAGE OF THE INVENTION According to this invention, the ignition coil secondary side spark by a capacitive discharge type ignition circuit can rise | start up quickly, and the ignition device with good ignition property with long discharge time can be provided with more stable performance.

  Further, since the starting circuit, which has been conventionally required in the self-excited thyristor series inverter ignition circuit, for example, the starting circuit 6 in FIG. 2, is not necessary, the cost and space can be reduced in manufacturing the device.

  Furthermore, according to a specific aspect of the present invention, the primary winding of the ignition coil can be shared by the capacity discharge ignition circuit and the self-excited thyristor series inverter ignition circuit, which is also reduced in size around the ignition device, Contributes to cost reduction.

1 is a configuration diagram of a preferred embodiment of an internal combustion engine ignition device according to the present invention. It is a block diagram in a typical example of an over-discharge type internal combustion engine ignition device using a conventional capacity discharge type ignition circuit and a self-excited thyristor series inverter type ignition circuit.

  FIG. 1 shows an internal combustion engine ignition device according to a preferred embodiment of the present invention. Since the present invention is substantially an improvement of the conventional internal combustion engine ignition device as shown and described in FIG. 2, the present embodiment also has a modified configuration of the circuit configuration of the conventional example shown in FIG. Show. Therefore, the portions already described with respect to the conventional example can be applied almost as they are except for the improved portion according to the present invention. Also, the same reference numerals as those in FIG. 2 denote the same or similar components, and the explanations relating to them can be applied in the same manner.

  Although repeated explanation is included, first, in order to explain this embodiment, first. In the capacitive discharge type ignition circuit 4, the operation is the same as in the conventional example shown in FIG. That is, the energy storage capacitor 4c for capacitive discharge is charged through the diode 4a and the resistor 4b from the high voltage output terminal 2a of the DC-DC converter 2 that is operated by the power source 1 that is a battery mounted on the vehicle, while the resistor 4d. In addition, a line through the trigger element 4e and the resistor 4f is connected to the gate of the thyristor 4g, and an ignition circuit 5i generated at an ignition timing from an appropriate circuit device for reporting the ignition timing, for example, an engine control computer (ECU). In response to this, the trigger element 4e that has received the trigger signal PC2 output from the trigger signal generator 5 is turned on, so that a trigger current flows through the thyristor 4g.

  As a result, when the thyristor 4g is turned on, the charge stored in the energy storage capacitor 4c is discharged to the primary winding 7a of the ignition coil 7 with the polarities (+) and (-) shown in the figure through the thyristor 4g. Then, a high voltage is generated in the secondary winding 7b of the ignition coil 7, a discharge spark is generated in the discharge gap Gp of the spark plug connected thereto, and the fuel of the internal combustion engine is ignited.

  As will be described later, in the case of an internal combustion engine ignition device configured in accordance with the present invention, at least a part or all of the ignition coil primary winding 7a is used as a discharge energy of a self-excited thyristor series inverter ignition circuit 3 described later. Can be shared as the primary winding 7d of the ignition coil to which is applied, but in this embodiment, as a basic configuration, a case where the primary windings 7a and 7d are provided in the respective circuits 3 and 4 is shown. ing.

  Conventionally, in response to the operation of the capacitive discharge ignition circuit 4 as described above, the ignition signal 5i is received and at the same time the self-excited thyristor series inverter ignition circuit 3 is activated by the trigger signal PC1 (FIG. 2). However, the present invention does not include the starting circuit 6 in the conventional configuration as shown in FIG. The self-excited thyristor series inverter ignition circuit 3 according to the present invention is assembled so as to operate as follows from the start-up.

  That is, the electric charge charged in the energy storage capacitor 4c in the capacitive discharge ignition circuit 4 is discharged to the primary winding 7a of the ignition coil 7 through the thyristor 4g with the polarities (+) and (-) shown in the figure, thereby igniting. When a high voltage is generated in the secondary winding 7b of the coil 7, a voltage is also generated in the polarity (+) and (-) shown in the feedback winding 7c wound around the ignition coil 7. Therefore, at this time, a current flows through the path of the diode 3h, the capacitor 3i, and the resistor 3g, and in the present invention, the capacitor 3i used for generating the trigger signal is charged from the start-up, and the voltage of the feedback winding 7c eventually becomes the voltage. At the timing when the voltage drops beyond the peak, the charge stored in the capacitor 3i accumulated so far flows into the gate of the thyristor 3c via the resistor 3b.

  As a result, when the thyristor 3c is turned on and the self-excited thyristor series inverter ignition circuit 3 is activated, an oscillation current is generated due to resonance of the resonance inductor 3d and the resonance capacitor 3e, and the current of the thyristor 3c is reversed when the resonance capacitor charging current is inverted. The thyristor 3c is turned off when is reversed. As a result, the charge of the resonant capacitor 3e, which is also an energy storage capacitor, is discharged to the self-excited thyristor series inverter type ignition circuit 3 in the illustrated case of the ignition coil 7 via the primary winding 7d that is dedicated in the illustrated embodiment. Then, a high voltage is generated in the secondary winding 7b, and discharge energy that forms a plurality of sparks is applied to the discharge gap Gp in a continuous and superimposed manner with respect to the discharge energy generated by the capacitive discharge ignition circuit 4.

  In other words, according to the present invention, the discharge spark generated on the basis of the capacity discharge energy of the capacity discharge ignition circuit 4 exceeds the energy peak, and in a sense, at a timing after having played an important role of early ignition with an early rise. Since the discharge spark based on the discharge energy generated by the self-excited thyristor series inverter type ignition circuit 3 is generated so as to succeed, the ignition coil secondary side high-voltage waveform that generates the discharge spark is not disturbed, Overcoming the blow-off phenomenon by the time-sequential multiple sparks of the self-excited thyristor series inverter ignition circuit 3 has a feature that is substantially long. Both of the characteristics that the discharge time can be obtained can be sufficiently exhibited.

  When a high voltage is applied to the discharge gap Gp by the operation of the self-excited thyristor series inverter ignition circuit 3, the polarity (+), (+) also shown in the feedback winding 7c provided in the ignition coil 7 is shown. A voltage with the opposite polarity to-) is generated, but this is short-circuited by the zener diode 3f that is forward in this voltage polarity via the resistor 3g, and the gate of the thyristor 3c is affected. Absent.

  Eventually, when the resonance current is reversed due to resonance between the resonance capacitor or energy storage capacitor 3e and the primary winding 7d, a high voltage is generated in the secondary winding 7b at this time, and the discharge gap Gp of the spark plug is generated. A spark discharge occurs. At the same time, a voltage is generated in the feedback winding 7c wound around the ignition coil 7 with the polarities (+) and (-) shown in the figure, so that the current flows through the path of the diode 3h, the capacitor 3i, and the resistor 3g. When the capacitor 3i for generating the trigger signal is charged again and the voltage of the feedback winding 7c decreases over time, the accumulated charge of the capacitor 3i that has been accumulated so far passes through the resistor 3b. It flows into the gate of 3c and turns it on. Thereafter, by repeating this resonance operation, a plurality of discharge sparks continuous in time are obtained in the discharge gap Gp. Therefore, the capacitor 3i in the illustrated embodiment functions as a trigger signal generation capacitor both for circuit startup and when the oscillation operation continues after startup.

  The self-excited oscillation of the self-excited thyristor series inverter type ignition circuit 3 is provided at a position opposite to the Zener diode 3f in response to the stop signal PC3 emitted from the trigger signal generator 5 that has received the stop signal 5s from the ECU. When the switching element for stop 3j is turned on, the voltage generated in the feedback winding 7c is canceled, and the operation of the feedback winding 7c is invalidated, so that the trigger signal generating capacitor 3i for turning on the thyristor 3c again. Stop charging so that it is not charged.

  Thus, in the internal combustion engine ignition device according to the present invention, the high voltage peak of the ignition coil secondary winding 7b obtained based on the operation of the capacitive discharge ignition circuit 4 and the self-excited thyristor series inverter ignition circuit 3 The high voltage peak of the ignition coil secondary winding 7b obtained based on the operation of the ignition coil does not overlap with the high voltage peak of the ignition coil secondary side generated based on the operation of the capacitive discharge ignition circuit 4 decreases from the peak. The ignition coil secondary side high voltage rises based on the operation of the self-excited thyristor series inverter type ignition circuit 3 at the timing of starting, and thereafter, the generation of a plurality of sparks is continued.

  That is, looking at the relationship between the two primary windings 7a and 7d shown in the figure, a large amount of discharge energy is not given to them at the same time, and there is a time difference. Sharing at least a part or all of the primary winding 7a for the circuit 4 to give discharge energy as the primary winding 7d for the self-excited thyristor series inverter ignition circuit 3 to give a plurality of spark discharge energy You can also. Since there is no improper synthesis of the phase waveform, there is no problem in operation.

  The preferred embodiment of the apparatus of the present invention has been described above. However, any modification is free as long as it conforms to the gist of the present invention.

1 Power supply (Battery mounted on motor vehicle)
2 DC-DC converter 3 Self-excited thyristor series inverter type ignition circuit 4 Capacity discharge type ignition circuit 5 Trigger signal generator 6 Self-excited thyristor series inverter type ignition circuit starting circuit 7 Ignition coil
3c thyristor
3i Trigger signal generation capacitor
3e Resonant capacitor (energy storage capacitor)
4c Energy storage capacitor
4g thyristor
5i ignition signal
7a Ignition coil primary winding
7b Ignition coil secondary winding
7c Ignition coil feedback winding
7d ignition coil primary winding
PC2 trigger signal
PC3 stop signal

Claims (2)

For generating discharge sparks in the discharge gap of the spark plug in the ignition coil secondary winding by the discharge energy of the capacitive discharge type ignition circuit that discharges the energy stored in the energy storage capacitor to the primary side of the ignition coil based on the ignition signal Once the thyristor is triggered, the multiple sparks from the self-excited thyristor series inverter ignition circuit that repeatedly generates multiple spark discharge energy on the primary side of the ignition coil until a stop signal is received. A multiple discharge internal combustion engine ignition device that obtains a high voltage for a plurality of spark discharges in the discharge gap of the ignition plug in the ignition coil secondary winding also by discharge energy;
When the high voltage is generated in the secondary winding of the ignition coil by the discharge energy of the capacitive discharge ignition circuit, the self-excited thyristor is generated by the voltage generated in the feedback winding provided in the ignition coil. The self-excited thyristor series inverter is triggered by charging the trigger signal generating capacitor of the series inverter type ignition circuit and triggering the thyristor by a discharge current from the trigger signal generating capacitor in the process of falling the voltage of the feedback winding. Starting the ignition circuit;
An internal combustion engine ignition device. An internal ignition device according to claim 1;
On the primary side of the ignition coil, at least a part or all of the primary winding for the capacitive discharge ignition circuit to supply the discharge energy, the self-excited thyristor series inverter ignition circuit ignites the multiple spark discharge energy. It also serves as the primary winding to feed to the primary side of the coil;
An internal combustion engine ignition device.

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