JP2011074906A - Ignitor for internal combustion engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an ignitor for an internal combustion engine, which is free from a blow-out phenomenon even if a discharge maintaining voltage is lowered and which includes a capacitor discharge ignitor and a self excitation thyristor series inverter ignitor. <P>SOLUTION: The ignitor for the internal combustion engine includes a self-excitation thyristor series inverter ignitor part 11, a capacitor discharge ignitor part 12, a DC-DC convertor 14, and a trigger signal generation part 15. A feedback winding and a primary winding of the self-excitation thyristor series invertor type ignitor part and a primary winding of the capacitor discharge ignitor part are wound around the same iron core 16, and a second winding is shared. The capacitor discharge ignitor and the self-excitation thyristor series inverter type ignitor which makes a thyristor series inverter circuit self-excited using an ignition coil as a load and which discharges a plurality of sparks to the discharge gap of the ignition plug by a high voltage generated on the secondary winding side of the ignition coil, perform overlapping discharge. Then, a large discharge energy is provided for a long period without being influenced by discharge and the like on the capacitor discharge ignitor side. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an ignition device for an internal combustion engine mounted on a vehicle such as an automobile, and more particularly to an ignition device for an internal combustion engine that performs multiple discharge.

  Today, internal combustion engines such as engines are required to reduce exhaust gas and improve fuel efficiency in consideration of environmental problems. In order to meet these demands, attempts have been made to introduce measures such as increasing exhaust gas recirculation (EGR) or performing stratified combustion with a direct injection engine. In this way, when used in an air-fuel mixture engine in which exhaust gas is re-introduced or a lean combustion engine (lean burn engine), improvement in ignitability is required, and a high energy type ignition device is required. As one means for improving the ignitability, a multiple discharge ignition device has been proposed in which a high-voltage output of a DC-DC converter is superimposed on a secondary side output of an ignition coil generated by a classic current interruption principle (Patent Literature). 1).

  In general, an ignition device for an internal combustion engine interrupts a primary current flowing in a primary coil, thereby causing a discharge breakdown in a discharge gap of an ignition plug due to a high voltage of several Kv generated in the secondary coil, so that the secondary coil of the ignition coil After starting the discharge current from the side, the output current from the booster circuit is maintained while maintaining the DC voltage (usually about 500V or more) higher than the discharge sustaining voltage value capable of maintaining this discharge state by a separately provided booster circuit. In addition, it is superimposed on the discharge current of the ignition coil. In the ignition device for an internal combustion engine by such a method, a large discharge energy can be obtained in the ignition plug for a relatively long time, so that the ignitability to the fuel can be improved and the fuel consumption can be improved.

In the case of an overlap discharge device in which a conventional capacity discharge ignition device (CDI: Capacitor Discharge Ignitor) circuit 1 and a self-excited thyristor series inverter ignition device circuit 2 are overlapped, as shown in FIG. The voltage is boosted by the DC-DC converter 3 and then supplied to the capacitive discharge igniter circuit 1 and the self-excited thyristor series inverter igniter circuit 2.
The ignition device includes a self-excited thyristor series inverter type ignition device primary winding 5 connected to the coil core 4 to the self-excited thyristor series inverter type ignition device circuit 2 and a self-excited thyristor series inverter type ignition device feedback. The winding 6 is composed of a primary winding 7 for a capacity discharge ignition device, a secondary winding 8, and a control circuit 9 for controlling the ignition timing.

  In the conventional ignition device configured as described above, the voltage boosted by the DC-DC converter 3 is in accordance with the control signal of the control circuit 9, the capacity discharge ignition device circuit 1 and the self-excited thyristor series inverter ignition device circuit 2. Are supplied to the primary winding 5 for the self-excited thyristor series inverter type ignition device 5, the feedback winding 6 for the self-excited thyristor series inverter type ignition device, and the primary winding 7 for the capacity discharge type ignition device at an appropriate timing. The Then, high voltage currents corresponding to the respective capacity discharge type ignition device circuit 1 and the self-excited thyristor series inverter type ignition device circuit 2 are generated in the secondary winding 8 and discharged in the discharge gap g of the ignition plug.

JP-A-8-68372

However, in an ignition device for a multi-discharge internal combustion engine that performs multi-discharge between a conventional capacitive discharge ignition device (CDI) and a self-excited thyristor series inverter ignition device, as shown in FIG. Since breakdown and initial ignition are performed, there is no problem if the output voltage of the self-excited thyristor series inverter multiple spark ignition device is a discharge sustaining voltage value (usually about 500 V or more), but it corresponds to the “blown out phenomenon”. In addition, a voltage that can be re-discharged (about 20 kV or more) is required.
For this reason, it is necessary to increase the primary oscillation voltage of the self-excited thyristor series inverter type multiple spark igniter, which requires parts having a high withstand voltage, increasing the manufacturing cost and increasing the installation space.

  The present invention has been proposed in view of the above, and can reduce the output voltage of the self-excited thyristor series inverter type multiple spark ignition device to a discharge sustaining voltage value of 500 V or less, reducing the component cost and the device. An object of the present invention is to provide an ignition device for an internal combustion engine that can be reduced in size.

  In order to achieve the above object, an internal combustion engine ignition device according to the present invention comprises a self-excited thyristor series inverter ignition device, a capacity discharge ignition device, a DC-DC converter, and a trigger signal generator. The return winding and primary winding of the excitation thyristor series inverter type ignition device unit and the primary winding of the capacitive discharge type ignition device unit are wound on the same iron core and the secondary winding is shared, and the capacitive discharge type ignition A self-excited thyristor series in which a device (CDI) and a thyristor series inverter circuit are oscillated self-excited with an ignition coil as a load, and a plurality of sparks are blown into a discharge gap of a spark plug by a high voltage generated on the secondary winding side of the ignition coil The inverter-type ignition device is overdischarged.

  In the present invention, the capacity discharge ignition device performs multiple discharges at an arbitrary timing.

  Since this invention consists of an above-described structure, there can exist an effect which is demonstrated below.

  In the present invention, a self-excited thyristor series inverter igniter unit, a capacity discharge igniter unit, a DC-DC converter, and a trigger signal generator unit are provided. The winding and the primary winding of the capacitive discharge ignition device are wound on the same iron core and the secondary winding is shared, and the capacitive discharge ignition device (CDI) and the thyristor series inverter circuit are loaded with the ignition coil. As a self-excited oscillation, the high-voltage generated on the secondary winding side of the ignition coil, and a self-excited thyristor series inverter type ignition device that discharges a plurality of sparks in the discharge gap of the spark plug is discharged in an overlapping manner Since the secondary winding of the capacitive discharge ignition device and the secondary winding of the self-excited thyristor series inverter ignition device are used, To improve ignition performance by integrating two types of ignition devices, which differ greatly in the required specifications of the capacity discharge type ignition device that requires good coupling and the self-excited thyristor series inverter type ignition device that cannot improve magnetic coupling more than necessary. Can do. Further, the increase in the number of parts can be minimized.

FIG. 1 is a schematic configuration diagram of an internal combustion engine ignition device according to the present invention. FIG. 2 is a voltage waveform diagram of the overlap discharge between the capacity discharge ignition device and the self-excited thyristor series inverter ignition device by the internal combustion engine ignition device of the present invention. FIG. 3 is a schematic configuration diagram of a conventional overlap discharge device including a capacity discharge ignition device and a self-excited thyristor series inverter ignition device. FIG. 4 is a no-load output voltage waveform diagram of overlap discharge by a conventional capacity discharge ignition device and a self-excited thyristor series inverter ignition device.

  The internal combustion engine ignition device according to the present invention includes a self-excited thyristor series inverter type ignition device unit, a capacity discharge type ignition device unit, a DC-DC converter, and a trigger signal generation unit, and the self-excited thyristor series inverter type ignition device unit. The primary winding and the primary winding of the capacitive discharge igniter unit are wound on the same iron core and the secondary winding is shared, and the capacitive discharge igniter (CDI) and thyristor series inverter The circuit is self-oscillated with the ignition coil as a load, and a self-excited thyristor series inverter type ignition device that ignites multiple sparks in the spark plug discharge gap with the high voltage generated on the secondary winding side of the ignition coil. The purpose of improving the ignitability of the air-fuel mixture under poor conditions can be achieved.

  Hereinafter, the present invention will be described in detail with reference to the drawings illustrating an embodiment. FIG. 1 is a schematic configuration diagram of an ignition device for an internal combustion engine according to the present invention, and FIG. 2 is a voltage waveform of overlap discharge between a capacitive discharge ignition device and a self-excited thyristor series inverter ignition device by the internal combustion engine ignition device of the present invention. FIG. Here, the internal combustion engine ignition device 10 includes a self-excited thyristor series inverter type ignition device unit 11, a capacity discharge type ignition device unit 12, a DC-DC converter 14 that boosts the battery power supply 13, and an engine control computer ( The trigger signal generating unit 15 is configured to operate the self-excited thyristor series inverter type ignition device unit 11 and the capacity discharge type ignition device unit 12 at an appropriate timing in response to the ignition signal 15a from the ECU.

  The self-excited thyristor series inverter igniter unit 11 charges the capacitor 11m from the output signal 14a from the DC-DC converter 14 through the resistor 11a and the resistor 11p. The capacitor 11m is connected to the gate of the thyristor 11e via the trigger element 11k and the resistor 11g, and receives the trigger signal PC1 from the trigger signal generation unit 15 to flow the trigger current of the thyristor 11e at an appropriate time. It has become. When this trigger current flows, it vibrates due to resonance of the resonant inductor 11d, thyristor 11e, and resonant capacitor 11f, and turns OFF when the current of the thyristor 11e is reversed when the charging current is reversed. Then, the charged charge of the resonance capacitor 11f is discharged through the coil 11u which is one of the primary windings of the ignition coil, a high voltage current is generated in the secondary winding 11z, and a spark discharge is generated in the discharge gap g of the spark plug. Wake up.

  At the same time, a voltage is generated in the return winding 11t of the ignition coil with the positive and negative polarities shown in FIG. 1 with respect to the primary winding coil 11u and the coil 11u. At this time, a Zener diode is connected via the resistor 11r. 11q is short-circuited and does not affect the gate of the thyristor 11e. Next, when resonance occurs between the resonance capacitor 11f and the coil 11u, which is the primary winding, the resonance current is reversed and voltage is generated in the primary winding with (+) and (-) polarity as shown in the figure. In addition, a high voltage is generated in the secondary winding 11z, a spark discharge occurs in the discharge gap g of the spark plug, and a voltage is also generated in the feedback winding 11t with the polarities (+) and (-) shown in the figure, The capacitor 11n is charged by a circuit connecting the diode 11i, the capacitor 11n, and the resistor 11r. When the voltage of the feedback winding 11t becomes zero, the charged charge of the capacitor 11n accumulated so far flows into the gate of the thyristor 11e via the resistor 11g, and turns on the thyristor 11e. Thereafter, this operation is sequentially repeated.

  Further, the primary winding 12k of the capacitive discharge igniter unit 12 and the coil 11u which is the primary winding of the self-excited thyristor series inverter igniter unit 11 are wound on the same iron core 16, and the secondary winding The line 11z is used. The capacity discharge type ignition device unit 12 includes known resistors 12a, 12g, 12e, a diode 12f, a thyristor 12i, a capacitor 12h, and the like. From the output signal 14c from the DC-DC converter 14, a diode 12f, a resistor The capacitor 12h is charged via 12g. The trigger element 12d is connected to the gate electrode of the thyristor 12i via the resistor 12e. The trigger element 12d receives the trigger signal PC2 from the trigger signal generation unit 15 and causes a trigger current to flow through the thyristor 12i, thereby causing the capacitor 12h. Is charged to the primary winding 12k, thereby generating a high-voltage current in the secondary winding 11z and causing a spark discharge in the discharge gap g of the spark plug.

  In the internal combustion engine ignition device configured as described above, the output waveform A (500 V) by the self-excited thyristor series inverter ignition device unit 11 and the output waveform B by the capacity discharge ignition device unit 12 are as shown in FIG. The self-excited thyristor series inverter ignition device 12 can be discharged without being influenced by the discharge on the capacitive discharge ignition device 11 side. Therefore, greatly different required specifications can be combined into one ignition coil device, and the outputs of both devices can be overlapped to obtain a large discharge energy over a relatively long time.

  In addition, an increase in manufacturing cost due to an increase in the number of parts can be prevented, and an increase in installation space can be suppressed in advance.

  The present invention is not limited to the above-described embodiments, and various design changes can be made based on the description of the scope of claims.

A Output waveform by self-excited thyristor series inverter type ignition device B Output waveform by capacity discharge type ignition device unit 10 Ignition device for internal combustion engine 11 Self-excited thyristor series inverter type ignition device unit 12 Capacity discharge type ignition device unit 13 Battery power supply 14 DC-DC converter 15 Trigger signal generator 16 Iron core

Claims (2)

A self-excited thyristor series inverter igniter unit, a capacity discharge igniter unit, a DC-DC converter, and a trigger signal generator; a feedback winding and a primary winding of the self-excited thyristor series inverter igniter unit; The primary winding of the capacity discharge igniter unit is wound on the same iron core and the secondary winding is shared,
A self-excited oscillation of a capacitive discharge ignition device (CDI) and a thyristor series inverter circuit with an ignition coil as a load, and a plurality of sparks are blown into the discharge gap of the spark plug with a high voltage generated on the secondary winding side of the ignition coil. An ignition device for an internal combustion engine, wherein a self-excited thyristor series inverter type ignition device is repeatedly discharged.   2. The internal combustion engine ignition device according to claim 1, wherein the capacitive discharge ignition device performs multiple discharges at an arbitrary timing.

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