JPH01200059A - Condenser electric discharge type ignitor for internal combustion engine - Google Patents

Abstract

PURPOSE:To permit the spark generation permitting speedy start up and secure a long electric discharge duration time by installing a plurality of condensers for storing ignition energy on the primary side of an ignition coil and installing a plurality of thyristors for controlling electric discharge and permitting the successive electric discharge of the condensers. CONSTITUTION:Each one edge of the first and second condensers C11 and C12 for storing ignition energy is connected with the terminal on the nongrounded side of the primary coil W1 of an ignition coil Ig through diodes Da1 and Da2, and the first and second thyristors S11 and S12 for controlling electric discharge are connected between the ground and the other edge. Each edge of a signal coil Ls is connected with the gate of each thyristor S11, S12 through a parallel circuit which constitutes a thyristor trigger circuit and consists of a diode D41; D42, condenser C21; C22, and a resistor R21; R22. The thyristor trigger circuit sets the generated phase of the first trigger signal so that the position where the thyristor S11 is applied with a trigger signal coincides with the ignition position of an engine.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a capacitor discharge type internal combustion 1fi Sekigawa ignition device.

[Prior Art] A conventional capacitor discharge type internal combustion engine starting ignition device includes an ignition coil, one ignition coil energy storage capacitor provided on the primary side of the ignition coil, and the ignition energy storage capacitor. a capacitor charging circuit that charges the ignition energy storage capacitor to one polarity, a discharge control thyristor that discharges the charge in the ignition energy storage capacitor to the primary coil of the ignition coil when conductive; and a thyristor trigger circuit that provides a trigger signal to the thyristor.

In this ignition system, the ignition energy storage capacitor is charged to one polarity by a capacitor charging circuit. When a trigger signal is applied from the thyristor trigger circuit to the discharge control thyristor at the ignition position of the internal combustion engine, the thyristor becomes conductive and discharges the charge in the ignition energy storage capacitor to the primary coil of the ignition coil. This causes a large magnetic flux change in the iron core of the ignition coil, and a high voltage for ignition is induced in the secondary coil of the ignition coil.

Since this high voltage is applied to a spark plug attached to a cylinder of the engine, a spark is generated in the spark plug and the engine is ignited.

[Problem to be Solved by the Invention 1] In outboard motors, in order to improve the stability of the internal combustion engine during trolling, the weight of the flywheel attached to the engine is increased to increase the inertia of the engine. If the inertia is increased, the high-speed performance of the engine will be reduced, and the acceleration and deceleration performance of the engine will be reduced. Therefore, instead of increasing the inertia of the engine, the discharge duration of the ignition spark is increased.

In addition to improving the stability of outboard motors when trolling, ignition sparks are also used in other internal combustion engines to improve combustion stability when using inferior gasoline or to improve fuel efficiency. Efforts are being made to lengthen the discharge duration.

When a capacitor discharge type ignition system for an internal combustion engine is used, it has been considered to change the winding specifications of the ignition coil to lengthen the duration of the spark. The discharge duration is at most 100
The limit was 0 μs, and it was difficult to obtain a longer discharge duration.

In addition, in capacitor discharge type ignition systems for internal combustion engines, if the discharge duration is increased, the spark rises later, which reduces the characteristic of capacitor discharge type ignition systems, which is that the spark rises quickly and the spark plug is less likely to become contaminated. There was a problem.

SUMMARY OF THE INVENTION An object of the present invention is to provide a capacitor discharge type ignition device for an internal combustion engine that can extend the duration of spark discharge longer than before without slowing down the rise of the spark.

[Means for Solving the 12 Problems] In order to achieve the above object, the present invention includes an ignition coil and first to nth (n is an integer of 2 or more) provided on the primary side of the ignition coil. a capacitor charging circuit that charges the first to nth ignition energy storage capacitors to one polarity, and a capacitor charging circuit that charges the ignition energy storage capacitors of the first to n-th discharge control thyristors provided to cause the coil to discharge;
or a thyristor trigger circuit that sequentially supplies the first to nth trigger signals to the first to nth discharge control thyristors respectively, and the position where the thyristor trigger circuit supplies the trigger signal to the first discharge control thyristor corresponds to the ignition of the internal combustion engine. The generation phase of the first trigger signal was set to match the position.

[Function] With the above configuration, the first to nth discharge control thyristors are sequentially turned on by the trigger signal given from the thyristor trigger circuit, and the charges in the first to nth ignition energy storage capacitors are ignited. The primary coils of the coils are sequentially discharged. Therefore, the duration of the high voltage induced in the secondary coil of the ignition coil is apparently longer, and the duration of the discharge is longer. Furthermore, since the winding specifications of the ignition coil may be set to induce a secondary voltage that rises quickly, the rise of the spark will not be delayed by increasing the discharge duration.

Therefore, according to the present invention, it is possible to obtain a capacitor discharge type ignition device for an internal combustion engine in which the spark rises quickly and the discharge duration is long.

[Example] The present invention will be described in detail below with reference to the accompanying drawings.

FIG. 1 shows an embodiment of the present invention, and in the same figure, 1g is an ignition coil formed by winding a primary coil W1 and a secondary coil W2 around an iron core. One ends of the primary coil W1 and the secondary coil W2 are grounded, and the non-ground terminal of the secondary coil W2 is connected to the non-ground terminal of a spark plug P attached to the Ia cylinder (not shown). Ignition coil [1
A diode [
) The anodes of al and Da2 are commonly connected, and diodes Db1 and D are connected between the cathodes of these diodes Dal and Da2 and the ground, respectively, with their cathodes facing the ground side.
b2 is connected. Also, the diodes [)at and D
One ends of first and second ignition energy storage capacitors C11 and C12 are connected to the cathode of a2, respectively, and the first and second ignition energy storage capacitors C1
First and second discharge control thyristors 811 and 81 with their cathodes facing the ground side between the other ends of C1 and C12 and the ground.
2 are connected. The other ends of the ignition energy storage capacitors C11 and C12 are connected to the cathodes of diodes 011 and C12, respectively, whose anodes are commonly connected, and an exciter coil Le is connected between the anodes of the diodes D11 and C12 and ground. ignition coil 1
A diode D2 with its cathode facing the ground side is connected to both ends of the secondary coil, and a diode D3 with its anode facing the ground side is connected to both ends of the exciter coil Le. Further, protective resistors R11 and R12 are connected in parallel to both ends of the thyristors 311 and 812, respectively.

The exciter coil Le is installed in a magnet generator attached to the internal combustion engine, and synchronizes with the rotation of the internal combustion engine to generate a positive half cycle voltage ep and a negative half cycle voltage. The voltage Ven is output. When the exciter coil 1e outputs a positive half-cycle voltage Vep, the exciter coil Le → diode D11 → capacitor C
11→Diode Db1→Exciter coil 1. The first ignition energy storage capacitor C1l is charged to the illustrated polarity in the path e, and the second ignition energy storage capacitor is charged in the path from exciter coil 1-e to diode D12 to capacitor C12 to diode Db2 to exciter coil Le. C12 is charged to the polarity shown. In this example, the exciter coil Le and the diodes Dll and C1
2 and diodes Db1 and Db2 constitute a capacitor charging circuit that charges the first and second ignition energy storage capacitors to one polarity.

LS is a signal generator attached to an internal combustion engine. A signal coil installed inside the machine outputs a negative polarity signal ■Sn that reaches the trigger level et at the ignition position θ11 of the internal combustion engine, as shown in FIG. A positive polarity signal Vsp reaching the trigger level et at θ12 is output.

One end of the signal coil LS is connected to the gate of the thyristor S11 through a bias circuit consisting of a parallel circuit of a diode 041, a capacitor C21, and a resistor R21, and the other end of the signal coil is connected to a diode D42 and a capacitor C22.
It is connected to the gate of the thyristor 812 through a bias circuit consisting of a parallel circuit of a resistor R22 and a resistor R22. Further, a diode D52 with its anode facing the ground side is connected between one end of the signal coil LS and the ground, and a diode 051 with its anode facing the ground side is connected between the other end of the signal coil LS and the ground.
is connected. In this embodiment, the signal coil LS, diodes D41 and C42, capacitors C21 and C22, resistors R21 and R22, and diode [)5
1 and C52 constitute a thyristor trigger circuit that sequentially applies first and second trigger signals to the first and second discharge control thyristors S1 and S2, respectively.

In this trigger circuit, the signal coil is connected to the negative polarity signal V
When Sn is generated, the capacitor C21 of the bias circuit is charged to the polarity shown, and the charge of this capacitor C21 is discharged at a constant time constant through the resistor R21 until the next signal Sn is applied to the capacitor C21. . Therefore, when the negative polarity signal ysn is generated, the capacitor C2
A predetermined bias voltage remains across the capacitor C21, and only when the negative polarity signal Vsn obtained from the signal coil LS reaches a predetermined trigger level et determined by the bias voltage across the capacitor C21, the diode D41 and the capacitor 021 A first trigger signal is applied to the gate of thyristor 312 through.

If a bias circuit consisting of the capacitor C21 and the resistor R21 is provided in this way, and the bias circuit applies a reverse bias to the negative polarity signal obtained from the signal coil LS, the negative polarity signal will exceed a predetermined level. Since the thyristor is not triggered until then, it is possible to prevent the thyristor from being erroneously fired due to a noise signal.

The action of the bias circuit consisting of the capacitor C22 and the resistor R22 is similar, and when the positive polarity signal Vsp obtained from the signal coil LS reaches the trigger level et determined by the bias voltage across the capacitor 0220, a second trigger is applied to the thyristor 322. A signal is given.

Figure 2 shows the configuration of a magnet generator provided with the exciter coil le and a signal generator provided with the signal coil Is. In the figure, 1 is an iron flywheel formed in a cup shape, and 2a to 2d are These are four arc-shaped permanent magnets fixed to the inner periphery of the flywheel 1, and the flywheel magnet rotor is constituted by the flywheel 1 and the magnets 2a to 2d. A boss portion 1a is formed at the center of the bottom of the flywheel 1, and the boss portion is fitted onto an output shaft of an internal combustion engine (not shown).

An armature 4 formed by winding an exciter coil e around an iron core 3 is arranged inside the flywheel magnet rotor,
The armature and magnet rotor constitute a magnet generator. The armature 4 is fixed to a stator base plate provided on a case, cover, etc. of the internal combustion engine.

An inductor 11t portion 5 projecting outward in the radial direction is formed on the peripheral wall portion of the flywheel 1, and a signal generator 6 is disposed so as to be able to face the inductor magnetic pole portion 5. The signal generator 6 has a U-shaped iron core 7 and a signal coil LS.
It is a well-known signal generator with a built-in magnet, in which a permanent magnet is provided in the middle of the magnetic path of the iron core 6a, and the mounting provided on the case, cover, etc. between the wires is fixed to the part.

In this example, the flip-flop circuit 1 and the signal generator 6 constitute a signal generator.
, 7b, a magnetic flux flows from the magnet in the signal generator through the iron core 7 and the inductor magnetic pole part 5, and as the relative positional relationship between the inductor magnetic pole part 5 and the iron core 7 changes, a signal is generated. A change occurs in the magnetic flux interlinking with the coil LS. Due to this change in magnetic flux, a signal voltage as shown in FIG. 3(B) is induced in the signal coil LS.

In this embodiment, when the output shaft of the internal combustion engine rotates, the exciter coil Le induces a voltage as shown in FIG. The positive half-cycle voltage ■ep causes the first and second ignition energy storage capacitors C1 to
1 and C12 are charged to the polarities shown. The terminal voltage Vc of these capacitors changes as shown in FIG. 3(C).

When the signal voltage vSn obtained from the signal coil LS at the ignition position θ11 of the internal combustion eigQ reaches the trigger level et,
A first trigger signal is applied to the discharge control thyristor 811, and the thyristor 311 becomes conductive.

As a result, the first ignition energy storage capacitor C1
1 charge is discharged through the thyristor 311, the primary coil W1 of the ignition coil, and the diode Dal, and a high voltage Vold is induced in the secondary coil W2 of the ignition coil. The waveform of this high voltage vh1 under no load is shown in FIG. 3(D). Since this high voltage is applied to the spark plug P,
A spark is produced in the spark plug, and the engine is ignited.

Subsequently, when the signal coil 1s outputs a positive polarity signal Vsp, when the positive polarity signal Vsp reaches the trigger level et determined by the bias voltage across the capacitor C21, a second trigger signal is given to the thyristor 812, and the thyristor 312 becomes conductive. As a result, the charge of the second ignition energy storage capacitor C12 is transferred to the thyristor 812.
is discharged through the primary coil of the ignition coil and the diode [)a2, and a voltage Vh2 is applied to the secondary coil of the ignition coil.
(See the third diagram) is induced. Second ignition energy storage capacitor C1 when thyristor 812 is conductive
The change in the terminal voltage of No. 2 is shown by the broken line in FIG. 3(C).

Therefore, as shown in FIG. 3(D), before the high voltage h1 induced in the secondary coil of the ignition coil when the first discharge control thyristor 811 is turned on disappears, the second discharge control thyristor 812 is By setting the trigger position of the second discharge i control thyristor so that the trigger signal is given, the apparent discharge duration can be lengthened. If the discharge duration is extended by sequentially discharging the charges of multiple ignition energy storage capacitors into the primary coil of the ignition coil in this way, the specifications of the ignition coil will be changed to lengthen the discharge duration. Since this is not necessary, the characteristics of the capacitor discharge type ignition system can be utilized to speed up the rise of high voltage for ignition.
It can prevent the spark plug from becoming dirty.

In the above embodiment, the signal coil LS may be configured to first generate a positive polarity signal and then generate a negative polarity signal. In that case, capacitors C12 and C11 would be the first and second ignition energy storage capacitors, respectively, and 821 and 811 would be the first and second ignition energy storage capacitors, respectively.
and a second discharge control thyristor.

In the embodiment described above, the diodes Dal and Da2 are provided to ensure that the charge of the ignition energy storage capacitor is discharged through the primary coil of the ignition coil. When these diodes [)al and []a2 are provided, it is necessary to provide diodes Db1 and Db2 to enable charging of capacitors C11 and C12.

In the above embodiment, when the diodes Da1 and Da2 are not provided and one ends of the capacitors C11 and C12 are directly connected to the non-ground terminal of the primary coil of the ignition coil, the capacitor C11 → thyristor S11 → the primary coil of the ignition coil Coil→discharge circuit of capacitor 011, and capacitor C12→thyristor 812→primary coil of ignition coil→capacitor C outside the discharge circuit of capacitor C12
11 → Thyristor 311 → Exciter coil Le → Diode D12 Capacitor C12 → Discharge circuit of capacitor C11 and capacitor C12 → Thyristor 812 → Exciter coil Le → Diode D11 Capacitor 011
→Since the discharge circuit of capacitor C12 is configured, depending on the state of the primary coil of the ignition coil, capacitor C1
1 and C12 are not necessarily all discharged through the primary coil of the ignition coil, and some of the charges may be discharged through the discharge circuit on the exciter coil side.

For example, after capacitor 011 is discharged, capacitor C1
When thyristor 812 conducts to discharge 2,
When the voltage induced in the primary coil of the ignition coil due to the discharge of capacitor C11 remains, capacitor C1
2 is first capacitor C12 → thyristor 812 → exciter coil 1e → diode D11 capacitor C11 →
Discharge occurs through the discharge circuit of the capacitor C12, and the discharge current flowing from the capacitor C12 through the primary coil of the ignition coil decreases. On the other hand, as in the above embodiment, the capacitor C11 and the ignition coil 1
If you insert a diode Dal between the next coil,
When the thyristor 312 is conductive, if the induced voltage due to the discharge current of the capacitor C11 remains in the primary coil of the ignition coil, the electric charge of the capacitor 012 is transferred from the exciter coil side to the capacitor C12 via the capacitor C11.
can be prevented from discharging through the discharge circuit back to the ignition coil, and all the charge on the capacitor C12 can be discharged through the primary coil of the ignition coil. Therefore, the wave value of the high voltage induced in the secondary coil of the ignition coil by the discharge of the capacitor C12 can be made sufficiently high, and the effect of the present invention in extending the duration of spark discharge can be enhanced. The above-mentioned effect of the diode [)al becomes particularly noticeable when the engine is operating at high speed, where the time from triggering the thyristor S11 to triggering the thyristor S12 becomes short.

In the above embodiment, the capacitor C11 and the ignition coil 1
1 between the next coil and the capacitor C12 and the ignition coil.
Diodes [)al and Da are connected between the next coil and the next coil, respectively.
However, with this configuration, no matter which of thyristors 811 and 812 is triggered first (whichever thyristor is set as the first thyristor), the discharge will occur later. The charge of the ignition energy storage capacitor can be reliably discharged to the primary coil of the ignition coil, thereby reliably achieving the effect of extending the duration of spark discharge. Therefore, when installing the ignition system into the engine,
There is no need to pay attention to the wiring between the gates of the thyristors S11 and 812 and the thyristor trigger circuit that provides trigger signals to both thyristors, and the device can be easily integrated. However, if there is no possibility that the order of discharge of the ignition energy storage capacitor will be changed later, the connection between one end of the ignition energy storage capacitor that is discharged first and the non-ground terminal of the primary coil of the ignition coil. A diode (Dal or [)a2) is inserted only in the ignition coil, and one end of the ignition energy storage capacitor to be discharged later can be directly connected to the non-ground terminal of the ignition coil.

In the above embodiment, two ignition energy storage capacitors were provided on the primary side of the ignition coil, but generally n (n
is an integer greater than or equal to 2), and the charge in these capacitors can be sequentially discharged to the primary coil of the ignition coil through a discharge control thyristor provided for each capacitor. can.

FIG. 4 shows a configuration in which n ignition energy storage capacitors are provided, and diodes Da1 to [[
]an are commonly connected, and between the cathodes of these diodes [)al to [)an and the ground, there are diodes [)bl to D with their cathodes facing the ground side, respectively.
bn is connected. Diode Da1 or Dan
One end of the first to nth ignition energy storage capacitors 011 to C1n are connected to the cathodes of the ignition energy storage capacitors 011 to C1n, respectively.
It is designed to be charged through the in. In addition, first to nth discharge control thyristors 311 to Sln are provided for the first to nth ignition energy storage capacitors C11 to C1n, respectively, and the electric charges in the capacitors C11 to C1n are reduced by conduction of these thyristors. It is designed to discharge to the primary coil of the ignition coil.

The thyristor trigger circuit includes a signal coil LS and a pulse generation circuit PG that receives the output of the signal coil as input and generates a series of pulses.

The pulse generation circuit PG is triggered by a signal generated by the signal coil LS at the ignition position of the internal combustion engine to generate a first pulsed trigger signal, and then generates second to nth pulsed trigger signals at predetermined levels. Occurs at time intervals of

The waveforms of the output voltages Ven and Vep of the positive and negative half cycles of the exciter coil Le, the terminal voltage waveforms of the capacitors C11 to C1n, and the waveforms of the secondary induced voltages Vhl to Vhn of the ignition coil in the embodiment of FIG. This is shown in (A) to (C) of the figure.

In this embodiment, the first discharge control thyristor S11 is triggered and conducts at the ignition position of the internal combustion engine, and the capacitor C
11 charges are discharged into the primary coil of the ignition coil. Thereafter, the second to nth discharge control thyristors 812 to Sin are sequentially turned on to discharge the charges in the capacitors C12 to C1n to the primary coil of the ignition coil. As a result, high voltages Vhl to Vhn are sequentially induced in the secondary coil of the ignition coil, and the discharge time is extended.

[Effects of the Invention] As described above, according to the present invention, the first to nth ignition energy storage capacitors are provided on the primary side of the ignition coil, and these capacitors are discharged to the primary coil of the ignition coil. The first to n-th discharge control thyristors are provided, and the first to n-th discharge control thyristors are sequentially made conductive by a trigger signal given from the thyristor trigger circuit, and the first to n-th ignition energy storage capacitors are Since the charge is sequentially discharged to the primary coil of the ignition coil, the duration of the high voltage induced in the secondary coil of the ignition coil is apparently increased, and the discharge duration can be extended. In this case, the winding specifications of the ignition coil can be set so as to induce a secondary voltage that rises quickly, so that the spark rises quickly.Therefore, according to the present invention, the spark rises quickly, Moreover, there is an advantage that a capacitor discharge type internal combustion ignition device for t!l can be obtained with a long discharge duration.

[Brief explanation of the drawing]

FIG. 1 is a circuit diagram showing an embodiment of the present invention, FIG. 2 is a configuration diagram showing the configuration of a generator used in the same embodiment, FIG. 3 is a waveform diagram showing voltage waveforms at various parts of FIG. 1, and FIG. FIG. 4 is a circuit diagram showing another embodiment of the present invention, and FIG. 5 is a waveform diagram showing voltage waveforms at various parts in FIG. Ia...Ignition coil, P...Spark plug, C11 to C1n...1st to 1nth ignition energy storage capacitors, 011 to Dln...Capacitor charging diode, 811 to 3in...th 1st to 10th discharge control thyristors, 1-e... exciter coil, LS... signal coil. Figure 2

Claims (1)

[Claims] an ignition coil, first to nth (n is an integer of 2 or more) ignition energy storage capacitors provided on the primary side of the ignition coil, and one of the first to nth ignition energy storage capacitors; a capacitor charging circuit that charges to the polarity of the capacitor, and first to nth discharge control thyristors provided so as to discharge the n ignition energy storage capacitors to the primary coils of the ignition coil when conductive. and a thyristor trigger circuit that sequentially applies first to nth trigger signals to the first to nth discharge control thyristors, respectively, wherein the thyristor trigger circuit applies a trigger signal to the first discharge control thyristor. A capacitor discharge type ignition device for an internal combustion engine, characterized in that the generation phase of the first trigger signal is set so that the applied position coincides with the ignition position of the internal combustion engine.