JPS6019961A - Ignition device for internal-combustion engine - Google Patents

Abstract

PURPOSE:To check a shortage of energy in time of high speed and a misfire in time of low speed for improvements in ignition capacity as well as to prevent any breakdown in a switching element from occurring. CONSTITUTION:When a thyristor 13 is triggered and turned to ON, an electric current flows in a closed circuit consisting of a condenser 4, the thyristor 13, a primary coil 16, and a condenser 15. This closed circuit resonates under the condition determined with capacity C of the condenser 15 and inductance L of the primary coil. When a discharge passage is formed up, the induced discharge is connected thereto, and when a duration of about 2msec expires, the next cycle starts immediately and thereby redischarge starts easily, thus the discharge is almost unintermittently maintained. With this constitution, ignition energy in time of high speed is secured and, what is more, a misfire in time of low speed is prevented from occurring.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field The present invention relates to an ignition system for an internal combustion engine using an ignition spark method. This device is mainly used for ignition of internal combustion engines for automobiles.

Conventional ignition devices used in internal combustion engines reduce ignition energy at high speeds and generate only one spark, making them vulnerable to blowout. In particular, the CDI method has the problem that it is prone to misfires because the flame does not grow during startup or at low speeds.

Purpose of the Invention The purpose of the present invention is based on the concept of continuously generating multiple sparks for an appropriate period in an extremely short cycle, ensuring that there is no shortage of ignition energy at high speeds, and preventing flame growth or misfires at low speeds. The purpose of this invention is to secure the flame duration so as not to cause the occurrence of ignition, thereby improving the ignition performance, and to prevent the destruction of the switching elements and operate these elements safely and reliably.

Structure of the Invention The present invention provides a DC power source that generates a DC voltage, an ignition coil that has a primary coil and a secondary coil, and the primary coil is divided into two parts by a center tap; an ignition gap connected to the secondary coil, a capacitor connected to the midpoint tap of the primary coil, a first switching element forming a closed circuit together with the first part of the quaternary coil, the capacitor, and the DC power source; a second switching element constituting a closed circuit together with the element, a second portion of the primary coil, and the capacitor; a signal generation circuit that generates an energization signal so that the switching elements of the switch are alternately rendered conductive at predetermined timing;
An ignition device for an internal combustion engine is provided.

Embodiment An ignition system for an internal combustion engine as an embodiment of the present invention is shown in FIG.

The DC power supply 1 is, for example, a power supply using a battery, and supplies DC voltage to the DC-DC converter 3 via the engine key switch 2. The engine key switch 2 is a switch that is closed when the engine is running and opened when the engine is stopped. Further, the DC-DC converter 3 is a converter that converts the DC voltage of the DC power supply 1, for example, 12V, into a DC voltage of about 200V.The DC-DC converter 3 is a converter that converts the DC voltage of the DC power supply 1, for example, 12V, into a DC voltage of about 200V. It is of a well-known circuit configuration. Capacitor 4 is DC-DC converter 3
This is to smooth and store the output voltage of , and to supply a large transient current, which will be described later.

The ignition timing detection device 5 includes a signal rotor 51, a signal rotor 51, and a rear and rear wheels 53. The signal rotor 51 is made of a magnetic material for detecting ignition timing, and has a number of protrusions 52 corresponding to the number of cylinders, and a distributing rotor (not shown) that rotates in synchronization with the engine speed. It is attached to the viewer shaft. The pickup 53 is for detecting ignition timing, and is composed of a coil 533 and a permanent magnet 532 wound around a magnetic core 531 made of a magnetic material. 531 so that a closed magnetic path is formed.

The phase relationship between the signal rotor 51 and the pickup 530 is as follows:
Although not shown, the timing changes appropriately depending on the engine speed and load, so that the optimum ignition timing can be obtained.

The shaping circuit 6 shapes the waveform of the output signal from the pickup 53 and sets it to a "1" level (hereinafter simply "1") corresponding to the ignition timing.
This is a circuit that outputs a signal (denoted as ). Details of the shaping circuit 6 in the Fuki 1 device are shown in FIG. 2. resistance 611
, 612. The bias voltage vb set by the capacitor 613 is applied to the coil 5 of the pickup 53 via the terminal 601.
33(7) is applied to one end. This bias voltage vb is further applied to the inverting input terminal of comparator 614 as a reference voltage. The non-inverting long terminal of the converter/arm regulator 614 is connected to the other end of the coil 533 via the terminal 602, and the output of the converter 614 is "1" depending on whether the electromotive force of the coil 533 is positive or negative. , or "0" level (
A signal (hereinafter simply referred to as "0") is generated.

A resistor 6 is connected from the output of the comparator 614 to the non-inverting input terminal.
Positive feedback is applied through the circuit 15, and since this positive feedback circuit has a Shemitt trigger function with hysteresis, it is effective in preventing malfunctions due to noise. The output of comparator 614 is inverted by inverter 616 and output as an ignition timing signal via terminal 603.

The trigger signal generation circuit 7 receives the ignition timing signal from the shaping circuit 6, and repeats the ignition timing signal from each other for a predetermined period in short cycles.
Two trigger signals 5 (A) with different phases.

Make S (B). Details of the trigger signal generation circuit 7 in the apparatus shown in FIG. 1 are shown in FIG. The ignition timing signal from the shaping circuit 6 is led to the one-seven-day multi-unit 711 via the terminal 701. The one-shot multi 711 is triggered by the rise of this ignition timing signal, and the capacitor 712. A signal of "1" is generated at the output terminal Q for a certain period of time (for example, 2 m5 ec) determined by the resistor 713.

The NOR gates 714 and 715 are connected to each other to form a set-reset flip-flop, and when the output of the one-shot multi 711 reaches "1", the NOR gate 7
The output of 14 is "0", and the output of Noah gate 715 is "1"
becomes. The binary presettable up/down counter 717 is a 4-bit counter circuit.The output of the NOR gate 714 is led to the reset terminal of the binary presettable up/down counter 717.When the output of the NOR gate 714 becomes rOJ, it starts counting, and when it becomes "1", it starts counting. will be reset. Note that this counter 717 is set to down count mode and does not use the preset function.

Clock generation circuit 716 is a circuit that continuously generates a clock signal with a frequency of, for example, about 80 kHz, and the clock signal is guided to a clock input terminal of counter 717. One input terminal of the NOR gate 718 is connected to the output terminal of the one-shot multi 711, and the other input terminal is connected to the QD output terminal which is the 1/16 frequency-divided output of the counter 717. And the level of both output terminals is "0"
When this happens, the output of the NOR gate 718 becomes "1".

This output is led to NOR gate 715 and inverts a flip-flop composed of NOR gates 714 and 715.

The output of the counter 717 is further passed through inverter buffers 719 and 720 to the one-shot multi-channel
21.728. one shot multi 7211
d It is triggered by the falling edge of the output of the inverter buffer 719, and continues for a certain period of time determined by the capacitor 722 and the resistor 723 (
For example, a signal of "0" is generated at the output terminal at 5 μBee). This signal is routed through resistors 724 and 725 to transistor 726. When the ■ terminal of the one-shot multi 721 is “0”, the transistor 72
6 is on and its collector, that is, terminal 702, is
1) to the trigger signal S).

One shot multi 728 is inverter buffer 720
is triggered by the rising edge of the output, and generates a "0" signal between the output terminals for a certain period of time (for example, 5μ8ee) determined by the capacitor 729 and resistor 730. This signal is conducted to the pace of the traxistav 33 via resistors 731, 732. One shot multi 728 mutual terminal is “O”
When , the transistor 733 is turned on and the trigger signal S (B) of "1" is applied to its collector, that is, the terminal 703.
Output.

The thyristor 13 has its anode connected to the positive terminal of the capacitor 4, and its cathode connected to one end of the primary coil 161 of the ignition coil 16.

A trigger signal generation circuit 7 is connected to the gate of this thyristor 13.
The signal 5 (A) is the insulating pulse transformer 14.
and a diode 131. Resistor 132, capacitor 133. The signal is supplied through a noise prevention circuit consisting of a resistor 134. The resonance capacitor 15 is connected to the center tap of the primary coils 161 and 162 of the ignition coil 16.

This thyristor 13 causes a capacitor 4. Thyristor 13° primary coil 161. One closed circuit consisting of the resonance capacitor 15 is formed.

The thyristor 20 has its anode connected to one end of the primary coil 162, and its cathode connected to one end (GND) of the resonance capacitor 15. A trigger signal S (B) is applied to the gate of the thyristor 20 from the signal generation circuit 7 via the mother transformer 21 and then to the diode 201.
．． The signal is supplied through a noise prevention circuit consisting of resistors 202 and 204° capacitor 203. This thyristor 20 causes the primary coil 162. Thyristor 20. Another closed circuit consisting of a resonant capacitor 15 is formed.

The ignition coil 16 includes primary coils 161, 162° and secondary coil 163. From core 164. Primary coil 161.1
The turns ratio between the primary coils 62 and the secondary coil 163 is set to about ioo to 200, and the primary coils 161 and 162 are wound in the same direction. Primary coil 161, 162. Secondary coil 1
63 is magnetically coupled via a core 164 and boosts the voltage generated in the primary coils 161 and 162 and outputs it from the secondary coil 163. One end of the secondary coil 163 is grounded (GND), and the other end is connected to the center electrode of the distributor 22 that distributes high voltage to each cylinder.

The distributor 22 has a well-known configuration, and is arranged in a predetermined cylinder by a distribution rotor 23 that rotates together with a shaft that rotates synchronously at one-half of the engine speed. Ignition gap 241.242.
High tension code 251.252 to 243.244
．． 253.254 to distribute high voltage.

The following semiconductor devices were used in the apparatus shown in FIG.

One-shot multi 711...Toshiba TC4
528BP Noah Game) 714,715,718...
... I/ TC4001BP up/down counter 717 ...... tt TC4516BP inverter 719, 720 ...... p TC4049
BP one shot multi 721.728...T
I9 74LS221 Next, the operation of the apparatus shown in FIG. 1 will be explained.

FIG. 4 is a signal waveform diagram of each part of the device shown in FIG. timing signal, (4) is the ignition period signal which is the output of the one-shot multi 711, (5) is the output signal of the NOR gate 714, (6) is the QD output signal of the counter 717, and (7) is the output of the 4y converter powder 719.720. Signal, (8)
is the trigger signal S (G), (9) is the trigger signal S (B)
hail waveform.

First, when you turn on the engine key switch 2, the DC-
A DC voltage of +12V is supplied from the DC power supply 1 to the DC converter 3 and boosted to +200V.
A DC voltage of v is constantly stored in the capacitor 4.

The signal rotor 51 rotates according to the rotation of the engine,
An electromotive force having a waveform shown in FIG. 4 (1) is generated in the coil 533 of the I-Fudge 53. The point at which this electromotive force switches from positive to negative is the ignition timing.

Since the coil 533 is biased by the bias voltage vb by the shaping circuit 6, the output voltage of the pickup 53 has a value that is the potential generated by the coil 533 raised by the bias voltage vb, as shown in FIG. 4(2). This signal is shaped by the shaping circuit 6 and becomes a signal that rises to "1" at the ignition timing shown in FIG. 4 (3).

The output signal of the shaping circuit 6 is input to the trigger signal generation circuit 7, and the one-shot multi 711 is triggered at the rising edge of the signal, and the A?
Generates a pulse-shaped ignition period signal.

this/? Let the pulse width be the ignition period. The ignition period signal enters the NOR gate 714 and inverts the 7 rig 70 consisting of NOR gates 714 and 715. As a result, as shown in FIG. 4 (5), the output of the NOR gate 714 is rO
It becomes J.

The output of NOR gate 714 is led to the reset terminal of counter 717, and when this output is rOJ, counter 717 is released from reset. By releasing this reset, the υ counter 717 receives approximately 80 kHz from the clock generation circuit 716.
Start counting at the clock frequency of z. Since the counter 717 is a 4-bit binary counter and is set in the down count mode, the contents of the counter 717 change from 0 to 15 at the first rising edge of the clock signal. In other words, the QD ratio output of the counter 717 is “O”
It becomes "1". From then on, each time a clock signal arrives, the down-count is repeated, and O115, 14, . . .
,2,1.0,15. ...and the contents change periodically. At this time, the QD ratio output, which is the 1/16 frequency division output,
When the content of the counter 717 is 8 to 15, it becomes "1", so a square wave with a data ratio of 50 chis as shown in FIG. 4 (6), which has a frequency of 1/16 of the clock frequency, is generated.

The width of one A Luz in Figure 4 (6) is 100μa@e
The interval between the s/# pulse and the pulse is Zooμsec.

Approximately 2m5ec after the ignition timing signal rises, the NOR gate 7140 input becomes "0". If the counter 717 is reset immediately at this time, the time width of the immediately preceding QD ratio output "1" will be shortened, and the commutation of the thyristor, which will be described later, will not be performed properly. - As a countermeasure for this, the output of the one-shot multi 711 and the counter 71
By leading the output of 7 to the input of NOR gate 718, the output of NOR gate 718 becomes ``1'' only when the QD ratio output is ``0'', inverting the 7 lip-flop consisting of 714.715 (NOR gate), and thereby Jino Game) 7
14 is set to "1" to reset the counter 717.

As explained above, from the ignition timing signal to the clock signal 1
An integral number of square waves of 1/16 (5 kHz) of the QD specific output clock frequency are generated at least during the ignition period with a delay within the period (12.5 μsec). This signal is inverted by inverter buffers 719 and 720 and is
) is the signal shown.

One shot multi 721 is invar p ha7a7
19, a pulse of approximately 5 μsec is generated, the transistor 726 is turned on, and the trigger signal 5(4) shown in FIG. 4(8) is output to the terminal 702. Also, the one-shot multi 728 is an inverter buffer 720
It is triggered by the rising edge of the output of , generates a pulse of approximately 5μ8ee, turns on the transistor 733, and as shown in FIG.
The trigger signal S (B) shown in 9) is output to the terminal 703. In other words, the trigger signals 5(4) and S(B) have a phase difference of 180° and a period of 2004 seconds.

This is a signal with a pulse width of 5 μsec.

Next, the operation of the high pressure generator will be explained. FIG. 5 is a waveform diagram showing the signals of each part in this embodiment in a temporally enlarged manner compared to FIG. 4. In Fig. 5, (1) is the trigger signal 5 (A), (2) is the trigger signal Saki B), (3), respectively.
is the terminal voltage of the capacitor 15, (4) is the thyristor 13
(5) is the current flowing through the thyristor 13,
(6) shows the anode voltage of the thyristor 20, and (7) shows the waveform of the current flowing through the thyristor 20.

A trigger signal 5(A) shown in FIG. 5(1) triggers the thyristor 13 via the pulse transformer 14 and the noise prevention circuit. Similarly, the trigger signal 5(B) shown in FIG. 5(2)
The thyristor 20 is triggered via the Hapulus transformer 21 and the noise prevention circuit.

First, when the thyristor 13 is triggered and turned on, current flows through a closed circuit consisting of the capacitor 4, the thyristor 13, the primary coil 161, and the capacitor 15. At this time,
Since the capacitance of capacitor 4 is sufficiently larger than that of capacitor 15, capacitor 4 is connected to a constant voltage (200V).
) can be thought of as a power source. In addition, the primary coil 16
1, the resistance of the thyristor 13, and the resistance of the click circuit are sufficiently small, so this first closed circuit is formed by the capacitance C of the capacitor 15 (for example, 1μF) and the primary coil noise inductance L (for example, 1ooμH). Resonates under certain conditions.

At resonance, the current flows through the positive terminal of capacitor 4, thyristor 13, primary coil 161, and capacitor 5 in Figure 1.
, flows in the direction of the ground terminal of capacitor 4, and the previous C and L
A sine wave shape is obtained using the following equation (1).

Further, the voltage generated in the primary coil 161 is as shown in equation (2).

“・=V=ρ了t −=−−−−−−−°−゛°°−(
2) The voltage applied to the capacitor 15 is as shown in equation (3).

The thyristor 13 remains on only when i>O, but when i≦0, it commutates and becomes off.

In this way, in the device shown in FIG. 1, since the oscillating current shown in equation (1) flows through the circuit including the primary coil t capacitor, the switching element, and the DC power supply, the thyristor 13 automatically commutates. , there is no need to add a special commutation circuit.

In the above equation (1), the time tl at which i becomes zero is tl = π.
・ (4) At this time, the thyristor 13 is off, and the voltage of the capacitor 15 calculated by equation (2) is DC-DC: + nharp (D voltage (200V
)02 times, which becomes 400V and is held.

Next, a case will be described in which the Cyrisk 20 is defeated. When the thyristor 20 turns on, the capacitor 15
, primary coil 162. A closed circuit consisting of the thyristor 20 is formed, and the charge stored in the capacitor 15 is transferred to the upper terminal of the capacitor 15, the primary coil 162. Thyristor 20
．． The current flows toward the lower terminal of the capacitor 15, and the current value at this time is as shown in equation (5).

Thyristor 20, like thyristor 13, has π7
Between 1) ON and υ, there is a natural commutation, so no special commutation circuit is required.

Thereafter, current alternately flows through the primary coils 161 and 162 by continuously and alternately triggering the thyristor 13 and the thyristor 20. Assuming there is a loss in the circuit, the current flowing in the circuit, the voltage of the capacitor 15, and the primary coil 161
．． The voltage of 162 increases and diverges each time switching is repeated, but in reality, energy is consumed through the secondary coil and there is loss in each part, so the voltage increases in the first 2.3 times. The peak value is almost constant.

In the explanation so far, the ignition coil 160 secondary coil 16
3 is not mentioned, but the primary coil 161.16
2 and the secondary coil 163 are transformer-coupled, so
Assuming that the transformation ratio is 1:50, the primary coil 16
150 times the applied voltage of 1,162 is generated in the secondary coil 163. That is, when the power supply voltage V=200V and the transformation ratio 150, the voltage v2 generated in the secondary coil 163 is v
! =2oo×x5o−=3okv −−−−−−−−
(6) The voltage becomes sufficient to cause ignition by discharge.

The voltage generated by the secondary coil 163 is
2, the high tension code 25 is distributed to predetermined cylinders.
Ignition gap 24 via 1.252.253.254
1, 242, 243, and 244, and is discharged to the ground electrode of the ignition gap for ignition.

Once a discharge path is formed during discharge, the air in the vicinity is ionized and an arc discharge occurs, and the induced discharge continues until the discharge sustaining voltage (approximately 500 V to 1 kV) or less falls below. This duration is that of a normal ignition device (approximately 2m5
Although it is shorter than ec), the next cycle starts immediately after this induced discharge ends, so the ions remaining between the discharge gap easily cause another discharge, and the discharge becomes l
The hills continue without interruption. Since this duration can be determined by the ignition period electrically set in the trigger signal generation circuit 7, it is easy to set it to a sufficiently long time to ensure complete ignition.

Furthermore, since the other thyristor is in the reverse blocking state for about half of the time when one thyristor is on, the repetition period of the trigger signals 5(A) and 5(B) can be shortened. In this way, the device shown in Figure 1 can continuously generate multiple sparks over an appropriate period of time in an extremely short cycle in the ignition control of an internal combustion engine for automobiles, thereby improving the ignition performance of the internal combustion engine. .

In the device shown in FIG. 1, an ignition coil 160 and a primary winding 161.
162, the thyristor 113 and the thyristor 20 become conductive at the same time due to noise or the like, and the charge in the capacitor 4 is transferred to the thyristor 13. Even if the discharge occurs all at once through the thyristor 20, the primary winding, 16
1,162 inductance and resistance prevent a sudden increase in current and overcurrent, and the thyristor's a
Breakdown of thyristors and switching elements other than thyristors due to i/dt or overcurrent can be prevented.

Furthermore, when the capacitor 15 is connected to the center tap of the primary coil 161 and 162, the thyristor 13.2
The rate of increase dV/dt of the voltage applied in the forward direction of 0 is determined by the time constants of the capacitor 15 and the primary coil 162, and the time constants of the capacitor 15 and the primary coil 161, respectively. It can be set to a low value of V/μ1HBe or less.

As a result, malfunctions caused by the dV/di applied to the other thyristor due to the operation of one thyristor can be eliminated.

Furthermore, the primary coils 161 and 162 are wound in the same direction and are configured to generate magnetic fields in the same direction.
The dV/d t applied to the switching element thereby
Safe and reliable off-site operation of the switching elements can be achieved.

In carrying out the present invention, various modifications are possible in addition to the embodiments described above. For example, in the above-mentioned embodiment, the primary coils 161 and 162 were wound in the same direction, but the present invention is not limited to this, and by winding them in opposite directions to generate magnetic fields in opposite directions, the secondary coil can be supplied with positive and negative high voltages. can also be generated alternately.

In addition, by providing a circuit 18 consisting of a thyristor 13° 20, an ignition coil 16, a capacitor 15, etc. in the first device for each cylinder of a multi-cylinder internal combustion engine, high voltage distribution for high tension cords, distributors, etc. It is possible to have a configuration in which the high voltage distribution means is omitted, thereby increasing the energy consumption of the high voltage distribution means, and eliminating the need for the high voltage distribution means, thereby reducing costs.

Furthermore, as another embodiment, the number of thyristors used can be reduced by using one thyristor 20 in the apparatus shown in FIG. It is also possible to reduce costs. Another embodiment is shown in FIG. Components that are the same as those of the device n in FIG.

161i[, the cylinder discrimination device 8 is the signal rotor 8
0 and a pickup 82. signal rotor 8o
is for cylinder discrimination, and is attached to a distributor shaft (not shown) that rotates synchronously at the engine speed of 172.
have. The pickup 82 is a pickup for cylinder discrimination, and has the same principle as the pickup 53 of the above-mentioned embodiment, but the pickup 53
The magnetic core of the pickup 82 has a structure that forms a closed magnetic path with the two protrusions of the signal rotor 51.
The magnetic core is an open magnetic path.

The phase relationship between the signal rotor 8o and the pickup 82 is different from that of the signal rotor 51 and the pickup 53 described above, and is fixed and does not change depending on the engine speed or load. When the signal signal 80 rotates once, the pickup 82 outputs 1 no or rus. This pulse position is set at 60 degrees before the top dead center of the first cylinder. The output of the pickup 82 is guided to the shaping circuit 6'. The shaping circuit 6' has the same circuit configuration as the shaping circuit 6.

Details of the trigger signal generation circuit 9 in the device shown in FIG.
As shown in the figure. Further, FIG. 8 shows signal waveform diagrams of various parts in FIGS. 6 and 7. In FIG. 8, (1) is the output of the pickup 53, (2) is the output of the pickup 82, and (3) is the output of the pickup 82.
) and (4) are the outputs of the shaping circuit 6 and 6', respectively,
(5), (6), (7), (s) are the outputs at the output terminals ■, ■, ■, ■ of the counter 912, respectively, (9), (10), (11), (12)
), (13) are each trigger signal 8 (A) 1.5
(A) 2.5 (A) 3.5 (A) 4° 5 (B) Each waveform is hailed.

In FIG. 7, the circuit portion of the trigger signal generation circuit 9 surrounded by a dashed line with reference numeral 7 has the same configuration as the trigger signal generation circuit 7 in the above-described embodiment, so a description of this circuit portion will be omitted. do. Counter 912 (Toshiba TC4
017) is a counter with a decoder, and the output signal of the shaping circuit 6' shown in FIG. 8(4) is input to its reset terminal R, and the p counter 912 is reset by this output signal.

In addition, the clock terminal C has a shaping circuit 6 shown in FIG. 3 (3).
The counter 912 counts this output signal.

Therefore, after the counter 912 is reset by the output signal from the shaping circuit 6', by receiving the first signal from the shaping circuit 6, the output terminal (■) of the counter 912 has the waveform shown in FIG. 8 (5). The decoded signal is output. Similarly, the second signal causes the output terminal ■
The waveform shown in Figure 8 (6) is transmitted to the output terminal ■ by the third signal, and the waveform shown in Figure 8 (8) is transmitted to the output terminal ■ by the fourth signal. Hail to each of you. Note that the time period at which the output terminal (3) is "1" is shorter than the other outputs because it is reset midway.

and goo) 908, 909, 910.911, the inputs are the output terminals of the counter 912, ■, ■,
The output waveforms ① and ② are input, and the trigger signal 5 (A) obtained by the trigger signal generation circuit 7 is input in common to the other input. Therefore, the terminal 903 receives the trigger signal 5(A)1 for the first cylinder, the terminal 904 receives the trigger signal 5(A)2 for the third cylinder, and the terminal 905 receives the trigger signal 5(A)2 for the fourth cylinder. A trigger signal 5(A)3 and a trigger signal 5(A)4 for the second cylinder are outputted to the terminal 906, respectively. Further, a trigger signal 5 (B) is output to the terminal 907. These trigger signals 5(A),.

The signal waveforms of 5(A), 2.8(A), 3.5(A), and 4.5(B) are shown in Figure 8 (9), (10), (11), and (12).
, (13).

Next, the operation of the apparatus shown in FIG. 6 will be explained. A trigger signal 5(A)1 is input to the dart terminal of the thyristor 13a for the first cylinder via the pulse transformer 14a, thereby turning on the thyristor 13a, and igniting the thyristor 13a for the first cylinder as in the previous embodiment. A high voltage is generated in the secondary coil of the coil 16a to generate a snort in the ignition gap 241, and energy is stored in the capacitor 15m. At this time, the energy stored in the capacitor 15a does not flow to the ignition coils 16b, 16c, and 16d of other cylinders due to the diodes 17b, 17c, and 17d.

Next, when the signal 5 (B) is applied to the dart terminal of the thyristor 2o via the pulse transformer 21, the charge stored in the capacitor 15a is discharged through the primary coil of the ignition coil 16a, the diode 17a1, and the thyristor 20. Accordingly, a high voltage is generated in the secondary coil of the ignition coil 16a, causing a spark in the spark gap 2241 and closing it.

The above steps are repeated a predetermined number of times, and the next cylinder is ignited. At this time, since the ignition of the first cylinder ends with the voltage of the capacitor 15a becoming negative, the diode 17a is in a reverse blocking state and does not affect the ignition of other cylinders at all.

The above operation is the first step. Third. 4th. By performing this in the order of the second cylinder, it is possible to obtain a spark with good ignitability near the top dead center of each cylinder. Moreover, the distribution of each cylinder is controlled by diode 17.
Since the steps a to 17d are carried out, the number of thyristors used can be significantly reduced, resulting in miniaturization of the device and cost reduction. Furthermore, by distributing the cylinders using the diodes 17a to 17d and providing an ignition coil for each cylinder, it is possible to eliminate high voltage distribution means such as a distributor and high-tension I-cord, thereby eliminating energy loss due to heat generated by these devices. This increases ignition energy and enables efficient ignition control.

Effects of the Invention According to the present invention, when igniting an internal combustion engine, a plurality of sparks can be generated continuously for an appropriate period at extremely short intervals, ensuring that ignition energy is not insufficient at high speeds, and ensuring that ignition energy is not insufficient at low speeds. Flame duration is ensured without flame growth or misfires, thereby improving ignition performance.

Further, it is possible to prevent switching elements such as thyristors from being destroyed, and to operate these elements safely and reliably.

[Brief explanation of drawings]

FIG. 1 is a circuit diagram showing an ignition system for an internal combustion engine as an embodiment of the present invention, FIG. 2 is a circuit diagram of a shaping circuit in the device shown in FIG. 1, and FIG. 3 is a trigger signal generation circuit in the device shown in FIG. 4 is a signal waveform diagram of each part in the device shown in FIG. 1, FIG. 5 is a waveform diagram of each part signal waveform in the device shown in FIG. A circuit diagram showing an ignition system for an internal combustion engine as another embodiment of the present invention, FIG. 7 is a circuit diagram of a signal generation circuit in the device shown in FIG. 6, and FIG. 8 is a signal waveform diagram of each part of the device shown in FIG. 6. It is. 3...DC-DC converter, 4...Capacitor,
5... Ignition timing detection device, 6, 6'... Shaping circuit,
7, 9...Trigger signal generation circuit, 8...Cylinder discrimination device, 13°13a to 13d, 20" thyristor,
14.14a-14d--pulse transformer, 15.
15a to 15d... Resonance capacitor, 16.16
a to 16d...Ignition coil, 161.162...1
Secondary coil, 163...Secondary coil, 22...Distributor, 241-244...Ignition gap, 2
51-254...High-tension 100n code. Fig. 4 2QQ7xSeC Fig. 5

Claims (1)

[Claims] 1. A DC power source that generates a DC voltage; an ignition coil that has a primary coil and a secondary coil, and the primary coil is divided into two parts by a center tap; 2. an ignition gap connected to a secondary coil; a capacitor connected to a midpoint tap of the primary coil; a first switching device forming a closed circuit with the first portion of the primary coil, the capacitor, and the DC power source; a second switching element forming a closed circuit together with a second portion of the primary coil and the capacitor; An ignition device for an internal combustion engine, comprising: a power generation circuit that generates an energization signal so that the switching elements of the switch are alternately rendered conductive at predetermined timings. 2. According to claim 1, a circuit including the first switching element, the second switching element, the capacitor, and the ignition coil is provided in common to each cylinder of a multi-cylinder internal combustion engine. equipment. 3. The circuit according to claim 1, wherein a circuit including the first switching element, the second switching element, the capacitor, and the ignition coil is provided for each cylinder of a multi-cylinder internal combustion engine. Device. 4. The device according to claim 3, wherein the second switching element is provided on one side common to all cylinders, and cylinder distribution is performed by a rectifying element such as a diode. 5. The device according to any one of claims 1 to 4, wherein the two portions of the primary coil generate magnetic fields in the same direction. 6. The device according to any one of claims 1 to 4, wherein the two parts of the primary coil generate magnetic fields in opposite directions.