JPS597774A - Ignition device for internal-combustion engine - Google Patents

Abstract

PURPOSE:To reduce the engine speed for the ignition action start and facilitate the engine start by providing an amplifying circuit having a base-grounded transistor at its first stage in the signal feed circuit of an ignition device for an internal-combustion engine. CONSTITUTION:When an exciter coil 1 outputs a voltage in the arrow direction, a condenser 3 is charged through a diode 2, and when a signal coil (f) outputs a signal, a transistor 701 conducts, a base current flows into a transistor 705 to conduct it through the condenser 3 transistor 705 resistor 704 transistor 701 diode 703 and through the signal coil (f) primary coil 49 condenser 3. At this time, a current flows through the condenser 3 transistor 705 resistor 708 thyristor 5 primary coil 49 condenser 3, thus the thyristor 5 conducts and the charges in the condenser 3 are discharged through the primary coil 49. Thereby, the thyristor 5 can be triggered even when the output of the signal coil (f) is low, and the engine speed for the ignition action start can be reduced.

Description

[Detailed description of the invention] The present invention relates to an ignition device for an internal combustion engine.

In non-contact internal combustion engine ignition systems that perform ignition by controlling the primary current of the ignition coil using a semiconductor switch, the output of a signal coil that generates a signal at a predetermined position in synchronization with engine rotation is used. The ignition position is determined. For example, FIG. 1 shows a capacitor discharge type ignition system, in which reference numeral 1 represents an exciter coil (ignition power source) disposed within a magnet generator driven by an engine. One end of the exciter coil 1 is connected to one end of a capacitor 3 via a diode 2, and the other end of the capacitor 3 is connected to one end of the primary filter 41 of the ignition coil 4 on the non-grounded side. Also connected to one end of the capacitor 3 is the anode of a thyristor 5, which serves as a semiconductor switch for controlling the primary current of the ignition coil, and the cathode of the thyristor 5 is grounded. A resistor 6 is connected in parallel between the r-) candos of the thyristor 5, and an ignition glove p attached to a cylinder of the engine is connected in parallel to the secondary coil 4b of the ignition coil 40. A diode 2, a capacitor 3, an ignition coil 4, a thyristor 5, a resistor 6, and a spark plug P constitute a capacitor discharge type ignition circuit k using the exciter coil 1 as an ignition power source. This ignition circuit generates a large magnetic flux change in the iron core of the ignition coil by discharging the electric charge of the capacitor 3 charged by the exciter coil 1 to the primary coil 4a through the thyristor 5, and causes a high magnetic flux in the secondary coil 4b. A voltage is induced, and this high voltage causes a spark to be generated at the high point plug p.

Conventionally, in the above-mentioned ignition circuit, in many cases,
A signal coil f is connected between the cathode and the cathode of the thyristor 5 through a diode D, and an ignition operation is performed by giving an ignition signal to the thyristor 5 from the signal coil f through the diode D at the ignition position of the engine. That's a lot of fish. However, when the output of the signal coil f is supplied to the dart of the thyristor 5 via the diode D, the firing signal required to trigger the thyristor 5 is reduced by the forward voltage drop of the diode D. The problem is that because the level (the level of the bird) increases, the ignition signal is not input to the thyristor 5 until the output of the signal coil increases to a certain degree when the engine is started, and the starting rotation speed (rpm) of the ignition system becomes high. was there. In particular, when starting the engine with the starter motor, the rotation speed at startup can only rise to about 100 rpm, so it is necessary to lower the rotation speed at which ignition starts, and in this case, the diode D The forward voltage drop due to this becomes a major problem.

An object of the present invention is to provide an ignition device for an internal combustion engine that can lower the rotational speed at which the ignition operation starts.

The present invention provides a signal supply circuit that supplies a control signal to a semiconductor switch that controls the primary current of an ignition coil, and includes an amplifier circuit having a transistor whose base is grounded at the first stage.
The present invention is characterized in that the output of the signal coil is supplied to the semiconductor switch through this amplifier circuit.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The ignition device of the present invention will be explained in detail below with reference to the illustrated embodiments.

FIG. 2 shows an embodiment of the present invention, and the ignition circuit in this embodiment is almost the same as that shown in FIG. A diode D1 is connected in parallel to the exciter coil 1, and when an output is generated in the exciter coil 1 in the direction of the arrow shown in the figure, a current flows through the path of the exciter coil 1 → diode 2 → capacitor 3 → diode D1 → exciter coil 1. Capacitor 3 is charged to the polarity shown. A signal supply circuit 7 for supplying a firing signal to the thyristor 5 is provided, and the firing signal is supplied from the signal supply circuit 7 to the thyristor 5 when the signal coil f generates a signal.

The signal coil f is disposed within a signal generator that rotates in synchronization with the engine, and in this embodiment induces a signal voltage in the direction of the arrow shown at the ignition position of the engine.

The signal supply circuit 7 includes a transistor 70 whose base is grounded.
The output of the signal coil f is applied between the base and emitter of the transistor 701. A resistor 702 is connected in parallel between the base emitter of the transistor 7010, and a (5) diode 703 is connected in parallel between the base and emitter of the transistor 701 to compensate for the reverse voltage between the base and emitter of the transistor 701. The base of a transistor 705 is connected to the collector of the transistor 701 through a resistor 704, and a capacitor 706 and a resistor 707 are connected in parallel between the base and emitter of the transistor 705. The emitter of the transistor 705 is connected to the diode 20 in the ignition circuit, and the collector is connected to the thyristor 5 via a resistor 708.

In the ignition system of FIG. 2, when the exciter coil 1 outputs a voltage in the direction of the arrow shown in the figure, the capacitor 3 is charged through the diode 2 to the polarity shown. Next, when the signal coil f outputs a signal in the direction of the arrow shown in the figure, a base current flows through the transistor 701.
becomes conductive. When the transistor 701 becomes conductive,
Capacitor 3 → transistor 1 base of transistor 705 → resistor 704 → collector emitter of transistor 701 → diode 703 and signal coil 11 Primary coil 4a
-→The base current flows through the transistor (6) Tough 05 in the path of the capacitor 3, and the transistor 705 becomes conductive. At this time, capacitor 3 → transistor 7
05 emitter/collector → resistor 708 → thyristor 5
A current flows through the path from the starter cathode to the primary coil 4a to the capacitor 3, and an ignition signal is input to the thyristor 5. Therefore, the thyristor 5 becomes conductive, and the charge in the capacitor 3 is discharged through the thyristor 5 to the primary coil 4a. This discharge of the capacitor 3 causes a large magnetic flux change in the iron core of the ignition coil 4, and a high voltage is induced in the secondary coil 4b, causing sparks to fly to the ignition glove p.

By supplying the output of the signal coil f to the thyristor f through the amplifier circuit as described above, the thyristor 5 can be triggered even when the output of the signal coil f is low, and the ignition operation is started. The rotation speed can be lowered. In particular, the input resistance Ri of the first stage common base transistor amplifier circuit of the signal supply circuit 7 is given by R1=re+rb(1-α), where re is the emitter resistance of the transistor, rbs is the base resistance, and α is the current amplification factor. Input resistance R1 of emitter common amplifier circuit = rb+re/(
1-α), approximately 1/3 of the input resistance of the collector-grounded amplifier circuit R1=Rt, /l-α (RL is the load resistance)
000, and can be made conductive with a small base current. Therefore, in the circuit shown in FIG. 2, it is important that the first stage of the signal supply circuit 7 is a common-base transistor amplifier circuit, and thereby the rotational speed at the start of operation can be significantly lowered.

In the example shown in FIG. 2, current is supplied to transistors 705 and 701 by part of the charge of capacitor v3, but since the current required to trip thyristor 5 is small, it is Even if the capacitor 3 is used as a power source for the circuit of the thyristor 5, the ignition performance will not deteriorate.

In the above embodiment, the ignition circuit is a capacitor discharge type circuit, but the ignition circuit may be any circuit that controls the primary current of the P ignition coil using a semiconductor switch to perform the ignition operation. However, it may be an interrupted circuit.

In the above embodiment, a simple ignition device that determines multiple ignition positions based only on the output of the signal coil was used as an example, but an electronically controlled ignition system that combines the signal coil and an electronic control circuit to obtain advance and retard characteristics. The present invention can also be applied to an ignition device. Embodiments in which the present invention is applied to various electronically controlled ignition devices will be described below.

Various electronically controlled ignition systems have been proposed, one of which is
One ignition cycle of the engine (the period from one ignition in each cylinder until the next ignition)
A charging section and a discharging section are set within a section with a length corresponding to , and the capacitor is charged with a constant current in the charging section, and then the capacitor is discharged in the discharging section, and the terminal voltage at the time of discharge of this capacitor is set as the reference voltage. In comparison, there is one that uses an advance angle circuit that advances the ignition position by generating an ignition signal at the angular position where the terminal voltage of the capacitor becomes less than the reference voltage. In addition, as a similar ignition method, a capacitor is discharged at the end position of a certain charging section set within a range not exceeding the length corresponding to one ignition cycle of the engine, and the voltage at the terminal (9) at the time of charging of the capacitor is used as the reference. Some engines use a retard circuit that generates an ignition signal when the terminal voltage exceeds a reference voltage to retard the ignition position as the rotational speed of the internal combustion engine increases. Ignition devices for internal combustion engines having various characteristics can be obtained by using these methods alone or in appropriate combinations.

FIG. 3 shows a general configuration of this type of ignition system for an internal combustion engine previously proposed by the present applicant, and the ignition system shown in the figure uses the advance angle circuit. In Fig. 3, a is an integral capacitor charged from a DC power supply through a constant current circuit and a discharge blocking diode ◎, and d
is a current limiting means (constant current circuit or resistor) constituting a discharge circuit that discharges capacitor a at a constant time constant, ・ is a switch for controlling the charging/discharging period, and the control terminal of switch ・ is connected to a signal that rotates in synchronization with the engine. The output of a rectangular wave generation circuit g which generates a rectangular wave signal by inputting the output of a signal coil f provided in the generator is input. As shown in Fig. 4B, the signal coil f generates a signal of one cycle per one ignition cycle of the engine at a predetermined rotation angle position of the engine, and in the example shown in Fig. 4B, One negative direction signal (first half cycle signal) Ksl is generated at the position of the angle θ2 before the top dead center of the engine, and then one positive direction signal (the first half cycle signal) is generated at the position of the angle θ1 before the top dead center of the engine. 2 half cycle signal) E82 is generated. The rectangular wave generating circuit g directly converts the negative direction signal Esl into a rectangular wave signal Vg (see FIG. 4C) having the same width, and makes the section switch e in which this rectangular wave signal is generated conductive. h is a voltage comparator, to which the terminal voltage Vo of capacitor a and the reference voltage Vr obtained from the reference voltage generation circuit 1 are input, The signal obtained by the voltage comparator when It is supplied to the ignition circuit k as an ignition signal, and at the same time it is supplied to the control terminal of a reset switch m connected in parallel to both ends of the capacitor a.When the ignition signal is given to the ignition circuit, a high A voltage is generated and this high Vt, FE is applied to the ignition glove to cause ignition operation.

In the above ignition system, a rectangular wave signal is generated from a rectangular wave generating circuit g by a capacitor a1, a constant current circuit, a diode C1, a current limiting means d1, a charge/discharge section control switch, a comparator, a reference voltage, and a pressure generating circuit 1. An ignition signal generation circuit (2) is configured that outputs an ignition signal whose generation position changes depending on the rotational speed of the engine while the ignition signal is being output. In this ignition system, the engine speed is idling speed No.
(RPM) to the set rotation speed N + (>'No), the negative direction signal E of the signal coil f
Since the peak value of LS does not reach the value that causes the rectangular wave generating circuit g to operate, the rectangular wave generating circuit g does not output a rectangular wave signal. At this time, the ignition signal generation circuit ■ does not generate an ignition signal,
An ignition signal is given to the ignition circuit k by the positive direction signal Ess obtained from the signal coil f.

If the rise of the positive direction signal Kss is made steep, this positive direction signal Ea! The position where the ignition signal is applied is approximately the rising position θl of the positive direction signal gsz, and the ignition position of the engine is approximately constant with respect to the rotational speed N (RPM). When the rotational speed of the engine exceeds N, the negative direction signal Es1 of the signal coil f reaches a level that causes the rectangular wave generating circuit g to operate, so that a rectangular wave signal is generated from the rectangular wave generating circuit g.

At this time, the waveform of the terminal voltage Va of the capacitor a with respect to the rotation angle θ is as shown in FIG. The waveform rises at a constant slope (constant current charging) up to the angle θ2 and falls at a constant slope from the angle θ2 to the next angle θ@. Then, at a position θa where the terminal voltage Vo at the time of discharging the capacitor a becomes equal to or lower than the reference voltage Vr, an ignition signal is given by the comparator.

The charging voltage of capacitor a at the angle of 0 times decreases as the rotational speed of the engine increases, as shown by the broken line in Figure 4 (4). (the position where the value becomes equal to or lower than Vr) θa advances as the rotational speed of the engine increases.

(13) When the engine speed reaches the set speed N1 or more, the terminal voltage Va of capacitor a is already below the reference voltage Vr when the square wave signal (negative direction signal H!sl) rises at an angle of θ. It is set to be . Therefore, in this case, the ignition signal is given by the comparator at the same time as the rectangular wave signal rises at the angle θ, and the ignition position will not advance beyond the angle 03 even if the rotational speed rises above N1. Due to the above operation, the characteristics of the ignition position θi with respect to the rotational speed N are as shown in Fig. 5. In the medium and high speed range where the rotational speed is from the set value N1 to N, t, the ignition position is at an angle θl before top dead center TDC. It has a characteristic of advancing from the position to the bottom dead center BTD side at an angle θ3t, and in this case, the advance angle width θW is expressed as 1θ3−θ凰1.

Next, FIG. 6 shows the general configuration of another ignition system previously proposed by the present applicant, and this ignition system uses the retard circuit. In the ignition circuit shown in Fig. 6, a circuit for discharging capacitor a at a constant current is not provided, and the comparator is configured to detect a high level when the terminal voltage of capacitor a exceeds the reference voltage Vr. It is designed to output a signal (14). This signal is input to the AND circuit t together with the rectangular wave signal obtained from the rectangular wave generating circuit g, and the AND circuit t is ignited when a high level signal is input from the comparator while the rectangular wave signal is being generated. A signal is supplied to an ignition circuit k through an OR circuit j. Other configurations are 3rd
This is similar to the example shown in the figure.

In the ignition system shown in Fig. 6, in the low speed range from idling speed No. to less than the set speed N1, the rectangular wave generating circuit g barely outputs the rectangular wave signal, so the ignition signal generating circuit ■ outputs the ignition signal. No output. In this region, an ignition signal is given to the ignition circuit k by the positive direction signal Es2 outputted from the signal coil f, and ignition is performed approximately at the rising position θ1 of the positive direction signal Eiz for both # and zero. On the other hand, the capacitor a is charged with a constant current from the position of the angle θ1, and when the reset switch m is made conductive by the positive direction signal Egg of the signal coil f at the next position of the angle θ1, it is discharged through the reset switch m. Therefore, the waveform of the terminal voltage VO of the capacitor a becomes as shown in FIG. 7B, and the terminal voltage Va of this capacitor becomes the reference voltage 'l/
When the voltage exceeds r, the comparator outputs a high level signal. In the low speed region of the engine, the position of this angle θX is the signal coil f
The position is sufficiently advanced from the rising position θ3 of the negative direction signal Ess. When the engine speed reaches the set value N,
The rectangular wave generating circuit g outputs a rectangular wave signal at the angle θ2 as shown in FIG. 7C. At this time, since the comparator is outputting a high level signal, the AND circuit t outputs an ignition signal at the same time as the rectangular wave signal is output at the angle θ2, and causes the ignition circuit k to perform an ignition operation. Therefore, the rotation speed N
1, the ignition position advances stepwise from the angle θ1 to the angle θ2. As the engine speed increases, the charging time of V& becomes shorter and its terminal voltage decreases as shown by the broken line in Figure 7B, so that the terminal voltage 0 becomes the reference voltage Vr. The angle θX that is greater than or equal to is the top dead center T
I'm falling behind the DC side. While the position of this angle θX is ahead of the position of angle θ2, the output of the comparator will not affect the ignition position, and the ignition position will be the rising position of the negative direction signal Ess of the signal coil f. It is fixed at θ. When the engine speed reaches the set value N2, the position of angle θX becomes the angle θ
When the second position is reached, the AND of the AND circuit t is established at the angle θX position, and the ignition position becomes the angle θ position. Since the position of the angle θX lags as the rotational speed of the engine increases, the ignition position lags toward the top dead center TDC in the region of rotation speed N3 or higher. The rotation speed reaches the set rotation speed N3, and the position of angle θX changes to angle θ1.
If it is delayed to the position of , the AND of r-)t no longer holds true, so the ignition signal generation circuit ■ will no longer generate the ignition signal, but at the position of the angle θl, the positive direction signal Eaz will be generated from the signal coil f. However, this positive direction signal gives an ignition signal to the ignition circuit k through the OR circuit j, so
The ignition position is again fixed at the angle θl. Therefore, the characteristics of the engine's ignition position θi with respect to the rotation speed N (RPM) are as shown in Fig. 8, and at the set rotation speed N or higher, a characteristic is obtained in which the ignition is retarded by the retard width θp (=lθ2−θtl). .

(17) By combining the advance angle circuit and the retard angle circuit shown in Figs. 3 and 6 above, a characteristic is obtained in which the angle is linearly advanced in the mid-high speed range and linearly retarded in the high speed range. I can do it with you.

In the circuits shown in Figures 3 and 6, the comparator is shown to output an ignition signal or a high-level signal, but an output switch is provided at the output stage of the comparator. When the on/off state of a switch is the output of the comparator, a configuration can be adopted in which the switch allows or prevents the supply of an ignition signal.

Furthermore, the AND circuit t shown in FIG. 6 does not necessarily have to be an independent circuit, but only when a predetermined condition is satisfied in the comparator and a rectangular wave signal is generated from the rectangular wave generating circuit g. This means that it is sufficient to include a circuit configuration that allows the supply of an ignition signal when the engine is in use. For example, the current flowing through the self-holding semiconductor switch of the square wave generating circuit is shunted from the ignition circuit through the normally closed output switch of the comparator, and a predetermined (18
) If a configuration is adopted in which the output switch of the comparator is opened when a condition is met to allow a signal to be supplied to the ignition circuit side, the self-holding semiconductor switch and the output switch of the comparator are Since an AND circuit is constructed, there is no need to provide a separate AND circuit.

Even in the electronically controlled internal combustion engine ignition system shown in FIGS. 3 and 6 above, the OR circuit j includes an element that causes a voltage drop, such as a diode. The level of the signal in the ignition circuit increases, and the rotational speed at which ignition starts increases. Therefore, the present invention is also effective for these electronically controlled ignition devices.

Next, an embodiment in which the present invention is applied to an electronically controlled ignition device for an internal combustion engine will be described with reference to FIG. 9 and subsequent figures.

FIG. 9 shows a specific configuration of an embodiment in which the present invention is applied to an electronically controlled internal combustion engine ignition device having the general configuration shown in FIG. This is an exciter coil, and the output of this exciter coil is the first
It is supplied to an ignition circuit k configured similarly to the example shown.

In this ignition circuit k, the conduction position of the thyristor (semiconductor switch for primary current control) 5 is the ignition position, so between the r-1 force sword (between the control terminals) of this thyristor 5.
The ignition position can be controlled by controlling the phase of the control signal given to the engine according to the engine rotational speed (rpm).

The DC power supply DC is a power supply capacitor 8 whose one end is grounded.
, a resistor 9 connected in series to the capacitor 8, a diode 10 whose cathode is connected to the opposite terminal of the resistor 9 from the capacitor 8, and a diode 10 . with its anode connected to the ground. It consists of a diode 11 connected in parallel to a series circuit of a resistor 9 and a capacitor 8.
The anode of 0 is connected to the non-grounded terminal of the exciter coil 1. In this power supply circuit, the capacitor 8 is charged to the polarity shown by the output of the exciter coil 1 in the direction of the arrow shown in the figure (half cycle for charging the capacitor 3 in the ignition circuit). pSupplies power to the control circuit described later. capacitor 8
The charging of the capacitor 3 to the ignition circuit is carried out at the same time as the charging of the capacitor 3 to the ignition circuit. However, in the present invention, since the power consumption of the control circuit is small as described later, part of the energy to be supplied to the ignition circuit k is Even if the energy is used as energy for the control power source, the ignition performance will not be degraded.

In the present invention, the half-cycle output of the exciter coil 1 having the polarity opposite to the illustrated arrow may be used as the control power source.

The drain of a field effect transistor (hereinafter referred to as FET) 12 is connected to one end of the non-grounded side of the power supply capacitor 8, and the source of the FET 12 is connected to the anode of a diode 14 through a resistor 13. diode 1
The anode of 4 is connected to the dart of PET 12, and an integrating capacitor a for controlling the ignition position is connected between the cathode of diode 14 and ground. The FET 12 and the resistor 13 constitute a constant current circuit, and this constant current circuit and the diode 14 constitute a charging circuit that constant current charges the capacitor (21) a with the output of the DC power supply DC. There is. The collector of a transistor 17 is connected to the non-grounded terminal of the capacitor a via a resistor 16, and the emitter of the transistor 17 is grounded.

The collector of transistor 17 is also connected to said diode 14.
The base of the transistor 17 is connected to the anode of the transistor 17 and grounded through the resistor 18. One end of a resistor 19 is also connected to the base of the transistor 17, and the other end of the resistor 19 is connected to an output end of a rectangular wave generating circuit g to be described later.

The collector of a transistor 20 whose emitter is grounded is connected to the non-grounded terminal of the capacitor a.
A resistor 21 is connected in parallel between the 00 base outputs. The base of the transistor 200 is also connected to one end of a resistor 22, and the other end of the resistor 22 is connected to the collector of a transistor 705 of a signal supply circuit 7, which will be described later. In this embodiment, the transistor 17 and the resistors 18 and 19 constitute a charging/discharging section control switch that controls charging and discharging of the capacitor a. In addition, the positive direction signal Egi of the signal coil f is
A reset switch m is configured to reset the capacitor a by discharging the capacitor a at the rising edge of the voltage.

The reference voltage generation circuit 1 consists of a resistor 23 whose one end is connected to the non-grounded terminal of the capacitor 8, and a Zener diode 24 whose cathode is connected to the other end of this resistor 23 and whose anode is grounded. The reference voltage Vr obtained across the Zener diode 240 of the circuit l is inputted to the comparator together with the terminal voltage Vc of the capacitor a. The comparator is equipped with a switch circuit at the final stage, and the switch circuit is opened when the terminal voltage Va of the capacitor a becomes lower than the reference voltage Vr.

The output of the comparator is connected through a diode 25 to the dart of the thyristor 5 in the ignition circuit.

The rectangular wave signal generating circuit g includes a thyristor 26 as a self-holding semiconductor switch, and the anode of this thyristor is connected to the non-grounded terminal of the power supply capacitor 8 through a resistor 27. The anode of the thyristor 26 is also connected to the collector of a transistor 28 whose emitter is grounded, and a resistor 29 is connected between the base emitter and the emitter of the transistor 28.
are connected in parallel. The entire pace line resistor 30 of the transistor 28 is connected to the collector of the transistor 705 (output end of the signal supply circuit) of the signal supply circuit 7, and when the positive direction signal Ess of the signal coil f is generated, the collector side of the transistor 705 is connected. A pace current is applied to the transistor 28 from. The transistor 28 and the resistors 29 and 30 constitute a switch cutoff circuit that turns off the thyristor 26 as a self-holding type semiconductor switch. Dart of thyristor 26 is resistance 31
The cathode of the Zener diode 320 is connected to the cathode of a diode 33 whose anode is connected to the non-ground terminal of the signal coil f. Each part of the thyristor 26 to the diode 33 constitutes a rectangular wave signal generation circuit g. In this circuit, the terminal t1 of the resistor 27 on the capacitor 8 side is the power supply terminal, and the terminal 1.1 of the resistor 30 on the opposite side from the transistor 28. and a terminal t connected to the anode of the diode 33
3 is an input terminal. Further, the terminal t4 connected to the cathode of the thyristor 26 is an output terminal, and this output terminal t4
is connected to the transistor 170 through the resistor 19 and to the anode of the diode 25 through the resistor 35.

In this embodiment, a signal supply circuit 7 is provided to provide an ignition signal to the thyristor 5 by the output of the signal coil f in the direction of the solid arrow shown in the figure. The configuration of this signal supply circuit 7 is similar to that shown in FIG. The end thereof is connected to the non-ground terminal of the signal coil f through a diode 711. In this embodiment, the emitter of the transistor 705 is connected to the non-ground terminal of the power supply capacitor 8, so that power is supplied from the power supply circuit DC to each transistor (25) of the signal supply circuit 7. . The parallel circuit of the resistor 709 and capacitor 710 is to prevent the V4 signal from being supplied to the thyristor 5 due to noise, and the capacitor 710 is connected when the transistor 701 is turned on by the output of the signal coil f in the direction of the solid arrow shown in the figure. When charged to the polarity shown. At low engine speeds, capacitor 7
Since the 100-photoelectric interval is long, the charge in the capacitor 710 is completely discharged through the resistor 709 before the next charging.

Therefore, at low speeds, the level of the capacitor 710 is not influenced by the transistor 701 at all. As the rotation of the engine increases, the noise level included in the output of the signal coil f increases, and this noise may cause the transistor 01 to become conductive. However, as the rotation of the engine increases, the charging interval of the capacitor 710 becomes shorter, so that charge gradually remains in the capacitor 710.

Therefore, the trigger level of the transistor 701 is increased by the terminal voltage of the capacitor 710, thereby preventing the transistor 701 from becoming conductive due to noise.

(26) In the signal supply circuit 7 shown in FIG. 9, a diode 711F is connected in series with the signal coil f, and when a signal in the direction of the solid arrow shown in the figure is induced in the signal coil f, the base current of the transistor 7010 is is this diode 71
1m). However, transistor 70
1 has its base grounded, has a very low input impedance, and conducts with a small pace current. Therefore, when the transistor 701 is turned on, the forward voltage drop of the diode 71111 is small, and this diode 7111
A forward voltage drop of 1 has only a slight effect on the level of the transistor 701. In the embodiment shown in FIG. 9, the diode 25 and the resistor 708 constitute an OR circuit j.

In the ignition device shown in FIG. 9, the signal coil f is the first
As shown in Figure 0 (A), the negative direction signal (signal of the first half cycle, signal in the direction of the broken line arrow in Figure 9) Ear and the positive direction signal (signal of the second half cycle, the solid line in Figure 9) A one-cycle signal consisting of Ellg (signal in the direction of the arrow) is generated 91 times per ignition cycle, and the signal is zero in the interval θ, '-θl between the negative direction signal Ell and the positive direction signal EsN. What will become. When a negative direction signal Elf is generated in the signal coil f and this negative direction signal 1i111 exceeds the Zener level of the Zener diode 32, an ignition signal is given to the thyristor 26. As a result, the thyristor 26 becomes conductive, and current flows from the DC power supply 11 through the resistor 27 and the thyristor 26. Since the thyristor 26 has a self-holding function, the signal El! at the angle θs' (see FIG. 10). Even if II becomes zero, the thyristor 26 continues to conduct. Next, at an angle θ1, a positive direction signal Ea is sent to the signal coil f.
When t occurs, a pace current flows through the transistor 28 and this transistor becomes conductive, so that the current flowing through the thyristor 26 is shunted by this transistor 28. As a result, the anode current of the thyristor 26 becomes equal to or less than the holding current, and the thyristor 26 is cut off. Therefore, as shown in FIG. 10B, the output terminal t4 of the rectangular wave signal generating circuit g is outputted after the negative direction signal Eat of the signal coil f rises (more precisely, it exceeds the Zener level of the Zener diode 32). A rectangular wave signal Vq is obtained that lasts until the positive direction signal E2 rises.

In this way, in the device of this embodiment, even if there is a section where the signal becomes zero between the first and second half-cycle signals obtained from the signal coil, the signal of the first half-cycle is Since it is possible to obtain a rectangular wave signal that lasts from the rising edge θ2 to the rising edge θl of the second half-cycle signal, there is no need to widen the width of the first half-cycle signal.

In addition, the self-holding switch (thyristor 26) of the rectangular wave generation circuit g is conductive only for a short period corresponding to the width of the rectangular wave signal, and is in an interrupted state for most of the remaining period. Power consumption in the generating circuit g can be significantly reduced. Therefore, as shown in Fig. 9, the DC power supply circuit DC can be configured to utilize a part of the half-cycle output that supplies the ignition energy of the exciter coil, and a simple configuration can be used as the power supply circuit DC. Can be used.

In the ignition system shown in Fig. 9, when the engine speed is low, (29
) Negative direction signal of signal coil f (signal in the direction of the dashed arrow in FIG. 9) Since EsI does not reach the Zener level of the Zener diode 32, the rectangular wave generating circuit g generates the rectangular wave signal Vq.
does not occur. At this time, an ignition signal is given to the thyristor 5 through the signal supply circuit 7 by the positive direction signal EI2 of the signal coil f (signal in the direction of the solid arrow in FIG. 9). Therefore, when the engine speed is low, ignition is performed at a certain position near the rising position θl of the positive direction signal Ess. On the other hand, the capacitor 1 is charged with a constant current from a direct current power source DC through a constant current circuit including an F'ET 12 and a diode 14 to the polarity shown in the figure. When the transistor 20 becomes conductive at the rising edge of the positive direction signal Egg, the charge of the capacitor 1 is instantaneously discharged through this transistor, and the terminal voltage Vc of the capacitor a returns to zero. (9) Speed dust of the engine rises, and the negative direction signal Ess of the signal coil f is transmitted to the Zener diode 32.
When the zener level exceeds the zener level, the above-described operation generates the 9 rectangular wave signal Yq. As a result, a pace current flows through the transistor 17, and the transistor 17 is maintained in a conductive state from θ2 to θ1 when the rectangular wave signal Vq(30) is generated.

Therefore capacitor a is resistor 16 and transistor 1
7, the capacitor a is discharged with a constant time constant over the angle 02 to θ1, and the terminal voltage Vc of the capacitor a decreases as shown in FIG. 4A. The terminal type of this capacitor a [EVO
Since the output contact of the comparator is closed while 27. is higher than the reference voltage Vr, the resistor 27. All the current flowing through the thyristor 26 and the resistor 35 flows to ground through the output contact of the comparator, and no ignition signal is given to the thyristor 6 in the ignition circuit. When the terminal voltage Vc of capacitor a becomes lower than the reference voltage Vr at the angle θi, the output contact of the comparator opens, so that the DC power supply D
C to resistor 27. The signal current flowing through the thyristor 26 and the resistor 35 passes through the diode 25 to the thyristor 6.
The ignition operation is performed at this angle θ1. The position of this angle θ1 advances toward the bottom dead center as the rotational speed of the engine increases, and the advance stops when the angle θl reaches the position of angle θ. These operations are similar to those described for the apparatus of FIG.

Next, referring to FIG. 11, there is shown another embodiment of the present invention, in which a transistor 4 is connected to the non-grounded terminal of the exciter coil l via a diode 41.
The collectors of transistor 42 are connected to each other, and the collector of transistor 42 is grounded.

One end of the primary coil 4a of the ignition coil is connected to the anode of the diode 41, and the other end of the primary coil 4m is connected to the anode of the thyristor 5 whose cathode is grounded. An anode of a diode 44 is connected to the anode of the thyristor 5 through a resistor 43, and a cathode of the diode 44 is connected to the base of the transistor 420. Diode 41, transistor 42. Resistance 43. A diode 44, a thyristor 5, and a resistor 6 constitute an ignition circuit k. In this ignition circuit k, base ti flows to the transistor 42 through the primary coil 4m, the resistor 43, and the diode 44 during a half cycle of the exciter coil 1 in the direction of the arrow shown in the figure.
conducts. This causes a short circuit current to flow from the exciter coil 1 through the diode 41 and the transistor 42.

When an ignition signal is applied to the dart of the thyristor 5 at an ignition position set at a position where this short circuit current has become sufficiently large, the thyristor 5 becomes conductive and the base current to the transistor 42 is bypassed from the transistor. As a result, the transistor 42 becomes inactive, and the current flowing through the exciter coil 1 is cut off. This interruption of current flow induces a high voltage in the exciter coil 1, and this voltage is further boosted by the ignition coil 4 to obtain a high voltage for ignition in the secondary coil 4b. In addition, in this embodiment, the power supply circuit D
C is a capacitor 8. It consists of a resistor 9 and a diode 10, and the diode 11 used in the embodiment of FIG. 9 is omitted. The rest of the structure is the same as that of the embodiment shown in FIG. 9, and the same operation as that of the embodiment shown in FIG. 9 is performed except for the operation of the ignition circuit.

Fig. 12 shows an embodiment in which the present invention is applied to an ignition device having the general configuration shown in Fig. 6. Switch e is omitted and capacitor a
This embodiment is similar to the embodiment shown in FIG. 9, except that the output switch of the comparator is opened when the terminal voltage VC of the terminal becomes equal to or higher than the reference voltage Vr, and the output switch is closed when Vo<Vr. In this embodiment, the square wave generating circuit g
The thyristor 26 and the comparator are connected to form an AND circuit, and ignition occurs when the thyristor 26 is conductive and the potential at the output terminal of the comparator is at a high level (when the output switch is open). An ignition signal is given to the thyristor 5 in the circuit. The overall operation of the embodiment shown in FIG. 12 is the same as that described for the circuit shown in FIG. Except for this, it is the same as the embodiment shown in FIG. 9, so a detailed explanation of the operation will be omitted.

As described above, according to the present invention, the signal supply circuit that provides a control signal to the semiconductor switch of the ignition circuit when a signal is induced in the signal coil is formed by an amplifier circuit (34 ), the ignition circuit can be triggered even when the output level of the signal coil is low, and the rotational speed at which the ignition device starts operating can be lowered.

Furthermore, if the starting rotation speed is the same as in the conventional case, the output of the signal coil can be lowered, so the signal generator can be made smaller and the number of turns of the signal coil can be reduced.

[Brief explanation of drawings]

FIG. 1 is a connection diagram showing a conventional example, FIG. 2 is a connection diagram showing an embodiment of the present invention, FIG. 3 is a block diagram showing a configuration example of an electronically controlled ignition device to which the present invention can be applied, and FIG. Figures A to C
3 is a signal waveform diagram of each part in FIG. 3, FIG. 5 is a diagram showing the advance angle characteristics obtained by the device in FIG. 3, and FIG. 6 is a configuration of another electronically controlled ignition system to which the present invention can be applied. 7A to 7A are signal waveform diagrams of each part in FIG. 6, and FIG.
The figure is a diagram showing the advance angle and retard angle characteristics obtained by the device shown in Fig. 6, and Figs. 9 and 11 respectively show different specific implementations when the present invention is applied to the ignition device of the type shown in Fig. 3. Connection diagrams showing examples, Figures 1O A to C are waveform diagrams showing the waveforms of the output of the signal coil, the rectangular wave signal, and the terminal voltage of the integrating capacitor in the embodiment of Figure 9, and Figure 12 shows the waveforms of the terminal voltage of the integrating capacitor. FIG. 6 is a connection diagram showing a specific example when applied to the ignition device of the type shown in FIG. 6; 1... Exciter coil, 2... Diode, 3...
... Capacitor, 4... Ignition coil, 5... Thyristor, 6... Resistor, 7... Signal supply circuit, 701.
705...Transistor, 702.706.708.
...Resistance 1.703...Diode, 707...Capacitor, f...Signal coil, k...Ignition circuit. Figure 4, Figure 5, page 7]

Claims (1)

[Claims] an ignition circuit that controls the primary current of the ignition coil using a semiconductor switch to obtain a high voltage for ignition on the secondary side of the ignition coil; a signal coil that generates a signal in synchronization with engine rotation; and the signal coil. and a signal supply circuit for supplying a control signal to the semiconductor switch when the semiconductor switch is generating the signal. 1. An ignition device for an internal combustion engine, comprising a transistor amplifier circuit having a transistor amplifier circuit, wherein an output signal of the signal coil is applied to a control terminal of the semiconductor switch through the amplifier circuit.