JPH0224953Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a capacitor discharge type ignition device for an internal combustion engine.

[Prior art]

In a capacitor discharge type ignition system, which performs ignition by discharging the charge of a capacitor installed on the primary side of the ignition coil to the primary coil of the ignition coil through a thyristor, a signal is generated in synchronization with the rotation of the engine. The output of the signal coil supplies an ignition signal to the thyristor to determine the ignition timing. Generally, in internal combustion engines, it is necessary to advance the ignition timing in the medium to high speed range.
Conventional ignition systems of this type advance the phase at which the output of the signal coil reaches the trigger level of the thyristor by utilizing the fact that the rising slope of the output of the signal coil becomes steeper as the engine speed increases. The ignition timing was advanced.

[Problem that the invention attempts to solve]

Depending on the internal combustion engine, it may be necessary to advance the ignition timing stepwise by a predetermined advance width in a medium to high speed range. However, as mentioned above, if the ignition timing is advanced using only the output characteristics of the signal coil, the ignition timing will gradually advance in the medium and high speed range, and the advance width will be relatively narrow. Therefore, it is not possible to obtain a characteristic that changes the ignition timing in steps at the set rotation speed.

Therefore, as seen in Utility Model Publication No. 53-19313, for example, a low speed signal coil that generates a signal that determines the ignition timing at low speeds and a high speed signal coil that generates a signal that determines the ignition timing in the medium and high speed range are provided. When the engine speed is less than the set value, the output of the low-speed signal coil supplies an ignition signal to the thyristor, and when the engine speed exceeds the set value, the output of the high-speed signal coil turns on the thyristor. Various ignition devices for internal combustion engines have been proposed that advance the ignition timing in steps above a set rotation speed by supplying an arc signal.

However, this type of ignition device requires two signal coils, resulting in a large ignition device and a disadvantage in that the generator in which the signal coil is arranged also becomes large.

An object of the present invention is to provide a capacitor discharge type ignition device for an internal combustion engine that can advance the ignition timing in steps above a set rotation speed using one signal coil.

[Means for solving problems]

The structure of the present invention that solves the above problems will be explained with reference to FIG. 1 showing an embodiment of the present invention. In FIG. , 2 are signal coils, and these coils are arranged in a magnet generator driven by the engine. 3 is the primary coil 3
4 is an ignition energy storage capacitor provided on the primary side of the ignition coil 3, and the capacitor 4 is a capacitor charging circuit (in this example, exciter coil 1 → diode 5 → capacitor 4 → primary coil 1a → diode 6 → exciter coil 1), the output voltage of the exciter coil 1 in one half cycle in the direction of the solid arrow shown in the figure (hereinafter referred to as positive direction output voltage). Charged to the polarity shown. 7 is a discharge control thyristor provided to discharge the electric charge of the capacitor 4 to the primary coil 3a of the ignition coil when conductive; 8 is a spark plug attached to the cylinder of the engine; The electric charge of the capacitor 4 is discharged to the primary coil 3a to induce a high voltage for ignition in the secondary coil 3b.

The present invention provides such an ignition device that includes a first signal supply circuit 10, a rotation speed detection circuit 11, a conductive signal supply control circuit 12, a second signal supply circuit 13, and a transistor switch for adjusting the ignition timing. 1
4.

The first signal supply circuit 10 controls the output of the exciter coil 1 when the output voltage of the other half cycle in the direction of the dashed arrow shown in the figure (hereinafter referred to as negative direction output voltage) reaches a predetermined trigger level. A signal supply switch 10a is provided which becomes conductive when a conduction signal is applied, and an ignition signal is supplied from the exciter coil 1 to the thyristor 7 through the signal supply switch 10a.

The rotation speed detection circuit 11 includes a rotation speed detection capacitor 11a charged to a constant voltage by the output of the exciter coil 1, and a rotation speed detection capacitor 11a.
A discharge circuit that discharges a at a constant time constant (in this example, it is composed of a variable resistor 11b).
and a rotation speed detection switch 11c that is conductive while the terminal voltage of the rotation speed detection capacitor 11a exceeds a certain value.

The conduction signal supply control circuit 12 includes a signal supply control switch 12a that is provided to block the supply of the conduction signal to the signal supply switch 10a when the switch is conductive. This signal supply control switch is connected to the rotation speed detection switch 1 so that it is conductive when the rotation speed detection switch 11c is in the cutoff state.
1c, and when the engine speed is above the set value, the signal supply switch 10a enters the cutoff state.
allow a conduction signal to be given to

The second signal supply circuit 13 is a circuit that supplies an ignition signal to the thyristor 7 with the output of one half cycle of the signal coil 2 in the direction of the solid arrow shown in the figure (hereinafter referred to as positive direction output).

The transistor switch 14 for adjusting the ignition timing is
The collector-emitter circuit is connected in parallel to the gate-cathode circuit of the thyristor 7, and the base is connected to one end of the signal coil 2 via an ignition timing adjustment capacitor 15 and a resistor 16.

In the present invention, the phase in which the ignition signal supplied from the exciter coil 1 to the thyristor 7 through the first signal supply circuit 10 reaches the trigger level of the thyristor is when the charging current of the ignition timing adjustment capacitor 15 stops flowing. The phase relationship between the output of the exciter coil 1 and the output of the signal coil 2 is set so as to lead the phase.

[Effect of invention]

In the above configuration, the ignition energy storage capacitor 4 is charged to the polarity shown in the figure by the positive output voltage of the exciter coil 1. The rotation speed detection capacitor 11a is charged to a constant voltage by the positive output voltage of the exciter coil 1, and when the output voltage of the exciter coil 1 becomes below a certain voltage, the capacitor 11a is discharged through a discharge circuit at a constant time constant. do. The discharge time constant of this capacitor 11a is, when the engine speed is less than the set value,
When the output of the exciter coil 1 reaches the trigger level of the signal supply switch 10a, the terminal voltage of the capacitor 11a changes to the rotation speed detection switch 11c.
It is set so that the voltage is below the level that makes it conductive.

Therefore, when the engine rotation speed (rpm) is less than the set value, the terminal voltage of the rotation speed detection capacitor 11a becomes less than a certain value before the output of the exciter coil 1 reaches the trigger level of the signal supply switch 10a. The rotation speed detection switch 11c is turned off. At this time, the signal supply control switch 12a
maintains the conductive state during the period when the output of the exciter coil 1 is at a level above which a conductive signal can be given to the signal supply switch, and the first signal supply circuit 1
0 to the thyristor 7 is prevented.

On the other hand, the ignition timing adjustment capacitor 15 is charged to the polarity shown by the output voltage of the signal coil 2 in the direction of the broken line arrow (hereinafter referred to as negative direction output), and then a voltage in the direction of the solid line arrow is induced in the signal coil 2. Then, from the signal coil 2, the ignition timing adjustment capacitor 15, the resistor 16, and the transistor switch 1 are connected.
A current flows through the base emitter circuit of 4,
The transistor switch 14 becomes conductive. The period during which this transistor switch 14 is conductive is
The supply of an ignition signal from the second signal supply circuit 13 to the thyristor 7 is prevented. When the charging of the ignition timing adjustment capacitor 15 is completed, the transistor switch 14 is cut off, so an ignition signal is supplied from the signal coil 2 to the thyristor 7 through the second signal supply circuit 13, and the thyristor 7 becomes conductive. . Due to this conduction of the thyristor 7, the electric charge of the capacitor 4 is discharged through the thyristor 7 to the primary coil 3a, and thereby the secondary coil 3b
A high voltage for ignition is induced in the spark plug 8, and a spark is generated in the spark plug 8. Charging of the ignition timing adjustment capacitor 15 is completed at the angle at which the positive direction output of the signal coil reaches its peak, so if the engine speed is below the set value, the angle at which the ignition signal is given to the thyristor is The angle is always at which the output of the signal coil 2 reaches its peak, and the ignition timing is constant regardless of the rotation speed. When the engine speed exceeds the set value, when the negative direction output voltage of the exciter coil 1 reaches the trigger level of the signal supply switch 10a, the terminal voltage of the rotation speed detection capacitor 11a still reaches the rotation speed detection switch 11c. It maintains a size that allows conduction. Therefore, when the engine rotation speed exceeds the set value, the rotation speed detection switch 11c remains conductive when the negative direction output voltage of the exciter coil 1 reaches the trigger level of the signal supply switch 10a, and the signal supply control is performed. switch 12a
will now remain in a blocked state. Therefore, in this case, when the output of the exciter coil 1 reaches the trigger level of the signal supply switch 10a, the switch 10a becomes conductive, and the exciter coil 1
An ignition signal is given to the thyristor 7 from the switch 10a. Therefore, in this state, the ignition timing is the angle at which the negative output voltage of the exciter coil reaches the trigger level of the thyristor 7, and the ignition timing is the angle θ2 at which the output of the signal coil 2 reaches its peak, as shown in FIG. The angle advances stepwise from .theta.1 to an angle .theta.1 at which the negative output voltage of the exciter coil 1 reaches the trigger level of the thyristor 7.

〔Example〕

Embodiments of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 shows the electrical configuration of one embodiment of the present invention. In the figure, numeral 1 is placed in a magnet generator driven by an engine (not shown), and an alternating current is generated in synchronization with the rotation of the engine. The exciter coil 2 that generates voltage is a signal coil that is disposed together with the exciter coil in the magnet generator and induces an alternating current voltage in synchronization with the rotation of the engine. Signal coil 2
One end is grounded, and one end 1 of the exciter coil 1
a is connected to the cathode of a diode 6 whose anode is grounded. Other end 1 of exciter coil 1
b is connected to the anode of a diode 5, and the cathode of the diode 5 is connected to one end of the ignition energy storage capacitor 4. capacitor 4
The other end is connected to the non-ground terminal of the primary coil 3a of the ignition coil 3, and the non-ground terminal of the secondary coil of the ignition coil is connected to the non-ground terminal of a spark plug 8 attached to a cylinder of an engine (not shown). A high voltage cord is passed through the terminal and connected. The exciter coil 1, the diode 5, the capacitor 4, the primary coil 3a, and the diode 6 constitute a capacitor charging circuit that charges the capacitor 4 to one polarity shown in the figure using the positive output voltage of the exciter coil 1.

At the connection point between diode 5 and capacitor 4,
The anode of a discharge control thyristor 7 whose cathode is grounded is connected so that when the thyristor 7 becomes conductive, the charge in the capacitor 4 is discharged through the thyristor 7 and the primary coil 3a of the ignition coil. When the capacitor discharges in this manner, a large change in magnetic flux occurs in the iron core of the ignition coil, which induces a high voltage in the secondary coil 3b and generates a spark in the ignition plug 8.

A first signal supply circuit 10 and a second signal supply circuit 13 are provided to supply a firing signal to the thyristor 7.

The first signal supply circuit 10 includes a thyristor Th1 whose anode is connected to the connection point between the exciter coil 1 and the diode 6, and resistors 10b and 10c connected between the gate anode and gate cathode of the thyristor Th1, respectively. , thyristor
A diode 10d whose anode is connected to the cathode of Th1, and a Zener diode 10e whose cathode is connected to the cathode of the diode 10d.
, a resistor 10f connected between the gate and cathode of the thyristor 7, and a cathode connected to the exciter coil 1.
A diode 10g connected to the other end and whose anode is grounded, a resistor 10h connected between one end 1a of the exciter coil 1 and the ground, and a diode 10
A diode 10i is connected between the cathode of the diode d and the cathode of the diode 5, with the anode facing the diode 10d.
1 constitutes a signal supply switch 10a.

In this first signal supply circuit, when a negative direction output voltage is induced in the exciter coil 1, a firing signal is applied to the thyristor Th1 and the thyristor becomes conductive. When thyristor Th1 conducts,
From exciter coil 1 to thyristor Th1, diode 10d, Zener diode 10e, between the gate and cathode of thyristor 7, and diode 1
A current flows through 0g to provide an ignition signal to the thyristor 7.

The second signal supply circuit 13 includes a resistor 13a having one end connected to the non-ground terminal of the signal coil 2, an anode connected to the other end of the resistor 13a, and a diode having a cathode connected to the gate of the thyristor 7. 13b, and when the positive direction output of the signal coil 2 reaches the trigger level of the thyristor 7, an ignition signal is given to the thyristor 7 through the resistor 91 and the diode 92.

In order to control the timing at which the ignition signal is applied to the thyristor 7 from the second signal supply circuit 9, an ignition timing adjusting transistor switch 14 is provided which is composed of an NPN transistor Tr1 whose emitter is grounded, and the collector of the transistor Tr1 is is connected to the gate of thyristor 7 through diode 13b. That is, the transistor switch 14 has its collector-emitter circuit connected in parallel to the gate-cathode circuit of the thyristor 7, and when the transistor switch 14 is conductive, the voltage from the second signal supply circuit 13 is It is arranged that the ignition signal is prevented from being supplied to the thyristor 7.

The base of the transistor switch 14 for adjusting the ignition timing is a resistor 16 and a capacitor 15 for adjusting the ignition timing.
A diode 1 is connected between the base of the transistor switch 14 and the ground with the cathode facing the ground side.
7 is connected. The capacitor 15 is charged by the negative output voltage of the signal coil 2 through the diode 17 to the polarity shown. Next, when a positive output voltage is generated in the signal coil 2, a base current flows from the signal coil to the transistor switch 10 through the capacitor 1517 and the resistor 16, and the transistor switch 10 becomes conductive. While the transistor switch 10 is conductive, the ignition signal is prevented from being supplied from the signal coil 2 to the thyristor 7. When the output voltage of signal coil 2 in the direction of the solid arrow exceeds the peak value, capacitor 1
5 is completed, the supply of base current to the transistor switch 14 is stopped, and the transistor switch 14 is turned off. At the same time as this transistor switch 14 is cut off, an ignition signal is supplied from the signal coil 2 to the thyristor 7 through the resistor 13a and the diode 13b (through the second signal supply circuit 13). capacitor 15
Since the angle at which charging is completed is always the angle at which the output voltage of the signal coil 2 reaches its peak value, the angle at which the firing signal is supplied from the second signal coil 2 to the thyristor 7 depends on the engine speed. It remains almost constant regardless.

A rotation speed detection circuit 11 and a signal supply control circuit 12 are provided to advance the ignition timing in steps when the rotation speed reaches a set value.

The rotation speed detection circuit 11 includes a rotation speed detection capacitor 11a whose one end is grounded, and the other end of the capacitor 11a is connected to a diode 1 via a resistor 11d.
It is connected to the cathode of 1e. diode 1
The anode 1e is the other end 1b of the exciter coil 1.
The positive direction output voltage of the exciter coil 1 charges the capacitor 11a to the illustrated polarity through the diode 11e and the resistor 11d.
A variable resistor 11b constituting a discharge circuit is connected in parallel to the rotation speed detection capacitor 11a, so that the electric charge of the capacitor 11a is discharged at a constant time constant through the variable resistor 11b. A Zener diode 11f with its anode facing the ground side is also connected in parallel to the capacitor 11a, and the non-ground terminal of the capacitor 11a is connected through a resistor 11g to the base of a transistor Tr2 constituting the rotation speed detection switch 11c. The emitter of the transistor Tr2 is grounded, and the collector is connected to one end 1a of the exciter coil 1 through a resistor 11h.
It is connected to the. A rotation speed detection circuit is constituted by the rotation speed detection capacitor 11a to the resistor 11h.

The conductive signal supply control circuit 12 includes a transistor Tr3 that constitutes a signal supply control switch 12a,
It consists of a resistor 12b connected between the base and emitter of the transistor Tr3. transistor
The emitter of Tr3 is grounded, and the collector is connected to the gate of thyristor Th1.

In the above embodiment, the thyristor 7 is connected to the exciter coil 1 through the first signal supply circuit 10.
The phase at which the ignition signal supplied to the thyristor reaches the trigger level of the thyristor is the ignition timing adjustment capacitor 1.
The phase relationship between the output of the exciter coil 1 and the output of the signal coil 2 is set so that the charging current of No. 5 is ahead of the phase at which it finishes flowing.

Figures 2 and 3 show an example of the configuration of a magnet generator in which the exciter coil and signal coil are arranged, and in these figures, 20 is a substantially cup-shaped fly made of magnetic material such as iron. Four-pole flywheel magnet rotors 30 and 40 configured by attaching permanent magnets 22 to the inner periphery of a wheel 21
is a stator placed inside the magnet rotor 20. The stator 30 is constructed by winding a power generating coil 32 for driving a load such as a lamp around an iron core 31 having magnetic pole portions 31a at both ends facing the magnetic poles of a magnet rotor through a predetermined gap. Further, as shown in FIG. 3, the stator 40 includes a first armature 42 configured by winding the exciter coil 1 around an iron core 41 having magnetic pole portions 41a at both ends, and a first armature 42 having magnetic pole portions 43a at both ends. Signal coil 2 to iron core 43
The first and second armatures 42 and 44 are arranged at the same position in the rotational direction of the generator and stacked in the axial direction of the generator. ing. The magnet rotor 20 is attached to a rotating shaft of an internal combustion engine (not shown), and the stators 30 and 40 are fixed with screws 51 or the like on a stator mounting base plate 50 provided in a case of the engine or the like.

The output voltage Ve of the exciter coil 1 and the output voltage Vs of the signal coil 2 of the magnet generator are as shown in FIGS. 4A and B, respectively.
Vs is set to have a phase difference of 180 degrees from each other. The negative direction output voltage of the exciter coil 1 reaches the Zener level Vz1 of the Zener diode 10e at the angle θ1, and the first signal supply circuit 10
gives a firing signal to the thyristor 7 at this angle θ1 when the thyristor Th1 is conductive.

Further, the positive direction output voltage of the signal coil 2 reaches a peak at an angle θ2, and the second signal supply circuit 9 supplies a firing signal to the thyristor 7 at this angle θ2. In this case, angles θ1 and θ2 are measured from the top dead center of the engine to the advance side.

In the embodiment described above, when the exciter coil 1 generates a positive output voltage, the ignition energy storage capacitor 4 is charged through the diode 5 to the polarity shown. Further, the terminal voltage Vc of the rotation speed detection capacitor 11a changes as shown in FIG. 4C. That is, when the rotation speed detection capacitor 11a is charged to the Zener voltage Vz2 of the Zener diode 11f by the positive direction output voltage of the exciter coil, and the output voltage of the exciter coil 1 becomes less than the Zener voltage Vz2, the capacitor 11a is charged to the variable resistor 11b. discharges at a constant time constant through the The discharge time constant of this capacitor 11a is such that when the engine speed is less than a set value, the terminal voltage of the capacitor 11a becomes lower than the level that makes the transistor Tr2 conductive at the time when the output of the exciter coil 1 reaches the trigger level of the thyristor Th1. When the rotation speed reaches the set value, the output of the exciter coil is set to thyristor Th1.
When the trigger level of the capacitor 11a is reached, the capacitor 11a
The terminal voltage of the transistor Tr2 is maintained at a level that makes the transistor Tr2 conductive.

Therefore, when the engine rotational speed N (rpm) is less than the set value Ns, for example when N=N1, the output voltage of the exciter coil 1 will decrease as shown by the solid line in Fig. 4C.
Before Ve reaches the trigger level Vz1 of the thyristor Th1 (signal supply switch) at the angle θ1, the terminal voltage of the rotation speed detection capacitor 11a becomes lower than the trigger level of the transistor Tr2, and the transistor Tr2 becomes cut off. Therefore, as shown in FIG. 4E, the transistor Tr3 maintains the conductive state during the period when the output voltage of the exciter coil 1 is at a level higher than that which can provide an ignition signal (conduction signal) to the thyristor Th1. The firing signal is prevented from being supplied from the signal supply circuit 10 to the thyristor 7.

On the other hand, the ignition timing adjustment capacitor 15 is charged with the output voltage of the signal coil 2 in the direction of the dashed arrow shown in the figure to the polarity shown in the figure, and then when a voltage in the direction of the solid line arrow shown in the figure is induced in the signal coil 2, the ignition timing adjustment capacitor 15 is charged from the signal coil 2 to the ignition timing. A current flows through the adjustment capacitor 15, the resistor 16, and the base-emitter circuit of the transistor switch 14.
conducts. During the period when the transistor switch 14 is conductive, the second signal supply circuit 13 is prevented from supplying the ignition signal to the thyristor 7. When the charging of the ignition timing adjustment capacitor 15 is completed, the transistor switch 14 is cut off, so an ignition signal is supplied from the signal coil 2 to the thyristor 7 through the second signal supply circuit 13, and the thyristor 7 becomes conductive. . Due to this conduction of the thyristor 7, the charge in the capacitor 4 is discharged through the thyristor 7 to the primary coil 3a, which induces a high voltage for ignition in the secondary coil 3b, and a spark is generated in the ignition plug 8. Charging of the ignition timing adjustment capacitor 15 is completed at the angle at which the output of one half cycle of the signal coil reaches its peak, so if the engine speed is below the set value,
The angle at which the ignition signal is applied to the thyristor is always the angle θ2 at which the output of the signal coil 2 reaches its peak, and the ignition timing is constant regardless of the rotation speed.

If the engine speed N exceeds the set value, for example N2
(>N1), N3 (>N2), the terminal voltage Vc of the rotation speed detection capacitor 11a at the point when the output of the exciter coil 1 reaches the trigger level of the thyristor Th1 as shown by the broken line in FIG. 4C. still maintains a size that allows the rotation speed detection switch 11c to conduct. Therefore, when the engine speed exceeds the set value, the transistor Tr2 remains conductive when the output of the exciter coil 1 reaches the trigger level of the thyristor Th1 (see Fig. 4D), and the transistor Tr3 switches off. (See Figure 4 E). Therefore, in this case, the output of exciter coil 1 is
When the trigger level of 1 is reached, the thyristor becomes conductive, and the thyristor Th
A firing signal is applied to the thyristor 7 through the thyristor 1. Therefore, in this state, the ignition timing is the angle θ1 at which the negative output voltage of the exciter coil reaches the trigger level of the thyristor 7, and the ignition timing is the angle at which the output of the signal coil 2 reaches its peak as shown in FIG. The angle advances stepwise from θ2 to an angle θ1 at which the output of the other half cycle of the exciter coil 1 reaches the trigger level of the thyristor 7.

In the above embodiment, the capacitor 4 is provided in series with the primary coil of the ignition coil.
For example, the positions of the capacitor 4 and the thyristor 7 may be swapped to provide the capacitor in parallel with the primary coil of the ignition coil.

In the above embodiment, the ignition timing adjusting transistor switch 14 is constructed from a single transistor, but the switch may also be constructed from a Darlington-connected composite transistor.

[Effect of idea]

As described above, according to the present invention, the ignition timing can be advanced in steps at a set rotation speed using only one signal coil. Therefore, there is an advantage in that it is possible to obtain an ignition device having the characteristic of advancing the angle in steps without increasing the size of the ignition device and the generator.

[Brief explanation of the drawing]

Figure 1 is a circuit diagram showing the electrical configuration of an embodiment of the present invention, Figure 2 is a sectional view showing an example of the configuration of a generator used in the present invention, and Figure 3 is a stator of the generator. FIG. 4 is a waveform diagram showing an example of the output voltage waveforms of the exciter coil and signal coil used in the present invention, and FIG. 5 is a diagram showing an example of the characteristics obtained by the present invention. 1...exciter coil, 2...signal coil,
3...Ignition coil, 4...Ignition energy storage capacitor, 7...Thyristor for discharge control, 8...
...Spark plug, 10...First signal supply circuit, 1
DESCRIPTION OF SYMBOLS 1...Rotation speed detection circuit, 11a...Rotation speed detection capacitor, 11b...Variable resistor constituting a discharge circuit, 11c...Rotation speed detection switch, 12
...Conduction signal supply control circuit, 12a...Signal supply control switch, 13...Second signal supply circuit,
14...Transistor switch for adjusting ignition timing,
15...Ignition timing adjustment capacitor, 16...Resistor, 20...Flywheel magnet rotor, 30,
40...Stator.

Claims (1)

[Claims for Utility Model Registration] A magnet generator including an exciter coil and a signal coil that induce an alternating current voltage in synchronization with the rotation of an internal combustion engine, an ignition coil, and a magnet generator provided on the primary side of the ignition coil. an ignition energy storage capacitor; a capacitor charging circuit that charges the ignition energy storage capacitor with the output of one half cycle of the exciter coil; and when electrical conduction occurs, the charge of the capacitor is discharged to the primary coil of the ignition coil. In the capacitor discharge type internal combustion engine ignition device, which is equipped with a discharge control thyristor provided to a first signal supply circuit comprising a signal supply switch that becomes conductive when a conduction signal is applied, and supplies an ignition signal from the exciter coil to the thyristor through the signal supply switch; and a constant voltage at the output of the exciter coil. A rotation speed detection capacitor that is charged with a rotation speed detection capacitor, a discharge circuit that discharges the rotation speed detection capacitor at a constant time constant, and a rotation speed detection circuit that is conductive while the terminal voltage of the rotation speed detection capacitor is above a certain value. a rotation speed detection circuit provided with a switch for detecting rotation speed; and a rotation speed detection circuit provided with a switch for detecting rotation speed, which is provided so as to block the supply of a conduction signal to the switch for supplying a signal when the switch is electrically conductive, and is configured to conduct when the switch for rotation speed detection is in a cutoff state. a conductive signal supply control circuit including a conductive signal control switch connected to the rotation speed detection switch; and a second signal that supplies an ignition signal to the thyristor with the output of one half cycle of the signal coil. a supply circuit; and a collector-emitter circuit connected in parallel to the gate-cathode circuit of the thyristor so as to prevent a firing signal from being applied to the thyristor from the second signal supply circuit when conductive. and the base is connected to one end of the signal coil via an ignition timing adjustment capacitor and a resistor, and a charging current flows through the ignition timing adjustment capacitor by the output of one half cycle of the signal coil. a transistor switch for adjusting ignition timing which is turned on when a base current is supplied thereto, and a phase at which an ignition signal supplied from the exciter coil to the thyristor through a first signal supply circuit reaches a trigger level of the thyristor; An ignition device for an internal combustion engine, characterized in that the phase relationship between the output of the exciter coil and the output of the signal coil is set so that the charging current of the ignition timing adjustment capacitor is ahead of the phase at which the charging current ends.