JPS6133992B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an engine ignition timing control device that controls engine ignition timing in accordance with engine parameters, such as engine speed.

Conventionally, this type of device detects the trigger level of the signal voltage of the signal generator, which is generated in synchronization with the engine rotational speed and corresponds to the ignition timing, and opens and closes the semiconductor switching element of the ignition device to control the secondary ignition coil. The signal voltage waveform was used to determine the ignition timing of the engine. Therefore, since the ignition timing is determined by the signal voltage waveform, it has not been possible to sufficiently correspond to the ignition timing required by the engine.

This invention solves the related problems, and firstly, the position where the first output of the integrator reaches the second reference value, that is, the position where the trigger signal is generated, is changed to a predetermined crank position as the engine speed increases. until the trigger signal generation position reaches a predetermined crank position, the trigger signal is used as a signal for determining the ignition timing,
After the trigger signal generation position reaches a predetermined crank position, the angle signal generated at the predetermined crank position is used as a signal for determining the ignition timing, so that the engine speed increases at a predetermined slope based on the trigger signal. The purpose is to obtain ignition timing characteristics in which the ignition timing advances and exhibits a constant advance angle based on the angle signal. 2
The angle signal is used as a signal for determining ignition timing, and the trigger signal is used as a signal for determining ignition timing until the trigger signal generation position passes the second crank position and reaches the first crank position. After reaching the crank position, by using the first angle signal as a signal for determining the ignition timing, a constant advance angle is exhibited based on the second angle signal, and a predetermined advance angle is exhibited as the engine speed increases based on the trigger signal. This is an engine ignition timing control device that aims to obtain an ignition timing characteristic in which the ignition timing advances with an inclination and further exhibits a constant advance angle based on a first angle signal.

The present invention will be explained below with reference to the embodiment shown in FIG. In the figure, is the ignition device,
This embodiment uses a well-known CD ignition device as an example, and is configured as follows. That is, 1 is a generating coil of a magnet generator (not shown), which generates positive and negative alternating current outputs in synchronization with the rotation of the engine. 2 and 3 are this power generation coil 1
4 is a capacitor charged by the rectified output of diode 2, 5 is a diode that rectifies the output of diode 2;
An ignition coil is connected to the discharge circuit of the capacitor 4, and is composed of a primary coil 5a connected in series with the capacitor 4 and a secondary coil 5b connected to the ignition plug 6. A thyristor 7 is a semiconductor switching element connected to the discharge circuit of the capacitor 4. When the thyristor 7 is conductive, the capacitor 4
The charged charges are discharged to the primary coil 5a. is an ignition timing control circuit which is a feature of the present invention, and is configured as follows. That is, 8 is a signal coil which is an angular position detection device, and is attached to the above-mentioned magnet generator together with the generator coil 1. This signal coil 8 generates positive and negative alternating current outputs in synchronization with the rotation of the engine. The output is rectified by a diode 10, and an output in direction b, ie, angle signal b, is generated corresponding to a predetermined crank position of the engine, for example, the maximum advance angle position _T1 required by the engine. This signal coil 8 is connected to a flip-flop circuit (hereinafter referred to as FF circuit) 1 via a diode 10.
It is connected to the set end S of 1. 12 is a register, 13 is a capacitor, and 14 is an operational amplifier (hereinafter referred to as an operational amplifier). The register 12 and the capacitor 13 constitute an integrator. 15 and 16 are voltage comparators (hereinafter referred to as comparators); 17 is a capacitor; and 18 is a diode; the capacitor 17 and diode 18 constitute a pulse rise detection circuit. An output terminal Q of the FF circuit 11 is connected to an inverting input terminal (hereinafter referred to as the (-) terminal) of an operational amplifier 14 via a register 12. The output terminal of the operational amplifier 14 is the (-) terminal of the comparator 15.
It is connected to the (-) end of the operational amplifier 14 via the capacitor 13. Further, the non-inverting input terminal (hereinafter referred to as the (+) terminal) of the operational amplifier 14 is biased to the reference voltage _V1 , and the (+) terminal of the comparator 15 is biased to the ground potential, which is the first reference value. The (-) end of the comparator 16, which is connected to the reset end R of the FF circuit 11 at the output end of the comparator 15, is connected to the output end of the operational amplifier 14, and the (+) end thereof is connected to the reference voltage V, which is the second reference value. Biased towards ₂ .

is a pulse rising detection circuit, and comparator 1
The output end of the diode 6 is connected to the gate of the thyristor 7 via the capacitor 17, and the cathode side of the diode 18 is connected to the gate of the thyristor 7, and the anode side is grounded. Also, diode 10
A connection point B between the set end S of the FF circuit 11 and the set end S of the FF circuit 11 is connected to the output end E of the comparator 16 via the resistor 21 and the diode 20, and the resistor 21
and is connected to the output terminal G of the pulse rise detection output circuit, that is, the gate of the thyristor 7 via the diode 19.

The operation of the embodiment configured as above will be explained in detail using the operation explanatory diagram shown in FIG. 2. A shown in FIG. 2 is the crank position of the engine, TDC is the top dead center of the engine, and T ₁ indicates the maximum advance angle position of the engine at which the angle signal b is generated, and M indicates the required ignition position. B~G
are the voltage waveforms and pulse waveforms of each part shown in FIG.

As shown in Figure 3, the engine advances at a predetermined slope as the engine speed increases until the engine speed rises to _N1 , and then the engine speed increases _. Even if it increases further, the maximum advance angle T ₁
The ignition timing characteristics are required to be constant at .

First, the operation when the engine is rotating at a rotation speed lower than the rotation speed N ₁ shown in FIG. 3 (N≦N ₁ ) is as follows. Once per revolution of the engine, the signal coil 8 generates an angle signal b whose angle width is narrow and changes sharply at the maximum advance angle position _T1 . When the angle signal b is input to the set end S of the FF circuit 11 via the diode 10, the output end Q
becomes a high level, so the capacitor 13, which has been charged in advance to the polarity shown, is discharged by a current I ₂ shown in the following equation.

I ₂ =F. High level voltage of F circuit 11 - reference voltage V ₁ /
Resistance value of resistor 12 When capacitor 13 discharges with discharge current _I2 ,
The output voltage D of the operational amplifier 14 falls linearly with a constant slope as shown in FIG. A pulse voltage is generated, and when this positive pulse voltage is input to the reset terminal R, the FF circuit 11 inverts and outputs the output terminal Q.
becomes low level.

When the output terminal Q of this FF circuit 11 becomes a low level, the capacitor 13 is charged again to the illustrated polarity with a current _I1 shown in the following equation.

I ₁ =Reference voltage V ₁ /Resistance value of resistor 12 As shown in the above formula, these charging and discharging currents I ₁ and I ₂ are F.
If the high level voltage of the F circuit 11, the resistance value of the register 12, and the reference voltage _V1 are constant, the values will be constant even if the engine speed changes. Therefore, the charging/discharging voltage of the capacitor 13, that is, the output voltage D of the operational amplifier 14, decreases or increases linearly with a constant slope, regardless of the rotation speed, as shown in FIG. 2D. become. In this way, the output voltage D of the operational amplifier 14 falls at a constant slope based on the discharge current I ₂ from the maximum advance angle position T ₁ where the angle signal b is generated,
When the ground potential of the (+) end of 5 is reached, the charging current resumes.
The output voltage is a triangular wave that rises with a constant slope based on I ₁ . This output voltage D is input to the (-) end of the comparator ₁₆ and compared with the reference voltage V ₂ at the (+) end of the comparator 16. Generates a high level output voltage E.

The output voltage E of the comparator 16 is differentiated by a pulse rise detection circuit to generate a trigger voltage I shown in FIG. 2G.

That is, the capacitor 17 is charged with the rising output voltage E of the comparator 16 to the polarity shown, and this charging current generates the trigger voltage of the thyristor 7 (A shown in FIG. 2 G) at the M position shown in FIG. let
Further, the charged capacitor 17 is discharged via the diode 18 due to the low level of the comparator 16 in preparation for the next operation. Incidentally, the angle signal b of the signal coil 8 is connected to the gate of the thyristor 7 via the resistor 21 and the diode 19, but when the engine speed is less than _N1 , the angle signal b of the signal coil 8 is Occurrence time is comparator 16
Since the angle signal b corresponds to the low level of the output of the comparator 16 through the diode 20, it is not applied to the gate of the thyristor 7.

Thus, the trigger voltage A from the comparator 16 is applied to the gate of the thyristor 7, and the thyristor 7 becomes conductive at the M position to discharge the charge in the capacitor 4 to the primary coil 5a of the ignition coil 5. A high voltage is induced in the secondary coil 5b of the ignition coil 5, causing the ignition plug 6 to spark. According to the above explanation, in the engine rotation speed range lower than N ₁ shown in Fig. 3, the operational amplifier 1
It will be understood that the point in time when the discharge output of the output voltage D of No. 4 reaches the reference voltage _V2 of the comparator 16 is the ignition timing, and the engine is ignited.

Next, the operation of advancing the ignition timing at a predetermined slope as the engine speed increases from zero to _N1 will be described in detail with reference to FIG. 4.
Output voltage D of the operational amplifier 14 during the period from the maximum advance angle position T ₁ to the next maximum advance angle position T ₁
This shows the triangular wave output. Here, as described above, the point in time when the discharge output of the output voltage D of the operational amplifier 14 reaches the reference voltage _V2 of the comparator 16 becomes the ignition timing of the engine. In addition, the charging current I ₁ and the discharging current of the capacitor 13 forming the output voltage D
As described above, I ₂ is a constant value regardless of the engine speed, and the slope of the rise and fall of the output voltage D is also constant.

Now, in Fig. 4, the crank angle α from the maximum advance angle position T ₁ where the angle signal b is generated until the discharge voltage of the output voltage D reaches the reference voltage V ₂ is calculated by dividing the crank angle of one revolution by 2π. , the period is T, the discharge section angle is β, and the engine speed is N, the following equation is obtained.

α=β−360°×t/T=β−360°×N×t/60 =β−6・N・t…(1) Here, t is the time after the discharge pressure reaches the reference voltage V ₂ It is the time until charging starts, that is, the time until the output voltage D reaches the ground potential at the (+) end of the comparator 15, and is expressed by the following equation.

t = V ₂ × capacitance value of capacitor 13 / I ₂ ... (2) Substituting this formula (2) into formula (1), crank angle α is α = β - 6 × N × V ₂ × capacitance value of capacitor 13 /I ₂ ...(3).

The discharge interval angle β shown in equation (3) is a constant value regardless of the rotation speed, so the ratio of the discharge interval to one revolution _2π is constant, that is _, it is a constant angle. , As a result, the discharge section angle β becomes constant regardless of the rotation speed N. Therefore, the reference voltage V ₂
If the capacitance value of the capacitor 13 is constant with respect to the rotational speed N, the crank angle α shown in FIG. 4 is determined as a function only of the rotational speed N, and decreases proportionally as the rotational speed increases. In other words, the position where the discharge voltage of the output voltage D reaches the reference voltage _V2 as the engine speed increases is the maximum advanced angle position where the angle signal b is generated.
As _a result, the rise timing of the output voltage E of the comparator 16 advances, and the generation timing of the differential voltage of the pulse rise detection circuit, that is, the generation timing of the trigger voltage A, advances to the maximum as the rotation speed increases. As a result, as shown in FIG. ₃ , the ignition timing is advanced at a predetermined slope as the engine speed increases to _N1 .

For example, the slope of the advance angle characteristic described above is determined by the reference voltage V ₁
is adjusted to change the discharge currents I ₁ and I ₂ of the capacitor 13, and the output voltage D of the operational amplifier 14 becomes the reference voltage.
The output voltage D of the operational amplifier 14 can be changed by changing the position at which V ₂ is reached, or by adjusting the reference voltage V ₂ .
It can be set arbitrarily by changing the position where the angle signal b reaches the reference voltage V ₂ or by changing the generation position of the angle signal b.Next, when the engine speed increases to N ₁ or more as shown in Fig. 3, The operation in the case (N≧N ₁ ) will be explained.

As mentioned above, as the rotation speed increases, the crank angle α decreases proportionally, that is, the timing of trigger voltage A advances toward the maximum advance angle position _T1 , but as the rotation speed increases further, the crank angle α becomes zero. become.
The rotational speed at this time is actually the advance end rotational speed N ₁
However, when the rotation speed increases further to N ₁ or more, the output voltage D of the operational amplifier 14 always becomes the reference voltage.
Since it is less than V ₂ (waveform D in the case of N≧N ₁ in FIG. 2), the output voltage E of the comparator 16 is always at a high level, and therefore, the trigger voltage E is not generated in the pulse rise detection circuit.

On the other hand, the angle signal b of the signal coil 8 generated at the maximum advance position T ₁ is input to the output terminal of the comparator 16 via the resistor 21 and the diode ₂₀ . Since the output voltage E of 16 is always at a high level,
The angle signal b is applied to the gate of the thyristor 7 via the diode 19, resulting in a trigger voltage b shown in FIG. 2G. That is, when the engine speed is _N1 or more, the angle signal b generated at the maximum advance angle position _T1 becomes the trigger signal b that determines the ignition timing, and therefore the ignition timing remains constant regardless of the increase in the engine speed. This is the maximum angle.

As detailed above, according to the embodiment of the present invention, the angle signal b that is synchronized with the rotation of the engine and corresponds to the maximum advance position T ₁ is used to control the rotation range in which the rotation speed is lower than N ₁ (N≦N ₁ ), the crank angle α from the maximum advanced angle position T ₁ where the angle signal b is generated until the discharge voltage of the output voltage D of the operational amplifier 14 reaches the reference voltage V ₂ decreases proportionally as the rotation increases. As a result, the generation position of the trigger signal A advances to the maximum advance angle position _T1 , which allows the angle to be advanced with a predetermined slope, and the rotational speed is within the rotation range of _N1 or more (N≧ _N1 ). By using the angle signal b as the trigger signal b for determining the ignition timing, it is possible to ignite at the maximum advanced angle position _T1 , and therefore, the ignition timing characteristics shown in FIG. 3 can be obtained. Incidentally, the maximum advance angle position _T1 can be arbitrarily set to adjust the generation position of the angle signal b.

In the above embodiment, the ignition timing is set at the point in time when the output voltage D of the operational amplifier 14 reaches the reference voltage _V2 of the comparator 16 in the process of falling toward the ground potential of the comparator 15 based on the discharge current _I2 . , conversely, in the process in which the output voltage D of the operational amplifier 14 rises toward the reference voltage of the comparator 15 (higher than the reference voltage V ₂ of the comparator 16) based on the charging current I ₁ , the reference voltage V ₂ of the comparator 16 increases.
It is also possible to set the ignition timing to be the point in time when .

5 showing this embodiment, the output end of the FF circuit 11 is connected to the (-) end of the operational amplifier 14 via the register 12, and the output end D of the operational amplifier 14 is connected to the (-) end of the operational amplifier 14.
The (-) end of the comparator 16 is biased to the reference voltage V ₂ and the (-) end of the comparator 15 is connected to the reference voltage V ₃ which is higher than the reference voltage V ₂ . Biased.

Next, this operation will be explained with reference to FIG. 6. When the angle signal b is generated at the maximum advance angle position _T1 , the output terminal of the FF circuit 11 is inverted from high level to low level, so that the capacitor 13 is The operational amplifier 14 is charged with the polarity shown in the charging current _I1 , which is a constant current, so that the output voltage D of the operational amplifier 14 increases linearly with a constant slope as shown in FIG. 6D. This rising output voltage D is applied to the comparator 15.
When it reaches the reference voltage ( _V3 ) at the (+) end of the FF circuit 11 is reset by the positive pulse voltage of the comparator 15, and the output end is inverted from low level to high level. The capacitor 13 is discharged with a constant current I ₂ , which causes the output voltage D of the operational amplifier 14 to increase.
falls linearly with a constant slope as shown in FIG. 6D, and when the angle signal b is generated again, the output voltage D of the operational amplifier 14 rises linearly with a constant slope as described above. Here, the output voltage D of the operational amplifier 14 rises toward the reference voltage V ₃ and is compared with the reference voltage V ₂ of the comparator 16 in the process of falling again.
generates a high-level output voltage E during a period when the output voltage D of the operational amplifier 14 is higher than the reference voltage _V2 , and when this output voltage E rises from a low level to a high level, it is differentiated by a pulse rise detection circuit, and G A trigger voltage A shown in FIG. 6G is generated at the point. Here, in the rotation range where the engine rotation speed is lower than N ₁ (N≦N ₁ ), the generation position of the trigger voltage A changes to the maximum advance angle as the engine rotation speed N increases due to the same operation as in the above embodiment. In the rotation range N≧N ₁ where the number of revolutions is N ₁ or _more , the ignition timing becomes the maximum advance angle position T ₁ , and therefore the third
As shown in the figure, the angle is advanced at a predetermined slope, and the rotational speed is
This results in an ignition timing characteristic with a constant maximum advance angle of N ₁ .

Next, FIG. 7 showing an embodiment of the second invention will be described. In the figure, positive and negative alternating current outputs b and h are generated in the signal coil 8 in synchronization with the rotation of the engine, and among these, the output in the b direction, that is, the first angle signal b
occurs at the maximum advance angle position _T1 required by the engine, which is the first crank position, as shown in FIG. 8B, and the h-direction output, that is, the second angle signal Minimum advanced angle position which is the second crank position delayed by a predetermined angle γ from the angular position T ₁
T ₂ and these first and second angle signals b, h
The angular width changes sharply and narrowly once per revolution of the engine. Further, the first and second angle signals b and h are transmitted through a diode 1 that full-wave rectifies the AC output of the signal coil 8.
0, 22, 23, and 24, the first angle signal b is input to the set end S of the F.FF circuit 11, and the second angle signal h is input directly to the gate of the thyristor 7.

To explain the operation of this embodiment, according to this embodiment, as shown in _FIG.
In the rotation range until the rotation speed rises to N 2 (N≦N ₂ ), the minimum advance angle is constant T ₂ , and in the rotation range until the rotation speed rises to N ₂ or more and rises to N ₁ (N ₂ ≦N≦N ₁ ) Then, as the rotation speed increases, the angle advances at a predetermined slope, and the rotation speed is within the rotation range of N ₁ or more (N≧
N ₁ ), an ignition timing characteristic with a constant maximum advance angle is obtained.

First, when the engine speed is in the rotation range of N ₂ ≦N≦N ₁ , an advance angle characteristic with a predetermined slope is obtained by the first angle signal b generated at the maximum advance angle position T ₁ , and when N≧ Similar to the embodiment described above, a constant maximum advance angle can be obtained in the rotation range of _N1 . Therefore, when the engine speed is in the rotation range N≦N ₂ , the second rotation occurs at the minimum advance angle position T ₂ .
Both the angle signal h and the trigger voltage A based on the first angle signal b are input to the gate of the thyristor 7, but the second angle signal h is generated angularly earlier than the trigger voltage A, and Since the second angle signal h is first input to the gate of the thyristor 7, the charge in the capacitor 4 is discharged at the time when the second angle signal h is generated, and the spark plug 6 sparks. Therefore, when the engine speed is below _N2 , the second angle signal h is used as the trigger signal for determining the ignition timing, and the timing of generation of the second angle signal h is constant regardless of the engine speed. Therefore, the ignition timing is effectively at the minimum advance angle position _T2 .

In this way, in the engine's low-speed rotation range (the rotation range of N≦N ₂ ), ignition can be performed at a constant minimum advance angle position T ₂ based on the second angle signal h, thereby stabilizing the idling of the engine. In addition, in the rotation range of N ₂ ≦N≦N ₁ , ignition can be performed with advance characteristics based on the first angle signal b, and in the rotation range of N≧N ₁ , that is, high speed. In the rotation range, the engine can be suitably driven by igniting at a constant maximum advance angle position _T1 based on the first angle signal b. Note that the minimum advanced angle position _T2 can be arbitrarily set by adjusting the generation timing of the second angle signal h. In addition, since the first and second angle signals b and h utilize the AC output of the signal coil 8, they can be achieved without adding a signal coil.
The device can be simplified.

Also in this embodiment, the output voltage D of the operational amplifier 14 is determined by the comparator 1 based on the discharge current _I2 .
The ignition timing is defined as the point in time when the reference voltage _V2 of the comparator 16 is reached in the process of decreasing towards the ground potential of the operational amplifier 14, but as in the embodiment of _FIG . Based on this, it is also possible to set the point in time when the reference voltage V ₂ of the comparator 16 is reached in the process of increasing toward the reference voltage V ₃ of the comparator 15 as the ignition timing.

The embodiment shown in FIG. 10 uses independent signal coils 81 and 82 as signal coils that generate the first and second angle signals b and h, respectively. , h can be arbitrarily adjusted.

As described in detail above, the present invention advances the position where the first output of the integrator reaches the second reference value and where the trigger signal is generated to a predetermined crank position as the engine speed increases. Until the trigger signal reaches a predetermined crank position, the trigger signal is used as a signal for determining ignition timing, and after the trigger signal generation position reaches a predetermined crank position, the angle signal generated at the predetermined crank position is used as a signal for determining ignition timing. So,
As the engine speed increases, the ignition timing advances at a predetermined slope, and the ignition timing has a constant advance angle, and is delayed by a predetermined angle from the first crank position where the first angle signal is generated. Since the second angle signal generated at the second crank position is used as a signal for determining the ignition timing until the trigger signal generation position reaches the second crank position, a constant minimum advance angle and the engine rotation speed from this advance angle are determined. This has the excellent effect of providing ignition timing characteristics in which the ignition timing advances at a predetermined slope as the value increases, and the ignition timing reaches a constant maximum advance angle.

[Brief explanation of the drawing]

Fig. 1 is an electric circuit diagram showing one embodiment of the first invention, Fig. 2 is an operating waveform diagram of the embodiment of Fig. 1, Fig. 3 is an ignition timing characteristic diagram of the embodiment of Fig. 1, and Fig. 4 is An operation waveform diagram for explaining the advance angle operation, Figure 5 is the first waveform diagram.
An electric circuit diagram showing another embodiment of the invention, FIG. 6 is an operation waveform diagram of the embodiment shown in FIG. 5, FIG. 7 is an electric circuit diagram showing an embodiment of the second invention, and FIG. FIG. 9 is an ignition timing characteristic diagram of the embodiment. FIG. 9 is an electric circuit showing another embodiment of the signal coil that generates the first and second angle signals b and h. It is a diagram. In the figure, ignition circuit, ignition timing control circuit, pulse rise detection circuit, 8, 81, 82
11 is a signal coil, 11 is an FF circuit, 12 and 21 are registers, 13 and 17 are capacitors, 14 is an operational amplifier, and 15 and 16 are comparators. Note that the same reference numerals in each figure indicate the same or corresponding parts.

Claims (1)

[Claims] 1. An angle signal generated at a predetermined crank position in synchronization with the rotation of the engine, a first output that descends or rises at a constant slope with a constant current when this angle signal is generated; an integrator that generates a second output that rises or falls at a constant current with a constant slope when the first output reaches a first reference value;
In the process until the output reaches the first reference value, the second
The circuit includes a circuit that generates a trigger signal for determining ignition timing when the reference value is reached, and the generation position of the trigger signal advances toward the predetermined crank position as the rotational speed of the engine increases, and the generation position of the trigger signal The trigger signal is used as a signal for determining ignition timing until the position of the trigger signal reaches the predetermined crank position, and the angle signal is used as a signal for determining ignition timing after the generation position of the trigger signal reaches the predetermined crank position. An engine ignition timing control device characterized by: 2. The integrator comprises an operational amplifier, a capacitor connected to an inverting input terminal and an output terminal of the operational amplifier, and a resistor connected to a charging/discharging path of the capacitor. engine ignition timing control device. 3 The circuit includes a voltage comparator that compares the charge/discharge voltages that are the first and second outputs of the integrator with a second reference voltage that is the second reference value, and a trigger signal that differentiates the output voltage of the voltage comparator. Claim 1 or 2, characterized in that it consists of a differentiating circuit that generates
The engine ignition timing control device described in . 4 A first angle signal generated at a first crank position in synchronization with the rotation of the engine, and a second angle signal generated at a second crank position synchronized with the rotation of the upper engine and delayed by a predetermined angle from the first crank position. An angle signal, a first output that decreases or increases with a constant slope with a constant current when the first angle signal is generated, and a first output that decreases or increases with a constant slope with a constant current when the first output reaches a first reference value. an integrator that generates a second output that increases or decreases over time; and a circuit that generates a trigger signal for determining ignition timing when the first output reaches a second reference value in the process of reaching the first reference value. The generation position of the trigger signal advances toward the first crank position as the rotational speed of the engine increases, and the second angle signal remains unchanged until the generation position of the trigger signal reaches the second crank position. is used as a signal for determining the ignition timing, and until the generation position of the trigger signal passes the second crank position and reaches the first crank position, the trigger signal is used as a signal for determining the ignition timing, and the generation position of the trigger signal is used as a signal for determining the ignition timing. An engine ignition timing control device characterized in that after the engine reaches the first crank position, the first angle signal is used as a signal for determining ignition timing.