JPH028148B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a non-contact type ignition device for an internal combustion engine.

In general, non-contact type ignition systems for internal combustion engines apply high voltage to the secondary side of the ignition coil by suddenly changing the primary current of the ignition coil through the operation of a semiconductor switch and changing the magnetic flux in the ignition coil iron core. The ignition position is controlled by controlling the position at which a trigger signal is applied to a semiconductor switch for primary current control. As a circuit for controlling the ignition position of this type of ignition device, the applicant first charged an advance angle capacitor with a constant current for a certain period and then discharged it with a certain time constant, and compared the triangular wave voltage obtained with a reference voltage. hand,
A lead-angle circuit that obtains lead-angle characteristics by triggering a semiconductor switch when the slope of the drop in the triangular wave voltage falls below the reference voltage, and a triangular wave obtained by charging a retard capacitor with a constant current for a certain period of time. In combination with a retard circuit that obtains retard characteristics by comparing the voltage with a reference voltage and triggering a semiconductor switch when the slope of the rise in the triangular wave voltage exceeds the reference voltage, We proposed an electronically controlled circuit that advances the ignition position and retards the ignition position in the high-speed range above the set rotation speed.

As mentioned above, the characteristic of retarding the ignition position in the region above the set rotation speed is necessary to prevent the engine from overspeeding or to retard the ignition position in the high-speed region in order to improve the output characteristics in the high-speed region. However, depending on the engine, a characteristic of retarding the ignition position in a high-speed region and then advancing it again may be required. The previously proposed devices could not cope with cases requiring such complex characteristics.

SUMMARY OF THE INVENTION An object of the present invention is to provide an electronically controlled ignition device for an internal combustion engine that is capable of retarding the ignition position as the rotational speed increases in a high-speed region and then advancing it again. It is in.

The present invention provides an advance angle circuit and a retard angle circuit that compare triangular wave voltages generated by charging and discharging an advance angle capacitor and a retard angle capacitor with a reference voltage, respectively, and obtain trigger signals for advance angle and retard angle. The above object is achieved by adding an advance angle circuit to the internal combustion engine ignition system for causing the advance angle operation to be performed again in a speed range above the rotational speed at which the retard operation ends.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below along with embodiments thereof with reference to the drawings.

FIG. 1 shows the basic configuration of one embodiment of the present invention, in which numeral 1 represents a capacitor discharge type ignition circuit. The ignition circuit 1 includes an ignition coil 2 having a primary coil 2a and a secondary coil 2b.
, a capacitor 3 connected in series to the primary coil 2a, a thyristor 4 as a semiconductor switch for primary current control connected in parallel to the series circuit of the capacitor 3 and the primary coil 2a, and a capacitor 3 and the primary coil 2a, and an exciter coil 6 connected in parallel via a diode 5 to both ends of the series circuit of the primary coil 2a and a spark plug 7 connected to both ends of the secondary coil 2b. The common connection point of the secondary coil 2b, the cathode of the thyristor 4, and one end of the exciter coil 6 are grounded. The exciter coil 6 is disposed within a generator driven by the engine, and induces an alternating current voltage in synchronization with the rotation of the engine. Exciter coil 6
When a half-cycle voltage is induced in the direction of the arrow shown in the figure, the capacitor 3 is charged through the diode 5 to the polarity shown in the figure. Next, when a trigger signal is applied to the gate of the thyristor 4 at the ignition position of the engine, the thyristor 4 becomes conductive, and the load on the capacitor 3 is discharged through the thyristor 4 and the primary coil 2a. This causes a large magnetic flux change in the iron core of the ignition coil 2, and a high voltage for ignition is induced in the secondary coil 2b. Since this high voltage is applied to the ignition plug 7, a spark is generated at the ignition plug 7,
An ignition operation is performed. The ignition circuit used in the present invention may be one that controls the primary current of the ignition coil using a semiconductor switch triggered at the ignition position and generates a high voltage for ignition on the secondary side of the ignition coil. For example, a current ignition type ignition device that performs ignition operation by switching a semiconductor switch installed in parallel with the exciter coil and the primary coil of the ignition coil from a conductive state to an inactive state at the ignition position. It may also be a circuit. In any case, this type of ignition circuit uses a semiconductor switch (first
In the illustrated example, the trigger position of the thyristor 4) is the ignition position, and by controlling this trigger position according to the rotational speed of the engine, predetermined advance and retard characteristics can be obtained.

In the example of FIG. 1, an ignition position control circuit 10 is provided to control the ignition position of the engine. The control circuit 10 includes first and second advance angle capacitors 1
1 and 12, and a retardation capacitor 13, one end of which is grounded. The cathodes of diodes 14 to 16 are connected to the non-grounded terminals of the capacitors 11 to 13, respectively, and the anodes of the diodes 14 to 16 are connected to the non-grounded output terminal of the power supply circuit 20 through constant current circuits 17 to 19, respectively. There is. The power supply circuit 20 is a circuit that rectifies and smoothes a part of the output of the exciter coil 6 or the output of a generator coil provided separately from the exciter coil, or a circuit that uses a battery as a power source. The capacitors 11 to 13 are charged with a constant current at a predetermined time constant by the output through constant current circuits 17 to 19. A series circuit of a variable resistor 21 and a constant current circuit 22 and a series circuit of a variable resistor 23 and a constant current circuit 24 are connected in parallel to both ends of the diodes 14 and 15, respectively. A discharge control switch 25 is connected in parallel to the two. The discharge control switch 25 is, for example, a transistor, and a switch 26 made of a transistor or the like is connected in parallel between its control terminal 25a and ground. A variable resistor 27 is connected between the non-grounded terminal of the switch 26 and the non-grounded terminal of the capacitor 13.

A resistor 2 is also connected to the non-grounded output end of the power supply circuit 20.
8 and 29 are connected, and the other end of the resistor 28 is connected to the non-ground terminal of the switch 26.
The other end of the resistor 29 is connected to one end of a switch 30 made of a transistor or the like.
The other end is grounded. The other end of the resistor 28 is also connected to the gate of the thyristor 4 through a series circuit of diodes 31 and 32, and the other end of the resistor 29 is connected to the gate of the thyristor 4 through a diode 33. The connection point between the diodes 31 and 32 is connected to one end of the signal coil 34, and the other end of the signal coil 34 is connected to the diode 3 whose anode is grounded.
It is connected to the cathode of 5. Signal coil 34
The other end is also connected to the anode of the diode 36, and the cathode of the diode 36 is connected to the negative input terminal of the comparator 37. Comparator 37
A reference voltage V _r0 obtained from the reference voltage generation circuit 38 is input to the positive input terminal of the reference voltage generating circuit 38 . The output of comparator 37 is connected to control terminals 26a and 30a of switches 26 and 30. The signal coil 34 is disposed in a signal generator that rotates in synchronization with the engine, and outputs a first signal v _s1 in the direction of the dashed arrow and a second signal v _s2 in the direction of the solid arrow for one ignition cycle (in each cylinder of the engine). This occurs sequentially once every period (from one ignition to the next ignition). The control terminals of the switches 26 and 30 are connected to the non-grounded output end of the power supply circuit 20 through a resistor 39, and a conduction signal is applied from the power supply circuit 20 to the switches 26 and 30 through the resistor 39. The comparator 37 has a switch circuit 37a at its output stage, and the switch circuit 37a is closed while the first signal v _s1 obtained from the signal coil 34 is higher than the reference voltage V _r0 . . During the period when the switch circuit 37a is closed, the potentials of the control terminals 26a and 30a of the switches 26 and 30 are maintained at approximately the ground potential, so that no conduction signal is given to the switches 26 and 30. Therefore, switches 26 and 30 are connected to signal coil 34.
During the period when the first signal v _s1 outputted from the reference voltage V _r0 is higher than the reference voltage V r0 , it is held in the off state, and during the other period, it is held in the conductive state. Further, when the switch 26 is in the off state, a conduction signal is applied from the power supply circuit 20 to the switch 25 through the resistor 28, and the switch 25 becomes in the conduction state. Therefore, the switch 25 determines that the first signal v _s1 is the reference voltage.
_The first and second advance angle capacitors 11 and 12 are connected to the constant current circuits 22 and 24 while the switch 25 is conductive.
and variable resistors 21 and 23.
Further, when the switch 26 is conducting, a part of the current flowing from the power supply circuit 20 to the retard capacitor 13 through the constant current circuit 19 and the diode 16 is bypassed through the variable resistor 27 and the switch 26, and the switch 26 is turned off. This shunt current is interrupted during the interruption period.

First and second advance angle capacitors 11 and 12
The terminal voltages v ₁ and v ₂ of are input to the minus side input terminals of the first and second comparators 41 and 42, respectively, and the terminal voltage v ₃ of the advance angle capacitor 13 is input to the plus side of the third comparator 43. being input to the input terminal. A reference voltage generator 44 is provided at the positive input terminal of the first comparator 41 and the second comparator 42, respectively.
and the first and second reference voltages obtained from 45
V _r1 and V _r2 are input, and the third reference voltage V _r3 is input to the negative input terminal of the third comparator 43 . In this embodiment, the same voltage as the first reference voltage V _r1 is used as the third reference voltage V _r3 . Note that the third reference voltage V _r3 does not necessarily have to be equal to the first reference voltage V _r1 ;
A reference voltage different from the reference voltage V _r1 may be applied to the negative input terminal of the third comparator 43 as the third reference voltage V _r3 . The output terminals of the first comparator 41 and the third comparator 43 are commonly connected to the anode of the diode 31, and the output terminal of the second comparator 42 is connected to the anode of the diode 33. First to third comparators 41 to 4
3 has switch circuits 41a to 4 at the output stage, respectively.
3a, and the switch circuits 41a and 42a of the first and second comparators 41 and 42 operate when the terminal voltages v ₁ and v ₂ of the capacitors 11 and 12 become larger than the reference voltages V _r1 and V _r2, respectively. When the diodes 31 and 33 are in a conductive state, the potentials of the anodes of the diodes 31 and 33 are reduced to approximately the ground potential. In this way, when the final stage switch circuits 41a and 42a of the comparators 41 and 42 are in a conductive state, the potential of the anodes of the diodes 31 and 33 is maintained at approximately the ground potential. No signal is given. The final stage switch circuits 41a and 42a of the comparators 41 and 42 use the terminal voltages v ₁ and v ₂ of the advance angle capacitors 11 and 12 as reference voltages, respectively.
When the voltage becomes lower than V _r1 and V _r2 , the voltage rises and the anode potential of the diodes 31 and 33 increases, allowing a trigger signal to be applied to the gate of the thyristor 4. Also, the third comparator 4
3, the final stage switch circuit 43a is the capacitor 13
When the terminal voltage v ₃ of the thyristor 4 becomes equal to or higher than the third reference voltage V _{r 3} , the thyristor 4 enters a step state and allows a trigger signal to be applied to the gate of the thyristor 4 through the diode 31 .

In order to instantaneously discharge the first to third capacitors 11 to 13 and reset the control circuit, the anodes of diodes 51 to 53 whose cathodes are commonly connected are connected to the non-grounded terminals of the capacitors 11 to 13, respectively. A reset switch 54 is connected between the common connection point of the cathodes 53 to 53 and ground. Reset switch 5
The control terminal 54a of the switch 54 is connected to the cathode of the diode 31, and when the second signal v _s2 in the direction of the solid arrow shown in the figure is output from the signal coil 34, a conduction signal is given to the reset switch 54, and the switch 54 is activated. conducts, causing capacitors 11 to 13 to be instantaneously discharged.

In the embodiment shown in FIG. 1 above, the constant current circuit 1
7, diode 14, constant current circuit 22, variable resistor 21, switch 25, switch 26, comparator 3
7. The diode 51 and the switch 54 constitute a first control circuit that receives the output of the signal coil 34 as an input and controls charging and discharging of the first advance angle capacitor 11. Also, constant current circuit 18, diode 15, constant current circuit 24, variable resistor 23, switches 25, 26, comparator 37, diode 52
and the switch 54 constitute a second charging/discharging control circuit that controls charging/discharging of the second advance angle capacitor 12 using the output of the signal coil 34 as input,
These first and second charge/discharge control circuits constitute an advance charge/discharge control circuit. Further, the first comparator 41 and the resistor 28 provide a first lead angle controller that outputs a first lead angle trigger signal when the terminal voltage of the lead angle capacitor 11 becomes equal to or lower than the first reference voltage. A trigger signal generation circuit is configured, and a second
The comparator 42 and the resistor 28 output a second lead angle trigger signal when the terminal voltage of the lead angle capacitor 12 becomes equal to or lower than the second reference voltage.
A lead angle trigger signal generation circuit is constructed.
Further, the third comparator 43 and the resistor 29 control the timing when the terminal voltage of the retard capacitor 13 becomes equal to or higher than the third reference voltage (equal to the first reference voltage in the above example). A retard trigger signal generation circuit is configured to output a trigger signal. Furthermore, the comparator 37, the switch 26, and the switch 30 are controlled by the output of the signal coil 34, and only the specified period from the generation of the first signal v _s1 until the generation of the second signal v _s2 is controlled by the output of the signal coil 34. A gate circuit is configured to allow the first and second advance angle trigger signals and retard angle trigger signals to be input to the thyristor 4 (semiconductor switch). Also diode 3
2 and 35 constitute a low-speed ignition position determination circuit that provides a trigger signal for low-speed ignition position determination to the thyristor 4 using the second signal V _s2 at the generation position of the second signal V _s2 .

The basic configuration of the ignition position control circuit 10 shown in FIG. 1 is expressed using a logic circuit as shown in FIG. 2. In FIG. 2, the AND circuit AND ₁ outputs a high potential trigger signal when the output ends of the first and third comparators 41 and 43 are at a high potential and the switch 26 is in the off state. In the example shown in FIG.
The AND circuit AND ₁ is configured by commonly connecting the output terminal of the switch 3 and the non-grounded terminal of the switch 26 to the anode of the diode 31. The AND circuit AND ₂ outputs a high potential trigger signal when the output terminal of the second comparator 42 is at a high potential and the switch 30 is in the off state. The AND circuit _AND 2 is constructed by commonly connecting the output terminals of the comparators 42 and the non-grounded terminal of the switch 30. The OR circuit OR ₁ outputs a high-potential trigger signal when a high-potential signal is applied from either the AND circuit AND ₁ or the signal coil 34. In the example shown in FIG. and a diode 35 constitute this OR circuit _OR1 . The OR circuit OR ₂ gives a trigger signal to the thyristor 4 when a trigger signal is given from either the AND circuit AND ₂ or the OR circuit OR _1. In the example of FIG.
3 constitutes this OR circuit _OR2 .

As is clear from FIG. 2, in the circuit of FIG. 1, a trigger signal is given to the thyristor 4 in any of the following cases.

(i) When the switch 26 is turned off, the first comparator 4
When both the output terminal of the comparator 1 and the output terminal of the second comparator 42 are at high potential. That is, when the first signal v _s1 becomes v ₁ <V _r1 and v ₃ >V _r3 during a period when the first signal v s1 is equal to or higher than the reference voltage V _r0 .

(ii) When the switch 30 is turned off, the second comparator 4
When the output terminal of 2 is at high potential. That is, the first signal
When v ₂ < V _r2 during a period when v _s1 is greater than or equal to the reference voltage V _r0 .

(iii) When the second signal v _s2 is generated in the signal coil 34.

In the circuit shown in Figure 1, the engine rotational speed N
The potentials at points a, b, b' and c to i when (rpm) is equal to N ₁ which is lower than the first set value N ₂ are shown in a, b, b' and c to i in Figure 3A, respectively. There is. That is, the signal coil 34 generates the first signal v s1 at a position of angle θ ₆ before top dead center (first reference position) as shown in FIG. 3A, and generates a first signal v _s1 at a position of angle θ ₁ before top dead center ( A second signal v _s2 is generated at a second reference position). Here, the first reference position θ ₆ corresponds to the maximum advance position, and the second
The reference position θ ₁ corresponds to the ignition position at low speed. During the period when the first signal v _s1 is higher than the reference voltage V _r0 , the output terminal of the comparator 37 becomes the ground potential, so the switches 26 and 30 are turned off, and the switches b and b' in FIG. The potential at the point becomes high as shown in FIG. 3A b and b'. Here, since the reference voltage V _r0 is set sufficiently small, the section where the potentials at points b and b' are high is approximately equal to the section from angle θ ₆ to _{θ 1} . In other words, the potentials at points b and b' are the interval heights from when the first signal v _s1 is generated at the first reference position θ ₆ until when the second signal v _s2 is generated at the second reference position θ ₁ . Becomes electric potential.

On the other hand, since the first advance angle capacitor 11 is charged through the constant current circuit 17 and the diode 14, the terminal voltage v ₁ (potential at point c) of this capacitor 11 has a constant slope as shown in Fig. 3A c. Rise. When the switch 26 is briefly disconnected at the first reference position θ ₆ , the switch 25 becomes conductive, so the capacitor 1
1 is stopped, and the charge in the capacitor 11 is transferred to the constant current circuit 22, the variable resistor 21, and the switch 25.
discharge through. Therefore, the first reference position θ ₆
From then on, the potential at point c decreases at a constant gradient. When the second signal v _s2 is generated at the second reference position _θ1 , the reset switch 54 becomes conductive, so that the capacitor 11
The charge at point c is discharged almost instantaneously, and the potential at point c returns to approximately zero. At this time, the switch 25 becomes conductive, so that charging of the capacitor 11 is restarted. As these operations are repeated, the terminal voltage v ₁ of the capacitor 11 rises at a constant slope from the second reference position θ ₁ to the first reference position θ ₆ and then returns to the first reference position θ ₆
It descends at a constant slope from to the second reference position θ ₁ ,
The waveform returns to zero at the second reference position θ ₁ . In exactly the same way, since the charging and discharging of the second advance angle capacitor 12 is controlled by the switch 25, the waveform of the terminal voltage v ₂ (ground potential at point g) of this capacitor 12 is as shown in Fig. 3A g. , the waveform is similar to that of the terminal voltage _v1 .

After the retard capacitor 13 is reset at the second reference position _θ1 , the constant current circuit 19 and the diode 1
6, its terminal voltage v ₃ (e
The potential at the point) increases as shown in FIG. 3A e. When the switch 26 is turned off at the first reference position θ ₆ , the current flowing through the variable resistor 27 is suddenly cut off, so the charging current of the capacitor 13 increases, and the slope of the rise in the terminal voltage v ₃ changes. becomes larger.

The first comparator 41 compares the voltage v ₁ with the first reference voltage V _r1 and raises its output terminal (point d) only during the period when the voltage v ₁ is below the first reference voltage V _r1 . potential. Therefore, the potential at the output end of the first comparator 41 changes as shown in FIG. 3A d. The second comparator 42 has its output terminal (point h) at a high potential only during the period when the voltage v ₂ is below the second reference voltage V _r2 . The potential waveform is as shown in Fig. 3A h. Further, the third comparator 43 sets its output terminal 43a to a high potential when the voltage v ₃ exceeds the third reference voltage. Therefore, the waveform of the potential at the output terminal of the third comparator 43 becomes as shown in FIG. 3A h.

In a low speed region where the engine rotational speed N (rpm) is lower than _the first _set value _N2 , as shown in FIG. Since the potential at the output end of the first comparator 41 is at ground potential, and the potential at the output end of the second comparator 42 is also at ground potential, the diodes 31 and 33
No trigger signal is applied through the signal coil 34 at the second reference position θ ₁ as shown in FIG.
A trigger signal is provided by a second signal v _s2 obtained from . Therefore, the ignition position in this low speed region is approximately the second reference position θ ₁ as shown in FIG.
becomes. In Fig. 4, TDC indicates the top dead center of the engine. As the rotation speed of the engine increases, the charging and discharging time of the capacitors 11 to 13 becomes shorter, so the terminal voltages of the capacitors 11 to 13 v ₁ to _{v 3}
The wave height value gradually decreases as the rotation speed increases.

When the rotational speed N exceeds the first set value _N2 and becomes, for example, N= _N3 (> _N2 ), the voltage waveforms at each part become as shown in a, b, b' and c to i in Figure 3B. , the potential at the output end of the first comparator 41 becomes high at an angle θ ₃ within the interval from the first reference position θ ₆ to the second reference position θ ₁ . In the section between angles θ ₃ and _{θ 1} , the potentials at point b, point d, and point f are all high potentials, so a trigger signal is given to the thyristor 4 . Therefore, at this rotational speed _N3 , the ignition operation is performed at an angle _θ3 . Output end of first comparator 41 (point d)
The position where the potential becomes high advances as the rotational speed increases, and when the rotational speed N reaches the second set value _N4 , it coincides with the position at the angle _θ6 . Therefore, the fourth
As shown in the figure, the ignition position advances from θ ₁ to θ ₆ while the rotational speed increases from the first set value N ₂ to the second set value N ₄ .

When the rotational speed of the engine is between the second set value N ₄ and the third set value N ₆ , the ignition position is maintained at the maximum advance angle position (first reference position) θ ₆ . For example, points a, b when N=N ₅ (N ₄ <N ₅ <N ₆ ),
The voltage waveforms of b' and c to i are as shown in a, b, b' and c to i of FIG. 3C, respectively, and the terminal voltage _v1 of the first advance angle capacitor 11 reaches the reference voltage _Vr1 . Therefore, the output terminal of the first comparator 41 remains at a high potential. Therefore, at the angle θ ₆ the first signal v _s1 is generated and the switching element 26 is turned off, at the same time a trigger signal is given to the thyristor 4, and ignition is performed at this angle θ ₆ .

Then, when the rotational speed reaches the third set value N ₆ ,
When the position where the terminal voltage v ₃ of the retard capacitor 13 reaches the third reference voltage V _r3 corresponds to the position of the angle θ ₆ before top dead center, and the rotation speed further increases, the terminal voltage v ₃
The position where the voltage reaches the reference voltage V _r3 lags behind the position of the angle θ ₆ toward the top dead center. For example, the rotation speed N is N ₇
(>N ₆ ), points a, b, b' and c~
The voltage waveform of i becomes as shown in FIG. 3D, and the terminal voltage v ₃ reaches the reference voltage V _r3 at the angle θ ₄ between the angles θ ₆ and θ ₁ . Therefore, at this time, the condition that a trigger signal is given to the thyristor 4 at the angle θ ₄ (points b, d, and f are all at high potential) is established, and the ignition operation is performed at this angle θ ₄ . . That is, when the rotational speed exceeds the third set value, the ignition position starts to be retarded toward the top dead center side.

In the above circuit, the second advance angle capacitor 1
The reference voltage V _r2 to be compared with the terminal voltage V ₂ of No. 2 is set sufficiently low, and in the speed range up to the rotation speed N ₈ which is a certain value higher than the third set value N ₆ ,
Terminal voltage v ₂ becomes the reference voltage at a position further than the angle θ ₁
It is designed so that it will never go below V _r2 . A certain value N ₈ where the rotational speed N is greater than the third set value N ₆
, the slope of the decline of the terminal voltage _v2 becomes below the reference voltage _Vr2 , and the position at which the output terminal (point g) of the second comparator 42 becomes high potential is at a position advanced by the angle _θ1 . Therefore, the condition for applying the trigger signal through the diode 33 is satisfied, but in the region where the rotational speed is less than the fourth set value _N9 , the terminal voltage _v2
Since the angle at which the slope of decline of V becomes less than the reference voltage _Vr2 is further delayed than the angle at which the terminal voltage _V3 of the retarding capacitor 13 becomes equal to or higher than the third reference voltage _Vr3 , the ignition operation This is done at an angle where the terminal voltage _v3 is equal to or higher than the reference voltage _Vr3 , and the second comparator 42 has no effect on the ignition operation. When the rotational speed N reaches the fourth set value _N9 , the angle at which the terminal voltage _v3 becomes equal to or higher than the reference voltage _Vr3 and the terminal voltage _v2
When the rotation speed exceeds the fourth set value N ₉ , the terminal voltage V ₂ coincides with the angle at which the terminal voltage V ₃ becomes equal to or higher than the reference voltage V _{r 2 .} The downward slope of becomes below the reference voltage V _r2 . Therefore, in the rotational speed range above the fourth set value N ₉ , a trigger signal is applied through the diode 33 at an angle where the downward slope of the terminal voltage v ₂ is below the reference voltage V _{r 2} and the ignition operation is performed. The position again advances as the rotational speed increases. For example, when the rotational speed reaches N ₁₁ (>N ₉ ), the voltage waveforms at points a, b, b' and c to i are as shown in FIG. 3E.

When the rotation speed reaches the fifth set value _N12 , the position where the terminal voltage _v2 becomes equal to or less than the reference voltage _Vr2 coincides with the position of the angle _θ6 , and the advance of the ignition position stops. Therefore, in a speed range equal to or higher than the fifth set value N ₁₂ , ignition is performed at the angle θ ₆ . Rotational speed N is N ₁₃
(>N ₁₂ )
It is shown in Figure F. Through the operations described above, advance angle and retard angle characteristics as shown in FIG. 4 can be obtained.

Next, the characteristics obtained by the circuit shown in FIG. 1 can be expressed using mathematical formulas as follows.

(1) Speed region of N ₂ ≦ N < N ₄ The advance angle width is α (= θ ₆ - θ ₁ ), the angle from the top dead center to the ignition position is θ _N , and the capacitance of the capacitor 11 is C _1. If the charging current of the capacitor 11 is I ₁ and the discharging current I ₁ ', then the rotation speed N is the first setting value (advance angle start rotation speed) N ₂ or more and the second setting value (advance angle end rotation speed) The ignition position θ _N and set values N ₂ and N ₄ in the speed range below N ₄ are given below.

θ _N = (6C ₁ V _r1 / I ₁ ) N − (360 − α) (I ₁ / I ₁ ′) + (θ ₁ + α) ...(1) N ₂ = (1/6C ₁ V _r1 ) { (360−α)I ₁ −αI ₁ ′} ……(2) N ₄ = (1/6C ₁ V _r1 ) (360−α) I ₁ ……(3) That is, the ignition position is relative to the rotational speed N. Changes linearly. Advance angle starting rotation speed N ₂ is C ₁ , V _r1 , I ₁
and I ₁ ', and by adjusting these, the advance start rotation speed can be adjusted. For example, by adjusting the resistance value of the variable resistor 21 and adjusting the discharge current I ₁ ', the advance start rotation speed N ₂ can be adjusted. Further, the advance end rotation speed N ₄ can be adjusted by adjusting any one of C ₁ , V _r1 and I ₁ .

(2) Speed region of N ₆ ≦N < N ₁₀ The resistance value of variable resistor 27 is R, capacitor 1
Assuming that the charging current of No. 3 is I ₃ and the capacitance of capacitor 13 is C ₃ , the ignition position θ _N and the rotation speed of No. 3
The set value (retard starting rotation speed) N ₆ is given by the following formula.

θ _N = (6C ₃ N/I ₃ ) [RI ₃ {1−exp(−360/6RC ₃
N}−V _r3 ]+(θ ₁ +α)…… ₍ 4) N ₆ = {(360−α)/6RC ₃ }{1/log(RI _3/3
- _r3 )}...(5) Also, the rotational speed at the end of the advance angle operation shown in Figure 4
N ₁₀ is obtained from the following formula.

_exp (-360/ _6RC3N10 ) _-α / _6RC3N10
= 1-V _r3 /RI ₃ ...(6) Here, if the bypass current of the capacitor 13 flowing through the variable resistor 27 is I ₃ ', then θ _N = (θ ₁ + α) + (360-α) (1 −I ₃ ′/I ₃
)−(6C ₃ V _r3 /I ₃ )N……(4a) N ₆ = {(360−α)/6C ₃ V _r3 }(I ₃ −I ₃ ′)……
(5a) N ₁₀ = (1/6C ₃ V _r3 ) {αI ₃ + (360−α) (I ₃ −
I ₃ ′)}……(6a) Here, if I ₃ ′ = I ₃ , that is, if the capacitor 13 is shorted until θ = θ ₆ , and the capacitor 13 is charged with I ₃ only in the period from θ = θ ₆ to θ ₁ . Considering θ _N , N ₆ and
_N10 is as follows.

θ _N = (θ ₁ + α) − {(6C ₃ V _r3 )/I ₃ } N……(4b) N ₆ = 0……(5b) N ₁₀ = αI ₃ /6C ₃ V _r2 ……(6b) In this case, the advance angle characteristic will be different from the characteristic shown in FIG. Moreover, when I ₃ '=0, that is, when the variable resistor 27 is removed, θ _N = (θ ₁ +360) − {(6C ₃ V _r3 )/I ₃ }N ... (4c) N ₆ = {(360−α)/6C ₃ V _r3 }I ₃ ... (5c) N ₁₀ = (60/C ₃ V _r3 ) I ₃ ... (6c).

(3) Speed region of N ₈ ≦N < N ₁₂ If the capacitance of the capacitor 12 is C ₂ , the charging current of the capacitor 12 is I ₂ , and the discharging current is I ₂ ', then the ignition position θ _N and the fourth setting The values (advance angle start rotation speed) N ₈ and advance angle end rotation speed N ₁₂ are given by the following formulas.

θ _N = {(6C ₂ V _r2 )/I ₂ ′}N-(360-α)(
I ₂ /I ₂ ′) + (θ ₁ + α)……(7) N ₈ = (1/6C ₂ V _r2 ) {(360−α) I ₂ − αI ₂ ′
}...(8) N ₁₂ = (1/6C ₂ V _r2 ) (360-α) I ₂ ...(9) In the above example, in the speed range from N ₆ to N ₁₂ , from retarded operation to The transition to advance angle operation is such that the position where the slope of the fall of the terminal voltage _v2 of the second advance angle capacitor 12 is equal to or less than the reference voltage _Vr2 is equal to the second reference position _θ1. rotational speed (advanced angle operation start rotational speed)
The magnitude relationship between N ₈ and the rotational speed (rotational speed at the end of retardation operation) N ₁₀ at which the position where the terminal voltage v ₃ of the retardation capacitor 13 becomes equal to or higher than the reference voltage _Vr3 is equal to the second reference position θ ₁ It varies depending on. That is, when N ₈ <N ₁₀ , the ignition position shifts from retard to advance operation before the ignition position is delayed to θ ₁ as shown in Fig. 4, but when N ₈ = N ₁₀ , as shown in Fig. 5. As shown in A, the ignition position is delayed until the angle θ ₁ and then the advance operation begins. In addition, in the case of N ₈ > N ₁₀ , as shown in FIG. 5B, after retarding the angle to θ ₁ , N ₁₀
In the region of ~ _N8 , the ignition position is fixed at the angle _θ1 , and at the rotational speed _N8 , the ignition position shifts to an advanced angle operation. In the case of Fig. 5A, the set value of the rotational speed at which the retard angle operation shifts to the advance angle operation (fourth set value)
N ₉ is equal to N ₈ and N ₁₀ , and in the case of figure B,
N ₉ will be equal to N ₈ .

Next, referring to FIG. 6, there is shown an example of a circuit embodying the configuration shown in FIG. 1, in which the same parts as those in FIG. 1 are given the same reference numerals.
In the example shown in FIG. 6, the power supply circuit 20 includes an exciter coil 6 and a diode connected in series with the exciter coil and whose anode is grounded.
D ₁ , thyristor SCR ₁ connected in parallel with diode D ₁ with the cathode on the ground side, and thyristor
Zener diode with anode and cathode connected to the gate and anode of SCR ₁ , respectively
ZD ₁ , a resistor R ₁ connected in parallel between the gate cathode of thyristor SCR ₁ , a power supply capacitor C _p whose one end is grounded and the other end is connected to the anode of thyristor SCR ₁ through diode D ₂ , and the anode is grounded. It consists of a diode D ₃ connected in parallel to a series circuit of an exciter coil 6 and a diode D ₁ toward the side. In this power supply circuit, the capacitor C _p is charged to the polarity shown by the induced voltage of the exciter coil 6 in the direction of the broken arrow shown in the figure, and when the induced voltage of the exciter coil 6 reaches the Zener level of the Zener diode ZD ₁ , the thyristor A firing signal is given to SCR ₁ . This causes thyristor SCR ₁ to conduct and limits the terminal voltage of capacitor C _p to a constant value. The constant voltage across capacitor C _p is used as the power supply voltage for the ignition position control circuit.

The switch 25 consists of a transistor _T1 whose emitter is grounded, and resistors _R2 and _R3 for biasing this transistor, and the switches 26 and 30 are transistors whose emitters are grounded.
Consists of T ₂ and T ₃ . The reset switch 54 consists of a resistor R ₄ connected in parallel between the thyristor SCR ₂ and the gate cathode of this thyristor, and a resistor R ₅ connected between the gate of the thyristor SCR ₂ and the non-ground terminal of the signal coil 34. Thus, at the same time that the second signal v _s2 is induced in the signal coil 34, an ignition signal is given to the thyristor SCR ₂ . This causes the thyristor SCR ₂ to conduct and instantly discharges the capacitors 11 to 13. The constant current circuits 17 to 19, 22, and 24 are each composed of a field effect transistor FET and a variable resistor VR connected between the source and gate of this FET, and each constant current value can be adjusted by adjusting the variable resistor VR. It is now possible to adjust the Further, in this example, a resistor R ₆ is connected in parallel between the gate and cathode of the thyristor 4, and a resistor R ₇ is connected between the negative input terminal of the comparator 37 and the ground. Furthermore, the cathode of a diode _D4 whose anode is grounded is connected to the non-grounded terminal of the signal coil 34. The reference voltage generation circuits 38, 44, and 45 each consist of a series circuit of resistors r ₁ , r ₂ , and r ₃ and Zener diodes ZD ₂ , ZD ₃ , and ZD ₄ , and the series circuit of these resistors and Zener diodes is connected to the power supply. The capacitor C is connected in parallel across both ends of _p . The rest of the configuration is the same as that described with reference to FIG. 1, and the same operation as in FIG. 1 is performed.

In the above embodiment, the advance angle capacitor is made up of the first advance angle capacitor 11 and the second advance angle capacitor 12, but this advance angle capacitor may be composed of one capacitor. The terminal voltage of the capacitor is measured by the first and second comparators 41 and 42.
It is also possible to input the . When the advance angle capacitor is configured with one capacitor in this way, the configuration can be simplified because only one circuit for controlling charging and discharging of the advance angle capacitor is provided.

In the above embodiment, the advance angle capacitors 11, 1
2 and the charging start position of the retard capacitor 13,
Although the capacitors are aligned with the second reference position θ ₁ , it is only necessary that charging of these capacitors starts at a position where the phase is advanced by a certain angle than the first reference position θ ₆ . Charging of these capacitors may be started at a certain position whose phase lags behind θ ₆ , for example, at a falling position of the second signal _vs2 .

In the above embodiment, the falling position of the first signal v _s1 coincides with the second reference position θ ₁ (the rising position of the second signal v _s2 ), but the first signal v _s1 It may be arranged to fall at a position where the phase is more advanced than the reference position θ ₁ of No. 2. In this case, by using the rising edge of the first signal v _s1 and the rising edge of the second signal v _s2 ,
By obtaining rectangular wave signals as shown in b and b' of FIGS. 3F to 3F, the same operation as in the above embodiment can be performed.

One embodiment of the present invention has been described above, but in short, the present invention controls the primary current of the ignition coil 2 by the semiconductor switch 4 triggered at the ignition position of the engine, and supplies the ignition current to the secondary side of the ignition coil. An ignition circuit 1 _{that generates} a high voltage of position θ ₁
a signal coil 34 for generating a second signal v _s2 at
An ignition device for an internal combustion engine, comprising an ignition position control circuit 10 that receives the first signal v _s1 and the second signal v _s2 as input to control the operating position of the semiconductor switch 4 to control the ignition position, (a) advance angle capacitors 11 and ₁₂ ; (b) retard angle capacitor 13; The advance angle capacitors 11 and 12 are charged and discharged at a constant time constant from the first reference position θ ₆ to the second reference position θ ₁ and are instantaneously discharged at the second reference position θ ₁ . (d) an advance angle charging/discharging control circuit that controls charging/discharging of the signal coil ₃₄ ;
The retarding capacitor 1 is charged in a section from the reference position to the second reference position θ ₁ so as to be charged with a predetermined constant current and instantaneously discharged at the second reference position θ ₁ .
(e) a first comparator 41 that compares the terminal voltage v ₁ of the advance angle capacitor 11 with a first reference voltage V _r1 ;
The terminal voltage of the advance angle capacitor 11 is v ₁
becomes the first reference voltage V _r1 or less, the first
a first lead angle trigger signal generation circuit that outputs a lead angle trigger signal; and the lead angle capacitor 1.
A second comparator 42 is provided to compare the terminal voltage v ₂ of the advance angle capacitor 12 with a second reference voltage V _r2 when the terminal voltage v ₂ of the advance angle capacitor 12 becomes equal to or lower than the second reference voltage V _r2 . a second lead angle trigger signal generation circuit that _outputs a second lead angle _trigger signal; comparator 43
The terminal voltage of the retarding capacitor 13 is v ₃
a retard trigger signal generation circuit that outputs a retard trigger signal when the voltage reaches a third reference voltage _Vr3 or more; The first and second advance angle trigger signals and retard angle trigger signals are input to the trigger signal input terminal of the semiconductor switch 4 only in a specific section from θ 6 _to the second reference position θ ₁ . (h) the second signal v _s2 at the second reference position θ ₁ ;
a low-speed ignition position determination circuit that provides a trigger signal for low-speed ignition position determination to the trigger signal input terminal of the semiconductor switch 4; Setting value
In a low speed region below _N2 , the semiconductor switch 4 is triggered at a substantially constant position by the low speed ignition position determination trigger signal, and the rotational speed N is greater than or equal to the first set value _N2 and less than the second set value _N4 . In the region, the semiconductor switch 4 is triggered by the first advance angle trigger signal to perform an advance angle operation, and the rotational speed N is greater than or equal to the second set value N4 _and less than the third set value _N6 . In the region, the semiconductor switch 4 is triggered at the first reference position, and in the region where the third set value _N6 is greater than or equal to the fourth set value, the semiconductor switch 4 is triggered by the retard trigger signal. The semiconductor switch 4 is triggered by the second advance trigger signal to perform the advance angle operation in a region where the fourth setting value N9 is higher than the fourth set value _N9 . The third reference voltages V _r1 to V _r3 , the charge/discharge currents I ₁ , I ₁ ', I ₂ , I ₂ ' of the advance angle capacitors 11 and 12, and the charging time constant of the retard angle capacitor 13 are It is characterized by the fact that it is set.

With the above configuration, according to the present invention, the ignition position is kept substantially constant in a low speed region where the engine rotational speed is less than the first set value, and the ignition position is kept substantially constant in a low speed region where the engine rotational speed is less than the first set value and less than the second set value. The ignition position is advanced in the range of , and the ignition position is fixed at the maximum advance position in the range of the second set value or more and less than the third set value, and the ignition position is fixed at the maximum advance position than the third set value or more and less than the fourth set value. It is possible to obtain complex advance and retard characteristics in which the ignition position is retarded in the region and the ignition position is advanced again in the region equal to or higher than the fourth set value. Furthermore, since the ignition position is electronically controlled, the ignition position can be precisely controlled in response to the complex ignition characteristics required by the engine.

[Brief explanation of drawings]

FIG. 1 is a connection diagram showing the basic configuration of an embodiment of the present invention, FIG. 2 is a block diagram expressing the basic configuration of FIG. 1 as a logic circuit, and FIGS. A waveform diagram showing voltage waveforms of various parts of the embodiment shown in the figure for different rotational speeds, FIG. 4 is a diagram showing an example of ignition characteristics obtained by the present invention,
5A and 5B are diagrams schematically showing other different examples of ignition characteristics obtained by the present invention, and FIG. 6 is a circuit diagram showing an embodiment embodying the embodiment of FIG. 1. be. DESCRIPTION OF SYMBOLS 1... Ignition circuit, 2... Ignition coil, 3... Capacitor, 4... Semiconductor switch, 6... Exciter coil, 10... Ignition position control circuit, 11...
...First advance angle capacitor, 12...Second advance angle capacitor, 13...Retard angle capacitor, 1
4, 15, 16, 31, 32, 33, 35, 3
6,51-55...Diode, 17,18,1
9, 22, 24...constant current circuit, 25, 26, 3
0...Switch, 28, 29, 39...Resistance, 3
7...Comparator, 38, 44, 45...Reference voltage generation circuit, 41-43...First to third comparators, 5
4... Reset switch, V _r1 to V _r3 ... 1st
~Third reference voltage.

Claims (1)

[Claims] 1. An ignition circuit that controls the primary current of an ignition coil by a semiconductor switch triggered at the ignition position of the engine to obtain a high voltage for ignition on the secondary side of the ignition coil; a signal coil that generates a first signal at a first reference position corresponding to the advance angle position and a second signal at a second reference position corresponding to the ignition position at low speeds of the engine; An ignition device for an internal combustion engine, comprising an ignition position control circuit that receives a signal and a second signal as input and controls a position at which the semiconductor switch is operated to thereby control an ignition position, the ignition device comprising an advance angle capacitor and a retard angle capacitor. Then, using the output of the signal coil as an input, charging is performed with a constant current for a certain period up to the first reference position, and discharging at a certain time constant from the first reference position to the second reference position. an advance angle charging/discharging control circuit that controls charging and discharging of the advance angle capacitor so as to instantaneously discharge the lead angle capacitor at the second reference position; retard charging and discharging that controls charging and discharging of the retard capacitor so that the section from the first reference position to the second reference position is charged with a predetermined constant current and is instantaneously discharged at the second reference position; a control circuit; and a first comparator that compares the terminal voltage of the advance angle capacitor with a first reference voltage. a first lead-angle trigger signal generation circuit that outputs a lead-angle trigger signal; and a second comparator that compares a terminal voltage of the lead-angle capacitor with a second reference voltage. a second lead-angle trigger signal generation circuit that outputs a second lead-angle trigger signal when the terminal voltage of the retard capacitor becomes equal to or lower than a second reference voltage; a retard trigger signal generation circuit that includes a third comparator for comparison with a reference voltage and outputs a retard trigger signal when the terminal voltage of the retard capacitor becomes equal to or higher than the third reference voltage; Controlled by the output of the signal coil, the first and second advance angle trigger signals and retard angle trigger signals trigger the semiconductor switch only in a specific section from the first reference position to the second reference position. a gate circuit for allowing a signal to be input to a signal input terminal; and a low-speed point ignition for providing a trigger signal for determining the low-speed point ignition position to a trigger signal input terminal of the semiconductor switch by the second signal at the second reference position. a position determining circuit, in a low speed region where the rotational speed of the engine is less than a first set value, the semiconductor switch is triggered by the trigger signal for determining the ignition position at low speed, and when the rotational speed is equal to or higher than the first set value. In a region where the rotational speed is less than the second set value, the semiconductor switch is triggered by the first advance angle trigger signal to perform an advance angle operation, and the rotational speed is greater than or equal to the second set value and less than the third set value. In the region, the semiconductor switch is triggered at the first reference position, and in the region above the third set value and less than the fourth set value, the semiconductor switch is triggered by the retard trigger signal and retards. operation is performed, and the first to third reference voltages are set so that the semiconductor switch is triggered by the second advance angle trigger signal and the advance angle operation is performed in a region equal to or higher than the fourth set value. An ignition device for an internal combustion engine, wherein a charging/discharging current of the advance angle capacitor and a charging time constant of the retard angle capacitor are set. 2. The advance angle capacitor includes a first capacitor and a second capacitor, and the advance angle charge/discharge control circuit includes a first charge/discharge control circuit that controls charging and discharging of the first capacitor, and a first charge/discharge control circuit that controls charging and discharging of the first capacitor. and a second charge/discharge control circuit that controls charging and discharging of the second capacitor, and the terminal voltages of the first and second capacitors are determined by the first and second comparators, respectively. The ignition device for an internal combustion engine according to claim 1, wherein the ignition device is compared with a reference voltage.