JP3149709B2 - Ignition device for internal combustion engine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ignition device for an internal combustion engine which calculates an ignition position by an integral operation.

[0002]

2. Description of the Related Art An ignition device for an internal combustion engine in which an ignition position is calculated by an integral operation, an ignition circuit for generating a high voltage for ignition when an ignition signal is given, and a maximum advance position of the internal combustion engine And a signal coil for generating a first signal and a second signal respectively reaching a threshold value at a minimum advance position, and an ignition signal at an ignition position of the internal combustion engine controlled by the first signal and the second signal. And an ignition position control device for generating the ignition position.

The signal coil is provided in a signal generator attached to the internal combustion engine, and assuming that the engine is moving at a constant speed, as shown by a solid line in FIG. A first signal Vs1 and a second signal Vs2 that reach the threshold value Vt at the maximum advance position θ1 and the minimum advance position θ2, respectively, are generated. The positions where these signals are generated are determined by the mechanical configuration of the signal generator.

When the first signal Vs1 reaches a threshold value, the ignition position control device instantaneously charges the first integration capacitor to a certain voltage, and then adds the first integration capacitor with a certain time constant. A first integration circuit for performing an integration operation for charging to generate a first integration voltage Vi1 as shown in FIG. 2C across the first integration capacitor; and a second signal V
When s2 occurs, an integration operation for charging the second integration capacitor with a constant time constant is started, and a second integration voltage Vi2 as shown in FIG. 2 (C) is generated across the second integration capacitor. A second integrating circuit for causing the first and second integrating capacitors to instantaneously discharge when the second signal Vs2 reaches a threshold, a first integrating voltage Vi1 and a second integrating circuit. An ignition position calculation circuit for generating an advanced position ignition position signal when the first integrated voltage Vi1 exceeds the second integrated voltage Vi2 by comparing the voltage with the voltage Vi2; And an ignition signal supply circuit that supplies an ignition signal to the ignition circuit when the second signal Vs2 reaches a threshold value.

In the low speed region of the engine, the integration constant is set so that the first integrated voltage Vi1 cannot exceed the second integrated voltage Vi2 as shown by the solid line in FIG. 2C. The ignition position signal generation circuit for the advance angle region cannot generate the ignition position signal. In this state, the second signal Vs2 generated by the signal coil at the minimum advance position θ2
When a threshold value is reached, an ignition signal is given to the ignition circuit.

The time required to charge the first integration capacitor and the second integration capacitor becomes shorter as the engine speed increases, so that the maximum of the first integration voltage Vi1 and the second integration voltage Vi2 becomes maximum. Although the value decreases as the rotation speed increases, the rotation speed of the second integration circuit having a longer integration interval is more affected by the rotation speed than the first integration circuit having a shorter integration interval. The rate of decrease of the integrated voltage with the rise is greater in the second integration circuit than in the first integration circuit. When the rotation speed of the engine exceeds a certain value, the first integrated voltage V is set at a position where the phase is advanced from the minimum advance position.
i1 exceeds the second integrated voltage Vi2, and when the first integrated voltage Vi1 exceeds the second integrated voltage Vi2, the ignition position signal for the advance angle region is generated. The position where the first integrated voltage exceeds the second integrated voltage advances as the rotation speed increases. Therefore, the position at which the ignition position signal for the advance angle region is generated advances as the rotation speed increases, and the ignition position advances as the rotation speed increases. When the rotation speed reaches the advance end rotation speed, the first integral voltage Vi1 exceeds the second integral voltage Vi2 at the maximum advance position θ1, and the advance operation ends.

[0007]

In the above conventional ignition device, if the crankshaft of the engine rotates at a constant speed, the characteristic of the ignition position θi with respect to the rotation speed of the engine is represented by a broken line abcce in FIG. −fgh, and the characteristic that the ignition position is advanced from the minimum advance position θ2 to the maximum advance position θ1 in the region where the rotation speed is from N2 to N4 is obtained.

However, in an actual engine (actual machine), the speed decreases as the piston approaches the top dead center in the compression stroke, and the rotation speed increases in the explosion stroke. Even when the rotation is maintained, the rotational movement of the engine during one rotation is microscopically observed.
The rotation speed is not constant, and the rotation speed of the engine changes as shown in FIG. 2A with respect to the rotation angle θ. In addition to such fluctuations in the rotational speed, there is actually a fluctuation in the average rotational speed due to the fluctuation in the load, so that it cannot be said that the actual internal combustion engine is performing a constant speed motion. In order to make the ignition characteristic of the actual machine the desired characteristic, it is necessary to accurately predict the fluctuation of the rotation speed near the top dead center of the crankshaft of the actual machine, but this speed fluctuation varies depending on the operating state or load. Therefore, it is difficult to accurately predict. Therefore, in general, an ignition device is designed so that desired ignition characteristics can be obtained when a crankshaft is rotated at a constant speed by a motor in a laboratory.

Assuming that the rotational speed of the engine fluctuates in the actual machine as shown in FIG. 2A, the second signal V generated at the minimum advance angle .theta.2 set near the top dead center of the engine is obtained.
Since the generation time of s2 is later than the generation time of the signal Vs2 in the case where the crankshaft of the engine is moving at a constant speed, the time at which the second integration circuit is reset is delayed.
Of the integrated voltage Vi2 is delayed. The waveform of the second signal Vs2 'indicated by a broken line in FIG. 2B shows an apparent waveform when the rotation speed decreases near the top dead center as shown in FIG. Since the position where the signal generator attached to the engine generates a signal is determined by the mechanical configuration of the signal generator, the position where the second signal Vs2 is generated depends on the rotation angle of the engine, depending on the rotation angle. Is always constant (= .theta.2) irrespective of the operation, but the circuit operation apparently lags behind the actual generation position .theta.2, as shown by the waveform Vs2 'shown by the broken line in FIG. 2B. Since this is the same as that occurring at the position θ2 ', it is shown as such in FIG.

If the generation of the second signal is delayed as shown by the waveform Vs2 'shown by the broken line in FIG. 2B, the reset of the second integration circuit is delayed, and the rise of the second integrated voltage Vi2 is delayed. . On the other hand, since the time at which the first signal Vs1 is generated does not change, the time at which the first integrated voltage Vi1 rises is the same as when the constant velocity motion is performed. Therefore, if the constant velocity motion is performed, the first integrated voltage Vi1 becomes the second integrated voltage V1.
Even in the low-speed region where i2 cannot be exceeded, FIG.
When the rotation speed decreases near the top dead center as shown in FIG. 2A, as shown by the broken line in FIG.
At the position .theta.a advanced from 2, the state where the first integrated voltage Vi1 exceeds the second integrated voltage Vi2 occurs, and the ignition position is advanced to the position .theta.a advanced from the minimum advanced position .theta.2.

As described above, in the conventional ignition device, when the engine crankshaft is designed to move at a constant speed and the desired ignition characteristic is obtained, the rotation speed lower than the actual advance start rotation speed N2 is obtained. Since the advance of the ignition position is started at the speed, the ignition characteristic of the actual machine is represented by a broken line abef in FIG.
−gh. In this case, the characteristics of the portion be are not constant, and in an actual engine, a straight line b
The ignition characteristic fluctuates in a region surrounded by -e and the broken line bce.

As described above, in the conventional ignition device, the ignition position in the low-speed region fluctuates due to the fluctuation of the rotation speed of the engine.
Depending on the operating state of the engine, the ignition position may be in an over-advanced state at low speed, so that it may not be possible to stably operate the engine.

[0013] The object of the present invention is to provide a control system in which the crankshaft of the engine is moving at a constant speed, and the rotation speed of the crankshaft decreases in the process of the piston approaching the top dead center.
It is an object of the present invention to provide an ignition device for an internal combustion engine that can stabilize an operation state of an engine while keeping an ignition position constant in a low speed region.

[0014]

According to the present invention, there is provided an ignition circuit for generating a high voltage for ignition when an ignition signal is applied;
A signal coil for generating a first signal and a second signal that respectively reach a threshold value at a maximum advance position and a minimum advance position of the internal combustion engine, and the internal combustion engine controlled by the first signal and the second signal And an ignition position control device for generating an ignition signal at the ignition position of the internal combustion engine.

In the present invention, the ignition position control device charges the first integrating capacitor to a constant voltage when the first signal reaches a threshold value, and then charges the first integrating capacitor to a constant value. A first integration circuit for performing an integration operation for additional charging with a time constant to generate a first integration voltage across the first integration capacitor, and a second integration capacitor that is fixed when a second signal is generated A second integration circuit for starting an integration operation for charging with a time constant of, and generating a second integration voltage across the second integration capacitor; and a second integration circuit when the first signal reaches a threshold value. A third integration circuit for starting an integration operation for charging the third integration capacitor with a constant time constant to generate a third integration voltage across the third integration capacitor; When the first to third integration condition A reset circuit that instantaneously discharges the first integrated voltage and a first integrated voltage and a second integrated voltage, and when the first integrated voltage exceeds the second integrated voltage, generates an ignition position signal for the advance angle region. An ignition position calculation circuit that generates the ignition signal; an ignition signal supply circuit that supplies an ignition signal to the ignition circuit when an ignition position signal for an advance angle region is generated or when the second signal reaches a threshold value; An ignition signal mask circuit for comparing the integrated voltage with a reference voltage and preventing the ignition signal from being supplied from the ignition signal supply circuit to the ignition circuit when the third integrated voltage is higher than the reference voltage.

When the rotation speed of the internal combustion engine is lower than the advance start rotation speed, the third integrated voltage exceeds the reference voltage at a position advanced in phase from the position where the advance position ignition position signal is generated, The third integration circuit is controlled so that the position where the ignition position signal for the advance angle region is generated when the rotation speed of the engine reaches the advance start rotation speed coincides with the position where the third integrated voltage reaches the reference voltage. A constant and a reference voltage were set.

[0017]

As described above, the first integration capacitor and the second integration capacitor
In addition to the first and second integration circuits for generating the first integration voltage and the second integration voltage which are used to charge the integration capacitors of A third integration circuit for charging the third integration capacitor with a constant time constant from the time when the signal of 1 reaches the threshold value to the time when the second signal reaches the threshold value; An ignition signal mask circuit for preventing an ignition signal from being supplied to the ignition circuit when the voltage is higher than the reference voltage, wherein a third integrated voltage is provided when the rotation speed of the engine is lower than the advance start rotation speed. Where the reference voltage is exceeded at a position where the phase is advanced from the generation position of the ignition region ignition position signal, and the advance region ignition position signal is generated when the engine speed reaches the advance start rotation speed. And where the third integrated voltage exceeds the reference voltage When the constant of the third integration circuit and the reference voltage are set so that the following equation is satisfied, the charge start time of the third integration capacitor is hardly affected by the fluctuation of the rotation speed near the top dead center. The rotation speed (advance start rotation speed) at which the region ignition position signal starts to be given to the ignition circuit as the ignition signal can be kept constant, and the ignition position in the region below the advance start rotation speed is the minimum advance position. Can be fixed. Therefore, the ignition characteristics (the characteristics of the ignition position with respect to the rotational speed N) are the same as those of the case where the crankshaft of the engine performs a constant speed movement, the case where the speed decreases near the top dead center, and abc- in FIG. dfgh,
In the actual machine, it is possible to prevent an over-advanced angle state from occurring at a low speed and making the operation state of the engine unstable.

[0018]

FIG. 1 shows an embodiment of the present invention. In FIG. 1, reference numeral 1 denotes an exciter coil provided in a magnet generator attached to an engine, and 2 denotes a signal generator provided in a signal generator attached to the engine. Signal coil. The exciter coil 1 has a voltage Ve1 of a positive half cycle synchronized with the rotation of the engine.
And an AC voltage consisting of a negative half cycle voltage Ve2, and the signal coil 2 has polarities at the maximum advance position θ1 and the minimum advance position θ2 of the engine, respectively, as shown by the solid line in FIG. Are different from each other in the first signal Vs1 and the second signal Vs2.
Occurs. Although the polarities of the first and second signals are arbitrary, in the present embodiment, the first signal Vs1 is a negative signal, and the second signal Vs2 is a positive signal.

One end of the exciter coil 1 is grounded, and the non-grounded terminal of the exciter coil is connected to one end of an ignition energy storage capacitor 3 through a diode Do. The other end of the capacitor 3 is connected to one end of a primary coil 4a of the ignition coil 4, and the other end of the primary coil 4a is grounded together with one end of a secondary coil 4b of the ignition coil. A discharge thyristor 5 having a cathode directed to the ground side is connected between one end of the capacitor 3 and the ground, and an ignition coil 4
A diode 6 whose cathode is directed to the ground side is connected to both ends of the primary coil 4a. The non-ground side terminal of the secondary coil of the ignition coil 4 is connected to the non-ground side terminal of a spark plug 7 attached to a cylinder of an engine (not shown). In this example, the ignition energy storage capacitor 3, the ignition coil 4, the thyristor 5, the diode 6, and the ignition plug 7 constitute an ignition circuit 8, and the exciter coil 1 and the diode Do constitute the ignition circuit. A power supply unit is configured. The ignition circuit 8 is known as a capacitor discharge type circuit. In this ignition circuit, when the exciter coil 1 generates a voltage Ve1 of a positive half cycle in the direction of the solid arrow shown in FIG. Is charged to the polarity. When the ignition signal Vg is applied to the gate of the thyristor 5 at the ignition position of the engine, the thyristor 5 conducts, so that the electric charge of the capacitor 3 is discharged through the thyristor 5 and the primary coil 4a of the ignition coil 4, and Large magnetic flux changes occur in the iron core. This change in magnetic flux induces a high voltage in the secondary coil of the ignition coil 4, and sparks are generated in the ignition plug 7.

The output of the exciter coil 1 is also supplied to a power supply circuit 9, and the voltage of the positive half cycle of the exciter coil is converted into a constant DC voltage by the power supply circuit 9. The power supply circuit 9 includes, for example, a power supply capacitor charged through a diode and a current limiting element (resistor) by the output of the positive half cycle of the exciter coil 1 and a Zener diode for maintaining a constant voltage across the power supply capacitor. Can be configured. The output voltage of the power supply circuit 9 is used as a power supply voltage of the ignition position control device 11 described later. A diode 10 whose anode is directed to the ground side is connected to both ends of the exciter coil 1, so that the voltage of the negative half cycle of the exciter coil 1 is short-circuited by the diode 10.

In this example, the voltage of the positive half cycle of the exciter coil 1 is supplied to the power supply circuit 9, but the voltage Ve2 of the negative half cycle of the exciter coil 1 is converted into a constant DC voltage by the power supply circuit 9. It can also be configured to do so.

The ignition position control device 11 includes a diode 12
, 13, a first waveform shaping circuit 14 and a second waveform shaping circuit 15, an integration control circuit 16, and a first integration circuit 1
7 and a second integrating circuit 18, a third integrating circuit 19,
It comprises a reset circuit 20, an ignition position calculation circuit 21, an ignition signal supply circuit 22, and an ignition signal mask circuit 23.

The first waveform shaping circuit 14 comprises a parallel circuit of a resistor R1 and a capacitor C1, and the second waveform shaping circuit 15 comprises a parallel circuit of a resistor R2 and a capacitor C2. A resistor R1 constituting the first waveform shaping circuit 14
One end of the parallel circuit including the capacitor C1 is grounded, and the other end is connected to the base of the NPN transistor TR1. The emitter of the transistor TR1 is connected to the non-ground side terminal of the signal coil 2 through a diode 12 whose anode is directed to the transistor TR1, and the collector is a resistor R3.
Through the PNP transistor TR2. The emitter of the transistor TR2 is connected to the non-grounded output terminal (positive output terminal) of the power supply circuit 9, and the collector is connected to the anode of the diode D1.
A resistor R4 is connected between the emitter and the base of the transistor TR2, and a capacitor C3 is connected between the cathode of the diode D1 and the ground. Transistors TR1 and T
An integration control circuit 16 is composed of R2, resistor R3, R4, diode D1, and capacitor C3.

The first waveform shaping circuit 14 includes the signal coil 2
Generates a pulse signal Vp1 when the first signal Vs1 at which the voltage Vt1 exceeds the voltage (threshold) Vt across the capacitor C1 at the maximum advance position θ1 of the engine. The pulse width of this pulse signal is equal to the time during which the first signal Vs1 exceeds the voltage across the capacitor C1. When the first waveform shaping circuit 14 outputs the pulse signal Vp1, a base current is supplied to the transistor TR1, so that the transistor TR1 is turned on. As a result, the transistor TR2 conducts, and the capacitor C3 is instantaneously charged with the output voltage of the power supply circuit 9 through the transistor TR2 and the diode D1.

The resistance R constituting the second waveform shaping circuit 15
One end of the parallel circuit composed of the capacitor 2 and the capacitor C2 is connected to the non-ground side terminal of the signal coil 2 through a diode 13 whose anode faces the signal coil 2, and the other end is connected to the base of a transistor TR4 whose emitter is grounded. . The collector of the transistor TR4 is connected to the cathodes of diodes D2 to D5, and the anode of the diode D2 is connected to the non-ground terminal of the capacitor C3.
A reset circuit 20 is constituted by the transistor TR4 and the diodes D2 to D5.

The second waveform shaping circuit outputs a pulse signal Vp2 when the second signal Vs2 exceeds the voltage (threshold) Vt across the capacitor C2 at the minimum advance position. The pulse width of the pulse signal Vp2 is equal to the time during which the second signal Vs2 exceeds the voltage across the capacitor C2. Since the pulse signal Vp2 is applied to the base of the transistor TR4, while the pulse signal Vp2 is being generated, the transistor TR4 is turned on, as shown in FIG.

The first integration circuit 17 includes an integration control circuit 16
Resistors R5 and R6 connected across capacitor C3
, A NPN transistor TR3 having a collector connected to the non-ground side terminal of the capacitor C3, a first integrating capacitor Ci1 connected between the emitter of the transistor TR3 and ground, and a collector connected between the collector and emitter of the transistor TR3. And the resistance R7. The non-ground terminal of the capacitor Ci1 is connected to the anode of the diode D3 of the reset circuit 20.

In the first integration circuit, when the first signal Vs1 reaches a threshold value and the transistor TR2 of the integration control circuit 16 is turned on, the capacitor C3 is instantaneously charged to the polarity shown in FIG. A base current is applied to the transistor TR3 through the resistor R5 by the voltage across C3, and the transistor TR3 is turned on. As a result, the first integration capacitor Ci1 is instantaneously charged.
When the voltage across the first integrating capacitor Ci1 becomes equal to the voltage across the resistor R6 (the voltage between the base and the emitter of the transistor TR3), the transistor TR3 is turned off. Thereafter, the voltage across the capacitor C3 causes the resistor R7 to turn off.
Through the first integration capacitor Ci1.
When the second waveform shaping circuit 15 generates a pulse signal at the minimum advance position .theta.2 and the transistor TR4 of the reset circuit 20 becomes conductive, the electric charge of the capacitor C3 is discharged instantaneously through the diode D2 and the transistor TR4, and the first integration is performed. The electric charge of the capacitor Ci1 is discharged instantaneously through the diode D3 and the transistor TR4. Therefore, at both ends of the first integrating capacitor Ci1, as shown in FIG. 2C, the voltage rises instantaneously to a constant voltage at the maximum advance position θ1 and then rises at a constant slope to the minimum advance position θ2. A first integrated voltage Vi1 having a waveform returning to zero at the minimum advance position θ2 is obtained.

The second integrating circuit 18 comprises a resistor R8 having one end connected to the output terminal of the power supply circuit 9, and a second integrating capacitor Ci2 connected between the other end of the resistor R8 and ground. The non-ground side terminal of the integrating capacitor Ci2 is connected to the anode of the diode D4 of the reset circuit.

In the second integration circuit, the second integration capacitor Ci2 is charged with a constant time constant through the resistor R8 at the output of the power supply circuit 9. Second integration capacitor C
The electric charge of i2 is instantaneously discharged through the diode D4 and the transistor TR4 when the second signal Vs2 reaches the threshold level and the transistor TR4 is turned on at the minimum advance position θ2. Therefore, as shown in FIG. 2 (C), each minimum advance position θ is provided at both ends of the second integration capacitor Ci2.
A second integrated voltage Vi2 having a waveform which rises at a constant gradient from 2 and returns to zero at the next minimum advance position θ2 is obtained.

The third integration circuit 19 includes an integration control circuit 16
A diode D6 having an anode connected to the cathode of a diode D1 through a resistor R9, and a third integrating capacitor Ci3 connected between the cathode of the diode D6 and ground.
The non-ground side terminal of the third integrating capacitor Ci3 is connected to the anode of the diode D5 of the reset circuit.

The third integration capacitor Ci3 is charged with a constant time constant through the resistor R9 and the diode D6 by the voltage across the capacitor C3 of the integration control circuit 16, and when the transistor TR4 of the reset circuit 20 becomes conductive, the diode D5 and the transistor Discharged through TR4. Therefore, the two ends of the third integration capacitor Ci3 are connected to each other in FIG.
As shown in (G), a third integrated voltage Vi3 having a waveform rising linearly from the maximum advance position θ1 and returning to zero at the minimum advance position θ2 is obtained.

The ignition position calculation circuit 21 comprises a comparator CP1 in which a first integrated voltage Vi1 and a second integrated voltage Vi2 are input to an inverting input terminal and a non-inverting input terminal, respectively.
The comparator CP1 compares the first and second integrated voltages, and when the first integrated voltage Vi1 is equal to or lower than the second integrated voltage Vi2, sets the potential of its output terminal to a high level (H level). When the integrated voltage Vi1 exceeds the second integrated voltage Vi2, the potential of the output terminal is set to a low level (L level). In this example, the potential of the output terminal of the comparator CP1 changes from H level to L level.
The fall to the level is defined as the advance position ignition position signal. When it is assumed that the crankshaft of the engine is moving at a constant speed (when the crankshaft of the engine is rotated at a constant rotational speed by a motor in a laboratory), the first integrated voltage Vi1 and the second Has a waveform as shown by the solid line in FIG. 2C, and the first integrated voltage Vi1 cannot exceed the second integrated voltage Vi2.
The potential Vcp1 of the output terminal 1 holds the H level state (a state in which the ignition position signal for the advance angle region is not generated) as shown by the solid line in FIG. On the other hand, FIG.
As shown in the above, in the case of an actual machine in which the rotation speed of the crankshaft decreases in the process of the piston approaching the top dead center, the threshold level is reached at the minimum advance position near the top dead center. Since the signal generation position is apparently delayed like Vs2 'in FIG. 2B, the first integrated voltage Vi1 and the second integrated voltage Vi2 are generated.
2C is as shown by a broken line in FIG. 2 (C), and the first integrated voltage Vi1 is obtained at the position .theta.a which is ahead of the minimum advance position .theta.2.
Exceeds the second integrated voltage Vi2. At this time, the potential Vcp1 of the output terminal of the comparator CP1 becomes L level at the position of the angle .theta.a, as shown by the broken line in FIG. .

The ignition signal supply circuit 22 includes a PNP transistor TR having an emitter connected to the output terminal of the power supply circuit 9.
5, a resistor R10 connected between the base of the transistor TR5 and the output terminal of the comparator CP1,
An anode is connected to the collector of R5 through a resistor R11, a diode D7 whose cathode is connected to the gate of the thyristor 5 of the ignition circuit, and a diode D8 whose anode is connected to the output terminal of the comparator CP1. The cathode is connected to the collector of the transistor TR4 of the reset circuit 20.

In this ignition signal supply circuit 22, when the comparator CP1 generates the ignition position signal for the advance angle region (when the potential of the output terminal of the comparator CP1 becomes L level) or when the minimum advance angle θ2 When the second signal Vs2 reaches the threshold value and the transistor TR4 is turned on, the transistor TR5 is turned on and the ignition signal Vg is supplied to the ignition circuit 8.

The ignition signal mask circuit 23 comprises a series circuit of resistors R12 and R13 connected between the output terminals of the power supply circuit 9, and outputs a reference voltage Vr across the resistor R13. And a comparator CP2 connected to the anode of the diode D7 of the ignition signal supply circuit.
The third integration voltage Vi3 and the reference voltage Vr are input to the inverting input terminal and the non-inverting input terminal of the comparator CP2, respectively. The comparator CP2 compares the third integrated voltage Vi3 with the reference voltage Vr, and when the third integrated voltage Vi3 is higher than the reference voltage Vr, sets the potential Vcp2 of its output terminal to the L level to set the ignition signal supply circuit 22 From the ignition circuit 8 to the ignition signal Vg
To be given.

According to the present invention, when the rotational speed of the internal combustion engine is lower than the advance start rotational speed N3, the third integrated voltage Vi3 is used to generate the advance position ignition position signal (comparator CP).
(The position where the output Vcp1 changes from H level to L level) exceeds the reference voltage Vr at a position where the phase has advanced, and when the engine speed reaches the advance start rotation speed N3, the ignition for the advance angle region is performed. The constant of the third integration circuit 19 and the reference voltage Vr are set so that the position where the position signal is generated coincides with the position where the third integrated voltage Vi3 exceeds the reference voltage Vr.

Next, the operation of the above embodiment will be described in relation to the operation of the conventional ignition device with reference to the waveform diagrams shown in FIGS. FIG. 2A is a diagram showing a change in rotation speed when the rotation movement of the engine is viewed microscopically,
FIG. 3B is a waveform diagram showing the first and second signals generated by the signal coil. FIG. 2 (C) shows the first and second
7D is a waveform chart showing the on / off operation of the transistor TR4 of the reset circuit. Further, FIGS. 2E and 2F show comparators C
FIG. 7G is a waveform diagram showing a change in the potential of the output terminal of P1 and a waveform of an ignition signal Vg supplied to an ignition circuit in a conventional ignition device. FIG. 7G shows a third integrated voltage Vi3 and a reference voltage Vr.
FIG. 6 is a waveform chart showing the waveform of FIG. FIGS. 2H and 2I show the potential of the output terminal of the comparator CP2 and the ignition signal V applied to the ignition circuit in the embodiment of the present invention, respectively.
FIG. 9 is a waveform diagram showing a waveform of g.

In FIG. 2, the waveform shown by the solid line shows the waveform when the crankshaft of the engine is moving at a constant speed, and the waveform shown by the broken line shows that the piston is dead top as shown in FIG. It shows an apparent waveform when the rotation speed decreases in the process of approaching a point.

The conventional ignition device corresponds to the embodiment shown in FIG. 1 in which the third integration circuit 19 and the ignition signal mask circuit 23 are removed. In this type of ignition device, when the crankshaft of the engine is moved at a constant speed, in the low speed region of the engine, as shown by the solid line in FIG. Since the voltage Vi2 is set so as not to exceed the voltage Vi2, in the low-speed region, FIG.
As shown by the solid line in (E), the output Vcp1 of the comparator CP1 of the ignition position calculation circuit 21 holds the H level, and no ignition position signal for the advance angle region is generated. In this state, when the second signal Vs2 reaches the threshold level at the minimum advance position .theta.2 and the transistor TR4 is turned on, the transistor TR5 of the ignition signal supply circuit 22 is turned on and the ignition circuit 8 is turned on.
To the ignition signal.

Since the time for charging the first integration capacitor Ci1 and the time for charging the second integration capacitor Ci2 become shorter as the engine speed increases, the first integration voltage Vi1 and the second integration voltage Vi2. Is lower as the rotation speed increases, but the second integration circuit 18 having a longer integration interval is more affected by the rotation speed than the first integration circuit 17 having a shorter integration interval. The rate of decrease of the integrated voltage with the increase in the rotation speed is larger in the second integration circuit than in the first integration circuit. When the rotational speed of the engine exceeds a certain value, the first integrated voltage Vi1 exceeds the second integrated voltage Vi2 at a position where the phase is advanced from the minimum advance position θ2, and the output of the comparator CP1 becomes L level. To become
The position at which the ignition position calculation circuit 21 generates the ignition position signal for the advance angle region advances as the rotational speed increases. In the conventional ignition device without the ignition signal mask circuit 23, the advance operation is started from the rotation speed at which the ignition position calculation circuit 21 starts generating the advance region ignition position signal. When the rotation speed reaches the advance end rotation speed, the first integrated voltage Vi1 exceeds the second integrated voltage Vi2 at the maximum advance position θ1, and the advance operation stops.

In the conventional ignition device, assuming that the rotation speed of the engine decreases as shown in FIG. 2A while the piston approaches the top dead center, the minimum advance angle set near the top dead center of the engine is set. Since the generation time of the second signal Vs2 generated at the position θ2 is later than the generation time of the signal Vs2 when it is assumed that the crankshaft of the engine is moving at a constant speed, the apparent appearance of the second signal Vs2 is The waveform becomes like the waveform Vs2 'shown by the broken line in FIG. 2B, and the operation of the circuit is the same as that generated at the apparent position .theta.2' delayed from the actual generation position .theta.2. . When such a state occurs, the charging start time of the second integration capacitor Ci2 is delayed as described above, and therefore, even in a region lower than the advance rotation start rotational speed, the first integration position is set at the position θa advanced from the minimum advance position θ2. The integration voltage Vi1 is the second
2 (C), a state exceeding the integral voltage Vi2 (a state indicated by a broken line in FIG. 2 (C)) occurs. Therefore, as shown by a broken line in FIG. V
g is given, and the ignition characteristics at this time are as shown by a polygonal line abeffgh in FIG. 3, and the ignition position is advanced even in a low speed region.

On the other hand, as shown in the embodiment of the present invention shown in FIG.
And the rotation speed of the internal combustion engine is set to the advance start rotation speed N
When the third integrated voltage Vi3 is lower than 3 (the output Vcp1 of the comparator CP1 is high).
Position at which the phase exceeds the reference voltage Vr at a position where the phase is advanced from the position where the level changes to the L level, and where the ignition position signal for the advance angle region is generated when the engine speed reaches the advance start rotation speed N3. If the constant of the third integrating circuit 19 and the reference voltage Vr are set so that the position where the third integrated voltage Vi3 reaches the reference voltage Vr coincides with the position where the third integrated voltage Vi3 reaches the reference voltage Vr, the piston approaches the top dead center in the compression process. The first integral voltage Vi1 exceeds the second integral voltage Vi2 at a position .theta.a that is ahead of the minimum advance position .theta.2 in a region lower than the advance start rotational speed N3 due to a decrease in the rotational speed of the engine in the process of moving forward. Comparator CP1
When the state of the third integrated voltage Vi3 exceeds the reference voltage Vr when the state of the output becomes low (the ignition area signal for the advance angle region is generated), the ignition signal mask circuit 23 Since the output of the comparator CP2 is at the L level, the comparator CP2 is at a position advanced from the minimum advance position θ2.
All of the ignition signals output from the first side through the transistor TR5 of the ignition signal supply circuit 22 are bypassed from the ignition circuit 8 through the output stage of the comparator CP2.

Therefore, even if the ignition position calculation circuit 21 generates an advance position ignition position signal at a position ahead of the minimum advance position θ2 at a rotational speed lower than the advance start rotational speed N3, the ignition position The ignition signal is not given to the ignition circuit 8 by the signal, and the ignition signal is generated as shown in FIG.
When the third integrated voltage Vi3 becomes zero at the position of the rotation angle .theta.2 'at which the second signal Vs2 reaches the threshold value as indicated by the broken line, and the output of the comparator CP2 becomes H level. Can be The position of the rotation angle θ 2 ′ is an apparent position viewed from above the circuit operation, and is actually the minimum advance position θ.
Equals 2. Therefore, according to the present invention, even if the rotational speed decreases in the process of the piston approaching the top dead center, the ignition operation is always performed at the minimum advance position θ2 in the region below the advance start rotational speed N3. Will be

The position where the third integrated voltage Vi3 exceeds the reference voltage Vr is delayed as the rotational speed increases. When the rotational speed of the engine reaches the advance start rotational speed N3, the comparator CP1 sets the advance angle. Position θx at which the region ignition position signal is generated
And the position where the third integrated voltage Vi3 reaches the reference voltage Vr. In a region exceeding the advance start rotation speed, the third integration voltage Vi3 is delayed at a position later than the position θx at which the comparator CP1 generates the advance position ignition position signal.
Exceeds the reference voltage Vr, the comparator CP1
Generates an ignition position signal for the advanced angle region, the ignition signal supply circuit 22 supplies an ignition signal to the ignition circuit 8,
The ignition position advances as the rotational speed increases.

Since the position where the first signal Vs1 reaches the threshold value is not affected by the rotation speed near the top dead center of the engine, the rising position of the third integrated voltage Vi3 is the rotation speed of the rotation speed near the top dead center. Not affected. Therefore, the position at which the third integrated voltage Vi3 exceeds the reference voltage Vr is not affected by the fluctuation of the rotation speed near the top dead center of the engine, so that the advance start rotation speed N3 is determined by the constant of the third integration circuit. With the reference voltage Vr, it can be set irrespective of the fluctuation of the rotation speed near the top dead center.

Therefore, according to the embodiment of the present invention, the characteristic of the ignition position with respect to the rotational speed is that the characteristic shown in FIG. , The broken line abc- in FIG.
dfgh, and it is possible to prevent an over-advance angle state from occurring in a low-speed region in an actual machine.

In the above embodiment, when the transistor TR4 of the reset circuit is turned on at the minimum advance position, the transistor TR5 of the ignition signal supply circuit 22 is turned on to generate an ignition signal in a low speed region. However, an ignition signal for a low-speed region may be supplied to the ignition circuit 8 from the output side of the waveform shaping circuit 15 through a diode.

[0049]

As described above, according to the present invention, the first integration capacitor and the second integration capacitor are charged respectively to determine the generation position of the ignition position signal for the advance angle region. In addition to the first and second integration circuits for generating the integration voltage and the second integration voltage, the third integration is performed between the time when the first signal reaches the threshold value and the time when the second signal reaches the threshold value. A third integration circuit that charges the integration capacitor with a constant time constant; an ignition signal mask circuit that prevents an ignition signal from being supplied to the ignition circuit when the voltage of the third integration capacitor is higher than a reference voltage; When the rotation speed of the engine is lower than the advance start rotation speed, the third integrated voltage exceeds the reference voltage at a position where the phase is advanced from the position where the advance position ignition position signal is generated, and When the rotation speed reaches the advance rotation speed Since the constant of the third integration circuit and the reference voltage are set so that the position where the ignition position signal for the angular region is generated and the position where the third integrated voltage exceeds the reference voltage are set, the ignition position for the advanced angle region The rotation speed at which the supply of the ignition signal is started by the signal (advance start rotation speed) can be kept constant, and the ignition position in a region lower than the advance start rotation speed can be fixed to the minimum advance position. it can. Therefore, the ignition characteristics can be kept constant both when the crankshaft of the engine moves at a constant speed and when the speed decreases near the top dead center. Can be prevented from becoming unstable.

[Brief description of the drawings]

FIG. 1 is a circuit diagram showing an embodiment of the present invention.

FIG. 2 is a waveform chart for explaining the operation of the embodiment of FIG.

FIG. 3 is a diagram showing ignition characteristics obtained by a conventional ignition device and an ignition device according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Exciter coil 2 Signal coil 3 Ignition energy storage capacitor 4 Ignition coil 5 Thyristor 7 Spark plug 8 Ignition circuit 11 Ignition position control device 12, 13 Diode 14 First waveform shaping circuit 15 Second waveform shaping circuit 16 Integration control circuit Reference Signs List 17 first integration circuit 18 second integration circuit 19 third integration circuit 20 reset circuit 21 ignition position calculation circuit 22 ignition signal supply circuit 23 ignition signal mask circuit

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-62-271965 (JP, A) JP-A-63-131868 (JP, A) JP-A-62-233478 (JP, A) JP-A-1- 240770 (JP, A) (58) Field surveyed (Int. Cl. ⁷ , DB name) F02P 3/08 302 F02P 5/155 F02P 11/02 303

Claims (1)

(57) [Claims] An ignition circuit for generating a high voltage for ignition when an ignition signal is applied, and a first signal and a second signal which reach threshold values at a maximum advance position and a minimum advance position of the internal combustion engine, respectively. 2. An ignition system for an internal combustion engine, comprising: a signal coil for generating a second signal; and an ignition position control device controlled by the first signal and the second signal to generate the ignition signal at an ignition position of the internal combustion engine. The ignition position control device, when the first signal reaches a threshold value, instantaneously charges the first integration capacitor to a certain voltage, and then additionally charges the first integration capacitor with a certain time constant. A first integration circuit for performing an integration operation to generate a first integration voltage across the first integration capacitor, and a second integration capacitor having a constant time constant when the second signal is generated. Start integration operation to charge To generate a second integrated voltage across the second integrating capacitor.
And an integration operation for charging the third integration capacitor with a constant time constant when the first signal reaches a threshold value, and a third integration capacitor is provided across both ends of the third integration capacitor. A third integration circuit for generating an integration voltage; a reset circuit for instantaneously discharging the first to third integration capacitors when the second signal reaches a threshold value; and a first integration voltage. And the second integrated voltage,
An ignition position calculation circuit for generating an advanced position ignition position signal when the integrated voltage of the second output signal exceeds the second integrated voltage; and An ignition signal supply circuit for providing an ignition signal to the ignition circuit when a threshold value is reached; and comparing the third integrated voltage with a reference voltage, and when the third integrated voltage is higher than the reference voltage, the ignition signal An ignition signal mask circuit for preventing an ignition signal from being supplied from the supply circuit to the ignition circuit, wherein the third integrated voltage is in the advance range when the rotation speed of the internal combustion engine is lower than the advance start rotation speed. A position where the reference voltage is exceeded at a position where the phase is advanced from the position where the ignition position signal is generated, and the advance region ignition position signal is generated when the rotational speed of the engine reaches the advance start rotational speed; Where the integrated voltage of Preparative the third integrating circuit constants and the reference voltage and the ignition device, characterized in that is configured to match.