JPS6217672B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a signal generating device that generates a signal that determines the ignition position of a non-contact ignition device for an internal combustion engine, and particularly to an internal combustion engine used when controlling the ignition position according to the intake negative pressure of the engine. The present invention relates to a signal generator for a non-contact ignition device.

Conventionally, a mechanical governor was used to change the ignition position of the engine according to the rotational speed, and an ignition position detector was used to advance the ignition position according to the negative pressure in the intake pipe. The ignition position was determined by mechanically moving the ignition position, but mechanical systems had the drawbacks of being extremely complex and expensive, and having a short lifespan. In addition, when the ignition position is determined using a conventional signal generator, when the accelerator is released and the engine is braked while the engine is rotating at high speed,
Since the intake negative pressure is large, the ignition position advances and approaches the engine's maximum output point, which has the disadvantage of suppressing the engine braking effect.

An object of the present invention is to advance the ignition position based on both the engine rotation speed and the intake negative pressure using a purely electronic configuration, and in addition, when the engine is rotating at high speed, the negative pressure is large (engine braking state). A signal generator for a non-contact ignition system for an internal combustion engine, which can avoid the engine's maximum output and increase the engine braking effect by retarding the ignition position to the position at the start of advance when the engine reaches its maximum output. Our goal is to provide the following.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The signal generating device of the present invention will be explained in detail below with reference to the drawings.

FIG. 1 shows an embodiment of the present invention in which an ignition timing signal is generated to be supplied to an ignition system for a 4-cycle, 2-cylinder internal combustion engine that alternately ignites two cylinders at intervals of 180 degrees. The ignition device 1 used in the embodiment includes an ignition coil i _g , a spark plug p _g attached to the first cylinder of the engine,
A first ignition circuit consisting of transistors TR _x , TR _y and resistors R _x , R _y , R _z , an ignition coil i _g ′, a spark plug p _g ′ attached to the second cylinder of the engine, and a transistor TR _x ′, TR _y ′ and resistance R _x ′, R _y ′, R _z
and a second ignition circuit consisting of . This ignition device is a known current interrupt type ignition device, and the first and second ignition circuits operate with a phase difference of 180° from each other. Since the operations of both ignition circuits are the same, the operation of the first ignition circuit will be explained. Although not shown, the collector of the transistor TR _y is connected to the positive terminal of a battery (not shown) through the primary coil of the ignition coil i _g , and the base of the transistor TR _y is connected to the positive terminal of the battery through a resistor R _z . Therefore, _{in the figure} , if _{transistor TR} A large current flows through the transistor TR _y . Next, when the ignition timing signal _S1 is applied through the resistor _Rx at the ignition position of the first cylinder, the transistor _TRx becomes conductive, and the transistor _TRy is turned off. This cuts off the primary current of the ignition coil i _g , causing a large magnetic flux change in the iron core of the ignition coil and inducing a high voltage in the secondary coil of the ignition coil.
This high voltage generates a spark in the spark plug p _g to ignite the first cylinder. In exactly the same way, when the ignition timing signal _S2 is applied to the transistor _TRx ' through the resistor _Rx ', a high voltage is generated in the secondary coil of the ignition coil _ig ', and the second cylinder is ignited.

The signal generating device of the present invention generates the ignition timing signals S ₁ and S ₂ while controlling them in accordance with the rotational speed of the engine and the intake negative pressure, and an example of its configuration will be described below with reference to the drawings. In Fig. 1, P ₁ generates a negative half-cycle signal e ₂ at a position where the phase is advanced by an angle θ ₁ from the top dead center TDC of the first cylinder of the engine, and an angle θ ₆ ( This is the first signal coil that generates a positive half-cycle signal e ₁ at a position where the phase is advanced by >θ ₁ ). Further, P ₂ is a second signal coil that generates signals e _{1 ′} and e _{2 ′} with a phase difference of 180 degrees (mechanical angle) with respect to the outputs e ₁ and e ₂ of the first signal coil 2. The first and second signal coils P ₁ and P ₂ are provided in a signal generator SG as shown in FIG. This signal generator includes rising portions 201 and 20 provided at positions 180 degrees apart from each other on the outer periphery of a base plate 200 made of a magnetic material.
Hyaku magnets 202 and 202' and iron core 2 at 1' respectively.
03, 203' and the iron cores 203, 20
A stator 204 with signal coils P ₁ and P ₂ wound around it, respectively, and a hole 20 provided in the center of the base plate 200.
At the end of the cylindrical part 206 always facing the iron core 2
03, 203' and a rotor 208 with a fan-shaped inductor 207 protruding from the opposite side, and the rotor 208 is attached to a shaft (for example, a crankshaft) that rotates in synchronization with the engine. In this signal generator,
The arc angle of the inductor 207 is set to |θ ₆ -θ ₁ |, and the rotor 208 moves in the direction of the arrow shown (clockwise).
When the piston _rotates to The inductor 207 begins to face the iron core of the signal coil, and the inductor 207 comes out of the iron core at a position (second position) that is an angle θ ₁ ahead of the top dead center TDC. Furthermore, the ends of the cores 203, 203' around which each signal coil is wound, facing the inductor, are formed to be sufficiently narrower than the inductor, so that when the inductor 207 begins to oppose the cores 203, 203', Due to the magnetic flux _change when each iron core comes off, signals _{e 1 and}
e ₁ ′, e ₂ , e ₂ ′ occur.

Referring to FIGS. 1 to 29, the signal waveforms of the respective parts indicated by reference numerals 1 to ₂₉ in FIG.
The waveforms of the output signals e ₁ , e ₂ and e ₁ ', e ₂ ' of P ₂ are shown in FIGS. 1 and 2, respectively. Further, FIGS. 6A to 6K show waveforms of important parts when the intake negative pressure V _ac is higher than the set value V _acs . Incidentally, although the angle θ is plotted on the horizontal axes of FIGS. 5 and 6, for convenience of explanation, it is assumed that the engine is in a low speed rotation region in the region of the horizontal axes in the same figures (see FIG. 5, 29). It is assumed that the engine is in the advanced rotation region and the high speed rotation region in the regions , and , respectively. Here, the advanced rotation range is a range in which the ignition position is advanced as the rotational speed increases, and the high-speed rotation range is a range in which the ignition position is fixed at the final advanced position.

In FIG. 1, a positive half-cycle signal e ₁ of the signal coil P ₁ is supplied to a first waveform shaping circuit 102 through a diode 101, and is converted into a pulse signal E ₁ as shown in FIG. 5. Also the signal coil
The signal e ₁ ' of the positive half cycle of P ₂ is connected to the diode 10
3 to the second waveform circuit 104, where it is converted into a pulse signal E ₁ ' as shown in FIG. Furthermore, the negative half-cycle signals e ₂ ′ and e ₂ ′ obtained from the signal coils P ₁ and P ₂ are supplied to the third waveform shaping circuit 107 through diodes 105 and 106, and are outputted as shown in FIG. It is converted into a pulse signal _E2 . Of these pulse signals, E ₁ and
E ₁ ' is a first position signal indicating a first position (a position at an angle θ ₆ from top dead center) that is approximately equal to the maximum advance position of the engine or slightly advanced from the maximum advance position; ₁ is the first position signal for the first cylinder, and E ₁ ' is the first position signal for the second cylinder. In addition, E ₂ is the second position corresponding to the minimum advance angle position of the engine (angle θ ₁ from top dead center
This is a second position signal indicating the position of . Among the pulse signals, the pulse signal E ₁ is supplied to the set terminal S of the first RS flip-flop circuit 108 and also supplied to one input terminal of the NAND circuit 109, and the pulse signal E ₁ ' is supplied to the set terminal S of the first RS flip-flop circuit 108. It is supplied to the reset terminal R of the circuit 108 and also to the other input terminal of the NAND circuit 109. The output of the NAND circuit 109 is supplied to the set terminal S of the second RS flip-flop circuit 111 through an inverter 110, and the pulse signal _E2 is supplied to the reset terminal R of the flip-flop circuit 111 through an inverter 112. The output ₂ obtained at the negative output terminal of the flip-flop circuit 111 is supplied to the base of a transistor 114 through a resistor 113, and an integrating capacitor C ₁ is connected in parallel between the collector and emitter of the transistor 114. Capacitor C ₁
is connected to a DC power supply (not shown) through a constant current circuit 115, and while the transistor 114 is in a cut-off state, the capacitor _C1 is charged with a constant current _i1 and an integral operation is performed. Resistor 113, transistor 1
14, the capacitor C ₁ and the constant current circuit 115 constitute a first integration circuit IT ₁ , and this integration circuit provides a triangular wave signal V _c1 with a constant slope.
On the other hand, pulse signal E ₂ is supplied to the base of transistor 117 through capacitor 116.
A resistor 160 is connected in parallel between the base and emitter of the transistor 117, and an integrating capacitor _C2 is connected in parallel between the collector and emitter of the transistor 117. The collector of transistor 118 is connected to one end of capacitor _C2 located on the collector side of transistor 117, and transistor 1
The emitter of transistor 18 is connected to the collector of transistor 119. One end of a resistor 120 is connected to the emitter of the transistor 119;
A resistor 121 is connected between the other end and the base of the transistor 118. Resistors 120 and 12
The connection point 1 is connected to a DC power supply (not shown) and to the base of a transistor 119 through a diode 122 and a resistor 123. The output terminal of an operational amplifier 125 is connected to the base of the transistor 119 through a resistor 124. A resistor 12 is connected to the positive input terminal of the operational amplifier 125.
The output signal of the negative pressure detector 127 is inputted through 6, and the negative input terminal of the operational amplifier 125 is directly connected to its output terminal.

The negative pressure detector 127 generates an output that changes linearly according to the engine's intake negative pressure, and includes, for example, a diaphragm that responds to the engine's intake negative pressure and a transducer that converts the displacement of this diaphragm into an electrical signal. It consists of Yusa. In this embodiment, the negative pressure detector 127 outputs a negative pressure detection signal voltage _Vo that increases linearly in substantially direct proportion to the intake negative pressure, as shown in FIG.

The transistor 117, the capacitor _C2 , and the transistor ₁₁₈ constitute a second integrating circuit IT2, and the signal _Q2 from the positive logic output terminal of the flip-flop circuit 111 is input to the base of the transistor 118 through a resistor 128. The transistor 118 has a signal _Q2 at a low level (hereinafter referred to as L).
It's called a level. ), and during the period when this transistor 118 is conducting, the operational amplifier 1
The capacitor C ₂ is charged by the negative pressure detection signal _Vo amplified by the transistor 25 and the transistor 119, and an integration operation is performed.

The signals V _c1 and V _c2 obtained from the first and second integrators IT ₁ and IT ₂ respectively are sent to the first comparator 12
9 is input. This first comparator 129 outputs a first advance angle signal _E3 having an advance angle corresponding to the intake negative pressure.
The signal _E3 is at a high level (hereinafter referred to as H level) during the period when the output voltage V _c1 of the first integrating circuit is equal to or higher than the output voltage V _c2 of the second integrating circuit. The period other than that is at L level. The first advance signal _E3 obtained from the first comparator 129 is applied to the third RS flip-flop circuit 130.
is input to the set terminal S of the flip-flop circuit 130, and the inverter 112 is input to the reset terminal R of the flip-flop circuit 130.
The output signal E ₂ ' of is input. This signal E ₂ ' is an inversion of the second position signal E ₂ and corresponds to the second position signal. A negative logic output terminal of the flip-flop circuit 130 is connected to a resistor 13 at the base of a transistor 132 whose emitter is grounded.
An integrating capacitor _C3 is connected in parallel between the collector and emitter of the transistor 132 via a resistor 133. Integrating capacitor C ₃ is connected to a DC power supply (not shown) through constant current circuit 134, and while transistor 132 is in a cut-off state, capacitor C ₃ is charged with constant current i ₃ to perform an integrating operation. transistor 132,
Resistor 133, capacitor C ₃ and constant current circuit 13
4 constitutes a third integrating circuit _IT3 .

On the other hand, the pulse signal E ₂ is passed through a capacitor 135 to a transistor 136 whose emitter is grounded.
is supplied to the base. transistor 136
A resistor 137 is connected in parallel between the base and emitter of the transistor, and an integrating capacitor 138 is connected in parallel between the collector and emitter of the transistor. transistor 140
The emitter of the transistor 140 is connected to a DC power supply (not shown) and connected to the transistor 140 via a resistor 141.
The base is connected to the positive logic output terminal of the flip-flop circuit 111 through a resistor 142. A fourth integration circuit _IT4 is configured by the transistor 136, the capacitor 138, the constant current circuit 139, and the transistor 140,
When transistor 136 is in a cutoff state and transistor 140 is in a conduction state, capacitor 13
8 is charged with a constant current _i4 and an integral operation is performed. The output voltage V _c4 of the fourth integrating circuit is input to the second comparator 143 together with the output voltage V _c3 of the third integrating circuit. Second comparator 143
generates a second advance angle signal _E4 having an advance angle corresponding to both the intake negative pressure and the rotational speed, and this signal _E4 remains at H level during the period when _Vc3 ≧ _Vc4 . . The output V _c4 of the fourth integration circuit IT ₄ is also the reference voltage V _r obtained from the reference voltage generation circuit 145.
is input to the third comparator 146, and the output _E5 of the comparator 146 is the period H during which V _c4 ≧V _r
become the level.

The output of the negative pressure detector 127 is also connected to a resistor 163.
The reference voltage V _x obtained from the reference voltage generation circuit 162 is input to the other input terminal of the fourth comparator 161. Here, the reference voltage V _x
is set to a value corresponding to the set value V _acs , which is the minimum value of the negative pressure (absolute value) of the engine's intake negative pressure V _ac during engine braking, and V _ac < V _acs (V _o <
V _x ), the output E ₁₂ of the fourth comparator 161 is at H level, and when V _ac ≧V _acs (V _o ≧ V _x ), that is, during engine braking, the output of the fourth comparator 161 is at H level. E ₁₂ is now at L level.

The output E ₄ of the second comparator 143 is input to the NAND circuit 147 together with the positive logic output Q ₃ of the third flip-flop circuit 130.
The output E ₆ is input to the NAND circuit 164 via the inverter 148. The output E ₁₂ of the fourth comparator 161 is also input to the NAND circuit 164, and the output E ₁₃ of the NAND circuit 164 is input to the inverter 1.
65 is input. Output of inverter 165
E ₇ is input to the NAND circuit 149 together with the output E ₅ of the third comparator 146, and the output E ₈ of the NAND circuit 149 is input to the NAND circuit 15 together with the pulse signal E ₂ '.
It is entered as 0. An ignition position signal E ₉ for determining the ignition position is obtained on the output side of the NAND circuit 150, and this signal E ₉ is sent to the NAND circuit 151 and 1.
52 is input. NAND circuit 151 and 1
The positive logic output Q1 and the negative logic output ₁ of the first flip-flop circuit 108 are input to the other input terminal of the flip-flop circuit 52 _, respectively. Nando circuit 15
The outputs E ₁₀ and E ₁₁ of 1 and 152 are respectively the fourth
Set terminal S of RS flip-flop circuit 153
and the reset terminal R, and the positive logic output _Q4 and the negative logic output of the flip-flop circuit 153.
₄ are adapted to be used as ignition timing signals S ₁ and S ₂ , respectively.

In the above embodiment, the second position advanced by an angle θ ₁ from the top dead center TDC of the engine is the ignition position in the low speed region of the engine. Further, angles θ ₂ to _{θ 4} are final advance angles (angles from top dead center TDC to the ignition position at the time of final advance) when the intake negative pressures are V _ac0 to V _ac2 , respectively. θ ₆ is the angle at which the first position signal E ₁ is generated (the angle calculated from TDC), and this θ ₆ is an angle slightly larger than the maximum advance angle. The angle θ ₁ is also the ignition position when engine braking is applied at high speed, and when the intake negative pressure V _ac exceeds the set value V _acs (V _ac ≧ V _acs ), the rotational speed increases. The ignition position is retarded to an advance start angle θ ₁ by canceling the advance caused by the increase in negative pressure.

In the above embodiment, the NAND circuit 109, the inverter 110, the flip-flop circuit 111,
The inverter 112 and the first integrating circuit IT ₁ output the first position signals E ₁ , E ₁ ' and the second position signal E _{2 .}
and from the first position θ ₆ to the second position θ
The first triangular wave signal V that rises at a constant slope to ₁
A first triangular wave generation circuit that generates _c1 is configured,
Mainly NAND circuit 109, inverter 110,
112, flip-flop circuit 111, second integration circuit IT ₂ , voltage detector 127 and operational amplifier 1
25, the first position signal, the second position signal, and the negative pressure detection signal are input, and a predetermined gradient according to the negative pressure detection signal is applied between the second position θ ₁ and the first position θ ₆ . The second triangular wave signal V rises and maintains its peak value from the first position to the second position.
A second triangular wave signal generation circuit that generates _c2 is configured. The first and second triangular wave signal generation circuits and the first comparator 129 generate a first advance angle signal having an advance angle corresponding to the intake negative pressure of the engine.
A first advance angle circuit that generates E ₃ is configured. In addition, the inverter 112, the flip-flop circuit 130, and the third integration circuit _IT3 input the second position signal _E2 and the first advance angle signal _E3 so that the first triangular wave signal coincides with the second triangular wave signal. A third triangular wave signal generation circuit is configured to generate a second triangular wave signal by adding a constant bias voltage to a triangular wave rising at a constant slope from the third position to the second position _θ1 , and circuit 109, inverters 110, 112, flip-flop circuit 11
The first and fourth integrating circuits IT ₄ input the first and second position signals and rise at a constant slope from the second position θ ₁ to the first position θ ₆ , and from the first position θ ₆ . A fourth triangular wave signal generation circuit is configured to generate a fourth triangular wave signal that maintains the peak value until the second position _θ1 . and the third and fourth triangular wave signal generation circuits and the second comparator 143.
A second advance angle circuit that outputs a second advance angle signal having an advance angle corresponding to both the intake negative pressure and the rotational speed is configured. Furthermore, a third comparator 14
6 and the NAND circuit 149, when the engine rotation speed N is lower than the advance start rotation speed N ₁ , the ignition position is fixed at a constant angle θ ₁ before top dead center, so that the second advance angle is A prohibition circuit is configured that prohibits the ignition position from being determined by the signal _E4 , and in the area where this circuit prohibits the ignition position from being determined, the ignition position signal _E9 is set by the signal _E2 ' which becomes L level at an angle _θ1 . is generated, and in a region where inhibition is not applied (a region where N≧ _N1 ), an ignition position signal _E9 is generated by the second advance angle signal _E4 . Also, a fourth comparator 161, a NAND circuit 16
4 and the inverter 165, the second advance angle signal _E6 is used to fix the ignition position at a constant angle _θ1 before top dead center when the intake negative pressure _Vac is larger than the set value _Vacs . An inhibit circuit is configured to inhibit the ignition position from being determined. Furthermore, the flip-flop circuit 108, the NAND circuits 151 and 152, and the flip-flop circuit 153
The ignition position signal E ₉ is distributed to the ignition circuits of the first and second cylinders, and the first and second ignition timing signals S ₁ and S ₂ are generated at the ignition positions of the first and second cylinders, respectively. A distribution circuit is configured to generate this. Note that in the case of a single-cylinder internal combustion engine, the above-mentioned distribution circuit is naturally unnecessary, and in this case, in the above embodiment, the NAND circuit 15
The ignition position signal obtained on the output side of 0 can be used as it is as the ignition timing signal.

Next, the operation of the above embodiment will be explained. When the engine rotates and the signals shown in FIGS. 1 and 2 are induced in the signal coils P ₁ and P ₂ , respectively, the waveform shaping circuit 10
5 from 2, 104 and 107 respectively.
and 6, pulse signals E ₁ , E ₁ ', and E ₂ are obtained. Angle θ from the top dead center of one cylinder of the engine
When the pulse signal (first position signal) _E1 is generated at a position advanced by ₆ , the flip-flop circuit 1
08 is set, the signal _Q1 becomes H level and the signal becomes L level as shown in FIGS. 7 and 8. The pulse signal E ₁ is also a NAND circuit 10
In order to set the flip-flop circuit 111 through the inverter 110 and the flip-flop circuit 110, the positive logic output _Q2 of the flip-flop circuit 111 becomes H level.
₂ becomes L level. ₂ becomes L level, the transistor 114 is cut off, so the capacitor C ₁ of the first integrating circuit IT ₁ is charged with a constant current i ₁ , and the first integrator circuit IT ₁ as shown in FIG. A triangular wave signal V _c1 is obtained. When the pulse signal (second position signal) E ₂ is generated at a position advanced by an angle θ ₁ (<θ ₆ ) from the top dead center of one of the cylinders, the flip-flop circuit 111 is reset and the signal Q ₂ goes low. At the same time, signal ₂ becomes H level. When the signal ₂ becomes H level, the transistor 114 becomes conductive and the capacitor
_C1 is discharged and the first integration circuit _IT1 is reset. A similar operation is performed for the other cylinder after the pulse signal E ₁ ' is generated until the pulse signal E ₂ is generated. Therefore, the first triangular wave signal V _c1 changes from the angle θ ₆ to θ ₁ before the top dead center TDC of each cylinder.
The waveform rises at a constant slope until then and returns to zero at an angle _θ1 .

On the other hand, in the second integrator IT ₂ , the pulse signal
When E ₂ is applied to transistor 118, transistor 118 conducts, discharging capacitor C ₂ , and then when pulse signal E ₂ becomes zero, transistor 118 turns off. Also at this time the signal
Since Q ₂ becomes L level, transistor 118 becomes conductive and charges capacitor C ₂ with current i ₂ . The charging current i ₂ of this capacitor C ₂ changes according to the negative pressure detector 127. That is, when the negative pressure is zero (V _ac0
), the input of the operational amplifier 125 is at its minimum and its output is small, so the collector current of the transistor 119 is at its maximum and the charging current i ₂ is at its maximum. When the negative pressure increases and the output of operational amplifier 125 increases, the collector current of transistor 119 decreases and charging current i ₂ decreases. Therefore, the voltage V _c2 (second triangular wave signal) across capacitor C ₂ is:
As shown by symbols a to d in FIG. 5, the gradient changes depending on the negative pressure. In the same figure, negative pressures a, b, c, and d are V _ac0 , V _ac1 , V _ac2 , and V _{a ,} respectively.
The case of _c3 (V _ac0 <V _ac1 <V _ac2 <V _ac3 ) is shown. The capacitor C ₂ is charged until the pulse signal E ₁ ' is generated and the flip-flop circuit 111 is set.
After C2 is set, transistor 118 is cut off, so that the terminal voltage of capacitor _C2 is kept constant. Then, when pulse signal E ₂ occurs, transistor 117 conducts for a short time to discharge capacitor C ₂ . The flip-flop circuit 111 is reset by this pulse signal _E2 , so that the transistor 118 becomes conductive and charging of the capacitor _C2 is resumed, and the same operation as described above is repeated thereafter.
Therefore, the _second
As shown in FIG. 5, the triangular wave signal V _c2 rises at a predetermined slope depending on the negative pressure from a position at an angle θ ₁ before the top dead center of one cylinder of the engine, and reaches the top dead center of the other cylinder. It stops rising at the position of front angle θ ₆ (position where pulse signal E ₁ ' is generated), and the position of angle θ ₁ before top dead center of the other cylinder (position where pulse signal E ₂ is generated)
The waveform will maintain a constant value until

First triangular wave signal V _c1 and second triangular wave signal V _c2
is compared by the comparator 129, and the output E ₃ (first advance angle signal) of the period comparator 129 where V _c1 ≧V _c2 becomes L level. This signal _E3 is L
Flip-flop circuit 13 at the fall of level
0 is set and the positive logic output _Q3 becomes H level, and when the pulse signal _E2 is generated, the flip-flop circuit 130 is reset and the signal _Q3 becomes L level. The negative logic output ₃ of the flip-flop circuit 130 has a waveform that is an inversion of the above _Q3 ,
This signal ₃ is at L level during the period when V _c1 =V _c2 . During the period when this signal ₃ is at L level, the transistor ₁₃ of the third integrating circuit IT3
2 is cut off, capacitor C ₃ is charged with a constant current i ₃ , and the voltage across capacitor C ₃ as shown in FIG.
6, a third triangular wave signal V _c3 is obtained. The capacitor C ₃ is discharged when the signal ₃ becomes H level and the transistor 132 becomes conductive. However, since the resistor 133 is inserted in this discharge circuit, the capacitor C ₃ is not completely discharged, and the resistor 133 is turned on. A residual voltage corresponding to the voltage drop occurs. Therefore, the third triangular wave signal V _c3 is shown in FIG.
As shown in FIG. 6, the waveform becomes a waveform to which a constant bias voltage V _p3 is applied.

As shown in FIG. 5, the period during which V _c1 ≧ V _c2 is longer as the intake negative pressure is larger, and _shorter as the intake negative pressure is smaller. The charging period of C ₃ ) also increases as the intake negative pressure increases, and decreases as the intake negative pressure decreases. Therefore, the waveforms of the third triangular wave signal V _c3 are as shown in waveforms a, b, and c in FIG. 16 for the intake negative pressures V _ac0 , V _ac1 , and V _ac2 , respectively.

On the other hand, in the fourth integration circuit _IT4 , after the pulse signal _E2 is generated, the flip-flop circuit 111
During the period when the output signal Q ₂ is at the L level, the capacitor C ₄ is charged by the constant current i ₄ , and the signal Q ₂ is at the H level.
The terminal voltage of capacitor _C4 is held constant during the period when the voltage level is reached. Therefore, the fourth triangular wave signal V _c4 obtained from this fourth integrating circuit has the same waveform as the second triangular wave signal V _c2 , but
Since the capacitor _C4 of the integrating circuit is charged with a constant current, the waveform of the fourth triangular wave signal _Vc4 does not change due to negative pressure. However, the period for charging capacitor _C4 becomes shorter as the engine speed increases, so as the engine speed increases,
The wave height value of the triangular wave signal V _c4 becomes gradually lower as shown by symbols A, B, and C in FIG. Here, A, B, and C indicate the waveforms of the fourth triangular wave signal in the low speed region, advanced angle rotation region, and high speed region, respectively.

Third triangular wave signal V _c3 and fourth triangular wave signal V _c4
is compared by the comparator 143, and the output _E4 of the comparator 143 is at L level during the period when _Vc4 ≧ _Vc3 . The output (second advance angle signal) E ₄ of this comparator 143 is supplied together with the signal Q ₃ to the NAND circuit 147, and the output E ₆ of the NAND circuit 147 is as shown in FIG.
As shown in FIG. 9, it becomes L level only when both Q ₃ and E ₄ are at H level. This NAND circuit 1
47 is inverted by an inverter ₁₄₈ to become a signal E ₇ shown in FIG. 5, which is input to a NAND circuit 164. The output voltage of the negative pressure detector 127 is also compared with a reference voltage V _x by a fourth comparator 161 . Output of the fourth comparator 161
_E12 is at H level when V _ac < V _acs , and V _ac ≧
It becomes L level when V _acs . When V _ac <V _acs , the H level output signal E ₁₂ of the fourth comparator 161 is
It is input to a NAND circuit 164 together with the output of the inverter 148, and the output of this NAND circuit 164 is
_E13 goes to the L level when the signal _E6 is at the L level, and goes to the H level when the signal _E6 is at the H level.
This H level signal E ₁₃ is inverted by the inverter 165 and becomes an L level signal E ₇ while V _ac ≧V
_acs , the output _E12 of the fourth comparator 161 is at the L level as shown in FIG. 6A, and this L level signal is input to the NAND circuit 164 together with the output of the inverter 148. When the signal E ₁₂ is at L level, the NAND circuit 16 is activated as shown in FIG. 6B.
4's output _E13 is H regardless of the level of signal _E6 .
level. Therefore, when V _ac ≧V _acs , signal E ₇ becomes L level regardless of the level of signal E ₆ and output E ₈ of NAND gate 149 becomes H level. (See FIG. 6C.) The fourth triangular wave signal V _c4 is also applied to the reference voltage V _r (fifth
See Figure 17. ), and as shown in _{FIG .}
The output _E5 becomes L level. This signal _E5 is input to the NAND circuit 149 together with the signal _E7 ,
The output signal E ₈ of the NAND circuit 149 is the signal E ₅ and
When both _E7 are at H level, it becomes L level. The output signal E ₈ of this NAND circuit 149 is input to the NAND circuit 150 together with the signal E ₂ ′, and the output (ignition position signal) E ₉ of the NAND circuit 150 is the signal E ₂ while the signal E ₈ is at H level. ’ becomes L level and while signal E ₂ ’ is at H level, signal E ₈
When the signal reaches the L level, each becomes the H level. The signal E ₉ is input to the NAND circuits 151 and 152 together with the signals Q ₁ and ₁ , and the output signal E ₁₀ of the NAND circuit 151 is when the signals Q ₁ and E ₉ are both high.
level, it becomes L level, and NAND circuit 15
The output signal E ₁₁ of No. 2 becomes L level when both signals ₁ and E ₉ are at H level. When the signal _E10 falls to the L level, the flip-flop circuit 153 is set, and the positive logic output signal _Q4 of the flip-flop circuit 153 goes to the H level, providing the ignition timing signal _S1 for the first cylinder. Furthermore, when the signal _E11 falls to the L level, the flip-flop circuit 153 is reset, and the negative logic output signal
₄ becomes H level, and the ignition timing signal _S2 for the second cylinder is given. Ignition of these cylinders is performed when the output E ₉ (ignition position signal) of the NAND circuit 150 becomes H level.

Here, the advance angle characteristics obtained by the above embodiment when V _ac <V _acs will be explained as follows.

(1) Low speed rotation region (N<N ₁ ) In this region, the comparator 146 and the NAND circuit 1
48 and 149, the advance angle operation is prohibited and the ignition position is set at an angle θ before top dead center.
Fixed at position ₁ . This inhibition circuit detects that the rotational speed N is lower than the advance start rotational speed _N1 by utilizing the fact that the fourth triangular wave signal _Vc4 changes depending on the rotational speed of the engine. The fourth triangular wave signal V _c4 is given by V _c4 = a ₄ (180°-α)/(6N) (1), where a ₄ is the slope of V _c4 with respect to the angle θ. This V _c4 is compared with a reference voltage V _r by a comparator 146, where V _r is set to a value expressed by the following equation, which corresponds to the set rotational speed N ₁ .

V _r = a ₄ (180° - α) / (6N ₁ ) ...... (2) In the rotation region of N < N ₁ , since the relationship of V _c4 > V _r exists, the output E ₅ of the comparator 146 is θ ₆ <θ
It is always at the L level in the range of ≦θ ₁ . Therefore, in the range of θ ₆ <θ≦θ ₁ , the NAND circuit 149
The output of the comparator 143 becomes H level regardless of the output of the comparator 143. Here, the angle before top dead center θ ₁
When the signal E ₂ ' goes to the L level at the position, the output E ₉ of the NAND circuit 150 goes to the H level, and Q ₁ goes to the H level.
When it is level, it is the first cylinder, and ₁ is H
When the level is reached, the ignition operation is performed in each of the second cylinders. Therefore, in the region of N<N ₁ , the ignition position is always at a constant angle θ ₁ before top dead center, regardless of the intake negative pressure, as shown in FIGS. 5 and 6.

(2) Advance angle rotation region (N ₁ ≦N≦N ₂ ) In this region, V _c4 ≦V _r is always satisfied, so the output E ₅ of the comparator 146 is always at H level. At this time, the NAND circuit 149 will work as an inverter, and the inhibition will be canceled. Now let the slope of the first triangular wave signal V _c1 be a ₁ and the slope of the second triangular wave signal V _c2 be a ₂ , and the angle θ _i at which V _c1 matches V _c2 is the angle θ as shown in FIG. When measured from position ₆ , V _c1 = (a ₁ θ _i ) / (6N) ...... (3) V _c2 = a ₂ (180° - α) / (6N) ...... (4) (3) , Calculating θ _i from equation (4), θ _i = a ₂ (180°−α)/a ₁ ......(5) Here, the gradient a ₂ of V _c2 is a ₂ = i ₂ / c ₂ ......(6). In this way, a ₂ is determined by the current i ₂ whose value changes according to the negative pressure, so the angle θ _i , that is, the falling position of the first advance signal E ₃ changes according to the intake negative pressure, and the intake negative pressure changes. The higher the pressure, the more the first advance signal
The falling position θ _i of E ₃ advances.

The signal ₃ obtained by operating the flip-flop circuit 130 by the fall of the signal E ₃ at the position θ _i and the signal E ₂ ' generates the third triangular wave signal V _c3 , and the signal Q ₂ generates the fourth triangular wave signal. A signal V _c4 is produced. These two triangular wave signals V _c3 and V _c4 are compared to give advance angle characteristics according to the rotational speed. Here, let the gradients of V _c3 and V _c4 be a ₃ and a ₄ respectively, and the angle at which V _c3 = V _c4 is θ _y
(Angle measured from the position of θ _i ), V _c3 = (a ₃ θ _y ) / (6N) + V _p3 ...... (7) V _c4 = a ₄ (180° - α) / (6N) ... ...(8) From equations (7) and (8), find the angle θ _y at which V _c3 matches V _c4 , θ _y a ₄ (180° − α) / a ₃ − (6NV _p3 ) / a ₃
......(9) becomes. If we change the position of this angle θ _y to the angle θ _f from top dead center TDC, θ _f = θ ₆ −θ _i −θ _y = θ ₆ − (180° − α) (a ₂ /a ₁ +a ₄ / a ₃ ) + (6NV _p3 )/a ₃ ......(10). When V _c3 matches V _c4 at this angle θ _f , period comparator 1 where V _c3 ≧ V _c4
The output E ₄ (second advance angle signal) of the NAND circuit 143 becomes H level, and the output E ₆ of the NAND circuit 147 to which the H level signal Q ₃ is input together with the signal E ₄ becomes L level. This L level signal _E6 is inverted by an inverter 148 to become an H level signal _E7 . When V _ac <V _acs , the fourth comparator 1
Since the output E ₁₂ of the NAND circuit 161 is at H level, the output E ₁₃ of the NAND circuit 164 is the inverted version of the output of the inverter 148 . This NAND circuit 164
The output E ₁₃ is further inverted by the inverter 165 to produce a signal at the same level as the output of the inverter 148.
E becomes ₇ . In this case, _E6 is at L level and the output of inverter 148 is at H level, so the output of inverter 165 also becomes H level. Since the output _E5 of the third comparator 146 is at the H level, the NAND circuit 149 works as an inverter, and the output _E8 of the NAND circuit 149 is at the L level.
Output of NAND circuit 150 (ignition position signal) E ₉
becomes H level, and the ignition operation is performed at the angle θ _f .

The angle θ _f (ignition position in the advanced rotation range) in Equation 10 above is a function of the rotation speed N. Furthermore, in Equation 10, since a ₂ changes according to the intake negative pressure as described above, θ _f also changes depending on the intake negative pressure, and the intake negative pressure is V _ac0 , V _ac1 , and V _ac2
The ignition position in the region of N ₁ ≦N≦N ₂ in the case of (V _ac0 <V _ac1 <V _ac2 ) is shown based on the top dead center TDC as shown by the parallel inclined lines a, b, and c in Fig. 7. become that way.

(3) High-speed rotation area after finishing the advance angle (N>
N ₂ ) In this region, the fourth triangular wave signal V _c4 is smaller than the third triangular wave signal V _c3 , so the output signal E ₄ of the second comparator 143 is always at H level. Therefore, one input terminal of the NAND circuit 147 is always at H level. At this time, since the NAND circuit 147 becomes an inverter, the output signal E ₆ of the NAND circuit 147 becomes a signal obtained by inverting the signal Q ₃ . That is, the output signal E ₆ of the NAND circuit 147 is equal to ₃ . Now, since V _ac <V _acs , the NAND circuit 150 includes an inverter 148,
A signal E ₈ and a signal E ₂ ' equal to ₃ are provided through a NAND circuit 164, an inverter 165, and a NAND circuit 149. Therefore, the output signal E ₉ (ignition position signal) of the NAND circuit 150 becomes an H level signal with a width that is the sum of the width of the signal and the width of the signal E ₂ ′, and in this case, the rising position of the signal E ₉ The ignition position is determined by (the rising position of signal _Q3 ). Flip-flop circuit 130
is the first position whose falling position changes due to intake negative pressure.
Since it is set by the advance angle signal _E3 , the signal
The rising position of Q ₃ also changes depending on the negative intake pressure.
Therefore, the final advanced angle position in the high speed rotation region (N>N ₁ ) when the intake negative pressure is V _ac0 , V _ac1 and V _ac2 is θ ₂ , θ ₄ and θ ₄ (<θ ₆ ) (both angles measured from top dead center), and the larger the negative pressure, the larger the final advance angle.

Combining the above characteristics, the characteristics of the ignition position (angle from top dead center) with respect to the rotational speed N are as shown in Figure 7, and the ignition position is constant up to the set rotational speed N ₁ . This prevents the ignition position from advancing due to intake negative pressure at low speeds, thereby preventing rotation from becoming unstable.

The above explanation is for the case where the value of negative pressure is smaller than V _acs , but when V _ac ≧ V _acs , the output E ₁₂ of the fourth comparator 161 goes to L level as shown in FIG. 6A. Therefore, the output of the NAND circuit 164 is always at H level. As a result, the L level signal E ₇ enters one input terminal of the NAND circuit 149, so the NAND circuit 149
The output _E8 becomes H level. At this time, the NAND circuit 150 acts as an inverter for the signal E ₂ ', and the ignition signal is always generated at a position θ ₁ before the top dead center. That is, the ignition position is retarded to a position of angle _θ1 .

Although a current interrupt type ignition device is shown in FIG. 1, the device of the present invention can be applied in exactly the same way when other types of non-contact ignition devices are used, such as capacitor discharge type ignition devices. can.

In the above embodiment, the set rotational speed _N1 is detected using the fact that the peak value of the fourth triangular wave signal _Vc4 changes depending on the rotational speed, but other speed detection means such as a speed generator are used. You may also do so.

It should be noted that each of the embodiments described above is merely an example of the configuration, and it goes without saying that many modifications can be made to the combinations of logic circuits, etc. without departing from the scope of the present invention.

Furthermore, in the above embodiment, the ignition timing signal for the ignition system for a two-cylinder internal combustion engine is generated, but the same applies when obtaining the ignition timing signal for the ignition system for a single-cylinder internal combustion engine or even a multi-cylinder internal combustion engine. The present invention can be applied to.

In the above embodiment, a negative pressure detector was used in which the output voltage increases linearly as the negative pressure increases, but a negative pressure detector in which the output voltage decreases linearly as the negative pressure increases is used. The present invention can also be carried out using the following methods.

As described above, according to the present invention, the advancing angle can be performed purely electronically in accordance with both the rotational speed of the engine and the intake negative pressure. In particular, according to the second invention, the ignition position can be kept constant regardless of the intake negative pressure in the low-speed rotation region below the set rotation speed, so that the rotation of the engine in the low-speed rotation region can be stabilized. It has the advantage of being able to Furthermore, since the ignition position is retarded when engine braking is applied at high speeds, the effect of engine braking can be increased and the safety of vehicles etc. driven by internal combustion engines can be improved.

[Brief explanation of the drawing]

Figure 1 is a connection diagram showing one embodiment of the present invention, Figure 2 is a connection diagram showing an embodiment of the present invention.
The figure is a block diagram of the signal generator used in the example of Figure 1, Figure 3 is a waveform diagram showing the signal waveform obtained from the signal generator, and Figure 4 is a line diagram showing the output characteristics of the negative pressure detector. Figures 1 to 29 are signal waveform diagrams of various parts of the embodiment shown in Figure 1, Figures 6A to K are signal waveform diagrams of important parts when the intake negative pressure is higher than the set value, and Figure 7 is FIG. 3 is a diagram showing an example of advance angle characteristics when using the device of the present invention. P ₁ , P ₂ ... Signal coil, 108, 111, 13
0,153...Flip-flop circuit, 129,
143,146... Comparator, 109,147,1
48, 149, 150, 151, 152... NAND circuit, 112... Inverter, IT ₁ , IT ₂ ,
IT ₃ , IT ₄ ...integrator circuit, V _c1 ... first triangular wave signal, V _c2 ... second triangular wave signal, V _c3 ... third triangular wave signal, V _c4 ... fourth triangular wave signal.

Claims (1)

[Claims] 1. In a signal generating device that generates an ignition timing signal that determines the ignition position of a non-contact ignition device for an internal combustion engine, a first position that is approximately equal to or slightly advanced from the maximum advance position of the internal combustion engine is set. a circuit that generates a first position signal indicating a position signal indicating a second position corresponding to a minimum advance position of the engine; and a circuit generating a second position signal indicating a second position corresponding to a minimum advance position of the engine; a negative pressure detector that generates an output signal;
a first triangular wave signal generation circuit that generates a first triangular wave signal that increases at a constant slope from the first position to the second position under the control of the first position signal and the second position signal; , the output signal of the negative pressure detector is controlled by the first position signal, the second position signal, and the output signal of the negative pressure detector between the second position and the next first position. a second triangular wave signal generation circuit that generates a second triangular wave signal that rises at a predetermined slope according to the first position and maintains the peak value from the first position to the next second position;
a first comparator that compares the first triangular wave signal and the second triangular wave signal and generates a first advance signal during a period when the first triangular wave signal is larger than the second triangular wave signal; A constant gradient is controlled by the second position signal and the first advance angle signal from a third position where the first triangular wave signal matches the second triangular wave signal to the second position. a third triangular wave signal generating circuit that generates a third triangular wave signal by adding a constant bias voltage to a rising triangular wave; a fourth triangular wave signal generation circuit that generates a fourth triangular wave signal that rises at a constant slope up to a first position and maintains a peak value from the first position to the next second position; a second comparator that compares the third triangular wave signal and the fourth triangular wave signal and outputs a second advance angle signal during a period when the third triangular wave signal is larger than the fourth triangular wave signal; a circuit that generates the ignition timing signal using the second advance angle signal; and a circuit that detects the rotational speed of the engine and generates the ignition timing signal using the second advance angle signal when the rotational speed is lower than a set value. a first prohibition circuit that prohibits generation of the ignition timing signal and generates the ignition timing signal by the second position signal or a signal corresponding to the second position signal; Prohibiting the generation of the ignition timing signal by the second advance angle signal when the advance angle signal is larger than a set value;
A signal generating device for a non-contact ignition device for an internal combustion engine, comprising: a second inhibit circuit that generates the ignition timing signal based on a position signal or a signal corresponding to the second position signal.