JPS6123869A - Ignition-timing controller - Google Patents

Abstract

PURPOSE:To improve the output of an engine by installing a frequency-voltage conversion circuit into an ignition-timing calculating circuit equipped with an integration circuit and a comparator and freely varying the advance-angle characteristic. CONSTITUTION:A spark condenser 3 is charged by the output of an ignition power-source coil 1, and this electric charge is discharged into an ignition coil 5 to generate the electric discharge in a spark plug 8, and an engine is ignited. A frequency-voltage conversion circuit 34 is instlled into an ignition-timing calculating circuit 20. When the output of the conversion circuit 34 exceeds a certain value, the control conditions of the ignition-timing calculating circuit 20 are varied continuously by the output. Therefore, the advance-angle characteristic can be varied freely, and the output of the engine can be improved.

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention uses electronic circuit calculation to control the ignition timing of a CDI ignition system using a magnet generator as a power source, so as to obtain the ignition advance characteristics required by the engine with high accuracy. This invention relates to an ignition timing control device that changes the advance angle characteristics by changing the calculation conditions after a certain rotation speed, thereby obtaining characteristics that better match the requirements of the engine.

[Prior art]

In engine ignition timing control systems, it is common to set the advance angle to a two-step or three-step advance characteristic in order to avoid the engine's knocking zone or to improve the engine's output characteristics in the mid-speed range. It is being done. Regarding ignition timing control using electronic circuit calculations, for example,
As seen in Japanese Patent No. 64156, it is described that the above characteristics can be obtained using a plurality of triangular wave oscillation circuits. Further, an advance angle device using normal electronic calculation is disclosed in Japanese Patent Application Laid-Open No. 56-759.
As seen in Publication No. 64, by synchronizing the triangular wave obtained by charging and discharging the capacitor of the integrating circuit with the rotation of the engine, and comparing the capacitor voltage with the reference voltage against the resulting constant angle wave oscillation. The ignition signal is obtained by controlling the charging and discharging current of the capacitor with a voltage that corresponds to the rotational speed of the engine at 42 meters, thereby obtaining advance angle characteristics. 9 However, in order to change the advance angle characteristic after a certain rotation in this device, it is necessary to change the voltage characteristic using the engine rotation as a parameter, as shown in Japanese Patent Application Laid-open No. 56-151266. However, the two examples described above require extremely complicated circuits to obtain the desired characteristics. Also, 4v Kaisho 57-5
No. 1956 proposes a device that uses an integrator and two comparators to charge and discharge the integrator's capacitor with a constant current to obtain a constant advance angle characteristic. Although a certain advance angle characteristic can be obtained with the circuit, the advance angle characteristic itself cannot be changed depending on the rotation speed.

[Summary of the invention]

The present invention was made in consideration of the above-mentioned problems, and consists of combining a rotational speed-voltage conversion circuit with an advance angle control circuit having an integrating circuit and two comparators, and Provided is an ignition timing control device that can realize a two-step lead angle characteristic with a simple circuit by continuously changing the control conditions of the advance angle control circuit according to the output when the output exceeds a certain value. The purpose is to

[Embodiments of the invention]

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

In Fig. 1, 1 is the ignition power coil of the magnet generator, 2
is a diode that rectifies the output of power supply coil 1, 3 is an ignition capacitor that is charged by the output of power supply coil 1, and 4 is a thyristor. Thyristor 4 receives a signal at its gate and transfers the charge of capacitor 3 to ignition coil 5. The high voltage is discharged to the primary coil 6, induces a high voltage in the secondary coil 7, and discharges it to the spark plug 8, thereby igniting the engine. 9 is a constant voltage power supply circuit consisting of a diode 10, a resistor 11, a constant voltage diode 12, and a capacitor 13, and its output is supplied to an ignition timing calculation circuit 20 and a frequency-voltage conversion circuit (
Hereinafter, this will be referred to as the F-V circuit. ) 34. 14
is a signal coil that is installed in the magnet generator and generates an ignition signal in synchronization with the rotation of the engine, and its output is connected to the diode 15,
It is applied to the gate of the thyristor 4 via the resistor 16 and to the F-V circuit 34 via the diode 17. Further, the negative wave generated by the signal coil 14 is applied to the ignition timing calculation circuit 20 via a diode 18 and a resistor 19. Ignition timing calculation circuit 2 (1: RS flip-flop (hereinafter abbreviated as ff) 21, operational amplifiers 22 to 24
, transistor 25, diode 26, capacitor 27
, resistors 28 to 33 are constructed. Also, the F-V circuit 34
is composed of transistors 35, 36, diodes 37, capacitors 38, 39 and resistors 40-44.

Next, the operation of the above device is controlled by the ignition timing calculation circuit 20 and F.
- FIGS. 2 and 3 centering on the mutual operation of the V circuit 34.
This will be explained using figures. First, the engine rotates and signal coil 1
When a voltage is generated at 4, the negative voltage generated at a rotation angle that advances in time flows through a resistor 19 and a diode 18, and a voltage (negative voltage) corresponding to the voltage drop across the resistor 19 is input to the ignition timing calculation circuit 20. be done. Further, the positive voltage at the time-delayed position is applied to the gate of the thyristor 4 via the diode 15 and the resistor 16, conducts the thyristor 4, and discharges the load of the capacitor 3 to the ignition coil 50 and the primary coil 6.
A high voltage is induced in the secondary coil 7 to discharge the spark plug 8 and ignite the engine, and the positive voltage is input to the F--circuit 34 via the diode 17. In FIG. 2, to is the position where a negative voltage is generated, 1. indicates the position where positive voltage is generated. When a negative voltage signal is input to the ignition timing calculation circuit 20, a positive voltage is applied to the base of the power supply circuit 9 via the resistor 28, and the transistor 2 is turned on.
A negative voltage is applied between the pace and the emitter of No. 5, the transistor 25 is turned off, and the voltage supplied from the power supply circuit 9 through the resistor 29 is applied to the set terminal (S) of the f-f circuit 21.
The (+)Q terminal of the f-f circuit 21 outputs a high-level voltage, and this voltage is applied to the inverting input terminal (hereinafter referred to as the (-) terminal) of the first operational amplifier 22 via the resistor 30. In this case, the operational amplifier 22 (
–) terminal is a non-inverting input terminal (hereinafter referred to as the (+) terminal).
If a higher voltage is applied, the operational amplifier 22
The output terminal of is shifted from high level to low level, and the capacitor 27, which had been charged, begins to discharge at a constant time constant as shown in FIG. 1, and as a result, the voltage at the output terminal of the f amplifier 22 increases due to the discharge of the capacitor 27, decreases for a while as shown by straight line a-b in FIG. This voltage is resistor 33
However, as long as the (-) terminal voltage is higher than the (+) terminal voltage, the output terminal of the operational amplifier 23 maintains a low level, and as shown in FIG. As shown in t, the K (-) terminal voltage is the (+) terminal voltage V
When the voltage becomes lower than 2, the output terminal of the operational amplifier 23 becomes high level, and this output is added to the reset terminal (hereinafter referred to as R terminal) of the f-f circuit 21, and the +Q of the f-f circuit 21. The terminal is shifted to a low level, and this voltage is applied to the (-) terminal as a voltage lower than the (+) terminal voltage v1 of the operational amplifier 22, and the output terminal of the operational amplifier 22 is at a high level. With a time constant, the output voltage of the photovoltaic n1 operational amplifier 22 increases as shown by straight line b-c in FIG.

Then, the same operation is repeated again with the negative voltage signal of the signal coil 14. Here, the triangle in Figure 2 (
In the first form abc, the -side aC is constant with one rotation of the engine,
The angle cab and the angle acb are constant due to the charging and discharging time constant of the capacitor 27, and the position of the reed, t, is constant in the upper cylinder, and the time required for rotation changes with changes in the engine rotational speed. Since the angle is also constant, it is called constant angle oscillation. On the other hand, the (+) Q terminal output of the f-f circuit 21 is inputted to the (+) terminal of the third operational amplifier 2'4 via the resistor 31, and the voltage of the capacitor 27, that is, the output voltage of the operational amplifier 22, is connected to the resistor 31. Same opamp 2 through 33
It is applied to the (-) terminal of 4. If the former is set to v3 and takes the value shown in Figure 2, the two voltages intersect at point t3,
At this point, the (-) terminal voltage of the operational amplifier 24 becomes a lower voltage than vs, so the output of the third operational amplifier 24 changes to a high level and is applied to the gate of the thyristor 4 via the differential capacitor 45. As mentioned above, the voltage at the output terminal of the fourth amplifier 22 has a charging/discharging gradient due to a constant time constant, so in the low speed rotation range, the voltage at point a in Fig. 2 is sufficiently high and does not change. The intersection of both voltages is a point close to t2. Then, as the rotation increases and the time for sea rotation decreases, the voltage at point A decreases, and point t3 approaches point t0, reaching a constant rotation.The voltage at point A matches the voltage at V3, and reaches t.

matches to. When the rotation increases further, f-f circuit 2
When the (+) Q terminal of 1 becomes high level, the neutral voltage of the (+) Q terminal is transmitted through the resistor 31 to the (+) of the third operational amplifier 24. ) terminal, the (-) terminal voltage of the operational amplifier 24 at that point is the voltage at point a in FIG. 2, which is lower than the (+) terminal voltage v3, so the output terminal of the fourth amplifier 24 changes to a high level. .

When the rotation speed exceeds a certain level, a signal is applied to the gate of the thyristor 4 at time t0 in FIG. 2. A signal is applied to the gate of thyristor 4 at 1° and at t8, but thyristor 4 conducts at the earlier signal and ignites the engine, so in the low speed rotation range, it ignites at tl and the rotation increases. When t3 becomes earlier than tl, ignition occurs at t, and as the rotation increases, t approaches to, and when a certain rotation is reached, t coincides with to and ignition occurs at to.

The d-e-f characteristics in FIG. 3 illustrate this using parameters relative to the rotational speed.

In FIG. 1, when a positive signal from the signal coil 14 is applied to the F-V circuit 34 via the diode 17, the transistor 35 is first turned on, and the voltage from the power supply circuit 9 is applied to the transistor 35, the resistor 41, and the capacitor 38. and is added to the series circuit of resistor 42. The capacitor 38 and the resistor 42 constitute a differentiating circuit, and a voltage with a constant width determined by a time constant is generated across the resistor 42, and this voltage turns on the transistor 36.

The voltage across the resistor 42 is constant at 4 regardless of engine rotation.
Therefore, the on-time of the transistor 36 is always constant,
Only the number of on and off cycles is proportional to the engine rotation. When the transistor 36 is turned on, current flows from the power supply circuit 9 through the transistor 36 and the resistor 44 to the capacitor 39, and during the period when the transistor 36 is off, the charge in the transistor 39 is discharged through the resistors 44 and 43; Since the ON time of the transistor 36 is constant and the number of ON times is proportional to the rotation of the engine, the current flowing into the capacitor 39 increases in proportion to the rotation of the engine.
Therefore, the output voltage of the F-V circuit 34 increases in proportion to the increase in rotational speed. As shown in FIG. 1, the output voltage of this F-V circuit 34 is
3, the (+) terminal voltage V of the operational amplifier 23 cannot be maintained at a constant value above a certain rotation, and V increases as the rotation increases. As shown in FIG. 2, when ■, changes to v,' and the voltage at the output terminal of the first operational amplifier 22 reaches ■2', the operational amplifier 23 is inverted and the f-f circuit 21 is inverted. Since it is reset, the output terminal voltage of the operational amplifier 22 is a'- in Figure 2.
As shown in b'-e', v2 changes to v,', and this voltage and the (+) terminal voltage V of the third operational amplifier 24 change.

The intersection point with t is later than t, as shown at t,' in Figure 2. As mentioned above, as the engine speed increases, t becomes t. However, if V is changed at a constant gradient as the rotation increases, t of t. The approach speed will be delayed. This is shown in Fig. 3. When the output of the F-V circuit 34 exceeds V, the advance characteristic of the ignition timing changes as the rotational speed n1 exceeds V, and the ignition timing has a two-stage bending characteristic. become.

FIG. 5 shows another embodiment, in which even if the output of the F-V circuit 34 changes the voltage of the fourth amplifier 24 or the V of the operational amplifier 22 (not shown), the The third limit is to set a threshold value for the output and apply it above a certain value.
As shown in the figure, the advance angle characteristic can be bent in two stages. Note that 26 is a diode. Further, as shown in the embodiment of FIG.
By dividing the voltage at the (+) terminal of the motor, the reverse n-characteristic as shown in FIG. 4 can be obtained by decreasing v2 as the revolution increases above a certain number of revolutions.

〔Effect of the invention〕

As described above, in the present invention, by adding a frequency-voltage conversion circuit to a normal electronic lead angle circuit, the lead angle characteristics can be changed freely, and the lead angle characteristics can be made small and inexpensive and meet the requirements of the engine. This can contribute to improving the engine's output. In winter, by increasing the number of frequency-voltage conversion circuits, it is possible to obtain characteristics of not only two-stage folding but also three-stage folding or more, but since it is a simple circuit, it is not cheap.
There isn't.

[Brief explanation of the drawing]

1 to 3 are circuit diagrams, operation explanatory diagrams, and characteristic diagrams of the first embodiment of the device of the present invention, FIG. 4 is a characteristic diagram of the third embodiment of the device of the present invention, and FIG. FIG. 6 is a partial circuit diagram of a second embodiment of the device of the present invention; FIG. 6 is a partial circuit diagram of a third embodiment of the device of the present invention; 1...Ignition power supply coil, 3...Ignition capacitor,
4... Thyristor, 5... Ignition coil, 8... Spark plug, 9... Constant voltage power supply circuit, 14... Signal coil, Addition... Ignition timing calculation circuit, 22-24... - Operational amplifier, 27... Capacitor, 34... Frequency-voltage conversion circuit. Note that the same reference numerals in the figures indicate the same or corresponding parts.

Claims (2)

[Claims] (1) The ignition capacitor is charged by the ignition power supply coil installed in the magnet generator, and when it receives a signal from the gate at the ignition timing of the engine, it becomes conductive and discharges the charge in the ignition capacitor to the primary coil of the ignition coil. A thyristor that induces high voltage in the coil and discharges the spark plug to ignite the engine; a signal coil installed in the magnet generator that generates a signal in synchronization with the rotation of the engine; and a fixed-angle wave oscillation that receives a signal from the signal coil. The oscillation voltage is compared with the first reference voltage, and the comparison condition is outputted as a signal to be applied to the gate of the thyristor.An ignition timing calculation circuit receives the signal from the signal coil and calculates the signal in proportion to the number of signals per unit time. It is equipped with a frequency-voltage conversion circuit that outputs voltage and applies this output to the ignition timing calculation circuit, and when the output voltage of the frequency-voltage conversion circuit exceeds a certain value, the ignition timing calculation circuit changes the output. An ignition timing control device characterized in that the advance angle characteristic is changed at a constant engine speed. (2) Constant angle wave oscillation of the ignition timing calculation circuit is performed by charging and discharging the capacitor, charging is started by a signal from the signal coil, and transition from charging to discharging is performed by comparing the capacitor voltage with the second reference voltage. And the amount of charge and discharge is set by a third reference voltage, the output of the frequency-voltage conversion circuit is added to one of the reference voltages, and this output is added when the output of the frequency-voltage conversion circuit exceeds a certain value. 2. The ignition timing control device according to claim 1, wherein the reference voltage varies linearly.