JPH0635866B2 - Internal combustion engine ignition device - Google Patents

Description

The present invention relates to an internal combustion engine ignition device.

[Conventional technology]

FIG. 4 shows a conventional internal combustion engine ignition device, 1 is a magneto coil of a magneto generator, 2 is a signal coil of a magneto generator, and 3 to 8
Is a diode, 9 is a capacitor, 10 is an ignition coil, 1
1 is a spark plug, 12 is a retard side ignition timing calculation circuit, 13
Is an ignition-side ignition timing calculation circuit, 14 is a switch that is closed when the engine is rapidly decelerating, 15 is a variable resistor, and 16 is a thyristor.

In the above structure, when the magneto-generator rotates, a voltage is generated in each of the coils 1 and 2, and the voltage is as shown in a and b of FIG. The voltage a is charged in the capacitor 9 via the diode 3. The voltage b has positive and negative waveforms, and the positive waveform is applied to the ignition timing calculation circuit 12 on the retard side via the diode 4, the arithmetic circuit 12 calculates the retard signal, and the retard signal is supplied via the diode 5 to the thyristor. Added to 16 gates. The position where the retard signal is generated can be changed by the variable resistor 15, but it hardly changes depending on the engine speed. The negative waveform of the voltage b is applied to the ignition side ignition timing calculation circuit 13 via the diode 6, the calculation circuit 13 calculates the advance signal, and the advance signal is supplied to the thyristor 1 via the diode.
Added to 6 gates. This advance signal does not occur when the rotation speed is lower than a predetermined value, and advances when the rotation speed increases. Therefore, the retard signal a and the advance signal b are input to the gate c of the thyristor 16 as shown in FIG. Due to these signals a and b, the thyristor 16 becomes conductive, the capacitor 9 is discharged, a high voltage is generated on the secondary side of the ignition coil 10, and an ignition spark is generated in the spark plug 11. The ignition timing characteristic is as shown by the solid line in FIG. 6, and at a low speed, a retarded ignition timing that secures stable engine rotation can be obtained, and at a medium to high speed, the ignition timing can be advanced to increase the engine output. . Further, when the engine decelerates suddenly, the switch 14 is turned on and the advance signal b is not generated, but only the retard signal a is provided, and the ignition timing is retarded, whereby the deceleration of the engine and the stability at low speed are achieved. Is improved.

In addition, an outboard motor engine is required to operate at an ultra-low speed, which is generally called trolling. Therefore, in order to reduce the engine speed to the trolling state, first,
A possible method is to squeeze (close) the carburetor valve. However, if the carburetor valve is excessively throttled, the air flow rate becomes too small, the fuel is not sufficiently vaporized, and the rotation speed becomes unstable, so that the rotation speed cannot be reduced.

Therefore, a method is adopted in which the engine output is reduced and the rotation speed is lowered by retarding the ignition timing. In this way, in order to realize stable operation at low speed, the rising timing of the retard signal a is set to ATDC1
It is desirable to set the angle to 0 ° (after the crank angle of 10 ° from the top dead center).

Further, as shown in FIG. 6, generally, the ignition timing of the advance signal changes according to the number of revolutions. However, in the case of sudden deceleration from a high speed operation state, the number of revolutions is sufficient even if the throttle is fully closed. The ignition timing is advanced until it decreases (until the slope of the ignition timing characteristic of FIG. 6 is reached). Therefore, the engine output does not decrease sufficiently, and especially in the case of a two-cycle engine, the rotation speed decreases slowly. Therefore, as described above, during the rapid deceleration, the advance signal B is stopped, so that the ignition timing is forcibly retarded to reduce the engine output, and the engine speed can be promptly reduced.

[Problems to be solved by the invention]

By the way, the signal widths of the retard signal a and the advance signal b are necessary until the discharge of the capacitor 9 is sufficiently completed, and the signal width is about 500.
μsec is required. Further, it is necessary to generate the signals a and b between the end of charging the capacitor 9 and the start of the next charging. If the signals a and b are generated before the charging is completed, the charging voltage is lowered, and if the signals a and b are generated after the charging is started, the thyristor 16 is turned on to turn the capacitor 9 on.
Will not be charged. For this reason, the 4
For polar generators, the signal generation time range is 45 °. However, the advance signal B is usually BTDC 30 ° (top dead center of piston 30
(Before ゜)), and the retard signal (i) is usually required up to ATDC 10 ° (10 ° after top dead center). Signal width of retarded signal a 500
Converting μs to an angle gives 3 ° at 1000 r / min, but 6
At 000r / min, it reaches 18 °. Therefore, as shown in the right end of FIG. 5, the rear end of the retard angle signal a enters at the start of charging, which causes a problem that the capacitor 9 cannot be charged. Because each of the signals a and b is a trigger signal of the thyristor 16, the thyristor 16 is conducting while the retard signal a is rising, and the thyristor 16 is turned on in a conducting state at the charging start time of the capacitor 9. This is because the voltage a continues to be turned on even after the retard signal a has fallen. Therefore, the thyristor 16
When the next charging period is reached while the power is on, the voltage a generated from the magneto coil 1 is all dropped to the ground via the thyristor 16, and the capacitor 9 cannot be charged.

Further, the retard signal a for retard control is generated even at a high speed that does not contribute to ignition regardless of the presence or absence of the advance signal b for advance control. This is because if the retard signal a is not output when the engine is operating at high speed, ignition control is performed by the advance signal b during sudden deceleration, and sufficient deceleration cannot be obtained.

In order to prevent such a state in which the capacitor 9 cannot be charged at a high speed, the rising timing of the retard angle control signal a is set to the advance side of ATDC 10 °, and the H level section of the retard angle signal a is set. It must be prohibited to enter the next charging period.

Therefore, ATDC1 which is desirable for stable operation at low speed
There was a problem that it could not be delayed to 0 ° and stable operation at low speed could not be performed.

The present invention has been made to solve the above-mentioned problems, and can perform stable operation at low speed and prevent the ignition signal from entering the charging period of the capacitor at middle and high speeds. An object of the present invention is to obtain an internal combustion engine ignition device.

[Means for solving problems]

The internal combustion engine ignition device according to the present invention is such that the output signal of the second ignition signal generating means for generating the retard signal is advanced at a predetermined rotational speed of the engine or more.

[Work]

In the present invention, the retard signal of the second ignition signal generating means is advanced at a predetermined rotation speed or more, and at the time of low speed, the ignition signal is sufficiently retarded to obtain the rotation stability. At middle and high speeds, the capacitor is smoothly charged by advancing a retard signal with a wider signal width.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings. First
In FIG. 2 and FIG. 2, 17 is a magnet generator, 18 is an engine starting ring gear, 19 is a gear signal pick-up, 2
Reference numeral 0 is a reference signal pole, 21 is a reference signal pickup, 22 to 26 are resistors, 27 and 28 are transistors, 2
9 is a flip-flop, 30 is a waveform shaping comparator,
31 is a counter, 32 is a ladder circuit, 33 is a rotation speed detection circuit, 34 is a transistor, 35 is a comparator, 36
Is a capacitor.

Next, the operation of the above configuration will be described with reference to FIG. A signal similar to the conventional one is output from the magneto coil 1 by the rotation of the magneto generator 17, and the capacitor 9 is charged. Also, the reference signal pick-up 21 and the gear signal pick-up 1
The signals shown in FIGS. 3 (a) and 3 (d) are output from 9 and the advance angle calculation circuit 13 outputs the advance angle signal B similar to the conventional one to the thyristor 1.
Added to 6 gates. On the other hand, on the delay angle calculation side, the positive signal of the output of the reference signal pick-up 21 is input to the S terminal of the flip-flop 29 through the diode 4, the resistor 22 and the transistors 27 and 28 as shown in FIG. The output from the terminal changes from H to L in accordance with (c), and this output is reset by the counter 31.
Input to the terminal. Also, the output of the gear signal pick-up 19 is input to the ▲ ▼ terminal of the counter 31 via the waveform shaping comparator 30 as shown in (e), the counter 31 advances the count according to this input, and its output is a ladder circuit. As shown in (f) via comparator 32
It is input to the (+) terminal of 5. On the other hand, the rotation speed detection circuit 33
Detects the engine speed from the output of the gear signal pick-up 19, and the output is input to the (-) terminal of the comparator 35 via the transistor 34 and the resistor 25. this(-)
The terminal input is preset as the reference voltage C by the variable resistor 15. When the output of the ladder circuit 32 exceeds the reference voltage C, the comparator 35 outputs a retard signal as shown by the solid line in FIG. Trigger and input to the R terminal of flip-flop 29. Therefore, the output becomes H and the counter 31 is reset. here,
When the engine speed becomes equal to or higher than the predetermined value N ₁ , the speed detection circuit 3
By the output of 3, the transistor 34 is turned on, the reference voltage is switched from C to D, the output of the comparator 35 becomes as shown by the dotted line in (g), and the retard signal advances. The ignition timing characteristic in this embodiment is as shown in FIG.

Here, the rising timing of the retard signal a at a rotation speed of a predetermined engine rotation speed N ₁ or more is, as described above, such that the H level section does not enter the next charging period of the capacitor 9 and is abrupt. It goes without saying that the selection is made to such an extent that the deceleration property during deceleration is not impaired. So, for example, BT
It is necessary to set DC 0 ° to BTDC 5 °.

In the above embodiment, the ignition timing is retarded by the retard signal at the low speed to stabilize the engine rotation, and the ignition timing is advanced at the middle and high speeds to increase the output, and at the time of sudden deceleration. In the case where the retard control is performed by the retard signal, the retard signal is advanced in the middle and high speed range, and the engine signal is stabilized by sufficiently retarding the ignition signal at low speed when the signal angle width is small. At the same time, when the signal angle width becomes large and the speed is high, the retard signal is advanced to prevent the retard signal from entering during the charging period of the capacitor 9 to enable normal ignition. However, the advance angle of the retard signal should be within a range that does not impair the deceleration during sudden deceleration.

〔The invention's effect〕

As described above, according to the present invention, the retard signal is advanced at a speed equal to or higher than the predetermined number of revolutions of the engine, and the retard signal is prevented from interfering with the charging of the capacitor in the medium and high speed regions where the signal angle width increases. be able to. Moreover, the retard signal can be sufficiently delayed at low speed, and stable engine rotation can be obtained.

[Brief description of drawings]

FIG. 1 is a circuit diagram of the device of the present invention, FIG. 2 is a schematic configuration diagram of a magnet generator according to the present invention, FIG. 3 is a timing chart showing the operation of the device of the present invention, and FIGS. Circuit diagram of conventional device, timing chart and ignition timing characteristic diagram,
FIG. 7 is an ignition timing characteristic diagram of the device of the present invention. 1 ... Generating coil, 9 ... Capacitor, 10 ... Ignition coil, 11 ... Ignition plug, 13 ... Advance angle calculation circuit, 1
4 ... Switch, 15 ... Variable resistance, 16 ... Thyristor, 17 ... Magnet generator, 19 ... Gear signal pick-up, 21 ... Reference signal pick-up, 29 ... Flip-flop, 31 ... Counter, 33 ... ... Rotation speed detection circuit, 34 ... Transistor, 35 ... Comparator. The same reference numerals in the drawings indicate the same or corresponding parts.

Claims (1)

[Claims] Claim: What is claimed is: 1. A capacitor charged by a capacitor charging source, a thyristor for discharging the charging voltage of the capacitor through an ignition coil when it is conductive, and an ignition advanced to a gate circuit of the thyristor based on the engine speed. A first ignition signal generating means for supplying a signal, a second ignition signal generating means for supplying a retarded ignition signal to the gate circuit of the thyristor, and a first ignition signal generating means at the time of sudden deceleration of the engine. And a switch means for short-circuiting the output of the internal combustion engine, wherein the retarded ignition signal of the second ignition signal generation means is advanced at a predetermined rotational speed of the engine or more.