JPS62271963A - Ignition device for internal combustion engine - Google Patents

Abstract

PURPOSE:To stabilize the ignition timing, by providing a counter for counting a predetermined number of clock pulses, and means for setting the time when the analog voltage exceeding a variable reference voltage, as the ignition timing so that an ignition coil is energized. CONSTITUTION:A reference signal pick-up coil 2 delivers a reference signal when it detects a reference signal pole. A gear signal pick-up coil 3 delivers clock pulses in accordance with the position of a gear. When the reference signal is delivered, a counter 10 counts a predetermined number of the clock pulses. A ladder circuit 11 converts the outputs of the counter 10, successively into analog voltages. A comparator 13 compares a variable reference voltage with each analog voltage, and when the analog voltage exceeds the variable reference voltage, the comparator triggers a thyristor 7 to energize an ignition coil 5 for ignition. Thus, it is possible to eliminate the necessity to regulate a link mechanism, thereby it is possible to stabilize the ignition timing.

Description

[Detailed Description of the Invention] 3. Detailed Description of the Invention [Field of Industrial Application] This invention is designed to enable variable ignition timing at low speeds and to obtain stable ignition timing even when there are rotational fluctuations. The present invention relates to an internal combustion engine ignition system.

[Conventional technology]

Conventionally, in an internal combustion engine ignition system, a device for igniting a multi-cylinder engine using a low-voltage power distribution system has been developed, for example, by Japanese Patent Publication No. 59-2.
It is disclosed in Japanese Patent No. 8751. In this bulletin,
A first pulse generator generates an angular position signal consisting of a plurality of pulse trains corresponding to the ignition position for each cylinder; a second pulse generator generates a reference pulse at a reference angular position of the engine; A detection device detects that the pulse interval generated from the pulse generator exceeds a predetermined time limit,
Once the output of this detection device is generated, from then until the output pulse of the second pulse generator is generated, regardless of the presence or absence of the output pulse of the first pulse generator,
A circuit is provided that stops or resets the counting function of a counter that is reset by the output of the second pulse generator and counts the output of the first pulse generator, and this circuit controls the counter to interrupt the engine starting operation. This is designed to prevent erroneous power distribution due to erroneous counting by the counter due to double counting of the output pulses of the first pulse generator when the engine reverses by a certain angle and then stops.

On the other hand, conventional ignition systems for outboard motors change the ignition timing by mechanically moving a signal coil in conjunction with the throttle. When trolling at low speeds, it is necessary to change the engine speed depending on the usage situation, but in the conventional method, the engine speed is changed by adjusting the link mechanism that links the throttle and signal coil and changing the ignition timing. Ta.

There is also a method of replacing the mechanical type with an electrically controlled type, calculating the low-speed ignition timing, and changing the ignition timing by switching to this calculated characteristic.

[Problem that the invention seeks to solve]

However, when moving the signal coil mechanically in conjunction with the aforementioned throttle, tools such as screwdrivers and spanners are required to adjust the link mechanism, and the outboard motor cover must be removed. The disadvantage was that it was difficult to operate on the water while the engine was in use, as the link mechanism could not be adjusted.

In addition, with the above calculation formula, the ignition timing can be easily switched using a rotary switch, etc., but at low speeds, the engine rotational fluctuation is large, the ignition timing obtained by the calculation is unstable, and the rotational stability is poor. There were drawbacks.

This invention was made to solve these problems, and it eliminates the need for mechanical adjustment of the link mechanism.
Ignition timing is completely unaffected by rotational fluctuations and is extremely stable.Variable rotational fluctuations and stable ignition timing are contradictory demands! ]l: The purpose is to obtain a satisfactory internal combustion engine ignition system.

[Means for solving problems]

The internal combustion engine ignition device according to the present invention includes a reference signal pickup coil that detects a reference signal ball of a magnetic generator and generates a reference signal, and a gear that generates a signal corresponding to the number of gear teeth of this magnet generator. a signal pickup coil; a counter that starts counting gear signals based on a reference signal;
means for converting the output of the counter into an analog voltage;
The apparatus is provided with means for igniting the engine at the time when this analog voltage becomes equal to or higher than a variable reference voltage as the ignition timing.

[For production]

In this invention, when the reference signal pickup coil generates the reference signal, the gear signal detected by the gear signal pickup coil is counted by the counter and sequentially outputted,
This output is converted into an analog voltage, and the point in time when this analog voltage becomes equal to or higher than the variable reference voltage is set as the ignition timing, and the ignition coil is energized to ignite.

〔Example〕

Embodiments of the internal combustion engine ignition system of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing the configuration of one embodiment. In FIG. 1, 1 is a power generation filter, 2 is a reference signal pickup coil, and 3 is a gear signal pickup coil.

The power generation filter 1 is a power generation coil of a magnet generator 4 shown in FIG. One end of the power generating filter 1 is grounded, the other end is grounded via the diode DI, the capacitor C1 and the primary winding 51 of the ignition filter 5, and the secondary winding 52 of the ignition filter 50 is grounded via the plug 6. There is.

Further, the connection point between the diode D1 and the capacitor C1 is grounded via the thyristor 7.

As is clear from FIG. 2, the magnet generator 4 has a reference signal ball 4a provided at a predetermined position on the rotor, and a gear 4b formed on the outer peripheral surface.

The reference signal ball 4a is the reference signal pickup coil 2
, the reference signal pickup coil 2 detects it and generates a reference signal (pulse).Similarly, each time each gear 4b faces the gear signal pickup coil 'A/3, Then, this gear signal pickup coil 3 detects this and generates a pulse.

One end of the reference signal pickup coil 2 is grounded, and the other end is connected to the input end of the advance angle calculation circuit 8 via a diode D2, and is connected to the pace of the transistor Tri via a diode D3 and a resistor R1. It is connected. Transistor Tr1. The collector of Tr2 is connected to the power supply via resistors R2 and R3, respectively.

The emitters of both transistors Tri and Tr2 are grounded. The collector of the transistor Tri is connected to the pace of the transistor Tr2, and the collector of the transistor Tri is connected to the pace of the transistor Tr2.
1 + Tr 2 constitutes a waveform shaping circuit, and a waveform-shaped pulse is generated at the collector of the transistor Tr2.

The collector of this transistor Tr2 is connected to a set input terminal S of a 7-lip/70-tub circuit (hereinafter referred to as FF) 9. The output terminal Q of the FF 9 is connected to the reset input terminal R of the counter 10.

The counter 10 has output terminals Q1 to Q4, and output terminals Q1 to Q4.
Q3 is connected to the input end of the ladder circuit 11 by a resistor network. The ladder circuit 11 is used as a digital to analog converter.

On the other hand, one end of the gear signal pickup coil 3 is grounded, and the other end is the non-inverting input terminal ((+
) input end). The comparator 12 is used as a waveform shaping circuit, and its inverting input terminal ((-
) input end) is grounded.

The output terminal of the comparator 12 is connected to the clock input terminal C of the counter 10. The output terminal Q4 of the counter 10 is connected to the reset input terminal R of the FF9.

Further, the output terminal of the ladder circuit 11 is connected to a comparator 13.
is connected to the non-inverting input terminal of The inverting input terminal of the humpator 13 is connected to the connection point between the resistor R4 and the variable resistor VRI, and a variable reference voltage Vr is applied thereto.

This series circuit of resistor R4 and variable resistor VRI is connected between the power supply and ground. This variable resistance VRI and resistance R
A reference voltage Vr is generated at the connection point with 4, and the reference voltage Vr can be varied by adjusting a variable resistor VRI.

The output terminal of the comparator 13 is connected to the gate of the thyristorph via a resistor R5. The internal combustion engine ignition system shown in FIG. 1 belongs to a general CDI ignition system.

Next, the operation of the internal combustion engine ignition system of the present invention configured as described above will be explained. As the magnet generator 4 rotates, as shown in FIG. 3(a), when the reference signal pickup coil 2 detects the reference signal pole 4a, a pulse signal is generated.

Among these pulses, the (-) pulse is input to the advance angle calculation circuit 8 through the diode D2, where it is calculated and becomes the ignition timing for medium to high speed rotation.

Also, the reference signal pickup coil 2 outputs (+
) pulses are generated by diode D3. is added to the pace of transistor Tri through resistor R1, and transistor Tri
, Tr2, and a pulse as shown in FIG. 3(b) appears at the collector of the transistor Tr2.

This pulse is applied to the set input terminal S of FF9, and this FF9 is set. As a result, the output toward the output end of the FF 9 becomes low level as shown in FIG. 3(C).

When the output terminal ζ becomes low level, the counter 10 is reset and starts counting.

, while the gear signal pickup coil 3 is connected to the magnet generator 4
Each time it faces the gear 4b, a sawtooth wave as shown in FIG. 3(d) is generated. This sawtooth wave is
2, where the waveform is shaped to become a lock pulse as shown in FIG. 3(e).

This clock pulse is the clock input terminal C of the counter 10.
added to. As a result, this clock pulse is
At the same time that the output terminal d of the counter 9 becomes low level, the counter 10
is counted. That is, the counter 10 starts counting gear signals at the same time as the reference signal generated by the reference signal pickup coil 2 is input.

As the clock pulses are counted by the counter 10, a diisotal output appears at the output terminals Q1 to Q4 in binary form. By passing this deisotal output through the ladder circuit 11, it is converted into a stepped analog voltage as shown in FIG. 3(f). This ladder circuit 11
is widely used for digital-to-analog conversion.

The stepped voltage obtained through this ladder circuit 11 is applied to the non-inverting input terminal of the comparator 13. The inverting input terminal of the comparator 13 is connected to the reference voltage Vr (see Fig. 3).
f)) is applied.

Therefore, the step voltage is compared with the reference voltage Vr by the comparator 13, and when the step voltage exceeds the reference voltage Vr, the output of the comparator 13 becomes a high level as shown in FIG. 3 (X), and this high level The voltage of resistance R
5 to the dart of the thyristor 7, triggering the thyristor 7, discharging the charge stored in the capacitor C1, causing 4 pulses to be generated in the secondary winding 52 of the ignition coil 5, and causing a pulse to be generated between the plug 6. Discharge and ignite.

As this counter 10 continues to count, the output terminal Q
4 (counting the 8th clock pulse), the output of the output terminal Q4 is sent to the reset input terminal R of FF9.
added to. As a result, FF9 is reset and FF9 is reset.
The output terminal ζ of 9 returns to the high level as shown in FIG. 3(C).

Therefore, the reset input terminal R of the counter 10 becomes high level, the counter 10 is reset, stops counting, and prepares for the next count.

Note that the reference voltage Vrit applied to the comparator 13 is varied by a variable resistor VR1 (1N lithium, which may be switched by a rotary switch). By varying this reference voltage Vr, the timing at which the stepped voltage exceeds the reference voltage changes, so the ignition timing can be changed as shown in FIG. 4.

This Figure 4 shows the rotation speed on the horizontal axis and the ignition timing on the vertical axis. This is the characteristic when Vr is varied.

〔Effect of the invention〕

As explained above, in this invention, when the reference signal pickup coil detects the reference signal, the gear signal detected by the gear signal pickup coil is counted by the counter,
The counter sequentially outputs the voltage, converts this output into an analog voltage, and then compares it with a variable reference voltage.The ignition coil is energized when the voltage exceeds the reference voltage, making it the ignition timing, so there is no need to adjust the link mechanism. At the same time, once the reference voltage is set, the ignition timing is stabilized without being affected by rotational fluctuations at all.

Therefore, it satisfies the conflicting demands of variable reference voltage and stable ignition timing.

[Brief explanation of the drawing]

FIG. 1 is a circuit diagram of an embodiment of the internal combustion engine ignition system of the present invention, and FIG. 2 is a diagram showing the positional relationship between the reference signal pickup coil, gear signal pickup coil, and magnet generator in the internal combustion engine ignition system. FIG. 3 is a time chart for explaining the operation of the internal combustion engine ignition system, and FIG. 4 is a diagram showing the relationship between rotational speed and ignition timing for explaining the operation of the internal combustion engine ignition system. 1... Generator coil, 2... Reference signal pickup coil, 3... Gear signal pickup coil, 4...
Magnet generator, 5... Ignition coil, 6... Plug, 7
...Thyristor, 8...Advance angle calculation circuit, 9...F
F, 10...Counter, 11...Ladder circuit, 12
．． 13... Comparator, VRI... Variable resistor. Note that the same reference numerals in the figures indicate all the same or corresponding parts.

Claims (1)

[Claims] a magnet generator having a reference signal pole and a gear in its rotor; a reference signal pickup coil that generates a reference signal when the reference signal pole is detected; a gear signal pickup coil that generates a clock pulse in accordance with the position of the gear; A counter that counts a predetermined number of clock pulses when the reference signal is generated, a circuit that sequentially converts the output of this counter into an analog voltage, and a circuit that compares the variable reference voltage with the analog voltage and detects that the analog voltage exceeds the variable reference voltage. An internal combustion engine ignition device comprising means for energizing an ignition coil using a certain point in time as an ignition timing.