JPS60145456A - Contactless ignition device for internal-combustion engine - Google Patents

Abstract

PURPOSE:To bring a step spark retarded ignition timing retard characteristic to full fruition, by installing a sensor, generating two-system alternating voltage and also a stratification circuit which stratifies a reference signal and a monostable circuit inputting the reference signal. CONSTITUTION:One sensor 2 outputting a two-system alternating signal to rotation in a magneto-generator 1 is installed. An ignition timing control circuit 10 is constituted of a power circuit 20, a waveform shaping circuit 300, a stratification circuit 200, a characteristic generating circuit 400, a monostable circuit 500 and a logical circuit 600, and inputs an output signal of the sensor 2, determining the ignition timing, and outputs a signal to a condenser discharge type ignition circuit. With this constitution, a step spark retarded ignition timing retarded characteristic is realizable with a simple circuit structure and, what is better, nonadjustment.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a non-contact ignition device applied to an internal combustion engine, particularly a two-stroke internal combustion engine.

[Background of prior art and invention]

Two-stroke internal combustion engines are required to have ignition timing characteristics that have high-speed retardation characteristics because they are in a horse-driven direction, and are also required to have step retardation to prevent overspeeding. Conventionally, to meet this requirement, (1) a combination of one sensor, a retardation calculation circuit, a step circuit detection circuit, a logic circuit, etc., and (2) a combination of two sensors, a monostable circuit, a step rotation detection circuit, a logic circuit, etc. Although a step-retard and retard characteristic was realized by the combination, both had the disadvantage that the configuration was complicated and expensive.

[Object of the present invention]

In order to eliminate the above-mentioned drawbacks, the present invention aims to provide a non-contact ignition device having a step retard characteristic with a simple circuit configuration (2) without providing a step rotation detection circuit. That is.

[Configuration of the present invention]

The present invention includes one sensor that generates two systems of alternating voltage, a waveform shaping circuit, a monostable circuit that inputs a reference signal of one polarity side of the sensor output, and a stratification circuit that stratifies the reference signal. , a characteristic generating circuit that generates a signal with a pulse width having a characteristic that is monotonous with respect to the engine rotational speed, and a logic circuit.

〔Example〕

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention shown in the drawings will be described. 1st
The figure is an electric circuit diagram showing the configuration of an embodiment of the present invention, in which a magnet generator 1 has two long protruding inductors 1b and l on the outer periphery of the rotor.
c, and the inductor 1b.

A sensor 2 is installed facing the IC. Capacitor charging coil la, diode 4. ．． 5, 6, an ignition capacitor 7, a thyristor 8, a gate resistor 9, and an ignition coil 3 constitute a capacitor charging type ignition circuit. The ignition timing control circuit 10 inputs the output signal of the sensor 2, determines the ignition timing, and outputs the signal to the capacitor discharge type ignition circuit (3). 200, characteristic generation circuit 400, monostable circuit 500,
It is constituted by a logic circuit 600 (consisting of an AND circuit 81 and an OR circuit 80). The power supply circuit 2o
Zener diodes 21, 26, resistors 22, 27, 2
B. It is composed of a thyristor 23, a diode 24, and a capacitor 25, which are constant voltage control elements, and supplies a constant voltage to each circuit of the ignition timing control circuit 10.

The waveform shaping circuit 300 includes comparators 31 and 32,
Reference resistance 36, 38, 39, input bias resistance 33, 3
4.35, and the dividing point of the resistors 34 and 35 is connected to the sensor 2.

The stratified circuit 200 includes a switching circuit and an inverter 4 that operate according to the voltage across a resistor 28 connected between the cathode of the thyristor 23 of the power supply circuit 20 and the ground.
2, AND circuits 43, 44, and the switching circuit, a transistor 41, and resistors 45, 46, 47 (4). The cough stratification circuit 200 separates the output fat of the comparator 32 into two reference angle signals (fl, (gl),
Works to stratify. The characteristic generating circuit 400 is a general R-S flip-flop circuit, and inputs the output signals (fl, (gl) of the layering circuit 200 as set and reset signals. Pulse width T depending on output signal (Q)
This is a circuit that emits an output signal.

FIG. 2 is a diagram showing the ignition relationship between the ignition timing characteristics and the output of the sensor 2 in the embodiment of the present invention. Figure 3 shows that the engine speed is N,
When the engine speed is below rpm, the engine speed is N, rpm ~ Norp
1 shows voltage waveforms at each point in the circuit shown in FIG. 1 in the case of m.

Hereinafter, in the configuration of the above embodiment that constitutes the present invention, FIGS. 1 and 2. ．． The action will be explained using Figure 3.4. When the rotor of the magnet generator 1 rotates once, if the rotor has four poles, the no-load voltage of the capacitor charging coil 1a (Fig.
Terminal a) becomes an alternating voltage as shown in Figure 3.4 (al).The output signal of sensor 2 is 2 as shown in Figure 3.4 (1).
The signal voltage of the system becomes (5) As shown in FIG. 2, θH1, θ and 1. θH2+θshi2
It is set so that signal voltages of 31, 32, and 33 degrees S4 are generated corresponding to the angular positions of . and,
The respective components are arranged such that the phase of the voltage (al) of the charging coil 1a and the signal voltage (b) is such that the signal voltage 84 of the second system is included in the negative polarity of the voltage of the charging coil 1a.

The positive direction output of the capacitor charging coil 1a is connected to the diode 4.
A current is passed through the capacitor 7, the primary coil of the ignition coil 3, and the diode 6 to charge the ignition capacitor 7, thereby obtaining an ignition power source. In addition, the negative direction voltage is generated by the diode 24,
A current flows through the capacitor 25 and the diode 5 to charge the power supply capacitor 25, and the ignition timing control circuit 1
0 power is obtained (Zener diodes 21, 26,
The resistors 22, 27 and the thyristor 23 are a regulator circuit for the power supply capacitor 25. The resistor 28 is a resistor for detecting the operating state of the Cyrisk 23).On the other hand, in the waveform shaping circuit 300 which uses the output signal (b) of the sensor 2 as the input signal (6), the waveform shaping circuit 300 shown in FIG.
1. (As shown in dl, the positive direction output SI of sensor 2
.

So that 1″ is output to the comparator 31 by S3,
Also, negative direction output 32. Sa causes the comparator 32 to output “
Resistor 33゜34.35.36,3 so that 1" is output.
7, 38, and 39 types are determined. Using the output signal fdl of the waveform shaping circuit 300 as an input signal, the stratification circuit 200 stratifies the two systems of (dl signals. When the negative direction output of the capacitor charging coil 1a is generated, the thyristor 2 Since the operating state of the transistor 41 can be detected by the voltage detected by the resistor 28, a signal such as el shown in FIGS. The reference angle signals (f) and (g) corresponding to the negative direction output S 2 + 34 of the sensor 2 can be obtained by performing logic between the signal te) and the <d) signal. The reset terminal R of the R-S flip-flop circuit, which is the characteristic generating circuit 400, receives the (along signal), and the cent terminal S receives the (fl
By inputting a signal, the Q output of the circuit (7) 400 can obtain a signal with a pulse width having monotonous characteristics depending on the rotation speed of the period, such as the hl signal. (A pulse signal (1) signal having a constant pulse width T is generated from the rising edge of the C1 signal.The reference angle signal (g) obtained in this way, the output signal (h) of the characteristic generation circuit 400, By taking the logic of the output signal (1) of the stabilizing circuit 500, the output signal color of the OR circuit BO is supplied to the gate of the Thyrisk 8, the thyristor 8 is made conductive, and the energy stored in the ignition capacitor 7 is transferred to the ignition coil 3. It is possible to instantly discharge electricity through the primary coil and generate a high voltage in the secondary coil.

Here, the angle of pulse width T at any Na rotation (
α) is, assuming that the angle between the reference angles 081 is 360°,
The following formula is obtained. α-6·Na-T Therefore, as can be understood from the above equation, when T is constant, the angle α is proportional to the rotational speed Na. In Figure 2, the engine speed is NI
If the rpm is more than or equal to or less than Norpll, as shown in FIG.

However, when the engine speed is above Norpm, α〉
θH1 - 〇H2, and the pulse signal is no longer obtained at the output of the AND circuit 81 (Jl), and the reference angle signal (river) becomes the ignition signal.In this way, in the Norpm, the ignition timing is retarded in steps from θH2 to θH2. make a corner

Although the above embodiment describes the case where the number of poles of the rotor and stator of the magnet generator is four, the present invention is not limited to four poles. Although the voltage of the resistor that detects the conduction state of the cyrisk 23 is used as the input signal, it goes without saying that other output signals synchronized with the rotation of the engine can be similarly effective.

〔Effect of the invention〕

As mentioned above, in the non-contact ignition device for an internal combustion engine according to the present invention, since the step retard angle and the step rotation speed can be freely set using the output generation circuit of one sensor, a step rotation detection circuit is provided (9). (This has a great effect in that a step retard characteristic can be realized with a simple circuit configuration and without any adjustment.

[Brief explanation of drawings]

FIG. 1 is an electric circuit diagram showing the configuration of an embodiment of a non-contact ignition device for an internal combustion engine according to the present invention, FIG. Figure 3 is a diagram of each line voltage waveform of the circuit shown in Figure 1 when the engine rotation speed is Nlrpm or less, and Figure 4 is a diagram of each line voltage waveform of the circuit shown in Figure 1 when the engine rotation speed is N+ rpm''N.rpm. 1a... Capacitor charging coil , 2...sensor, 1
0... Ignition timing control circuit, 20... Power supply circuit, 20
0... Layered circuit, 300... Waveform shaping circuit, 400
... Characteristic generation circuit, 500 ... Monostable circuit, 600
...Logic circuit, 81...AND circuit, 80...O
R circuit, 7...Ignition capacitor, 8...Sirisk, 3...Ignition coil. Representative Patent Attorney Takashi Okabe (10)

Claims (1)

[Claims] A capacitor discharge type ignition circuit and a magnet generator with two
one sensor that outputs an alternating signal of the first system; an ignition timing control circuit that inputs the output signal of the sensor as a reference angle signal and outputs an ignition timing signal to the ignition circuit; The ignition timing control circuit includes a capacitor charging coil having a phase such that it generates a positive output voltage when outputting the signal voltage of the second system and generates a negative output voltage when outputting the signal voltage of the second system, a stratification circuit that stratifies the output signal of one polarity of the sensor according to the output voltage of the charging coil; and a characteristic generation circuit that emits a signal having a pulse width that has a monotonous relationship with the output signal of the stratification circuit. and,
It is composed of (1) a monostable circuit that operates in response to a signal voltage of one polarity of the sensor, and a logic circuit that inputs the output pulse of the characteristic generation circuit and the output signal of the stratification circuit. A non-contact ignition device for an internal combustion engine characterized by: