JPS62111165A - Contactless ignitor for internal combustion engine - Google Patents

Abstract

PURPOSE:To suppress the reduction of the charging voltage of an ignition condenser, namely the ignition performance, by charging a smoothing condenser by the condenser charging side half-wave output after the charge of the ignition condenser of the condenser charging coil. CONSTITUTION:In a dc power source circuit 200, a peak detecting circuit 210 is connected between the normal direction output terminal of a condenser charging coil 1 and a grounding, and detects the peak of the normal direction output wave form of the condenser charging coil 1 for charging an ignition condenser 4. In correspondence with the peak detecting circuit 210, a smoothing condenser 19 charged by the output succeeding to the peak of the output wave form of the condenser charging coil 1 supplies the charging voltage as the power source of an ignition timing control circuit 100. Thus, since the smoothing condenser 19 is charged in the division where the output voltage of the condenser charging coil 1 becomes zero through peak, the charging voltage of the ignition condenser 4 is not reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a non-contact ignition device for an internal combustion engine using a magnet generator as a power source.

[Conventional technology]

Conventional methods charge a smoothing capacitor with the capacitor charging side half-wave output of the magnet generator capacitor charging coil, or charge the smoothing capacitor with the anti-capacitor charging side half-wave output of the capacitor charging coil. The charging voltage of the capacitor is supplied as a power source to an electronic ignition signal generation circuit (for example, Japanese Patent Laid-Open No. 60-304
Publication No. 73).

[Problem that the invention seeks to solve]

However, in the case where the smoothing capacitor is charged by the half-wave output on the capacitor charging side of the conventional capacitor charging coil described above, the smoothing capacitor is charged by the capacitor charging coil at the same time as the ignition capacitor, so the ignition There is a problem in that the charging voltage of the capacitor decreases, resulting in a decrease in ignition performance.

In addition, in the case of charging a smoothing capacitor using the half-wave output on the anti-capacitor charging side of the conventional capacitor charging coil described above, although there is no deterioration in ignition performance, the terminal on the anti-capacitor charging side of the capacitor charging coil is floated by the ground to smooth the capacitor. Since it is necessary to connect to the capacitor side, it becomes impossible to ground one side of the capacitor charging coil, and an extra wire is required to connect between the capacitor charging coil of the magnet generator and the DC power circuit including the smoothing capacitor. There is a problem that.

Therefore, the present invention makes it possible to charge a smoothing capacitor without substantially causing a decrease in ignition performance, and also allows one side of the capacitor charging coil to be grounded.

[Means for solving problems]

Therefore, in the present invention, one end of the capacitor charging coil of the magnet generator is grounded, the ignition capacitor is charged from the positive direction output terminal at the other end, and the ignition timing is electronically determined by an electronic ignition signal generation circuit. In a non-contact ignition device for an internal combustion engine, the charge charged in the capacitor is discharged via a primary coil of an ignition coil through an ignition semiconductor switching element that conducts in response to an ignition signal, wherein the charge in the positive direction of the capacitor charging coil is A peak detection circuit is connected between the output terminal and ground, and detects the peak of the positive output waveform of this capacitor charging coil, and in response to this peak detection circuit, charging is performed by the output after the peak of the output waveform of the capacitor charging coil. The present invention provides a non-contact ignition device for an internal combustion engine, which includes a DC power supply circuit including a smoothing capacitor, and supplies charging voltage of the smoothing capacitor as a power source for the electronic ignition signal generation circuit. .

[Effect]

As a result, the smoothing capacitor is charged by the half-wave output on the capacitor charging side after charging the ignition capacitor of the capacitor charging coil.

〔Example〕

The present invention will be described below with reference to embodiments shown in the drawings.

In FIG. 1, 1 is a capacitor charging coil of a magnet generator, one end of which is grounded. 2.3 is a diode, 4 is an ignition capacitor, 5 is a primary coil 5a and 2
An ignition coil consisting of a secondary coil 5b, 6 an ignition plug, 7 a silisk forming a semiconductor switching element for ignition, and 8 its gate resistance. The circuit components 1 to 8 described above constitute a known capacitor discharge type ignition circuit.

Reference numeral 100 uses the output signal of a timing sensor 9 that generates an output signal at a reference position in synchronization with the rotation of the internal combustion engine as a human power source, and uses a DC power supply circuit 200 (described later) as a power source to electronically determine the ignition timing and generate an ignition signal. This is a known ignition timing control circuit that generates an electronic ignition signal.

In addition, 10.13, 14.20 are resistors, 11° and 17 are diodes, 18 is a Zener diode, 15 is a peak detection capacitor, 19 is a smoothing capacitor, 12 is a transistor, and 16 is a thyristor, and these make up the DC power supply circuit. 200. Then, the DC power supply circuit 200
Among them, resistance 10, 13. 14. 20. Diode 11, transistor 12, peak detection capacitor 15
The peak detection circuit 210 is composed of the thyristor 16 and the thyristor 16.

Next, the operation of the above configuration will be explained.

When a positive direction output (half-wave output on the capacitor charging side indicated by the solid line arrow in the figure) is generated in the capacitor charging coil 1 in synchronization with the rotation of the internal combustion engine, the diode 3, the ignition capacitor 4, and the primary coil of the ignition coil 5 5a, the ignition capacitor 4 is charged to the polarity shown. Next, the thyristor 7 is made conductive by the ignition signal generated in the ignition timing control circuit 100 that determines the ignition timing based on the reference signal generated in the timing sensor 9, and the charge in the ignition capacitor 4 is transferred to the anode of the thyristor 7. Cathode, ignition coil 5
A sudden discharge is caused through the primary coil 5a of the spark plug 6, a high voltage is generated in the secondary coil 5b, and an ignition spark is generated in the ignition plug 6. On the other hand, the negative direction output of capacitor charging coil 1 (half-wave output on the anti-capacitor charging side indicated by the broken line arrow in the figure)
are shorted by diode 2.

Next, the operation of the DC power supply circuit 200 will be described based on FIGS. 1 and 2, taking as an example the case where an 8-pole magnet generator is used.

The capacitor charging coil 1 charges the ignition capacitor 4 four times per rotation of the magnet generator, and the voltage waveform at the time of load becomes as shown in FIG. When there is, the dashed line indicates when it is not present). Further, the voltage waveform of the ignition capacitor 4 is as shown in FIG. 2(a). At this time, the positive direction output of the capacitor charging coil 1 charges the peak detection capacitor 15 through a resistor 10 and a parallel circuit of a diode 11 and a resistor 20, and the charging voltage waveform is as shown in Fig. 2 fc). become. Then, when the positive direction output voltage of the capacitor charging coil 1 passes the peak value and begins to fall, a part of the charge charged in the peak detection capacitor 15 is transferred to the resistor 20.10.
The capacitor is discharged through the charging coil l, and the voltage drop across the resistor 20 becomes the base-emitter voltage V of the transistor 12.
When IE (approximately 0.7V) is reached, this transistor 12 becomes conductive. When the transistor 12 becomes conductive, the charge in the peak detection capacitor 15 is transferred to the transistor 12.
, resistors 13 and 14, and a series circuit of diode 17 and capacitor 19, and a parallel circuit of Zener diode 18. When the voltage drop generated between the terminals of the resistor 14 due to the discharge current of the capacitor 5 (see FIG. 2(d)) reaches the gate trigger voltage VGT (approximately 0°7V) of the thyristor 16, the thyristor 16 becomes conductive. The positive output of the capacitor charging coil 1 charges the smoothing capacitor 19 via the anode/cathode of the thyristor 16 and the diode 17.

Here, the Zener diode 18 is connected to the smoothing capacitor 1
The terminal voltage of the smoothing capacitor 19, that is, the output voltage waveform of the DC power supply circuit 200 is as shown in FIG. 2(e).

By the way, since the charging of the smoothing capacitor 19 uses the period from when the output voltage of the capacitor charging coil 1 reaches its peak until it reaches zero, the charging voltage of the ignition capacitor 4 is not lowered.

Furthermore, charging of the peak detection capacitor 15 is performed during the period in which the positive direction output voltage of the capacitor charging coil 1 reaches a peak from zero, but the charging charge required for the peak detection capacitor 15 is the same as that of the ignition capacitor 4 and the smoothing capacitor. 19, the charging voltage drop of the ignition capacitor 4 is about 2% and can be ignored.

〔Effect of the invention〕

As described above, since the DC power supply circuit according to the present invention utilizes the positive direction output voltage of the capacitor charging coil after the peak value, there is not only almost no drop in the charging voltage of the ignition capacitor, that is, a drop in ignition performance. Since the capacitor charging coil can be grounded on one side, there is no need for additional wires, which is an excellent effect.

[Brief explanation of drawings]

FIG. 1 is an electric circuit diagram showing one embodiment of the device of the present invention, and FIG.
The figures are waveform diagrams of various parts for explaining the operation of the apparatus shown in FIG. 1. DESCRIPTION OF SYMBOLS 1... Capacitor charging coil, 4... Capacitor for ignition, 5... Ignition coil, 7... Cyrisk forming a semiconductor switching element for ignition, 19... Smoothing capacitor, 100... Electronic ignition Ignition timing control circuit forming a signal generation circuit, 200... DC power supply circuit, 210...
・Peak detection circuit.

Claims (1)

[Claims] One end of the capacitor charging coil of the magnet generator is grounded, the ignition capacitor is charged from the positive direction output terminal at the other end, and the ignition signal is turned on by the ignition signal from the electronic ignition signal generation circuit that electronically determines the ignition timing. In a non-contact ignition device for an internal combustion engine, in which the charge charged in the capacitor is discharged via a primary coil of an ignition coil via a semiconductor switching element for ignition, the connection between the positive direction output terminal of the capacitor charging coil and the ground is provided. a peak detection circuit that is connected to the capacitor charging coil and detects the peak of the positive output waveform of the capacitor charging coil; and a smoothing capacitor that is charged by the output after the peak of the output waveform of the capacitor charging coil in response to the peak detection circuit. A non-contact ignition device for an internal combustion engine, comprising a DC power supply circuit including a DC power supply circuit, and supplying the charging voltage of the smoothing capacitor as a power supply to the electronic ignition signal generation circuit.