JPS585092Y2 - internal combustion engine ignition system - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a non-contact ignition device for an internal combustion engine, and particularly to an ignition signal generation circuit thereof.

In general, in non-contact ignition devices for internal combustion engines, the size of the ignition signal width affects the ignition performance, and for example, ignition failure may occur due to the signal width being too large.

In other words, a capacitor is charged with a DC power source obtained by rectifying the AC output of the generator coil of a magnet generator, and a silisk is installed in the discharge circuit of this capacitor in series with the ignition coil, and an ignition signal is generated at the ignition position of the engine. In the well-known capacitor discharge type ignition device, the ignition signal from the generator is applied to the gate of the thyristor to make the thyristor conductive, and the discharged charge of the capacitor is discharged to the ignition coil to ignite the engine. When an ignition signal with a large signal width is applied to the gate of the cyrisk from an ignition signal generator at a certain position, the cyrisk continues to be conductive while the ignition signal is applied to the gate of the cyrisk, so that the capacitor is During that period, the charging DC power source is short-circuited by Cyrisk, and the period for charging the capacitor in preparation for the next engine ignition is shortened, resulting in insufficient charging. Due to the holding action, a short-circuit current flows through the cylisk, which may cause it to turn off, and there is a risk of ignition failure due to the next ignition signal being applied to the cylisk before it has been fully charged.

In other words, the time width of the ignition signal needs to be set appropriately so that it does not become too large.

The present invention has been developed in view of the above, and is an invention that can generate an ignition signal with an appropriate time width by using the positive and negative direction voltages even when the time width of the voltage generated by the signal generator is long. A contact ignition device is provided.

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

In Fig. 1, 1 is a magnet generator which has a generating coil 2 and is driven by the engine, and 3 is an ignition signal generator which synchronizes with the engine and generates ignition signals in positive and negative directions in accordance with the ignition timing. Occur.

5 is an ignition coil having a primary coil 6 and a secondary coil 7; the primary coil 6 is connected to the charge/discharge capacitor 4, and the secondary coil 7 is connected to a spark plug 8.

9 is a diode that rectifies the positive half wave of the AC output of the generator coil 2 of the magnet generator 1 to charge the charging/discharging capacitor 4; 10 is a diode that transfers the electric charge charged in the capacitor 4 to the primary coil of the ignition coil 5 This is a cyrisk installed in the circuit that causes the discharge to occur.

13 is a diode 1 caused by the positive half wave of the ignition signal generator 3.
This is a charging/discharging capacitor for ignition signals that is charged via 1.12.

16 is a diode 15 due to the negative half wave of the ignition signal generator.
．． This is a thyristor which is triggered via the ignition signal charge/discharge capacitor 14 and causes the charged charge of the ignition signal charging/discharging capacitor 13 to be discharged to the gate of the thyristor 10.

FIG. 2 is a waveform diagram for explaining the operation of the apparatus shown in FIG. 1, and the horizontal axis represents the rotational angular position of the engine.

Figure a shows the no-load voltage waveform of the generator coil 2 due to engine rotation, and the figure shows the voltage waveform of the charging/discharging capacitor charged by the above voltage. Indicates that you will be late.

Figure C shows the ignition signal waveform of the ignition signal generator 3, Figure d
is a charging voltage waveform of the ignition signal charge/discharge capacitor 13 charged by the ignition signal, and e in the figure is a trigger signal waveform of the thyristor 10 due to discharge of the ignition signal charge/discharge capacitor 13.

Next, the operation of the apparatus of the embodiment shown in FIG. 1 will be explained using a second operation waveform chart.

First, when the magnet generator 1 rotates due to the rotation of the engine, an alternating current output (■) is generated in the generator coil 2.

This AC output is shown in Figure 2a.

This alternating current output is rectified by a diode 9, and the charge/discharge capacitor 4 is charged by the output in only a certain direction through the primary coil 6 of the ignition coil 5 as shown in the charging voltage waveform Vc.

Now, if a trigger signal is given to the gate of thyristor 10 at the ignition timing required by the engine to make thyristor 10 conductive, the charge accumulated in charge/discharge capacitor 4 will be transferred to thyristor 1.
0 and is discharged to the primary coil of the ignition coil 5, a high voltage is generated in the secondary coil I of the ignition coil 5, and an ignition spark is generated at the ignition plug 8.

This thyristor 10 is controlled by the signal output vsct generated in the ignition signal generator 3.

That is, the generation phase of the ignition signal sG that is generated in synchronization with the engine is set as shown in Figure 2C from the relationship with the charging/discharging capacitor 4's charging position.The positive half wave of this ignition signal is The ignition signal charging/discharging capacitor 13 is charged via the D/1 odes 11 and 12.

The charging waveform vsct is shown in FIG. 2d. When the ignition signal charging/discharging capacitor 13 is charged, the polarity of the ignition signal vsct of the ignition signal generator 3 is reversed to become a negative half wave, and this negative half wave voltage is passed through the diode 14.15. Apply to the gate of thyristor 16 and its trigger level■.

At the point when the thyristor 16 reaches a conductive state, the electric charge stored in the ignition signal charging/discharging capacitor 13 is applied to the gate of the thyristor 10 via the thyristor 16, and the thyristor 10 becomes conductive as shown in FIG. 2e. The trigger signal Vs is generated to cause the spark plug 8 to generate an ignition spark.

The signal that triggers this thyristor 10 is constituted by the discharge current of the ignition signal charging/discharging capacitor 13 which causes the thyristor 16 to conduct due to the negative signal of the ignition signal generator 3 and passes through this, and therefore, the signal The time width is determined by the discharge time constant, and by inserting a resistor into the discharge circuit and setting the discharge time constant, the width of the ignition signal applied to the thyristor 10 can be freely set. It is possible to obtain an ignition signal with a small signal width necessary and sufficient to make the thyristor 10 conductive, and it is possible to reliably bring the thyristor 10 into the cut-off state after the charging/discharging capacitor 40 is discharged.

The above describes a capacitor charge/discharge type non-contact ignition device that uses a magnet generator as a power source, but a battery and DC-D
A similar effect can be obtained with a capacitor charge/discharge type non-contact ignition device using a C converter as a power source.

As described above, the present invention is a capacitive discharge type ignition device in which a capacitor is charged by one polarity voltage of an ignition signal generated from an ignition signal generator, and the capacitor's discharge circuit is made conductive by the other polarity voltage. Since the control signal for the ignition coil control silisk is configured by the discharge current passing through the silisk, it is possible to obtain an ignition signal with a small signal width even when the signal time width of the ignition signal generator is large. It can solve the problem of deterioration in ignition performance due to insufficient charge for discharging the ignition coil due to It is possible to provide an effective signal generating device because the battery can be charged with a sufficient amount of discharge current.

[Brief explanation of drawings]

FIG. 1 is an electric circuit diagram showing an embodiment of the present invention, and FIG. 2 is an operational waveform diagram for explaining the operation of the embodiment of FIG. In the figure, 1 is a magnet generator, 2 is a generator coil, 3 is an ignition signal generator, 4 is a charge/discharge capacitor, 6 is an ignition coil,
8 is a spark plug, 10.13 is a cyrisk, and 16 is an ignition signal charging/discharging capacitor.

Claims (1)

[Scope of utility model registration request] A first cyrisk is connected in series with the ignition coil to a discharge circuit of a first capacitor charged from a DC power supply, and the electrical charge of the first capacitor is discharged to the ignition coil by conduction of the thyrisk. □, which generates an ignition voltage, includes a signal generator that generates an AC signal voltage in response to the rotation of the engine, a second capacitor that is charged by the unidirectional polarity voltage of the AC signal voltage, and a second capacitor that is charged by the one-way polarity voltage of the AC signal voltage. a second thyristor provided in a path/path capable of discharging the charge of the capacitor and triggered by a voltage of the other polarity of the alternating current signal voltage, and discharging the second capacitor passing through the second thyristor; An internal combustion engine ignition device configured to trigger the first sirisk by an electric current.