JPH0579827B2 - - Google Patents

Description

[Detailed description of the invention] (Industrial application field) The present invention relates to a non-contact ignition device for an internal combustion engine.

(Prior Art) Conventionally, an ignition thyristor charges an ignition capacitor with the positive output of a capacitor charging coil of a magnet generator, and conducts by an ignition signal from an electronic ignition signal generation circuit that electronically determines the ignition timing. The charge in the ignition capacitor is discharged through the primary coil of the ignition coil to generate an ignition spark at the ignition plug. Further, the charging voltage of the signal source capacitor charged by the negative output of the capacitor charging coil is supplied to the electronic ignition signal generation circuit as a power supply voltage, and a voltage regulator is connected in series with the signal source capacitor. There is a voltage regulator that conducts only when the charging voltage drops and charges the signal source capacitor with the negative output of the capacitor charging coil (for example,
Publication No. 30473).

(Problem to be Solved by the Invention) However, in the conventional device described above, when the charging voltage of the signal source capacitor is sufficiently high, the voltage regulator maintains the cut-off state and the negative half-wave output of the capacitor charging coil is disabled. Under load, the negative half-wave voltage of the capacitor charging coil and the charging voltage of the ignition capacitor due to the lack of armature reaction increase linearly as the rotation speed increases, exceeding the withstand voltage of the element and causing destruction. There is a problem of inviting

Therefore, the present invention prevents excessive heat generation in the capacitor charging coil by flowing positive and negative currents in a well-balanced manner without wasting the capacitor charging coil, and also prevents destruction of the element due to overvoltage.

(Means for Solving the Problems) Therefore, the present invention uses an electronic ignition signal generation circuit that charges an ignition capacitor with the positive output of a capacitor charging coil of a magnet generator and electronically determines the ignition timing. The charged charge of the capacitor is discharged to the primary coil of the ignition coil through the ignition semiconductor switching element which is turned on by the ignition signal, and the charging voltage of the signal source capacitor is further charged by the negative output of the capacitor charging coil. is supplied as a power supply voltage to the electronic ignition signal generation circuit, the voltage regulator being connected in series with the signal source capacitor, and the voltage regulator being connected between the capacitor charging coil and the ignition capacitor; The present invention provides a non-contact ignition device for an internal combustion engine, comprising an auxiliary charging circuit that charges the ignition capacitor with the negative output of the capacitor charging coil when the voltage regulator is cut off.

(Function) As a result, the signal source capacitor is charged via the voltage regulator by the negative output of the capacitor charging coil, and when the charging voltage of this capacitor exceeds a predetermined value, the voltage regulator shuts off and the capacitor charging coil The negative direction output charges the ignition capacitor via the auxiliary charging circuit.

(Example) The present invention will be described below with reference to an example shown in the drawings. In the first embodiment shown in FIG. 1, 1 is a capacitor charging coil of a 12-pole multi-pole magnet generator driven by an internal combustion engine, and 2 is a timing sensor that generates an output signal at the reference position of the internal combustion engine. ,3,
4 is a diode, 5 to 10 are resistors that constitute the voltage regulator Re, thyristor, Zener diode,
They are resistors, transistors and diodes. 1
1 is a signal source capacitor, 12 is a diode, 1
3 and 18 are diodes and Zener diodes constituting an auxiliary charging circuit, and 14 is an ignition capacitor. Reference numeral 15 designates an electronic ignition signal generation circuit that uses the output signal from the timing sensor 2 as a reference input signal and the charging voltage of the signal source capacitor 11 as the power supply voltage to electronically calculate the ignition timing and generate an ignition signal. . 16 is a thyristor forming a semiconductor switching element for ignition; 17 is a thyristor 16
gate resistance, 19 is the ignition coil, 19a, 1
9b is its primary coil and secondary coil, and 20 is a spark plug.

Next, the operation of the above configuration will be explained.
At the positive half-wave output of capacitor charging coil 1,
The ignition capacitor 14 is charged through the route of capacitor charging coil 1 → diode 12 → ignition capacitor 14 → primary coil 19a of ignition coil 19 → diode 4. Then, the thyristor 16 becomes conductive due to the ignition signal generated in the electronic ignition signal generation circuit 15 at the ignition timing, and the ignition capacitor 1
4 is transferred from the ignition capacitor 14 to the anode/cathode of the thyristor 16 to the ignition coil 19.
A sudden discharge is caused in the path of the primary coil 19a to generate a high voltage in the secondary coil 19b, causing an ignition spark to be generated in the ignition plug 20.

In addition, the signal source capacitor 11 is charged by the negative half-wave output of the capacitor charging coil 1 through the path of capacitor charging coil 1 → collector/emitter of transistor 9 → diode 10 → signal source capacitor 11 → diode 3. . When the charging voltage of the signal source capacitor 11 reaches a predetermined value, the Zener diode 7 becomes conductive, and the signal source capacitor 11 is charged in the path of the signal source capacitor 11 → Zener diode 7 → the gate/cathode of the thyristor 6. Discharge the charge. As a result, the thyristor 6 becomes conductive, and the base current of the transistor 9 is bypassed, so that the transistor 9 is cut off and the charging current of the signal source capacitor 11 is cut off. At this time, due to the excessive induced voltage generated in the capacitor charging coil 1, the capacitor charging coil 1 → Zener diode 18 → diode 13 → ignition capacitor 14 → primary coil 19a of the ignition coil 19 → diode 3 is used for ignition. Charge the capacitor 14.

As a result, the current due to the negative half-wave output of the capacitor charging coil 1 is transferred to the signal source capacitor 11.
Alternatively, the current flows through the ignition capacitor 14 in a well-balanced manner with the current from the positive half-wave output and without waste, preventing excessive heat generation in the capacitor charging coil 1, and the negative half-wave output from the capacitor charging coil 1 with no load. As a result, not only does the negative half-wave output voltage of the capacitor charging coil 1 not become excessive, but also the armature reaction caused by the flow of negative current causes the ignition capacitor 1 to
This prevents the charging voltage of the capacitor charging coil 1 from becoming excessive, and even if the charging voltage of the ignition capacitor 14 at high speed becomes insufficient due to this armature reaction, the negative half of the capacitor charging coil 1 is By additionally charging the ignition capacitor 14 by the wave output,
To compensate for insufficient charging of the ignition capacitor 14 in the high speed rotation range.

FIG. 2 shows a second embodiment of the present invention, in which a diode 26, a resistor 2
7, 28, a short-circuit open circuit SO consisting of a thyristor 29, a resistor 30, and a transistor 31 is provided in parallel with the capacitor charging coil 1, and a resistor 3
A high voltage responsive short circuit HS consisting of 2, 33 and a thyristor 34 is provided in parallel with the short circuit opening circuit SO.

According to this second embodiment, the positive half-wave output of the capacitor charging coil 1 is short-circuited by the transistor 31, and when this short-circuit current exceeds a predetermined value, the thyristor 29 is turned on and the transistor 31 is cut off.
As a result, the short-circuit current in the capacitor charging coil 1 is abruptly interrupted and a high voltage is induced.The ignition capacitor 14 is charged by this high voltage, and when the induced high voltage exceeds a predetermined value, the thyristor 3
conducts and shorts out the high voltage.

FIG. 3 shows a third embodiment of the present invention, in which a resistor 21, a Zener diode 23, a thyristor 2
4 and a diode 25 constitute a voltage regulator.

According to this third embodiment, when the voltage of the signal source capacitor 11 is below a predetermined value at the rise of the negative half-wave output of the capacitor charging coil 1, the capacitor charging coil 1→thyristor 24→diode 2
5→signal source capacitor 11→diode 3, the signal source capacitor 11 is charged. Furthermore, when the negative half-wave output of the capacitor charging coil 1 rises, if the voltage of the signal source capacitor 11 is higher than a predetermined value, the Zener diode 23 becomes conductive, and the gate current of the thyristor 24 changes from the resistor 21 to
The thyristor 24 is not conductive because it is bypassed by the path of the Zener diode 23. Therefore, in this negative direction half-wave output, capacitor charging coil 1 →
The ignition capacitor 14 is charged through the path of Zener diode 18 → diode 13 → ignition capacitor 14 → primary coil 19a of ignition coil 19 → diode 3.

In each of the above-described embodiments, the Zener diode 18 of the auxiliary charging circuit has a short interval in which the transistor 9 or the thyristor 24 conducts in the high-speed rotation range, so that no reverse bias is applied to the thyristor 16, and the thyristor 16 is turned off. Although this is to prevent failure, it can be omitted depending on how the constants of the signal source capacitor 11 and the electronic ignition signal generation circuit 15 are selected.

〔Effect of the invention〕

As described above, in the present invention, the positive and negative outputs of the capacitor charging coil flow in a well-balanced manner and without waste, and it is possible to prevent excessive heat generation of the capacitor charging coil, and to reduce the negative voltage of the capacitor charging coil and ignition. This has the excellent effect of preventing the charging voltage of the capacitor from becoming excessive, thereby preventing destruction of the element due to overvoltage.

[Brief explanation of drawings]

1 to 3 are electrical circuit diagrams respectively showing first to third embodiments of the apparatus of the present invention. 1... Capacitor charging coil, 11... Signal source capacitor, 13, 18... Diode and Zener diode forming the auxiliary charging circuit, 14...
...Ignition capacitor, 15...Electronic ignition signal generation circuit, 16...Thyristor forming a semiconductor switching element for ignition, 19...Ignition coil, Re...
...voltage regulator.

Claims (1)

[Claims] 1 The ignition capacitor is charged by the positive output of the capacitor charging coil of the magnet generator, and the ignition timing is electronically determined via the ignition semiconductor switching element which is made conductive by the ignition signal from the electronic ignition signal generation circuit. The charge in the capacitor is discharged to a primary coil of an ignition coil, and the charge voltage of a signal source capacitor charged by the negative output of the capacitor charging coil is supplied as a power supply voltage to the electronic ignition signal generation circuit. a voltage regulator connected in series with the signal source capacitor; and a voltage regulator connected between the capacitor charging coil and the ignition capacitor, the negative direction output of the capacitor charging coil when the voltage regulator is cut off; a non-contact ignition device for an internal combustion engine, comprising: an auxiliary charging circuit that charges the ignition capacitor by the ignition capacitor;