JPS61286581A - Contactless ignition device for internal-combustion engine - Google Patents

Abstract

PURPOSE:To prevent the occurrence of undue generation of heat in a coil, by installing a voltage regulator in series with a signal source condenser to be charged by a negative sense output of the condenser charging coil of a magnetogenerator, while possess an auxiliary charging circuit conducive at a time when this voltage regulator is cut off. CONSTITUTION:A device bearing the above caption charges an ignition condenser 14 with a positive sense output of a condenser charging coil 1 of a magnetogenerator, and discharges the charged voltage of the condenser 14 to an ignition coil 19 via a thyristor 16 being conducted by an ignition signal out of an electronic type ignition signal generating circuit 15. Also it feeds the circuit 15 with the charged voltage of a signal source condenser 11 to be charged by a negative sense output of the coil 1 as supply voltage. In this case, a voltage regulator Re is connected to the signal source condenser 11 in series, while both auxiliary charging circuits 13 and 18, which charges the ignition condenser 14 with the negative sense output of the charging coil 1 at a time when the voltage regulator Re is cut off, are connected to an interval between the charging coil 1 and the ignition condenser 14.

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. Some voltage regulators conduct only when the charging voltage drops and charge the signal source capacitor with the negative output of the capacitor charging coil (for example,
(Japanese Patent Application Laid-Open No. 60-30473).

(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 transferred to one of the ignition coils through an ignition semiconductor switching element that conducts in response to an ignition signal.
A charging voltage of a signal source capacitor charged by a negative output of the capacitor charging coil is supplied to the electronic ignition signal generating circuit as a power supply voltage, the capacitor being connected in series with the signal source capacitor. and an auxiliary charger connected between the capacitor charging coil and the ignition capacitor to charge the ignition capacitor with the negative output of the capacitor charging coil when the voltage regulator is cut off. A non-contact ignition device for an internal combustion engine is provided.

(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 the capacitor charging. The negative output of the coil charges the ignition capacitor via the auxiliary charging circuit.

(Example) The present invention will be described below with reference to embodiments 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, 2 is a timing sensor that generates an output signal at a reference position of the internal combustion engine, and 3 .4 is a diode, and 5 to 10 are resistors, silices, Zener diodes, resistors, transistors, and diodes that constitute the voltage regulator Re. 11 is a signal source capacitor, 12 is a diode, 1
3.18 is a diode and a Zener diode that constitute 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 gate resistor of thyrisk 16, 19 is an ignition coil, 19a,
19b is its primary coil and secondary coil, and 2o is a spark plug.

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

The ignition capacitor 14 is charged by the positive half-wave output of the capacitor charging coil 1 through the path of capacitor charging coil 1 - diode 12 - ignition capacitor 14 -> primary coil 19a of ignition coil 19 -> diode 4. Then, the thyristor 16 is made conductive by the ignition signal generated in the electronic ignition signal generation circuit 15 at the ignition timing, and the charged charge of the ignition capacitor 14 is transferred from the ignition capacitor 14 to the anode/cathode of the thyristor 16 to the ignition coil 19. 1
A sudden discharge is caused in the path of the secondary coil 19a to generate a high voltage in the secondary coil 19b, causing the ignition plug 20 to generate an ignition spark.

In addition, at the negative half-wave output of the capacitor charging coil 1,
Capacitor charging coil 1 → collector of transistor 9
Emitter diode 1〇-signal source capacitor 11→
The signal source capacitor 11 is charged through the path of the diode 3. Then, 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 1
1 is discharged. 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 transient induced voltage generated in the capacitor charging coil 1, in the path of the capacitor charging coil 1 → Tsuner diode 18 → diode 13 → ignition capacitor 14 → primary coil 19a of the ignition coil 19 - diode 3, Charge the ignition capacitor 14.

As a result, the current caused by the negative half-wave output of the capacitor charging coil 1 flows through the signal source capacitor 11 or the ignition capacitor 14 in a well-balanced manner with the current caused by the positive half-wave output, and without waste. In addition to preventing excessive heat generation of the capacitor charging coil 1, the negative half-wave output of the capacitor charging coil 1 does not become a no-load state, so not only does the negative half-wave output voltage of the capacitor charging coil 1 not become excessive, This prevents the charging voltage of the ignition capacitor 14 from becoming excessive due to the armature reaction caused by the flow of directional current, and furthermore prevents the charging voltage of the ignition capacitor 14 from becoming insufficient at high speeds due to this armature reaction. Even so, by additionally charging the ignition capacitor 14 by the negative half-wave output of the capacitor charging coil l, insufficient charging of the ignition capacitor 14 in the high speed rotation range is compensated for.

FIG. 2 shows a second embodiment of the present invention. In contrast to the first embodiment, a short-circuit open circuit SO consisting of a diode 26, a resistor 27, 28, a thyristor 29, a resistor 30, and a transistor 31 is connected to a capacitor charging coil. 1, and a high voltage responsive short circuit H3 consisting of resistors 32 and 33 and a thyristor 34 is provided in parallel with the short circuit open 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 of the capacitor charging coil 1 is abruptly cut off 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 34 becomes conductive and the ignition capacitor 14 is charged. Short circuit the voltage.

FIG. 3 shows a third embodiment of the present invention, in which a resistor 21,
A Zener diode 23, a thyristor 24, and a diode 25 constitute a voltage regulator.

According to this third embodiment, when the voltage of the signal source capacitor 11 is lower than a predetermined value when the negative half-wave output of the capacitor charging coil 1 rises, the capacitor charging coil 1 → thyristor 24 → diode 25 → signal source capacitor 11
→Charge the signal source capacitor 11 through the diode 3 path. 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 Zener diode 23. The thyristor 24 is not conductive because it is bypassed by the path. Therefore, with this negative direction half-wave output, the ignition capacitor 14 is charged through the path of capacitor charging coil 1 → Tsuner diode 18 → diode 13 → ignition capacitor 14 → primary coil 19a of ignition coil 19 → diode 3. do.

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 it is necessary to prevent this from becoming impossible, 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.

(Effects 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. By preventing the negative direction voltage and the charging voltage of the ignition capacitor from becoming excessive,
This has the excellent effect of preventing element destruction 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. DESCRIPTION OF SYMBOLS 1... Capacitor charging coil, 11... Signal source capacitor, 13.18... Diode and Zener diode forming an auxiliary charging circuit, 14... Ignition capacitor, 15... Electronic ignition signal Generation circuit, 16...
・Thyristor, which serves as a semiconductor switching element for ignition;
19...Ignition coil, Re...Voltage regulator.

Claims (1)

[Claims] The ignition capacitor is charged by the positive output of the capacitor charging coil of the magnet generator, and the ignition semiconductor switching element is turned on by an ignition signal from an electronic ignition signal generation circuit that electronically determines the ignition timing. Discharging the charge of the capacitor to the primary coil of the ignition coil, and further supplying the charging voltage of the signal source capacitor charged by the negative output of the capacitor charging coil to the electronic ignition signal generation circuit as a power supply voltage. A voltage regulator is connected in series with the signal source capacitor, and is connected between the capacitor charging coil and the ignition capacitor, and when the voltage regulator is cut off, the negative output of the capacitor charging coil A non-contact ignition device for an internal combustion engine, comprising an auxiliary charging circuit that charges the ignition capacitor.