KR910000036B1 - Condenser discharge type ignitor for engine - Google Patents

Abstract

The system of a closed type, increases ignition output power of the ignition plug for improving fuel efficiency and redycing air pollution from exhaust gas, and keeps a constant value of ignition power regardless of changes of battery voltage or engine speed for preventing deterioration of engine performance. The system comprises DC-DC converting circuit using IC (3), thyristor (19) for charging, condenser (16), ignition coil (20), an electric discharging circuit including IC (3) and transistors (7)(8)(9)(10), and choke coil (15) for keeping SCR (14).

Description

Capacitor Discharge Ignition System for Internal Combustion Engines

1 is an electric circuit diagram of a capacitor discharge type ignition device of the present invention.

2 is a waveform diagram of each part of the dynamic ignition device.

3 shows a capacitor charge and discharge voltage waveform, (a) is a capacitor charge and discharge voltage waveform of the conventional method (self-generation DC-DC conversion method), (b) is a capacitor charge of the capacitor discharge type ignition device of the present invention Discharge voltage waveform.

* Explanation of symbols for main parts of the drawings

1, 4, 5, 6, 24, 25, 26, 29, 30, 31, 33, 34, 35, 36, 37, 39, 41, 43, 44, 46: resistance

2, 16, 23, 38, 40, 45, 47: condenser

3: IC 7, 8, 27, 28, 42: transistor

9, 10: electrical effect transistor (FET) 11: boost transformer

12: bridge diode 13, 17, 18: diode

14, 19: thyristor 15: choke coil

20: ignition coil 21: engine distributor

22: ignition flash 32: voltage comparator

48: contact

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a capacitive discharge ignition system for an internal combustion engine, and more particularly to an ignition device of a closed loop type.

The induction ignition apparatus used in the related art can cut a direct current flowing through an inductor into a mechanical contact point of an engine distributor to obtain a high voltage. spark) occurs and burnout of contact and misfire due to this result in deterioration of engine performance.In case of transistor, capacitor using ignition device, thyristor and condenser which replace mechanical contact with transistor Although there is a discharge type ignition device, this is a method of obtaining a high voltage ignition output by storing electrical energy in a capacitor and discharging it instantaneously.

All of them are self-powered open-loop type using a DC-DC converter, so the charging time of the capacitor is too long, so the ignition output varies depending on the battery voltage or the engine speed. There is a drawback that this remarkably falls.

The present invention by increasing the ignition output applied to the spark plug to solve the above drawbacks significantly improve the combustion rate of the fuel in the engine cylinder, resulting in a fuel saving effect and contribute to preventing pollution due to exhaust Regardless of battery voltage fluctuations or engine speed (low speed-high speed), constant ignition output can be obtained at all times, preventing engine performance deterioration due to speed increase.

When the ignition device of the present invention will be described in detail with reference to FIG.

The switching regulator IC (3) causes square wave pulses to be alternately generated at the output terminals 11 and 13, the frequency of which is set by the resistor (1) and the condenser (2). Is determined.

The transistors 7 and 8 are alternately turned on and off by the square wave pulses generated alternately at the output terminals 11 and 13 of the IC 3 so that the transistors 9 and 10 When alternately turns on and off, the high voltage square wave pulse voltage is induced by the boost transformer 11 to the secondary winding (e). In other words, this part is part of the DC-DC converter.

The high-voltage square wave pulse voltage induced in the secondary winding (e) of the transformer 11 is rectified by the bridge diode 12 and then charged in the capacitor 16.

At this time, the charging current of the condenser 16 turns on the thyristor 19 so that it flows through the diodes 17 and 18 and the thyristor 19 without passing through the primary winding of the ignition coil 20. .

At this time, the time when the capacitor is charged is the period in which the contact point 48 in the engine distributor 21 is turned on. At this time, the transistor 28 is turned off, and thus the battery voltage V _B is transferred to the thyristor 19 through the resistor 26. Since the current flows through the gate, the thyristor 19 remains in the on state while the contact 48 is on.

The diodes 17 and 18 here are for compensating the breakdown voltage of the thyristor 19.

That is, the path through which the charging current of the capacitor 16 flows is from the (+) side of the bridge diode to the (1) side of the capacitor 16-diode 17 (18)-thyristor 19-bridge diode.

At this time, the charging voltage of the capacitor 16 rises and is divided by the resistors 34 and 35 so that the voltage applied to the terminal 5 of the voltage comparator 32 becomes higher than the reference voltage of the terminal 6. Since the voltage at the output terminal 7 of the comparator 32 is increased and the voltage at terminal 6 of the switching regulator IC 3 is increased to block the output voltage at the terminals 11 and 13, the charging voltage of the capacitor 16 no longer increases. It is kept constant. That is, the reference voltage of the sixth terminal of the voltage comparator 32 determines a voltage, that is, a set voltage, which determines a capacitor termination voltage of a predetermined value.

The reference voltage of terminal 6 of the voltage comparator maintains a constant voltage supplied from terminal 9 of the switching regulator IC 3.

At this time, the contact 48 of the engine distributor is configured to generate a spark in the spark plug 22 at the moment of opening. The moment the contact 48 is opened, the transistors 27 and 28 are turned on and the thyristor is turned on. (19) is turned off and away from the charging path of the capacitor (16). The voltage at terminal 15 of the switching regulator IC (3) becomes zero, and the terminals 11 and 13 of the IC (3) The output will be cut off.

On the other hand, instantaneous resistances 36, 37, 39, 41, 43, 44, 46, capacitors 38, 40, 45, 47, and transistors 42 at the point of contact 48 being opened. The thyristor 14 is composed of a high-voltage direct current voltage charged in the capacitor 16 by generating a short width square wave pulse from a gate trigger circuit and turning on the thyristor 14. Is instantaneously applied to the primary side of the ignition coil 20, and at this moment, the charging voltage of the capacitor 16 discharges through a discharge passage consisting of the primary winding of the ignition coil 20 of the capacitor 16. At this time, the discharging operation of the capacitor 16 is first discharged through the primary winding of the capacitor 16, the diode 13, the thyristor 14, the choke coil 15, and the ignition coil 20 during the half cycle. (16) is charged to the reverse polarity of the first time and then discharged in the opposite direction again through the capacitor 16, the ignition coil (20) primary winding-bridge diode (12), and again the capacitor (16) Recharge in the same direction.

The charging and discharging of the capacitor 16 is continued until the discharge passage is changed every half cycle until the charge energy is used up. During this period, the spark plug 22 connected to the secondary winding of the ignition coil 20 is sparked. Is generated to explode while igniting the mixed gas in the combustion chamber of the engine cylinder.

The diode 13 is for supplementing the reverse breakdown voltage of the thyristor 14 and the choke coil 15 is a protective element for preventing the thyristor 14 from being destroyed by a surge voltage.

Capacitor 23 is Tran registers 9 and 10 to alternately a surge voltage to the primary winding of the step-up transformer 11 when the switching occurs as there is impact the power supply side of the surge voltage absorbed sikimeuroseo single supply (V _B ) To secure the operation of all other circuits in common use.

The resistor 4 is connected to the dead-time regulating voltage terminal 7 for the pulse voltage by the outputs of the terminals 11 and 13 of the switching regulator IC 3 so as to keep the voltage of the terminal 7 at zero. This is to maximize the output pulse width.

As described above, in the condenser discharge type ignition device for an internal combustion engine, a DC-DC converter operates to charge the capacitor 16 to a desired voltage while the contact 48 in the distributor is closed. By supplying the high voltage electrical energy accumulated in 16) to the spark plug, it is possible to improve the combustion rate of the fuel and to maintain the end-of-charge voltage of the condenser 16 at the desired value by using the Peruuf method. Will be discharged.

2 shows waveforms of the respective parts of the ignition device, in which (a) and (b) are output terminal voltages (c) and (d) of switching regulator ICs (3). Drain voltage (e) of the (10) is the secondary winding voltage of the transformer 11, (f) is the voltage across the capacitor (g) of the capacitor 16, the primary winding voltage of the ignition coil (20), (h) is the voltage of the contact 48, (i) is the gate trigger voltage of the thyristor 14, (j) is the sixth terminal voltage of the switching regulator IC (3), (k) is the switching regulator IC Terminal voltage 15 of (3), (l) is the waveform of the gate trigger voltage of the thyristor (19). In the case of a four-cylinder engine vehicle, the relationship between the engine speed and the discharge cycle is the engine speed = 30 / discharge cycle [rpm].

Engine RPM = 30 / (2.8 × 10 ^-3 ) = 10714.3 [rpm]

That is, a constant ignition output can be obtained even up to 10,000 rpm.

3 shows the capacitor charging and discharging voltage waveforms. In the case of the conventional method 3a, when the engine speed increases from low speed to high speed, the discharge timing moves from t ₃ → t ₂ → t ₁ , and thus the capacitor charging voltage at the instant of discharge. Although the ignition output is decreased by decreasing (Vc ₃ → Vc ₂ → Vc ₁ ), the present invention shows that when the engine speed increases from low speed to high speed as shown in (b), the discharge timing is t ₃ → t ₂ → t ₁ . Even if it moves, the capacitor charge voltage is always discharged at a constant size (Vc), so the ignition output is always constant even if the engine speed increases to about 10,000rpm or more.

The circuit diagram of FIG. 1 increases the engine speed range to obtain a constant ignition output because increasing the power up ratio ratio of the boost transformer 11 of the DC-AC converter can shorten the interval from ₀ to t ₀ in FIG. 3b. You can do it.

The present invention can also increase Vc in FIG. 3B, that is, the magnitude (ignition output) of the capacitor charging voltage by increasing the set voltage at the resistor 33 in FIG. However, the ignition coil 20 of FIG. 1 can be increased within the range of insulation breakdown voltage of the secondary winding.

Referring to the operation and effect of the present invention configured as described above, the present invention is a conventional capacitor discharge type ignition device using a DC-DC converter of the self-power generation method is improved the engine performance than the induction ignition device, but even if the battery voltage is slightly When the engine speed is lowered or the engine speed is increased, the ignition output is significantly lowered. However, the present invention significantly improves the combustion rate of fuel in the combustion chamber of the engine cylinder even when the ignition output of the condenser discharge type ignition device is increased. In addition, the charging time is also significantly shorter than that of the conventional method, thereby reducing the charging time of the capacitor, thereby reducing the power consumed by the ignition device.

Furthermore, the ignition device of the present invention can arbitrarily adjust the ignition output which is impossible in the conventional method, and by increasing the transformer boosting range of the DC-DC converter, a constant ignition output can be obtained even at a very high engine speed (about 15,000 rpm). It is also possible to use. In addition, the vehicle's starting characteristics are very good, and it can greatly contribute to preventing pollution of the exhaust gas due to the improvement of the combustion rate, and also closes the combustion rate of the fuel to almost 100%, so that the intake / exhaust valve (valves) and the piston ring in the engine cylinder are This invention is useful because it is used almost semi-permanently because it extends the life of cylinder head and muffler remarkably and the electric current flowing in distributor contact is only tens of ㎃. to be.

Claims (4)

In the capacitor discharge type ignition device, the DC-DC conversion circuit using the forced drive generation method using the IC (3) and the primary winding of the ignition coil (20) do not pass through to detect the capacitor charging voltage when the capacitor (16) is charged. A capacitor discharge type ignition device for an internal combustion engine, comprising a feedback circuit configured to be charged through a thyristor (19) without a charge and to keep a constant voltage at the end of charging of the capacitor (16). The discharge circuit according to claim 1, wherein the forced drive oscillation circuit comprises an IC (3) and a transistor (7) (8) (9) (10). The element for protecting against breakdown voltage of the SCR 14, 19 used in charging and discharging, the choke coil 15 for preventing breakage of the SCR 14 due to surge. Circuit composed of. The circuit of claim 1, wherein the circuit is configured to be charged only when the charging contact (48) of the capacitor (16) is turned on in order to extend the life of the capacitor (16) and reduce power consumption of the ignition device.

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