JPS58126472A - Ignition device of internal-combustion engine - Google Patents

Abstract

PURPOSE:To have a small-sized and lightweight ignition coil by permitting a DC booster circuit to generate two kinds of boosted outputs with different voltages and by supplying one of them to the primary winding of the ignition coil and the other to the secondary. CONSTITUTION:The secondary side of a transformer 14 is constructed so as to generate two kinds of boosted outputs +VA, -VB with different voltages. The number of turns in No.1 booster 19 to output the boosted output voltage +VA is selected so that the voltage +VA becomes several tens to hundreds volts, and this boosted output voltage +VA given out by No.1 booster 19 is supplied to the primary winding of the ignition coil 26. The number of turns in No.2 booster 20 to output the other boosted output voltage -VB is selected so that -VB becomes several kilovolts in minus to -10kV, and this boosted output voltage -VB given out by No.2 booster 20 is supplied to the secondary side of ignition coil through capacitors C3, C4 and coils L1, L2.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an ignition system for an internal combustion engine, and more particularly to an ignition system that has a DC booster circuit for injecting ignition energy into the secondary side of an ignition coil in addition to a normal ignition system.

As a conventional ignition device of this type, for example, 5AE-75
034.7 (American Society of Automotive Engineers Paper No.), there is one as shown in FIG.

The characteristics of this ignition device are that there is no + common of the ignition coil 7, the primary winding 11ijJ7a and the secondary winding 7b are separated, and the secondary winding 7b has a DC/DC booster circuit.
A DC converter (Royer circuit) 12 is connected.

Based on the signal generated from the pickup coil 5 in accordance with the rotation of the rotor 6 of the electromagnetic signal generator, the power transistor 4 is turned on and off by the ignition signal output from the full-torque ignition unit 6, and the ignition coil 7 The current in the primary winding 7a of the ignition coil 7 is interrupted, thereby generating a high voltage in the secondary winding 7b of the ignition coil 7.

The high voltage generated in the secondary winding 7b is transferred to the center cord 9.
．． Distributor 8. Then, the spark plug 11 of each cylinder is sequentially guided between the electrodes of the spark plug 11 for each cylinder via the high tension cable 10 to cause discharge breakdown between the electrodes, thereby causing D C/D
Ignition energy is supplied from discharge capacitors C1 and C2 of the C converter 12.

The characteristics of this discharge waveform are shown in FIG. Breakdown voltage Vs is generated by intermittent current in primary winding 7a of ignition coil 7, and then sustained discharge voltage Vc is supplied from discharge capacitors CI and C2 during discharge period Ds.

When the distributor 80 rotor and the high voltage terminal are separated, the circuit resistance increases and the recovery voltage VR increases, so that the discharge ends.

In addition, in FIG. 1, 1 is a battery, and 2 is an ignition switch.

However, such a conventional ignition system for an internal combustion engine uses a DC/D booster circuit called a Royer circuit.
Since it uses a C converter, the power conversion efficiency is poor.
In order to obtain the necessary discharge breakdown voltage, it was necessary to prepare a large ignition coil with a large winding ratio.

As a result, the power consumption of the ignition coil increases, resulting in problems such as a decrease in vehicle fuel efficiency.

This invention was made by focusing on the conventional problem, and in the ignition system for an internal combustion engine as described above, two types of voltages with different voltages are connected to the DC/DC converter, which is a DC boost circuit. A step-up output is generated, and one step-up output is supplied to the primary winding of the ignition coil, and the other step-up output is supplied to the secondary winding of the ignition coil. The aim is to reduce the number of cases and solve the above-mentioned problem.

Embodiments of the present invention will be described below with reference to FIG. 6 and subsequent drawings.

FIG. 3 is a circuit diagram showing an embodiment of the present invention.
In this figure, parts corresponding to those in FIG. 1 are designated by the same reference numerals, and explanations of those parts will be omitted.

In FIG. 3, the DC/DC converter 16 is
3- Apply battery voltage (+12V) to the middle tap of the primary winding 14a of the transformer 14, and apply several K11z to both terminals.
An oscillation circuit 15 that generates a signal 0 with a frequency of up to ~10 Kl (z and a signal O obtained by inverting it).It is composed of an ε ivy follower 16, which serves as an inheatance converter, and a flip-flop (F/F) circuit 18. The output of the circuit is applied. Then, as the oscillation frequency of the oscillation circuit 15, the iron loss of the core (ferrite) of the transformer 14, l/
Darlington connected transistors Ql and Q of F circuit 18
Taking into account the switching characteristics of No. 2 and the copper loss of the winding of the transformer 14, the optimum oscillation frequency (see FIG. 4) at which the total loss is the lowest value is selected and operated.

Further, the secondary side of the transformer 14 is configured to generate two types of boosted output terminals VA and -VB having different voltages.

That is, this is done by dividing the secondary windings 14b and 14c as shown in the figure, or by dividing the voltage from one secondary winding and dividing it into two.

Then, the number of windings of the 4-1st booster 19 that outputs one boosted output voltage element VA is selected so that the voltage element VA is several tens to several hundreds of volts, and this first booster 19
The boosted output voltage element VA output from the ignition coil 260
Supplies to the primary winding.

In addition, the number of windings of the second booster 20 that outputs the other boosted output voltage -VB is selected so that -VB is a few KV to -IOKV, and the boosted voltage output from this second booster 20 is The output voltage -VB is supplied to the secondary side of the ignition coil 26 via capacitors C3, C4 and coils L1, L2.

In other words, this voltage -VB is always charged in a large-capacity storage capacitor C3, and a discharge capacitor C4 with a smaller capacitance than C3 is connected to the coil L1 with low AC loss and the anode of the capacitor C3. is connected through a connection point with a grounded diode D.

Note that the coil L2 is provided to lengthen the discharge period D2 (FIG. 2).

In this way, the primary winding 26a of the ignition coil 26
Since the boosted output voltage voltage VA higher than the voltage of the battery 1 is applied to the ignition coil 26, the winding ratio of the ignition coil 26, which is required to generate the necessary discharge breakdown voltage Vs, can be significantly reduced.

Moreover, since the boosted output voltage -VB, which is the ignition energy, is connected and supplied to the secondary winding 26b of the ignition coil 26, the core of the ignition coil 26 can be made smaller, and in addition to the effect of reducing the winding ratio, the ignition coil 26 can be made ultra-small and lightweight. Thereby, the power loss of the ignition coil 26 can be significantly improved.

However, since the primary side voltage of this ignition coil 26 is high,
A high-voltage transistor is required to turn on and off the voltage of the primary winding 26a as a through-power transistor 27.

Therefore, as shown in the figure, a high voltage semiconductor element Q3. A power transistor 27 formed by cascading transistors Q4 or, as shown in FIG. 5, Darlington connected transistors Qs, Q6 can be used.
And Q? , QB are connected in cascade.

However, in order to increase the power conversion efficiency of the transformer 14 to 80 to 90ch and reduce power consumption, the boosted output voltage -VB is constantly charged to the large capacitor C3, and the discharge breakdown caused by the ignition coil 26 is prevented. The sustained discharge voltage (FIG. 2) after generation of voltage Vs VC is obtained by discharging the discharge capacitor C4.

That is, the charge on capacitor C3 slowly moves to capacitor C4 via coil L1.

Note that an example of the component configuration of the ignition device in the above embodiment is shown in the sixth example.
It is shown in FIG.

FIG. 6 shows the micro ignition coil 26. A power supply circuit 29 in which a full-circuit ignition unit 6 and a DC/DC converter 16 are integrated. Distributor 8, center code q
, and r: i-tension cable 10 .

Figure 7 shows I) Distributor 0.00, which has a built-in power supply from a C/DC converter 16, an ultra-compact ignition coil 26, and a printed compact full-circle ignition unit 6. and high tension cable 10
This is an example of the component configuration of an ignition device consisting of three types.

Note that it is effective to use an open magnetic circuit coil in order to improve the efficiency of this ultra-small ignition coil 26.

As explained above, the ignition device for an internal combustion engine according to the present invention generates two types of boosted outputs with different voltages from its DC booster circuit, and sends one of them to the primary winding of the ignition coil. Since the other side is supplied to the secondary winding of the ignition coil, the ignition coil can be made smaller and lighter, and power consumption can also be reduced, which has the effect of improving the fuel efficiency of the vehicle. .

[Brief explanation of the drawing]

FIG. 1 is a circuit diagram showing an example of a conventional ignition system for an internal combustion engine, FIG. 2 is a discharge characteristic diagram in FIG. 1, FIG. 6 is a circuit diagram showing an embodiment of the present invention, and FIG. The figure shows the DC in Figure 6.
A diagram showing the relationship between the oscillation frequency of the 8-oscillation circuit and the loss of each part in the /DC converter. Figure 5 is a circuit diagram showing different examples of the power transistor in Figure 6. and FIG. 4 are explanatory diagrams showing different component configurations of the ignition device of FIG. 3, respectively. 1...Battery 2...Ignition switch 3
...Full-torra ignition unit 4.27.28...Power transistor 7.26...
Ignition coil 8... Distributor 11... Spark plug i2
．． i6...DC/DC converter (DC boost circuit) Figure 1L
J Figure 2 Procedural Amendment (Spontaneous) March 8, 1980 Director General of the Japan Patent Office Shima 1) Mr. Haruki ■, Indication of Case Patent Application No. 1987-9768 2, Title of Invention 3 Amendment Case for Ignition Device of Internal Combustion Engine Patent applicant: 2-2 Takaracho, Kanayō-ku, Yokohama-shi, Kanagawa Prefecture (399) Nissan Motor Co., Ltd. 4 Agent: 5-5 Higashiikebukuro 1-chome, Toshima-ku, Tokyo 5. Scope of patent claims of the specification subject to amendment Correction as per attached sheet + Eiji
・Claim 1 An ignition coil, an ignition circuit for completely intermittent current in the primary winding of the ignition coil, a spark plug provided for each cylinder of an internal combustion engine, and a secondary winding of the ignition coil. A distributor that distributes and sequentially supplies all of the generated high voltage to each of the spark plugs, boosts the DC power supply voltage, charges a capacitor, and connects the secondary winding of the ignition coil and all valves of the distributor to the In an ignition system for an internal combustion engine, which includes a DC booster circuit that injects ignition energy into a spark plug, the DC booster circuit generates two types of boosted outputs with different voltages, and one of the boosted outputs is connected to all of the ignition coils. The boost output of the other is supplied to the primary winding of the ignition coil, and the boost output of the other is supplied to the secondary winding of the ignition coil. Characteristics of the ignition system for internal combustion engines.

Claims (1)

[Scope of Claims] 1. An ignition coil, an ignition circuit that intermittents the primary line current of the ignition coil, a spark plug provided for each cylinder of an internal combustion engine, and a secondary winding of the ignition coil. a distributor that distributes and sequentially supplies a high voltage to each of the spark plugs; and a distributor that boosts the DC power voltage to charge a capacitor and supplies the high voltage to the spark plugs via the secondary winding of the ignition coil and the distributor. In an ignition system for an internal combustion engine, the DC booster circuit is configured to generate two types of boosted outputs with different voltages, and one of the boosted outputs is sent to the primary of the ignition coil. An ignition device for an internal combustion engine, characterized in that the boosted output of the other side is supplied to the secondary winding of the ignition coil.