JPS5823270A - Ignition device for internal combustion engine - Google Patents

Abstract

PURPOSE:To improve ignition performance, by providing a circuit, in which applicable each ignition coil is driven at each ignition timing, and obtaining high energy of ignition in a spark plug from low power consumption. CONSTITUTION:An ignition signal generator circuit 9 is input with an ignition timing signal S1 and cylinder decision signal S2 to decide ignition timing of each cylinder and output ignition signals SA-SD becoming ''0'' level at every ignition timing of each cylinder. This ignition signal turns off applicable transistors Q1-Q4 to disconnect a primary current in an applicable ignition coil and generate high voltage in a secondary coil. In this way, the necessity for a distributor is eliminated to substantially reduce energy loss in a transmission route and obtain high energy of ignition in a spark plug with small power consumption, and ignition performance can be improved.

Description

[Detailed description of the invention] The present invention relates to an ignition device for a multi-cylinder internal combustion engine.

In particular, it relates to an ignition device with improved ignition performance. .

In recent years, internal combustion engines have become popular in terms of resource and energy conservation.

It has been necessary to improve the fuel consumption rate (hereinafter referred to as 10 fuel efficiency) even in automobiles equipped with fuel efficiency. .

In addition, the quality of fuel may deteriorate in the future.

However, even in that case, it is necessary to ensure ignition and obtain the desired performance.

One possible solution to this problem is to increase the ignition energy 15, but this has been difficult to achieve with conventional ignition devices for various reasons.

FIG. 1 is an example of a conventional ignition device.

In FIG. 1, the contact point 6 (or 20 semiconductor switch) is opened and closed in conjunction with the rotation of the engine, and - current flows from the battery 1 to the primary coil L1 of the ignition coil 2.

When the current is intermittent, 2, due to electromagnetic induction.

When contact point 3 turns off, secondary coil L
2, a high voltage is generated.

This high voltage is distributed via high voltage capes 4.

Sent to tripulator 7, distributed by tough.

A discharge occurs in the gap between the rotor electrode and the side electrode, and is applied to the spark plug (applicable item from 6A to 6D) 1 via the high voltage cable (applicable item from , 5, A to 5D). 1 Spark discharge opens between the electrodes of the spark plug.

Begins. and the inductance of ignition coil 2.

The energy stored in the spark plug is injected into the spark plug.

The discharge continues, and the air-fuel mixture in the cylinder is ignited and burned. 1゜As mentioned above, the energy supplied from battery 1 (replenished from the generator/electric machine if it is insufficient) is connected to two points: the fire coil, the high voltage cable, and the
It is transmitted through the ◇ and supplied to the 2 spark plugs.

However, in conventional ignition systems, the above transmission
3. The energy loss in the path is large.2 Therefore, the ignition energy that reaches the spark plug is only about 8 to 10% of the energy supplied from the bunch and the spark plug, resulting in very poor efficiency.

Among the above transmission paths, the part with particularly large loss is (1
) distributor and (2) high pressure cape.

It is le.

First, in the distributor (1), discharge occurs due to the gap between the first rotor electrode and the side electrode.

However, due to this discharge, the transmission efficiency becomes very low at around 50 coefficients.

In addition, when using high-voltage cables (2), in order to suppress radio noise caused by spark discharge, it is usually 15 to 2 o・kΩ/
A cable containing a resistor of 1.5 m is used, and the loss of this resistor is large. 1'i To increase the ignition energy supplied to the spark plug, the inductance L of the primary coil of the 2 ignition coil or 1
The next step is to increase the breaking current ■.

That is, the energy E of the ignition coil is E=-LI'i
Since it is given by n, E can be increased by increasing TJ or ■.

However, if L is increased, the primary coil becomes larger, and in order to maintain the secondary voltage as specified, it is necessary to set the turns ratio of both the primary and secondary coils to a predetermined value, so the secondary coil also becomes larger. Become. As a result, the ignition coil becomes very large, making it impractical. .

Also, increasing ■ indicates the energy supplied from the battery.

rugie increases. Since the battery's energy is supplied by a generator driven by an internal combustion engine, the energy released from the battery is 1".

The more it increases, the more it will have a negative effect on fuel efficiency. .

Further, as mentioned above, the transmission efficiency is 8 to 10%.

Increase the energy in the ignition coil by one.

However, the amount of energy wasted in the transmission path increases by 15%, and the electrode wear of the IJ repeater becomes more severe, but the ignition energy actually supplied to the spark plug does not increase that much.

The present invention was made to solve the above problem, and reduces the loss of the transmission path, actually reducing the loss by 2°.4.
- The purpose of the present invention is to provide an ignition device with improved ignition performance by increasing the ignition energy supplied to the spark plug.

In order to achieve the above object, the present invention:

A distributor is created by providing an ignition coil for each cylinder and a circuit that drives the appropriate ignition coil at each ignition timing.

This eliminates the need for a distributor and improves transmission efficiency by eliminating losses in the distributor.

The following is a detailed explanation of the present invention based on the drawings.
The figure shows an embodiment of the present invention.

In FIG. 2, 2A to 2D are ignition coils, 8 is an ignition control circuit, 9 is an ignition signal generation circuit, Q1 to Q4 are transistors, and the same symbols and symbols as in FIG. 1 indicate the same components. 15. The ignition control circuit 8 is composed of two ignition signal generation circuits 9 and transistors Q, -Q4 for switching on/off the primary current of the ignition/coil.

The ignition signal generation circuit 9 has an ignition timing signal S.

The cylinder discrimination signal S2 is inputted, the ignition timing of each cylinder is discriminated by 2 degrees, and ignition signals 5A to 8D that become level ``0'' are output in sequence every time the ignition timing of each cylinder reaches the ignition timing. -8r is applied, the corresponding transistors Q1 to Q4 are turned off, the primary current of the corresponding ignition coil is cut off, a high voltage is generated in the secondary coil, and a discharge occurs at the corresponding spark plug. Then 2 ignitions are performed.

Incidentally, the ignition timing signal S1 is 1, for example, an engine crank.

input every 180° (for a 4-cylinder engine).

The cylinder discrimination signal S2 is still 1, for example, 1.

This is a signal that is input every 720 degrees at the crank angle.

These signals S, , S2 are for example the crank of an engine.

synchronized with the crankshaft (one revolution for every two revolutions of the crankshaft)
A magnetic body that rotates and a fixed one for detection.

1'i using the output of a crank angle sensor consisting of a coil
I can do it.

The ignition signal generation circuit 9 is composed of, for example, a 2-bit binary counter and four monostable multivibrators connected to each output of the counter. The output becomes ignition signal SA, ""-ST).

In the apparatus shown in FIG. 2 as described above, there is no need to use a distributor, so the transmission meridian.

can significantly reduce energy loss.

If you increase the power consumption of battery 1, it will not work.

The ignition energy actually supplied to the spark plug can be increased by a large amount.

According to experiments, the energy supplied by the spark plug in a conventional ignition system is 15~3'5' mJ.

However, increasing this to 70 mJ or more will greatly contribute to lean combustion and engine stability.

It turned out that it was. It also reduces fuel consumption by up to 8~
It was found that it improved by 10%.

However, increasing the supplied energy to 200 mJ or more is disadvantageous in terms of increased energy consumption and the need for larger ignition coils, making it impractical. In the device shown in Figure 2, the supply energy is 70 to 200
It is best to set it within the range of mJ.・Next, FIG. 3 shows another embodiment of the present invention. - In Fig. 6, 10 is an ignition timing sensor, and 11A20 to 11D are ignition circuits.

The ignition timing sensor 10 is composed of a rotor that is linked to, for example, a crankshaft, and the same number of sensors as the number of cylinders, and outputs ignition signals 83 to S at each ignition timing of each cylinder.

The ignition circuits 11A to 11D are transistor switching circuits, and each time one ignition signal S, 1-8D is applied, one firebox of the ignition coil is activated for a certain period of time.

The ignition operation is performed by cutting off the flow.

The effect of the device of FIG. 3 is the same as that of FIG. 2. Next, as shown in FIG. 4, one ignition coil 12. - Shield the high-voltage cable 14 and the spark plug 13 with a shielding means (for example, a shield case and a shield cable) 15, and install a feed-through capacitor at the output end of the lead wire from the ignition coil 12 to the vano lfiter 1 and the ignition control circuit 8. 16
．． By providing 17.

Even if a normal cable without a resistor is used as the high voltage cable 14, noise radio waves due to spark discharge will occur.

Q2+ can be sufficiently reduced compared to conventional methods.
1. b. If a normal cable is used as the high-voltage cable as described above, the resistance value will be much smaller than that of a resistor-containing cable, so the energy loss in the high-voltage cable can be significantly reduced.

Note that the feedthrough capacitors 16 and 17 preferably have a capacity of several hundred PF to several thousand PF.

Also, as shown in Fig. 4 (b), if one ignition coil is 12° and the primary coil and secondary coil are not connected internally, then the secondary coil is used.

It is necessary to ground one end of the coil, in which case 10 is through a shielding means 15 as shown in FIG.

Grounding is desirable for functionality and noise prevention.

Also, as shown in FIG. 5, one ignition coil 12 is turned on.

If the spark plug 16 is installed near the spark plug 16 and both are integrated and housed in the shield case 18, it is advantageous in terms of dual functionality, practicality, noise prevention, and energy loss reduction.

Note that the shield case 18 is fixed to the engine main body 19 with screws or the like.・Also, 20 is a piston, and 21 is a combustion chamber.

Furthermore, if two ignition coils and a spark plug are installed as one unit as shown in FIG. 5, the length of the high voltage cable connecting the two can be extremely shortened.

In the conventional device, the voltage applied to the two spark plugs was about 51 V lower than that at the output end of the ignition coil because the stray capacitance of the high voltage cable was large.

By shortening the length of the high-voltage cable as mentioned above, the voltage drop mentioned above can be greatly reduced.

I can do it.

Also, as shown in Fig. 6, as a single spark plug, the center electrode 22 and the side electrodes 2 are wider than usual.

When the protruding part is used in the device of the present invention, two conventional ones are used.

Fuel consumption is 3 to 4 times lower than when using a plug.

It turned out to be higher.

This is because the electrode protrudes into the center of the combustion chamber).

Because a flame kernel is formed from the center of the combustion chamber and propagates in all directions, combustion occurs more rapidly than in the past, which is thought to have a positive effect on fuel efficiency.

available.

In addition, Fig. 6 (a) has four side electrodes and is 2.t.
・ 11 ・ The combustion stability is better than the one shown in (b) with one side electrode.

However, using a spark plug with a notch or groove in the electrode or a creeping discharge type discharge path is also effective in stabilizing the spark as described above.

As explained above, according to the present invention, since a distributor is not required, energy loss in the transmission path can be greatly reduced.

Therefore, the spark energy at the spark plug can be increased with less power consumption, and the ignition performance can be improved by 10%, resulting in better fuel efficiency.

It becomes.

Furthermore, if the spark plug and ignition coil are housed in an integrated shielded case, energy loss in the high-voltage cable can be greatly reduced (1), making it possible to further improve the ignition performance. .

[Brief explanation of drawings]

Fig. 1 is an example of a conventional device, and Figs. 2 to 6 are illustrations of embodiments of the present invention, respectively. 3...Contact point 4.58~5D...High voltage cable 68~6D...Spark plug 7...Distributor 8...Ignition control circuit 9...Ignition signal generation circuit 10...Ignition Timing sensor River 11A to 11D...Ignition circuit agent Patent attorney Nakamura Nasai/Suke 1 piece 1 piece
-12nott1 Figure-4 Figure 6 Figure (A) '45 Figure (B)

Claims (1)

[Scope of Claims] 1. In a multi-cylinder internal combustion engine, an ignition coil provided for each cylinder and a spark plug connected thereto, the ignition timing of each cylinder being detected, and each of the ignition coils being activated at each ignition timing. This corresponds to the ignition timing. - means for interrupting the current flow, Each cylinder 1゛1 from the ignition coil provided for each cylinder.
An internal combustion engine configured to supply power to a spark plug. ignition device. 2 Ignition energy supplied to the above spark plug. The ignition device for an internal combustion engine according to claim 1, wherein the ignition device is set to a value of 70 m+J or more and 200 mJ or less. 6. Integrally shield the ignition coil and spark plug, and penetrate the primary terminal of the ignition coil. Claim 1 characterized in that a capacitor is provided.
The ignition device for an internal combustion engine as described in . ...)4,
The internal combustion engine according to claim 1, characterized in that the spark plug is shaped so that a gap portion between a center electrode and a side electrode that generates a spark discharge projects into the combustion chamber of the internal combustion engine. . Engine ignition system.