JPH01159985A - Spark plug - Google Patents

Abstract

PURPOSE:To enhance the igniting performance by arranging at least one aux. electrode between No.1 and No.2 electrode of a spark plug. wherein the aux. electrode shall diverge from another electrode through an electric element having a certain resistance. CONSTITUTION:A center electrode 16 as No.1 electrode and a ground electrode 18 as No.2 electrode are furnished in such a way as protruding inside a combustion chamber 10, and a voltage generated by an ignition coil is applied between the two electrodes 16, 18 and discharge is made. Between those electrodes 16, 18 at least one aux. electrode 20 is installed in such a way as in straight line. To perform discharge from the ground electrode 18 as one of the electrodes toward the other electrode 16 through this aux. electrode 20, this aux. electrode 20 shall diverge from the other electrode, for ex. center electrode 16, via an electric element having a certain electric resistance, for ex. a resistance 22.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a spark plug, and in particular increases the distance between a first electrode and a second electrode without increasing the voltage,
The present invention relates to a spark plug that improves the ignition performance of the spark plug to increase the output of an internal combustion engine, and that can also ensure the same appropriate spark as a conventional one even when the voltage is lowered.

[Conventional technology]

In a spark plug used as an ignition device for an internal combustion engine, the voltage generated by the ignition coil is applied between the first electrode and the second electrode, and a predetermined dielectric breakdown voltage (500
When the temperature reaches C1 to 1000'OV), the air insulation between the two electrodes is broken and a current flows between the two electrodes, causing a so-called discharge and igniting with a spark.

[Problem that the invention seeks to solve]

By the way, in a spark plug, the distance between the first electrode and the second electrode, that is, the expansion of the spark surface area during discharge, is
This improves the ignition performance of spark plugs and increases the output of internal combustion engines.

However, the distance between the first electrode and the second electrode is set by the voltage applied between the two electrodes, and simply expanding the flying surface area during discharge will reduce the ignitability of the spark plug. There is this inconvenience.

In addition, if you want to prevent the ignitability of the spark plug from deteriorating while expanding the flying surface area during discharge, it is sufficient to increase the voltage applied between both electrodes, but when increasing the voltage, the ignition This requires processing such as increasing the size of the coil and adding other accessory parts, making the configuration complicated, difficult to manufacture, and increasing the cost, which is economically disadvantageous.

[Purpose of the invention]

SUMMARY OF THE INVENTION In order to eliminate the above-mentioned disadvantages, it is an object of the present invention to dispose at least one auxiliary electrode in a predetermined manner between a first electrode and a second electrode of an ignition spark plug. The auxiliary electrode is provided so as to be branched from the other electrode via an electric element having an electric resistance value so as to sequentially discharge from one of the two electrodes to the other electrode via the auxiliary electrode. This allows the distance between the first electrode and the second electrode to be increased without increasing the voltage applied between the first and second electrodes, improving the ignitability of the spark plug. The present invention aims to realize a spark plug which can improve the output of an internal combustion engine and can also ensure an appropriate spark as in the past even if the voltage applied between both electrodes is lowered.

[Means for solving problems]

To achieve this object, the present invention provides a spark plug for ignition of an internal combustion engine, in which at least one auxiliary electrode is disposed in a predetermined manner between a first electrode and a second electrode of the spark plug; The auxiliary electrode is branched from the other electrode through an electric element having an electric resistance value so as to cause a discharge to be sequentially discharged from one of the electrodes and the second electrode to the other electrode via the auxiliary electrode. It is characterized by having been provided.

[Effect]

By configuring as described above, the distance between the first electrode and the second electrode can be increased without increasing the voltage applied between the first electrode and the second electrode. , it is possible to improve the ignition performance of the spark plug and increase the output of the internal combustion engine. Further, when the distance between the two electrodes is the same as in the conventional case, even if the voltage applied between the two electrodes is lowered, it is possible to secure an appropriate spark as in the conventional case.

〔Example〕

Embodiments of the present invention will be described in detail below based on the drawings.

1 to 3 show a first embodiment of the invention.

In Fig. 1.2, 2 is an internal combustion engine, and 4 is an internal combustion engine 20.
Spark plug for ignition, 6 is intake boat, 8 is intake valve,
10 is a combustion chamber, 12 is an exhaust port, and 14 is an exhaust valve.

As shown in FIG. 2, the spark plug 4 has a center electrode 16 as a first electrode and a ground electrode 18 as a second electrode, and these electrodes 16 and 18 are installed so as to project into the combustion chamber 10. A voltage generated by an ignition coil (not shown) is applied between the inner and outer electrodes 16 and 18, causing discharge and ignition by a spark.

Between the center electrode 16 and the ground electrode 18, there is at least one auxiliary electrode 2, for example one auxiliary electrode 2, as shown in FIG.
0 is provided in a straight line, and the auxiliary electrode 20 is electrically connected in order to sequentially discharge from the ground electrode 18, which is one of the electrodes 16 and 18, through the auxiliary electrode 20 toward the center electrode 16, which is the other electrode. An electrical element of resistance value, e.g. resistor 22
Other electrodes of the picture electrode 16 and 18, in this embodiment, are provided branching off from the center electrode 16. In addition, the code 24
In other words, it is an insulator.

When a voltage generated by an ignition coil (not shown) is applied between the picture electrodes 16 and 18, the ground electrode 18 becomes an anode, the center electrode 16 becomes a cathode, and
Via the resistor 22, the auxiliary electrode 20 also becomes a cathode.

When a predetermined dielectric breakdown voltage (for example, 5,000 to 10,000 V) is reached between the ground electrode 18 and the auxiliary electrode 20, the air insulation between the ground electrode 18 and the auxiliary electrode 20 is broken, and the air flows from the ground electrode 18 to the auxiliary electrode 20. current flows,
A discharge occurs.

Due to this discharge, the ground electrode 18 and the auxiliary electrode 20 are brought into a connected state, the polarity of the auxiliary electrode 20 changes from a cathode to an anode, and a current attempts to flow from the auxiliary electrode 20 to the center electrode 16.

At this time, since the auxiliary electrode 20 and the center electrode 16 are connected via the resistor 22 having an electrical resistance value, no current flows through the resistor 22, and the auxiliary electrode 20 and the center electrode 1
A voltage generated by an ignition coil (not shown) is applied between 6 and 6.

When a predetermined dielectric breakdown voltage is reached between the auxiliary electrode 20 and the center electrode 16, the air insulation between the auxiliary electrode 20 and the center electrode 16 is broken, a current flows from the auxiliary electrode 20 to the center electrode 16, and a discharge occurs. It is something that is done.

As a result, the current from the ground electrode 1B temporarily flows to the auxiliary electrode 20, without increasing the voltage applied between the center electrode 16 provided with one auxiliary electrode 20 and the ground electrode 18. A current will flow to
Distance between center electrode 16 and ground electrode 18 (distance α1 between center electrode 16 and auxiliary electrode 20 + auxiliary electrode 20 and ground electrode 1
8) can be made larger (1.6 times or more according to experimental values) compared to the conventional one. Therefore, the spark surface area during discharge can be expanded, and discharge can be performed twice, improving the ignitability of the spark plug.
The output of the internal combustion engine can be improved.

Furthermore, if the distance between the center electrode 16 and the ground electrode 18 is maintained as in the conventional one, even if the voltage applied between the center electrode 16 and the ground electrode 18 is lowered, the distance between the center electrode 16 and the ground electrode 18 can be lowered. The spark can be secured, the ignition coil and other accessory parts can be made smaller, the configuration is simpler, manufacturing is easier, and costs can be reduced.
It is economically advantageous.

No. 40 shows a second embodiment of the present invention. In this second embodiment, parts that perform the same functions as those in the first embodiment described above will be described with the same reference numerals.

This second embodiment is characterized by the following points.

Between the center electrode 16, which is the first electrode, and the ground electrode 18, which is the second electrode, of the spark plug 4,
, a third auxiliary electrode 30.32.34 is provided in a straight line, and these first, second and third auxiliary electrodes 30.32.3
4 are branched from the inner electrode 16 via electrical elements having electrical resistance values, such as first, second, and third resistors 36, 38, and 40.

That is, from the ground electrode 18 side, the first resistor 36
A first auxiliary electrode 30 is provided branching from the center electrode 16 via the second resistor 38, a second auxiliary electrode 32 is branched from the center electrode 16 via the second resistor 38, and the third resistor 40 is branched from the center electrode 16 via the second resistor 38.
A third auxiliary electrode 34 is provided branching off from the center electrode 16 via the third auxiliary electrode 34 . In addition, the code|symbol 42 is an insulator.

If configured as in the second embodiment described above, the picture electrode 16.1
When a voltage generated by an ignition coil (not shown) is applied between 8 and 8, the ground electrode 18 becomes an anode, the center electrode 16 becomes a cathode, and the first, second, and third resistors 36, 38, 4 After that, the first, second and third auxiliary electrodes 30, 32, 34 also become cathodes.

A predetermined dielectric breakdown voltage (for example, 5000 to 100 OOV) is set between the ground electrode 18 and the first auxiliary electrode 30.
), the air insulation between the ground electrode 18 and the first auxiliary electrode 30 is broken, current flows from the ground electrode 18 to the first auxiliary electrode 30, and discharge occurs.

Due to this first discharge, the ground electrode 18 and the first auxiliary electrode 30 are brought into a connected state, the polarity of the first auxiliary electrode 30 changes from a cathode to an anode, and the first auxiliary electrode 30 is connected to the center electrode 16. Current tries to flow.

At this time, the first auxiliary electrode 30 and the center electrode 16 are connected via the first resistor 36 having an electrical resistance value, and no current flows through the first resistor 36, and the first auxiliary electrode 30
A voltage generated by an ignition coil (not shown) is applied between the second auxiliary electrode 32 and the second auxiliary electrode 32 .

When a predetermined dielectric breakdown voltage is reached between the first auxiliary electrode 30 and the second auxiliary electrode 32, the first auxiliary electrode 3
The air insulation between the first auxiliary electrode 30 and the second auxiliary electrode 32 is broken, current flows from the first auxiliary electrode 30 to the second auxiliary electrode 32, and discharge occurs.

Also, due to this second discharge, the ground electrode 18 and the second
The auxiliary electrode 32 is brought into a connected state, the polarity of the second auxiliary electrode 32 changes from a cathode to an anode, and a current attempts to flow from the second auxiliary electrode 32 to the center electrode 16 .

At this time, the second auxiliary electrode 32 and the center electrode 16 are connected via the second resistor 38 having an electrical resistance value, and the second resistor 38 prevents current from flowing through the second auxiliary electrode 32.
A voltage generated by an ignition coil (not shown) is applied between the third auxiliary electrode 34 and the third auxiliary electrode 34 .

When a predetermined dielectric breakdown voltage is reached between the second auxiliary electrode 32 and the third auxiliary electrode 34, the second auxiliary electrode 3
The air insulation between the second and third auxiliary electrodes 34 is broken, current flows from the second auxiliary electrodes 32 to the third auxiliary electrodes 34, and discharge occurs.

Furthermore, due to this third discharge state, the ground electrode 18 and the third auxiliary electrode 34 are brought into a connected state, and the third auxiliary electrode 3
4 changes from a cathode to an anode, and a current is about to flow from the third auxiliary electrode 34 to the center electrode 16.

At this time, the third auxiliary electrode 34 and the center electrode 16 are connected via the third resistor 40 having an electrical resistance value, and no current flows through the third resistor 40, and the third auxiliary electrode 34
A voltage generated by an ignition coil (not shown) is applied between the center electrode 16 and the center electrode 16.

When a predetermined dielectric breakdown voltage is reached between the third auxiliary electrode 34 and the center electrode 16, the air insulation between the third auxiliary electrode 34 and the center electrode 16 is broken, and the third auxiliary electrode 34
A current flows from the center electrode 16 to the center electrode 16, and discharge occurs.

As a result, the three first, second, and third auxiliary electrodes 30
．． Center electrode 16 and ground electrode 1 with 32 and 34 provided in parallel
8, the current from the ground electrode 18 flows temporarily through the first, second and third auxiliary electrodes 30, 32, 34 and then through the center electrode 16. A current will flow between the center electrode 16 and the ground electrode 18.
The distance between the spark plugs (α1+α2+α3+α4) can be made extremely large compared to conventional ones.This allows the flying surface area during discharge to be further expanded, and discharge can be performed four times, improving the ignitability of the spark plug. This can dramatically improve the output of the internal combustion engine.

In addition, the center electrode 16 and the ground electrode 18 are similar to the conventional ones.
If the distance between the center electrode 16 and the ground electrode 18 is maintained, even if the voltage applied between the center electrode 16 and the ground electrode 18 is extremely low, a proper spark can be secured as in the conventional case, and the ignition coil and other attached parts can be maintained. It is economically advantageous because it can be miniaturized and costs can be reduced.

Note that this invention is not limited to the cylinder 1 and the second embodiment described above, and various applications and modifications are possible.

For example, in the second embodiment of the present invention, three first, second, and third auxiliary electrodes 30, 32, and 34 are arranged between the center electrode 16 and the ground electrode 18 of the spark plug 4, upper and lower in FIG. These first,
The second and third auxiliary electrodes 30, 32, and 34 are branched from the center electrode 16 via the first, second, and third resistors 36, 38, and 40 having electrical resistance values, but as shown in FIG. As shown in the figure, three first, second,
The third auxiliary electrode 50-1.52-2.50-3 is provided in a straight line in the left-right direction in the figure, and is connected via the first, second and third resistors 52-1.52-2.52-3. Center electrode 1
It is also possible to branch from 6 and provide it. In addition, code 5
Fourth, it is an insulator.

Further, as a modification of the second embodiment of the present invention, as shown in FIG. The electrodes 60-1...60-8 may be provided, and may also be provided branching off from the center electrode 16 via a resistor (not shown) having an electrical resistance value. In addition, code 6
2 is an insulator.

In this example, an electrical resistance having a resistance value of 100Ω was used. However, a certain range of resistance values may be used. In other words, the value of electrical resistance is so large that when the spark from one electrode reaches the other electrode on the branch side, a current flows and the potential difference does not quickly become zero. It is necessary that the potential of the electrode be less than the resistance value so as to have a slight influence on the auxiliary electrode.

Further, in the first and second embodiments of the present invention, a resistor is used as the electric element having an electric resistance value, but it is also possible to use a semiconductor having a similar function.

Furthermore, in the first and second embodiments of the present invention, an auxiliary electrode is provided between the first electrode and the second electrode, using a spark plug for ignition of an internal combustion engine as an example. , other discharge equipment, such as lighting equipment such as fluorescent lamps, or industrial equipment such as electric welding machines that use highly heat-resistant auxiliary electrodes. It can also be applied to increase the distance between electrodes.

〔Effect of the invention〕

As explained in detail above, according to the present invention, at least one
A plurality of auxiliary electrodes are arranged in a predetermined manner, and the auxiliary electrode is connected to a required voltage in order to sequentially discharge from one of the first electrode and the second electrode toward the other electrode via the auxiliary electrode. Since it is branched from the other electrode via an electric element with a resistance value, the voltage between the first electrode and the second electrode can be increased without increasing the voltage applied between the first electrode and the second electrode. The distance can be increased, the ignition performance of the spark plug can be improved, and the output of the internal combustion engine can be improved. Also,
When configured to maintain the distance between the first electrode and the second electrode, it is possible to secure an appropriate spark as in the past even if the voltage applied between the two electrodes is lowered.
This makes it possible to downsize the ignition coil and other accessory parts, thereby reducing costs and being economically advantageous.

[Brief explanation of the drawing]

Parts 1 to 3 show the first embodiment of the present invention, Fig. 1 is a diagram showing the state of installation of an ignition spark plug to an internal combustion engine, Fig. 2 is a schematic diagram of the spark plug, and Fig. 3 is a diagram showing the state of installation of an ignition spark plug to an internal combustion engine. This is a country where the main parts of spark plug electrodes are expanding. FIG. 4 is an enlarged view of the main part of the electrode portion of an ignition spark plug showing a second embodiment of the present invention. FIG. 5.6 is an enlarged view of the main part of the electrode portion of an ignition spark plug showing a modification of the second embodiment of the present invention. In the figure, 2 is an internal combustion engine, 4 is an ignition spark plug, 16 is a center electrode, 18 is a ground electrode, 20 is an auxiliary electrode,
22 is a resistance.

Claims (1)

[Claims] 1. In a spark plug for ignition of an internal combustion engine, at least one auxiliary electrode is disposed in a predetermined manner between a first electrode and a second electrode of the spark plug; The auxiliary electrode is provided so as to be branched from the other electrode via an electric element having an electric resistance value so as to sequentially discharge from one of the two electrodes to the other electrode via the auxiliary electrode. A spark plug featuring: 2. The auxiliary electrode is arranged linearly between the center electrode, which is the first electrode, and the ground electrode, which is the second electrode, of the spark plug, and is connected to the center electrode through a resistance having an electrical resistance value. The spark plug according to claim 1, which is an auxiliary electrode provided in a branched manner. 3. Three of the auxiliary electrodes are arranged in a line between the center electrode, which is the first electrode, and the ground electrode, which is the second electrode, of the spark plug. The spark plug according to claim 1, which is an auxiliary electrode provided in a branched manner. 4. A plurality of the auxiliary electrodes are arranged in a spiral shape with the inner electrode as the center between the center electrode, which is the first electrode, and the ground electrode, which is the second electrode, of the spark plug. The spark plug according to claim 1, wherein the spark plug is an auxiliary electrode branched from the center electrode via a resistor.