JP2007048562A - Spark plug for internal combustion engine, and internal combustion engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a spark plug for internal combustion engines and an internal combustion engine which are excellent in ignitability. <P>SOLUTION: The spark plug 1 is equipped with a fixing metal fixture 2 provided on the outer periphery with a fixing screw 21, an insulator 3 held on the center axis side of the fixing metal fixture 2, a center electrode 4 held on the center axis side of the insulator 3, a ground electrode 5 fixed to the fixing metal fixture 2 and forming a spark discharge gap G between the ground electrode and the tip end 41 of the center electrode 4, and an O<SP>-</SP>ion generator 6 to generate O<SP>-</SP>ions. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a spark plug and an internal combustion engine for an internal combustion engine used for automobiles, cogeneration, gas pumps, and the like.

In an internal combustion engine used for automobiles, cogeneration, gas pressure pumps, etc., an air-fuel mixture obtained by mixing fuel and air is introduced into the combustion chamber, and combustion is caused by reacting the fuel and oxygen in the combustion chamber. The expansion force is used as a power source.
The reaction between the fuel and oxygen is caused by spark discharge by a spark plug.

However, in order to cause a reaction between the fuel and oxygen, as shown in FIG. 16, a certain amount of activation energy E1, E2 is required. FIG. 16 shows an energy curve when the fuel (C _n H _m ) is burned (oxidized) into CO ₂ and H ₂ O, and the curve L shows oxygen (O ₂ ) and fuel (C _n H _m ) and an energy curve when the O ⁻ ion and fuel (C _n H _m ) are reacted. As shown by the curve L, the activation energy E1 for reacting oxygen (O ₂ ) and fuel (C _n H _m ) is relatively large. Therefore, if the energy given to the air-fuel mixture becomes insufficient, the ignitability may be reduced. In particular, in a lean combustion engine or the like, a decrease in ignitability becomes a problem.

JP 2004-75431 A

In view of this, it is conceivable to improve the ignitability by reacting an O ⁻ ion having an activation energy E2 lower than that of oxygen (O ₂ ) with the fuel. That is, for example, it is conceivable to generate O 2 ⁻ ions using the O 2 ⁻ ion generator disclosed in Patent Document 1 and introduce them into the combustion chamber of the internal combustion engine.
However, since the lifetime of O 2 ⁻ ions is as short as several milliseconds or less, when O 2 ⁻ ions are supplied from the outside, most of them disappear before reacting with the fuel.

  The present invention has been made in view of such conventional problems, and an object of the present invention is to provide a spark plug for an internal combustion engine and an internal combustion engine having excellent ignitability.

The first invention is a mounting bracket having a mounting screw portion on the outer periphery;
An insulator held on the central axis side of the mounting bracket;
A central electrode held on the central axis side of the insulator;
A grounding electrode that is attached to the mounting bracket and forms a spark discharge gap with the tip of the center electrode;
O ^- O generating ions ^- in the spark plug for an internal combustion engine, characterized by comprising a ion generator (claim 1).

Next, the effects of the present invention will be described.
The spark plug includes the O ⁻ ion generator. Then, O ^- O generated from the ion generating unit ^- ions by reacting with the fuel by the spark discharge of the spark plug can be ignited easily mixture.
That is, since the activation energy is small, the O ⁻ ion easily reacts with the fuel with low energy and easily causes combustion. Therefore, the ignitability of the air-fuel mixture can be improved.

Moreover, although the above-mentioned O ⁻ ions have an extremely short life, the reaction with the fuel can be performed before the O ⁻ ions disappear because the O ⁻ ion generation part is provided in the spark plug itself. That is, even if an O ⁻ ion is introduced from the outside to be reacted with the fuel, the O ⁻ ion may disappear before the reaction. In contrast, O was equipped spark plug ^- O generated from the ion generating unit ^- ions can be used in the combustion reaction in the vicinity of the spark gap immediately. That is, spark discharge can be performed in a state where O ⁻ ions and fuel are sufficiently coexisting in the vicinity of the spark discharge gap, thereby enabling efficient ignition.

In addition, when O ⁻ ions are present in the vicinity of the spark discharge gap, dielectric breakdown is likely to occur in the spark discharge gap, and discharge can be performed at a low voltage. From this point of view, the ignitability can be improved.

  As described above, according to the present invention, a spark plug for an internal combustion engine having excellent ignitability can be provided.

A second invention is an internal combustion engine for using an expansion force generated by burning an air-fuel mixture introduced into a combustion chamber as a power source,
The internal combustion engine, a spark plug for igniting the above mixture, the tip portion of the spark plug is then disposed so as to be exposed to the combustion chamber, the tip portion of the spark plug, O ^- ions An internal combustion engine characterized in that an O ⁻ ion generating part for generating the gas is disposed.

The internal combustion engine, O the tip of the spark plug exposed to the combustion chamber ^- formed by arranging the ion generating unit. Then, O ^- O generated from the ion generating unit ^- by reacting with the fuel at the tip of the spark plug ion can be ignited easily mixture.
That is, since the activation energy is small, the O ⁻ ion easily reacts with the fuel with low energy and easily causes combustion. Therefore, the ignitability of the air-fuel mixture can be improved.

The O ⁻ ions have a very short life, but the O ⁻ ion generation part is arranged at the tip of the spark plug in the combustion chamber, so that it reacts with the fuel before the O ⁻ ions disappear. Can be done. That is, even if an O ⁻ ion is introduced from the outside to be reacted with the fuel, the O ⁻ ion may disappear before the reaction. In contrast, O was equipped at the tip portion of the combustion chamber of a spark plug ^- O generated from the ion generating unit ^- ions can be used immediately in the combustion reaction. That is, spark discharge can be performed in the state where O ⁻ ions and fuel are sufficiently coexistent in the vicinity of the tip of the spark plug of the combustion chamber, thereby enabling efficient ignition.

  As described above, according to the present invention, an internal combustion engine having excellent ignitability can be provided.

  In the first invention (Invention 1) and the second invention (Invention 7), the internal combustion engine can be, for example, an internal combustion engine such as an automobile, a cogeneration system, or a gas pump.

Also, the O ^- ion generation portion is preferably made of an ion-conductive solid electrolyte body, for example, an active oxygen-containing _{substances, 12CaO-7Al 2 O 3,} Ca 12 Al 10 Si 4 O 35, CaFe 2 It is preferably made of O ₅ or the like. In this case, O ⁻ ions can be generated more effectively.

In the first aspect of the invention, it is preferable that the O ⁻ ion generator is disposed on the ground electrode.
In this case, the O ^- the volume of the ion generating unit can be easily increased. That is, usually, in comparison with the center electrode, the ground electrode having a large surface area sufficiently, large O volume ^- can be disposed ion generating unit. Thereby, many O ⁻ ions can be generated, and a spark plug excellent in ignitability can be obtained.
In addition, by arranging the O ⁻ ion generating portion on the ground electrode, O ⁻ ions can be generated in or near the spark discharge gap. Therefore, O ^- efficient before the ions disappear O ^- ions can be burned by reaction with the fuel. As a result, ignitability can be improved.

Moreover, it is preferable that the O ⁻ ion generator is disposed on the insulator.
In this case, O the insulator having a sufficiently large surface area ^- for arranging the ion generating unit, a large O more volume ^- can be disposed ion generating unit. As a result, a spark plug excellent in ignitability can be obtained.

The O ⁻ ion generator is configured to apply a voltage between the center electrode and the ground electrode, and at least one of the center electrode and the ground electrode is connected to the O ⁻ ion generator. It is preferable that a resistor for suppressing the voltage is provided.
In this case, O ^- it prevents the overvoltage is applied to the ion generation portion, O ^- it is possible to prevent the erosion of the ion generating unit. That, O ^- O in order to release ions ^- the voltage applied to the ion generating unit, by generating between the center electrode and the ground electrode, spark discharge and O ^- be performed by ion generation and a common electrode it can. However, O ^- the voltage applied to the ion generating section is too large, O ^- there is a possibility that the ion generating section is melting. Therefore, by disposing the resistor, O ^- by suppressing the voltage applied to the ion generating section, O ^- it is possible to prevent the erosion of the ion generating unit.

In addition, it is preferable that a gap is formed between the O ⁻ ion generating part and the spark plug body.
In this case, oxygen (O ₂ ) can also be supplied to the O ⁻ ion generator from the gap. Therefore, generation of O ⁻ ions from the O ⁻ ion generation part can be promoted.

Moreover, it is preferable that the spark plug has a heater for heating the O ⁻ ion generator.
In this case, excellent ignitability can be ensured even when the internal combustion engine is started. That is, when the internal combustion engine is started, the O ⁻ ion generating portion is at a low temperature. Therefore, it is difficult to sufficiently generate O ⁻ ions even when a voltage is applied in this state. Therefore, by using the heater to maintain the O ⁻ ion generating portion at a high temperature even at the start, the O ⁻ ions can be sufficiently generated even at the start.

Example 1
A spark plug for an internal combustion engine according to an embodiment of the present invention will be described with reference to FIGS.
As shown in FIG. 1, the spark plug 1 for an internal combustion engine of the present example includes a mounting bracket 2 provided with a mounting screw portion 21 on the outer periphery, an insulator 3 held on the central axis side of the mounting bracket 2, and an insulation. a center electrode 4 is held in the central axis side of the insulator 3, and the ground electrode 5 which forms the spark discharge gap G between the tip portion 41 of the center electrode 4 with attached to mounting bracket 2, O ^- generate ions And an O ⁻ ion generation unit 6 to be made.

As shown in FIGS. 1 and 2, the O ⁻ ion generator 6 is disposed on the ground electrode 5. Specifically, the O ⁻ ion generator 6 is joined to the surface of the ground electrode 5 facing the center electrode 4.
O ^- ion generator 6 is made of an ion-conductive solid electrolyte body, a reactive oxygen-containing material, 12CaO-7Al ₂ O ₃ (alumina _{cement), Ca 12 Al 10 Si 4} O 35, CaFe 2 O 5 , etc. Consists of.

The O ⁻ ion generator 6 is configured such that a voltage is applied between the center electrode 4 and the ground electrode 5. The center electrode 4 is provided with a resistor 403 for suppressing the voltage applied to the O ⁻ ion generator 6.
That is, as shown in FIG. 1, the center electrode 4 is composed of a base end side center electrode portion 402 having a connection terminal 404 for supplying a voltage on the base end side, and a tip end side center electrode portion 401 having a tip end portion 41. A resistor 403 is disposed between the base end side center electrode portion 402 and the tip end side center electrode portion 401.
Note that the spark plug 1 for an internal combustion engine of this example can be used as an ignition means in an automobile engine.

When the spark plug 1 is used, as shown by a curve S in FIG. 3, a voltage in a range where no discharge occurs is applied between the center electrode 4 and the ground electrode 5 immediately before the discharge timing (see S1 in FIG. 3). ). For example, a voltage of 1 V to 10 kV is applied for 0.1 to 5 msec so that the center electrode 4 side is positive and the ground electrode 5 side is negative. At this time, O ⁻ ions are generated from the O ⁻ ion generator 6 disposed on the ground electrode 5.

Next, a large voltage of, for example, 10 to 30 kV is applied between the center electrode 4 and the ground electrode 5 so that the center electrode 4 side is negative and the ground electrode 5 side is positive, thereby causing a spark discharge in the spark discharge gap G. (See S2 in FIG. 3). As a result, the O ⁻ ions generated as described above react with the fuel and ignite.

Then, O ^- O in the ion generating section 6 ^- per estimation mechanism of the ion generating will be described with reference to FIG.
That is, a negative voltage is applied to the center electrode 4 on the ground electrode 5 to which the O ⁻ ion generator 6 is attached. A positive charge appears on the surface of the center electrode 5 serving as the positive electrode on the ground electrode 5 side. Thus, O ^- O which has been occluded in the ion generating section 6 ^- is released to the center electrode 4 side, that is the spark discharge gap G.

Further, oxygen O ₂ in the air supplied to the combustion chamber adheres to the O ⁻ ion generator 6 (solid electrolyte), and electrons e are supplied from the ground electrode 5 that is the negative electrode. As a result, in the O ⁻ ion generator 6 (solid electrolyte), oxygen O ₂ obtains electrons e and ionizes to become O ₂ ⁻ , and O and O ⁻ are separated to generate O ⁻ ions. The O ⁻ ion generator 6 is replenished. Then, the O ⁻ ions are supplied to the spark discharge gap G one after another.

The voltage applied between the center electrode 4 and the ground electrode 5 is supplied by a power source connected to the connection terminal 404 of the center electrode 4 (not shown). The power source, an ignition voltage generator for generating a spark discharge in the spark discharge gap G, O ^- and a ion generating voltage generating unit for generating ions ^- O from the ion generator 6. Further, a diode is interposed between the ion generating voltage generating unit and the ignition voltage generating unit, and the O ⁻ ion generating unit is controlled so that a large current does not flow through the ion generating voltage generating unit. 6 is configured so that no overvoltage is applied.

Further, as shown in FIG. 5, the spark plug 1 is attached to the internal combustion engine 7, and the spark discharge gap G at the tip portion 13 of the spark plug 1 is disposed in the combustion chamber 71. Accordingly, in the combustion chamber 71, the ignition region ignite air-fuel mixture, O ^- it is possible to obtain the internal combustion engine 7 is disposed the ion generator 6.
The “ignition region” refers to a region serving as a starting point of combustion in the combustion chamber 71 where an oxidation chemical reaction proceeds after mixing of fuel and air and local heat generation occurs.

Next, the function and effect of this example will be described.
As shown in FIGS. 1 and 2, the spark plug 1 includes the O ⁻ ion generator 6. Then, O ^- O generated from the ion generator 6 ^- ions by reacting with the fuel by the spark discharge of the spark plug 1 can be ignited easily mixture.
That is, since the activation energy is small, the O ⁻ ion easily reacts with the fuel with low energy and easily causes combustion. Therefore, the ignitability of the air-fuel mixture can be improved.

The O ⁻ ions have a very short lifetime, but the O ⁻ ion generator 6 is provided in the spark plug 1 itself so that it can react with the fuel before the O ⁻ ions disappear. It becomes. That is, even if an O ⁻ ion is introduced from the outside to be reacted with the fuel, the O ⁻ ion may disappear before the reaction. In contrast, O was installed in the spark plug 1 ^- O generated from the ion generator 6 ^- ions, it can be used for the combustion reaction in the vicinity of the spark discharge gap G immediately. That is, spark discharge can be performed in a state where O ⁻ ions and fuel are sufficiently coexisting in the vicinity of the spark discharge gap G, thereby enabling efficient ignition.

In addition, when O ⁻ ions are present in the vicinity of the spark discharge gap G, dielectric breakdown is likely to occur in the spark discharge gap G, and discharge can be performed at a low voltage. From this point of view, the ignitability can be improved.

Further, since the O ⁻ ion generator 6 is disposed on the ground electrode 5, the volume of the O ⁻ ion generator 6 can be easily increased. That is, in general, the O ⁻ ion generator 6 having a large volume can be disposed on the ground electrode 5 having a sufficiently large surface area compared to the center electrode 4. Thereby, many O ⁻ ions can be generated, and the spark plug 1 having excellent ignitability can be obtained.
Further, by arranging the O ⁻ ion generator 6 on the ground electrode 5, O ⁻ ions can be generated in the spark discharge gap G or in the vicinity thereof. Therefore, O ^- efficient before the ions disappear O ^- ions can be burned by reaction with the fuel. As a result, ignitability can be improved.

Further, as shown in FIG. 1, since the center electrode 4 is resistance 403 is disposed, O ^- it prevents the overvoltage is applied to the ion generating section 6, O ^- prevent melting of the ion generator 6 be able to. That is, as described above, O ^- O in order to release ions ^- the voltage applied to the ion generating section 6, by generating between the center electrode 4 and the ground electrode 5, the spark discharge and O ^- the ion generator 5 Can be performed by a common electrode. However, O ^- the voltage applied to the ion generating section 6 is too large, O ^- there is a possibility that the ion generator 6 is melting. Therefore, by disposing the resistor 403, O ^- by suppressing the voltage applied to the ion generating 6, O ^- it is possible to prevent the erosion of the ion generator 6.

Further, as shown in FIG. 5, the spark plug 1 is disposed in the internal combustion engine 7, so that the O ⁻ ion generator 6 is disposed in the ignition region of the combustion chamber 71. Thereby, the internal combustion engine 7 excellent in ignitability can be obtained easily.

  As described above, according to this example, it is possible to provide a spark plug and an internal combustion engine for an internal combustion engine having excellent ignitability.

(Example 2)
This example is an example of the spark plug 1 in which a gap 51 is formed between the O ⁻ ion generating portion 6 and the spark plug 1 main body as shown in FIGS.
The gap 51 is formed in the ground electrode 5 to which the O ⁻ ion generator 6 is joined. The gap 51 is formed in a groove shape so as to face the O ⁻ ion generator 6 and penetrates in the width direction of the ground electrode 5.
Others are the same as in the first embodiment.

In the case of this example, oxygen (O ₂ ) can also be supplied to the O ⁻ ion generator 6 from the gap 51. Therefore, generation of O ⁻ ions from the O ⁻ ion generator 6 can be promoted.
In addition, the same effects as those of the first embodiment are obtained.

(Example 3)
This embodiment, as shown in FIG. 8, O ^- ion generator 6 is an example of the spark plug 1 and disposed on the surface of the ground electrode 5 at the side of the center electrode 4.
The ground electrode 5 in the spark plug 1 of the present example includes a side portion 52 extending in parallel to the center electrode 4 from the tip of the mounting bracket 2 and the tip of the two side portions 52 and the tip of the center electrode 4. 41 and a front end portion 53 disposed opposite to the front end 41. The O ⁻ ion generator 6 is disposed on the inner surface of the side portion 52 of the ground electrode 5.
Others are the same as in the first embodiment.

In the case of this example, since the spark discharge is mainly performed between the center electrode 4 and the front portion 53 of the ground electrode 5, it is possible to prevent the O ⁻ ion generator 6 from being melted.
In addition, since the O ⁻ ion generator 6 is provided at two locations on the side of the center electrode 4, a large amount of O ⁻ ions can be generated, and the ignitability can be improved.
In addition, the same effects as those of the first embodiment are obtained.

Example 4
This example is an example of a spark plug 1 in which an O ⁻ ion generator 6 is disposed on an insulator 3 as shown in FIG.
That is, the O ⁻ ion generator 6 is wound around the side surface of the tip of the insulator 4.
Others are the same as in the first embodiment.

In the case of this example, it is possible to arrange the O ⁻ ion generator 6 having a larger volume. As a result, the spark plug 1 having excellent ignitability can be obtained.
In addition, since the ceramic O ^- ion generator 6 is joined to the ceramic insulator 4, the thermal expansion coefficients of the insulator 4 and the O ^- ion generator 6 are approximated. Therefore, it is possible to obtain a spark plug 1 that suppresses the generation of stress and has excellent durability.
In addition, the same effects as those of the first embodiment are obtained.

(Example 5)
This embodiment, as shown in FIG. 10, O ^- is an example of the spark plug 1 of the ion generating unit 6 formed by disposing in succession toward the side surface of the center electrode 4 from the side of the distal end portion of the insulator 3.
Others are the same as in the fourth embodiment.
In the case of this example, large O more volume ^- can be disposed ion generator 6. As a result, the spark plug 1 having excellent ignitability can be obtained.
In addition, the same effects as those of the fourth embodiment are obtained.

(Example 6)
In this example, as shown in FIG. 11, the heater 11 is disposed in the vicinity of the attachment portion of the O ⁻ ion generation portion 6.
That is, the heater 11 is attached to the tip of the insulator 3 of the spark plug 1. As the heater 11, for example, a ceramic heater can be used.
Further, in this example, the O ⁻ ion generator 6 is joined to the tip 41 of the center electrode 4. In addition, the center electrode 4 serves as a negative electrode when O ⁻ ions are generated.

Then, when using the spark plug 1, especially at the start of the internal combustion engine, by energizing the heater 11, O ^- subjected to heat of the ion generating unit 6, the O ^- raising the ion generator 6 to 600 to 800 ° C. Warm up.
Thereby, the solid electrolyte body which comprises the O < ^- > ion generation part 6 is made into an active state, and generation | occurrence | production of O < ^- > ion is accelerated | stimulated.
Others are the same as in the first embodiment.

In the case of this example, excellent ignitability can be ensured even when the internal combustion engine is started. That is, when the internal combustion engine is started, the solid electrolyte body constituting the O ⁻ ion generation unit 6 is at a low temperature. Therefore, it is difficult to sufficiently generate O ⁻ ions even when a voltage is applied in this state. Accordingly, by using the heater 11 to keep the solid electrolyte body at a high temperature and active even at the start, O ⁻ ions can be sufficiently generated even at the start.
In addition, the same effects as those of the first embodiment are obtained.
In the present example, an example in which the O ⁻ ion generating part 6 is joined to the center electrode 4 is shown, but the present example can be applied to an embodiment in which the O ⁻ ion generating part 6 is joined to the ground electrode 5 or the insulator 3. Can be applied.

(Example 7)
In this example, as shown in FIGS. 12 and 13, the porous conductor 12 is disposed between the O ⁻ ion generating portion 6 and the center electrode 4, and a gap is formed in the tip portion 41 of the center electrode 4. It is an example of the spark plug 1 provided with the part 42. FIG.
The void portion 42 is formed in a groove shape facing the porous conductor 12 and penetrates in the radial direction of the center electrode 4.
Further, the point that the O ⁻ ion generation part 6 is joined to the tip part 41 of the center electrode 4 and the center electrode 4 becomes a negative electrode even when O ⁻ ions are generated is the same as in Example 6.
Others are the same as in the first embodiment.

In the case of this example, oxygen can also be supplied from the gap 42 to the O ⁻ ion generator 6 through the porous conductor 12. Therefore, more oxygen can be supplied to the O ⁻ ion generator 6. Therefore, more O ⁻ ions can be generated in the O ⁻ ion generator 6.
In addition, the same effects as those of the first embodiment are obtained.

(Example 8)
In this example, as shown in FIG. 14, the oxidation rate by O ⁻ ions is compared with the oxidation rate by oxygen (O ₂ ).
In this example, the oxidation rate when NO is oxidized to NO ₂ was measured. The measurement results are shown in FIG.
From the figure, it can be seen that the oxidation rate by O ⁻ ions is extremely high, about 3 × 10 ⁷ times the oxidation rate by oxygen (O ₂ ).
Therefore, as described above, it can be seen that, by reacting O 2 ⁻ ions with fuel in the combustion chamber of the internal combustion engine, combustion can be easily performed and ignitability can be improved.

Example 9
This embodiment, as shown in FIG. 15, O near the spark discharge gap G ^- and the concentration of ions is an example of examining the relationship between ignitability.
That is, the air-fuel ratio A / F that becomes the lean combustion limit when the concentration of O ⁻ ions in the vicinity of the spark discharge gap G was changed was measured. The higher the lean combustion limit air-fuel ratio, the better the ignitability.
The measurement results are shown in FIG.

As seen from FIG, O ^- higher ion concentration increases lean combustion limit air-fuel ratio becomes higher. Then, for example, O ^- Increasing the ion concentration above 1000 ppm, the lean combustion limit air-fuel ratio becomes high as A / F = about 25 or more.
Therefore, it can be seen that the ignitability can be improved by increasing the O ⁻ ion concentration in the vicinity of the spark discharge gap.

1 is a longitudinal sectional view of a spark plug in Embodiment 1. FIG. In Example 1, O of the spark plug ^- illustration of the vicinity of the ion generating unit. FIG. 3 is a diagram showing a voltage waveform applied to a center electrode in Example 1. In Example 1, O ^- explanatory view showing an estimated mechanism of the ion generating. 1 is a cross-sectional view of an internal combustion engine in Embodiment 1. FIG. In Example 2, O of the spark plug ^- illustration of the vicinity of the ion generating unit. FIG. Sectional explanatory drawing of the O < ^- > ion generating part vicinity of a spark plug in Example 3. FIG. Sectional explanatory drawing of the O < ^- > ion generating part vicinity of a spark plug in Example 4. FIG. FIG. 10 is a cross-sectional explanatory view of the vicinity of an O ⁻ ion generation part of a spark plug in Example 5. FIG. 10 is a cross-sectional explanatory view of the vicinity of an O ⁻ ion generation part of a spark plug in Example 6. In Example 7, O of the spark plug ^- cross-sectional view illustrating the neighborhood of the ion generating unit. B view of FIG. The diagram which shows the measurement result of the oxidation rate in Example 8. In Example 9, O ^- graph showing the relationship between ion concentration and the lean burn limit air-fuel ratio. Diagram showing an energy curve at the time of fuel (C _n H _m) is burned (oxidized).

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Spark plug 2 Mounting bracket 3 Insulator 4 Center electrode 41 Tip part 5 Ground electrode 6 O ^- ion generation part 7 Internal combustion engine

Claims (7)

A mounting bracket with a mounting screw on the outer periphery;
An insulator held on the central axis side of the mounting bracket;
A central electrode held on the central axis side of the insulator;
A grounding electrode that is attached to the mounting bracket and forms a spark discharge gap with the tip of the center electrode;
O ^- O generating ions ^- spark plug for an internal combustion engine, characterized by comprising a ion generating unit. According to claim 1, said O ^- ion generation portion, a spark plug for an internal combustion engine, characterized by comprising disposed on said ground electrode. The spark plug for an internal combustion engine according to claim 1 or 2, wherein the O ^- ion generation part is disposed on the insulator. 4. The O ⁻ ion generation unit according to claim 1, wherein a voltage between the center electrode and the ground electrode is applied, and at least one of the center electrode and the ground electrode. A spark plug for an internal combustion engine, characterized in that a resistor for suppressing the voltage applied to the O ⁻ ion generator is disposed. 5. The spark plug for an internal combustion engine according to claim 1, wherein a gap is formed between the O ⁻ ion generation portion and the spark plug body. 6. 6. The spark plug for an internal combustion engine according to claim 1, wherein the spark plug includes a heater for heating the O ⁻ ion generation unit. In an internal combustion engine for using an expansion force generated by burning an air-fuel mixture introduced into a combustion chamber as a power source,
The internal combustion engine, a spark plug for igniting the above mixture, the tip portion of the spark plug is then disposed so as to be exposed to the combustion chamber, the tip portion of the spark plug, O ^- ions O to generate ^- an internal combustion engine, characterized in that are arranged an ion generating unit.

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