KR101407525B1 - Plasma ignition plug - Google Patents

Abstract

The present invention relates to a plasma ignition plug. According to the present invention, combustion stability is secured in a lean-burn condition or ERG condition and damage to an insulation unit is prevented by providing the plasma ignition plug of a multi point ignition type. The plasma ignition plug according to the present invention includes a cylindrical body part and a disk-shaped flange part.

Description

[0001] PLASMA IGNITION PLUG [0002]

The present invention relates to a plasma ignition plug, and more particularly to a plasma ignition plug capable of stably combustion even under EGR (Exhaust Gas Recirculation) conditions in which exhaust gas is recycled under lean burn conditions where fuel is less than theoretical air- .

Lean combustion engines or EGR engines are generally operated at low equivalence ratios, thereby lowering the combustion temperature to prevent the production of nitrogen oxides and enable high efficiency operation. However, there is a problem that the combustion stability is deteriorated at such a low equivalent ratio.

Particularly, in the case of the lean burn or EGR engine using gasoline, the supply of the heat source or the ignition source is not sufficient, so that misfire frequently occurs, and it has been difficult to realistically extend the lean region. Therefore, a multi-point ignition system capable of exhibiting stable combustion performance in a non-uniform mixture state instead of a single point ignition has been proposed, and a plasma ignition system using DBD (Di-electric Barrier Discharge) This is one of the multi-point ignition methods.

1 is a schematic view of a spark plug according to a plasma ignition method using a conventional DBD.

In the general plasma ignition method, a dielectric such as ceramic is applied to the household electrode 30 to which a voltage is applied, and then a high voltage is applied to the household electrode 30 to generate plasma between the household electrode 30 and the ground electrode 20 And ignition occurs in the cylinder (70).

In the conventional plasma ignition system using the DBD, the ground electrode 20 is positioned in the vertical direction below the electric household electrode 30 to which the dielectric is applied, the generation of plasma is perpendicular to the dielectric body 10, There is a problem in that the end of the dielectric part 10, which is concentrated at the end of the dielectric part 10 and has a small thickness, has a large risk of breakage.

In addition, there is a problem that the plasma is formed between the ground electrode 20 and the dielectric portion 10 surrounding the current collector electrode, and the combustion is unstable under the lean burn condition and the EGR condition.

The present invention provides a plasma ignition plug capable of reducing the risk of breakage of a dielectric portion by causing a discharge in a portion where a dielectric, which is not the end of a dielectric having poor durability, is induced by inducing plasma.

It is also intended to provide a plasma ignition plug capable of multipoint ignition by concentrated energy by inducing plasma to a plurality of ignition points to concentrate energy.

The present invention relates to a method of manufacturing a semiconductor device, which comprises a main body part, a part of which is installed in a cylinder, a first electrode provided inside the main body part and to which an anode is applied, And a dielectric portion formed to surround the first electrode. The plasma ignition plug for igniting the in-cylinder fuel, the dielectric portion comprising: a cylindrical body portion to which the plasma reaches; And a disk-shaped flange portion having a larger diameter than the body portion, in which the plasma moves and ignition occurs, is disclosed.

At this time, hemispherical protrusions may be formed at the ends of the body part.

In addition, one or more guide grooves for moving the plasma along the longitudinal direction may be formed on the outer circumferential surface of the body part.

At this time, the guide groove may become narrower toward the flange portion.

In addition, the flange portion may be formed with a discharge cutoff groove for preventing the plasma from discharging along the circumferential direction on the outer circumferential surface.

The present invention provides a plasma ignition plug of a multi-point ignition type using DBD, so that combustion stability can be ensured even under lean or EGR conditions.

Further, it is possible to prevent a phenomenon that energy is concentrated on the end of the insulating portion and the insulating portion is broken.

1 is a schematic view of a spark plug according to a plasma ignition method using a conventional DBD.
2 is a perspective view of a plasma ignition plug according to an embodiment of the present invention.
3 is a front view of a plasma spark plug according to an embodiment of the present invention.
4 is a partial enlarged view of a plasma spark plug according to an embodiment of the present invention.
5 to 9 are perspective views showing various embodiments of the plasma ignition plug.
10 is an experimental photograph of a flame propagation process of a plasma spark plug according to an embodiment of the present invention.

Hereinafter, embodiments of the plasma ignition plug according to the present invention will be described in detail with reference to the accompanying drawings.

It is to be understood that the term device or element orientation (e.g., terms such as "front", "back", "up", "down", " Are used merely to simplify the description of the present invention and do not indicate or imply that the associated device or element should have a particular orientation.

FIG. 2 is a perspective view of a plasma ignition plug according to an embodiment of the present invention, and FIG. 3 is a front view thereof.

The plasma ignition plug according to the present embodiment includes a main body 500, a first electrode 300, a second electrode 200, and a plasma P for igniting the in-cylinder fuel including the dielectric portion 100 ) A spark plug comprising a body part (110) and a flange part (150).

The body portion 500 is installed in the cylinder.

Specifically, the body portion 500 has one end positioned through the wall surface of the cylinder and the other end positioned outside the cylinder.

At this time, the body portion 500 may be provided in the cylinder by forming a screw groove on the outer surface thereof and screwing the cylinder with the cylinder.

The body portion 500 has a cylindrical rod shape (i.e., a round bar shape) as shown and is an insulative member.

Here, the 'insulating material' need not be limited to any specific kind, and any material may be used as long as it is used as an insulator of a widely known plasma ignition electrode.

The first electrode 300 is installed in the main body 500 and one end thereof is exposed to the inside of the cylinder.

A positive voltage is applied to the first electrode 300 through the AC power source and a voltage higher than the voltage applied to the spark plug of the conventional one-point ignition type is applied. This is for discharging the plasma P by forming a high potential difference with the second electrode 200 to be described later.

The second electrode 200 is bent at an end of the main body 500 in the cylinder inward direction and spaced apart from the first electrode 300 to form a predetermined gap.

That is, the second electrode 200 is in the form of a " b "shape extending from the main body part 500, is installed at the end of the main body part 500, is located inside the cylinder, and is grounded to the main body part 500.

The dielectric unit 100 may be formed of a ceramic material such as alumina or boron nitride.

Specifically, the dielectric portion 100 includes a cylindrical body portion 110 and a disk-shaped flange portion 150.

Referring to FIG. 4, when a high voltage is applied to the first electrode 300 located in the body 110, a potential difference is generated between the second electrode 200 and the second electrode 200, which is a relatively negative electrode. (P) is generated as electrons protrude from the first electrode (200) and move to the first electrode (300), and the plasma (P) reaches the end of the body part (110).

When an electric field is applied to the dielectric material, polarized molecules are aligned in a direction opposite to the electric field to generate a dielectric polarization that is electrically charged on the surface. The plasma P arriving at the body 110 due to dielectric polarization is a dielectric body The plasma P (1) is applied to the interface between the flange 155 of the flange portion 150 and the body portion 110 where the shape of the flange portion 150 changes rapidly due to inertia without passing through the end portion of the body portion 110 ).

The energy is concentrated at the place where the plasma P coheres to generate the first electrode 300 and the dielectric barrier discharge DBD in the dielectric portion 100 to ignite.

Thus, the risk of breakage of the ends of the dielectric part 100 can be reduced because ignition occurs at the interface between the body part 110 and the flange part 150 where the dielectric material is not thicker than the end of the dielectric part 100 having low durability. (See Fig. 3)

At this time, the hemispherical protrusion 130 may be formed at the end of the trunk 110.

The hemispherical protrusion 130 is smoothly formed on the outer surface so that the plasma P can smoothly flow along the outer surface of the dielectric portion 100 as compared with the case where the upper surface of the body 110 is flat. Reference)

Referring to FIG. 7, one or more guide grooves 113 may be formed on the outer circumferential surface of the body 110 along the longitudinal direction.

The guide groove 113 guides the plasma P reaching the dielectric portion 100 so that the plasma P is concentrated on the interface between the body 110 and the flange portion 150.

At this time, since the plasma condensing unit 170 is ignited by the energy concentration, the plurality of plasma condensing units 170 become the ignition point, and multi-point ignition is possible.

At this time, the guide groove 113 may have a shape in which the cross section becomes narrower toward the flange portion 150.

형태이나, 상술한 바와 같이 가이드 홈(113)은 도달한 플라즈마(P)를 플랜지(155)로 유도할 수 있는 공간을 제공하는 것을 목적으로 하는바, 이러한 목적을 달성하는 한, 가이드 홈(113)이 다른 형상의 단면을 가지는 경우라도 모두 본 발명의 범주에 속한다.In the present embodiment, the shape of the guide groove 113 is a cross-

As described above, the guide groove 113 is intended to provide a space through which the reached plasma P can be guided to the flange 155. As long as this object is achieved, the guide groove 113 ) Have different cross-sectional shapes belong to the category of the present invention.

8 and 9, the flange portion 150 may have a discharge preventing groove 153 formed along the circumferential direction on the outer circumferential surface thereof.

The discharge preventing grooves 153 are formed in one or more grooves having various depths and having a predetermined depth around the outer peripheral surface of the flange portion 150. The discharge preventing groove 153 prevents the plasma P from flowing along the outer circumferential surface of the flange portion 150 to prevent energy from being dispersed for generating ignition.

10 is an experimental photograph of a flame propagation process of a plasma spark plug according to an embodiment of the present invention.

10, when the first electrode 300 surrounded by the dielectric is electrified, a plasma P is formed at the end of the body 110 and the plasma P moves along the outer circumference of the body 110. (a)

Energy is concentrated as the plasma P coheres to the flange 155 of the flange portion 150 whose shape changes rapidly and ignition occurs at various points of the flange 155. (b)

After the multipoint ignition occurs, the flame is propagated and the mixer is burned. (C)

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, A deformation can be made.

100: dielectric part 110: body part 113: guide groove
130: protruding portion 150: flange portion 153: discharge preventing groove
155: flange 170: plasma agglomerating part 200: second electrode
300: first electrode 500: main body P: plasma

Claims (5)

A first electrode provided inside the body part and having an anode applied thereto, and a second electrode extended from the end of the body part toward the inward direction of the cylinder and having a predetermined gap with the first electrode, A plasma ignition plug for igniting an in-cylinder fuel, comprising: a second electrode spaced apart from the first electrode; and a dielectric portion formed to surround the first electrode,
Wherein the dielectric portion comprises: a cylindrical body portion to which the plasma reaches; And
And a disc-shaped flange portion having a larger diameter than the body portion, wherein the plasma is moved and ignited. The method according to claim 1,
The body part,
And a hemispherical protrusion is formed at an end thereof. The method according to claim 1,
The body part,
And at least one guide groove for moving the plasma along the longitudinal direction is formed on an outer circumferential surface of the plasma ignition plug. The method of claim 3,
Wherein the guide groove is narrowed in section toward the flange portion. The method according to claim 1,
The flange portion
And a discharge preventing groove is formed on the outer circumferential surface to prevent discharge of the plasma along the circumferential direction.

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