KR101372877B1 - High voltage igniter and the ignition control method using the same - Google Patents

Abstract

Disclosed are a high voltage ignition apparatus and a ignition control method using the same, which can ensure stable combustion performance and improve durability through preventing contamination of electrodes.
According to one embodiment of the high voltage ignition apparatus of the present invention, the inner electrode is formed along the outer diameter of the insulator, the inner electrode having a protruding tip length relative to the covering length of the insulator, the outer electrode formed surrounding the outer diameter of the insulator, and the inner And a dielectric cover member for sealing the exposed portion of the protruding tip of the electrode as a whole.

Description

HIGH VOLTAGE IGNITER AND THE IGNITION CONTROL METHOD USING THE SAME}

The present invention relates to a high voltage ignition apparatus and an ignition control method using the same, and more particularly, stable combustion performance can be secured during operation of a lean burn engine or a premixed compression ignition engine using gasoline, and contamination of the electrode can be prevented. The present invention relates to a high voltage ignition device capable of improving durability and an ignition control method using the same.

Recently, the demand for energy saving due to the depletion of fossil fuels and the air pollution caused by greenhouse gases and harmful emissions have emerged as social issues to be solved urgently.

Accordingly, in the field of automotive engine technology, new combustion engine technology that can maximize the efficiency of engine and reduce greenhouse gas and harmful emission gas is spurred.

In the case of an electric ignition engine using gasoline and gas fuel, the direct injection method is used to solve problems such as high pumping loss, lower compression ratio, and limitations of lean combustion. Efforts are underway to improve fuel efficiency and respond to emissions regulations.

In particular, in the case of a lean burn engine and a premixed compression ignition engine using gasoline, the supply of a heat source or an ignition source is not sufficient, so that a misfire occurs frequently and it is difficult to expand the lean area.

In order to improve such a problem, it is possible to secure more stable combustion performance compared to the ignition apparatus introduced previously, and to develop a high voltage ignition apparatus having an improved durability structure by preventing electrode contamination problems in the combustion chamber. It is.

The present invention provides a high voltage ignition apparatus and an ignition control method using the same, which can ensure stable combustion performance and prevent electrode contamination, thereby improving durability.

The problems to be solved by the present invention are not limited to the above-mentioned problems, and other problems not mentioned here can be clearly understood by those skilled in the art from the following description.

According to an embodiment of the high-voltage ignition device of the present invention, the insulator is formed along the outer diameter, the internal electrode having a protruding tip length relative to the coating length of the insulator; An external electrode formed to surround the outer diameter of the insulator; And a dielectric cover member that seals the exposed portion of the protruding tip of the inner electrode as a whole.

The outer electrode may surround the outer diameter of the insulator with a protruding tip length than the inner electrode, and a gap may be formed between the inner diameter of the outer electrode and the outer circumference of the dielectric cover member.

At this time, the size of the gap is made of 1/8 times the thickness of the insulator, the thickness of the dielectric cover member may be made of 1/4 times the thickness of the insulator.

In addition, the tip of the external electrode may be provided with an annular stepped connection portion bent in the inner diameter direction. As another embodiment, a plurality of rectangular stepped connection parts may be formed at the front end of the external electrode by bending in an inner diameter direction and spaced apart from each other by a center angle set along the circumferential direction.

In addition, the outer electrode surrounds the outer diameter of the insulator with a shorter tip length than the inner electrode, while the dielectric cover member includes a first cover part for simultaneously sealing the insulator and the inner electrode, and the first cover part. The second cover part may be formed in multiple stages having a reduced outer diameter compared to the cover part and padded in the tip direction.

On the other hand, according to an embodiment of the ignition control method using the high voltage ignition device of the present invention, (a) determining the engine speed and load; (b) predicting the pressure condition at the set operating condition using the pre-measured in-cylinder pressure value; (c) applying a voltage at which the stability of plasma ignition can be ensured under the predicted pressure condition; And (d) determining whether misfire is performed using an air-fuel ratio sensor.

Here, the method of selecting the voltage applied in the step (c) is, in consideration of the size of the gap in the high voltage ignition device and the estimated pressure conditions in the range that can be plasma discharge through the high voltage ignition device can occur. Can be done.

Further, after the step (d), (e) using the misfire determination information, adjusting the applied voltage upward when a misfire occurs; And (f) judging whether misfire occurs by using the air-fuel ratio sensor after the voltage adjustment.

According to the present invention, it is possible to ensure stable combustion performance during operation of a lean burn engine or a premixed compression ignition engine using gasoline.

More specifically, it is possible to suppress the phenomena that frequently occurred due to insufficient supply of the heat source or the ignition source, and at the same time, expand the lean region.

In addition, it is possible to fundamentally prevent the phenomenon that the electrode generating plasma is exposed in the combustion chamber and the electrode surface can be easily contaminated.

Accordingly, durability of the ignition device can be improved, and product competitiveness and reliability can be improved.

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a simplified diagram showing the three-dimensional shape and internal structure of a first embodiment of a high voltage ignition apparatus of the present invention.
FIG. 2 is an enlarged view of the PP cross section of FIG. 1 (FIG. 2A) and a front view of the first embodiment of the high voltage ignition apparatus of FIG. 1 (FIG. 2B).
Figure 3 is a simplified view showing the three-dimensional shape and internal structure of the second embodiment of the high voltage ignition device of the present invention.
FIG. 4 is a view showing a P'-P 'cross section of FIG. 3 (FIG. 4A) and a front view of a second embodiment of the high voltage ignition apparatus of FIG. 3 (FIG. 4B).
FIG. 5 is a view schematically showing a three-dimensional shape and an internal structure of a third embodiment of the high voltage ignition apparatus of the present invention. FIG.
FIG. 6 is a view showing a P ″ -P ″ section of FIG. 5 (FIG. 6A) and a front view of a third embodiment of the high voltage ignition device of FIG. 5 (FIG. 6B).
Figure 7 is a flow chart according to an embodiment of the ignition control method using the high voltage ignition device of the present invention.
8 is a graph showing the relationship between the pressure change and the applied voltage according to the engine operating conditions using the ignition control method using the high voltage ignition device of the present invention.

Brief Description of the Drawings The advantages and features of the present invention, and how to achieve them, will become apparent with reference to the embodiments described in detail below with reference to the accompanying drawings. However, the present invention is not limited by the embodiments disclosed below but may be embodied in various different forms. The embodiments to be described herein are provided so that the disclosure of the present invention is complete and that those skilled in the art will fully understand the scope of the present invention. In the following description, well-known functions or constructions are not described in detail since they would obscure the invention in unnecessary detail.

The high voltage ignition device and the ignition control method using the same will be described in detail with reference to the accompanying drawings.

First, a specific embodiment of the high voltage ignition apparatus of the present invention includes an inner electrode, an outer electrode, and a dielectric cover member. In the case of corona discharge, it proceeds in the form of brush corona, streamer corona, spark, arc with increasing electric field. During the process of discharge from arc to arc, when an electron avalanche occurs with discharge, the low temperature plasma is formed by preventing the streamer from reaching the opposite electrode by blocking the electric field and preventing the generation of arc.

In this case, a gap between the internal and external electrodes (hereinafter, referred to as a gap G in FIG. 2) in which the plasma may be generated varies according to the applied voltage and the combustion chamber atmosphere pressure. Therefore, a ignition device having a predetermined gap is first provided, and the pressure change according to the operating conditions of the engine is measured in advance, and the predicted applied voltage is set differently so that stable ignition can be achieved. In particular, in the high voltage ignition device of the present invention, since the gap between the internal electrode and the external electrode is provided at the front end portion, that is, the front end, the generation of plasma can be made horizontal, thereby enabling efficient operation of the engine.

First embodiment of high voltage ignition device

1 is a view schematically showing the three-dimensional shape and the internal structure of the first embodiment of the high voltage ignition apparatus of the present invention, and FIG. 2 is an enlarged view of the PP cross section of FIG. 1 (FIG. 2B) and FIG. 1. The front view (Fig. 2 (c)) of the first embodiment of the high voltage ignition device is shown briefly.

As shown in FIG. 1, the first embodiment 100 of the high voltage ignition apparatus of the present invention includes an insulator 120 interposed in a length direction between an internal electrode 110 and an internal electrode, and is formed to surround an outside. The dielectric cover member 150 may be configured to seal the exposure of the external electrode 130 and the protruding tip portion of the internal electrode.

The internal electrode 110 according to the first embodiment of the present invention is an electrode member disposed along the centerline of the high voltage ignition device, and may have a rod shape having a circular cross section as shown in the figure. It may be changed and implemented.

The insulator 120 is formed to cover the outer diameter of the internal electrode 110 in the longitudinal direction. Such an insulator 120 is typically used insulator (?? 子) used for the insulation of the wire.

The length range in which the insulator 120 is provided may be equal to or shorter than the protruding tip length of the internal electrode 110. Referring to FIG. 2A, it can be seen that the protruding tip of the internal electrode 110 is formed longer than the covering length of the insulator 120.

Meanwhile, the diameter of the internal electrode 110 may be appropriately selected and manufactured according to the thickness of the external electrode 130 and the insulator 120.

The external electrode 130 in the first embodiment of the present invention is disposed in such a manner as to surround the entire outer circumferential surface of the insulator 120 surrounding the internal electrode 110. That is, as shown in (b) of Figure 2 it can be provided in a pipe shape having an annular cross section.

The external electrode 130 has a tip length that protrudes more than the internal electrode 110 described above, and has a structure in which the external electrode 130 is in close contact with the outer circumferential surface of the insulator 120. This structure will be described in more detail in the description of the dielectric cover member 150 to be described later.

The external electrode 130 may be made of the same or similar electrode material together with the internal electrode 110, and need not be limited to a specific material.

Meanwhile, in the related art, the tip of the internal electrode 110 is exposed as it is in the combustion chamber. As a result of repeated ignition, there is a problem in that contamination occurs as the use time increases, which prevents the occurrence of contamination. As a dielectric cover member 150 is included.

The dielectric cover member 150 is an insulator (or dielectric) member that seals the exposed portion of the protruding tip of the internal electrode 110 as a whole. As shown in FIG. 1, the dielectric cover member 150 caps the protruding portion of the internal electrode 110. It has a structure that covers the shape. More specifically, the dielectric cover member 150 may be formed in a structure that completely connects the end of the insulator 110 formed around the outer diameter of the internal electrode 110 to completely block the exposure of the internal electrode 110. As the material of the dielectric cover member 150, a dielectric such as ceramic or alumina may be used. Here, the dielectric is a general term for a material that is polar and electrically conductive when a voltage of a predetermined level or more is applied in a given condition.

Referring to FIG. 2A, cross-sectional structures of the internal electrode 110, the insulator 120, the external electrode 130, and the dielectric cover member 150 may be confirmed. As shown, according to the first embodiment of the present invention, the external electrode 130 is formed to surround the outer diameter of the insulator 120 with the tip length protruding more than the internal electrode.

In addition, the dielectric cover member 150 is formed by applying a circular shape to the end of the insulator 120 to seal the protruding portion of the internal electrode 110.

In this case, a gap G is formed between the inner diameter of the external electrode 130 and the outer circumference of the dielectric cover member 150 to a predetermined size, and stable ignition occurs between them. Unlike the conventional method, since the exposed portion of the internal electrode 110 is completely sealed even when the internal electrode 110 and the external electrode 130 cause ignition in the combustion chamber, the problem of contamination of the internal electrode 110 is not yet disclosed. Is blocked.

At this time, the gap (G) is one of the important variables that can be selected by the user, the gap (G) determines the number of revolutions and load of the engine, the pressure conditions in the corresponding operating conditions are predicted, the estimated pressure The condition can be set by the user prior to the process of determining the required applied voltage at which the plasma discharge can occur.

For example, when the gap G between the internal electrode 110 and the external electrode 130 is determined to be 0.5 mm, the required applied voltage may be determined to be 9.0 kV or more when the atmospheric pressure condition is 4 bar. In the same relationship, stable ignition performance can be secured.

Thus, the size of the gap (G) in the embodiment of the present invention can be determined through the results obtained through repeated experiments in Figure 8 the size of the gap (G) in the range from 0.5mm to 2.0mm The correlation graph between the obtained pressure condition (Chamber Pressure) and the applied voltage (Plasma onset Voltage) divided by 0.5mm is shown as an example.

The size of the gap G may be related to the thickness b of the insulator 120, as shown in FIG. 2A, and the thickness a of the dielectric cover member 150 is also the insulator 120. The relationship with the thickness (b) of can be established. That is, the size of the gap G may be 1/8 times the thickness b of the insulator, and the thickness a of the dielectric cover member may be 1/5 times the thickness b of the insulator.

As a specific example, the thickness of the insulator 120 may be 4 mm or more, the thickness of the dielectric cover member 150 may be about 1 mm, and the size of the gap G may be 0.5 mm.

And (b) of FIG. 2 is a front view which looked at the front-end | tip part of 1st Example of the high voltage ignition apparatus of this invention.

Second embodiment of high voltage ignition device

3 is a view schematically showing the three-dimensional shape and the internal structure of the second embodiment of the high voltage ignition device of the present invention, and FIG. 4 is a view showing a P'-P 'cross section of FIG. 3 (FIG. 4A), and FIG. The front view (Fig. 4 (b)) of the second embodiment of the high voltage ignition device shown in Fig. 3 is shown briefly.

Unlike the first embodiment described above, the second embodiment 200 of the high voltage ignition device according to the present invention is characterized in that the stepped connection part 270 is bent at the front end portion of the external electrode 230 in the direction of the inner electrode. have. All other components are the same or similar, and only differences from the first embodiment will be described.

Referring to FIG. 3, the second embodiment 200 of the high voltage ignition apparatus of the present invention illustrated is formed with an insulator 220 interposed in the length direction between an internal electrode 210 and an internal electrode and wrapped around an outer portion thereof. The dielectric cover member 250 may be configured to seal the exposure of the external electrode 230 and the protruding tip portion of the internal electrode.

In this case, the external electrode 230 further includes a stepped connection part (reference numeral 270 of FIG. 4) formed by bending a tip portion of the external electrode 230 at a right angle to the internal electrode 210. Such a shape can be more clearly understood with reference to FIG. 4A.

Referring to Figure 4 (a), it can be seen the basic form of the stepped connection portion 270.

4 (b) is a front view of the front end of the second embodiment 200 of the high voltage ignition apparatus of the present invention. As shown, the basic shape of the stepped connection portion 270 is formed to be bent at a right angle in the inner diameter direction and the front shape has an annular shape.

4 (c) is a modified form of the stepped connection portion, the specific shape is formed by bending in the inner diameter direction from the tip of the external electrode, a plurality of rectangular stepped connection portion 270 disposed to be spaced apart from each other by the center angle set along the circumferential direction ′). This is an embodiment in which ignition characteristics are slightly considered in comparison with the first embodiment described above.

In the case of the modified stepped connection portion 270 ′ shown in FIG. 4 (c), the stepped portion 270 ′ is spaced apart from each other at a center angle of 45 degrees, and the total number thereof is shown as eight, but this is in one exemplary embodiment. Only the present invention is not limited thereto.

Third embodiment of high voltage ignition device

FIG. 5 is a view schematically showing the three-dimensional shape and the internal structure of the third embodiment of the high voltage ignition apparatus of the present invention, and FIG. 6 is a view showing the P ″ -P ″ cross section of FIG. 5 (FIG. Fig. 6 is a schematic front view (Fig. 6 (b)) of the third embodiment of the high voltage ignition device shown in Fig. 5.

The third embodiment 300 of the high voltage ignition apparatus of the present invention has a structure different from that of the first and second embodiments described above. Referring to FIG. 5, the third embodiment 300 of the high voltage ignition apparatus of the present invention illustrated is formed with an insulator 320 interposed in the length direction between an inner electrode 310 and an inner electrode and wrapped around an outer portion thereof. It includes an external electrode 330, and includes a dielectric cover member 350 to seal the exposure of the protruding tip portion of the internal electrode.

However, unlike the first and second embodiments described above with reference to FIGS. 1 to 4, the external electrode 330 has a structure surrounding the outer diameter of the insulator 320 with a shorter tip length than the internal electrode. Consists of The dielectric cover member 350 may be formed in a multilayer structure, that is, a multistage structure. Here, the division into multiple stages is only divided for convenience of explanation in terms of structure, and should not be understood as different configurations and members.

As shown, the dielectric cover member 350 has a first cover portion 350a for simultaneously sealing the insulator 320 and the internal electrode 310, and has a reduced outer diameter compared to the first cover portion 350a. The second cover part 350b formed to be padded in the direction may be formed in multiple stages.

That is, the first cover part 350a of the dielectric cover member is formed to seal the insulator 320 and to seal the end of the external electrode 330 in a circular cross section, and the second cover part 350b of the dielectric cover member. The pad is formed to have a thickness that completely seals the tip protruding portion of the internal electrode 310 along the circumferential surface of the first cover portion 350a. Accordingly, the internal electrode 310 is contaminated in the combustion chamber during the ignition action between the internal electrode and the external electrode, thereby reducing the durability.

According to the first, second, and third embodiments of the high voltage ignition apparatus of the present invention as described above, it is possible to ensure stable combustion performance when operating a lean burn engine or a premixed compression ignition engine using gasoline, in particular, a heat source or an ignition source is sufficient. It can be supplied so that the misfire phenomenon can be prevented. And the improvement of durability can be expected.

Next, an embodiment of the ignition control method using the high voltage ignition device of the present invention will be described.

7 is a flow chart according to an embodiment of the ignition control method using a high voltage ignition device of the present invention.

Engine speed and load determination stages ( S100 )

In the ignition control method using the high voltage ignition apparatus of the present invention, the steps to be basically preceded, the operation of determining the rotational speed and load of the engine is performed.

Pressure condition prediction step ( S200 )

In this step, the atmospheric pressure condition (ie, chamber pressure) in the combustion chamber under the engine operating condition is predicted from the pre-measured pressure value in the cylinder. At this time, the pressure condition prediction work in the combustion chamber is observed by mounting the combustion pressure sensor.

In case of emergency, by directly measuring the combustion chamber pressure under the given operating conditions and storing the combustion chamber pressure data for each operating condition in the engine control unit (ECU) in advance. Can even predict the combustion chamber pressure

Voltage determination and application step S300 )

In this step, when the atmospheric pressure condition in the combustion chamber is predicted through the pressure condition prediction step (S200), the operation of determining and applying a voltage value capable of generating stable plasma ignition under the pressure condition is performed.

As a specific example, first, the user determines the size of the gap (reference G in FIG. 2A) between the internal electrode and the external electrode according to the ignition conditions.

Thereafter, as shown in the graph of FIG. 8, the required applied voltage at which the plasma discharge can occur under the atmospheric pressure condition in the combustion chamber is determined according to the selected gap size. Next, the determined voltage is applied.

As a result of repetitive experiments, when the gap size was determined to be 0.5mm, stable plasma discharge could be realized at a voltage value of 9 kV or more under a pressure condition of 4 bar. In the case of other conditions, the graph of FIG. 8 may appropriately determine the voltage value to be applied according to the gap size and the pressure condition. This operation is determined by the engine control unit (ECU), and plasma discharge occurs when the applied voltage determined by the engine control unit is applied to the high voltage ignition device by the ignition coil or a corresponding power supply.

Misfire determination step (S400)

In this step, it is determined whether misfire is performed by using the air-fuel ratio sensor after the application of the performed voltage.

As a specific example, when using a general oxygen sensor of zirconia or titania type, a value of 0.5 V or less is continuously output as the amount of surplus oxygen increases when stable combustion does not occur. Through this, it is possible to determine whether the misfire. As another example, when a wide-range oxygen sensor is used, a voltage of 1 V or more is continuously output to determine whether misfire occurs.

After the misfire determination step (S400), it is divided into a case in which misfire occurs and a case in which misfire occurs using the information obtained through the misfire determination step (S400). Here, the next step can then be performed only if it is determined that misfire has occurred.

Step of adjusting the voltage when misfire occurs (S500)

This step is a process that is performed after it is determined that misfire has occurred using the information obtained through the misfire determination step S400 described above, and if it is determined that misfire has occurred, the process is determined in the previous step of applying voltage (S300). It is determined that there was a problem with the voltage, and then adjusts the voltage up compared to the voltage determined in the previous step.

True facts trial stage (S600)

This step is a step of determining again whether or not the misfire occurs again, even though the voltage has been adjusted upward when the misfire has occurred previously, and the same operation as the misfire determination step S400 is performed repeatedly using the air-fuel ratio sensor.

As the above-described steps are sequentially performed, it is possible to secure stable ignition performance using the high voltage ignition device.

As described above, according to the high voltage ignition device and the ignition control method using the same, it is possible to ensure stable combustion performance during operation of the lean burn engine or the premixed compression ignition engine using gasoline.

As a specific effect, it is possible to suppress the misfire phenomenon which has frequently occurred in the past due to insufficient supply of a heat source or an ignition source, and to expand the lean area.

In addition, it is possible to fundamentally prevent a phenomenon in which the plasma generating electrode is exposed in the combustion chamber and the surface of the electrode may be easily contaminated. As a result, the durability of the ignition device can be improved to improve product competitiveness and reliability.

In particular, since the plasma is generated horizontally at the outer end between the electrodes, it is possible to ensure the durability and efficient operation of the engine.

And when using such a high voltage ignition device to predict the pressure change in accordance with the operating conditions of the engine in advance to control the ignition by setting the applied voltage differently, it is possible to ensure a more stable ignition characteristics.

The above has been described with respect to a preferred embodiment of a high voltage ignition device and an ignition control method using the same according to the present invention.

It is to be understood that the above-described embodiments are to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, All changes or modifications that come within the scope of the equivalent concept are to be construed as being included within the scope of the present invention.

G: gap
100, 200, 300: high voltage ignition device according to an embodiment of the present invention
110, 210, 310: internal electrode
120, 220, 320: insulator
130, 230, 330: external electrode
150, 250, 350: dielectric cover member
270, 270 ': step connection
350a: first cover part 350b: second cover part

Claims (9)

An inner electrode covering the outer diameter and having an end length protruding from the covering length of the insulator;
An external electrode formed to surround the outer diameter of the insulator; And
And a dielectric cover member for sealing the exposed portion of the protruding tip of the inner electrode as a whole.
The method according to claim 1,
The external electrode surrounds the outer diameter of the insulator with a tip length that protrudes more than that of the inner electrode, and a high voltage ignition device having a predetermined size is formed between the inner diameter of the outer electrode and the outer circumference of the dielectric cover member. .
The method according to claim 2,
The gap is 1/8 times larger than the thickness of the insulator, and the thickness of the dielectric cover member is a high voltage ignition device, characterized in that made of 1/4 times the thickness of the insulator.
The method according to claim 1,
A high voltage ignition device having an annular stepped connection portion formed at an end of the external electrode by bending in an inner diameter direction.
The method according to claim 1,
A high voltage ignition device having a plurality of rectangular stepped connection portions formed at the front end of the external electrode by bending in an inner diameter direction and spaced apart from each other by a center angle set in the circumferential direction.
The method according to claim 1,
The outer electrode surrounds the outer diameter of the insulator with a shorter tip length than the inner electrode,
The dielectric cover member,
And a first cover portion for simultaneously sealing the insulator and the internal electrode, and a second cover portion formed in the leading direction while having a reduced outer diameter compared to the first cover portion.
An ignition control method using the high voltage ignition device according to any one of claims 1 to 6,
(a) determining the engine speed and load;
(b) predicting a pressure condition at a set operating condition using a pre-measured in-cylinder pressure value;
(c) applying a voltage capable of ensuring stability of the plasma ignition under the pressure conditions predicted in the pressure condition prediction step; And
(d) determining whether misfire is performed using an air-fuel ratio sensor.
The method of claim 7,
The method of selecting a voltage applied in the step (c),
In consideration of the size of the gap formed between the inner diameter of the external electrode of the high voltage ignition device and the outer circumference of the dielectric cover member and the predicted pressure condition, a plasma discharge may be generated through the high voltage ignition device. Ignition control method using high voltage ignition device.
The method of claim 7,
After the step (d)
(e) adjusting the voltage determined in the voltage applying step when the misfire has occurred, using the misfire determination information obtained in the misfire determination step; And
(f) judging whether or not misfire by using the air-fuel ratio sensor after the voltage adjustment in the voltage upward adjustment step.

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