KR20210148605A - Engine - Google Patents

Abstract

Disclosed is an engine. The engine according to an embodiment of the present invention comprises: an engine including a plurality of combustion chambers for generating power required for driving of a vehicle by combustion of a fuel; an intake port formed so that a mixture introduced into the combustion chamber flows in a tumble direction within the combustion chamber; and a spark plug installed in the combustion chamber and igniting the mixture introduced into the combustion chamber through the intake port. A center electrode and a ground electrode of the spark plug may be formed to extend along the flow direction of a mixer introduced through the intake port. An objective of the present invention is to provide the engine capable of improving combustion stability in dilute combustion conditions.

Description

engine {ENGINE}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an engine, and more particularly, to an engine capable of improving combustion stability under diluted combustion conditions.

Diluted combustion is used for the purpose of controlling the rapid reaction of the fuel-air mixture in the combustion process of a gasoline engine, reducing the heat transfer loss by reducing the combustion temperature, and reducing the pumping loss occurring in the intake and exhaust process.

Methods of dilution combustion include exhaust gas recirculation (EGR), lean burn combustion, and dilution by supplying a non-reactive fluid such as water.

If the mixer is diluted, combustion instability may occur during the initial combustion process.

The stability of the initial combustion process is a function of the size of the flame core generated from the spark plug, the supplied ignition energy, and the laminar flame velocity.

Depending on the supplied ignition energy and the laminar flame speed, the critical radius for the growth of the flame core is determined.

Since the laminar flame speed of the air-fuel ratio decreases under the dilution combustion condition, it is necessary to increase the size of the initial flame core in order to improve combustion efficiency in the combustion process.

Therefore, for the stable implementation of dilution combustion, a technology for realizing volumetric ignition capable of maximizing the size of the initial flame nucleus is being studied.

Volumetric ignition techniques that maximize the size of the initial flame nucleus include volumetric ignition using non-thermal plasma and volumetric ignition using arc discharge.

Volume ignition using non-thermal plasma increases manufacturing cost, system complexity, engine volume, and engine weight, and has problems in that it is difficult to ignite robustly against conditions such as combustion chamber temperature, pressure, volume, and electrode surface condition.

Volumetric ignition using arc discharge can be implemented at low cost and has the advantage of being able to implement stable volumetric ignition without complex system changes. However, since a random flow in the combustion chamber is used, a problem arises in that it is difficult to control the ignition volume and the arc channel. In addition, since a high ignition energy is required, there is a problem in that the electrode of the spark flux is corroded.

Matters described in this background section are prepared to improve understanding of the background of the invention, and may include matters that are not already known to those of ordinary skill in the art to which this technology belongs.

An object of the present invention is to solve the above problems, and an object of the present invention is to provide an engine capable of improving combustion stability under dilute combustion conditions.

An engine according to an embodiment of the present invention for achieving the above object includes an engine including a plurality of combustion chambers for generating power necessary for driving a vehicle by combustion of fuel; an intake port formed so that the mixture introduced into the combustion chamber flows in a tumble direction within the combustion chamber; and a spark plug installed in the combustion chamber to ignite the mixer introduced into the combustion chamber through the intake port, wherein a center electrode and a ground electrode of the spark plug determine the flow direction of the mixer introduced through the intake port It may be formed to extend along.

The center electrode may include a central straight portion extending inside the insulating body of the spark plug; and a central extension extending from an end of the straight part in the flow direction of the mixer.

The ground electrode may include a ground straight portion extending from the metal body of the spark plug; a ground bending part bent from the ground straight line part and facing the center straight part; and a ground extension extending from the ground bending part and facing the center extension part.

An end of the ground extension may be bent in a direction away from the central extension.

A maximum distance between the center electrode and the ground electrode may be smaller than a minimum distance between an end of the central extension portion of the center electrode and the combustion chamber.

The length of the central extension part and the ground extension part may be formed to be smaller than an outer diameter of the metal body.

The central extension portion may be formed by being deviated by a predetermined angle in a direction away from the ground straight line portion.

The center electrode may include a central straight portion extending inside the insulating body of the spark plug; a first central extension part that is spaced at a predetermined angle from an end of the central straight part with respect to the flow direction of the mixer; and a second central extension extending at a predetermined angle with respect to the flow direction of the mixer at an end of the central straight portion in a direction opposite to the first central extension.

The ground electrode may include a ground straight portion extending from the metal body of the spark plug; a ground bending part bent from the ground straight line part and facing the center straight part; a first ground extension extending from an end of the ground bending part to face the first central extension; and a second ground extension extending from an end of the ground bent part in a direction opposite to the first ground extension to face the second central extension.

The center electrode may include a central straight portion extending inside the insulating body of the spark plug; And it may include; and a central extension at a predetermined angle with respect to the flow direction of the mixer at the end of the central straight portion.

The ground electrode may include a ground straight portion extending from the metal body of the spark plug; and a ground extension extending in a direction away from the center extension at an end of the ground straight line portion.

The intake port may be provided to be inclined at a predetermined angle from the upper portion of the combustion chamber, the upper side of the intake port may extend flatly, and the intake port may be formed to have a smaller cross-sectional area as it approaches the combustion chamber.

The inclined angle of the upper side of the intake port may be formed to be the same as the installation angle of the exhaust valve mounted in the combustion chamber.

According to the engine according to the embodiment of the present invention as described above, since the position of the flame generated from the spark plug moves similarly to the flow velocity of the mixer, ignition energy can be supplied to the mixer with a relatively small resistance, and under dilution combustion conditions can improve combustion stability.

These drawings are for reference in describing an exemplary embodiment of the present invention, and the technical spirit of the present invention should not be construed as being limited to the accompanying drawings.
1 is a diagram showing the configuration of an engine according to an embodiment of the present invention.
2 is a diagram illustrating a configuration of an intake port according to an embodiment of the present invention.
3 is a perspective view illustrating a configuration of a spark plug according to an embodiment of the present invention.
4 is a side view illustrating a configuration of a spark plug according to an embodiment of the present invention.
5 is a bottom view illustrating the configuration of a spark plug according to an embodiment of the present invention.
6 is a view for explaining an operation of a spark plug according to an embodiment of the present invention.
7 is a perspective view illustrating a configuration of a spark plug according to another embodiment of the present invention.
8 is a side view illustrating a configuration of a spark plug according to another embodiment of the present invention.
9 is a bottom view illustrating a configuration of a spark plug according to another embodiment of the present invention.
10 is a side view illustrating a configuration of a spark plug according to another embodiment of the present invention.
11 is a bottom view illustrating the configuration of a spark plug according to another embodiment of the present invention.
12 is a side view illustrating a configuration of a spark plug according to another embodiment of the present invention.
13 is a bottom view illustrating the configuration of a spark plug according to another embodiment of the present invention.

With reference to the accompanying drawings, embodiments of the present invention will be described in detail so that those of ordinary skill in the art to which the present invention pertains can easily implement them. However, the present invention may be implemented in several different forms and is not limited to the embodiments described herein.

In order to clearly explain the present invention, parts irrelevant to the description are omitted, and the same reference numerals are assigned to the same or similar components throughout the specification.

In addition, since the size and thickness of each component shown in the drawings are arbitrarily indicated for convenience of explanation, the present invention is not necessarily limited to the bar shown in the drawings, and the thickness is enlarged to clearly express various parts and regions. it was

Hereinafter, an engine according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

1 is a diagram showing the configuration of an engine according to an embodiment of the present invention.

1, the engine according to the embodiment of the present invention includes a cylinder body 13 forming a plurality of combustion chambers 11 for generating power by combustion of fuel, and an upper portion of the cylinder body 13. It may include a cylinder head 15 that covers it.

The cylinder body 13 is formed in a substantially cylindrical shape, the combustion chamber 11 is formed therein, and the upper part is opened. The cylinder head 15 covers the upper part of the opened cylinder body 13 so that a combustion chamber 11 is formed between the cylinder body 13 and the cylinder head 15 .

The upper portion of the cylinder head 15 may be formed in a substantially conical shape in an upward direction of the center thereof so that the upper portion of the combustion chamber 11 has a pent-roof shape.

The cylinder head 15 may include an intake port 20 through which intake air flows into the combustion chamber 11 , and an exhaust port 30 through which exhaust gas generated in the combustion chamber 11 is discharged.

An intake valve 17 for selectively opening and closing the combustion chamber 11 is installed in the intake port 20 , and an exhaust valve 19 for selectively opening and closing the combustion chamber 11 is installed in the exhaust port 30 . The intake valve 17 and the exhaust valve 19 are provided in the cylinder head 15 , and may be installed at a predetermined angle from the center of the cylinder head 15 .

An injector for injecting fuel is installed in the intake port 20 , and a mixture of air and fuel is introduced into the combustion chamber 11 .

A piston 12 for compressing the mixture introduced through the intake port 20 is provided inside the combustion chamber 11 . The piston 12 moves up and down in the combustion chamber 11 in the lower side 23 and compresses the mixture.

A spark plug 100 for igniting the mixture flowing into the combustion chamber 11 is installed in the upper center of the cylinder head 15 .

Hereinafter, the configuration of the intake port 20 according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

2 is a view showing the configuration of the intake port 20 according to an embodiment of the present invention.

As shown in FIG. 2 , the intake port 20 may be inclined at a predetermined angle from the inclined side of the cylinder head 15 .

The intake port 20 may include an upper side 21 and a lower side 23 based on a cross-section thereof. In this case, the intake port 20 may be formed so that the mixer introduced into the combustion chamber 11 flows in a tumble direction.

To this end, the upper side 21 of the intake port 20 may extend flat. In other words, the lower side 23 and the upper side 21 of the intake port 20 may extend in a straight line without forming a curvature. At this time, the inclined angle of the upper side 21 of the intake port 20 (refer to the 'b' indicator in FIG. 1 ) is the installation angle of the exhaust valve 19 mounted in the combustion chamber 11 (the 'a' indicator in FIG. 1 ) See) may be formed in the same way.

The lower side 23 of the intake port 20 may be formed to have a smaller cross-sectional area as it approaches the combustion chamber 11 . That is, as the lower side 23 of the intake port 20 approaches the combustion chamber 11, the port inclined portion 25 that is sharply inclined toward the center of the intake port 20 is formed. The cross-sectional area may be rapidly reduced as it approaches the combustion chamber 11 .

In order to strengthen the flow in the tumble direction of the mixer in the combustion chamber 11, the mixer flowing into the upper side 21 of the intake port 20 must have a large linear momentum, and flowing into the lower side 23 of the intake port 20 The mixer should have a relatively small momentum.

By allowing the upper side 21 of the intake port 20 to extend in a straight line, the mixer flowing into the upper side 21 of the intake port 20 can have a large linear momentum. And by forming the port inclined portion 25 on the lower side 23 of the intake port 20, the flow of the mixer flowing into the lower side 23 of the intake port 20 is restricted to relatively reduce the linear momentum of the mixer. can

In this way, the strong tumble direction of the mixer flowing inside the combustion chamber 11 due to the difference in the magnitude and direction of the momentum of the mixer flowing into the combustion chamber 11 from the upper side 21 and the lower side 23 of the intake port 20 . The flow may be generated, and the flow of the gap between the electrodes of the spark plug 100 may be strengthened by the flow in the tumble direction of the mixer.

Next, the configuration of the spark plug 100 according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

3 is a perspective view illustrating a configuration of a spark plug 100 according to an embodiment of the present invention. 4 is a side view showing the configuration of the spark plug 100 according to an embodiment of the present invention. And Figure 5 is a bottom view showing the configuration of the spark plug 100 according to an embodiment of the present invention.

3 to 5 , the spark plug 100 according to an embodiment of the present invention includes a metal body made of a metal, an insulating body 120 made of an insulating material provided inside the metal body, and an insulating body 120 . ) may include a center electrode 130 provided inside, and a ground electrode 140 extending from the metal body 110 and generating a spark discharge between the center electrode 130 and the center electrode 130 .

The metal body 110 is a portion mounted on the cylinder head 15 of the engine and is formed in a substantially cylindrical shape, and the lower outer side of the metal body 110 includes a threaded portion for coupling with the cylinder head 15 . do. Another thread corresponding to the thread of the metal body 110 is formed in the cylinder head 15 of the engine. That is, the spark plug 100 and the cylinder head 15 of the engine are screwed to each other. The metal body 110 and the cylinder head 15 of the engine are screwed to each other, and the metal body 110 and the ground electrode 140 form a ground terminal (or (-) electrode).

The insulating body 120 may be formed of a ceramic material, and may be provided inside the metal body 110 .

The center electrode 130 is provided inside the insulating body 120 , and may be installed eccentrically by a predetermined distance from the center of the insulating body 120 . The center electrode 130 is electrically connected to the ignition coil to receive a high current. That is, the center electrode 130 forms a (+) electrode.

The center electrode 130 may include a central straight part 131 extending from the inside of the insulating body 120 , and a central extending part 132 extending from an end of the straight part in the flow direction of the mixer.

The ground electrode 140 is bent toward the center straight part 131 of the center electrode 130 from the ground straight line part 141 extending downward from the metal body 110 and the ground straight line part 141 to form a central straight line part ( 131) and the ground bending portion 142 facing, and the grounding extension portion 143 extending in the same direction as the center extension portion 132 from the ground bending portion 142 and facing the center straight portion 131. can

In this case, the end of the ground extension 143 may be bent in a direction away from the center extension 132 . In other words, the distance between the ground extension 143 and the central extension 132 may be formed to gradually increase along the flow direction of the mixer.

That is, the distance between the end of the center straight portion 131 of the center electrode 130 and the end of the ground bent portion 142 of the ground electrode 140 is the minimum distance between the center electrode 130 and the ground electrode 140 . The distance between the end of the center extension 132 of the center electrode 130 and the end of the ground extension 143 of the ground electrode 140 is the maximum between the center electrode 130 and the ground electrode 140 . becomes an interval.

And so that the flame generated between the center electrode 130 and the ground electrode 140 is not formed on the inner surface of the combustion chamber 11, the maximum distance between the center electrode 130 and the ground electrode 140 is the center electrode 130. It may be formed smaller than the minimum distance between the end of the central extension 132 and the combustion chamber 11 of the.

In addition, in order to smoothly assemble the spark plug 100 to the cylinder head 15 , the length of the center extension 132 of the center electrode 130 and the ground extension 143 of the ground electrode 140 is equal to the length of the metal body. It may be formed smaller than the outer diameter of 110 (or the diameter of the thread formed in the metal body 110).

6 is a view for explaining the operation of the spark plug 100 according to an embodiment of the present invention.

Referring to (a) of FIG. 6 , when a high voltage is applied from the ignition coil to the center electrode 130 , the insulation is broken at the minimum distance between the two electrodes due to the high voltage difference between the center electrode 130 and the ground electrode 140 . occurs and an arc discharge occurs.

Referring to FIG. 6 (b), the plasma moves at a speed similar to the flow rate of the mixer by the flow of the internal mixer in the combustion chamber 11, and the volume of the plasma is gradually expanded. At this time, the temperature of the plasma is maintained at a high temperature.

Referring to FIG. 6C , as the volume of the plasma increases, the resistance between the two electrodes increases and the cooling of the plasma proceeds. Even if the cooling of the plasma proceeds, since the conductivity of the plasma is high, the movement and expansion of the plasma continues. Plasma moves and expands in the form of low-temperature plasma, so the ignition efficiency is excellent.

Referring to (d) of FIG. 6 , when power consumption due to an increase in resistance between the two electrodes is greater than the supplied energy, the plasma is extinguished and dielectric breakdown occurs again at the minimum gap between the two electrodes at the same time.

Hereinafter, a configuration of a spark plug according to another embodiment of the present invention will be described in detail with reference to the accompanying drawings.

7 is a perspective view illustrating a configuration of a spark plug according to another embodiment of the present invention. 8 is a side view illustrating a configuration of a spark plug according to another embodiment of the present invention. And FIG. 9 is a bottom view showing the configuration of a spark plug according to another embodiment of the present invention.

7 to 9 , the spark plug 200 according to another embodiment of the present invention is similar to the configuration of the spark plug 100 described above. However, only the configuration of the central extension portion and the ground extension portion is different.

Specifically, the center extension portion 232 of the center electrode 230 according to another embodiment of the present invention may be formed by being twisted in a direction away from the ground straight line portion 241 of the ground electrode 240 .

In other words, when the spark plug 200 is viewed from the bottom up, the central extension 232 may be formed to gradually move away from the ground extension 243 toward each end (refer to FIG. 9 ). ).

The configuration of the spark plug 300 according to another embodiment of the present invention will be described in detail with reference to the accompanying drawings.

10 is a side view illustrating a configuration of a spark plug according to another embodiment of the present invention. And FIG. 11 is a bottom view showing the configuration of a spark plug according to another embodiment of the present invention.

Only parts that are different from the spark plug 100 described in the embodiment of the present invention will be described.

As shown in FIGS. 10 and 11 , the center electrode 330 has a central straight line portion 331 extending inside the insulating body 320 , and an end of the central straight line portion 331 with respect to the flow direction of the mixer. A first central extension portion 332 extending at a predetermined angle, and a second center extending at an angle apart from the flow direction of the mixer at the end of the central straight portion 331 in the opposite direction to the first central extension portion 332 An extension 333 may be included.

In other words, when the spark plug 300 is viewed from the bottom up, the first central extension 332 and the second central extension 333 may be formed to move away from each other toward each end ( see Fig. 10).

The ground electrode 340 is bent toward the center straight part 331 of the center electrode 330 from the ground straight part 341 extending downward from the metal body 310 and the ground straight part 341 to form a central straight part ( 331) facing the ground bent portion 342, the first ground extension 343 extending to face the first center extension 332 at the end of the ground bent portion 342, and the first ground extension portion ( A second ground extension part 344 extending to face the second central extension part 332 at an end of the ground bending part 342 in the opposite direction to 343 may be included.

In other words, when the spark plug 300 is viewed from the bottom up, the first grounding extension 343 and the second grounding extension 344 may be formed to gradually move away from each other toward each end. There is (see Fig. 10).

The configuration of the spark plug 400 according to another embodiment of the present invention will be described in detail with reference to the accompanying drawings.

12 is a side view illustrating a configuration of a spark plug according to another embodiment of the present invention. And FIG. 13 is a bottom view showing the configuration of a spark plug according to another embodiment of the present invention.

Only parts that are different from the spark plug 100 described in the embodiment of the present invention will be described.

12 and 13 , the center electrode 430 has a central straight line portion 431 extending inside the insulating body 420 , and a flow direction of the mixer at the end of the central straight line portion 431 . It may include a central extension portion 432 formed to be spaced at a predetermined angle.

The ground electrode 440 includes a ground straight portion 441 extending downward from the metal body 410 , and a ground extension extending in a direction away from the end of the central extension 432 from the end of the ground straight portion 441 . part 443 .

According to the engine according to the embodiment of the present invention as described above, the flame (plasma) generated between the two electrodes of the spark plug 100 is introduced into the combustion chamber 11 through the intake port 20. The electrode life of the spark plug 100 increases as it expands and moves into the combustion chamber 11 by the strong tumble direction flow.

In addition, since the flame generated from the spark plug 100 is guided and moved according to the shape of the electrode, the extinguishing position of the flame generated from the spark plug 100 can be controlled.

In addition, since the position of the flame generated from the spark plug 100 moves similarly to the flow velocity of the mixer, ignition energy can be supplied to the mixer with a relatively low resistance.

Although preferred embodiments of the present invention have been described above, the present invention is not limited thereto, and it is possible to carry out various modifications within the scope of the claims, the detailed description of the invention, and the accompanying drawings, and this also It goes without saying that it falls within the scope of the invention.

10: engine
11: combustion chamber
12: piston
13: cylinder body
15: cylinder head
17: intake valve
19: exhaust valve
20: intake port
21: upper side
23: lower
25: port slope
29: sandblast
30: exhaust port
100: spark plug
110: metal body
120: insulated body
130: center electrode
131: center straight part
132: central extension
140: ground electrode
141: ground straight part
142: ground bend
143: ground extension

Claims (13)

an engine including a plurality of combustion chambers for generating power necessary for driving of a vehicle by combustion of fuel;
an intake port formed so that the mixture introduced into the combustion chamber flows in a tumble direction within the combustion chamber; and
a spark plug installed in the combustion chamber and igniting the mixture introduced into the combustion chamber through the intake port;
including,
The center electrode and the ground electrode of the spark plug are formed to extend along a flow direction of the mixer introduced through the intake port. According to claim 1,
The center electrode is
a central straight portion extending inside the insulating body of the spark plug; and
a central extension portion extending from an end of the straight portion in the flow direction of the mixer;
engine containing 3. The method of claim 2,
The ground electrode is
a ground straight portion extending from the metal body of the spark plug;
a ground bending part bent from the ground straight line part and facing the center straight part; and
a ground extension portion extending from the ground bending portion and facing the center extension portion;
engine containing 4. The method of claim 3,
An end of the ground extension is bent in a direction away from the central extension. 5. The method of claim 4,
and a maximum distance between the center electrode and the ground electrode is formed to be smaller than a minimum distance between an end of the central extension portion of the center electrode and the combustion chamber. 5. The method of claim 4,
The length of the central extension part and the ground extension part is formed to be smaller than an outer diameter of the metal body. 5. The method of claim 4,
The central extension portion is formed by being twisted at a predetermined angle in a direction away from the ground straight portion. According to claim 1,
The center electrode is
a central straight portion extending inside the insulating body of the spark plug;
a first central extension part that is spaced at a predetermined angle from an end of the central straight part with respect to the flow direction of the mixer; and
a second central extension extending at a predetermined angle with respect to the flow direction of the mixer at an end of the central straight portion in a direction opposite to the first central extension;
engine containing 9. The method of claim 8,
The ground electrode is
a ground straight portion extending from the metal body of the spark plug;
a ground bending part bent from the ground straight line part and facing the center straight part;
a first ground extension extending from an end of the ground bending part to face the first central extension; and
a second ground extension extending from an end of the ground bent part in a direction opposite to the first ground extension to face the second central extension;
engine containing According to claim 1,
The center electrode is
a central straight portion extending inside the insulating body of the spark plug; and
a central extension part which is spaced at a predetermined angle with respect to the flow direction of the mixer at the end of the central straight part;
engine containing 11. The method of claim 10,
The ground electrode is
a ground straight portion extending from the metal body of the spark plug; and
a ground extension extending from an end of the ground straight line in a direction away from the central extension;
engine containing According to claim 1,
The intake port is provided to be inclined at a predetermined angle with the upper portion of the combustion chamber,
The upper side of the intake port extends flat,
The engine is formed such that the cross-sectional area of the intake port becomes smaller as it approaches the combustion chamber. 13. The method of claim 12,
The inclined angle of the upper side of the intake port is formed to be the same as the installation angle of the exhaust valve mounted in the combustion chamber.

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