KR20190033342A - Swirl chamber type diesel engine - Google Patents

Abstract

The present invention relates to a swirl chamber type diesel engine. A guide structure capable of guiding combustion gas ejected from an auxiliary combustion chamber to a main combustion chamber by division into three parts is provided in a connection passage connecting the auxiliary combustion chamber and the main combustion chamber in the swirl chamber type diesel engine, and thus diffusion combustion is promoted in the diesel engine and the generation of harmful gases such as smog can be suppressed. The present invention includes an auxiliary combustion chamber assembly (2) including a swirl guide part (2d) having a curved shape on the inner wall surface and a connection passage (2b) formed at the lower end of the swirl guide part (2d) and coupled to a cylinder head (1) to constitute an auxiliary combustion chamber (2a); and a piston (3) including a trench part (3c) communicating with the connection passage (2b) and a clover part (3b) formed on both sides of the trench part (3c) and constituting a main combustion chamber (3a). The connection passage (2b) is provided with a guide structure (2e) capable of guiding combustion gas ejected from the auxiliary combustion chamber (2b) to the main combustion chamber (3a) by division into three parts.

Description

{SWIRL CHAMBER TYPE DIESEL ENGINE}

The present invention relates to a vortex type diesel engine, and more particularly, to a vortex type diesel engine which guides a combustion gas blown from the subordinate combustion chamber to the main combustion chamber into three parts in a connection passage connecting the subordinate combustion chamber and the main combustion chamber Which is capable of promoting diffusion combustion in a diesel engine and suppressing generation of harmful gas such as smog.

Diesel engines are essentially no different from gasoline engines in the structure of the major parts (cylinder heads, cylinder blocks, piston connecting assemblies, crankshafts, camshafts, valve mechanisms) that convert thermal energy into mechanical energy.

However, in the combustion process of the fuel, the gasoline engine compresses a mixture of air and fuel and then ignites it with an electrical flame, whereas the diesel engine sucks only air and makes the temperature higher than 500 ~ 600 ° C There is a difference in that the fuel is injected into the cylinder by the injection nozzle while being pressurized by the injection pump to self-ignite (compression ignition).

The combustion chamber of the diesel engine should satisfy the following conditions. That is, the injected fuel must be completely burned in the shortest possible time, the average effective pressure must be high, and the fuel consumption rate must be low. Further, the combustion state at high speed rotation should be good, the start-up must be easy, and the diesel knock must be small.

An injection nozzle installed in the cylinder head is provided above the combustion chamber. The injection nozzle is a device for injecting high-pressure fuel sent from the injection pump into the combustion chamber in the form of fine smoke. The fuel spray injected by such an injection nozzle must have good atomization characteristics, large penetration force, uniform spraying, proper jetting rate and injection rate, and accurate nozzle flowmeter.

The combustion chamber type of the diesel engine is a single-chamber type, direct-injection type, a complex type, a pre-combustion chamber, and a vortex type. The direct injection type is a structure in which the combustion chamber is formed by the irregularities provided on the cylinder head and the piston head, and the fuel is injected directly into the combustion chamber. The combustion chamber is composed of only the main combustion chamber and is referred to as a single- I have.

In the precombustion chamber, a combustion chamber is placed above the main combustion chamber formed between the piston and the cylinder head, and a part of the injected fuel is combusted in the precombustion chamber to generate high temperature and high pressure gas, whereby the remaining fuel is injected into the main combustion chamber And has a structure for completely burning.

The vortex chamber has a vortex chamber in the cylinder or cylinder head, and a vortex is generated in the vortex chamber during the compression stroke. When the fuel is injected from the swirling chamber, the injected fuel mixes with the swirling air and is ejected into the main combustion chamber while being ignited and burnt, and the unburned fuel is burned while meeting the fresh air in the main combustion chamber .

1 is a view showing the internal structure of a conventional vortex type diesel engine combustion chamber. In Fig. 1, the structure of the secondary combustion chamber (swirl chamber) 2a is mainly shown.

1, a sub-combustion chamber assembly 2 is separately assembled to a cylinder head 1 to provide a sub-combustion chamber 2a, and a main combustion chamber 3a is formed on an upper surface of the piston 3. As shown in FIG. The injection nozzle 4 is installed in the upper central cylinder head 1 of the sub combustion chamber 2a so as to inject fuel into the sub combustion chamber 2a in a deflected manner and a preheating plug 2a 5 are mounted. The preheating plug 5 is installed because the temperature of the combustion chamber is low at startup or at low speed. At the lower end of the sub-combustion chamber 2a, a connecting passage 2b through which the air flows from the main combustion chamber 3a is inclined. The connection passage 2b is mainly provided in the tangential direction of the sub-combustion chamber 2a. A cooling water passage 1a is formed around the sub-combustion chamber 2a.

In the swirling type combustion chamber constructed as described above, when the compressed air introduced from the main combustion chamber 3a during the compression stroke flows into the sub-combustion chamber 2a through the connection passage 2b, A vortex is formed. At this time, the fuel is injected from the injection nozzle 4 and almost burned in the sub-combustion chamber 2a.

The conventional vortex chamber type combustion chamber is a Comet Vb type of Ricardo, and in particular, the shape of the sub-combustion chamber assembly 2 is such that the fuel injected from the injection nozzle 4 collides with a straight line The connecting passage 2b is formed in a structure tangential to the vortex inducing portion 2d, and in particular, the vortex inducing portion 2b is formed in a tangential manner with the vortex inducing portion 2d, As can be seen from FIG. 2, the shape of the connection passage 2b is a single-piece cross-sectional shape composed of two circles and tangent arcs.

When the mixed gas combusted in the sub-combustion chamber 2a is ejected into the main combustion chamber 3a, the shape of the connection passage 2b having such a structure is such that the diffusion is concentrated in the straight- And the diffusion combustion is lowered, thereby increasing the emission of harmful components of the exhaust gas, especially smog.

Korean Patent Publication No. 2002-0053242

Disclosure of the Invention The present invention has been conceived to solve the above problems. It is an object of the present invention to solve the above-mentioned problems, and it is an object of the present invention to provide a gas- Which is capable of effectively suppressing the generation of harmful components such as smog contained in the exhaust gas.

Other objects and advantages of the present invention will become apparent to those skilled in the art from the following detailed description.

The vortex type diesel engine according to an embodiment of the present invention includes a vortex induction portion 2d having a curved inner wall surface and a connection passage 2b formed at a lower end of the vortex induction portion 2d A sub-combustion chamber assembly (2) coupled to the cylinder head (1) to form a sub-combustion chamber (2a); And a piston 3 constituting a main combustion chamber 3a including a trench portion 3c communicating with the connection passage 2b and a clover portion 3b formed on both sides of the trench portion 3c, And the guide passage 2b is provided with a guide structure 2e for guiding the combustion gas sprayed into the main combustion chamber 3a from the auxiliary combustion chamber 2b into three parts.

At this time, the combustion gases guided by the guide structure 2e and divided into three parts are respectively introduced in the trench portion 3c in the straight direction or in the direction of the clubber portion 3b on both sides of the trench portion 3c Can be guided in.

In addition, the guide structure 2e may have three curved shapes that are connected to each other on the upper surface of the connection passage 2b.

At this time, the three curved shapes provided on the upper surface of the connection passage 2b can maintain the same shape throughout the connection passage 2b.

At this time, the three curved surfaces provided on the upper surface of the connection passage 2b may have a curved surface shape having the same radius.

The guide structure 2e includes a first guide groove 21e positioned at the center and a second guide groove 22e and a third guide groove 23e located on both sides of the first guide groove 21e And the center of the first guide groove 21e may be positioned higher than a straight line connecting the centers of the second guide groove 22e and the third guide groove 23e.

The guide structure 2e includes a first guide groove 21e positioned at the center and a second guide groove 22e and a third guide groove 23e located on both sides of the first guide groove 21e And a distance D between the second guide groove 22e and the third guide groove 23e is formed to be three times the radius r of the first guide groove 21e (D = 3r) .

Further, the guide structure 2e includes a first guide groove 21e located at the center and a second guide groove 22e and a third guide groove 23e located on both sides of the first guide groove 21e And the first guide groove 21e may be positioned higher than the second guide groove 22e and the third guide groove 23e.

Here, the first guide groove 21e, the second guide groove 22e, and the third guide groove 23e can guide the combustion gas by dividing the combustion gas substantially uniformly.

At this time, the first guide groove 21e, the second guide groove 22e, and the third guide groove 23e may have the same cross-sectional area.

In the vortex-type diesel engine according to an embodiment of the present invention, the vortex chamber diesel engine has a guide structure for guiding the combustion gas into three parts in a connecting passage connecting the sub-combustion chamber and the main combustion chamber, The combustion gas ejected to the main combustion chamber is divided and guided and ejected, thereby promoting diffusion combustion in the diesel engine and suppressing generation of harmful gas such as smog.

1 is an exemplary view of a combustion chamber structure of a conventional swirl-type diesel engine.
2 is an exemplary view of a sub-combustion chamber assembly 2 constituting a sub-combustion chamber 2a in a conventional swirl type diesel engine.
3 is a view for explaining a combustion chamber structure of a swirl type diesel engine according to an embodiment of the present invention.
4 is a view illustrating a swirl-type diesel engine having a connection passage 2b of a general structure.
5 is a diagram illustrating a feature of a swirl-type diesel engine having a connecting passage 2b according to an embodiment of the present invention.
6 and 7 are views for explaining the connection passage 2b according to an embodiment of the present invention.
8 is a view for explaining an improvement of the combustion gas flow according to the connection passage 2b in the vortex type diesel engine according to the embodiment of the present invention.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the drawings, the same reference numerals are used to designate the same or similar components throughout the drawings. In the following description of the present invention, a detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present invention rather unclear. Further, the preferred embodiments of the present invention will be described below, but it is needless to say that the technical idea of the present invention is not limited thereto and can be practiced by those skilled in the art.

First, the construction and operation of a general vortex type diesel engine will be schematically described with reference to FIG. 3, and technical features of the present invention will be described.

More specifically, in a medium- and large-sized diesel engine, since sufficient time is given to the formation of a mixture, fuel injection alone can sufficiently bring the air into contact with each other. However, in a small or high speed diesel engine, . In order to solve such a problem, various types of combustion chamber structures such as a vortex chamber type are used. In particular, a vortex type diesel engine has a structure in which fuel is injected into a vortex generated in a sub-combustion chamber 2a by a compression stroke.

Accordingly, as can be seen from Fig. 3 (a), the vortex type diesel engine can generally be configured to include the main combustion chamber 3a and the sub combustion chamber 2a. At this time, the sub-combustion chamber 2a may be formed with the sub-combustion chamber assembly 2 in the cylinder head 1. [

Further, the main combustion chamber 3a may be formed on the upper surface of the piston 3.

A spray nozzle 4 is provided at the upper center of the sub combustion chamber 2a to inject the fuel into the fuel collision portion 2c having a straight cross section formed on one side wall of the sub combustion chamber 2a. The other side wall surface of the sub combustion chamber 2a has a curved vortex induction portion 2d so that the compressed air flowing from the main combustion chamber 3a flows into the sub combustion chamber 2a through the connection passage 2b. So that it forms a vortex.

The lower combustion chamber 2a is connected to the sub combustion chamber 2a and the main combustion chamber 3a to provide a passage through which the air flows from the main combustion chamber 3a to the sub combustion chamber 2a The connecting passage 2b may be inclined and the connecting passage 2b is preferably provided in a tangential direction with the vortex inducing portion 2d of the secondary combustion chamber 2a.

Further, the auxiliary combustion chamber 2a is provided with a preheating plug 5 to prevent the temperature of the combustion chamber from being lowered at startup or at low-speed driving. A cooling water passage 1a may be formed around the secondary combustion chamber 2a.

In the general swirl-type diesel engine, when the combustion gas generated in the sub-combustion chamber 2a is ejected into the main combustion chamber 3a, the combustion gas introduced into the trench portion 3c in FIG. 3 (b) The diffusion is concentrated so that the eddy current is not appropriately formed in the clovers 3b located on both sides of the trench portion 3c and diffusion combustion can be lowered and further the harmful components of the exhaust gas, The problem of increasing emissions can be followed.

3 and 4, in the conventional vortex type diesel engine, the sub-combustion chamber 2a may be formed with the sub-combustion chamber assembly 2 in the cylinder head 1, The auxiliary combustion chamber 2a is connected to the main combustion chamber 3a through the connection passage 2b to blow out the combustion gas generated in the auxiliary combustion chamber 2a to the main combustion chamber 3a.

4A, the shapes of the sub-combustion chamber assembly 2 and the connecting passage 2b constituting the sub-combustion chamber 2a are shown in the directions of the upper surface a1, the lower surface a2 and the side surface a3 . 4 (b) is a sectional view showing the shapes of the sub-combustion chamber assembly 2 and the connection passage 2b constituting the sub-combustion chamber 2a. More specifically, FIG. 4 (b) b3), the cross-sectional shape of the connecting passage 2b is shown in detail.

Particularly, as can be seen from (b3) of FIG. 4 (b), the connecting passage 2b connecting the main combustion chamber 3a and the sub-combustion chamber 2a of the conventional vortex type diesel engine has two circles and a tangent (3c in Fig. 3 (b)) when the mixed gas burned in the sub-combustion chamber 2a is ejected into the main combustion chamber 3a while forming the integral cross- The diffusion is concentrated in the straight direction of the gas so that the eddy current is not appropriately formed in the clover portion (3b in Fig. 3 (b)) located on both sides of the trench portion 3c, There is a problem of increasing the emission of harmful components of exhaust gas, particularly smog.

In contrast, FIG. 5 specifically illustrates the characteristics of a swirl-type diesel engine having a connecting passage 2b according to an embodiment of the present invention.

5A shows a swirl type diesel engine having a connecting passage 2b according to an embodiment of the present invention. The shape of the sub-combustion chamber assembly 2 and the connecting passage 2b constituting the sub- Are shown in the directions of the upper surface a1, the lower surface a2 and the side surface a3.

5 (b), in the swirl-type diesel engine having the connecting passage 2b according to the embodiment of the present invention, the sub-combustion chamber assembly 2 and the connecting passage 2b. More specifically, FIG. 5 (b) (b3) shows the cross-sectional shape of the connection passage 2b in detail.

Particularly, as can be seen from (a2) of FIG. 5 (a) and FIG. 5 (b) of FIG. 5 (b), the main combustion chamber 3a and the sub combustion chamber 2a may be provided with a guide structure 2e for guiding the combustion gas ejected from the sub combustion chamber 2b into the main combustion chamber 3a in three parts.

6 is a cross-sectional view of a guide structure 2e formed in the connection passage 2b to explain the connection passage 2b according to an embodiment of the present invention.

As shown in FIG. 6, the guide structure 2e may include three curved shapes provided on the upper surface of the connection passage 2b. According to the shape of the guide structure 2e, the combustion gas can be guided into three parts.

At this time, the guide structure 2e may have three curved shapes having the same radius on the upper surface of the connection passage 2b.

More specifically, the combustion gas guided in three parts by the guide structure 2e is introduced into the trench portion 3c in the straight direction, or the combustion gas introduced into the trench portion 3c, which is located on both sides of the trench portion 3c, 3b. Accordingly, in the present invention, by using the guide structure 2e capable of guiding the combustion gas into three parts in the connection passage 2b connecting the sub combustion chamber 2a and the main combustion chamber 3a, The combustion gas injected into the main combustion chamber 3a in the sub combustion chamber 2a can be divided into three parts and the combustion gas can be ejected in the third combustion chamber 2a. Further, conventionally, the combustion gas is concentrated in the trench portion 3c in the straight- The ratio of the combustion gas ejected to the trench portion 3b and the clover portion 3b is adjusted by using the guide structure 2e while the vortex in the diesel engine 3b is not properly formed, And it is possible to effectively suppress generation of harmful gas such as smog.

Further, the guide structure 2e having three curved surfaces connected to each other on the upper surface of the connection passage 2b has a first guide groove 21e located at the center, a first guide groove 21d located at the center of the first guide groove 21e, And a second guide groove 22e and a third guide groove 23e located on both sides.

At this time, the center of the first guide groove 21e may be positioned higher than a straight line connecting the centers of the second guide groove 22e and the third guide groove 23e. 6, the first guide groove 21e is formed in the second guide groove 22e with reference to the center line (C in FIG. 5 (b)) of the connection passage 2b, And the third guide groove 23e. 5B, the first guide groove 21e is located closest to the center line of the connecting passage 2b (refer to (C) in FIG. 5B) So that it can be seen that it is located at a height.

The first guide groove 21e is located at the center of the second guide groove 22e and the third guide groove 23e and the first guide groove 21e is located at the second guide groove 22e The first guide groove 21e, the second guide groove 22e and the third guide groove 23e can divide and guide the combustion gas so that the first guide groove 21e, the second guide groove 22e and the third guide groove 23e have the same sectional area as the first guide groove 23e and the third guide groove 23e. .

Further, the first guide groove 21e, the second guide groove 22e, and the third guide groove 23e are guided by dividing the combustion gas substantially uniformly through a structure having the same radius or the same cross sectional area The combustion gas concentrated in the trench portion 3c can be uniformly sprayed to the trench portion 3c and the clover portion 3b located at both ends of the trench portion 3c.

That is, in the present invention, the guide grooves 21e, the second guide grooves 22e and the third guide grooves 23e divide the combustion gas substantially uniformly to guide the fuel gas in the connection passage 2b The first guide groove 21e, the second guide groove 22e and the third guide groove 23e have the same radius or the same cross sectional area as that of the first guide groove 21e, the second guide groove 22e and the third guide groove 23e, while the majority of the combustion gas is concentrated and ejected to the trench portion 3c. The amount of the combustion gas ejected to the clovers 3b located in the trench portions 3c is increased to such an extent that the amount of the combustion gases ejected to the trench portions 3c can be uniformly guided .

Particularly, the distance (D in FIG. 6) between the second guide groove 22e and the third guide groove 23e is set to be three times (D = 3) times the radius of the first guide groove 21e 3r to optimize the ratio of the combustion gas ejected to the trench portion 3c and the clover portion 3b so that the eddy current is efficiently formed in the clover portion 3b to promote diffusion combustion, it is possible to effectively suppress the generation of harmful components of the exhaust gas such as smog

Further, the ratio of the combustion gas guided by the first guide groove 21e can be adjusted by adjusting the height of the first guide groove 21e and adjusting the cross-sectional area of the first guide groove 21e, Furthermore, the ratio of the combustion gas introduced in the straight direction in the trench portion 3c and the combustion gas introduced into the trench portion 3c in the direction of the cylinder portion 3b may be appropriately adjusted.

7 shows the internal structure of the connection passage 2b to explain the connection passage 2b according to an embodiment of the present invention.

As shown in Fig. 7 (a), the connection passage 2b is formed in the same shape from the starting point S to the end point E. The cross sections a1, a2 and a3 parallel to the lower surface (the B surface in Fig. 7 (c)) of the sub-combustion chamber assembly 2 all have the same shape.

7 (b), the cross-sections b1, b2 and b3 perpendicular to the traveling direction central axis (DD in Fig. 7 (c)) of the connecting passage 2b are all formed in the same shape .

Fig. 8 illustrates the improvement of combustion gas flow in a swirl-type diesel engine having a connecting passage 2b according to an embodiment of the present invention. 8 (a), in the conventional swirl-type diesel engine, when the combustion gas generated in the sub-combustion chamber 2a is ejected into the main combustion chamber 3a (Fig. 7 (a)), The diffusion of the combustion gas into the trench portion 3c is concentrated in the straight direction ((A2) in FIG. 7A) (A1) and (A3) in Fig. 7 (a)) can not be appropriately formed in the portion 3b and the diffusion combustion can be lowered. Further, the emission of harmful components, particularly smog, The problem can be followed.

On the other hand, in the vortex type diesel engine according to the embodiment of the present invention, the combustion gas is divided into three parts and guided to the connection passage 2b connecting the sub combustion chamber 2a and the main combustion chamber 3a (B0 in Fig. 7B) by dividing the combustion gas ejected into the main combustion chamber 3a from the sub-combustion chamber 2a into three parts using the guide structure 2e having the guide structure 2e, (B2 in Fig. 7 (b)) and the combustion gas (Fig. 7 (b)) drawn in the direction of the straight line in the portion 3c of the trench 3c and the combustion gas (B1) and (B2) in Fig. 3 (b)).

Accordingly, in the vortex type diesel engine according to the embodiment of the present invention, the vortex is formed more strongly in the clover portion 3b located on both sides of the trench portion 3c, thereby promoting diffusion combustion in the diesel engine , And further, generation of harmful gas such as smog can be effectively suppressed.

It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims. It will be possible. Therefore, the embodiments disclosed in the present invention and the accompanying drawings are intended to illustrate and not to limit the technical spirit of the present invention, and the scope of the technical idea of the present invention is not limited by these embodiments and the accompanying drawings . The scope of protection of the present invention should be construed according to the following claims, and all technical ideas within the scope of equivalents thereof should be construed as being included in the scope of the present invention.

(1): cylinder head (1a): cooling water passage
(2): Sub-combustion chamber assembly (2a): Sub-combustion chamber
(2b): connecting passage (2c): fuel collision part
(2d): vortex induction part (2e): guide structure
(3): piston (3a): main combustion chamber
(3b): clover portion (3c): trench portion
(4) Injection nozzle (5): Preheating plug
(21e): first guide groove (22e): second guide groove
(23e): third guide groove

Claims (10)

And a connecting passage 2b formed at the lower end of the vortex inducing portion 2d and having a curved shape on the inner wall of the subordinate combustion chamber assembly 2. The subordinate combustion chamber assembly 2c is connected to the cylinder head 1, (2); And
A piston 3 constituting a main combustion chamber 3a including a trench portion 3c communicating with the connecting passage 2b and a clover portion 3b formed on both sides of the trench portion 3c,
Wherein the connecting passage is provided with a guide structure for guiding the combustion gas injected into the main combustion chamber in the sub combustion chamber to divide the combustion gas into three parts. The method according to claim 1,
The combustion gases guided by the guide structure 2e and divided into three portions are respectively guided in the trench portion 3c in the straight forward direction or in the direction of the clubber portion 3b on both sides of the trench portion 3c A whirlwind diesel engine characterized by being guided. The method according to claim 1,
The guide structure (2e)
Wherein the connecting passage (2b) has three curved surfaces connected to each other on the upper surface of the connecting passage (2b). The method of claim 3,
Wherein the three curved shapes provided on the upper surface of the connection passage (2b) maintain the same shape throughout the connection passage (2b). The method of claim 3,
Wherein the three curved surfaces provided on the upper surface of the connecting passage (2b) are curved surfaces having the same radius. 6. The method of claim 5,
The guide structure 2e includes a first guide groove 21e positioned at the center and a second guide groove 22e and a third guide groove 23e located on both sides of the first guide groove 21e ,
Wherein the center of the first guide groove (21e) is positioned higher than a straight line connecting the center of the second guide groove (22e) and the center of the third guide groove (23e). 6. The method of claim 5,
The guide structure 2e includes a first guide groove 21e positioned at the center and a second guide groove 22e and a third guide groove 23e located on both sides of the first guide groove 21e ,
The distance D between the second guide groove 22e and the third guide groove 23e is formed to be three times the radius r of the first guide groove 21e (D = 3r) A vortex real estate diesel engine. The method according to claim 1,
The guide structure 2e includes a first guide groove 21e positioned at the center and a second guide groove 22e and a third guide groove 23e located on both sides of the first guide groove 21e ,
Wherein the first guide groove (21e) is located higher than the second guide groove (22e) and the third guide groove (23e). 9. The method of claim 8,
Wherein the first guide groove (21e), the second guide groove (22e), and the third guide groove (23e) divide the combustion gas substantially uniformly to guide the combustion gas. 10. The method of claim 9,
Wherein the first guide groove (21e), the second guide groove (22e), and the third guide groove (23e) have the same cross-sectional area as each other.

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