CN212716877U

CN212716877U - Combustion chamber of engine

Info

Publication number: CN212716877U
Application number: CN202021192270.4U
Authority: CN
Inventors: 朴准正; 俞德根; 张贤模; 金永楸; 郭承雨
Original assignee: Doosan Infracore Co Ltd
Current assignee: HD Hyundai Infracore Co Ltd
Priority date: 2019-12-06
Filing date: 2020-06-23
Publication date: 2021-03-16
Anticipated expiration: 2030-06-23
Also published as: KR20210071264A

Abstract

The utility model provides a combustion chamber of engine, its burning is from the fuel that fuel injection portion jetted, the combustion chamber of engine includes: a piston body disposed in the cylinder body; a main combustion chamber in which a main recess is formed in a recessed manner in an upper portion of the piston body, and into which fuel injected from the fuel injection portion flows; a sub-combustion chamber having a sub-recess formed so as to be recessed closer to an upper outer circumferential surface of the piston body than the main combustion chamber; a rib portion disposed between the primary combustion chamber and the secondary combustion chamber and formed to protrude so as to have a curved surface protruding toward the fuel injection portion; and an inclined region formed on one side of the sub recess connected to the curved surface of the rib, and formed to be inclined in a lower direction of the piston body.

Description

Combustion chamber of engine

Technical Field

Embodiments of the present invention relate to a combustion chamber of an engine, and more particularly, to a combustion chamber of an engine that efficiently mixes injected fuel.

Background

In general, a combustion chamber is defined as a space provided to enable fuel injected into the interior of a combustion chamber formed in a cylinder of an engine to be mixed with air and efficiently combusted.

Specifically, the fuel injected into the combustion chamber collides with the inner wall of the combustion chamber, and the fuel can move and mix with air based on the shape of the inner wall of the combustion chamber. At this time, the inside of the combustion chamber, i.e., the upper appearance of the piston, should be designed to allow such injected fuel to be effectively mixed with air.

The conventional combustion chamber has a problem in that the injected fuel collides with an inner wall of the combustion chamber formed at an upper portion of the piston to lose kinetic energy, and thus cannot be normally mixed with air.

When mixing with injected fuel and air is not performed efficiently in such a combustion chamber, there is a problem that the temperature inside the combustion chamber increases to burden the engine, or the concentration of soot or nitrogen oxide in exhaust gas increases.

SUMMERY OF THE UTILITY MODEL

Embodiments of the present invention provide a combustion chamber of an engine capable of efficiently burning injected fuel.

The above-mentioned utility model can be realized through following technical scheme.

According to an embodiment of the present invention, there is provided a combustion chamber of an engine that burns fuel injected from a fuel injection portion, the combustion chamber of the engine including: a piston body disposed in the cylinder body; a main combustion chamber in which a main recess is formed in a recessed manner in an upper portion of the piston body, and into which fuel injected from the fuel injection portion flows; a secondary combustion chamber having a secondary recess formed in a recessed manner so as to be adjacent to the upper outer circumferential surface of the piston body than the primary combustion chamber; a rib portion disposed between the primary combustion chamber and the secondary combustion chamber and formed to protrude so as to have a curved surface protruding toward the fuel injection portion; and an inclined region formed on one side of the sub recess connected to the curved surface of the rib, and formed to be inclined in a lower direction of the piston body.

Wherein the combustion chamber of the engine comprises: and an imaginary horizontal axis extending from one end of a curved surface of the rib portion in a direction parallel to a radial direction of the piston body perpendicular to a central axis direction of the piston body, wherein a tilt angle between the horizontal axis and a tilt region is formed to be 1 degree or less in a direction in which the tilt region is adjacent to a lower portion of the piston body in a direction in which the tilt region is closer to an outer circumferential direction of the piston body.

Wherein the combustion chamber of the engine comprises: a rib line parallel to an imaginary central axis in a longitudinal direction of the piston body and contacting a portion closest to the central axis in a curved surface of the rib line; and an outer contour line that contacts a position of the main recess that is farthest from the center axis, wherein the rib line and the outer contour line are spaced apart from each other such that the rib line is relatively adjacent to the imaginary center axis of the piston body than the outer contour line.

Wherein the rib line is spaced from the outer profile line in the range of 0.8mm to 1.2 mm.

Wherein the volume of the primary combustion chamber is 1.4 to 1.8 times greater than the volume of the secondary combustion chamber.

Wherein a distance from a position farthest from an imaginary center axis of the piston body in the main recess is formed in a range of 0.52 to 0.60 of an entire radius of the piston body.

Wherein an uppermost end of the outer surface of the rib connected to the sub recess is formed at a position higher than an uppermost end of a protrusion formed by a center portion of the piston body facing the fuel injection part.

The utility model has the following effects.

According to the embodiment of the present invention, in the combustion chamber of the engine, the fuel injected into the combustion chamber can be effectively mixed with the air without losing kinetic energy even after colliding with the inner wall of the combustion chamber formed in the piston.

Drawings

Fig. 1 shows a cross section of a combustion chamber of an engine according to an embodiment of the present invention.

Fig. 2 is an enlarged view showing an upper portion of the piston of fig. 1.

Reference numerals

100: cylinder, 101: combustion chamber of engine, 110: piston body, 200: main combustion chamber, 210: main recess, 300: auxiliary combustion chamber, 310: minor recessed portion, 400: rib, 410: curved surface, 500: inclined area, E: center axis, F: rib line, G: outer contour, 20: fuel injection portion, 40: a protrusion portion.

Detailed Description

Embodiments of the present invention will be described in detail below with reference to the accompanying drawings so that those skilled in the art can easily implement the embodiments of the present invention. The present invention can be realized in various forms, and is not limited to the embodiments described herein.

It is noted that the drawings are diagrammatic and not to scale. Relative dimensions and proportions of parts shown in the figures have been shown exaggerated or reduced in size for the sake of clarity and convenience in the drawings, and any dimensions are exemplary only and not limiting. In addition, the same reference numerals are used for the same structures, elements, or components appearing in two or more drawings to represent similar features.

Embodiments of the present invention specifically show desirable embodiments of the present invention. As a result, various modifications of the illustration are expected. Thus, embodiments are not limited to the particular form of the illustrated region, and may include variations in form resulting from manufacturing, for example.

A combustion chamber 101 of an engine according to an embodiment of the present invention will be described with reference to fig. 1 and 2.

As illustrated in fig. 1, a combustion chamber 101 of an engine is an internal space of a cylinder block 100 of the engine that burns fuel. Specifically, the combustion chamber 101 includes a region of the cylinder interior 30 of the cylinder block 100 and a region disposed at an upper portion of the piston body 110 in the cylinder. The fuel injection unit 20 is provided in the cylinder head 10 disposed above the cylinder block 100.

As illustrated in fig. 2, the piston body 110 may include a primary recess 210, a secondary recess 310, and a rib 400. The secondary recess 310 may include a sloped region 500.

The piston body 110 is disposed in the cylinder interior 30 of the cylinder block 100 of the engine. Specifically, the piston body 110 is connected to a connecting rod, not shown, and moves up and down along the cylinder interior 30 by an explosive force generated when the fuel injected by the fuel injection part 20 is combusted.

The primary combustion chamber 200 is formed by a primary recess 210. The main recess 210 is formed in an upper portion of the piston body 110 facing the fuel injection part 20. The main recess 210 may be concavely and annularly formed at an upper portion of the piston body 110 to guide the fuel injected from the fuel injection part 20 to be mixed with air and moved.

Specifically, the main recess 210 of the main combustion chamber 200 may be concavely formed from the center portion of the piston body 110 toward the outer circumferential direction of the piston body 110 and the lower portion of the piston body 110. Further, the main recess 210 may be formed to be recessed from the center of the piston body 110 in the circumferential direction and in the outer circumferential direction of the piston body 110, and guide the movement of the fuel injected from the fuel injection part 20 while maintaining the opened state with the fuel injection part 20. Further, a distance D1 in the main recess 210 to a position farthest from the center portion of the piston body 110 may be formed in a range of 0.52 to 0.60 of the entire radius of the piston body 110.

The sub recess 310 may be disposed at an upper portion of the piston body 110 than the main combustion chamber 200 to form the sub combustion chamber 300. Further, the sub recess 310 may be formed to be recessed more than the main recess 210 to be relatively adjacent to the outer circumferential surface of the piston body 110. Therefore, the sub recess 310 can guide the fuel injected from the fuel injection part 20 to move by mixing with the air in the sub combustion chamber 300.

Specifically, the sub-recess 310 may be concavely formed from the center portion of the piston body 110 toward the outer circumferential direction of the piston body 110. Further, the sub-recess 310 can guide the movement of the fuel injected from the fuel injection portion 20 while maintaining the opened state with the fuel injection portion 20.

The rib 400 is disposed between the primary combustion chamber 200 and the secondary combustion chamber 300. The rib 400 may be formed to protrude in such a manner as to have a curved surface 410 that is raised toward the fuel injection part 20. Specifically, the rib 400 may connect the primary recess 210 and the secondary recess 310. Further, the rib 400 may be convexly formed to have a curved surface 410 that is raised in a direction in which the center portion of the piston body 110 extends. The fuel injected from the fuel injection portion 20 may collide with such a rib 400 formed convexly to move to the main combustion chamber 200 and the sub-combustion chamber 30 and be mixed with air.

The inclined region 500 may be formed at one side of the sub recess 310 connected with the rib 400. In addition, inclined region 500 is a region where one surface between curved surface 410 of rib 400 and sub-recess 310 is formed obliquely in the lower direction of piston body 110. Specifically, inclined region 500 may be formed such that one surface of curved surface 410 of linking rib 400 and sub-recess 310 is inclined toward the lower portion of piston body 110 from an imaginary outer peripheral line extending from one end of curved surface 410 of rib 400 in a direction parallel to the radial direction of piston body 110 orthogonal to central axis E of piston body 110. That is, the inclined region 500 may be formed not to be orthogonal to the central axis E of the piston body 110, but to incline the curved surface 410 of the rib 400 adjacent to the sub combustion chamber 300 and a region connected to the sub recess 310 of the sub combustion chamber 300 in a direction adjacent to the main recess 210 of the main combustion chamber 200.

For example, the inclination angle a between the inclined region 500 and the virtual horizontal axis H extending from one end of the curved surface 410 of the rib 400 in the direction parallel to the radial direction of the piston body 110 orthogonal to the central axis direction of the piston body 110 may be formed to be 1 degree (degree) or less in a direction adjacent to the lower portion of the piston body 110 as it goes toward the outer circumferential direction of the piston body 110.

When the inclination angle a exceeds 1 degree, there is a problem that the inclination angle a of the inclined region 500 stagnates the injected fuel between the inclined region 500 and the sub-recess 310, and it is difficult to perform effective combustion in the sub-combustion chamber 300. In this case, there occurs a problem that the concentration of soot contained in the exhaust gas by the combustion is increased and the efficiency of the engine is lowered.

When the inclination angle a is 0 degree or less, the inclined region 500 may be formed in parallel with an imaginary outer circumferential line extending in a direction parallel to the radial direction of the piston body 110. In this case, the fuel injected from the fuel injection portion 20 collides with the inclined region 500 at an early stage, so that the kinetic energy of the fuel corresponding to the injection direction can be prevented from being reduced more than necessary and moving along the sub-recess 310. Therefore, the fuel is difficult to combust in the sub-combustion chamber 300, so that explosive force generated when the injected fuel is combusted is reduced, possibly resulting in a decrease in the efficiency of the engine.

However, according to the inclined region 500 of the exemplary embodiment, the fuel injected from the fuel injection part 20 may be guided to move in the direction of the inclined region 500 toward a direction similar to the direction when injected from the fuel injection part 20. Therefore, the fuel can be moved into the auxiliary combustion chamber 300 without decreasing the kinetic energy of the fuel injected from the fuel injection portion 20. Specifically, the inclined region 500 may burn the fuel mixed with the air by spraying without losing kinetic energy through the same directional guidance as the spraying direction B Of the fuel injected at the End Of injection time point (EOI: End Of Ignition) Of the fuel. That is, the fuel injected from the fuel injection portion 20 can be guided by the inclined region 500 without stagnation and can be combusted without losing kinetic energy.

In addition, the combustion chamber 101 of the engine according to an embodiment of the present invention may further include a protrusion 40.

Specifically, one surface of the center portion of the piston body 110 facing the fuel injection part 20 may be convexly formed toward the fuel injection part 20 in a manner of having a curved surface to form a protrusion part 40, and the protrusion part 40 guides the movement of the fuel in a manner of effectively mixing the fuel injected from the fuel injection part 20 with the air without stagnation. That is, the protrusion 40 may be formed on one surface of the center of the piston body 110 facing the fuel injection part 20.

In the protrusion 40, a center portion of the piston body 110 is formed to protrude toward the fuel injection part 20 so that fuel can be guided to move based on the shape of the main recess 210 of the main combustion chamber 200. That is, the protrusion 40 can smoothly guide the fuel into the main combustion chamber 200.

Further, according to the exemplary embodiment, it is possible to form a rib F contacting a position closest to the center of the piston body 110 among the curved surfaces 410 of the rib 400 and formed in parallel with the imaginary central axis E in the longitudinal direction of the piston body 110 of the combustion chamber 101 of the engine, and an outer contour G contacting the outermost contour of the main recess 210 and formed in parallel with the central axis E, spaced apart from each other. Further, an uppermost end P of the outer surface of the rib 400 connected to the sub-recess 310 may be disposed at a higher position than an uppermost end of the protrusion 40.

Therefore, it is possible to guide the fuel colliding with the curved surface 410 of the rib 400 to effectively move to the main combustion chamber 200 or the sub-combustion chamber 300.

Further, according to an exemplary embodiment, the centerline E and the rib line F may be disposed relatively adjacently than a spaced distance between the centerline E and the outer profile line G. That is, the rib line F may be spaced apart from the outer contour line G by a distance d in the range of 0.8mm to 1.2 mm.

In addition, the volume ratio of the main combustion chamber 200 to the auxiliary combustion chamber 300 of the combustion chamber 101 of the engine according to an embodiment of the present invention may be 1.4-1.8: 1.

The volume of the primary combustion chamber 200 and the volume of the secondary combustion chamber 300 may be divided on the basis of the injection base line a.

As illustrated in fig. 1 and 2, the injection base line a is an injection line of the fuel injected from the fuel injection portion 20. Such an injection base line A is located between the fuel injection line B at the end Of fuel injection (EOI) and the fuel injection line C at the Top Dead Center (TDC) Of the piston body 110. Such an injection base line a may be defined as an intermediate position at the time of actual injection at the injection time point corresponding to the up-and-down movement of the piston body 110.

When fuel is injected along the injection base line a, actual combustion may be divided into the main combustion chamber 200 and the sub-combustion chamber 300 based on the reference, and combustion may be performed.

At this time, the volume of the main combustion chamber 200 may be formed to be 1.4 to 1.8 times larger than the volume of the sub-combustion chamber 300 so that the fuel injected from the fuel injection part 20 is efficiently combusted in the main combustion chamber 200 and the sub-combustion chamber 300, thereby reducing the concentration of nitrogen oxides and soot included in the exhaust gas compared to the conventional one and also having an effect of improving the efficiency of the engine.

In addition, in the combustion chamber 101 of the engine according to an embodiment of the present invention, the distance D1 from the position farthest from the imaginary center axis E of the piston body 110 in the main recess 210 may be formed in the range of 0.52 to 0.60 of the entire radius of the piston body 110.

A distance D1 between the imaginary center axis E of the piston body 110 and the outermost contour of the main recess 210 that is most adjacent to the outer circumferential surface of the piston body 110 may be formed within a range of 0.52 to 0.60 of the entire radius of the piston body 110. That is, a distance D1 between the imaginary center axis E of the piston body 110 and the outer contour line G may be in the range of 0.52 to 0.60 of the overall radius of the piston body 110.

In the combustion chamber 101 of the engine according to the embodiment of the present invention, the uppermost end P of the rib 400 connected to the sub-recessed portion 310 may be located at an upper portion than the highest position of the protrusion 40.

The uppermost end P, which is a position of the outer surface of the rib 400 connected to the sub-recess 310, may be disposed relatively higher than the uppermost end of the protrusion 40 of the piston body 110.

In addition, a position where the upper surface of the piston body 110 adjacent to the sub-chamber 300 of an embodiment of the present invention intersects with the sub-chamber 300 may be formed to form an obtuse angle on the longitudinal section of the piston body 110.

That is, the upper surface of the piston body 110 and the sub-chamber 300 can be smoothly connected to each other at a position where the upper surface of the piston body 110 and the sub-chamber 300 intersect each other in the vertical cross section of the piston body 110. Due to the connection shape between the upper surface of the piston body 110 and the sub-chamber 300, the fuel injected from the fuel injection part 20 smoothly flows into the outer space of the sub-chamber 300 with respect to the central axis E, and is not stagnated between the sub-chamber 300 and the piston body 110, thereby enabling efficient combustion.

With such a structure, the combustion chamber 101 of the engine according to the embodiment of the present invention can guide the fuel injected into the combustion chamber to effectively move to the main combustion chamber 200 or the auxiliary combustion chamber 300 while maintaining the injection direction without losing kinetic energy.

Furthermore, the combustion chamber 101 of the engine according to an embodiment of the present invention enables the injected fuel to be optimally combusted to improve the efficiency of the engine by improving its explosive power. In addition, the combustion chamber 101 of the engine according to an embodiment of the present invention can reduce the concentration of soot and nitrogen oxide included in exhaust gas discharged from the combustion chamber of the engine, compared to the piston of the conventional engine, by effective combustion of injected fuel.

Although the embodiments of the present invention have been described above with reference to the drawings, it will be understood by those skilled in the art that the present invention may be embodied in other specific forms without changing the technical spirit or essential features of the present invention.

Therefore, the above-described embodiments should be construed as illustrative in all aspects and not restrictive, the scope of the present invention being indicated by the following claims, and all changes and modifications derived from the meaning and scope of the claims and the equivalent concepts thereof should be construed as falling within the scope of the present invention.

Claims

1. A combustion chamber of an engine that combusts fuel injected from a fuel injection portion, characterized by comprising:

a piston body disposed in the cylinder body;

a main combustion chamber in which a main recess is formed in a recessed manner in an upper portion of the piston body, and into which fuel injected from the fuel injection portion flows;

a sub-combustion chamber having a sub-recess formed so as to be recessed closer to an upper outer circumferential surface of the piston body than the main combustion chamber;

a rib portion disposed between the primary combustion chamber and the secondary combustion chamber and formed to protrude so as to have a curved surface protruding toward the fuel injection portion; and

and an inclined region formed at one side of the sub recess connected to the curved surface of the rib, and formed to be inclined in a lower direction of the piston body.

2. The combustion chamber of an engine according to claim 1, comprising:

a virtual horizontal axis extending from one end of the curved surface of the rib portion in a direction parallel to a radial direction of the piston body perpendicular to a central axis direction of the piston body,

the inclination angle between the horizontal axis and the inclination region is formed to be 1 degree or less in a direction in which the inclination region is adjacent to the lower portion of the piston body in a direction in which the inclination region is closer to the outer periphery of the piston body.

3. The combustion chamber of an engine according to claim 1, comprising:

a rib line parallel to an imaginary central axis in a longitudinal direction of the piston body and contacting a portion closest to the central axis in a curved surface of the rib line; and

an outer contour contacting a location in the main recess furthest from the central axis,

the rib and the outer contour are spaced apart from each other such that the rib is in relatively adjacent relation to an imaginary center axis of the piston body than the outer contour.

4. The combustion chamber of an engine according to claim 3,

the ribs are spaced from the outer profile in the range of 0.8mm to 1.2 mm.

5. The combustion chamber of an engine according to claim 1,

the volume of the primary combustion chamber is 1.4 to 1.8 times greater than the volume of the secondary combustion chamber.

6. The combustion chamber of an engine according to claim 1,

the distance from the main recess to the position farthest from the virtual central axis of the piston body is in the range of 0.52 to 0.60 of the overall radius of the piston body.

7. The combustion chamber of an engine according to claim 1,

an uppermost end of an outer surface of the rib connected to the sub-recess is formed at a position higher than an uppermost end of a protrusion formed to protrude toward the fuel injection part from a center portion of the piston body.