Combustion chamber, piston and engine

Abstract

The utility model provides a combustion chamber, a piston and an engine, the combustion chamber comprises a base with a top surface and a combustion cavity concavely arranged on the top surface along a first direction, and the combustion cavity is eccentrically arranged relative to the piston; wherein the bottom wall of the combustion cavity is convexly provided with a central convex part and a central annular part which is concavely arranged around the circumferential direction of the central convex part, and a boss guide surface is arranged between the central convex part and the central annular part. According to the combustion chamber, due to the fact that the combustion cavity is eccentrically arranged relative to the piston, mixed gas in the combustion cavity can be optimally matched with an oil injection beam, the falling point of the oil beam cannot be injected to the top face of the piston or the lower position in the combustion cavity, meanwhile, the protruding part in the center of the bottom wall of the combustion cavity can guide flame propagation, the combustion speed is increased, and the combustion efficiency is improved. The central annular part is beneficial to forming a specific vortex and further promoting mixing of fuel and air, and the boss guide surface is beneficial to smoothing an airflow path, reducing turbulence loss and ensuring that airflow can efficiently enter the combustion cavity and participate in the combustion process.

Description

Technical Field

[0001] The utility model relates to the technical field of diesel engines, in particular to a combustion chamber, a piston and an engine. Background Art

[0002] As energy conservation and emissions reduction efforts become increasingly stringent, diesel engine emissions are becoming increasingly stringent, particularly regarding soot and NOx emissions. Fuel enters the cylinder in a jet stream and burns around the jet stream, causing localized high temperatures and oxygen depletion near the jet stream, generating large amounts of soot and NOx. Therefore, it is crucial to distribute the fuel more widely within the cylinder, fully utilizing the air and space within the cylinder to minimize the occurrence of high temperatures and oxygen depletion. This improves diesel engine fuel consumption and reduces soot and NOx emissions. Utility Model Content

[0003] In view of the deficiencies in the prior art, the present invention provides a combustion chamber, a piston and an engine to solve the technical problems in the above-mentioned background technology.

[0004] A first aspect of the present invention provides a combustion chamber, comprising:

[0005] a base having a top surface;

[0006] a combustion chamber, recessed in the top surface along a first direction, and the combustion chamber is eccentrically arranged relative to the piston;

[0007] The bottom wall of the combustion chamber is convexly provided with a central convex portion and a central annular portion circumferentially concave around the central convex portion, and a boss guide surface is provided between the central convex portion and the central annular portion.

[0008] Furthermore, in the first direction, the boss guide surface smoothly transitions the highest point of the central convex portion and the lowest point of the central annular portion, and the distance between the boss guide surface and the central axis of the base gradually increases.

[0009] Furthermore, the combustion chamber includes a squeeze flow guide surface, and the squeeze flow guide surface is respectively continuous with the wall surface and the top surface of the central annular portion.

[0010] Furthermore, in the first direction, the squeeze flow guide surface smoothly transitions the highest point of the central annular portion and the lowest point of the top surface, and the distance between the squeeze flow guide surface and the central axis of the base gradually increases.

[0011] Furthermore, the intersection line between the boss guide surface and the longitudinal section and the intersection line between the squeeze flow guide surface and the longitudinal section are both straight lines.

[0012] Furthermore, the central annular portion is tilted and recessed outward.

[0013] Furthermore, the center line of the combustion chamber is located on a side of the center line of the piston close to the injector.

[0014] Furthermore, the central convex portion is a plane.

[0015] A second aspect of the present invention provides a piston comprising the above-mentioned combustion chamber, wherein the base is arranged at the end of the piston, and a piston skirt is provided at one end of the piston away from the end.

[0016] A third aspect of the present invention provides an engine, comprising the above-mentioned piston.

[0017] Compared with the prior art, the present invention has the following beneficial effects:

[0018] The combustion chamber of the present invention can achieve optimal coordination between the mixed gas in the combustion chamber and the injection oil beam by eccentrically arranging the combustion chamber relative to the piston. The landing point of the oil beam will not hit the top surface of the piston or a lower position in the combustion chamber. At the same time, the central convex portion of the bottom wall of the combustion chamber can guide the flame propagation and accelerate the combustion speed. An annular recessed area arranged around the central convex portion helps to form a specific vortex, further promoting the mixing of fuel and air. The boss guide surface is arranged on the transition surface between the central convex portion and the central annular portion, which helps to smooth the airflow path, reduce turbulent losses, and ensure that the airflow can efficiently enter the combustion chamber and participate in the combustion process. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is a schematic diagram of a combustion chamber according to an embodiment of the present invention;

[0020] Figure 2 This is a cross-sectional schematic diagram of a combustion chamber according to an embodiment of the present invention;

[0021] Figure 3 for Figure 2 A local enlarged schematic diagram in FIG.

[0022] Figure 4 This is a schematic diagram of a piston according to an embodiment of the present invention;

[0023] Description of Figure Numbers:

[0024] 10. Base; 11. Top;

[0025] 20. Combustion chamber; 21. Central convex portion; 22. Central annular portion; 23. Boss guide surface; 24. Squeeze flow guide surface;

[0026] 30. Piston skirt; 40. Piston groove.

[0027] The realization of the purpose, functional features and advantages of the present invention will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0028] In order to make the purpose, technical solution and beneficial effects of the present invention more clearly understood, the technical solution of the present invention is further described below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0029] In the description of the present invention, it should be noted that the structures, proportions, sizes, etc. illustrated in the drawings of the present specification are only used to match the contents disclosed in the specification so as to facilitate understanding and reading by those familiar with the technology, and are not intended to limit the applicable conditions of the present invention. Therefore, they have no substantial technical significance. Any modification of the structure, change in the proportional relationship, or adjustment of the size should still fall within the scope of the technical content disclosed in the present invention without affecting the efficacy and purpose of the present invention. At the same time, terms such as "upper", "lower", "left", "right", "middle", and "one" cited in the present specification are only for the convenience of description and are not intended to limit the applicable scope of the present invention. Changes or adjustments in their relative relationships should also be considered as the applicable scope of the present invention without substantially changing the technical content.

[0030] Example 1

[0031] like Figure 1-3 As shown, an embodiment of the present invention provides a combustion chamber, comprising a base 10 having a top surface 11 and a combustion chamber 20 recessed in the top surface 11 along a first direction, wherein the combustion chamber 20 is eccentrically arranged relative to the piston; wherein, the bottom wall of the combustion chamber 20 is convexly provided with a central protrusion 21 and a central annular portion 22 recessed circumferentially around the central protrusion 21, and a boss guide surface 23 is provided between the central protrusion 21 and the central annular portion 22, so that the fuel vapor can continue to extend upward along the boss guide surface 23, so that the fuel vapor can be mixed with the air more thoroughly.

[0032] In an embodiment of the present invention, by arranging the combustion chamber 20 eccentrically relative to the piston, the mixed gas in the combustion chamber 20 and the injection oil beam can be optimally matched, and the landing point of the oil beam will not hit the top surface 11 of the piston or a lower position in the combustion chamber 20. At the same time, the central protrusion 21 of the bottom wall of the combustion chamber 20 can guide the flame propagation and accelerate the combustion speed. An annular recessed area arranged around the central protrusion 21 helps to form a specific vortex, further promoting the mixing of fuel and air, and the boss guide surface 23 is arranged on the transition surface between the central protrusion 21 and the central annular portion 22, which helps to smooth the airflow path, reduce turbulent losses, and ensure that the airflow can efficiently enter the combustion chamber 20 and participate in the combustion process.

[0033] like Figure 1-3 As shown, in an embodiment of the present invention, in the first direction, the boss guide surface 23 smoothly transitions the highest point position of the central protrusion 21 and the lowest point position of the central annular portion 22, avoiding sharp edges and corners, reducing turbulence and energy loss, and at the same time, the smooth transition surface reduces the sudden change of airflow, reduces the turbulence intensity, and improves combustion efficiency, and the distance between the boss guide surface 23 and the central axis of the base 10 gradually increases, that is, the boss guide surface 23 is inclined relative to the central axis of the base 10, and the gradually increasing distance can guide the airflow to flow along a specific path, forming a more effective vortex, and improving the mixing effect of fuel and air. At the same time, the optimized airflow path helps to evenly distribute the fuel in the combustion chamber, ensuring more sufficient and stable combustion.

[0034] like Figure 1-3 As shown, in an embodiment of the present invention, the combustion chamber 20 includes a squeeze flow guide surface 24, which is continuous with the wall surface of the central annular portion 22 and the top surface 11 respectively. The squeeze flow guide surface 24 guides the airflow along a predetermined path through a smooth transition, reduces turbulence and energy loss, and enhances the squeeze flow effect. That is, when the piston moves upward, the airflow will be squeezed to the upper part of the combustion chamber 20. The squeeze flow guide surface 24 can effectively guide this part of the airflow, so that it can be better mixed with the fuel, thereby improving the combustion efficiency. In addition, the squeeze flow guide surface 24 helps to evenly distribute the fuel in the combustion chamber, ensuring more complete and stable combustion.

[0035] like Figure 1-3As shown, in the embodiment of the present invention, in the first direction, the squeezing guide surface 24 smoothly transitions the highest point position of the central annular portion 22 and the lowest point position of the top surface 11, so that the fuel vapor can continue to extend upward along the boss guide surface 23, so that the fuel vapor can be mixed with the air more thoroughly, and the distance between the squeezing guide surface 24 and the central axis of the base 10 gradually increases. The gradually increasing distance can expand the mixing area of ​​the fuel vapor and the air, improve the mixing effect, and the smooth transition surface reduces the sudden change of the airflow, reduces the local turbulence intensity, and improves the combustion efficiency.

[0036] like Figure 1-3 As shown, in the embodiment of the present invention, the intersection line of the boss guide surface 23 and the longitudinal section and the intersection line of the squeeze flow guide surface 24 and the longitudinal section are both straight lines. In actual use, the structure of the boss guide surface 23 can be selected according to the injection angle of the diesel engine and the overall shape of the diesel engine combustion chamber to ensure that the fuel and air can be reasonably matched in the diesel engine combustion chamber to avoid the occurrence of too rich or too lean mixture.

[0037] like Figure 1-3 As shown, in the embodiment of the present invention, the central annular portion 22 is tilted and recessed outward to enhance the vortex intensity of the fresh air into the combustion chamber 20 .

[0038] like Figure 1-3 As shown, in the embodiment of the present invention, the center line of the combustion chamber 20 is located on the side of the center line of the piston close to the injector, so that the mixed gas in the combustion chamber 20 and the injection oil beam can be optimally matched, and the landing point of the oil beam will not hit the top surface 11 of the base 10 or be at a lower position in the combustion chamber 20.

[0039] like Figure 1-3 As shown, in the embodiment of the present invention, the central protrusion 21 is a plane. The planar central protrusion 21 can provide a more uniform surface, which helps the flame to spread faster and more evenly, thereby reducing the combustion time and improving the combustion efficiency. At the same time, it can reduce the risk of local excessive temperature and avoid the formation of hot spots, thereby reducing incomplete combustion and carbon deposition.

[0040] Example 2

[0041] like Figure 3-4As shown, an embodiment of the present invention provides a piston, including a combustion chamber in the above-mentioned embodiment 1, wherein the base 10 is arranged at the end of the piston, and a piston skirt 30 is provided at the end of the piston away from the end. It should be noted that, in actual use, the base 10 can be integrally formed with the piston, or the base 10 can be assembled on the piston. When the base 10 is integrally formed with the piston, a piston groove 40 for installing a piston ring is provided on the base 10. The specific structure of the combustion chamber refers to the above-mentioned embodiment 1. Since this piston adopts all the technical solutions of the above-mentioned embodiment 1, it has at least all the beneficial effects brought by the technical solutions of the above-mentioned embodiment 1, which will not be repeated here.

[0042] Example 3

[0043] An embodiment of the present utility model provides an engine, including a piston in the above-mentioned embodiment 2. Since this engine adopts all the technical solutions of the above-mentioned embodiment 2, it has at least all the beneficial effects brought by the technical solutions of the above-mentioned embodiment 2, which will not be described one by one here.

[0044] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the utility model and are not limiting. Although the utility model is described in detail with reference to the preferred embodiments, ordinary technicians in this field should understand that the technical solution of the utility model can be modified or replaced by equivalents without departing from the purpose and scope of the technical solution of the utility model, which should be included in the scope of the claims of the utility model.

Claims

1. A combustion chamber, provided on a piston, characterized in that: include: a substrate (10) having a top surface (11); A combustion chamber (20) is recessed in the top surface (11) along a first direction, and the combustion chamber (20) is eccentrically arranged relative to the piston; The bottom wall of the combustion chamber (20) is convexly provided with a central convex portion (21) and a central annular portion (22) circumferentially concave around the central convex portion (21), and a boss guide surface (23) is provided between the central convex portion (21) and the central annular portion (22).

2. A combustion chamber according to claim 1, characterized in that: In the first direction, the boss guide surface (23) smoothly transitions the highest point of the central protrusion (21) and the lowest point of the central annular portion (22), and the distance between the boss guide surface (23) and the central axis of the base (10) gradually increases.

3. A combustion chamber according to claim 1, characterized in that: The combustion chamber (20) includes a squeeze flow guide surface (24), and the squeeze flow guide surface (24) is respectively continuous with the wall surface of the central annular portion (22) and the top surface (11).

4. A combustion chamber according to claim 3, characterized in that: In the first direction, the squeeze flow guide surface (24) smoothly transitions the highest point of the central annular portion (22) and the lowest point of the top surface (11), and the distance between the squeeze flow guide surface (24) and the central axis of the base (10) gradually increases.

5. A combustion chamber according to claim 3, characterized in that: The intersection line between the boss guide surface (23) and the longitudinal section and the intersection line between the squeeze flow guide surface (24) and the longitudinal section are both straight lines.

6. A combustion chamber according to claim 1, characterized in that: The central annular portion (22) is arranged to be inclined and recessed outward.

7. A combustion chamber according to claim 1, characterized in that: The center line of the combustion chamber (20) is located on the side of the center line of the piston close to the fuel injector.

8. A combustion chamber according to claim 1, characterized in that: The central convex portion (21) is a plane.

9. A piston, characterized in that: The combustion chamber comprises a combustion chamber as claimed in any one of claims 1 to 8, wherein the base (10) is arranged at the end of the piston, and a piston skirt (30) is provided at one end of the piston away from the end.

10. An engine, characterized in that: Comprising a piston as claimed in claim 9.

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