CN116398315A - Diesel engine combustion chamber, piston and diesel engine - Google Patents

Abstract

The invention relates to a diesel engine combustion chamber, a piston and a diesel engine, wherein the diesel engine combustion chamber comprises: a substrate having a top surface; the first combustion chamber is concavely arranged on the top surface; the second combustion chamber is concavely arranged on the top surface around the circumference of the first combustion chamber; and the convex point of the throttling ridge is higher than the concave point of the second combustion chamber in the convex setting direction of the throttling ridge. The diesel engine combustion chamber can fully utilize the space and air in the cylinder, improve the combustion efficiency of fuel oil, reduce the emission of soot particles, and heat more space and working medium in the cylinder under the same heat release amount of the fuel oil, so that the temperature in the cylinder is reduced, the generation of a high-temperature area is reduced, and NO is effectively inhibited _x Generates and further reduces NO _x Is arranged in the air.

Description

Diesel Combustion Chambers, Pistons and Diesel Engines

technical field

The invention relates to the technical field of diesel engines, in particular to a combustion chamber of a diesel engine, a piston and a diesel engine.

Background technique

Due to the increasingly severe situation of energy saving and emission reduction, the requirements for the emission level of diesel engines are becoming more and more stringent, especially the emission levels of soot particles and _NOx . Fuel enters the cylinder in the form of injected oil beams, and burns around the oil beams, resulting in local high temperature and oxygen deficiency near the oil beams, and a large amount of soot particles and _NOx are generated. Therefore, it is necessary to distribute the fuel more widely in the cylinder, make full use of the air and space in the cylinder, and reduce the occurrence of high temperature and oxygen deficiency, so as to improve the fuel consumption of diesel engines and reduce the emission levels of soot particles and _NOx .

Contents of the invention

Based on this, it is necessary to provide a combustion chamber, a piston and a diesel engine for how to make full use of the air and space in the cylinder of the diesel engine.

A combustion chamber of a diesel engine, comprising:

a base having a top surface;

The first combustion chamber is recessed on the top surface;

The second combustion chamber is recessed on the top surface around the circumference of the first combustion chamber;

A throttling ridge is protrudingly arranged between the first combustion chamber and the second combustion chamber around the circumference of the first combustion chamber, and the throttling ridge is a very high annular raised ridge strip, thereby separating In the double cavity, in the convex direction of the throttle ridge, the position of the convex point of the throttle ridge is higher than the position of the concave point of the second combustion chamber.

In one embodiment, in the protruding direction of the throttle ridge, the position of the convex point of the throttle ridge is not higher than the top surface.

In one of the embodiments, the bottom inner wall of the first combustion chamber is provided with a central convex portion arranged around the central axis of the base, and a central annular portion recessed around the central convex portion.

In one of the embodiments, the combustion chamber of the diesel engine further includes a first guide surface, the first guide surface is respectively continuous with the wall surface of the central convex part and the wall surface of the central annular part, and the first guide surface The intersection line with the longitudinal section is a straight line or an arc, and the longitudinal section is coplanar with the central axis of the base.

In one of the embodiments, the combustion chamber of the diesel engine further includes a second guide surface, the second guide surface is respectively continuous with the wall surface of the central annular portion and the wall surface of the throttle ridge, and the second guide surface The intersection line between m and the longitudinal section is a straight line or an arc, and the longitudinal section is coplanar with the central axis of the base.

In one of the embodiments, the combustion chamber of the diesel engine further includes a third guide surface, the third guide surface is respectively continuous with the wall surface of the second combustion chamber and the wall surface of the throttling ridge, and the third guide surface The intersection line of the surface and the longitudinal section is a straight line or an arc, and the longitudinal section is coplanar with the central axis of the base.

In one of the embodiments, the combustion chamber of the diesel engine further includes a fourth guide surface, the fourth guide surface is respectively continuous with the wall surface of the second combustion chamber and the top surface, and the fourth guide surface is connected with the longitudinal The intersecting lines of the sections are straight lines or arcs, and the longitudinal section is coplanar with the central axis of the base.

In one of the embodiments, the fourth guide surface is connected to the top surface through rounded corners;

And/or, when the intersection line of the fourth guide surface and the longitudinal section is a straight line, the angle between the extension line of the intersection line of the fourth guide surface and the longitudinal section and the top surface is greater than 65° °;

And/or, when the intersection line of the fourth guide surface and the longitudinal section is an arc, the angle between the tangent line of the intersection line of the fourth guide surface and the longitudinal section and the top surface is greater than 65° °.

A piston includes the combustion chamber of a diesel engine as described above, the base is arranged at the end of the piston.

A diesel engine includes the above-mentioned piston.

In the combustion chamber of the above-mentioned diesel engine, a second combustion chamber is added on the periphery of the first combustion chamber, which is also used as a main space for fuel combustion. The combustion chamber of the above-mentioned diesel engine will divert part of the fuel to the second combustion chamber, reducing the distribution of fuel in the first combustion chamber, so that the high-temperature and oxygen-poor combustion of fuel in the first combustion chamber is significantly improved. Because the second combustion chamber has a larger radius, the fuel vapor diverted to the second combustion chamber can obtain a longer penetration distance, fully entrain the surrounding air, and the second combustion chamber has sufficient oxygen, so good combustion will also be obtained.

In the combustion chamber of the diesel engine, a throttling ridge is arranged on the top surface of the base, which is higher than the concave point of the second combustion chamber, so that a throttling passage is formed between the throttling ridge and the cylinder head above the piston. The fuel vapor flowing to the second combustion chamber is throttled and flattened at the throttling channel, spread out in the circumferential direction, fully occupies and utilizes the space and air between the oil jets, and then enters the second combustion chamber, thereby achieving high space occupancy and air utilization. In this way, the combustion chamber of the above-mentioned diesel engine can make full use of the space and air in the cylinder, improve the combustion efficiency of fuel, reduce the emission of soot particles, and due to the same heat release of fuel, more space and working fluid in the cylinder are processed Heating reduces the temperature in the cylinder and reduces the generation of high temperature areas, thereby effectively inhibiting the generation of NO _x and reducing the emission of NO _x .

Description of drawings

Fig. 1 is the structural representation of diesel engine combustion chamber in some embodiments of the present invention;

Fig. 2 is the structural dimension schematic diagram of diesel engine combustion chamber in Fig. 1 embodiment;

Fig. 3 is the structural representation of A being in an embodiment in the combustion chamber of the diesel engine in the embodiment of Fig. 1;

Fig. 4 is a schematic view of the structure of A in another embodiment in the combustion chamber of the diesel engine in the embodiment of Fig. 1;

Fig. 5 is a structural schematic view of A being in another embodiment in the combustion chamber of the diesel engine in the embodiment of Fig. 1;

Fig. 6 is a structural schematic view of B in an embodiment in the diesel engine combustion chamber in the embodiment of Fig. 1;

Fig. 7 is a schematic view showing the structure of B in another embodiment in the combustion chamber of the diesel engine in the embodiment of Fig. 1;

Fig. 8 is a structural schematic diagram of an embodiment in which C is in the combustion chamber of the diesel engine in the embodiment of Fig. 1;

Fig. 9 is a structural schematic view of another embodiment in which C is in the combustion chamber of the diesel engine in the embodiment of Fig. 1;

Fig. 10 is a structural schematic diagram of another embodiment in which C is in the combustion chamber of the diesel engine in the embodiment of Fig. 1;

Fig. 11 is a schematic structural view of D in an embodiment in the combustion chamber of the diesel engine in the embodiment of Fig. 1;

Fig. 12 is a structural schematic diagram of another embodiment in which D is located in the combustion chamber of the diesel engine in the embodiment of Fig. 1 .

Explanation of reference signs:

base 10; top surface 11; piston groove 13;

The first combustion chamber 100; the central convex portion 110; the central annular portion 120;

the second combustion chamber 200;

throttle ridge 300;

The first guide surface 400 ; the second guide surface 410 ; the third guide surface 420 ; the fourth guide surface 430 .

Detailed ways

In order to make the above objects, features and advantages of the present invention more comprehensible, specific implementations of the present invention will be described in detail below in conjunction with the accompanying drawings. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention. However, the present invention can be implemented in many other ways different from those described here, and those skilled in the art can make similar improvements without departing from the connotation of the present invention, so the present invention is not limited by the specific embodiments disclosed below.

In describing the present invention, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", " Back", "Left", "Right", "Vertical", "Horizontal", "Top", "Bottom", "Inner", "Outer", "Clockwise", "Counterclockwise", "Axial" , "radial", "circumferential" and other indicated orientations or positional relationships are based on the orientations or positional relationships shown in the drawings, which are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying the referred device or Elements must have certain orientations, be constructed and operate in certain orientations, and therefore should not be construed as limitations on the invention.

In addition, the terms "first" and "second" are used for descriptive purposes only, and cannot be interpreted as indicating or implying relative importance or implicitly specifying the quantity of indicated technical features. Thus, the features defined as "first" and "second" may explicitly or implicitly include at least one of these features. In the description of the present invention, "plurality" means at least two, such as two, three, etc., unless otherwise specifically defined.

In the present invention, unless otherwise clearly specified and limited, terms such as "installation", "connection", "connection" and "fixation" should be understood in a broad sense, for example, it can be a fixed connection or a detachable connection , or integrated; it may be mechanically connected or electrically connected; it may be directly connected or indirectly connected through an intermediary, and it may be the internal communication of two components or the interaction relationship between two components, unless otherwise specified limit. Those of ordinary skill in the art can understand the specific meanings of the above terms in the present invention according to specific situations.

In the present invention, unless otherwise clearly specified and limited, the first feature may be in direct contact with the first feature or the first and second feature may be in direct contact with the second feature through an intermediary. touch. Moreover, "above", "above" and "above" the first feature on the second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. "Below", "beneath" and "beneath" the first feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is less horizontally than the second feature.

It should be noted that when an element is referred to as being “fixed on” or “disposed on” another element, it may be directly on the other element or there may be an intervening element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or intervening elements may also be present. As used herein, the terms "vertical", "horizontal", "upper", "lower", "left", "right" and similar expressions are for the purpose of illustration only and are not intended to represent the only embodiments.

Most of the current diesel engine combustion systems use pits formed on the top surface of the base as the main space for fuel combustion. The pits formed on the top surface are the combustion chambers. In the pit of the combustion chamber, as the piston moves upward to perform the compression stroke, the fuel is gradually vaporized and mixed with the air in the pit to form a mixture, and finally the fuel burns and expands to push the piston to move down to do work.

From the working process of the above-mentioned diesel engine, it can be known that after the fuel enters the pit of the combustion chamber, it is only fully mixed with the air in the pit of the combustion chamber, and the air outside the pit of the combustion chamber, especially with the outside and top of the pit of the combustion chamber. The air above the surface is not mixed thoroughly, which aggravates the localized combustion of fuel, resulting in high temperature and oxygen deficiency during diesel combustion, which in turn produces a large amount of soot particles and NO _x .

Based on this, referring to Fig. 1, the piston provided by an embodiment of the present invention has a diesel engine combustion chamber, and the diesel engine combustion chamber includes a base 10, a first combustion chamber 100, a second combustion chamber 200, and a piston between the first combustion chamber 100 and the second combustion chamber The throttling ridge 300 between the two combustion chambers 200, wherein the base 10 is arranged at the end of the piston, the base 10 can be integrally formed with the piston, when the base 10 can be integrally formed with the piston, the base 10 is provided with a useful Piston groove 13 for installing piston rings. In other embodiments, the base 10 can also be installed on the piston in an assembled manner.

The first combustion chamber 100 is recessed on the top surface 11 of the base 10, the second combustion chamber 200 is recessed on the top surface 11 of the base 10 around the circumference of the first combustion chamber 100, and the throttling ridge 300 surrounds the first combustion chamber 100. It is convexly arranged between the first combustion chamber 100 and the second combustion chamber 200 in the circumferential direction. When the fuel enters the combustion chamber of the diesel engine, it will gasify to form fuel vapor, and then it will be split by the throttling ridge 300 to form two parts, one of which flows into the In the first combustion chamber 100 , another part flows into the second combustion chamber 200 . In this way, the fuel will not be concentrated in the first combustion chamber 100 or the second combustion chamber 200 , avoiding too concentrated combustion of the fuel, and improving the high-temperature and oxygen-lean combustion of the fuel. Because the second combustion chamber 200 has a larger radius, the fuel vapor diverted to the second combustion chamber 200 can obtain a longer penetration distance, fully entrain the surrounding air, and the second combustion chamber 200 has sufficient oxygen, so it will also get good results. of burning.

Wherein, in the protruding direction of the throttle ridge 300, the position of the convex point of the throttle ridge 300 is higher than the position of the concave point of the second combustion chamber 200. The distance between the cylinder heads is smaller than the distance between the second combustion chamber 200 concave point and the cylinder heads. In this way, when the diesel engine is performing a compression stroke, as the piston approaches the cylinder head, the distance between the throttle ridge 300 and the cylinder head will also decrease continuously. There is still a certain distance between the throttle ridge 300 and the cylinder head, and since the throttle ridge is closer to the cylinder head than the first combustion chamber 100 and the second combustion chamber 200, the distance between the throttle ridge 300 and the cylinder head The space will form a throttling channel.

When the piston moves close to the top dead center, the fuel will also be injected into the first combustion chamber 100 through the fuel injector. When the fuel enters the first combustion chamber 100 and gasifies to form fuel vapor, it will be throttled The stream ridge 300 divides the flow to form two parts, one part flows into the first combustion chamber 100 , and the other part flows into the second combustion chamber 200 . The fuel vapor flowing to the second combustion chamber 200 is throttled and flattened at the throttling passage, spread out in the circumferential direction, fully occupies and utilizes the space and air between the oil jets, and then enters the second combustion chamber 200, so that The fuel vapor can diffuse in the second combustion chamber 200 and above the second combustion chamber 200 , and fully entrain the surrounding air during the diffusion process, so that the fuel vapor can interact with the second combustion chamber 200 and the air above the second combustion chamber 200 The air is thoroughly mixed.

In the combustion chamber of the above-mentioned diesel engine, a second combustion chamber 200 is added on the periphery of the first combustion chamber 100, which is also used as a main space for fuel combustion. The combustion chamber of the above-mentioned diesel engine will divert part of the fuel to the second combustion chamber 200, reducing the distribution of fuel in the first combustion chamber 100, so that the high-temperature lean combustion of fuel in the first combustion chamber 100 is significantly improved. Because the second combustion chamber 200 has a larger radius, the fuel vapor diverted to the second combustion chamber 200 can obtain a longer penetration distance, fully entrain the surrounding air, and the second combustion chamber 200 has sufficient oxygen, so it will also get good results. of burning.

In the combustion chamber of the diesel engine, a throttling ridge 300 is arranged on the top surface 11 of the base 10 higher than the concave point of the second combustion chamber 200, so that a throttling passage is formed between the throttling ridge 300 and the cylinder head above the piston. The fuel vapor flowing to the second combustion chamber 200 is throttled and flattened at the throttling passage, spread out in the circumferential direction, fully occupies and utilizes the space and air between the oil jets, and then enters the second combustion chamber 200, so that The fuel vapor can diffuse in the second combustion chamber 200 and above the second combustion chamber 200 , and fully entrain the surrounding air during the diffusion process, so that the fuel vapor can interact with the second combustion chamber 200 and the air above the second combustion chamber 200 The air is fully mixed to achieve high space occupancy and air utilization. In this way, the combustion chamber of the above-mentioned diesel engine can make full use of the space and air in the cylinder, improve the combustion efficiency of fuel, reduce the emission of soot particles, and due to the same heat release of fuel, more space and working fluid in the cylinder are processed Heating reduces the temperature in the cylinder and reduces the generation of high temperature areas, thereby effectively inhibiting the generation of NO _x and reducing the emission of NO _x .

In the embodiment of the present invention, referring to FIG. 2 , in the protruding direction of the throttle ridge 300 , the position of the convex point of the throttle ridge 300 is not higher than the top surface 11 , that is, the position of the convex point of the throttle ridge 300 is lower than or flat. Aligned with the top surface 11 of the base 10, if the throttle ridge 300 is higher than the top surface 11 of the base 10, the flow of fuel vapor will be unreasonable, for example, the throttle ridge 300 may hit the cylinder head, and the processing cost of the piston will increase. . Optionally, the minimum distance between the throttle ridge 300 and the top surface 11 is H3 in FIG. 2, H3=0D-0.035D, and the diameter of the throttle ridge 300 is D3 in FIG. 2, and D3 is the throttle ridge The diameter of the outline formed by the salient position of 300, D3=0.52D-0.7D, where D is the bore of the cylinder where the piston is located.

Further, the distance between the position of the concave point of the first combustion chamber 100 and the top surface 11, that is, H1 in FIG. is the maximum contour diameter formed by the first combustion chamber 100 around the central axis of the base 10, D1=0.5D-0.65D. The distance between the concave point position of the second combustion chamber 200 and the top surface 11, namely H2 among Fig. 2, H2=0.035D-0.07D, the diameter of the second combustion chamber 200, namely D2 among Fig. 2, D2 is the second The maximum profile diameter formed by the combustion chamber 200 around the central axis of the base 10 is D2 = 0.75D-0.9D. Above, the specific values of H1, H2, H3 and D1, D2, D3 can be adjusted according to the fuel injection angle of the diesel engine and the overall shape of the combustion chamber of the diesel engine to ensure that the fuel and air can be reasonably matched in the combustion chamber of the diesel engine to avoid over-concentration Or a too lean mixture appears.

It should be noted that, in actual use, since the base 10 can be integrally formed with the piston, or the base 10 is assembled on the piston, the central axis of the base 10 coincides with the central axis of the piston, that is to say, the base The central axis of 10 is the central axis of the piston.

In the embodiment of the present invention, referring to FIG. 1, the bottom inner wall of the first combustion chamber 100 is provided with a central convex portion 110 arranged around the central axis of the base 10, and a central annular portion 120 recessed around the central convex portion 110, so that the first A combustion chamber 100 has an omega-like cross-section along the central axis of the base 10 . That is to say, the bottom of the first combustion chamber 100 is uneven, so when the air flow passes through the first combustion chamber 100, the uneven bottom can properly interfere with the swirling flow of the fuel vapor in the first combustion chamber 100, so as to Reduced mixture suitable for NO _x production. Optionally, the height of the central convex portion 110, namely H4 in FIG. 2, H4=0.08D-0.14D.

In some embodiments, referring to FIG. 1 , FIG. 3 , FIG. 4 and FIG. 5 , the combustion chamber of the diesel engine further includes a first guide surface 400 , and the first guide surface 400 is connected to the wall surface of the central convex portion 110 and the wall surface of the central annular portion 120 respectively. Continuously, the first guide surface 400 is an annular surface arranged circumferentially around the central axis of the base 10 . Wherein, the intersection line between the first guide surface 400 and the longitudinal section can be a straight line in the embodiment of FIG. 3 or an arc, and the longitudinal section is coplanar with the central axis of the base 10 . Further, when the intersection line of the first guide surface 400 and the longitudinal section is an arc, the intersection line may be convex toward the top surface 11 of the base 10 , as shown in FIG. 4 . In other embodiments, when the intersection line between the first guide surface 400 and the longitudinal section can also be recessed in the direction away from the top surface 11 of the base 10, refer to FIG. 5 here. In actual use, the first guide surface The structure of 400 can be selected according to the fuel 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 appearance of too rich or too lean mixture.

In some embodiments, referring to Fig. 1, Fig. 6 and Fig. 7, the combustion chamber of the diesel engine further includes a second guide surface 410, the second guide surface 410 is continuous with the wall surface of the central annular portion 120 and the wall surface of the splitter ridge 310 respectively, the second The guide surface 410 is an annular surface arranged circumferentially around the central axis of the base 10 . Wherein, the intersection line between the second guide surface 410 and the longitudinal section may be a straight line in the embodiment of FIG. 6 or an arc. Further, when the intersection line between the second guide surface 410 and the longitudinal section is an arc, the intersection line may be recessed toward the top surface 11 of the base 10 , as shown in FIG. 7 . In the actual use process, the structure of the second guide surface 410 can be selected according to the fuel injection angle of the diesel engine and the overall shape of the diesel engine combustion chamber, so as to ensure that the fuel and air can be reasonably matched in the diesel engine combustion chamber, and avoid too rich or too lean mixture appears.

In some embodiments, referring to FIG. 1 , FIG. 8 , FIG. 9 and FIG. 10 , the third guide surface 420 is continuous with the wall surface of the second combustion chamber 200 and the wall surface of the throttling ridge 300 respectively, and the third guide surface 420 is around the base The torus that the central axis of 10 is arranged circumferentially. Wherein, the intersection line of the third guide surface 420 and the longitudinal section may be a straight line in the embodiment of FIG. 8 or an arc. Further, when the intersection line of the third guide surface 420 and the longitudinal section is an arc, the arc may protrude toward the top surface 11 of the base 10 , as shown in FIG. 9 . In other embodiments, the intersection line between the third guide surface 420 and the longitudinal section can also be recessed in the direction away from the top surface 11 of the base 10. Here, refer to FIG. 10. In actual use, the third guide surface 420 The structure of the diesel engine can be selected according to the fuel 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 appearance of too rich or too lean mixture.

In some embodiments, referring to FIG. 1 , FIG. 11 and FIG. 12 , the fourth guide surface 430 is continuous with the wall surface of the second combustion chamber 200 and the top surface 11 of the base 10 respectively, and the fourth guide surface 430 is around the center of the base 10 A torus with an axis arranged circumferentially. Wherein, the intersection line between the fourth guide surface 430 and the longitudinal section may be a straight line in the embodiment of FIG. 11 or an arc. Furthermore, when the intersection line of the fourth guide surface 430 and the longitudinal section is an arc, the arc can be recessed toward the top surface 11 of the base 10, as shown in FIG. 12 . In actual use, the fourth The structure of the guide surface 430 can be selected according to the fuel injection angle of the diesel engine and the overall shape of the combustion chamber of the diesel engine, so as to ensure that the fuel and air can be reasonably matched in the combustion chamber of the diesel engine, and avoid the occurrence of too rich or too lean mixture.

Wherein, the fourth guide surface 430 is connected to the top surface 11 of the base 10 through rounded corners, so that the transition between the fourth guide surface 430 and the top surface 11 of the base 10 is smoother. And when the intersection line of the fourth guide surface 430 and the longitudinal section is a straight line, the angle between the extension line of the intersection line of the fourth guide surface 430 and the longitudinal section and the top surface 11 of the base 10 is greater than 65°. When the intersection line of the surface 430 and the longitudinal section is an arc, the angle between the tangent of the intersection line of the longitudinal section of the fourth guide surface 430 and the top surface 11 of the base 10 is greater than 65°. The purpose of controlling the included angle between the fourth guide surface 430 and the top surface 11 is to control the movement direction of the high-temperature gas generated after the combustion of fuel and air, so as to prevent the high-temperature gas from rushing to the cylinder wall of the cylinder, resulting in increased heat transfer loss.

In a preferred embodiment, above-mentioned D1=59mm, H1=19mm, D2=100.8mm, H2=6.7mm, D3=61.2mm, H3=1.1mm, H4=9mm, at the same time the first guide surface 400, the second The guiding surface 410 , the third guiding surface 420 and the fourth guiding surface 430 all adopt a straight line structure. By simulating the diesel engine combustion chamber with the above parameters, according to the calculation results, compared with the traditional diesel engine combustion chamber, the above diesel engine combustion chamber has the same fuel consumption and the maximum efficiency of the diesel engine. The emission of NO _x 5.8% reduction, and in the maximum torque condition of the diesel engine, the NO _x emission is reduced by 9.2%.

The embodiment of the present invention also provides a diesel engine, including the piston in any of the above embodiments, and the diesel engine combustion chamber of the piston, and a second combustion chamber 200 is added on the periphery of the first combustion chamber 100, which is also used as a main space for fuel combustion . The combustion chamber of the above-mentioned diesel engine will divert part of the fuel to the second combustion chamber 200, reducing the distribution of fuel in the first combustion chamber 100, so that the high-temperature lean combustion of fuel in the first combustion chamber 100 is significantly improved. Because the second combustion chamber 200 has a larger radius, the fuel vapor diverted to the second combustion chamber 200 can obtain a longer penetration distance, fully entrain the surrounding air, and the second combustion chamber 200 has sufficient oxygen, so it will also get good results. of burning.

The diesel engine combustion chamber is provided with a throttle ridge 300 higher than the concave point of the second combustion chamber 200 on the top surface of the base, so that a throttle passage is formed between the throttle ridge 300 and the cylinder head above the piston. The fuel vapor flowing to the second combustion chamber 200 is throttled and flattened at the throttling passage, spread out in the circumferential direction, fully occupies and utilizes the space and air between the oil jets, and then enters the second combustion chamber 200, so that The fuel vapor can diffuse in the second combustion chamber 200 and above the second combustion chamber 200 , and fully entrain the surrounding air during the diffusion process, so that the fuel vapor can interact with the second combustion chamber 200 and the air above the second combustion chamber 200 The air is fully mixed to achieve high space occupancy and air utilization. In this way, the combustion chamber of the above-mentioned diesel engine can make full use of the space and air in the cylinder, improve the combustion efficiency of fuel, reduce the emission of soot particles, and due to the same heat release of fuel, more space and working fluid in the cylinder are processed Heating reduces the temperature in the cylinder and reduces the generation of high temperature areas, thereby effectively inhibiting the generation of NO _x and reducing the emission of NO _x .

The technical features of the above-mentioned embodiments can be combined arbitrarily. To make the description concise, all possible combinations of the technical features in the above-mentioned embodiments are not described. However, as long as there is no contradiction in the combination of these technical features, should be considered as within the scope of this specification.

The above-mentioned embodiments only express several implementation modes of the present invention, and the descriptions thereof are relatively specific and detailed, but should not be construed as limiting the patent scope of the invention. It should be noted that, for those skilled in the art, several modifications and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent for the present invention should be based on the appended claims.

Claims (10)

1. A diesel combustion chamber, the diesel combustion chamber comprising:

a substrate (10) having a top surface (11);

the first combustion chamber (100) is concavely arranged on the top surface (11);

a second combustion chamber (200) recessed on the top surface (11) around the circumference of the first combustion chamber (100);

and a throttle ridge (300) protruding between the first combustion chamber (100) and the second combustion chamber (200) around the circumference of the first combustion chamber (100), wherein the protruding point position of the throttle ridge (300) is higher than the concave point position of the second combustion chamber (200) in the protruding direction of the throttle ridge (300).

2. The diesel combustion chamber according to claim 1, characterized in that the bump point of the throttle ridge (300) is not higher than the top surface (11) in the protruding direction of the throttle ridge (300).

3. The diesel combustion chamber according to claim 1, characterized in that the bottom inner wall of the first combustion chamber (100) is provided with a central protrusion (110) arranged around the central axis of the base (10), and a central annular portion (120) recessed circumferentially around the central protrusion (110).

4. A diesel combustion chamber according to claim 3, characterized in that it further comprises a first guiding surface (400), said first guiding surface (400) being continuous with the wall surface of the central protrusion (110) and the wall surface of the central annular portion (120), respectively, the intersection of the first guiding surface (400) with a longitudinal section being a straight line or an arc, said longitudinal section being coplanar with the central axis of the substrate (10).

5. A diesel combustion chamber according to claim 3, characterized in that it further comprises a second guiding surface (410), said second guiding surface (410) being continuous with the wall surface of the central annular portion (120) and the wall surface of the throttling ridge (300), respectively, the intersection of the second guiding surface (410) with a longitudinal section being a straight line or an arc, said longitudinal section being coplanar with the central axis of the substrate (10).

6. The diesel combustion chamber according to claim 1, characterized in that it further comprises a third guiding surface (420), said third guiding surface (420) being continuous with the wall of the second combustion chamber (200) and the wall of the throttle ridge (300), respectively, the intersection of said third guiding surface (420) with a longitudinal section being a straight line or an arc, said longitudinal section being coplanar with the central axis of the substrate (10).

7. The diesel combustion chamber according to claim 1, characterized in that it further comprises a fourth guiding surface (430), said fourth guiding surface (430) being continuous with the wall surface and the top surface (11) of the second combustion chamber (200), respectively, the intersection of said fourth guiding surface (430) with a longitudinal section being a straight line or an arc, said longitudinal section being coplanar with the central axis of the substrate (10).

8. The diesel combustion chamber according to claim 7, characterized in that the fourth guiding surface (430) is connected to the top surface (11) by means of rounded corners;

and/or when the intersection line of the fourth guiding surface (430) and the longitudinal section is a straight line, the included angle between the extension line of the intersection line of the fourth guiding surface (430) and the longitudinal section and the top surface (11) is larger than 65 degrees;

and/or, when the intersection line of the fourth guiding surface (430) and the longitudinal section is an arc line, the included angle between the tangent line of the intersection line of the fourth guiding surface (430) and the longitudinal section and the top surface (11) is larger than 65 degrees.

9. A piston comprising a diesel combustion chamber according to any one of claims 1-8, said base (10) being arranged at the end of said piston.

10. A diesel engine comprising a piston as claimed in claim 9.

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