Pre-combustion chamber and engine

Abstract

The pre-combustion chamber is characterized in that a center injection hole and a plurality of circumferential injection holes are formed in the side face of the bottom of the pre-combustion chamber, and the circumferential injection holes are distributed in the circumferential direction of the center injection hole at intervals; the inclined lower end of the central injection hole faces the air inlet side of the main combustion chamber; the horizontal section where the center of the upper end of the circumferential injection hole is located is a transverse section, the connecting line of the center of the upper end of the circumferential injection hole and the central axis of the bottom of the pre-combustion chamber on the transverse section is a radial connecting line, and the included angle between the projection of the central axis of the circumferential injection hole on the transverse section and the radial connecting line is an included angle alpha, the value range of the included angle alpha is 20-35 degrees; the included angle between the projection of the circumferential jet holes in the vertical plane and the central axis of the bottom of the pre-combustion chamber is beta, and the value range of the included angle beta is 55-85 degrees. The combustion effect in the main combustion chamber can be improved by obliquely arranging the center injection hole and arranging the included angle alpha and the included angle beta between the circumferential injection holes.

Description

Technical Field

[0001] The present application relates to the field of engine technology, and in particular to a precombustion chamber and an engine. Background Art

[0002] The pre-chamber ignition system utilizes distributed, multi-point ignition. After the spark plug ignites in the pre-chamber, the mixture begins to burn. The resulting reactive radicals form jets through nozzles, spraying combustion gas into the main combustion chamber to form multiple ignition points. The high-speed jets increase the combustion reaction rate within the main combustion chamber, suppressing knock and extending the lean burn limit, thereby improving the engine's thermal efficiency.

[0003] The intake side of some main combustion chambers is larger than the exhaust side of the main combustion chamber. When the injection hole at the bottom of the pre-combustion chamber is set as a straight hole, the combustion effect of the main combustion chamber is poor.

[0004] The above information disclosed in this Background section is only for enhancement of understanding of the background of the present disclosure and therefore it may contain information that does not form the prior art that is already known to a person of ordinary skill in the art. Summary of the Invention

[0005] Based on this, a pre-combustion chamber and an engine are provided, wherein the injection holes at the bottom of the pre-combustion chamber are arranged tilted to improve the combustion effect of the main combustion chamber.

[0006] In a first aspect, an embodiment of the present application provides a pre-combustion chamber, wherein a central injection hole communicating with a main combustion chamber and a plurality of circumferential injection holes are provided on a bottom side of the pre-combustion chamber, wherein the plurality of circumferential injection holes are arranged at intervals along the circumference of the central injection hole;

[0007] The central injection hole is arranged obliquely, and the inclined lower end of the central injection hole faces the intake side of the main combustion chamber;

[0008] The circumferential injection hole is arranged obliquely, the horizontal section where the center of the upper end of the circumferential injection hole is located is a transverse section, the connecting line between the center of the upper end of the circumferential injection hole and the central axis of the bottom of the pre-combustion chamber in the transverse section is a radial connecting line, and the angle between the projection of the central axis of the circumferential injection hole on the transverse section and the radial connecting line is an angle α, and the value range of the angle α is 20°-35°;

[0009] The angle between the projection of the circumferential injection hole on the vertical plane and the central axis of the bottom of the pre-combustion chamber is angle β, and the value range of angle β is 55°-85°.

[0010] In one embodiment, the plurality of circumferential injection holes include:

[0011] a first hole, facing the intake side of the main combustion chamber, wherein the horizontal section where the center of the upper end of the first hole is located is a first transverse section, a connecting line between the center of the upper end of the first hole and the central axis of the bottom of the pre-combustion chamber in the first transverse section is a first radial connecting line, an angle α1 is included between the projection of the central axis of the first hole in the first transverse section and the first radial connecting line, and an angle β1 is included between the projection of the first hole in the vertical plane and the central axis of the bottom of the pre-combustion chamber;

[0012] a second hole facing the exhaust side of the main combustion chamber, wherein the horizontal section where the center of the upper end of the second hole is located is a second transverse section, a connecting line between the center of the upper end of the second hole and the central axis of the bottom of the precombustion chamber in the second transverse section is a second radial connecting line, an angle α2 is included between the projection of the central axis of the second hole on the second transverse section and the second radial connecting line, and an angle β2 is included between the projection of the second hole on the vertical plane and the central axis of the bottom of the precombustion chamber;

[0013] The included angle α1 is greater than the included angle α2, and the included angle β1 is greater than the included angle β2.

[0014] In one embodiment, the angle α1 is in the range of 20°-35°, the angle α2 is in the range of 20°-35°, the angle β1 is in the range of 75°-85°, and the angle β2 is in the range of 55°-65°.

[0015] In one embodiment, the angle α1 is in the range of 20°-35°, the angle α2 is in the range of 20°-35°, the angle β1 is in the range of 75°-85°, and the angle β2 is in the range of 55°-65°.

[0016] In one embodiment, the diameter of the first hole is larger than the diameter of the second hole.

[0017] In one embodiment, the aperture of the first hole ranges from 0.9 mm to 1.9 mm, and the aperture of the second hole ranges from 0.7 mm to 1.7 mm.

[0018] In one embodiment, the diameter of the central injection hole is smaller than that of the first hole, the diameter of the central injection hole is greater than or equal to that of the second hole, and the diameter range of the central injection hole is 0.7 mm-1.7 mm.

[0019] In one embodiment, the distance between the upper center of the first hole and the central axis of the bottom of the pre-combustion chamber is distance H1, and the distance between the upper center of the second hole and the central axis of the bottom of the pre-combustion chamber is H2, and the distance H1 is smaller than the distance H2.

[0020] In one embodiment, three adjacent first holes are provided and arranged at intervals, and three adjacent second holes are provided and arranged at intervals.

[0021] In one embodiment, the angle between the central injection hole and the central axis of the bottom of the pre-combustion chamber is angle θ, and the value range of the angle θ is 15°-25°.

[0022] In a second aspect, an embodiment of the present application provides an engine comprising a pre-combustion chamber and a main combustion chamber as described in any one of the above items, wherein the intake side of the main combustion chamber is larger than the exhaust side of the main combustion chamber.

[0023] According to the precombustion chamber and engine provided by the embodiment of the present application, a central injection hole and a plurality of circumferential injection holes are provided on the side surface of the bottom of the precombustion chamber, which are connected to the main combustion chamber. The plurality of circumferential injection holes are arranged at intervals along the circumference of the central injection hole; the central injection hole is arranged at an angle, with the inclined lower end of the central injection hole facing the intake side of the main combustion chamber; the circumferential injection holes are arranged at an angle, the horizontal section where the center of the upper end of the circumferential injection hole is located is the transverse section, the connecting line between the center of the upper end of the circumferential injection hole and the central axis of the bottom of the precombustion chamber in the transverse section is the radial connecting line, the angle between the projection of the central axis of the circumferential injection hole in the transverse section and the radial connecting line is the angle α, and the value range of the angle α is 20°-35°; the angle between the projection of the circumferential injection hole in the vertical plane and the central axis of the bottom of the precombustion chamber is the angle β, and the value range of the angle β is 55°-85°. The present application can improve the combustion effect in the main combustion chamber where the intake side is larger than the exhaust side by arranging the central injection hole at an angle α and the angle β of the circumferential injection holes. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 A schematic structural diagram of a pre-combustion chamber and a main combustion chamber provided in an embodiment of the present application is shown;

[0025] Figure 2 A schematic structural diagram of a pre-combustion chamber bottom provided in an embodiment of the present application is shown;

[0026] Figure 3 A top view of the bottom of a pre-combustion chamber provided in an embodiment of the present application is shown;

[0027] Figure 4 Show Figure 3 A cross-sectional view of the bottom of the pre-combustion chamber along direction AA is shown;

[0028] Figure 5 Show Figure 3 A cross-sectional view of the bottom of the pre-combustion chamber along direction BB is shown;

[0029] Figure 6 Show Figure 3A cross-section of the pre-chamber bottom along direction CC is shown.

[0030] Description of reference numerals:

[0031] 1. Bottom of the pre-combustion chamber; 11. Central injection hole; 12. Circumferential injection holes; 121. First hole; 122. Second hole; 2. Main combustion chamber; 21. Intake side; 22. Exhaust side. DETAILED DESCRIPTION

[0032] In order to make the purpose, technical solutions and advantages of this application more clear, the following further describes this application in detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain this application and are not intended to limit this application.

[0033] It should be noted that the illustrations provided in this embodiment are only used to schematically illustrate the basic concept of the present invention. Therefore, the illustrations only show components related to the present invention and are not drawn according to the number, shape and size of components in actual implementation. In actual implementation, the type, quantity and proportion of each component can be changed at will, and the component layout type may also be more complicated.

[0034] The structures, proportions, sizes, etc. depicted in the drawings of this specification are only used to match the contents disclosed in the specification so as to facilitate understanding and reading by persons familiar with this technology. They are not intended to limit the conditions under which the present invention can be implemented and therefore have no substantive technical significance. Any structural modifications, changes in proportional relationships, or adjustments in size should still fall within the scope of the technical contents disclosed in the present invention without affecting the effects and objectives that can be achieved by the present invention.

[0035] Terms such as "upper," "lower," "left," "right," "center," "longitudinal," "transverse," "horizontal," "inner," "outer," "radial," and "circumferential" used in this specification to indicate positions or locations are based on those shown in the accompanying drawings and are intended solely for ease of description. They do not indicate or imply that the devices or components referred to must have, be constructed, or operate in a specific orientation, and are therefore not to be construed as limitations on the present invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.

[0036] The intake side 21 of part of the main combustion chamber 2 is larger than the exhaust side 22 of the main combustion chamber 2. This can reduce the flow resistance of the mixed gas when entering the main combustion chamber 2 and enhance the uniformity of the mixing of fuel and air. At the same time, the small space on the exhaust side 22 of the main combustion chamber 2 accelerates the discharge of exhaust gas and shortens the residence time of high-temperature gas in the main combustion chamber 2. However, if the injection hole at the bottom 1 of the pre-combustion chamber is set as a straight hole, the combustion effect of the main combustion chamber 2 will be poor.

[0037] Reference Figures 1-6 , Figure 1 A schematic structural diagram of a pre-combustion chamber and a main combustion chamber provided in an embodiment of the present application is shown. Figure 2 A schematic structural diagram of the bottom of a pre-combustion chamber provided in an embodiment of the present application is shown. Figure 3 FIG. 1 shows a top view of the bottom of a pre-combustion chamber provided in an embodiment of the present application. Figure 4 Show Figure 3 The cross-sectional view of the bottom of the pre-combustion chamber along the direction AA is shown, Figure 5 Show Figure 3 The cross-sectional view of the bottom of the pre-combustion chamber along the direction BB is shown, Figure 6 Show Figure 3 A cross-section of the pre-chamber bottom along direction CC is shown.

[0038] In order to solve the above problems, the present application provides a precombustion chamber, wherein a central injection hole 11 and a plurality of circumferential injection holes 12 connected to the main combustion chamber 2 are provided on the side of the bottom 1 of the precombustion chamber, and the plurality of circumferential injection holes 12 are arranged at intervals along the circumference of the central injection hole 11; the central injection hole 11 is arranged at an angle, and the inclined lower end of the central injection hole 11 faces the intake side 21 of the main combustion chamber 2; the circumferential injection holes 12 are arranged at an angle, and the horizontal section where the center of the upper end of the circumferential injection hole 12 is located is a transverse section, and the connecting line between the center of the upper end of the circumferential injection hole 12 and the central axis of the bottom 1 of the precombustion chamber in the transverse section is a radial connecting line, and the angle between the projection of the central axis of the circumferential injection hole 12 in the transverse section and the radial connecting line is angle α, and the value range of angle α is 20°-35°; the angle between the projection of the circumferential injection hole 12 in the vertical plane and the central axis of the bottom 1 of the precombustion chamber is angle β, and the value range of angle β is 55°-85°.

[0039] It should be understood that the precombustion chamber is provided with a precombustion chamber inner cavity, the precombustion chamber bottom 1 is cone-shaped, and the large end faces the precombustion chamber inner cavity, and the upper end of the precombustion chamber bottom 1 is provided with a cone-shaped inner cavity connected to the precombustion chamber inner cavity, and the side of the precombustion chamber bottom 1 is provided with a central injection hole 11 and a circumferential injection hole 12. The central injection hole 11 and the circumferential injection hole 12 connect the inner cavity of the precombustion chamber bottom 1 with the inner cavity of the main combustion chamber 2, and then connect the inner cavity of the precombustion chamber with the inner cavity of the main combustion chamber 2. When the fuel is ignited in the precombustion chamber inner cavity, high-temperature and high-pressure combustion gas is formed, and the combustion gas enters the inner cavity of the main combustion chamber 2 through the central injection hole 11 and the circumferential injection hole 12.

[0040] Since the intake side 21 of the main combustion chamber 2 is larger than the exhaust side 22 of the main combustion chamber 2, the central injection hole 11 is arranged at an angle, and the inclined lower end of the central injection hole 11 is facing the intake side 21 of the main combustion chamber 2, so that the combustion gas in the inner cavity of the pre-combustion chamber is more biased toward the intake side 21 of the main combustion chamber 2, which can make the gas in the main combustion chamber 2 burn more evenly and fully.

[0041] Furthermore, the circumferential injection holes 12 are also arranged at an angle, with the upper ends of the circumferential injection holes 12 facing the center of the inner cavity of the pre-combustion chamber bottom 1, and the lower ends of the circumferential injection holes 12 facing the inner cavity of the main combustion chamber 2. The horizontal section where the center of the upper end of the circumferential injection hole 12 is located is defined as the transverse section. The connecting line between the center of the upper end of the circumferential injection hole 12 and the central axis of the pre-combustion chamber bottom 1 in the transverse section is defined as the radial connecting line. The angle α between the projection of the central axis of the circumferential injection hole 12 in the transverse section and the radial connecting line is defined as the angle α. The value range of the angle α is 20°-35°, and the angle α can be 20°, 23°, 25°, 27°, 30°, 33°, or 35°.

[0042] At the same time, there are multiple circumferential injection holes 12, and multiple circumferential injection holes 12 are arranged at intervals along the circumference of the central injection hole 11. The inclination angles of the multiple circumferential injection holes 12 can be set the same or differently, and this application does not impose any restrictions. The multiple circumferential injection holes 12 are all inclined, so that the combustion gas injected from the multiple circumferential injection holes 12 toward the inner cavity of the main combustion chamber 2 is in a vortex shape along the clockwise or counterclockwise direction. Compared with direct injection, the vortex-shaped combustion gas can enhance the mixing effect, extend the reaction path, and thereby improve the combustion efficiency in the inner cavity of the main combustion chamber 2. At the same time, it can also maintain the stability of combustion of the combustion gas, improve the uniformity of temperature distribution in the inner cavity of the main combustion chamber 2, and thereby improve the combustion effect in the main combustion chamber 2.

[0043] When the angle α is less than 20°, the angle of the combustion gas ejected by the multiple circumferential injection holes 12 is too small, which makes the circumferential radiation range of the combustion gas in the inner cavity of the main combustion chamber 2 too small, resulting in insufficient mixing of the fuel and air in the main combustion chamber 2, resulting in poor combustion effect in the main combustion chamber 2. When α is greater than 35°, the angle of the combustion gas ejected by the circumferential injection holes 12 is too large, which can easily cause uneven circumferential fuel distribution in the main combustion chamber 2 and offset of the combustion area.

[0044] The angle between the projection of the circumferential injection hole 12 on the vertical plane and the central axis of the pre-combustion chamber bottom 1 is angle β, and the value range of angle β is 55°-85°. Angle β can be 55°, 60°, 65°, 70°, 75°, 80° or 85°, so that the injection direction of the circumferential injection hole 12 is tilted downward. The downward tilt setting can improve the vortex formed by the injection of multiple circumferential injection holes 12, improve the mixing effect, and improve the combustion stability of the combustion gas. At the same time, it can also adapt to the airflow direction of the main combustion chamber 2 and reduce flow resistance.

[0045] When the angle β is less than 55°, the fuel does not spend enough time in the inner cavity of the pre-combustion chamber to fully mix with the air and complete the pre-combustion process. The incompletely burned fuel may directly enter the main combustion chamber 2, causing delayed or uneven combustion in the main combustion chamber, and even leading to "afterburning" (combustion continuing during the exhaust phase). When the angle β is greater than 85°, the deflection angle is too large, and the fuel injection direction approaches the pre-combustion chamber wall instead of pointing to the high-energy area in the center of the pre-combustion chamber. This causes the fuel to adhere to the pre-combustion chamber wall, forming a "wall oil film" or "fuel accumulation", resulting in poor atomization and slow evaporation.

[0046] In the present application, the central injection hole 11 is tilted and the circumferential injection holes 12 are arranged with angles α and β, which can improve the combustion effect in the main combustion chamber 2 where the intake side 21 is larger than the exhaust side 22.

[0047] In some optional embodiments, the plurality of circumferential injection holes 12 include a first hole 121 and a second hole 122; the first hole 121 faces the intake side 21 of the main combustion chamber 2, the horizontal section where the center of the upper end of the first hole 121 is located is a first transverse section, the connecting line between the center of the upper end of the first hole 121 and the central axis of the pre-combustion chamber bottom 1 in the first transverse section is a first radial connecting line, the angle between the projection of the central axis of the first hole 121 in the first transverse section and the first radial connecting line is an angle α1, and the angle between the projection of the first hole 121 in the vertical plane and the central axis of the pre-combustion chamber bottom 1 is an angle α2. The angle is angle β1; the second hole 122 faces the exhaust side 22 of the main combustion chamber 2, the horizontal section where the center of the upper end of the second hole 122 is located is the second transverse section, and the connecting line between the center of the upper end of the second hole 122 and the central axis of the pre-combustion chamber bottom 1 in the second transverse section is the second radial connecting line, and the angle between the projection of the central axis of the second hole 122 in the second transverse section and the second radial connecting line is angle α2, and the angle between the second projection in the vertical plane and the central axis of the pre-combustion chamber bottom 1 is angle β2; angle α1 is greater than angle α2, and angle β1 is greater than angle β2.

[0048] The multiple circumferential injection holes 12 are divided into two groups, one group is the first hole 121, the lower end of the first hole 121 is toward the intake side 21 of the main combustion chamber 2, that is, the combustion gas in the inner cavity of the pre-combustion chamber is injected toward the intake side 21 of the main combustion chamber 2 through the first hole 121; the other group is the second hole 122, the lower end of the second hole 122 is toward the exhaust side 22 of the main combustion chamber 2, that is, the combustion gas in the inner cavity of the pre-combustion chamber is injected toward the exhaust side 22 of the main combustion chamber 2 through the second hole 122.

[0049] Since the angle α1 is greater than the angle α2, and the angle β1 is greater than the angle β2, that is, the range radiated by the vortex-shaped combustion gas ejected by multiple first holes 121 is greater than the range radiated by the vortex-shaped combustion gas ejected by multiple second holes 122, the range of radiation of the combustion gas in the intake side 21 of the main combustion chamber 2 is greater than the range of radiation of the combustion gas in the exhaust side 22 of the main combustion chamber 2, which can further improve the combustion effect in the main combustion chamber 2 where the intake side 21 is greater than the exhaust side 22.

[0050] In some optional embodiments, the value range of angle α1 is 20°-35°, and angle α1 can be 20°, 23°, 25°, 27°, 30°, 33° or 35°, etc. The value range of angle α2 is 20°-35°, and angle α2 can be 20°, 23°, 25°, 27°, 30°, 33° or 35°, etc. The value range of angle β1 is 75°-85°, and angle β1 can be 75°, 80° or 85°, etc. The value range of angle β2 is 55°-65°, and angle β2 can be 55°, 60° or 65 degrees, etc.

[0051] In one example, the angle α1 is 26°, the angle α2 is 25°, the angle β1 is 80°, and the angle β2 is 60°.

[0052] In some optional embodiments, the aperture of the first hole 121 is larger than that of the second hole 122. During the intake process within the main combustion chamber 2, air flows from the intake side 21 to the exhaust side 22. The larger aperture of the first hole 121, 122, enhances the combustion gas jet's ability to penetrate the airflow disturbances within the main combustion chamber 2, ensuring reliable ignition even under lean burn conditions. The larger aperture of the first hole 121 more effectively guides the leading edge of ignition on the intake side 21, while the smaller aperture of the exhaust side 22 guides the trailing edge of ignition slightly later, thereby achieving uniform combustion. The exhaust side 22 is located near the exhaust gas discharge path, and the pressure in the late stages of combustion in the main combustion chamber 2 is high. The smaller aperture of the second hole 122 limits reverse flow of the gas and maintains thermal stability in the pre-combustion chamber. The provision of the first hole 121 on the intake side 21 shortens the combustion duration of the main combustion chamber 2, reduces localized high-temperature zones, and reduces hydroxide formation. The exhaust side 22 typically experiences higher temperatures, and the provision of the second hole 122 slows flame propagation, preventing detonation caused by spontaneous combustion of the tail-end mixture. During the exhaust process, the larger aperture of the first hole 121 on the intake side 21 can assist in the discharge of residual exhaust gas in the inner cavity of the pre-combustion chamber, creating better conditions for the next cycle.

[0053] In some optional embodiments, the aperture range of the first hole 121 is 0.9mm-1.9mm, and the aperture of the first hole 121 can be 0.9mm, 1.2mm, 1.5mm, 1.7mm or 1.9mm and other values; the aperture range of the second hole 122 is 0.7mm-1.7mm, and the aperture of the second hole 122 can be 0.7mm, 1mm, 1.3mm, 1.5mm or 1.7mm and other values.

[0054] When the aperture of the first hole 121 is greater than 1.9 mm, it will cause energy leakage in the pre-combustion chamber, weaken the ignition enhancement effect of the pre-combustion chamber, and cause combustion disorder and emission problems. When the aperture of the second hole 122 is less than 0.9 mm, it is easy to cause insufficient ignition energy in the main combustion chamber 2, combustion delay or misfire.

[0055] In some optional embodiments, the aperture of the central injection hole 11 is smaller than the aperture of the first hole 121, the aperture of the central injection hole 11 is greater than or equal to the aperture of the second hole 122, and the aperture range of the central injection hole 11 is 0.7mm-1.7mm. The aperture of the central injection hole 11 can be a value such as 0.7mm, 1mm, 1.3mm, 1.5mm or 1.7mm. When the aperture of the central injection hole 11 is larger than the aperture of the first hole 121, it is easy to affect the vortex-shaped combustion gas formed by the multiple circumferential injection holes 12. When the aperture of the central injection hole 11 is smaller than the aperture of the second hole 122, the injection effect of the central injection hole 11 toward the main combustion chamber 2 is not obvious, affecting the combustion effect in the main combustion chamber 2 where the intake side 21 is larger than the exhaust side 22.

[0056] In some optional embodiments, the distance between the upper center of the first hole 121 and the central axis of the pre-combustion chamber bottom 1 is distance H1, and the distance between the upper center of the second hole 122 and the central axis of the pre-combustion chamber bottom 1 is distance H2, where distance H1 is less than distance H2. That is, first hole 121 is closer to the center of the pre-combustion chamber bottom 1 than second hole 122, thereby facilitating the delivery of combustion gases from the inner cavity of the pre-combustion chamber to the intake side 21 of the main combustion chamber 2. Furthermore, the height of first hole 121 is lower than that of second hole 122, thereby facilitating the delivery of combustion gases from the first hole 121 to the intake side 21 of the main combustion chamber 2.

[0057] In some optional embodiments, the distance range of H1 is 1.9mm-2.9mm, and the distance of H1 can be 1.9mm, 2.3mm, 2.5mm, 2.7mm or 2.9mm and other values; the distance range of H2 is 2.1mm-3.1mm, and the distance of H2 can be 2.1mm, 2.3mm, 2.5mm, 2.7mm, 2.9mm or 3.1mm and other values.

[0058] In one example, the distance H1 is 2.4 mm and the distance H2 is 2.6 mm.

[0059] In some optional embodiments, the number of the first holes 121 may be two, three, or four, and the number of the second holes 122 may be two, three, or four.

[0060] In one example, three adjacent first holes 121 are arranged at intervals, the three first holes 121 are spaced apart at equal distances, and the first holes 121 face the intake side 21 of the main combustion chamber 2; three adjacent second holes 122 are arranged at intervals, the three second holes 122 are spaced apart at equal distances, and the second holes 122 face the exhaust side 22 of the main combustion chamber 2.

[0061] In some optional embodiments, the angle between the central injection hole 11 and the central axis of the pre-combustion chamber bottom 1 is angle θ, and the value range of angle θ is 15°-25°. The value of angle θ can be 15°, 20° or 25°, etc. In one example, the value of angle θ is 25°. When the angle θ is less than 15°, the inclination angle of the central injection hole 11 is too small, so that the combustion gas injected into the intake side 21 of the main combustion chamber 2 is small, and the combustion of the main combustion chamber 2 is not uniform. When the angle θ is greater than 25°, the inclination angle of the central injection hole 11 is too large, so that the combustion gas injected into the intake side 21 of the main combustion chamber 2 is large, and the combustion of the main combustion chamber 2 is not uniform.

[0062] The present application also includes an engine, including a pre-combustion chamber and a main combustion chamber as described in any of the above items, wherein the intake side 21 of the main combustion chamber 2 is larger than the exhaust side 22 of the main combustion chamber 2, which can reduce the flow resistance of the mixture when entering the main combustion chamber 2 and enhance the mixing uniformity of the fuel and air. At the same time, the small space on the exhaust side 22 of the main combustion chamber 2 accelerates the discharge of exhaust gas and shortens the residence time of high-temperature gas in the main combustion chamber 2.

[0063] A central injection hole 11 and a plurality of circumferential injection holes 12 are provided on the side of the pre-combustion chamber bottom 1, which are connected to the main combustion chamber 2. The plurality of circumferential injection holes 12 are arranged at intervals along the circumference of the central injection hole 11; the central injection hole 11 is arranged at an angle, and the inclined lower end of the central injection hole 11 faces the intake side 21 of the main combustion chamber 2; the circumferential injection holes 12 are arranged at an angle, and the horizontal section where the center of the upper end of the circumferential injection hole 12 is located is a transverse section, and the connecting line between the center of the upper end of the circumferential injection hole 12 and the central axis of the pre-combustion chamber bottom 1 in the transverse section is a radial connecting line, and the angle between the projection of the central axis of the circumferential injection hole 12 in the transverse section and the radial connecting line is angle α, and the value range of angle α is 20°-35°; the angle between the projection of the circumferential injection hole 12 in the vertical plane and the central axis of the pre-combustion chamber bottom 1 is angle β, and the value range of angle β is 55°-85°.

[0064] In the present application, the central injection hole 11 is tilted and the circumferential injection holes 12 are arranged with angles α and β, which can improve the combustion effect in the main combustion chamber 2 where the intake side 21 is larger than the exhaust side 22.

[0065] The technical features of the above embodiments can be combined arbitrarily. In order to make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0066] The above-described embodiments merely represent several implementation methods of the present application. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that a person skilled in the art could make various modifications and improvements without departing from the spirit of the present application, all of which fall within the scope of protection of the present application. Therefore, the scope of protection of the present patent application shall be determined by the appended claims.

Claims

1. A pre-combustion chamber, characterized in that: The side surface of the bottom (1) of the pre-combustion chamber is provided with a central injection hole (11) communicating with the main combustion chamber (2) and a plurality of circumferential injection holes (12), and the plurality of circumferential injection holes (12) are arranged at intervals along the circumference of the central injection hole (11); The central injection hole (11) is arranged obliquely, and the inclined lower end of the central injection hole (11) faces the intake side (21) of the main combustion chamber (2); The circumferential injection hole (12) is arranged obliquely, the horizontal section where the center of the upper end of the circumferential injection hole (12) is located is a transverse section, the connecting line between the center of the upper end of the circumferential injection hole (12) and the central axis of the bottom of the pre-combustion chamber (1) in the transverse section is a radial connecting line, and the angle between the projection of the central axis of the circumferential injection hole (12) on the transverse section and the radial connecting line is an angle α, and the value range of the angle α is 20°-35°; The angle between the projection of the circumferential injection hole (12) on the vertical plane and the central axis of the pre-combustion chamber bottom (1) is an angle β, and the value range of the angle β is 55°-85°.

2. The pre-combustion chamber according to claim 1, characterized in that The plurality of circumferential injection holes (12) include: A first hole (121) faces the air intake side (21) of the main combustion chamber (2), a horizontal section where the center of the upper end of the first hole (121) is located is a first transverse section, a connecting line between the center of the upper end of the first hole (121) and the central axis of the pre-combustion chamber bottom (1) in the first transverse section is a first radial connecting line, an angle between a projection of the central axis of the first hole (121) in the first transverse section and the first radial connecting line is an angle α1, and an angle between the projection of the first hole in the vertical plane and the central axis of the pre-combustion chamber bottom (1) is an angle β1; The second hole (122) faces the exhaust side (22) of the main combustion chamber (2), the horizontal section where the center of the upper end of the second hole (122) is located is a second transverse section, the connecting line between the center of the upper end of the second hole (122) and the central axis of the pre-combustion chamber bottom (1) in the second transverse section is a second radial connecting line, the angle between the projection of the central axis of the second hole (122) in the second transverse section and the second radial connecting line is an angle α2, and the angle between the projection of the second axis in the vertical plane and the central axis of the pre-combustion chamber bottom (1) is an angle β2; The included angle α1 is greater than the included angle α2, and the included angle β1 is greater than the included angle β2.

3. The pre-combustion chamber according to claim 2, characterized in that The value range of the angle α1 is 20°-35°, the value range of the angle α2 is 20°-35°, the value range of the angle β1 is 75°-85°, and the value range of the angle β2 is 55°-65°.

4. The pre-combustion chamber according to claim 2, characterized in that The aperture of the first hole (121) is larger than the aperture of the second hole (122).

5. The pre-combustion chamber according to claim 2 or 4, characterized in that: The aperture range of the first hole (121) is 0.9 mm-1.9 mm, and the aperture range of the second hole (122) is 0.7 mm-1.7 mm.

6. The pre-combustion chamber according to claim 2, characterized in that The aperture of the central injection hole (11) is smaller than that of the first hole (121), the aperture of the central injection hole (11) is greater than or equal to the aperture of the second hole (122), and the aperture range of the central injection hole (11) is 0.7 mm-1.7 mm.

7. The pre-combustion chamber according to claim 2, characterized in that The distance between the center of the upper end of the first hole (121) and the central axis of the bottom (1) of the pre-combustion chamber is distance H1, and the distance between the center of the upper end of the second hole (122) and the central axis of the bottom (1) of the pre-combustion chamber is H2, and the distance H1 is smaller than the distance H2.

8. The pre-combustion chamber according to claim 2, characterized in that The first holes (121) are provided in three adjacent and spaced-apart arrangements, and the second holes (122) are provided in three adjacent and spaced-apart arrangements.

9. The pre-combustion chamber according to claim 1, characterized in that The included angle between the central injection hole (11) and the central axis of the pre-combustion chamber bottom (1) is an included angle θ, and the value range of the included angle θ is 15°-25°.

10. An engine, characterized in that: The invention comprises a pre-combustion chamber and a main combustion chamber (2) according to any one of claims 1 to 9, wherein the intake side (21) of the main combustion chamber (2) is larger than the exhaust side (22) of the main combustion chamber (2).

Images