Opposed piston internal combustion engine and combustion system

Abstract

The invention discloses an opposed-piston internal combustion engine and a combustion system, and belongs to the technical field of internal combustion engines, the opposed-piston internal combustion engine comprises an air cylinder internally provided with a cavity, the cavity comprises an exhaust section and an air inlet section which are communicated, the length of the air inlet section is larger than that of the exhaust section, the air inlet section is communicated with an air inlet hole, and the exhaust section is communicated with an exhaust hole; the exhaust piston is arranged in the exhaust section and is in sliding connection with the exhaust section, and the exhaust piston is configured to be capable of opening and closing the exhaust hole; and the air inlet piston is arranged in the air inlet section and is in sliding connection with the air inlet section, the air inlet piston is configured to be capable of opening and closing the air inlet hole, the sliding stroke of the air inlet piston is larger than that of the exhaust piston, the oil-gas mixing effect in the cylinder is improved, and the heat efficiency and the combustion effect are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of internal combustion engines, and in particular to an opposed-piston internal combustion engine and a combustion system. Background Art

[0002] The opposed-piston internal combustion engine eliminates the traditional cylinder head structure. The top surfaces of the two opposing pistons together form a combustion chamber. Scavenging and exhaust are achieved through the reciprocating movement of the two pistons and the hole design of the cylinder.

[0003] In the related art, opposed piston internal combustion engines generally have defects such as poor oil-gas mixing and poor combustion effect in the cylinder. Summary of the invention

[0004] The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, the present invention provides an opposed piston internal combustion engine, which is conducive to improving the oil-gas mixing effect in the cylinder, and improving the thermal efficiency and combustion effect.

[0005] The invention also provides a combustion system.

[0006] According to an opposed-piston internal combustion engine of an embodiment of the first aspect of the present invention, the opposed-piston internal combustion engine comprises: a cylinder having a cavity therein, the cavity comprising an exhaust section and an intake section which are connected to each other, the length of the intake section being greater than the length of the exhaust section, the intake section being connected to an intake hole, and the exhaust section being connected to an exhaust hole; an exhaust piston disposed in the exhaust section and slidably connected to the exhaust section, the exhaust piston being configured to be able to open and close the exhaust hole; an intake piston disposed in the intake section and slidably connected to the intake section, the intake piston being configured to be able to open and close the intake hole, and the sliding stroke of the intake piston being greater than the sliding stroke of the exhaust piston.

[0007] The opposed-piston internal combustion engine according to the embodiment of the present invention has at least the following beneficial effects: the cavity of the cylinder comprises an exhaust section and an intake section which are connected to each other, the length of the intake section is greater than that of the exhaust section, the exhaust piston is arranged in the exhaust section and is slidably connected to the exhaust section, and during the sliding stroke of the exhaust piston, the exhaust piston can open and close the exhaust hole, and suitably, the intake piston is arranged in the intake section and is slidably connected to the intake section, and during the sliding stroke of the intake piston, the intake piston can open and close the intake hole to realize the scavenging of the opposed-piston internal combustion engine, and during the scavenging process, the air flow direction in the cavity is from the intake section to the exhaust section, and the length of the intake section is greater than that of the exhaust section, so that more fresh air can be passed into the cavity, thereby reducing the coefficient of residual exhaust gas in the cavity, and during the compression stroke, the intake piston closes the intake hole, and the exhaust piston closes the exhaust hole, and when the exhaust piston enters the compression stroke, the exhaust piston The movement direction of the piston is opposite to the air flow direction in the exhaust section during the scavenging process. Therefore, the movement of the exhaust piston will weaken the air flow movement in the exhaust section, causing the air flow velocity in the exhaust section to gradually decrease. The sliding stroke of the exhaust piston of the opposed-piston internal combustion engine is smaller than the sliding stroke of the intake piston. By reducing the sliding stroke of the exhaust piston, the movement speed of the exhaust piston can be reduced, thereby further achieving the effect of reducing the air flow velocity in the exhaust section. Conversely, when the intake piston enters the compression stroke, the movement direction of the intake piston is consistent with the air flow direction in the intake section during the scavenging process. By increasing the sliding stroke of the intake piston, the movement speed of the intake piston can be increased, thereby further increasing the air flow velocity in the intake section, which is beneficial to accelerate the oil-gas mixing between the intake piston and the exhaust piston, improve the oil-gas mixing effect, and thereby improve the thermal efficiency and combustion effect of the opposed-piston internal combustion engine.

[0008] According to some embodiments of the present invention, a ratio of a sliding stroke of the exhaust piston to a sliding stroke of the intake piston is 0.6 to 0.85.

[0009] Specifically, the ratio of the sliding stroke of the exhaust piston to the sliding stroke of the intake piston is 0.6 to 0.85. The opposed-piston internal combustion engine controls the sliding stroke of the exhaust piston and the sliding stroke of the intake piston, which is beneficial to controlling the movement speed of the exhaust piston and the movement speed of the intake piston. By reducing the movement speed of the exhaust piston and increasing the movement speed of the intake piston, it is beneficial to accelerate the oil-gas mixing between the intake piston and the exhaust piston, improve the oil-gas mixing effect, and thus improve the thermal efficiency and combustion effect of the opposed-piston internal combustion engine.

[0010] According to some embodiments of the present invention, the opposed piston internal combustion engine further comprises an intake side crankshaft, an intake connecting rod, an exhaust side crankshaft and an exhaust connecting rod, wherein the two ends of the intake connecting rod are respectively connected to the intake side crankshaft and the intake piston, and the two ends of the exhaust connecting rod are respectively connected to the exhaust side crankshaft and the exhaust piston;

[0011] Wherein, the length of the exhaust connecting rod is smaller than the length of the intake connecting rod; and / or, the crank radius of the exhaust side crankshaft is smaller than the crank radius of the intake side crankshaft.

[0012] Specifically, the opposed-piston internal combustion engine also includes an intake-side crankshaft and an intake connecting rod, wherein the two ends of the intake connecting rod are respectively connected to the intake-side crankshaft and the intake piston, and the intake-side crankshaft rotates in a cranked manner under the driving action of the intake connecting rod. Suitable, the opposed-piston internal combustion engine also includes an exhaust-side crankshaft and an exhaust connecting rod, wherein the two ends of the exhaust connecting rod are respectively connected to the exhaust-side crankshaft and the exhaust piston, and the exhaust-side crankshaft rotates in a cranked manner under the driving action of the exhaust connecting rod; wherein the length of the exhaust connecting rod is smaller than the length of the intake connecting rod; and / or the crank radius of the exhaust-side crankshaft is smaller than the crank radius of the intake-side crankshaft, so that the intake piston and the exhaust piston can generate different speeds during movement, so that the movement speed of the intake piston is greater than the movement speed of the exhaust piston, allowing the intake piston to cover a larger stroke in the same time, thereby increasing the intake volume, allowing more fresh air to pass into the cavity, providing more oxygen for the combustion process, and being conducive to accelerating the oil-gas mixing speed, improving the oil-gas mixing effect, so as to improve the combustion efficiency and power output of the opposed-piston internal combustion engine.

[0013] According to some embodiments of the present invention, the cavity further includes an ignition chamber, the ignition chamber is disposed between the exhaust section and the intake section, and is in communication with the exhaust section and the intake section, the intake piston and the exhaust piston are configured to form a main combustion chamber together with the ignition chamber, and the distance between the intake hole and the ignition chamber is greater than the distance between the exhaust hole and the ignition chamber; and / or,

[0014] The length of the air inlet is shorter than the length of the air outlet.

[0015] Optionally, the cavity further includes an ignition chamber, which is disposed between the intake section and the exhaust section and is connected to the intake section and the exhaust section, the intake piston and the exhaust piston are configured to form a main combustion chamber together with the ignition chamber, the injector can inject fuel into the main combustion chamber, the spark plug can ignite the fuel in the main combustion chamber, and the energy burst by the combustion of the fuel drives the intake piston and the exhaust piston to enter an expansion stroke, the distance between the intake hole and the ignition chamber is greater than the distance between the exhaust hole and the ignition chamber, and in the expansion stroke, the exhaust piston opens the exhaust hole earlier than the intake piston opens the intake hole, so that the residual exhaust gas in the cavity can be discharged from the exhaust hole to a greater extent. The exhaust gas discharged from the air holes, combined with the fresh air introduced into the air intake section, is beneficial to improving the scavenging efficiency of the opposed-piston internal combustion engine, so that more residual exhaust gas is discharged from the cavity, so as to improve the thermal efficiency and combustion effect of the opposed-piston internal combustion engine; optionally, the length of the intake hole is smaller than the length of the exhaust hole, so that the opening time of the exhaust hole is longer than the opening time of the intake hole, so that the residual exhaust gas in the cavity can be discharged from the exhaust hole to a greater extent, which is beneficial to improving the scavenging efficiency of the opposed-piston internal combustion engine by combining with the fresh air introduced into the air intake section, so that more residual exhaust gas is discharged from the cavity, so as to improve the thermal efficiency and combustion effect of the opposed-piston internal combustion engine.

[0016] According to some embodiments of the present invention, a plurality of air intake holes are provided, the plurality of air intake holes are arranged at intervals around the axis of the air intake section, and the plurality of air intake holes are configured as vortex air intakes.

[0017] Specifically, a plurality of intake holes are provided, and the plurality of intake holes are circumferentially spaced around the axis of the intake section, and the plurality of intake holes are constructed as vortex inlet ports. When the intake piston opens the intake hole, the fresh air introduced from the plurality of intake holes forms a rotating vortex air mass at the head of the intake piston, and the exhaust gas in the cavity is pushed out by the vortex air mass. At the same time, the vortex characteristics of the vortex air mass are conducive to reducing the mixing of the exhaust gas and the fresh air, thereby solving the problem of difficulty in cleaning the residual exhaust gas in the cavity, and is conducive to improving the scavenging efficiency of the opposed-piston internal combustion engine, and improving the thermal efficiency and combustion effect of the opposed-piston internal combustion engine.

[0018] According to some embodiments of the present invention, the surface opposite to the intake piston and the exhaust piston is a first surface, and the surface opposite to the exhaust piston and the intake piston is a second surface. One of the first surface and the second surface is provided with a first convex portion, and the other is provided with a first concave portion. The first convex portion is opposite to and complementary to the first concave portion.

[0019] Specifically, the surface opposite to the intake piston and the exhaust piston is a first surface, and correspondingly, the surface opposite to the exhaust piston and the intake piston is a second surface. One of the second surface and the first surface is provided with a first convex portion, and the other is provided with a first concave portion. The first convex portion is opposite to and complementary to the first concave portion. When the intake piston and the exhaust piston enter a compression stroke, after the intake port and the exhaust port are closed, the first convex portion and the first concave portion move relative to each other, and a strong tumble flow distributed around a perpendicular axis of the cavity can be formed in the cavity of the cylinder, thereby driving the fuel and air in the cavity to mix, thereby improving the effect of oil-gas mixing, and forming a more intense combustion under the ignition action of the spark plug, which is beneficial to improving the thermal efficiency and combustion effect of the opposed-piston internal combustion engine.

[0020] According to some embodiments of the present invention, a contraction section is provided at the outer edge of the first surface, and a radial dimension of the contraction section along the air inlet section gradually decreases toward the direction approaching the second surface.

[0021] Specifically, a contraction section is provided at the outer edge of the first surface, and the radial size of the contraction section along the intake section gradually decreases toward the second surface, that is, the size of the head of the intake piston in the contraction section gradually decreases toward the second surface. The contraction section can guide the gas flowing in from the intake hole, thereby guiding the gas to flow to the center of the cavity at high speed, thereby ensuring that the airflow still has a high flow rate when flowing to the center of the cavity, which is conducive to solving the problem of difficulty in cleaning residual exhaust gas in the center of the cavity, and is conducive to improving the scavenging efficiency of the opposed-piston internal combustion engine, and improving the thermal efficiency and combustion effect of the opposed-piston internal combustion engine.

[0022] According to some embodiments of the present invention, the first surface is provided with a first concave portion and a second convex portion adjacent to each other, the second convex portion is arranged around the first convex portion, and the outer edge of the second convex portion is configured as a contraction section.

[0023] Specifically, the first surface is provided with a first concave portion and a second convex portion adjacent to each other. When the intake piston and the exhaust piston enter a compression stroke, the first concave portion and the second convex portion are complementary to the first convex portion, and can form a strong tumble flow distributed around a perpendicular axis of the cavity in the cavity, and enhance the strength of the tumble flow, thereby driving the fuel and air in the cavity to mix, thereby improving the oil-gas mixing effect, and forming a more intense combustion under the ignition action of the spark plug, which is beneficial to improving the thermal efficiency and combustion effect of the opposed-piston internal combustion engine, and the first convex portion is provided on the second surface of the exhaust piston, which is beneficial to reducing the exhaust dead zone formed by the curved surface of the second surface, reducing the amount of residual exhaust gas in the exhaust section, so as to improve the combustion effect of the opposed-piston internal combustion engine.

[0024] According to some embodiments of the present invention, the opposed-piston internal combustion engine also includes an injector, a spark plug and a pre-combustion chamber, the cavity also includes an ignition chamber, the ignition chamber is arranged between the intake section and the exhaust section, and is connected to the intake section and the exhaust section, the first surface and the second surface are configured to be able to form a main combustion chamber together with the ignition chamber, the pre-combustion chamber is connected to the main combustion chamber, the spark plug is connected to one end of the pre-combustion chamber away from the main combustion chamber, the injector is constructed to inject fuel into the main combustion chamber, and the spark plug is constructed to ignite the fuel in the pre-combustion chamber.

[0025] Specifically, the opposed-piston internal combustion engine also includes an injector, a spark plug and a pre-combustion chamber, and the cavity also includes an ignition chamber arranged between the intake section and the exhaust section. When the intake piston and the exhaust piston are close to the top dead center of compression, the first surface and the second surface can form a main combustion chamber together with the ignition chamber. Since the volume between the exhaust piston and the intake piston is reduced, under the cooperation of the first convex portion and the first concave portion, the large-sized strong tumble is broken into strong turbulent kinetic energy under the extrusion action. The injector is constructed to inject fuel into the main combustion chamber, and the spark plug is constructed to ignite the fuel in the pre-combustion chamber. Under the action of turbulent kinetic energy, it is helpful to accelerate the mixing of oil and gas, increase the flame propagation speed, and improve the combustion efficiency. The energy generated by the combustion of the fuel drives the intake piston and the exhaust piston to expand and do work.

[0026] A combustion system according to an embodiment of the second aspect of the present invention comprises the opposed-piston internal combustion engine shown in the first aspect.

[0027] The combustion system according to the embodiment of the present invention has at least the following beneficial effects: the combustion system comprises an opposed-piston internal combustion engine as in the first aspect, the cavity of the cylinder comprises an exhaust section and an intake section which are connected to each other, the length of the intake section is greater than the length of the exhaust section, the exhaust piston is arranged in the exhaust section and is slidably connected to the exhaust section, during the sliding stroke of the exhaust piston, the exhaust piston can open and close the exhaust hole, suitably, the intake piston is arranged in the intake section and is slidably connected to the intake section, during the sliding stroke of the intake piston, the intake piston can open and close the intake hole to realize scavenging of the opposed-piston internal combustion engine, during the scavenging process, the air flow direction in the cavity is from the intake section to the exhaust section, the length of the intake section is greater than the length of the exhaust section, so that more fresh air can be passed into the cavity, thereby reducing the coefficient of residual exhaust gas in the cavity, and during the compression stroke, the intake piston closes the intake hole, and the exhaust piston closes the exhaust hole When the intake piston enters the compression stroke, the movement direction of the exhaust piston is opposite to the air flow direction. Therefore, the movement of the exhaust piston will weaken the air flow movement in the exhaust section, causing the air flow velocity in the exhaust section to gradually decrease. The sliding stroke of the exhaust piston of the opposed-piston internal combustion engine is smaller than the sliding stroke of the intake piston. By reducing the sliding stroke of the exhaust piston, the movement speed of the exhaust piston can be reduced, thereby further achieving the effect of reducing the air flow velocity in the exhaust section. Conversely, when the intake piston enters the compression stroke, the movement direction of the intake piston is consistent with the air flow direction. By increasing the sliding stroke of the intake piston, the movement speed of the intake piston can be increased, thereby further increasing the air flow velocity in the intake section, which is beneficial to accelerate the oil-gas mixing between the intake piston and the exhaust piston, improve the oil-gas mixing effect, and thereby improve the thermal efficiency and combustion effect of the opposed-piston internal combustion engine.

[0028] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The present invention will be further described below with reference to the accompanying drawings and embodiments, wherein:

[0030] Figure 1 It is a structural schematic diagram of an expansion stroke of an opposed-piston internal combustion engine according to an embodiment of the present invention;

[0031] Figure 2 It is a structural schematic diagram of a compression stroke of an opposed-piston internal combustion engine according to an embodiment of the present invention;

[0032] Figure 3 A schematic structural diagram of a cylinder of an opposed-piston internal combustion engine according to an embodiment of the present invention;

[0033] Figure 4 for Figure 2 FIG. 1 is a partial enlarged view of point A of the cylinder of an opposed-piston internal combustion engine.

[0034] Figure Number:

[0035] 100, cylinder; 110, cavity; 111, exhaust section; 1111, exhaust hole; 112, ignition chamber; 113, intake section; 1131, intake hole; 114, main combustion chamber; 115, first mounting hole; 116, second mounting hole;

[0036] 200, exhaust piston; 210, second surface; 211, first convex portion;

[0037] 300, intake piston; 310, first surface; 311, first concave portion; 312, second convex portion; 3121, contraction section;

[0038] 410, intake connecting rod; 420, intake side crankshaft; 430, exhaust connecting rod; 440, exhaust side crankshaft;

[0039] 510, first mounting sleeve; 520, ejector;

[0040] 610. Second mounting sleeve; 611. Pre-combustion chamber; 620. Spark plug. DETAILED DESCRIPTION

[0041] Embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0042] In the description of the present invention, it should be understood that descriptions involving orientation, such as orientation or positional relationship indicated as up, down, etc., are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0043] In the description of the present invention, "a plurality" means more than two. If there is a description of "first" or "second", it is only used for the purpose of distinguishing technical features, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features or implicitly indicating the order of the indicated technical features.

[0044] In the description of the present invention, unless otherwise clearly defined, terms such as setting, installing, connecting, etc. should be understood in a broad sense, and technicians in the relevant technical field can reasonably determine the specific meanings of the above terms in the present invention based on the specific content of the technical solution.

[0045] In the related art, the opposed pistons of the opposed piston internal combustion engine are arranged in the same cylinder, which greatly improves the compactness, power-to-weight ratio and running stability of the whole machine, and has good application prospects. However, since the opposed piston internal combustion engine cancels the traditional cylinder head structure, the end faces of the two pistons form the combustion chamber, and the injector and spark plug are arranged on the cylinder wall. This arrangement increases the oil beam propagation distance and flame propagation distance, and increases the difficulty of forming the oil-gas mixture and flame propagation.

[0046] Specifically, due to the scavenging characteristics of the opposed piston internal combustion engine, more than 40% of the fresh air is discharged from the cylinder during the scavenging process, which not only causes great waste, affects thermal efficiency, but also increases the load of the supercharger. At the same time, the scavenging efficiency of the opposed piston internal combustion engine is low, and there is a high residual exhaust gas coefficient in the cylinder, which significantly affects the combustion effect in the cylinder.

[0047] Specifically, opposed piston internal combustion engines require side-mounted injectors, which results in a long jet of oil from the injector and insufficient space utilization; at the same time, two-stroke engines have a narrow fuel injection window and a short oil-gas mixing time, so the oil-gas mixing effect in the cylinder is poor. Some opposed piston internal combustion engines use a configuration of 2 or 4 injectors per cylinder to improve the uniformity of oil-gas mixing in the cylinder, which increases costs and design difficulty.

[0048] Reference Figures 1 to 4 As shown, an opposed piston internal combustion engine according to an embodiment of the present invention includes: an injector 520 , a spark plug 620 , a cylinder 100 , an exhaust piston 200 , and an intake piston 300 .

[0049] Reference Figure 1 , Figure 2 and Figure 3 As shown, a cavity 110 is provided in the cylinder 100, and the cavity 110 can be used for fresh air to enter and exhaust gas to be discharged. Specifically, the cavity 110 includes an intake section 113, an ignition chamber 112 and an exhaust section 111 which are connected in sequence. The injector 520 is used to inject fuel into the ignition chamber 112, and the spark plug 620 is used to ignite the fuel in the ignition chamber 112.

[0050] Reference Figure 1 , Figure 2 and Figure 3As shown, the exhaust piston 200 is disposed in the exhaust section 111 and is slidably connected to the exhaust section 111. During the sliding stroke of the exhaust piston 200, the exhaust piston 200 can open and close the exhaust hole 1111. The intake piston 300 is disposed in the intake section 113 and is slidably connected to the intake section 113. During the sliding stroke of the intake piston 300, the intake piston 300 can open and close the intake hole 1131 to achieve scavenging of the opposed piston internal combustion engine. During the scavenging process, the airflow direction in the cavity 110 is from the intake section 113 to the exhaust section 111. The length of the intake section 113 is greater than the length of the exhaust section 111, so that more fresh air is passed into the cavity 110, reducing the coefficient of residual exhaust gas in the cavity 110.

[0051] Reference Figure 1 , Figure 2 and Figure 3 As shown, in the compression stroke, the intake piston 300 closes the intake hole 1131, and the exhaust piston 200 closes the exhaust hole 1111. When the exhaust piston 200 enters the compression stroke, the movement direction of the exhaust piston 200 is opposite to the airflow direction in the intake section 113 during the scavenging process. Therefore, the movement of the exhaust piston 200 will weaken the airflow movement in the intake section 113, resulting in a gradual decrease in the airflow velocity in the exhaust section 111. The sliding stroke of the exhaust piston 200 of the opposed piston internal combustion engine is smaller than the sliding stroke of the intake piston 300. By reducing the sliding stroke of the exhaust piston 200, the movement speed of the exhaust piston 200 can be reduced, further achieving the effect of reducing the airflow velocity in the exhaust section 111.

[0052] In contrast, when the intake piston 300 enters the compression stroke, the movement direction of the intake piston 300 is consistent with the air flow direction of the intake section 113 during the scavenging process. By increasing the sliding stroke of the intake piston 300, the movement speed of the intake piston 300 can be increased, so as to increase the air flow speed in the intake section 113, which is beneficial to accelerate the oil and gas mixing between the intake piston 300 and the exhaust piston 200, improve the oil and gas mixing effect, and thus improve the thermal efficiency and combustion effect of the opposed piston internal combustion engine.

[0053] Reference Figure 1 , Figure 2 and Figure 3 As shown, it can be understood that the ratio of the sliding stroke of the exhaust piston 200 to the sliding stroke of the intake piston 300 is 0.6 to 0.85. The opposed-piston internal combustion engine controls the sliding stroke of the exhaust piston 200 and the sliding stroke of the intake piston 300, which is beneficial to controlling the movement speed of the exhaust piston 200 and the movement speed of the intake piston 300. By reducing the movement speed of the exhaust piston 200 and increasing the movement speed of the intake piston 300, it is beneficial to accelerate the oil-gas mixing between the intake piston 300 and the exhaust piston 200, improve the oil-gas mixing effect, and then improve the thermal efficiency and combustion effect of the opposed-piston internal combustion engine.

[0054] It should be understood that in some other embodiments, the opposed-piston internal combustion engine may control the ratio of the length of the exhaust section 111 to the length of the intake section 113 to be 0.6 to 0.85, so that the ratio of the sliding stroke of the exhaust piston 200 to the sliding stroke of the intake piston 300 is 0.6 to 0.85.

[0055] Reference Figure 1 , Figure 2 and Figure 3 As shown, it can be understood that in this embodiment, the opposed-piston internal combustion engine also includes an intake side crankshaft 420, an intake connecting rod 410, an exhaust side crankshaft 440 and an exhaust connecting rod 430, and the two ends of the intake connecting rod 410 are respectively connected to the intake side crankshaft 420 and the intake piston 300, and the two ends of the exhaust connecting rod 430 are respectively connected to the exhaust side crankshaft 440 and the exhaust piston 200.

[0056] The length of the exhaust connecting rod 430 is smaller than that of the intake connecting rod 410, and the ratio of the length of the exhaust connecting rod 430 to the length of the intake connecting rod 410 is 0.6 to 0.85. The crank radius of the exhaust side crankshaft 440 is smaller than the crank radius of the intake side crankshaft 420, and the crank radius of the exhaust side crankshaft 440 to the crank radius of the intake side crankshaft 420 is 0.6 to 0.85.

[0057] Reference Figure 1 , Figure 2 and Figure 3 As shown, under the driving action of the intake connecting rod 410, the intake side crankshaft 420 rotates in a crank manner. The opposed piston internal combustion engine also includes an exhaust side crankshaft 440 and an exhaust connecting rod 430. The two ends of the exhaust connecting rod 430 are respectively connected to the exhaust side crankshaft 440 and the exhaust piston 200. Under the driving action of the exhaust connecting rod 430, the exhaust side crankshaft 440 rotates in a crank manner. The opposed piston internal combustion engine converts the ratio of the crank radius of the exhaust side crankshaft 440 to the intake side crankshaft 420 and the ratio of the length of the exhaust connecting rod 430 to the length of the intake connecting rod 410 into a ratio box. The ratios of the two angles are controlled to be 0.6 to 0.85, so that the intake piston 300 and the exhaust piston 200 can have different speeds during movement, so that the movement speed of the intake piston 300 is greater than the movement speed of the exhaust piston 200, allowing the intake piston 300 to cover a larger stroke in the same time, thereby increasing the intake volume of the cavity 110, allowing more fresh air to pass into the cavity 110, providing more oxygen for the combustion process, and facilitating the acceleration of the oil-gas mixing speed and improving the oil-gas mixing effect, so as to improve the combustion efficiency and power output of the opposed-piston internal combustion engine.

[0058] It should be understood that in some other embodiments, the crank radius of the exhaust side crankshaft 440 is the same as the crank radius of the intake side crankshaft 420, and the length of the exhaust connecting rod 430 is smaller than the length of the intake connecting rod 410, so that the intake piston 300 and the exhaust piston 200 can produce different speeds during movement, so that the movement speed of the intake piston 300 is greater than the movement speed of the exhaust piston 200, allowing the intake piston 300 to cover a larger stroke in the same time, thereby increasing the intake volume of the cavity 110, allowing more fresh air to pass into the cavity 110, providing more oxygen for the combustion process, and facilitating acceleration of the oil-gas mixing speed, improving the oil-gas mixing effect, so as to improve the combustion efficiency and power output of the opposed piston internal combustion engine.

[0059] It should be understood that the length of the exhaust connecting rod 430 is the same as that of the intake connecting rod 410, and the crank radius of the exhaust side crankshaft 440 is smaller than the crank radius of the intake side crankshaft 420, so that the intake piston 300 and the exhaust piston 200 can produce different speeds during movement, so that the movement speed of the intake piston 300 is greater than the movement speed of the exhaust piston 200, allowing the intake piston 300 to cover a larger stroke in the same time, thereby increasing the intake volume of the cavity 110, allowing more fresh air to pass into the cavity 110, providing more oxygen for the combustion process, and helping to accelerate the oil-gas mixing speed, improve the oil-gas mixing effect, so as to improve the combustion efficiency and power output of the opposed piston internal combustion engine.

[0060] Reference Figure 1 , Figure 2 and Figure 3 As shown, it can be understood that the intake piston 300 and the exhaust piston 200 are configured to form a main combustion chamber 114 together with the ignition chamber 112, and the distance between the intake hole 1131 and the ignition chamber 112 is greater than the distance between the exhaust hole 1111 and the ignition chamber 112.

[0061] Reference Figure 1 , Figure 2 and Figure 3 As shown, the injector 520 can inject fuel into the main combustion chamber 114, and the spark plug 620 can ignite the fuel in the main combustion chamber 114. The energy generated by the combustion of the fuel drives the intake piston 300 and the exhaust piston 200 to enter the expansion stroke. The distance between the intake hole 1131 and the ignition chamber 112 is greater than the distance between the exhaust hole 1111 and the ignition chamber 112. In the expansion stroke, the exhaust piston 200 opens the exhaust hole 1111 earlier than the intake piston 300 opens the intake hole 1131, so that the residual exhaust gas in the cavity 110 can be discharged from the exhaust hole 1111 to a greater extent. Combined with the fresh air introduced into the intake section 113, it is beneficial to improve the scavenging efficiency of the opposed-piston internal combustion engine, so that the residual exhaust gas is discharged from the cavity 110 to a greater extent, so as to improve the thermal efficiency and combustion effect of the opposed-piston internal combustion engine.

[0062] Reference Figure 1 , Figure 2 and Figure 3 As shown, it can be understood that the length of the intake hole 1131 is smaller than the length of the exhaust hole 1111, so that the opening time of the exhaust hole 1111 is longer than the opening time of the intake hole 1131, so that the residual exhaust gas in the cavity 110 can be discharged from the exhaust hole 1111 to a greater extent, and combined with the fresh air introduced into the intake section 113, it is beneficial to improve the scavenging efficiency of the opposed-piston internal combustion engine, so that the residual exhaust gas is discharged from the cavity 110 to improve the thermal efficiency and combustion effect of the opposed-piston internal combustion engine.

[0063] Reference Figure 1 , Figure 2 and Figure 3 As shown, it can be understood that, specifically, a plurality of intake holes 1131 are provided, and the plurality of intake holes 1131 are circumferentially spaced around the axis of the intake section 113, and the plurality of intake holes 1131 are constructed as vortex inlet ports. When the intake piston 300 opens the intake hole 1131, the fresh air introduced from the plurality of intake holes 1131 forms a rotating vortex air mass at the head of the intake piston 300, and the exhaust gas in the cavity 110 is pushed out by the vortex air mass. At the same time, the vortex characteristics of the vortex air mass are conducive to reducing the mixing of the exhaust gas and the fresh air, thereby solving the problem of difficulty in cleaning the residual exhaust gas in the cavity 110, and is conducive to improving the scavenging efficiency of the opposed-piston internal combustion engine, and improving the thermal efficiency and combustion effect of the opposed-piston internal combustion engine.

[0064] Reference Figure 1 , Figure 2 and Figure 3 As shown, specifically, the swirl ratio of the opposed-piston internal combustion engine is 3.5 to 5, which is beneficial to speed up the mixing speed of fuel and air, making the mixture more uniform, thereby improving combustion efficiency.

[0065] Reference Figure 1 , Figure 2 and Figure 3 As shown, it can be understood that a plurality of exhaust holes 1111 are also provided, and the plurality of exhaust holes 1111 are circumferentially spaced around the axis of the exhaust section 111. Through the provision of the plurality of exhaust holes 1111, the residual exhaust gas in the cavity 110 can be discharged more from the exhaust holes 1111, and combined with the fresh air introduced from the intake section 113, it is beneficial to improve the scavenging efficiency of the opposed-piston internal combustion engine, so that the residual exhaust gas is discharged more from the cavity 110, so as to improve the thermal efficiency and combustion effect of the opposed-piston internal combustion engine.

[0066] Reference Figure 1 , Figure 2 and Figure 3As shown, it can be understood that the air duct opening height of the exhaust hole 1111 is higher than the air duct opening height of the intake hole 1131, which helps to form a better airflow organization, improve the scavenging effect of the opposed-piston internal combustion engine, and help to better separate the exhaust gas and fresh air during the scavenging process, reduce the mixing between the two, thereby improving the scavenging efficiency.

[0067] Reference Figure 1 , Figure 2 and Figure 3 As shown, the width of the intake hole 1131 is greater than the width of the exhaust hole 1111. The opposed-piston internal combustion engine helps to reduce intake resistance and improve intake efficiency by increasing the width of the intake hole 1131, allowing more air to enter the cavity 110, thereby increasing the amount of oxygen in the cavity 110 in the cylinder 100 and improving combustion efficiency.

[0068] Reference Figure 1 , Figure 2 and Figure 4 As shown, it can be understood that the surface opposite to the intake piston 300 and the exhaust piston 200 is the first surface 310, and the surface opposite to the exhaust piston 200 and the intake piston 300 is the second surface 210. One of the first surface 310 and the second surface 210 is provided with a first protrusion 211, and the other is provided with a first recess 311. The first protrusion 211 is opposite to and complementary to the first recess 311.

[0069] Reference Figure 1 , Figure 2 and Figure 4 As shown, when the intake piston 300 and the exhaust piston 200 enter the compression stroke, after the intake hole 1131 and the exhaust hole 1111 are closed, the first protrusion 211 and the first recess 311 move relative to each other, and a strong tumble flow distributed around the axis perpendicular to the cavity 110 can be formed in the cavity 110, thereby driving the fuel and air in the cavity 110 to mix, thereby improving the oil-gas mixing effect, and under the ignition action of the spark plug 620, a more intense combustion is formed, which is beneficial to improving the thermal efficiency and combustion effect of the opposed piston internal combustion engine.

[0070] Reference Figure 1 , Figure 2 and Figure 4 As shown, it can be understood that a contraction section 3121 is provided on the outer edge of the first surface 310, and the radial dimension of the contraction section 3121 along the intake section 113 gradually decreases toward the direction approaching the second surface 210, that is, the dimension of the head of the intake piston 300 in the contraction section 3121 gradually decreases toward the direction approaching the second surface 210.

[0071] Reference Figure 1 , Figure 2 and Figure 4As shown, the contraction section 3121 can guide the gas flowing in from the air inlet 1131, thereby guiding the high-speed gas to flow to the center of the cavity 110, thereby ensuring that the airflow still has a high flow rate when flowing to the center of the cavity 110, which is beneficial to solving the problem of difficulty in cleaning the residual exhaust gas in the center of the cavity 110, and is beneficial to improving the scavenging efficiency of the opposed-piston internal combustion engine, and improving the thermal efficiency and combustion effect of the opposed-piston internal combustion engine.

[0072] Reference Figure 1 , Figure 2 and Figure 4 As shown, it can be understood that the first surface 310 is provided with a first concave portion 311 and a second convex portion 312 adjacent to each other, the second convex portion 312 is arranged around the first convex portion 211 , and the outer edge of the second convex portion 312 is configured as a contraction section 3121 .

[0073] Reference Figure 1 , Figure 2 and Figure 4 As shown, when the intake piston 300 and the exhaust piston 200 enter the compression stroke, the first recess 311 and the second protrusion 312 are complementary to the first protrusion 211, and can form a strong tumble flow distributed around the axis perpendicular to the cavity 110 in the cavity 110, and enhance the strength of the tumble flow, thereby driving the fuel and air in the cavity 110 to mix, thereby improving the oil-gas mixing effect, and forming a more intense combustion under the ignition action of the spark plug 620, which is beneficial to improving the thermal efficiency and combustion effect of the opposed-piston internal combustion engine, and the first protrusion 211 is arranged on the second surface 210 of the exhaust piston 200, which is beneficial to reducing the exhaust dead zone formed by the curved surface of the second surface 210, and is beneficial to reducing the amount of residual exhaust gas in the exhaust section 111, so as to improve the combustion effect of the opposed-piston internal combustion engine.

[0074] Specifically, the second protrusion 312 includes a first protrusion and a second protrusion, and the first protrusion and the second protrusion are respectively located at the upper end and the lower end of the first recess 311, the first protrusion is connected to the upper end of the first recess 311, and the second protrusion is connected to the lower end of the first recess 311. When the intake piston 300 and the exhaust piston 200 enter the compression stroke, the first protrusion can complement the upper end of the first protrusion 211, and the second protrusion can complement the lower end of the first protrusion 211, and can form a strong tumble flow distributed around the axis perpendicular to the cavity 110 in the cavity 110, and enhance the strength of the tumble flow, thereby driving the fuel and air in the cavity 110 to mix, thereby improving the oil-gas mixing effect, and the upper end of the first protrusion and the lower end of the second protrusion together constitute a contraction section 3121.

[0075] It should be understood that in some other embodiments, the second protrusion 312 is an annular protrusion, which is arranged around the first recess 311, and the outer edge of the annular protrusion is constructed as a contraction section 3121. When the intake piston 300 and the exhaust piston 200 enter the compression stroke, the annular protrusion can complement the outer edge of the first protrusion 211, and can form a strong tumble flow distributed around the axis perpendicular to the cavity 110 in the cavity 110, and enhance the strength of the tumble flow, thereby driving the fuel and air in the cavity 110 to mix, thereby improving the oil-gas mixing effect.

[0076] It should be understood that in some other embodiments, the first surface 310 is provided with a first protrusion 211, and the second surface 210 is provided with a first recess 311. When the intake piston 300 and the exhaust piston 200 enter the compression stroke, after the intake hole 1131 and the exhaust hole 1111 are closed, the first protrusion 211 and the first recess 311 move relative to each other, and a strong tumble flow distributed around the axis perpendicular to the cavity 110 can be formed in the cavity 110, thereby driving the fuel and air in the cavity 110 to mix, thereby improving the oil-gas mixing effect, and under the ignition action of the spark plug 620, a more intense combustion is formed, which is beneficial to improving the thermal efficiency and combustion effect of the opposed piston internal combustion engine.

[0077] It should be understood that in some other embodiments, the first surface 310 is provided with adjacent first convex portions 211 and second concave portions, that is, the head of the first surface 310 is concave-convex. Matchingly, the second surface 210 is provided with adjacent first concave portions 311 and second convex portions 312, that is, the head of the second surface 210 is also concave-convex. When the intake piston 300 and the exhaust piston 200 enter the compression stroke, after the intake hole 1131 and the exhaust hole 1111 are closed, the first convex portion 211 and the first concave portion 311 move relative to each other, and the second convex portion 312 and the second concave portion move relative to each other, which can form a strong tumble flow distributed around the axis perpendicular to the cavity 110 in the cavity 110 and enhance the strength of the tumble flow, thereby driving the fuel and air in the cavity 110 to mix, thereby improving the oil-gas mixing effect, and forming a more intense combustion under the ignition action of the spark plug 620, which is beneficial to improving the thermal efficiency and combustion effect of the opposed piston internal combustion engine.

[0078] The protruding height of the second protrusion 312 is smaller than the protruding height of the first protrusion 211, which is beneficial to reducing the obstruction of the exhaust corresponding to the head of the exhaust piston 200, so as to ensure that more exhaust gas is discharged from the exhaust section 111 through the exhaust hole 1111, thereby reducing the amount of residual exhaust gas in the cavity 110, which is beneficial to improving the scavenging efficiency of the opposed-piston internal combustion engine, and improving the thermal efficiency and combustion effect of the opposed-piston internal combustion engine.

[0079] The depth of the first recess 311 is less than the depth of the second recess, which is beneficial to reducing the exhaust dead zone or blind zone at the exhaust piston 200 to ensure that more exhaust gas is discharged from the exhaust hole 1111 to the exhaust section 111, thereby reducing the residual exhaust gas in the cavity 110, which is beneficial to improving the scavenging efficiency of the opposed-piston internal combustion engine, and improving the thermal efficiency and combustion effect of the opposed-piston internal combustion engine.

[0080] That is, in general, the fluctuation amplitude of the exhaust piston 200 at the second surface 210 is smaller than the fluctuation amplitude of the intake piston 300 at the first surface 310, which is beneficial to reducing the exhaust dead zone or blind spot at the exhaust piston 200 to ensure that more exhaust gas is discharged from the exhaust hole 1111 to the exhaust section 111, thereby reducing the residual exhaust gas in the cavity 110.

[0081] Reference Figure 1 , Figure 2 and Figure 4 As shown, it can be understood that in this embodiment, the opposed-piston internal combustion engine also includes a pre-combustion chamber 611, the first surface 310 and the second surface 210 are configured to be able to form a main combustion chamber 114 together with the ignition chamber 112, the pre-combustion chamber 611 is connected to the main combustion chamber 114, the spark plug 620 is connected to the end of the pre-combustion chamber 611 away from the main combustion chamber 114, the injector 520 is constructed to inject fuel into the main combustion chamber 114, and the spark plug 620 is constructed to ignite the fuel in the pre-combustion chamber 611.

[0082] Reference Figure 1 , Figure 2 and Figure 4 As shown, when the intake piston 300 and the exhaust piston 200 are close to the compression top dead center, the first concave portion 311 and the second convex portion 312 of the first surface 310 are matched with the first convex portion 211 of the second surface 210, so that the main combustion chamber 114 is wavy. Since the volume between the exhaust piston 200 and the intake piston 300 is reduced, the large-sized strong tumble flow is broken into strong turbulent kinetic energy under the action of the first convex portion 211 and the first concave portion 311. The injector 520 is constructed to inject fuel into the main combustion chamber 114, and the spark plug 620 is constructed to ignite the fuel in the main combustion chamber 114. Under the action of turbulent kinetic energy, it is helpful to accelerate the oil-gas mixing, increase the flame propagation speed, and improve the combustion efficiency. The energy burst out by the fuel combustion drives the intake piston 300 and the exhaust piston 200 to expand and do work.

[0083] Reference Figure 2 , Figure 3 and Figure 4As shown, specifically, the lower end and the upper end of the ignition chamber 112 are respectively provided with a first mounting hole 115 and a second mounting hole 116, and the opposed-piston internal combustion engine also includes a first mounting sleeve 510 and a second mounting sleeve 610, the first mounting sleeve 510 is engaged with the first mounting hole 115, the first mounting sleeve 510 has a first cavity, the second mounting sleeve 610 is engaged with the second mounting hole 116, and the second mounting sleeve 610 has a second cavity.

[0084] Reference Figure 2 , Figure 3 and Figure 4 As shown, the injector 520 is connected to the first mounting sleeve 510 and placed in the first cavity. The injection port of the injector 520 is arranged opposite to the first mounting hole 115, so that the fuel is injected into the main combustion chamber 114 through the first mounting hole 115.

[0085] Reference Figure 2 , Figure 3 and Figure 4 As shown, the spark plug 620 is connected to the second mounting sleeve 610, and the spark plug 620 and the second cavity of the second mounting sleeve 610 jointly define the pre-combustion chamber 611. Under the compression stroke of the intake piston 300 and the exhaust piston 200, the mixture of fuel and air can enter the pre-combustion chamber 611 through the second mounting hole 116, and the spark plug 620 can ignite the fuel in the pre-combustion chamber 611 to form a pre-combustion flame in the pre-combustion chamber 611, and the pre-combustion flame jets into the main combustion chamber 114 to enhance the ignition effect of the opposed piston internal combustion engine, so as to realize the ignition of the main combustion chamber 114 by the spark plug 620.

[0086] Reference Figure 1 , Figure 2 and Figure 4 As shown, a combustion system according to an embodiment of the present invention comprises an opposed-piston internal combustion engine as shown in any of the above embodiments.

[0087] The cavity 110 of the cylinder 100 includes an exhaust section 111 and an intake section 113 that are connected to each other. The length of the intake section 113 is greater than that of the exhaust section 111. The exhaust piston 200 is disposed in the exhaust section 111 and is slidably connected to the exhaust section 111. During the sliding stroke of the exhaust piston 200, the exhaust piston 200 can open and close the exhaust hole 1111. The intake piston 300 is disposed in the intake section 113 and is slidably connected to the intake section 113. During the sliding stroke of the intake piston 300, the intake piston 300 can open and close the exhaust hole 1111. 300 can open and close the intake hole 1131 to realize the scavenging of the opposed piston internal combustion engine. During the scavenging process, the air flow direction in the cavity 110 is from the intake section 113 to the exhaust section 111. The length of the intake section 113 is greater than the length of the exhaust section 111, so that more fresh air can be introduced into the cavity 110, reducing the coefficient of residual exhaust gas in the cavity 110. In the compression stroke, the intake piston 300 closes the intake hole 1131, the exhaust piston 200 closes the exhaust hole 1111, and the exhaust piston 200 closes the exhaust hole 1111. When entering the compression stroke, the movement direction of the exhaust piston 200 is opposite to the air flow direction of the exhaust section 111 during the scavenging process. Therefore, the movement of the exhaust piston 200 will weaken the air flow movement, resulting in a gradual decrease in the air flow velocity in the exhaust section 111. The sliding stroke of the exhaust piston 200 of the opposed-piston internal combustion engine is smaller than the sliding stroke of the intake piston 300. By reducing the sliding stroke of the exhaust piston 200, the movement speed of the exhaust piston 200 can be reduced, thereby further achieving the effect of reducing the air flow velocity in the exhaust section 111. Conversely, when the intake piston 300 enters the compression stroke, the movement direction of the intake piston 300 is consistent with the air flow direction of the intake section 113 during the scavenging process. By increasing the sliding stroke of the intake piston 300, the movement speed of the intake piston 300 can be increased, so as to further increase the air flow velocity in the intake section 113, which is beneficial to accelerate the oil-gas mixing between the intake piston 300 and the exhaust piston 200, improve the oil-gas mixing effect, and thereby improve the thermal efficiency and combustion effect of the opposed-piston internal combustion engine.

[0088] A control method provided in one embodiment of the present invention is applied to an opposed-piston internal combustion engine shown in any of the above embodiments. The control method comprises the following steps:

[0089] The exhaust piston 200 is designed to be 5° to 15° earlier in phase than the intake piston 300 .

[0090] That is, in the working cycle of the opposed piston internal combustion engine, the opening time of the exhaust port 1111 is 5° to 15° earlier than the opening time of the intake port 1131. When the intake piston 300 is at the top dead center, the exhaust piston 200 has already moved downward.

[0091] During the expansion stroke, the intake piston 300 and the exhaust piston 200 move downward respectively, the exhaust hole 1111 opens in advance, and the exhaust gas is freely exhausted to release the pressure in the cavity 110, thereby increasing the exhaust gas discharge in the free exhaust stage.

[0092] The embodiments of the present invention are described in detail above with reference to the accompanying drawings, but the present invention is not limited to the above embodiments, and various changes can be made within the knowledge scope of ordinary technicians in the relevant technical field without departing from the purpose of the present invention.

Claims

1. An opposed piston internal combustion engine, characterized in that: include: A cylinder (100) is provided with a cavity (110) therein, wherein the cavity (110) comprises an exhaust section (111) and an intake section (113) which are connected to each other, wherein the length of the intake section (113) is greater than the length of the exhaust section (111), the intake section (113) is connected to an intake hole (1131), and the exhaust section (111) is connected to an exhaust hole (1111); an exhaust piston (200), disposed in the exhaust section (111) and slidably connected to the exhaust section (111), the exhaust piston (200) being configured to be able to open and close the exhaust hole (1111); An intake piston (300) is disposed in the intake section (113) and is slidably connected to the intake section (113). The intake piston (300) is configured to be able to open and close the intake hole (1131). The sliding stroke of the intake piston (300) is greater than the sliding stroke of the exhaust piston (200).

2. The opposed-piston internal combustion engine according to claim 1, characterized in that: The ratio of the sliding stroke of the exhaust piston (200) to the sliding stroke of the intake piston (300) is 0.6 to 0.

85.

3. The opposed-piston internal combustion engine according to claim 1, characterized in that: The opposed-piston internal combustion engine further comprises an intake-side crankshaft (420), an intake connecting rod (410), an exhaust-side crankshaft (440) and an exhaust connecting rod (430); two ends of the intake connecting rod (410) are respectively connected to the intake-side crankshaft (420) and the intake piston (300); and two ends of the exhaust connecting rod (430) are respectively connected to the exhaust-side crankshaft (440) and the exhaust piston (200); Wherein, the length of the exhaust connecting rod (430) is smaller than the length of the intake connecting rod (410); and / or the crank radius of the exhaust side crankshaft (440) is smaller than the crank radius of the intake side crankshaft (420).

4. The opposed-piston internal combustion engine according to claim 1, characterized in that: The cavity (110) further comprises an ignition chamber (112), the ignition chamber (112) being arranged between the exhaust section (111) and the intake section (113), and being in communication with the exhaust section (111) and the intake section (113); the intake piston (300) and the exhaust piston (200) being configured to form a main combustion chamber (114) together with the ignition chamber (112); the distance between the intake hole (1131) and the ignition chamber (112) being greater than the distance between the exhaust hole (1111) and the ignition chamber (112); and / or, The length of the air inlet (1131) is smaller than the length of the air outlet (1111).

5. The opposed-piston internal combustion engine according to claim 1, characterized in that: A plurality of the air inlet holes (1131) are provided, and the plurality of the air inlet holes (1131) are arranged at intervals around the axis of the air inlet section (113), and the plurality of the air inlet holes (1131) are constructed as vortex air inlets.

6. The opposed-piston internal combustion engine according to claim 1, characterized in that: The surface of the intake piston (300) opposite to the exhaust piston (200) is a first surface (310), and the surface of the exhaust piston (200) opposite to the intake piston (300) is a second surface (210). One of the first surface (310) and the second surface (210) is provided with a first convex portion (211), and the other is provided with a first concave portion (311). The first convex portion (211) and the first concave portion (311) are opposite to and complementary to each other.

7. The opposed-piston internal combustion engine according to claim 6, characterized in that: A contraction section (3121) is provided on the outer edge of the first surface (310), and the radial dimension of the contraction section (3121) along the air inlet section (113) gradually decreases in a direction approaching the second surface (210).

8. The opposed-piston internal combustion engine according to claim 7, characterized in that: The first surface (310) is provided with the first concave portion (311) and the second convex portion (312) adjacent to each other, the second convex portion (312) is arranged around the first convex portion (211), and the outer edge of the second convex portion (312) is constructed as the contraction section (3121).

9. The opposed-piston internal combustion engine according to claim 6, characterized in that: The opposed-piston internal combustion engine further comprises an injector (520), a spark plug (620) and a pre-combustion chamber (611); the cavity (110) further comprises an ignition chamber (112); the ignition chamber (112) is disposed between the intake section (113) and the exhaust section (111) and is in communication with the intake section (113) and the exhaust section (111); the first surface (310) and the second surface (210) are configured to be capable of communicating with the The ignition chamber (112) and the ignition chamber (112) together constitute a main combustion chamber (114); the pre-combustion chamber (611) is connected to the main combustion chamber (114); the spark plug (620) is connected to one end of the pre-combustion chamber (611) away from the main combustion chamber (114); the injector (520) is configured to inject fuel into the main combustion chamber (114); and the spark plug (620) is configured to ignite the fuel in the pre-combustion chamber (611).

10. A combustion system, characterized in that: Comprising an opposed-piston internal combustion engine as claimed in any one of claims 1 to 9.

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