Opposed piston engine and combustion system thereof

Abstract

The invention discloses an opposed piston engine and a combustion system, and belongs to the technical field of internal combustion engines, the opposed piston engine comprises an air cylinder, an air inlet piston and an exhaust piston, a cavity is formed in the air cylinder, the cavity comprises an air inlet section, a necking section and an exhaust section which are communicated in sequence, and the inner diameter of the air inlet section is larger than that of the exhaust section; the inner diameter of the necking section is gradually reduced from the air inlet section to 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 air inlet piston is arranged on the air inlet section and is in sliding connection with the air inlet section, and the air inlet piston is configured to open and close the air inlet hole; the exhaust piston is arranged on the exhaust section and slidably connected with the exhaust section, the exhaust piston is configured to be capable of opening and closing the exhaust hole, scavenging efficiency is improved, residual waste gas is reduced, 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, in particular to an opposed piston engine and a combustion system thereof. Background Art

[0002] The opposed-piston engine eliminates the traditional cylinder head structure. The two opposing piston top surfaces 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, due to the scavenging characteristics of the opposed-piston engine, a large amount of fresh air introduced into the cylinder is directly discharged from the cylinder during the scavenging process, and a large amount of exhaust gas remains in the cylinder, affecting the thermal efficiency and combustion effect. 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 engine, which is conducive to improving scavenging efficiency, reducing residual exhaust gas coefficient, and improving thermal efficiency and combustion effect.

[0005] The invention also provides a combustion system.

[0006] According to an opposed-piston engine of an embodiment of the first aspect of the present invention, the opposed-piston engine comprises: a cylinder having a cavity therein, the cavity comprising an intake section, a reduction section and an exhaust section which are connected in sequence, the inner diameter of the intake section being larger than the inner diameter of the exhaust section, the inner diameter of the reduction section gradually decreasing from the intake section to the exhaust section, the intake section being connected with an intake hole, and the exhaust section being connected with an 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; 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.

[0007] The opposed-piston engine according to the embodiment of the present invention has at least the following beneficial effects: the cavity comprises an intake section, a constriction section and an exhaust section which are connected in sequence, wherein the inner diameter of the intake section is larger than the inner diameter of the exhaust section, the two ends of the constriction section are respectively connected to the intake section and the exhaust section, and the inner diameter of the constriction section gradually decreases from the intake section to the exhaust section, that is, the inner diameter of the cavity in the cylinder is variable, and the inner diameter of the cavity decreases in sequence at the intake section, the constriction section and the exhaust section, and the intake piston can open the intake hole by sliding the intake piston in the intake section, and the exhaust piston opens the exhaust hole in cooperation with the sliding of the exhaust piston in the exhaust section, so that fresh gas enters the cavity, and under the rectifying effect of the constriction section, the fresh gas pushes the residual exhaust gas to move toward the exhaust section, which is beneficial to discharge the residual exhaust gas in the cavity, and is beneficial to reducing the amount of fresh air directly discharged from the cavity during the scavenging process, which is beneficial to improving the scavenging effect of the opposed-piston engine, and is beneficial to improving the thermal efficiency and combustion effect of the opposed-piston engine.

[0008] According to some embodiments of the present invention, a ratio of an inner diameter of the exhaust section to an inner diameter of the intake section is 0.7 to 0.9.

[0009] Specifically, the ratio of the inner diameter of the exhaust section to the inner diameter of the intake section is 0.7 to 0.9, which is beneficial to reducing the amount of fresh air discharged from the cavity and increasing the amount of residual exhaust gas discharged from the cavity, which is beneficial to improving the scavenging effect of the opposed-piston engine and improving the thermal efficiency and combustion effect of the opposed-piston engine.

[0010] According to some embodiments of the present invention, the cavity further includes an ignition chamber, which is disposed between the constricted section and the exhaust section and is in communication with the constricted 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, 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,

[0011] The length of the air inlet is shorter than the length of the air outlet.

[0012] Optionally, the cavity also includes an ignition chamber, which is arranged between the contraction section and the exhaust section and is connected to the contraction 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, and the spark plug can ignite the fuel in the main combustion chamber. 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. 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, and cooperates with the intake section to open. The fresh gas introduced into the engine and the rectifying effect of the tapered section are beneficial to improving the scavenging efficiency of the opposed-piston 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 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 more residual exhaust gas in the cavity can be discharged from the exhaust hole, which, in combination with the fresh gas introduced into the intake section and the rectifying effect of the tapered section, is beneficial to improving the scavenging efficiency of the opposed-piston 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 engine.

[0013] 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.

[0014] 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 gas introduced from the plurality of intake holes forms a rotating vortex air mass at the head of the intake piston, and the exhaust gas 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 gas, 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 engine, and improving the thermal efficiency and combustion effect of the opposed-piston engine.

[0015] 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.

[0016] Specifically, the surface opposite to the intake piston and the exhaust piston is the first surface, and correspondingly, the surface opposite to the exhaust piston and the intake piston is the second surface, one of the second surface and the first surface is a first convex portion, and the other is a first concave portion, the first convex portion is opposite to and complementary to the first concave portion, and 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, 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 engine.

[0017] 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.

[0018] 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, 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 engine, and improving the thermal efficiency and combustion effect of the opposed-piston engine.

[0019] According to some embodiments of the present invention, the first surface is provided with a first convex portion and a second concave portion adjacent to each other, and the second surface is provided with a first concave portion and a second convex portion adjacent to each other, and the second convex portion is opposite to and complementary to the second concave portion.

[0020] The first surface is provided with adjacent first convex and second concave portions, that is, the head of the first surface is concave-convex. Matchingly, the second surface is provided with adjacent first concave and second convex portions, that is, the head of the second surface is also concave-convex. When the intake piston and the exhaust piston enter the 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 the second convex portion and the second concave portion move relative to each other, which 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 engine.

[0021] According to some embodiments of the present invention, the protrusion height of the second protrusion is smaller than the protrusion height of the first protrusion; and / or,

[0022] The depth of the first recess is smaller than the depth of the second recess.

[0023] Optionally, the protruding height of the second protrusion is smaller than the protruding height of the first protrusion, which is beneficial to reduce the obstruction of the exhaust by the head protrusion of the exhaust piston, so as to ensure that more exhaust gas is discharged from the exhaust section through the exhaust hole, thereby reducing the amount of residual exhaust gas in the cavity, which is beneficial to improve the scavenging efficiency of the opposed-piston engine, and improve the thermal efficiency and combustion effect of the opposed-piston engine; optionally, the depth of the first recess is smaller than the depth of the second recess, which is beneficial to reduce the exhaust dead zone or blind spot at the exhaust piston, so as to ensure that more exhaust gas is discharged from the exhaust section through the exhaust hole, thereby reducing the amount of residual exhaust gas in the cavity, which is beneficial to improve the scavenging efficiency of the opposed-piston engine, and improve the thermal efficiency and combustion effect of the opposed-piston engine.

[0024] According to some embodiments of the present invention, the opposed-piston 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 tapered section and the exhaust section, and is connected to the tapered 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 engine also includes an injector, a spark plug and a pre-combustion chamber, and the cavity also includes an ignition chamber arranged between the constricted 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 beneficial to accelerate the mixing of oil and gas, increase the flame propagation speed, and improve the combustion efficiency. The energy burst out 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 an opposed-piston engine as shown in any one of the first aspects.

[0027] According to the combustion system of the embodiment of the present invention, there is at least the following beneficial effect: the combustion system comprises an opposed-piston engine as shown in any one of the first aspects, the cavity comprises an intake section, a constriction section and an exhaust section which are connected in sequence, wherein the inner diameter of the intake section is larger than the inner diameter of the exhaust section, the two ends of the constriction section are respectively connected to the intake section and the exhaust section, the inner diameter of the constriction section gradually decreases from the intake section to the exhaust section, that is, the inner diameter of the cavity in the cylinder is variable, and the inner diameter of the cavity decreases in sequence at the intake section, the constriction section and the exhaust section, the intake piston can open the intake hole by sliding of the intake piston in the intake section, and the exhaust piston opens the exhaust hole in cooperation with the sliding of the exhaust piston in the exhaust section, so that fresh gas enters the cavity, and under the rectifying effect of the constriction section, the fresh gas pushes the residual exhaust gas to move toward the exhaust section, which is beneficial to discharge the residual exhaust gas in the cavity, and is beneficial to reducing the amount of fresh air directly discharged from the cavity during the scavenging process, which is beneficial to improving the scavenging effect of the opposed-piston engine, and is beneficial to improving the thermal efficiency and combustion effect of the opposed-piston 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 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 engine according to an embodiment of the present invention;

[0032] Figure 3 The figure is a schematic structural diagram of a cylinder of an opposed-piston engine according to an embodiment of the present invention.

[0033] Figure Number:

[0034] 100, cylinder; 110, cavity; 111, air intake section; 1111, air intake hole; 112, constriction section; 113, ignition chamber; 1131, first mounting hole; 1132, second mounting hole; 114, exhaust section; 1141, exhaust hole; 120, main combustion chamber;

[0035] 200, intake piston; 210, first surface; 211, first convex portion; 212, second concave portion; 213, contraction section;

[0036] 300, exhaust piston; 310, second surface; 311, first concave portion; 312, second convex portion;

[0037] 410, first mounting sleeve; 411, pre-combustion chamber; 420, spark plug;

[0038] 510. Second mounting sleeve; 520. Injector. DETAILED DESCRIPTION

[0039] 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.

[0040] 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.

[0041] 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.

[0042] 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 in combination with the specific content of the technical solution.

[0043] In the related art, the opposed pistons of the opposed piston 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 engine cancels the traditional cylinder head structure, the end faces of the two pistons form the combustion chamber, and the injector and the spark plug 420 are arranged on the cylinder wall, this arrangement increases the oil beam propagation distance and the flame propagation distance, and increases the difficulty of forming the oil-gas mixture and the flame propagation.

[0044] Specifically, due to the scavenging characteristics of the opposed piston engine itself, 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 engine is low, and there is a high residual exhaust gas coefficient in the cylinder, which significantly affects the combustion effect in the cylinder.

[0045] Specifically, the opposed piston engine requires the side-mounted injector 520, which results in the injector 520 having a long jet of oil and insufficient space utilization; at the same time, the two-stroke engine has 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 engines use a configuration of 2 or 4 injectors per cylinder to improve the uniformity of oil-gas mixing in the cylinder, which increases the cost and the design difficulty.

[0046] Reference Figures 1 to 3 As shown, an opposed piston engine according to an embodiment of the present invention includes: a cylinder 100, an intake piston 200 and an exhaust piston 300.

[0047] Reference Figure 1 and Figure 3 As shown, a cavity 110 is provided in the cylinder 100, and the cavity 110 can provide space for the reciprocating motion of the intake piston 200 and the exhaust piston 300, the intake of fresh air, the exhaust of exhaust gas, and ignition. Specifically, the cavity 110 includes an intake section 111, a constricted section 112, an ignition chamber 113, and an exhaust section 114 that are connected in sequence. Taking the length direction of the cavity 110 as the left-right direction as an example, the intake section 111, the constricted section 112, the ignition chamber 113, and the exhaust section 114 are arranged in sequence from left to right.

[0048] Reference Figure 1 and Figure 3As shown, the inner diameter of the intake section 111 is larger than the inner diameter of the exhaust section 114, the inner diameter of the ignition chamber 113 is the same as the inner diameter of the exhaust section 114, the inner diameter of the tapered section 112 gradually decreases from the intake section 111 to the exhaust section 114, the intake section 111 is connected to an intake hole 1111, and the exhaust section 114 is connected to an exhaust hole 1141; that is, the inner diameter of the cavity 110 in the cylinder 100 changes gradually, and the inner diameter of the cavity 110 decreases in the intake section 111, the tapered section 112 and the exhaust section 114 in turn.

[0049] Reference Figure 1 and Figure 3 As shown, the intake piston 200 is disposed at the intake section 111 and is slidably connected to the intake section 111, and the intake piston 200 is configured to be able to open and close the intake hole 1111; the exhaust piston 300 is disposed at the exhaust section 114 and is slidably connected to the exhaust section 114, and the exhaust piston 300 is configured to be able to open and close the exhaust hole 1141.

[0050] Reference Figure 2 and Figure 3 As shown, the opposed-piston engine can open the intake hole 1111 through the sliding of the intake piston 200 in the intake section 111, and cooperate with the sliding of the exhaust piston 300 in the exhaust section 114, so that the exhaust piston 300 opens the exhaust hole 1141, allowing fresh gas to enter the cavity 110. Under the rectification effect of the constricted section 112, the fresh gas pushes the residual exhaust gas to move toward the exhaust section 114, which is beneficial to discharge the residual exhaust gas in the cavity 110 and to reduce the amount of fresh air directly discharged from the cavity 110 during the scavenging process, which is beneficial to improve the scavenging effect of the opposed-piston engine and to improve the thermal efficiency and combustion effect of the opposed-piston engine.

[0051] Reference Figure 1 and Figure 3 As shown, it can be understood that the ratio of the inner diameter of the exhaust section 114 to the inner diameter of the intake section 111 is 0.7 to 0.9, which is beneficial to increase the intake volume of the intake section 111 and increase the proportion of residual exhaust gas discharged from the cavity 110, which is beneficial to improve the scavenging effect of the opposed-piston engine and is beneficial to improve the thermal efficiency and combustion effect of the opposed-piston engine.

[0052] Reference Figure 1 and Figure 3As shown, it can be understood that the ignition chamber 113 is disposed between the constricted section 112 and the exhaust section 114, and is in communication with the constricted section 112 and the exhaust section 114, and the intake piston 200 and the exhaust piston 300 are configured to form a main combustion chamber 120 together with the ignition chamber 113. The opposed piston engine further includes a spark plug 420 and an injector 520, the injector 520 is configured to inject fuel into the main combustion chamber 120, and the spark plug 420 is configured to ignite the fuel in the main combustion chamber 120, and the energy generated by the combustion of the fuel drives the intake piston 200 and the exhaust piston 300 to expand and do work.

[0053] Reference Figure 1 and Figure 3 As shown, the distance between the intake hole 1111 and the ignition chamber 113 is greater than the distance between the exhaust hole 1141 and the ignition chamber 113. In the expansion stroke, the exhaust piston 300 opens the exhaust hole 1141 earlier than the intake piston 200 opens the intake hole 1111, so that the residual exhaust gas in the cavity 110 can be discharged from the exhaust hole 1141 to a greater extent. Combined with the fresh gas introduced into the intake section 111 and the rectifying effect of the contraction section 112, it is beneficial to improve the scavenging efficiency of the opposed-piston 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 engine.

[0054] Reference Figure 1 and Figure 3 As shown, it can be understood that the length of the intake hole 1111 is smaller than the length of the exhaust hole 1141, which is beneficial for making the opening time of the exhaust hole 1141 longer than the opening time of the intake hole 1111, so that the residual exhaust gas in the cavity 110 can be discharged from the exhaust hole 1141 to a greater extent. In combination with the fresh gas introduced into the intake section 111 and the rectifying effect of the tapered section 112, it is beneficial to improve the scavenging efficiency of the opposed-piston 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 engine.

[0055] Reference Figure 1 and Figure 3 As shown, it can be understood that a plurality of intake holes 1111 are provided, and the plurality of intake holes 1111 are circumferentially spaced around the axis of the intake section 111, and the plurality of intake holes 1111 are constructed as vortex inlets. When the intake piston 200 opens the intake hole 1111, the fresh gas introduced from the plurality of intake holes 1111 forms a rotating vortex air mass at the head of the intake piston 200, and the exhaust gas is pushed out by the vortex air mass. At the same time, the vortex characteristics of the vortex air mass are utilized to reduce the mixing of the exhaust gas and the fresh gas, thereby solving the problem of difficulty in cleaning the residual exhaust gas in the cavity 110, and is beneficial to improving the scavenging efficiency of the opposed-piston engine, and improving the thermal efficiency and combustion effect of the opposed-piston engine.

[0056] Reference Figure 1 and Figure 3 As shown, specifically, the swirl ratio of the opposed-piston engine is 2.5-4, which is beneficial to speed up the mixing speed of fuel and air, making the mixture more uniform, thereby improving combustion efficiency.

[0057] Reference Figure 1 and Figure 2 As shown, it can be understood that a plurality of exhaust holes 1141 are also provided, and the plurality of exhaust holes 1141 are circumferentially spaced around the axis of the exhaust section 114. Through the provision of the plurality of exhaust holes 1141, the residual exhaust gas in the cavity 110 can be discharged more from the exhaust holes 1141, which, in conjunction with the fresh gas introduced into the intake section 111 and the rectifying effect of the contraction section 112, is beneficial to improving the scavenging efficiency of the opposed-piston 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 engine.

[0058] Reference Figure 1 and Figure 2 As shown, it can be understood that the surface opposite to the intake piston 200 and the exhaust piston 300 is the first surface 210, and the surface opposite to the exhaust piston 300 and the intake piston 200 is the second surface 310. One of the first surface 210 and the second surface 310 is provided with a first protrusion 211, and the other is provided with a first recess 311. The first protrusion 211 and the first recess 311 are opposite and complementary to each other.

[0059] Reference Figure 1 and Figure 2 As shown, when the intake piston 200 and the exhaust piston 300 enter the compression stroke, after the intake hole 1111 and the exhaust hole 1141 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 420, a more intense combustion is formed, which is beneficial to improving the thermal efficiency and combustion effect of the opposed piston engine.

[0060] Reference Figure 1 and Figure 2 As shown, it can be understood that the first surface 210 is provided with adjacent first convex portion 211 and second concave portion 212 , and the second surface 310 is provided with adjacent first concave portion 311 and second convex portion 312 , and the second convex portion 312 is opposite to and complementary to the second concave portion 212 .

[0061] Reference Figure 1 and Figure 2As shown, the first surface 210 is provided with adjacent first convex portion 211 and second concave portion 212, that is, the head of the first surface 210 is concave-convex. Matchingly, the second surface 310 is provided with adjacent first concave portion 311 and second convex portion 312, that is, the head of the second surface 310 is also concave-convex. When the intake piston 200 and the exhaust piston 300 enter the compression stroke, after the intake hole 1111 and the exhaust hole 1141 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 212 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 effect of oil-gas mixing, and forming a more intense combustion under the ignition action of the spark plug 420, which is beneficial to improving the thermal efficiency and combustion effect of the opposed piston engine.

[0062] It should be understood that in some other embodiments, the first surface 210 is provided with a first recess 311, and the second surface 310 is provided with a first convex portion 211. When the intake piston 200 and the exhaust piston 300 enter the compression stroke, after the intake hole 1111 and the exhaust hole 1141 are closed, the first convex portion 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 420, a more intense combustion is formed, which is beneficial to improving the thermal efficiency and combustion effect of the opposed piston engine.

[0063] It should be understood that in some other embodiments, the second surface 310 is provided with a raised first bump, the first surface 210 is provided with a second bump and a third bump arranged at intervals, a pit is formed between the second bump and the third bump, and the first bump is opposite to and complementary to the pit. When the intake piston 200 and the exhaust piston 300 enter the compression stroke, after the intake hole 1111 and the exhaust hole 1141 are closed, the first bump and the pit move toward each other, which can form a strong tumble flow distributed around the axis of the cavity 110 perpendicular to the cavity 110 in the cavity 110, thereby driving the fuel and air in the cavity 110 to mix, thereby improving the effect of oil-gas mixing, and forming a more intense combustion under the ignition of the spark plug 420, which is conducive to improving the thermal efficiency and combustion effect of the opposed piston engine. The single bump design of the exhaust piston 300 is conducive to reducing or avoiding the flow dead zone formed by the airflow at the exhaust piston 300, so that more residual exhaust gas in the cavity 110 is discharged from the cavity 110.

[0064] Reference Figure 1 and Figure 2As shown, it can be understood that in this embodiment, the protruding height of the second protrusion 312 is less than the protruding height of the first protrusion 211, which is beneficial to reduce the obstruction of the exhaust corresponding to the head of the exhaust piston 300, so as to ensure that more exhaust gas is discharged from the exhaust section 114 through the exhaust hole 1141, thereby reducing the residual exhaust gas in the cavity 110, which is beneficial to improve the scavenging efficiency of the opposed-piston engine, and improve the thermal efficiency and combustion effect of the opposed-piston engine.

[0065] Reference Figure 1 and Figure 2 As shown, it can be understood that the depth of the first recess 311 is less than the depth of the second recess 212, which is beneficial to reducing the exhaust dead zone or blind zone at the exhaust piston 300 to ensure that more exhaust gas is discharged from the exhaust hole 1141 to the exhaust section 114, thereby reducing the residual exhaust gas in the cavity 110, which is beneficial to improving the scavenging efficiency of the opposed-piston engine, and improving the thermal efficiency and combustion effect of the opposed-piston engine.

[0066] Reference Figure 1 and Figure 2 As shown, in general, the fluctuation amplitude of the exhaust piston 300 at the second surface 310 is smaller than the fluctuation amplitude of the intake piston 200 at the first surface 210, which is beneficial to reducing the exhaust dead zone or blind zone at the exhaust piston 300 to ensure that more exhaust gas is discharged from the exhaust section 114 through the exhaust hole 1141, thereby reducing the residual exhaust gas in the cavity 110.

[0067] Reference Figure 1 and Figure 2 As shown, it can be understood that, specifically, a contraction section 213 is provided at the outer edge of the first surface 210, and the radial size of the contraction section 213 along the intake section 111 gradually decreases toward the direction approaching the second surface 310, that is, the size of the head of the intake piston 200 in the contraction section 213 gradually decreases toward the direction approaching the second surface 310, and the contraction section 213 can guide the gas flowing in from the intake hole 1111, thereby guiding the 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 conducive to solving the problem of difficulty in cleaning the residual exhaust gas at the center of the cavity 110, and is conducive to improving the scavenging efficiency of the opposed piston engine, and improving the thermal efficiency and combustion effect of the opposed piston engine.

[0068] Specifically, the contraction section 213 is arranged in a conical shape, and the taper of the contraction section 213 is arranged toward the second surface 310. The contraction section 213 can be connected with the necking section 112 to improve the sliding stability of the intake piston 200.

[0069] Reference Figure 1 and Figure 2As shown, it can be understood that the opposed-piston engine also includes a pre-combustion chamber 411, the first surface 210 and the second surface 310 are configured to be able to form a main combustion chamber 120 together with the ignition chamber 113, the pre-combustion chamber 411 is connected to the main combustion chamber 120, the spark plug 420 is connected to the end of the pre-combustion chamber 411 away from the main combustion chamber 120, the injector 520 is constructed to inject fuel into the main combustion chamber 120, and the spark plug 420 is constructed to ignite the fuel in the pre-combustion chamber 411.

[0070] Reference Figure 1 and Figure 2 As shown, when the intake piston 200 and the exhaust piston 300 are close to the compression top dead center, the first convex portion 211 of the first surface 210 cooperates with the first concave portion 311 of the second surface 310, and the second concave portion 212 of the first surface 210 cooperates with the second convex portion 312 of the second surface 310, so that the main combustion chamber 120 is S-shaped. Since the volume between the exhaust piston 300 and the intake piston 200 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 under the action of extrusion. The injector 520 is constructed to inject fuel into the main combustion chamber 120, and the spark plug 420 is constructed to ignite the fuel in the pre-combustion chamber 411. Under the action of turbulent kinetic energy, it is beneficial to accelerate the oil-gas mixing, increase the flame propagation speed, and improve the combustion efficiency. The energy burst by the fuel combustion drives the intake piston 200 and the exhaust piston 300 to expand and do work.

[0071] Reference Figure 1 and Figure 3 As shown, specifically, the upper end and the lower end of the ignition chamber 113 are respectively provided with a first mounting hole 1131 and a second mounting hole 1132, and the opposed-piston engine also includes a first mounting sleeve 410 and a second mounting sleeve 510, the first mounting sleeve 410 is engaged with the first mounting hole 1131, the first mounting sleeve 410 has a first cavity, the spark plug 420 is connected to the first mounting sleeve 410, and the spark plug 420 and the first cavity of the first mounting sleeve 410 jointly define a pre-combustion chamber 411, under the action of the compression stroke of the intake piston 200 and the exhaust piston 300, the mixture of fuel and air can enter the pre-combustion chamber 411 through the first mounting hole 1131, the spark plug 420 can ignite the fuel in the pre-combustion chamber 411, so that a pre-combustion flame is formed in the pre-combustion chamber 411, and the pre-combustion flame jets into the main combustion chamber 120 to enhance the ignition effect of the opposed-piston engine.

[0072] Reference Figure 1 and Figure 3As shown, the second mounting sleeve 510 is engaged with the second mounting hole 1132, and the second mounting sleeve 510 has a second cavity. The injector 520 is connected to the second mounting sleeve 510 and placed in the second cavity. The injection port of the injector 520 is arranged opposite to the second mounting hole 1132, so that the fuel is injected into the main combustion chamber 120 through the second mounting hole 1132.

[0073] A combustion system provided by an embodiment of the present invention includes an opposed piston engine as shown in any of the above embodiments. The cavity 110 includes an intake section 111, a constricted section 112, and an exhaust section 114 which are connected in sequence, wherein the inner diameter of the intake section 111 is larger than the inner diameter of the exhaust section 114, and the two ends of the constricted section 112 are respectively connected to the intake section 111 and the exhaust section 114, and the inner diameter of the constricted section 112 gradually decreases from the intake section 111 to the exhaust section 114, that is, the inner diameter of the cavity 110 in the cylinder 100 is variable, and the inner diameter of the cavity 110 decreases in sequence at the intake section 111, the constricted section 112, and the exhaust section 114, and the intake piston 200 slides in the intake section 111. 00 can open the intake hole 1111, and cooperate with the sliding of the exhaust piston 300 in the exhaust section 114, the exhaust piston 300 opens the exhaust hole 1141, so that fresh gas enters the cavity 110, and under the rectification effect of the constricted section 112, the fresh gas pushes the residual exhaust gas to move toward the exhaust section 114, which is beneficial to discharge the residual exhaust gas in the cavity 110, and is beneficial to reducing the amount of fresh air directly discharged from the cavity 110 during the scavenging process, which is beneficial to improving the scavenging effect of the opposed-piston engine, and is beneficial to improving the thermal efficiency and combustion effect of the opposed-piston engine.

[0074] A control method provided in one embodiment of the present invention is applied to the opposed-piston engine shown in any of the above embodiments. The control method comprises the following steps:

[0075] The exhaust piston 300 is designed to be 5° to 15° earlier in phase than the intake piston 200.

[0076] That is, in the working cycle of the opposed piston engine, the opening time of the exhaust port 1141 is 5° to 15° earlier than the opening time of the intake port 1111. When the intake piston 200 is at the top dead center, the exhaust piston 300 has already moved downward.

[0077] During the expansion stroke, the intake piston 200 and the exhaust piston 300 move downward respectively, the exhaust hole 1141 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.

[0078] 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 engine, characterized in that: include: A cylinder (100) is provided with a cavity (110) therein, wherein the cavity (110) comprises an intake section (111), a constricted section (112) and an exhaust section (114) which are connected in sequence, the inner diameter of the intake section (111) is greater than the inner diameter of the exhaust section (114), the inner diameter of the constricted section (112) gradually decreases from the intake section (111) to the exhaust section (114), the intake section (111) is connected to an intake hole (1111), and the exhaust section (114) is connected to an exhaust hole (1141); An air intake piston (200) is disposed on the air intake section (111) and is slidably connected to the air intake section (111), and the air intake piston (200) is configured to be able to open and close the air intake hole (1111); An exhaust piston (300) is disposed on the exhaust section (114) and is slidably connected to the exhaust section (114). The exhaust piston (300) is configured to be able to open and close the exhaust hole (1141).

2. The opposed-piston engine according to claim 1, characterized in that: The ratio of the inner diameter of the exhaust section (114) to the inner diameter of the intake section (111) is 0.7 to 0.

9.

3. The opposed-piston engine according to claim 1, characterized in that: The cavity (110) further comprises an ignition chamber (113), the ignition chamber (113) being arranged between the constricted section (112) and the exhaust section (114), and being in communication with the constricted section (112) and the exhaust section (114); the intake piston (200) and the exhaust piston (300) are configured to form a main combustion chamber (120) together with the ignition chamber (113); the distance between the intake hole (1111) and the ignition chamber (113) is greater than the distance between the exhaust hole (1141) and the ignition chamber (113); and / or, The length of the air inlet (1111) is smaller than the length of the air outlet (1141).

4. The opposed-piston engine according to claim 1, characterized in that: A plurality of the air inlet holes (1111) are provided, and the plurality of the air inlet holes (1111) are arranged at intervals around the axis of the air inlet section (111), and the plurality of the air inlet holes (1111) are constructed as vortex air inlets.

5. The opposed-piston engine according to claim 1, characterized in that: The surface of the intake piston (200) opposite to the exhaust piston (300) is a first surface (210), and the surface of the exhaust piston (300) opposite to the intake piston (200) is a second surface (310). One of the first surface (210) and the second surface (310) 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.

6. The opposed-piston engine according to claim 5, characterized in that: A contraction section (213) is provided on the outer edge of the first surface (210), and the radial dimension of the contraction section (213) along the air inlet section (111) gradually decreases in a direction approaching the second surface (310).

7. The opposed-piston engine according to claim 5, characterized in that: The first surface (210) is provided with the first convex portion (211) and the second concave portion (212) adjacent to each other, and the second surface (310) is provided with the first concave portion (311) and the second convex portion (312) adjacent to each other, and the second convex portion (312) is opposite to and complementary to the second concave portion (212).

8. The opposed-piston engine according to claim 7, characterized in that: The protruding height of the second protrusion (312) is smaller than the protruding height of the first protrusion (211); and / or, The depth of the first recess (311) is smaller than the depth of the second recess (212).

9. The opposed-piston engine according to claim 5, characterized in that: The opposed-piston engine further comprises an injector (520), a spark plug (420) and a pre-combustion chamber (411); the cavity (110) further comprises an ignition chamber (113); the ignition chamber (113) is arranged between the constricted section (112) and the exhaust section (114), and is in communication with the constricted section (112) and the exhaust section (114); the first surface (210) and the second surface (310) are configured to be able to communicate with the The ignition chamber (113) and the pre-combustion chamber (411) together constitute a main combustion chamber (120); the pre-combustion chamber (411) is connected to the main combustion chamber (120); the spark plug (420) is connected to one end of the pre-combustion chamber (411) away from the main combustion chamber (120); the injector (520) is configured to inject fuel into the main combustion chamber (120); and the spark plug (420) is configured to ignite the fuel in the pre-combustion chamber (411).

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

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