Engine assembly and vehicles having it

Abstract

This invention provides an engine assembly and a vehicle having the same. The engine assembly includes: a cylinder having a combustion chamber; an exhaust pipe connected to the cylinder, the exhaust pipe having an exhaust passage, one end of the exhaust passage having multiple exhaust ports, the exhaust passage communicating with the combustion chamber through the exhaust ports, and the other end of the exhaust passage communicating with the exhaust gas chamber; and an intake pipe connected to the cylinder, the intake pipe having an intake passage, the intake passage having multiple intake vents arranged side-by-side along the cylinder axis, the intake passage communicating with the intake vents, the intake vents communicating with the combustion chamber through multiple intake ports, and the other end of the intake passage communicating with an air source; wherein, the axis of the airflow direction of at least one intake vent is angled to the line connecting the geometric center point of the radial section of the cylinder to the geometric center point of the corresponding intake port near the combustion chamber. This solution solves the problem of poor direct-flow scavenging performance in engines.

Description

Technical Field

[0001] This invention relates to the field of engine technology, and more specifically, to an engine assembly and a vehicle having the same. Background Technology

[0002] Hydrogen, as a clean energy carrier, produces water as its main combustion byproduct, making it a carbon-neutral fuel with broad application prospects. The opposed-piston two-stroke (OP2S) engine, with its inherent structural advantages of a cylinder headless design, high power density, and low heat loss, is considered a potential architecture for hydrogen fuel. The pre-combustion chamber turbulent jet ignition technology replaces the traditional spark plug with a pre-combustion chamber. After ignition by the internal spark plug, high-energy products are injected at high speed into the main combustion chamber through the pre-combustion chamber nozzles, achieving multi-point ignition. This can improve combustion stability under lean combustion and partial load conditions, and shorten the combustion duration.

[0003] In existing technologies, opposed piston two-stroke engines use a direct current scavenging mode, where intake and exhaust occur simultaneously. However, there are usually limitations in simultaneously improving scavenging efficiency and fresh charge capture rate.

[0004] There is currently no effective solution to the aforementioned technical problems. Summary of the Invention

[0005] The main objective of this invention is to provide an engine assembly and a vehicle having the same, in order to solve the problem of poor DC scavenging performance of engines in the prior art.

[0006] To achieve the above objectives, according to one aspect of the present invention, an engine assembly is provided, comprising: a cylinder having a combustion chamber; an exhaust pipe connected to the cylinder, the exhaust pipe having an exhaust passage, one end of the exhaust passage having a plurality of exhaust ports, the exhaust passage communicating with the combustion chamber through the exhaust ports, and the other end of the exhaust passage communicating with an exhaust gas chamber; and an intake pipe connected to the cylinder, the intake pipe having an intake passage, the intake passage having a plurality of intake manifolds, the plurality of intake manifolds being arranged side by side along the cylinder axis, the intake passage communicating with the intake manifolds, the intake manifolds communicating with the combustion chamber through the plurality of intake ports, and the other end of the intake passage communicating with an air source; wherein, the axis of the intake airflow direction of at least one intake manifold is angled to the line connecting the geometric center point of the radial section of the cylinder to the geometric center point of the corresponding intake port near the combustion chamber.

[0007] Furthermore, the airflow direction of at least one of the two adjacent intake manifolds has an angle α with the line connecting the geometric center of the radial section of the cylinder to the geometric center of the corresponding intake port on the side near the combustion chamber, where 10°≤α≤40°.

[0008] Furthermore, the multiple intake manifolds include direct-flow intake manifolds and vortex intake manifolds. The direct-flow intake manifolds have multiple direct-flow intake ports, which are spaced apart along the circumference of the cylinder. The vortex intake manifolds have multiple vortex intake ports, which are spaced apart along the circumference of the cylinder. The airflow direction of the direct-flow intake ports passes through the axis of the cylinder, and the airflow direction of the vortex intake ports is angled to the line connecting the geometric center point of the radial section of the cylinder to the geometric center point of the corresponding vortex intake port near the combustion chamber.

[0009] Furthermore, the engine assembly also includes an intake piston, one end of which is connected to the crankshaft, and the other end of which is movably disposed in the cylinder along the cylinder axis. The intake piston has a top dead center position where it can move to block the intake manifold with the side wall, and a bottom dead center position where it can move to avoid the intake manifold with the side wall.

[0010] Furthermore, the direct-flow intake exhaust is located on the side closer to the crankshaft, while the vortex intake exhaust is located on the side farther from the crankshaft. The intake piston moves from the top dead center position to the bottom dead center position, and the vortex intake exhaust and the direct-flow intake exhaust are connected to the combustion chamber in sequence.

[0011] Furthermore, the intake pipe includes: an intake section, which forms a first channel, at least a portion of which extends radially along the cylinder, and one end of which is connected to an air source; and an outlet section, which is connected to the intake section, which forms a second channel, one end of which is connected to the first channel, and the other end of which is connected to the intake exhaust, and at least a portion of which extends circumferentially along the cylinder; wherein the intake section is located on one side of the outlet section, so that the first channel is located on one side of the cylinder.

[0012] Furthermore, the geometric center line of the first channel is set at a distance from the central axis parallel to the cylinder.

[0013] Furthermore, the engine assembly also includes an injector, with injection holes on the cylinder, through which the injector injects fuel into the combustion chamber.

[0014] Furthermore, a pre-combustion chamber outlet is provided on the cylinder, which is located on the side opposite to the injection port. The airflow direction of the pre-combustion chamber outlet is the same as the airflow direction of the vortex intake manifold.

[0015] According to another aspect of the present invention, a vehicle is provided having an engine assembly, the engine assembly being the aforementioned engine assembly.

[0016] By applying the technical solution of this invention, multiple intake manifolds arranged side-by-side along the cylinder axis are provided in the intake pipe, with at least one intake manifold having an intake airflow direction at a non-zero angle to the line connecting the center of the cylinder radial section to the corresponding intake port. This solves the problem of the difficulty in simultaneously improving scavenging efficiency and fresh charge capture rate in engines. The airflow entering the combustion chamber through this intake manifold forms a rotational component around the cylinder axis upon entering the combustion chamber, which slows down the axial advancement speed of the scavenging surface, reduces fresh gas short-circuiting, and thus improves the capture rate. Simultaneously, the inclined intake airflow enhances the in-cylinder vortex intensity, promotes radial scavenging of residual exhaust gas, and improves scavenging efficiency. This arrangement, through geometric optimization of a single intake structure, simultaneously achieves improved scavenging efficiency, enhanced capture rate, and strengthened in-cylinder flow field, effectively overcoming the inherent contradiction between scavenging and capture in traditional direct-flow scavenging. Attached Figure Description

[0017] The accompanying drawings, which form part of this application, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings:

[0018] Figure 1 A schematic diagram of an embodiment of an engine assembly according to the present invention is shown;

[0019] Figure 2 A schematic diagram of the structure of a first embodiment of the air intake pipe according to the present invention is shown;

[0020] Figure 3 A schematic diagram of the structure of a second embodiment of the intake pipe according to the present invention is shown;

[0021] Figure 4 A schematic diagram of a third embodiment of the intake pipe according to the present invention is shown.

[0022] The above figures include the following reference numerals:

[0023] 1. Cylinder;

[0024] 2. Exhaust pipe;

[0025] 20. Exhaust port;

[0026] 3. Air intake pipe;

[0027] 30. Air intake and exhaust;

[0028] 301. DC intake exhaust;

[0029] 302. Vortex intake exhaust;

[0030] 31. Intake section;

[0031] 310. Direct current air inlet;

[0032] 32. Exhaust section;

[0033] 320. Vortex air inlet. Detailed Implementation

[0034] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0035] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments according to this application. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0036] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such terms can be used interchangeably where appropriate so that the embodiments of this application described herein can be implemented, for example, in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0037] Exemplary embodiments according to this application will now be described in more detail with reference to the accompanying drawings. However, these exemplary embodiments may be implemented in many different forms and should not be construed as being limited to the embodiments set forth herein. It should be understood that these embodiments are provided so that the disclosure of this application is thorough and complete, and that the concept of these exemplary embodiments is fully conveyed to those skilled in the art. In the drawings, for clarity, the thickness of layers and regions may be exaggerated, and the same reference numerals are used to denote the same devices, and therefore their description will be omitted.

[0038] In addition to the limitations of existing technologies in opposing piston two-stroke engines employing a direct-flow scavenging mode where intake and exhaust occur simultaneously, improving both scavenging efficiency and fresh charge capture rate is often constrained. The following technical problems also exist:

[0039] 1. In ICG (Injected Compression Ignition Gasoline) hydrogen internal combustion engines, the passive pre-combustion chamber suffers from the accumulation of residual exhaust gas from the previous combustion cycle, which reduces the combustion rate and turbulent jet ignition energy within the pre-combustion chamber.

[0040] 2. To avoid abnormal combustion phenomena such as backfire, a strategy of injecting hydrogen after scavenging is required. The short injection window of a two-stroke engine affects the formation of the hydrogen-air mixture.

[0041] Combination Figures 1 to 4 As shown, according to a specific embodiment of this application, an engine assembly is provided.

[0042] Specifically, such as Figures 1 to 4 As shown, the engine assembly includes a cylinder 1, an exhaust pipe 2, and an intake pipe 3. The cylinder 1 has a combustion chamber. The exhaust pipe 2 is connected to the cylinder 1 and has an exhaust passage. One end of the exhaust passage has multiple exhaust ports 20, and the exhaust passage communicates with the combustion chamber through the exhaust ports 20. The other end of the exhaust passage communicates with the exhaust gas chamber. The intake pipe 3 is connected to the cylinder 1 and has an intake passage. Multiple intake vents 30 are provided on the intake passage. The multiple intake vents 30 are arranged side by side along the axial direction of the cylinder 1. The intake passage communicates with the intake vents 30, and the intake vents 30 communicate with the combustion chamber through multiple intake ports. The other end of the intake passage communicates with an air source. The axis of the intake airflow direction of at least one intake vent 30 is angled to the line connecting the geometric center point of the radial section of the cylinder 1 to the geometric center point of the corresponding intake port near the combustion chamber.

[0043] By applying the technical solution of this embodiment, multiple intake manifolds 30 arranged side-by-side along the axial direction of cylinder 1 are provided in the intake pipe 3, and the airflow direction of at least one intake manifold 30 forms a non-zero angle with the line connecting the center of the radial section of cylinder 1 to the corresponding intake port. This solves the problem of the difficulty in simultaneously improving scavenging efficiency and fresh charge capture rate in the engine. The airflow entering the combustion chamber through this intake manifold 30 forms a rotational component around the axis of cylinder 1 when entering the combustion chamber, which can slow down the axial advancement speed of the scavenging surface, reduce fresh gas short-circuiting, and thus improve the capture rate. At the same time, the inclined airflow direction can enhance the vortex intensity in the cylinder, promote the radial removal of residual exhaust gas, and improve scavenging efficiency. This arrangement, through geometric optimization of a single intake structure, can simultaneously achieve improved scavenging efficiency, enhanced capture rate, and enhanced in-cylinder flow field, effectively overcoming the inherent contradiction between scavenging and capture in traditional direct-flow scavenging.

[0044] Specifically, such as Figure 4As shown, the airflow direction of at least one of two adjacent intake ducts 30 forms an angle α with the line connecting the geometric center of the radial section of cylinder 1 to the geometric center of the corresponding intake port near the combustion chamber, where 10°≤α≤40°. The airflow direction of at least one of the two adjacent intake ducts 30 forms an angle α of 10° to 40° with the line connecting the radial center of cylinder 1 to the corresponding intake port. This controlled radial tilt guides the airflow to generate a stable and moderate circumferential rotation component upon entering the combustion chamber, enhancing the in-cylinder vortex intensity without causing airflow blockage or flow loss due to excessive angle. Setting the angle α within the aforementioned range effectively slows the axial advance speed of the scavenging surface, reduces the risk of fresh charge short-circuiting, improves the capture rate, and avoids the problems of insufficient vortex intensity and weak exhaust gas scavenging ability caused by excessively small angles. Simultaneously, this angle coordinates with the adjacent intake ducts, ensuring a reasonable spatial distribution of vortex and direct airflow, balancing intake flow rate and flow field organization. Preferably, α is 20°.

[0045] In one embodiment of this application, the engine is a two-stroke engine. By setting the tilt angle α of the airflow direction in the above embodiment, the uniformity of the in-cylinder mixture can be improved, providing favorable flow field conditions for the rapid diffusion and efficient combustion of hydrogen fuel. Thus, without increasing structural complexity and flow resistance, the scavenging efficiency and capture rate are synergistically improved.

[0046] Furthermore, such as Figure 1 , Figure 2As shown, the multiple intake sprues 30 include a direct intake sprue 301 and a vortex intake sprue 302. The direct intake sprue 301 has multiple direct intake ports 310, which are spaced apart circumferentially around the cylinder 1. The vortex intake sprue 302 has multiple vortex intake ports 320, which are also spaced apart circumferentially around the cylinder 1. The airflow direction of the direct intake ports 310 passes through the axis of the cylinder 1. The airflow direction of the vortex intake ports 320 is angled relative to the line connecting the geometric center point of the radial section of the cylinder 1 to the geometric center point of the corresponding vortex intake port 320 near the combustion chamber. By dividing the multiple intake sprues 30 into direct intake sprues 301 and vortex intake sprues 302, and respectively providing direct intake ports 310 and vortex intake ports 320, structural decoupling and coordinated control of the intake function are achieved. The direct-flow intake port 310 is uniformly arranged around the cylinder 1, with its airflow direction passing through the cylinder axis. It primarily maintains the total intake flow rate and charge coefficient, ensuring sufficient air supply to the combustion chamber. The vortex intake port 320 is also circumferentially distributed, but its airflow direction deviates from the radial centerline, forming an intake airflow with a circumferential rotational component. This actively induces the generation of in-cylinder vortices, delays the axial migration of the scavenging surface, suppresses fresh gas short-circuiting, significantly improves the capture rate, and enhances the removal of residual exhaust gas in the cylinder wall area. The parallel operation of the vortex and direct-flow intakes allows the intake system to construct a composite flow field structure without sacrificing flow rate. This ensures both scavenging efficiency and improved mixing uniformity, solving the problem of balancing scavenging efficiency and fresh charge capture rate in two-stroke engines.

[0047] Furthermore, the engine assembly also includes an intake piston. One end of the intake piston is connected to the crankshaft, and the other end is axially movable within the cylinder 1. The intake piston has a top dead center position where its sidewall blocks the intake manifold 30, and a bottom dead center position where its sidewall avoids the intake manifold 30. The intake piston, with one end connected to the crankshaft and the other end reciprocating axially within the cylinder 1, achieves periodic opening and closing of the intake manifold 30 by controlling its top and bottom dead center positions. When the intake piston reaches top dead center, its sidewall completely blocks the intake manifold 30, cutting off the intake passage and ensuring compression stroke sealing. When it reaches bottom dead center, its sidewall avoids the intake manifold 30, allowing the intake passage to remain open and enabling fresh charge to enter the combustion chamber. This structure allows the intake process to be entirely controlled by piston movement, eliminating the need for an additional valve mechanism, which aligns with the simplicity and high power density characteristics of a two-stroke engine. By precisely matching the axial position of the intake manifold 30 with the piston stroke, the timing and duration of the intake opening can be effectively controlled, ensuring that sufficient airflow is introduced during the scavenging phase and that the intake is closed in time during the initial compression phase to prevent backflow or gas backflow, thereby improving ventilation efficiency and charge utilization.

[0048] Specifically, the direct-flow intake exhaust 301 is located on the side closer to the crankshaft, while the vortex intake exhaust 302 is located on the side farther from the crankshaft. As the intake piston moves from top dead center to bottom dead center, the vortex intake exhaust 302 and the direct-flow intake exhaust 301 sequentially connect to the combustion chamber. The direct-flow intake exhaust 301 being located closer to the crankshaft and the vortex intake exhaust 302 being located farther from the crankshaft ensures that when the intake piston moves downwards from top dead center, the vortex intake exhaust 302 (far from the crankshaft) is activated first, followed by the direct-flow intake exhaust 301 (closer to the crankshaft), creating a stepped intake sequence from the outer side of the cylinder wall to the inner side. This configuration prioritizes the introduction of vortex airflow, creating a stable circumferential rotating flow field in the upper part of the combustion chamber. This effectively slows down the axial advance of the scavenging surface, improves the fresh charge capture rate, and enhances the radial removal of residual exhaust gases. Subsequently, the directly connected intake exhaust 301 supplements the axial airflow in the lower part of cylinder 1, compensating for the total intake flow loss caused by the limited cross-sectional area of ​​the vortex exhaust and maintaining a stable charge coefficient. This sequential connection matches the direction of intake piston movement, ensuring that the vortex-dominated flow field is formed in the early stages of compression, creating optimal mixing conditions for subsequent hydrogen fuel injection and pre-combustion chamber ignition.

[0049] It should be noted that the timing control in this embodiment does not require an additional drive mechanism and is achieved entirely by the natural movement of the piston. The structure is simple and reliable. Without increasing the complexity of the system, it realizes the collaborative air intake logic of first creating vortices and then supplementing the airflow, which significantly improves the scavenging efficiency, capture rate and mixing uniformity.

[0050] Furthermore, such as Figure 2 , Figure 3 As shown, the intake duct 3 includes an intake section 31 and an outlet section 32. The intake section 31 forms a first channel, at least a portion of which extends radially along the cylinder 1, with one end connected to the air source. The outlet section 32 connects to the intake section 31 and forms a second channel, with one end connected to the first channel and the other end connected to the intake manifold 30. At least a portion of the second channel extends circumferentially along the cylinder 1. The intake section 31 is located on one side of the outlet section 32, so that the first channel is located on one side of the cylinder 1. Through a segmented structural design, the intake duct 3 decouples the functions of the intake section 31 and the outlet section 32. A portion of the intake section 31 extends radially along the cylinder 1 and is directly connected to the air source. The outlet section 32 extends circumferentially around the cylinder 1, smoothly redirecting the radially input airflow and evenly distributing it to the circumferentially arranged intake manifold 30, allowing the airflow to undergo spatial redistribution before entering the combustion chamber, thus avoiding uneven local flow. By placing the intake section 31 on one side of the exhaust section 32, the entire intake pipe 3 is concentrated on one side of the cylinder 1. This allows the cross-sectional area of ​​the intake section 31 to change asymmetrically along the airflow direction, thereby achieving uneven air intake and enhancing the intensity of the intake vortex.

[0051] Specifically, such as Figure 3As shown, the geometric centerline of the first channel is positioned at a distance from the central axis parallel to cylinder 1. The geometric centerline of the first channel is offset from the central axis of cylinder 1, causing the intake airflow to shift laterally before entering the outlet section 32, forming an asymmetric flow field guiding structure. This offset design actively introduces initial momentum deflection within the intake section 31, providing pre-swirl power for the subsequent circumferential outlet airflow direction change, enhancing the rotational intensity at the vortex intake exhaust, and simultaneously weakening the radial symmetry of the direct-flow intake exhaust side, making it easier for the airflow to form a non-uniform, directional scavenging distribution when entering the combustion chamber. This configuration allows for active flow field control without relying on external guide components, solely through the offset of the channel's spatial geometry. Without increasing flow resistance, it effectively enhances the vortex generation capability in the cylinder wall region, slows down the axial movement of the scavenging surface, improves the fresh charge capture rate, and synergistically improves the exhaust gas replacement efficiency around the pre-combustion chamber.

[0052] Furthermore, the engine assembly also includes an injector. Injection holes are provided on cylinder 1, through which the injector injects fuel into the combustion chamber. The injector directly injects fuel into the combustion chamber through the injection holes on the cylinder, achieving precise fuel injection after scavenging and during the initial compression phase, avoiding the risk of backfire caused by fuel prematurely entering the intake passage or pre-combustion chamber. Simultaneously, it ensures that the fuel mixes only with fresh charge in the main combustion chamber, accelerating diffusion through the established vortex flow field, overcoming the problem of uneven mixing caused by the extremely short injection window of a two-stroke engine. The position of the injection holes is coordinated with the layout of the intake exhaust 30, aligning the fuel injection direction with the main axis of the in-cylinder vortex, enhancing the breakup and uniform distribution of fuel particles in the high-temperature airflow, and improving the consistency of the combustible mixture.

[0053] Furthermore, a pre-combustion chamber outlet is provided on cylinder 1, located on the side opposite the injection port. The airflow direction of the pre-combustion chamber outlet is the same as the airflow direction of the vortex intake duct 302. The pre-combustion chamber outlet's location opposite the injection port and its airflow direction aligned with the airflow direction of the vortex intake duct 302 ensure that the high-temperature, high-speed turbulent jet ejected from the pre-combustion chamber is sprayed along the main axis of the vortex already formed within the cylinder, coordinating with the rotating airflow within the cylinder. This configuration allows the jet to achieve stronger momentum transfer and diffusion capabilities in the vortex-dominated rotating flow field, significantly extending the flame propagation path, increasing the flame front coverage, and promoting the complete entrainment and combustion of unburned mixture. Simultaneously, this directional matching enhances the scavenging efficiency of the pre-combustion chamber area, utilizing the vortex airflow to continuously scour the area surrounding the pre-combustion chamber outlet, rapidly expelling residual exhaust gas and providing a clean, oxygen-rich environment for the next ignition.

[0054] According to another specific embodiment of this application, a vehicle is also provided, the vehicle having an engine assembly, the engine assembly being the engine assembly in the above embodiment.

[0055] This application also provides a preferred embodiment of an engine assembly, which can optimize scavenging performance indicators through the design of the intake pipe 3, optimize the scavenging efficiency of the pre-combustion chamber, regulate the in-cylinder flow field, and optimize hydrogen-air mixing.

[0056] Specifically, the intake manifold 3 of the engine assembly includes an intake section 31, an exhaust section 32, a direct intake manifold 301, and a vortex intake manifold 302. The intake section 31 is connected to the intake system, and the direct intake manifold 301 and the vortex intake manifold 302 are connected to the cylinder 1.

[0057] The wall interface agent of the intake section 31 changes asymmetrically along the airflow direction, and there is a predetermined offset between the inlet axis and the central axis parallel to the cylinder 1 to achieve uneven air intake and enhance the intake vortex intensity. Two parallel layers of intake ducts 30 are provided in the outlet section 32: an upper vortex intake duct 302 and a lower direct-flow intake duct 301. The direct-flow intake duct 301 is located on the side away from the center of the cylinder 1, and the airflow direction of the direct-flow intake port 310 passes through the axis of the cylinder 1 (i.e., the tilt angle α=0), mainly used to supplement the intake flow and ensure the charge coefficient. The vortex intake duct 302 is located on the side closer to the center of the cylinder 1, and the airflow direction of the vortex intake port 320, along with the line connecting the geometric center point of the radial section of the cylinder 1 to the geometric center point of the corresponding vortex intake port 320 near the combustion chamber, has an tilt angle α, where 10°≤α≤40°, used to generate an intake vortex rotating around the cylinder axis, forming a vortex scavenging surface.

[0058] Its working principle and beneficial effects are as follows:

[0059] The direct-flow intake exhaust 301 and the vortex intake exhaust 302 work together to improve scavenging efficiency and capture rate. The vortex intake exhaust 302 forms a vortex scavenging surface, which, compared to the direct-flow scavenging surface, has a higher velocity around the axis and a lower velocity along the axis. This effectively slows down the movement speed of the scavenging surface towards the exhaust port, thereby reducing fresh charge short-circuiting and improving the capture rate. Simultaneously, this vortex effectively removes residual exhaust gas around the cylinder wall, improving scavenging efficiency. The direct-flow intake exhaust 301 reduces the impact of the reduced total intake flow rate caused by the smaller cross-sectional area of ​​the vortex exhaust.

[0060] Targeted optimization of pre-combustion chamber scavenging: The airflow generated by the vortex intake exhaust 302 can significantly enhance the airflow velocity along the cylinder wall. This high-speed airflow region matches the nozzle layout of the passive pre-combustion chamber, effectively displacing residual exhaust gas in the pre-combustion chamber and introducing fresh charge, thereby improving the scavenging efficiency of the pre-combustion chamber and laying the foundation for subsequent high-energy ignition.

[0061] Enhanced hydrogen-air mixing: The strong in-cylinder swirl generated by the swirl intake exhaust 302 (with a significantly increased peak swirl ratio) greatly promotes hydrogen diffusion and air mixing when hydrogen is injected after scavenging, overcoming the mixing challenges posed by the short injection window of a two-stroke engine.

[0062] The vortex ratio is defined as the ratio of the angular velocity ω of the fluid inside the cylinder around its center of mass in the Z direction to the angular velocity ω of the crankshaft. CA The ratio, expressed by the formula, is:

[0063] Eddy ratio = ;

[0064] Scavenging efficiency S R The definition is: after each scavenging cycle, the mass of fresh charge in the cylinder G0 and the total mass of gas in the cylinder after scavenging G0 are equal. C The ratio, expressed by the formula, is:

[0065] S R = ;

[0066] Capture rate T E The definition is: after each scavenging cycle, the mass of fresh charge in the cylinder G0 and the mass of fresh charge delivered through the intake manifold G0 are equal. S The ratio, expressed by the formula, is:

[0067] T E = ;

[0068] Pre-combustion chamber scavenging efficiency S RPC The definition is: the mass of fresh charge in the pre-combustion chamber, G0-P, after each scavenging cycle. C Total mass G of pre-combustion chamber gas PC The ratio, expressed by the formula, is:

[0069] S RPC = .

[0070] Calculated operating conditions: 2000 r / min, intake pressure 104 kPa, exhaust pressure 100 kPa.

[0071] The vortex scavenging surface formed by the vortex intake exhaust 302 has a smaller axial velocity compared to the direct scavenging surface, which reduces the scavenging surface's movement speed in the negative axial direction. In this embodiment, the lowest point of the scavenging surface reaches the exhaust port 20 later than the original engine, reducing the short circuit of fresh charge and improving the capture rate. Compared to the original engine's direct scavenging port, the combination of the vortex intake exhaust 302 facilitates the scavenging of exhaust gas around the cylinder wall, improving scavenging efficiency.

[0072] The combined design of the vortex intake exhaust 302 and the direct-flow intake exhaust 301 results in a significantly higher airflow velocity along the cylinder wall than the original engine. This, combined with the passive pre-combustion chamber nozzle design, facilitates scavenging of residual exhaust gas in the pre-combustion chamber and the entry of fresh charge. The overall scavenging efficiency, capture rate, and pre-combustion chamber scavenging efficiency are all superior to the original engine design. It effectively organizes vortices, achieving a peak in-cylinder vortex ratio of 1.8.

[0073] As can be seen from the above description, the engine assembly in the above embodiments has the following beneficial effects:

[0074] 1) Layered intake ports to address the constraints of scavenging efficiency and capture rate: To address the challenge of simultaneously achieving high scavenging efficiency and fresh charge capture rate in opposed piston two-stroke engines, a dual-layer intake port design is implemented, consisting of a vortex intake 302 and a direct-flow intake 301, in conjunction with an optimized non-uniform intake chamber. The vortex intake 302 creates an axially oriented vortex scavenging surface (with reduced speed in the negative axial direction), minimizing fresh charge short-circuiting and improving capture rate. The direct-flow intake 301 supplements the intake flow, preventing insufficient intake due to the reduced cross-section of the vortex intake 302, ultimately achieving synergistic optimization of scavenging efficiency and capture rate.

[0075] 2) Directional control of vortex scavenging surface to improve the scavenging efficiency of the pre-combustion chamber: In response to the problem that residual exhaust gas in the passive pre-combustion chamber affects the flame propagation and ignition energy in the pre-combustion chamber, the characteristics of the scavenging surface formed by the vortex intake exhaust 302 are used to increase the airflow velocity near the cylinder wall. Combined with the pre-combustion chamber nozzle layout, the fresh charge replacement efficiency in the pre-combustion chamber is enhanced in a directional manner, the residual exhaust gas coefficient is reduced, and the combustion rate and turbulent jet ignition energy in the pre-combustion chamber are improved.

[0076] 3) Active control of in-cylinder swirl intensity to adapt to hydrogen-air mixing in short injection window: To address the problem of poor hydrogen-air mixing caused by the short injection window after hydrogen injection in a two-stroke engine, the radial inclination angle α of the swirl intake exhaust 302 and the shape design of the intake pipe 3 are used to actively increase the in-cylinder swirl ratio. The strong swirl accelerates the diffusion of hydrogen fuel and accelerates the uniform mixing of hydrogen and air, avoiding local over-rich / over-lean conditions. This is specifically designed to address the mixing challenges of hydrogen fuel under short injection window conditions.

[0077] For ease of description, spatial relative terms such as "above," "on top of," "on the upper surface of," "above," etc., are used herein to describe the spatial positional relationship of a device or feature as shown in the figures to other devices or features. It should be understood that spatial relative terms are intended to encompass different orientations in use or operation beyond the orientation of the device as described in the figures. For example, if the device in the figures were inverted, a device described as "above" or "on top of" other devices or structures would subsequently be positioned as "below" or "under" other devices or structures. Thus, the exemplary term "above" can include both "above" and "below." The device may also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatial relative descriptions used herein will be interpreted accordingly.

[0078] In addition to the above, it should be noted that the terms "one embodiment," "another embodiment," and "embodiment" used in this specification refer to specific features, structures, or characteristics described in connection with that embodiment, which are included in at least one embodiment described in the general description of this application. The appearance of the same expression in multiple places in the specification does not necessarily refer to the same embodiment. Furthermore, when a specific feature, structure, or characteristic is described in connection with any embodiment, the intention is to suggest that implementing such a feature, structure, or characteristic in conjunction with other embodiments also falls within the scope of this invention.

[0079] In the above embodiments, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions in other embodiments.

[0080] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. An engine assembly, characterized in that, include: Cylinder (1), the cylinder (1) having a combustion chamber; Exhaust pipe (2), the exhaust pipe (2) is connected to the cylinder (1), the exhaust pipe (2) has an exhaust passage, one end of the exhaust passage is provided with multiple exhaust ports (20), the exhaust passage is connected to the combustion chamber through the exhaust ports (20), and the other end of the exhaust passage is connected to the exhaust gas chamber; An intake pipe (3) is connected to the cylinder (1). The intake pipe (3) has an intake channel. Multiple intake vents (30) are provided on the intake channel. The multiple intake vents (30) are arranged side by side along the axial direction of the cylinder (1). The intake channel is connected to the intake vents (30). The intake vents (30) are connected to the combustion chamber through multiple intake ports. The other end of the intake channel is connected to an air source. Among them, the axis of the intake airflow direction of at least one of the intake outlets (30) is set at an angle to the line connecting the geometric center point of the radial section of the cylinder (1) to the geometric center point of the corresponding intake port near the combustion chamber.

2. The engine assembly according to claim 1, characterized in that, The airflow direction of at least one of the two adjacent air intakes (30) has an angle α with the line connecting the geometric center of the radial section of the cylinder (1) to the geometric center of the corresponding air intake on the side near the combustion chamber, where 10°≤α≤40°.

3. The engine assembly according to claim 1 or 2, characterized in that, The plurality of intake ducts (30) include a direct intake duct (301) and a vortex intake duct (302). The direct intake duct (301) is provided with a plurality of direct intake ports (310), which are spaced apart circumferentially along the cylinder (1). The vortex intake duct (302) is provided with a plurality of vortex intake ports (320), which are spaced apart circumferentially along the cylinder (1). The intake airflow direction of the direct intake port (310) passes through the axis of the cylinder (1), and the intake airflow direction of the vortex intake port (320) is angled to the line connecting the geometric center point of the radial section of the cylinder (1) to the geometric center point of the corresponding vortex intake port (320) near the combustion chamber.

4. The engine assembly according to claim 3, characterized in that, The engine assembly also includes an intake piston, one end of which is connected to the crankshaft, and the other end of which is movably disposed within the cylinder (1) along the axial direction of the cylinder (1). The intake piston has a top dead center position where it moves to the side wall to block the intake manifold (30), and a bottom dead center position where it moves to the side wall to avoid the intake manifold (30).

5. The engine assembly according to claim 4, characterized in that, The DC intake manifold (301) is located on the side close to the crankshaft, and the vortex intake manifold (302) is located on the side away from the crankshaft. The intake piston moves from the top dead center position to the bottom dead center position. The vortex intake manifold (302) and the DC intake manifold (301) are connected to the combustion chamber in sequence.

6. The engine assembly according to claim 4 or 5, characterized in that, The air intake pipe (3) includes: An intake section (31) is formed to enclose a first channel, at least a portion of which extends radially along the cylinder (1), and one end of the first channel is connected to the air source. The exhaust section (32) is connected to the intake section (31). The exhaust section (32) forms a second channel. One end of the second channel is connected to the first channel, and the other end of the second channel is connected to the intake outlet (30). At least part of the second channel extends circumferentially along the cylinder (1). The intake section (31) is located on one side of the exhaust section (32) so that the first channel is located on one side of the cylinder (1).

7. The engine assembly according to claim 6, characterized in that, The geometric center line of the first channel is set at a distance from the central axis parallel to the cylinder (1).

8. The engine assembly according to claim 7, characterized in that, The engine assembly also includes an injector, and the cylinder (1) has an injection hole, through which the injector injects fuel into the combustion chamber.

9. The engine assembly according to claim 8, characterized in that, The cylinder (1) is also provided with a pre-combustion chamber outlet, which is located on the side opposite to the injection hole. The airflow direction of the pre-combustion chamber outlet is the same as the airflow direction of the vortex intake (302).

10. A vehicle, characterized in that, The vehicle has an engine assembly, which is the engine assembly according to any one of claims 1-9.

Images