Layered piston ring and method for determining parameters of a layered piston ring

Abstract

The application provides a layered piston ring and a method for determining parameters of the layered piston ring. The layered piston ring comprises at least one set of matching structures. The matching structures comprise a first ring body and a second ring body. The first ring body is used for sealing between a cylinder wall and a piston. The second ring body is used for sealing between the cylinder wall and the piston. The first ring body has an opening part. The second ring body has a protruding part. Alternatively, the first ring body has a protruding part. The second ring body has an opening part. The opening part and the protruding part are distributed along a circumferential direction. The shape of the opening part is matched with the shape of the protruding part. The opening part and the protruding part are matched one by one. The protruding part is located in the opening part. The protruding part is limited and matched with the inner wall of the opening part. The scheme solves the problem that the service life of the piston ring is short and the piston ring is prone to breaking in the prior art.

Description

Technical Field

[0001] This application relates to the field of piston rings, and more specifically, to a layered piston ring, a method for determining the parameters of a layered piston ring, a device for determining the parameters of a layered piston ring, a computer program product, and a layered piston ring analysis system. Background Technology

[0002] In the field of internal combustion engine technology, piston rings, as one of the core components of an engine, directly affect engine efficiency, emissions, and lifespan. Traditional piston ring designs have focused on optimizing radial dimensions to improve sealing and wear resistance. However, with the development of engine technology, especially the widespread application of high-performance diesel engines, the working environment of piston rings has become increasingly harsh. High speeds, high loads, and high power densities have brought unprecedented challenges, with piston ring breakage becoming one of the key factors limiting breakthroughs in heat engine performance.

[0003] With the continuous improvement of power density, piston ring reliability has become a major bottleneck restricting engine performance. Specifically, piston rings in high-strength diesel engines are prone to breakage due to their short lifespan, which not only affects the engine's sealing performance but also leads to significant energy waste and reduced efficiency. Summary of the Invention

[0004] The main objective of this application is to provide a layered piston ring, a method for determining the parameters of a layered piston ring, a device for determining the parameters of a layered piston ring, a computer program product, and a layered piston ring analysis system, so as to at least solve the problems of short lifespan and easy breakage of piston rings in the prior art.

[0005] To achieve the above objectives, according to one aspect of this application, a layered piston ring is provided, comprising: at least one set of mating structures, the mating structures including a first ring body and a second ring body, the first ring body for sealing between a cylinder wall and a piston, and the second ring body for sealing between the cylinder wall and the piston; wherein the first ring body has an opening, and the second ring body has a protrusion, or the first ring body has the protrusion, and the second ring body has the opening, the opening and the protrusion being distributed circumferentially; wherein the shape of the opening and the protrusion are adapted to each other, the opening and the protrusion are correspondingly fitted one-to-one, the protrusion is located within the opening and the protrusion is limitedly fitted with the inner wall of the opening; wherein the outer surface of the first ring body has a plating layer, and the outer surface of the second ring body has a plating layer.

[0006] Optionally, the opening is in the shape of a ring, and the protrusion is in the shape of a cylinder.

[0007] Optionally, for internal combustion engines with a cylinder diameter greater than or equal to 150 mm, the ratio of the coating thickness to the cylinder diameter ranges from 0.55 to 0.76‰, the ratio of the height of the first ring body to the cylinder diameter ranges from 1.01 to 1.27%, and the height ratio of the first ring body to the second ring body ranges from 1.2 to 1.5; for internal combustion engines with a cylinder diameter less than 150 mm, the ratio of the coating thickness to the cylinder diameter ranges from 0.43 to 0.55‰, the ratio of the height of the first ring body to the cylinder diameter ranges from 0.84 to 1.01%, and the height ratio of the first ring body to the second ring body ranges from 1.1 to 1.3.

[0008] To achieve the above objectives, according to one aspect of this application, a method for determining the parameters of a layered piston ring is provided. The method includes: obtaining design parameters of the layered piston ring, wherein the design parameters include one or more of the following: plating thickness, ring height, number of openings, and fit clearance; the ring height being the height of the first ring body and the height of the second ring body; and the fit clearance being the limiting distance between the opening and the protrusion; obtaining the wear depth and contact stress of the layered piston ring, wherein the wear depth is the amount of material loss caused by friction in the layered piston ring, and the contact stress is the stress between the layered piston ring and the piston; and using a multi-objective optimization algorithm to optimize and adjust the design parameters until the wear depth reaches a minimum wear value and the contact stress reaches a minimum stress value, thereby obtaining updated design parameters, wherein the updated design parameters are used to construct the layered piston ring.

[0009] Optionally, obtaining the wear depth and contact stress of the layered piston ring includes: obtaining a prediction model, wherein the prediction model is a model for predicting multiple values; forming a training set by combining historical design parameters and corresponding structural health labels, and training the prediction model using the training set to obtain a piston ring prediction model, wherein the structural health labels are the historical wear depth and historical contact stress of the layered piston ring in the training set; and inputting the design parameters into the piston ring prediction model to obtain the wear depth and contact stress corresponding to the design parameters.

[0010] Optionally, after inputting the design parameters into the piston ring prediction model to obtain the wear depth and contact stress corresponding to the design parameters, the method further includes: obtaining the actual wear depth and actual contact stress, wherein the actual wear depth is the actual material loss of the layered piston ring due to friction, and the actual contact stress is the actual stress between the layered piston ring and the piston; calculating the difference between the actual wear depth and the wear depth to obtain a wear difference; calculating the difference between the actual contact stress and the contact stress to obtain a stress difference; optimizing the piston ring prediction model when the wear difference is greater than or equal to a preset wear threshold, and / or the stress difference is greater than or equal to a preset stress threshold, to obtain an optimized piston ring prediction model, wherein the optimization method includes one or more of adjusting weights, adjusting biases, adjusting model structure, feature selection, and regularization; training the optimized piston ring prediction model using the training set to obtain an updated piston ring prediction model; inputting the design parameters into the updated piston ring prediction model to obtain the wear depth and contact stress corresponding to the design parameters.

[0011] Optionally, a multi-objective optimization algorithm is used to optimize the design parameters until the wear depth reaches the minimum wear value and the contact stress reaches the minimum stress value, thus obtaining updated design parameters. This includes: using a multi-objective optimization algorithm to adjust the design parameters as variables multiple times, and obtaining the wear depth and contact stress after each adjustment; extracting the minimum value of the wear depth and the minimum value of the contact stress among multiple adjustments; and extracting the adjusted design parameters corresponding to the minimum wear depth and the minimum contact stress to obtain the updated design parameters.

[0012] According to another aspect of this application, a device for determining the parameters of a layered piston ring is provided. The device includes: a first acquisition unit for acquiring design parameters of the layered piston ring, wherein the design parameters include one or more of the following: plating thickness, ring height, number of openings, and fit clearance; the ring height is the height of the first ring body and the height of the second ring body; and the fit clearance is the limiting distance between the opening and the protrusion; a second acquisition unit for acquiring the wear depth and contact stress of the layered piston ring, wherein the wear depth is the amount of material loss caused by friction in the layered piston ring, and the contact stress is the stress between the layered piston ring and the piston; and a determination unit for using a multi-objective optimization algorithm to optimize and adjust the design parameters until the wear depth reaches the minimum wear value and the contact stress reaches the minimum stress value, thereby obtaining updated design parameters, wherein the updated design parameters are used to construct the layered piston ring.

[0013] According to another aspect of this application, a computer program product is provided, comprising a computer program that, when executed by a processor, implements the steps of a method for determining the parameters of any of the layered piston rings.

[0014] According to another aspect of this application, a layered piston ring analysis system is provided, the layered piston ring analysis system comprising: a layered piston ring, wherein the layered piston ring is any of the layered piston rings described above; and a parameter determination device for the layered piston ring, the determination device being used to execute a parameter determination method for any of the layered piston rings described above.

[0015] By applying the technical solution of this application, through a layered structural design and the fitting of the opening and protrusion, not only is the negative impact of geometric changes on fatigue life reduced, but the sealing performance and wear resistance are also improved. This design ensures that the piston ring can maintain stable performance under the extreme operating conditions of high-strength diesel engines, significantly extend its service life, and reduce the risk of fracture, thereby solving the problems of short piston ring life and easy fracture in the prior art. Attached Figure Description

[0016] The accompanying drawings, which form part of this application, are used to provide a further understanding of this application. The illustrative embodiments and descriptions of this application are used to explain this application and do not constitute an undue limitation of this application. In the drawings:

[0017] Figure 1 A schematic diagram of a traditional piston ring structure is shown;

[0018] Figure 2 A schematic diagram of the layered piston ring structure of this application is shown;

[0019] Figure 3 A schematic diagram of the upper ring structure is shown;

[0020] Figure 4 A hardware block diagram of a mobile terminal for performing a method for determining parameters of a layered piston ring according to an embodiment of this application is shown.

[0021] Figure 5 A flowchart illustrating a method for determining parameters of a layered piston ring according to an embodiment of this application is shown.

[0022] Figure 6 A schematic diagram illustrating the design process of a layered piston ring structure is shown.

[0023] Figure 7 A schematic diagram of the bench verification results is shown;

[0024] Figure 8 A structural block diagram of a device for determining the parameters of a layered piston ring according to an embodiment of this application is shown.

[0025] The above figures include the following reference numerals:

[0026] 10. Upper end face; 11. Lower end face; 12. First ring body; 13. Second ring body; 14. Opening; 15. Protrusion; 16. Plating position; 17. Ring height; 102. Processor; 104. Memory; 106. Transmission device; 108. Input / output device; 100. First acquisition unit; 200. Second acquisition unit; 300. Determination unit. Detailed Implementation

[0027] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0028] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present application.

[0029] 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 data can be interchanged where appropriate for the embodiments of this application described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover 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.

[0030] For ease of description, the following explains some of the nouns or terms used in the embodiments of this application:

[0031] Piston rings: Internal combustion engine piston rings are metal rings embedded inside the piston grooves to prevent combustion gas leakage, control oil lubrication, and conduct heat.

[0032] Piston ring-piston friction dynamics model (i.e., subsequent piston ring prediction model): The piston ring-piston friction dynamics model is a mechanical analysis framework for studying the dynamic friction behavior and stress state between the piston ring and the ring groove during engine operation.

[0033] Training samples: Training samples are the input data for the proxy model and directly determine the accuracy of the proxy model.

[0034] Proxy models: Proxy models are alternatives to complex and costly models, used for fast approximate predictions, and are commonly used in engineering optimization and simulation analysis.

[0035] Multi-objective optimization design: Multi-objective optimization design is a decision-making process that seeks the best balance among multiple conflicting design objectives and finds the optimal solution that satisfies each objective through optimization algorithms.

[0036] Ring fatigue strength test: The ring fatigue strength test is a test of the piston ring’s resistance to crack initiation and propagation under alternating stress by simulating cyclic loads under actual working conditions, and to evaluate its durability and reliability.

[0037] Traditional piston ring structures typically improve sealing through structural optimization. However, under the extreme operating conditions of modern high-performance diesel engines, the effect of minute changes in the geometric features of the ring end face on fatigue life differs by orders of magnitude compared to changes in radial dimensions. This discovery overturns the traditional design theory's understanding of the equivalence of wear modes, necessitating a more rational piston ring structure.

[0038] The conventional structure of a traditional piston ring is as follows: Figure 1As shown, a notched annular structure is illustrated, with the annular structure distinguishing an upper end face 10 and a lower end face 11. Under normal conditions, small changes in the geometric features of the piston ring's end face can have a difference in magnitude in terms of fatigue life reduction. This invention addresses the technical problem of piston ring fracture in the prior art by providing a layered piston ring to overcome the shortcomings of the prior art.

[0039] As described in the background section, piston rings in the prior art have a short lifespan and are prone to breakage. To solve the above problems, embodiments of this application provide a layered piston ring, a method for determining the parameters of a layered piston ring, a device for determining the parameters of a layered piston ring, a computer program product, and a layered piston ring analysis system.

[0040] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention.

[0041] This application provides a layered piston ring, such as Figure 2 As shown, the layered piston ring includes:

[0042] At least one set of mating structures, the mating structures including a first ring 12 and a second ring 13, the first ring 12 for sealing between the cylinder wall and the piston, the second ring 13 for sealing between the cylinder wall and the piston; wherein the first ring has an opening 14, the second ring has a protrusion 15, or the first ring 12 has the protrusion 15, the second ring 13 has the opening 14, the opening 14 and the protrusion 15 are distributed circumferentially; wherein the opening 14 and the protrusion 15 are adapted in shape, the opening 14 and the protrusion 15 are in one-to-one correspondence, the protrusion 15 is located within the opening 14 and the protrusion 15 is limited by the inner wall of the opening 14; wherein the outer surface of the first ring has a coating, the outer surface of the second ring has a coating.

[0043] This embodiment, through a layered structural design and the fitting of the opening and protrusion, not only reduces the negative impact of geometric changes on fatigue life of the ring end face, but also improves sealing performance and wear resistance. This design ensures that the piston ring maintains stable performance under the extreme operating conditions of high-performance diesel engines, significantly extends its service life, and reduces the risk of breakage, thereby solving the problems of short piston ring life and easy breakage in the prior art.

[0044] The first ring has an opening, and the second ring has a protrusion, or vice versa. This structural design allows the protrusion to be embedded in the opening, forming a precise guide and stable fit. This ensures the stability of the relative position of the two rings during the high-speed reciprocating motion of the piston, reducing uneven friction or sealing failure caused by eccentricity or tilting.

[0045] The openings and protrusions are distributed circumferentially, which means that they are evenly spaced on the circumference of the ring body. This can evenly distribute the pressure and friction force on the piston ring during operation, avoid local stress concentration, and thus reduce the risk of breakage.

[0046] The shapes of the opening and the protrusion are matched to ensure a tight fit between the two rings. When the protrusion is located inside the opening, the limiting fit between the two can effectively reduce relative movement, reduce wear, and to a certain extent compensate for thermal expansion, avoiding the increased possibility of breakage due to expansion jamming at high temperatures.

[0047] Specifically, the layered structure design more effectively disperses heat flow and stress, reducing thermal stress and contact fatigue in individual rings, thus significantly extending piston ring life. The design of the openings and protrusions ensures the relative stability of the rings during high-speed movement, reducing piston ring positional shifts caused by piston movement. Simultaneously, the limiting effect of the openings and protrusions maintains good sealing even under wear or thermal expansion conditions, reducing leakage and improving engine efficiency and reliability. The precise fit between the openings and protrusions significantly reduces the fretting amplitude of the lower end face of the ring, thereby reducing friction and wear and extending piston ring fatigue life.

[0048] The above embodiments emphasize at least one mating structure consisting of a first ring (hereinafter referred to as the upper ring) and a second ring (hereinafter referred to as the lower ring). The upper ring primarily undertakes the sealing task inside the cylinder, preventing high-pressure gas leakage and also transferring heat. The upper ring assists in sealing and focuses on managing the heat flow path, enhancing its thermal stability through a coating. The mating of the upper rings more effectively disperses heat flow, reduces the thermal load on individual rings, and lowers the risk of breakage. Openings and protrusions are arranged circumferentially along the rings. The opening exists in one ring, while the other ring has a protrusion at its corresponding position. This design ensures a stable connection between the rings while allowing for thermal expansion compensation, reducing uneven friction caused by eccentricity or tilting. The precise mating mechanism between the opening and the protrusion ensures stable contact and restraint between them. The design of the opening matches the shape of the protrusion, which, when the piston ring is subjected to external force, reduces the degree of ring deformation by restraining the inner wall of the opening through the protrusion, preventing excessive expansion or contraction of the ring under high-pressure gas, thereby reducing wear.

[0049] The first ring has a gap, and the second ring also has a gap. The gap can be used to accommodate deformation.

[0050] The shapes of the openings and protrusions are meticulously designed to perfectly match and form a tight mechanical fit. The opening can be a rectangular notch, and the corresponding protrusion is a raised portion that seamlessly fills this notch, ensuring a tight fit that will not easily separate. Each opening has a corresponding protrusion to mate with it. For example, if openings are placed every 90 degrees, then protrusions will also be placed at the same interval, ensuring that each opening has a protrusion to fill and limit its movement. This one-to-one fit ensures uniform contact and stability between the rings. Multiple mating structures can be used, not limited to two.

[0051] like Figure 2 As shown, the first ring body has 4 openings, and the second ring body has 4 protrusions.

[0052] In another implementation, the opening can be located on either the first or second ring; that is, the design of the upper and lower rings is not a single structure. The upper ring can have both an opening and a protrusion; both forms are possible.

[0053] In this embodiment, the layered piston ring, through the combination of the upper and lower ring bodies, can distribute the load and thermal stress borne by the piston ring during reciprocating motion to the two ring bodies, thereby reducing the stress borne by each ring body, reducing the thermal stress concentration of a single ring body, and thus extending the life of the piston ring.

[0054] Piston rings are a critical component of internal combustion engines, and their reliability is essential for the engine's stability. Piston ring breakage is a key failure mode. Traditional theoretical frameworks attribute ring breakage primarily to two factors: insufficient material strength and fatigue of the outer surface contact. Based on this, technical improvements have focused on adjusting the clearance. However, practice shows that such improvements have limited effectiveness in dealing with the extreme operating conditions of modern high-performance diesel engines. Especially with the continuous increase in power density, piston ring breakage has become a key bottleneck restricting breakthroughs in heat engine efficiency. Therefore, providing a more effective piston ring structure is of great significance.

[0055] Compared to changes in radial dimensions, minute alterations to the geometry of the lower end face of the piston ring have an order-of-magnitude difference in their impact on fatigue life. This finding overturns the traditional design theory's understanding of the equivalence of wear modes. Existing piston ring design paradigms, failing to adequately consider this failure mechanism, struggle to achieve breakthrough improvements in reliability metrics in practical engineering applications. This invention aims to propose a high-strength, layered piston ring structure to address the piston ring breakage problem in the context of continuously increasing power density.

[0056] The key feature of the layered piston ring of this invention is that it comprises upper and lower rings. In one embodiment, the upper ring is a rectangular ring with a rectangular cross-section, and small cylindrical positioning holes (i.e., openings) are arranged on the ring at regular intervals. These holes are symmetrically arranged from left to right, with the center of the piston ring opening as the starting point. Taking four-hole positioning as an example, the arrangement of the positioning holes is as follows... Figure 3 As shown, the dashed line indicates the starting position of the axial direction. The lower ring is a rectangular cross-section with a corresponding mating cylinder on it, the height of which matches the depth of the upper ring's cylindrical hole. The two rings fit tightly together. The double-layer structure disperses the heat flow path, reducing the thermal stress of individual rings, which is particularly beneficial to the thermal stability of the lower ring's coating. Furthermore, the double-layer structure allows for graded control of airtightness. The upper ring typically handles the main gas sealing, while the lower ring's coating design focuses on auxiliary sealing functions; together, they enable dynamic pressure gradient management. The cylindrical and hole-fitting design of the two rings provides precise guidance and stability, ensuring a stable relative position during high-speed reciprocating motion and reducing uneven friction or leakage caused by eccentricity or tilting. Additionally, the clearance fit design also provides thermal expansion compensation, preventing jamming due to expansion at high temperatures while maintaining sealing. The coating on the lower end face of the upper ring reduces boundary friction between the lower end face and the ring groove, reducing power loss and better mitigating the impact of fretting wear on the geometric features of the lower end face of the ring on fatigue life.

[0057] The outer surface of the first ring body and the outer surface of the second ring body are both coated. The coating location 16 is as follows. Figure 2 As shown. The ring height is 17 (the height of the ring body). Figure 2 As shown. Specifically, the presence of the coating significantly reduces boundary friction and extends fatigue fracture life. The coefficient of friction between the outer surface of the piston ring and the cylinder wall is significantly reduced, decreasing power loss during operation and enhancing the ring's resistance to thermal stress and contact fatigue. The coating on the upper ring, in particular, plays a crucial role in reducing fretting wear, thus significantly improving the overall fatigue strength and reliability of the piston ring. The outer surface of the rings is coated; this design aims to reduce friction between the piston ring and the cylinder wall, improving wear resistance and thermal stability. The coating not only reduces direct contact between the ring and the cylinder wall, lowering friction and reducing wear, but also provides additional heat dissipation and corrosion protection, helping to maintain the structural integrity and reliability of the piston ring under high temperature and high pressure environments.

[0058] In one embodiment of this application, the shape of the opening is roughly annular, and the shape of the protrusion is roughly cylindrical.

[0059] Specifically, the design of the ring and cylinder conforms to the assembly principles of mechanical parts, providing precise guidance and contact. In the high-speed reciprocating motion of the piston ring, this shape fit helps to reduce sealing problems caused by eccentricity, tilting or thermal expansion, ensuring the reliability of the piston ring under long-term, high-intensity operating conditions.

[0060] In the above embodiments, the high compatibility between the ring-like and cylindrical parts allows for uniform contact pressure along the circumference of the ring body, reducing local stress concentration and preventing uneven wear at the ring opening. The cylindrical shape of the protrusion provides precise guidance and rigid support in the axial direction, reducing radial wobble of the piston ring, enhancing the stability of the entire piston ring system, avoiding additional friction and wear caused by positional misalignment, and extending the service life of the piston ring. Through the limiting fit design of the opening and protrusion, good sealing performance can be maintained even when the piston ring is thermally expanded or compressed, especially under alternating positive and negative pressure, reducing gas leakage and improving engine reliability.

[0061] The opening is designed in a near-annular shape, meaning it forms an approximately annular notch or groove on the ring body, while the protrusion is cylindrical, allowing it to be precisely inserted into the corresponding opening to achieve a stable connection and seal between the ring bodies. This design ensures that the piston rings maintain good mechanical properties and airtightness under different pressures, reducing fretting wear and extending fatigue life even under extreme operating conditions.

[0062] In the design of layered piston rings, besides the annular shape of the opening and the cylindrical shape of the protrusion, the shapes of the opening and protrusion can vary depending on different operating conditions and design requirements. To accommodate greater radial deformation and thermal expansion, the opening can be designed as an ellipse, while the protrusion is designed as an elliptical cone shape to match its shape. This design allows the ring to expand more freely during thermal expansion, and the conical design of the protrusion provides better guidance and restraint, especially when the ring is subjected to uneven stress, thus better maintaining sealing performance. In scenarios requiring additional airtightness, a V-shaped opening and V-shaped protrusion can be designed. When the V-shaped protrusion is inserted into the V-shaped opening, it forms a tighter contact. This design can significantly improve airtightness and thermal sealing performance, especially under high pressure conditions, where the V-shaped opening can further compress as the pressure increases, improving the sealing effect.

[0063] Of course, it can also be trapezoidal, wavy, sawtooth, or wedge-shaped.

[0064] The trapezoidal opening and trapezoidal protrusion design provides better mechanical stability. When the trapezoidal protrusion is inserted into the trapezoidal opening, a stable contact is formed. At the same time, the trapezoidal design helps to reduce the radial displacement of the ring body during reciprocating motion, improving the consistency and reliability of the seal.

[0065] The design of the wavy openings and protrusions is suitable for environments requiring higher compressive strength and wear resistance. The wavy ring openings and protrusions can reduce single-point wear by increasing the contact area and dispersing pressure, thereby improving the overall mechanical strength and lifespan of the ring.

[0066] The serrated opening and serrated protrusion design improves sealing and guidance by increasing friction between the opening and the protrusion. The serrated design allows the ring to expand along the serrated path when thermally expanded, reducing the ring jamming or twisting caused by expansion. At the same time, the serrated protrusion can better fit into the opening, forming a stable mechanical connection.

[0067] The wedge design automatically adjusts the sealing effect according to pressure changes. The opening is wedge-shaped, and the protrusion is also wedge-shaped. When the piston ring is subjected to high-pressure gas or liquid, the wedge-shaped protrusion further compresses the wedge-shaped opening, thereby increasing the sealing pressure. This design is particularly suitable for sealing requirements in high-pressure environments.

[0068] In one embodiment of this application, for an internal combustion engine with a cylinder diameter greater than or equal to 150 mm, the ratio of the coating thickness to the cylinder diameter ranges from 0.55 to 0.76‰, the ratio of the height of the first ring body to the cylinder diameter ranges from 1.01 to 1.27%, and the height ratio of the first ring body to the second ring body ranges from 1.2 to 1.5; for an internal combustion engine with a cylinder diameter less than 150 mm, the ratio of the coating thickness to the cylinder diameter ranges from 0.43 to 0.55‰, the ratio of the height of the first ring body to the cylinder diameter ranges from 0.84 to 1.01%, and the height ratio of the first ring body to the second ring body ranges from 1.1 to 1.3.

[0069] For large-bore internal combustion engines (bore ≥ 150mm):

[0070] The ratio of coating thickness to cylinder diameter is set between 0.55 and 0.76‰, which is based on the special design requirements of layered piston rings. The main function of the coating is to improve the wear resistance and thermal stability of the ring body and reduce friction between the lower end face and the ring groove. In large-bore engines, due to higher power density, the requirements for piston ring wear resistance and heat dissipation are also more stringent. Optimizing the coating thickness can effectively reduce wear, reduce power loss, improve thermal stability, and thus extend the service life of the piston rings.

[0071] The ratio of the first ring height to the cylinder diameter is set at 1.01~1.27%. This design ensures that the upper ring (first ring) maintains good sealing performance under high pressure and high temperature. A higher ring height means greater mechanical strength and better thermal conductivity, which helps reduce fractures caused by thermal stress.

[0072] The height ratio of the first and second rings ranges from 1.2 to 1.5. By adjusting the height ratio of the upper and lower rings, graded control of airtightness and dynamic pressure gradient management can be achieved. The upper ring undertakes the main sealing, while the lower ring provides auxiliary sealing. This structure improves sealing efficiency and reduces overall wear.

[0073] For small and medium-sized internal combustion engines (cylinder bore < 150mm):

[0074] The ratio of coating thickness to cylinder diameter is set to 0.43~0.55‰, which is slightly lower than that of large-diameter models. This is because smaller engines have lower power density and heat load, but more stringent space constraints. An appropriate coating thickness can enhance wear resistance while avoiding excessive occupation of annular groove space and reducing frictional resistance.

[0075] The ratio of the first piston ring height to the cylinder bore ranges from 0.84 to 1.01%. Within a limited space, sufficient ring height is maintained to support effective sealing and heat conduction. A smaller cylinder bore means a more compact design, but the performance requirements for piston rings are not reduced. The moderate height design balances sealing and durability.

[0076] The height ratio of the first and second piston rings ranges from 1.1 to 1.3, which is reduced compared to large-bore engines, but still allows for graded control of airtightness. This optimization of parameters further enhances the stability and adaptability of the structure, ensuring that the piston rings maintain efficient and reliable operation even in space-constrained small engines.

[0077] The precise ratio range of coating thickness to cylinder diameter (0.55~0.76‰ and 0.43~0.55‰) ensures that a thicker coating increases the surface hardness of the ring and reduces wear, while simultaneously balancing thermal expansion to prevent seizing. An appropriate thickness (which varies depending on the cylinder diameter) ensures a balance between wear resistance and thermal stability.

[0078] The settings for the heights of the first and second rings (1.01~1.27% and 0.84~1.01% respectively) and the adjustments to their height ratios (1.2~1.5 and 1.1~1.3) are based on an in-depth analysis of the piston ring material properties and an understanding of the sealing requirements. A higher first ring height provides stronger sealing capability, while an appropriate second ring height ensures structural stability and auxiliary sealing.

[0079] The methods and embodiments provided in this application can be executed on a mobile terminal, computer terminal, or similar computing device. Taking running on a mobile terminal as an example, Figure 4 This is a hardware structure block diagram of a mobile terminal for a method of determining the parameters of a layered piston ring according to an embodiment of the present invention. Figure 4 As shown, a mobile terminal may include one or more ( Figure 4 Only one is shown in the diagram. A processor 102 (which may include, but is not limited to, a microprocessor MCU or a programmable logic device FPGA, etc.) and a memory 104 for storing data are also shown. The mobile terminal may further include a transmission device 106 for communication functions and an input / output device 108. Those skilled in the art will understand that... Figure 4 The structure shown is for illustrative purposes only and does not limit the structure of the mobile terminal described above. For example, the mobile terminal may also include components that are more... Figure 4 The more or fewer components shown, or having the same Figure 4 The different configurations shown.

[0080] The memory 104 can be used to store computer programs, such as application software programs and modules, like the computer program corresponding to the method for determining the parameters of the layered piston rings in this embodiment of the invention. The processor 102 executes various functional applications and data processing by running the computer program stored in the memory 104, thereby implementing the above-described method. The memory 104 may include high-speed random access memory and may also include non-volatile memory, such as one or more magnetic storage devices, flash memory, or other non-volatile solid-state memory. In some instances, the memory 104 may further include memory remotely located relative to the processor 102, and these remote memories can be connected to the mobile terminal via a network. Examples of the aforementioned networks include, but are not limited to, the Internet, corporate intranets, local area networks, mobile communication networks, and combinations thereof. The transmission device 106 is used to receive or send data via a network. Specific examples of the aforementioned networks may include wireless networks provided by the mobile terminal's communication provider. In one example, the transmission device 106 includes a network interface controller (NIC), which can be connected to other network devices via a base station to communicate with the Internet. In one example, the transmission device 106 may be a radio frequency (RF) module, which is used to communicate with the Internet wirelessly.

[0081] This embodiment provides a method for determining the parameters of a layered piston ring that operates on a mobile terminal, computer terminal, or similar computing device. It should be noted that the steps shown in the flowchart in the accompanying drawings can be executed in a computer system such as a set of computer-executable instructions. Furthermore, although a logical order is shown in the flowchart, in some cases, the steps shown or described may be executed in a different order than that shown here.

[0082] Figure 5 This is a flowchart illustrating a method for determining the parameters of a layered piston ring according to an embodiment of this application. Figure 5 As shown, the method includes the following steps:

[0083] Step S501: Obtain the design parameters of the layered piston ring, wherein the design parameters include one or more of the plating thickness, ring height, number of openings, and fitting clearance, the ring height is the height of the first ring body and the height of the second ring body, and the fitting clearance is the limiting distance between the opening and the protrusion.

[0084] Specifically, this step describes the process of obtaining design parameters, which cover the key elements of the layered piston ring structure design. Among these, the coating thickness, ring height (including the heights of the first and second ring bodies), the number of openings, and the mating clearance (i.e., the limiting distance between the openings and protrusions) are crucial for improving the wear resistance and stability of the piston rings, as they directly affect the contact state and stress conditions between the piston rings and the piston and cylinder wall. In the above embodiment, obtaining parameters such as coating thickness, ring height, number of openings, and mating clearance provides the basic data for the subsequent optimization process. By precisely controlling these parameters, the wear resistance and sealing performance of the piston rings can be significantly improved, thereby extending their service life.

[0085] Generally, increasing the coating thickness can reduce wear depth to some extent, as a thicker coating provides better wear resistance and a lower coefficient of friction. However, thicker coatings are not always better. Excessively thick coatings may lead to insufficient heat dissipation, causing thermal stability and thermal expansion problems, which could actually increase wear depth. Increasing coating thickness also reduces contact pressure; the coating acts as a buffer layer, reducing the direct contact area between the ring and the cylinder wall, thereby lowering the pressure per unit area.

[0086] Increasing the ring height means greater ring rigidity, better resistance to pressure and thermal deformation, thus indirectly reducing wear depth. It also increases contact pressure because a taller ring generates greater force over a larger contact area, especially during compression. However, a taller ring also provides better airtightness and support; therefore, a balance needs to be found in the optimized design to ensure sufficient sealing without excessively increasing contact pressure.

[0087] The number of openings has a relatively indirect effect on wear depth. More openings provide more positioning and guiding mechanisms, which positively impacts reducing radial wobble and axial misalignment of the piston rings. However, excessive openings also introduce additional assembly complexity and potential strength reduction. The number of openings does not affect contact pressure as directly as it affects wear depth. More openings mean a more complex ring structure, which improves the ring's guiding and positioning accuracy, helping to maintain constant contact pressure. However, excessive openings may also introduce additional stress concentration points, potentially increasing localized contact pressure under certain conditions.

[0088] If the clearance is set too large, it will increase the piston ring's range of motion in the ring groove, potentially causing unnecessary vibration during reciprocating motion and intensifying the contact between the ring and the cylinder wall or ring groove, thus increasing the wear depth. Conversely, an appropriate clearance ensures proper guidance and positioning of the piston ring in the ring groove, helping to maintain a lower wear level. A proper increase in clearance can reduce contact pressure. With a smaller clearance, the contact between the ring and the ring groove is tighter, resulting in relatively higher contact pressure. An appropriate clearance avoids excessively tight contact, reducing local pressure peaks and thus lowering the overall contact pressure. However, an excessively large clearance can also lead to decreased sealing performance and ring stability issues.

[0089] Different materials affect the wear resistance, thermal stability, and frictional behavior of piston rings against the cylinder wall. The width of the piston ring groove affects the fit of the piston ring within the groove, as well as the contact pressure and friction between the ring edge and the groove wall. Besides the ring height, the ring thickness should also be considered, as it affects the ring's rigidity and heat dissipation ability. The diameter of the piston ring affects its overall dimensions and fit within the cylinder.

[0090] Step S502: Obtain the wear depth and contact stress of the layered piston ring, wherein the wear depth is the amount of material loss caused by friction in the layered piston ring, and the contact stress is the stress between the layered piston ring and the piston.

[0091] Specifically, obtaining wear depth and contact stress is the core of evaluating piston ring performance. Wear depth reflects the wear condition of the piston ring under working conditions, while contact stress reflects the stress state of the piston ring-piston contact surface. By monitoring and analyzing these two indicators, we can gain a deeper understanding of the wear mechanism and stress characteristics of the piston ring in practical applications, providing fundamental data for subsequent parameter optimization. In the above embodiment, obtaining specific values ​​for wear depth and contact stress can intuitively reflect the wear condition and stress state of the piston ring during operation. This provides a direct basis for the optimization process of multi-objective optimization algorithms, ensuring that the optimization results can significantly reduce piston ring wear and stress concentration, thereby increasing its fatigue life.

[0092] Wear depth is used to represent the amount of material loss caused by friction on the material surface. The unit is usually a unit of length, most commonly millimeters (mm) or micrometers (μm); contact stress is a physical quantity that measures the pressure between two contacting surfaces. It is usually measured in units of pressure, namely Pascals (Pa).

[0093] Step S503: A multi-objective optimization algorithm is used to optimize the design parameters until the wear depth reaches the minimum wear value and the contact stress reaches the minimum stress value, thereby obtaining the updated design parameters. The updated design parameters are used to construct the layered piston ring.

[0094] Specifically, a multi-objective optimization algorithm is employed to optimize and adjust the design parameters, aiming to simultaneously minimize wear depth and contact stress. The optimization goal is to find a set of design parameters that minimize both wear depth and contact stress. This is achieved through iterative iteration and evaluation of different combinations of design parameters using the multi-objective optimization algorithm, ensuring optimal overall performance of the piston ring design. After the above optimization process, the updated design parameters are determined and used to finally construct the layered piston ring. In the above embodiment, the multi-objective optimization algorithm can find a set of design parameters that achieve the best balance between minimizing wear depth and minimizing contact stress. It overcomes the limitations of traditional single-objective optimization, simultaneously satisfying multiple design objectives and enhancing the innovation and optimization level of the piston ring structure. This type of piston ring can effectively avoid ring breakage under the extreme operating conditions of high-performance diesel engines, significantly improving the efficiency of internal combustion engines.

[0095] The multi-objective optimization algorithm in the above embodiments can be a genetic algorithm (GA) or a differential evolution algorithm (DE), etc.

[0096] In the process of constructing layered piston rings, firstly, updated design parameters, including plating thickness, ring height, number of openings, and fit clearance, are derived based on a multi-objective optimization algorithm. After the design adjustments are completed, a prototype piston ring is built. Once manufactured, the geometric features of the piston ring are rigorously inspected, including the ring diameter, thickness, height, opening dimensions, and fit clearance, to ensure they are consistent with the updated design parameters and meet engineering standards. The upper and lower rings are then assembled according to the positioning holes and cylindrical fit specified in the design parameters, ensuring the correct and stable relative position of the upper and lower rings.

[0097] In this embodiment, design parameters are crucial to the wear resistance and sealing performance of piston rings, directly affecting the contact state and stress distribution between the piston ring and the piston and cylinder wall. Wear depth is a quantitative indicator of material loss caused by friction during piston ring operation, while contact stress reflects the stress state between the piston ring and the piston and is a key parameter for evaluating piston ring durability. A multi-objective optimization algorithm is used to optimize and adjust the design parameters, finding a set of updated design parameters that can simultaneously minimize wear depth and contact stress. Compared with traditional single-objective optimization methods, multi-objective optimization can comprehensively consider multiple design objectives, avoiding the reduction of other performance in pursuit of optimization of a certain indicator, resulting in a better piston ring model constructed subsequently.

[0098] This invention proposes a layered piston ring structure for internal combustion engines with different cylinder diameters. Combining a piston ring-piston friction dynamics model (i.e., the subsequent piston ring prediction model) and multi-objective optimization design methods, the optimal design scheme that meets requirements such as fatigue strength and reliability is determined. The main structural design process is as follows: Figure 6 As shown. Starting with the input of the internal combustion engine cylinder diameter, first determine whether the cylinder diameter is ≥150mm. Based on the determination result, input the coating thickness and ring height respectively. When it is >150mm, additional input parameters for the positioning hole and fitting clearance are used. Then, establish a piston ring-piston friction dynamics model, extract the wear depth and contact stress of the lower section of the ring to generate training samples for the surrogate model, construct a computer surrogate model and verify its accuracy. If it is not satisfactory, resample and model. After the accuracy meets the standard, carry out multi-objective optimization design to form an optimized ring structure scheme. After environmental fatigue strength test verification, determine the final structural scheme.

[0099] In the specific implementation process, obtaining the wear depth and contact stress of the layered piston ring includes: obtaining a prediction model, wherein the prediction model is a model for predicting multiple values; forming a training set by combining historical design parameters and corresponding structural health labels, and training the prediction model using the training set to obtain a piston ring prediction model, wherein the structural health labels are the historical wear depth and historical contact stress of the layered piston ring in the training set; and inputting the design parameters into the piston ring prediction model to obtain the wear depth and contact stress corresponding to the design parameters.

[0100] In this scheme, since the piston ring prediction model is obtained through extensive machine learning training, the piston ring prediction model can predict the wear depth and contact stress of the piston ring, thus obtaining relatively accurate wear depth and contact stress.

[0101] The above embodiments, through extensive training data, enable the model to gradually learn how to map design parameters to structural health labels. This process is equivalent to finding a relationship in the design space that allows the model to predict the wear depth and contact stress closest to reality given the design parameters. The model's accuracy is validated on independent test sets to ensure that it not only learns patterns from the training data but also generalizes to unseen data, thus demonstrating its reliability and effectiveness. Once the model is validated as reliable, it can be applied to predict wear depth and contact stress corresponding to new design parameters. This allows for the early elimination of designs that lead to high wear or high contact stress, avoiding unnecessary attempts and wasted resources later on.

[0102] During implementation, a large amount of piston ring design parameter data needs to be collected and organized, including but not limited to coating thickness, ring height, number of openings, and fit clearance, as well as historical wear depth and historical contact stress data of the piston rings in actual operation corresponding to these design parameters. This data constitutes the training set for building the prediction model. Using the above training set, the model parameters are adjusted through an iterative training process to ensure that the model can accurately predict the wear depth and contact stress of the input design parameters. The goal of model training is to reduce the error between the predicted values ​​and the actual structural health label values, thereby obtaining a high-precision piston ring prediction model. Once training is complete, the above piston ring prediction model can accept new design parameters as input and quickly predict the corresponding wear depth and contact stress.

[0103] For example, for large-bore internal combustion engines (bore ≥ 150mm), the ratio of the lower end face plating thickness to the cylinder diameter ranges from 0.55 to 0.76‰, the ratio of the upper ring height to the cylinder diameter ranges from 1.01 to 1.27%, and the ratio of the upper and lower ring heights ranges from 1.2 to 1.5. By inputting these design parameters into the piston ring prediction model, the predicted wear depth and contact stress can be quickly obtained, thereby avoiding blind guessing and trial and error in the design process and ensuring that each design iteration moves towards the goal of reducing wear and contact stress. Furthermore, for small and medium-sized internal combustion engines (bore < 150mm), the ratio of the lower end face plating thickness to the cylinder diameter ranges from 0.43 to 0.55‰, the ratio of the upper ring height to the cylinder diameter ranges from 0.84 to 1.01%, the ratio of the upper and lower ring heights ranges from 1.1 to 1.3, the number of locating holes is 4 to 6, and the ratio of the mating clearance to the diameter of the locating cylinder ranges from 0.95 to 1.33‰. The setting of these specific parameters is also based on the guidance of the piston ring prediction model, ensuring that the wear depth and contact stress can be optimized in the design of piston rings under different operating conditions and sizes, effectively improving the reliability of piston rings and extending fatigue fracture life.

[0104] The aforementioned prediction model can be a neural network model (NN) or a support vector regression (SVR) model, etc.

[0105] The structural characteristics of this design determine the risk of piston ring breakage under continuously increasing power density. The layered structure can also effectively solve the leakage problem under alternating positive and negative pressure. The key structural design parameters are selected as follows: (height of upper and lower rings), positioning parameters (fitting clearance, number of positioning holes), and coating thickness.

[0106] Two design methods were developed based on the cylinder bore of internal combustion engines. For large-bore internal combustion engines, the optimization parameters are often selected as the height of the upper and lower rings and the coating thickness as variables, while for small and medium-sized engines, the coating thickness, the height of the upper and lower rings, the number of positioning holes, and the fit clearance are used as independent variables.

[0107] A piston ring-piston friction dynamics model, i.e. a piston ring prediction model, was built. By calculating multiple sets of independent variables (coating thickness, upper and lower ring height, (number of positioning holes, and fit clearance)) and corresponding dependent variables (wear depth and contact stress on the lower end face of the ring), the data were obtained.

[0108] A high-precision proxy model is obtained through iterative optimization of computational accuracy between independent variables (coating thickness, upper and lower ring heights, number of positioning holes, and fit clearance) and dependent variables (wear depth and contact stress on the lower end face of the ring).

[0109] Based on the surrogate model, a multi-objective optimization design scheme for the layered ring structure is obtained: the coating thickness, the height of the upper and lower rings, and the mating clearance of the positioning holes are used as optimization variables, and the minimum wear depth and contact stress of the lower end face of the ring are used as optimization objectives.

[0110] In some embodiments, after inputting the design parameters into the piston ring prediction model to obtain the wear depth and contact stress corresponding to the design parameters, the method further includes: obtaining the actual wear depth and actual contact stress, wherein the actual wear depth is the actual material loss of the layered piston ring due to friction, and the actual contact stress is the actual stress between the layered piston ring and the piston; calculating the difference between the actual wear depth and the wear depth to obtain a wear difference; calculating the difference between the actual contact stress and the contact stress to obtain a stress difference; optimizing the piston ring prediction model when the wear difference is greater than or equal to a preset wear threshold, and / or the stress difference is greater than or equal to a preset stress threshold, to obtain an optimized piston ring prediction model, wherein the optimization method includes one or more of adjusting weights, adjusting biases, adjusting model structure, feature selection, and regularization; training the optimized piston ring prediction model using the training set to obtain an updated piston ring prediction model; inputting the design parameters into the updated piston ring prediction model to obtain the wear depth and contact stress corresponding to the design parameters.

[0111] In this approach, optimizing the model can significantly improve the reliability and accuracy of the prediction model. By periodically verifying the performance of the prediction model and optimizing it when there are significant differences between the model prediction and the actual test results, we can avoid blind and erroneous decisions in the design process and ensure that the designed piston ring has good performance and reliability in practical applications.

[0112] In the above embodiments, a set of actual wear depth and actual contact stress data are obtained through ring fatigue strength tests. The wear depth and contact stress output by the prediction model are compared with the above actual data to calculate the wear difference and stress difference. Preset wear thresholds and preset stress thresholds are set. When the wear difference and / or stress difference exceeds the above preset thresholds, the prediction performance of the prediction model is considered poor and needs to be optimized. Based on the magnitude of the wear difference and stress difference, one or more of the following methods are selected for model optimization: weight adjustment, bias adjustment, model structure adjustment, feature selection, and regularization. The optimized prediction model is then verified again using actual test data to ensure that its prediction performance is improved.

[0113] The actual wear depth and actual contact stress are obtained through ring fatigue strength tests. This step ensures the consistency between the predicted values ​​of the prediction model and the actual piston ring performance data. By comparing the wear depth and contact stress output by the prediction model with those obtained from actual tests, the wear difference and stress difference can be obtained. If the wear difference and / or stress difference exceed a preset threshold, it indicates that the prediction performance of the prediction model under the current design parameters is not ideal and optimization is required.

[0114] Suppose that in a design iteration, the predicted wear depth is 0.035 mm and the contact stress is 130 MPa. However, the actual wear depth obtained through ring fatigue strength testing is 0.045 mm and the actual contact stress is 140 MPa. The calculated wear difference is 0.01 mm and the stress difference is 10 MPa. A preset wear threshold of 0.005 mm and a preset stress threshold of ±5 MPa are set. Since the wear difference (0.01 mm) > the preset wear threshold (0.005 mm) and the stress difference (10 MPa) > the preset stress threshold ±5 MPa, the model optimization mechanism is triggered. The prediction model is optimized by adjusting weights and regularization. The optimized model predicts a wear depth of 0.046 mm and a contact stress of 141 MPa under the same design parameters, which is closer to the actual test results, improving the accuracy and reliability of the prediction model.

[0115] The optimization methods described in the above embodiments include weight adjustment, bias adjustment, model structure adjustment, feature selection, and regularization. These methods adjust different aspects of the piston ring prediction model to improve its prediction accuracy and generalization ability. Weight adjustment involves updating the values ​​of these weights based on the model's prediction error using a backpropagation algorithm to minimize the prediction error and make the model's output closer to the actual test data. Bias is another important parameter in the model used to adjust the output. It allows the model to produce non-zero outputs even without input, helping the model learn non-linear relationships. By adjusting the bias, the model can better adapt to the distribution of actual data, avoiding predictions that are always biased towards a fixed value. Adjusting the model structure typically involves increasing or decreasing the model's complexity to accommodate more complex or simpler relationships. Feature selection refers to selecting the parameters that have the greatest impact on the prediction results from the original design parameters, removing redundant parameters or those that contribute little to the prediction effect. Regularization adds a penalty mechanism during model training to prevent the model from overfitting the training data. It is usually achieved by adding a penalty term with weights. Each optimization method has its specific purpose and effect. By combining these methods, the discrepancy between model predictions and actual test results can be addressed in a targeted manner.

[0116] In the specific implementation process, a multi-objective optimization algorithm is used to optimize the above design parameters until the wear depth reaches the minimum wear value and the contact stress reaches the minimum stress value, thus obtaining the updated design parameters. This includes: using the multi-objective optimization algorithm to adjust the above design parameters as variables multiple times, and obtaining the wear depth and contact stress after each adjustment; extracting the minimum value of the wear depth and the minimum value of the contact stress among multiple adjustments; and extracting the adjusted design parameters corresponding to the minimum wear depth and the minimum contact stress to obtain the updated design parameters.

[0117] This approach utilizes multi-objective optimization to simultaneously minimize wear depth and contact stress, thereby significantly enhancing the fatigue strength and reliability of piston rings. This method overcomes the limitations of traditional optimization methods, which often only target a single objective. It allows for more comprehensive adjustment of design parameters, better adapting to the extreme operating conditions of modern high-performance diesel engines, avoiding performance bottlenecks caused by single-objective optimization, and improving the precision and efficiency of piston ring design.

[0118] In the above embodiments, a set of initial design parameters are set, such as coating thickness, upper and lower ring heights, number of positioning holes, and mating clearance. In each iteration, the multi-objective optimization algorithm predicts the corresponding wear depth and contact stress based on the above design parameters, and fine-tunes the design parameters through the algorithm's intelligent optimization mechanism to find parameter combinations that simultaneously reduce wear depth and contact stress. After the algorithm converges, the minimum wear depth and minimum contact stress are selected, and the corresponding design parameter combinations are recorded. The selected design parameter combinations are used as updated design parameters to guide subsequent piston ring design.

[0119] The purpose of using multi-objective optimization algorithms is to find a set of design parameters that minimize both wear depth and contact stress through a series of calculations and adjustments. This process is tailored to the specific requirements of piston ring design, where even small changes in the geometric features of the ring end face can have orders-of-magnitude effects on fatigue life. To overcome this challenge, the optimization algorithm must comprehensively consider multiple objectives, rather than simply pursuing the minimization of a single objective.

[0120] Assuming that at the start of optimization, the coating thickness is 0.006 mm, the upper ring height is 2 mm, the lower ring height is 1.5 mm, the number of openings is 4, and the clearance is 0.01 mm, an updated set of design parameters was found through iterative optimization using a multi-objective optimization algorithm: the coating thickness is 0.007 mm, the upper ring height is 1.95 mm, the lower ring height is 1.55 mm, the number of openings remains at 4, but the clearance is adjusted to 0.0095 mm. Under these optimized design parameters, the wear depth predicted by the piston ring prediction model is 0.013 mm, and the contact stress is 105 MPa. Under the design parameters before optimization, the predicted wear depth is 0.028 mm, and the contact stress is 120 MPa. It can be seen that through the optimization method described above, the wear depth is reduced by 53.6%, and the contact stress is reduced by 12.5%, significantly improving the overall performance of the piston ring design, extending the service life of the piston ring, reducing power loss, and improving the efficiency of the internal combustion engine.

[0121] When using a multi-objective optimization algorithm to optimize and adjust design parameters, firstly, based on design requirements and preliminary analysis, a set of initial design parameter values ​​is set, including coating thickness, upper and lower ring heights, number of locating holes, and fit clearance. A surrogate model is established using a piston ring-piston friction dynamics model, which can predict the wear depth and contact stress of the layered piston ring under specific design parameters. The initial design parameters are input into the prediction model, and the multi-objective optimization algorithm is used for optimization. The algorithm automatically adjusts the design parameters multiple times, searching the design space to find a set of parameters that simultaneously minimizes both wear depth and contact stress. After each parameter adjustment, the algorithm calculates and records the predicted values ​​of wear depth and contact stress. Through iterative optimization, the minimum wear depth and minimum contact stress, along with the corresponding combination of design parameters, are finally extracted; this combination constitutes the updated design parameters.

[0122] Assume the initial design parameters are: plating thickness 0.005mm, upper ring height 1.0mm, upper ring height 0.8mm, number of locating holes 4, and mating clearance 0.005mm. The goal is to find a set of design parameters that simultaneously minimizes wear depth and contact stress by adjusting these parameters. An initial population containing different combinations of design parameters is generated; for example, the population might contain the design parameter combination {plating thickness 0.005mm, upper ring height 1.0mm, upper ring height 0.8mm, number of locating holes 4, mating clearance 0.005mm}. Each set of design parameters is input into a prediction model to simulate the output of wear depth and contact stress, forming the evaluation result set of generation 0. Through iterative optimization, the minimum wear depth and minimum contact stress are selected from the final population, and the corresponding design parameter combinations are recorded. The obtained design parameter combinations are used as updated design parameters to guide the final design of the layered piston ring.

[0123] The final design scheme of the double-layer piston ring structure was determined through fatigue strength tests of the piston rings. Analysis revealed that for large-bore internal combustion engines (bore ≥ 150mm), the ratio of the lower end face plating thickness to the cylinder diameter ranges from 0.55 to 0.76‰, the ratio of the upper ring height to the cylinder diameter ranges from 1.01 to 1.27%, and the height ratio of the upper and lower rings ranges from 1.2 to 1.5. For medium and small internal combustion engines (bore < 150mm), the ratio of the lower end face plating thickness to the cylinder diameter ranges from 0.43 to 0.55‰, the ratio of the upper ring height to the cylinder diameter ranges from 0.84 to 1.01%, the height ratio of the upper and lower rings ranges from 1.1 to 1.3, the number of locating holes is 4 to 6, and the ratio of the mating clearance to the diameter of the locating cylinder ranges from 0.95 to 1.33‰. Based on this design process, the obtained piston ring structure for a large-bore engine was bench-tested. Figure 7 As shown, the fatigue fracture life has been improved by a breakthrough of 203%, successfully solving the bottleneck problem of the reliability of high-strength diesel engine piston rings.

[0124] The main advantage of this solution lies in its more rational piston ring reinforcement structure. It provides a reasonable design range for different cylinder diameters, improving the fatigue fracture life of the piston rings and solving the piston ring breakage problem under continuously increasing power density. Furthermore, the layered piston ring structure with different parameters for different cylinder diameters is more beneficial to the thermal stability of the upper ring coating and effectively solves the leakage problem under alternating positive and negative pressure.

[0125] This application also provides a device for determining the parameters of a layered piston ring. It should be noted that this device can be used to execute the method for determining the parameters of a layered piston ring provided in this application. This device is used to implement the above embodiments and preferred embodiments; details already described will not be repeated. As used below, the term "module" can refer to a combination of software and / or hardware that performs a predetermined function. Although the device described in the following embodiments is preferably implemented in software, hardware implementation, or a combination of software and hardware, is also possible and contemplated.

[0126] The following describes the device for determining the parameters of a layered piston ring provided in the embodiments of this application.

[0127] Figure 8 This is a structural block diagram of a device for determining the parameters of a layered piston ring according to an embodiment of this application. Figure 8 As shown, the device includes:

[0128] The first acquisition unit 100 is used to acquire the design parameters of the layered piston ring, wherein the design parameters include one or more of the plating thickness, ring height, number of openings, and fitting clearance, the ring height is the height of the first ring body and the height of the second ring body, and the fitting clearance is the limiting distance between the opening and the protrusion.

[0129] The second acquisition unit 200 is used to acquire the wear depth of the layered piston ring and the contact stress of the layered piston ring, wherein the wear depth is the amount of material loss caused by friction in the layered piston ring, and the contact stress is the stress between the layered piston ring and the piston.

[0130] The determination unit 300 is used to perform optimization using a multi-objective optimization algorithm to adjust the above design parameters until the wear depth reaches the minimum wear value and the contact stress reaches the minimum stress value, thereby obtaining updated design parameters. The updated design parameters are used to construct the above layered piston ring.

[0131] In this embodiment, design parameters are crucial to the wear resistance and sealing performance of piston rings, directly affecting the contact state and stress distribution between the piston ring and the piston and cylinder wall. Wear depth is a quantitative indicator of material loss caused by friction during piston ring operation, while contact stress reflects the stress state between the piston ring and the piston and is a key parameter for evaluating piston ring durability. A multi-objective optimization algorithm is used to optimize and adjust the design parameters, finding a set of updated design parameters that can simultaneously minimize wear depth and contact stress. Compared with traditional single-objective optimization methods, multi-objective optimization can comprehensively consider multiple design objectives, avoiding the reduction of other performance in pursuit of optimization of a certain indicator, resulting in a better piston ring model constructed subsequently.

[0132] In the specific implementation process, the second determining unit includes an acquisition module, a training module, and a processing module. The acquisition module is used to acquire a prediction model, wherein the prediction model is a model for predicting multiple values. The training module is used to form a training set by combining historical design parameters and corresponding structural health labels, and to train the prediction model using the training set to obtain a piston ring prediction model. The structural health labels are the historical wear depth and historical contact stress of the layered piston ring in the training set. The processing module is used to input the design parameters into the piston ring prediction model to obtain the wear depth and contact stress corresponding to the design parameters.

[0133] In this scheme, since the piston ring prediction model is obtained through extensive machine learning training, the piston ring prediction model can predict the wear depth and contact stress of the piston ring, thus obtaining relatively accurate wear depth and contact stress.

[0134] In some embodiments, the above-described apparatus further includes a third acquisition unit, a first calculation unit, a second calculation unit, an optimization unit, and a training unit. The third acquisition unit is used to acquire the actual wear depth and actual contact stress after inputting the design parameters into the piston ring prediction model to obtain the wear depth and contact stress corresponding to the design parameters. The actual wear depth is the actual material loss of the layered piston ring due to friction, and the actual contact stress is the actual stress between the layered piston ring and the piston. The first calculation unit is used to calculate the difference between the actual wear depth and the wear depth to obtain the wear difference. The second calculation unit is used to calculate the actual wear depth... The difference between the contact stress and the aforementioned contact stress is used to obtain the stress difference value. The optimization unit is used to optimize the piston ring prediction model when the aforementioned wear difference value is greater than or equal to a preset wear threshold, and / or when the aforementioned stress difference value is greater than or equal to a preset stress threshold, to obtain an optimized piston ring prediction model. The optimization method includes one or more of the following: adjusting weights, adjusting biases, adjusting model structure, feature selection, and regularization. The training unit is used to train the optimized piston ring prediction model using the aforementioned training set to obtain an updated piston ring prediction model. The aforementioned design parameters are input into the updated piston ring prediction model to obtain the aforementioned wear depth and the aforementioned contact stress corresponding to the aforementioned design parameters.

[0135] In this approach, optimizing the model can significantly improve the reliability and accuracy of the prediction model. By periodically verifying the performance of the prediction model and optimizing it when there are significant differences between the model prediction and the actual test results, we can avoid blind and erroneous decisions in the design process and ensure that the designed piston ring has good performance and reliability in practical applications.

[0136] In the specific implementation process, the training unit includes an adjustment module and an extraction module. The adjustment module is used to use a multi-objective optimization algorithm to adjust the above design parameters as variables multiple times, and obtain the above wear depth and the above contact stress after each adjustment of the above design parameters. The extraction module is used to extract the minimum value of the above wear depth and the minimum value of the above contact stress after multiple adjustments of the above design parameters, and extract the adjusted above design parameters corresponding to the minimum value of the above wear depth and the minimum value of the above contact stress, so as to obtain the above updated design parameters.

[0137] This approach utilizes multi-objective optimization to simultaneously minimize wear depth and contact stress, thereby significantly enhancing the fatigue strength and reliability of piston rings. This method overcomes the limitations of traditional optimization methods, which often only target a single objective. It allows for more comprehensive adjustment of design parameters, better adapting to the extreme operating conditions of modern high-performance diesel engines, avoiding performance bottlenecks caused by single-objective optimization, and improving the precision and efficiency of piston ring design.

[0138] The device for determining the parameters of the aforementioned layered piston ring includes a processor and a memory. The first acquisition unit, the second acquisition unit, and the determination unit are all stored as program units in the memory, and the processor executes the program units stored in the memory to achieve the corresponding functions. All of the above modules are located in the same processor; alternatively, the modules may be located in different processors in any combination.

[0139] The processor contains a core, which retrieves the corresponding program units from memory. One or more cores can be configured, and their parameters can be adjusted to address the problem of short lifespan and easy breakage of piston rings in existing technologies.

[0140] The memory may include non-permanent memory in computer-readable media, such as random access memory (RAM) and / or non-volatile memory, such as read-only memory (ROM) or flash RAM, and the memory includes at least one memory chip.

[0141] This invention provides a computer-readable storage medium including a stored program, wherein, when the program is executed, it controls the device containing the computer-readable storage medium to perform the method for determining the parameters of the layered piston ring.

[0142] This invention provides a processor for running a program, wherein the program executes a method for determining the parameters of the layered piston ring.

[0143] This invention provides a device including a processor, a memory, and a program stored in the memory and executable on the processor. When the processor executes the program, it implements a method for determining the parameters of at least a layered piston ring. The device described herein may be a server, PC, PAD, mobile phone, etc.

[0144] This application also provides a computer program product, which, when executed on a data processing device, is adapted to perform a method step of determining parameters for initializing a piston ring with at least layered rings.

[0145] This invention provides a layered piston ring analysis system, comprising: a layered piston ring, wherein the layered piston ring is any of the aforementioned layered piston rings; and a parameter determination device for the layered piston ring, wherein the determination device is used to execute any of the aforementioned parameter determination methods for the layered piston ring.

[0146] It is obvious to those skilled in the art that the modules or steps of the present invention described above can be implemented using general-purpose computing devices. They can be centralized on a single computing device or distributed across a network of multiple computing devices. They can be implemented using computer-executable program code, and thus can be stored in a storage device for execution by a computing device. In some cases, the steps shown or described can be performed in a different order than those described herein, or they can be fabricated as separate integrated circuit modules, or multiple modules or steps can be fabricated as a single integrated circuit module. Thus, the present invention is not limited to any particular combination of hardware and software.

[0147] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product embodied on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0148] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart... Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0149] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1The function specified in one or more boxes.

[0150] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0151] In a typical configuration, a computing device includes one or more processors (CPU), input / output interfaces, network interfaces, and memory.

[0152] Memory may include non-persistent memory in computer-readable media, such as random access memory (RAM) and / or non-volatile memory, such as read-only memory (ROM) or flash RAM. Memory is an example of computer-readable media.

[0153] Computer-readable media includes both permanent and non-permanent, removable and non-removable media that can store information using any method or technology. Information can be computer-readable instructions, data structures, modules of programs, or other data. Examples of computer storage media include, but are not limited to, phase-change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technologies, CD-ROM, digital versatile optical disc (DVD) or other optical storage, magnetic tape, disk storage or other magnetic storage devices, or any other non-transferable medium that can be used to store information accessible by a computing device. As defined herein, computer-readable media does not include transient computer-readable media, such as modulated data signals and carrier waves.

[0154] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0155] It should also be noted that the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element.

[0156] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A layered piston ring analysis system, characterized in that, The layered piston ring analysis system includes a layered piston ring and a device for determining the parameters of the layered piston ring. The device for determining the parameters of the layered piston ring executes a method for determining the parameters of the layered piston ring. Layered piston rings include: At least one set of mating structures, the mating structures including a first ring body (12) and a second ring body (13), the first ring body (12) being used to seal between the cylinder wall and the piston, and the second ring body (13) being used to seal between the cylinder wall and the piston; Wherein, the first ring body (12) has an opening (14), and the second ring body (13) has a protrusion (15), or, the first ring body (12) has the protrusion (15), and the second ring body (13) has the opening (14), and the opening (14) and the protrusion (15) are distributed along the circumferential direction; Wherein, the opening (14) and the protrusion (15) are adapted to each other in shape, the opening (14) and the protrusion (15) are in one-to-one correspondence, the protrusion (15) is located inside the opening (14) and the protrusion (15) is in a limiting fit with the inner wall of the opening (14); The outer surface of the first ring body (12) has a coating, and the outer surface of the second ring body (13) has a coating. For internal combustion engines with a cylinder diameter greater than or equal to 150 mm, the ratio of the coating thickness to the cylinder diameter is 0.55 to 0.76‰, the ratio of the height of the first ring (12) to the cylinder diameter is 1.01 to 1.27%, and the height ratio of the first ring (12) to the second ring (13) is 1.2 to 1.5; for internal combustion engines with a cylinder diameter less than 150 mm, the ratio of the coating thickness to the cylinder diameter is 0.43 to 0.55‰, the ratio of the height of the first ring (12) to the cylinder diameter is 0.84 to 1.01%, and the height ratio of the first ring (12) to the second ring (13) is 1.1 to 1.

3. Methods for determining the parameters of layered piston rings include: The design parameters of the layered piston ring are obtained, including multiple parameters such as coating thickness, ring height, number of openings, and fit clearance. The ring height is the height of the first ring body and the height of the second ring body, and the fit clearance is the limiting distance between the opening and the protrusion. The wear depth and contact stress of the layered piston ring are obtained, where the wear depth is the amount of material loss caused by friction, and the contact stress is the stress between the layered piston ring and the piston. A multi-objective optimization algorithm is used to optimize and adjust the design parameters until the wear depth reaches the minimum wear value and the contact stress reaches the minimum stress value, resulting in updated design parameters. The updated design parameters are used to construct the layered piston ring.

2. The layered piston ring analysis system according to claim 1, characterized in that, The opening (14) is in the shape of a ring, and the protrusion (15) is in the shape of a cylinder.

3. The layered piston ring analysis system according to claim 1, characterized in that, Obtaining the wear depth and contact stress of the layered piston ring includes: Obtain a prediction model, wherein the prediction model is a model used to predict multiple values; The historical design parameters and corresponding structural health labels are combined into a training set. The prediction model is trained using the training set to obtain the piston ring prediction model. The structural health labels are the historical wear depth and historical contact stress of the layered piston ring in the training set. The design parameters are input into the piston ring prediction model to obtain the wear depth and contact stress corresponding to the design parameters.

4. The layered piston ring analysis system according to claim 3, characterized in that, After inputting the design parameters into the piston ring prediction model to obtain the wear depth and contact stress corresponding to the design parameters, the method further includes: The actual wear depth and actual contact stress are obtained, wherein the actual wear depth is the actual material loss of the layered piston ring due to friction, and the actual contact stress is the actual stress between the layered piston ring and the piston; Calculate the difference between the actual wear depth and the wear depth to obtain the wear difference value; Calculate the difference between the actual contact stress and the contact stress to obtain the stress difference; When the wear difference is greater than or equal to a preset wear threshold and / or the stress difference is greater than or equal to a preset stress threshold, the piston ring prediction model is optimized to obtain an optimized piston ring prediction model. The optimization method includes one or more of the following: adjusting weights, adjusting biases, adjusting model structure, feature selection, and regularization. The optimized piston ring prediction model is trained using the training set to obtain an updated piston ring prediction model. The design parameters are then input into the updated piston ring prediction model to obtain the wear depth and contact stress corresponding to the design parameters.

5. The layered piston ring analysis system according to claim 1, characterized in that, A multi-objective optimization algorithm is used to optimize the design parameters until the wear depth reaches the minimum wear value and the contact stress reaches the minimum stress value, resulting in updated design parameters, including: A multi-objective optimization algorithm is used to adjust the design parameters as variables multiple times, and the wear depth and contact stress are obtained after each adjustment of the design parameters; Extract the minimum value of the wear depth among multiple adjusted design parameters, extract the minimum value of the contact stress among multiple adjusted design parameters, and extract the adjusted design parameters corresponding to the minimum value of the wear depth and the minimum value of the contact stress to obtain the updated design parameters.

Images