Wear-resistant internal combustion engine piston ring and surface treatment method thereof

Abstract

The application discloses a wear-resistant piston ring of an internal combustion engine, which comprises an internal combustion engine piston body, the outer surface of the internal combustion engine piston body is movably provided with a piston top ring, a piston gas ring and an oil ring assembly respectively, the oil ring assembly comprises a piston oil ring, the upper surface of the piston oil ring is movably provided with an upper oil ring scraping piece, and the lower surface of the piston oil ring is movably provided with a lower oil ring scraping piece; a multi-interface wear-resistant system of a chromium-based ceramic composite plating layer, a molybdenum alloy spraying layer and a metallurgical alloy layer is adopted, and the surface of a clamping groove is subjected to hardening treatment, so that all-round wear-resistant protection is formed from the working surface of the piston ring to the key friction pairs of the piston body, abrasive wear and adhesive wear under the working conditions of high temperature, high pressure and reciprocating sliding are effectively resisted, and the overall service life of the piston ring assembly is greatly prolonged.

Description

Technical Field

[0001] This invention belongs to the field of internal combustion engine technology, specifically relating to a wear-resistant internal combustion engine piston ring and its surface treatment method. Background Technology

[0002] Piston rings are one of the key moving parts in an internal combustion engine, including the piston crown ring, piston compression ring, and oil ring assembly. Their main functions are to achieve gas sealing between the cylinder and the piston, oil control, and heat transfer. During the high-speed reciprocating motion of the engine, the piston rings are subjected to high temperature, high pressure, and high sliding speed conditions for extended periods. This results in severe friction and wear between their outer circumferential surface and the cylinder wall, becoming a key factor affecting the lifespan and emissions performance of the internal combustion engine.

[0003] Traditional piston rings often employ single surface treatment processes such as electroplating hard chrome and phosphating. However, these processes still present problems during long-term service. Firstly, the single hard coating has poor toughness and is prone to micro-cracks or even peeling under alternating loads and thermal stress, leading to seal failure and increased blow-by. Furthermore, the sealing and oil control systems of traditional piston rings struggle to achieve both high-pressure gas sealing and precise oil control, which can easily result in excessive oil consumption. Summary of the Invention

[0004] The purpose of this invention is to provide a wear-resistant piston ring for internal combustion engines to solve the problems mentioned in the background art.

[0005] In a first aspect, the present invention provides a wear-resistant internal combustion engine piston ring, comprising: An internal combustion engine piston body, wherein a piston top ring, a piston compression ring and an oil ring assembly are movably mounted on the outer surface of the internal combustion engine piston body, the oil ring assembly includes a piston oil ring, an upper oil ring scraper is movably mounted on the upper surface of the piston oil ring, and a lower oil ring scraper is movably mounted on the lower surface of the piston oil ring.

[0006] In one possible implementation of the first aspect, the piston body of the internal combustion engine is provided with a top ring groove, a gas ring groove and an oil ring groove in sequence from top to bottom.

[0007] In one possible implementation of the first aspect, the piston top ring is used in conjunction with a top ring groove, and the outer surface of the piston top ring is a chromium-based ceramic composite coating.

[0008] In one possible implementation of the first aspect, the piston ring is used in conjunction with a ring groove, and the outer surface of the piston ring is sprayed with a molybdenum alloy coating.

[0009] In one possible implementation of the first aspect, the piston oil ring, the upper oil ring scraper, and the lower oil ring scraper are used in conjunction with the oil ring groove, and both the upper oil ring scraper and the lower oil ring scraper are provided with radial oil return holes.

[0010] In one possible implementation of the first aspect, the piston oil ring is an elastic structure, and the piston body of the internal combustion engine has a piston pin hole, the inner wall of which is made of a metallurgical alloy.

[0011] Compared with the prior art, the present invention provides a wear-resistant piston ring for internal combustion engines, which has the following beneficial effects: I. The multi-interface wear-resistant system, consisting of chromium-based ceramic composite coating, molybdenum alloy spray coating, and metallurgical alloy layer, combined with the surface hardening treatment of the groove, forms all-round wear-resistant protection from the working surface of the piston ring to the key friction pair of the piston body. It effectively resists abrasive wear and adhesive wear under high temperature, high pressure and reciprocating sliding conditions, and significantly extends the overall service life of the piston ring assembly. Second, this invention achieves dual optimization of high-pressure gas sealing and precise oil control through a multi-layer sealing structure design of piston top ring, piston compression ring and oil ring assembly, combined with the radial expansion effect of trapezoidal ring, the self-lubricating properties of molybdenum alloy spray coating, and the elastic tension and radial oil return structure of oil ring assembly. This effectively reduces blow-by and oil consumption, and significantly improves engine combustion efficiency and emission performance.

[0012] Secondly, the present invention provides a surface treatment method for wear-resistant internal combustion engine piston rings, comprising: Data on the substrate material and load spectrum of the piston ring to be processed are collected. The thermophysical parameters and surface energy states in the substrate material data are determined. Based on the thermophysical parameters, the deposition energy threshold corresponding to the plasma spraying equipment used for piston ring processing is calibrated to set the initial powder feeding rate of the powder feeder during processing. Based on the surface energy state and the working condition load spectrum, the coating gradient structure of the composite spray gun of the plasma spraying equipment is generated to perform path optimization control of the robotic arm and monitor the actual plasma jet temperature in the processing chamber of the plasma spraying equipment. Based on the actual plasma jet temperature and the deposition energy threshold, power adjustment parameters for the radio frequency power supply driving the composite spray gun are generated. The operation of the radio frequency power supply is controlled according to the power adjustment parameters, and the surface strengthening treatment of the piston ring is performed using the composite spray gun to obtain a wear-resistant coating product.

[0013] In one possible implementation of the second aspect, determining the thermal properties and surface energy states in the matrix material data includes: The material grade information and measured material data are separated from the matrix material data; Obtain the preprocessing record corresponding to the piston ring; Based on the material grade information, the corresponding standard thermophysical property data set is queried from the standard material database and output. By combining the measured data of the material and the standard thermophysical property data set, the thermophysical property parameters applied to the piston rings are analyzed. Based on the preprocessed records, the surface energy states of the piston rings are analyzed to obtain the surface energy states.

[0014] In one possible implementation of the second aspect, calibrating the deposition energy threshold corresponding to the plasma spraying equipment used for piston ring processing based on the thermophysical parameters includes: Obtain the thermal conductivity and specific heat capacity from the matrix material data; Consult the corresponding spray gun output power range and plasma gas flow rate range for the plasma spraying equipment. Based on the thermal conductivity, specific heat capacity, spray gun output power range, and plasma gas flow range, the basic energy threshold required for the heating and melting of the sprayed material during flight is calculated. Obtain the substrate surface roughness value and surface cleanliness level corresponding to the surface energy state, and calculate the interfacial bonding compensation amount required for the bonding between the sprayed particles and the substrate in combination with the basic energy threshold. By combining the basic energy threshold with the interface compensation amount, the deposition energy threshold corresponding to the plasma spraying equipment is calibrated.

[0015] In one possible implementation of the second aspect, generating the coating gradient structure of the composite spray gun of the plasma spraying equipment based on the surface energy state and the operating condition load spectrum includes: The surface energy states are analyzed by surface partitioning to obtain the activation distribution region on the surface of the piston ring matrix; Based on a preset ideal activation region, weak binding regions of activation energy in the activation distribution region are identified; Analyze the spatial deviation trend between the activated distribution region and the preset ideal activated region to determine the direction of activation energy change; The load application location corresponding to the load spectrum under the operating conditions is detected to obtain the coordinates of the concentrated area of ​​thermal and mechanical load on the piston ring surface; Based on the weak section, the spatial deviation direction, and the load application location, determine the moving speed adjustment value and moving trajectory correction value corresponding to each spraying channel of the composite spray gun; The coating gradient structure of the composite spray gun is generated by combining the moving speed adjustment value and the moving trajectory correction value.

[0016] As can be seen, by determining the thermophysical parameters and surface energy states in the substrate material data, this invention can provide a basis for the thermal response characteristics of the material itself for calibrating the deposition energy threshold, so that the energy output of the plasma jet matches the actual needs of the substrate. Furthermore, by mastering the activation state of the substrate surface, it can provide a reference for setting the initial powder feeding rate of the powder feeder, improving the spreading and adhesion quality of the sprayed particles on the substrate surface, thereby ensuring the forming stability of the wear-resistant coating. This invention generates the coating gradient structure of the composite spray gun based on the surface energy state and the working load spectrum, allowing the robotic arm to match the substrate surface activity and working load distribution during the spraying process, improving the uniformity of the coating's structure transition in the thickness direction, and providing reliable support for the service life of the piston ring under alternating loads. This invention generates the power adjustment parameters of the radio frequency power supply by combining the actual plasma jet temperature and the deposition energy threshold, thereby obtaining the direction and magnitude of the increase or decrease of the radio frequency power supply output power, so as to improve the matching degree between plasma heat input and coating deposition efficiency. Attached Figure Description

[0017] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used together with the embodiments of the invention to explain the invention, but do not constitute a limitation thereof. In the drawings: Figure 1 This is a schematic diagram of a three-dimensional structure of a wear-resistant internal combustion engine piston ring according to an embodiment of the present invention; Figure 2 This is a schematic diagram of a piston top ring structure according to an embodiment of the present invention; Figure 3 This is a schematic diagram of a top ring slot structure proposed in an embodiment of the present invention; Figure 4 A flowchart illustrating a surface treatment method for wear-resistant internal combustion engine piston rings according to an embodiment of the invention; In the diagram: 1. Piston body of internal combustion engine; 11. Piston pin hole; 12. Top ring groove; 13. Compression ring groove; 14. Oil ring groove; 2. Piston top ring; 3. Piston compression ring; 4. Oil ring assembly; 5. Upper scraper of oil ring; 6. Piston oil ring; 7. Lower scraper of oil ring; 8. Radial oil return hole. Detailed Implementation

[0018] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0019] Please see Figure 1-3The engine includes an internal combustion engine piston body 1. The outer surface of the internal combustion engine piston body 1 is respectively movably fitted with a piston top ring 2, a piston compression ring 3, and an oil ring assembly 4. The oil ring assembly 4 includes a piston oil ring 6. The upper surface of the piston oil ring 6 is movably fitted with an upper oil ring scraper 5, and the lower surface of the piston oil ring 6 is movably fitted with a lower oil ring scraper 7. Together, they form a sealing and lubrication system between the piston and the cylinder wall, which is used to achieve gas sealing, oil control, and heat conduction during engine operation.

[0020] The internal combustion engine piston body 1 is provided with a top ring groove 12, a piston ring groove 13, and an oil ring groove 14 sequentially from top to bottom. The top ring groove 12 is used to embed the piston top ring 2, the piston ring groove 13 is used to embed the piston piston ring 3, and the oil ring groove 14 is used to embed the oil ring assembly 4. The bottom and wall of each groove are surface hardened, which can improve the fit and sealing between each piston ring and the groove, reduce fretting wear, and extend the service life of the ring body and the groove.

[0021] The piston top ring 2 is used in conjunction with the top ring groove 12. The outer surface of the piston top ring 2 is a chromium-based ceramic composite coating. This coating is bonded to the base material of the piston top ring 2 by electrodeposition or physical vapor deposition. During the high-speed reciprocating motion of the piston, it can effectively reduce the friction coefficient between the piston top ring 2 and the cylinder wall, resist the impact corrosion of high-temperature and high-pressure combustion gases on the ring surface, and avoid problems such as blow-by, power reduction and increased oil consumption caused by top ring wear.

[0022] The piston ring 3 is used in conjunction with the ring groove 13. The outer surface of the piston ring 3 is sprayed with a molybdenum alloy coating. This coating is prepared by plasma spraying or supersonic flame spraying. It forms a dual interface with the piston ring 3 substrate, which is mechanically interlocked and micrometallurgically bonded. It has excellent self-lubricating properties, high-temperature oxidation resistance and anti-adhesive wear ability, which can effectively alleviate the risk of abrasive wear and cylinder scoring of the piston ring 3 in high-speed reciprocating motion.

[0023] The piston oil ring 6, upper oil ring scraper 5, and lower oil ring scraper 7 are used in conjunction with the oil ring groove 14. Both the upper and lower oil ring scrapers 5 and 7 have radial oil return holes 8, which are evenly distributed along the circumference of the scraper and have a diameter of 0.5–1.2 mm. These holes are used to guide excess oil scraped from the cylinder wall by the upper and lower oil ring scrapers 5 and 7 back to the crankcase, reducing oil consumption and engine emissions. The piston oil ring 6 is an elastic structure made of high-elasticity alloy steel. The internal combustion engine piston body 1 is provided with a piston pin hole 11. The inner wall of the piston pin hole 11 is made of a metallurgical alloy, which is a copper-based sintered wear-resistant layer. This wear-resistant layer is combined with the inner wall substrate of the piston pin hole 11 through powder metallurgy process to form a wear-resistant friction pair with the piston pin, reduce the contact stress and wear rate at the piston pin hole 11, avoid abnormal noise, jamming and other faults caused by excessive wear of the piston pin hole 11, and improve the durability and reliability of the piston under high load conditions.

[0024] The working principle and usage process of a wear-resistant internal combustion engine piston ring of the present invention are as follows: In use, the piston top ring 2, piston compression ring 3 and oil ring assembly 4 are sequentially assembled into the corresponding slots on the internal combustion engine piston body 1. The piston top ring 2 is embedded in the top ring slot 12, the piston compression ring 3 is embedded in the compression ring slot 13 and the helical support spring at its opening is kept in a compressed state. The oil ring upper scraper 5, piston oil ring 6 and oil ring lower scraper 7 are stacked and embedded in the oil ring slot 14. After assembly, the internal combustion engine piston body 1 is installed into the cylinder, and the outer circumferential surface of each piston ring forms an elastic contact seal with the cylinder wall.

[0025] When the engine is running, the piston top ring 2 acts as the first sealing barrier. Its trapezoidal ring structure expands radially under the action of gas pressure, so that the chromium-based ceramic composite coating on the outer surface is tightly attached to the cylinder wall, forming a high-pressure gas seal. The piston compression ring 3 acts as the second sealing barrier. The molybdenum alloy spray coating on its outer surface has self-lubricating properties, which further prevents residual gas leakage. The upper scraper 5 and lower scraper 7 of the oil ring assembly 4 scrape off the excess oil on the cylinder wall under the elastic tension of the piston oil ring 6. The scraped oil is guided back to the crankcase through the radial oil return hole 8.

[0026] During the above process, the surface hardening treatment of each slot can effectively withstand fretting wear. The metallurgical alloy layer on the inner wall of the piston pin hole 11 forms a wear-resistant friction pair with the piston pin, reducing contact stress. Through the synergistic effect of each piston ring, the optimized balance of gas sealing, oil control and heat conduction is achieved, effectively reducing oil consumption and extending the service life of the piston rings and piston body.

[0027] See Figure 4 The diagram shown is a flowchart of a surface treatment method for wear-resistant internal combustion engine piston rings according to an embodiment of the present invention, including: S1. Collect the substrate material data and working condition load spectrum of the piston ring to be processed, determine the thermophysical parameters and surface energy state in the substrate material data, and calibrate the deposition energy threshold corresponding to the plasma spraying equipment used for piston ring processing based on the thermophysical parameters, so as to set the initial powder feeding rate of the powder feeder.

[0028] This invention, by determining the thermophysical parameters and surface energy states in the substrate material data, provides a basis for calibrating the deposition energy threshold based on the material's thermal response characteristics. This ensures that the energy output of the plasma jet matches the actual needs of the substrate. Furthermore, by understanding the activation state of the substrate surface, it provides a reference for setting the initial powder feeding rate of the powder feeder, improving the spreading and adhesion quality of the sprayed particles on the substrate surface, thereby ensuring the formation stability of the wear-resistant coating. The piston ring to be treated is an annular component in an internal combustion engine used for sealing the cylinder and conducting heat. The substrate material data is a summary of the thermal conductivity, melting point range, coefficient of thermal expansion, and other physical properties of the material used for the piston ring. The load spectrum is a time-series record of the temperature changes, pressure fluctuations, and reciprocating motion frequency experienced by the piston ring during its working cycle. The thermophysical parameters are inherent material properties related to heat conduction, such as thermal conductivity, specific heat capacity, and phase transition temperature, extracted from the matrix material data. The surface energy state is a comprehensive characterization of the cleanliness, roughness, and surface activation energy level of the piston ring matrix surface after pretreatment. Furthermore, the matrix material data can be obtained by consulting the material quality certificate or by measuring it using equipment such as differential scanning calorimeters and laser thermal conductivity meters. The load spectrum can be continuously recorded by temperature and pressure sensors arranged in the engine bench test.

[0029] As an embodiment of the present invention, determining the thermophysical parameters and surface energy states in the matrix material data includes: The material grade information and measured material data are separated from the matrix material data; Obtain the preprocessing record corresponding to the piston ring; Based on the material grade information, the corresponding standard thermophysical property data set is queried from the standard material database and output. By combining the measured data of the material and the standard thermophysical property data set, the thermophysical property parameters applied to the piston rings are analyzed. Based on the preprocessed records, the surface energy states of the piston rings are analyzed to obtain the surface energy states.

[0030] The material grade information refers to the standard code that identifies the type and grade of the piston ring matrix material; the measured material data refers to the specific performance values ​​obtained through laboratory analysis of piston ring matrix samples; the pretreatment record is a record of the type, process conditions, and results of surface treatment steps such as cleaning, roughening, and preheating that the piston ring undergoes before spraying; the standard thermophysical property data set is a set of typical thermophysical property values ​​of the material as specified by national or industry standards, associated with the material grade information; the accurate thermophysical property parameters are specific values ​​representing the thermophysical properties of the current specific piston ring matrix material, obtained after correction of actual sample data; and the energy state assessment is a comprehensive analysis and judgment of the state of the piston ring surface in terms of microstructure, chemical activity, and cleanliness.

[0031] Optionally, material grade information and measured material data can be separated from the substrate material data using an identification function compiled by a scripting language, such as JAVA. The production reports of the pre-coating process are consulted to extract the type of cleaning agent used in the piston ring cleaning process, the sandblasting particle size and pressure used in the roughening process, and the preheating temperature and holding time reached in the preheating process, summarizing these into a pretreatment record. The material grade information is entered into the national standard material performance database, and the thermal conductivity of the material within the standard range from room temperature to melting temperature is retrieved and exported by grade. Standard thermophysical property data sets such as specific heat capacity and coefficient of linear expansion are used. The chemical composition in the material's measured data is compared with the benchmark values ​​of the corresponding grades in the standard thermophysical property data sets. The standard thermophysical property data are linearly corrected according to the degree of deviation of the chemical composition to obtain the specific heat capacity and thermal conductivity values ​​applicable to the current batch of piston rings. Based on the roughening process parameters in the pretreatment record and the actual contour values ​​measured by the surface roughness meter, the micro-interlocking ability of the substrate surface is determined. At the same time, the surface oxidation degree and activation state are evaluated by referring to the cleaning and preheating conditions in the pretreatment record, and the surface energy state is obtained by comprehensive analysis.

[0032] This invention calibrates the deposition energy threshold corresponding to the plasma spraying equipment based on the aforementioned thermophysical parameters, which can provide a basis for setting the initial powder feeding rate of the powder feeder, enabling the spraying material to form a good bonding layer on the piston ring substrate surface.

[0033] The deposition energy threshold is the minimum energy input value required for the sprayed particles to achieve effective adhesion and fusion when they impact the substrate. The powder feeder is a device used to transport the processing powder during the process. The initial powder feeding rate is a set value for the amount of powder that the powder feeder delivers to the spray gun per unit time at the beginning of the spraying operation.

[0034] As an embodiment of the present invention, the step of calibrating the deposition energy threshold corresponding to the plasma spraying equipment for piston ring processing based on the thermophysical parameters includes: Obtain the thermal conductivity and specific heat capacity from the matrix material data; Consult the corresponding spray gun output power range and plasma gas flow rate range for the plasma spraying equipment. Based on the thermal conductivity, specific heat capacity, spray gun output power range, and plasma gas flow range, the basic energy threshold required for the heating and melting of the sprayed material during flight is calculated. Obtain the substrate surface roughness value and surface cleanliness level corresponding to the surface energy state, and calculate the interfacial bonding compensation amount required for the bonding between the sprayed particles and the substrate in combination with the basic energy threshold. By combining the basic energy threshold with the interface compensation amount, the deposition energy threshold corresponding to the plasma spraying equipment is calibrated.

[0035] Wherein, the thermal conductivity is an indicator of the substrate material's ability to conduct heat; the specific heat capacity is a physical property parameter of the substrate material requiring the amount of heat absorbed to increase its temperature per unit area; the spray gun output power range is the adjustable range of electrical power output of the plasma spraying equipment; the plasma gas flow range is the adjustable flow range of the main gas and auxiliary gas during the operation of the spray gun; the basic energy threshold is the minimum energy input value calculated considering only the heat required for the melting of the spraying material itself; the substrate surface roughness value is a quantitative value of the microscopic unevenness of the substrate surface; the surface cleanliness level is a classification of the degree to which the substrate surface is free of contaminants such as oil and oxide layers; the interface bonding compensation amount is an additional energy correction value introduced considering the influence of the actual state of the substrate surface on the particle adhesion effect; and the deposition energy threshold is the minimum energy input requirement value determined by comprehensively considering the melting requirements of the spraying material and the substrate bonding conditions.

[0036] Optionally, the thermal conductivity and specific heat capacity of the substrate material are determined using a differential scanning calorimeter; the output power range of the spray gun and the plasma gas flow rate range are obtained from the instruction manual of the plasma spraying equipment; the thermal conductivity and specific heat capacity are substituted into the heat transfer calculation formula, and combined with the output power range of the spray gun and the plasma gas flow rate range, the basic energy threshold required for the sprayed particles to reach a molten state in the flight path is calculated; the surface roughness value of the substrate is measured using a surface roughness meter, and the surface cleanliness level is determined according to the standard comparison chart, thereby assessing the surface energy. The contribution of the surface energy state to the bonding strength is determined, and the interfacial bonding compensation is calculated. The deposition energy threshold is obtained by adding the base energy threshold to the interfacial bonding compensation. Finally, the initial powder feeding rate of the powder feeder is adjusted according to this threshold. If the deposition energy threshold is high, it indicates that the substrate has fast thermal conductivity or the surface energy state is low. The initial powder feeding rate should be reduced to 15 grams per minute to prolong the residence time of individual particles in the plasma jet to fully store heat. Conversely, if the threshold is low, the powder feeding rate can be increased to 25 grams per minute to balance spraying efficiency and bonding quality.

[0037] S2. Based on the surface energy state and the working condition load spectrum, generate the coating gradient structure of the composite spray gun of the plasma spraying equipment to perform path optimization control of the robotic arm and monitor the actual plasma jet temperature in the processing chamber of the plasma spraying equipment.

[0038] This invention generates a coating gradient structure for the composite spray gun based on the surface energy state and the working load spectrum. This allows the robotic arm to match the surface activity of the substrate with the working load distribution during the spraying process, improving the uniformity of the coating's microstructure transition in the thickness direction and providing reliable support for the service life of the piston rings under alternating loads. The coating gradient structure is an arrangement determined by the surface energy state and the working load spectrum to arrange different spraying materials layer by layer within the coating, such as the material ratio change from the bonding layer to the working layer.

[0039] As an embodiment of the present invention, generating the coating gradient structure of the composite spray gun of the plasma spraying equipment based on the surface energy state and the working condition load spectrum includes: The surface energy states are analyzed by surface partitioning to obtain the activation distribution region on the surface of the piston ring matrix; Based on a preset ideal activation region, weak binding regions of activation energy in the activation distribution region are identified; Analyze the spatial deviation trend between the activated distribution region and the preset ideal activated region to determine the direction of activation energy change; The load application location corresponding to the load spectrum under the operating conditions is detected to obtain the coordinates of the concentrated area of ​​thermal and mechanical load on the piston ring surface; Based on the weak section, the spatial deviation direction, and the load application location, determine the moving speed adjustment value and moving trajectory correction value corresponding to each spraying channel of the composite spray gun; The coating gradient structure of the composite spray gun is generated by combining the moving speed adjustment value and the moving trajectory correction value.

[0040] The activated distribution region refers to the spatial distribution of activation levels in different areas of the substrate surface obtained by surface partitioning and analyzing the surface energy states. For example, after sandblasting pretreatment, the surface energy distribution values ​​at different circumferential positions on the outer circle of a piston ring measured by a surface energy tester. The preset ideal activated region is the ideal activation energy distribution map required for good bonding on the substrate surface under the target process conditions, such as the reference value for uniform surface energy distribution calibrated according to the requirements of the bonding layer material. The weak bonding region is the area in the activated distribution region where the difference between the activation energy and the ideal activation distribution exceeds the allowable range, such as the arc segment position corresponding to the actual surface energy being 0.2 mN / m lower than the ideal value. The spatial deviation direction is the direction between the activated distribution region and the preset ideal activation region. The spatial variation trend of the differences between ideal activation regions, such as the gradual decrease of activation energy from the upper end face to the lower end face of the piston ring; the load application position is the data of the area of ​​action of thermal load and mechanical load on the piston ring surface corresponding to the working condition load spectrum, such as the ring surface angle position and axial height corresponding to the highest combustion pressure; the moving speed adjustment value and the moving trajectory correction value are the amount of change in the moving speed and the amount of movement path offset of the robotic arm determined by combining the weak joint area, the spatial deviation trend and the load application position, such as determining that the robotic arm reduces the spraying moving speed by 10 mm / s when passing through the weak joint area, and at the same time the spraying center line shifts 1.5 mm towards the load concentration area.

[0041] Furthermore, the surface energy state can be analyzed by surface partitioning using a surface energy analyzer to obtain the activation distribution area on the piston ring substrate surface. For example, before piston ring coating, the surface energy analyzer collects surface energy values ​​every 15° along the circumference of the ring surface and plots the activation energy distribution curve. The activation distribution area is compared with a preset ideal activation area through region matching to identify weak bonding regions where the activation energy is lower than the ideal requirement. For example, comparing the activation energy values ​​of both with the circumferential angle reveals a localized area where the actual activation energy is lower than the ideal value at the piston ring opening. Spatial trend analysis determines the spatial deviation between the activation distribution area and the preset ideal activation area, such as analyzing the gradual recovery trend of activation energy from the piston ring opening towards both sides. The corresponding load spectrum under operating conditions is detected using finite element load inversion. The load application location is determined by, for example, based on the engine cylinder pressure curve and piston ring movement law, the maximum radial clamping force occurs at a position 90° opposite the piston ring opening; combining the weak joint area, the spatial deviation direction, and the load application location, the moving speed adjustment value and moving trajectory correction value corresponding to each spraying channel of the composite spray gun are determined through spraying path planning. For example, by planning and integrating various data, it is calculated that when the robotic arm passes through the arc corresponding to the weak joint area, the moving speed is reduced from the standard 30mm / s to 20mm / s, and at the same time, the spraying center line is offset by 1.5mm towards the load concentration area; combining the moving speed adjustment value and the moving trajectory correction value, the coating gradient structure of the composite spray gun is generated according to the thermal spraying process requirements. For example, according to the adjustment parameters, the material ratio and layer overlap sequence data from the bonding layer, intermediate layer to the working layer are obtained.

[0042] This invention optimizes the path control of the robotic arm and monitors the actual plasma jet temperature in the processing chamber of the plasma spraying equipment. This dynamically ensures that each coating material is always deposited in the predetermined activation area and load-matching position during the spraying process, reducing the risk of coating peeling due to uneven surface conditions or differences in heat load distribution, and significantly improving the bonding strength and durability of the gradient coating. The actual plasma jet temperature is the real-time temperature value of the plasma flame at the spray gun exit in the processing chamber. Furthermore, after obtaining the coating gradient structure, this structure is converted into the robotic arm's moving speed and spatial trajectory settings in each spraying pass, which are then adjusted by the robot control system. Corresponding to the actual motion parameters of the joint axis, during the spraying process, the laser displacement sensor provides real-time feedback on the distance between the spray gun and the substrate to the control unit, forming a closed-loop adjustment to ensure that the deposition position and residence time of each spraying channel are stably maintained within the range required by the target gradient structure. For example, if the target gradient structure is a bonding layer thickness of 20%, an intermediate layer of 30%, and a working layer of 50%, and the total number of spraying passes is 10, then the robotic arm moving speed is set to 25 mm / s for the first two passes and the spray gun is kept 100 mm away from the substrate. The moving speed for the middle three passes is adjusted to 30 mm / s and the distance is adjusted to 120 mm. The moving speed for the last five passes is adjusted to 35 mm / s and the distance is adjusted to 150 mm. After the control system writes the motion parameters of each pass into the trajectory through the robot controller, the laser displacement sensor detects that the actual distance of the third pass is 125mm. The control unit then reduces the feed speed of the robotic arm for that pass according to the deviation until the laser feedback value stabilizes at 120mm, thus completing the precise conversion and closed-loop maintenance of the motion parameters. The actual plasma jet temperature in the processing chamber of the plasma spraying equipment can be monitored in real time by a dual-color infrared thermometer.

[0043] S3. Based on the actual plasma jet temperature and the deposition energy threshold, generate power adjustment parameters for the radio frequency power supply that drives the composite spray gun, control the operation of the radio frequency power supply according to the power adjustment parameters, and use the composite spray gun to perform surface strengthening treatment on the piston ring to obtain a wear-resistant coating product.

[0044] This invention generates power adjustment parameters for the radio frequency (RF) power supply by combining the actual plasma jet temperature and the deposition energy threshold, thereby obtaining the direction and magnitude of the RF power supply's output power increase or decrease. This improves the matching degree between plasma heat input and coating deposition efficiency. The power adjustment parameters are a set of values ​​representing the adjustment amount and direction of the RF power supply's output power during the spraying process. Further, firstly, the heating capability of the plasma jet on the sprayed particles is evaluated based on the actual plasma jet temperature. Then, the deviation between the current jet temperature and the required energy input is calculated based on the deposition energy threshold. According to the RF power supply's rated output power and the transmission efficiency of the matching network, the temperature deviation is converted into the required power adjustment amount for the RF power supply. Finally, based on the time required for the composite spray gun to complete a single spray pass and the cooling interval required for particle spreading and solidification after coating deposition, the duration for which the RF power supply maintains its current output power is determined, thus forming complete power adjustment parameters.

[0045] This invention determines the correspondence between the output power of the RF power supply and the current plasma jet temperature based on the deposition energy threshold. This ensures that the RF power supply can accurately respond to changes in energy input after receiving an adjustment command, avoiding a decrease in coating adhesion strength due to power response lag. The correspondence is a numerical conversion ratio between the adjustment range of the RF power supply output power and the deviation value of the plasma jet temperature. Furthermore, based on the lower and upper energy limits in the deposition energy threshold, combined with the rated output power range of the RF power supply and the load characteristics of the matching network, the invention calculates the power reduction required when the jet temperature reaches the upper energy limit and the power increase required when the jet temperature reaches the lower energy limit. This ensures that the RF power supply can quickly adjust the actual plasma jet temperature back to the temperature range required by the deposition energy threshold after receiving the adjustment command, while avoiding excessive power adjustment that could cause abrupt changes in plasma flame morphology or overheating of the sprayed particles.

[0046] Furthermore, combining the power adjustment parameters and the corresponding relationship, the power of the composite spray gun is controlled by the radio frequency power supply. The output power of the radio frequency power supply is changed according to the power adjustment parameters, driving the composite spray gun to operate at the adjusted power level. The process of matching the temperature change of the plasma jet, fully melting and accelerating the sprayed particles in the flame, and stably depositing the molten particles onto the surface of the piston ring substrate is completed in sequence. After the plasma jet temperature stabilizes, the radio frequency power supply enters the power maintenance stage. At this time, the composite spray gun completes the spraying action according to the preset robotic arm path, depositing each coating material layer by layer to form a gradient structure. After the coating cools and solidifies, the strengthening treatment is completed, and a continuous and dense wear-resistant coating product is obtained.

[0047] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A wear-resistant piston ring for an internal combustion engine, comprising an internal combustion engine piston body (1), characterized in that: The piston body (1) of the internal combustion engine is movably fitted with a piston top ring (2), a piston gas ring (3) and an oil ring assembly (4). The oil ring assembly (4) includes a piston oil ring (6). The upper surface of the piston oil ring (6) is movably fitted with an upper oil ring scraper (5), and the lower surface of the piston oil ring (6) is movably fitted with a lower oil ring scraper (7).

2. The wear-resistant internal combustion engine piston ring as described in claim 1, characterized in that, The piston body (1) of the internal combustion engine is provided with a top ring groove (12), a gas ring groove (13) and an oil ring groove (14) from top to bottom.

3. The wear-resistant internal combustion engine piston ring as described in claim 2, characterized in that, The piston top ring (2) is used in conjunction with the top ring groove (12), and the outer surface of the piston top ring (2) is a chromium-based ceramic composite coating.

4. The wear-resistant internal combustion engine piston ring as described in claim 2, characterized in that, The piston ring (3) is used in conjunction with the ring groove (13), and the outer surface of the piston ring (3) is sprayed with a molybdenum alloy coating.

5. A wear-resistant internal combustion engine piston ring as described in claim 2, characterized in that, The piston oil ring (6), the upper scraper (5) and the lower scraper (7) are used in conjunction with the oil ring groove (14). The upper scraper (5) and the lower scraper (7) are provided with radial oil return holes (8).

6. A wear-resistant internal combustion engine piston ring as described in claim 1, characterized in that, The piston oil ring (6) is an elastic structure, and the piston body (1) of the internal combustion engine is provided with a piston pin hole (11), the inner wall of the piston pin hole (11) is made of metallurgical alloy.

7. A method for performing surface treatment on wear-resistant internal combustion engine piston rings according to any one of claims 1 to 6, characterized in that, The method includes: Collect the substrate material data and working condition load spectrum of the piston ring to be processed, determine the thermophysical parameters and surface energy state in the substrate material data, and calibrate the deposition energy threshold corresponding to the plasma spraying equipment used for piston ring processing based on the thermophysical parameters, so as to set the initial powder feeding rate of the powder feeder during processing. Based on the surface energy state and the working condition load spectrum, the coating gradient structure of the composite spray gun of the plasma spraying equipment is generated to perform path optimization control of the robotic arm and monitor the actual plasma jet temperature in the processing chamber of the plasma spraying equipment. Based on the actual plasma jet temperature and the deposition energy threshold, power adjustment parameters for the radio frequency power supply driving the composite spray gun are generated. The operation of the radio frequency power supply is controlled according to the power adjustment parameters, and the surface strengthening treatment of the piston ring is performed using the composite spray gun to obtain a wear-resistant coating product.

8. The method according to claim 7, characterized in that, The determination of the thermophysical parameters and surface energy states in the matrix material data includes: The material grade information and measured material data are separated from the matrix material data; Obtain the preprocessing record corresponding to the piston ring; Based on the material grade information, the corresponding standard thermophysical property data set is queried from the standard material database and output. By combining the measured data of the material and the standard thermophysical property data set, the thermophysical property parameters applied to the piston rings are analyzed. Based on the preprocessed records, the surface energy states of the piston rings are analyzed to obtain the surface energy states.

9. The method according to claim 7, characterized in that, The step of calibrating the deposition energy threshold of the plasma spraying equipment used for piston ring processing based on the aforementioned thermophysical parameters includes: Obtain the thermal conductivity and specific heat capacity from the matrix material data; Consult the corresponding spray gun output power range and plasma gas flow rate range for the plasma spraying equipment. Based on the thermal conductivity, specific heat capacity, spray gun output power range, and plasma gas flow range, the basic energy threshold required for the heating and melting of the sprayed material during flight is calculated. Obtain the substrate surface roughness value and surface cleanliness level corresponding to the surface energy state, and calculate the interfacial bonding compensation amount required for the bonding between the sprayed particles and the substrate in combination with the basic energy threshold. By combining the basic energy threshold with the interface compensation amount, the deposition energy threshold corresponding to the plasma spraying equipment is calibrated.

10. The method according to claim 7, characterized in that, The process of generating the coating gradient structure of the composite spray gun in the plasma spraying equipment based on the surface energy state and the operating condition load spectrum includes: The surface energy states are analyzed by surface partitioning to obtain the activation distribution region on the surface of the piston ring matrix; Based on a preset ideal activation region, weak binding regions of activation energy in the activation distribution region are identified; Analyze the spatial deviation trend between the activated distribution region and the preset ideal activated region to determine the direction of activation energy change; The load application location corresponding to the load spectrum under the operating conditions is detected to obtain the coordinates of the concentrated area of ​​thermal and mechanical load on the piston ring surface; Based on the weak section, the spatial deviation direction, and the load application location, determine the moving speed adjustment value and moving trajectory correction value corresponding to each spraying channel of the composite spray gun; The coating gradient structure of the composite spray gun is generated by combining the moving speed adjustment value and the moving trajectory correction value.

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