Method for treating cylinder working surface or cylinder liner of cylinder by means of laser action

Abstract

The invention relates to a method for treating a cylinder working surface or a cylinder liner of a cylinder, comprising the contactless action of a pulsed laser beam on a honing surface (5) of the cylinder working surface or the cylinder liner, the honing surface (5) having a honing pattern (7) and / or a secondary pattern, the action of the pulsed laser beam being arranged such that the honing pattern (7) and / or the secondary pattern (7) are aligned with each other. The iron carbide body component (2) on the honed surface (5) is re-melted to form an iron carbide body layer (8).

Description

Technical Field

[0001] This invention relates to a method for processing the cylinder working surface or cylinder liner of a reciprocating piston engine cylinder. Background Technology

[0002] Cylinder liners, or cylinder working surfaces, are critical components in reciprocating piston engines, providing durable surfaces for piston movement and combustion. These liners can be made of flake graphite cast iron with a pearlitic structure, consisting of ferrite, carbide, and graphite flakes. The surface properties of the cylinder liner have a significant impact on engine performance, efficiency, and lifespan.

[0003] Over time, cylinder liners are subjected to extreme conditions such as high temperatures, high pressures, and mechanical stresses. This can lead to wear, deterioration of surface properties, and accumulation of combustion residues in the honing and secondary textures of the cylinder liner surface. These factors can negatively impact engine performance, increase oil consumption, and potentially shorten engine life.

[0004] Various methods have been employed to improve the surface properties of cylinder liners, including honing, which creates a cross-grind pattern that aids in oil retention and distribution. However, traditional honing methods do not always provide optimal surface properties for modern high-performance engines.

[0005] Whether manufacturing new engines or refurbishing old ones, there is always a need for improved methods and technologies to treat cylinder working surfaces and cylinder liners. Advances in this field could lead to engines with better performance, higher efficiency, lower emissions, and longer service life. Summary of the Invention

[0006] Based on the known prior art, the purpose of this invention is to provide an improved method for processing the cylinder working surface or cylinder liner of a reciprocating piston engine, and in particular an improved method for improving the surface characteristics of the cylinder working surface or cylinder liner.

[0007] This objective is achieved by a method having the features of claim 1. Advantageous improvements are available from the appended claims, the specification, and the drawings.

[0008] According to one aspect of this disclosure, a method for treating a cylinder working surface or cylinder liner is provided, the method comprising applying a pulsed laser beam non-contactly to a honed surface of the cylinder working surface or cylinder liner, the honed surface having a honed texture and / or a secondary texture, wherein the pulsed laser beam is configured to remelt the ferrocarbide components on the honed surface into a ferrocarbide layer.

[0009] Ferric carbide (also known as iron carbide) is characterized by its very high hardness. Therefore, the ferric carbide layer on the honed surface improves the stability and wear resistance of the cylinder working surface or cylinder liner. In this way, the durability of the cylinder working surface or cylinder liner is improved.

[0010] The cylinder working surface or cylinder liner may include or be composed of flake graphite cast iron with a pearlescent structure, and includes cementite, ferrite and graphite flake components, wherein the pulsed laser beam may also be configured to expose the graphite flake components on the honing surface and cause the ferrite components to evaporate.

[0011] This improves the tribological properties of the honed surface because exposing the graphite flakes improves oil retention and lubrication. This increases wear resistance, improves oil retention, and extends engine life, thereby improving the characteristics of the treated engine.

[0012] To refurbish honing patterns and / or secondary patterns clogged by combustion residues (especially in the form of oil carbon in liquid fuel engines or carbon deposits in gas engines), a pulsed laser beam can be configured to remove the combustion residues from the honing patterns and / or secondary patterns on the honed surface by evaporation.

[0013] Therefore, this method can be used not only to treat new cylinder working surfaces or cylinder liners, but also to refurbish used cylinder working surfaces or cylinder liners. Thus, the application of this method is very flexible.

[0014] In particular, the above advantages can be achieved through a single pulsed laser beam treatment. Therefore, this treatment can simultaneously achieve the following effects in a single step of applying a pulsed laser beam to the honed surface: remelting the ferrocarbide components into a ferrocarbide layer, exposing the graphite components, evaporating the ferrite components, and cleaning by evaporating combustion residues.

[0015] The pulsed laser beam can be repeated until a layer of iron carbide that is substantially or completely closed (preferably with a uniform surface structure) is formed on the honed surface.

[0016] The essentially closed surface of the ferrocarbide layer refers, for example, to a surface in which the ferrocarbide layer extends throughout all areas of the honed surface, except for the honing pattern and / or secondary pattern. In other words, the ferrocarbide layer does not form within the honing pattern or secondary pattern.

[0017] A completely enclosed surface of the ferrocarbide layer refers to a surface in which the ferrocarbide layer exists throughout the entire honing surface, including within the honing core and / or secondary core. In such cases, the ferrocarbide layer follows the surface profile, so the honing core and secondary core remain, but are covered by the ferrocarbide layer.

[0018] The thickness of the iron carbide body layer can be constructed to be 2 nm to 1 µm, preferably 3 to 10 nm.

[0019] The pulsed laser beam can be configured to melt the honed surface by applying the pulsed laser beam, and to round the edges of sharp-edged structures and / or honed textures and / or protruding material tongues and / or secondary textures, especially to improve the tribological properties of the honed surface.

[0020] By rounding the corners of the above structure, wear on the honed surface can be reduced, and the tribological properties can be improved by homogenizing the surface.

[0021] The pulsed laser beam can be configured to melt and / or redistribute the material on the honing surface to obtain a more uniform surface structure with reduced sharp edges and protrusions than before the pulsed laser beam was applied.

[0022] In this way, the wear of the treated surface can also be improved.

[0023] The average laser power of the pulsed laser beam is 90-300 W, the wavelength is 1060-1070 nm, the pulse frequency is 135-165 kHz, and the pulse width is 18-22 ns.

[0024] In this way, the above advantages can be achieved.

[0025] The above objective can be further achieved by a method for treating cylinder working surfaces or cylinder liners with honed surfaces (with honed texture and / or secondary texture), wherein a pulsed laser beam is applied to the honed surface, the pulsed laser beam having an average laser power of 90-300 W, a wavelength of 1060-1070 nm, a pulse frequency of 135-165 kHz, and a pulse width of 18-22 ns.

[0026] The above-mentioned processing steps and advantages can be achieved by using a pulsed laser beam with appropriate settings to act on the honing surface.

[0027] For all the methods and variations described above, the average laser power can be adjusted according to the load on the honed surface with combustion residue. Preferably, for a new honed surface not subjected to combustion residue load, the average laser power is adjusted to 90-110 W; for a honed surface subjected to a slight combustion residue load, the average laser power is adjusted to 125-155 W; and for a honed surface subjected to a severe combustion residue load, the average laser power is adjusted to 180-220 W.

[0028] As mentioned earlier, this method can be used very flexibly and independently of the specific condition of the honed surface. Correspondingly, both new and old cylinder working surfaces or cylinder liners can be treated.

[0029] The pulsed laser beam can be configured to expose the graphite flakes on the honing surface, causing the ferrite components to evaporate and the remaining ferrocarbide components to remelt into a ferrocarbide layer. The cylinder working surface or cylinder liner of the cylinder includes or is composed of flake graphite cast iron with a pearlescent structure, and includes ferrocarbide components, ferrite components and graphite flakes.

[0030] Through optical components, a pulsed laser beam can be applied to the honing surface, causing the honing surface to be treated by a processing spot with a length of 28-32 nm and a width of 1.9-2.1 nm.

[0031] A pulsed laser beam can move across the honing surface at a scanning speed of 7200 - 8800 mm / s to subject it to laser beam action.

[0032] This surface scanning method allows the entire honed surface to be subjected to the pulsed laser beam, and all areas of the honed surface to be processed accordingly. Through this scanning, the processing method can be easily adjusted according to the specific geometry and size of the honed surface.

[0033] The single-pulse energy of the pulsed laser beam can reach up to 1.8 mJ, preferably 0.2 - 2.5 µJ.

[0034] This enables reliable and fast processing.

[0035] This method can be implemented with the engine installed.

[0036] Therefore, especially when refurbishing used cylinder working surfaces or cylinder liners, the process can be carried out in a particularly simple and efficient manner without extensive disassembly of the engine.

[0037] The above objective can also be achieved by a cylinder or cylinder liner of a reciprocating piston engine having a honed surface (with honed texture and / or secondary texture), wherein the honed surface has a ferrocarbide body layer with a thickness of 2 nm to 1 µm (preferably 3 - 10 nm).

[0038] This type of cylinder or cylinder liner has the following advantages: due to the unique surface structure produced by the laser processing technology, wear resistance is improved, oil retention is enhanced, and service life is extended.

[0039] The iron carbide body layer can be substantially closed or completely closed, and preferably forms a uniform surface structure, wherein the iron carbide body layer is particularly preferably extended throughout the honing surface.

[0040] The essentially closed surface of the ferrocarbide layer refers, for example, to a surface in which the ferrocarbide layer extends throughout all areas of the honed surface, except for the honing pattern and / or secondary pattern. In other words, the ferrocarbide layer does not form within the honing pattern or secondary pattern.

[0041] A completely enclosed surface of the ferrocarbide layer refers to a surface in which the ferrocarbide layer exists throughout the entire honing surface, including within the honing core and / or secondary core. In such cases, the ferrocarbide layer follows the surface profile, so the honing core and secondary core remain, but are covered by the ferrocarbide layer.

[0042] The cylinder or cylinder liner may include a pearlescent structure having carbide, ferrite and graphite components, wherein the graphite components may be exposed on the honed surface and the ferrite components may be removed, preferably evaporated.

[0043] Sharp-edged structures and / or honed mesh edges and / or protruding material tongues and / or secondary mesh edges can be rounded by melting.

[0044] The ferrocarbide layer on the honing surface can be formed as a substantially closed surface or a closed surface, preferably as having a uniform surface structure, and particularly preferably on the entire honing surface.

[0045] Graphite flakes can be exposed on the honing surface to create an exposed graphite flake network, thereby improving the tribological properties of the surface.

[0046] Methods and apparatus for laser-treating cylinder working surfaces or cylinder liners offer several technical advantages. First, the laser treatment process achieves multiple beneficial effects simultaneously in a single step. It effectively removes combustion residues and impurities from the honed surface through evaporation, including clogged honing patterns and secondary patterns. This cleaning effect restores the original tribological properties of the surface texture, which is crucial for proper lubrication and reduced friction during engine operation.

[0047] Simultaneously, laser processing exposes graphite flakes on the honed surface. This exposure improves the self-lubricating properties of the cylinder liner material, further reducing friction and wear during engine operation.

[0048] Laser-induced thermal effects also lead to the rounding of sharp edges, honed textured edges, and protruding material tongues. This rounding effect produces a more uniform surface morphology that is less prone to the accumulation of combustion residues and has better tribological properties.

[0049] Laser treatment alters the surface microstructure by evaporating the ferrite component and remelting the remaining ferrocarbide component into a ferrocarbide layer. This ferrocarbide layer, with a thickness ranging from a few nanometers to 1 μm, exhibits a ceramic-like structure on the honed surface. The presence of this ferrocarbide layer significantly improves the wear resistance of the cylinder liner, extending its service life. Furthermore, the ferrocarbide layer reduces the material affinity of friction components such as piston rings and piston rods, thereby reducing the tendency for adhesive wear.

[0050] The versatility of this method is another significant advantage. It can be used for new cylinder liners as well as honed surfaces subjected to light or heavy loads of combustion residue, with laser parameters adjustable to suit different surface conditions. This flexibility enables the processing of engines at various stages of their life cycle, from manufacturing to maintenance and refurbishment.

[0051] Furthermore, this method can be performed with the cylinder liners installed in the engine, requiring only the removal of the cylinder head. Compared to traditional refurbishment methods, this in-situ treatment capability significantly reduces maintenance time and costs, which may require complete engine disassembly or cylinder liner replacement.

[0052] Finally, this method also offers excellent process control and repeatability. Consistency in quality can be ensured through visual inspection of treated surfaces or by using automated magnetic wave induction surface inspection technology, reducing reliance on subjective judgment. This characteristic is particularly valuable in industrial applications where consistency and quality control are critical. Attached Figure Description

[0053] Other preferred embodiments of the invention will be described in detail with reference to the following figures.

[0054] Figure 1 The diagram shows a cross-sectional view of the cylinder working surface or cylinder liner of a reciprocating piston engine before processing, with the cross-section magnified approximately 800 times.

[0055] Figure 2 The following are examples of laser-beam treatment according to some aspects of the invention. Figure 1 A schematic diagram of the cross-section of the honing surface.

[0056] Figure 3 A scanning electron microscope image of an untreated honed surface is shown.

[0057] Figure 4 Scanning electron microscope images of honed surfaces treated with laser beams according to some aspects of this disclosure are shown. Detailed Implementation

[0058] Preferred embodiments will now be described with reference to the accompanying drawings. Identical, similar, or equivalent elements in different figures are referred to by the same reference numerals; to avoid repetition, some elements will not be described in detail here.

[0059] This disclosure provides a method for treating the cylinder working surface or cylinder liner of a reciprocating piston engine cylinder, particularly those made of flake graphite cast iron. The method uses a pulsed laser to perform non-contact treatment on the honed surface of the cylinder working surface or cylinder liner, the honed surface having a honing pattern and / or secondary pattern.

[0060] The purpose of applying a pulsed laser beam to the honed surface is primarily to remelt the ferrocarbide components on the honed surface into a ferrocarbide layer. This method can provide a hard and wear-resistant honed surface.

[0061] Applying heat to the honed surface can also expose graphite flakes and evaporate ferrite components. If there are combustion residues on the honed surface, they can also be evaporated using pulsed laser treatment. This cleaning, reshaping, and surface property improvement of the honed surface can enhance engine performance and extend its service life.

[0062] This method is versatile and can be used on newly honed surfaces, honed surfaces subjected to light combustion residue loads, and honed surfaces subjected to heavy combustion residue loads. The treatment parameters can be adjusted according to the different conditions of the honed surface before treatment. This flexibility allows for the treatment of engines at different stages of their life cycle, from manufacturing to maintenance and refurbishment.

[0063] refer to Figure 1 and Figure 2 These figures show a portion of a cylinder (particularly the cylinder working surface) or cylinder liner, and in the examples shown, they all include a pearlescent structure 1.

[0064] The honing surface 5 is shown in the cross-sectional schematic diagram. Figure 1 The surface shown is before it is treated with a pulsed laser beam. Figure 2 In the middle, it is processed afterward.

[0065] The cylinder or cylinder liner with a cylinder working surface comprises or is made of flake graphite cast iron having a pearlescent structure 1. This structure 1 comprises a carbide component 2, a ferrite component 3, and a graphite flake component 4. The honed surface 5 includes a honing pattern 7 and / or a secondary pattern.

[0066] The honed surface 5 is treated non-contactly using a pulsed laser. This process involves the application of a pulsed laser beam. As previously described, applying the pulsed laser beam to the honed surface 5 remelts the iron carbide component 2 into an iron carbide layer 8. This remelting process improves the surface properties of the honed surface 5, thereby improving the cylinder working surface or cylinder liner and creating a more durable and efficient surface for engine operation.

[0067] Furthermore, pulsed laser treatment can expose the graphite flakes 4 on the honing surface 5. Exposure of the graphite flakes 4 can improve the tribological properties of the honing surface 5, thereby enhancing engine performance and lifespan.

[0068] The pulsed laser beam can also evaporate the ferrite component 3. This evaporation process can also clean the honed surface 5, removing unwanted materials and impurities.

[0069] For new cylinder working surfaces or cylinder liners that have not yet been put into use, a honed surface 5 can be provided in this way: this surface does not contain any residues or additives left over from the manufacturing of the honed surface 5, such as chips or honing oil. This allows for a gentle break-in of the engine, reduces wear, and thus helps extend engine life.

[0070] Laser processing can be applied to newly honed surfaces, honed surfaces subjected to light combustion residue loads, and honed surfaces subjected to heavy combustion residue loads.

[0071] In some aspects, laser parameters can be adjusted to account for different surface conditions. This flexibility enables the processing of engines at different stages of their life cycle, from manufacturing to maintenance and refurbishment.

[0072] In other words, the process involves remelting the pearlescent structure 1 into a closed iron carbide layer 8. The formation of this iron carbide layer 8 can improve the surface properties of the cylinder liner, thereby improving engine performance and lifespan.

[0073] Treatment using a laser beam can significantly impact the surface structure of the honed surface 5. For example, the honing patterns 7 and / or secondary patterns on the cylinder working surface 5 may be clogged by combustion residues 6 or dirt. These combustion residues may include, for example, oil carbon from liquid fuel engines (e.g., operating on diesel, light oil, or heavy oil) or carbon deposits from gas engines (e.g., operating on natural gas). During treatment, the laser beam can re-expose these patterns by evaporating the combustion residues 6.

[0074] Therefore, this cleaning process can restore the function of the texture, enabling it to once again effectively benefit the tribological properties of the honed surface 5.

[0075] Additionally or alternatively, in addition to cleaning the honing texture and / or secondary texture, treatment with a pulsed laser beam can also round off sharp edges on the honing surface 5 of the cylinder working face. These structures include the edges of the honing texture 7 and / or protruding material tabs and / or the edges of the secondary texture. The rounding process is achieved by melting these structures during laser beam treatment. This results in a smoother surface structure and reduces sharp edges and protrusions compared to the surface structure before pulsed laser beam treatment.

[0076] This rounded corner treatment process can improve the tribological properties of the surface, reduce friction and wear during engine operation, and thus restore the engine's lifespan in this way.

[0077] For new cylinder working surfaces or cylinder liners that have not yet been put into use, this method can provide honing surfaces 5, allowing the engine to be gently broken in, reducing wear, and thus helping to extend the engine's life.

[0078] Pulsed laser beam treatment can also redistribute the material on the honed surface 5. This is achieved by partially melting the material on the honed surface 5 during the laser beam's action. The molten material is then redistributed on the honed surface 5 to fill voids and level irregularities. This results in a more uniform surface structure and reduced roughness compared to the surface structure before laser treatment.

[0079] The average laser power of the pulsed laser beam acting on the honing surface 5 is 90-300 W, the wavelength is 1060-1070 nm, the pulse frequency is 135-165 kHz, and the pulse width is 18-22 ns.

[0080] The laser power can be adjusted according to the load of combustion residue 6 on the honed surface 5. Specifically, for a new honed surface 5 without a load of combustion residue 6, the average laser power can be adjusted to 90-110 W. For a honed surface 5 subjected to a slight load of combustion residue 6, the average laser power can be adjusted to 125-155 W. For a honed surface 5 subjected to a severe load of combustion residue 6, the average laser power can be adjusted to 180-220 W.

[0081] The single-pulse energy of the pulsed laser beam can reach up to 1.8 mJ, preferably 0.2 - 2.5 µJ.

[0082] These settings are designed to effectively handle the cylinder working surfaces or cylinder liners without causing unnecessary damage or wear.

[0083] In order to fully process the honing surface 5, a pulsed laser beam can be applied to the honing surface 5 through an optical component, so that the honing surface 5 is subjected to a processing spot with a length of 28-32 nm and a width of 1.9-2.1 nm.

[0084] Under such conditions, the pulsed laser beam can move on the honing surface 5 at a scanning speed of 7200 - 8800 mm / s so that it is subjected to the pulsed laser beam.

[0085] The laser beam can be applied to the honing surface 5 once or multiple times until a basically closed and uniformly structured iron carbide layer 8 is formed on the honing surface 5. Preferably, this iron carbide layer 8 is achieved over the entire honing surface 5.

[0086] Such repeated laser beam action can ensure that the entire honing surface 5 is uniformly treated, thereby bringing a consistent and uniform iron carbide body layer 8 to the entire surface.

[0087] The iron carbide body layer formed by applying a pulsed laser beam to the honing surface 5 can produce an iron carbide body layer 8 with a thickness of 2 nm to 1 µm (preferably 3-10 nm).

[0088] This can improve the overall performance and lifespan of the engine by providing a consistent and durable surface for engine operation.

[0089] refer to Figure 3 and Figure 4 These schematic diagrams show scanning electron microscope images of honed surfaces at different processing stages.

[0090] Figure 3 A cross-sectional view of the untreated honed surface is shown. Pearlescent structure 1 can be seen as the substrate. A layer of combustion residue 6 is present on the honed surface, appearing as a dark band at the top edge of the image. The scale bar indicates that the thickness of the combustion residue layer is only a few micrometers.

[0091] Figure 4 This shows a cross-sectional view of the honed surface after laser treatment. Pearl structure 1 can still be seen as the base material.

[0092] Graphite flakes 4 can be seen extending from the substrate to the surface. This exposure creates a network of exposed graphite flakes, which improves the oil retention properties of the surface. This can improve engine performance and lifespan by reducing friction and wear during operation.

[0093] Laser processing also resulted in the formation of a layer of iron carbide 8, which is visible as a light-colored band along the top surface. Figure 3Compared to the combustion residue layer 6 in the previous layer, the iron carbide layer 8 appears more uniform and continuous. The scale bar shows that the thickness of the iron carbide layer 8 is significantly less than 1 μm.

[0094] Figure 3 and Figure 4 The comparison illustrates the effect of laser treatment on the honed surface, including the removal of combustion residues and the formation of the iron carbide layer 8. In some aspects, the thickness of the iron carbide layer 8 is from 2 nm to 1 µm, preferably 3–10 nm. This layer provides a durable and efficient surface for engine operation.

[0095] In some aspects, there are significant differences between cylinder liners treated with laser methods and those without. These differences can be observed using a scanning electron microscope, such as... Figure 3 and Figure 4 As shown, the treated cylinder liner has a more uniform and continuous layer of iron carbide, less combustion residue, and fewer exposed graphite flakes. The changes in surface structure and composition resulting from laser treatment can improve engine performance and service life.

[0096] In some aspects, the laser used in the processing method to provide the laser beam is a pulsed laser. Pulsed lasers have wavelengths of 1060 to 1070 nm, pulse widths of 10 to 500 ns, pulse frequencies of 1 to 4000 kHz, and maximum single-pulse energies of up to 1.8 mJ.

[0097] In some cases, it specifically refers to a 1064 nm Nd:YAG laser. This laser is known for its high power and high precision, making it ideal for processing cylinder liners.

[0098] In some cases, the treatment of the cylinder working surface or cylinder liner is performed while the engine is mounted. This characteristic allows the processing to be carried out without extensive engine disassembly, thus reducing downtime and operating costs. In some cases, the laser device or its output optics used in this method are mounted on a linear actuator. This arrangement facilitates the movement of the laser device or its output optics along the length of the cylinder liner and ensures uniform treatment of the entire surface.

[0099] In some implementations, the method is carried out under a variety of environmental conditions. For example, the method can be carried out at humidity levels ranging from 10% to 95% and with room temperatures ranging from 0 to 40°C. This flexibility in environmental conditions allows the method to be used in a variety of environments, from controlled indoor settings to outdoor environments with varying weather conditions.

[0100] In some cases, this method results in a roughening treatment of the cylinder liner interior. This treatment involves the partial melting and redistribution of material on the cylinder working surface during laser beam application. This can result in a more uniform surface structure and reduced roughness compared to the surface before laser treatment. This can improve the tribological properties of the surface and reduce friction and wear during engine operation.

[0101] In some aspects, this method is performed manually. This characteristic allows the process to be carried out without complex machines or automated systems. This makes the method easier to use and less expensive, especially for small businesses or situations where advanced equipment is not available. Although the method is manual, the precision and control provided by the laser equipment still allow for effective and uniform treatment of the honed surface.

[0102] In some respects, the results of laser treatment on honed surfaces can be inspected and verified in several ways. One method is visual inspection based on the obvious changes in the surface texture of the honed surface. After laser treatment, the cylinder working surface can have a more uniform and continuous layer of iron carbide, reducing combustion residues and exposing graphite flakes. These changes in surface structure and composition can be observed visually, providing a simple and easy way to verify the results of the laser treatment process.

[0103] In some cases, automation techniques can be used to inspect and verify the results of laser processing. For example, automated magnetic wave induction surface inspection, also known as the Tom method, can be used. This method involves inspecting the surface of a cylinder's working face using magnetic waves. Magnetic waves can detect changes in surface structure and composition, providing a detailed and accurate assessment of the laser processing results. This automated inspection method is particularly useful when high precision and accuracy are required, or when human factors such as fatigue or changes in condition may affect the reliability of visual inspection.

[0104] In some aspects, multiple inspection and verification methods can be used in combination to provide a comprehensive assessment of the results of laser processing. For example, visual inspection can be used for an initial assessment of surface changes, followed by a more detailed and accurate assessment using automated magnetic wave induction surface inspection. This combination of methods ensures that the laser processing effectively treats the honed surface, improves its tribological properties, and enhances engine performance and lifespan.

[0105] In several ways, the quality of a laser-treated honed surface can be determined. One approach may involve using profilometry techniques to measure surface roughness parameters. For example, a tactile cutter or optical profilometer can be used to measure the arithmetic mean roughness (Ra), the square mean roughness (Rq), and the maximum peak-to-valley height (Rz) of the treated surface. These measurements provide quantitative data on the smoothness and uniformity of the laser-treated surface.

[0106] In some cases, advanced microscopy techniques can be used to experimentally determine the surface structure of the laser-treated cylinder working surface. Scanning electron microscopy (REM) can be used to observe the surface morphology at high magnification and display details of the iron carbide layer 8, exposed graphite flakes 4, and residual honing texture 7. In addition, atomic force microscopy (AFM) can be used to create three-dimensional surface maps and provide surface features at nanometer-level resolution.

[0107] In some respects, X-ray diffraction (XRD) analysis can be performed to determine the crystal structure of the laser-treated surface. This technique can confirm the presence and relative abundance of ferrocarbide in the newly formed layer 8, and detect changes in the underlying pearlescent structure 1.

[0108] Various measurements can be performed on the laser-treated honed surface to evaluate its quality and properties. In some cases, the thickness of the iron carbide body layer 8 can be measured using a cross-sectional scanning electron microscope or a transmission electron microscope (TEM). Depending on the specific laser treatment parameters used, the thickness of this layer can range from a few nanometers to 1 μm.

[0109] In some aspects, this method involves adjusting the treatment and laser parameters based on the condition of the cylinder liner surface. For new cylinder liners, the treatment may not include the removal of oil carbon or combustion gas deposits, as these impurities are not typically found on unused cylinder liners. However, the treatment may still include the removal of honing residues, such as honing oil. In this case, the laser parameters can be adjusted to focus primarily on the exposure of graphite flakes and the formation of the ferrocarbide layer, rather than the removal of combustion residues.

[0110] For lightly used cylinder liners, this method may include a light cleaning process to remove minor oil or fuel gas carbon deposits. Laser parameters can be adjusted to provide sufficient energy for cleaning while still focusing on surface resurfacing. In some cases, laser power can be increased by 5-10% compared to parameters used with new cylinder liners, and the pulse frequency can also be adjusted to optimize cleaning results.

[0111] For heavily used cylinder liners with significant amounts of oil or fuel gas carbon deposits, this method can incorporate a more robust cleaning process. Laser parameters can be adjusted to provide higher energy for effective removal of these deposits. In some aspects, laser power can be increased by 15-25% compared to parameters used with new cylinder liners, and pulse widths can be extended for more thorough evaporation of impurities. Scanning speed can also be reduced to ensure sufficient exposure time for cleaning and surface remodeling.

[0112] In some cases, this method may include a pretreatment assessment of the honed surface to determine its condition and the presence of impurities. This assessment may include visual inspection, profilometry, or spectral analysis to characterize the surface composition. Based on the assessment results, laser parameters and processing techniques can be customized for the specific condition of each cylinder liner to ensure optimal results regardless of its service history.

[0113] The method and apparatus for laser treatment of cylinder working surfaces and cylinder liners described herein have broad industrial application prospects, particularly in the automotive, shipbuilding, and heavy machinery manufacturing industries. This technology is suitable for industrial applications in engine manufacturing, maintenance, and refurbishment. It can be used on new engine production lines as well as in repair and overhaul facilities for older engines. The versatility of this method allows it to be applied to engines of various types and sizes, from small car engines to large marine diesel engines. While the examples above focus on internal combustion engines, the principles and techniques of this invention can be adapted for other industries requiring precision surface treatment of cylinder bores, such as hydraulic systems, pneumatic cylinders, or even engine component treatment in the aerospace industry. The scalability and adaptability of this laser treatment method make it a valuable tool for improving the performance, efficiency, and lifespan of various industrial machinery and equipment.

[0114] Where applicable, the various features described in all embodiments can be combined and / or substituted for each other without departing from the scope of the invention.

[0115] List of reference numerals

[0116] 1 Pearl structure

[0117] 2. Composition of iron carbide

[0118] 3 Ferrite composition

[0119] 4 graphite sheets

[0120] 5 Honing the surface

[0121] 6. Combustion residue

[0122] 7 Honed mesh

[0123] 8. Iron carbide body layer

Claims

1. A method for treating the cylinder working face or cylinder liner of a cylinder, wherein, The method includes the following steps: - A pulsed laser beam is applied non-contactly to the honed surface (5) of the cylinder working surface or the cylinder liner, wherein the honed surface (5) has honed texture (7) and / or secondary texture, wherein, - The function of the pulsed laser beam is to remelt the iron carbide components (2) on the honed surface (5) into an iron carbide layer (8).

2. The method according to claim 1, wherein, The cylinder working surface or the cylinder liner of the cylinder comprises or is composed of flake graphite cast iron having a pearlescent structure (1), and includes iron carbide components and cementite components (2), ferrite components (3) and graphite flake components (4), wherein the function of the pulsed laser beam can also be configured to expose the graphite flake components (4) on the honing surface (5) and cause the ferrite components (3) to evaporate.

3. The method according to claim 1 or 2, wherein, In order to refurbish the honing texture (7) and / or secondary texture that are clogged by combustion residue (6) (especially in the form of oil carbon in liquid fuel engines or carbon deposits in gas engines), the pulsed laser beam is configured to remove the combustion residue (6) from the honing texture (7) and / or secondary texture of the honing surface (5) by evaporation.

4. The method according to any one of the preceding claims, wherein, The pulsed laser beam is applied repeatedly until the iron carbide body layer (8) with a substantially closed or completely closed surface (preferably with a uniform surface structure) is formed on the honed surface (5).

5. The method according to any one of the preceding claims, wherein, The iron carbide body layer (8) is formed with a thickness of 2 nm to 1 µm, preferably 3 to 10 nm.

6. The method according to any one of the preceding claims, wherein, The pulsed laser beam is configured to melt the edges of the sharp edge structure and / or the honing texture (7) and / or the protruding material tongue and / or the edges of the secondary texture by means of the pulsed laser beam, in particular to improve the tribological properties of the honing surface (5).

7. The method according to any one of the preceding claims, wherein, The pulsed laser beam is configured to melt and / or redistribute the material on the honing surface (5) to obtain a more uniform surface structure with fewer sharp edges and protrusions than the surface structure before the pulsed laser beam was applied.

8. The method according to any one of the preceding claims, wherein, The pulsed laser beam has an average laser power of 90-300 W, a wavelength of 1060-1070 nm, a pulse frequency of 135-165 kHz, and a pulse width of 18-22 ns.

9. A method for treating a cylinder working surface or cylinder liner having a honed surface (5) (with honed texture (7) and / or secondary texture), wherein, The pulsed laser beam is applied to the honed surface (5). The pulsed laser beam has an average laser power of 90-300 W, a wavelength of 1060-1070 nm, a pulse frequency of 135-165 kHz, and a pulse width of 18-22 ns.

10. The method according to claim 8 or 9, wherein, The average laser power is adjusted according to the load on the honed surface (5) with combustion residue (6). Preferably, for a new honed surface (5) not subjected to combustion residue (6) load, the average laser power is adjusted to 90-110 W; for a honed surface (5) subjected to slight combustion residue (6) load, the average laser power is adjusted to 125-155 W; and for a honed surface (5) subjected to severe combustion residue (6) load, the average laser power is adjusted to 180-220 W.

11. The method according to claim 9 or 10, wherein, The pulsed laser beam is configured to expose the graphite flake component (4) on the honing surface (5), cause the ferrite component (3) to evaporate, and remelt the remaining iron carbide component (2) into an iron carbide layer (8). The cylinder working surface or the cylinder liner of the cylinder includes or is composed of flake graphite cast iron with a pearlescent structure (1), and includes iron carbide component (2), ferrite component (3) and graphite flake (4) components.

12. The method according to any one of the preceding claims, wherein, The pulsed laser beam is applied to the honing surface (5) by means of an optical component, so that the honing surface (5) is subjected to a processing spot with a length of 28-32 nm and a width of 1.9-2.1 nm.

13. The method according to any one of the preceding claims, wherein, The pulsed laser beam moves on the honing surface (5) at a scanning speed of 7200-8800 mm / s, so that the honing surface is subjected to the pulsed laser beam.

14. The method according to any one of the preceding claims, wherein, The single-pulse energy of the pulsed laser beam can reach up to 1.8 mJ, preferably 0.2 - 2.5 µJ.

15. The method according to any one of the preceding claims, wherein, The method is performed with the engine installed.

16. A cylinder or cylinder liner of a reciprocating piston engine having a honed surface (5) (with honed texture (7) and / or secondary texture), wherein, The honed surface (5) has a ferrocarbide body layer (8) with a thickness of 2 nm to 1 µm (preferably 3 - 10 nm).

17. The cylinder or cylinder liner according to claim 16, wherein, The iron carbide body layer (8) is closed or substantially closed, and preferably forms a uniform surface structure, wherein the iron carbide body layer (8) is particularly preferably extended throughout the entire honing surface (5).

18. The cylinder or cylinder liner according to claim 16 or 17, wherein, The cylinder working surface or the cylinder liner of the cylinder includes a pearlescent structure (1) having a carbide component (2), a ferrite component (3) and a graphite flake component (4), the graphite flake component (4) being exposed on the honing surface (5), and the ferrite component (3) being removable, preferably evaporated.

19. The cylinder or cylinder liner according to any one of claims 16 to 18, wherein, The edges of the sharp edge structure and / or the honed mesh (7) and / or the protruding material tongue and / or the secondary mesh are rounded by melting.

20. The cylinder or cylinder liner according to any one of claims 16 to 19, wherein, Graphite flakes (4) are exposed on the honing surface (5) to create an exposed graphite flake network that improves the tribological properties of the honing surface (5).

21. A cylinder or cylinder liner for a reciprocating piston engine, the cylinder liner having a honed surface (5) (with honed texture (7) and / or secondary texture), wherein the honed surface (5) is treated using the method of any one of claims 1 to 15.

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