Grinding tool and method for sealing surface of rear moving ring

Abstract

The invention belongs to the field of aero-engine manufacturing, and discloses a grinding tool and method for a rear moving ring sealing face, the grinding tool comprises a tool body designed to be of a disc-shaped structure, a first round positioning groove is formed in the end face to be in clearance fit with the outer edge of a rear moving ring, a center concave groove is in clearance fit with and accommodates a center convex part of the rear moving ring, and an annular boss structure is formed between the first round positioning groove and the center concave groove; a plurality of second positioning grooves are formed in the boss in the circumferential direction and matched and clamped with boss ribs of the rear moving ring one by one, and it is ensured that the bottom face of the moving ring cavity is tightly attached to the end face of the tool after assembly. Through the synergistic effect of the multiple stages of positioning grooves, displacement and vibration of the rear moving ring in the grinding process can be precisely restrained, relative sliding between a tool and a part is reduced, and excessive abrasion, caused by the material hardness difference, of a universal platform is avoided. By the adoption of the tool, tool abrasion is remarkably reduced, it is guaranteed that the flatness and roughness of the sealing face reach the standard, the machining qualification rate and quality stability are improved, the rework requirement is reduced, and the grinding efficiency and reliability are overall improved.

Description

TECHNICAL FIELD

[0001] The application belongs to the field of aero-engine manufacturing, in particular to the field of mechanical processing, and particularly relates to a grinding tool and method for a rear ring sealing surface. BACKGROUND

[0002] In the field of aero-engine manufacturing, the rear ring is a key part of the turbine part, and the performance of the sealing surface thereof has an important influence on the overall performance of the engine. The sealing surface not only needs to prevent gas leakage to improve the thermal efficiency and propulsion efficiency, but also needs to maintain stable airflow and ensure uniform stress on the turbine blade, thereby improving the stability and reliability of the engine. For a specific model of rear ring, the sealing surface thereof is significantly larger than that of conventional products, with a maximum outer diameter of φ116mm and an effective sealing surface range of 84mm, while meeting the high-precision requirements of flatness of 0.003mm and roughness of Ra0.05μm. The part is made of 38CrMoAlA high-grade nitriding steel, the sealing surface has a hardness of HRC≥58 after nitriding treatment, the remaining surface is protected by chemical oxidation treatment, and the sealing surface needs to be ground to ensure a thickness of 0.3mm.

[0003] The current general grinding platform has obvious defects when processing: first, due to the high hardness of the part surface, grinding the large sealing surface can easily cause platform wear, making it difficult to ensure flatness, and the platform needs to be frequently repaired and repaired, which requires high accuracy and is difficult to process; second, due to the difference in material and hardness between the part and the platform, the platform is easily worn and has gaps, and the remaining grinding paste can scratch the sealing surface, making it difficult to meet the roughness standard; third, the processing qualified rate is only 40%, the rework rate is high, and the quality stability is poor.

[0004] Therefore, in the grinding process of the large sealing surface of the rear ring, there are problems such as difficulty in ensuring accuracy, unstable quality, and low efficiency. SUMMARY

[0005] The application provides a grinding tool and method for a rear ring sealing surface, which can effectively solve the problems of difficulty in ensuring accuracy, unstable quality, and low efficiency in the grinding process of the large sealing surface of the rear ring.

[0006] In order to achieve the above purpose, the application adopts the following technical content: A grinding tool for a rear ring sealing surface, comprising: a tool body; The tool body is in a disc-shaped structure, a circular first positioning groove is formed on the end face, the outer edge of the rear ring is in gap cooperation with the first positioning groove, and the outer edge of the rear ring can be clamped into the first positioning groove; ​The center of the end face of the tool body is provided with a concave groove, the center convex structure of the rear dynamic ring is matched with the concave groove in a clearance fit, and the center convex structure of the rear dynamic ring can be embedded in the concave groove. The first positioning groove and the concave groove form a boss structure in the form of a ring, a plurality of second positioning grooves are formed on the boss structure in the circumferential direction, the number of the second positioning grooves matches the number of the boss ribs of the rear dynamic ring, and each boss rib can be clamped into the corresponding second positioning groove. When the rear dynamic ring is assembled with the grinding tool, the cavity bottom surface of the rear dynamic ring is tightly fitted with the end face of the grinding tool.

[0007] Further, the first positioning groove and the end face of the tool body, the first positioning groove and the boss structure, and the two side edges of the second positioning groove all adopt circular arc transitions.

[0008] Further, the angle of the circular arc transition is R0.5~R1; wherein R is the radius size of the circular arc; R0.5~R1 indicates that the radius size of the circular arc is between 0.5 units and 1 unit.

[0009] Further, the tool body is made of polytetrafluoroethylene material.

[0010] 5. The rear dynamic ring sealing surface grinding tool according to claim 4, further characterized in that the tool body is made of SFB-2 in polytetrafluoroethylene.

[0011] A rear dynamic ring sealing surface grinding method based on the above-mentioned rear dynamic ring sealing surface grinding tool, comprising: An 8-shaped motion combined with 180° rotation is used to grind the rear dynamic ring sealing surface on a cast iron platform to remove the chemical oxide layer of the sealing surface; wherein the rear dynamic ring is driven by the rear dynamic ring sealing surface grinding tool to move; An 8-shaped motion combined with 180° rotation is used to grind the rear dynamic ring sealing surface with a chemical oxide layer on a glass platform to obtain a preliminary ground rear dynamic ring; Three preliminary ground rear dynamic rings are randomly selected, and a sawtooth cycle method is used to grind the preliminary ground rear dynamic rings against each other in pairs to obtain a finished ground rear dynamic ring; wherein during the grinding, any one rear dynamic ring is loaded into the rear dynamic ring sealing surface grinding tool.

[0012] Further, after the three preliminary ground rear dynamic rings are randomly selected and ground against each other in pairs using the sawtooth cycle method, the method further comprises: The sealing surface of the finished ground rear dynamic ring is polished on a felt wheel to obtain a well-grounded rear dynamic ring.

[0013] Further, the grinding method of 8-shaped motion matched with 180° rotation, before grinding the sealing surface of the rear moving ring on the cast iron platform, further comprises: nitriding process treatment is performed on the rear moving ring; After the polishing treatment of the fine-grinding sealing surface of the rear moving ring on the felt wheel, further comprising: The ground rear moving ring is sequentially cleaned, detected, and oil-sealed.

[0014] Further, in the grinding of the sealing surface of the rear moving ring on the cast iron platform, W7-W10 diamond grinding paste is used to grind the sealing surface of the rear moving ring on the cast iron platform. In the grinding of the sealing surface of the rear moving ring with chemical oxidation layer on the glass platform, W7-W10 diamond grinding paste is used to grind the sealing surface of the rear moving ring with chemical oxidation layer on the glass platform. In the mutual grinding of the two preliminary ground rear moving rings, W7-W10 diamond grinding paste is used to grind the two preliminary ground rear moving rings.

[0015] Further, the random selection of three preliminary ground rear moving rings, the sawtooth-shaped cycle method, and the mutual grinding of the two preliminary ground rear moving rings, comprise: Among all the preliminary ground rear moving rings, three preliminary ground rear moving rings are randomly selected and defined as No. 1, No. 2, and No. 3. The cycle grinding process is divided into three steps: First step: Put No. 2 into the rear moving ring sealing surface grinding tool, grind the sealing surface of No. 2 against No. 1; Put No. 1 into the rear moving ring sealing surface grinding tool, grind the sealing surface of No. 1 against No. 3; Put No. 3 into the rear moving ring sealing surface grinding tool, grind the sealing surface of No. 3 against No. 2; Second step: Put No. 1 into the rear moving ring sealing surface grinding tool, grind the sealing surface of No. 1 against No. 2; Put No. 2 into the rear moving ring sealing surface grinding tool, grind the sealing surface of No. 2 against No. 3; Put No. 3 into the rear moving ring sealing surface grinding tool, grind the sealing surface of No. 3 against No. 1; Third step: Put No. 2 into the rear moving ring sealing surface grinding tool, grind the sealing surface of No. 2 against No. 3; After the No. 3 is loaded into the rear ring sealing surface grinding tool, the sealing surface of No. 3 is ground against No. 1; After the No. 1 is loaded into the rear ring sealing surface grinding tool, the sealing surface of No. 1 is ground against No. 2.

[0016] Compared with the prior art, the present application has the following beneficial effects: The present application provides a rear ring sealing surface grinding tool, which comprises a tool body designed as a disc structure, a circular first positioning groove is opened in the end face to gap fit the outer edge of the rear ring, a central concave groove gap fits to accommodate the central convex part of the rear ring, an annular boss structure is formed between the two, a plurality of second positioning grooves are provided on the boss in the circumferential direction, and are matched and clamped with the convex rib of the rear ring, so as to ensure that the bottom surface of the rear ring cavity is closely attached to the end face of the tool. Through the synergistic effect of the multi-stage positioning grooves, the displacement and vibration of the rear ring during the grinding process can be accurately constrained, the relative sliding between the tool and the part is reduced, and excessive wear caused by the difference in material hardness of the universal platform is avoided; at the same time, the end face is closely attached to form a sealed interface, and the penetration of the grinding paste into the gap is effectively isolated. The use of the tool significantly reduces tool wear, ensures that the flatness and roughness of the sealing surface meet the standards, improves the processing qualification rate and quality stability, reduces the need for rework, and overall improves the grinding efficiency and reliability.

[0017] Preferably, in the present application, the circular arc transition treatment significantly reduces the stress concentration phenomenon of the edge of the positioning groove, and avoids microcosmic damage caused by rigid contact when the workpiece is assembled. This design further protects the surface integrity of the workpiece, reduces accidental scratches caused by mechanical interference, and ensures the uniformity of the roughness of the sealing surface during the grinding process.

[0018] Preferably, in the present application, the limited circular arc radius range ensures the balance between the smoothness of the transition surface and the structural strength: too small cannot effectively disperse stress, and too large weakens the positioning accuracy. This optimization enables the tool to buffer assembly impact while maintaining rigid support for the workpiece, enhancing the reliability of the grinding process.

[0019] Preferably, in the present application, the polytetrafluoroethylene material gives the tool self-lubricating property and low friction coefficient, greatly reducing the wear probability with the workpiece. Its softness can absorb vibration energy, avoid scratching the sealing surface by hard platforms, and at the same time reduce the tool's own loss, prolong its service life.

[0020] Preferably, in the present application, SFB-2 type polytetrafluoroethylene is selected to further improve wear resistance and dimensional stability. This material maintains deformation resistance in high-pressure grinding environment, ensuring long-term accuracy of the positioning structure and avoiding batch quality fluctuations caused by tool deformation.

[0021] The application also provides a grinding method for the rear dynamic ring sealing surface, based on the grinding tool for the rear dynamic ring sealing surface, the method removes the oxide layer by using the cast iron platform combined with the special tool to drive the rear dynamic ring to perform "8-shaped motion + 180° rotation", and then the dynamic grinding method is repeated on the glass platform to achieve preliminary fine grinding, finally, three preliminary ground workpieces are randomly taken, and two-by-two fine grinding is performed by using the sawtooth-shaped circulation method. The phased grinding strategy fully gives play to the cutting force of the cast iron platform and the flatness advantage of the glass platform, and the dynamic composite motion eliminates the one-way texture; the special tool ensures accurate positioning of the workpiece and stability of force transmission throughout the process, so as to avoid surface scratches caused by vibration; the self-matching material characteristics of the workpieces are utilized in the final fine grinding stage, so that the sealing surface is micro-corrected in a controlled state. The dynamic grinding method adopted in the method homogenizes the stress distribution and avoids local over-difference; the system error is automatically compensated during the fine grinding process, so that the flatness and roughness of the sealing surface are simultaneously improved, the processing qualified rate and quality stability are significantly enhanced, and the rework rate is greatly reduced.

[0022] Preferably, in the application, the felt wheel polishing process effectively removes the micro-peaks and valleys remaining after fine grinding, and further reduces the surface roughness value through flexible contact. This process makes up for the limitations of mechanical grinding, so that the sealing surface reaches the mirror effect and meets the sealing requirements of high working conditions.

[0023] Preferably, in the application, the nitriding pretreatment enhances the hardness of the base, providing a uniform material basis for subsequent grinding; the terminal cleaning-detection-oil closed loop process ensures rust prevention and quality traceability of the finished product, forming a whole-chain quality control.

[0024] Preferably, in the application, the same particle size range of diamond grinding paste is used throughout the process to maintain the consistency of the cutting force at each stage. This standardized setting avoids introducing process fluctuations due to abrasive switching, and ensures the coherence of the surface texture and the parameter compliance rate.

[0025] Preferably, in the application, the sawtooth-shaped circulation method forcibly disperses system errors through multiple rounds of cross-grinding: three workpiece circulation pairs make each sealing surface serve as a reference for each other, and the errors are offset to each other under the guidance of the tool, so that the flatness super-fine matching is finally achieved. BRIEF DESCRIPTION OF DRAWINGS

[0026] Figure 1 The structure diagram of the rear dynamic ring provided for the embodiment of the application is shown in the figure; Figure 2 The structure diagram of the rear dynamic ring provided for the embodiment of the application is shown in the figure; Figure 1 The A-A sectional view of the rear dynamic ring provided for the embodiment of the application is shown in the figure; Figure 3 The structure diagram of the rear dynamic ring provided for the embodiment of the application is shown in the figure; Figure 4 The structure diagram of the rear dynamic ring provided for the embodiment of the application is shown in the figure; Figure 5 The structure diagram of the rear dynamic ring provided for the embodiment of the application is shown in the figure;Figure 4 Cross-sectional view along A-A; Figure 6 Assembly view of the grinding tool and the rear moving ring provided by the embodiment of the present application; Figure 7 Flow chart of the grinding method of the rear moving ring sealing surface provided by the embodiment of the present application; Figure 8 Sawtooth cycle method schematic view provided by the embodiment of the present application.

[0027] Reference signs: 1, first positioning groove; 2, concave groove; 3, boss structure; 4, second positioning groove; 5, rear moving ring; 6, end face; 5-1, cavity bottom surface; 5-2, sealing surface; 5-3, boss rib. DETAILED DESCRIPTION

[0028] In order to make the technical problems solved by the present application, the technical solutions and beneficial effects more clearly understood, the following specific embodiments will further describe the present application in detail. It should be understood that the specific embodiments described herein are only used to explain the present application, and are not used to limit the present application.

[0029] In order to make the purpose, technical solutions and advantages of the embodiments of the present application more clear, the technical solutions of the embodiments of the present application will be described clearly and completely below in combination with the drawings of the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. The components of the embodiments of the present application described and shown in the drawings herein can be arranged and designed in various different configurations.

[0030] Therefore, the following detailed description of the embodiments of the present application provided in the drawings is not intended to limit the scope of the claimed application, but only represents selected embodiments of the present application. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in the present application without creative labor are within the scope of protection of the present application.

[0031] It should be noted that: similar signs and letters represent similar items in the following drawings, therefore, once an item is defined in one drawing, it does not need to be further defined and explained in the subsequent drawings.

[0032] As mentioned in the background, in practical applications, due to the large range of the sealing surface of the rear moving ring, the general method is used to grind on the grinding platform, and the processing difficulties are as follows: first, when grinding the large sealing surface, the grinding platform is easily worn due to the high surface hardness of the part, it is difficult to ensure the flatness of the sealing surface of the rear moving ring to be 0.003 mm, the grinding platform needs to be frequently repaired, the accuracy of the repaired platform is high, and the processing difficulty is great; second, due to the difference between the material of the part and the material of the grinding platform, the grinding platform is easily worn during processing, the grinding paste remaining in the small gap of the grinding platform is easy to scratch the surface of the part, and it is difficult to ensure the roughness Ra of the sealing surface to be 0.05; third, the qualified rate of the part can only reach 40%, the rework rate is high, and the processing quality is unstable.

[0033] In order to solve the above problems, the embodiment provides a grinding tool for the sealing surface of the rear moving ring, which can solve the processing difficulty of the large sealing surface of the rear moving ring, ensure the product quality, improve the qualified rate of the part, and realize zero rework.

[0034] As shown in Figure 1 , Figure 2 and Figure 3 , the embodiment provides a grinding object of the grinding tool, which is a rear moving ring 5; the front surface of the rear moving ring 5 is a sealing surface 5-2, the back surface is a cavity bottom surface 5-1, and a convex structure protruding towards the cavity bottom surface 5-1 is arranged in the middle; a plurality of convex rib 5-3 are connected between the convex structure and the outer edge; the rear moving ring 5 has four convex ribs 5-3; as can be seen, the sealing surface 5-2 of the rear moving ring 5 is large, which leads to the problem of difficult processing, and the embodiment provides a grinding tool for the sealing surface of the rear moving ring, as shown in Figure 4 , specifically comprising a tool body; the tool body is preferably made of SFB-2 material in polytetrafluoroethylene, which is soft, and can effectively avoid scratching the surface of the rear moving ring 5 during contact with the rear moving ring 5, thereby providing a basic guarantee for the grinding quality of the rear moving ring 5.

[0035] As shown in Figure 5 , the tool body is in a disc structure, and a circular first positioning groove 1 is formed on the end surface 6 thereof, and the outer edge of the rear moving ring 5 is gap-fitted with the first positioning groove 1; this fitting mode enables the outer edge of the rear moving ring 5 to be smoothly clamped into the first positioning groove 1, thereby achieving the preliminary positioning of the rear moving ring 5 in the radial direction, and preventing the rear moving ring 5 from appearing excessive radial displacement during grinding.

[0036] The concave groove 2 is arranged at the center of the end face of the tool body, the center convex structure of the rear ring 5 is in clearance fit with the concave groove 2, and the center convex structure of the rear ring 5 can be embedded in the concave groove 2. Through the cooperation of the concave groove 2 and the center convex structure of the rear ring 5, the positioning stability of the rear ring 5 on the tool is further enhanced, so that the rear ring 5 is not easy to be deflected during grinding, and the uniformity of grinding is ensured.

[0037] In the embodiment, the boss structure 3 in the form of a ring is formed between the first positioning groove 1 and the concave groove 2, and a plurality of second positioning grooves 4 are arranged on the boss structure 3 in the circumferential direction. The number of the second positioning grooves 4 matches the number of the convex ribs 5-3 of the rear ring 5, each convex rib 5-3 can be clamped into the corresponding second positioning groove 4, and four second positioning grooves 4 are used in the embodiment. The width of the second positioning groove 4 is designed to be mm, and the width of the convex rib 5-3 of the rear ring 5 is mm. Such a size design forms a small clearance fit, which not only effectively reduces the friction between the grinding tool and the part, but also effectively avoids the defect that the chemical oxidation layer on the assembly surface falls off during grinding. At the same time, this structural design increases the grinding pressure range, makes the clamping more stable, and makes it easier to ensure the size mm, the flatness 0.003 and the roughness Ra0.05 of the rear ring sealing surface during grinding.

[0038] When the rear ring 5 is assembled with the grinding tool, the cavity bottom surface 5-1 of the rear ring 5 is tightly attached to the end face 6 of the grinding tool, which further ensures the stability of the rear ring 5 during grinding and avoids affecting the grinding accuracy due to looseness.

[0039] For example, the first positioning groove 1 and the end face 6 of the tool body, the first positioning groove 1 and the boss structure 3, and the two side edges of the second positioning groove 4 all adopt circular arc transitions, and the angle of the circular arc transition is R0.5~R1. This circular arc transition design can effectively avoid scratching the surface of the part during assembly, and ensure the quality of the rear ring 5 from the details.

[0040] As shown in Figure 7 , the embodiment also provides a grinding method for a rear ring sealing surface, which is based on the above-mentioned grinding tool for the rear ring sealing surface, and the specific steps are as follows: First, the rear ring 5 is subjected to nitriding process. The nitriding treatment can improve the hardness and wear resistance of the surface of the rear ring 5, lay a good foundation for subsequent grinding processing, and make the rear ring 5 maintain good performance in the long-term use process.

[0041] Before nitriding and chemical oxidation, the sealing surface needs to be corrected by a surface grinder and a single-end face honing machine to ensure that the flatness is less than or equal to 0.008 mm and the roughness Ra is 0.2. This step is crucial. Only when the initial state of the sealing surface meets the requirements can the final technical requirements be met in subsequent lapping. If the initial flatness and roughness do not meet the requirements, subsequent lapping processing can hardly make up for it, which will affect the sealing performance and use effect of the final back ring 5.

[0042] For example, before lapping, as shown in Figure 6 the lapping tool provided in this embodiment is assembled with the back ring 5; the specific lapping stages are as follows: First, the back ring sealing surface is lapped on a cast iron platform using a W10 diamond lapping paste by adopting an 8-shaped motion combined with 180° rotation lapping method. The chemical oxidation layer on the sealing surface is removed. The 8-shaped motion combined with 180° rotation lapping method can make the lapping more uniform, avoiding the situation of excessive or insufficient lapping in some areas. The W10 diamond lapping paste has strong cutting ability, which can quickly and effectively remove the chemical oxidation layer, preparing for subsequent fine lapping. During the lapping process, the lapping force and time need to be controlled to ensure that only the chemical oxidation layer is removed without affecting the basic size and structure of the back ring 5.

[0043] Second, the part is lapped on a glass platform using an 8-shaped motion combined with 180° rotation lapping method by selecting a W7 diamond lapping paste, so that the flatness of the sealing surface is 0.004 mm and the roughness is Ra 0.1. The glass platform has high flatness, which can provide an accurate reference surface for lapping. The particles of the W7 diamond lapping paste are finer than those of the W10, which can perform more precise lapping and further improve the flatness and smoothness of the sealing surface. The requirement of 0.004 mm flatness needs to be ensured by using a lever dial gauge to push the surface on the platform. Through accurate measurement, deviations in the lapping process can be found in time and adjusted to ensure that the expected accuracy requirements are met.

[0044] Third, randomly select 3 back rings 5 after preliminary lapping, and install the wide mm convex rib 5-3 of any one of the back rings 5 into the corresponding wide mm second positioning groove 4 of the counter-lapping tool, so that the cavity bottom surface 5-1 of the back ring 5 is in close contact with the end surface 6 of the counter-lapping tool. This assembly process must be accurate. The convex rib 5-3 and the second positioning groove 4 must be in place, and the cavity bottom surface 5-1 and the end surface 6 must be in close contact, otherwise the accuracy of counter-lapping will be affected.

[0045] Then, the 3 back rings 5 are counter-lapped with each other using a "zigzag cycle method" and a W7 diamond lapping paste. As shown inFigure 8 As shown, the cycle grinding process of the specific zigzag cycle method is divided into three steps: S1: Install the No. 2 back ring into the back ring sealing surface grinding tool, and grind the sealing surface of the No. 2 back ring against the No. 1 back ring; Install the No. 1 back ring into the back ring sealing surface grinding tool, and grind the sealing surface of the No. 1 back ring against the No. 3 back ring; Install the No. 3 back ring into the back ring sealing surface grinding tool, and grind the sealing surface of the No. 3 back ring against the No. 2 back ring.

[0046] S2: Install the No. 1 back ring into the back ring sealing surface grinding tool, and grind the sealing surface of the No. 1 back ring against the No. 2 back ring; Install the No. 2 back ring into the back ring sealing surface grinding tool, and grind the sealing surface of the No. 2 back ring against the No. 3 back ring; Install the No. 3 back ring into the back ring sealing surface grinding tool, and grind the sealing surface of the No. 3 back ring against the No. 1 back ring.

[0047] S3: Install the No. 2 back ring into the back ring sealing surface grinding tool, and grind the sealing surface of the No. 2 back ring against the No. 3 back ring; Install the No. 3 back ring into the back ring sealing surface grinding tool, and grind the sealing surface of the No. 3 back ring against the No. 1 back ring; Install the No. 1 back ring into the back ring sealing surface grinding tool, and grind the sealing surface of the No. 1 back ring against the No. 2 back ring.

[0048] During the grinding process, when replacing the back ring 5 installed on the grinding tool, the entire sealing surface of the back ring 5 should be exposed to light, and the next back ring 5 can be replaced. "The entire sealing surface is exposed to light" means that the sealing surface has been sufficiently and uniformly ground, which ensures the effect of the grinding. After mutual grinding, the flatness of the sealing surface of the back ring 5 can be guaranteed to be 0.003 mm, and the roughness can reach Ra0.05 technical requirements. Among them, the flatness of 0.003 mm is guaranteed by 100% three-coordinate measurement method, and the three-coordinate measuring instrument can accurately measure the flatness of the sealing surface, ensuring that each back ring 5 meets the requirements; the roughness Ra0.05 is guaranteed by 100% measurement method of roughness meter, and the roughness meter can accurately measure the roughness value of the sealing surface, providing reliable detection data for the quality of the back ring 5.

[0049] After the grinding is completed, the sealing surface of the finished and ground rear ring 5 is polished on a φ125*50mm felt wheel to obtain the ground rear ring 5. The felt wheel is soft and will not scratch the sealing surface during polishing, which can further improve the smoothness of the sealing surface and make the sealing surface smoother, thereby improving the sealing performance of the rear ring 5.

[0050] Finally, the ground rear ring 5 is sequentially cleaned, detected and oil sealed. The cleaning process can remove the grinding paste, metal debris and other impurities remaining on the surface of the rear ring 5, so as to avoid the influence of the impurities on the use of the rear ring 5 and the accuracy of subsequent detection. The detection process is the final inspection of various performance indicators of the rear ring 5, so as to ensure that the rear ring 5 meets the design requirements. The oil sealing process can prevent the rear ring 5 from rusting during storage and transportation, so as to ensure that the quality of the rear ring 5 is not affected.

[0051] By using the grinding tool and the grinding method, the grinding platform wear caused by different materials and hardness and the processing problem of the sealing surface being easily scratched are eliminated, the efficient grinding processing of the large sealing surface of the rear ring is realized, and the processing quality is stable and reliable. Meanwhile, the three parts are ground against each other, so that the processing efficiency of the parts is improved by 3 times, the production efficiency is greatly improved under the premise of ensuring the quality, and the method has important practical application value.

[0052] Therefore, the grinding tool and method for the sealing surface of the rear ring have the following advantages compared with the existing grinding means. Firstly, the grinding tool is simple to clamp, stable and reliable, and easy to operate. Secondly, the grinding tool and method can stabilize the processing quality of the parts and meet the size requirements of the design drawing. Thirdly, the grinding tool and method can improve the first-time qualified rate of the parts to 100%, and realize zero rework.

[0053] Fourthly, the grinding tool and method can improve the processing efficiency by 3 times.

[0054] The above embodiment is only one of the implementation manners of the technical scheme of the present application, and the scope of protection of the present application is not limited to the above embodiment, but also includes any changes, substitutions and other implementation manners easily thought by those skilled in the art within the technical range disclosed by the present application.

Claims

1. A polishing tool for a rear dynamic ring seal face, characterized by, The utility model relates to a kind of rear ring sealing surface grinding tools, including: Tool body; The tool body is in disc structure, and circular first positioning slot (1) is set on end face (6), gap cooperation between the outer edge of rear ring (5) and the first positioning slot (1), the outer edge of rear ring (5) can be inserted into the first positioning slot (1); The recessed groove (2) is set in the center of the tool body end face, and the center convex part structure of rear ring (5) is gap cooperated with the recessed groove (2), and the center convex part structure of rear ring (5) can be embedded in the recessed groove (2); The first positioning slot (1) and the recessed groove (2) form annular boss structure (3) between them, and a plurality of second positioning slots (4) are set on the boss structure (3) along the circumference;The number of the second positioning slot (4) is matched with the number of the convex rib (5-3) of the rear ring (5), and each convex rib (5-3) can be inserted into the corresponding second positioning slot (4); When the rear ring (5) is assembled with the grinding tool, the cavity bottom surface (5-1) of the rear ring (5) is closely attached to the end face (6) of the grinding tool.

2. The polishing tool for a rear seal face of a dynamic ring according to claim 1, wherein The first positioning slot (1) and the end face (6) of the tool body, the first positioning slot (1) and the boss structure (3), and the two side edges of the second positioning slot (4) all adopt circular arc transition.

3. The polishing tool for a rear seal face of a dynamic ring according to claim 1, wherein The angle of the circular arc transition is R0.5~R1;Wherein, R is the radius of the circular arc;R0.5~R1 indicates that the radius of the circular arc is between 0.5 units and 1 unit.

4. The polishing tool for a rear seal face of a dynamic ring according to claim 1, wherein The tool body is made of polytetrafluoroethylene material.

5. The polishing tool for a rear dynamic ring seal face according to claim 4, wherein The tool body is made of SFB-2 in polytetrafluoroethylene.

6. A method of lapping a back dynamic ring seal surface, characterized by, The rear ring sealing surface grinding tool according to any one of claims 1-5, comprising: An 8-shaped motion and 180° rotation matched grinding method is used to grind the rear ring sealing surface on a cast iron platform to remove the chemical oxide layer of the sealing surface, wherein the rear ring grinding motion is driven by the rear ring sealing surface grinding tool; An 8-shaped motion and 180° rotation matched grinding method is used to grind the chemical oxide layer of the rear ring on a glass platform to obtain a preliminary ground rear ring. Three preliminary ground rear rings are randomly selected, and a sawtooth cycle method is used to mutually grind the preliminary ground rear rings to obtain finished ground rear rings.

7. The method of claim 6, wherein the rear dynamic ring seal surface is a rear dynamic ring seal surface of a piston ring. After the three preliminary ground rear rings are randomly selected and the sawtooth cycle method is used to mutually grind the preliminary ground rear rings, the method further comprises: The sealing surface of the finished ground rear ring is polished on a felt wheel to obtain a well-grounded rear ring.

8. The rear ring sealing surface grinding method according to claim 7, wherein Before the 8-shaped motion and 180° rotation matched grinding method is used to grind the rear ring sealing surface on a cast iron platform, the method further comprises: nitriding process is performed on the rear ring; After the sealing surface of the finished ground rear ring is polished on a felt wheel, the method further comprises: The well-grounded rear ring is sequentially cleaned, detected, and oil-sealed.

9. The grinding method of a rear dynamic ring sealing surface according to claim 6, wherein the grinding method of the 8-shaped motion matched with the 180° rotation is used to grind the rear dynamic ring sealing surface on the cast iron platform with W7-W10 diamond grinding paste; the grinding method of the 8-shaped motion matched with the 180° rotation is used to grind the rear dynamic ring sealing surface of the chemical oxidation layer on the glass platform with W7-W10 diamond grinding paste; the three preliminary ground rear dynamic rings are randomly selected, and the sawtooth cycle method is used to grind the preliminary ground rear dynamic rings two by two; the three preliminary ground rear dynamic rings are randomly selected, and the sawtooth cycle method is used to grind the preliminary ground rear dynamic rings two by two, comprising:

10. The method of claim 6, wherein the rear dynamic ring seal surface is a rear dynamic ring seal surface of a turbine engine. in all the preliminary ground rear dynamic rings, three preliminary ground rear dynamic rings are randomly selected and defined as No. 1, No. 2 and No. 3 respectively; the cycle grinding process is divided into three steps: the first step: No. 2 is installed in the rear dynamic ring sealing surface grinding tool, and No. 2 is ground against No. 1; No. 1 is installed in the rear dynamic ring sealing surface grinding tool, and No. 1 is ground against No. 3; No. 3 is installed in the rear dynamic ring sealing surface grinding tool, and No. 3 is ground against No. 2; the second step: No. 1 is installed in the rear dynamic ring sealing surface grinding tool, and No. 1 is ground against No. 2; No. 2 is installed in the rear dynamic ring sealing surface grinding tool, and No. 2 is ground against No. 3; No. 3 is installed in the rear dynamic ring sealing surface grinding tool, and No. 3 is ground against No. 1; the third step: No. 2 is installed in the rear dynamic ring sealing surface grinding tool, and No. 2 is ground against No. 3; No. 3 is installed in the rear dynamic ring sealing surface grinding tool, and No. 3 is ground against No. 1; No. 1 is installed in the rear dynamic ring sealing surface grinding tool, and No. 1 is ground against No.

2. ​

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