A method of repairing a blade spline

Abstract

The present application belongs to the field of turbine blade repair, and discloses a kind of blade tenon tooth repair method, comprising: grinding out the grinding part matched with the tenon tooth of blade to be repaired on oilstone;Wherein, the surface shape of grinding part and the tenon tooth of blade to be repaired is consistent, and the size is reduced by preset proportion;Grinding part of oilstone is soaked in lubricating oil for a preset time;The surface of the grinding part of oilstone after soaking is tightly attached to the surface of the tenon tooth of blade to be repaired for grinding repair, and the error between the actual size and the target size of the relative tenon roller is measured during the repair process, until the error is less than the preset error threshold, the tenon repair of blade to be repaired is completed.By analyzing the tool form, operation mode and the surface quality of the blade to be repaired during the repair process, the problems that the repaired blade cannot meet the design and assembly test requirements are overcome, the effective repair of the blade with defective tenon is realized, and the manufacturing cost is effectively reduced and the resource waste is reduced.

Description

Technical Field

[0001] This invention belongs to the field of turbine blade repair and relates to a method for repairing blade tenons. Background Technology

[0002] As a critical component of engines, blades play a vital role in aircraft and gas turbines. The relevant mating dimensions of blades are not only an important assembly indicator before the initial test run but also a crucial inspection requirement during engine overhauls. Tenons, as a critical part of the blade, have always received close attention during blade machining, assembly, testing, and engine return to the factory. Surface quality issues with tenons mainly include cracks, wrinkles, and dimensional deviations, with cracks and wrinkles accounting for a significant proportion during fluorescent inspections upon engine return. These problems will prevent the blade from being properly assembled with the turbine disk, affecting engine safety.

[0003] Currently, due to the lack of precise repair methods, the solution in such cases is usually to replace the blades. However, blades are typically made of special alloy materials, which are not only expensive but also difficult to process, making the manufacturing cost of a single blade quite considerable. Furthermore, replacing blades requires precise operations by skilled technicians, including disassembling the old blade, cleaning the mounting surface, installing the new blade, and debugging, all of which consume significant manpower and time. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings of the prior art and provide a method for repairing blade tenons.

[0005] To achieve the above objectives, the present invention employs the following technical solution:

[0006] This invention provides a method for repairing blade tenons, comprising: grinding a grinding portion on an oilstone to match the tenon of the blade to be repaired; wherein the grinding portion has the same surface shape as the tenon of the blade to be repaired, and the size is reduced according to a preset ratio; immersing the grinding portion of the oilstone completely in lubricating oil for a preset time; grinding and repairing the surface of the grinding portion of the oilstone in close contact with the surface of the tenon of the blade to be repaired, and measuring the error between the actual size and the target size between the relative tenon rollers during the repair process at intervals, until the error is less than a preset error threshold, and then completing the tenon repair of the blade to be repaired.

[0007] Optionally, when grinding a grinding part on the oilstone to match the tenon teeth of the blade to be repaired, the length of the grinding part shall not exceed 2 / 3 of the length of the oilstone, the width of the grinding part shall not exceed 1 / 2 of the width of the oilstone, and the height of the grinding part shall not exceed 1 / 6 of the height of the oilstone.

[0008] Optionally, the oilstone is a triangular prism-shaped oilstone, and the included angle of the bottom surface of the side of the oilstone where the grinding part is set is smaller than the tenon angle of the blade to be repaired.

[0009] Optionally, when the thermal conductivity and thermal diffusivity of the material of the blade to be repaired are both higher than the corresponding preset threshold, before grinding and repairing the surface of the grinding part of the soaked oilstone in close contact with the tenon surface of the blade to be repaired, the method further includes: using a rubber wheel to enter along one side of the tenon surface of the blade to be repaired and repairing it on a polishing machine along the entire tenon surface, and repairing the blade base and blade back of the tenon symmetrically during the repair process.

[0010] Optionally, when the rubber wheel enters along one side of the tenon tooth surface of the repair blade and performs repair on the polishing machine along the entire tenon tooth surface, the linear speed of the rubber wheel is 18-22 m / s.

[0011] Optionally, when the rubber wheel is used to enter along one side of the tenon tooth surface of the repair blade and to repair along the entire tenon tooth surface on the polishing machine, the diameter of the rubber wheel is 60-125mm.

[0012] Optionally, when the rubber wheel enters along one side of the tenon tooth surface of the repair blade and is used to repair it on the polishing machine along the entire tenon tooth surface, the speed of the polishing machine is 3000 to 7000 rpm.

[0013] Optionally, before grinding the grinding part on the oilstone to match the tenon teeth of the blade to be repaired, the method further includes: obtaining the defect type of the tenon teeth of the blade to be repaired; when the defect type of the tenon teeth of the blade to be repaired is wrinkles on the non-working surface and width dimension deviation, continuing the subsequent repair steps; when the defect type of the tenon teeth of the blade to be repaired is wrinkles on the working surface and surface cracks, ending the repair.

[0014] Optionally, when the material of the blade to be repaired is a cast high-temperature alloy with Co as the main component, the lubricating oil does not contain copper or lead; when the material of the blade to be repaired is a cast high-temperature alloy with Cr as the main component, the lubricating oil does not contain copper, lead, tin, or bismuth.

[0015] Optionally, after completing the tenon repair of the blade to be repaired, the method further includes: visually inspecting and fluorescently examining the surface of the tenon of the blade to be repaired.

[0016] Compared with the prior art, the present invention has the following beneficial effects:

[0017] This invention relates to a method for repairing blade tenons. Using an oilstone as the repair tool, it is adapted to the unique structural, material, and defect characteristics of blade tenons, achieving a highly stable repair process with no scratches on the repaired surface and requiring virtually no further adjustments. Simultaneously, by grinding a matching grinding section on the oilstone to the tenon of the blade to be repaired, the precision and targeted nature of the repair tool are ensured, improving repair accuracy and effectively avoiding damage that could lead to poor repair results. Furthermore, by reducing the size of the oilstone, it is ensured that surfaces requiring repair are not damaged during grinding, allowing for gradual and even removal of the necessary parts, thus achieving the desired repair effect. Immersing the grinding section of the oilstone entirely in lubricating oil for a preset time effectively reduces friction and heat during grinding, further facilitating the removal of surface defects. Moreover, periodically measuring the error between the actual and target dimensions of the relative tenon rollers during the repair process allows for timely adjustments to the grinding force and angle, ensuring accurate tenon dimensions after repair, and providing real-time monitoring of the repair progress, preventing over-repair that could render the blade unusable. Attached Figure Description

[0018] Figure 1 This is a flowchart of the blade tenon repair method according to an embodiment of the present invention.

[0019] Figure 2 This is a schematic diagram of a blade tenon structure according to an embodiment of the present invention.

[0020] Figure 3 This is a schematic diagram of rubber wheel repair according to an embodiment of the present invention.

[0021] Figure 4 This is a schematic diagram of the oilstone structure according to an embodiment of the present invention.

[0022] Figure 5 This is a schematic diagram of oilstone repair according to an embodiment of the present invention.

[0023] Figure 6 This is a schematic diagram of another blade tenon structure according to an embodiment of the present invention.

[0024] Wherein: 1-Non-working surface of tenon; 2-Rubber wheel; 3-Oilstone; 4-Lifting position; 5-Pressing position. Detailed Implementation

[0025] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. 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 should fall within the scope of protection of the present invention.

[0026] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0027] The present invention will now be described in further detail with reference to the accompanying drawings:

[0028] See Figure 1 In one embodiment of the present invention, a method for repairing blade tenons is provided, which enables effective repair of blades with defects in tenons, reduces manufacturing costs and reduces resource waste.

[0029] Specifically, the blade tenon repair method of the present invention includes the following steps:

[0030] S1: Grind a grinding part on an oilstone to match the tenon teeth of the blade to be repaired; wherein the surface shape of the grinding part is consistent with the tenon teeth of the blade to be repaired, and the size is reduced according to a preset ratio.

[0031] S2: Immerse the grinding part of the whetstone in lubricating oil for a preset time.

[0032] S3: The surface of the grinding part of the soaked oilstone is pressed against the surface of the tenon tooth of the blade to be repaired for grinding and repair. During the repair process, the error between the actual size and the target size between the relative tenon tooth rollers is measured at intervals. When the error is less than the preset error threshold, the tenon tooth repair of the blade to be repaired is completed.

[0033] Specifically, by analyzing the tool shape, operation method, and surface quality to be repaired during the repair process, the problem that the original blades could not meet the design and assembly test requirements after repair was overcome.

[0034] In selecting repair tools, we analyzed and tested tools of different materials, such as files and small grinding wheels. Since the part to be repaired is the tenon of a blade, the main characteristics to be repaired are shallow wrinkles with a depth not exceeding 0.02mm or dimensional deviations. Using a small grinding wheel would increase stress concentration in the repaired area, causing more noticeable cracks; using a file would leave obvious scratches on the repaired area and its surroundings; both of these repair methods would result in a complete lack of safety assurance.

[0035] This invention uses an oilstone as a repair tool. This gentler method is highly stable during the repair process, and the final repaired surface is free of any scratches. It basically does not require any further repairs. From the perspective of quality and economy, this type of repair method is also more suitable for engineering applications.

[0036] This invention relates to a method for repairing blade tenons. Using an oilstone as the repair tool, it is adapted to the unique structural, material, and defect characteristics of blade tenons, achieving a highly stable repair process with no scratches on the repaired surface and requiring virtually no further adjustments. Simultaneously, by grinding a matching grinding section on the oilstone to the tenon of the blade to be repaired, the precision and targeted nature of the repair tool are ensured, improving repair accuracy and effectively avoiding damage that could lead to poor repair results. Furthermore, by reducing the size of the oilstone, it is ensured that surfaces requiring repair are not damaged during grinding, allowing for gradual and even removal of the necessary parts, thus achieving the desired repair effect. Immersing the grinding section of the oilstone entirely in lubricating oil for a preset time effectively reduces friction and heat during grinding, further facilitating the removal of surface defects. Moreover, periodically measuring the error between the actual and target dimensions of the relative tenon rollers during the repair process allows for timely adjustments to the grinding force and angle, ensuring accurate tenon dimensions after repair, and providing real-time monitoring of the repair progress, preventing over-repair that could render the blade unusable.

[0037] In one possible implementation, when grinding a grinding portion on the oilstone to match the tenon teeth of the blade to be repaired, the length of the grinding portion does not exceed 2 / 3 of the length of the oilstone, the width of the grinding portion does not exceed 1 / 2 of the width of the oilstone, and the height of the grinding portion does not exceed 1 / 6 of the height of the oilstone.

[0038] Specifically, limiting the dimensions of the grinding section ensures the efficiency and precision of the grinding operation. The width of the grinding section should not exceed 1 / 2 of the width of the whetstone, which helps to achieve more precise grinding control. This is especially helpful when dealing with complex or delicate tenons, as it can reduce errors and improve grinding accuracy. Limiting the height of the grinding section to 1 / 6 of the height of the whetstone helps to maintain stability during the grinding process, reducing vibration or instability caused by an excessively high grinding section, and further improving grinding quality and safety.

[0039] In one possible implementation, the oilstone is a triangular prism-shaped oilstone, and the included angle of the bottom surface of the side of the oilstone where the grinding part is located is smaller than the tenon angle of the blade to be repaired.

[0040] Specifically, the included angle of the bottom surface on one side of the limit oilstone setting grinding section is smaller than the tenon angle of the blade to be repaired, which can effectively avoid damage to the surface that does not need to be ground during grinding.

[0041] In one possible implementation, before grinding the grinding portion on the oilstone to match the tenon teeth of the blade to be repaired, the method further includes: obtaining the defect type of the tenon teeth of the blade to be repaired; when the defect type of the tenon teeth of the blade to be repaired is wrinkles on the non-working surface and width dimension deviation, continuing the subsequent repair steps; when the defect type of the tenon teeth of the blade to be repaired is wrinkles on the working surface and surface cracks, ending the repair.

[0042] Specifically, the surface quality of tenons is classified into three categories: surface cracks, surface wrinkles, and width dimensional deviations. Among them, surface cracks are not allowed to be repaired; surface wrinkles can only be repaired on the non-working surfaces of the tenons, while width dimensional deviations can also be repaired on the non-working surfaces.

[0043] In one possible implementation, when the thermal conductivity and thermal diffusivity of the material of the blade to be repaired are both higher than the corresponding preset threshold, before grinding and repairing the surface of the grinding part of the soaked oilstone against the tenon surface of the blade to be repaired, the method further includes: using a rubber wheel to enter along one side of the tenon surface of the blade to be repaired and repairing it on a polishing machine along the entire tenon surface, and repairing the blade base and blade back of the tenon symmetrically during the repair process.

[0044] Specifically, for blades requiring repair with thermal conductivity and thermal diffusivity exceeding preset thresholds, a mechanical processing method combining rubber wheels and a polishing machine is used for pretreatment before oilstone grinding. This significantly improves repair speed by rapidly removing damaged or irregular parts from the blade tenon surface through mechanization, laying a good foundation for subsequent oilstone grinding. Furthermore, the flexibility of the rubber wheels ensures a tight fit with the tenon surface, reducing secondary damage that might occur from direct hard contact and protecting the blade's integrity. Moreover, symmetrical repair of the blade base and blade back ensures the uniformity and balance of the tenons, which is crucial for the blade's subsequent performance and lifespan.

[0045] In one possible implementation, when the rubber wheel enters along one side of the tenon tooth surface of the repair blade and is used for repair on the polishing machine along the entire tenon tooth surface, the linear velocity of the rubber wheel is 18-22 m / s.

[0046] Optionally, when the rubber wheel is used to enter along one side of the tenon tooth surface of the repair blade and to repair along the entire tenon tooth surface on the polishing machine, the diameter of the rubber wheel is 60-125mm.

[0047] Optionally, when the rubber wheel enters along one side of the tenon tooth surface of the repair blade and is used to repair it on the polishing machine along the entire tenon tooth surface, the speed of the polishing machine is 3000 to 7000 rpm.

[0048] In the pre-treatment of tenon teeth on repair blades using a rubber wheel combined with a polishing machine, precise control of parameters such as the linear speed and diameter of the rubber wheel and the rotation speed of the polishing machine brings multiple advantages. An appropriate linear speed ensures efficient contact and friction between the rubber wheel and the tenon tooth surface, quickly removing damage without causing overheating or exacerbating the damage due to excessive speed. The wide range of rubber wheel diameters allows for flexible handling of tenons of different sizes and shapes, achieving more comprehensive coverage and a more uniform repair effect. Precise control of the polishing machine's rotation speed makes the entire repair process smoother and more controllable.

[0049] In one possible implementation, after the tenon repair of the blade to be repaired is completed, the method further includes: visually inspecting and fluorescently examining the surface of the tenon of the blade to be repaired.

[0050] Specifically, the tenon repair process is verified on-site, and visual and fluorescent inspections are used to determine whether the blades are free of cracks and meet the surface integrity requirements, thereby ensuring the quality of the repair.

[0051] In one possible implementation, the blade tenon repair method of the present invention is illustrated using a certain machine blade as an example. This blade material has a high Co content, is a cast high-temperature alloy, and has poor machinability. The dimensions and repair locations of the tenons to be repaired are as follows... Figure 2 As shown.

[0052] The specific implementation steps are as follows:

[0053] 1. Before repair, measure the actual dimensions between the relative tenon and hob, and repair within the dimensional tolerance range.

[0054] 2. For manual operation, please refer to [link / reference]. Figure 3 Use a rubber wheel (A80K) 2 to enter along one side of the tenon, and polish it on the polishing machine JX-22 along the entire tooth surface. During the repair, ensure that the tenon blade basin and blade back are repaired symmetrically.

[0055] 3. Grind the tenon teeth to the required dimensions using an oilstone, see [reference]. Figure 4 Grind the bottom surface of the grinding part on one side of the oilstone to an angle α of 38 degrees (slightly smaller than the tenon angle). The length L of the grinding part is 7mm, the width D of the grinding part is 5mm, and the height H of the grinding part is 1mm.

[0056] 4. Immerse the oilstone within 7mm in lubricating oil (excluding copper and lead).

[0057] 5. See Figure 5 During repair, the surface of the grinding part of the oilstone 3 should be pressed tightly against the surface of the tenon. While supporting the bottom of the oilstone 3 at the supporting position 4, press the oilstone 3 at the pressing position 5 and polish the surface along the entire tenon surface. During operation, the pressure on the entire surface should be uniform.

[0058] 6. When repairing, use calipers to measure the actual dimensions between the relative tenon and tooth rollers, and do not exceed the target value.

[0059] 7. Clean the repaired surfaces of the blades after repair.

[0060] 8. Perform visual and fluorescent inspections on the repaired surfaces.

[0061] In this embodiment, the tools used and specific parameters are shown in Table 1:

[0062] Table 1

[0063] Serial Number name Specifications / Parameters 1 rubber wheels 60mm in diameter 2 Polishing machine 7000 rpm 3 Oilstone WA300P ST 150×10×10

[0064] On-site processing of tenon teeth was verified. Visual inspection and fluorescence inspection showed no cracks and met the surface integrity requirements. Assembly was completed in one go without replacing the blades, and the test run performance met all design specifications.

[0065] In one possible implementation, the blade tenon repair method of the present invention is illustrated using a certain machine blade as an example. This blade material has a high Cr content, belongs to a cast high-temperature alloy, and has good high-temperature performance, but its thermal conductivity and thermal diffusivity are very low, resulting in poor machinability and a high susceptibility to cracks and wrinkles. The tenon shape and repair location of the working blade are as follows. Figure 6 As shown.

[0066] The specific technical implementation is as follows:

[0067] 1. Grind the oilstone according to the size of the tenon to be repaired. Grind the bottom angle α of the side of the oilstone where the grinding part is set to 38 degrees (slightly smaller than the tenon angle). The length L of the grinding part is 10mm, the width D of the grinding part is 7mm, and the height H of the grinding part is 2mm.

[0068] 2. Immerse the oilstone within 15mm in lubricating oil (excluding copper, lead, tin and bismuth).

[0069] 3. When repairing, place one side of the oilstone tightly against the surface of the tenon, support the bottom of the oilstone with the other side, and press the oilstone down while polishing the surface along the entire tenon. During the operation, the pressure should be even across the entire surface.

[0070] 4. When repairing, use calipers to measure the actual dimensions between the relative tenon and tooth rollers, and do not exceed the target value.

[0071] 5. Clean the repaired surfaces of the blades after repair.

[0072] 6. Perform visual and fluorescent inspections on the repaired surfaces.

[0073] In this embodiment, the tools used and specific parameters are shown in Table 2:

[0074] Table 2

[0075] Serial Number name Specifications / Parameters 1 Oilstone WA210P ST 150×10×10

[0076] On-site processing of tenon teeth was verified. Visual inspection and fluorescence inspection showed no cracks and met the surface integrity requirements. Assembly was completed in one go without replacing the blades, and the test run performance met all design specifications.

[0077] The above content is only for illustrating the technical concept of the present invention and should not be construed as limiting the scope of protection of the present invention. Any modifications made to the technical solution based on the technical concept proposed in this invention shall fall within the scope of protection of the claims of this invention.

Claims

1. A method for repairing blade tenons, characterized in that, include: A grinding part is ground on an oilstone to match the tenon teeth of the blade to be repaired; wherein the surface shape of the grinding part is consistent with the tenon teeth of the blade to be repaired, and the size is reduced according to a preset ratio. Immerse the grinding part of the whetstone in lubricating oil for a preset time; The surface of the grinding part of the soaked oilstone is pressed against the surface of the tenon tooth of the blade to be repaired for grinding and repair. During the repair process, the error between the actual size and the target size between the relative tenon tooth rollers is measured at intervals. When the error is less than the preset error threshold, the tenon tooth repair of the blade to be repaired is completed. When grinding a grinding part on an oilstone to match the tenon teeth of the blade to be repaired, the length of the grinding part shall not exceed 2 / 3 of the length of the oilstone, the width of the grinding part shall not exceed 1 / 2 of the width of the oilstone, and the height of the grinding part shall not exceed 1 / 6 of the height of the oilstone. Before grinding a grinding section on an oilstone to match the tenon teeth of the blade to be repaired, the process also includes: Obtain the defect type of the tenon teeth of the blade to be repaired; if the defect type of the tenon teeth of the blade to be repaired is wrinkles on the non-working surface and width dimension deviation, continue with the subsequent repair steps; if the defect type of the tenon teeth of the blade to be repaired is wrinkles on the working surface and surface cracks, end the repair.

2. The blade tenon repair method according to claim 1, characterized in that, The oilstone is a triangular prism-shaped oilstone, and the included angle of the bottom surface on the side where the grinding part is set is smaller than the tenon angle of the blade to be repaired.

3. The blade tenon repair method according to claim 1, characterized in that, When the thermal conductivity and thermal diffusivity of the material of the blade to be repaired are both higher than the corresponding preset thresholds, before grinding and repairing the tenon teeth surface of the blade by tightly pressing the surface of the soaked oilstone against the surface of the tenon teeth, the process further includes: The rubber wheel is used to enter along one side of the tenon surface of the blade and is used to repair it on the polishing machine along the entire tenon surface. During the repair process, the blade base and blade back of the tenon are repaired symmetrically.

4. The blade tenon repair method according to claim 3, characterized in that, When the rubber wheel is used to enter along one side of the tenon tooth surface of the repair blade and to repair it on the polishing machine along the entire tenon tooth surface, the linear speed of the rubber wheel is 18~22m / s.

5. The blade tenon repair method according to claim 3, characterized in that, When the rubber wheel is used to enter along one side of the tenon tooth surface of the repair blade and to repair along the entire tenon tooth surface on the polishing machine, the diameter of the rubber wheel is 60~125mm.

6. The blade tenon repair method according to claim 3, characterized in that, When the rubber wheel is used to enter along one side of the tenon tooth surface of the repair blade and to repair it on the polishing machine along the entire tenon tooth surface, the speed of the polishing machine is 3000~7000 rpm.

7. The blade tenon repair method according to claim 1, characterized in that, When the material of the blade to be repaired is a cast high-temperature alloy with Co as the main component, the lubricating oil does not contain copper or lead; when the material of the blade to be repaired is a cast high-temperature alloy with Cr as the main component, the lubricating oil does not contain copper, lead, tin, or bismuth.

8. The blade tenon repair method according to claim 1, characterized in that, After completing the tenon repair of the blade to be repaired, the process also includes: Visual and fluorescent inspections were performed on the tenon surface of the blade to be repaired.

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