A method for repairing a blade shroud lock plate slot

Abstract

This invention belongs to the field of turbine blade repair technology and discloses a method for repairing the locking groove of a blade rim plate. The method includes: clamping the blade to be repaired using a whole-plate turning process; using a grooving tool with the same size as the locking groove of the blade to be repaired, performing a one-time forming repair of the locking groove through turning; wherein, during turning, the grooving tool enters along the side of the blade tenon and closely adheres to the side of the blade tenon; when turning the part is the side of the blade tenon, a continuous feed is used; when turning the part is the locking groove, a feed is stopped for 1-3 minutes after every 0.1-0.3 mm of feed; after turning, the bottom edge of the locking groove of the blade to be repaired is ground. This method can effectively repair dimensional defects in the locking groove of a blade rim plate, significantly reducing manufacturing costs and saving resources compared to current blade replacement methods.

Description

Technical Field

[0001] This invention belongs to the field of turbine blade repair technology and relates to a method for repairing blade edge plate locking grooves. Background Technology

[0002] As a key component of the engine, blades play a crucial role in aircraft or gas turbines. The various assembly dimensions of the blades are key characteristics that have always been a focus of attention during processing, assembly, testing, and engine return to the factory.

[0003] As a crucial characteristic of blade assembly, the blade rim size is particularly critical. Blade rim problems during engine assembly mainly manifest in two ways: one is that the dimensions exceed design requirements, making assembly impossible; the other is surface defects on the rim, such as cracks. In some cases, during turbine rotor assembly, it was found that the locking plate could not be properly installed into the locking plate slot. Due to the large number of blades, this situation not only results in significant economic losses but also severely impacts engine manufacturing time. Furthermore, the most common issue encountered during engine overhauls and return to the factory is blade rim cracks. These cracks appear randomly and without a pattern, seriously affecting engine safety.

[0004] However, there is currently no precise repair method for out-of-tolerance dimensions in the blade edge locking groove. When this occurs, the usual approach is to replace the entire blade to achieve stable and qualified blade assembly. However, replacing the entire blade significantly increases manufacturing costs and results in a certain waste of resources. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of the prior art and provide a method for repairing blade edge plate locking grooves.

[0006] To achieve the above objectives, the present invention employs the following technical solution:

[0007] This invention provides a method for repairing the locking groove of a blade edge plate, comprising: clamping the blade to be repaired using a whole-plate turning method; using a grooving tool with the same size as the locking groove of the blade to be repaired, performing a one-time forming repair of the locking groove of the blade to be repaired by turning; wherein, during the turning process, the grooving tool enters along the side of the blade tenon tooth of the blade to be repaired and closely adheres to the side of the blade tenon tooth; and when the turning part is the side of the blade tenon tooth of the blade to be repaired, a continuous feed without interruption is adopted; when the turning part is the locking groove of the blade to be repaired, a feed is stopped for 1 to 3 minutes every 0.1~0.3mm; after the turning process is completed, the bottom edge of the locking groove of the blade to be repaired is ground.

[0008] Optionally, the clamping of the blades to be repaired using a whole-plate turning method includes: clamping at least 15 blades to be repaired using a whole-plate turning method; wherein, when there are fewer than 15 blades to be repaired, waste blades of the same specification are used as blades to be repaired.

[0009] Optionally, when performing the turning process to repair the locking plate groove of the blade to be repaired in one step by turning, the spindle speed is 6 r / min, the feed rate is 0.01 mm / r, and the turning depth is 0.05 mm.

[0010] Optionally, during the turning process of performing one-time forming repair of the locking plate groove of the blade to be repaired by turning, the shank of the grooving cutter is perpendicular to the surface of the blade to be repaired, and the interference between the grooving cutter and the blade to be repaired is eliminated by grooving and sharpening the side of the grooving cutter.

[0011] Optionally, when performing the turning process to repair the locking plate groove of the blade to be repaired in one step by turning, the turning process is performed on the locking plate groove of the blade to be repaired within the 0±0.05mm dimensional acceptable range.

[0012] Optionally, the width of the grooving blade is the minimum width of the locking plate groove of the blade to be repaired; the radius (R) of the grooving blade is the minimum radius (R) of the locking plate groove of the blade to be repaired.

[0013] Optionally, the grooving cutter insert is made of carbide or carbide with a coating; the grooving cutter shank of the grooving cutter insert is made of a metal shank with a Rockwell hardness of 100 or higher.

[0014] Optionally, the bottom edge of the locking plate groove of the blade to be repaired is ground by: wrapping the blade to be repaired with gauze with a thickness of not less than 1 mm, and grinding the bottom edge of the locking plate groove of the blade to be repaired with a sanding belt.

[0015] Optionally, the size of the sanding belt is consistent with the bottom size of the locking plate groove of the blade to be repaired, and it is a 240~320 mesh sanding belt.

[0016] Optionally, it also includes: after grinding, inspecting the dimensions of the locking plate groove of the blade to be repaired.

[0017] Compared with the prior art, the present invention has the following beneficial effects:

[0018] This invention discloses a method for repairing blade rim locking grooves. First, the blade to be repaired is clamped using a whole-plate turning method, ensuring stability and consistency during processing, thereby significantly improving repair efficiency and precision. Then, a grooving tool with dimensions matching the locking groove of the blade to be repaired is used to perform a one-time forming repair of the locking groove through turning, avoiding the cumulative errors that may result from multiple machining operations and ensuring high-precision restoration of the locking groove dimensions. Simultaneously, during turning, the grooving tool enters along and closely adheres to the side of the blade tenon teeth. By precisely controlling the size of the grooving tool and the machining path, the repair effect and efficiency are guaranteed. Furthermore, when machining the tenon side of the blade to be repaired, a continuous feed method is used; when machining the locking plate groove of the blade to be repaired, a method is used where the feed is stopped for 1-3 minutes after every 0.1-0.3 mm. Different feed strategies are adopted according to the different machining parts. In particular, when machining the locking plate groove, the intermittent feed method effectively controls cutting heat and cutting force, reduces the thermal impact and mechanical stress on the blade substrate material, helps maintain the integrity of the blade and extends its service life. Moreover, the locking plate groove is relatively small, and this machining method can also effectively prevent the grooving tool from breaking. Finally, after the turning process, the bottom edge of the locking plate groove of the blade to be repaired is ground, which not only removes burrs and sharp edges that may have been generated during the machining process, but also further improves the surface quality of the locking plate groove, which is conducive to the smooth assembly and improved sealing performance. The blade repaired using the blade edge locking plate groove repair method of this invention can effectively pass the test performance verification. Compared with the current blade replacement method, it can greatly reduce manufacturing costs and save resources. Attached Figure Description

[0019] Figure 1 This is a flowchart of a blade edge plate locking groove repair method according to an embodiment of the present invention.

[0020] Figure 2 This is a schematic diagram of a slotting blade according to an embodiment of the present invention.

[0021] Figure 3 This is a schematic diagram of the repair status of the slotting blade in an embodiment of the present invention.

[0022] Figure 4 This is a schematic diagram of the bottom blade edge of the locking plate groove according to an embodiment of the present invention.

[0023] Among them: 1-anti-interference grooving; 2-grooving blade; 3-tool holder; 4-tool receiving edge. Detailed Implementation

[0024] 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.

[0025] 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.

[0026] The present invention will now be described in further detail with reference to the accompanying drawings:

[0027] See Figure 1 In one embodiment of the present invention, a method for repairing blade edge plate locking groove is provided, which can effectively repair the dimensional defects of blade edge plate locking groove.

[0028] Specifically, the method for repairing the blade rim locking groove of the present invention includes the following steps:

[0029] S1: The blade to be repaired is clamped using a whole-plate turning method.

[0030] S2: Using a grooving tool with the same size as the locking plate groove of the blade to be repaired, the locking plate groove of the blade to be repaired is repaired in one turn by turning. During the turning process, the grooving tool enters along the side of the blade tenon and is close to the side of the blade tenon. When the turning part is the side of the blade tenon, the machining method is continuous feed without interruption. When the turning part is the locking plate groove of the blade, the machining method is to stop the feed for 1 to 3 minutes after every 0.1 to 0.3 mm of feed.

[0031] S3: After turning, grind the bottom of the locking plate groove of the blade to be repaired to meet the cutting edge.

[0032] Specifically, the dimensional deviations in the blade edge plate locking groove are categorized, and appropriate repair solutions are determined based on the different types of problems. Dimensional deviations exceeding 0.01mm are repaired using machining equipment, while deviations within 0.01mm are repaired manually.

[0033] Depending on the repair plan, different tools are selected for repair, such as grinding wheels, lathe tools, files, reamers, drill bits, and oilstones made of different materials. For the blade edge plate locking groove, an attempt was made to repair it using a grinding wheel and a lathe tool. However, the minimum width of the locking groove is 1.15mm, while the minimum width of blade grooves currently machined using corundum is 2mm. The excessively narrow groove width makes the effective grinding area of ​​the grinding wheel unstable, easily causing cracks and chipping during grinding, leading to wheel breakage and directly causing safety accidents. CBN grinding wheels were selected, as they are high-hardness abrasives with strong stability during grinding and a large cutting depth. However, using such grinding wheels for repair is uneconomical, and the radius (R) at the bottom of the locking groove cannot be guaranteed.

[0034] In summary, the blade edge plate locking groove can be repaired by turning, which avoids the need for further repair. Another advantage of turning is that the whole plate method makes it easier to keep the blade size consistent and facilitates assembly.

[0035] This invention discloses a method for repairing blade rim locking grooves. First, the blade to be repaired is clamped using a whole-plate turning method, ensuring stability and consistency during processing, thereby significantly improving repair efficiency and precision. Then, a grooving tool with dimensions matching the locking groove of the blade to be repaired is used to perform a one-time forming repair of the locking groove through turning, avoiding the cumulative errors that may result from multiple machining operations and ensuring high-precision restoration of the locking groove dimensions. Simultaneously, during turning, the grooving tool enters along and closely adheres to the side of the blade tenon teeth. By precisely controlling the size of the grooving tool and the machining path, the repair effect and efficiency are guaranteed. Furthermore, when turning the blade tenon side of the blade to be repaired, a continuous feed without interruption is adopted; when turning the locking plate groove of the blade to be repaired, a feed stop of 1-3 minutes is adopted after every 0.1~0.3mm of feed. Different feed strategies are adopted according to different machining parts. In particular, when machining the locking plate groove, the intermittent feed effectively controls cutting heat and cutting force, reduces the thermal impact and mechanical stress on the blade substrate material, helps maintain the integrity of the blade and extends its service life. In addition, the locking plate groove is small in size, and the corresponding cutting tool is thin and has low strength. Intermittent feed stops can also effectively prevent the cutting tool from breaking. Finally, after turning, the bottom edge of the locking plate groove of the blade to be repaired is ground. This not only removes burrs and sharp edges that may have been generated during machining, but also further improves the surface quality of the locking plate groove, which is conducive to the smooth assembly and improved sealing performance. The blades repaired using the blade edge plate locking groove repair method of the present invention can effectively pass the test performance verification. Compared with the current method of replacing blades, it can greatly reduce manufacturing costs and save resources.

[0036] In one possible implementation, clamping the blades to be repaired using a whole-plate turning method includes: clamping at least 15 blades to be repaired using a whole-plate turning method; wherein, when there are fewer than 15 blades to be repaired, scrap blades of the same specification are used as blades to be repaired.

[0037] Specifically, clamping at least 15 blades to be repaired using a whole-plate turning method can effectively avoid weight eccentricity when the number of parts is small during plate machining, and prevent excessive part jump during rotation.

[0038] In one possible implementation, during the turning process of repairing the locking plate groove of the blade to be repaired in one step by turning, the spindle speed is 6 r / min, the feed rate is 0.01 mm / r, and the turning depth is 0.05 mm. Optionally, in this implementation, the feed rate is approximately 0.1 mm and then paused for 1 minute during the repair of the locking plate groove.

[0039] In one possible implementation, during the turning process of performing a one-time forming repair on the locking plate groove of the blade to be repaired by turning, the shank of the grooving cutter is perpendicular to the surface of the blade to be repaired, and the interference between the grooving cutter and the blade to be repaired is eliminated by grooving and sharpening the side of the grooving cutter.

[0040] For details, see Figure 2 and 3 The shank 3 of the grooving cutter 2 is perpendicular to the surface of the blade to be repaired to ensure repair accuracy. Furthermore, after the blade to be repaired is clamped using a full-disc turning method, interference will occur between the general-purpose grooving cutter and the blade to be repaired. At this time, an anti-interference groove 1 is made on the side of the general-purpose grooving cutter to create a special tool to eliminate the interference between the grooving cutter 2 and the blade to be repaired.

[0041] Optionally, when performing the turning process to repair the locking plate groove of the blade to be repaired in one step by turning, the turning process is performed on the locking plate groove of the blade to be repaired within the 0±0.05mm dimensional acceptable range.

[0042] Specifically, by setting a dimensional requirement of 0±0.05mm, the dimensional accuracy of the locking plate groove of the blade to be repaired is ensured during the turning process, thereby improving the interchangeability and reliability of the blade.

[0043] Optionally, the grooving cutter insert 2 is made of carbide or carbide with a coating, and the grooving cutter shank of the grooving cutter insert 2 is made of a metal shank with a Rockwell hardness of 100 or higher.

[0044] Specifically, carbide inserts or carbide-coated inserts are used to maintain the sharpness of the cutting edge during long-term cutting, reduce the generation of cutting force and cutting heat, thereby reducing the thermal and mechanical stress on the blade material and protecting the integrity and performance of the blade.

[0045] Optionally, the width of the grooving blade 2 is the minimum width of the locking plate groove of the blade to be repaired; the radius (R) of the grooving blade 2 is the minimum radius (R) of the locking plate groove of the blade to be repaired.

[0046] Specifically, the tool dimensions are designed to be the minimum width and minimum radius of the locking groove, ensuring that the grooving tool insert 2 can meet the dimensional requirements of the locking groove during machining.

[0047] In one possible implementation, the bottom edge of the locking plate groove of the blade to be repaired is polished by: wrapping the blade to be repaired with gauze with a thickness of not less than 1 mm, and polishing the bottom edge of the locking plate groove of the blade to be repaired with a sanding belt.

[0048] For details, see Figure 4Due to the inconsistency between the blade reference and the original dimensions of the locking plate groove, a cutting edge exists between the machined and unmachined surfaces, typically at the bottom of the locking plate groove, i.e., bottom cutting edge 4. This is repaired by using sanding belts. The sanding belt is trimmed to match the bottom dimensions of the locking plate groove, ensuring the belt size matches the bottom dimensions of the groove. During repair, the blade is secured, and soft gauze can be wrapped around it to prevent damage. The wrapping thickness should be no less than 1mm. Then, the sanding belt is held by both sides and used to sand the bottom cutting edge 4, observing the repair process continuously.

[0049] Among them, abrasive belts with a mesh size of 240 to 320 are generally selected.

[0050] In one possible implementation, the blade edge plate locking groove repair method further includes: after grinding, inspecting the dimensions of the locking groove of the blade to be repaired.

[0051] Specifically, by inspecting the dimensions of the locking plate groove of the blade to be repaired, any possible dimensional deviations or non-conformities can be detected and corrected in a timely manner to ensure the quality of the repaired blade. Furthermore, problems in the repair method can be analyzed and improved in a timely manner.

[0052] In one possible implementation, this invention addresses the repair of a narrow locking groove on a turbine blade. The blade material has a high Cr content, is a cast high-temperature alloy with good high-temperature performance, but has very low thermal conductivity and thermal diffusivity, resulting in poor machinability. Furthermore, the machining of this narrow, deep groove makes it prone to localized overheating during processing. Because the locking groove cannot be properly installed during assembly, inspection revealed that the dimensions of the locking groove on the lower edge plate are out of tolerance, requiring repair of the relevant dimensions. The blade edge plate locking groove repair method of this invention is used for repair, and the machining parameters are shown in Table 1.

[0053] Table 1

[0054]

[0055] 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.

[0056] 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 a blade edge plate locking groove, characterized in that, include: The blade to be repaired is clamped using a whole-disc turning method; Using a grooving tool with the same size as the locking groove of the blade to be repaired, the locking groove of the blade to be repaired is repaired in one turn by turning. During the turning process, the grooving tool enters along the side of the blade tenon and is close to the side of the blade tenon. When the turning part is the side of the blade tenon, the machining method is continuous feed without interruption. When the turning part is the locking groove of the blade, the machining method is to stop the feed for 1 to 3 minutes every 0.1 to 0.3 mm. After the turning process is completed, grind the bottom of the locking plate groove of the blade to be repaired to obtain the cutting edge; The method of clamping the blade to be repaired using a whole-disc turning process includes: At least 15 blades to be repaired are clamped using a whole-plate turning method; if there are fewer than 15 blades to be repaired, scrap blades of the same specification are used as blades to be repaired. When performing a one-time forming repair of the locking plate groove of the blade to be repaired by turning, the shank of the grooving cutter is perpendicular to the surface of the blade to be repaired, and the interference between the grooving cutter and the blade to be repaired is eliminated by grooving and sharpening the side of the grooving cutter.

2. The method for repairing the blade rim plate locking groove according to claim 1, characterized in that, When performing the turning process to repair the locking plate groove of the blade to be repaired in one step, the spindle speed is 6 r / min, the feed rate is 0.01 mm / r, and the turning depth is 0.05 mm.

3. The method for repairing the blade rim plate locking groove according to claim 1, characterized in that, When performing a one-time forming repair of the locking plate groove of the blade to be repaired by turning, the locking plate groove of the blade to be repaired is turned within the dimensional range of 0±0.05mm.

4. The method for repairing the blade rim locking groove according to claim 1, characterized in that, The width of the grooving blade is the minimum width of the locking plate groove of the blade to be repaired; the radius (R) of the grooving blade is the minimum radius (R) of the locking plate groove of the blade to be repaired.

5. The method for repairing the blade rim plate locking groove according to claim 1, characterized in that, The grooving cutter insert is made of cemented carbide or cemented carbide with a coating; the grooving cutter shank is made of a metal shank with a Rockwell hardness of 100 or higher.

6. The method for repairing the blade rim plate locking groove according to claim 1, characterized in that, The bottom edge of the locking plate groove for grinding the blade to be repaired includes: Wrap the blade to be repaired with gauze with a thickness of not less than 1 mm, and use a sanding belt to grind the bottom edge of the locking plate groove of the blade to be repaired.

7. The method for repairing the blade rim plate locking groove according to claim 6, characterized in that, The size of the sanding belt is consistent with the bottom size of the locking plate groove of the blade to be repaired, and it is a 240~320 mesh sanding belt.

8. The method for repairing the blade rim plate locking groove according to claim 1, characterized in that, Also includes: After grinding, the dimensions of the locking plate groove of the blade to be repaired are inspected.

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