Method for repairing a double ring of a flame tube of an aircraft engine

Abstract

The application discloses an aero-engine flame tube double-ring repair method, which comprises the following steps: obtaining a to-be-repaired double ring and a target double ring, and removing the to-be-repaired double ring from the flame tube; polishing the barrel wall of the flame tube to ensure that the thickness of the barrel wall is not less than 0.75 mm; positioning the flame tube and the target double ring through a positioning clamp; and continuously spot welding the target double ring and the flame tube by using a Z-shaped electrode to extend into the gap between the target double ring and the flame tube, so that the target double ring and the flame tube are welded with each other, and the repair of the flame tube and the target double ring is completed. Based on the above, after the to-be-repaired double ring is removed, the target double ring and the flame tube are repositioned and connected, so that the deformation of the flame tube can be effectively prevented when welding is performed subsequently, and the interference of the target double ring and the flame tube with the electrode during welding can be flexibly avoided by using the Z-shaped electrode, and the convenience of the aero-engine flame tube double-ring repair is improved.

Description

Technical Field

[0001] This application belongs to the field of aero-engine testing technology, and in particular relates to a method for repairing a double-ring aero-engine flame tube. Background Technology

[0002] The flame tube and double ring on an aero-engine are precision components that play a crucial role in the engine's operational reliability. During assembly and welding of the double ring to the flame tube, the double ring is first welded to the inner ring of the flame tube using resistance seam welding, and then welded to the outer ring. After welding, the inner ring wall of the flame tube is sprayed with a ceramic thermal barrier coating. Over long-term use, the double ring may suffer damage. Replacing the double ring presents significant challenges. First, the welding process to the flame tube causes structural changes to the original flame tube, and the structure must remain unchanged during welding. Second, the inner and outer rings of the flame tube are already welded together, with a very small weld seam, typically less than 55mm. During welding, the electrode needs to be inserted into the weld seam of the inner ring, but interference occurs during this process, making it impossible to smoothly insert the electrode into the gap for re-welding of the flame tube and double ring. Third, positioning is difficult, and deformation is prone to occur during welding. Therefore, due to the lack of a suitable replacement method for the double ring, the entire flame tube and double ring usually need to be replaced, undoubtedly resulting in unnecessary waste.

[0003] Currently, deformation during welding can usually be addressed using tooling for assisted positioning. For example, patent CN119501455A discloses a repair tooling and method for the inner ring of the combustion chamber flame tube of an aero-engine. The tooling includes: a base bearing, comprising a bearing plate, a base plate with an outer diameter larger than the outer diameter of the bearing plate, and a connecting cylinder connecting the base plate and the bearing plate; a top plate placed on the bearing plate; a pressure column placed in the middle of the top plate, the pressure column having a circular cross-section with its diameter gradually decreasing from one end to the other so that when the pressure column presses against one end of the bearing plate, it can push the top plate towards the outer diameter of the bearing plate; a cover plate, comprising a support plate placed on the pressure column and at least two pressure plates fixed around the support plate by bolts, the top plate being placed between the pressure column and the pressure plates; and adjusting bolts, used to fix the base bearing, pressure column, and cover plate and to adjust the depth of the pressure column pressed into the top plate. This effectively reduces deformation and improves repair quality during welding.

[0004] Although this method can solve the deformation problem during welding, considering the small gap between the flame tube and the double ring, there will still be some difficulties in reducing deformation by using this tooling for positioning, and welding will still be difficult. Summary of the Invention

[0005] This application provides a method for repairing the double ring of an aero-engine flame tube, which improves the convenience of repairing the double ring of an aero-engine flame tube.

[0006] According to a first aspect of this application, embodiments of this application provide a method for repairing a double-ring flame tube of an aircraft engine, which may include:

[0007] S1. Obtain the double ring to be repaired and the target double ring, and remove the double ring to be repaired from the flame tube;

[0008] S2. Grind the wall of the flame tube to ensure that the wall thickness is not less than 0.75mm;

[0009] S3. Position the flame tube and the target double ring using a positioning fixture. The positioning fixture includes a base plate, a top plate, and multiple support columns mounted on the base plate. The base plate includes a first connecting part and a positioning cylinder disposed on the first connecting part. The end face of the positioning cylinder is connected to the first connecting part. The multiple support columns are arranged in a circumferential shape on the first connecting part and surround to form a receiving cavity. The positioning cylinder is located in the receiving cavity, and there is a gap between the support columns and the positioning cylinder. The top plate includes a second connecting part and a positioning ring disposed on the second connecting part. The end face of the positioning ring is connected to the second connecting part.

[0010] First, the target double ring is placed in the receiving cavity and a positioning cylinder is fitted on the side away from the first connecting part, with the edge of the target double ring positioned in the gap. The positioning cylinder supports and centers the target double ring. Then, the flame tube is placed in the receiving cavity, with its first side extending into the gap and positioned close to the outer periphery of the target double ring. The edge of the second side of the flame tube rests on the end of the support column away from the first connecting part. Next, the positioning ring is inserted into the inner cavity of the flame tube to center it, ensuring that the gap between the target double ring and the first layer of the inner ring wall of the flame tube is [missing information]. mm, and press the second connecting part against the second side of the flame tube, and drive the second connecting part to move closer to the first connecting part, so that the total height of the target double ring and the flame tube is 135±0.3mm;

[0011] S4. Using a Z-shaped electrode inserted into the gap between the target double ring and the flame tube, perform continuous spot welding on the target double ring and the flame tube to weld them together, thus completing the repair of the flame tube and the target double ring.

[0012] Optionally, both the first connecting part and the second connecting part are cylinders, the positioning cylinder is concentrically arranged with the first connecting part and connected to each other, and the positioning ring is concentrically arranged with the second connecting part and connected to each other.

[0013] Optionally, after placing the target double ring in the receiving cavity and fitting it onto the side of the positioning cylinder away from the first connecting portion, the method further includes:

[0014] The target double ring is secured to the side of the positioning cylinder away from the first connection part using fasteners.

[0015] Optionally, the positioning fixture also includes a height adjustment device, which includes an adjusting screw and a fastening head. One end of the adjusting screw is vertically fixed to the first connecting part. The adjusting screw passes through the positioning cylinder and the second connecting part in sequence. The fastening head is located on the side of the second connecting part away from the first connecting part and is detachably connected to the adjusting screw.

[0016] Pressing the second connecting part against the second side of the flame tube and driving the second connecting part to move closer to the first connecting part includes:

[0017] Press the second connecting part against the second side of the flame tube, and rotate the fastening head to drive the second connecting part to move closer to the first connecting part.

[0018] Optionally, the wall of the flame tube is ground to ensure that the wall thickness is not less than 0.75 mm, including:

[0019] The double ring to be repaired is machined using a turning machine to remove the first area of ​​the double ring to be repaired, while retaining the second area that connects the double ring to be repaired with the flame tube. The thickness of the second area is 0.5 mm.

[0020] The second area is polished using a polishing machine to ensure that the thickness of the cylinder wall is not less than 0.75mm.

[0021] Optionally, the second region is ground using a grinding machine to ensure that the thickness of the cylinder wall is not less than 0.75 mm, including:

[0022] The wall thickness of the flame tube is measured using testing instruments;

[0023] If the wall thickness of the flame tube is less than 0.75 mm, stop grinding and removing material from the second area.

[0024] Alternatively, the grinding equipment may include an angle grinder or a grinding mill.

[0025] Optionally, a Z-shaped electrode is inserted into the gap between the target double ring and the flame tube to perform continuous spot welding on the target double ring and the flame tube, so that the target double ring and the flame tube are welded together, completing the repair of the flame tube and the target double ring, including:

[0026] By using a medium-frequency inverter spot welding machine to continuously spot weld the target double ring and flame tube according to preset spot welding parameters, the target double ring and flame tube are welded together. The medium-frequency inverter spot welding machine includes a Z-type electrode.

[0027] Optionally, the preset spot welding parameters include:

[0028] Welding interval: 15 cycles;

[0029] The time during which pressure is applied to the workpiece after the electrode contacts the workpiece but no current is applied: 25 cycles;

[0030] Duration of the first weld: 8 cycles;

[0031] First welding pulse current: 4.3kA;

[0032] Cooling time after pausing power following the first welding: 5 cycles;

[0033] Duration of the second welding: 11 cycles;

[0034] Second welding pulse current: 5.7kA;

[0035] Pressure holding time after welding: 25 cycles;

[0036] Welding pressure: 0.24 MPa.

[0037] Optionally, before removing the double ring to be repaired from the flame tube to ensure that the wall thickness of the flame tube is not less than a first preset thickness, the method further includes:

[0038] The coating was removed from the connection between the flame tube and the double ring to be repaired using a sandblasting process.

[0039] The technical solutions provided by the embodiments of this application bring at least the following beneficial effects:

[0040] This application provides a method for repairing a double-ring flame tube of an aero-engine. First, the aero-engine to be repaired and the target double ring are obtained. The flame tube and the target double ring are disassembled from the aero-engine to be repaired, ensuring the thickness of the flame tube wall is not less than 0.75mm. This sufficient thickness allows the flame tube to meet design requirements even during deformation during re-welding. Before spot welding the target double ring and the flame tube again, the target double ring is pre-positioned using a positioning cylinder. The edge of the second side of the flame tube is then placed on the end of the support column away from the first connection part, with the second side of the flame tube extending into the gap between the positioning cylinder and the support column. A top plate is then placed on the first side of the flame tube, and the flame tube is centered using the positioning ring, ensuring the gap between the target double ring and the first layer of the inner ring wall of the flame tube is [missing information]. mm, and then drive the second connecting part to move closer to the first connecting part to ensure that the total height between the target double ring and the flame tube is 135±0.3mm. This can further reduce the possibility of deformation of the flame tube during subsequent welding. Then, insert one end of the Z-shaped electrode into the gap between the target double ring and the flame tube to weld the target double ring and the flame tube. This can reduce the possibility of interference between the welding equipment and the flame tube or the target double ring during spot welding, thereby improving the convenience of repairing the double ring of the aero-engine flame tube.

[0041] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and do not limit this application. Attached Figure Description

[0042] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application, and do not constitute an undue limitation of this application.

[0043] Figure 1 This is a flowchart illustrating a double-ring repair method for an aircraft engine flame tube according to an exemplary embodiment;

[0044] Figure 2 This is a schematic diagram illustrating the positioning of the positioning fixture for the flame tube and the target double ring in a repair method for a double ring of an aero-engine flame tube according to an exemplary embodiment;

[0045] Figure 3 This is a partial enlarged view of region A in a schematic diagram illustrating the positioning of the positioning fixture for the flame tube and the target double ring in a repair method for a double ring of an aero-engine flame tube according to an exemplary embodiment;

[0046] Figure 4 This is a schematic diagram illustrating the welding of a Z-shaped electrode to the target double ring and the flame tube in a double ring repair method for an aero-engine flame tube according to an exemplary embodiment.

[0047] Legend:

[0048] Detailed Implementation

[0049] To better understand the above-mentioned objectives, features, and advantages of this disclosure, the solutions disclosed herein will be further described below. It should be noted that, unless otherwise specified, the embodiments and features described herein can be combined with each other.

[0050] Numerous specific details are set forth in the following description in order to provide a full understanding of this disclosure, but this disclosure may also be implemented in other ways different from those described herein; obviously, the embodiments in the specification are only some, and not all, of the embodiments of this disclosure.

[0051] As described in the background section, when replacing existing double rings, the welding process of the double rings to the flame tube causes structural changes to the original flame tube, and the small gap between the double rings in the flame tube also makes welding difficult. Therefore, usually only the entire flame tube and double rings can be replaced, which undoubtedly causes a lot of unnecessary losses.

[0052] Based on this, this application provides a method for repairing a double-ring aero-engine flame tube. The method for repairing a double-ring aero-engine flame tube provided in the embodiments of this application will be described below.

[0053] like Figure 1 - Figure 3 As shown;

[0054] Example 1;

[0055] The repair method for the double ring of the aircraft engine flame tube 20 may include the following steps:

[0056] S1. Obtain the double ring to be repaired and the target double ring 10, and remove the double ring to be repaired from the flame tube 20;

[0057] S2. Grind the wall of the flame tube 20 to ensure that the wall thickness is not less than 0.75mm;

[0058] S3. Position the flame tube 20 and the target double ring 10 using a positioning fixture 30. The positioning fixture 30 includes a base plate 31, a top plate 32, and multiple support columns 33 mounted on the base plate 31. The base plate 31 includes a first connecting part 312 and a positioning cylinder 311 disposed on the first connecting part 312. The end face of the positioning cylinder 311 is connected to the first connecting part 312. The multiple support columns 33 are arranged in a circumferential shape on the first connecting part 312 and surround to form a receiving cavity. The positioning cylinder 311 is located in the receiving cavity, and there is a gap between the support columns 33 and the positioning cylinder 311. The top plate 32 includes a second connecting part 322 and a positioning ring 321 disposed on the second connecting part 322. The end face of the positioning ring 321 is connected to the second connecting part 322.

[0059] First, the target double ring 10 is placed in the receiving cavity and the positioning cylinder 311 is fitted onto the side away from the first connecting part 312, with the edge of the target double ring 10 placed in the gap. The positioning cylinder 311 supports and centers the target double ring 10. Then, the flame tube 20 is placed in the receiving cavity, with the first side of the flame tube 20 extending into the gap and positioned close to the outer periphery of the target double ring 10. The edge of the second side of the flame tube 20 rests on the end of the support column 33 away from the first connecting part 312. Next, the positioning ring 321 is inserted into the inner cavity of the flame tube 20 to center the flame tube 20, so that the gap between the target double ring 10 and the first layer wall of the inner ring of the flame tube 20 is... mm, and press the second connecting part 322 against the second side of the flame tube 20, and drive the second connecting part 322 to move towards the first connecting part 312, so that the total height of the target double ring 10 and the flame tube 20 is 135±0.3mm;

[0060] S4. Using a Z-shaped electrode inserted into the gap between the target double ring 10 and the flame tube 20, continuously spot weld the target double ring 10 and the flame tube 20 to weld them together, thus completing the repair of the flame tube 20 and the target double ring 10.

[0061] Based on the above embodiments, by first obtaining the aircraft engine to be repaired and the target double ring 10, the flame tube 20 and the double ring to be repaired in the aircraft engine to be repaired are first disassembled, so that the thickness of the tube wall of the flame tube 20 is not less than 0.75mm. This ensures sufficient thickness so that the flame tube 20 can still meet design requirements when deformed during re-welding. Before spot welding the target double ring 10 and the flame tube 20 again, the target double ring 10 is pre-positioned using a positioning cylinder 311. Then, the edge of the second side of the flame tube 20 is placed on the end of the support column 33 away from the first connecting part 312, and the second side of the flame tube 20 extends into the gap between the positioning cylinder 311 and the support column 33. The top plate 32 is then placed on the first side of the flame tube 20, and the flame tube 20 is centered using a positioning ring 321, ensuring that the gap between the target double ring 10 and the first layer of the inner ring wall of the flame tube 20 is... mm, and then drive the second connecting part 322 to move closer to the first connecting part 312 to ensure that the total height between the target double ring 10 and the flame tube 20 is 135±0.3mm. This can further reduce the possibility of deformation of the flame tube 20 during subsequent welding. Then, insert one end of the Z-shaped electrode into the gap between the target double ring 10 and the flame tube 20 to weld the target double ring 10 and the flame tube 20. This can reduce the possibility of interference between the welding equipment and the flame tube 20 or the target double ring 10 during spot welding, thereby improving the convenience of repairing the double ring of the aero-engine flame tube 20.

[0062] In an aircraft engine, the flame tube 20 and the double ring are welded together. The aircraft engine to be repaired is being acquired; the double ring in this engine is damaged, and the flame tube 20 and the double ring to be repaired are welded together.

[0063] A target double ring 10 for replacing the double ring to be repaired also needs to be obtained.

[0064] The double ring to be repaired and the double ring to be repaired in the flame tube 20, which were originally welded together, are removed, so that the double ring to be repaired and the flame tube 20 are separated. After separation, the tube wall of the flame tube 20 is ground to ensure that the thickness of the tube wall of the flame tube 20 is not less than the first preset thickness (0.75mm), so as to leave the deformation allowance of the flame tube 20 when welding the flame tube 20 and the target double ring 10.

[0065] 0.75mm is a critical value. If the thickness of the flame tube 20 is ground to 0.75mm as the target, it may be less than 0.75mm if not careful, which will cause the flame tube 20 to be scrapped. Therefore, preferably, the thickness of the wall of the flame tube 20 is 0.8mm. Considering the error during the grinding of the flame tube 20, when grinding with 0.8mm as the target, the possibility of the wall thickness of the flame tube 20 being less than 0.75mm is greatly reduced, which reduces the possibility of the flame tube 20 being scrapped when repairing it and saves the maintenance cost of the flame tube 20.

[0066] like Figure 2 and Figure 3 As shown, the positioning fixture 30 includes a base plate 31, a top plate 32, and multiple support columns 33 mounted on the base plate 31. During the positioning process of the positioning fixture 30, the target double ring 10 is a new double ring, which is first fixed on the positioning cylinder 311. Then, the first side of the flame tube 20 is connected to the first end of the support column 33 away from the base plate 31, and the edge of the other side of the flame tube 20 is supported by the end of the support column 33 away from the first connecting part 312. The top plate 32 is placed on the first side of the flame tube 20, and the positioning ring 321 is inserted into the inner cavity of the flame tube 20 to center the flame tube 20. This ensures that the gap between the first wall surface of the inner ring of the flame tube 20 and the target double ring 10 originally fixed on the positioning cylinder 311 meets the requirements. mm (e.g.) Figure 3 (at point b), then press the second connecting part 322 onto the second side of the flame tube 20, so that the flame tube 20 can move towards the target double ring 10 through the second connecting part 322, thereby ensuring that the height between the target double ring 10 and the flame tube 20 is 135±0.3mm, so that the positioning fixture 30 completes the positioning of the target double ring 10 and the flame tube 20.

[0067] The base plate 31 includes a first connecting part 312 and a positioning cylinder 311 that are connected to each other. By adapting the size of the positioning cylinder 311 to the outer contour of the target double ring 10, the target double ring 10 can be centered by the positioning cylinder 311. Furthermore, the edge of the target double ring 10 extends into the gap between the positioning cylinder 311 and the support column 33, thereby enabling the edge of the target double ring 10 to better wrap around the positioning cylinder 311, improving the accuracy and stability of the positioning cylinder 311 in positioning the target double ring 10.

[0068] Similarly, the top plate 32 also includes a second connecting part 322 and a positioning ring 321 that are connected to each other. The size of the positioning ring 321 is also adapted to the size of the inner cavity of the target double ring 10, which can further improve the centering of the positioning ring 321 on the flame tube 20.

[0069] Multiple support columns 33 are arranged in a circular pattern on the first connecting part 312 and form a receiving cavity. Thus, when the flame tube 20 is placed in the receiving cavity, the interaction of the multiple support columns 33 can restrict the horizontal movement of the flame tube 20 and position the flame tube 20 in the horizontal direction.

[0070] The Z-shaped electrode is the upper electrode 40 of the welding equipment. The first end of the upper electrode 40 is connected to the welding equipment, and the second end of the upper electrode 40 is used to weld with the lower electrode 50. The first and second ends of the upper electrode 40 are bent together to form a Z shape. The second end of the upper electrode 40 is inserted into the narrow gap between the flame tube 20 and the target double ring 10 to weld the target flame tube 20 and the double ring. This can effectively reduce the possibility of interference between the upper electrode 40 and the flame tube 20 or the target double ring 10, overcome the inconvenience of operating in a narrow gap when using conventional electrodes, and make the welding of the target double ring 10 and the flame tube 20 more convenient.

[0071] In this example, the target double ring 10 and flame tube 20 are welded using the upper electrode 40 and lower electrode 50 of a spot welding machine. Figure 4As shown, the Z-type electrode refers to the upper electrode 40 of the spot welding machine. It works together with the lower electrode 50 to weld the target double ring 10 and the flame tube 20. One end of the upper electrode 40 is connected to the handle of the spot welding machine, positioned outside the target double ring 10 and the flame tube 20, while the other end extends into the gap between the target double ring 10 and the flame tube 20, ensuring sufficient space for the upper electrode 40 to lift during welding. One end of the lower electrode 50 is directly connected to the lower arm of the spot welding machine, and the other end also extends into the gap between the target double ring 10 and the flame tube 20, positioned opposite the upper electrode 40. This overcomes the inconvenience of operating in narrow gaps during conventional electrode welding, making the welding of the target double ring 10 and the flame tube 20 much more convenient.

[0072] Optionally, in one example, both the first connecting part 312 and the second connecting part 322 are cylinders, the positioning cylinder 311 is concentrically arranged with the first connecting part 312 and connected to each other, and the positioning ring 321 is concentrically arranged with the second connecting part 322 and connected to each other.

[0073] By setting the first connecting part 312 and the second connecting part 322 as cylinders, and by setting the positioning cylinder 311 and the first connecting part 312 concentrically, and setting the positioning ring 321 and the second connecting part 322 concentrically, the first connecting part 312 and the positioning cylinder 311, as well as the second connecting part 322 and the positioning ring 321, can be machined by turning process. This improves the machining accuracy of the top plate 32 and the bottom plate 31, and improves the positioning accuracy of the positioning fixture 30 for the target double ring 10 and the flame tube 20.

[0074] Optionally, in one example, after placing the target double ring 10 in the receiving cavity and fitting the positioning cylinder 311 on the side away from the first connecting portion 312, the method further includes:

[0075] The target double ring 10 is fixed to the side of the positioning cylinder 311 away from the first connecting part 312 by fasteners.

[0076] By using fasteners to fix the target double ring 10 to the positioning cylinder 311, the possibility of the target double ring 10 shaking or shifting during subsequent positioning operations is further reduced, thereby improving the positioning accuracy of the positioning fixture 30 for the target double ring 10 and the flame tube 20.

[0077] Optionally, in one example, the positioning clamp 30 further includes a height adjustment device 34, which includes an adjusting screw 341 and a fastening head 342. One end of the adjusting screw 341 is vertically fixed to the first connecting part 312. The adjusting screw 341 passes through the positioning cylinder 311 and the second connecting part 322 in sequence. The fastening head 342 is located on the side of the second connecting part 322 away from the first connecting part 312 and is detachably connected to the adjusting screw 341.

[0078] Pressing the second connecting part 322 against the second side of the flame tube 20 and driving the second connecting part 322 to move towards the first connecting part 312 includes:

[0079] The second connecting part 322 is pressed against the second side of the flame tube 20, and the fastening head 342 is rotated to drive the second connecting part 322 to move closer to the first connecting part 312.

[0080] By fixing one end of the adjusting screw 341 to the first connecting part 312 and allowing the adjusting screw 341 to pass through the positioning cylinder 311 and the second connecting part 322 in sequence, when adjusting the total height of the target double ring 10 and the flame tube 20, the adjusting screw 341 can be moved by rotating the fastening head 342, thereby changing the magnitude of the force applied by the fastening head 342 to the second connecting part 322, and thus enabling fine adjustment of the total height of the target double ring 10 and the flame tube 20.

[0081] Furthermore, since the adjusting screw 341 is vertically fixed to the first connecting part 312, the force applied by the fastening head 342 to the second connecting part 322 is also vertical. As a result, this force can be evenly applied to the flame tube 20 to ensure that the total height of the flame tube 20 and the target double ring 10 is consistent in all positions, thereby improving the positioning accuracy of the positioning fixture 30.

[0082] Optionally, in one example, grinding the wall of the flame tube 20 to ensure that the wall thickness is not less than 0.75 mm may include:

[0083] The double ring to be repaired is machined using a turning machine to remove the first area of ​​the double ring to be repaired, while retaining the second area that connects the double ring to be repaired with the flame tube 20. The thickness of the second area is 0.5 mm.

[0084] The second area is polished using a polishing machine to ensure that the thickness of the cylinder wall is not less than 0.75mm.

[0085] By using a turning process to machine the double ring to be repaired, the double ring to be repaired can be quickly separated from the flame tube 20. However, since the turning accuracy is difficult to control and the turning process is relatively rough, in order to avoid damaging the flame tube 20 connected to the double ring to be repaired during turning, only the first area of ​​the double ring to be repaired can be machined by turning. The second area connected to the flame tube 20 also needs to be retained. The thickness of the second area should be kept at 0.5mm.

[0086] The second area remaining on the flame tube 20 can be further removed by grinding with an angle grinder or milling machine. It should be noted that damage to the flame tube 20 should be avoided as much as possible during the grinding process, and the thickness of the flame tube 20 wall must be ensured to be not less than 0.75mm.

[0087] Optionally, in one example, grinding the second region with a grinding device to ensure that the cylinder wall thickness is not less than 0.75 mm may also include:

[0088] The wall thickness of the flame tube 20 is measured using a testing instrument;

[0089] If the wall thickness of the flame tube 20 is less than 0.75 mm, stop grinding and removing the second area.

[0090] By setting up a detection instrument to monitor the wall thickness of the flame tube 20, the wall thickness of the flame tube 20 can be detected in real time during the grinding process of the second area by the grinding equipment; or the wall thickness of the flame tube 20 can be detected by the detection instrument after a certain period of time or a certain degree of grinding.

[0091] Preferably, the grinding equipment may include an angle grinder or a grinding mill.

[0092] If the wall thickness of the flame tube 20 is less than 0.75mm, it means that the wall of the flame tube 20 after grinding no longer meets the process requirements for further welding and replacement of the new target double ring 10. Therefore, the flame tube 20 needs to be scrapped.

[0093] Since the flame tube 20 needs to be welded to the new target double ring 10 again during subsequent maintenance, in order to ensure the accuracy after welding, the original double ring to be repaired needs to be completely removed. However, the double ring to be repaired and the flame tube 20 have already been welded together. Even if the first area of ​​the double ring to be repaired is ground off, the double ring to be repaired will still remain and be welded to the flame tube 20 in the second area. Further grinding of the second area is required. However, the grinding process may damage the flame tube 20. Therefore, the thickness of the flame tube 20 needs to be tested before welding the target double ring 10. If the thickness of the flame tube 20 is less than the first preset thickness (0.75mm), it means that the structural strength of the flame tube 20 will not meet the standard after welding with the target double ring 10. Therefore, the flame tube 20 with a wall thickness less than the first preset thickness (0.75mm) needs to be scrapped.

[0094] Example 2:

[0095] Optionally, in one example, using a Z-shaped electrode inserted into the gap between the target double ring 10 and the flame tube 20 to perform continuous spot welding on the target double ring 10 and the flame tube 20, so that the target double ring 10 and the flame tube 20 are welded together, the repair of the flame tube 20 and the target double ring 10 may include:

[0096] By using a medium-frequency inverter spot welding machine to perform continuous spot welding on the target double ring 10 and flame tube 20 according to preset spot welding parameters, the target double ring 10 and flame tube 20 are welded to each other. The medium-frequency inverter spot welding machine includes a Z-type electrode.

[0097] Medium-frequency inverter spot welding machines, through their core design of high-frequency inverter technology and DC output, are significantly superior to traditional industrial frequency welding machines in terms of energy efficiency, precision, adaptability, and intelligence, making them particularly suitable for industrial production scenarios with high cycle times and high quality requirements.

[0098] Specifically, in one example, the preset spot welding parameters include:

[0099] Welding interval: 15 cycles;

[0100] The time during which pressure is applied to the workpiece after the electrode contacts the workpiece but no current is applied: 25 cycles;

[0101] Duration of the first weld: 8 cycles;

[0102] First welding pulse current: 4.3kA;

[0103] Cooling time after pausing power following the first welding: 5 cycles;

[0104] Duration of the second welding: 11 cycles;

[0105] Second welding pulse current: 5.7kA;

[0106] Pressure holding time after welding: 25 cycles;

[0107] Welding pressure: 0.24 MPa.

[0108] The processing qualification rate can reach 100% using the process method of this embodiment.

[0109] The above-described embodiment 2 can implement all the processes of the above-described embodiment 1 and achieve the same technical effect. To avoid repetition, it will not be described again here.

[0110] Example 3:

[0111] Optionally, in one example, prior to the above-described S101, the double-ring repair method for the aircraft engine flame tube 20 may further include:

[0112] The coating was removed from the connection between the flame tube 20 and the double ring to be repaired using a sandblasting process.

[0113] After the flame tube 20 of the aero-engine and the double ring to be repaired are welded, a ceramic thermal barrier coating is sprayed onto the inner ring wall of the flame tube 20. The thermal barrier coating is a ceramic material that is non-conductive. A sandblasting process can quickly remove the thermal barrier coating, exposing the metal substrate (the inner ring wall of the flame tube 20), thereby further ensuring the welding requirements for subsequent re-welding. The sandblasting process removes the coating without damaging the substrate and produces a uniform surface thickness, which is more conducive to ensuring the quality of subsequent welding.

[0114] The above embodiment 3 can implement the various processes of the above embodiment 1 and / or 2, and can achieve the same technical effect. To avoid repetition, it will not be described again here.

[0115] The above are merely specific embodiments of this application. Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working processes of the systems, modules, and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here. It should be understood that the protection scope of this application is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in this application, and these modifications or substitutions should all be covered within the protection scope of this application.

Claims

1. A method of repairing a double- ring flame tube of an aircraft engine, the method comprising: The steps of the method are as follows: S1. Obtain the double ring to be repaired and the target double ring, and remove the double ring to be repaired from the flame tube; S2. Grind the wall of the flame tube to ensure that the thickness of the wall is not less than 0.75mm; S3. Position the flame tube and the target double ring using a positioning fixture. The positioning fixture includes a base plate, a top plate, and multiple support columns mounted on the base plate. The base plate includes a first connecting part and a positioning cylinder disposed on the first connecting part. The end face of the positioning cylinder is connected to the first connecting part. The multiple support columns are arranged in a circumferential shape on the first connecting part and surround to form a receiving cavity. The positioning cylinder is located in the receiving cavity, and there is a gap between the support columns and the positioning cylinder. The top plate includes a second connecting part and a positioning ring disposed on the second connecting part. The end face of the positioning ring is connected to the second connecting part. First, the target double ring is placed in the receiving cavity, and the positioning cylinder is fitted on the side away from the first connecting part. The edge of the target double ring is placed in the gap, and the positioning cylinder supports and centers the target double ring. Then, the flame tube is placed in the receiving cavity, with the first side of the flame tube extending into the gap and positioned close to the outer periphery of the target double ring. The edge of the second side of the flame tube rests on the end of the support column away from the first connecting part. Next, the positioning ring is inserted into the inner cavity of the flame tube to center the flame tube, so that the gap between the target double ring and the first layer of the inner ring wall of the flame tube is... mm, and press the second connecting part against the second side of the flame tube, and drive the second connecting part to move closer to the first connecting part, so that the total height of the target double ring and the flame tube is 135±0.3mm; S4. Using a Z-shaped electrode inserted into the gap between the target double ring and the flame tube, continuously spot weld the target double ring and the flame tube to weld them together, thus completing the repair of the flame tube and the target double ring.

2. The double-ring repair method for the flame tube of an aero-engine as described in claim 1, characterized in that, Both the first connecting part and the second connecting part are cylindrical. The positioning cylinder is concentrically arranged with the first connecting part and connected to each other, and the positioning ring is concentrically arranged with the second connecting part and connected to each other.

3. The double-ring repair method for the flame tube of an aero-engine as described in claim 1, characterized in that, After placing the target double ring in the receiving cavity and fitting the positioning cylinder on the side away from the first connecting portion, the method further includes: The target double ring is secured to the side of the positioning cylinder away from the first connecting part by fasteners.

4. The double-ring repair method for the flame tube of an aero-engine as described in claim 1, characterized in that, The positioning fixture further includes a height adjustment device, which includes an adjustment screw and a fastening head. One end of the adjustment screw is vertically fixed to the first connecting part. The adjustment screw passes through the positioning cylinder and the second connecting part in sequence. The fastening head is placed on the side of the second connecting part away from the first connecting part and is detachably connected to the adjustment screw. The step of pressing the second connecting part against the second side of the flame tube and driving the second connecting part to move closer to the first connecting part includes: The second connecting part is pressed against the second side of the flame tube, and the fastening head is rotated to drive the second connecting part to move closer to the first connecting part.

5. The double-ring repair method for the flame tube of an aero-engine as described in claim 1, characterized in that, The grinding of the wall of the flame tube to ensure that the wall thickness is not less than 0.75 mm includes: The double ring to be repaired is machined using a turning machine to remove the first region of the double ring to be repaired, while retaining the second region that connects the double ring to be repaired to the flame tube. The thickness of the second region is 0.5 mm. The second area is polished using a polishing device to ensure that the thickness of the cylinder wall is not less than 0.75 mm.

6. The double-ring repair method for the flame tube of an aero-engine as described in claim 5, characterized in that, The step of grinding the second area using a grinding device to ensure that the thickness of the cylinder wall is not less than 0.75mm includes: The wall thickness of the flame tube is measured using a testing instrument. If the wall thickness of the flame tube is less than 0.75 mm, stop grinding and removing material from the second area.

7. The double-ring repair method for the flame tube of an aero-engine as described in claim 5, characterized in that, The grinding equipment includes: an angle grinder or a grinding mill.

8. The double-ring repair method for the flame tube of an aero-engine as described in claim 1, characterized in that, The repair of the target double ring and the flame tube involves using a Z-shaped electrode inserted into the gap between the target double ring and the flame tube to perform continuous spot welding on the target double ring and the flame tube, thereby welding the target double ring and the flame tube together and completing the repair of the flame tube and the target double ring. By using a medium-frequency inverter spot welding machine to continuously spot weld the target double ring and the flame tube according to preset spot welding parameters, the target double ring and the flame tube are welded together. The medium-frequency inverter spot welding machine includes the Z-shaped electrode.

9. The double-ring repair method for the flame tube of an aero-engine as described in claim 8, characterized in that, The preset spot welding parameters include: Welding interval: 15 cycles; The time during which pressure is applied to the workpiece after the electrode contacts the workpiece but no current is applied: 25 cycles; Duration of the first welding: 8 cycles; First welding pulse current: 4.3kA; Cooling time after pausing power following the first welding: 5 cycles; Duration of the second welding: 11 cycles; Second welding pulse current: 5.7kA; Pressure holding time after welding: 25 cycles; Welding pressure: 0.24 MPa.

10. The method for repairing the double-ring flame tube of an aircraft engine as described in any one of claims 1-9, characterized in that, Before removing the double ring to be repaired from the flame tube to ensure that the wall thickness of the flame tube is not less than a first preset thickness, the method further includes: The coating is removed from the connection between the flame tube and the double ring to be repaired using a sandblasting process.

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