A method of repairing an engine cooling tube

Abstract

The application discloses a kind of repair methods of engine cooling pipe, it is related to engine cooling pipe maintenance technical field.It includes the following steps: step 1: three-dimensional scanning engine cooling pipe overall appearance;Step 2: reverse modeling draws the three-dimensional numerical model of engine cooling pipe, ear piece;Step 3: the position size of upper ear piece and lower ear piece in ear piece is confirmed by three-dimensional numerical model;Step 4: new upper ear piece and lower ear piece are machined;Step 5: polishing removes the ear piece of engine cooling pipe damage;Step 6: new upper ear piece and lower ear piece are welded, and new ear piece is formed;Step 7: determine installation position;Step 8: new ear piece is welded to inlet cavity;Complete repair.The application saves cost, improves the availability of engine cooling pipe.

Description

Technical Field

[0001] This invention relates to the field of engine cooling pipe repair technology, and more specifically, to a method for repairing engine cooling pipes. Background Technology

[0002] The low-pressure turbine casing cooling pipe is a common engine component in modern civil aircraft engine systems. It is used to cool the LPT4 stage disc and housing components, protecting them from the effects of high airflow temperatures.

[0003] During the repair of the cooling pipe of a certain engine's low-pressure turbine casing, it is frequently found that the mounting lugs of the cooling pipe are broken. Since the lugs are flame-brazed to the engine cooling pipe, they cannot be replaced directly as a separate part. Once broken, they cannot be fixed to the engine casing, which is crucial to the installation and use of the product. Because the new parts of the engine's low-pressure turbine casing cooling pipe are expensive and have a long ordering cycle, and the component maintenance manual for this cooling pipe does not specify the repair method for this damage, if the lugs are broken, the entire cooling pipe set must be scrapped.

[0004] Therefore, it is necessary to develop a repair method for engine cooling pipes. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of the above-mentioned background technology and to provide a method for repairing engine cooling pipes.

[0006] To achieve the above objectives, the technical solution of the present invention is as follows: a method for repairing an engine cooling pipe, characterized in that the engine cooling pipe includes an intake chamber, a plurality of cooling pipes spaced apart on both sides of the intake chamber, a lug welded to one end of the intake chamber, and a fixed lug disposed at the other end of the intake chamber, wherein the lug includes an upper lug and a lower lug.

[0007] Includes the following steps:

[0008] Step 1: Perform a 3D scan of the overall shape of the engine cooling pipes;

[0009] Step 2: Reverse modeling to create 3D digital models of the engine cooling pipes and lugs;

[0010] Step 3: Confirm the position and dimensions of the upper and lower ear pieces using a 3D digital model;

[0011] Step 4: Based on the three-dimensional digital model of the ear piece, machine the new upper and lower ear pieces;

[0012] Step 5: Grind and remove the damaged lugs of the engine cooling pipe and remove any remaining weld beads;

[0013] Step 6: Based on the positional relationship between the upper and lower ear pieces; based on the positional dimensions between the upper and lower ear pieces, use flame brazing to weld the new upper and lower ear pieces to form a new ear piece;

[0014] Step 7: Confirm the positional relationship between the intake chamber and the lugs using the 3D digital model of the engine cooling pipe; install the new lugs and engine cooling pipe onto the welding and fixing fixture, and position and fix the lugs and support the engine cooling pipe to determine the installation position;

[0015] Step 8: Use flame brazing to weld the new ear piece to the intake chamber; repair complete.

[0016] In the above technical solution, the air intake chamber includes a first air intake chamber component and a second air intake chamber component, and the first air intake chamber component and the second air intake chamber component are connected at an obtuse angle;

[0017] The upper ear piece is L-shaped and includes a first upper ear piece component and a second upper ear piece component. The first upper ear piece component is provided with a first positioning hole. The lower ear piece is L-shaped and includes a first lower ear piece component and a second lower ear piece component. The second lower ear piece component has a curvature.

[0018] The first lower ear piece component is welded onto the second upper ear piece component, and the second lower ear piece component is located at the end of the first lower ear piece component away from the first upper ear piece component.

[0019] The second upper ear piece component, at the end furthest from the first upper ear piece component, is welded to the first lower ear piece component and then to the first air intake cavity component.

[0020] The fixed ear piece is connected to the second air intake chamber component.

[0021] In the above technical solution, in step 7, the welding fixing fixture includes a base plate, a column set at the left end of the base plate, a first support set at the right end of the base plate, a second support set in the middle of the base plate, and a third support set on the base plate and located between the first support and the second support.

[0022] The first positioning screw on the inner side of the column positions the first positioning hole of the upper ear piece, the second positioning screw hole on the top of the first support positions and fixes the second positioning hole of the ear piece, and the first support and the second support support the second air intake chamber component.

[0023] In the above technical solution, in step 5, after removing the residual weld beads, the engine cooling pipe is cleaned with a cleaning agent.

[0024] In the above technical solution, in step 8, after welding is completed, the welding area is cleaned with a cleaning agent.

[0025] In the above technical solution, in step 8, after cleaning, the welding area is inspected, and there should be no missing or overflowing solder, and no signs of overheating; the engine cooling pipe is inspected by fluorescent penetrant testing, and there should be no cracks; the dimensions after final repair should meet the requirements of the drawings.

[0026] Compared with the prior art, the present invention has the following advantages:

[0027] 1) This invention saves costs, improves the usability of engine cooling pipes, repairs the lugs of engine cooling pipes without damaging the structure and stress layout of engine cooling pipes, has no impact on the installation and use of engine cooling pipes, and can meet the usage requirements of engine cooling pipes.

[0028] 2) This invention uses 3D scanning to visualize the overall shape of the engine cooling pipe; reverse modeling to create 3D digital models of the engine cooling pipe and lugs; obtaining the original positional relationship between the lugs and the engine cooling pipe and lugs; and then welding new upper and lower lugs based on the original positional relationship of the lugs. This can accurately restore the original position of the lugs, and then use a welding fixture to precisely position the lugs and the engine cooling pipe, thus avoiding the problem that the welded parts cannot be accurately installed.

[0029] 3) This invention uses flame brazing for repair. This welding repair method has a low heating temperature, does not melt the base material, has small base material deformation, high weld strength, and strong corrosion resistance. It does not damage the structure and stress distribution of the engine cooling pipe, has no impact on installation and use, and can meet the usage requirements of the engine cooling pipe.

[0030] 4) This invention precisely machines the shape of the ear piece, and when used in conjunction with positioning fixtures, it can ensure that the installation dimensions of the engine cooling pipe meet the requirements of the machine.

[0031] 5) This invention employs fluorescent penetrant testing, a non-destructive testing method with high detection sensitivity, capable of detecting minute defects in parts. This ensures the quality of parts after repair.

[0032] 6) This invention saves costs. The price of a new engine cooling pipe is $15,000 and the ordering cycle is 5 months. The repair cost of this invention is $200 and only 10 hours of labor are required to complete the repair; it also improves the availability of engine cooling pipes. Attached Figure Description

[0033] Figure 1 This is a schematic diagram of the engine cooling pipe of the present invention.

[0034] Figure 2 This is a front view of the upper ear piece.

[0035] Figure 3 This is a top view of the upper ear piece.

[0036] Figure 4 This is a front view of the lower ear piece.

[0037] Figure 5 This is a top view of the lower ear piece.

[0038] Figure 6 This is a schematic diagram of the ear piece.

[0039] Figure 7 This is a schematic diagram for checking the position and dimensions of the engine cooling pipes and lugs.

[0040] Figure 8 This is a schematic diagram of the ear piece.

[0041] Figure 9 This is a schematic diagram of the upper ear piece.

[0042] Figure 10 This is a schematic diagram of the lower ear piece.

[0043] Figure 11 This is a schematic diagram of the welding fixture.

[0044] Figure 12 This is a diagram showing the connection relationship between the pillar, upper ear plate, and air intake chamber.

[0045] Figure 13 This diagram shows the connection relationships between the welding fixture, lugs, air intake chamber, and fixing lugs.

[0046] Figure 14 This diagram shows the connection between the welding fixture and the air intake chamber.

[0047] Figure 15 A photograph of an engine cooling pipe supported by a welding fixture.

[0048] Figure 16 This is a photograph of the actual welding fixture.

[0049] Figure 17 This is a picture of the actual parts when repairing the engine cooling pipe.

[0050] Among them, 100-engine cooling pipe, 110-intake chamber, 111-first intake chamber component, 112-second intake chamber component, 120-cooling pipe, 130-ear, 131-upper ear, 1311-first upper ear component, 1312-second upper ear component, 1313-first positioning hole, 132-lower ear, 1321-first lower ear component, 1322-second lower ear component, 140-fixed ear, 141-second positioning hole, 150-fixed bracket, 200-welding fixing fixture, 210-base plate, 220-column, 221-first positioning screw, 230-first support, 231-second positioning screw hole, 240-second support, 250-third support. Detailed Implementation

[0051] The embodiments of the present invention will be described in detail below with reference to the accompanying drawings, but these descriptions are not intended to limit the invention and are merely illustrative. The advantages of the present invention will become clearer and easier to understand through this description.

[0052] Referring to the accompanying drawings, a method for repairing an engine cooling pipe is characterized in that the engine cooling pipe 100 includes an intake chamber 110, a plurality of cooling pipes 120 spaced apart on both sides of the intake chamber 110, a lug 130 welded to one end of the intake chamber 110, and a fixing lug 140 disposed at the other end of the intake chamber 110, wherein the lug 130 includes an upper lug 131 and a lower lug 132;

[0053] Includes the following steps:

[0054] Step 1: Perform a 3D scan of the overall shape of the engine cooling pipe 100;

[0055] Step 2: Reverse modeling to create 3D digital models of engine cooling pipe 100 and lug 130;

[0056] Reverse modeling refers to the process of scanning the shape of a physical object with a laser, converting the surface of a three-dimensional model into a two-dimensional model, and then generating a new three-dimensional solid model using computer software.

[0057] Step 3: Confirm the positional dimensions of the upper ear piece 131 and the lower ear piece 132 in the ear piece 130 using the 3D digital model; the positional dimensions confirmed by the 3D digital model of the engine cooling pipe 100 and the ear piece 130 are as follows: Figure 2-8 As shown, the unit is mm;

[0058] Step 4: Based on the 3D digital model of ear piece 130, machine new upper ear piece 131 and lower ear piece 132; the material of upper ear piece 131 and lower ear piece 132 is 321 stainless steel, and the dimensions of upper ear piece 131 and lower ear piece 132 are as follows. Figure 2 and Figure 3 As shown.

[0059] Step 5: Grind and remove the damaged lug 130 of the engine cooling pipe 100, and remove any remaining weld beads; after removing the remaining weld beads, clean the engine cooling pipe 100 with a cleaning agent (ARDROX 5503).

[0060] Step 6: Based on the positional relationship between the upper ear piece 131 and the lower ear piece 132, and based on the positional dimensions between the upper ear piece 131 and the lower ear piece 132, use flame brazing (AWSC3.4M) to weld the new upper ear piece 131 and the lower ear piece 132 to form a new ear piece 130.

[0061] Flame brazing is a process that uses the flame generated by the combustion of the gasification products of combustible gas or liquid fuel with oxygen or air to heat the brazing process and weld the ear plate area.

[0062] Step 7: Confirm the positional relationship between the intake chamber 110 and the lug 130 using the three-dimensional digital model of the engine cooling pipe 100; install the new lug 130 and the engine cooling pipe 100 onto the welding and fixing fixture 200, the welding and fixing fixture 200 positions the lug 130 and fixes the lug 140, and supports the engine cooling pipe 100 to determine the installation position;

[0063] Step 8: Use flame brazing (AWSC3.4M) to weld the new lug 130 to the intake chamber 110; after welding, clean the welded area with a cleaning agent (ARDROX 5503); after cleaning, inspect the welded area, ensuring there is no missing or overflowing solder, and no signs of overheating; perform fluorescent penetrant testing (ASTM E1417) on the engine cooling pipe 1, ensuring there are no cracks; check the final repair dimensions. Figure 7 The requirements; complete the repair.

[0064] Fluorescent penetrant testing is a non-destructive testing method for defects in parts. It uses a penetrant containing fluorescent substances. After cleaning, the penetrant remaining in the defect is adsorbed by a developer. When irradiated with an ultraviolet light source, the fluorescent substances produce visible light with a longer wavelength. The surface of the irradiated workpiece is observed in a dark room, and the size, location, and shape of the defect are determined by the fluorescent image that appears.

[0065] The air intake chamber 110 includes a first air intake chamber component 111 and a second air intake chamber component 112, which are connected at an obtuse angle.

[0066] The upper ear piece 131 is L-shaped and includes a first upper ear piece component 1311 and a second upper ear piece component 1312. The first upper ear piece component 1311 is provided with a first positioning hole 1313. The lower ear piece 132 is L-shaped and includes a first lower ear piece component 1321 and a second lower ear piece component 1322. The second lower ear piece component 1322 is wavy.

[0067] The first lower ear piece 1321 is welded to the second upper ear piece 1312, and the second lower ear piece 1322 is located at the end of the first lower ear piece 1321 away from the first upper ear piece 1311.

[0068] The second upper ear piece component 1312 is welded to the first air intake cavity component 111 at the end away from the first upper ear piece component 1311 and the first lower ear piece component 1321;

[0069] The fixed ear piece 140 is connected to the second air intake chamber component 112.

[0070] In step 7, the welding fixing fixture 200 includes a base plate 210, a column 220 disposed at the left end of the base plate 210, a first support 230 disposed at the right end of the base plate 210, a second support 240 disposed in the middle of the base plate 210, and a third support 250 disposed on the base plate 210 and located between the first support 230 and the second support 240.

[0071] The first positioning screw 221 on the inner side of the column 220 positions the first positioning hole 1313 of the upper ear piece 131, the second positioning screw hole 231 on the top of the first support 230 positions the second positioning hole 141 of the fixed ear piece 140, and the first support 230 and the second support 240 support the second air intake chamber component 112.

[0072] All other unspecified parts belong to the prior art.

Claims

1. A method for repairing an engine cooling pipe, characterized in that, The engine cooling pipe (100) includes an intake chamber (110), a plurality of cooling pipes (120) spaced apart on both sides of the intake chamber (110), a lug (130) welded to one end of the intake chamber (110), and a fixed lug (140) disposed at the other end of the intake chamber (110). The lug (130) includes an upper lug (131) and a lower lug (132). The air intake chamber (110) includes a first air intake chamber component (111) and a second air intake chamber component (112), and the first air intake chamber component (111) and the second air intake chamber component (112) are connected at an obtuse angle; The upper ear piece (131) is L-shaped and includes a first upper ear piece component (1311) and a second upper ear piece component (1312). The first upper ear piece component (1311) is provided with a first positioning hole (1313). The lower ear piece (132) is L-shaped and includes a first lower ear piece component (1321) and a second lower ear piece component (1322). The second lower ear piece component (1322) has an arc. Includes the following steps: Step 1: 3D scanning of the overall shape of the engine cooling pipe (100); Step 2: Reverse modeling to create 3D digital models of the engine cooling pipe (100) and lugs (130); Step 3: Confirm the position and dimensions of the upper ear piece (131) and the lower ear piece (132) in the ear piece (130) using a three-dimensional digital model; Step 4: Based on the three-dimensional digital model of the ear piece (130), machine the new upper ear piece (131) and lower ear piece (132); Step 5: Grind and remove the damaged lugs (130) of the engine cooling pipe (100) and remove any remaining weld beads; Step 6: Based on the positional relationship between the upper ear piece (131) and the lower ear piece (132), and based on the positional dimensions between the upper ear piece (131) and the lower ear piece (132), use flame brazing to weld the new upper ear piece (131) and the lower ear piece (132) to form a new ear piece (130). Step 7: Confirm the positional relationship between the intake chamber (110) and the lug (130) using the three-dimensional digital model of the engine cooling pipe (100); install the new lug (130) and the engine cooling pipe (100) onto the welding fixture (200), the welding fixture (200) positions the lug (130) and fixes the lug (140), and supports the engine cooling pipe (100), thus determining the installation position; Step 8: Use flame brazing to weld the new ear piece (130) onto the intake chamber (110); repair complete; In step 7, the welding fixing fixture (200) includes a base plate (210), a column (220) disposed at the left end of the base plate (210), a first support (230) disposed at the right end of the base plate (210), a second support (240) disposed in the middle of the base plate (210), and a third support (250) disposed on the base plate (210) and located between the first support (230) and the second support (240). The first positioning screw (221) on the inner side of the column (220) positions the first positioning hole (1313) of the upper ear piece (131), the second positioning screw hole (231) on the top of the first support (230) positions the second positioning hole (141) of the fixed ear piece (140), and the first support (230) and the second support (240) support the second air intake chamber component (112).

2. The method for repairing an engine cooling pipe according to claim 1, characterized in that, The first lower ear piece (1321) is welded to the second upper ear piece (1312), and the second lower ear piece (1322) is located at the end of the first lower ear piece (1321) away from the first upper ear piece (1311); The second upper ear piece (1312) is welded to the first air intake cavity piece (111) at the end away from the first upper ear piece (1311) and the first lower ear piece (1321); The fixed ear piece (140) is connected to the second air intake chamber component (112).

3. The method for repairing an engine cooling pipe according to claim 1, characterized in that, In step 5, after removing any remaining weld beads, the engine cooling pipe (100) is cleaned with a cleaning agent.

4. The method for repairing an engine cooling pipe according to claim 1, characterized in that, In step 8, after welding is completed, the welded area is cleaned with a cleaning agent.

5. A method for repairing an engine cooling pipe according to claim 4, characterized in that, In step 8, after cleaning, inspect the welding area. No missing or overflowing solder is allowed, and no signs of overheating are allowed. Perform fluorescent penetrant testing on the engine cooling pipe (100). No cracks are allowed. Check that the final repaired dimensions meet the drawing requirements.

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