Method for repairing engine cooling pipe

Abstract

The invention discloses a method for repairing an engine cooling pipe, and relates to the technical field of engine cooling pipe maintenance. The method comprises the following steps that 1, the overall appearance of the engine cooling pipe is subjected to three-dimensional scanning; 2, drawing a three-dimensional mathematical model of the cooling pipe and the lug of the engine through reverse modeling; 3, determining the position sizes of an upper lug and a lower lug in the lugs through a three-dimensional mathematical model; 4, machining a new upper lug and a new lower lug; 5, damaged lugs of the engine cooling pipe are polished and removed; step 6, welding the new upper lug and the new lower lug to form a new lug; step 7, determining a mounting position; 8, the new lug is welded to the air inlet cavity; and finishing the repair. The cost is saved, and the usability of the engine cooling pipe is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of engine cooling pipe repair, and more specifically, it is a repair method for engine cooling pipes. Background Art

[0002] The engine low-pressure turbine casing cooling pipe is a commonly used engine component in the engine system of modern civil aircraft. The low-pressure turbine casing cooling pipe is used to cool the LPT4-stage disk and casing components to protect them from the influence of high air flow temperature.

[0003] During the repair of a certain engine low-pressure turbine casing cooling pipe, it is often found that the installation lug of the cooling pipe is broken. Since the lug is welded to the engine cooling pipe by flame brazing and cannot be directly replaced as a single part, once it is broken, it cannot be fixed to the engine casing, which plays a crucial role in the installation and use of the product; due to the high price of the new part of the engine low-pressure turbine casing cooling pipe and the long ordering cycle, and the repair method for this damage is not specified in the component maintenance manual of this cooling pipe, if the lug is broken, the entire set of cooling pipes can only be scrapped.

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

[0005] The purpose of the present invention is to overcome the deficiencies of the above background art and provide a repair method for engine cooling pipes.

[0006] To achieve the above purpose, the technical solution of the present invention is: a repair method for engine cooling pipes, characterized in that the engine cooling pipe includes an intake cavity, a plurality of cooling pipes arranged at intervals on both sides of the intake cavity, an earpiece welded to one end of the intake cavity, and a fixed earpiece arranged at the other end of the intake cavity, and the earpiece includes an upper earpiece and a lower earpiece;

[0007] It includes the following steps:

[0008] Step 1: Three-dimensionally scan the overall shape of the engine cooling pipe;

[0009] Step 2: Reverse model to draw the three-dimensional digital model of the engine cooling pipe and the earpiece;

[0010] Step 3: Confirm the position dimensions of the upper earpiece and the lower earpiece in the earpiece through the three-dimensional digital model;

[0011] Step 4: According to the three-dimensional digital model of the earpiece, machine new upper earpieces and lower earpieces;

[0012] Step 5: Grind and remove the damaged earpiece of the engine cooling pipe and remove the remaining welding beads;

[0013] Step 6: According to the positional relationship between the upper lug and the lower lug; according to the positional dimensions between the upper lug and the lower lug, use flame brazing to weld the new upper lug and the lower lug to form a new lug.

[0014] Step 7: Confirm the positional relationship between the intake cavity and the lug through the 3D digital model of the engine cooling pipe; install the new lug and the engine cooling pipe onto the welding and fixing fixture, and the welding and fixing fixture positions the lug and fixes the lug, and supports the engine cooling pipe to determine the installation position.

[0015] Step 8: Use flame brazing to weld the new lug to the intake cavity; complete the repair.

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

[0017] The upper lug is L-shaped, the upper lug includes a first upper lug component and a second upper lug component, and a first positioning hole is provided on the first upper lug component; the lower lug is L-shaped, the lower lug includes a first lower lug component and a second lower lug component, and the second lower lug component has a curvature.

[0018] The first lower lug component is welded to the second upper lug component, and the second lower lug component is located at one end of the first lower lug component away from the first upper lug component.

[0019] Between one end of the second upper lug component away from the first upper lug component and the first lower lug component is welded to the first intake cavity component.

[0020] The fixed lug is connected to the second intake cavity component.

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

[0022] The first positioning screw inside the column positions the first positioning hole of the upper lug, the second positioning screw hole at the top of the first support positions the second positioning hole of the fixed lug, and the first support and the second support support the second intake cavity component.

[0023] In the above technical solution, in Step 5, after removing the residual welding beads, use a cleaning agent to clean the engine cooling pipe.

[0024] In the above technical solution, in Step 8, after welding is completed, use a cleaning agent to clean the welding area.

[0025] In the above technical solution, in step 8, after cleaning is completed, check the welding area. There shall be no solder shortage or overflow, and no sign of overheating is allowed; perform fluorescent penetrant inspection on the engine cooling pipe, and no cracks are allowed; check that the dimensions after final repair shall meet the requirements of the drawing.

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

[0027] 1) The present invention saves costs and improves the usability of the engine cooling pipe. Repair the lugs of the engine cooling pipe without damaging the structure and force layout of the engine cooling pipe, which has no impact on the installation and use of the engine cooling pipe and can meet the usage requirements of the engine cooling pipe.

[0028] 2) The present invention scans the overall shape of the engine cooling pipe in three dimensions; reverse models to draw the three-dimensional digital models of the engine cooling pipe and the lugs; obtains the original positional relationship of the lugs and the original positional relationship between the engine cooling pipe and the lugs; then welds the new upper and lower lugs according to the original positional relationship of the lugs, which can accurately restore the original position of the lugs, and then accurately positions the lugs and the engine cooling pipe through the welding fixture, avoiding the problem that the welded parts cannot be accurately installed in place.

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

[0030] 4) The present invention accurately machines the shape of the lugs through machining. By cooperating with the positioning tooling, it can ensure that the installation dimensions of the engine cooling pipe meet the requirements of the installation and use;

[0031] 5) The present invention adopts fluorescent penetrant inspection. This method is a non-destructive testing method with high detection sensitivity and can detect minute defects of parts. It meets the quality of parts after repair;

[0032] 6) The present invention saves costs. The price of a new engine cooling pipe is $15,000 and the order period is 5 months. The repair cost of the present invention is $200 and it only takes 10 hours of working hours to complete the repair; it improves the usability of the engine cooling pipe. BRIEF DESCRIPTION OF THE DRAWINGS

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

[0034] Figure 2 It is a front view of the upper lug.

[0035] Figure 3 It is a top view of the upper lug.

[0036] Figure 4 It is the front view of the lower lug.

[0037] Figure 5 It is the top view of the lower lug.

[0038] Figure 6 It is the structural schematic diagram of the lug.

[0039] Figure 7 It is the schematic diagram for checking the position dimensions of the engine cooling pipe and the lug.

[0040] Figure 8 It is the structural schematic diagram of the lug.

[0041] Figure 9 It is the structural schematic diagram of the upper lug.

[0042] Figure 10 It is the structural schematic diagram of the lower lug.

[0043] Figure 11 It is the structural schematic diagram of the welding fixture.

[0044] Figure 12 It is the connection diagram of the column, upper lug and intake cavity.

[0045] Figure 13 It is the connection diagram of the welding fixture, lug, intake cavity and fixed lug.

[0046] Figure 14 It is the connection diagram of the welding fixture and the intake cavity.

[0047] Figure 15 It is the physical diagram when the welding fixture supports the engine cooling pipe.

[0048] Figure 16 It is the physical diagram of the welding fixture.

[0049] Figure 17 It is the physical diagram when repairing the engine cooling pipe.

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

[0051] The following will describe in detail the implementation of the present invention in conjunction with the accompanying drawings. However, they do not constitute a limitation to the present invention and are only for illustration purposes. At the same time, the advantages of the present invention will become clearer and easier to understand through the description.

[0052] Referring to the accompanying drawings, it can be seen that: A repair method for an engine cooling pipe, characterized in that the engine cooling pipe 100 includes an intake cavity 110, a plurality of cooling pipes 120 arranged at intervals on both sides of the intake cavity 110, a lug 130 welded to one end of the intake cavity 110, and a fixed lug 140 arranged at the other end of the intake cavity 110. The lug 130 includes an upper lug 131 and a lower lug 132;

[0053] It includes the following steps:

[0054] Step 1: Three-dimensionally scan the overall shape of the engine cooling pipe 100;

[0055] Step 2: Reverse model to draw the three-dimensional digital models of the engine cooling pipe 100 and the lug 130;

[0056] Reverse modeling refers to the process of two-dimensionally processing the surface of a three-dimensional model by laser scanning the physical shape and then generating a new three-dimensional solid model through computer software;

[0057] Step 3: Confirm the position dimensions of the upper lug 131 and the lower lug 132 on the lug 130 through the three-dimensional digital model; The position dimensions confirmed through the three-dimensional digital models of the engine cooling pipe 100 and the lug 130 are as Figure 2-8 shown, with the unit of mm;

[0058] Step 4: Machine-process new upper lugs 131 and lower lugs 132 according to the three-dimensional digital model of the lug 130; The materials of the upper lugs 131 and the lower lugs 132 are 321 stainless steel, and the dimensions of the upper lugs 131 and the lower lugs 132 are as Figure 2 and Figure 3 shown.

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

[0060] Step 6: According to the positional relationship between the upper lug 131 and the lower lug 132; according to the positional dimensions between the upper lug 131 and the lower lug 132, use flame brazing (AWSC3.4M) to weld the new upper lug 131 and the lower lug 132 to form a new lug 130.

[0061] Flame brazing uses the flame formed by the combustion of the gasification products of combustible gases or liquid fuels mixed with oxygen or air for brazing heating and welds the lug area.

[0062] Step 7: Confirm the positional relationship between the intake cavity 110 and the lug 130 through the 3D 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 cavity 110; after welding is completed, clean the welding area with a cleaning agent (ARDROX 5503); after cleaning is completed, inspect the welding area. There shall be no solder shortage or overflow, and no signs of overheating are allowed; perform fluorescent penetrant inspection (ASTME1417) on the engine cooling pipe 1, and no cracks are allowed; check the requirements for the dimensions after the final repair; complete the repair. Figure 7 of the requirements; complete the repair.

[0064] Fluorescent penetrant inspection is a method for non-destructively detecting part defects. A penetrant containing a fluorescent substance is used. After cleaning, the penetrant remaining in the defects is adsorbed by the developer; irradiated with an ultraviolet light source, the fluorescent substance generates visible light with a longer wavelength, and the surface of the workpiece after irradiation is observed in a dark room, and the size, position, and shape of the defects are judged through the visible fluorescent image.

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

[0066] The upper lug 131 is L-shaped. The upper lug 131 includes a first upper lug component 1311 and a second upper lug component 1312. A first positioning hole 1313 is provided on the first upper lug component 1311; the lower lug 132 is L-shaped. The lower lug 132 includes a first lower lug component 1321 and a second lower lug component 1322. The second lower lug component 1322 is wavy;

[0067] The first lower lug component 1321 is welded to the second upper lug component 1312. The second lower lug component 1322 is located at one end of the first lower lug component 1321 away from the first upper lug component 1311;

[0068] Between one end of the second upper lug component 1312 away from the first upper lug component 1311 and the first lower lug component 1321, it is welded to the first intake cavity component 111;

[0069] The fixed lug 140 is connected to the second intake cavity component 112.

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

[0071] The first positioning screw 221 inside the column 220 positions the first positioning hole 1313 of the upper lug 131. The second positioning screw hole 231 at the top of the first support 230 positions the second positioning hole 141 of the fixed lug 140. The first support 230 and the second support 240 support the second intake cavity component 112.

[0072] Other parts not described belong to the prior art.

Claims

1. A repair method for an engine cooling pipe, characterized in that, The engine cooling pipe (100) includes an intake cavity (110), a plurality of cooling pipes (120) spaced on both sides of the intake cavity (110), lugs (130) welded to one end of the intake cavity (110), and a fixed lug (140) provided at the other end of the intake cavity (110). The lug (130) includes an upper lug (131) and a lower lug (132). It includes the following steps: Step 1: Three-dimensionally scan the overall shape of the engine cooling pipe (100). Step 2: Reverse model to draw the three-dimensional digital models of the engine cooling pipe (100) and the lugs (130). Step 3: Confirm the position dimensions of the upper lug (131) and the lower lug (132) on the lug (130) through the three-dimensional digital model. Step 4: Machine new upper lugs (131) and lower lugs (132) according to the three-dimensional digital model of the lugs (130). Step 5: Grind and remove the damaged lugs (130) of the engine cooling pipe (100) and remove the remaining weld beads. Step 6: According to the positional relationship between the upper lug (131) and the lower lug (132); according to the position dimensions between the upper lug (131) and the lower lug (132), use flame brazing to weld the new upper lug (131) and the new lower lug (132) to form a new lug (130). Step 7: Confirm the positional relationship between the intake cavity (110) and the lugs (130) through the three-dimensional digital model of the engine cooling pipe (100); install the new lugs (130) and the engine cooling pipe (100) on the welding and fixing fixture (200). The welding and fixing fixture (200) positions the lugs (130) and the fixed lugs (140) and supports the engine cooling pipe (100) to determine the installation position. Step 8: Use flame brazing to weld the new lugs (130) to the intake cavity (110); complete the repair.

2. The repair method of an engine cooling pipe according to claim 1, wherein, The intake cavity (110) includes a first intake cavity component (111) and a second intake cavity component (112). The first intake cavity component (111) and the second intake cavity component (112) are connected at an obtuse angle. The upper lug (131) is L-shaped. The upper lug (131) includes a first upper lug component (1311) and a second upper lug component (1312). A first positioning hole (1313) is provided on the first upper lug component (1311); the lower lug (132) is L-shaped. The lower lug (132) includes a first lower lug component (1321) and a second lower lug component (1322). The second lower lug component (1322) has a curvature. The first lower lug component (1321) is welded to the second upper lug component (1312), and the second lower lug component (1322) is located at one end of the first lower lug component (1321) away from the first upper lug component (1311). The end of the second upper lug component (1312) away from the first upper lug component (1311) is welded to the first lower lug component (1321) and is welded to the first intake cavity component (111). The fixed lug (140) is connected to the second intake cavity component (112).

3. A repair method for an engine cooling pipe according to claim 2, characterized in that, In step 7, the welding and fixing fixture (200) includes a bottom plate (210), a column (220) arranged at the left end of the bottom plate (210), a first support (230) arranged at the right end of the bottom plate (210), a second support (240) arranged in the middle of the bottom plate (210), and a third support (250) arranged on the bottom plate (210) and located between the first support (230) and the second support (240); The first positioning screw (221) inside the column (220) positions the first positioning hole (1313) of the upper lug (131), and the second positioning screw hole (231) at the top of the first support (230) positions the second positioning hole (141) of the fixing lug (140). The first support (230) and the second support (240) support the second intake cavity component (112).

4. A repair method for an engine cooling pipe according to claim 1, characterized in that, In step 5, after removing the residual welding beads, the engine cooling pipe (100) is cleaned with a cleaning agent.

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

6. A repair method for an engine cooling pipe according to claim 5, characterized in that, In step 8, after cleaning is completed, the welding area is inspected. Solder shortage and overflow are not allowed, and no sign of overheating is allowed; the engine cooling pipe (100) is inspected by fluorescent penetrant inspection, and no crack is allowed; the dimensions after final repair are inspected and should meet the requirements of the drawing.

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