A method and system for precise repair of high-strength thick-walled conduits for liquid rocket engines

Abstract

A method for precisely fitting a high-strength, thick-walled duct for a liquid rocket engine comprises the following steps: 1) installing adjustment gaskets at the connection points at both ends of the duct to control the gap between the connection points and ensure uniformity of the gap to meet subsequent assembly requirements; 2) installing and adjusting a measurement conversion device to convert spatial dimensions into planar dimensions; 3) installing spherical bolts at the connection points at both ends of the duct to align the center lines of the connecting flanges; 4) fine-tuning the butt joints of each section of the port using an angle grinder and a file to ensure uniformity of the gap between the parts and controllable welding deformation; 5) performing a bottom lock weld to control the wall misalignment and butt joint gap of the bottom lock weld before duct formation by welding on the engine, and then disassembling the weld after the weld is completely cooled to ensure smooth closure of the duct; 6) producing a high-strength, thick-walled duct for a liquid rocket engine according to the above steps, thereby completing precise fitting of the high-strength, thick-walled duct for a liquid rocket engine. The present invention can solve the problems of difficult duct production and low processing efficiency.

Description

Technical Field

[0001] The present invention relates to a precise repair method and system for a high-strength, thick-walled conduit of a liquid rocket engine, and belongs to the technical field of production and assembly of special pipes with complex spatial orientations. Background Art

[0002] The liquid rocket engine oxidizer pump outlet conduit and fuel pump outlet conduit connect the pump and related valves to provide high-pressure oxidizer and fuel to the engine combustion chamber. The working pressure is as high as 37.5MPa and it is a key component of the engine, such as Figure 1 This type of duct is made of high-strength steel S-03 or S-06, with a wall thickness of 5 to 8 mm. The entire duct is welded together from multiple parts, with at least five welds, making it difficult to manufacture. The original processing method accounts for approximately 20% of the total assembly workload for a single engine. This duct is difficult to produce and has low processing efficiency.

[0003] Summary of the Invention

[0004] The technical problem to be solved by the present invention is to overcome the shortcomings of the existing technology and propose a precise repair method and system for high-strength thick-walled liquid rocket engine conduits, solve the difficulties in the production of the conduits and improve the processing efficiency, ensure the quality of the engine, and provide a reference for improving the production efficiency, production cycle demonstration and production model of liquid rocket engines.

[0005] The technical solution adopted in the present invention is:

[0006] A method for accurately repairing a high-strength, thick-walled conduit for a liquid rocket engine, comprising:

[0007] (1) Install adjustment gaskets at the connection parts at both ends of the catheter to control the gap between the connection parts and ensure that the gap is uniform to meet the subsequent assembly requirements;

[0008] (2) Install and adjust the measurement conversion device to convert spatial dimensions into plane dimensions;

[0009] (3) Install spherical bolts at the connection parts at both ends of the conduit to align the center lines of the connecting flanges;

[0010] (4) Use angle grinder and file to fine-tune the joint surface of each section to ensure uniform gap between parts and controllable welding deformation;

[0011] (5) Perform bottom lock welding. By welding on the engine, control the wall offset and butt clearance of the bottom lock weld before the tube is formed to meet the requirements. After the weld is completely cooled, disassemble it to ensure that the tube is closed smoothly.

[0012] (6) According to the above steps, the high-strength thick-walled duct of the liquid rocket engine is produced, and the high-strength thick-walled duct of the liquid rocket engine is precisely repaired.

[0013] Furthermore, the conduit has a wall thickness of 5 to 8 mm, includes a flange, an elbow, a straight pipe and a locking bottom ring, has ≥5 welds, and the interface normals are skewed and non-parallel.

[0014] Furthermore, the measurement conversion device converts the spatial dimensions into the plane dimensions, specifically including:

[0015] Left and right supports, center axis and independent supports;

[0016] The left and right supports are used in conjunction with the middle shaft to replace the longer straight pipe and connect with the parts at both ends;

[0017] Independent supports are used to replace shorter straight pipes and connect to parts at both ends;

[0018] Connect the left and right supports and the independent support with the elbow through flanges to form a whole. By measuring the size of the independent support and the distance between the left and right supports, the length of each straight pipe section can be obtained.

[0019] Furthermore, spherical bolts are installed at the connection parts of both ends of the conduit to align the center lines of the connecting flanges. The flange deflection is controlled by measuring the flange gap, including:

[0020] (3.1) When installing flanges, since the connection surface is spherical, there is deflection and centerline misalignment between the flanges;

[0021] (3.2) Install the spherical bolts. The conical connection form can align the flange center line through the flange mounting hole;

[0022] (3.3) Control flange deflection by adjusting the clearance around the flange.

[0023] Furthermore, after finishing, the flatness of the rear end face is ≯0.1mm, the groove is uniform, the angle deviation is ≤±2°, and the wall misalignment of the connection part is ≯1mm.

[0024] Furthermore, the method of fine-grinding the butt joint surfaces of each section of the ports by using an angle grinder and a file specifically includes the following steps:

[0025] (4.1) Use an angle grinder to quickly remove the excess of the port interface;

[0026] (4.2) Use a file to accurately remove the excess on the butt joint surface;

[0027] (4.3) Use a file to smooth the end surface and remove burrs and flash.

[0028] Furthermore, the bottom lock welding specifically includes the following steps:

[0029] (5.1) The bottom lock weld is manually refined to control the misalignment of the connection part to ≯1mm, and a 2-3mm butt joint gap is reserved to ensure smooth closure of the catheter and reduce welding defects;

[0030] (5.2) Perform argon arc welding;

[0031] (5.3) After the weld has completely cooled, disassemble the pipe to ensure that the overall welding deformation of the pipe is controlled within ±1mm and the assembly stress is within a controllable range.

[0032] Furthermore, the present invention also provides a precise repair system for a high-strength, thick-walled duct of a liquid rocket engine, comprising:

[0033] Connection gap adjustment module: Install adjustment gaskets at the connection points at both ends of the catheter to control the connection gap and ensure uniformity to meet subsequent assembly requirements;

[0034] Spatial dimension conversion module: install and adjust the measurement conversion device to convert spatial dimensions into plane dimensions;

[0035] Connecting flange centerline alignment module: Install spherical bolts at the connecting parts of both ends of the conduit to align the centerlines of the connecting flanges;

[0036] Finishing module: Use angle grinder and file to finish the joint surface of each section of the port to ensure uniform gap between parts and controllable welding deformation;

[0037] Lock bottom welding module: Perform lock bottom welding on the engine to control the wall misalignment and butt clearance of the lock bottom weld connection end before the catheter is formed to meet the requirements. The module will be disassembled after the weld is completely cooled to ensure smooth closing of the catheter. This completes the precise fitting of the high-strength thick-walled catheter for the liquid rocket engine.

[0038] The beneficial effects of the present invention compared with the prior art are:

[0039] (1) Quality improvement: The deformation of the duct is controlled, with the deformation of the entire duct ≤1mm, the assembly gap is uniform, the overall assembly stress is small, and the airtightness is qualified in one go after assembly. More than 80 engines produced using this method have been successfully tested and delivered for flight use;

[0040] (2) Improved efficiency: Most of the excess material at the catheter end can be removed in advance through mechanical processing, reducing the manual removal workload by 80% to 90%, resulting in fewer weld defects. The production time for the entire catheter is shortened from 10 days to 3 days, increasing efficiency by more than 3 times.

[0041] (3) Improved efficiency: The labor cost is reduced from 3 to 4 people working together to 1 person working independently. Combined with the effects of reducing scrap rate and shortening production cycle, the goal of improved efficiency is achieved.

[0042] (4) The overall welding deformation of the high-strength thick-walled conduit for liquid rocket engines produced according to the method of the present invention is controlled within ±1 mm, the assembly stress is small, and the leakage inside the connected components does not change before and after assembly, ultimately meeting the spatial assembly requirements of the entire conduit. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 Schematic diagram of the connection between the outlet conduit of the oxidizer pump and the outlet conduit of the fuel pump of the liquid rocket engine;

[0044] Figure 2 It is a schematic diagram of the measurement conversion device. DETAILED DESCRIPTION

[0045] The present invention will be described in further detail below with reference to the accompanying drawings and specific embodiments:

[0046] The present invention converts spatial dimensions into plane dimensions by manufacturing a measurement conversion device, thereby reducing the difficulty of measurement; ensures the accuracy and consistency of measurement by manufacturing a spherical guide bolt with self-positioning; forms a precise control method for welding shrinkage by manufacturing adjustment gaskets and statistics of welding shrinkage, and determines the length of each section after repair; manually refines the docking surface of each section of the port by using an angle grinder + a file; arranges the bottom lock weld before the catheter is formed on the engine to weld and control the wall misalignment and docking gap of the connection part to meet the requirements, thereby ensuring that the catheter is smoothly closed and ultimately meeting the spatial assembly requirements of the entire catheter.

[0047] Catheter features:

[0048] (1) The material is high-strength steel S-03 or S-06;

[0049] (2) Large wall thickness (wall thickness up to 5-8 mm);

[0050] (3) A large number of welds (≥5 welds)

[0051] Features of the present invention:

[0052] Measuring conversion device;

[0053] Spherical guide bolt with self-positioning;

[0054] Precise control method of welding shrinkage;

[0055] Angle grinder + file manual finishing method;

[0056] Lock bottom welding process and corresponding control requirements;

[0057] 1. Device for converting spatial dimensions into plane dimensions: A device used to convert spatial dimensions into plane dimensions, simulates the adjustment of the dimensions of each straight pipe section and curved pipe section, simplifies the spatial structure, and only needs to measure the length of the straight pipe section to determine the corresponding dimensions of each section.

[0058] 2. The self-positioning spherical guide bolt automatically aligns the center lines of the two flanges during flange docking, ensuring the accuracy and consistency of subsequent measurements, which is both accurate and safe.

[0059] 3. Precise control method of welding shrinkage: By making adjustment gaskets, controlling the flange butt gap, and forming a precise control method of welding shrinkage of each section of the catheter through statistics of welding shrinkage, the length of each section after repair can be determined, so that the welding shrinkage can be controlled.

[0060] 4. Manual finishing method with angle grinder + file: Manually finish the butt joint surface of each section with angle grinder + file. The flatness of the rear end surface after finishing is ≯0.1mm, the groove is uniform, the angle deviation is ≤±2°, and the wall misalignment of the connection part is ≯1mm, so as to ensure that the gap between the parts is uniform and the welding deformation is controllable.

[0061] 5. Lock bottom welding process and corresponding control requirements: By arranging the lock bottom weld before the catheter is formed on the engine, the wall misalignment and butt gap of the connection part are controlled to meet the requirements. After the weld is completely cooled, it is disassembled to ensure that the overall welding deformation of the catheter is controlled within ±1mm, the assembly stress is small, and the leakage of the connected components does not change before and after assembly. This ensures that the catheter is successfully closed and ultimately meets the spatial assembly requirements of the entire catheter.

[0062] Specifically, the present invention provides a method for precisely repairing high-strength, thick-walled conduits for liquid rocket engines, which reduces the difficulty of conduit production and improves processing efficiency, ensures engine quality, and provides a reference for improving the production efficiency, production rhythm demonstration, and production model of liquid rocket engines.

[0063] The specific implementation process of this method is as follows:

[0064] (1) Install adjustment gaskets at the connection parts at both ends of the catheter to control the gap between the connection parts and ensure that the gap is uniform to meet the subsequent assembly requirements;

[0065] The conduit has a wall thickness of 5 to 8 mm and includes a flange, an elbow, a straight pipe and a locking bottom ring. The number of welds is ≥5, and the interface normals are not in the same plane and are not parallel.

[0066] (2) Install and adjust the measurement conversion device to convert spatial dimensions into plane dimensions;

[0067] like Figure 2 As shown, the measurement conversion device converts the spatial dimensions into the plane dimensions, specifically including:

[0068] Left and right supports, center axis and independent supports;

[0069] The left and right supports are used in conjunction with the middle shaft to replace the longer straight pipe and connect with the parts at both ends;

[0070] Independent supports are used to replace shorter straight pipes and connect to parts at both ends;

[0071] Connect the left and right supports and the independent support with the elbow through flanges to form a whole. By measuring the size of the independent support and the distance between the left and right supports, the length of each straight pipe section can be obtained.

[0072] (3) Install spherical bolts at the connection points at both ends of the conduit to align the center lines of the connecting flanges; control the flange deflection by measuring the flange gap, including:

[0073] (3.1) When installing flanges, since the connection surface is spherical, there is deflection and centerline misalignment between the flanges;

[0074] (3.2) Install the spherical bolts. The conical connection form can align the flange center line through the flange mounting hole;

[0075] (3.3) Control flange deflection by adjusting the clearance around the flange.

[0076] (4) Use angle grinder and file to fine-tune the joint surface of each section to ensure uniform gap between parts and controllable welding deformation;

[0077] (4.1) Use an angle grinder to quickly remove the excess of the port interface;

[0078] (4.2) Use a file to accurately remove the excess on the butt joint surface;

[0079] (4.3) Use a file to smooth the end surface and remove burrs and flash.

[0080] The flatness of the rear end face after fine finishing is ≯0.1mm, the groove is uniform, the angle deviation is ≤±2°, and the wall misalignment of the connection part is ≯1mm.

[0081] (5) Perform bottom lock welding. By welding on the engine, control the wall offset and butt clearance of the bottom lock weld before the tube is formed to meet the requirements. After the weld is completely cooled, disassemble it to ensure that the tube is closed smoothly.

[0082] (5.1) The bottom lock weld is manually refined to control the misalignment of the connection part to ≯1mm, and a 2-3mm butt joint gap is reserved to ensure smooth closure of the catheter and reduce welding defects;

[0083] (5.2) Perform argon arc welding;

[0084] (5.3) After the weld has completely cooled, disassemble the pipe to ensure that the overall welding deformation of the pipe is controlled within ±1mm and the assembly stress is within a controllable range.

[0085] (6) According to the above steps, the high-strength thick-walled duct of the liquid rocket engine is produced, and the high-strength thick-walled duct of the liquid rocket engine is precisely repaired.

[0086] Furthermore, the present invention also provides a precise repair system for a high-strength, thick-walled duct of a liquid rocket engine, comprising:

[0087] Connection gap adjustment module: Install adjustment gaskets at the connection points at both ends of the catheter to control the connection gap and ensure uniformity to meet subsequent assembly requirements;

[0088] Spatial dimension conversion module: install and adjust the measurement conversion device to convert spatial dimensions into plane dimensions;

[0089] Connecting flange centerline alignment module: Install spherical bolts at the connecting parts of both ends of the conduit to align the centerlines of the connecting flanges;

[0090] Finishing module: Use angle grinder and file to finish the joint surface of each section of the port to ensure uniform gap between parts and controllable welding deformation;

[0091] Lock bottom welding module: Perform lock bottom welding on the engine to control the wall misalignment and butt clearance of the lock bottom weld connection end before the catheter is formed to meet the requirements. The module will be disassembled after the weld is completely cooled to ensure smooth closing of the catheter. This completes the precise fitting of the high-strength thick-walled catheter for the liquid rocket engine.

[0092] The present invention converts spatial dimension measurement into plane dimension measurement by manufacturing a measurement conversion device, thereby reducing measurement difficulty; automatically aligns the interface flange connection center by manufacturing a self-positioning spherical guide bolt, thereby ensuring measurement accuracy and consistency; forms a precise control method for welding shrinkage by manufacturing an adjustment gasket and statistics of welding shrinkage, thereby determining the length of each section after repair, thereby achieving controllable welding shrinkage; manually fine-tune the butt joint surfaces of each section of the port by using an angle grinder + a file, and after fine-tune, the flatness of the rear end surface is ≤0.1mm, the groove is uniform, the angle deviation is ≤±2°, and the misalignment of the connection part is ≤1mm, thereby ensuring uniform gaps between the part butt joint surfaces and controllable welding deformation; arranges the bottom lock weld before the catheter is formed on the engine for welding to control the misalignment of the connection part and the butt joint gap to meet requirements, and disassembles the catheter after the weld is completely cooled, thereby ensuring that the overall welding deformation of the catheter is controlled within ±1mm, the assembly stress is small, and the leakage in the connected components does not change before and after assembly, thereby ensuring that the catheter is smoothly closed, ultimately meeting the spatial assembly requirements of the entire catheter.

[0093] Parts of the present invention that are not described in detail belong to common knowledge among those skilled in the art.

Claims

1. A method for accurately repairing a high-strength, thick-walled conduit for a liquid rocket engine, characterized in that include: Install adjustment gaskets at the connection points at both ends of the conduit to control the gap between the connection points and ensure that the gap is uniform to meet subsequent assembly requirements; Install and adjust the measurement conversion device to convert the spatial dimensions into plane dimensions; specifically including: left and right supports, center axis and independent supports; the left and right supports are used in conjunction with the center axis to replace the longer straight pipes and connect to the parts at both ends; the independent supports are used to replace the shorter straight pipes and connect to the parts at both ends; the left and right supports and the independent supports are connected to the elbows through flanges to form a whole. By measuring the independent support size and the distance between the left and right supports, the length of each straight pipe section can be obtained; Install spherical bolts at the connection parts at both ends of the conduit to align the center lines of the connecting flanges; Use angle grinder and file to fine-tune the joint surface of each section to ensure uniform gap between parts and controllable welding deformation; Perform bottom lock welding on the engine to control the wall offset and butt clearance of the bottom lock weld before the duct is formed to meet the requirements. After the weld is completely cooled, disassemble it to ensure smooth closure of the duct. According to the above steps, high-strength thick-walled ducts for liquid rocket engines are produced, and precise repair of high-strength thick-walled ducts for liquid rocket engines is completed.

2. The method for accurately repairing a high-strength, thick-walled conduit for a liquid rocket engine according to claim 1, characterized in that: The conduit has a wall thickness of 5 to 8 mm and includes a flange, an elbow, a straight pipe and a locking bottom ring. The number of welds is ≥5, and the interface normals are not in the same plane and are not parallel.

3. The method for accurately repairing a high-strength, thick-walled conduit for a liquid rocket engine according to claim 1, characterized in that: Install spherical bolts at the connection points at both ends of the conduit to align the center lines of the connecting flanges. Control flange deflection by measuring the flange gap, including: (3.1) When installing flanges, since the connection surface is spherical, there is deflection and centerline misalignment between the flanges; (3.2) Install the spherical bolts. The conical connection form can align the flange center line through the flange mounting hole; (3.3) Control flange deflection by adjusting the clearance around the flange.

4. The method for accurately repairing a high-strength, thick-walled conduit for a liquid rocket engine according to claim 1, characterized in that: The flatness of the rear end face after fine finishing is ≯0.1mm, the groove is uniform, the angle deviation is ≤±2°, and the wall misalignment of the connection part is ≯1mm.

5. The method for accurately repairing a high-strength, thick-walled conduit for a liquid rocket engine according to claim 1, characterized in that: The method of fine-tune the butt joint surfaces of each section of the port by using an angle grinder and a file specifically includes the following steps: (4.1) Use an angle grinder to quickly remove the excess of the port interface; (4.2) Use a file to accurately remove the excess on the butt joint surface; (4.3) Use a file to smooth the end surface and remove burrs and flash.

6. The method for accurately repairing a high-strength, thick-walled conduit for a liquid rocket engine according to claim 1, characterized in that: The bottom lock welding specifically includes the following steps: (5.1) The bottom lock weld is manually refined to control the misalignment of the connection part to ≯1mm, and a 2-3mm butt joint gap is reserved to ensure smooth closure of the catheter and reduce welding defects; (5.2) Perform argon arc welding; (5.3) After the weld has completely cooled, disassemble the pipe to ensure that the overall welding deformation of the pipe is controlled within ±1mm and the assembly stress is within a controllable range.

7. A liquid rocket engine high-strength thick-walled conduit precision repair system, characterized in that include: Connection gap adjustment module: Install adjustment gaskets at the connection points at both ends of the catheter to control the connection gap and ensure uniformity to meet subsequent assembly requirements; Spatial dimension conversion module: Install and adjust the measurement conversion device to convert spatial dimensions into plane dimensions, specifically including left and right supports, center axis, and independent supports. The left and right supports are used in conjunction with the center axis to replace longer straight pipes and connect to parts at both ends. Independent supports are used to replace shorter straight pipes and connect to parts at both ends. The left and right supports and independent supports are connected to the elbows via flanges to form a whole. By measuring the independent support dimensions and the spacing between the left and right supports, the length dimensions of each straight pipe section can be obtained. Connecting flange centerline alignment module: Install spherical bolts at the connecting parts of both ends of the conduit to align the centerlines of the connecting flanges; Finishing module: Use angle grinder and file to finish the joint surface of each section of the port to ensure uniform gap between parts and controllable welding deformation; Lock bottom welding module: Perform lock bottom welding on the engine to control the wall misalignment and butt clearance of the lock bottom weld connection end before the catheter is formed to meet the requirements. The module will be disassembled after the weld is completely cooled to ensure smooth closing of the catheter. This completes the precise fitting of the high-strength thick-walled catheter for the liquid rocket engine.

8. The precise repair system for high-strength, thick-walled conduits of liquid rocket engines according to claim 7, characterized in that: The conduit has a wall thickness of 5 to 8 mm, including flanges, elbows, straight pipes, and lock rings, with ≥5 welds, and the interface normals are not parallel and in different planes. Install spherical bolts at the connection points at both ends of the conduit to align the center lines of the connecting flanges. Control flange deflection by measuring the flange gap, including: (3.1) When installing flanges, since the connection surface is spherical, there is deflection and centerline misalignment between the flanges; (3.2) Install the spherical bolts. The conical connection form can align the flange center line through the flange mounting hole; (3.3) Control flange deflection by adjusting the gap around the flange; The flatness of the rear end face after fine finishing is ≯0.1mm, the groove is uniform, the angle deviation is ≤±2°, and the wall misalignment of the connection part is ≯1mm.

9. The precise repair system for high-strength, thick-walled conduits of liquid rocket engines according to claim 7, characterized in that: The method of fine-tune the butt joint surfaces of each section of the port by using an angle grinder and a file specifically includes the following steps: (4.1) Use an angle grinder to quickly remove the excess of the port interface; (4.2) Use a file to accurately remove the excess on the butt joint surface; (4.3) Use a file to smooth the end surface and remove burrs and flash; The bottom lock welding specifically includes the following steps: (5.1) The bottom lock weld is manually refined to control the misalignment of the connection part to ≯1mm, and a 2-3mm butt joint gap is reserved to ensure smooth closure of the catheter and reduce welding defects; (5.2) Perform argon arc welding; (5.3) After the weld has completely cooled, disassemble the pipe to ensure that the overall welding deformation of the pipe is controlled within ±1mm and the assembly stress is within a controllable range.

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