A method for manufacturing an oil supply pipe assembly with cooling function for an aero-engine

Abstract

A kind of oil supply pipe assembly with cooling function for aero-engine preparation method, the oil supply pipe assembly with cooling function is double-layer structure pipe, the overall length of assembly 470mm, inner layer pipe is circular pipe oil pipe, outer layer pipe is oval tube, inner and outer layer are fixed in a joint, the clamping cavity formed by outer layer pipe and inner layer pipe is air passage, inner layer pipe is oil passage, there is hollow retainer in the clamping cavity of inner layer pipe and outer layer pipe, all the parts involved in the whole assembly are high-temperature alloy (GH141) material;Air passage in assembly is three-section structure, joint, conversion sheet and air pipe, conversion sheet is the vertical fixed sheet of inner and outer layer pipe fixed at joint, three are required to be connected by manual argon arc welding way gradually, weld requirement is II weld, according to HB / Z164-1990 is executed, according to HB5456-1990 is accepted;Air pipe is oval tube with long axis 25mm×short axis 14mm, wall thickness is 1mm, length is 350mm.

Description

TECHNICAL FIELD

[0001] The present application relates to the manufacturing and processing technology of aero-engine components, in particular to a preparation process control of an oil supply pipe assembly with cooling function for a turbine component of an aero-engine. BACKGROUND

[0002] The oil supply pipe and the gas supply pipe play an important role in an aero-engine, and they serve to supply oil and gas. Any problem of the pipe may cause quality accidents of different degrees, and may even cause irreversible serious quality accidents of the whole engine, and even cause casualties.

[0003] The assembly is an oil supply pipe assembly with cooling function, which is used to supply lubricating oil to the bearing of the rear supporting part of the turbine of an aero-engine for lubrication and cooling. The whole pipe assembly is used to work at high temperature, and all the parts involved in the pipe assembly are made of high-temperature alloy (GH141) material. The overall length of the pipe assembly is 420 mm. Since the engine vibrates greatly in the working state, the pipe assembly also has to bear great vibration stress, so the overall quality requirement is very high. The pipe assembly has a cooling function for the oil supply pipe, and the design structure is also very complex. The pipe assembly is a double-layer structure, the inner layer pipe is a circular pipe with a diameter of Φ10 and a length of 350 mm, and the outer layer pipe is an elliptical pipe with a length of 25 mm and a width of 16 mm. The inner layer pipe and the outer layer pipe share one joint, the gap between the inner layer pipe and the outer layer pipe forms an air passage, the inner layer pipe forms an oil passage, and there is a hollow retainer in the gap between the inner layer pipe and the outer layer pipe.

[0004] The air passage is used to cool the lubricating oil in the pipe and to cool the whole pipe. During assembly, the pipe has to penetrate through the rear end of the turbine, the outer casing, the supporting ring, the inner casing and other components to reach the oil passage hole on the bearing seat. Good sealing effect is required at the contact positions of the pipe with the multiple parts, so that the dimensions of the pipe assembly at different positions meet the precision requirements under the requirements of coaxiality and concentricity.

[0005] The air passage of the assembly is a three-section structure, including a joint, a conversion sheet and an air passage pipe. The three sections are connected by manual argon arc welding, and the welding seam is required to be a class II welding seam according to HB / Z164-1990 and to be accepted according to HB5456-1990. The air passage pipe is an elliptical pipe with a long axis of 25 mm, a short axis of 14 mm, a wall thickness of 1 mm and a length of 350 mm. The direction of the ellipse has strict angular requirements in the assembly.

[0006] The oil passage part in the assembly is also a three-section structure, and the joint, oil supply pipe and oil outlet nozzle are connected by manual argon arc welding, the welding seam is required to be a class II welding seam, and the acceptance is performed according to HB / Z164-1990 and HB5456-1990. The oil supply pipe is a long circular pipe with a diameter of 10, a wall thickness of 1mm and a length of 370mm, the oil outlet nozzle 5 is a stepped tubular part with a maximum diameter of 14mm, a length of 30mm and an elastic ring mounting groove, and the outer circle size tolerance is only (0- -0.015mm).

[0007] The joint is designed as a D-shaped structure, the oil passage nozzle is parallel to the overall axis at the front end of the joint, the air passage nozzle is perpendicular to the overall axis on the D-shaped plane of the joint, the rear end of the joint is divided into an inner layer structure and an outer layer structure, the outer layer is an air passage, the inner layer is an oil passage, the inner layer and the outer layer are coaxial, the overall structure is complex, and the joint is a forged and machined part; the retainer is a 1mm thick plate part, the shape of the retainer is consistent with the inner cavity of the air passage pipe, and the retainer is welded to the inner cavity of the air passage pipe at a position 5mm away from the rear end; the inner cavity is a circular hole, and the outer diameter of the oil supply pipe has a gap of 0.02mm-0.05mm.

[0008] The design precision of the air outlet end and the oil outlet end of the pipe assembly, i.e. the sealing connection with the bearing seat assembly, is required to be high, the roundness runout of the outer shape surface of the air outlet end within a range of 10mm and the reference outer circle on the joint is required to be only 0.05mm, the roundness runout of the outer circle surface of the oil outlet nozzle and the reference outer circle on the joint is required to be only 0.015mm, and the pipe has the characteristics of small pipe diameter, thin wall and long length, and welding deformation is easily generated in the welding process.

[0009] Due to the high design precision requirement of the parts and the welding performance limitation of the part materials, slight manufacturing deviation may cause the pipe assembly to be unable to be correctly installed into the bearing seat assembly, resulting in a serious quality accident. The welding cannot guarantee the high precision requirement, cannot meet the design requirement at all, the welding quality directly affects the service life and safety of the engine, and the pipe assembly requires super technical and experienced personnel in the manufacturing process. SUMMARY

[0010] The purpose of the present application is to provide a welding preparation method for the above-mentioned problems in the prior art, which can effectively reduce the quality problems of the pipe assembly caused by raw materials, welding, heat treatment and the like, improve the quality of the pipe assembly, and the preparation method is simple and effective, and low in cost.

[0011] To solve the above technical problems, the technical scheme adopted by the present application is: a preparation method of an oil supply pipe assembly with cooling function for an aero-engine, the oil supply pipe assembly with cooling function is designed as a double-layer structure pipe assembly, the overall length of the assembly is 470 mm, the inner layer pipe is a circular pipe, the outer layer pipe is an elliptical pipe, the inner layer and the outer layer share one joint, the clamping cavity formed by the outer layer pipe and the inner layer pipe is an air passage cavity, the inner layer pipe is an oil passage cavity, and there is a hollow retainer in the clamping cavity of the inner layer pipe and the outer layer pipe, and all the parts involved in the whole assembly are made of high-temperature alloy (GH141) material.

[0012] The air passage part in the assembly is a three-section structure, the joint, the conversion sheet and the air passage pipe are connected by manual argon arc welding, the welding seam is required to be a class II welding seam, which is executed according to HB / Z164-1990 and accepted according to HB5456-1990. The air passage pipe is an elliptical pipe with a long axis of 25 mm, a short axis of 14 mm, a wall thickness of 1 mm and a length of 350 mm, and the elliptical direction has strict angular requirements in the assembly.

[0013] The oil passage part in the assembly is also a three-section structure, the joint, the oil supply pipe and the oil outlet nozzle are connected by manual argon arc welding, the welding seam is required to be a class II welding seam, which is executed according to HB / Z164-1990 and accepted according to HB5456-1990. The oil supply pipe is a long circular pipe with a diameter of Φ10, a wall thickness of 1 mm and a length of 370 mm, and the oil outlet nozzle is a tubular part with an elastic ring installation groove, and the outer circular surface size tolerance is only (0- -0.015 mm).

[0014] The joint is designed as a D-shaped structure, the oil passage nozzle is parallel to the overall axis at the front end of the joint, the air passage nozzle is perpendicular to the overall axis on the D-shaped plane of the joint, the rear end of the joint is divided into inner and outer layer structures, the outer layer is for air passage and the inner layer is for oil passage, the inner and outer layers are coaxial, the overall structure is complex and is a forged and machined part; the retainer is a 1 mm thick plate part, the outer shape of which is consistent with the inner cavity of the air passage pipe, and the inner cavity is welded to the inner cavity of the air passage pipe at a position 5 mm away from the rear end, the inner cavity is a circular hole with a gap of 0.02 mm-0.05 mm with the outer diameter of the oil supply pipe.

[0015] The outer shape of the air outlet port and the outer circular surface of the oil outlet port of the pipe assembly have high precision requirements in design because they need to be tightly connected with the installation support hole in the bearing seat assembly. The round runout requirement of the outer shape of the air outlet port within a range of 10 mm and the reference outer circle on the joint is only 0.05 mm, and the round runout requirement of the outer circular surface of the oil outlet port and the reference outer circle on the joint is only 0.015 mm.

[0016] The complexity of the shape of the assembly, and the extremely high design precision requirements, slight manufacturing deviation can cause the pipe assembly to be unable to be correctly installed into the bearing seat assembly, and the high precision requirements cannot be guaranteed by solely relying on welding, the design requirements cannot be met at all, and the quality of the welding will directly affect the service life and safety of the engine, and the personnel requirements during the manufacturing process of the pipe assembly require superb technology and experience.

[0017] In summary, we optimized the processing technology and reasonably arranged the process route during the assembly preparation process, and left a 1 mm combined machining allowance on the outer shape of the part during the part machining, and the whole assembly was machined after welding; the welding process was optimized, and the oil and air passages were welded in batches and sections in a symmetrical manner;

[0018] Due to the small pipe diameter, thin wall, long length, and material being high-temperature alloy (GH141), etc., the welding process is prone to welding deformation, the deformation amount cannot be controlled, and the welding quality cannot be guaranteed, etc., so the welding process is optimized during welding, the welding parameters are solidified, and the corresponding welding fixture is designed, so that the welding deformation of the assembly is controlled to be less than 0.4 mm, the heat treatment process is optimized after welding, vacuum furnace is used for heat treatment, to control the excessive oxidation of the assembly during stress relief, prevent contamination of the pipe cavity, and achieve better effect of removing residual stress after welding, to ensure the precision of the assembly after welding and the material performance. Limiting fixtures are also used during heat treatment to limit the shape, so that the deformation can be controlled within an effective range, to ensure high welding precision and the overall quality of the pipe assembly.

[0019] Optimize the processing technology and reasonably arrange the process route, according to the technical precision requirements of the assembly and the difficulties existing in subsequent processing, leave a 1 mm combined machining allowance at the position with extremely high precision requirements, so that it can be machined in place according to the precision requirements of the part in the assembly state, strictly control the cutting parameters during finishing machining, to ensure the final assembly precision requirements. The specific process route is as follows: 10 assembly, 20 cleaning, 30 pre-assembly before welding (check the size according to the technical document, confirm the allowance), 40 oil supply pipe welding, 50 vacuum stress relief heat treatment, 60 shape correction (this process can not be performed according to the specific situation, the circumferential direction runout is ≤0.1), 70 fluorescent inspection, 80 (X-ray) radiographic inspection, 90 pressure detection, 100 air pipe welding and oil pipe outlet end welding, 110 vacuum stress relief heat treatment, 120 shape correction (this process can not be performed according to the specific situation, the circumferential direction runout is ≤0.1), 140 fluorescent inspection, 150 (X-ray) radiographic inspection, 160 pressure detection, 170 finishing machining (combined machining allowance left in the part state), 180 polishing, 190 final inspection, 200 cleaning and storage.

[0020] The welding process is optimized, and the oil and air passages are welded in batches and sections in a symmetrical manner. By controlling the welding speed and the time and mode of inert gas passage, the formation of the weld is more reliable, and the excessive thermal stress deformation caused by one-time welding is avoided, thereby improving the welding quality stability. In the batch welding process, a welding fixture is used for fixing and limiting to control the excessive deformation of the assembly and limit the relative angular position of the outer tube, thereby fully ensuring the positional accuracy of the weld and achieving higher welding quality. The welding process becomes reliable and convenient.

[0021] The welding process is optimized, and the assembly material is high-temperature alloy (GH141). The material has a high temperature and large thermal stress during welding, which is prone to crack. Therefore, the welding temperature needs to be strictly controlled during welding to control the speed of thermal stress release. Due to the high risk of stress cracking and the particularity of the environment in which the assembly is used, welding experiments are performed according to the optimized welding process before formal welding. Non-destructive testing and metallographic examination are performed on the experimental pieces according to relevant technical requirements. After the inspection results meet the requirements, the welding parameters obtained from the simulation welding are solidified. In the subsequent pipe assembly preparation process, the solidified parameters are strictly followed to achieve the best welding quality and make the welding process controllable and traceable.

[0022] Although manual argon arc welding is a high-quality and efficient welding method, considering the high welding technical requirements, high operation difficulty, high requirements for equipment and environment, and the particularity of the high-temperature alloy (GH141) used as the welding material of the assembly, the high precision requirement of the final form of the assembly, and the environment in which the assembly is used, slight negligence during the welding of the assembly and the post-weld heat treatment is prone to stress cracking. Therefore, after optimizing the welding process, simulation welding is performed. During welding, the inner cavity of the pipe is filled with argon for protection and cooling. The gas flow is strictly controlled to ensure that the pressure in the cavity is 0.1-0.15 MPa. The appropriate welding voltage, current, arc length (0.5-1 mm), and welding speed are selected. The welding position and welding angle are controlled. Through the simulation welding of the experimental pieces and the continuous optimization of the welding parameters, the welding parameters (see Table 1) are obtained. After the inspection results meet the requirements, the welding parameters are solidified. In the pipe assembly preparation process, the solidified parameters are strictly followed to make the welding process controllable and traceable.

[0023]

[0024] Table 1 Welding parameters

[0025] The heat treatment process is optimized, the conventional resistance furnace heat treatment method is abandoned, and the vacuum furnace is started. The vacuum furnace can effectively control the heat treatment environment and strictly control the furnace temperature and time to avoid stress cracking and excessive oxidation of the part vent cavity during conventional heat treatment in the furnace. The formed oxide skin adheres to the vent cavity and cannot be processed, affecting the overall quality and performance of the assembly. A special heat treatment tool is provided during the heat treatment process to limit the deformation caused by the release of tensile stress during heat treatment, which can cause serious deformation and ensure the overall quality of the assembly. The assembly and tool are loaded into the furnace according to the corresponding requirements, heated to 800℃±10℃ for 2-2.5h, then cooled to 260℃ at a rate of ≤200℃ / h, and then air-cooled. The use of the tool during heat treatment can effectively limit the deformation caused by the release of tensile stress during heat treatment, which can cause serious deformation. After heat treatment, a comprehensive shape detection is performed, the circumferential direction jump is ≤0.1, and according to the deformation of the part, a shape correction treatment is arranged, and after determining that the shape is correct, a comprehensive non-destructive testing of the weld quality is performed to ensure the weld quality.

[0026] According to the technical precision requirements of the assembly and the difficulty of subsequent processing, a 1mm combined machining allowance is left at the position where the design precision requirements cannot be guaranteed after welding (see Figure 3 ), and machining is performed in the assembly state after welding. The allowance at the vent pipe is removed by milling, and a double-drive five-axis linkage is used for milling during the milling process. Select the appropriate tool and strictly control the cutting parameters to ensure the machining accuracy. The allowance at the oil outlet is removed by turning, and a four-jaw clamping and tail seat clamping method is used for machining during the turning process. A shallow cutting depth and low feed rate method is used, and the cutting parameters are strictly controlled. The cutting depth is 0.1mm, the feed rate is 0.1mm / r, and the speed is 300r / min, which can ensure the final assembly accuracy requirements.

[0027] Beneficial effects: The weld seam requirements of the components of this invention are Class II weld seams, implemented according to HB / Z164-1990, and accepted according to HB5456-1990. The following high-quality oil supply pipe is achieved: a long cylindrical pipe with a diameter of Φ10, a wall thickness of 1mm, and a length of 370mm; the oil outlet is a tubular component with an elastic retainer mounting groove, and the outer circular surface dimensional tolerance reaches (0~-0.015mm); the rear end of the connector has an inner and outer layer structure, with the outer layer for ventilation and the inner layer for oil transmission, the inner and outer layers being coaxial, resulting in a complex overall structure, and is a forged integral machined part; the retainer is welded to the inner cavity of the ventilation pipe 5mm from the rear end; the outer surface parameters of the air outlet and oil outlet of the pipe assembly are as follows: the circular runout requirement between the outer surface of the air outlet and the reference outer circle on the connector within 10mm is only 0.05mm, and the oil outlet end... The circular runout between the outer circle of the port and the reference outer circle on the joint is required to be 0.015mm; the welding process was optimized, and specialized tooling was used; during the welding process, the oil and air passages were welded in batches and sections in a symmetrical manner; the welding process was optimized, the welding parameters were solidified, and corresponding welding tooling fixtures were designed to control the welding deformation of the components to below 0.4mm; after welding, the heat treatment process was optimized, and a vacuum furnace was used for heat treatment to control excessive oxidation of the components during the stress relief process, prevent contamination of the cavity, and achieve a better effect in removing residual stress after welding, thus ensuring the accuracy of the components after welding and the material properties. Attached Figure Description

[0028] Figure 1 This is a 3D schematic diagram of the pipe assembly;

[0029] Figure 2 This is a 3D schematic diagram of the welding fixture;

[0030] Figure 3 This is a schematic diagram of the combined processing area;

[0031] Figure 4 This is a schematic diagram of the welding fixtures.

[0032] Figure 5 3D schematic diagram of welding positioning for processing a three-section vent pipe assembly using welding fixtures;

[0033] Figure 6 yes Figure 1 A magnified cross-sectional view of a section. Detailed Implementation

[0034] The present invention will be further described in detail below with reference to the accompanying drawings:

[0035] The pipe assembly is shown in the figure as an inner and outer layer structure, 21 joint, 22 conversion sheet, 23 oil supply pipe, 24 holder, 25 oil outlet nozzle, 26 breather pipe. 27 is the combined processing area; the inner and outer layers share a joint 21, the outer layer is the breather part, the inner layer is the oil supply part, the breather part and the oil supply part are designed with a hollow holder 24, and all the parts involved in the entire assembly are made of high-temperature alloy (GH141) material. In the figure: 1 screw rod, 2 nut, 3 slide rail, 4 positioning slide block, 5 block gauge, 6 T-shaped slide block, 7 pressing beam, 8 gasket, 9 pressing screw, 10 pressing block, 11 joint screw, 12 gasket, 13 screw.

[0036] The breather part of the pipe assembly is a three-section structure, joint 21, conversion sheet 22 and breather pipe 26, which are connected by manual argon arc welding, and the weld is required to be a class II weld, in accordance with HB / Z164-1990, and is accepted in accordance with HB5456-1990. The breather pipe 26 is an oval pipe with a long axis of 25mm x short axis of 14mm, a wall thickness of 1mm and a length of 350mm, and its oval direction has strict angular requirements in the assembly state.

[0037] The oil supply part of the pipe assembly is also a three-section structure, joint 21, oil supply pipe 23 and oil outlet nozzle 25, which are connected by manual argon arc welding, and the weld is required to be a class II weld, in accordance with HB / Z164-1990, and is accepted in accordance with HB5456-1990. The oil supply pipe 23 is a long circular pipe with a diameter of Φ10, a wall thickness of 1mm and a length of 370mm, and the oil outlet nozzle 25 is a stepped tubular part with a maximum diameter of Φ14mm, a length of 30mm and an elastic collar installation groove, with an outer circle size tolerance of only (0~ -0.015mm).

[0038] The joint 21 is designed as a D-shaped structure, with the oil outlet nozzle parallel to the overall axis at the front end of the joint, and the breather nozzle perpendicular to the overall axis on the D-shaped plane of the joint. The rear end of the joint is divided into inner and outer layer structures, with the outer layer being the breather and the inner layer being the oil supply. The inner and outer layers are coaxial, and the overall structure is complex, being a forged whole machining part. The holder 24 is a 1mm thick plate part, with an oval shape consistent with the inner cavity of the breather pipe, and an inner hole with a 0.02mm~0.05mm gap with the outer diameter of the oil supply pipe. The final position state is that the inner cavity of the breather pipe is welded together at a distance of 5mm from the rear end.

[0039] The optimized process route is implemented in accordance with the following requirements:

[0040] 1. According to the requirements of the process technical document, all parts are assembled and tested after assembly, and the size is checked according to the technical document, and the excess amount and other related dimensions are confirmed to meet the requirements, and then disassembled for use.

[0041] 2. The joint of piece 21 and the oil supply pipe of piece 23 are fixed and clamped by a welding tool (see Figure 2 ), the round surface of piece 21 is placed on the front end positioning V-shaped block of the welding tool, the pressing plate is pressed tightly, piece 23 is placed on the middle end positioning V-shaped block of the welding tool, the pressing plate is pressed tightly, and the axial length size is ensured, the circumferential relative runout between piece 21 and piece 23 is ensured to be not more than 0.1 mm, and the first welding is performed. The welding parameters and the welding process are strictly performed according to the solidification, the whole welding process of welding is performed by fixing the parts on the tool, and the welding overall deformation is ensured to be controlled below 0.4 mm.

[0042] 3. After welding, vacuum stress relief heat treatment is performed, special tool is used for limiting, relevant technical documents are strictly followed for furnace loading, and the furnace temperature and time are controlled, and technical monitoring is timely completed.

[0043] 4. Rectification treatment, before rectification treatment, piece 25 is detected in the circumferential direction jump based on piece 21, if the circumferential direction jump of piece 25 is less than or equal to 0.1 mm, this process can not be performed, when it is determined that rectification treatment is needed, the parts are properly protected to avoid defects such as indentation and fold.

[0044] 5. Non-destructive testing is performed, the assembly is subjected to fluorescence detection, X-ray detection and pressure detection according to the corresponding technical requirements, and the detection results need to meet the design technical requirements.

[0045] 6. Welding of piece 26 air pipe and piece 25 oil outlet end, three-section fixing of welding tool is used, the round surface of piece 1 in the piece 21 and 23 welded assembly is placed on the front end positioning V-shaped block of the welding tool, the pressing plate is pressed tightly, piece 26 is placed on the middle end positioning V-shaped block of the welding tool according to the angular requirement, piece 25 is placed on the rear end positioning V-shaped block of the welding tool, the pressing plate is pressed tightly, the axial length size is ensured, the relative circumferential runout between the parts is controlled to be not more than 0.1, and the second welding is performed. Due to the limitation of the design structure of the parts, the minimum size of the internal air pipe of piece 26 is the same size as the external diameter of the oil outlet nozzle of piece 25, and there is a 0.5 mm fine turning allowance on the outer circle of piece 25, so piece 22 conversion sheet, piece 26 air pipe and piece 24 retainer need to be welded and then sleeved on piece 23 oil supply pipe before assembling piece 5 oil outlet nozzle, to ensure that piece 2 conversion sheet, piece 24 retainer and piece 26 air pipe can move along the pipe axis in the axial direction of piece 23 oil supply pipe in the welded assembly state. When welding, piece 25 oil outlet end and piece 23 oil supply pipe are welded first, and then piece 2 conversion sheet and piece 1 joint are welded after the thermal stress of the welded assembly is removed. The positioning block in the welding tool of piece 26 air pipe is used to limit the angular position when piece 22 conversion sheet and piece 21 joint are welded (see the figure). The welding parameters and the welding process are strictly performed according to the solidification, the whole welding process of welding is performed by fixing the parts on the tool, and the welding deformation is ensured to be controlled below 0.4 mm.

[0046] 7. Perform according to the above 3, 4, 5.

[0047] 8. Finish machining, finish milling, finish turning the combined machining allowance area left by the part state of the vent pipe of part 26 and the oil outlet nozzle of part 25, (see Figure 3 ), the allowance at the vent pipe of part 6 is removed by milling, double-drive five-axis linkage is used in the milling process, appropriate tools are selected, and cutting parameters are strictly controlled to ensure machining accuracy. The allowance at the oil outlet nozzle of part 5 is removed by turning, four-jaw clamping and tail seat clamping are used in the turning process, shallow cutting depth and low feed rate are used, cutting parameters are strictly controlled, cutting depth is 0.1mm, feed rate is 0.1mm / r, and rotating speed is 300r / min, which achieves the effect of ensuring the final assembly accuracy requirement.

[0048] 9. Finally, the assembly is repaired, polished and finally detected to ensure that the assembly meets the design requirements.

[0049] 10. The universal limiting tool for welding oil and gas pipe assemblies of an aero-engine comprises a guide element, a front limiting element, a rear limiting element and a middle limiting element. The guide element comprises a pair of sliding rails, an internal hexagonal screw and a flat washer. The front limiting element comprises a positioning sliding block, a V-shaped sliding block, a pressing beam, a pressing screw, a screw rod, a nut, a washer, a pressing screw, a joint screw and a universal block gauge. The positioning sliding block is provided with grooves on both sides for accommodating and matching the embedded sliding rails, and the screw passes through the sliding rail slot to fix the positioning sliding block and the sliding rail. The positioning sliding block is provided with holes at both ends of the upper end for fixing two vertical screw rods. The upper part of the two screw rods is provided with a universal block gauge and a V-shaped sliding block. The positioning sliding block is provided with a pressing beam above. The pressing beam is provided with holes on both sides through the screw rod, and the nut is used to fix the pressing beam above the screw rod. The rear limiting element and the middle limiting element are the same in structure as the front limiting element. The guide element is fixed and connected with the front limiting element, the middle limiting element and the rear limiting element through the positioning (concave) clamping grooves on both sides of the positioning sliding block and the screw, to form the universal limiting tool for welding oil and gas pipe assemblies of an aero-engine. When assembling, the guide rail in the guide element is positioned and clamped into the positioning groove on both sides of the positioning sliding block contained in the three limiting elements, and the internal hexagonal screw is used for fastening connection. The universal block gauge is selected according to the actual situation of the pipe assembly. The rear limiting element and the middle limiting element are consistent in structure with the front limiting element.

[0050] When assembling, the guide rail in the guide element is positioned and clamped into the positioning (concave) clamping groove on both sides of the positioning sliding block contained in the three limiting elements, and the internal hexagonal screw is used for fastening connection of the guide rail and the positioning sliding block.

[0051] A reversed V-shaped groove clamp block is fixed under the beam, and the block gauge is a metal block with different thicknesses for supporting welding workpieces with different heights.

Claims

1. A method for manufacturing a fuel supply pipe assembly with cooling function for an aero-engine, characterized in that, The oil supply pipe assembly with cooling function is a double-layer structure pipe with an overall length of 470mm. The inner pipe is a round oil pipe and the outer pipe is an elliptical pipe. The inner and outer layers are fixed to a joint. The cavity formed by the outer and inner pipes is a venting cavity, and the inner pipe is an oil passage cavity. There is a hollow retainer in the cavity between the inner and outer pipes. All parts involved in the entire assembly are made of high-temperature alloy materials. The ventilation section of the component has a three-section structure: a connector, a conversion plate, and a ventilation pipe. The conversion plate is a vertical fixing plate with the inner and outer tubes fixed at the connector. The three sections are required to be connected by manual argon arc welding. The weld is required to be a Class II weld, in accordance with HB / Z164-1990. The ventilation pipe is an elliptical pipe with a major axis of 25mm × minor axis of 14mm, a wall thickness of 1mm, and a length of 350mm. The oil pipe in the component is also a three-section structure, consisting of a connector, an oil supply pipe, and an oil outlet. The three sections are required to be connected by manual argon arc welding. The weld is required to be a Class II weld, in accordance with HB / Z164-1990. The oil supply pipe has a diameter of Φ10mm, a wall thickness of 1mm, and a length of 370mm. The oil outlet is a tubular component with a flexible retaining ring mounting groove, and the outer diameter tolerance is 0 to -0.015mm. The overall cross-section of the connector is designed as a D-shaped structure. The oil inlet is located at the front end of the connector and is parallel to the overall axis. The vent is located on the overall D-shaped cross-section of the connector and is perpendicular to the overall axis. The rear end of the connector is divided into inner and outer layers. The outer layer is for venting and the inner layer is for oiling. The inner and outer layers are coaxial. The retainer is made of 1mm thick plate. Its shape is elliptical, consistent with the inner cavity of the vent pipe. The inner hole is a round hole with a gap of 0.02mm to 0.05mm from the outer diameter of the oil supply pipe. It is welded to the inner cavity of the vent pipe 5mm from the rear end. The circular runout requirement between the outer surface of the air outlet and the reference outer circle on the connector within a 10mm range is only 0.05mm, and the circular runout requirement between the outer circle of the oil outlet and the reference outer circle on the connector is 0.015mm. When processing double-layer structure pipe fittings, a 1mm machining allowance is left on the outer surface of the part for assembly. The whole part is then machined after the components are welded. The welding process was optimized by using a batch-by-batch, segment-by-segment symmetrical welding method for the oil and gas passages. The welding process was optimized, welding parameters were solidified, and corresponding welding fixtures were designed to control the welding deformation of the components to below 0.4mm. The heat treatment process was optimized after welding by using a vacuum furnace to control excessive oxidation of the components during stress relief.

2. The method for manufacturing a fuel supply pipe assembly with cooling function for an aero-engine according to claim 1, characterized in that, The specific process route is as follows:

10. Assembly, 20. Cleaning, 30. Pre-assembly before welding, check dimensions according to technical documents and confirm allowance, 40. Welding of oil supply pipe, 50. Vacuum stress relief heat treatment, 60. Shaping treatment, circumferential runout ≤0.1mm, 70. Fluorescent inspection, 80. X-ray inspection, 90. Pressure test, 100. Welding of vent pipe and oil pipe outlet, 110. Vacuum stress relief heat treatment, 120. Shaping treatment, circumferential runout ≤0.1mm, 140. Fluorescent inspection, 150. X-ray inspection, 160. Pressure test, 170. Finishing, i.e., the combined machining allowance left in the state of precision milling and precision turning of parts, 180. Fitting and polishing, 190. Final inspection, 200. Cleaning and warehousing.

3. The method for manufacturing a fuel supply pipe assembly with cooling function for an aero-engine according to claim 1, characterized in that, During the welding process, the oil and gas passages were welded in batches and sections in a symmetrical manner. By controlling the welding speed and the time and method of inert gas ventilation, the weld formation was made more reliable, avoiding excessive thermal tensile stress deformation caused by a single welding, and improving the stability of welding quality. During welding, the inner cavity of the pipe fitting is filled with argon gas for protection and cooling. The gas flow rate is controlled to ensure an internal pressure of 0.1–0.15 MPa. Appropriate welding voltage and current are selected, and the arc length is maintained at 0.5–1 mm along with a suitable welding speed. The welding position and welding angle are controlled, and the welding parameters are obtained as follows. The solidified parameters are strictly followed during the pipe assembly preparation process: Welding material GH141, welding material specification φ1mm, current 40±5A, voltage 11±0.5V, gas flow rate 13±1L / min, argon purity ≥99.99%, tube cavity pressure 0.1~0.15MPa, arc length 0.5~1mm.

4. The method for manufacturing a fuel supply pipe assembly with cooling function for an aero-engine according to claim 1, characterized in that, Heat treatment is performed using a vacuum furnace. The vacuum furnace can effectively control the heat treatment environment and strictly control the furnace temperature and time, avoiding the generation of stress cracks and preventing excessive oxidation of the ventilation cavity of the parts during heat treatment in a conventional heat treatment furnace. The resulting oxide scale adheres to the ventilation cavity and cannot be removed, affecting the overall quality and performance of the components. During the heat treatment process, a special heat treatment fixture is used. The components and fixture are loaded into the furnace according to the corresponding furnace loading requirements. After heating to 800℃±10℃ and holding for 2~2.5h, the temperature is cooled to 260℃ at a rate of ≤200℃ / h, and then the components are removed from the furnace and air-cooled.

5. The method for manufacturing a fuel supply pipe assembly with cooling function for an aero-engine according to claim 1, characterized in that, The excess material at the oil outlet is removed by turning. During the turning process, a four-jaw chuck is used and the tailstock is tightened. The machining is carried out with a shallow depth of cut and a low feed rate. The depth of cut is 0.1 mm, the feed rate is 0.1 mm / r, and the speed is 300 r / min.

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