Method for processing a cylindrical oil storage device

Abstract

The application discloses a cylindrical oil storage equipment processing method, which comprises the following steps: firstly, processing process steps, process notches and process bosses respectively at the butt joint of a flange plate and a connecting plate before welding; secondly, adopting electron beam to weld the flange plate and the connecting plate, and adopting copper sleeve protection on the axis of a clamp corresponding to the electron beam influence area to ensure that the axis of the clamp does not deform; and thirdly, adding a positioning process boss as a fixed support point to the outer side of a first mounting base, inserting a coaxial welding mandrel into the inner holes of the first mounting base and a second mounting base and fixing and supporting, fixing and supporting at the positioning process boss, and supporting the outer surface of the second mounting base. The application realizes correct butt joint of the welding surface of the flange plate and the connecting plate, prevents the welding seam from collapsing, guarantees the connecting strength and quality after welding, and ensures that the inner hole coaxiality of the first mounting base and the second mounting base meets the installation precision requirement of an oil level sensor.

Description

Technical Field

[0001] This invention relates to a novel method for processing and manufacturing cylindrical oil storage equipment for aviation, as well as tooling fixtures designed to improve manufacturing quality. It belongs to the field of airborne equipment processing and manufacturing and is used to improve the processing quality of cylindrical oil storage equipment. Background Technology

[0002] The new cylindrical oil storage device has a thin-walled aluminum alloy structure, as shown in the diagram. Figure 1 This cylindrical oil storage device is lightweight, has a large capacity, and requires high precision. The runout between its end face and inner diameter is no more than 0.05 mm, the weld quality is Grade II, and it can still ensure sealing under a pressure of 0.12 MPa.

[0003] The main body of the cylindrical oil storage device is constructed by welding connecting plates and flanges. The connection point is a butt weld, which is a crucial load-bearing component. Due to the high precision requirements, this weld is of paramount importance. Because this structure involves a thin-walled butt joint, it is essential to ensure good joint strength. Furthermore, the cylindrical oil storage device has an irregular curved surface, which is complex and difficult to position precisely.

[0004] In addition, the manufacturing risk of cylindrical oil storage equipment also lies in the fact that the oil level sensor is installed in the first and second mounting bases, and the dimensional and positional tolerance requirements are as follows: Figure 1 The coaxiality accuracy within a length of 300mm needs to be guaranteed to be 0.05mm. According to the information found, the coaxiality accuracy that can usually be achieved by welding HB5800 sheet metal parts is 0.32mm.

[0005] Based on the above analysis, the problems that urgently need to be solved include: First, the cylindrical oil storage equipment has an irregular curved surface, resulting in large welding deformation. Due to the poor welding appearance, it has been the subject of many complaints from users, making it urgent to improve the appearance quality.

[0006] Secondly, according to the precision requirements of cylindrical oil storage equipment, the welding deformation at the joint should be small. At the same time, the welding quality at the flange and connecting plate joint will affect the overall strength, and the selection of the welding method at this point will affect the overall quality of the equipment.

[0007] Currently, commonly used welding methods include argon arc welding and electron beam welding. When using manual welding methods such as argon arc welding, the weld seam often has many large pores, failing to meet the requirements for Class II weld seams.

[0008] Electron beam welding is used because it offers high energy density, concentrated energy, a small heat-affected zone, and a large aspect ratio. Welding in a vacuum environment can improve joint strength and prevent defects such as hot cracking. However, misalignment is prone to occur at the joint, and weld collapse after welding can reduce weld strength.

[0009] Third, during electron beam welding, due to the strong penetrating power of the electron beam, the electron beam will hit the rod in the middle of the fixture, and the energy will also be concentrated on the rod of the fixture. As a result, the fixture shaft will deform. After several welding operations, the rod in the middle of the fixture will no longer be coaxial. Since the clamping part is on one side of the fixture during the welding process, after the rod is twisted, the welding position will no longer fall in the same position when rotating in the circumference.

[0010] Fourth, the oil level sensor requires high installation accuracy. How can we achieve high coaxiality between the first and second mounting bases during the manufacturing process?

[0011] Fifth, the challenge of controlling welding deformation on irregularly shaped surfaces. Summary of the Invention

[0012] This invention aims to provide a method for processing cylindrical oil storage equipment, solving the problem of welding deformation of irregular curved surfaces during the welding process of cylindrical oil storage equipment, ensuring the welding quality of flanges and connecting plates, especially coaxiality and misalignment, ensuring the coaxiality of the first mounting base and the second mounting base, and meeting the installation accuracy requirements of oil level sensors.

[0013] To achieve the above objectives, the present invention adopts the following technical solution: A method for manufacturing a cylindrical oil storage device includes welding a flange to a connecting plate, and welding a first mounting base and a second mounting base. The manufacturing method includes the following steps: Step 1: Before welding the flange and connecting plate, machine process steps, process notches, and process bosses at the mating point of the flange and connecting plate, including: The process steps include a first step surface located on the flange mating end face and a second step surface located on the connecting plate mating end face. The first step surface and the second step surface are completely fitted at the mating interface after they are mated. The process notch includes a first notch located on the inner wall of the flange mating end and a second notch located on the inner wall of the connecting plate mating end, the first notch and the second notch having the same circumference length; The process boss includes a first boss located on the outer wall of the flange mating end and extending along the end of the first step surface, and a second boss located on the outer wall of the connecting plate mating end and extending along the end of the second step surface. The thickness of the first boss and the second boss is calculated based on the shrinkage of the butt weld between the flange and the connecting plate. Step 2: Electron beam welding is used to weld the flange and connecting plate. During the welding process, a clamp is used to press the flange and connecting plate together, and a copper sleeve is used to protect the area affected by the electron beam on the axis of the clamp to ensure that the axis of the clamp does not deform. Step 3: Before welding the first and second mounting seats, add a perforated positioning process boss as a fixed support point on the outer side of the first mounting seat. Use a fixture to clamp the first and second mounting seats before welding. The fixture clamping method includes: simultaneously inserting a coaxial welding mandrel into the inner holes of the first and second mounting seats that have coaxiality requirements and fixing and supporting both ends of the coaxial welding mandrel; fixing and supporting the positioning process boss of the first mounting seat; and supporting the outer surface of the second mounting seat.

[0014] Alternatively, in step one, the first step surface and the second step surface may contain the same number of steps.

[0015] Alternatively, in step two, the fixtures for electron beam welding the flange and connecting plate include: The clamp rod is a straight rod with a surface including a smooth surface and an external threaded surface. A connecting plate positioning seat is installed on the smooth surface of the clamp rod body, and a connecting plate inner hole positioning stop is provided on the end face of the connecting plate positioning seat. A flange positioning seat is mounted on the smooth surface of the clamp rod, and a flange inner hole positioning stop is provided on the end face of the flange positioning seat. A protective copper sleeve, which is a cylindrical tube and is installed on the clamp rod in the electron beam weld influence area between the connecting plate positioning seat and the flange positioning seat; A clamping nut and a clamping spring are provided. The clamping nut is installed on the external thread surface of the clamping rod. One end of the clamping nut is in close contact with the first end of the clamping spring, and the second end of the clamping spring is in close contact with the flange positioning seat.

[0016] Alternatively, the protective copper sleeve may be made of H62 or T2 material.

[0017] Alternatively, in step three, the fixture used for welding the first mounting base and the second mounting base may further include: The base plate is fixedly mounted with supports A, B and C, and is detachably mounted with a coaxiality limiting seat. A process boss positioning shaft, one end of which is inserted into the hole of a positioning process boss via a pin, thereby forming a support for the first mounting base; The second mounting base positioning shaft has a support surface at one end that is consistent with the outer surface of the second mounting base. A coaxiality measuring rod, which is used to measure the coaxiality between the inner hole of the first mounting base and the inner hole of the second mounting base; The support A is connected to one side of the coaxiality welding mandrel corresponding to the first mounting seat, and is used to fix and support the coaxiality welding mandrel or the coaxiality measuring rod. The support B is connected to the positioning shaft of the process boss; The support C is connected to the positioning shaft of the second mounting base; The coaxiality limiting seat is connected to one side of the second mounting seat corresponding to the coaxiality welding mandrel, and is used to fix and support the coaxiality welding mandrel or the coaxiality measuring rod.

[0018] As an option, the fixture also includes: An upper pressure plate is pressed against the end face of the connecting disc; The cassette is clamped around the outer surface of the cylindrical oil storage device along its circumference. There is one cassette at the weld between the flange and the connecting plate, and another cassette at the assembly point between the connecting plate and the upper pressure plate.

[0019] As an alternative, both the inner holes of the first and second mounting seats, which have coaxiality requirements, retain machining allowances. After the first and second mounting seats are welded, the coaxiality of the inner holes of the first and second mounting seats is first measured, and then the coaxiality of the inner holes of the first and second mounting seats is ensured to meet the design requirements by machining the inner holes.

[0020] As an alternative, the processing method for cylindrical oil storage equipment also includes step four: when the first mounting base and the second mounting base are welded together and the coaxiality of the inner holes of the first mounting base and the second mounting base meets the design requirements, the positioning process boss on the outer side of the first mounting base is removed.

[0021] Compared with the prior art, the processing method of the present invention has the following characteristics: 1. By using process bosses, process notches, and process steps, the welding surfaces of the flange and the connecting plate are correctly aligned, the weld does not collapse, and the connection strength and quality after welding are guaranteed, ensuring good consistency in the production of large batches of cylindrical oil storage equipment; 2. Electron beam welding is used for flanges and connecting plates, and a protective copper sleeve is introduced into the electron beam welding fixture to avoid welding misalignment and edge misalignment caused by fixture deformation; 3. Use a fixture to ensure that the coaxiality of the inner holes of the first and second mounting bases meets the requirements of the oil level sensor installation accuracy; 4. The welding deformation of the irregular surface of the cylindrical oil storage device is controlled by the fixture. Specifically, this is achieved by designing the welding shrinkage allowance, calculating the dimensional chain, setting the welding fixture rod (including eccentricity), pressing the upper pressure plate during welding, and using clamps to tighten the outer surface of the cylindrical oil storage device, as well as post-weld correction. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of a cylindrical oil storage device. Figure 2 A schematic diagram of the main structure and connection strength enhancement solution for a cylindrical oil storage device; Figure 3 This is a schematic diagram of the weld type for a butt joint; Figure 4 Schematic diagram of the copper sleeve protection structure of the electron beam welding fixture; Figure 5 A schematic diagram of the structure and process improvement of the first mounting base; Figure 6 A schematic diagram of the coaxiality lifting fixture structure for the first and second mounting seats; In the diagram: 1-Coaxiality welding mandrel; 2-Support A; 3-Process boss positioning shaft; 4-Support B; 5-Support C; 6-Second mounting seat positioning shaft; 7-Coaxiality limit seat; 8-Coaxiality measuring rod; 9-Upper pressure plate; 10-Clamping belt; 11-Clamping rod; 12-Connecting disc positioning seat; 13-Protective copper sleeve; 14-Flange positioning seat; 15-Compression spring; 16-Compression nut. Detailed Implementation

[0023] The present invention will be further described below with reference to the accompanying drawings and specific embodiments. However, it should not be construed that the scope of the subject matter of the present invention is limited to the following embodiments. All modifications, substitutions and alterations made based on ordinary technical knowledge and common practices in the art without departing from the above-described technical concept of the present invention are included within the scope of the present invention.

[0024] like Figure 1 As shown, this invention relates to a cylindrical oil storage device that needs to be processed. To address the processing quality problems described in the background art, this invention designs a processing method for a cylindrical oil storage device, which achieves this from the following aspects: First, process steps, process notches, and process bosses are added at the joint between the flange and the connecting plate.

[0025] Second, electron beam welding is used for flanges and connecting plates.

[0026] Third, a protective sleeve is designed in the middle of the electron beam welding fixture.

[0027] Fourth, a positioning protrusion is provided on the surface of the first mounting base.

[0028] Fifth, design a coaxiality positioning seat (composed of support A2 and coaxiality limiting seat 7).

[0029] Sixth, support A2 and coaxiality limit seat 7 are set together as a common axis to evaluate coaxiality, and together they constitute the manufacturing and inspection benchmark for coaxiality.

[0030] The specific implementation details for the above six aspects are as follows: (1) such as Figure 2 A process step and a process notch are added at the joint between the flange and the connecting plate. The process step ensures that the flange and the connecting plate are correctly joined; the process notch ensures that the position is unique when joined (the two process notches distributed on the flange and the connecting plate have the same circumferential length, and when the edges are aligned, it proves that there is no misalignment between the flange and the connecting plate in the circumferential direction, and no rotation within the circumference will occur), thus ensuring good consistency in mass production.

[0031] (2) Regarding the problem of weld collapse during the welding process, such as Figure 3 By calculating the welding shrinkage allowance, adding a reserved process boss, and pre-setting the weld collapse amount, the connection strength and quality of the flange and connecting plate after welding are guaranteed.

[0032] (3) such as Figure 4 An electron beam welding fixture was designed, which includes a fixture rod 11, a connecting plate positioning seat 12, a protective copper sleeve 13, a flange positioning seat 14, a compression spring 15, and a compression nut 16.

[0033] The clamp rod 11 is a stepped shaft with two external threads on its surface. Figure 4 The connecting plate positioning seat 12 has an external thread at its mounting position for installing a flange with internal threads. The connecting plate positioning seat 12 is connected to the flange with internal threads by multiple screws. The flange with internal threads serves two purposes: firstly, it limits the axial installation position of the connecting plate positioning seat 12, and secondly, it prevents the connecting plate positioning seat 12 from rotating. Both the end faces of the connecting plate positioning seat 12 and the flange positioning seat 14 have positioning stops, which are used to insert into the inner holes of the connecting plate and the flange, respectively, to achieve inner circle positioning. The flange positioning seat 14 is clamped by a compression spring 15 and a compression nut 16 on another external thread.

[0034] Based on copper's high reflectivity, high thermal conductivity, low laser absorption, and rapid heat dissipation, a protective copper sleeve 13 is installed on the fixture rod 11. The sleeve is made of H62 copper, which is cheaper than T2 copper. The protective copper sleeve 13 is fixed to the step of the fixture rod 11 through an inner hole and secured with bolts. This rapidly dissipates the heat transferred from the electron beam to the fixture during welding, resulting in no weld marks on the surface of the protective copper sleeve 13.

[0035] (4) such as Figure 5A welding fixture for the first and second mounting seats was designed. The fixture includes a base plate, a coaxiality welding mandrel 1, a support A2, a process boss positioning shaft 3, a support B4, a support C5, a second mounting seat positioning shaft 6, a coaxiality limiting seat 7, a coaxiality measuring rod 8, an upper pressure plate 9, and a clamp 10 (i.e., a common clamp). Supports A2, B4, and C5 are all fixed on the same base plate, and the coaxiality limiting seat 7 is detachably connected to the base plate. The process boss positioning shaft (3) has one end inserted into the hole of the positioning process boss through a pin, thereby forming a support for the first mounting seat. One end of the second mounting base positioning shaft 6 includes a support surface consistent with the outer surface of the second mounting base; the coaxiality measuring rod 8 is used to measure the coaxiality between the inner holes of the first mounting base and the second mounting base; the support A2 is connected to the coaxiality welding mandrel 1 on the side corresponding to the first mounting base, and is used to fix and support the coaxiality welding mandrel 1 or the coaxiality measuring rod 8; the support B4 is connected to the process boss positioning shaft 3; the support C5 is connected to the second mounting base positioning shaft 6; the coaxiality limiting seat 7 is connected to the coaxiality welding mandrel 1 on the side corresponding to the second mounting base, and is used to fix and support the coaxiality welding mandrel 1 or the coaxiality measuring rod 8. The support A2, the process boss positioning shaft 3, the second mounting base positioning shaft 6, and the coaxiality limiting seat 7 together limit the movement.

[0036] To ensure the accuracy of the inner hole position of the first mounting base, if positioning is only achieved from the threaded nozzle at the end of the first mounting base, the rear part of the first mounting base will be tilted upwards or downwards, thus increasing the difficulty of ensuring coaxiality. Therefore, a positioning process boss is added to it as a fixed support point during welding (e.g., Figure 5 (As shown). Simultaneously, a composite structure is designed on the welding fixture, as shown in the diagram. Figure 6 As shown, the composite structure includes support A2 and support B4. Supports A2 and B4 together ensure the position of the first mounting seat. The positioning shaft 6 of the second mounting seat ensures the external position of the second mounting seat through a profile support. The coaxiality limiting seat 7 is a detachable structure and together with support A2 forms a coaxiality assembly datum. A certain process allowance is reserved in the inner holes of the first and second mounting seats. After inserting the coaxiality welding mandrel 1, tack welding is performed. The coaxiality is checked after welding using a coaxiality measuring rod 8, and machining is performed to ensure the final required coaxiality. The positioning process boss is removed after welding. (5) According to Figure 1It is known that the φ18 coaxiality reference on the second mounting base is the φ20 inner hole on the first mounting base. The length of the φ20 inner hole is only 1 / 6 of the total measurement length. The reference magnification error alone is enough to amplify the measurement error value and lead to poor measurement repeatability. Therefore, coaxiality positioning seats (composed of support A2 and coaxiality limiting seat 7) are designed at the front and rear ends to establish a common axis, and a common axis is designed at both ends of the coaxiality measuring rod 8. This fixture design greatly improves the manufacturing and measurement accuracy of coaxiality.

[0037] (6) The upper pressure plate 9 is used on the welding fixture of the first mounting base and the second mounting base to control the upper and lower end faces (i.e. the lower end face of the flange and the upper end face of the connecting plate) of the cylindrical oil storage device to prevent up and down undulation. The upper pressure plate 9 is pressed on the axial end face of the connecting plate. The upper pressure plate 9 is connected to the base plate by a screw. Two clamps 10 are used to ensure that the outer surface (cylindrical profile) of the cylindrical oil storage device is tightly fitted. The clamps 10 are common metal clamps or nylon clamps. By shrinking the length of the clamps 10, the clamps 10 are tightened along the circumference of the cylindrical oil storage device on the outer surface of the cylindrical oil storage device. There is one clamp at the weld between the flange and the connecting plate, and one clamp at the assembly point between the connecting plate and the upper pressure plate 9.

[0038] This invention effectively improves the welding quality of cylindrical oil storage devices and controls welding deformation through the above methods. Finally, it finds a general processing method for this type of product, which greatly improves the product's appearance quality and the strength of important welds.

[0039] Those skilled in the art can make various adjustments to this application based on the actual circumstances. The general principles defined in this application can be implemented in other embodiments without departing from their connotations. Therefore, this application is not limited to the structure shown in the specific embodiments, but is to be accorded the widest scope consistent with the principles and features set forth in the claims of this application.

Claims

1. A method for manufacturing a cylindrical oil storage device, comprising welding a flange to a connecting plate, and welding a first mounting base and a second mounting base, characterized in that, The processing method includes the following steps: Step 1: Before welding the flange and connecting plate, machine process steps, process notches, and process bosses at the mating point of the flange and connecting plate, including: The process steps include a first step surface located on the flange mating end face and a second step surface located on the connecting plate mating end face. The first step surface and the second step surface are completely fitted at the mating interface after they are mated. The process notch includes a first notch located on the inner wall of the flange mating end and a second notch located on the inner wall of the connecting plate mating end, the first notch and the second notch having the same circumference length; The process boss includes a first boss located on the outer wall of the flange mating end and extending along the end of the first step surface, and a second boss located on the outer wall of the connecting plate mating end and extending along the end of the second step surface. The thickness of the first boss and the second boss is calculated based on the shrinkage of the butt weld between the flange and the connecting plate. Step 2: Electron beam welding is used to weld the flange and connecting plate. During the welding process, a clamp is used to press the flange and connecting plate together, and a copper sleeve is used to protect the area affected by the electron beam on the axis of the clamp to ensure that the axis of the clamp does not deform. Step 3: Before welding the first mounting base and the second mounting base, add a positioning process boss with a hole on the outer side of the first mounting base as a fixed support point. Use a fixture to clamp the first mounting base and the second mounting base before welding. The fixture clamping method includes: simultaneously inserting a coaxial welding mandrel (1) into the inner hole of the first mounting base and the inner hole of the second mounting base which have coaxiality requirements and fixing and supporting both ends of the coaxial welding mandrel (1), fixing and supporting the positioning process boss of the first mounting base, and supporting the outer surface of the second mounting base. In step two, the fixtures for electron beam welding the flange and connecting plate include: The clamp rod (11) is a straight rod with a smooth surface and an external thread surface. Connecting disk positioning seat (12), the connecting disk positioning seat (12) is installed on the smooth surface of the clamp rod (11), and the end face of the connecting disk positioning seat (12) is provided with a connecting disk inner hole positioning stop; Flange positioning seat (14) is installed on the smooth surface of the clamp rod (11), and a flange inner hole positioning stop is provided on the end face of the flange positioning seat (14). Protective copper sleeve (13), the protective copper sleeve (13) is a round tube and is installed on the clamp rod (11) in the electron beam weld influence area between the connecting plate positioning seat (12) and the flange positioning seat (14); A clamping nut (16) and a clamping spring (15) are provided. The clamping nut (16) is installed on the external thread surface of the clamping rod (11). One end face of the clamping nut (16) is in close contact with the first end of the clamping spring (15), and the second end of the clamping spring (15) is in close contact with the flange positioning seat (14).

2. The method for processing a cylindrical oil storage device according to claim 1, characterized in that: In step one, the first step surface and the second step surface contain the same number of steps.

3. The method for processing a cylindrical oil storage device according to claim 1, characterized in that: The protective copper sleeve (13) is made of H62 or T2 material.

4. The method for processing a cylindrical oil storage device according to claim 1, characterized in that: In step three, the fixture used for welding the first mounting base and the second mounting base also includes: The base plate is fixedly installed with supports A (2), B (4) and C (5), and is detachably installed with a coaxiality limiting seat (7). Process boss positioning shaft (3), one end of which is inserted into the hole of the positioning process boss through a pin, thereby forming a support for the first mounting seat; The second mounting base positioning shaft (6) has a support surface at one end that is consistent with the outer surface of the second mounting base; A coaxiality measuring rod (8) is used to measure the coaxiality between the inner hole of the first mounting base and the inner hole of the second mounting base. The support A (2) is connected to one side of the first mounting seat corresponding to the coaxiality welding mandrel (1) for fixing and supporting the coaxiality welding mandrel (1) or the coaxiality measuring rod (8). The support B (4) is connected to the positioning shaft (3) of the process boss; The support C (5) is connected to the positioning shaft (6) of the second mounting seat; The coaxiality limiting seat (7) is connected to one side of the second mounting seat corresponding to the coaxiality welding mandrel (1) for fixing and supporting the coaxiality welding mandrel (1) or the coaxiality measuring rod (8).

5. The method for processing a cylindrical oil storage device according to claim 4, characterized in that, The fixture also includes: Upper pressure plate (9) is pressed against the end face of the connecting plate; The cassette (10) is clamped around the outer surface of the cylindrical oil storage device along the circumference of the cylindrical oil storage device. There is one cassette at the weld of the flange and the connecting plate, and one cassette at the assembly point of the connecting plate and the upper pressure plate (9).

6. The method for processing a cylindrical oil storage device according to claim 1, characterized in that: Both the inner holes of the first and second mounting seats, which have coaxiality requirements, retain machining allowances. After the first and second mounting seats are welded, the coaxiality of the inner holes of the first and second mounting seats is first measured, and then the coaxiality of the inner holes of the first and second mounting seats is ensured to meet the design requirements by machining the inner holes.

7. The method for processing a cylindrical oil storage device according to claim 1, characterized in that: It also includes step four, when the welding of the first mounting base and the second mounting base is completed and the coaxiality of the inner holes of the first mounting base and the second mounting base meets the design requirements, the positioning process boss on the outer side of the first mounting base is removed.

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