Casing outer wall mounting seat connecting structure and assembling method

Abstract

The invention discloses a cartridge receiver outer wall mounting seat connecting structure, and belongs to the technical field of aero-engine cartridge receivers, the cartridge receiver outer wall mounting seat connecting structure is characterized in that a boss is arranged on the outer wall of a cartridge receiver, an end face threaded hole is formed in the end face of the boss, and a part of the area of the end face of the boss is concaved inwards to form an inner hole matching surface; the inner hole matching surface is vertical to the end surface of the boss; the mounting cover plate is provided with a groove, a connecting bolt hole and a centering matching surface, the connecting bolt hole is formed in the bottom of the groove, and the groove is formed in the side, away from the centering matching surface, of the mounting cover plate; and the connecting bolt penetrates through the connecting bolt hole and is connected with the end face threaded hole, and the mounting cover plate is in centering connection with the inner hole matching surface of the boss through the centering matching surface. According to the mounting structure, flexible adjustment according to different mounting requirements is achieved, different mounting cover plates can be rapidly replaced according to actual requirements, and the flexibility and universality of the mounting structure are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of aero-engine casings, specifically to a connection structure and an assembly method for mounting seats on the outer wall of the casing. Background Art

[0002] In the field of aero-engines, as an important structural carrier, the outer wall of the casing usually needs to connect various pipelines for different purposes, such as fuel supply pipelines, return pipelines, and test pipelines, etc. In the prior art, the mounting seats on the outer wall of the casing are usually fixed by welding connection methods. However, the welding connection method has a series of prominent problems, including but not limited to thermal deformation generated during the welding process, the risk of cracks caused by welding stress concentration, difficult-to-guarantee assembly accuracy, complex maintenance and replacement processes, and high maintenance costs. These problems seriously affect the reliability and service life of the overall engine structure.

[0003] Specifically, during welding connection, the high-temperature welding zone is likely to cause changes in the microstructure of the casing material, resulting in a reduction in the local material properties of the connection area and generating welding defects and internal cracks. Especially under the high-precision and high-reliability requirements of aero-engines, even minor welding defects or deformations may lead to catastrophic consequences. In addition, the welding connection method requires construction personnel to have a high skill level and experience, and strict requirements are imposed on welding process parameters such as current intensity, welding speed, and temperature control during the construction process. Once the operation is improper, it is extremely easy to generate quality defects.

[0004] On the other hand, using the welding method to fix the mounting seat also has the problem of insufficient flexibility. Since various pipelines with different purposes need to be connected to the aero-engine casing, the interface sizes and positions of various pipelines often vary. Therefore, a variety of different types of mounting seats are required to match the pipeline requirements. Once the welding connection structure is formed, its position and type are fixed. If the pipeline structure or installation position needs to be changed and adjusted later, it will be impossible to achieve convenient replacement and adjustment, severely restricting the convenience and economy of the engine's later maintenance work. In terms of maintenance, the maintenance and repair of the welding connection structure are very difficult. If the mounting seat or pipeline interface is damaged or needs to be adjusted, it is necessary to use cutting or destructive demolition methods for replacement and re-welding. The operation is complex, the cost is high, and it is time-consuming and laborious. If the disassembly is improper, it may even further damage the casing body, affecting the overall structural performance and life.

[0005] Based on the above situation, the traditional welded mounting structure has been difficult to meet the requirements of modern aero-engine development for high precision, easy maintenance, high reliability, and high economy. There is an urgent need to develop a new connection structure technical solution that can not only ensure the firmness and reliability of the installation connection but also achieve the functions of rapid disassembly, assembly, and repeated interchange of the installation structure to meet the requirements of efficient maintenance and modern management of aero-engines. Summary of the Invention

[0006] The present invention provides a connection structure and an assembly method for a mounting seat on the outer wall of a casing to solve the technical problem of poor flexibility in welding connection of the existing casing mounting seat.

[0007] According to one aspect of the present invention, there is provided a connection structure for a mounting seat on the outer wall of a casing. A boss is provided on the outer wall of the casing. A face thread hole is provided on the end face of the boss. A part of the area of the end face of the boss is recessed to form an inner hole mating surface, and the inner hole mating surface is perpendicular to the end face of the boss. A mounting cover plate is provided with a groove, a connection bolt hole and a centering mating surface. The connection bolt hole is located at the bottom of the groove, and the groove is provided on the side of the mounting cover plate away from the centering mating surface. A connection bolt passes through the connection bolt hole and is connected to the face thread hole, and the mounting cover plate is centered and connected to the inner hole mating surface of the boss through the centering mating surface.

[0008] Optionally, a lockwire insert is installed in the face thread hole. The lockwire insert is wound by elastic metal wire, has an external thread matching the face thread hole on the outer surface, and has an internal thread matching the connection bolt on the inner surface, and is tightly fitted with the face thread hole of the boss through its own elasticity.

[0009] Optionally, the depth of the groove is greater than the height of the bolt head of the connection bolt, so that the top end of the connection bolt does not protrude beyond the end face of the mounting cover plate.

[0010] Optionally, the side wall of the groove includes an arc surface, and the center of the arc surface is coaxial with the center of the connection bolt hole.

[0011] Optionally, a flared nut for cooperating with an external connecting member is further provided on the mounting cover plate.

[0012] Optionally, a plurality of bosses are distributed along the circumferential direction of the outer wall of the casing. The included angle between the center connection line of the two face thread holes on each boss and the radial direction of the casing is the installation direction adjustment angle θ, and the installation direction adjustment angle θ of each boss is independent of each other.

[0013] Optionally, a plurality of flared nuts are provided, and the flared nuts are distributed on both sides of the center connection line of the face thread holes.

[0014] Optionally, the cross sections of the inner hole mating surface and the centering mating surface of the boss can be circular, polygonal or toothed for mating and assembling.

[0015] According to another aspect of the present invention, an assembly method for a connection structure of an outer wall mounting seat of a casing is further provided, which includes the following steps: S1, machining a boss on the outer wall of the casing, the overall shape of the boss being a cylindrical or polygonal structure, the boss including an inner hole mating surface and two end face threaded holes, and the inner hole mating surface being perpendicular to the end face of the boss; S2, installing a wire insert for locking in the end face threaded hole; S3, mating and centering the centering mating surface with the inner hole mating surface; S4, connecting and fixing the mounting cover plate to the boss through a connecting bolt; S5, assembling a flare nut on the mounting cover plate for connecting an external component.

[0016] Optionally, when it is necessary to meet different installation methods and functional requirements such as the fuel supply pipe, the fuel return pipe, and the test pipe, the following replacement steps are included: S5, disassembling the connecting bolt; S6, replacing the mounting cover plate corresponding to the functional requirement; S7, reconnecting and fixing the replaced mounting cover plate to the boss through the connecting bolt.

[0017] In summary, the present application includes at least one of the following beneficial technical effects:

[0018] By providing a boss on the outer wall of the casing, and providing a concave inner hole mating surface and an end face threaded hole on the end face of the boss, and at the same time designing a mounting cover plate that cooperates with the boss, the mounting cover plate and the boss are threadedly connected and centered through a connecting bolt. Compared with the prior art in which the mounting seat is directly connected to the casing by welding, this solution eliminates the welding process and no longer requires welding to fix the mounting seat, avoiding the influence of thermal deformation and welding defects during the welding process on the overall structural performance of the casing. In addition, the mounting cover plate and the boss in this solution are connected and centered by bolts, enabling the mounting cover plate to be quickly installed, disassembled, and replaced, thereby achieving flexible adjustment for different installation requirements. Different mounting cover plates can be quickly replaced according to actual needs to meet the connection requirements of different functional pipelines such as fuel supply, fuel return, and test pipes, greatly improving the flexibility and versatility of the installation structure, and solving the technical problem of poor flexibility of the existing welding connection method for the casing mounting seat.

[0019] In addition to the objectives, features, and advantages described above, the present invention has other objectives, features, and advantages. The present invention will be further described in detail below with reference to the drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The drawings constituting a part of this application are used to provide a further understanding of the present invention. The schematic embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0021] Figure 1 is a schematic diagram of the connection structure of the outer wall mounting seat of the present invention;

[0022] Figure 2Schematic diagram of the structure of the boss of the present invention;

[0023] Figure 3 Schematic diagram of the structure of the mounting cover plate of the present invention;

[0024] Figure 4 is Figure 1 cross-sectional structure diagram of.

[0025] Legend description:

[0026] 1. Inner hole mating surface; 2. End face threaded hole; 3. Installation direction adjustment angle θ; 4. Groove; 5. Connecting bolt hole; 6. Centering mating surface; 7. Connecting bolt; 8. Locking wire insert; 9. Flared nut; 10. Boss; 11. Mounting cover plate. Specific embodiments

[0027] The following will describe in detail the embodiments of the present invention with reference to the accompanying drawings. However, the present invention can be implemented in many different ways defined and covered by the following.

[0028] The following will be further described in detail with reference to the attached Figures 1-4 This application will be further described in detail.

[0029] The embodiment of this application discloses a connection structure for the mounting seat on the outer wall of the casing.

[0030] Referring to Figure 1 , the connection structure of the mounting seat on the outer wall of the casing includes a boss 10, a mounting cover plate 11 and a connecting bolt 7. Among them, the boss 10 is used to be fixed on the outer wall of the casing to provide a reliable and stable mounting reference for the mounting cover plate 11; the mounting cover plate 11 is used to cooperate with the boss 10 for connection to realize the interface function for external pipelines such as fuel supply pipes, return oil pipes and test pipes; the connecting bolt 7 is used to realize the firm connection between the boss 10 and the mounting cover plate 11, so that the mounting cover plate 11 and the boss 10 form a detachable fastening structure to meet the installation requirements of different pipelines and realize the rapid replacement and flexible adjustment of the installation structure.

[0031] The boss 10 structure is arranged on the outer wall of the casing. In this embodiment, the boss 10 is preferably a cylindrical structure, which is convenient for processing and precision control. At the same time, it can also be designed into a polygonal structure according to actual use requirements to meet the specific requirements for functions such as fitting positioning and anti-rotation under different working conditions. The material of the boss 10 can be preferably high-strength aluminum alloy, titanium alloy or superalloy and other common structural materials for aeroengines to meet the working conditions of the engine under high temperature, high pressure, vibration and complex environments. Two end face threaded holes 2 are provided on the end face of the boss 10 for realizing the connection and fixation with the connecting bolt 7; the end face threaded holes 2 are processed by a precision numerical control machine tool to ensure that the thread size, depth and precision strictly meet the design standards, and ensure the safety, reliability and durability of the bolt connection.

[0032] The inner hole mating surface 1 is provided on the end face of the boss 10. The inner hole mating surface 1 is designed with an inner concave shape and is precisely perpendicular to the end face of the boss 10. During processing, the perpendicularity tolerance is strictly controlled within 0.01 mm to ensure accurate positioning and centering functions between the boss 10 and the mounting cover plate 11. In addition, the surface of the boss 10 can be strengthened, such as shot peening or anodizing, to enhance the fatigue resistance, wear resistance, and corrosion resistance of the boss 10, thereby further extending the service life and reliability of the connection structure of the mounting seat on the outer wall of the casing. In the specific implementation process, multiple bosses 10 are usually arranged along the circumferential direction of the outer wall of the casing to meet the connection requirements of multiple different pipelines, facilitate the quick installation and disassembly of the mounting cover plate 11, and effectively improve the efficiency and flexibility of engine installation and maintenance work.

[0033] The cross-sectional shapes of the inner hole mating surface 1 and the centering mating surface 6 of the boss 10 can be flexibly selected as circular, polygonal, or toothed according to specific application requirements to meet different types of installation environments and functional requirements. When the inner hole mating surface 1 and the centering mating surface 6 adopt a circular cross-section, it can provide extremely high machining accuracy and centering, which is beneficial to achieving precise centering fit between the mounting cover plate 11 and the boss 10. The circular cross-section has a mature process in machining and manufacturing, and can ensure small geometric tolerances, thereby achieving high-precision and high-stability axial and radial positioning. This structure is particularly suitable for assembly environments with high coaxiality requirements and structural symmetry, and can effectively improve the stability and service life of the connection components in high-speed or high-vibration working environments. If a polygonal cross-section (such as a hexagon, octagon, or other regular polygon) is adopted, on the basis of ensuring the basic centering function, it can also provide additional anti-rotation ability. Through the mutual cooperation of the polygonal corners, a mechanical self-locking effect can be formed between the mounting cover plate 11 and the boss 10, thereby significantly enhancing the anti-torsion ability of the structure under axial or radial load. This structure is particularly suitable for working conditions where the pipeline interface may bear large torque loads, preventing connection loosening or displacement problems caused by vibration or external forces during operation. In more complex application scenarios, a toothed cross-section (such as a spline tooth shape, a sawtooth shape, etc.) can be selected to further enhance the anti-sliding and anti-rotation abilities of the assembly structure. The toothed fit realizes a more stable force transmission effect through the meshing of the tooth surfaces, and can effectively resist relative displacement under complex stress and high-frequency vibration conditions. Especially under special application conditions where the external pipeline needs to bear high-pressure fluid impact, frequent loading and unloading, or high dynamic loads, the toothed fit structure has better safety performance and long-term reliability.

[0034] In this embodiment, a plurality of bosses 10 are evenly arranged along the circumferential direction of the outer wall of the casing, that is, a plurality of bosses 10 are distributed on the circumferential surface of the outer wall of the casing at equal intervals. This design method facilitates the installation of multiple different types of external pipelines or connectors at the same time, significantly improving the integrity of the structure, space utilization efficiency and installation convenience. The end face of each boss 10 is provided with two end face threaded holes 2, and the angle between the center line of the two end face threaded holes 2 and the radial direction of the casing is defined as the installation direction adjustment angle θ3. The specific value of the installation direction adjustment angle θ3 is not fixed, but can be flexibly adjusted according to the installation orientation and spatial layout requirements of the specific external connector or pipeline. By accurately controlling the size of the angle θ, the precise installation and matching of the external pipeline or connector in multiple different spatial orientations can be effectively achieved, avoiding additional bending or switching caused by inconsistent pipeline directions, thereby improving assembly accuracy, reducing the use of additional connectors, and optimizing installation efficiency and economy. In addition, the installation direction adjustment angle θ3 of each boss 10 is relatively independent of each other, which means that the angle θ on each boss 10 can be designed and processed separately according to the actual working conditions without affecting the design and layout of other bosses 10, which makes the overall installation structure of the casing highly versatile and flexible. Even on the same engine, multiple pipeline interfaces with different functions can also use different angle settings at the same time to meet their specific installation requirements, significantly improving the overall adaptability of the engine's external pipeline system, and is particularly suitable for actual application scenarios with complex spatial layouts or multiple functional pipelines coexisting.

[0035] The mounting cover plate 11 is designed with a groove 4, connection bolt holes 5, and a centering mating surface 6. Among them, the connection bolt holes 5 are located at the bottom of the groove 4, and the groove 4 is provided on the side of the mounting cover plate 11 away from the centering mating surface 6. The main purpose of this structural layout is to accommodate the head of the connection bolt 7, thereby effectively preventing the bolt head from protruding beyond the end face of the mounting cover plate 11 after assembly, significantly reducing the risk of the connection bolt 7 head being exposed to the external environment, preventing damage to the bolt head due to external mechanical collision or wear, and ensuring the safety and stability of the bolt connection. At the same time, the head of the connection bolt 7 is completely sunk into the groove 4, effectively improving the flatness of the surface of the mounting cover plate 11 and the overall structural appearance neatness, facilitating subsequent inspection and maintenance work, and contributing to the improvement of aerodynamic performance, especially applicable to the external structure of an aeroengine with strict requirements for airflow characteristics. In addition, in this embodiment, the depth of the groove 4 is specifically designed to be greater than the height of the head of the connection bolt 7. This structural design takes into account the assembly error, machining tolerance, and dimensional changes that may be caused by the change of bolt pre-tightening force during long-term operation, ensuring that the top of the connection bolt 7 head will not protrude above the end face of the mounting cover plate 11 under any circumstances, further improving the safety and reliability of the structure, and avoiding possible structural interference, damage or other accidental risks caused by the protruding bolt head. In a specific embodiment, the depth of the groove 4 is at least 0.5 mm greater than the height of the bolt head of the connection bolt 7. This value is optimized and selected, taking into account the standard deviation of the bolt head size, machining process error, and uncertainty during the installation process, fully ensuring that the expected functions of the structure can be stably achieved during actual production and use.

[0036] The centering mating surface 6 and the inner hole mating surface 1 cooperate with each other to form a centering structure. This structural design can effectively ensure the good coaxiality between the mounting cover plate 11 and the boss 10 after assembly, making the positional relationship between the two components accurate and stable, reducing the difficulty in the part assembly process, reducing the influence of human factors on the accuracy during assembly, making the assembly process more stable and reliable, improving the assembly production efficiency, and at the same time enhancing the stability and long-term reliability of the overall structure of the mounting seat.

[0037] In order to further improve the safety and stability of the connection structure and effectively prevent the connection bolt 7 from loosening due to factors such as vibration, temperature change, and stress fluctuation during long-term operation, in this embodiment, a wire thread insert 8 for preventing loosening is particularly provided inside the threaded hole 2 at the end face of the boss 10. The wire thread insert 8 for preventing loosening is made of stainless steel wire or other high-performance alloy metal wires with high strength and good elasticity through a precision winding process. Its overall cross-section presents a diamond or approximately diamond shape, having good elastic deformation ability and self-locking performance. The outer surface of the wire thread insert 8 for preventing loosening is processed with a high-precision external thread structure, which is precisely matched with the thread size and pitch on the inner wall of the threaded hole 2 at the end face of the boss 10; while the inner surface of the wire thread insert has a standard-sized internal thread, which is precisely matched with the external thread structure of the connection bolt 7, enabling a stable and firm threaded connection relationship. During the installation process of the wire thread insert 8 for preventing loosening, a special installation tool is used to precisely screw the wire thread insert 8 into the threaded hole 2 at the end face of the boss 10. During the screwing process, the outer thread surface of the wire thread insert will produce a small amount of elastic deformation, making the wire thread insert closely fit with the inner wall of the threaded hole 2 at the end face of the boss 10, generating a radial elastic pressure, effectively increasing the friction and contact stiffness between the threads. This structural characteristic of elastic close fit enables the connection bolt 7 to be subjected to a continuous and uniform pre-tightening force after being screwed into the internal thread of the wire thread insert 8 for preventing loosening, enhancing the ability of the bolt connection to resist vibration and impact in a dynamic environment, and effectively eliminating the problem of the connection bolt 7 gradually loosening under long-term operating conditions. The wire thread insert 8 for preventing loosening itself has excellent material properties, with good wear resistance and fatigue resistance, enabling the threaded connection part to have a longer service life and effectively avoiding the occurrence of thread surface wear or slipping under high-frequency vibration and high cyclic loads.

[0038] To meet the diverse installation requirements of external components, in this embodiment, a flared nut 9 is provided on the mounting cover 11. The flared nut 9 is used to achieve convenient connection and disconnection with external connectors. Multiple flared nuts 9 can be provided, evenly distributed on both sides of the center line connecting the connection bolt holes 5, enhancing the diversity, versatility, and convenience of the structural connection.

[0039] The side wall of the groove 4 of the mounting cover plate 11 is designed as an arc surface structure, and the center of the circle of the arc surface is arranged coaxially with the center of the connecting bolt hole 5. Without increasing the overall size or depth of the groove 4, this arc surface forms a smoother transition surface, avoiding the common tool interference problems in the design of conventional right-angle or acute-angle grooves 4. The key point of this structure design is to ensure that during the installation or disassembly of the bolts, common bolt-tightening tools such as Allen wrenches and socket wrenches can smoothly enter the connecting bolt hole 5 and achieve efficient operation. Since the arc surface is coaxially arranged with the connecting bolt hole 5, the tool can be naturally aligned along the central axis of the bolt, reducing the angular deviation, thereby improving the convenience and reliability of the tightening or disassembly operation. Especially in complex environments with limited space or dense installations, this arc surface design significantly increases the operating space of the tool, avoiding problems such as insufficient tightening or difficult disassembly of bolts caused by structural interference. In summary, this arc surface design not only improves the assembly efficiency and operating convenience.

[0040] The specific implementation process of the assembly method of the present invention is as follows:

[0041] Step S1: Machine a boss 10 on the outer wall of the casing. The overall shape of the boss 10 is a cylindrical or polygonal structure. The boss 10 includes an inner hole mating surface 1 and two end face threaded holes 2, and the inner hole mating surface 1 is perpendicular to the end face of the boss 10.

[0042] According to the design requirements of the casing and the structural requirements of the mounting seat, machine the boss 10 in the specified installation area on the outer wall of the casing. This boss 10 serves as the basic installation structure for the mounting cover plate 11, and its machining method can adopt the overall machining process to ensure that the boss 10 is integrally formed with the casing, with high structural strength and overall rigidity. In some complex structures or multi-functional requirements, a composite process of casting and machining can also be selected, that is, initially form the basic contour of the boss 10 by casting, and then use a high-precision CNC machine tool for fine machining to ensure the geometric accuracy of the key mating surfaces.

[0043] The overall shape of the boss 10 can be cylindrical or polygonal according to the design requirements. Among them, the cylindrical shape helps to improve the versatility and centering accuracy of the assembly, while the polygonal shape has stronger anti-rotation ability. In the structure of the boss 10, the inner hole mating surface 1 must be precisely machined. This mating surface is a concave structure, specifically used for high-precision positioning and mating with the centering mating surface 6 of the mounting cover plate 11. At the same time, two end face threaded holes 2 are evenly distributed and machined on the end face of the boss 10. The position and size of the threaded holes should strictly control the tolerance according to the design drawing to ensure the mating accuracy with the connecting bolt 7. The inner hole mating surface 1 and the end face of the boss 10 must be strictly perpendicular to each other, and the perpendicularity control standard is preferably within 0.01 mm. This high-precision machining requirement is the key to ensuring the coaxial positioning and stable connection of the subsequent mounting cover plate 11 and the boss 10, and is directly related to the performance and reliability of the entire mounting seat system.

[0044] Step S2: Install the anti-loosening wire insert 8 into the end face threaded hole 2.

[0045] Using a special wire insert installation tool, precisely install the anti-loosening wire insert 8 into the end face threaded hole 2 of the boss 10. The anti-loosening wire insert 8 is made of high-strength elastic metal wire wound. Its external thread is precisely matched with the pitch and tooth profile of the threaded hole of the boss 10. During the installation process, the wire insert is screwed into the end face threaded hole 2 through a special installation tool. During the screwing process, the wire insert generates a slight radial elastic deformation and closely fits with the inner wall of the hole to ensure the anti-loosening effect. After the installation of the insert is completed, the geometric accuracy and coaxiality of the external thread and the internal thread need to be confirmed to be qualified by a detection tool to ensure that the subsequent connecting bolt 7 can be smoothly screwed in and tightened. This step effectively enhances the strength and wear resistance of the end face threaded hole 2, significantly improves the anti-loosening ability and reusability of the connecting bolt 7, and avoids the problem of thread hole failure after long-term service.

[0046] Step S3: Mate and center the centering mating surface 6 with the inner hole mating surface 1.

[0047] Precisely position the pre-machined mounting cover plate 11 through its centering mating surface 6 with the inner hole mating surface 1. Before positioning, the mounting cover plate 11 needs to be subjected to quality inspection and dimensional recheck to ensure that the geometric tolerance of the centering mating surface 6 of the cover plate meets the design requirements. During the positioning process, the operator needs to slowly insert the cover plate into the inner hole mating surface 1 to ensure that there is no interference or jamming during the mating process, and a good sliding mating state is maintained between the mating surfaces to ensure the accuracy of radial positioning. Through high-precision centering and mating, the mounting cover plate 11 can achieve high coaxial assembly with the boss 10, effectively ensuring the balance and installation accuracy of the external connecting pipeline or component interface, reducing the risk of pipeline vibration and fatigue damage, and providing a stable and reliable foundation for the entire installation system.

[0048] Step S4: Connect and fix the mounting cover plate 11 to the boss 10 through the connecting bolt 7.

[0049] Select a connecting bolt 7 that meets the design requirements, usually a standard part made of high-strength corrosion-resistant alloy material. The connecting bolt 7 needs to undergo pretreatment and coating treatment such as lubrication and anti-seizure treatment to ensure excellent mechanical properties and durability in high-temperature and high-pressure environments. The bolt passes through the connecting bolt hole 5 that has been machined on the mounting cover plate 11, inserts into the threaded hole 2 on the end face of the boss 10, and is screwed into the internal thread of the wire thread insert 8 for anti-loosening. During the process of tightening the bolt, a torque wrench or other special torque control tools should be used to perform uniform and symmetric tightening operations according to the predetermined torque value in the process document. During the torque control process, over-torque or under-torque phenomena should be avoided to ensure that the bolt reaches the optimal pre-tightening force state and improve the stability and safety of the connection structure.

[0050] After the bolt is tightened, a secondary torque review and locking mark treatment should be carried out to prevent the bolt from loosening and ensure that the entire connection system reaches the required stiffness and load-bearing capacity of the design.

[0051] Step S5: Assemble a flared nut 9 on the mounting cover plate 11 for connecting external components.

[0052] Assemble the flared nut 9 at the designated mounting hole or interface position on the mounting cover plate 11. The flared nut 9 is a special sealing joint assembly that is suitable for pipeline systems such as external supply oil pipes, return oil pipes, or test pipes, and can achieve reliable pipeline connection and sealing performance. When assembling the flared nut 9, first, the mounting hole needs to be cleaned to ensure that the interface has no burrs, foreign objects, or oil stains. The flared nut 9 should be screwed into the mounting hole through standard tools and precisely engaged with the threaded interface of the cover plate until the end face of the flared nut 9 is closely fitted and flush with the mating surface of the cover plate. When tightening the flared nut 9, the standard process torque value should be controlled to ensure that the flared surface can be closely fitted with the tapered surface of the external pipeline, thereby ensuring the sealing reliability and use safety of the pipeline system under high-pressure and high-vibration conditions.

[0053] When different external installation methods and functional requirements such as supply oil pipes, return oil pipes, and test pipes need to be met, this embodiment also provides an efficient replacement step, specifically:

[0054] Step S6: Disassemble the connecting bolt 7 and remove the original mounting cover plate 11.

[0055] When different external installation function requirements need to be met in actual applications, such as replacing different types of fuel supply pipes, return pipes or test pipe interfaces, the disassembly and replacement of the installation cover plate 11 can be quickly realized as required. First, disassemble the installed connecting bolts 7, loosen them counterclockwise with a special tool, and keep the torque uniform during disassembly to avoid deformation of the cover plate or jamming of the bolts caused by unbalanced forces. After the bolts are disassembled, slowly remove the original installation cover plate 11 to avoid bumping the mating surface and sealing surface of the boss 10.

[0056] Step S7: Replace the installation cover plate 11 corresponding to the functional requirements.

[0057] According to the new functional requirements, select an installation cover plate 11 with a suitable structural form or interface configuration. Confirm that the mating dimensions of the new installation cover plate 11 are consistent with the inner hole mating surface 1 and there are no machining defects. After ensuring that the surface is clean and undamaged, reposition it accurately according to step S3. This step allows users to flexibly configure the interfaces according to external requirements, supports multiple interface standards and installation angles, and significantly improves the modularity and versatility of the system.

[0058] Step S8: Reconnect and fix the replaced installation cover plate 11 to the boss 10 through the connecting bolts 7.

[0059] Re-pass the connecting bolts 7 through the new cover plate connection holes in sequence and screw them into the end face threaded holes 2 of the boss 10. Perform torque control according to step S4 to ensure that the tightened state of the bolts meets the requirements of the process document. After the connection of the replaced installation cover plate 11 is completed, perform a sealing test and function check again to ensure that the system after replacing the components still maintains stable operating performance and sealing performance and meets the design indicators. The entire replacement process is fast and efficient, avoiding complex processes such as welding and recasting required by traditional structures, greatly reducing the maintenance cycle and labor costs, and significantly improving the maintenance convenience and reliability of the system.

[0060] This embodiment significantly improves the machining accuracy, assembly convenience and structural stability of the casing structure, avoids structural deformation and welding defects caused by welding, shortens the processing cycle, reduces production costs, improves production efficiency and the qualified rate of parts processing, and has broad industrial practical value.

[0061] The above are only the preferred embodiments of the present invention and are not used to limit the present invention. For those skilled in the art, the present invention can have various changes and modifications. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. The casing outer wall mounting seat connection structure is characterized in that: include: A boss (10) is arranged on the outer wall of the casing, an end face threaded hole (2) is opened on the end face of the boss (10), a part of the end face of the boss (10) is concave to form an inner hole matching surface (1), and the inner hole matching surface (1) is perpendicular to the end face of the boss (10); The mounting cover plate (11) is provided with a groove (4), a connecting bolt hole (5) and a centering matching surface (6), wherein the connecting bolt hole (5) is located at the bottom of the groove (4), and the groove (4) is arranged on a side of the mounting cover plate (11) away from the centering matching surface (6); The connecting bolt (7) passes through the connecting bolt hole (5) and is connected to the end surface threaded hole (2); the mounting cover plate (11) is connected to the inner hole matching surface (1) of the boss (10) through the centering matching surface (6).

2. The casing outer wall mounting seat connection structure according to claim 1, characterized in that: An anti-loosening wire screw sleeve (8) is installed in the end face threaded hole (2). The anti-loosening wire screw sleeve (8) is made of elastic metal wire, and its outer surface is provided with an external thread matching the end face threaded hole (2) of the boss (10), and its inner surface is provided with an internal thread matching the connecting bolt (7). The anti-loosening wire screw sleeve (8) is tightly matched with the end face threaded hole (2) of the boss (10) through its own elasticity.

3. The casing outer wall mounting seat connection structure according to claim 1, characterized in that: The depth of the groove (4) is greater than the height of the bolt head of the connecting bolt (7), so that the top end of the connecting bolt (7) does not exceed the end surface of the mounting cover plate (11).

4. The casing outer wall mounting seat connection structure according to claim 1, characterized in that: The side wall of the groove (4) comprises an arcuate surface, the center of which is coaxial with the center of the connecting bolt hole (5).

5. The casing outer wall mounting seat connection structure according to claim 1, characterized in that: The installation cover plate (11) is also provided with a flared nut (9) for cooperating with an external connecting piece.

6. The casing outer wall mounting seat connection structure according to claim 1, characterized in that: A plurality of bosses (10) are distributed along the circumferential direction of the outer wall of the casing, and an angle between a center line of two end face threaded holes (2) on each boss (10) and the radial direction of the casing is an installation direction adjustment angle θ (3), and the installation direction adjustment angle θ (3) of each boss (10) is independent of each other.

7. The casing outer wall mounting seat connection structure according to claim 5, characterized in that: The flared nuts (9) are provided in plurality, and the flared nuts (9) are distributed on both sides of the center line of the end face threaded holes (2).

8. The casing outer wall mounting seat connection structure according to claim 1, characterized in that: The cross-sections of the inner hole matching surface (1) and the centering matching surface (6) of the boss (10) can be circular, polygonal or toothed for matching assembly.

9. An assembly method for a casing outer wall mounting seat connection structure, used for the casing outer wall mounting seat connection structure according to any one of claims 1 to 8, characterized in that: The following steps are involved: S1, machining a boss (10) on the outer wall of the casing, wherein the overall shape of the boss (10) is a cylindrical or polygonal structure, and the boss (10) comprises an inner hole matching surface (1) and two end surface threaded holes (2), wherein the inner hole matching surface (1) is perpendicular to the end surface of the boss (10); S2, installing the anti-loosening wire screw sleeve (8) in the end surface threaded hole (2); S3, centering the centering mating surface (6) and the inner hole mating surface (1); S4, connecting and fixing the mounting cover plate (11) and the boss (10) by means of connecting bolts (7); S5, assemble the flared nut (9) on the mounting cover (11) for connecting external components.

10. The method for assembling the casing outer wall mounting seat connection structure according to claim 9, characterized in that: When it is necessary to meet different installation methods and functional requirements of the oil supply pipe, oil return pipe and test pipe, the following replacement steps are included: S6, remove the connecting bolts (7); S7, replacing the installation cover plate (11) corresponding to the functional requirements; S8, reconnect and fix the replaced installation cover plate (11) to the boss (10) by connecting bolts (7).

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