Low-stress assembly method for force bearing frame of aero-engine

Abstract

The invention provides a low-stress assembly method for a force bearing frame of an aero-engine, which belongs to the technical field of aero-engine assembly, and particularly comprises the following steps of: respectively placing parts, connecting pieces and the force bearing frame which need to be treated in an electromagnetic field, respectively connecting the parts, the connecting pieces and the force bearing frame which need to be treated with positive and negative electrodes, and assembling the parts, the connecting pieces and the force bearing frame; the electrodes are connected with a power source and start an electromagnetic field, and electromagnetic coupling processing is conducted on the connecting piece and the force bearing frame; drilling is conducted on the treated force bearing frame, and the treated force bearing frame is connected with the treated part through the treated connecting piece and the drilled hole site; placing the force bearing frame and the parts which are connected in an electromagnetic field, connecting the force bearing frame with positive and negative electrodes, connecting the electrodes with a power supply, starting the electromagnetic field, and performing electromagnetic coupling treatment on the force bearing frame and the parts which are connected. By means of the treatment scheme, the time cost and the economic cost of aero-engine force bearing frame assembling are reduced, and the assembling quality of force bearing frame assembling is improved.

Description

Technical Field

[0001] The present application relates to the field of aero-engine assembly, and in particular, to a low-stress assembly method for an aero-engine load-bearing frame. Background Art

[0002] Under the requirement of weight reduction of aircraft, thin-walled parts such as steel and aluminum are widely used. Among them, aluminum alloy is the most widely used material in the aviation industry, with the characteristics of low density, high strength, and strong connectivity. The load-bearing frame of an aero-engine is a typical aluminum alloy thin-walled part, which can disperse and bear various forces and torques generated during the operation of the engine, ensuring the structural integrity and operation safety of the engine. During the assembly process of the load-bearing frame, due to factors such as the fit tolerance between components, thermal expansion, and high part stress values, large assembly stresses are often caused, and stress concentration is likely to occur, thus affecting the assembly accuracy, structural stability, and service life. Its stress state after assembly directly affects various performance indicators of the aero-engine operation.

[0003] In order to achieve low-stress assembly of the load-bearing frame, currently, thermal and cold assembly processes and hydraulic assembly processes are often used. The thermal and cold assembly process can reduce the stress during the assembly process and achieve high-precision fitting of components through thermal expansion and cooling contraction. However, this process requires special heating equipment and cooling equipment, with high requirements for equipment and increased production costs. At the same time, it is necessary to precisely control the temperature and time during the heating and cooling processes, and the operation is relatively complex. In addition, the thermal and cold assembly process is a holistic treatment, and due to the different shapes and structures of components, a temperature gradient is easily formed inside the parts, introducing new stresses. The hydraulic assembly process can control the expansion amount of components through a hydraulic device to reduce the assembly stress during the assembly process. However, the hydraulic assembly process requires special hydraulic equipment, with high costs. And it has great limitations on the size and shape of components and is not suitable for components with irregular shapes. At the same time, there are safety hazards such as hydraulic leakage and bursting during the assembly process using the hydraulic assembly process. Summary of the Invention

[0004] In view of this, the present application provides a low-stress assembly method for an aero-engine load-bearing frame, which solves the problems in the prior art, reduces the time cost and economic cost of the aero-engine load-bearing frame assembly, and improves the assembly quality of the load-bearing frame assembly.

[0005] A low-stress assembly method for an aero-engine load-bearing frame provided by the present application adopts the following technical solutions:

[0006] A low-stress assembly method for an aero-engine load-bearing frame includes:

[0007] Step 1: Place the parts to be processed in an electromagnetic field, connect the positive and negative electrodes to the parts to be processed, turn on the power supply of the electrodes and start the electromagnetic field, and perform electromagnetic coupling treatment on the parts.

[0008] Step 2: Place the connectors to be processed in an electromagnetic field, connect the positive and negative electrodes to the parts to be processed, turn on the power supply of the electrodes and start the electromagnetic field, and perform electromagnetic coupling treatment on the parts.

[0009] Step 3: Place the load-bearing frame in an electromagnetic field, connect the positive and negative electrodes to the load-bearing frame, turn on the power supply of the electrodes and start the electromagnetic field, and perform electromagnetic coupling treatment on the load-bearing frame.

[0010] Step 4: Drill holes in the load-bearing frame processed in Step 3, and connect the load-bearing frame processed in Step 3 with the parts processed in Step 1 through the connectors processed in Step 2 and the drilled hole positions.

[0011] Step 5: Place the connected load-bearing frame and parts in Step 4 in an electromagnetic field, connect the positive and negative electrodes to the load-bearing frame, turn on the power supply of the electrodes and start the electromagnetic field, and perform electromagnetic coupling treatment on the connected load-bearing frame and parts.

[0012] Optionally, Step 1 specifically includes:

[0013] After fixing all the parts to be processed with a fixture, the clamping force of the fixture on the parts is 1.0 KN, and each part is conductively connected through the fixture.

[0014] Place the fixture with the parts fixed in an electromagnetic field. The electromagnetic field generates a pulsed magnetic field. The fixture is connected to the positive and negative electrodes, and pulsed electricity is applied to the parts through the positive and negative electrodes to perform electromagnetic coupling treatment on the parts. The voltage magnitude of the electromagnetic coupling treatment is 4.3 V, the pulsed current frequency is 50 Hz, the pulsed current action time is 20 s, the magnetic field magnitude is 1.5 T, the pulsed magnetic field frequency is 50 Hz, and the pulsed magnetic field action time is 20 s.

[0015] Optionally, Step 2 specifically includes:

[0016] After fixing all the connectors to be processed with a fixture, the clamping force of the fixture on the connectors is 0.1 KN, and each connector is conductively connected through the fixture.

[0017] Place the fixture with the connectors fixed in an electromagnetic field. The electromagnetic field generates a pulsed magnetic field. The fixture is connected to the positive and negative electrodes, and pulsed electricity is applied to the connectors through the positive and negative electrodes to perform electromagnetic coupling treatment on the connectors. The voltage magnitude of the electromagnetic coupling treatment is 0.5 V, the pulsed current frequency is 50 Hz, the pulsed current action time is 20 s, the magnetic field magnitude is 0.5 T, the pulsed magnetic field frequency is 50 Hz, and the pulsed magnetic field action time is 20 s.

[0018] Optionally, step 3 specifically includes:

[0019] After fixing the load-bearing frame with a fixture, the clamping force of the fixture on the load-bearing frame is 0.5 KN;

[0020] Place the fixture with the receiving part fixed in an electromagnetic field. The electromagnetic field generates a pulsed magnetic field. The fixture is connected to positive and negative electrodes. Pulse electricity is applied to the load-bearing frame through the positive and negative electrodes to perform electromagnetic coupling treatment on the load-bearing frame. The voltage magnitude of the electromagnetic coupling treatment is 2.2 V, the pulsed current frequency is 50 Hz, the pulsed current action time is 20 s, the magnetic field magnitude is 1 T, the pulsed magnetic field frequency is 50 Hz, and the pulsed magnetic field action time is 20 s.

[0021] Optionally, step 4 specifically includes:

[0022] Place the load-bearing frame on the tooling and press the load-bearing frame tightly on the tooling through a compactor;

[0023] Determine the relative positional relationship between the combination of the load-bearing frame and the tooling and the robot, and then use TopSolid offline programming software to perform machining layout on the machining points to determine the machining path;

[0024] Call the AGV through the central control system to transport the load-bearing frame assembly and the tooling to the automatic hole-making station, confirm and execute the reference hole machining program through the central control system, and perform automatic hole-making machining;

[0025] After completing the automatic hole-making machining task of the load-bearing frame, call the AGV through the central control system to transport the load-bearing frame and the tooling to the manual assembly station for manual supplementary riveting connection, and install the components on the load-bearing frame through the connecting parts and the drilled hole positions.

[0026] Optionally, step 5 specifically includes:

[0027] After fixing the load-bearing frame with assembled components with a fixture, the clamping force of the fixture on the load-bearing frame is 0.8 KN, and the assembled components, connecting parts, and load-bearing frame form an electrically conductive connection;

[0028] Place the fixture with the receiving part fixed in an electromagnetic field. The electromagnetic field generates a pulsed magnetic field. The fixture is connected to positive and negative electrodes. Pulse electricity is applied to the load-bearing frame with assembled components through the positive and negative electrodes to perform electromagnetic coupling treatment on the load-bearing frame with assembled components. The voltage magnitude of the electromagnetic coupling treatment is 3 V, the pulsed current frequency is 50 Hz, the pulsed current action time is 20 s, the magnetic field magnitude is 0.9 T, the pulsed magnetic field frequency is 50 Hz, and the pulsed magnetic field action time is 20 s.

[0029] In summary, the present application includes the following beneficial technical effects:

[0030] In view of the defects existing in the current cold-hot assembly and hydraulic assembly processes, the present invention innovatively proposes a process method for low-stress assembly of an aero-engine load-bearing frame assisted by an electromagnetic coupling energy field. The electromagnetic coupling treatment technology couples an electric field and a magnetic field, and through electromagnetic force, regulates the stress states of various components before and after assembly. A part of the pulsed current is directly applied to the workpiece to be processed, and the other part generates a pulsed magnetic field through an excitation coil to act on the components. The electromagnetic coupling treatment technology has a short time and quick effect for regulating residual stress. The entire treatment process only takes 2-4 minutes; magnetic coupling treatment will not cause obvious thermal effects. The temperature of the components before and after electromagnetic coupling treatment is almost unchanged, there will be no temperature gradient inside the components, no new stress will be introduced, electromagnetic coupling treatment will not cause changes in the shape and structure of the components, will not change the original mating relationship and reduce the assembly accuracy, and the electromagnetic coupling treatment has a low cost. No other raw materials are consumed during the treatment process, reducing the economic cost of the aero-engine load-bearing frame assembly link.

[0031] The electromagnetic coupling treatment equipment is easy to operate and has low requirements for the working environment. Only need to use a special fixture to fix the components and connectors to be processed in the working chamber, connect them to the electrodes, and input the electromagnetic coupling treatment parameters to start the treatment. The treatment process is automatic without any other steps. Just take out the parts after the treatment is completed.

[0032] Electric energy is used throughout the process, which is green and pollution-free. For components with complex shapes and large sizes, the electromagnetic coupling local treatment method can be used to regulate residual stress, so it is not limited by the shape and size of the components. Compared with the overall treatment of the cold-hot assembly process, the electromagnetic coupling treatment technology has a higher energy utilization rate. The electromagnetic coupling treatment technology can reduce the time cost and economic cost of the aero-engine load-bearing frame assembly and improve the assembly quality of the parts. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0034] Figure 1 It is a schematic flow chart of the method for low-stress assembly of an aero-engine load-bearing frame. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0035] The embodiments of the present application will be described in detail below with reference to the drawings.

[0036] The following describes the implementation manners of the present application through specific specific examples. Those skilled in the art can easily understand other advantages and effects of the present application from the content disclosed in this specification. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. The present application can also be implemented or applied through other different specific implementation manners. Various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present application. It should be noted that, without conflict, the following embodiments and the features in the embodiments can be combined with each other. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope protected by the present application.

[0037] It should be noted that the following describes various aspects of the embodiments within the scope of the appended claims. It should be obvious that the aspects described herein can be embodied in a wide variety of forms, and any specific structure and / or function described herein is illustrative only. Based on the present application, those skilled in the art should understand that one aspect described herein can be implemented independently of any other aspect, and two or more of these aspects can be combined in various ways. For example, any number of aspects described herein can be used to implement the device and / or practice the method. In addition, this device can be implemented and this method can be practiced using other structures and / or functions in addition to one or more of the aspects described herein.

[0038] It should also be noted that the drawings provided in the following embodiments only illustrate the basic concept of the present application in a schematic manner. The drawings only show the components related to the present application, rather than being drawn according to the number, shape and size of the components in actual implementation. The type, quantity and proportion of each component in its actual implementation can be an arbitrary change, and the component layout type may also be more complex.

[0039] In addition, in the following description, specific details are provided to facilitate a thorough understanding of the examples. However, those skilled in the art will understand that the described aspects can be practiced without these specific details.

[0040] The embodiment of the present application provides a low-stress assembly method for an aero-engine load-bearing frame.

[0041] As Figure 1 shown, a low-stress assembly method for an aero-engine load-bearing frame includes:

[0042] Step 1, place the parts to be processed in an electromagnetic field, connect the positive and negative electrodes of the parts to be processed, turn on the power supply of the electrodes and start the electromagnetic field, and perform electromagnetic coupling processing on the parts.

[0043] Step 2: Place the connector to be processed in the electromagnetic field, connect the positive and negative electrodes to the components to be processed, turn on the power supply of the electrodes and activate the electromagnetic field, and perform electromagnetic coupling processing on the components.

[0044] Step 3: Place the load-bearing frame in the electromagnetic field, connect the positive and negative electrodes to the load-bearing frame, turn on the power supply of the electrodes and activate the electromagnetic field, and perform electromagnetic coupling processing on the load-bearing frame.

[0045] Step 4: Drill holes in the load-bearing frame processed in Step 3, and connect the load-bearing frame processed in Step 3 with the components processed in Step 1 through the connector processed in Step 2 and the drilled hole positions.

[0046] Step 5: Place the load-bearing frame and the components connected in Step 4 in the electromagnetic field, connect the positive and negative electrodes to the load-bearing frame, turn on the power supply of the electrodes and activate the electromagnetic field, and perform electromagnetic coupling processing on the connected load-bearing frame and components.

[0047] In the embodiment of the present application, the electromagnetic field is provided by the working cavity composed of the excitation coil.

[0048] Step 1 specifically includes: After fixing all the components to be processed with a fixture, the clamping force of the fixture on the components is 1.0 KN, and each component is conductively connected through the fixture; Place the fixture with the components fixed in the electromagnetic field, the electromagnetic field generates a pulsed magnetic field, the fixture is connected to the positive and negative electrodes, and pulsed electricity is applied to the components through the positive and negative electrodes to perform electromagnetic coupling processing on the components. The voltage magnitude of the electromagnetic coupling processing is 4.3 V, the pulsed current frequency is 50 Hz, the pulsed current action time is 20 s, the magnetic field magnitude is 1.5 T, the pulsed magnetic field frequency is 50 Hz, and the pulsed magnetic field action time is 20 s.

[0049] Step 2 specifically includes: After fixing all the connectors to be processed with a fixture, the clamping force of the fixture on the connectors is 0.1 KN, and each connector is conductively connected through the fixture;

[0050] Place the fixture with the connectors fixed in the electromagnetic field, the electromagnetic field generates a pulsed magnetic field, the fixture is connected to the positive and negative electrodes, and pulsed electricity is applied to the connectors through the positive and negative electrodes to perform electromagnetic coupling processing on the connectors. The voltage magnitude of the electromagnetic coupling processing is 0.5 V, the pulsed current frequency is 50 Hz, the pulsed current action time is 20 s, the magnetic field magnitude is 0.5 T, the pulsed magnetic field frequency is 50 Hz, and the pulsed magnetic field action time is 20 s.

[0051] Step 3 specifically includes: after the load-bearing frame is fixed by a clamp, the clamping force of the clamp on the load-bearing frame is 0.5KN; the clamp with the receiving part is placed in an electromagnetic field, the electromagnetic field generates a pulsed magnetic field, the clamp is connected to positive and negative electrodes, pulse electricity is applied to the load-bearing frame through the positive and negative electrodes, and the load-bearing frame is electromagnetically coupled. The voltage of the electromagnetic coupling treatment is 2.2V, the pulse current frequency is 50Hz, the pulse current action time is 20s, the magnetic field size is 1T, the pulse magnetic field frequency is 50Hz, and the pulse magnetic field action time is 20s.

[0052] The step 4 specifically includes: placing the load-bearing frame on the tooling, and pressing the load-bearing frame on the tooling by a clamp; determining the relative position relationship between the combination of the load-bearing frame and the tooling and the robot, and then using the Toppu offline programming software to perform processing layout on the processing points and determine the processing path;

[0053] Check and confirm the equipment status, product status and tooling status, check and confirm the required materials and tools such as cutting tools, fasteners, rivet heads, and probes; call the AGV through the central control system to transport the load-bearing frame components and tooling to the automatic hole-making station; confirm and execute the reference hole processing program through the central control system to perform automatic hole-making processing;

[0054] After completing the automatic hole-making task of the load-bearing frame, the central control system calls the AGV to transport the load-bearing frame and tooling to the manual assembly station for manual riveting connections, and the components are installed on the load-bearing frame through the connectors and drilled holes.

[0055] The step 5 specifically includes: fixing the load-bearing frame assembled with parts by a clamp, the clamping force of the clamp on the load-bearing frame is 0.8KN, and the assembled parts, connectors and load-bearing frame form a conductive connection; placing the clamp fixed with the receiving parts in an electromagnetic field, the electromagnetic field generates a pulsed magnetic field, the clamp is connected to positive and negative electrodes, pulse electricity is applied to the load-bearing frame assembled with parts through the positive and negative electrodes, and electromagnetic coupling treatment is performed on the load-bearing frame assembled with parts, the voltage of the electromagnetic coupling treatment is 3V, the pulse current frequency is 50Hz, the pulse current action time is 20s, the magnetic field size is 0.9T, the pulse magnetic field frequency is 50Hz, and the pulse magnetic field action time is 20s.

[0056] Finally, the tooling is removed, the load-bearing frame components are manually taken down and placed in the parts storage area.

[0057] Assembly stress was measured on the assembly that had undergone electromagnetic coupling treatment and the assembly that had been removed from the electromagnetic coupling treatment. The results showed that the stress peak in the joint area of ​​the assembly that had undergone electromagnetic coupling treatment was reduced by 16.7MPa, the assembly stress dispersion was reduced by 11.3%, and the stress distribution was more uniform.

[0058] In the embodiments of the present application, in step 1, before performing electromagnetic coupling treatment on components, the components can be classified first to distinguish the components that need to be treated and those that do not need to be treated, and then the components that need to be treated are clamped and subjected to electromagnetic coupling treatment.

[0059] As described above, the above are only specific embodiments of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed by the present application should be covered within the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A low-stress assembly method for an aero-engine load-bearing frame, characterized in that Including: Step 1: Place the parts to be processed in an electromagnetic field, connect the positive and negative electrodes to the parts to be processed, turn on the power supply of the electrodes and start the electromagnetic field, and perform electromagnetic coupling processing on the parts; Step 2: Place the connectors to be processed in an electromagnetic field, connect the positive and negative electrodes to the parts to be processed, turn on the power supply of the electrodes and start the electromagnetic field, and perform electromagnetic coupling processing on the parts; Step 3: Place the load-bearing frame in an electromagnetic field, connect the positive and negative electrodes to the load-bearing frame, turn on the power supply of the electrodes and start the electromagnetic field, and perform electromagnetic coupling processing on the load-bearing frame; Step 4: Drill holes in the load-bearing frame processed in Step 3, and connect the load-bearing frame processed in Step 3 with the parts processed in Step 1 through the connectors processed in Step 2 and the drilled hole positions; Step 5: Place the connected load-bearing frame and parts in Step 4 in an electromagnetic field, connect the positive and negative electrodes to the load-bearing frame, turn on the power supply of the electrodes and start the electromagnetic field, and perform electromagnetic coupling processing on the connected load-bearing frame and parts.

2. The low-stress assembly method of the load-bearing frame of an aero-engine according to claim 1, characterized in that, Step 1 specifically includes: After fixing all the parts to be processed with a fixture, the clamping force of the fixture on the parts is 1.0 KN, and each part is conductively connected through the fixture; Place the fixture with the parts fixed in an electromagnetic field. The electromagnetic field generates a pulsed magnetic field. The fixture is connected to the positive and negative electrodes. Pulse electricity is applied to the parts through the positive and negative electrodes to perform electromagnetic coupling processing on the parts. The voltage magnitude of the electromagnetic coupling processing is 4.3 V, the pulse current frequency is 50 Hz, the pulse current action time is 20 s, the magnetic field magnitude is 1.5 T, the pulsed magnetic field frequency is 50 Hz, and the pulsed magnetic field action time is 20 s.

3. The low-stress assembly method of the load-bearing frame of an aero-engine according to claim 1, wherein Step 2 specifically includes: After fixing all the connectors to be processed with a fixture, the clamping force of the fixture on the connectors is 0.1 KN, and each connector is conductively connected through the fixture; Place the fixture with the connectors fixed in an electromagnetic field. The electromagnetic field generates a pulsed magnetic field. The fixture is connected to the positive and negative electrodes. Pulse electricity is applied to the connectors through the positive and negative electrodes to perform electromagnetic coupling processing on the connectors. The voltage magnitude of the electromagnetic coupling processing is 0.5 V, the pulse current frequency is 50 Hz, the pulse current action time is 20 s, the magnetic field magnitude is 0.5 T, the pulsed magnetic field frequency is 50 Hz, and the pulsed magnetic field action time is 20 s.

4. The low-stress assembly method of the load-bearing frame of an aero-engine according to claim 1, characterized in that, Step 3 specifically includes: After fixing the load-bearing frame with a fixture, the clamping force of the fixture on the load-bearing frame is 0.5 KN; Place the fixture with the load-bearing member fixed in an electromagnetic field. The electromagnetic field generates a pulsed magnetic field. The fixture is connected to the positive and negative electrodes. Pulse electricity is applied to the load-bearing frame through the positive and negative electrodes to perform electromagnetic coupling processing on the load-bearing frame. The voltage magnitude of the electromagnetic coupling processing is 2.2 V, the pulse current frequency is 50 Hz, the pulse current action time is 20 s, the magnetic field magnitude is 1 T, the pulsed magnetic field frequency is 50 Hz, and the pulsed magnetic field action time is 20 s.

5. The low-stress assembly method of the load-bearing frame of an aero-engine according to claim 1, characterized in that, Step 4 specifically includes: Place the load-bearing frame on the tooling, and press the load-bearing frame tightly on the tooling through a presser; Determine the relative positional relationship between the combination of the load-bearing frame and the tooling and the robot, and then use TopSolid offline programming software to perform machining layout on the machining points and determine the machining path. The central control system calls the AGV to transport the load-bearing frame components and tooling to the automatic hole-making station, and the central control system confirms and executes the reference hole processing program to perform automatic hole-making processing; After completing the automatic hole-making task of the load-bearing frame, the central control system calls the AGV to transport the load-bearing frame and tooling to the manual assembly station for manual riveting connections, and the components are installed on the load-bearing frame through the connectors and drilled holes.

6. The low-stress assembly method of the load-bearing frame of an aero-engine according to claim 1, characterized in that, The step 5 specifically includes: After the bearing frame with the assembled parts is fixed by the clamp, the clamping force of the clamp on the bearing frame is 0.8KN, and the assembled parts, connectors and bearing frame form a conductive connection; The clamp with the receiving parts fixed is placed in an electromagnetic field, which generates a pulsed magnetic field. The clamp is connected to positive and negative electrodes, and pulse electricity is applied to the load-bearing frame assembled with parts through the positive and negative electrodes. The load-bearing frame assembled with parts is subjected to electromagnetic coupling treatment. The voltage of the electromagnetic coupling treatment is 3V, the pulse current frequency is 50Hz, the pulse current action time is 20s, the magnetic field size is 0.9T, the pulse magnetic field frequency is 50Hz, and the pulse magnetic field action time is 20s.

Images