Manufacturing method suitable for electromagnetic shape correction coil of anti-shaking plate of thin-wall part

Abstract

The manufacturing method comprises the following steps: pre-treating an annealed red copper bar to be provided with a linear section and a bent section, designing a core mold according to the size of a reinforcing rib of the anti-shaking plate, winding the core mold in cooperation with an insulating film to form a wire, and applying epoxy glue; and after clamping and glue filling, embedding into an epoxy plate processed with a matching groove and a reinforcing rib accommodating space, and heating, curing and forming. According to the method, the geometrical shape of the coil is highly matched with the height of the reinforcing rib of the anti-shaking plate, the good insulation performance and structural strength are achieved, and the accuracy and consistency of electromagnetic shape correction of the anti-shaking plate are improved.

Description

Technical Field

[0001] This invention belongs to the field of electromagnetic forming and straightening technology, and relates to a method for manufacturing an electromagnetic straightening coil suitable for anti-sway plates of thin-walled parts. Background Technology

[0002] Anti-sloshing baffles have extremely wide applications; almost any container storing liquids that may experience movement needs to be considered. In the aerospace field, the structural requirements for anti-sloshing baffles are extremely high. In rocket propellant tanks, the liquid propellant inside the tank experiences violent sloshing during launch, flight, and trajectory changes. The role of the anti-sloshing baffle is to maintain the stability of the liquid within the tank and reduce the adverse effects of the liquid on the tank structure. Therefore, the flatness accuracy of the anti-sloshing baffle is crucial.

[0003] Electromagnetic forming technology is an emerging high-energy metal plastic forming process. It utilizes the impact of a high-voltage, strong-pulse magnetic field to induce plastic deformation in materials, belonging to the category of high-speed forming technology. Because the electromagnetic force is generated instantaneously, the strain rate of sheet metal can reach 10⁻⁶. 3 The above methods can significantly improve the forming limit of materials, enabling large-deformation plastic forming of aluminum alloys that are difficult to deform at room temperature, while effectively controlling springback and suppressing wrinkling and cracking. Because it directly converts electrical energy into mechanical energy, it eliminates the need for complex force transmission structures, resulting in simple forming equipment and good process flexibility. Based on the advantages of electromagnetic forming technology, such as strong force and process flexibility, it provides a reliable solution to the problem of difficult-to-shape high-strength sheet metal.

[0004] However, to accurately correct a local area of ​​a thin-walled anti-sway plate with reinforcing ribs using electromagnetic correction technology, the geometry of the electromagnetic correction coil needs to be highly matched with the reinforcing ribs and the surrounding area on the anti-sway plate. Otherwise, the area where the electromagnetic force acts will not accurately cover the target area, affecting the correction effect and repeatability.

[0005] Existing coil manufacturing methods mostly involve winding coils in simple geometric shapes (such as circles, rectangles, and straight line segments), making it difficult to precisely adapt them to specific anti-sway plate reinforcing rib structures. Furthermore, the lack of systematic design in terms of coil insulation, mechanical strength, and assembly matching with fixtures and workpieces limits the application of electromagnetic alignment technology in such complex thin-walled parts. Summary of the Invention

[0006] The purpose of this invention is to overcome the problems in the prior art, such as the difficulty in local shaping of thin-walled anti-sway plates with reinforcing ribs, low efficiency and poor accuracy of manual shaping, and the difficulty in matching electromagnetic coils with specific reinforcing rib structures. This invention proposes a method for manufacturing electromagnetic shaping coils suitable for thin-walled anti-sway plates. Through optimized design of steps such as copper busbar pretreatment, insulating film setting, epoxy resin impregnation, and epoxy board slotting and encapsulation, the resulting electromagnetic shaping coils can meet the requirements for local electromagnetic shaping of thin-walled anti-sway plates with reinforcing ribs in terms of geometry, electrical insulation performance, and structural strength, thereby improving shaping accuracy and consistency.

[0007] To achieve the above objectives, the present invention employs the following technical solutions: A method for manufacturing an electromagnetic alignment coil suitable for anti-sway plates of thin-walled parts includes the following steps: S1. Annealing and softening treatment is performed on the copper busbar, and the annealed copper busbar is pre-treated to give the copper busbar a straight section for winding coils and a bent section for clamping. S2. Design the core mold according to the length, width and height of the reinforcing ribs on the anti-sway plate to be corrected, and cut the insulating film according to the size of the copper busbar; S3. Fix the first ends of the copper busbar and the insulating film on the core mold. While rotating the core mold, make the copper busbar and the insulating film wind together to form a coil. During the winding process, apply curable epoxy glue between adjacent copper busbars and between the copper busbar and the insulating film so that the inside of the coil is impregnated and filled with epoxy glue. S4. Clamp and fix the wound coil, and continue to add epoxy glue to its outer surface to reduce the remaining gap inside the coil. S5. A mounting groove matching the shape of the coil is machined on the epoxy board, and a receiving space matching the shape of the anti-sway plate reinforcing rib is reserved inside the mounting groove. S6. Embed the coil into the mounting groove, and fill the gap between the coil and the epoxy board with epoxy material to form an integral encapsulation structure between the coil and the epoxy board; S7. The assembled coil and epoxy board are subjected to heat curing treatment to completely cure the epoxy material, thereby obtaining the electromagnetic correction coil.

[0008] As a preferred method, the annealing and softening treatment includes one of the following methods: heating and softening the surface of the copper busbar by means of flame heating, especially heating it from both ends of the copper busbar until the surface is red-hot; or placing the copper busbar in an atmosphere-protected furnace and heating it to about 500°C and holding it at that temperature to achieve softening.

[0009] As a preferred method, the pretreatment of the copper busbar involves: polishing the surface of the copper busbar to remove oxide scale, straightening the copper busbar, and bending the copper busbar at a predetermined position from one end of the copper busbar at 90° with a rounded corner transition structure at the bend, and cutting a notch at the bend for cooperation with the clamp to achieve clamping and fixing of the starting end of the coil.

[0010] As a preferred embodiment, the insulating film is a polyimide film, which is placed between adjacent copper busbars as an inter-turn insulation layer during winding.

[0011] As a preferred embodiment, the epoxy adhesive is prepared by mixing epoxy curing agent and epoxy resin adhesive in a mass ratio of 1:1, and the epoxy curing agent and epoxy resin adhesive are liquefied by heating and then mixed evenly to obtain a flowable epoxy adhesive.

[0012] As a preferred method, the heat curing treatment is carried out by placing the coil and epoxy board together in a drying oven, with the ambient temperature inside the drying oven being 70℃~90℃ and the heat curing duration being 20h~30h.

[0013] The present invention has the following advantages: By designing the core mold according to the geometric dimensions of the anti-sway plate reinforcing ribs and reserving space for the reinforcing ribs on the epoxy board, the prepared electromagnetic correction coil is geometrically highly matched with the anti-sway plate reinforcing ribs and its surrounding area. This allows the electromagnetic force to be concentrated on the local area that needs correction, improving the targeting and effect of the correction.

[0014] By annealing the copper busbar, winding it on the core mold, and then filling and curing it with epoxy resin, the dimensions of the coil conductor and its encapsulation structure are stabilized and the electromagnetic field distribution is controllable. This avoids random errors caused by differences in operational skill in traditional manual calibration, and improves the accuracy of local calibration of the anti-sway plate and the consistency between batches.

[0015] An insulating film layer is placed between adjacent copper busbars, and then impregnated and cured with epoxy resin to fill the gaps inside the coil, forming a stable electrical insulation system and an overall support structure. The heat curing process eliminates residual liquid epoxy inside, reducing the risk of coil breakdown or damage under high current surges, and significantly improving coil lifespan and safety. Attached Figure Description

[0016] Figure 1 A schematic diagram of the structure of the thin-walled anti-sway plate component to be calibrated; Figure 2 This is a schematic diagram of the core mold structure. Detailed Implementation

[0017] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0018] Example: The target workpiece is a sway guard plate for a rocket propellant storage tank. The plate is made of 5A06 aluminum alloy, 1.5mm thick, with a 30° angle between each reinforcing rib. Each reinforcing rib is approximately 210mm long and 20mm wide. The plate radius is approximately 440mm. The structure of the sway guard plate is as follows: Figure 1 As shown.

[0019] A method for manufacturing an electromagnetic alignment coil suitable for anti-sway plates of thin-walled parts includes the following steps: S1, Annealed and softened copper busbar A copper busbar with dimensions of 4600mm×50mm×2mm was selected as the coil conductor material. The copper busbar was placed in a protective air furnace and heated to about 500℃ and held for a period of time to soften it as a whole. In particular, the area about 350mm from both ends of the copper busbar was fully annealed to facilitate subsequent bending and winding.

[0020] S2, Pretreatment of copper busbar After annealing, the copper busbar is surface-polished to remove the oxide layer and then straightened on a fitter's bench. The copper busbar is then bent 90° at approximately 350mm from one end, with a rounded corner of about 15mm radius at the bend to reduce stress concentration. A notch is cut at the bend location according to clamping requirements to secure the coil's starting end with a fixture.

[0021] S3, Core mold design and insulating film cutting Based on the geometric parameters of the target anti-slip plate's reinforcing ribs, a coil winding mandrel is designed to match the overall shape of the mandrel with the shape of the corresponding reinforcing ribs in the local area of ​​the anti-slip plate. A schematic diagram of the mandrel structure is shown below. Figure 2 As shown. Cut the polyimide film according to the width of the copper busbar, so that its width is comparable to that of the copper busbar and its length is sufficient to wind the required number of turns with the copper busbar. During winding, the polyimide film is placed between adjacent copper busbar turns as an insulating layer.

[0022] S4. Wrap the coil and apply epoxy resin. Weigh the epoxy curing agent and epoxy resin adhesive in a 1:1 mass ratio and place them in a container. Heat the container with a hot air gun to liquefy the two and mix them thoroughly to obtain an epoxy adhesive with moderate fluidity. Fix the first ends of the copper busbar and polyimide film to the mandrel using bow-shaped clamps. Slowly rotate the mandrel or the turntable containing the mandrel, keeping the copper busbar taut while winding. During the winding process, evenly apply epoxy adhesive between the copper busbar and the polyimide film, ensuring that the gaps between adjacent copper busbars and between the copper busbar and the polyimide film are impregnated with epoxy adhesive. After winding to the predetermined number of turns, trim off the excess polyimide film to ensure that the coil cross-sectional shape matches the mandrel.

[0023] S5, Coil clamping and glue repair Keeping the coil still mounted on the core mold or support, use clamps such as bow clamps to clamp the coil at multiple points, minimizing the gaps between adjacent copper busbars. Place the entire coil on a steel plate to maintain a reference plane, and continue applying epoxy resin to the outer surface of the coil until no more air bubbles form. If necessary, use a hot air gun to appropriately heat the coil surface, increasing the fluidity of the epoxy resin and thus more fully filling the gaps inside the coil.

[0024] S6, Epoxy Board Processing After the epoxy adhesive on the coil surface has initially cured, the area to be processed is outlined on two epoxy boards according to the shape of the coil. Then, mounting grooves matching the coil shape and mounting holes for fixing bolts and screws are machined according to design requirements. Inside the mounting grooves, areas of appropriate depth and width are carved out according to the height and width of the anti-sway plate reinforcing ribs to form a space to accommodate the reinforcing ribs, ensuring that the coil can finally mate with the anti-sway plate reinforcing ribs during final assembly.

[0025] S7. Coil embedding and packaging After removing the coil from the mandrel, it is embedded into the pre-fabricated epoxy board mounting slot. Pre-fabricated epoxy blocks or sheets are inserted into areas with larger gaps between the coil and the epoxy board, while epoxy resin is filled into areas with smaller gaps, until there are virtually no gaps between the coil and the epoxy board and no more air bubbles form on the surface. This securely encapsulates the coil within the epoxy board, while providing space on the inner side for the anti-sway reinforcement ribs.

[0026] S8, Heat curing treatment The encapsulated coil and epoxy board assembly are placed in a drying oven and heated at approximately 70°C for about 30 hours to fully cure the epoxy adhesive, ensuring that no liquid epoxy remains inside or on the surface of the coil. After curing, the coil assembly is removed and its appearance and dimensions are inspected. Confirming that the coil structure is intact, without cracks, bulges, or leaks, it is ready for use as an electromagnetic correction coil suitable for local electromagnetic correction of anti-sway boards.

[0027] Practical application verification shows that the electromagnetic alignment coil prepared in this embodiment can effectively fit the local area around the reinforcing rib of the 5A06 aluminum alloy thin-walled anti-sway plate. After electromagnetic alignment, the flatness and local geometric accuracy of the anti-sway plate are significantly improved, avoiding the deviations and surface damage that are easy to occur in traditional mechanical or manual alignment, and significantly improving the consistency of alignment and production efficiency.

[0028] This invention is not limited to the specific embodiments described above. The invention extends to any new feature or combination disclosed in this specification, as well as any new method or process step or combination disclosed herein.

Claims

1. A method for manufacturing an electromagnetic alignment coil suitable for anti-sway plates of thin-walled parts, characterized in that, Includes the following steps: S1. Annealing and softening treatment is performed on the copper busbar, and the annealed copper busbar is pre-treated to give the copper busbar a straight section for winding coils and a bent section for clamping. S2. Design the core mold according to the length, width and height of the reinforcing ribs on the anti-sway plate to be corrected, and cut the insulating film according to the size of the copper busbar; S3. Fix the first ends of the copper busbar and the insulating film on the core mold. While rotating the core mold, make the copper busbar and the insulating film wind together to form a coil. During the winding process, apply curable epoxy glue between adjacent copper busbars and between the copper busbar and the insulating film so that the inside of the coil is impregnated and filled with epoxy glue. S4. Clamp and fix the wound coil, and continue to add epoxy glue to its outer surface to reduce the remaining gap inside the coil. S5. A mounting groove matching the shape of the coil is machined on the epoxy board, and a receiving space matching the shape of the anti-sway plate reinforcing rib is reserved inside the mounting groove. S6. Embed the coil into the mounting groove, and fill the gap between the coil and the epoxy board with epoxy material to form an integral encapsulation structure between the coil and the epoxy board; S7. The assembled coil and epoxy board are subjected to heat curing treatment to completely cure the epoxy material, thereby obtaining the electromagnetic correction coil.

2. The method for manufacturing an electromagnetic alignment coil suitable for anti-sway plates of thin-walled parts according to claim 1, characterized in that, The annealing and softening treatment includes one of the following methods: heating and softening the surface of the copper busbar by flame heating, especially heating it from both ends of the copper busbar until the surface is red-hot; or placing the copper busbar in an atmosphere-protected furnace and heating it to about 500°C and holding it at that temperature to achieve softening.

3. The method for manufacturing an electromagnetic alignment coil suitable for anti-sway plates of thin-walled parts according to claim 1, characterized in that, The pretreatment of the copper busbar involves polishing the surface of the copper busbar to remove oxide scale, straightening the copper busbar, and bending the copper busbar at a predetermined position at one end of the copper busbar at 90° with a rounded corner transition structure. A cut is also made at the bend to cooperate with the fixture, so as to achieve clamping and fixing of the starting end of the coil.

4. The method for manufacturing an electromagnetic alignment coil suitable for anti-sway plates of thin-walled parts according to claim 1, characterized in that, The insulating film is a polyimide film, which is placed between adjacent copper busbars as an inter-turn insulation layer during winding.

5. A method for manufacturing an electromagnetic alignment coil suitable for anti-sway plates of thin-walled parts according to claim 1, characterized in that, The epoxy adhesive is prepared by mixing epoxy curing agent and epoxy resin adhesive in a mass ratio of 1:1, and the epoxy curing agent and epoxy resin adhesive are liquefied by heating and then mixed evenly to obtain a flowable epoxy adhesive.

6. The method for manufacturing an electromagnetic alignment coil suitable for anti-sway plates of thin-walled parts according to claim 1, characterized in that, The heating and curing process is carried out by placing the heating and curing coil and the epoxy board together in a drying oven. The ambient temperature inside the drying oven is 70℃~90℃, and the heating and curing duration is 20h~30h.

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