Thick-wall metal pipe fitting electromagnetic flanging method and device based on polygon prism coil

Abstract

The invention belongs to the field of metal forming and manufacturing, and relates to a thick-wall metal pipe fitting electromagnetic flanging method and device based on a polygon prism coil, and the method comprises the steps: generating a higher-density induction eddy current at a pipe wall part, close to a corner angle of the polygon prism coil, of a pipe fitting by utilizing the corner angle, protruding towards the pipe fitting, of the polygon prism coil; the radial electromagnetic force and the circumferential shear stress of the pipe wall flanging area are increased, the pipe fitting flanging angle is increased, and the pipe fitting flanging forming effect is improved. According to the method, the flanging forming effect of the pipe fitting is remarkably improved, and the method is suitable for flanging machining of the thick-wall metal pipe fitting; by adjusting the parameters of the polygon prism coil, pipe fittings of different specifications and materials can be flexibly adapted, and the accurate forming effect is achieved; the flanging device is low in cost, easy to manufacture and operate and convenient to maintain and replace.

Description

Technical Field

[0001] The invention belongs to the field of metal forming and manufacturing, and in particular relates to a method and a device for electromagnetic flanging of thick-walled metal pipes based on a polygonal prism coil. Background Art

[0002] In recent years, with the rapid development of the economy, key equipment parts in related industries have been moving towards lightweight and high performance. As a key strategy for energy conservation, emission reduction and environmental protection, lightweighting has shown significant advantages, including improving energy efficiency, reducing pollution emissions and enhancing corrosion resistance. These advantages have made it widely used in many industrial fields. In this context, electromagnetic forming, as a high-rate pulse forming technology, has been widely used in the metal manufacturing industry.

[0003] Existing electromagnetic forming methods are mainly used for processing and forming lightweight thin-walled metal workpieces, while the demand for lightweight thick-walled metal in the fields of aerospace, automobile, and shipbuilding has greatly increased. Using the traditional coil electromagnetic flanging method to generate a greater electromagnetic force to achieve the processing of thick-walled metal pipes requires a significant increase in the discharge voltage of the driving coil used to generate the electromagnetic field to increase the forming electromagnetic force, which not only increases safety hazards, but also significantly reduces energy utilization.

[0004] The Chinese patent "A device for increasing electromagnetic force in electromagnetic forming" with publication number CN209465519U uses two sets of capacitor power supplies and a set of delay switches for timing coordination, which can continuously increase the electromagnetic force applied by the drive coil, and the workpiece forming effect is improved. Although this patent increases the forming electromagnetic force, it is only applicable to thin-walled metal pipes, and the maximum electromagnetic force applied at a single time is difficult to reach the yield strength of thick-walled metal pipes. Summary of the invention

[0005] The technical problem of the present invention is that the prior art lacks a flanging processing method for thick-walled metal pipes.

[0006] The purpose of the present invention is to address the above-mentioned problems and to provide a method for electromagnetic flanging of thick-walled metal pipes based on a polygonal coil, by utilizing the protruding edges of the polygonal coil toward the pipe to generate induced eddy currents of greater density in the pipe wall portion close to the edges of the polygonal coil, thereby increasing the radial electromagnetic force and annular shear stress in the flanging area of ​​the pipe wall, increasing the flanging angle of the pipe, and improving the flanging forming effect of the pipe.

[0007] In order to achieve the above object, the technical solution provided by the present invention is: The electromagnetic flanging method for thick-walled metal pipes based on a polygonal coil comprises the following steps: Step 1: Determine the parameters of the polygonal coil according to the material and forming specifications of the pipe to be formed; Step 2: According to the parameters of the polygonal coil, a regular polygonal coil reinforcement layer is made, and the wire is wound on the coil reinforcement layer to make a polygonal coil; Step 3: Use a mold to fix the pipe to be formed, and arrange and fix the polygonal column coil inside the forming area of ​​the pipe to be formed; Step 4: Connect the polygonal coil to the pulse power supply via a switch, control the air switch to power the polygonal coil, control the discharge time of the pulse power supply, and perform electromagnetic flanging on the bulging tube to be formed; Step 5: Determine whether the pipe fitting meets the forming specifications. If it does, the process ends. If it does not, execute step 4 to flanging the pipe fitting again until the flanging of the pipe fitting meets the forming specifications.

[0008] Preferably, in step 1, the parameters of the polygonal coil include the cross-sectional shape of the polygonal coil and the size, number of turns and parameters of a single-turn coil of the polygonal coil.

[0009] Preferably, in step 1, finite element software is used to construct a pipe electromagnetic flanging simulation model including a polygonal prism coil and a pipe, a pulse current is applied to the polygonal prism coil of the pipe electromagnetic flanging simulation model, the flanging effect of the pipe is simulated, the parameters of the polygonal prism coil are adjusted so that the pipe flanging effect meets the forming specification requirements, and the parameters of the polygonal prism coil are determined by simulation.

[0010] Preferably, the distance between the corner lines of the polygonal prism coil and the pipe to be formed is no more than 2 mm.

[0011] Preferably, in step 4, the discharge pulse width of the pulse power supply is 50-800 μs.

[0012] The flanging device of the electromagnetic flanging method for thick-walled metal pipes based on the polygonal coil comprises a polygonal coil, a pulse power supply and a mold for fixing the pipe. The polygonal coil is electrically connected to the pulse power supply via a switch, and the cross-section of the polygonal coil is a regular polygon.

[0013] Compared with the prior art, the beneficial effects of the present invention include: 1) The present invention uses a polygonal coil with a regular polygonal cross section to generate a higher density of induced eddy currents at the pipe wall near the corners of the coil. This design increases the radial electromagnetic force and annular shear stress in the flanging area of ​​the pipe wall, thereby increasing the flanging angle of the pipe and significantly improving the flanging forming effect of the pipe, and is suitable for flanging processing of thick-walled metal pipes.

[0014] 2) The present invention determines the parameters of the polygonal coil according to the material and forming specifications of the pipe to be formed, ensuring the accuracy and controllability of the flanging process. By adjusting the parameters of the coil, it can flexibly adapt to pipes of different specifications and materials to achieve precise forming effects.

[0015] 3) The present invention winds the conductive wire of the polygonal coil on a coil reinforcement layer, and arranges the coil reinforcement layer between the inner and outer coils. This structure not only improves the stability of the coil, but also enhances its durability, so that the polygonal coil can maintain stable performance during long-term use.

[0016] 4) The pipe flanging device of the present invention has low cost, is easy to manufacture and operate, and is convenient to maintain and replace. It is economical and more energy-saving and environmentally friendly than traditional mechanical or hydraulic flanging processing devices. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0018] Figure 1 It is a schematic diagram of the process of electromagnetic flanging method for thick-walled metal pipes based on polygonal coils.

[0019] Figure 2 FIG. 4 is an equivalent circuit diagram of a power supply circuit of a polygonal coil according to an embodiment of the present invention.

[0020] Figure 3 Schematic diagram of the electromagnetic flanging device for pipes of Example 1.

[0021] Figure 4 Schematic diagram of the cross section of the pentagonal prism coil in the first embodiment.

[0022] Figure 5 Schematic diagram of the electromagnetic flanging device for pipes according to the second embodiment.

[0023] Figure 6 It is a schematic cross-sectional view of the hexagonal prism coil in the second embodiment.

[0024] Figure 7 Schematic diagram of the electromagnetic flanging device for pipes of the third embodiment.

[0025] Figure 8 Schematic diagram of the cross section of the octagonal prism coil in the third embodiment.

[0026] Fig. 9 It is a comparison diagram of the forming effects of the method of the present invention and the traditional coil tube flanging method.

[0027] Explanation of the reference numerals: mold 1 , pipe to be formed 2 , pentagonal prism coil 3 , hexagonal prism coil 4 , octagonal prism coil 5 , coil reinforcement layer 6 , coil conductor 7 . DETAILED DESCRIPTION

[0028] Embodiment 1 like Figure 3As shown, the pipe flanging device of the first embodiment includes a mold 1, a pipe 2 to be formed, a pentagonal coil 3 and a pulse power supply. The pipe 2 of the embodiment is a thick-walled metal pipe. The cross section of the pentagonal coil is a regular pentagon, as shown in FIG. Figure 4 In the embodiment, the distance between the pipe 2 to be formed and the corners of the pentagonal prism coil is less than 2 mm. The pentagonal prism coil 3 is connected to the pulse power supply through an air switch. The equivalent circuit of the pentagonal prism coil 3 is as follows: Figure 2 shown.

[0029] like Figure 1 As shown, the electromagnetic flanging method for thick-walled metal pipes based on a polygonal coil comprises the following steps: Step 1: Determine the size, number of turns and number of layers of the pentagonal prism coil 3 and the parameters of the coil conductor 7 according to the material, wall thickness and forming specifications of the pipe to be formed; In the embodiment, the finite element software COMSOL Multiphysics is used to construct a pipe electromagnetic flanging simulation model including a pentagonal prism coil and a thick-walled metal pipe, a pulse current is applied to the pentagonal prism coil of the pipe electromagnetic flanging simulation model, the flanging effect of the pipe is simulated, the parameters of the pentagonal prism coil are adjusted so that the flanging effect of the pipe meets the forming specifications, and the parameters of the pentagonal prism coil are determined by simulation.

[0030] Step 2: According to the coil parameters obtained in step 1, the wire is wound on the coil reinforcement layer 6 to make a pentagonal prism coil; Step 3: Use a mold to fix the pipe to be formed, and arrange a pentagonal prism coil inside the forming area of ​​the pipe to be formed, and the pentagonal prism coil is placed coaxially with the pipe; Step 4: Connect the pentagonal coil to the pulse power supply via a switch, control the air switch to power the pentagonal coil, control the discharge time of the pulse power supply, and perform electromagnetic flanging on the bulging tube; Step 5: Determine whether the pipe fitting meets the forming specifications. If it does, the process ends. If it does not, execute step 4 to flanging the pipe fitting again until the flanging of the pipe fitting meets the forming specifications.

[0031] In the embodiment, the coil reinforcement layer 6 is made of Chailong material.

[0032] Embodiment 2 The pipe flanging device of the second embodiment is as follows Figure 5 As shown, it includes a mold 1, a pipe to be formed 2, a hexagonal coil 4 and a pulse power supply. The cross section of the hexagonal coil is a regular hexagon, as shown in FIG. Figure 6 As shown, the distances between the pipe 2 to be formed and the six corners of the hexagonal prism coil are all less than 2 mm. The hexagonal prism coil 4 is connected to the pulse power supply through an air switch.

[0033] The electromagnetic flanging method for thick-walled metal pipes based on a polygonal coil comprises the following steps: Step 1: Determine the size, number of turns and number of layers of the hexagonal prism coil 4 and the parameters of the coil conductor 7 according to the material, wall thickness and forming specifications of the pipe to be formed; In the embodiment, the finite element software COMSOL Multiphysics is used to construct a pipe electromagnetic flanging simulation model including a hexagonal coil and a thick-walled metal pipe, a pulse current is applied to the hexagonal coil of the pipe electromagnetic flanging simulation model, the flanging effect of the pipe is simulated, the parameters of the hexagonal coil are adjusted so that the flanging effect of the pipe meets the forming specifications, and the parameters of the hexagonal coil are determined by simulation.

[0034] Step 2: According to the coil parameters obtained in step 1, the wire is wound on the coil reinforcement layer 6 to make a hexagonal prism coil; Step 3: Use a mold to fix the pipe to be formed, and arrange a hexagonal prism coil inside the forming area of ​​the pipe to be formed, and the hexagonal prism coil is placed coaxially with the pipe; Step 4: Connect the hexagonal coil to the pulse power supply through the switch, control the air switch to power the hexagonal coil, control the discharge time of the pulse power supply, and perform electromagnetic flanging on the bulging tube; Step 5: Determine whether the pipe fitting meets the forming specifications. If it does, the process ends. If it does not, execute step 4 to flanging the pipe fitting again until the flanging of the pipe fitting meets the forming specifications.

[0035] The implementation results show that the method of the present invention can generate greater radial electromagnetic force and annular shear stress under the same discharge energy compared with the traditional coil electromagnetic flanging method, so that the flanging of thick-walled metal pipes is more complete and the energy utilization rate is high.

[0036] Embodiment 3 The pipe flanging device of the third embodiment is as follows Figure 7 As shown, it includes a mold 1, a tube 2 to be formed and an octagonal prism coil 5. The cross section of the octagonal prism coil is a regular octagon. Figure 8 As shown. The distance between the tube 2 to be formed and the eight corners of the octagonal prism coil is less than 2 mm. The octagonal prism coil 5 is connected to the pulse power supply through an air switch. The pulse power supply in the embodiment is a capacitor power supply, and the discharge pulse width of the pulse power supply is 800 μs.

[0037] The electromagnetic flanging method for thick-walled metal pipes based on a polygonal coil comprises the following steps: Step 1: Determine the size, number of turns and number of layers of the octagonal prism coil 5 and the parameters of the coil wire 7 according to the material, wall thickness and forming specifications of the pipe to be formed; In the embodiment, the finite element software COMSOL Multiphysics is used to construct a pipe electromagnetic flanging simulation model including an octagonal prism coil and a thick-walled metal pipe, a pulse current is applied to the octagonal prism coil of the pipe electromagnetic flanging simulation model, the flanging effect of the pipe is simulated, the parameters of the octagonal prism coil are adjusted so that the flanging effect of the pipe meets the forming specifications, and the parameters of the octagonal prism coil are determined by simulation.

[0038] Step 2: According to the coil parameters obtained in step 1, the wire is wound on the coil reinforcement layer 6 to make an octagonal prism coil; Step 3: Use a mold to fix the pipe to be formed, and arrange an octagonal prism coil inside the forming area of ​​the pipe to be formed, and the octagonal prism coil is placed coaxially with the pipe; Step 4: Connect the octagonal prism coil to the pulse power supply through the switch, control the air switch to power the octagonal prism coil, control the discharge time of the pulse power supply, and perform electromagnetic flanging on the bulging tube to be formed; Step 5: Determine whether the pipe fitting meets the forming specifications. If it does, the process ends. If it does not, execute step 4 to flanging the pipe fitting again until the flanging of the pipe fitting meets the forming specifications.

[0039] In the embodiment, the forming effect of the method of the present invention is compared with the forming effect of the electromagnetic flanging method of the pipe based on the traditional solenoid coil. Fig. 9 shown. Fig. 9 The upper part shows the flanging effect of thick-walled metal pipes using the traditional solenoid coil electromagnetic flanging method. Fig. 9 The lower part shows the flanging effect of the electromagnetic flanging method for thick-walled metal pipes based on the octagonal prism coil, i.e., the method of the present invention. Fig. 9 It can be seen that, under the same discharge energy, the method of the present invention increases the flanging angle of the thick-walled metal pipe.

Claims

1. A method for electromagnetic flanging of thick-walled metal pipes based on a polygonal coil, characterized in that: The cross section of the polygonal coil is a regular polygon. The edges and corners of the polygonal coil protruding toward the pipe fitting are utilized to generate an induced eddy current with a greater density at the pipe wall portion of the pipe fitting close to the edges and corners of the polygonal coil, thereby increasing the radial electromagnetic force and the annular shear stress in the flanging area of ​​the pipe wall, increasing the flanging angle of the pipe fitting, and improving the flanging forming effect of the pipe fitting. The electromagnetic flanging method for pipe fittings comprises the following steps: Step 1: Determine the parameters of the polygonal coil according to the material and forming specifications of the pipe to be formed; Step 2: According to the parameters of the polygonal coil, a regular polygonal coil reinforcement layer is made, and the wire is wound on the coil reinforcement layer to make a polygonal coil; Step 3: Use a mold to fix the pipe to be formed, and arrange and fix the polygonal column coil inside the forming area of ​​the pipe to be formed; Step 4: Connect the polygonal coil to the pulse power supply via a switch, control the air switch to power the polygonal coil, control the discharge time of the pulse power supply, and perform electromagnetic flanging on the bulging tube to be formed; Step 5: Determine whether the pipe fitting meets the forming specifications. If it does, the process ends. If it does not, execute step 4 to flanging the pipe fitting again until the flanging of the pipe fitting meets the forming specifications.

2. The electromagnetic flanging method for thick-walled metal pipes based on a polygonal coil according to claim 1, characterized in that: In step 1, the parameters of the polygonal coil include the cross-sectional shape of the polygonal coil, the size of the polygonal coil, the number of turns, and the parameters of a single-turn coil.

3. The electromagnetic flanging method for thick-walled metal pipes based on a polygonal coil according to claim 2, characterized in that: In step 1, finite element software is used to construct a pipe electromagnetic flanging simulation model including a polygonal coil and a pipe, a pulse current is applied to the polygonal coil of the pipe electromagnetic flanging simulation model, the flanging effect of the pipe is simulated, the parameters of the polygonal coil are adjusted so that the flanging effect of the pipe meets the forming specifications, and the parameters of the polygonal coil are determined by simulation.

4. The method for electromagnetic flanging of thick-walled metal pipes based on a polygonal coil according to claim 1, characterized in that: The distance between the corner line of the polygonal coil and the pipe to be formed is not greater than 2 mm.

5. The method for electromagnetic flanging of thick-walled metal pipes based on a polygonal coil according to claim 1, characterized in that: In step 4, the discharge pulse width of the pulse power supply is 50-800 μs.

6. The electromagnetic flanging method for thick-walled metal pipes based on a polygonal coil according to claim 1, characterized in that: The multi-prism coil is a pentagonal prism coil, a hexagonal prism coil or an octagonal prism coil.

7. The flanging device of the electromagnetic flanging method for thick-walled metal pipes based on a polygonal coil as claimed in any one of claims 1 to 6, characterized in that: The flanging device includes a polygonal coil, a pulse power supply and a mold for fixing the pipe fitting. The polygonal coil is electrically connected to the pulse power supply via a switch, and the cross section of the polygonal coil is a regular polygon.

Images