Combined electromagnetic forming device for power cable

Abstract

The invention relates to the technical field of metal forming and manufacturing, in particular to a combined electromagnetic forming device for a power cable, which comprises a control module, a power supply module and a plurality of magnetic collectors arranged in an array, the power supply module comprises a plurality of pulse power supplies; each magnetic collector is provided with a through circular-truncated-cone-shaped hole; forming coils are uniformly distributed on the periphery of each magnetic collector; each pulse power supply is electrically connected with each forming coil; the control module comprises a parameter acquisition module and a discharge control module; the parameter acquisition module is used for acquiring workpiece parameters of the to-be-machined workpiece; and the discharge control module is used for generating discharge parameters according to the workpiece parameters of the workpiece to be machined and controlling each pulse power supply to discharge according to the generated discharge parameters. By the adoption of the scheme, the working area of single-time machining can be increased, accurate control over the electromagnetic force is achieved by optimizing the discharging parameters of the pulse power source, and therefore the forming quality and precision of the workpiece to be machined are effectively improved.

Description

Technical Field

[0001] The invention relates to the technical field of metal forming and manufacturing, and in particular to a combined electromagnetic forming device for power cables. Background Art

[0002] In modern industrial manufacturing, electromagnetic pulse welding technology is widely used in the connection processing of various metal materials due to its high efficiency and reliability. However, the problem that traditional electromagnetic pulse welding coils are difficult to achieve a longer connection area in a single processing process limits its use in a wider range of application scenarios. For standard cable connectors, such as DT-70 connectors, the connection area can reach 50mm, but traditional electromagnetic pulse welding single processing is difficult to meet the actual connection requirements between connectors and cables. The conventional method is to repeatedly weld the joint to expand its connection area, but this method has significant defects: during repeated welding, most areas can only achieve pressure welding, and the typical metallurgical bonding of electromagnetic pulse welding joints is not achieved.

[0003] The main reasons why electromagnetic pulse welding is difficult to achieve a longer working area in a single process are as follows:

[0004] Energy requirements and insulation limitations: The longer the single processing area is, the longer the area that needs to be deformed is, and the higher the total input energy of the electromagnetic pulse required is. Although the input energy can be increased by increasing the voltage of the energy storage capacitor, the voltage of the energy storage capacitor is subject to many limitations and cannot be increased indefinitely. First, the voltage of the energy storage capacitor cannot exceed the withstand voltage of the discharge switch, otherwise the welding process will be unreliable; secondly, the increase in capacitor voltage will also increase the voltage between coil turns. When the voltage between turns is higher than the insulation strength between turns, the coil will short-circuit. These problems seriously restrict the application of electromagnetic pulse welding in long area connections.

[0005] Inherent process problems: Electromagnetic pulse welding is a process that achieves connection by applying electromagnetic force to the pipe, driving the pipe to deform and collide with the target tube / rod. During the electromagnetic pulse welding process, the electromagnetic force on the surface of the pipe is distributed relatively evenly, and except for the ends of the pipe, which are more easily deformed, the deformation degree of the remaining areas is basically the same. This results in the longer the single processing area, the more areas with similar deformation. The deformation of these areas is similar, causing this part of the pipe to collide with the target tube / rod in a straight shape, and the collision angle is basically 0°. However, electromagnetic pulse welding needs to meet a certain collision angle to achieve connection, so this part of the area is basically unable to achieve effective connection, and can only achieve physical compression.

[0006] In summary, to solve the problem that electromagnetic pulse welding is difficult to achieve a longer working area in a single process, two major challenges need to be overcome: one is the insulation problem caused by increasing energy; the other is the problem that the middle area cannot be connected due to the increase in the processing area. Solving these two problems will help expand the application scope of electromagnetic pulse welding technology and improve its practicality and reliability in industrial production. Summary of the invention

[0007] The present invention provides a combined electromagnetic forming device for power cables, which can increase the working area of ​​a single processing and realize precise control of the electromagnetic force by optimizing the discharge parameters of a pulse power supply, thereby effectively improving the forming quality and precision of the workpiece to be processed.

[0008] In order to achieve the above objectives, this application provides the following technical solutions:

[0009] A combined electromagnetic forming device for power cables, comprising a control module, a power module and a plurality of magnetic collectors arranged in an array; the power module comprises a plurality of pulse power supplies;

[0010] The magnetic collector is a cylindrical structure, each magnetic collector is provided with a through truncated cone-shaped hole, and a large hole edge and a small hole edge are respectively provided at both ends of the truncated cone-shaped hole, and the hole edges at the abutment positions of two adjacent magnetic collectors have the same diameter;

[0011] The outer periphery of each magnetic collector is evenly distributed with a forming coil; each pulse power supply is electrically connected to each forming coil, and the pulse power supply is used to pass a pulse current to the forming coil;

[0012] The control module includes a parameter acquisition module and a discharge control module;

[0013] The parameter acquisition module is used to acquire the workpiece parameters of the workpiece to be processed;

[0014] The discharge control module is used to generate discharge parameters according to the workpiece parameters of the workpiece to be processed, and control the discharge of each pulse power supply according to the generated discharge parameters; the discharge parameters include optimal pulse current and reference discharge time.

[0015] Furthermore, the axis center lines of each magnetic collector and the axis center lines of the truncated cone-shaped holes in each magnetic collector are all on the same straight line.

[0016] Furthermore, the workpiece parameters include electrical conductivity, thermal conductivity and diameter.

[0017] Further, the discharge control module includes a pulse current generation module, a discharge time generation module and a discharge timing control module;

[0018] The pulse current generating module is used to generate an optimal pulse current according to the workpiece parameters of the workpiece to be processed;

[0019] The discharge time generation module is used to generate a reference discharge time according to the optimal pulse current and pre-stored circuit parameters;

[0020] The discharge timing control module is used to control the discharge of each pulse power source according to the optimal pulse current and the reference discharge time.

[0021] Furthermore, the calculation formula of the optimal pulse current is as follows:

[0022]

[0023] In the formula, I opt is the optimal pulse current, I is the preset conventional pulse current, H r is the correction parameter, K is the conductivity of the workpiece to be processed, λ is the thermal conductivity of the workpiece to be processed, Φ is the diameter of the workpiece to be processed, α is the conductivity influence coefficient, β is the thermal conductivity influence coefficient, and γ is the diameter influence coefficient.

[0024] Furthermore, the pre-stored circuit parameters include the total resistance of the circuit and the total energy stored in the capacitor bank in the pulse power supply.

[0025] Furthermore, the calculation formula of the reference discharge time is as follows:

[0026]

[0027] Where, T ref is the reference discharge time, K r is the preset conventional conductivity, K is the conductivity of the workpiece to be processed, t is the preset conventional discharge time, E is the total energy stored in the capacitor bank, I opt is the optimal pulse current, and R is the total resistance of the circuit.

[0028] The principles and advantages of the present invention are:

[0029] 1. This solution adopts an array layout of multiple magnetic collectors, and each magnetic collector outer ring is equipped with an independent forming coil and powered by its own pulse power supply. This not only expands the area coverage of a single processing, but also reduces the demand for a single pulse power supply voltage, fundamentally solving the insulation problem caused by high voltage and improving the safety and reliability of the system.

[0030] 2. Based on the electrical conductivity, thermal conductivity and diameter of the workpiece to be processed, the optimal pulse current and reference discharge time suitable for the corresponding workpiece to be processed are analyzed, thereby ensuring that the workpieces of different materials and specifications can obtain the best forming effect, significantly improving the processing accuracy and product consistency.

[0031] 3. The discharge of each pulse power supply is controlled according to the discharge parameters through the discharge timing control module, so as to finely adjust the working state of each pulse power supply and support synchronous and asynchronous discharge modes between forming coils. In the synchronous discharge mode, although the pulse power supplies connected to each coil work independently, the energy output of each pulse power supply can be adjusted according to needs to achieve differentiated electromagnetic force application; while asynchronous discharge uses the time difference to further optimize the distribution and timing of force. Both trans modes can avoid the discontinuity problem of the connection area of ​​each magnetic collector, and considering that the two methods are different in the magnitude and time of electromagnetic force application, and the mechanism of action is different, they can also be used in combination to achieve better connection. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 It is a cross-sectional view of a forming coil in an embodiment of a combined electromagnetic forming device for power cables of the present invention.

[0033] Figure 2 The present invention is a schematic structural diagram of a magnetic collector in an embodiment of a combined electromagnetic forming device for power cables.

[0034] Figure 3 The present invention is a schematic structural diagram of a forming coil in an embodiment of a combined electromagnetic forming device for power cables.

[0035] Figure 4 The present invention is a logic block diagram of a control module in an embodiment of a combined electromagnetic forming device for power cables. DETAILED DESCRIPTION

[0036] The following is further described in detail through specific implementation methods:

[0037] The symbols in the drawings of the specification include: a magnetic collector 1, a truncated cone-shaped hole 2, a forming coil 3, a large hole edge 4, and a small hole edge 5.

[0038] Embodiment 1:

[0039] A combined electromagnetic forming device for power cables includes a control module, a power module and a plurality of array-arranged magnetic collectors. The power module includes a plurality of pulse power supplies, and specifically, the power modules and the magnetic collectors are arranged in a one-to-one correspondence.

[0040] like Figure 2 As shown, the magnetic collector is a cylindrical structure, and each magnetic collector is provided with a through-conical hole, such as Figure 1As shown, the two ends of the truncated cone hole are respectively provided with a large hole edge and a small hole edge, the hole edge diameters of the adjacent two magnetism collectors are the same, and the axis lines of each magnetism collector and the axis lines of the truncated cone hole in each magnetism collector are all on the same straight line. Specifically, it includes 2n magnetism collectors arranged in an array, and the magnetism collectors at both ends have large hole edges facing outwards. In this embodiment, n=1, as Figure 2 As shown, there are two magnetic collector arrays. Figure 3 As shown, forming coils are evenly distributed on the periphery of each magnetic collector; each pulse power supply is electrically connected to each forming coil, and the pulse power supply is used to pass pulse current to the forming coil.

[0041] In summary, this scheme adopts an array layout of 2n magnetic collectors, each magnetic collector outer ring is equipped with an independent forming coil, and is powered by its own pulse power supply. This not only expands the area coverage of a single processing, but also reduces the demand for a single pulse power supply voltage.

[0042] like Figure 4 As shown, the control module includes a parameter acquisition module and a discharge control module.

[0043] The parameter acquisition module is used to acquire the workpiece parameters of the workpiece to be processed; the workpiece parameters include electrical conductivity, thermal conductivity and diameter. In this embodiment, the operator directly inputs the electrical conductivity, thermal conductivity and diameter of the workpiece through the keyboard. In other embodiments of the present application, the image of the workpiece to be processed can be collected and identified, the type of the workpiece to be processed can be analyzed, and the electrical conductivity and thermal conductivity of the corresponding workpiece type in the type parameter comparison table can be retrieved, and the diameter of the workpiece to be processed can be analyzed based on the image of the workpiece to be processed, so as to realize intelligent recognition of the workpiece parameters.

[0044] The discharge control module is used to generate discharge parameters according to the workpiece parameters of the workpiece to be processed, and control the discharge of each pulse power supply according to the generated discharge parameters; the discharge parameters include the optimal pulse current and the reference discharge time. Figure 4 As shown, the discharge control module includes a pulse current generation module, a discharge time generation module and a discharge timing control module.

[0045] The pulse current generating module is used to generate an optimal pulse current according to the workpiece parameters of the workpiece to be processed; the calculation formula of the optimal pulse current is as follows:

[0046]

[0047] In the formula, I opt is the optimal pulse current, I is the preset conventional pulse current, H ris the correction parameter, K is the conductivity of the workpiece to be processed, λ is the thermal conductivity of the workpiece to be processed, Φ is the diameter of the workpiece to be processed, α is the conductivity influence coefficient, β is the thermal conductivity influence coefficient, and γ is the diameter influence coefficient.

[0048] The discharge time generation module is used to generate a reference discharge time according to the optimal pulse current and pre-stored circuit parameters; the pre-stored circuit parameters include the total resistance of the circuit and the total energy stored in the capacitor bank in the pulse power supply. The calculation formula of the reference discharge time is as follows:

[0049]

[0050] Where, T ref is the reference discharge time, K r is the preset conventional conductivity, K is the conductivity of the workpiece to be processed, t is the preset conventional discharge time, E is the total energy stored in the capacitor bank (the maximum energy storage of the capacitor bank), I opt is the optimal pulse current, and R is the total resistance of the circuit.

[0051] The discharge timing control module is used to control the discharge of each pulse power supply according to the optimal pulse current and the reference discharge time. Specifically, the pulse power supplies corresponding to the 2n magnetic collectors are grouped according to the arrangement order of the magnetic collectors, and the pulse power supplies corresponding to the odd numbers in the arrangement order are grouped into group A, and the pulse power supplies corresponding to the even numbers in the arrangement order are grouped into group B. In the synchronous discharge mode, all pulse power supplies discharge synchronously, and the discharge size of each pulse power supply in group A is controlled to be the optimal pulse current I opt , the discharge size of each pulse power supply in group B is at the optimal pulse current I opt The discharge size of each pulse power supply in group B can be exactly the same, or each can be randomly increased by 10% to 20%, and the discharge time reaches the reference discharge time T ref After that, all pulse power supplies are synchronously turned off. In the asynchronous discharge mode, each pulse power supply in group A is controlled to discharge synchronously, and each pulse power supply in group B is controlled to start discharging after 1μs to 2μs (the discharge time of each pulse power supply in group B can be exactly the same, or each can be randomly extended by 1μs to 2μs relative to group A). ​​During the discharge process, the discharge size of all pulse power supplies is the optimal pulse current I opt , when the discharge time of group A reaches the reference discharge time T ref After that, all pulse power supplies are turned off synchronously.

[0052] Both of the above two reverse methods can avoid the discontinuity problem of the connection area of ​​each magnetic collector. For different workpieces to be processed, the control strategy can be adjusted according to the material properties. And considering that the two methods are different in the magnitude and time of electromagnetic force application, and the mechanism of action is different, they can also be used in combination to achieve better connection.

[0053] The above are only embodiments of the present invention. Common knowledge such as the known specific structures and characteristics in the scheme is not described in detail here. Ordinary technicians in the relevant field know all the common technical knowledge in the technical field to which the invention belongs before the application date or priority date, can obtain all the existing technologies in the field, and have the ability to apply conventional experimental means before that date. Ordinary technicians in the relevant field can improve and implement this scheme in combination with their own abilities under the enlightenment given by this application. Some typical known structures or known methods should not become obstacles for ordinary technicians in the relevant field to implement this application. It should be pointed out that for those skilled in the art, without departing from the structure of the present invention, several deformations and improvements can be made, which should also be regarded as the scope of protection of the present invention, and these will not affect the effect of the implementation of the present invention and the practicality of the patent. The scope of protection required by this application shall be based on the content of its claims, and the specific implementation methods and other records in the specification can be used to interpret the content of the claims.

Claims

1. A combined electromagnetic forming device for power cables, characterized in that: It includes a control module, a power module and a plurality of magnetic collectors arranged in an array; the power module includes a plurality of pulse power supplies; The magnetic collector is a cylindrical structure, each magnetic collector is provided with a through truncated cone-shaped hole, and a large hole edge and a small hole edge are respectively provided at both ends of the truncated cone-shaped hole, and the hole edges at the abutment positions of two adjacent magnetic collectors have the same diameter; The outer periphery of each magnetic collector is evenly distributed with a forming coil; each pulse power supply is electrically connected to each forming coil, and the pulse power supply is used to pass a pulse current to the forming coil; The control module includes a parameter acquisition module and a discharge control module; The parameter acquisition module is used to acquire the workpiece parameters of the workpiece to be processed; The discharge control module is used to generate discharge parameters according to the workpiece parameters of the workpiece to be processed, and control the discharge of each pulse power supply according to the generated discharge parameters; the discharge parameters include optimal pulse current and reference discharge time.

2. The combined electromagnetic forming device for power cables according to claim 1, characterized in that: The axis center lines of each magnetic collector and the axis center lines of the truncated cone-shaped holes in each magnetic collector are all on the same straight line.

3. The combined electromagnetic forming device for power cables according to claim 1, characterized in that: The workpiece parameters include electrical conductivity, thermal conductivity and diameter.

4. The combined electromagnetic forming device for power cables according to claim 3, characterized in that: The discharge control module includes a pulse current generation module, a discharge time generation module and a discharge timing control module; The pulse current generating module is used to generate an optimal pulse current according to the workpiece parameters of the workpiece to be processed; The discharge time generation module is used to generate a reference discharge time according to the optimal pulse current and pre-stored circuit parameters; The discharge timing control module is used to control the discharge of each pulse power source according to the optimal pulse current and the reference discharge time.

5. The combined electromagnetic forming device for power cables according to claim 4, characterized in that: The calculation formula of the optimal pulse current is as follows: In the formula, I opt is the optimal pulse current, I is the preset conventional pulse current, H r is the correction parameter, K is the conductivity of the workpiece to be processed, λ is the thermal conductivity of the workpiece to be processed, Φ is the diameter of the workpiece to be processed, α is the conductivity influence coefficient, β is the thermal conductivity influence coefficient, and γ is the diameter influence coefficient.

6. The combined electromagnetic forming device for power cables according to claim 4, characterized in that: The pre-stored circuit parameters include the total resistance of the circuit and the total energy stored in the capacitor bank in the pulse power supply.

7. The combined electromagnetic forming device for power cables according to claim 6, characterized in that: The calculation formula of the reference discharge time is as follows: Where, T ref is the reference discharge time, K r is the preset conventional conductivity, K is the conductivity of the workpiece to be processed, t is the preset conventional discharge time, E is the total energy stored in the capacitor bank, I opt is the optimal pulse current, and R is the total resistance of the circuit.

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