WO2022236849A1

WO2022236849A1 - Conductive channel-based electromagnetic forming apparatus and forming method

Info

Publication number: WO2022236849A1
Application number: PCT/CN2021/094320
Authority: WO
Inventors: 李亮; 王紫叶; 赖智鹏; 韩小涛; 曹全梁
Original assignee: 华中科技大学
Priority date: 2021-05-13
Filing date: 2021-05-18
Publication date: 2022-11-17
Also published as: CN113333561A; CN113333561B

Abstract

An electromagnetic forming apparatus and forming method based on a conductive channel (3). The electromagnetic forming apparatus comprises a mold (5) and a conductive channel (3) provided on one side of the mold (5); the mold (5) comprises a left region, a right region and a middle concave region; the conductive channel (3) comprises first, second and third sub-conductive channels (3-1, 3-2, 3-3); the first and second sub-conductive channels (3-1, 3-2) are provided on the left region side of the mold (5) and the the right region side of the mold (5) respectively, and the third sub-conductive channel (3-3) is connected to the first and second sub-conductive channels (3-1, 3-2) to form an annular conductive channel (3) provided with a gap, and the direction of the gap is toward the middle concave region of the mold (5). The forming method comprises: a metal workpiece (2) is placed at the gap inside the conductive channel (3); the metal workpiece (2) and the conductive channel (3) form a conductive loop; a uniform pressure driving coil (1) is placed inside the conductive channel (3) and is placed above the metal workpiece (2); and a pulse current is fed into the uniform pressure driving coil (1) to drive the metal workpiece (2) to deform toward the middle concave region of the mold (5).

Description

Electromagnetic forming device and forming method based on conductive channel

【Technical field】

The invention belongs to the field of metal forming and manufacturing, and more specifically relates to an electromagnetic forming device and forming method based on a conductive channel.

【Background technique】

The use of light alloy materials provides an effective way to achieve lightweight industrial production in the fields of automobiles, aerospace, etc., but due to the poor formability and plasticity of commonly used light alloy materials such as aluminum alloys and titanium alloys at room temperature Low, small elastic modulus, the effect of traditional processing technology is not ideal. Studies have shown that high-speed forming technology can effectively improve the formability of light alloys at room temperature. Therefore, electromagnetic forming, as a high-speed forming technology, has been widely used in the processing field of aluminum alloy and other light alloy materials.

In the electromagnetic forming technology of non-axisymmetric plate, it is an effective method to use uniform force to drive the coil. In the electromagnetic forming of the plate, there are the following common problems: 1. In the traditional forming method of the external field uniform pressure coil, the plate is placed above the mold, the conductive channel is placed above the metal workpiece, and the conductive channel is placed on the metal workpiece through the external preload. The channel is tightened with the plate to form a conductive loop. However, it is unavoidable that when the plate is deformed by the downward electromagnetic force during the forming process, the conductive channel directly pressed above the plate will also be forced to separate the plate from the conductive channel by the upward electromagnetic force, so that The gap between the plate and the conductive channel increases, resulting in poor contact between the plate and the conductive channel, and arcing occurs. When the arc occurs, the temperature can reach thousands or even tens of thousands of degrees Celsius, causing severe ablation of the plate and the conductive channel. phenomenon, which seriously affects the surface quality of the plate, and it is difficult to avoid the defective rate caused by the disadvantages of the forming method, and at the same time increase the cost of replacing the ablated conductive channel; The workpiece is placed inside the coil. For the forming of large-sized parts, it is necessary to design a larger uniform pressure coil, which will greatly increase the difficulty of coil design and reduce the forming efficiency; 3. In the forming method of the inner field uniform pressure coil, Since the mold is inside the coil, the space inside the coil is usually limited, which limits the size of the target part to be formed. For the above problems, the method of using a special shape to drive the coil will increase the difficulty of coil design, increase the manufacturing cost, and the forming quality will be poor, and the scope of application of the coil will be single.

【Content of invention】

In view of the defects of the prior art, the purpose of the present invention is to provide an electromagnetic forming device and forming method based on conductive channels, aiming to solve the problem of poor contact during the forming of the traditional internal field uniform pressure coil, difficulties in the size design of the uniform pressure coil or pending forming The problem of limited board size.

In order to achieve the above object, the present invention provides an electromagnetic forming device based on a conductive channel in the first aspect, including: a uniform pressure driving coil, a conductive channel and a mold;

The conductive channel is placed on one side of the mold; the mold includes a left side area, a right side area and a middle concave area; the conductive channel includes a first sub-conductive channel, a second sub-conductive channel and a third sub-conductive channel ; The first sub-conductive channel and the second sub-conductive channel are respectively placed on one side of the left area of the mold and one side of the right area of the mold, and the third sub-conductive channel connects the first sub-conductive channel and the second sub-conductive channel A conductive channel, forming an annular conductive channel with a notch, and the direction of the notch is towards the middle concave area of the mould;

The metal workpiece to be formed is placed at the gap inside the conductive channel; the length of the metal workpiece is greater than the length of the gap, and the two ends of the metal workpiece are respectively in close contact with the first sub-conductive channel and the second sub-conductive channel, The metal workpiece forms a conductive loop with the conductive channel;

The uniform pressure driving coil is placed inside the conductive channel, and the outer contour shape of the uniform pressure coil matches the inner contour shape of the conductive channel;

After the pulse current is fed into the uniform pressure drive coil, the pulse magnetic field generated by it induces eddy current in the conductive circuit, and the pulse magnetic field interacts with the eddy current to generate electromagnetic force on the metal workpiece, driving the metal workpiece to The middle concave area of the mold is deformed.

In an optional example, the mold, the metal workpiece to be formed, the first sub-conductive channel, the second sub-conductive channel and the third sub-conductive channel are all N; N is an integer greater than or equal to 1;

The electromagnetic forming device can shape N metal workpieces, and the conductive path forms the conductive loop with the N metal workpieces.

In an optional example, the interaction between the pulsed magnetic field and the eddy current generates an electromagnetic force on the metal workpiece, and the electromagnetic force provides the two ends of the metal workpiece with a blank-holding force that is in contact with the conductive channel and adheres closely to ensure that the metal workpiece During the forming process, the metal workpiece has good electrical contact with the conductive path.

In an optional example, the first sub-conductive channel is facing the left area of the mold, and the second sub-conducting channel is facing the right area of the mold; the area of the first sub-conducting channel is smaller than or equal to the left area of the mold. The area of the side area, the area of the second sub-conductive channel is less than or equal to the area of the right area of the mould.

In an optional example, the inner contour of the gap in the conductive channel is parallel to the metal workpiece, so that the metal workpiece can be placed inside the conductive channel, and can be stably placed at the gap in the conductive channel, so that the metal workpiece and the conductive channel can be form a conductive loop;

The outer contour of the gap of the conductive channel is designed according to the forming target of the metal workpiece, and is mechanically matched with the mold.

In an optional example, the uniform pressure driving coil may include: a core uniform pressure driving coil and a blank-holder uniform pressure driving coil;

The blank-holding uniform pressure driving coil is placed on one side of both ends of the metal workpiece so as to provide blank-holding force for both ends of the metal workpiece, and the core uniform pressure driving coil is placed above the area to be formed of the metal workpiece so as to provide The workpiece provides the driving force to deform the middle concave area of the mold; there are at least two edge-press uniform pressure drive coils to ensure that there are edge-holder uniform pressure drive coils on one side of both ends of the workpiece, and the core uniform pressure drive coils Nor is it limited to a single.

In an optional example, the electromagnetic shaping device further includes: a uniform pressure driving coil skeleton;

The uniform pressure driving coil is placed inside the conductive channel through the uniform pressure driving coil skeleton.

In a second aspect, the present invention provides an electromagnetic forming method based on a conductive channel, comprising the following steps:

The conductive channel is placed on one side of the mold; the mold includes a left side area, a right side area and a middle concave area; the conductive channel includes a first sub-conductive channel, a second sub-conductive channel and a third sub-conductive channel; The first sub-conductive channel and the second sub-conductive channel are placed on one side of the left area of the mold and one side of the right area of the mold respectively, and the third sub-conductive channel connects the first sub-conductive channel and the second sub-conductive channel. a channel, forming an annular conductive channel with a notch, and the direction of the notch is towards the middle concave area of the mould;

The metal workpiece to be formed is placed at the gap inside the conductive channel; the length of the metal workpiece is greater than the length of the gap, and the two ends of the metal workpiece are respectively in close contact with the first sub-conductive channel and the second sub-conductive channel , the metal workpiece and the conductive channel form a conductive loop;

The electromagnetic forming method can shape N metal workpieces, and the conductive path forms the conductive loop with the N metal workpieces.

Generally speaking, compared with the prior art, the above technical solution conceived by the present invention has the following beneficial effects:

The invention provides an electromagnetic forming device and forming method based on a conductive channel. Through the design of the conductive channel including the sub-conductive channels on the left and right sides of the mould, the metal workpiece is placed on the left and right sub-conductive channels, and the conductive channel is connected with the conductive channel. To form a conductive circuit, the conductive circuit formed by placing the metal workpiece inside the conductive channel, during the forming process, the metal plate above the sub-conductive channel on the left and right sides of the mold receives a downward electromagnetic force, and the sub-conductive channel below the metal plate Under the upward electromagnetic force, the force direction of the metal plate and the conductive channel is opposite, so that the two are closely bonded at the contact surface of the conductive channel, which fundamentally solves the problem of the conductive channel and the metal plate in the forming process of the traditional internal field uniform pressure coil. The unavoidable separation problem of parts, greatly reducing or even eliminating the extra blank holder force applied to prevent the coil from separating from the conductive channel during the traditional uniform pressure coil forming process, and reducing the contact caused by poor contact between the metal workpiece and the conductive channel Resistance can effectively improve the electric spark phenomenon caused by poor contact between the conductive channel and the metal plate, increase the electromagnetic force generated in the forming area of the workpiece, improve the forming quality of the workpiece, reduce the forming cost of the workpiece, and expand the application range of the uniform pressure coil.

【Description of drawings】

Fig. 1 is a structural schematic diagram of the electromagnetic forming device in the first embodiment of the present invention;

2 is a schematic diagram of a conductive channel and a conductive circuit provided by an embodiment of the present invention;

Fig. 3 is a top view of the structure of the electromagnetic forming device according to the first embodiment of the present invention;

Fig. 4 is the schematic diagram of the principle of blank holder force and forming force in the embodiment of the present invention;

5 is a schematic diagram of a coil current waveform provided by a capacitor energy storage type power supply in an embodiment of the present invention;

Fig. 6 is a schematic diagram of the high-efficiency electromagnetic forming device in the second embodiment of the present invention;

Fig. 7 is a schematic diagram of an electromagnetic punching device in a third embodiment of the present invention;

Fig. 8 is a schematic diagram of a multi-coil electromagnetic forming device in a fourth embodiment of the present invention;

Fig. 9 is a flow chart of the electromagnetic forming method provided by the embodiment of the present invention;

In all the drawings, the same reference numerals are used to represent the same elements or structures, wherein: 1 is a uniform pressure driving coil, 2 is a metal workpiece, 3 is a conductive channel, 4 is a power supply, and 5 is a mold.

【Detailed ways】

In order to make the object, technical solution and advantages of the present invention more clear, the present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described here are only used to explain the present invention, not to limit the present invention.

In one embodiment, the present invention provides an electromagnetic forming device based on a conductive channel, including: a uniform pressure driving coil, a conductive channel, and a mould;

The conductive channel is placed on one side of the mold; the mold includes a left side area, a right side area and a middle concave area; the conductive channel includes a first sub-conductive channel, a second sub-conductive channel and a third sub-conductive channel; the The first sub-conductive channel and the second sub-conductive channel are respectively placed on one side of the left area of the mold and one side of the right area of the mold, and the third sub-conductive channel connects the first sub-conductive channel and the second sub-conductive channel , forming a ring-shaped conductive channel with a gap, and the direction of the gap is toward the middle concave area of the mold; the metal workpiece to be formed is placed at the gap inside the conductive channel; the length of the metal workpiece is greater than that of the gap length, the two ends of the metal workpiece are respectively in close contact with the first sub-conductive channel and the second sub-conductive channel, and the metal workpiece and the conductive channel form a conductive loop; the uniform pressure driving coil is placed inside the conductive channel, and the uniform pressure coil The shape of the outer contour matches the shape of the inner contour of the conductive channel; after the pulse current is passed into the uniform pressure drive coil, the pulse magnetic field generated by it induces eddy current in the conductive circuit, and the pulse magnetic field interacts with the eddy current An electromagnetic force is generated on the metal workpiece, driving said metal workpiece to deform towards the central concave region of the mold.

In an optional example, the first sub-conductive channel is facing the left area of the mold, and the two areas are the same, and the second sub-conducting channel is facing the right area of the mold, and the two areas are the same; or

The area of the first sub-conductive channel is smaller than or equal to the area of the left side of the mould, and the area of the second sub-conductive channel is smaller than or equal to the area of the right side of the mould.

Specifically, the shape area of the first and second sub-conductive channels and the positional relationship with the mold can refer to the specific examples in (a) in Figure 1 and Figure 6 of the present application, wherein the two sides of the mold can be as shown in Figure 1 For the raised platform, the first and second sub-conductive channels are laid flat on the raised platforms on both sides, and overlap with the area of the raised platform. In addition, both sides of the mold can also be a combination of the outer platform part and the inner raised part shown in (a) in Figure 6, and the first and second sub-conductive channels are laid flat on the outer platform parts on both sides, In addition, the thicknesses of the first and second sub-conducting channels are the same as the protruding height of the protruding part relative to the platform part.

It can be understood that the shape area of the first and second sub-conductive passages and the positional relationship with the mold include but are not limited to the above examples, as long as the two ends of the metal workpiece can be tightly placed on the first sub-conductive passage and the mold. On the second sub-conductive channel, it is enough to ensure the contact stability between the metal workpiece and the first and second sub-conductive channels, and ensure the stable structural cooperation between the first and second sub-conductive channels and the mold.

The present invention provides an electromagnetic forming device and forming method based on conductive channels. During the electromagnetic forming process of plates, the conductive circuits designed above and the conductive circuits established by the metal plates are used. The metal plate is subjected to a downward electromagnetic force, and the sub-conductive channel under the opposite metal plate is subjected to an upward electromagnetic force. The direction of the force on the metal plate and the conductive channel is opposite, so that the two are closely bonded at the contact surface of the conductive channel, which greatly reduces Minimize or even eliminate the additional blank holder force applied to prevent the coil from separating from the conductive channel during the traditional uniform pressure coil forming process, reduce the contact resistance caused by poor contact between the metal workpiece and the conductive channel, and effectively improve the conductive channel and the metal plate The electric spark phenomenon caused by the poor contact of the workpiece can be improved, the electromagnetic force generated in the forming area of the workpiece can be increased, and the forming quality of the workpiece can be improved.

In order to achieve the above object, according to one aspect of the present invention, an electromagnetic forming device and forming method based on a conductive channel is provided, including: a uniform pressure driving coil, a conductive channel, a mold, and a power supply; the conductive channel is opposite to the mold Placement; the metal workpiece is placed on the internal gap of the conductive channel, and the two are connected to each other to form a conductive circuit; the uniform pressure drive coil is placed inside the conductive channel and placed on the metal workpiece, and connected to the The pulsed magnetic field generated by the driving coil of the pulsed current induces a current in the conductive channel, so that the interaction between the pulsed magnetic field and the pulsed current generates an electromagnetic force on the plate, which not only provides the forming force to drive the deformation of the plate, but also provides the deformation of the plate. The contact with the conductive channel provides the contact force and at the same time acts as a blank holder force for forming the panel; the power supply is used to power the drive coil.

Furthermore, the width of the inner contour of one side of the conductive channel carrying the metal workpiece is greater than or equal to the width of the metal workpiece, the width of the gap of the conductive channel at the side is smaller than the width of the metal workpiece, and the inner contour at the gap of the conductive channel is consistent with the metal workpiece. Parallel, so that the metal workpiece can be placed inside the conductive channel, and can be stably placed on the gap of the conductive channel, so that the metal workpiece and the conductive channel can form a conductive loop. The outer contour at the notch of the conductive channel is designed according to the forming object, and is mechanically matched with the mold.

Furthermore, the outer contour shape of the uniform pressure driving coil is the same as the inner contour shape of the conductive channel, and the outer contour size of the uniform pressure driving coil is smaller than the inner contour size of the conductive channel, so that the uniform pressure driving coil can be placed in the conductive channel. over metal workpieces. The pulsed magnetic field generated in the space by the current uniform pressure drive coil interacts with the eddy current induced in the conductive circuit to generate electromagnetic driving force on the metal workpiece, providing forming force for the deformation area of the metal workpiece, and providing The contact force and blank holder force enable the metal workpiece not only to be formed under the action of the electromagnetic driving force, but also to strengthen the electrical contact and improve the forming quality and forming limit.

Furthermore, under the action of the self-gravity of the uniform pressure driving coil, the mechanical blank-holding force on both ends of the metal workpiece can be reduced or even not additionally pre-applied, so that the initial contact between the metal workpiece and the conductive channel is good. Moreover, by changing the gap length of the conductive channel, the length of the contact surface between the metal workpiece and the conductive channel can be adjusted to control the electromagnetic blank holder force, or the mechanical force loaded on the uniform pressure coil skeleton can be transmitted to both ends of the metal workpiece to adjust the mechanical pressure. The size of the edge force can strengthen the electrical contact between the metal workpiece and the conductive channel, and improve the forming effect.

Further, the conductive channel can be a whole, or can be composed of multiple separate conductive arms, which can not only realize the forming of a single metal plate, but also realize the simultaneous forming of multiple metal plates. And the forming efficiency can be improved by optimizing the structural parameters of the uniform pressure driving coil and the conductive channel.

Further, the uniform force driving coil winding can not only be a single one, but also can be composed of multiple coil windings connected in series and parallel, so as to cope with the forming of large-sized metal plate parts.

Furthermore, the geometric shape and size of the mold are not limited by the size of the driving coil, which can not only realize electromagnetic forming, but also be applied in fields such as electromagnetic punching, electromagnetic embossing, and electromagnetic welding, expanding the application range of uniform pressure coils.

According to another aspect of the present invention, there is provided an electromagnetic forming method based on conductive channels, comprising the following steps:

Step (1): placing the conductive channel on the mold;

Step (2): placing the metal workpiece inside the conductive channel and above the gap of the conductive channel;

Step (3): placing the uniform pressure drive coil inside the conductive channel and on the metal workpiece to be electrically connected to the power supply;

Step (4): Using the power supply to discharge the uniform pressure driving coil to generate a pulse current, excite a pulse strong magnetic field around the coil, and then induce an eddy current in the conductive circuit formed by the conductive channel and the metal workpiece, thereby Electromagnetic blank-holding force is generated at both ends of the metal workpiece to strengthen the electrical contact between the metal workpiece and the conductive channel, and electromagnetic forming force is generated on the deformation area of the metal workpiece to drive the plate to deform at a high speed, and finally complete the forming of the metal workpiece.

As shown in Figure 1, the present invention provides an electromagnetic forming device, comprising: uniform pressure driving coil 1, conductive channel 3, power supply 4, and mold 5. Wherein, the conductive channel 3 and the mold 5 are placed opposite to each other, the metal workpiece 2 is placed above the gap inside the conductive channel 3 , the uniform pressure drive coil 1 is placed above the metal workpiece 2 , and the power source 4 is electrically connected to the uniform pressure drive coil 1 . The conductive channel 3 is used to form a conductive circuit with the metal workpiece 2, and the uniform pressure drive coil 1 is used to generate pulse current to convert electrical energy into mechanical energy. The workpiece 2 provides forming force and blank-holding force to drive the metal workpiece to undergo plastic deformation, and adjust the blank-holding force by optimizing the gap width of the conductive channel 3 to strengthen the contact between the plate and the conductive channel 3, and control the lateral flow of the plate to the inside of the mold quantity. The power supply 4 is used to supply power to the uniform pressure driving coil 1, and the power supply type is not limited, and a capacitor type power supply or a battery pack pulse power supply can also be used.

Specifically, as shown in (a) in FIG. 2 and (b) in FIG. -3; the first sub-conductive channel 3-1 and the second sub-conductive channel 3-2 are respectively placed on one side of the left area of the mold and one side of the right area of the mold, and the third sub-conductive channel 3- 3. Connect the first sub-conductive channel 3-1 and the second sub-conductive channel 3-2 to form a ring-shaped conductive channel 3 with a notch, and the direction of the notch faces the middle concave area of the mold. Referring to (b) in Fig. 2, (b) in Fig. 2 is forming to two metal workpieces, if more metal workpieces are formed, for example to forming more than 2 metal workpieces, then the first sub-conductive channel 3-1, The second sub-conductive channel 3-2 and the third sub-conductive channel 3-3 are more than two, that is, for forming N metal workpieces, the first sub-conductive channel 3-1, the second sub-conductive channel 3-2 and the second sub-conductive channel 3-2 There are N corresponding to the three sub-conductive channels 3-3, and N is an integer greater than or equal to 1. Wherein, referring to Fig. 2 (a) and Fig. 2 (b), N metal workpieces and N first sub-conducting passages 3-1, N second sub-conducting passages 3-2 and N third The sub conductive channels 3-3 form a conductive loop.

Among them, the top view of the device is shown in Figure 3, the outer contour shape of the uniform pressure driving coil is the same as the inner contour shape of the conductive channel, and the outer contour size of the uniform pressure driving coil is smaller than the inner contour size of the conductive channel, so that the uniform pressure driving coil It can be placed over the metal workpiece within the conductive pathway, and can be placed just between the metal workpiece and the conductive pathway. The material selection criteria of the conductive channel 3 are generally the magnitude of the electrical conductivity and the strength of the material, and copper or aluminum alloy materials can be selected.

According to another aspect of the present invention, the present invention also provides an electromagnetic forming method, comprising the following steps:

(1) Place the conductive channel opposite to the mold;

(2) Place the metal workpiece on the gap inside the conductive channel, place the uniform pressure drive coil above the metal plate, the air gap between the uniform pressure drive coil and the conductive channel should be as small as possible, and the distance between the uniform pressure drive coil and the metal workpiece as small as possible;

Among them, the gap value needs to consider the following factors: the smaller the air gap between the uniform pressure drive coil and the conductive channel, the more conducive to restraining the deformation of the uniform pressure drive coil itself, and avoiding the damage of the uniform pressure coil due to excessive deformation. The smaller the distance from the metal workpiece, the greater the electromagnetic force can be provided to the metal workpiece. However, the uniform pressure driving coil should have sufficient insulating layer to prevent discharge between the uniform pressure coil and the metal workpiece or conductive channel during the forming process.

(3) Connect the uniform pressure driving coil to the power supply, start the power supply, and the driving coil is fed with a rapidly changing current to induce a pulsed magnetic field in the space, and at the same time induce eddy currents and pulsed magnetic fields in the conductive circuit formed by the conductive channel and the metal workpiece The interaction with the induced current generates an electromagnetic force on the workpiece to drive the deformation of the workpiece.

Fig. 4 is a schematic diagram of the principles of blankholder force (contact force) and forming force in an embodiment of the present invention, wherein, B indicates magnetic induction intensity, I indicates current, f _blankholder indicates blankholder electromagnetic force, and f _forming indicates forming electromagnetic force.

For the power supply 5, a capacitor bank power supply can be used, and the specific current waveform is shown in FIG. 5 .

(a) in FIG. 6 is a schematic diagram of a plate electromagnetic punching device according to the second embodiment of the present invention, the main components include: uniform pressure driving coil 1 , conductive channel 3 , power supply 4 , and mold 5 . Among them, the mold is a trapezoidal boss with a punching contour, which is placed opposite to the conductive channel. The gap between the two is made as small as possible through reasonable size design and perfect mechanical cooperation. The top view of the mold is shown in Figure 6 (b); The workpiece is a metal plate, which is placed on the gap of the conductive channel; the uniform pressure drive coil is placed on the metal plate, and the discharge energy in the drive coil is transferred to the surface of the plate to be punched through electromagnetic induction, and the plate is deformed. The punching is done; the power supply is used to power the uniform pressure drive coil.

Fig. 7 is a schematic diagram of a high-efficiency plate electromagnetic forming device according to the third embodiment of the present invention. The main components include: a uniform pressure driving coil 1, a conductive channel 3, a power source 4, and a mold 5. Wherein, the conductive channel is composed of two pairs of conductive arms, which are placed opposite to the corresponding mould. The metal workpiece is a metal plate, which is respectively placed above and below the uniform pressure driving coil, and the uniform pressure driving coil just clamps the metal plate to restrict its positional movement. The uniform pressure driving coil fed with pulse current transmits the discharge energy to multiple metal plates, and drives the metal plates to complete forming at the same time; the power supply is used to supply power to the uniform pressure driving coil. The structure of the high-efficiency plate electromagnetic forming device is not limited to the high-efficiency forming of the two metal plates, but can also optimize the design of the conductive arm of the conductive channel according to the requirements, and combine the optimized design of the uniform pressure drive coil to achieve higher efficiency. Sheet electromagnetic forming.

Fig. 8 is a schematic diagram of a multi-coil multi-step progressive electromagnetic forming method according to the fifth embodiment of the present invention. The device mainly includes: core uniform pressure driving coil 1-1, edge uniform pressure driving coil 1-2, conductive channel 3, power supply 4 , mold 5. Wherein, the mold is placed opposite to the conductive channel, and the metal workpiece is a metal plate, which is placed opposite to the conductive channel. The uniform pressure driving coil group consists of a core uniform pressure driving coil and two edge uniform pressure driving coils. The two edge uniform pressure driving coils are placed at both ends of the metal plate, and the core uniform pressure driving coil is placed on the metal plate to be above the deformed area and fixed in position by an external mechanical structure. The uniform pressure driving coil group can be powered by one set of power supply or multiple sets of power supply. The core uniform pressure driving coil fed with current provides deformation driving force for the metal plate to shape the plate. The blank-holding uniform pressure coil supplied with current provides blank-holding force for both ends of the metal plate, keeps the metal plate in good contact with the conductive channel, controls the material flow of the plate during the forming process, and improves the forming quality.

The multi-coil progressive electromagnetic forming method comprises the following steps:

(1) The conductive channel 3 and the mold 5 are relatively placed;

(2) placing the metal workpiece 2 above the gap inside the conductive channel 3;

(3) The uniform pressure driving coil group is placed inside the conductive channel 3, wherein the edge uniform pressure driving coil 1-2 is placed at both ends of the metal workpiece 2, and the core uniform pressure driving coil 1-1 is placed in the area of the metal workpiece 2 to be formed above, and fixed by an external mechanical structure;

(4) Electrically connect the core uniform pressure drive coil 1-1 and the pressure edge uniform pressure drive coil 1-2 to the power supply 4, which can be controlled by a single or multiple sets of power supplies;

(5) Select the appropriate discharge energy, discharge the uniform pressure driving coil group through the power supply 4, and the core uniform pressure driving coil 1-1 generates electromagnetic force to drive the deformation of the workpiece, as shown in (a) in Figure 8, the uniform pressure driving of the edge Coil 1-2 controls the contact tightness between the workpiece and the conductive channel, and adjusts the material flow of the workpiece;

(6) As shown in (b) in Figure 8, the core uniform pressure drive coil 1-1 is moved downwards, so that the gap between it and the metal workpiece 2 is as small as possible, so that the electromagnetic force acting on the workpiece 2 is maximized . The position of the core uniform pressure driving coil 1-1 is fixed by the external mechanical structure, and step (5) is repeated until the workpiece is completely coated.

Fig. 9 is a flow chart of the electromagnetic forming method provided by the embodiment of the present invention, as shown in Fig. 9, including the following steps:

S101, place the conductive channel on one side of the mold; the mold includes a left area, a right area, and a middle concave area; the conductive channel includes a first sub-conductive channel, a second sub-conductive channel, and a third sub-conductive channel channel; the first sub-conductive channel and the second sub-conductive channel are respectively placed on one side of the left area of the mold and one side of the right area of the mold, and the third sub-conductive channel connects the first sub-conductive channel and the second sub-conductive channel The sub-conductive channel forms a ring-shaped conductive channel with a gap, and the direction of the gap is toward the middle concave area of the mould;

S102, placing the metal workpiece to be formed at the gap inside the conductive channel; the length of the metal workpiece is greater than the length of the gap, and the two ends of the metal workpiece are respectively connected to the first sub-conductive channel and the second sub-conductive channel close to each other, the metal workpiece forms a conductive loop with the conductive channel;

S103, placing the uniform pressure driving coil inside the conductive channel, and the outer contour shape of the uniform pressure coil matches the inner contour shape of the conductive channel;

S104, after the pulse current is passed into the uniform pressure driving coil, the pulse magnetic field generated by it induces eddy current in the conductive circuit, and the pulse magnetic field interacts with the eddy current to generate electromagnetic force on the metal workpiece, driving the metal workpiece The workpiece is deformed towards the central concave area of the mold.

Specifically, for the specific implementation manners of the above steps, reference may be made to the introduction of the foregoing device embodiments, and details are not repeated here.

It is easy for those skilled in the art to understand that the above descriptions are only preferred embodiments of the present invention, and are not intended to limit the present invention. Any modifications, equivalent replacements and improvements made within the spirit and principles of the present invention, All should be included within the protection scope of the present invention.

Claims

An electromagnetic forming device based on a conductive channel, characterized in that it includes: a uniform pressure driving coil, a conductive channel and a mold;

The conductive channel is placed on one side of the mold; the mold includes a left side area, a right side area and a middle concave area; the conductive channel includes a first sub-conductive channel, a second sub-conductive channel and a third sub-conductive channel ; The first sub-conductive channel and the second sub-conductive channel are respectively placed on one side of the left area of the mold and one side of the right area of the mold, and the third sub-conductive channel connects the first sub-conductive channel and the second sub-conductive channel A conductive channel, forming an annular conductive channel with a notch, and the direction of the notch is towards the middle concave area of the mould;

The metal workpiece to be formed is placed at the gap inside the conductive channel; the length of the metal workpiece is greater than the length of the gap, and the two ends of the metal workpiece are respectively in close contact with the first sub-conductive channel and the second sub-conductive channel, The metal workpiece forms a conductive loop with the conductive channel;

The uniform pressure driving coil is placed inside the conductive channel, and the outer contour shape of the uniform pressure coil matches the inner contour shape of the conductive channel;

After the pulse current is fed into the uniform pressure drive coil, the pulse magnetic field generated by it induces eddy current in the conductive circuit, and the pulse magnetic field interacts with the eddy current to generate electromagnetic force on the metal workpiece, driving the metal workpiece to The middle concave area of the mold is deformed.
The electromagnetic forming device according to claim 1, wherein, the mold, the metal workpiece to be formed, the first sub-conductive channel, the second sub-conductive channel, and the third sub-conductive channel are all N; N is greater than an integer equal to 1;

The electromagnetic forming device can shape N metal workpieces, and the conductive path forms the conductive loop with the N metal workpieces.
The electromagnetic forming device according to claim 1 or 2, characterized in that, the interaction between the pulsed magnetic field and the eddy current generates an electromagnetic force on the metal workpiece, and the electromagnetic force provides the two ends of the metal workpiece to be in contact with the conductive channel and to be in close contact with the metal workpiece. The blank holder force ensures good electrical contact between the metal workpiece and the conductive channel during the forming process of the metal workpiece.
The electromagnetic forming device according to claim 1 or 2, characterized in that, the first sub-conductive channel is facing the left area of the mould, the second sub-conducting channel is facing the right area of the mould, and the first sub-conducting channel is facing the right area of the mold. The area of the conductive channel is smaller than or equal to the area of the left side of the mould, and the area of the second sub-conductive channel is smaller than or equal to the area of the right side of the mould.
The electromagnetic forming device according to claim 1 or 2, characterized in that, the inner contour at the gap of the conductive channel is parallel to the metal workpiece, so that the metal workpiece can be placed inside the conductive channel and can be stably placed in the gap of the conductive channel place, so that the metal workpiece and the conductive channel can form a conductive loop;

The outer contour of the gap of the conductive channel is designed according to the forming target of the metal workpiece, and is mechanically matched with the mold.
The electromagnetic forming device according to claim 1 or 2, characterized in that, the uniform pressure driving coil may comprise: a core uniform pressure driving coil and a blank-holder uniform pressure driving coil;

The blank-holding uniform pressure driving coil is placed on one side of both ends of the metal workpiece so as to provide blank-holding force for both ends of the metal workpiece, and the core uniform pressure driving coil is placed above the area to be formed of the metal workpiece so as to provide The workpiece provides the driving force to deform the middle concave area of the mold; there are at least two edge-press uniform pressure drive coils to ensure that there are edge-holder uniform pressure drive coils on one side of both ends of the workpiece, and the core uniform pressure drive coils Nor is it limited to a single.
The electromagnetic forming device according to claim 6, further comprising: a uniform pressure driving coil skeleton;

The uniform pressure driving coil is placed inside the conductive channel through the uniform pressure driving coil skeleton.
A kind of electromagnetic forming method based on conductive channel, it is characterized in that, comprises the steps:

The conductive channel is placed on one side of the mold; the mold includes a left side area, a right side area and a middle concave area; the conductive channel includes a first sub-conductive channel, a second sub-conductive channel and a third sub-conductive channel; The first sub-conductive channel and the second sub-conductive channel are placed on one side of the left area of the mold and one side of the right area of the mold respectively, and the third sub-conductive channel connects the first sub-conductive channel and the second sub-conductive channel. a channel, forming an annular conductive channel with a notch, and the direction of the notch is towards the middle concave area of the mould;

The metal workpiece to be formed is placed at the gap inside the conductive channel; the length of the metal workpiece is greater than the length of the gap, and the two ends of the metal workpiece are respectively in close contact with the first sub-conductive channel and the second sub-conductive channel , the metal workpiece and the conductive channel form a conductive loop;

The uniform pressure driving coil is placed inside the conductive channel, and the outer contour shape of the uniform pressure coil matches the inner contour shape of the conductive channel;

After the pulse current is fed into the uniform pressure drive coil, the pulse magnetic field generated by it induces eddy current in the conductive circuit, and the pulse magnetic field interacts with the eddy current to generate electromagnetic force on the metal workpiece, driving the metal workpiece to The middle concave area of the mold is deformed.
The electromagnetic forming method according to claim 8, wherein the mold, the metal workpiece to be formed, the first sub-conductive channel, the second sub-conductive channel, and the third sub-conductive channel are all N; N is greater than an integer equal to 1;

The electromagnetic forming method can shape N metal workpieces, and the conductive path forms the conductive loop with the N metal workpieces.
The electromagnetic forming method according to claim 8 or 9, characterized in that, the interaction between the pulsed magnetic field and the eddy current generates an electromagnetic force on the metal workpiece, and the electromagnetic force provides the two ends of the metal workpiece to be in contact with the conductive channel and to be in close contact with the metal workpiece. The blank holder force ensures good electrical contact between the metal workpiece and the conductive channel during the forming process of the metal workpiece.