阅读说明：本技术 一种电磁驱动-电液管件成形装置及方法 (Electromagnetic drive-electrohydraulic pipe fitting forming device and method ) 是由 李亮 张毅 曹全梁 李潇翔 欧阳少威 韩小涛 赖智鹏 于 2020-06-12 设计创作，主要内容包括：本发明公开了一种电磁驱动-电液管件成形装置及方法,所述装置包括：电源模块、成形模块、助推模块、成形模具以及固定单元；通过触发成形用电源1-2,使金属丝2-2与腔室6中的液体发生化学反应,产生爆炸冲击波,驱使待成形工件发生塑性变形,并在模具型腔4-1的约束作用下成形；此外,通过助推用电源1-1触发助推线圈3-1在驱动板3-2上产生感应涡流和时变磁场,通过时序配合,为整个成形过程提供轴向助推电磁力,同时,通过驱动板3-2传递电磁作用力到待成形工件7的端部,从而增大管件的轴向运动趋势,提高材料的流动性。如此,在高速冲击波载荷和驱动板轴向助推力的协同作用下,实现对待成形工件7的塑性变形加工,能有效提高工件的成形能力和贴模性能。(The invention discloses an electromagnetic drive-electrohydraulic pipe fitting forming device and a method, wherein the device comprises: the device comprises a power supply module, a forming module, a boosting module, a forming die and a fixing unit; by triggering the forming power supply 1-2, the metal wire 2-2 and the liquid in the cavity 6 are subjected to chemical reaction to generate explosion shock waves, so that the workpiece to be formed is driven to be subjected to plastic deformation and is formed under the constraint action of the die cavity 4-1; in addition, the boosting power supply 1-1 for boosting triggers the boosting coil 3-1 to generate induced eddy current and a time-varying magnetic field on the driving plate 3-2, axial boosting electromagnetic force is provided for the whole forming process through time sequence matching, and meanwhile, electromagnetic acting force is transmitted to the end part of the workpiece 7 to be formed through the driving plate 3-2, so that the axial movement tendency of a pipe fitting is increased, and the flowability of materials is improved. Therefore, under the synergistic effect of the high-speed shock wave load and the axial boosting force of the driving plate, the plastic deformation processing of the workpiece 7 to be formed is realized, and the forming capability and the die attaching performance of the workpiece can be effectively improved.)

1. An electro-magnetically actuated-electro-hydraulic pipe forming apparatus, comprising:

the power supply module comprises a boosting power supply (1-1) and a forming power supply (1-2), wherein the boosting power supply (1-1) provides a first pulse current for a boosting coil (3-1), the forming power supply (1-2) provides a second pulse current for a metal wire (2-2), and the pulse width of the second pulse current is smaller than that of the first pulse current;

a forming module comprising an electrode (2-1), a wire (2-2) for generating an explosive shock wave; wherein the metal wire (2-2) is wound on the electrode (2-1) and is placed in the chamber (6);

the boosting module comprises a boosting coil (3-1) and a driving plate (3-2), wherein the driving plate (3-2) is positioned between the boosting coil (3-1) and the end part of a workpiece (7) to be formed; the boosting coil (3-1) generates an alternating magnetic field and induces eddy current in the driving plate (3-2), and the eddy current and the magnetic field generate axial boosting force on the driving plate (3-2) to enable the driving plate (3-2) to act and further enable the end of the workpiece (7) to be formed to flow axially;

The forming die comprises a die cavity (4-1), an exhaust hole (4-2) and a sealing plug (4-3); wherein the mould cavity (4-1) is used for providing space and appearance constraints for workpiece forming, and the sealing plug (4-3) and the workpiece (7) to be formed form the cavity (6);

the fixing unit comprises a fixing frame (5-1) and a telescopic backing ring (5-2) and provides a mounting and fixing structure for the device.

2. The electro-magnetically actuated-electro-hydraulic tube forming device of claim 1, wherein the drive plate (3-2) geometry is a combination of two coaxial hollow cylinders of different wall thickness and axial length, with a "T" section along the axis; the boosting coil (3-1) is placed on the top of the T-shaped part, and the bottom of the T-shaped part is connected with the workpiece (7) to be formed.

3. Electro-magnetically actuated-electro-hydraulic pipe forming device according to claim 1, wherein the telescopic backing ring (5-2) is formed by laminating a plurality of thin plates.

4. The electromagnetic drive-electrohydraulic pipe fitting forming device according to claim 3, wherein when a die cannot be effectively attached in one-step forming, follow-up of the boosting coil (3-1) is achieved by adjusting the telescopic backing ring (5-2), so that pushing force is increased, and die attaching forming is achieved.

5. The electro-magnetically actuated-electro-hydraulic tube forming device as claimed in claim 1, wherein the boost coil (3-1) is wound in upper and lower cover plates of the stationary unit.

6. The electro-magnetically driven-electro-hydraulic pipe forming apparatus of any one of claims 1-5, wherein the boost power source (1-1) and the forming power source (1-2) are adapted to achieve timing coordination of pulse current through a timing control system.

7. A pipe forming method of the electromagnetically driven-electrohydraulic pipe forming device as claimed in claim 1, characterized by comprising the steps of:

s1: the workpiece (7) to be formed is arranged opposite to the forming die, and a liquid medium is stored in a cavity (6); the metal wire (2-2) is wound on the electrode (2-1) and is placed in the cavity (6);

s2: -placing the driving plate (3-2) at the end of the piece to be formed (7) and placing the booster coil (3-1) on the driving plate (3-2); the boosting power supply (1-1) and the forming power supply (1-2) are connected;

s3: a first pulse current is provided for the boosting coil (3-1) through the boosting power supply (1-1), and axial boosting force is provided for the driving plate (3-2) through the action of electromagnetic induction, so that the workpiece (7) to be formed flows axially;

S4: in the action process of the axial boosting force, a second pulse current is provided for the metal wire (2-2) through the forming power supply (1-2) to generate an explosion shock wave and provide a forming impact load for the workpiece (7) to be formed, and then the die attaching forming is realized under the synergistic action of the explosion shock wave and the axial boosting force.

8. The method for forming a pipe fitting according to claim 7, wherein when the one-time forming cannot be effectively attached to the mold, the follow-up of the booster coil is realized by adjusting the telescopic backing ring (5-2), and the steps S3 and S4 are repeated to perform the multiple composite forming.

Technical Field

The invention belongs to the field of metal forming and manufacturing, and particularly relates to an electromagnetic drive-electrohydraulic pipe fitting forming device and method.

Background

Metals are the most common processing materials, and light alloys such as magnesium alloys and aluminum alloys are important ways for realizing light weight, energy conservation and emission reduction, and are widely adopted in the aerospace industry, the automobile industry and the like. In the processing and manufacturing such as pipe deep forming and corrugated pipe manufacturing, the deformation of a workpiece is large, and the local part is excessively thinned or even torn in the processing process, so that the processing and manufacturing industry is always difficult. Patent document CN103406418B discloses a radial and axial bidirectional loading type metal pipe electromagnetic forming method and device, which can apply pulse electromagnetic force to provide axial pushing at the end of the pipe in the radial bulging process of the metal pipe, thereby enhancing the fluidity of the material, improving the forming limit of the workpiece, and increasing the radial deformation of the pipe. However, this method is only suitable for metal materials with good conductivity, such as aluminum alloy, and for materials with poor conductivity, such as magnesium alloy and steel, it is difficult to realize electromagnetic force loading. Meanwhile, the method has the problems of easy axial instability of the pipe fitting, poor die attaching performance and the like.

Electro-hydraulic forming is a processing technology for high-speed forming. The metal wire is rapidly heated and exploded under the condition of large current, and the metal wire and surrounding liquid react to rapidly expand in volume, so that shock waves are generated and transmitted to the surface of a workpiece, and the workpiece is plastically deformed under the action of shock load to be processed and manufactured. Compared with the traditional quasi-static processing mode, the high-speed impact load of electro-hydraulic forming can greatly improve the forming limit of the material. Compared with electromagnetic forming, the workpiece does not need to have good conductive performance, so that the applicability is wider; because the liquid is used as a medium for transmitting the shock wave and has certain incompressibility, the axial instability of the pipe fitting caused by excessive pushing of the end part can be well inhibited, and the die attaching performance can be obviously improved. However, the action time of the shock wave load formed by electro-hydraulic molding is extremely short and uncontrollable, and meanwhile, the problem of an actual tool for effectively sealing liquid exists, so that the continuous and stable axial pushing force is difficult to provide in the whole processing process in a quasi-static manner; and the low-conductivity material is difficult to directly load enough axial electromagnetic pushing force in a coil discharging mode.

Disclosure of Invention

The invention provides an electromagnetic drive-electro-hydraulic pipe forming device and method aiming at overcoming the defects and improvement requirements of the prior art, and aims to solve the problems that when a pipe is subjected to large deformation processing such as deep forming, corrugated pipe manufacturing and the like, a workpiece is easy to thin and break, and the electromagnetic forming process cannot directly act on a non-benign conductor workpiece, and the like.

To achieve the above object, as one aspect of the present invention, there is provided an electromagnetically driven-electrohydraulic pipe forming apparatus comprising:

the power module comprises a boosting power supply and a forming power supply, wherein the boosting power supply provides first pulse current for a boosting coil, the forming power supply provides second pulse current for a metal wire, the second pulse current pulse width is smaller than the first pulse current pulse width, the second pulse current is asynchronous with the first pulse current, and the second pulse current can be triggered at different positions of the first pulse current.

A forming module comprising an electrode, a wire, for generating an explosive shock wave; wherein the metal wire is wound on the electrode and is placed in the cavity;

the boosting module comprises a boosting coil and a driving plate, and the driving plate is positioned between the boosting coil and the end part of the workpiece to be formed; the boosting coil generates an alternating magnetic field and induces eddy current in the driving plate, and the eddy current and the magnetic field generate axial boosting force on the driving plate to enable the driving plate to act and further enable the end part of the workpiece to be formed to axially flow;

The forming die comprises a die cavity, an exhaust hole and a sealing plug; the die cavity is used for providing space and appearance constraint for workpiece forming, and the sealing plug and the workpiece to be formed form the cavity;

and the fixing unit comprises a fixing frame and a telescopic backing ring and provides a mounting and fixing structure for the device.

Further, the geometric shape of the driving plate is a combination of two coaxial hollow cylinders with different wall thicknesses and different axial lengths, and the cross section of the driving plate along the axial line is T-shaped; the boosting coil is placed at the top of the T-shaped part, and the bottom of the T-shaped part is connected with the workpiece to be formed.

Further, the telescopic backing ring is formed by overlapping a plurality of thin plates.

Furthermore, when the die cannot be effectively attached in one-step forming, the follow-up of the boosting coil is realized by adjusting the telescopic backing ring, so that the pushing force is increased, and the die attaching forming is realized.

Further, the boosting coil is wound in the upper cover plate and the lower cover plate of the fixing unit.

Furthermore, the boosting power supply and the forming power supply realize the time sequence matching of pulse current through a time sequence control system.

As another aspect of the present invention, there is provided a pipe forming method of an electromagnetically driven-electrohydraulic pipe forming apparatus, comprising the steps of:

S1: placing the workpiece to be formed opposite to the forming die, and storing a liquid medium in a cavity; the metal wire is wound on the electrode and is placed in the cavity;

s2: placing the drive plate at an end of the workpiece to be formed and placing the boost coil on the drive plate; connecting the boosting power supply and the forming power supply;

s3: providing a first pulse current for the boosting coil through the boosting power supply, and providing axial boosting force for the driving plate through electromagnetic induction to enable the workpiece to be formed to axially flow;

s4: in the action process of the axial boosting force, a second pulse current is provided for the metal wire through the forming power supply to generate an explosive shock wave, a forming impact load is provided for the workpiece to be formed, and then die attachment forming is realized under the synergistic action of the explosive shock wave and the axial boosting force.

Further, when the die cannot be effectively attached in one-time forming, the telescopic backing ring is adjusted to realize follow-up of the boosting coil, and the steps S3 and S4 are repeated to perform multiple times of composite forming.

Generally, by the above technical solution conceived by the present invention, the following beneficial effects can be obtained:

(1) The forming method combining electro-hydraulic and electromagnetic is adopted, plastic deformation processing of the workpiece to be formed is realized under the synergistic effect of high-speed shock wave load and axial boosting force of the driving plate, and compared with single-method forming, material flowing is effectively increased, workpiece thinning and tearing are inhibited, and the forming limit of the material is improved.

(2) The electro-hydraulic forming mode and the electromagnetic pushing mode that the driving coil acts electromagnetic force on the driving plate so as to be indirectly loaded on the end part of the workpiece are adopted, the requirements on the conductivity of the material of the workpiece are met, the electro-hydraulic forming method is suitable for processing and manufacturing various metal materials such as aluminum alloy, magnesium alloy, steel and the like, and the constraint of the conductivity of the material of the workpiece is successfully eliminated.

(3) The main body of the invention adopts an electro-hydraulic bulging mode, and due to the incompressibility of liquid, the axial instability problem caused by axial excessive pushing can be inhibited while the shock wave load is transferred, and the die attaching performance of the workpiece is obviously improved.

(4) According to the invention, the push coil is fixed in the upper cover plate and the lower cover plate of the fixing unit, so that the structure of the device is simplified, and the reaction force borne by the coil is effectively counteracted.

(5) The design of flexible backing ring for the device can carry out accurate location to the boosting coil, can realize progressively following simultaneously, makes the boosting coil press close to the drive plate all the time, thereby realizes taking shape many times, further promotes the limit of taking shape.

Drawings

FIG. 1 is a schematic diagram of a typical current timing coordination for an electro-magnetically driven-electro-hydraulic pipe forming apparatus provided in accordance with the present invention;

FIG. 2 is a schematic view of a pipe fitting force fit forming process of the electromagnetic drive-electrohydraulic pipe fitting forming device provided by the invention;

FIG. 3 is a schematic structural diagram of an electro-hydraulic pipe forming apparatus with electromagnetic driving according to an embodiment of the present invention;

FIG. 4 is a schematic diagram of a process of multiple forming in an electromagnetically driven-electrohydraulic pipe forming device according to an embodiment of the present invention; wherein, fig. 4-1 is a state schematic diagram after the primary forming, before the coil following and the secondary forming start, and fig. 4-2 is a state schematic diagram of the final sticking mold forming;

FIG. 5 is a schematic structural diagram of an electromagnetically driven-electrohydraulic pipe forming device according to a second embodiment of the present invention;

FIG. 6 is a schematic structural diagram of an electromagnetically driven-electrohydraulic pipe forming device provided by a third embodiment of the invention;

the same reference numbers will be used throughout the drawings to refer to the same or like elements or structures, wherein: 1-1 is a power supply for boosting, 1-2 is a power supply for forming, 2-1 is an electrode, 2-2 is a metal wire, 3-1 is a boosting coil, 3-2 is a driving plate, 4-1 is a die cavity, 4-2 is an exhaust hole, 4-3 is a sealing plug, 5-1 is a fixed frame, 5-2 is a telescopic backing ring, 6 is a cavity, and 7 is a workpiece to be formed.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention. In addition, the technical features involved in the embodiments of the present invention described below may be combined with each other as long as they do not conflict with each other.