Device and method for realizing electromagnetic forming radial thrust of plate by adopting axial constant magnetic field and induced eddy current
Technical Field
The invention belongs to the field of metal processing, and particularly relates to a device and a method for realizing electromagnetic forming radial thrust of a plate by adopting an axial constant magnetic field and induced eddy current, which are mainly used for increasing the metal fluidity in the plate forming process and preventing the plate from being torn.
Background
When the traditional electromagnetic plate is formed, axial electromagnetic force is applied to a deformation area to enable the plate to be expanded; at the moment, because the bottom of the plate is stressed to drive the edge of the plate to flow towards the center, the plate is mainly expanded, the flowability is poor in the deformation process, and the plate is very easy to tear.
the document "Radial L-oriented force with respect to large-area drawing using a novel two-dimensional electromagnetic forming system (Journal of materials Processing Technology, 2015, 22213-20)" proposes that an electromagnetic drawing process is achieved by an axial-Radial bi-directional loading electromagnetic forming method, which can increase the Radial fluidity of a plate and improve the forming performance of a workpiece.
Disclosure of Invention
Therefore, the invention provides a device and a method for realizing electromagnetic forming radial thrust of a plate by adopting an axial constant magnetic field and induced eddy current, wherein the axial constant magnetic field is generated by adopting a constant magnetic field coil, the annular induced eddy current is generated by adopting a pulse magnetic field coil, and the radial electromagnetic thrust is generated by the combined action of the axial constant magnetic field and the annular induced eddy current; the method can greatly increase the radial electromagnetic force and further improve the flowability and the forming performance of the plate.
The technical scheme adopted by the invention is as follows:
A device for realizing electromagnetic forming radial thrust of a plate by adopting an axial constant magnetic field and induced eddy current comprises:
The first constant magnetic field coil and the second constant magnetic field coil are used for generating an axial constant magnetic field at the edge of the metal plate to be formed;
The first pulse magnetic field coil and the second pulse magnetic field coil are used for generating induced eddy current at the edge of the metal plate to be formed;
The edge pressing magnetic yoke, the magnetic female die and the magnetic soft gasket are used for forming a constant magnetic field magnetic loop;
A pulse force coil for providing a forming force to the sheet metal piece to be formed;
The edge pressing magnetic yoke comprises a first annular groove, and the section of the first annular groove is rectangular; the inner edge of the first annular groove is attached to the outer edge of the metal plate to be formed; the outer edge of the first annular groove is superposed with the inner edge of the magnetic soft gasket;
The magnetic female die comprises a second annular groove, and the section of the second annular groove is rectangular; the inner side edge of the second annular groove is attached to the outer side edge of the metal plate to be formed; the outer edge of the second annular groove is superposed with the inner edge of the magnetic soft gasket;
The first constant magnetic field coil is positioned at the upper part in the first annular groove of the blank holder magnet yoke, and the second constant magnetic field coil is positioned at the lower part in the second annular groove of the magnetic female die; the first constant magnetic field coil and the second constant magnetic field coil are vertically symmetrical relative to a plane where the metal plate to be formed is located; the first constant magnetic field coil and the second constant magnetic field coil are connected in series with a direct current power supply;
The first pulse magnetic field coil is positioned at the lower part in the first annular groove of the blank holder magnet yoke, and the second pulse magnetic field coil is positioned at the upper part in the second annular groove of the magnetic female die; the first pulse magnetic field coil and the second pulse magnetic field coil are vertically symmetrical relative to the plane of the metal plate to be formed; the first and second pulse magnetic field coils are connected in series with a pulse power supply.
The edge pressing magnetic yoke is formed by laminating insulating silicon steel sheets with the thickness of 0.2 mm.
The magnetic concave die is formed by laminating insulating silicon steel sheets with the thickness of 0.2 mm.
The first annular groove of the edge pressing magnetic yoke and the second annular groove of the magnetic concave die are located at the same radius position, and the width and the depth of the grooves are consistent.
The magnetic soft gasket is a circular ring with a flat rectangular cross section; the thickness of the magnetic soft gasket is the same as that of the metal plate to be formed; the magnetic soft gasket is formed by laminating insulating silicon steel sheets with the thickness of 0.2 mm.
The metal plate to be formed is a circular thin plate; the thickness of the metal plate to be formed is 2-5 mm.
A method for realizing electromagnetic forming radial thrust of a plate by adopting an axial constant magnetic field and induced eddy current is characterized in that a first constant magnetic field coil is arranged at the upper part in a first annular groove of a blank holder magnet yoke, and a second constant magnetic field coil is arranged at the lower part in a second annular groove of a magnetic female die;
Placing a first pulse magnetic field coil at the lower part in a first annular groove of the blank holder magnetic yoke, and placing a second pulse magnetic field coil at the upper part in a second annular groove of the magnetic female die;
Sequentially placing a magnetic female die, a metal plate to be formed, a magnetic soft gasket and a blank holder magnetic yoke, and enabling the symmetry axes to coincide;
A direct-current power supply is adopted to supply power to the first constant magnetic field coil and the second constant magnetic field coil in series, so that an axial constant magnetic field is generated at the outer edge of the metal plate to be formed;
A pulse power supply is adopted to supply power to the first pulse magnetic field coil and the second pulse magnetic field coil in series, and pulse current generates circumferential induced eddy current on the outer edge of the metal plate to be formed;
The axial constant magnetic field and the annular induction eddy current interact to generate radial electromagnetic thrust;
And a pulse force coil is adopted to provide forming electromagnetic force for the metal plate to be formed, so that electromagnetic forming of the plate under the state of radial electromagnetic thrust is realized.
The action of the axially downward constant magnetic field and the anticlockwise annular induced eddy current generates radially inward electromagnetic thrust; or the action of the axially upward constant magnetic field and the clockwise annular induced eddy current generates radially inward electromagnetic thrust.
The invention relates to a device and a method for realizing electromagnetic forming radial thrust of a plate by adopting an axial constant magnetic field and induced eddy current, wherein a constant magnetic field coil is adopted to generate an axial constant magnetic field, a pulse magnetic field coil is adopted to generate annular induced eddy current, and the axial constant magnetic field and the annular induced eddy current jointly act to generate radial electromagnetic thrust; the method can greatly increase the radial electromagnetic force and further improve the flowability and the forming performance of the plate.
Drawings
The invention is further illustrated by the following examples in conjunction with the accompanying drawings:
FIG. 1 is a schematic cross-sectional view of a 2/3 device for realizing electromagnetic forming radial thrust of a plate by adopting an axial constant magnetic field and induced eddy currents.
Wherein:
1.1-a first constant magnetic field coil, 1.2-a second constant magnetic field coil;
2.1-a first pulse magnetic field coil, 2.2-a second pulse magnetic field coil;
3-edge pressing magnet yoke
4-magnetic concave die;
5-magnetic soft gasket;
6-a metal sheet to be formed;
7-a pulsed force coil;
8-a direct current power supply;
9-pulse power supply.
Detailed Description
A device for realizing electromagnetic forming radial thrust of a plate by adopting an axial constant magnetic field and induced eddy current comprises:
The first constant magnetic field coil 1.1 and the second constant magnetic field coil 1.2 are used for generating an axial constant magnetic field at the edge of the sheet metal part 6 to be formed;
The first pulse magnetic field coil 2.1 and the second pulse magnetic field coil 2.2 are used for generating induced eddy current at the edge of the metal plate 6 to be formed;
The edge pressing magnetic yoke 3, the magnetic concave die 4 and the magnetic soft gasket 5 are used for forming a constant magnetic field magnetic circuit;
A pulse force coil 7 for providing a forming force to the sheet metal element 6 to be formed.
The first constant magnetic field coil is a traditional coil and is formed by winding a copper wire, and the geometric dimension of the first constant magnetic field coil and the first pulse magnetic field coil can be placed in a first annular groove of the side pressing magnetic yoke at the same time for limitation.
The second constant magnetic field coil is a traditional coil and is formed by winding a copper wire, and the geometric dimension of the second constant magnetic field coil is limited by the fact that the second constant magnetic field coil and the second pulse magnetic field coil can be placed in a second annular groove of the magnetic female die at the same time.
The first pulse magnetic field coil is a traditional coil and is formed by winding a copper wire, and the geometric dimension of the first pulse magnetic field coil and the first constant magnetic field coil can be placed in a first annular groove of the side pressing magnetic yoke at the same time for limitation.
The second pulse magnetic field coil is a traditional coil and is formed by winding a copper wire, and the geometric dimension of the second pulse magnetic field coil is limited by the fact that the second pulse magnetic field coil and the second constant magnetic field coil can be placed in a second annular groove of the magnetic female die at the same time.
The pulse force coil 7 is a traditional coil and is formed by winding a copper wire; the specific position coincides with the axis of the metal plate 6 to be formed, clings to the metal plate 6 to be formed and is positioned on the same side with the side pressing magnetic yoke.
The edge pressing magnet yoke 3 comprises a first annular groove, and the section of the first annular groove is rectangular; the edge of the inner side of the first annular groove is attached to the edge of the outer side of the metal plate 6 to be formed; the outer edge of the first annular groove coincides with the inner edge of the magnetic soft gasket 5. The edge-pressing magnet yoke 3 comprises a first annular groove, the cross section of the first annular groove is rectangular, and the first constant magnetic field coil 1.1 and the first pulse magnetic field coil 2.1 are arranged in order to be placed. The inner edge of the first annular groove is attached to the outer edge of the metal plate 6 to be formed, so that a larger constant magnetic field is generated at the metal plate 6 to be formed. The outer edge of the first annular groove coincides with the inner edge of the magnetic soft gasket 5, and in order to make the magnetic resistance of the whole magnetic circuit smaller, the magnetic field is larger.
The magnetic concave die 4 comprises a second annular groove, and the section of the second annular groove is rectangular; the inner side edge of the second annular groove is attached to the outer side edge of the metal plate 6 to be formed; the outer edge of the second annular groove is coincident with the inner edge of the magnetic soft gasket 5. The magnetic concave die 4 comprises a second annular groove, the cross section of the second annular groove is rectangular, and the second annular groove is used for placing a second constant magnetic field coil 1.2 and a second pulse magnetic field coil 2.2.
The inner edge of the second annular groove is attached to the outer edge of the metal sheet 6 to be formed, so as to generate a larger constant magnetic field at the metal sheet 6 to be formed.
The outer edge of the second annular groove coincides with the inner edge of the magnetic soft gasket 5, so that the magnetic resistance of the whole magnetic circuit is smaller and the magnetic field is larger.
The first constant magnetic field coil 1.1 is positioned at the upper part in the first annular groove of the edge pressing magnet yoke 3, and the second constant magnetic field coil 1.2 is positioned at the lower part in the second annular groove of the magnetic female die 4; the first constant magnetic field coil and the second constant magnetic field coil are vertically symmetrical relative to the plane of the metal plate 6 to be formed; the first and second constant magnetic field coils are connected in series with a direct current power supply 8;
The first pulse magnetic field coil 2.1 is positioned at the lower part in the first annular groove of the blank-holding magnetic yoke 3, and the second pulse magnetic field coil 2.2 is positioned at the upper part in the second annular groove of the magnetic concave die 4; the first pulse magnetic field coil and the second pulse magnetic field coil are vertically symmetrical relative to the plane of the metal plate 6 to be formed; the first and second pulse magnetic field coils are connected in series with a pulse power supply 9.
The edge pressing magnetic yoke 3 is formed by laminating insulating silicon steel sheets with the thickness of 0.2 mm. No induced eddy current exists in the side-pressing magnetic yoke 3, and the loss is reduced. The cost increases when the silicon steel sheet is too thin, and the loss increases when the silicon steel sheet is too thick.
The magnetic concave die 4 is formed by laminating insulating silicon steel sheets with the thickness of 0.2 mm. No induced eddy current exists in the magnetic concave die 4, and the loss is reduced. The cost increases when the silicon steel sheet is too thin, and the loss increases when the silicon steel sheet is too thick.
The first annular groove of the edge pressing magnetic yoke 3 and the second annular groove of the magnetic concave die 4 are in the same radius position, and the width and the depth of the grooves are consistent. The first constant magnetic field coil 1.1 and the first pulse magnetic field coil 2.1 are placed in the first annular groove of the edge pressing magnetic yoke 3. And a second constant magnetic field coil 1.2 and a second pulse magnetic field coil 2.2 are placed in a second annular groove of the magnetic concave die 4.
Since the first constant magnetic field coil 1.1 and the first pulsed magnetic field coil 2.1 are identical in size to the second constant magnetic field coil 1.2 and the second pulsed magnetic field coil 2.2, the width and depth of the groove are required to be identical.
The magnetic soft gasket 5 is a circular ring with a flat rectangular cross section; the thickness of the magnetic soft gasket 5 is the same as that of the metal plate 6 to be formed; the magnetic soft gasket 5 is formed by laminating insulating silicon steel sheets with the thickness of 0.2 mm. The magnetic soft gasket 5 is a circular ring with a flat rectangular cross section; the thickness of the magnetic soft gasket 5 is the same as that of the metal plate 6 to be formed, and the magnetic soft gasket is matched with the gap between the edge pressing magnetic yoke 3 and the magnetic concave die 4.
The magnetic soft gasket 5 is formed by laminating insulating silicon steel sheets with the thickness of 0.2mm, so that no induced eddy current exists in the magnetic soft gasket 5, and the loss is reduced. The cost increases when the silicon steel sheet is too thin, and the loss increases when the silicon steel sheet is too thick.
The metal plate 6 to be formed is a circular thin plate; the thickness of the metal plate 6 to be formed is 2-5 mm.
A method for realizing electromagnetic forming radial thrust of a plate by adopting an axial constant magnetic field and induced eddy current comprises the steps of placing a first constant magnetic field coil 1.1 at the upper part in a first annular groove of a blank holder magnetic yoke 3, and placing a second constant magnetic field coil 1.2 at the lower part in a second annular groove of a magnetic female die 4;
Placing a first pulse magnetic field coil 2.1 at the lower part in a first annular groove of the blank holder magnet yoke 3, and placing a second pulse magnetic field coil 2.2 at the upper part in a second annular groove of the magnetic concave die 4;
Sequentially placing a magnetic female die 4, a metal plate 6 to be formed, a magnetic soft gasket 5 and a blank pressing magnetic yoke 3, and enabling symmetry axes of the magnetic female die, the metal plate 6 to be formed, the magnetic soft gasket 5 and the blank pressing magnetic yoke 3 to coincide;
The first constant magnetic field coil 1.1 and the second constant magnetic field coil 1.2 are powered in series by a direct current power supply 8, so that an axial constant magnetic field is generated on the outer edge of the metal plate part 6 to be formed. And a direct current power supply 8 is adopted to supply power to the first constant magnetic field coil 1.1 and the second constant magnetic field coil 1.2 in series, so that the sizes of the generated axial constant magnetic fields are consistent.
A pulse power supply 9 is adopted to supply power to the first pulse magnetic field coil 2.1 and the second pulse magnetic field coil 2.2 in series, and pulse current generates annular induced eddy current on the outer edge of the metal plate 6 to be formed; the pulse power supply 9 is adopted to supply power to the first pulse magnetic field coil 2.1 and the second pulse magnetic field coil 2.2 in series, so that the generated toroidal induced eddy currents are consistent.
F = JXB, the axial constant magnetic field interacts with the annular induction eddy current to generate radial electromagnetic thrust.
The pulse force coil 7 is adopted to provide forming electromagnetic force for the metal plate 6 to be formed, and electromagnetic forming of the plate under the radial electromagnetic thrust state is achieved. The pulse current provided by the pulse force coil 7 generates induced eddy currents with opposite directions in the middle of the metal plate 6 to be formed, and the pulse current and the induced eddy currents have opposite directions to provide electromagnetic force for the metal plate 6 to be formed. Meanwhile, the first and second constant magnetic field coils and the first and second pulse magnetic field coils provide electromagnetic thrust for the sheet metal part 6 to be formed, so that the sheet metal part 6 to be formed is electromagnetically formed in a state of radial electromagnetic thrust.
the axial downward constant magnetic field and the counterclockwise circumferential induced eddy current act to generate radial inward electromagnetic thrust, or the axial upward constant magnetic field and the clockwise circumferential induced eddy current act to generate radial inward electromagnetic thrust.
Example 1:
Placing a first constant magnetic field coil 1.1 at the upper part in the groove of the side pressing magnet yoke, and placing a second constant magnetic field coil 1.2 at the lower part in the groove of the magnetic female die; placing a first pulse magnetic field coil 2.1 at the lower part in the groove of the edge pressing magnet yoke, and placing a second pulse magnetic field coil 2.2 at the upper part in the groove of the magnetic concave die;
Sequentially placing a magnetic female die, a metal plate to be formed, a magnetic soft gasket and a blank holder magnetic yoke, and enabling the symmetry axes to coincide; a direct-current power supply is adopted to supply power to the first constant magnetic field coil 1.1 and the second constant magnetic field coil 1.2 in series, so that an axial constant magnetic field is generated at the outer edge of the metal plate to be formed;
A pulse power supply is adopted to supply power to the first pulse magnetic field coil 2.1 and the second pulse magnetic field coil 2.2 in series, and pulse current generates annular induced eddy current on the outer edge of the metal plate to be formed;
The axial constant magnetic field and the circumferential induced eddy current interact to generate radial electromagnetic thrust; the axial downward constant magnetic field and the anticlockwise circumferential induced eddy current act to generate radial inward electromagnetic thrust, or the axial upward constant magnetic field and the clockwise circumferential induced eddy current act to generate radial inward electromagnetic thrust; and a pulse force coil is adopted to provide forming electromagnetic force for the metal plate to be formed, so that electromagnetic forming of the plate under the state of radial electromagnetic thrust is realized.