CN113695464B

CN113695464B - Plate forming device and method for eliminating springback and warping through electromagnetic pulse

Info

Publication number: CN113695464B
Application number: CN202110991797.6A
Authority: CN
Inventors: 崔晓辉; 杜志浩
Original assignee: Central South University
Current assignee: Enpu Sai (Xiangyang) Technology Co.,Ltd.
Priority date: 2021-08-26
Filing date: 2021-08-26
Publication date: 2022-11-08
Anticipated expiration: 2041-08-26
Also published as: CN113695464A

Abstract

The invention discloses a plate forming device for eliminating springback and warping through electromagnetic pulse, which comprises a forming die and a pulse current generating circuit for forming pulse current in a plate, wherein the forming die is provided with a forming surface for forming the plate, and the pulse current generating circuit is arranged to form the pulse current on the plate which is attached to the forming surface after forming, wherein the pulse current can be directly connected in series to be introduced into the pulse current, and can also generate induced pulse current through an electromagnetic forming coil. According to the invention, larger pulse current can be formed on the plate and pulse electromagnetic force is applied to the plate, so that dislocation vacancies in the plate are accelerated to move and the plate generates a high-frequency oscillation effect, and the rebound and warpage of the plate are eliminated.

Description

Plate forming device and method for eliminating springback and warping through electromagnetic pulse

Technical Field

The invention relates to the technical field of material processing and forming, in particular to a plate forming device and method for eliminating springback and warping through electromagnetic pulses.

Background

In the forming process of the plate-type part, residual stress distribution inside the formed part is not uniform due to anisotropy of materials, uneven contact between the blank holders and the plate, uneven friction, local load bearing of the plate and the like. When the force applying devices such as the die and the like are unloaded, the plate can be obviously rebounded and warped. In order to eliminate the springback and warpage of the parts, the conventional methods mainly include methods such as die compensation and heating. The mould compensation method repeatedly modifies the shape of the mould so that the shape of the part after rebounding meets the design requirement.

However, repeated modifications to the mold can significantly increase the cost of the mold and make it difficult to adapt to complex structural parts. The heating method needs to heat the formed part to a certain temperature and then preserve heat for a period of time, the preheating time and the heat preservation time are both long, and the efficiency is low. In addition, the surface of the plate material is easily oxidized at high temperature. When the size of the part is large, the part is easy to be heated unevenly, so that the problems of cracking, warping and the like of the plate can be caused, and the quality of the part is seriously influenced.

Disclosure of Invention

The invention aims to provide a plate forming device and a method for eliminating springback and warping through electromagnetic pulse, thereby solving the problems.

In order to achieve the above object, the present invention firstly discloses a plate forming apparatus for eliminating springback and warpage by electromagnetic pulse, comprising a forming die and a pulse current generating circuit for forming a pulse current in the plate, wherein the forming die is provided with a forming surface for forming the plate, and the pulse current generating circuit is configured to form the pulse current on the plate which is attached to the forming surface after forming.

Furthermore, an electromagnetic forming coil which can be introduced with pulse current is arranged on the pulse current generating circuit, and the electromagnetic forming coil is arranged close to the plate on the forming surface.

Furthermore, an elastic pad is arranged between the plate and the forming surface after the plate is formed by the forming die, or the forming die is provided with a gap for the plate to vibrate after the plate is formed.

Further, the forming die comprises a stamping male die and a stamping female die, the forming surface is a stamping hole wall which is arranged on the stamping female die and can be matched with the stamping male die, a stamping blank holder used for pressing a plate blank is arranged on the upper side of the stamping female die, the electromagnetic forming coil is arranged in a coil framework, the coil framework is provided with a sleeve ring which can be sleeved outside the stamping female die, and a lateral driving plate edge is arranged in the sleeve ring.

Further, the forming die comprises a stamping male die and a stamping female die, the forming surface is a stamping hole wall which is arranged on the stamping female die and can be matched with the stamping male die, a stamping blank holder used for pressing the blank of the plate is arranged on the upper side of the stamping female die, and the electromagnetic forming coil is arranged in a coil framework and is positioned above the stamping female die.

Furthermore, the forming die comprises a spinning female die, a spinning wheel and a spinning blank holder for pressing the plate on the spinning female die, the forming surface is arranged on the spinning female die, and the electromagnetic forming coil is arranged behind the moving direction of the spinning wheel and close to the plate.

Furthermore, the forming die comprises a pressing male die and a pressing plate assembly capable of clamping a plate to move up and down relative to the pressing male die, the forming surface is a forming convex surface arranged on the upper side of the pressing male die, and the pressing plate assembly comprises a pressing plate which is tightly pressed from the upper side and the lower side and is attached to the forming convex surface.

Further, the forming die comprises a pressing male die and a pressing female die, a forming convex surface is arranged on the upper side of the pressing male die, a forming concave surface is arranged in the pressing female die, the electromagnetic forming coil is arranged on the inner side of the forming convex surface and/or the forming concave surface, and the pulse current generating circuit is arranged in a manner that the forming convex surface and the forming concave surface are both attached to the plate and then are discharged by the electromagnetic forming coil.

Further, the forming die comprises a drawing male die and a drawing female die, the forming surface is arranged at the bottom of the drawing female die and can be matched with the drawing male die through the drawing counter bore, the electromagnetic forming coil is arranged in the drawing male die, or the electromagnetic forming coil is arranged at the corners at two ends of the drawing counter bore.

Then, the invention discloses a plate forming method for eliminating springback and warping through electromagnetic pulse, which adopts any one of the plate forming devices for eliminating springback and warping through electromagnetic pulse, and comprises the following steps:

s1, controlling a forming die to form a plate, wherein the plate is attached to the forming surface, and an elastic cushion is arranged between the plate and the forming surface or a gap for the plate to vibrate is formed between the plate and the forming surface;

s2, after the forming of the forming die is finished, controlling a pulse current generating circuit to form pulse current on the plate which is attached to the forming surface after forming, wherein the mode of forming the pulse current comprises a mode of generating induced pulse current on the plate through the electromagnetic forming coil and a mode of directly introducing the pulse current into the plate.

Compared with the prior art, the invention has the advantages that:

according to the invention, through forming larger pulse current on the plate, dislocation vacancies inside the plate move in an accelerated manner, so that the effects of eliminating the resilience and warping of the plate are achieved; furthermore, the combined action of mould forming and electromagnetic pulse for eliminating resilience and warping is adopted, the electromagnetic coil can form larger electromagnetic force on the formed plate, the plate is driven to deform in the direction away from the coil, and induced pulse current can be formed in the plate, and the combined action of the mould forming and the electromagnetic pulse improves the effect of eliminating resilience and warping of the plate; simultaneously, through set up the cushion at panel and shaping surface to can drive panel production high frequency oscillation effect, the combined action of three has further improved the effect of eliminating the resilience and the warpage of panel.

The present invention will be described in further detail below with reference to the accompanying drawings.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this application, illustrate embodiments of the invention and, together with the description, serve to explain the invention and not to limit the invention. In the drawings:

FIG. 1 is a schematic view of a forming die of a sheet forming apparatus for eliminating springback and warpage by electromagnetic pulses according to an embodiment of the present invention;

FIG. 2 is a schematic diagram illustrating the springback or warpage of a sheet material after the forming die is unloaded according to an embodiment of the present invention;

FIG. 3 is a schematic diagram of a side-push electromagnetic forming coil for eliminating springback and warpage (a plate is clamped and provided with an elastic pad) according to an embodiment of the present invention;

FIG. 4 is a schematic diagram of a side-push electromagnetic forming coil according to an embodiment of the present invention to eliminate spring back and warpage (the plate is not clamped);

FIG. 5 is a schematic diagram of a side-push electromagnetic forming coil for eliminating spring back and warp according to an embodiment of the present invention (the plate is clamped and has no elastic pad);

FIG. 6 is a schematic diagram of an embodiment of the present invention for eliminating springback and warpage of a blank-pressing electromagnetic forming coil (a plate is clamped and provided with an elastic pad);

FIG. 7 is a schematic diagram of a blank-pressing electromagnetic forming coil for eliminating springback and warpage according to an embodiment of the present invention (a plate is clamped and an elastic pad is not provided);

FIG. 8 is a schematic diagram of a blank-holder electromagnetic forming coil according to an embodiment of the present invention for eliminating spring back and warp (the sheet is not clamped);

FIG. 9 is a schematic view of a spin forming process of a forming mold according to a second embodiment of the present invention;

FIG. 10 is a schematic diagram of the rebound or warpage of the unloaded spin-formed sheet according to the second embodiment of the present invention;

FIG. 11 is a schematic view of spin forming to eliminate spring back and warp by electromagnetic forming of the coil according to the second embodiment of the present invention;

FIG. 12 is a schematic view of the electromagnetic forming coil for eliminating springback and warpage in the case of spin forming after installation of the elastic pad according to the second embodiment of the present invention;

FIG. 13 is a schematic forming diagram of a high-efficiency and high-precision magnetic pulse forming device for a plate material disclosed in the third embodiment of the present invention;

FIG. 14 is a schematic forming diagram of a high-efficiency and high-precision magnetic pulse forming device for a sheet material according to a fourth embodiment of the present invention;

FIG. 15 is a schematic forming diagram of a high-efficiency and high-precision magnetic pulse forming device for a plate material disclosed in the fifth embodiment of the invention;

FIG. 16 is a schematic forming diagram of a high-efficiency and high-precision magnetic pulse forming device for a plate according to a sixth embodiment of the present invention;

fig. 17 is a schematic forming diagram of a high-efficiency and high-precision magnetic pulse forming device for a plate material, which is disclosed by the seventh embodiment of the invention.

Illustration of the drawings:

1. a pulse current generating circuit; 2. an electromagnetic forming coil; 3. a plate material; 4. a forming surface; 5. an elastic pad; 6. stamping a male die; 7. stamping a female die; 8. stamping a blank holder; 9. a coil former; 10. a collar; 11. spinning a blank holder; 12. spinning a female die; 13. a spinning wheel; 14. pressing a male die; 15. a platen assembly; 16. pressing a female die; 17. drawing a male die; 18. drawing the female die; 19. turning; 20. and an electrode.

Detailed Description

Embodiments of the invention will be described in detail below with reference to the drawings, but the invention can be implemented in many different ways as defined and covered by the claims.

The first embodiment is as follows:

as shown in fig. 1 to 8, the embodiment of the invention discloses a plate forming device for eliminating springback and warpage by electromagnetic pulse, which comprises a forming die and a pulse current generating circuit 1, wherein an electromagnetic forming coil 2 is arranged on the pulse current generating circuit 1, the pulse current generating circuit 1 comprises a capacitor C, a resistor R and an inductor L, a forming surface 4 for forming a plate 3 is arranged on the forming die, and the electromagnetic forming coil 2 is arranged close to the plate 3 which is attached to the forming surface 4 after being formed by the forming die. Therefore, on one hand, the electromagnetic forming coil 2 can form large electromagnetic force on the formed plate 3 to drive the plate 3 to deform in the direction away from the coil; meanwhile, larger induced pulse current can be formed on the plate 3, dislocation vacancies in the plate 3 move in an accelerated manner, the dislocation density is reduced, and the rebound and warpage of the plate 3 are eliminated under the combined action of the dislocation vacancies and the dislocation density.

In the embodiment, the forming die comprises a stamping male die 6 and a stamping female die 7, the forming surface 4 is a stamping hole wall arranged on the stamping female die 7 and capable of being matched with the stamping male die 6, and a stamping blank holder 8 for holding the sheet material 3 is arranged on the upper side surface of the stamping female die 7, so that the edge of the sheet material 3 is fixed in the forming process. The electromagnetic forming coil 2 is installed in a coil frame 9 for enhancing the strength of the electromagnetic forming coil 2 and preventing it from being deformed and damaged by the reaction force. The coil framework 9 is provided with a lantern ring 10 which can be sleeved outside the stamping female die 7, the lantern ring 10 is internally provided with the electromagnetic forming coil 2 which laterally drives the edge of the plate 3, and the mode is a mode for eliminating the rebounding and warping of the plate 3, optionally, the electromagnetic forming coil 2 is installed in the coil framework 9 and located above the stamping female die 7, and the effect of eliminating the rebounding and warping of the plate 3 can also be achieved. Optionally, referring to fig. 4 and 8, a gap is provided between the coil bobbin 9 and the formed plate 3, and since the plate is not clamped, the electromagnetic forming coil 2 may also generate high-frequency vibration in the gap after pulse current is applied to the plate 3, so as to eliminate springback and warpage. Of course, it is also possible to clamp and eliminate warpage and spring back by inducing current.

Furthermore, an elastic pad 5 is arranged between the plate 3 and the forming surface 4 after the forming of the forming die, and the elastic pad 5 can be a high-temperature resistant rubber pad, so that when the electromagnetic force is increased, the plate 3 moves downwards and the elastic pad 5 is compressed; when the electromagnetic force is reduced, the elastic pad 5 returns to enable the plate 3 to move reversely, so that the high-frequency oscillation effect of the plate 3 in a small local range is achieved, the plate 3 is cooperated with the electromagnetic force and the induced pulse current, and the rebound and warping effects of the plate 3 are controlled to be more remarkable.

Then, the embodiment of the invention discloses a plate forming method for eliminating springback and warping through electromagnetic pulse, and the plate forming device adopting the scheme for eliminating springback and warping through electromagnetic pulse comprises the following steps:

s1, controlling a forming die to form a plate 3, keeping the plate 3 attached to a forming surface 4, and arranging an elastic pad 5 between the plate 3 and the forming surface 4 or arranging a gap for the plate 3 to vibrate;

s2, after the forming of the forming die is finished, controlling the pulse current generating circuit 1 to form pulse current on the plate 3 attached to the forming surface 4 after forming, wherein the mode of forming the pulse current comprises a mode of generating induced pulse current on the plate 3 through an electromagnetic forming coil 2 connected in series on the pulse current generating circuit 1 and a mode of directly introducing the pulse current into the plate 3 and the pulse current generating circuit 1 in series. Alternatively, the forming die may be provided with an elastic pad 5 or a gap for oscillation of the sheet 3. At this time, the electromagnetic force, the induced pulse current and the high-frequency oscillation can act synergistically, and the effect of eliminating the springback and the warpage of the plate 3 is further achieved.

Example two:

as shown in fig. 9-12, in the present embodiment, the forming mold includes a spinning female mold 12, a spinning wheel 13 and a spinning blank holder 11 for pressing the sheet material 3 onto the spinning female mold 12, the spinning forming is completed together, the forming surface 4 is disposed on the spinning female mold 12, the electromagnetic forming coil 2 is disposed behind the moving direction of the spinning wheel 13 and near the sheet material 3, and the elastic pad 5 can be disposed between the bottom of the forming cavity and the sheet material 3, so that the springback and warpage of the sheet material 3 can be eliminated through the combined action of the pulse current, the electromagnetic force and the high frequency oscillation after the spinning is completed.

Example three:

as shown in fig. 13, in the present embodiment, the forming die includes a press punch 14 and a platen assembly 15 capable of holding the sheet material 3 and moving up and down with respect to the press punch 14, the forming surface 4 is a forming convex surface provided on the upper side of the press punch 14, and the platen assembly 15 includes a platen for pressing the sheet material 3 against the forming convex surface from the upper and lower sides. After the pressing plate assembly 15 clamps the plate 3 until the plate 3 is attached to the forming convex surface, the electromagnetic forming coil 2 can be controlled to perform the operation of eliminating the springback and the warping of the plate 3, and the mechanism is that the electromagnetic forming coil 2 can form an induced pulse current in the plate 3. Similarly, an elastic pad 5 can be arranged between the forming convex surface and the plate 3, so that the rebound and the warpage of the plate 3 are eliminated under the combined action of the pulse current, the electromagnetic force and the high-frequency oscillation.

Example four:

as shown in fig. 14, in the present embodiment, the forming mold includes a press-forming punch 14 and a press-forming die 16, a forming convex surface is provided on the upper side of the press-forming punch 14, a forming concave surface is provided in the press-forming die 16, and the surfaces of the forming convex surface and the forming concave surface are both forming surfaces 4 and are matched with each other. The electromagnetic forming coil 2 is arranged on the inner side of the forming convex surface and the forming concave surface, and the pulse current generating circuit 1 is arranged to discharge electricity to the electromagnetic forming coil 2 after the forming convex surface and the forming concave surface are attached to the plate 3, so that the effect of eliminating the rebound and warpage of the plate 3 can be achieved.

Example five:

as shown in fig. 15, in the present embodiment, the forming die includes a drawing male die 17 and a drawing female die 18, so as to draw a counter bore to the sheet material, the forming surface 4 is a drawing counter bore which is arranged at the bottom 18 of the drawing female die and can be matched with the drawing male die 17, and the electromagnetic forming coil 2 is arranged in the drawing male die 17, so that the effect of eliminating the springback and warpage of the drawing hole of the sheet material 3 can be achieved by inducing a pulse current.

Example six:

as shown in fig. 16, in the present embodiment, the forming mold includes a drawing punch 17 and a drawing die 18, the forming surface 4 is a drawing counterbore arranged at the bottom 18 of the drawing die and capable of cooperating with the drawing punch 17, and the electromagnetic forming coil 2 is arranged at a corner 19 at two ends of the drawing counterbore, and can also achieve the effect of eliminating the springback and warpage of the drawing hole of the sheet material 3 by inducing a pulse current.

Example seven:

as shown in fig. 17, in the present embodiment, the pulse current generating circuit 1 is not provided with the electromagnetic forming coil 2, but the capacitor C, the resistor R, the inductor L, and the electrode 20 on the pulse current generating circuit 1 are connected in series with the sheet material 3, so that the pulse current directly passes through the sheet material 3 without being induced, and the effect of eliminating the springback and the warpage of the elongated hole of the sheet material 3 can be also obtained, and the present invention is suitable for the low-conductivity metal sheet material 3 in which the induced current is difficult to be generated.

The above is only a preferred embodiment of the present invention, and is not intended to limit the present invention, and various modifications and changes will occur to those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. The plate forming device for eliminating springback and warping through electromagnetic pulses is characterized by comprising a forming die and a pulse current generating circuit (1) for forming pulse current in a plate (3), wherein the forming die is provided with a forming surface (4) for forming the plate (3), and the pulse current generating circuit (1) is arranged to form the pulse current on the plate (3) which is attached to the forming surface (4) after forming; the pulse current generating circuit (1) is provided with an electromagnetic forming coil (2) which can be introduced with pulse current, and the electromagnetic forming coil (2) is arranged close to the plate (3) on the forming surface (4).

2. The sheet forming device for eliminating springback and warpage through electromagnetic pulses according to claim 1, wherein the forming mold comprises a stamping male mold (6) and a stamping female mold (7), the forming surface (4) is a stamping hole wall which is arranged on the stamping female mold (7) and can be matched with the stamping male mold (6), a stamping blank holder (8) for holding a blank for the sheet (3) is arranged on the upper side of the stamping female mold (7), the electromagnetic forming coil (2) is arranged in a coil frame (9), the coil frame (9) is provided with a sleeve ring (10) which can be sleeved outside the stamping female mold (7), and the electromagnetic forming coil (2) for laterally driving the edge of the sheet (3) is arranged in the sleeve ring (10).

3. The device for forming sheet material with electromagnetic pulse to eliminate springback and warpage according to claim 1, wherein the forming mold comprises a stamping male mold (6) and a stamping female mold (7), the forming surface (4) is a stamping hole wall which is arranged on the stamping female mold (7) and can be matched with the stamping male mold (6), a stamping binder ring (8) for binding the sheet material (3) is arranged on the upper side of the stamping female mold (7), and the electromagnetic forming coil (2) is arranged in a coil frame (9) and is positioned above the stamping female mold (7).

4. The device for forming sheet material with elimination of springback and warpage by electromagnetic pulses as set forth in claim 1, characterized in that said forming die comprises a spinning female die (12), a spinning wheel (13) and a spinning blankholder (11) for pressing the sheet material (3) against the spinning female die (12), said forming surface (4) being disposed on said spinning female die (12), said electromagnetic forming coil (2) being disposed following behind the moving direction of said spinning wheel (13) and being disposed close to said sheet material (3).

5. The apparatus for forming a sheet material with the rebound and warp eliminated by the electromagnetic pulse as set forth in claim 1, wherein the forming die comprises a press punch (14) and a platen assembly (15) which can hold the sheet material (3) to move up and down relative to the press punch (14), the forming surface (4) is a forming convex surface provided on an upper side of the press punch (14), and the platen assembly (15) comprises a platen which presses the sheet material (3) against the forming convex surface from upper and lower sides.

6. The sheet material forming device for eliminating springback and warpage through electromagnetic pulse according to claim 1, wherein the forming die comprises a pressing male die (14) and a pressing female die (16), a forming convex surface is arranged on the upper side of the pressing male die (14), a forming concave surface is arranged in the pressing female die (16), the electromagnetic forming coil (2) is arranged on the inner side of the forming convex surface and/or the forming concave surface, and the pulse current generating circuit (1) is arranged to discharge electricity to the electromagnetic forming coil (2) after the forming convex surface and the forming concave surface are attached to the sheet material (3).

7. The apparatus for forming a sheet material with rebound and warpage eliminated by electromagnetic pulse as claimed in claim 1, wherein the forming die comprises a drawing punch (17) and a drawing die (18), the forming surface (4) is a drawing counterbore which is arranged at the bottom of the drawing die (18) and can be matched with the drawing punch (17), the electromagnetic forming coil (2) is arranged in the drawing punch (17), or the electromagnetic forming coil (2) is arranged at a corner (19) at two ends of the drawing counterbore.

8. A method for forming a sheet material with spring back and warp eliminated by electromagnetic pulse, characterized in that the apparatus for forming a sheet material with spring back and warp eliminated by electromagnetic pulse as claimed in any one of claims 1 to 7 is used, comprising the steps of:

s1, controlling a forming die to form a plate (3), wherein the plate (3) is attached to the forming surface (4);

s2, after the forming of the forming die is finished, controlling a pulse current generating circuit (1) to form pulse current on the plate (3) attached to the forming surface (4) after forming, wherein the mode of forming the pulse current comprises a mode of generating induction pulse current on the plate (3) through the electromagnetic forming coil (2) and a mode of directly introducing the pulse current into the plate (3).