CN103191971A - Electromagnetism-assisted forming device and method for dissimilar metal composite boards - Google Patents

Abstract

The invention relates to an electromagnetically assisted forming device and method for a heterogeneous metal composite sheet, which relates to a device and a method for forming a composite sheet, in order to solve the problem that the sheet is seriously thinned until it is broken during the deep drawing and forming process of the existing metal composite sheet. Device: The coil is set in the annular coil groove, there is a liquid passage between the inner wall of the blank holder and the cylinder, the upper liquid inlet is arranged horizontally on the side wall of the blank holder, and the lower liquid inlet is arranged horizontally on the side wall of the die road. Method: 1. Put the composite sheet on the bottom surface of the blank holder groove; 2. Apply forward liquid to the liquid channel, apply reverse liquid to the die cavity, and use the coil to align the outer edge of the flange of the composite sheet. Apply radial electromagnetic force F _d ; 3. The composite sheet is formed under the joint action of reverse pressure Fp ₂ , forward pressure Fp ₁ , and radial electromagnetic force F _d ; 4. Unload positive liquid pressure P ₁ first, and then unload Reverse liquid pressure P ₂ , the punch returns, and the formed parts are taken out. The invention is used for forming heterogeneous metal composite plates.

Description

Electromagnetic-assisted forming device and method for dissimilar metal composite sheet

technical field

The invention relates to a device and method for forming a composite plate, in particular to a forming method for improving the forming limit of a heterogeneous metal composite plate by using electromagnetic assistance.

Background technique

With the development of modern industrial technology and the emergence of various new technologies and new industries, people's requirements for material performance are increasing. Under some special conditions, the performance of a single component material has been difficult to meet the use requirements. A single metal material is composited into one body through various connection methods to prepare a metal composite board. This layered composite board after rational design and combination combines the respective advantages of different metal components, and obtains a single-layer metal material. It does not have unique physical, chemical and mechanical properties, and meets the requirements of high strength, high specific stiffness, fatigue resistance, dimensional stability, wear resistance, vibration resistance, etc., while saving rare and precious materials and reducing production costs. Due to the good comprehensive performance and superior cost performance of composite panels, both at home and abroad attach great importance to its research and development. In terms of varieties, titanium series, stainless steel series, aluminum series, copper series clad plates, etc. have been developed according to different service conditions of materials. Solid phase composite method and so on. The emergence of advanced methods such as liquid phase composite method and semi-solid pressure composite method makes it possible to produce metal composite panels in large quantities and continuously, reduces the manufacturing cost of composite panels, and has a high cost performance. Therefore, the forming method of metal composite panels has become the focus of further research in the field of material processing. The forming of metal composite panels is much more complicated than that of a single metal sheet. It not only needs to consider the relevant process factors of forming, but also considers the plastic mechanical properties and deformation coordination capabilities of each component of the metal sheet. During the forming process, the deformation of the upper and lower two-layer boards will be uncoordinated, and misalignment and wrinkling will easily occur. The forming mechanism is far more complicated than that of a single-layer board.

The traditional hydroforming of sheet metal is to apply liquid pressure on the lower surface of the formed sheet, so that the blank is pressed against the punch under the action of liquid pressure to realize the forming of sheet metal parts, as shown in Figure 2. In order to solve the problem that too low reverse pressure will easily lead to the rupture of punch round corners and too high reverse pressure will cause rupture of the suspended area during the forming process of conical parts and spherical bottom cylindrical parts, etc., a forward and reverse pressurized liquid-filled pull The deep method is to apply hydraulic pressure on the upper surface of the forming blank to cooperate with the liquid-filled deep drawing at the bottom to form double-sided pressurized composite forming. The positive pressure on the upper surface can partly or even completely offset the anti-expansion caused by the reverse pressure on the bottom, allowing greater reverse pressure to suppress thinning and improve the forming limit. However, although the existence of positive pressure can increase the value of reverse pressure, it also reduces the beneficial friction between the sheet and the punch, and its positive and negative effects cancel each other out. The effect of ratio is limited.

The traditional radial force application method, as shown in Figure 3, is to introduce the pressure of the liquid chamber to the outer edge of the blank flange to realize radial loading. The radial pressure is equal to the pressure of the liquid chamber and cannot be adjusted independently. Compared with the method of applying radial hydraulic pressure through a hydraulic system, the use of a magnetic pulse shaping device is simpler, more efficient, easier to control, and saves cost and space.

Contents of the invention

The purpose of the present invention is to solve the problem that the forming limit is low in the deep-drawing forming process of the existing metal composite sheet, which leads to the serious thinning of the sheet until it breaks during the forming process, and to provide an electromagnetic-assisted forming device for dissimilar metal composite sheets and its method.

The present invention is achieved by the following technical solutions:

Device: the device includes a punch, a binder ring, a sealing ring, a coil and a die, and the upper end surface of the die is provided with a die cavity and a binder ring groove from the inside to the outside, and the bottom surface of the binder ring groove is There is an annular coil groove, the coil is set in the annular coil groove, the inner wall of the blank holder is provided with an annular sealing ring groove, the punch of the punch is a round table, the tail of the punch is a cylinder, and the blank holder is set on the cylinder , and there is a liquid passage between the inner wall of the blank holder ring and the cylinder, the sealing ring is set on the cylinder and arranged in the annular sealing ring groove, the side wall of the blank holder ring is provided with an upper liquid channel horizontally, and the side wall of the die A lower liquid inlet channel is arranged on the upper side, the punch and the binder ring are located above the die, and the punch and the die cavity are facing each other, and the binder ring is facing the groove of the binder ring.

Method: The method is achieved through the following steps:

Step 1. Place the composite sheet on the bottom surface of the blankholder groove, move the blankholder down until the lower end surface of the blankholder is 0.5mm to 2mm from the upper end surface of the composite sheet, and apply a blankholder force to the blankholder _FBH is 5kN～200kN;

Step 2. The punch moves down to the upper surface of the composite sheet, and at the same time, a _positive liquid is applied to the liquid channel from the upper liquid inlet. Reverse liquid is applied inside, the reverse liquid pressure P ₂ should be greater than 1.5 times the forward liquid pressure P ₁ and less than 100MPa, and then the radial electromagnetic force F _d is 10MPa ~ 100Mpa applied to the outer edge of the flange of the composite sheet through the coil ;

Step 3: The composite sheet is formed under the joint action of reverse pressure Fp ₂ , forward pressure Fp ₁ , and radial electromagnetic force F _d . When the punch reaches the stroke after forming the composite sheet, the forming of the part is completed;

Step 4: After forming, unload the positive liquid pressure P ₁ first, then unload the reverse liquid pressure P ₂ , return the punch, take out the formed parts, and complete a forming process.

The present invention has the following beneficial effects:

1. Utilize the device of the present invention to complete the electromagnetic-assisted forming method of dissimilar metal composite sheets. This method is based on the application of hydraulic pressure on the upper and lower surfaces of the sheets, and then realizes the discharge of the flange outer edge of the composite sheets through coils. Active real-time control can be carried out according to the loading curve, so that the radial electromagnetic force matches the positive and negative hydraulic pressure, and the radial pressure pushes the flange outer edge of the sheet to flow downward, participating in the active deformation of the sheet at the bottom of the punch, so that the pull Deep deformation is easier and achieves a strain distribution that tends to be uniform, thereby maximizing the formability of the sheet, especially for dissimilar metal composite sheets. The method of the invention reduces the radial tensile stress in the deformation zone, avoids the occurrence of cracks, and forms double-sided fluid lubrication effects, so that the plate is in a better deformation state and its formability is improved. The coupling effect of bidirectional pressure and radial force delays the traction deformation of the composite plate and the formation and growth of internal voids, and increases its forming limit. A radial electromagnetic force is applied on the outer edge of the flange. With the increase of the radial force, the radial tensile stress in the deformation zone of the billet decreases and the tangential compressive stress increases, which is beneficial to the flow and deformation of the billet and avoids serious thinning.

2. The present invention can delay the traction deformation of the composite plate and the viscous action of the interface, form a pressure difference between the upper and lower surfaces of the composite plate, reduce the radial tensile stress in the deformation zone, avoid the occurrence of cracks, and form a double-sided The fluid lubrication effect improves the forming limit of the composite plate and the uniformity of the wall thickness distribution of the formed part. Moreover, due to the increase of the reverse pressure, the mold-fitting and shape stability of the composite plate member are good, the rebound after hydraulic unloading is small, and the dimensional accuracy is high.

3. The wall thickness distribution of the formed component by the method of the present invention is more uniform than that of the traditional forming method. Therefore, this method can make up for the lack of material formability, save processes, improve efficiency, and provide a new way for high-precision forming of dissimilar metal composite plate components.

Description of drawings

Fig. 1 is a main cross-sectional view of the structure of Embodiment 1, Fig. 2 is a schematic diagram of the principle of traditional liquid-filled deep drawing, and Fig. 3 is a schematic diagram of a traditional radial force application method.

Detailed ways

Specific embodiment 1: This embodiment is described in conjunction with FIG. 1. This embodiment includes a punch 1, a blank holder 2, a sealing ring 3, a coil 4, and a die 5. The upper end surface of the die 5 is arranged from the inside to the outside. There is a die cavity 5-1 and a blankholder groove 5-2, and the bottom surface of the blankholder groove 5-2 is provided with an annular coil groove 5-2-1, and the coil 4 is arranged in the annular coil groove 5-2-1 , the inner wall of the blank holder 2 is provided with an annular sealing ring groove 2-2, the punch of the punch 1 is a round table 1-1, the tail of the punch 1 is a cylinder 1-2, and the blank holder 2 is set on the cylinder 1 -2, and a liquid channel 6 is provided between the inner wall of the blank holder 2 and the cylinder 1-2, the sealing ring 3 is set on the cylinder 1-2 and arranged in the annular sealing ring groove 3-1, the blank holder 2 The upper liquid inlet channel 2-1 is horizontally provided on the side wall of the die 5, and the lower liquid inlet channel 5-3 is horizontally provided on the side wall of the die 5, the punch 1 and the blank holder 2 are located above the die 5, and the punch 1 is directly opposite to the die cavity 5-1, and the blank holder 2 is directly opposite to the blank holder groove 5-2.

Embodiment 2: This embodiment is described with reference to FIG. 1 . In this embodiment, the upper liquid inlet channel 2-1 and the lower liquid channel 6-1 are arranged facing each other up and down. Other connection relationships are the same as those in the first embodiment.

Specific embodiment three: illustrate this embodiment in conjunction with Fig. 1, this embodiment is realized through the following steps:

Step 1. Place the composite sheet 7 on the bottom surface of the blankholder groove 5-2, and move the blankholder 2 down to a place where the lower end surface of the blankholder 2 is 0.5mm to 2mm away from the upper end surface of the composite sheet 7. The blank-holding force F _BH applied by the blank-holding ring 2 is 5kN～200kN;

Step 2. The punch 1 is moved down to the upper surface of the composite sheet 7, and at the same time, the positive liquid is applied from the upper liquid channel _2-1 to the liquid channel 6. The liquid channel 5-3 applies reverse liquid to the die cavity 5-1, and its reverse liquid pressure P ₂ should be greater than 1.5 times the forward liquid pressure P ₁ and less than 100MPa (that is, 100MPa≥P ₂ ≥P ₁ ), and then The radial electromagnetic force F _d applied to the outer edge of the flange of the composite sheet 7 through the coil 4 is 10MPa-100Mpa; electromagnetic forming is a high-speed forming process that uses instantaneous high-voltage pulsed magnetic fields to process workpieces indirectly or directly. The energy is easy to control, real-time high-speed forming can be realized conveniently, and the control of various process parameters and forming process can be realized conveniently.

Step 3: The composite sheet 7 is formed under the joint action of the reverse pressure Fp ₂ , the forward pressure Fp ₁ , and the radial electromagnetic force F _d . When the punch 1 reaches the stroke after the composite sheet 7 is formed, the part is completed the formation of

During the forming process, according to the shape and material characteristics of the formed part, the values of the forward liquid pressure P ₁ , the reverse liquid pressure P ₂ and the radial electromagnetic force F _d can be adjusted to form different forward pressure Fp ₁ , reverse pressure The combination of forward pressure Fp ₂ and radial electromagnetic force F _d ; the purpose of adjusting the values of forward liquid pressure P ₁ , reverse liquid pressure P ₂ and radial electromagnetic force F _d is to obtain the best combination of process parameters, that is, positive The best matching relationship between the liquid pressure P ₁ , the reverse liquid pressure P ₂ and the radial electromagnetic force F _d , for example: for a composite plate composed of 5A06 aluminum alloy and No. 20 steel, it is formed into a cylindrical part , the best combination of parameters is forward liquid pressure P ₁ =20MPa, reverse liquid pressure P ₂ =40MPa, radial electromagnetic force F _d =25MPa, the thinning rate of the part wall thickness after forming under this parameter combination minimum.

Step 4: After forming, unload the positive liquid pressure P ₁ first, and then unload the reverse liquid pressure P ₂ , the punch 1 returns, and the formed parts are taken out, that is, a forming process is completed.

The application of the radial electromagnetic force F _d is realized by the discharge of the coil 4 embedded in the die, which can be actively and real-time controlled according to the loading curve, so that the radial electromagnetic force F _d can achieve the best match with the positive and negative pressure. The electromagnetic force F _d pushes the flange outer edge of the composite sheet 7 to flow downward, and participates in the active deformation of the composite sheet 7 at the bottom of the punch, so that the drawing deformation is easier to carry out, and the strain distribution tends to be uniform, thereby maximizing Greatly improve the formability of the sheet, especially for dissimilar metal composite sheets.

Embodiment 4: This embodiment is described with reference to FIG. 1 . In this embodiment, the material of the composite sheet 7 in step 1 is low carbon steel, aluminum alloy, pure aluminum, stainless steel, copper alloy, titanium alloy or magnesium alloy. Other steps are the same as those in the third embodiment.

Embodiment 5: This embodiment is described with reference to FIG. 1 . In this embodiment, the thickness of the composite sheet 7 in step 1 is 1.0 mm to 4.0 mm. Other steps are the same as those in Embodiment 3 or 4.

Embodiment 6: This embodiment is described with reference to FIG. 1 . In this embodiment, the thickness of the composite sheet 7 in step 1 is 2.0 mm. Other steps are the same as those in Embodiment 5.

Embodiment 7: This embodiment is described with reference to FIG. 1 . In this embodiment, the thickness of the composite sheet 7 in step 1 is 3.0 mm. Other steps are the same as those in Embodiment 5.

Embodiment 8: This embodiment is described in conjunction with FIG. 1. In this embodiment, the positive liquid pressure _P1 is applied to the liquid passage 6 from the upper liquid passage 2-1 in step 2. The reverse liquid pressure _P2 applied to the cavity 5-1 is 30MPa, and the radial electromagnetic force _Fd applied to the outer edge of the flange of the composite sheet 7 through the coil 4 is 50Mpa. Other steps are the same as those in the third embodiment.

Nine specific embodiments: This embodiment is described in conjunction with Fig. 1. In this embodiment, in step 2, the positive liquid pressure P1 is applied to the liquid channel 6 from the upper liquid channel 2-1, and the liquid pressure _P1 is 30 MPa from the lower liquid channel 5-3. The reverse liquid pressure _P2 applied to the die cavity 5-1 is 45MPa, and the radial electromagnetic force _Fd applied to the outer edge of the flange of the composite sheet 7 by the coil 4 is 60Mpa. Other steps are the same as those in the third embodiment.

Embodiment 10: This embodiment is described with reference to FIG. 1 . In this embodiment, during the forming process in step 3, the sealing ring 3 should ensure the sealing of the upper mold cavity when the punch 1 is descending. Other steps are the same as those in the third embodiment.

Claims (10)

1. dissimilar metal clad plate material electromagnetism assist formation device, it is characterized in that: described device comprises punch (1), blank holder (2), sealing ring (3), coil (4) and die (5), the upper surface of described die (5) is provided with matrix cavity (5-1) and flanging ring recess (5-2) from inside to outside, the bottom surface of flanging ring recess (5-2) is provided with toroid ring recess (5-2-1), coil (4) is arranged in the toroid ring recess (5-2-1), the madial wall of blank holder (2) is provided with ring packing ring recess (2-2), the drift of punch (1) is round platform (1-1), the afterbody of punch (1) is cylinder (1-2), blank holder (2) is sleeved on the cylinder (1-2), and be provided with fluid passage (6) between the inwall of blank holder (2) and the cylinder (1-2), sealing ring (3) is sleeved on cylinder (1-2) and goes up and be arranged in the ring packing ring recess (3-1), laterally be provided with liquid inlet channel (2-1) on the sidewall of blank holder (2), laterally be provided with down liquid inlet channel (5-3) on the sidewall of die (5), punch (1) and blank holder (2) are positioned at the top of die (5), and punch (1) and matrix cavity (5-1) over against, blank holder (2) and flanging ring recess (5-2) over against.

2. according to the described dissimilar metal clad plate material of claim 1 electromagnetism assist formation device, it is characterized in that: it is upper and lower over against setting with following fluid passage (6-1) to go up liquid inlet channel (2-1).

3. one kind is utilized the described device of claim 1 to realize dissimilar metal clad plate material electromagnetism assist formation method, and it is characterized in that: described method realizes by following steps:

Step 1, compound plate (7) is placed on the bottom surface of flanging ring recess (5-2), blank holder (2) is displaced downwardly to the lower surface of blank holder (2) apart from the upper surface 0.5mm～2mm place of compound plate (7), and it is 5kN～200kN that blank holder (2) is applied pressure-pad-force FBH;

Step 2, punch (1) move down into the upper surface of compound plate (7), simultaneously in fluid passage (6), apply forward liquid by last liquid inlet channel (2-1), its forward fluid pressure P1 is 2MPa～50MPa, in matrix cavity (5-1), apply reversed liquid by following liquid inlet channel (5-3), its reversed liquid pressure P 2 should be greater than 1.5 times of forward fluid pressure P1, less than 100MPa, and by coil (4) the flange outer rim of compound plate (7) being applied radial electromagnetic force Fd then is 10MPa～100Mpa;

Step 3, compound plate (7) are shaped under buffer brake Fp2, positive pressure Fp1, radial electromagnetic force Fd synergy, when punch (1) reaches the stroke that makes after compound plate (7) is shaped, namely finish part forming;

After step 4, the end that is shaped, unload forward fluid pressure P1 earlier, unload reversed liquid pressure P 2 again, formation of parts is taken out in punch (1) backhaul, namely finishes a forming process.

4. according to the described dissimilar metal clad plate material of claim 3 electromagnetism assist formation method, it is characterized in that: the material of the compound plate (7) in the described step 1 is mild steel, aluminium alloy, fine aluminium, stainless steel, copper alloy, titanium alloy or magnesium alloy.

5. according to claim 3 or 4 described dissimilar metal clad plate material electromagnetism assist formation methods, it is characterized in that: the thickness of the compound plate (7) in the described step 1 is 1.0mm～4.0mm.

6. according to the described dissimilar metal clad plate material of claim 5 electromagnetism assist formation method, it is characterized in that: the thickness of the compound plate (7) in the described step 1 is 2.0mm.

7. according to the described dissimilar metal clad plate material of claim 5 electromagnetism assist formation method, it is characterized in that: the thickness of the compound plate (7) in the described step 1 is 3.0mm.

8. according to the described dissimilar metal clad plate material of claim 3 electromagnetism assist formation method, it is characterized in that: applying forward fluid pressure P1 by last liquid inlet channel (2-1) in the fluid passage (6) in the described step 2 is 20MPa, apply reversed liquid pressure P 2 by following liquid inlet channel (5-3) in the matrix cavity (5-1) and be 30MPa, by coil (4) the flange outer rim of compound plate (7) being applied radial electromagnetic force Fd is 50Mpa.

9. according to the described dissimilar metal clad plate material of claim 3 electromagnetism assist formation method, it is characterized in that: applying forward fluid pressure P1 by last liquid inlet channel (2-1) in the fluid passage (6) in the described step 2 is 30MPa, apply reversed liquid pressure P 2 by following liquid inlet channel (5-3) in the matrix cavity (5-1) and be 45MPa, by coil (4) the flange outer rim of compound plate (7) being applied radial electromagnetic force Fd is 60Mpa.

10. according to the described dissimilar metal clad plate material of claim 3 electromagnetism assist formation method, it is characterized in that: in the forming process in the described step 3, sealing ring (3) should guarantee the sealing of upper cavity when punch (1) is descending.

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