Electrically assisted variable cross-section roll forming device and method

Abstract

The present invention discloses an electrically assisted variable cross-section roll forming device and method, which belongs to the technical field of metal sheet forming. The electrically assisted variable cross-section roll forming device comprises: a frame, a base, an upper die, a lower die, a pulse power supply and two forming roller systems; the frame is slidably arranged on the base; the upper die is liftably arranged on the frame; the lower die is fixedly arranged on the frame, and the lower die is opposite to the upper die; the frame is arranged between the two forming roller systems; the positive pole of the pulse power supply is connected to the upper die and the lower die, and the negative pole of the pulse power supply is connected to the two forming roller systems. The electrically assisted variable cross-section roll forming device and method of the present invention reduces equipment load, energy consumption and cost, and enables difficult-to-deform metals to form complex cross-section parts.

Description

Technical Field

[0001] The invention relates to the technical field of metal sheet forming, and in particular to an electrically assisted variable-section roll forming device and method. Background Art

[0002] In the fields of transportation, aerospace, etc., due to the requirements of lightweight, the application of high-strength materials or light metals is increasing. For example, in automobile bodies, ultra-high-strength steel with a tensile strength greater than 780MPa has gradually become the mainstream, mainly used for structural parts or safety parts. At present, cold-formed martensitic steel with a tensile strength of 1500MPa has also been used in automobile body-in-white. Most of the structural parts or safety parts of automobile bodies are long parts, such as columnar parts such as A / B / C pillars, beam parts such as front / rear longitudinal beams, reinforcing plates / rods, bumpers, etc. Under the requirements of automobile appearance aesthetics, aerodynamics, lightweight and safety, these parts generally have complex geometric features such as curved surfaces, variable cross-sections, and multiple structural features. In addition, based on the current trend of flexible automobile platform and family design of vehicle models, parts must also meet the production characteristics of variable batch flexibility. Compared with ordinary steel, ultra-high-strength steel has greatly increased strength and decreased plasticity. On the one hand, a reasonable choice of forming method is required, and on the other hand, the complexity of formable parts is limited. At present, the manufacturing methods of ultra-high-strength car body components mainly include cold stamping, hot forming and roll forming.

[0003] Cold stamping is the most common forming method for steel sheets for car bodies, but it is limited by the tonnage of the press and the strength and wear of the mold material. When forming ultra-high-strength steel, especially steel sheets with a strength of more than 1000MPa, there are great challenges. As the strength increases, the sheet forming performance decreases, and the complexity of the shape of the stamped parts is also limited.

[0004] Hot forming is an advanced forming technology that has been developed in recent years as the demand for lightweighting continues to increase. It is achieved by rapidly heating boron steel to austenitization, then stamping and quenching in a mold with a cooling system to obtain parts with a strength of more than 1300MPa. However, since the parts need to be heated and quenched in the mold, it also has major disadvantages, such as large investment, slow production cycle, high mold price, high energy consumption, and relatively harsh working environment.

[0005] Roll forming, also known as cold bending, is particularly suitable for the production of large batches of single-section long workpieces, but it is not suitable for the forming of complex-shaped ultra-high-strength steel parts. In addition, in the field of aerospace, titanium alloy components are widely used. Due to the low plasticity of titanium alloy plates, they are currently mainly formed by heating, which consumes a lot of energy and has many restrictions on the flexible manufacturing of parts.

[0006] Difficult-to-form metals present challenges when forming components with complex shapes. As such components are increasingly used in fields such as transportation and aerospace, there is an urgent need to explore and develop new methods and technologies for high-performance, low-cost, high-efficiency, and flexible plastic forming of complex components made of difficult-to-deform metals. Summary of the invention

[0007] The present invention provides an electrically assisted variable-section roll forming device and method, which solves or partially solves the technical problem in the prior art that parts are formed by traditional stamping, hot forming, rolling and the like, resulting in large equipment load requirements.

[0008] In order to solve the above technical problems, the present invention provides an electrically assisted variable-section roll-forming device including: a frame, a base, an upper die, a lower die, a pulse power supply and two forming roller systems; the frame is slidably arranged on the base; the upper die is liftably arranged on the frame; the lower die is fixedly arranged on the frame, and the lower die is opposite to the upper die; the frame is arranged between the two forming roller systems; the positive pole of the pulse power supply is connected to the upper die and the lower die, and the negative pole of the pulse power supply is connected to the two forming roller systems.

[0009] Furthermore, a first insulating member is fixedly disposed between the lower mold and the frame.

[0010] Furthermore, the electrically assisted variable-section roll forming device further comprises: a lifting mechanism; a fixed end of the lifting mechanism is fixedly connected to the frame, and an actuating end of the lifting mechanism is connected to the upper die.

[0011] Furthermore, a second insulating member is fixedly disposed between the action end of the lifting mechanism and the upper mold.

[0012] Furthermore, a wedge-shaped block is fixedly provided on the base; a wedge-shaped groove is fixedly provided on the frame, and the wedge-shaped block is embedded in the wedge-shaped groove.

[0013] Furthermore, the forming roller system includes: a support seat, a position adjustment mechanism, a connecting seat and a pressure roller; the fixed end of the position adjustment mechanism is fixedly arranged on the support seat, and the action end of the position adjustment mechanism is hinged to the connecting seat; the pressure roller is rotatably arranged on the connecting seat; the pressure roller is connected to the negative pole of the pulse power supply.

[0014] Furthermore, the position adjustment mechanism includes: at least six drive motors and at least six ball screws; the six drive motors correspond to the at least six ball screws one by one, the fixed end of the drive motor is fixedly connected to the support seat, and the action end of the drive motor is fixedly connected to the corresponding ball screw; at least three hinge points are staggered on the end surface of the connecting seat facing the support seat; at least every two ball screws among the six ball screws are hinged to one of the hinge points.

[0015] Furthermore, the connecting seat includes: a support plate, a third insulating member, a support column and a connecting plate; the third insulating member is fixedly connected to the end face of the support plate facing away from the position adjustment mechanism; the first end of the support column is fixedly connected to the third insulating member, and the second end of the support column is fixedly connected to the connecting plate; a clamping roller is rotatably provided on the connecting plate.

[0016] Furthermore, the current density of the pulse power supply ranges from 0 to 35 A.mm- 2 , the duty cycle range is 0-100%, and the pulse frequency range is 0-999Hz.

[0017] Based on the same inventive concept, the present application also provides an electrically assisted variable-section roll-forming method, including: placing the blank on the lower die, the upper die moves toward the lower die, clamping the blank, and realizing the bottom forming of the part; turning on the pulse power supply, the pulse power supply supplies power to the upper die, the lower die and two forming roller systems; the frame moves on the base, and the two forming roller systems perform conformal rolling on the two sides of the blank to realize rolling deformation.

[0018] One or more technical solutions provided in the embodiments of the present application have at least the following technical effects or advantages:

[0019] Since the frame is slidably arranged on the base, the upper die is liftably arranged on the frame, the lower die is fixedly arranged on the frame, the lower die is opposite to the upper die, the frame is arranged between the two forming roller systems, the positive pole of the pulse power supply is connected to the upper die and the lower die, and the negative pole of the pulse power supply is connected to the two forming roller systems, so the blank can be placed on the lower die, the upper die moves toward the lower die, the blank is clamped, the bottom of the part is formed, and the pulse power supply is turned on. The pulse power supply supplies power to the upper die, the lower die and the two forming roller systems, and the electroplastic effect is realized by using the power to form a migration electron wind inside the metal material, which can effectively improve the steel material and the plasticity of titanium alloy materials. Therefore, by passing a pulse current of a certain current density through the blank and ensuring a certain power-on time, the plasticity of the material can be improved and the complexity of part forming can be increased. The frame moves on the base, and the two forming rollers perform conformal rolling on the two sides of the blank to achieve rolling deformation. The combination of electroplasticity and rolling technology is smaller than that required for stamping, and the heating process and energy consumption caused by forming in a hot state are eliminated, reducing the manufacturing process, and the plasticity requirements of the material are not high, which can reduce the equipment load, reduce energy consumption and cost, and enable difficult-to-deform metals to form complex cross-section parts. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 A schematic diagram of the structure of an electrically assisted variable-section roll forming device provided in an embodiment of the present invention;

[0021] Figure 2 for Figure 1 Left view of the CEC-assisted variable-section roll forming device;

[0022] Figure 3 for Figure 1 Right view of the Zhongdian assisted variable-section roll forming device;

[0023] Figure 4 for Figure 1 Schematic diagram of the structure of the forming roller system of the CEC-assisted variable-section roll forming device. DETAILED DESCRIPTION

[0024] See also Figure 1-3 An electric-assisted variable-section roll-forming device provided in an embodiment of the present invention includes: a frame 1, a base 2, an upper die 3, a lower die 4, a pulse power supply 5 and two forming roller systems 6.

[0025] The frame 1 is slidably disposed on the base 2 .

[0026] The upper mold 3 is arranged on the frame 1 in a liftable manner.

[0027] The lower die 4 is fixedly arranged on the frame 1 , and the lower die 4 is opposite to the upper die 3 .

[0028] The machine frame 1 is arranged between two forming roller systems 6 .

[0029] The positive electrode of the pulse power supply 5 is connected to the upper mold 3 and the lower mold 4 , and the negative electrode of the pulse power supply 5 is connected to the two forming roller systems 6 .

[0030] In the specific implementation mode of the present application, since the frame 1 is slidably arranged on the base 2, the upper mold 3 is liftably arranged on the frame 1, the lower mold 4 is fixedly arranged on the frame 1, the lower mold 4 is opposite to the upper mold 3, the frame 1 is arranged between the two forming roller systems 6, the positive pole of the pulse power supply 5 is connected to the upper mold 3 and the lower mold 4, and the negative pole of the pulse power supply 5 is connected to the two forming roller systems 6, so the blank 7 can be placed on the lower mold 4, the upper mold 3 moves toward the lower mold, the blank 7 is clamped, and the bottom of the part is formed, and the pulse power supply 5 is turned on. The pulse power supply 5 supplies power to the upper mold 3, the lower mold 4 and the two forming roller systems 6, and the migration electron wind is formed inside the metal material by powering on. Realizing the electroplastic effect can effectively improve the plasticity of steel and titanium alloy materials. Therefore, by passing a pulse current of a certain current density through the blank 7 and ensuring a certain power-on time, the plasticity of the material can be improved and the complexity of part forming can be increased. The frame 1 moves on the base 2, and the two forming rollers 6 perform conformal rolling on the two sides of the blank to achieve rolling deformation. The combination of electroplasticity and rolling technology is smaller than that required for stamping, and the heating process and energy consumption caused by forming in a hot state are eliminated. The plasticity requirements of the material are not high, which can reduce the equipment load, reduce energy consumption and cost, and enable difficult-to-deform metals to form complex cross-section parts.

[0031] Specifically, a first insulating member is fixedly provided between the lower mold 4 and the frame 1 to prevent the frame 1 from being electrified and causing accidental contact by personnel, thereby preventing a safety accident.

[0032] Specifically, the electrically assisted variable-section roll forming device further includes: a lifting mechanism 8 .

[0033] The fixed end of the lifting mechanism 8 is fixedly connected to the frame 1 , and the moving end of the lifting mechanism 8 is connected to the upper mold 3 .

[0034] When the blank 7 is formed, the lifting mechanism 8 is started, and the action end of the lifting mechanism 8 drives the upper mold 3 to move in the direction of the lower mold 4 to clamp the blank 7. At the same time, if the part has changes in the depth direction, the upper mold 3 and the lower mold 4 can press out the bottom surface shape of the part.

[0035] In this embodiment, the lifting mechanism 8 may be a hydraulic cylinder.

[0036] A second insulating member is fixedly provided between the action end of the lifting mechanism 8 and the upper mold 3 to prevent the frame 1 from being electrified and causing accidental contact by personnel, thereby preventing a safety accident.

[0037] Specifically, a wedge block is fixedly provided on the base 2; a wedge groove is fixedly provided on the frame 1, the wedge block is embedded in the wedge groove, and the wedge groove is positioned by the wedge block.

[0038] The frame 1 can slide on the wedge block through the wedge groove to realize the movement of the frame 1 on the base 2.

[0039] Specifically, the forming roller system 6 includes: a supporting seat 6-1, a position adjustment mechanism 6-2, a connecting seat 6-3 and a pressing roller 6-4.

[0040] The fixed end of the position adjustment mechanism 6-2 is fixedly arranged on the support seat 6-1, and the action end of the position adjustment mechanism 6-2 is hinged to the connecting seat 6-3.

[0041] The pressure roller 6-4 is rotatably arranged on the connecting seat 6-3.

[0042] The pressure roller 6 - 4 is connected to the negative electrode of the pulse power supply 5 .

[0043] See also Figure 4 The position adjustment mechanism 6-2 includes: at least six drive motors and at least six ball screws.

[0044] The six drive motors correspond to at least six ball screws one by one, the fixed end of the drive motor is fixedly connected to the support seat, and the action end of the drive motor is fixedly connected to the corresponding ball screw.

[0045] At least three hinge points are staggeredly arranged on the end surface of the connecting seat 6-3 facing the supporting seat 6-1.

[0046] Every two ball screws in the at least six ball screws are articulated with a joint point.

[0047] The support seats 6-1 of the two forming roller systems 6 are placed on both sides of the frame 1 respectively. According to the shape of the parts, the rolling angle of the forming roller system 6 and the spatial motion parameters of the forming roller system 6 in this pass are set through programming. The motion parameters of the frame 1 along the base 2 drive the corresponding ball screw to move, and the ball screw drives the connecting seat 6-3 to realize the six-degree-of-freedom movement in space, and then drives the pressure roller 6-4 to move through the connecting seat 6-3, and accurately follows the rolling of the side of the blank 7, which can realize multi-pass progressive forming, making the shape and size of the formable parts more diversified and flexible.

[0048] According to the shape of the part, the frame 1 moves on the base 2 to realize the reciprocating motion of the upper die 3, the lower die 4 and the blank 7 along the length direction of the part, and cooperates with the rolling action of the two forming roller systems 6 to perform multiple passes of conformal rolling on the part.

[0049] In this embodiment, a driving motor is used to drive the ball screw, and its function is to ensure accuracy.

[0050] The connecting seat 6-3 includes: a supporting plate 6-31, a third insulating member 6-32, a supporting column 6-33 and a connecting plate 6-34.

[0051] The third insulating member 6-32 is fixedly connected to the end face of the support plate away from the position adjustment mechanism 6-2 to prevent the support seat 6-1 from being electrified and causing accidental touch by personnel and resulting in safety accidents.

[0052] In this embodiment, the material of the first insulating member, the second insulating member and the third insulating member 6-32 can all be rubber sheet.

[0053] The first end of the support column 6-33 is fixedly connected to the third insulating member 6-32, and the second end of the support column 33 is fixedly connected to the connecting plate 6-34. There is an angle between the connecting plate 6-34 and the third insulating member 6-32, so that the pressing roller 6-4 can press the blank 7, which is convenient for the blank 7 to be formed.

[0054] A clamping roller 6-5 is rotatably provided on the connecting plate 6-34. In the present embodiment, the distance between the clamping rollers 6-5 of the forming roller system 6 is equal to the width of the blank 7 ± 0.1-03 mm. The blank 7 can be clamped during the rolling process of the blank 7 to ensure the stability of the blank 7. At the same time, wrinkles generated during the deformation of the blank 7 can be suppressed.

[0055] Specifically, the current density of the pulse power supply ranges from 0 to 35 A.mm- 2 The duty cycle range is 0-100%, and the pulse frequency range is 0-999Hz. According to the material of the blank 7, the current parameters, frequency parameters and power-on time that are beneficial to changing the material can be selected.

[0056] Based on the same inventive concept, the present application also provides an electrically assisted variable cross-section roll forming method comprising:

[0057] The blank 7 is placed on the lower die 4, and the upper die 3 moves toward the lower die 4 to clamp the blank 7 to achieve the bottom forming of the part.

[0058] The pulse power supply 5 is turned on, and the pulse power supply 5 supplies power to the upper mold 3, the lower mold 4 and the two forming roller systems 6.

[0059] The frame 1 moves on the base 2, and the two forming rollers 6 perform conformal rolling on the two side edges of the blank 7 to achieve rolling deformation.

[0060] Specifically, the support seats 6-1 of the two forming roller systems 6 are respectively placed on both sides of the frame 1. According to the shape of the part, the rolling angle of the forming roller system 6 and the spatial motion parameters of the forming roller system 6 in this pass are set through programming. The motion parameters of the frame 1 along the base 2 drive the corresponding ball screw to move, and the ball screw drives the connecting seat 6-3 to realize the movement of six degrees of freedom in space, and then the connecting seat 6-3 drives the pressing roller 6-4 to move, and the side of the blank 7 is accurately followed by rolling, which can realize multi-pass progressive forming, so that the shape and size of the formable parts are more diversified and flexible.

[0061] According to the shape of the part, the frame 1 moves on the base 2 to realize the reciprocating motion of the upper die 3, the lower die 4 and the blank 7 along the length direction of the part, and cooperates with the rolling action of the two forming roller systems 6 to perform multiple passes of conformal rolling on the part.

[0062] Finally, it should be noted that the above specific implementation methods are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to examples, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the spirit and scope of the technical solution of the present invention, which should be included in the scope of the claims of the present invention.

Claims

1. An electrically assisted variable cross-section roll forming device, characterized in that: include: Frame, base, upper die, lower die, pulse power supply and two forming roller systems; The frame is slidably arranged on the base; The upper mold is arranged on the frame in a liftable manner; The lower die is fixedly arranged on the frame, and the lower die is opposite to the upper die; The frame is arranged between the two forming roller systems; The positive electrode of the pulse power supply is connected to the upper mold and the lower mold, and the negative electrode of the pulse power supply is connected to the two forming rollers; The current density of the pulse power supply ranges from 0 to 35 A.mm -2 , the duty cycle range is 0-100%, and the pulse frequency range is 0-999Hz; The electrically assisted variable cross-section roll forming method comprises: placing a blank on a lower die, moving the upper die toward the lower die, clamping the blank, and realizing the bottom forming of the part; Turn on the pulse power supply, which supplies power to the upper die, lower die and two forming rollers; The frame moves on the base, and the two forming rollers perform conformal rolling on the two side edges of the blank to achieve rolling deformation.

2. The electrically assisted variable cross-section roll forming device according to claim 1, characterized in that: A first insulating member is fixedly arranged between the lower mold and the frame.

3. The electrically assisted variable cross-section roll forming device according to claim 1, characterized in that: The electrically assisted variable cross-section roll forming device further comprises: a lifting mechanism; The fixed end of the lifting mechanism is fixedly connected to the frame, and the action end of the lifting mechanism is connected to the upper mold.

4. The electrically assisted variable cross-section roll forming device according to claim 3, characterized in that: A second insulating member is fixedly arranged between the action end of the lifting mechanism and the upper mold.

5. The electrically assisted variable cross-section roll forming device according to claim 1, characterized in that: A wedge-shaped block is fixedly arranged on the base; A wedge-shaped groove is fixedly arranged on the frame, and the wedge-shaped block is embedded in the wedge-shaped groove.

6. The electrically assisted variable cross-section roll forming device according to claim 1, characterized in that: The forming roller system comprises: a supporting seat, a position adjustment mechanism, a connecting seat and a pressing roller; The fixed end of the position adjustment mechanism is fixedly arranged on the support seat, and the action end of the position adjustment mechanism is hinged to the connecting seat; The pressing roller is rotatably arranged on the connecting seat; The pressing roller is connected to the negative electrode of the pulse power supply.

7. The electrically assisted variable cross-section roll forming device according to claim 6, characterized in that: The position adjustment mechanism includes: at least six drive motors and at least six ball screws; At least six of the drive motors correspond to at least six of the ball screws one by one, the fixed end of the drive motor is fixedly connected to the support seat, and the action end of the drive motor is fixedly connected to the corresponding ball screw; At least three hinge points are staggeredly arranged on the end surface of the connecting seat facing the supporting seat; At least every two of the six ball screws are hinged to one of the hinge points.

8. The electrically assisted variable cross-section roll forming device according to claim 6, characterized in that: The connecting base comprises: a supporting plate, a third insulating member, a supporting column and a connecting plate; The third insulating member is fixedly connected to the end surface of the support plate facing away from the position adjustment mechanism; The first end of the support column is fixedly connected to the third insulating member, and the second end of the support column is fixedly connected to the connecting plate; The connecting plate is rotatably provided with a clamping roller.

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