A brush array current loading device and control system for electrically assisted extreme thin strip rolling

Abstract

The application discloses a brush array current loading device and a control system for electrically assisted extremely thin strip rolling, and belongs to the technical field of electrically assisted plastic processing of metal materials, and comprises an uncoiler, a front guide roller, a front brush device, a rolling mill, a rear brush device, a rear guide roller and a coiler which are sequentially arranged; the front brush device and the rear brush device are respectively arranged on the front and rear sides of the rolling mill; the front guide roller and the rear guide roller are respectively arranged on the front and rear sides of the rolling mill and are arranged on the side, away from the rolling mill, of the front brush device or the rear brush device; and the rolling mill comprises a rolling mill rack and twenty rolling rollers arranged at the center of the rolling mill rack and symmetrically distributed along a metal strip for rolling work. The device and the control system can independently adjust pulse current parameters at multiple nodes in the width direction of the strip, cooperate with closed-loop feedback circuit control, and significantly improve the shape uniformity, structure consistency and process stability of the extremely thin strip rolling.

Description

Technical Field

[0001] This invention relates to the field of electro-assisted plastic forming technology of metal materials, and in particular to a brush array current loading device and control system for electro-assisted ultra-thin strip rolling. Background Technology

[0002] Ultra-thin metal strips, typically with thicknesses below 0.1 mm or even at the micrometer level, are indispensable key materials in national strategic and emerging industries such as lithography machines, electronics (3C), nuclear power, and military applications. In recent years, key components such as precision fluid control compression films for lithography machines, high-resolution photomasks, and precision sensors have created an urgent demand for thinner, more precise, better-shaped, and higher-performance, difficult-to-deform ultra-thin metal strips. In the production of ultra-thin metal strips, rolling is the core process for obtaining the target thickness and controlling the microstructure and properties. However, ultra-thin strip rolling faces significant technical challenges: due to the extremely small strip thickness, the reduction per pass is strictly limited, making it difficult for deformation to fully penetrate the core of the strip, easily leading to problems such as concentrated surface deformation, high residual stress, and uneven distribution; simultaneously, as the ratio of grain size to strip thickness increases, the material exhibits a significant size effect, increasing deformation resistance and narrowing the plastic processing window, making further thinning using traditional cold rolling processes extremely difficult, resulting in frequent defects such as edge cracking, poor shape, and uneven microstructure.

[0003] In existing technologies, electric-assisted forming technology softens materials through the Joule heating effect and improves material plasticity through the electroplastic effect by passing an electric current through the formed part, which can effectively control the evolution of the microstructure and reduce the deformation resistance. However, the strip is always in motion during the rolling process, and the introduction of electric-assisted forming technology inevitably leads to the problem of sliding electrical contact. Furthermore, due to the large strip width, uneven shape, and the influence of edge effects, the current flow space inside the strip is large and complex, making it difficult to control as a whole.

[0004] Existing methods for introducing current into electrically assisted rolling mostly employ single-contact technology, where a brush or conductive roller is placed before and after the rolling zone, and connected to the positive and negative terminals of a pulse power supply to form a circuit. This method suffers from significant circuit control defects: there is only a single current channel along the strip width, making it impossible to independently adjust the current at different locations along the width, resulting in an inability to accurately match the current with the forming performance; furthermore, existing solutions generally lack real-time monitoring and feedback control of the voltage and current in the electrically assisted rolling zone, meaning the current parameters cannot be adaptively adjusted when operating conditions fluctuate, affecting process stability.

[0005] Therefore, there is an urgent need for a brush array current loading device and control method that can be used in electrically assisted ultra-thin strip rolling to achieve independent loading of multiple channels current and has closed-loop control capability. Summary of the Invention

[0006] The purpose of this invention is to provide a brush array current loading device and control system for electrically assisted ultra-thin strip rolling, so as to solve the problems mentioned in the background art.

[0007] To achieve the above objectives, the present invention provides a brush array current loading device for electrically assisted ultra-thin strip rolling, comprising an uncoiler, a front guide roll, a front brush device, a rolling mill, a rear brush device, a rear guide roll, and a winding machine arranged sequentially; the front brush device and the rear brush device are respectively disposed on the front and rear sides of the rolling mill; the front guide roll and the rear guide roll are respectively arranged on the front and rear sides of the rolling mill, and are disposed on the side of the front brush device or the rear brush device away from the rolling mill; The rolling mill includes a mill stand and twenty rolls disposed at the center of the mill stand. The twenty rolls are symmetrically distributed along the metal strip for rolling operations. The metal strip is mounted on the uncoiler drum, and after straightening, it is driven by a motor to pass sequentially through the front guide roller, the front brush device, the rolling mill, the rear brush device, and the rear guide roller, and finally wound onto the winding machine to complete the threading process.

[0008] Preferably, both the front brush assembly and the rear brush assembly include a base, a cover plate, and a brush array. The base is used to control the position of the front brush assembly or the rear brush assembly as a whole. The cover plate is fixed to the base by a threaded connection. The brush array is disposed at a countersunk hole in the base. Through the clearance fit of the brush array disposed at the countersunk hole in the base and the threaded connection between the base and the cover plate, the brush array is fixed to the lower part of the base and extends appropriately beyond the electrical contact portion, thereby achieving stable electrical connection.

[0009] Preferably, the brush array is configured with 9 brushes, each brush array including a brush head, a wire, a spring and a washer. The brush head is fixedly connected to the wire and the wire is positioned above the brush head. The spring is sleeved on the outside of the wire, and the upper and lower ends of the spring are fixedly connected to the brush head and the washer, respectively. The wire is led out of the cover plate through the middle part between the spring and the washer.

[0010] Preferably, the brush head is made of carbon fiber composite material.

[0011] Preferably, both the front brush device and the rear brush device are in contact with the upper surface of the metal strip through the lower surface of the brush head, and the front brush device and the rear brush device are respectively connected to the anode and cathode of the power supply to form a conductive circuit, thereby inputting pulse current to the metal strip.

[0012] The present invention also provides a brush array current loading control system for electrically assisted ultrathin strip rolling, comprising: The low-frequency rectifier unit is used to perform full-wave rectification on the 50Hz power frequency AC power input through the input terminal to output pulsating DC power. The filter unit is connected in parallel to the rectifier output terminal of the low-frequency rectifier unit to filter out the ripple after rectification so as to output a stable DC. An inverter, composed of high-power switching electronic components, is used to convert low-frequency DC into high-voltage medium-frequency AC. Transformers are used to reduce high-voltage medium-frequency AC power to low-voltage medium-frequency power suitable for electro-assisted molding. The intermediate frequency rectifier unit is used to rectify the low-voltage intermediate frequency AC power output from the transformer secondary to form an intermediate frequency pulse DC bus; the intermediate frequency pulse DC bus is directly used as the common power supply bus of the subsequent brush array, and the negative terminal of the intermediate frequency pulse DC bus is connected to the common cathode. The multi-output and closed-loop control unit has nine branches drawn from the intermediate frequency pulse DC bus.

[0013] Preferably, each branch circuit consists of an independent series MOSFET, a reactor, and a closed-loop control unit; the MOSFET is used to receive the modulation signal and control the conduction state; the reactor is used to smooth the current and suppress spikes; the closed-loop control unit is used to detect the current or voltage on the branch circuit, compare it with the current or voltage of the given circuit, and modulate the feedback control through the electronic control circuit to form a pulse current of the designed parameters on the branch circuit.

[0014] Therefore, the present invention employs the above-described brush array current loading device and control system for electrically assisted ultra-thin strip rolling, which has the following beneficial effects: 1. The present invention sets up an array of nine independent brushes on the front and rear sides of the rolling mill, so that pulse currents of different sizes and waveforms can be applied at different positions in the width direction of the strip, thereby achieving a synergistic match between current and forming performance, and significantly improving the uniformity of strip shape and consistency of microstructure in ultra-thin strip rolling. 2. By setting up independent closed-loop control units for each circuit, this invention can maintain stable electrical auxiliary parameters when the strip thickness, temperature, and surface contact state change during the rolling process, which greatly improves the repeatability and stability of the process. 3. This invention, through multi-channel independent current control of the brush array, can provide non-uniform current assistance for non-uniform deformation in the width direction of the strip during the rolling process of ultra-thin strip, effectively reducing local deformation resistance and suppressing edge cracks and strip shape defects.

[0015] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of a brush array current loading device for electrically assisted ultrathin strip rolling according to an embodiment of the present invention; Figure 2 This is a schematic diagram of the brush device according to an embodiment of the present invention; Figure 3 This is a cross-sectional view of the brush array according to an embodiment of the present invention; Figure 4 This is a schematic diagram of the brush array structure according to an embodiment of the present invention; Figure 5 This is a schematic diagram of a brush array current loading control system for electrically assisted ultra-thin strip rolling according to an embodiment of the present invention; Figure Labels 1. Uncoiler; 2. Front guide roll; 3. Front brush assembly; 4. Mill stand; 5. Twenty rolls; 6. Rear brush assembly; 7. Rear guide roll; 8. Metal strip; 9. Rewinder; 10. Base; 11. Cover plate; 12. Brush array; 13. Brush head; 14. Wire; 15. Spring; 16. Gasket; VD1, Low-frequency rectifier unit; LC1, Filter unit; Q, Inverter; T, Transformer; VD2, Medium-frequency rectifier unit; NMOS, N-channel enhancement-mode MOSFET; L2, Reactor. Detailed Implementation

[0017] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0018] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0019] Example like Figure 1 As shown, the present invention provides a brush array current loading device for electrically assisted ultra-thin strip rolling, comprising an uncoiler 1, a front guide roll 2, a front brush device 3, a rolling mill, a rear brush device 6, a rear guide roll 7, and a winding machine 9 arranged in sequence.

[0020] The rolling mill includes a rolling mill stand 4 and twenty rolls 5 set at the center of the rolling mill stand 4. The twenty rolls 5 are symmetrically distributed along the metal strip 8 for rolling operations. The rolling mill stand 4 is used to fix the twenty rolls 5.

[0021] The front brush device 3 and the rear brush device 6 are respectively installed on the front and rear sides of the rolling mill. Both the front brush device 3 and the rear brush device 6 are in contact with the upper surface of the metal strip 8 through the lower surface of the brush head 13. The front brush device 3 and the rear brush device 6 are respectively connected to the anode and cathode of the power supply to form a conductive circuit, thereby inputting pulse current to the metal strip 8.

[0022] The front guide roller 2 and the rear guide roller 7 are respectively arranged on the front and rear sides of the rolling mill, and are set on the side away from the rolling mill of the front brush device 3 or the rear brush device 6. During the feeding process, the metal strip 8 is kept straight and smoothly discharged from the uncoiler 1 and introduced into the coiler 9.

[0023] The metal strip 8 is mounted on the drum of the uncoiler 1. After straightening, the metal strip 8 is driven by the motor to pass through the front guide roller, the front brush device 3, the rolling mill, the rear brush device 6, and the rear guide roller 7 in sequence, and finally wound on the winding machine 9 to complete the threading.

[0024] This invention combines an existing 20-roll mill with an electric brush device to introduce pulse current into the rolling zone during the rolling process of metal strip. By utilizing electric-assisted forming technology, it can effectively control the microstructure evolution and reduce deformation resistance, thereby achieving a better and more controllable rolling effect for ultra-thin metal strips.

[0025] Furthermore, such as Figure 2 As shown, both the front brush device 3 and the rear brush device 6 include a base 10, a cover plate 11 and a brush array 12. The base 10 is used to control the position of the front brush device 3 or the rear brush device 6 as a whole. The cover plate 11 is fixed to the base 10 by a threaded connection. The brush array 12 is set at the countersunk hole of the base 10.

[0026] By using the clearance fit of the brush array 12 at the countersunk hole of the base 10, and the threaded connection between the base 10 and the cover plate 11, the brush array 12 is fixed to the lower part of the base 10 and extends appropriately beyond the electrical contact portion, thus achieving stable electrical connection.

[0027] Furthermore, the brush head 13 is made of carbon fiber composite material. By using carbon fiber composite material as the material of the brush head 13, its high conductivity, self-lubrication and excellent wear resistance can be utilized to maintain a low and stable sliding contact resistance between the brush head 13 and the relatively sliding metal strip 8, while reducing scratches on the strip surface and improving the long-term stability of electric assisted rolling and the surface quality of the strip.

[0028] Furthermore, such as Figures 3-4 As shown, the brush array 12 is configured with 9 brushes. Each brush array 12 includes a brush head 13, a wire 14, a spring 15, and a washer 16. The brush head 13 is fixedly connected to the wire 14, and the wire 14 is positioned above the brush head 13. The spring 15 is sleeved on the outside of the wire 14. The upper and lower ends of the spring 15 are fixedly connected to the brush head 13 and the washer 16, respectively. The wire 14 is led out of the cover plate 11 through the middle part between the spring 15 and the washer 16.

[0029] The wire 14 is fixedly connected to the brush head 13. The upper and lower ends of the spring 15 are fixedly connected to the brush head 13 and the washer 16, respectively. The wire 14 is led out from the central hole of the spring 15 and the washer 16, so that the elastic force of the spring 15 can be applied directly and evenly to the brush head 13, ensuring that the contact pressure between the brush head 13 and the metal strip 8 is constant. At the same time, the wire 14 is led out from the center, avoiding interference with the spring 15 and preventing the wire 14 from fatigue breaking due to repeated compression, thereby improving the mechanical reliability and electrical stability of the brush device.

[0030] Both the front brush device 3 and the rear brush device 6 are equipped with nine identical brush heads 13, which can realize independent input of anode current at nine nodes in the width direction during the rolling process of metal strip 8.

[0031] like Figure 5 As shown, the present invention provides a brush array current loading control system for electrically assisted ultra-thin strip rolling, comprising: The low-frequency rectifier unit VD1 is used to perform full-wave rectification on the 50Hz power frequency AC power input through the input terminal to output pulsating DC power. The filter unit LC1 is connected in parallel to the rectifier output terminal of the low-frequency rectifier unit VD1 to filter out the ripple after rectification so as to output a stable DC. Inverter Q, composed of high-power switching electronic components, is used to invert low-frequency DC into high-voltage medium-frequency AC. Transformer T is used to reduce the high-voltage medium-frequency AC power to a low-voltage medium-frequency power suitable for electro-assisted molding. The intermediate frequency rectifier unit VD2 is used to rectify the low-voltage intermediate frequency AC power output from the secondary of transformer T into an intermediate frequency pulse DC bus; the intermediate frequency pulse DC bus is directly used as the common power supply bus of the subsequent brush array 12, and the negative terminal of the bus is connected to the common cathode. The multi-output and closed-loop control unit consists of nine branches originating from a mid-frequency pulse DC bus. Each branch independently connects a MOSFET, an inductor L2, and a closed-loop control unit in series. The MOSFET receives the modulation signal and controls its conduction state. The inductor L2 smooths the current and suppresses spikes. The closed-loop control unit detects the current or voltage on the branch, compares it with the current or voltage of the given circuit, and uses electronic control circuitry to modulate feedback control to generate the designed pulse current on the branch. The MOSFETs used are N-channel enhancement-mode MOSFETs (NMOS).

[0032] Therefore, the present invention employs the above-mentioned brush array current loading device and control system for electrically assisted ultra-thin strip rolling, which can independently adjust the pulse current parameters at multiple nodes in the strip width direction. Combined with closed-loop feedback circuit control, it significantly improves the uniformity of strip shape, consistency of microstructure and process stability of ultra-thin strip rolling.

[0033] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the technical solutions of the present invention, and these modifications or equivalent substitutions cannot cause the modified technical solutions to deviate from the spirit and scope of the technical solutions of the present invention.

Claims

1. A brush array current loading device for electrically assisted ultrathin strip rolling, characterized in that: The device includes an uncoiler, a front guide roll, a front brush device, a rolling mill, a rear brush device, a rear guide roll, and a coiler arranged in sequence; the front brush device and the rear brush device are respectively arranged on the front and rear sides of the rolling mill; the front guide roll and the rear guide roll are respectively arranged on the front and rear sides of the rolling mill, and are located on the side of the front brush device or the rear brush device away from the rolling mill. The rolling mill includes a mill stand and twenty rolls disposed at the center of the mill stand. The twenty rolls are symmetrically distributed along the metal strip for rolling operations. The metal strip is mounted on the uncoiler drum, and after straightening, it is driven by a motor to pass sequentially through the front guide roller, the front brush device, the rolling mill, the rear brush device, and the rear guide roller, and finally wound onto the winding machine to complete the threading process.

2. The brush array current loading device for electrically assisted ultra-thin strip rolling according to claim 1, characterized in that: Both the front brush assembly and the rear brush assembly include a base, a cover plate, and a brush array. The base is used to control the position of the front brush assembly or the rear brush assembly as a whole. The cover plate is fixed to the base by a threaded connection. The brush array is disposed at the countersunk hole of the base. Through the clearance fit of the brush array disposed at the countersunk hole of the base and the threaded connection between the base and the cover plate, the brush array is fixed to the lower part of the base and extends appropriately beyond the electrical contact portion, thereby achieving the stability of the electrical connection.

3. The brush array current loading device for electrically assisted ultra-thin strip rolling according to claim 2, characterized in that: The brush array is configured with 9 brushes. Each brush array includes a brush head, a wire, a spring, and a washer. The brush head is fixedly connected to the wire and the wire is positioned above the brush head. The spring is sleeved on the outside of the wire. The upper and lower ends of the spring are fixedly connected to the brush head and the washer, respectively. The wire is led out of the cover plate through the middle part between the spring and the washer.

4. The brush array current loading device for electrically assisted ultrathin strip rolling according to claim 3, characterized in that: The brush head is made of carbon fiber composite material.

5. A brush array current loading device for electrically assisted ultrathin strip rolling according to claim 3, characterized in that: Both the front brush device and the rear brush device are in contact with the upper surface of the metal strip through the lower surface of the brush head. The front brush device and the rear brush device are respectively connected to the anode and cathode of the power supply to form a conductive circuit and input pulse current to the metal strip.

6. A brush array current loading control system for electrically assisted ultra-thin strip rolling, applied to the brush array current loading device for electrically assisted ultra-thin strip rolling as described in any one of claims 1-5, characterized in that, include: The low-frequency rectifier unit is used to perform full-wave rectification on the 50Hz power frequency AC power input through the input terminal to output pulsating DC power. The filter unit is connected in parallel to the rectifier output terminal of the low-frequency rectifier unit to filter out the ripple after rectification so as to output a stable DC. An inverter, composed of high-power switching electronic components, is used to convert low-frequency DC into high-voltage medium-frequency AC. Transformers are used to reduce high-voltage medium-frequency AC power to low-voltage medium-frequency power suitable for electro-assisted molding. The intermediate frequency rectifier unit is used to rectify the low-voltage intermediate frequency AC power output from the transformer secondary to form an intermediate frequency pulse DC bus. The intermediate frequency pulsed DC bus is directly used as the common power supply bus for the subsequent brush array, and the negative terminal of the intermediate frequency pulsed DC bus is connected to the common cathode; The multi-output and closed-loop control unit has nine branches drawn from the intermediate frequency pulse DC bus.

7. A brush array current loading control system for electrically assisted ultra-thin strip rolling according to claim 6, characterized in that: Each branch circuit consists of an independent series MOSFET, reactor, and closed-loop control unit; the MOSFET is used to receive the modulation signal and control the conduction state; the reactor is used to smooth the current and suppress spikes; the closed-loop control unit is used to detect the current or voltage on the branch circuit, compare it with the current or voltage of the given circuit, and modulate the feedback control through electronic control circuit to form the pulse current of the designed parameters on the branch circuit.

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