Post-processing equipment for rolled strip

Abstract

The present invention discloses a post-processing device for rolled strip, which relates to the technical field of post-processing of strip rolling, and aims to solve the problem of wavy edge warping and overall warping caused by uneven residual stress distribution between the edge and center regions of metal strips after rolling in the prior art. The device comprises: a gradient annealing device and an edge stress grading control device; the gradient annealing device comprises at least a plurality of heating roller groups; the plurality of heating roller groups are arranged at equal intervals along the direction of strip movement, each heating roller group comprises two heating rollers, and the two heating rollers heat the upper and lower surfaces of the rolled strip respectively; each heating roller comprises at least a magnetic induction coil, and the coil density of the magnetic induction coil decreases from the edge to the center; the edge stress grading control device comprises at least a plurality of edge pressure roller groups arranged along the direction of strip movement; the angle between each edge pressure roller group and the width direction of the strip decreases step by step along the direction of strip movement. The present invention is used to achieve precise control of residual stress.

Description

Technical Field

[0001] The present invention relates to the technical field of post-processing of strips after rolling, and in particular to post-processing equipment for rolled strips. Background Art

[0002] During the metal strip rolling process, factors such as roll elastic deformation, uneven material flow, and temperature distribution can easily lead to uneven residual stress distribution at the edges and center of the strip. This can cause defects such as edge wavy warping and overall warping in the rolled strip. These defects not only affect the strip's surface flatness and dimensional accuracy, but also reduce the yield rate of subsequent further processing, becoming a major obstacle to the production of high-precision metal strip.

[0003] Existing technologies often use annealing to control residual stress in rolled strip. Conventional annealing, which employs uniform heating across the entire strip, can partially eliminate residual stress but cannot specifically address the stress differences between the edges and the center, making the edge wave problem difficult to resolve. Conventional mechanical straightening technology, which uses roller levelers to apply force to the strip to force leveling, can only temporarily correct the strip's geometry without eliminating internal residual stress, making it prone to recurrence of warping during subsequent processing. Summary of the Invention

[0004] The purpose of the present invention is to provide a post-processing equipment for rolled strips, which is used to solve the problem of edge wavy warping and overall warping caused by uneven residual stress distribution between the edge and center areas after metal strip rolling in the prior art, and to achieve precise control of residual stress.

[0005] In order to achieve the above object, the present invention provides the following technical solutions:

[0006] In a first aspect, the present invention provides a post-processing device for rolled strip, comprising: a gradient annealing device and an edge stress grading control device; the outlet end of the gradient annealing device is connected to the inlet end of the edge stress grading control device;

[0007] The gradient annealing device comprises at least a plurality of heating roller groups; the plurality of heating roller groups are arranged at equal intervals along the moving direction of the strip, each heating roller group comprises two heating rollers, and the two heating rollers heat the upper and lower surfaces of the rolled strip respectively; each heating roller comprises at least a magnetic induction coil, and the coil density of the magnetic induction coil decreases from the edge to the middle;

[0008] The edge stress grading control device includes at least a plurality of edge pressing roller groups arranged along the moving direction of the strip; each of the edge pressing roller groups includes four edge pressing rollers; the angle between each edge pressing roller group and the width direction of the strip decreases step by step along the moving direction of the strip.

[0009] Optionally, each of the heating rollers further comprises a supporting roller core, an inner roller cover, an outer roller cover and two end covers;

[0010] The support roller core is located at the center of the roller body of the heating roller; the material of the support roller core is ceramic insulating material;

[0011] The inner roller sleeve is sleeved on the outside of the supporting roller core, and the outer roller sleeve is sleeved on the outside of the inner roller sleeve, and a heating roller cavity is formed between the inner roller sleeve and the outer roller sleeve;

[0012] The magnetic induction coil is wound around the outer surface of the inner roller sleeve, and high-frequency alternating current is passed through both ends of the magnetic induction coil;

[0013] The two end covers are respectively fixed to the two ends of the roller body of the heating roller.

[0014] Optionally, the gradient annealing device further includes: a plurality of temperature acquisition devices; each of the temperature acquisition devices is connected to one of the heating rollers; the temperature acquisition device includes a sensor base and at least three temperature sensors fixed on the sensor base; the at least three temperature sensors are evenly distributed along the axial direction of the heating roller.

[0015] Optionally, the gradient annealing device further comprises an upper box, a lower box and a tension roller group;

[0016] The upper box body and the lower box body are connected to form a closed cavity;

[0017] The tension roller group is arranged at the entrance of the closed cavity.

[0018] Optionally, the tension roller group includes a first tension roller, a second tension roller and a third tension roller;

[0019] The first tension roller and the second tension roller are at the same level; the third tension roller is located below the first tension roller and the second tension roller.

[0020] Optionally, the gradient annealing device further comprises a heat dissipation device; the heat dissipation device is arranged above the plurality of heating rollers;

[0021] The heat dissipation device includes a heat dissipation box, multiple cooling motors and multiple fans; the heat dissipation box is provided with grid-shaped heat dissipation holes;

[0022] A plurality of cooling motors are arranged on the heat dissipation box;

[0023] The plurality of fans are all installed inside the heat dissipation box;

[0024] Each of the cooling motors is connected to one of the fans.

[0025] Optionally, the gradient annealing device further includes a protective gas tank and at least one nozzle, the protective gas tank and the at least one nozzle are both arranged on the upper box body, and the at least one nozzle is connected to the protective gas tank.

[0026] Optionally, the edge stress grading control device further comprises a main box, an upper pressing plate, a lower pressing plate and two telescopic connecting rod mechanisms;

[0027] The main box is a U-shaped frame consisting of a bottom plate and two side plates;

[0028] The upper pressing plate and the lower pressing plate are both arranged between the two side plates, and each side plate is provided with an inlet and outlet for the strip to pass through;

[0029] Each of the telescopic link mechanisms comprises a plurality of telescopic link pairs, a guide plate, a ball screw seat, a ball screw and a drive motor;

[0030] The upper pressing plate and the lower pressing plate are both connected to each telescopic link pair, and each telescopic link pair is also connected to the guide plate;

[0031] The guide plate is also connected to the first end of the ball screw seat, the second end of the ball screw seat is connected to the first end of the ball screw, and the second end of the ball screw is connected to the drive motor.

[0032] Optionally, each of the pressure rollers includes: a flange seat, a rod shaft, a roller and a set screw; the roller is fixed to the upper pressure plate or the lower pressure plate through the flange seat; the flange seat is sleeved on the outside of the rod shaft; the upper end of the flange seat and the rod shaft are both provided with threaded holes, and the threaded holes are locked to the rod shaft by assembling the set screw to achieve angle fixation of the pressure roller.

[0033] Optionally, the edge stress grading control device further includes a plurality of first insulation boxes arranged on the upper pressing plate and a plurality of second insulation boxes arranged on the lower pressing plate; one first insulation box and one second insulation box are arranged between two adjacent edge pressing roller groups.

[0034] The beneficial effects of the present invention are as follows: compared with the prior art, the present invention provides a post-processing equipment for rolled strips. In the embodiment of the present invention, non-uniform, gradient heating is achieved through the magnetic induction coil of the heating roller in the gradient annealing device, and graded stress is applied to the rolled strip by using the edge pressure roller with graded angles set by the edge stress grading control device, thereby constructing a composite control mechanism for coordinated thermal release bonding force, accurately targeting the residual stress difference between the edge and center of the strip, overcoming the uniformity defect of traditional annealing, and compensating for the stress residual problem of mechanical straightening, thereby reducing warping defects from the root and improving the flatness and processing stability of the strip. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] The drawings described herein are used to provide a further understanding of the present invention and constitute a part of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0036] Figure 1 A schematic diagram of the overall structure of post-processing equipment for rolled strip provided in one embodiment of the present invention;

[0037] Figure 2 A schematic diagram of the overall structure of a strip processing device provided by one embodiment of the present invention;

[0038] Figure 3 A schematic structural diagram of a gradient annealing device provided in one embodiment of the present invention;

[0039] Figure 4 A schematic structural diagram of a heating roller provided in one embodiment of the present invention;

[0040] Figure 5 A schematic cross-sectional view of a heating roller according to an embodiment of the present invention;

[0041] Figure 6 A schematic structural diagram of an edge stress grading control device provided in one embodiment of the present invention;

[0042] Figure 7 A schematic diagram showing the angles between multiple edge holding roller sets and the moving direction of the strip, provided in accordance with an embodiment of the present invention;

[0043] Figure 8 A schematic structural diagram of a temperature acquisition device provided in one embodiment of the present invention;

[0044] Figure 9 A schematic structural diagram of a heat dissipation device provided in one embodiment of the present invention;

[0045] Figure 10 A schematic cross-sectional view of a pressure roller according to an embodiment of the present invention;

[0046] Figure 11 A schematic structural diagram of a pressure roller provided in one embodiment of the present invention;

[0047] Figure numerals: 1- gradient annealing device; 2- edge stress grading control device; 11- heating roller; 111- magnetic induction coil; 112- support roller core; 113- inner roller cover; 114- outer roller cover; 115- end cover; 116- heating roller cavity; 12- temperature acquisition device; 121- sensor base; 122- temperature sensor; 13- upper box; 14- lower box; 15- tension roller group; 151- first tension roller; 152- second tension roller; 153- third tension roller; 16- heat dissipation device; 161- heat dissipation box; 162- cooling motor; 163- fan; 17- protective gas tank; 18 -nozzle; 21-edge-pressing roller assembly; 211-first edge-pressing roller; 212-second edge-pressing roller; 213-third edge-pressing roller; 214-fourth edge-pressing roller; 215-flange seat; 216-rod shaft; 217-roller; 218-fastening screw; 219-threaded hole; 22-main box; 221-bottom plate; 222-first side plate; 223-second side plate; 23-upper pressure plate; 24-lower pressure plate; 241-second insulation box; 25-telescopic connecting rod pair; 251-first connecting rod; 252-second connecting rod; 26-guide plate; 27-ball screw seat; 28-ball screw; 29-drive motor. DETAILED DESCRIPTION

[0048] To facilitate a clear description of the technical solutions of the embodiments of the present invention, the words "first" and "second" are used in the embodiments of the present invention to distinguish between identical or similar items with substantially the same functions and effects. For example, the first threshold and the second threshold are merely used to distinguish between different thresholds and do not limit their order. Those skilled in the art will understand that the words "first" and "second" do not limit the quantity or execution order, and the words "first" and "second" do not necessarily mean different.

[0049] It should be noted that, in the present invention, words such as "exemplary" or "for example" are used to indicate examples, illustrations, or descriptions. Any embodiment or design described as "exemplary" or "for example" in the present invention should not be construed as being preferred or advantageous over other embodiments or designs. Rather, the use of words such as "exemplary" or "for example" is intended to present the relevant concepts in a concrete manner.

[0050] In the present invention, "at least one" means one or more, "more than one" means two or more, and "and / or" describes the association relationship between associated objects, indicating that three types of relationships can exist.

[0051] like Figure 1 As shown, the embodiment of the present invention provides a post-processing device for rolled strip, which may include: a gradient annealing device 1 and an edge stress grading control device 2, wherein the outlet end of the gradient annealing device 1 is connected to the inlet end of the edge stress grading control device 2; Figure 2 It is understood that the post-processing equipment for the rolled strip in this embodiment is connected to the rolling equipment for post-processing the rolled strip; the rolling equipment rolls the input strip, and the rolled strip enters the post-processing equipment for further processing, and outputs the output strip;

[0052] The gradient annealing device 1 comprises a plurality of heating roller groups; the plurality of heating roller groups are arranged at equal intervals along the moving direction of the strip, see Figure 3 Each of the heating roller groups includes two heating rollers 11, which heat the upper and lower surfaces of the rolled strip respectively, so as to ensure that both the upper and lower surfaces of the rolled strip can be uniformly annealed; see Figure 4 and Figure 5 Each heating roller 11 includes at least a magnetic induction coil 111. The coil density of the magnetic induction coil 111 decreases from the edge to the middle. That is, the coil density of the magnetic induction coil 111 decreases from any one of the two edges of the heating roller to the middle. The coil density is symmetrically distributed along the axial center of the heating roller.

[0053] See also Figure 6 The edge stress grading control device 2 at least includes a plurality of edge pressing roller groups 21 arranged along the moving direction of the strip; each edge pressing roller group 21 includes four edge pressing rollers, or in other words, each edge pressing roller group includes a first edge pressing roller 211, a second edge pressing roller 212, a third edge pressing roller 213 and a fourth edge pressing roller 214; the first edge pressing roller 211 and the second edge pressing roller 212 are symmetrically arranged along the center line of the strip width direction, and the third edge pressing roller 213 and the fourth edge pressing roller 214 are symmetrically arranged along the center line of the strip width direction; the first edge pressing roller 211 and the third edge pressing roller 213 are symmetrically arranged in the vertical direction of the strip thickness direction; the second edge pressing roller 212 and the fourth edge pressing roller 214 are symmetrically arranged in the vertical direction of the strip thickness direction;

[0054] See also Figure 7 , the angle between each pressure roller set and the width direction of the strip decreases step by step along the direction of strip movement. It can be understood that along the width direction of the strip, the four angles between the axial direction of the four pressure rollers in each pressure roller set and the width direction of the strip are the same, for example Figure 7 In the first one ( Figure 7 The angle between the axial direction of each pressure roller and the width direction of the strip is 15 0 , the second one ( Figure 7 The angle between the axis of each pressure roller and the width direction of the strip is 10 0 , the third one ( Figure 7 The angle between the axis of each pressure roller and the width direction of the strip is 5 0 , the fourth one ( Figure 7 The angle between the outer normal of each pressure roller in the pressure roller group and the moving direction of the strip is 0 0 .

[0055] It's understandable that in the field of strip processing, "width" is a conventional term referring to the lateral dimension perpendicular to the strip's direction of travel (i.e., its length). For example, when a strip is conveyed, its length (also its direction of travel) is the forward direction, the horizontal direction perpendicular to the forward direction is the width, and the direction perpendicular to the plane of the strip is the thickness. The width centerline is an imaginary line that bisects the width of the strip, parallel to the length and equidistant from the left and right edges of the strip.

[0056] It can be said that the angle between each pressure roller group and the width direction of the strip refers to the acute angle between the axial direction of any pressure roller in each pressure roller group and the width direction of the strip, or it can be said that the angle between each pressure roller group and the moving direction of the strip refers to the acute angle between the outer normal of any pressure roller in each pressure roller group and the moving direction of the strip. The angles in these two cases are the same.

[0057] The edge of the strip after rolling is a free surface and the transverse stress is relaxed However, due to the temperature difference between the edge and middle of the strip, residual tensile stress is generated. .

[0058] When the strip passes through the edge pressing roller (for example, the first edge pressing roller 211), the axial rotation of the first edge pressing roller 211 will provide a stress to the strip along the roller moving direction. , which can be divided into rolling stress and transverse stress , Pointing to the inner direction of the strip, it can effectively balance some of the residual tensile stress. The formula is as follows:

[0059] (1)

[0060] In formula (1), To regulate the lateral residual stress in the front edge; is the control value of the side lateral stress; is the actual transverse residual stress after regulation.

[0061] By adjusting the edge holding roller group at multiple different angles along the moving direction of the strip in stages, the residual tensile stress at the edge is reduced step by step, and the stress distribution at the edge is optimized by reasonably controlling the transverse compressive stress. It should be noted that the amount of transverse compressive stress should be reasonably controlled according to actual conditions to prevent the residual tensile stress from being converted into residual compressive stress, which will affect the surface quality of the strip.

[0062] The beneficial effects of this implementation are analyzed as follows:

[0063] First, a gradient annealing device is provided in the post-processing equipment of the rolled strip, which has the following advantages: 1) The two heating roller groups are arranged symmetrically up and down. The two symmetrical heating roller groups ensure the overall heating uniformity of the rolled strip, avoiding the "one-size-fits-all" problem of traditional annealing, and eliminating uneven stress distribution through local temperature differences; 2) The magnetic induction coil density of each heating roller decreases from the edge to the middle, that is, the magnetic induction coil density is high at the edge and low in the middle → the heating power at the edge is higher → the temperature of the strip edge is higher than that of the center area → the temperature gradient is used to make the thermal expansion of the edge material more significant, and the residual stress at the edge is released in a targeted manner (because the edge usually bears greater tensile stress during rolling); in general, compared with traditional overall annealing, the stress difference between the edge and the center can be more accurately controlled, reducing defects such as edge waves.

[0064] Second, the post-processing equipment for rolled strips is equipped with a graded edge stress control device. Two edge-holding roller groups are symmetrically distributed along the strip's width centerline. The angle between the axial direction and the strip's width decreases step by step in the direction of strip movement. This provides the following benefits: 1) Graded mechanical stress application: The angle decreases step by step, resulting in a gradual decrease in the compressive stress on the strip edge by the rollers along the strip's travel direction, simulating a progressive stress release process. 2) Coordinated edge plastic deformation: Multiple rollers apply varying degrees of compressive stress to the edge, resulting in controlled plastic deformation of the edge material, offsetting the tensile stress accumulated during rolling while avoiding material damage caused by excessive pressure from a single roller. 3) Coordinated stress and geometry correction: Combined with the temperature field after gradient annealing, the mechanical compressive stress further promotes the release of residual stress in the edge, achieving dual control of "thermal-mechanical coupling." In summary, compared to traditional mechanical straightening, this not only corrects the geometry but also eliminates internal residual stresses through graded stress application, reducing the risk of defect recurrence.

[0065] Third, the gradient annealing device is combined with the edge stress graded control device to realize a thermal-mechanical coupling control process. The first step is gradient annealing pretreatment: the concentrated stress at the edge is released through the temperature gradient, reducing the hardness and stress level of the material. Then, graded mechanical straightening is performed: based on thermal annealing, the angle gradient of the pressure roller is used to further coordinate the stress state of the edge and the center to achieve precise matching of residual stress. The gradient annealing device combined with the edge stress graded control device has the following advantages: 1) Traditional methods only rely on thermal control or force control, while the present invention designs a thermal-mechanical coordinated control method to solve the problem of non-uniform stress from the dual dimensions of "stress release" and "stress reconstruction"; 2) The dual-dimensional gradient design (temperature gradient and angle gradient) makes the control process more consistent with the stress distribution characteristics of the strip, improving the pertinence and effectiveness of addressing the shortcomings of existing technologies.

[0066] In summary, the embodiments of the present invention construct a composite control mechanism of "heat release + force coordination" through non-uniform and gradient heating of gradient annealing and graded stress application of the pressure roller, which accurately targets the residual stress difference between the edge and center of the strip, overcomes the uniformity defect of traditional annealing, and compensates for the stress residual problem of mechanical straightening, reduces warping defects from the root, and improves the flatness and processing stability of the strip.

[0067] Alternatively, as Figure 4 Shown and Figure 5 As shown, each heating roller 11 further includes a supporting roller core 112, an inner roller cover 113, an outer roller cover 114 and two end covers 115;

[0068] The supporting roller core 112 is located at the center of the roller body of the heating roller 11; the supporting roller core 112 is made of insulating materials such as ceramics;

[0069] The inner roller cover 113 is sleeved on the outside of the supporting roller core 112, and the outer roller cover 114 is sleeved on the outside of the inner roller cover 113. A heating roller cavity 116 is formed between the inner roller cover 113 and the outer roller cover 114.

[0070] The magnetic induction coil 111 is wound around the outer surface of the inner roller sleeve 113, and high-frequency alternating current is passed through both ends of the magnetic induction coil 111;

[0071] The two end covers 115 are respectively fixed to the two ends of the roller body of the heating roller 11 .

[0072] Furthermore, both the inner and outer sleeves 113 and 114 are made of metal. The metal surface of the inner sleeve 113 provides support for the magnetic induction coil. The heating roller cavity 116 between the inner and outer sleeves 113 and 114 can be filled with a thermally conductive medium to optimize heat transfer efficiency. The thermally conductive medium fills the coil gaps through convection or conduction, dissipating localized heat across the sleeve surface, reducing hot spots and ensuring a more uniform temperature distribution along the axial direction of the outer sleeve. The thermally conductive medium (such as insulating oil) provides both insulation and heat dissipation properties, preventing coil aging or short circuits due to high temperatures. It also dissipates Joule heat generated by the coil's own resistance, preventing overheating and damage. (Long-term high temperatures can easily lead to insulation failure of the enameled wire.) Once filled with the thermally conductive medium, the magnetic induction coil is secured in the cavity between the inner and outer sleeves, minimizing relative motion between the coil and sleeve during high-speed rotation and reducing the risk of wear.

[0073] Optionally, the heat conducting medium in the heating roller cavity 116 can be heat conducting oil or high thermal conductivity insulating silicone grease. Compared with air, these two heat conducting media can greatly reduce thermal resistance, so that the heat of the inner roller sleeve is quickly transferred to the outer roller sleeve, thereby improving the overall thermal response speed.

[0074] High-frequency alternating current is passed through both ends of the magnetic induction coil 111, and the metal inner roller sleeve is heated by the Joule heating effect generated by the eddy current flowing through the conductor. The denser the coil is wound, the more significant the heating effect is, so that the surface temperature of the roller decreases from the edge to the middle, compensating for the residual stress concentration caused by the rapid temperature drop at the edge of the strip after rolling.

[0075] In this embodiment, the heating roller generates heat through electromagnetic induction, combined with a gradient density distribution of magnetic coils to achieve differentiated heating between the edges and center of the strip. The specific principles are as follows: 1. Electromagnetic induction heating: High-frequency alternating current is applied to the magnetic coils, generating an alternating electromagnetic field. Eddy currents are induced within the inner and outer metal roller sleeves. Eddy currents generate heat, raising the roller body temperature. Heat conduction then heats the strip surface. 2. Gradient heating: The density of the magnetic coils decreases from the edges to the center of the heating roller (with more coil turns at the edges and fewer in the center). The higher coil density at the edges creates a higher alternating electromagnetic field intensity, stronger eddy currents, and greater heat generation. The lower coil density in the center generates less heat, resulting in a gradient distribution on the heating roller surface, with higher temperatures at the edges and lower temperatures in the center. When the strip contacts the rolled strip, the edges absorb more heat, while the center receives less heat, thus achieving non-uniform heating. 3. Synergistic effect of the upper and lower symmetrical heating roller groups: The upper and lower heating roller groups simultaneously apply gradient heat → a temperature gradient is formed in the corresponding areas of the upper and lower surfaces of the strip → thermal deformation caused by unilateral heating is avoided, while the symmetry and uniformity of stress release at the edge are enhanced to compensate for the residual stress concentration caused by the rapid temperature drop at the edge of the strip after rolling. This can be further understood in conjunction with the following specific formula (2):

[0076] (2)

[0077] in, is the material Poisson’s ratio of the strip; is the coefficient of thermal expansion; is the material elastic modulus of the strip; is the thermal stress term (temperature difference between the edge and the middle); is the stress in the rolling direction; is the transverse stress; is the stress in the thickness direction. The edge of the strip is a free surface and the transverse stress is relaxed. However, due to the temperature difference between the edge and middle of the strip, residual tensile stress may be generated. The greater the temperature difference, the more likely it is to cause residual stress concentration at the edge. By using magnetic induction coils with different coil densities in the heating roller to compensate for the temperature drop at the edge of the strip, the residual stress at the edge is released, which can effectively improve the edge waves and warping of the strip after rolling.

[0078] The heating roller in this embodiment has the following structural features: 1) A multi-layer nested roller design (support roller core + inner roller sleeve + outer roller sleeve). The support roller core provides mechanical strength to prevent the roller from expanding due to heat or deformation due to external forces. The inner and outer roller sleeves form an independent heating cavity, isolating the magnetic induction coil within the cavity to prevent direct contact between the coil and the strip, which could cause short circuits or wear. Heat is also evenly transferred through the metal roller sleeve. The end cap seals secure the roller structure, preventing dust and impurities from entering the cavity and affecting coil performance, thereby improving equipment reliability. 2) An external magnetic induction coil layout (wound around the outer surface of the inner roller sleeve): The coil is not embedded in the roller body, allowing the outer roller sleeve to be directly removed and replaced during maintenance, reducing maintenance costs. By adjusting the ratio of the number of coil turns at the edges and the center, the temperature gradient can be flexibly adjusted to meet the stress control requirements of different strip specifications. 3) The eddy currents excited by the high-frequency current are concentrated on the roller sleeve surface (skin effect), resulting in a fast heating response. The heat generation can be controlled in real time by adjusting the current frequency or intensity, achieving dynamic temperature adjustment. 4) The supporting roller core is made of non-metallic materials such as ceramics, which plays a supporting role and prevents current from flowing through the box when power is turned on, causing safety hazards.

[0079] Conventional heating rollers are resistive heating rollers, which heat evenly. Compared to conventional heating rollers, the heating roller and its heating method in this embodiment: 1) Conventional annealing provides uniform heating but fails to address stress concentration at the edges. In this embodiment, the magnetic induction coils feature a density gradient design, generating more heat at the edges and less heat in the center, creating a temperature gradient that allows targeted heating at the edges to relieve stress. 2) Conventional heating equipment is complex and difficult to maintain. In this embodiment, the multi-layered, nested modular design (support roller core + inner / outer roller sleeves + end caps) allows for removable components, and coil maintenance does not require complete roller replacement. 3) Conventional heating rollers have low temperature control accuracy. In this embodiment, the high-frequency AC drive coils provide adjustable temperature distribution, enabling quantifiable control of the temperature gradient and high control accuracy. 4) Conventional heating rollers have low heating efficiency and high energy consumption. In this embodiment, electromagnetic induction heating directly acts on the metal roller sleeve, resulting in a heat conversion efficiency exceeding 90% (compared to approximately 60-70% for conventional resistance heating).

[0080] From the above content, it can be seen that the heating roller structure in this embodiment systematically solves the shortcomings of the traditional annealing process in terms of stress control accuracy, equipment maintainability and energy efficiency through the combination of gradient heating design and modular mechanical structure, thereby improving the accuracy of post-processing of metal strips.

[0081] Alternatively, see Figure 8 The gradient annealing device also includes: multiple temperature acquisition devices 12; each temperature acquisition device 12 is connected to a heating roller 11; the temperature acquisition device 12 includes a sensor base 121 and at least three temperature sensors 122 fixed on the sensor base 121; for example, the three temperature sensors 122 are evenly distributed.

[0082] For example Figure 8 As shown, each heating roller 11 is connected to three temperature sensors 122, evenly distributed along the roller's axis. The temperature sensors 122 at the ends of the roller 11 are used to measure the temperature, while the temperature sensor 122 in the middle is used to measure the temperature in the middle of the roller. It should be noted that the temperature sensors 122 are generally not in direct contact with the roller surface. High roller surface temperatures could easily exceed the threshold and directly burn out the sensors. The sensor heads are typically spaced approximately 1 mm from the roller surface to measure the approximate temperature.

[0083] Traditional annealing equipment is usually equipped with only 1-2 temperature sensors, and in most cases single-point monitoring is used (for example, only one sensor is set in the middle of the heating roller or at a fixed position near the heating source). In a few scenarios, one sensor may be set at each end (a total of two), but the distribution density is low and lacks regularity. This sensor arrangement has a limited monitoring range, low control accuracy, and weak fault tolerance. This embodiment uses three evenly distributed temperature sensors, which offer the following advantages: First, a temperature sensor is located at each end and the center of the heating roller, forming a basic "end + midpoint" monitoring network. This network directly captures the following key information: 1) Axial temperature gradient: By comparing the data from the sensors at both ends with the center, it is possible to determine whether the heating roller is overheating in the center, undercooling at both ends, or experiencing an abnormality with one end being too high or too low (e.g., edge effects, which are difficult to detect with traditional devices). 2) Symmetry verification: If the difference in data from the sensors at both ends exceeds a threshold, it can quickly identify a faulty heating element or uneven heat dissipation on the left and right sides of the heating roller (traditional single-point solutions cannot locate such deviations). For example, assuming a heating roller length of 1 meter, the error of traditional single-point monitoring can reach ±5°C (only the midpoint is measured, and the actual temperatures at both ends are unknown). However, the three evenly distributed sensors can control the overall temperature monitoring error to within ±2°C and directly quantify the gradient value (e.g., "left end 200°C → midpoint 220°C → right end 210°C"; the gradient is low on the left, high in the middle, and slightly mid-right). The second and third sensors form a minimally redundant network. If any one fails, the remaining two sensors can still support system operation (for example, using only data from both ends to estimate the midpoint temperature, or using only data from the midpoint and one end to determine the gradient trend), thus avoiding the downtime risk associated with traditional single-point failures. Third, the three sensors divide the heating roller into three control zones: left, center, and right. The system independently adjusts the heating power at each location based on real-time data from each zone, avoiding the lag inherent in traditional, one-size-fits-all solutions. For example, if the left sensor detects a temperature 20°C below the setpoint, the system increases the power only to the left heating element, while maintaining the original settings for the center and right ends. This reduces response time by over 50% compared to traditional solutions (no need to wait for the temperature to reach the midpoint before adjusting). Fourth, by comparing the differences between the three sensor data (for example, if the temperature difference between the two ends, normally less than 5°C, suddenly increases to 15°C), it can directly pinpoint heating element failure, heat conduction problems (such as scaling), or poor sensor contact in the corresponding area, improving maintenance efficiency by over 70% (traditional solutions require section-by-section troubleshooting). Fifth, gradient annealing requires a specific temperature gradient to form on the material surface (e.g., increasing temperature along the direction of travel). Three sensors can directly verify whether the designed gradient is achieved (e.g., 200°C on the left end → 250°C at the midpoint → 300°C on the right end, with an error of ±3°C). Traditional single-point solutions cannot provide gradient data and can only rely on empirical adjustments.

[0084] Alternatively, see Figure 2 , the gradient annealing device 1 further includes an upper box 13, a lower box 14 and a tension roller group 15;

[0085] The upper box body 13 and the lower box body 14 are connected to form a closed cavity;

[0086] The tension roller group 15 is arranged at the entrance of the closed cavity; the tension roller group 15 is used to tension the rolled strip entering the gradient annealing device.

[0087] In this embodiment, a tension roller group is arranged at the entrance of the closed cavity to tension the rolled strip entering the gradient annealing device. This is because: when the rolled strip enters the heating roller in an untensioned state, it may become loose, droopy or partially stacked due to its own weight or uneven friction of the roller. For example, the strip in the wrinkled area is not in sufficient contact with the heating roller, resulting in local temperature abnormalities (such as insufficient heating or overheating), and regional differences in material properties (such as hardness and flatness) after annealing; the rolled strip without tension control is prone to lateral deviation (such as deviation), and may leave the effective range of the heating roller, resulting in the annealing process being unable to completely cover the strip surface, and even causing equipment failures such as scratches and tears.

[0088] The benefits of installing a tension roller assembly in this embodiment include providing constant tension to the rolled strip. First, it ensures the strip maintains a straight trajectory, preventing deviation, wrinkling, or stacking. Second, it ensures a close fit between the strip and the heated rollers, ensuring efficient heat transfer and uniform temperature distribution. Third, in conjunction with the speed control system, it precisely matches the annealing time and temperature gradient. The design of the tension roller assembly in this embodiment addresses the quality fluctuations caused by uncontrolled tension in traditional annealing equipment. By providing a pre-tensioning mechanism, it lays the foundation for subsequent gradient annealing processes. This is particularly suitable for high-end materials requiring high flatness and uniformity.

[0089] Further, see Figure 3 The tension roller assembly 15 includes a first tension roller 151, a second tension roller 152, and a third tension roller 153. The first and second tension rollers 151 and 152 are positioned at the same height. The third tension roller 153 is vertically positioned below and horizontally positioned between the first and second tension rollers 151 and 152. These three tension rollers work together to tension the strip and adjust the height of the strip at the inlet, facilitating subsequent stress control at the strip edge.

[0090] Specifically, the advantages of having three tension rollers are as follows: 1) The first and second tension rollers are positioned at the same height, providing uniform initial tension in the strip's transverse direction. This ensures balanced force across the strip's width, preventing deviation and wrinkling. The third tension roller, located below, works in conjunction with the first two rollers to apply tension to the strip in the vertical direction. These two-dimensional interactions provide more stable overall tension in the strip. For example, when processing wide metal strips, uniform force in the transverse direction prevents wrinkling at the strip's edges, while vertical tension prevents sagging. 2) This layout creates a specific strip path, effectively guiding the strip smoothly into subsequent components such as the heating rollers. As the strip shuttles between the three tension rollers, its trajectory is constrained, minimizing the possibility of strip sway and deviation, ensuring accurate entry into the annealing zone and improving consistent annealing quality. For example, in a continuous annealing line, this stable trajectory ensures uniform heating of the strip throughout the entire annealing process. 3) The tension applied to the strip can be flexibly adjusted by adjusting parameters such as the spacing and rotational speed of the three tension rollers. For example, when processing strips of varying thicknesses and materials, the tension roller settings can be tailored to meet the tension requirements of the various strips. For thinner, more easily deformed foils, the tension can be appropriately reduced; for thicker, more rigid strips, the tension can be increased. This adjustability enhances the equipment's adaptability to different strips. 4) The relatively compact layout of three tension rollers occupies less equipment space, facilitating overall miniaturization and ensuring structural stability. During operation, this coordinated layout effectively disperses the forces generated by strip tension, reducing the stress on individual components and extending the equipment's service life.

[0091] Alternatively, see Figure 3 The gradient annealing device 1 further includes a heat dissipation device 16; the heat dissipation device 16 is disposed above the plurality of heating rollers 11; see Figure 9 The heat dissipation device 16 includes a heat dissipation box 161, multiple cooling motors 162 and multiple fans 163; the heat dissipation box 161 is provided with a grid-like heat dissipation hole; multiple cooling motors 162 are arranged on the heat dissipation box 161; multiple fans 163 are all installed inside the heat dissipation box 161; each cooling motor 162 is connected to or directly connected to a fan 163.

[0092] The temperature sensor transmits the detected temperature information to a controller in the post-processing equipment for the rolled strip. When the temperature information indicates that the temperature at both ends of the heating roller exceeds a set threshold, the controller controls the fan to dissipate heat from the roller surface through the heat dissipation holes, thereby reducing the roller surface temperature. The controller can be located somewhere in the upper housing 13.

[0093] Alternatively, see Figure 3The gradient annealing device 1 further includes a protective gas tank 17 and at least one nozzle 18. Both the protective gas tank 17 and the at least one nozzle 18 are disposed on the upper housing 13, and the at least one nozzle 18 is connected to the protective gas tank 17. The protective gas tank 17 passes a protective gas into the closed cavity formed by the upper housing 13 and the lower housing 14 through the nozzle 18. The protective gas is an inert gas such as argon to prevent oxidation of the strip during the annealing process.

[0094] Alternatively, see Figure 6 In addition to a plurality of edge pressing roller groups 21, the edge stress grading control device 2 also includes: a main box 22, an upper pressing plate 23, a lower pressing plate 24 and two telescopic connecting rod mechanisms; it should be noted that for each edge pressing roller group 21, the first edge pressing roller 211 and the second edge pressing roller 212 are both arranged on the upper pressing plate 23, and the third edge pressing roller 213 and the fourth edge pressing roller 214 are both arranged on the lower pressing plate 24;

[0095] The main box body 22 is a U-shaped frame consisting of a bottom plate 221 and two side plates. Figure 6 As shown in FIG, a first side plate 222 and a second side plate 223 are sequentially arranged along the direction of strip movement; each side plate is provided with an inlet and an outlet for the strip to pass through, for example, the first side plate 222 is provided with a strip inlet, and the second side plate 223 is provided with a strip outlet, and the strip inlet and the strip outlet are at the same level;

[0096] The upper pressing plate 23 and the lower pressing plate 24 are both arranged between the two side plates, and the upper pressing plate 23 and the lower pressing plate 24 are both parallel to the bottom plate 221;

[0097] The two telescopic link mechanisms are symmetrically distributed along the center line of the strip width direction, and each telescopic link mechanism is connected to the upper pressing plate 23 and the lower pressing plate 24 to drive the upper pressing plate 23 and the lower pressing plate 24 to extrude the rolled strip;

[0098] Each telescopic link mechanism includes a plurality of telescopic link pairs 25, a guide plate 26, a ball screw seat 27, a ball screw 28 and a drive motor 29; the number of the plurality of telescopic link pairs is the same as the number of the plurality of pressure roller groups;

[0099] The upper pressing plate 23 and the lower pressing plate 24 are both connected to each telescopic link pair 25, and each telescopic link pair 25 is also connected to the guide plate 26; specifically, each telescopic link pair 25 includes a first link 251 and a second link 252, wherein a first end of the first link 251 is connected to the upper pressing plate 23, a second end of the first link 251 is connected to the guide plate 26, a first end of the second link 252 is connected to the lower pressing plate 24, and a second end of the second link 252 is connected to the guide plate 26, and the first link 251 and the second link 252 are symmetrically distributed in the upper and lower directions along the thickness direction of the strip;

[0100] The guide plate 26 is also connected to the first end of the ball screw seat 27, the second end of the ball screw seat 27 is connected to the first end of the ball screw 28, and the second end of the ball screw 28 is connected to the drive motor 29; the drive motor 29 drives the guide plate 26 to move horizontally through the ball screw 28 and then drives the upper and lower pressure plates to press the strip.

[0101] See also Figure 10 and Figure 11 Each pressure roller includes: a flange seat 215, a rod shaft 216, a roller 217 and a set screw 218; the roller 217 is fixed to the upper pressure plate or the lower pressure plate through the flange seat 215; the flange seat 215 is sleeved on the outside of the rod shaft 216; the upper end of the flange seat 215 and the rod shaft 216 are both provided with threaded holes 219, and the threaded holes 219 are assembled with set screws 218 to lock the rod shaft 216 to achieve angle fixation of the pressure roller.

[0102] Alternatively, see Figure 6 The edge stress grading control device 2 may further include multiple first insulation boxes installed on the upper platen and multiple second insulation boxes 241 installed on the lower platen. A first insulation box and a second insulation box 241 are positioned between two adjacent edge-holding roller sets. The first and second insulation boxes utilize built-in heating wires to uniformly heat the strip, maintaining its temperature and preventing a rapid temperature drop after gradient annealing that could affect edge residual stress control.

[0103] An embodiment of the present invention provides post-processing equipment for rolled strip, wherein the rolled strip sequentially passes through a gradient annealing device and an edge stress grading control device. The gradient annealing device comprises an upper and lower housings forming a closed chamber. The incoming strip is tensioned by a tension roller assembly, then passes through a plurality of heating rollers arranged symmetrically along the axial direction. The electric heating rollers anneal the strip using a temperature gradient created by magnetic induction coils, compensating for temperature drops at the strip edges and initially addressing residual stress concentrations at the strip edges after rolling. A protective gas is injected into the chamber via a nozzle to prevent high-temperature oxidation of the strip. A temperature sensor monitors the roller surface temperature in real time. If the roller surface temperature exceeds a set threshold, a controller in the gradient annealing device activates a cooling fan to reduce the roller surface temperature.

[0104] The edge stress grading control module includes at least a heat preservation box, an upper pressure plate, and a lower pressure plate. Multiple pairs of telescopic links are symmetrically arranged on both sides of the upper and lower pressure plates. The strip is pressed by a drive motor. The upper and lower pressure plates are laterally symmetrically arranged with edge pressure rollers. The angles of the edge pressure rollers are arranged in a graded manner from 15 degrees to 0 degrees. During the movement of the strip, lateral compressive stress is applied to the edge, so that the residual stress is gradually released. During the stress control process, the annealing temperature is maintained by the heat preservation box to alleviate the edge wave and warping caused by residual tensile stress at the edge of the strip. The device of the present invention improves the defects of the rolled strip such as edge wave and edge warping caused by residual stress concentration in the continuous production process through the coordinated design of strip gradient annealing and edge stress grading control, thereby improving the surface quality and forming stability of the rolled strip.

[0105] Although the present invention has been described herein in conjunction with various embodiments, in the process of implementing the claimed invention, those skilled in the art may understand and implement other variations of the disclosed embodiments by reviewing the drawings, the disclosure, and the appended claims. In the claims, the word "comprising" does not exclude other components or steps, and "a" or "an" does not exclude multiple situations. A single processor or other unit may implement several functions listed in the claims. Certain measures are recorded in different dependent claims, but this does not mean that these measures cannot be combined to produce good results.

[0106] Although the present invention has been described with reference to specific features and embodiments thereof, it will be apparent that various modifications and combinations may be made thereto without departing from the spirit and scope of the invention. Accordingly, this specification and drawings are merely illustrative of the invention as defined by the appended claims and are deemed to cover any and all modifications, variations, combinations or equivalents within the scope of the invention. It will be apparent that various modifications and variations may be made to the present invention by those skilled in the art without departing from the spirit and scope of the invention. Thus, the present invention is intended to include such modifications and variations as fall within the scope of the claims of the present invention and their equivalents.

Claims

1. A post-processing equipment for rolled strip, characterized in that: include: A gradient annealing device and an edge stress grading control device; the outlet of the gradient annealing device is connected to the inlet of the edge stress grading control device; The gradient annealing device comprises at least a plurality of heating roller groups; the plurality of heating roller groups are arranged at equal intervals along the moving direction of the strip, each heating roller group comprises two heating rollers, and the two heating rollers heat the upper and lower surfaces of the rolled strip respectively; each heating roller comprises at least a magnetic induction coil, and the coil density of the magnetic induction coil decreases from the edge to the middle; The edge stress grading control device includes at least a plurality of edge pressing roller groups arranged along the moving direction of the strip; each of the edge pressing roller groups includes four edge pressing rollers; the angle between each edge pressing roller group and the width direction of the strip decreases step by step along the moving direction of the strip.

2. The post-processing equipment for rolled strip according to claim 1, characterized in that: Each of the heating rollers further comprises a supporting roller core, an inner roller cover, an outer roller cover and two end covers; The support roller core is located at the center of the roller body of the heating roller; the material of the support roller core is ceramic insulating material; The inner roller sleeve is sleeved on the outside of the supporting roller core, and the outer roller sleeve is sleeved on the outside of the inner roller sleeve, and a heating roller cavity is formed between the inner roller sleeve and the outer roller sleeve; The magnetic induction coil is wound around the outer surface of the inner roller sleeve, and high-frequency alternating current is passed through both ends of the magnetic induction coil; The two end covers are respectively fixed to the two ends of the roller body of the heating roller.

3. The post-processing equipment for rolled strip according to claim 1, characterized in that: The gradient annealing device also includes: multiple temperature acquisition devices; each of the temperature acquisition devices is connected to one of the heating rollers; the temperature acquisition device includes a sensor base and at least three temperature sensors fixed on the sensor base; the at least three temperature sensors are evenly distributed along the axial direction of the heating roller.

4. The post-processing equipment for rolled strip according to claim 1, characterized in that: The gradient annealing device also includes an upper box, a lower box and a tension roller group; The upper box body and the lower box body are connected to form a closed cavity; The tension roller group is arranged at the entrance of the closed cavity.

5. The post-processing equipment for rolled strip according to claim 4, characterized in that: The tension roller group includes a first tension roller, a second tension roller and a third tension roller; The first tension roller and the second tension roller are at the same level; the third tension roller is located below the first tension roller and the second tension roller.

6. The post-processing equipment for rolled strip according to claim 1, characterized in that: The gradient annealing device further includes a heat dissipation device; the heat dissipation device is arranged above the plurality of heating rollers; The heat dissipation device includes a heat dissipation box, multiple cooling motors and multiple fans; the heat dissipation box is provided with grid-shaped heat dissipation holes; A plurality of cooling motors are arranged on the heat dissipation box; The plurality of fans are all installed inside the heat dissipation box; Each of the cooling motors is connected to one of the fans.

7. The post-processing equipment for rolled strip according to claim 4, characterized in that: The gradient annealing device further includes a protective gas tank and at least one nozzle. The protective gas tank and the at least one nozzle are both arranged on the upper box body, and the at least one nozzle is connected to the protective gas tank.

8. The post-processing equipment for rolled strip according to claim 1, characterized in that: The edge stress grading control device also includes a main box, an upper pressing plate, a lower pressing plate and two telescopic connecting rod mechanisms; The main box is a U-shaped frame consisting of a bottom plate and two side plates; The upper pressing plate and the lower pressing plate are both arranged between the two side plates, and each side plate is provided with an inlet and outlet for the strip to pass through; Each of the telescopic link mechanisms comprises a plurality of telescopic link pairs, a guide plate, a ball screw seat, a ball screw and a drive motor; The upper pressing plate and the lower pressing plate are both connected to each telescopic link pair, and each telescopic link pair is also connected to the guide plate; The guide plate is also connected to the first end of the ball screw seat, the second end of the ball screw seat is connected to the first end of the ball screw, and the second end of the ball screw is connected to the drive motor.

9. The post-processing equipment for rolled strip according to claim 8, characterized in that: Each of the pressure rollers includes: a flange seat, a rod shaft, a roller and a set screw; the roller is fixed to the upper pressure plate or the lower pressure plate through the flange seat; the flange seat is sleeved on the outside of the rod shaft; the upper end of the flange seat and the rod shaft are both provided with threaded holes, and the threaded holes are assembled with the set screws to lock the rod shaft to achieve angle fixation of the pressure roller.

10. The post-processing equipment for rolled strip according to claim 9, characterized in that: The edge stress grading control device also includes a plurality of first insulation boxes arranged on the upper pressing plate and a plurality of second insulation boxes arranged on the lower pressing plate; one first insulation box and one second insulation box are arranged between two adjacent edge pressing roller groups.

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