An ultra-high strength steel heating and rolling production line

Abstract

The application discloses a kind of super high-strength steel heating roll production line, it is related to sheet metal processing technical field, including from left to right sequentially arranged feeding frame, preheating box, heating box, roll box and cooling box, the bottom of preheating box is fixedly installed with third installation box, gas cooling assembly is arranged in third installation box, the bottom of cooling box is fixedly installed with second installation box, and gas heating part is arranged in second installation box;Roll box is provided with upper roll die set and lower roll die set.The application constructs feeding, preheating, heating, rolling and cooling whole-process continuous link, and realizes no stop roll changing with the design of double sets of sliding seat and sealed cavity, greatly improves production continuity and efficiency;Subsection temperature control and nitrogen closed loop system avoid steel thermal shock cracking, oxidation corrosion, guarantee forming precision and mechanical property stability, and also realize waste heat recovery energy saving.

Description

Technical Field

[0001] This invention belongs to the field of metal plate processing technology, specifically, it relates to a heating and rolling production line for ultra-high strength steel. Background Technology

[0002] The ultra-high strength steel heated roll forming production line is a specialized forming equipment designed for the characteristics of ultra-high strength steel materials. Through a combination of heating pretreatment and continuous roll forming processes, it achieves high-precision and high-efficiency forming of ultra-high strength steel, and is widely used in the production of structural components in the automotive, engineering machinery and other fields.

[0003] A search revealed Chinese invention patent CN111496107B, which discloses a hot-forming steel plate roll forming production line and method. The production line includes forming rollers, straightening and positioning rollers, a heating system, and a cooling system. The forming rollers are located at the front end of the production line. The heating system is located behind the forming rollers and includes an induction heating power supply, an electromagnetic induction heater, a heating conveying roller, and a temperature sensor. The cooling system is located behind the heating system and includes a cooling device, a cooling conveying roller, and a cooling system control box. The straightening and positioning rollers are located behind the cooling system.

[0004] The replacement of hot rollers in the aforementioned production lines and traditional hot roller pressing equipment mainly relies on two methods: shutdown replacement or simple sliding mechanism. Shutdown replacement requires a series of processes, including shutdown and belt breakage, natural cooling of the roller body, disassembly and replacement, reheating, and roller gap adjustment. The total time for a single operation generally exceeds 1.5 hours. Even if a quick clamping mechanism or modular roller group design is adopted to shorten the disassembly time, the core cooling and heating cycle cannot be avoided. During periods of tight schedules, the drawbacks of this traditional roller replacement method will be further amplified, directly exacerbating production conflicts and indirectly affecting delivery time. In view of the above problems, a new ultra-high strength steel heated roller pressing production line is proposed. Summary of the Invention

[0005] To address the problems mentioned in the background section, the present invention adopts the following technical solution:

[0006] A heating and rolling production line for ultra-high strength steel includes, from left to right, a feeding rack, a preheating box, a heating box, a rolling box, and a cooling box. A third mounting box is fixedly installed at the bottom of the preheating box, and a gas cooling component is installed inside the third mounting box. A second mounting box is fixedly installed at the bottom of the cooling box, and a gas heating section is installed inside the second mounting box. An upper rolling die and a lower rolling die are installed inside the rolling box. Both the upper and lower rolling dies include a sealing cover, and the two sets of sealing covers are symmetrically arranged. A mounting seat is rotatably installed on the sealing cover. Two sets of symmetrically arranged sliding seats are slidably connected to each mounting seat, and a hot pressing roller is rotatably mounted on the sliding seat.

[0007] In a preferred embodiment of the present invention: a transmission housing is rotatably mounted on the side wall of the roller press box; a spline shaft is fixedly mounted on each of the two output ends of the transmission housing; the two sets of spline shafts are symmetrically arranged; the rotation ratio of the two sets of spline shafts is 1:1; and the rotation directions are consistent; a coupling sleeve is rotatably mounted on the sliding seat; the coupling sleeve is connected to the spline shaft; a drive handle is fixedly mounted on the side wall of the transmission housing; and the input shaft of the transmission housing passes through the drive handle and extends to the outside of the roller press box where a drive shaft is fixedly mounted.

[0008] As a preferred embodiment of the present invention: multiple drive shafts in the upper roller pressing die group rotate synchronously through a first pulley group, multiple drive shafts in the lower roller pressing die group rotate synchronously through a second pulley group, the first pulley group is connected to a second motor fixedly installed on the top of the heating box, and one of the drive shafts in the upper roller pressing die group and one of the drive shafts in the lower roller pressing die group are connected to each other through a gear transmission module.

[0009] In a preferred embodiment of the present invention: a conveying assembly is provided on the preheating box, heating box, roller pressing box, and cooling box. The conveying assembly includes a conveying roller that rotates in the preheating box, heating box, roller pressing box, and cooling box respectively. A first mounting box is fixedly installed on the side wall of the preheating box and the cooling box. A first motor is fixedly installed on the end of each of the two first mounting boxes. A drive shaft is rotatably installed in the first mounting box. The drive shaft is connected to the conveying roller through a bevel gear set.

[0010] As a preferred embodiment of the present invention, it further includes a pressing assembly disposed on the top of the preheating box. The pressing assembly includes an electric hydraulic cylinder fixedly installed on the top of the preheating box. A connecting arm is slidably installed on the preheating box. A mounting frame is fixedly installed on one end of the connecting arm extending into the preheating box. A pressing roller is rotatably installed on the mounting frame. The end of the connecting arm extending into the top of the preheating box is fixedly connected to the output end of the electric hydraulic cylinder.

[0011] As a preferred embodiment of the present invention: an electromagnetic heater is fixedly installed inside the heating box.

[0012] As a preferred embodiment of the present invention: a feeding plate is slidably installed on the feeding rack, the feeding plate is magnetically fixed and sealed to the feeding rack, the feeding plate is provided with a feeding groove that matches the cross-section of the ultra-high strength steel plate during feeding, and a first sealing plate is rotatably installed on the side of the feeding plate located inside the preheating box.

[0013] As a preferred embodiment of the present invention: a discharge plate is slidably installed at the discharge end of the cooling box, the discharge plate is magnetically fixed and sealed to the cooling box, the discharge plate is provided with a discharge groove that matches the cross section of the steel part after hot roll forming, and a second sealing plate is rotatably installed on the side of the discharge plate outside the cooling box, the second sealing plate is magnetically fixed to the discharge plate.

[0014] In a preferred embodiment of the present invention: multiple sets of cooling components connected in sequence are fixedly installed inside the third mounting box. The cooling components include a second compressor and a heat exchanger fixedly installed on the inner wall of the bottom of the third mounting box. A fan is fixedly installed inside the third mounting box, and the fan is positioned above the second compressor and the heat exchanger. A sealing plate is fixedly installed on the side wall of the roller press box. The sealing plate, the sealing cover, the box body of the roller press box, and the mounting base cooperate to form a first sealing cavity. An air inlet pipe, an exhaust pipe, and a ventilation pipe communicating with the first sealing cavity are fixedly installed on the sealing cover. A second sealing cavity communicating with the preheating box is provided inside the third mounting box. The air inlet of the second compressor located at the first end is connected to the second sealing cavity. The air inlet of the heat exchanger is connected to the exhaust end of the second compressor on one side. The exhaust end of the heat exchanger is connected to the air inlet of the second compressor on the other side through an expansion valve. The second exhaust ends of multiple sets of expansion valves are all connected to the same main air pipe, and the main air pipe is connected to the air inlet end of the air inlet pipe.

[0015] In a preferred embodiment of the present invention: the gas heating section in the second mounting box includes a first compressor, the inlet of the first compressor is connected to the outlet of the cooling box, the outlet of the cooling box is located at one end near the roller press box, the preheating box is provided with a first split jet box at one end near the heating box, the inlet of the first split jet box is connected to the output end of the first compressor; a second split jet box is fixedly installed in the cooling box, the first exhaust end of the expansion valve of the tail cooling component is connected to the second split jet box, the exhaust end of the first compressor is connected to the first split jet box, and the exhaust end of the exhaust pipe is connected to the inlet of the first compressor.

[0016] Compared with the prior art, the present invention has the following beneficial effects:

[0017] This invention, through the design of a sealed cavity and pressure balance, combined with a mechanism for pre-loading spare hot press rollers and an automated control system, allows spare hot press rollers to be pre-loaded into the equipment. This enables rapid production switching in the event of a hot press roller failure, significantly reducing downtime required for replacement and maintenance. It achieves rapid switching of hot press rollers without shutting down the line, allowing for the repair and replacement of replaced hot press rollers while the production line continues to operate. This significantly improves the overall operating efficiency and flexibility of the production line, avoids prolonged downtime for repairs due to hot press roller failures, reduces production interruptions, ensures order delivery, and lowers the risk of production delays caused by emergencies.

[0018] This invention preheats spare hot press rollers by recovering and utilizing the waste heat generated during production line operation and the internal heating system of the hot press roller. This reduces preheating consumption and shortens preheating time through dual internal and external preheating, significantly improving the overall energy efficiency of the system. This not only reduces energy waste and operating costs, but also helps maintain the temperature stability of the hot press roller, reduces thermal shock, and thus extends the life of the hot press roller.

[0019] This invention employs a multi-stage compression and expansion system, working in conjunction with a nitrogen closed-loop system, to ensure precise temperature control. This avoids the energy waste associated with hot rollers in traditional solutions and enables precise temperature control during the processing of ultra-high-strength steel. This ensures that the microstructure and mechanical properties of the steel reach their optimal state. By strictly controlling the holding temperature, heating rate, and cooling rate, it effectively avoids problems such as coarse grains, crack defects, or substandard martensite structure, thereby guaranteeing the final product quality and performance of ultra-high-strength steel.

[0020] The specific embodiments of the present invention will now be described in further detail with reference to the accompanying drawings. Attached Figure Description

[0021] In the attached diagram:

[0022] Figure 1 This is a three-dimensional structural diagram of an ultra-high strength steel heating and rolling production line proposed in this invention. Figure 1 ;

[0023] Figure 2 This is a three-dimensional structural diagram of an ultra-high strength steel heating and rolling production line proposed in this invention. Figure 2 ;

[0024] Figure 3 This is a three-dimensional structural diagram of an ultra-high strength steel heating and rolling production line proposed in this invention. Figure 3 ;

[0025] Figure 4 This is a schematic diagram of the internal structure of the preheating box and heating box of an ultra-high strength steel heating roll forming production line proposed in this invention.

[0026] Figure 5 This is a schematic diagram of the internal structure of the cooling box in a heating roll forming production line for ultra-high strength steel proposed in this invention.

[0027] Figure 6 This is a schematic diagram of the mounting base for an ultra-high strength steel heated roll forming production line proposed in this invention. Figure 1 ;

[0028] Figure 7 This is a schematic diagram of the mounting base for an ultra-high strength steel heated roll forming production line proposed in this invention. Figure 2 ;

[0029] Figure 8 This is a schematic diagram of the structure of the first sealing cavity in an ultra-high strength steel heating and rolling production line proposed in this invention;

[0030] Figure 9 This is a schematic diagram of the structure of a sealing cover for an ultra-high strength steel heating roll forming production line proposed in this invention;

[0031] Figure 10 This is a schematic diagram of the transmission housing of an ultra-high strength steel heating roll forming production line proposed in this invention;

[0032] Figure 11 This is a schematic diagram of the pressing component of an ultra-high strength steel heated roller pressing production line proposed in this invention;

[0033] Figure 12 This is a schematic diagram of the feed plate structure of an ultra-high strength steel heated roll forming production line proposed in this invention. Figure 1 ;

[0034] Figure 13 This is a schematic diagram of the feed plate structure of an ultra-high strength steel heated roll forming production line proposed in this invention. Figure 2 ;

[0035] Figure 14 This is a schematic diagram of the discharge plate of an ultra-high strength steel heating roll forming production line proposed in this invention;

[0036] Figure 15 This is a schematic diagram of the conveying component of an ultra-high strength steel heating and rolling production line proposed in this invention;

[0037] Figure 16 This is a right sectional view of an ultra-high strength steel heating and rolling production line proposed in this invention;

[0038] Figure 17 for Figure 16 Schematic diagram of the structure at point A;

[0039] Figure 18This invention presents a flowchart of nitrogen circulation in a heated roll forming production line for ultra-high strength steel.

[0040] In the diagram: 1. Feeding rack; 11. Feeding plate; 12. Feeding chute; 13. First sealing plate; 2. Preheating box; 21. Conveying assembly; 211. Conveying roller; 212. First mounting box; 213. Drive shaft; 214. Bevel gear set; 215. First motor; 22. Pressing assembly; 221. Electric hydraulic cylinder; 222. Connecting arm; 223. Mounting frame; 224. Pressing roller; 23. First diverting jet box; 3. Heating box; 31. Electromagnetic heater; 4. Roller press box; 41. Sealing cover; 411. Air inlet pipe; 412. Exhaust pipe; 4 13. Ventilation pipe; 42. First sealing chamber; 43. Mounting base; 44. Transmission housing; 441. Splined shaft; 442. Drive handle; 443. Drive shaft; 45. Sliding seat; 451. Coupling sleeve; 46. Hot press roller; 47. Sealing plate; 48. Second motor; 5. Cooling box; 51. Second diversion jet box; 6. Second mounting box; 61. First compressor; 7. Third mounting box; 71. Second compressor; 72. Heat exchanger; 73. Fan; 74. Second sealing chamber; 8. Discharge plate; 81. Second sealing plate; 82. Discharge chute. Detailed Implementation

[0041] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments will be clearly and completely described below with reference to the accompanying drawings. The following embodiments are used to illustrate the present invention, but are not intended to limit the scope of the present invention.

[0042] Reference Figures 1-18 A type of ultra-high strength steel heated roll forming production line, (such as...) Figure 1 As shown, from left to right, the following components are arranged: a feeding rack 1, a preheating box 2, a heating box 3, a roller pressing box 4, and a cooling box 5. A third mounting box 7 is fixedly installed at the bottom of the preheating box 2, and a gas cooling component is installed inside the third mounting box 7. A second mounting box 6 is fixedly installed at the bottom of the cooling box 5, and a gas heating section is installed inside the second mounting box 6. An upper roller pressing module and a lower roller pressing module are arranged inside the roller pressing box 4. Both the upper and lower roller pressing modules include a sealing cover 41. The two sets of sealing covers 41 are symmetrically arranged. A mounting seat 43 is rotatably installed on the sealing cover 41. Two sets of symmetrically arranged sliding seats 45 are slidably connected to each mounting seat 43. A hot pressing roller 46 is rotatably installed on the sliding seat 45. When it is necessary to replace the hot pressing roller 46, the mounting seat 43 is driven to rotate and the positions of the two sets of sliding seats 45 are changed, and the unused hot pressing roller 46 is moved to the working position of the rolled steel.

[0043] The ultra-high strength steel billet released from the steel coil unloading machine is fed to the loading rack 1. From left to right, it is first conveyed through the loading rack 1 into the preheating box 2. The billet is first preheated at a low temperature in the preheating box 2 (to reduce the thermal stress of subsequent high-temperature heating), and then enters the heating box 3 to be heated to the process temperature required for rolling (ultra-high strength steel usually requires a specific high temperature to ensure plasticity). The high-temperature billet enters the rolling box 4, where it is rolled into shape by the hot pressing rollers 46 of the upper and lower rolling die groups (the hot pressing rollers 46 maintain a specific temperature to avoid the billet cooling too quickly and affecting its formability). The formed steel enters the cooling box 5 and is cooled according to process requirements (such as controlling the cooling rate to optimize the metallographic structure). During use, nitrogen circulates inside the device. After being cooled by the gas cooling component, the nitrogen is blown onto the formed steel in the cooling box 5, absorbing the heat of the steel. Then, it is heated again by the heating component and then discharged into the preheating box 2 to preheat the steel plate.

[0044] A sealing plate 47 is bolted to the outer wall of the roller pressing box 4. The sealing covers 41 of the upper and lower roller pressing modules are symmetrically arranged. The sealing plate 47, sealing cover 41, the box body of the roller pressing box 4 and the mounting base 43 cooperate to form the first sealing cavity 42. The unused hot pressing roller 46 and its sliding seat 45 are placed in the first sealing cavity 42. When the hot pressing roller 46 needs to be replaced, the used hot pressing roller 46 inside the first sealing cavity 42 is first cooled down. After cooling, the nitrogen gas inside the first sealing cavity 42 is extracted to reduce the nitrogen content inside the first sealing cavity 42. Then, air is injected to balance the pressure inside and outside the first sealing cavity 42. Then, the sliding seat 45 inside the first sealing cavity 42 is extracted. The replacement of the hot pressing roller 46 is completed outside. At the same time, the steel plate is continuously rolled inside the roller pressing box 4.

[0045] It should be noted that a new hot press roller 46 can be sent into the first sealing cavity 42 when the corresponding hot press roller 46 is about to reach the end of its service life or is damaged.

[0046] In summary, the production line, from left to right, is connected via a loading rack 1, a preheating box 2, a heating box 3, a rolling box 4, and a cooling box 5, forming a continuous chain of loading, preheating, heating, rolling, and cooling: the steel billet is conveyed from the loading rack 1 to the preheating box 2 for low-temperature preheating (reducing thermal stress from subsequent high-temperature heating), then enters the heating box 3 to be heated to the high temperature required for rolling (ensuring plasticity), subsequently formed in the rolling box 4, and finally cooled in the cooling box 5 according to the process (optimizing the metallographic structure). On the one hand, this avoids deformation or performance fluctuations of the steel due to cooling and stress during inter-process transfer; on the other hand, segmented temperature control reduces thermal shock, prevents cracking of the steel caused by direct high-temperature heating, and ensures the consistency of the mechanical properties (such as tensile strength and toughness) of ultra-high strength steel.

[0047] The hot press roller 46, in operation, presses the high-temperature billet within a sealed environment, avoiding interference from the low-temperature air outside and maintaining a stable temperature in the hot pressing area (preventing the billet from cooling down too quickly and affecting its plasticity). The unused hot press roller 46 and sliding seat 45 are stored in the first sealed cavity 42, which can be preheated to the working temperature in advance to ensure rapid adaptation to production after switching. This solves the problems of rapid cooling of high-temperature billets and low forming accuracy caused by the lack of sealing protection in traditional roll forming equipment, and the time-consuming process of reheating the spare roller. It significantly improves the stability and efficiency of roll forming.

[0048] The production line constructs a nitrogen closed loop through the gas cooling component in the third mounting box 7 and the gas heating section in the second mounting box 6: after being cooled by the cooling component, the nitrogen is blown onto the formed steel in the cooling box 5 to absorb heat (achieving uniform cooling); the heated nitrogen is then heated by the gas heating section and sent to the preheating box 2 to preheat the steel billet. This cycle not only recovers and utilizes the waste heat from the cooling process (replacing additional preheating energy) to solve the energy waste problem of traditional production lines, but also, due to the inertness of nitrogen, isolates oxygen to prevent the high-temperature steel from oxidizing and rusting, solving the surface quality defects of processing in an air environment and ensuring the internal performance and appearance precision of ultra-high strength steel.

[0049] When the hot press roller 46 needs to be replaced, the used hot press roller 46 in the first sealing cavity 42 is first cooled down, nitrogen gas in the cavity is extracted (to reduce the content) and air is injected to balance the pressure. Then, the sliding seat 45 is pulled out to complete the roller replacement outside. After the sliding seat 45 is pushed back into the first sealing cavity 42, the air in the sealing cavity is extracted and nitrogen gas is injected to reduce the oxygen content in the first sealing cavity 42. While the hot press roller 46 is being replaced, another set of hot press rollers 46 in the roller press box 4 continues to work. The new hot press roller 46 can be sent into the first sealing cavity 42 for preheating in advance. On the one hand, there is no need to stop the machine for replacement, avoiding production interruption. On the other hand, by cooling and balancing the pressure, there is no need to operate in a high-temperature environment, thereby avoiding the risk of burns. The spare roller is preheated in advance (reducing the debugging time after switching), minimizing the impact of roller replacement on production and adapting to the mass production needs of ultra-high strength steel.

[0050] Reference Figures 6-10 A transmission housing 44 is rotatably mounted on the side wall of the roller press 4. Splined shafts 441 are fixedly mounted on both output ends of the transmission housing 44. The two sets of splined shafts 441 are symmetrically arranged, with a rotation ratio of 1:1 and the rotation direction is the same. A coupling sleeve 451 is rotatably mounted on the sliding seat 45 and is connected to the splined shafts 441. A drive handle 442 is fixedly mounted on the side wall of the transmission housing 44. The input shaft of the transmission housing 44 passes through the drive handle 442 and extends to the outside of the roller press 4, where a drive shaft 443 is fixedly mounted.

[0051] Reference Figure 2Multiple drive shafts 443 in the upper roller pressing die group rotate synchronously through the first pulley group, and multiple drive shafts 443 in the lower roller pressing die group rotate synchronously through the second pulley group. The first pulley group is connected to the second motor 48 fixedly installed on the top of the heating box 3. One of the drive shafts 443 in the upper roller pressing die group and one of the drive shafts 443 in the lower roller pressing die group are connected through the gear transmission module. The spline shaft 441 in the upper roller pressing die group and the spline shaft 441 in the lower roller pressing die group rotate at a 1:1 rotation ratio. When the spline shaft 441 in the upper roller pressing die group rotates clockwise, the spline shaft 441 in the lower roller pressing die group rotates counterclockwise.

[0052] The drive handle 442 is fixed to the outer wall of the roller box 4 by a fixing pin. When the hot press roller 46 needs to be replaced, the fixing pin is removed and the drive handle 442 is rotated to drive the hot press roller 46 to change position.

[0053] In the upper roller pressing die, the input shafts of multiple transmission housings 44 rotate synchronously through the first pulley set, while the lower roller pressing die ensures that the internal transmission housings 44 rotate at the same speed through the second pulley set. With the drive output of the second motor 48, the hot pressing rollers 46 in both the upper and lower dies can maintain a uniform speed. At the same time, the upper and lower roller pressing dies achieve power linkage through the gear transmission module, ensuring that the spline shaft 441 rotates in opposite directions at a 1:1 rotation ratio (upper roller clockwise, lower roller counterclockwise). This serves two purposes: first, it avoids uneven stress on the steel caused by differences in the speed of a single roller, resulting in forming defects such as side bending and thickness deviation; second, the synchronous rotation in opposite directions ensures that the steel is subjected to balanced forces during the rolling process, preventing slippage or surface scratches, and significantly improving the forming accuracy and surface quality consistency of ultra-high strength steel.

[0054] The entire transmission system uses the second motor 48 as a single power source. It achieves multi-axis synchronization within the module through a pulley assembly, and then completes the power connection between the upper and lower modules through a gear transmission module, forming a highly efficient transmission link with single power and multiple executions. The pulley assembly transmission has buffering and shock absorption characteristics, which can reduce the impact load during motor start-up and operation; the gear transmission ensures a precise and constant speed ratio and avoids power transmission loss. This design solves the problems of poor speed synchronization, high energy consumption, and complex maintenance in traditional multi-motor drives. It not only reduces the energy consumption and failure probability of the equipment, but also simplifies the maintenance process and further adapts to the stability requirements of mass production of ultra-high strength steel.

[0055] Reference Figure 1 , Figure 4 , Figure 5 , Figures 15-17Each of the preheating box 2, heating box 3, roller pressing box 4, and cooling box 5 is equipped with a conveying assembly 21. The conveying assembly 21 includes a conveying roller 211 that rotates in the preheating box 2, heating box 3, roller pressing box 4, and cooling box 5 respectively. A first mounting box 212 is fixedly installed on the side wall of the preheating box 2 and the cooling box 5. A first motor 215 is fixedly installed on the end of each of the two first mounting boxes 212. A drive shaft 213 is rotatably installed inside the first mounting box 212. The drive shaft 213 is connected to the conveying roller 211 through a bevel gear set 214.

[0056] When in use, the first motor 215 is started. The two first motors 215 drive the transmission rollers 211 in the preheating box 2, heating box 3, roller pressing box 4 and cooling box 5 to rotate through the two transmission shafts 213 respectively, so as to transfer the ultra-high strength steel in the preheating box 2, heating box 3, roller pressing box 4 and cooling box 5.

[0057] Reference Figure 3 and Figure 11 It also includes a pressing assembly 22 disposed on the top of the preheating box 2. The pressing assembly 22 includes an electric hydraulic cylinder 221 fixedly installed on the top of the preheating box 2. A connecting arm 222 is slidably installed on the preheating box 2. A mounting bracket 223 is fixedly installed on one end of the connecting arm 222 extending into the preheating box 2. A pressing roller 224 is rotatably installed on the mounting bracket 223. The end of the connecting arm 222 extending into the top of the preheating box 2 is fixedly connected to the output end of the electric hydraulic cylinder 221.

[0058] In use, the connecting arm 222 can be driven to rise or fall by the electric hydraulic cylinder 221, thereby driving the mounting frame 223 and the pressing roller 224 to rise or fall, and working in conjunction with the transmission roller 211 inside the preheating box 2 to correct the bent ultra-high strength steel plate.

[0059] In summary, by cooperating with the pressing roller 224 and the bottom transmission roller 211, uniform pressure is applied to the bent ultra-high strength steel plate to achieve correction. On the one hand, this avoids the forming accuracy deviation caused by the bent steel plate entering the subsequent heating and rolling processes, ensuring the baseline flatness of the steel in subsequent processing. On the other hand, the electric hydraulic cylinder 221 can precisely adjust the pressing pressure to adapt to steel plates of different thicknesses and degrees of bending, avoiding damage to the steel plate caused by uneven manual correction pressure. At the same time, the rotating design of the pressing roller 224 reduces friction and scratches with the steel plate, ensuring surface quality.

[0060] The automatic lifting and lowering of the correction mechanism is achieved by using an electric hydraulic cylinder 221, eliminating the need for manual operation inside the high-temperature preheating box 2. This avoids safety risks in high-temperature environments and improves correction efficiency. At the same time, the lifting stroke of the pressing roller 224 can be precisely controlled by the electric hydraulic cylinder 221, which can dynamically adjust the correction force and height according to the bending condition of the steel plate, adapting to the straightening requirements of ultra-high strength steel of different specifications. On the one hand, it avoids the instability of straightening effect caused by errors in manual operation, and on the other hand, it eliminates the need for manual adjustment by stopping the machine, ensuring the continuous connection between the preheating process and subsequent processes, and further improving the automation level and processing adaptability of the production line.

[0061] Reference Figure 4 An electromagnetic heater 31 is fixedly installed inside the heating box 3. The ultra-high strength steel plate, which has been preheated in the preheating box 2, enters the heating box 3. The electromagnetic heater 31 uses the principle of electromagnetic induction to make the steel plate generate heat quickly, achieving uniform heating from the inside to the surface, and accurately reaching the process temperature required for rolling. On the one hand, it avoids the serious waste of gas heating energy and the generation of pollutants, reducing production energy consumption and environmental protection costs. On the other hand, it eliminates the need for complicated smoke exhaust and heat insulation facilities, simplifies the internal structure of the heating box 3, and reduces the impact of high-temperature heat leakage on the workshop environment, thereby improving the safety of the production environment.

[0062] Reference Figure 2 , Figure 12 and Figure 15 A feeding plate 11 is slidably installed on the feeding rack 1. The feeding plate 11 is fixed and sealed to the feeding rack 1 by magnetic attraction. The feeding plate 11 is provided with a feeding groove 12 that matches the cross section when the ultra-high strength steel plate is fed. A first sealing plate 13 is rotatably installed on one side of the feeding plate 11 inside the preheating box 2.

[0063] Reference Figure 4 and Figure 14 A discharge plate 8 is slidably installed on the discharge end of the cooling box 5. The discharge plate 8 is magnetically fixed and sealed to the cooling box 5. The discharge plate 8 is provided with a discharge groove 82 that matches the cross section of the steel part after hot roll forming. A second sealing plate 81 is rotatably installed on the side of the discharge plate 8 outside the cooling box 5. The second sealing plate 81 is magnetically fixed to the discharge plate 8.

[0064] The diameter of the feed trough 12 gradually decreases from the outside to the inside (the inside is the side facing the preheating box 2), and the slot near the preheating box 2 matches the ultra-high strength steel plate being fed. The diameter of the discharge trough 82 gradually increases from the outside to the inside (the inside is the side facing the cooling box 5), and the slot near the outside of the feed trough 12 matches the formed steel part.

[0065] In summary, the feed trough 12 adopts a gradually changing aperture structure with a larger outer opening and a smaller inner opening. The larger outer opening facilitates the initial introduction of the steel plate, while the inner aperture (facing the preheating box 2) precisely matches the feed steel plate. This avoids jamming or scratching caused by slight deviations in the steel plate due to the fixed aperture slot. The gradual aperture transition guides the steel plate to automatically align with the transmission path, improving the smoothness of feeding. On the other hand, the precisely matched slot on the inner side minimizes the gap with the steel plate. Combined with the magnetically sealed feed plate 11, this further reduces the infiltration of outside air into the preheating box 2, ensuring the stability of the nitrogen circulation environment and preventing oxidation of the steel plate during preheating.

[0066] The discharge trough 82 adopts a gradually changing aperture structure with a smaller outer diameter and a larger inner diameter. The larger opening on the inner side (facing the cooling chamber 5) facilitates the removal of the formed steel parts from the chamber (to accommodate any minor deformations that may occur in the steel parts). The outer aperture precisely matches the formed steel parts. On the one hand, this avoids obstruction of discharge or surface scratches caused by slight deformation of the steel parts due to the fixed aperture trough opening. The larger inner opening provides sufficient space for the steel parts to move, while the precise outer fit guides the steel parts to be discharged smoothly. On the other hand, the smaller outer aperture fits snugly against the steel parts. Together with the magnetically fixed discharge plate 8 and the second sealing plate 81, this significantly reduces the entry of outside air into the cooling chamber 5, maintains a stable cooling atmosphere and nitrogen environment inside the chamber, ensures precise and controllable cooling rate, reduces cold loss, and improves cooling efficiency.

[0067] Reference Figure 8 , Figure 9 , Figure 17 and Figure 18 The third mounting box 7 has multiple sets of cooling components connected in sequence. The cooling components include a second compressor 71 and a heat exchanger 72 fixedly installed on the inner wall of the bottom of the third mounting box 7. A fan 73 is fixedly installed in the third mounting box 7. The fan 73 is located above the second compressor 71 and the heat exchanger 72 and draws in external air to blow towards the heat exchanger 72.

[0068] The first sealing cavity 42 in the lower roller pressing die is the lower roller changing cavity, and the first sealing cavity 42 in the upper roller pressing die is the upper roller changing cavity.

[0069] An air inlet pipe 411, an exhaust pipe 412, and an air exchange pipe 413, which are connected to the first sealed cavity 42, are fixedly installed on the sealing cover 41. The air exchange pipe 413 is connected to a vacuum pump and a nitrogen tank outside the device through a control valve, which facilitates vacuum exhaust and replenishment of nitrogen to reduce the oxygen content in the first sealed cavity 42.

[0070] The heat exchanger 72 has its inlet end connected to the outlet end of the second compressor 71 on one side. The outlet end of the heat exchanger 72 is connected to the inlet end of the second compressor 71 on the other side through an expansion valve. The second outlet ends of multiple expansion valves are all connected to the same main gas pipe. The main gas pipe is connected to the inlet end of the inlet pipe 411. The expansion valve is equipped with a temperature sensor for detecting the temperature of the gas inside the control valve. The sealing cover 41 is equipped with a temperature sensor for detecting the temperature of the gas inside the first sealing cavity 42.

[0071] The third installation box 7 is provided with a second sealed cavity 74 that communicates with the preheating box 2, such as Figure 17 As shown, the air inlet of the second compressor 71 located at the first end is connected to the second sealing cavity 74, and is used to extract nitrogen gas after heat exchange and cooling with the ultra-high strength steel plate in the preheating box 2.

[0072] The gas heating section inside the second mounting box 6 includes a first compressor 61. The inlet of the first compressor 61 is connected to the outlet of the cooling box 5. The outlet of the cooling box 5 is located at one end near the roller pressing box 4. The preheating box 2 is provided with a first split jet box 23 at one end near the heating box 3. The inlet of the first split jet box 23 is connected to the output of the first compressor 61.

[0073] The second split jet box 51 is fixedly installed inside the cooling box 5. The first exhaust end of the expansion valve of the tail cooling component is connected to the second split jet box 51. The exhaust end of the first compressor 61 is connected to the first split jet box 23. The exhaust end of the exhaust pipe 412 is connected to the intake end of the first compressor 61.

[0074] In summary, the nitrogen gas in the preheating box 2, which has cooled down after exchanging heat with the steel plate before rolling, is collected in the second sealed cavity 74 in the third installation box 7 and then sent to the second compressor 71 at the beginning. This part of the nitrogen gas serves as the starting point of the circulation and carries a small amount of residual heat into the cooling system.

[0075] After being compressed by the second compressor 71 at the beginning, nitrogen enters the corresponding heat exchanger 72. At this time, the fan 73 in the third installation box 7 draws in outside air and blows it onto the heat exchanger 72 to accelerate heat exchange and initially cool the nitrogen. The cooled nitrogen is further depressurized and cooled through the expansion valve, and then enters the second compressor 71 of the next cooling assembly, repeating the compression, heat exchange, and expansion process. Multiple sets of cooling assemblies connected in sequence form a stepped cooling system, ultimately reducing the nitrogen temperature to a level suitable for the cooling box 5. The first exhaust end of the expansion valve of the tail cooling assembly delivers the finally cooled nitrogen to the second diversion jet box 51 in the cooling box 5. The diversion box evenly distributes the nitrogen and blows it onto the high-temperature steel after roll forming. The nitrogen absorbs the heat from the steel, completing the cooling process. Cooling (at this time, the nitrogen temperature rises due to heat absorption). The nitrogen, whose temperature rises after absorbing heat from the steel, is discharged from the exhaust port of the cooling box 5 near the end of the roller pressing box 4 and is drawn by the first compressor 61 in the second mounting box 6. The first compressor 61 heats the nitrogen through compression to reach the preheating temperature required by the preheating box 2. The heated nitrogen is then transported by the first compressor 61 to the first split jet box 23 in the preheating box 2. After the split box evenly distributes the nitrogen, it is blown onto the steel plate that has just entered the preheating box 2 through the first split jet box 23 near the end of the heating box 3. The nitrogen releases heat to preheat the steel plate at a low temperature (at this time, the nitrogen temperature decreases due to heat release). After the preheating is completed, the nitrogen is recovered again by the second sealing cavity 74 and enters the next cycle.

[0076] When replacing the hot press roller 46, according to the temperature data detected by the temperature sensors on the first sealing chamber 42 and the expansion valve, the corresponding low temperature air is discharged into the first sealing chamber 42 to cool the hot press roller 46, and then the nitrogen gas that has absorbed heat is discharged into the first compressor 61 for compression and heating.

[0077] In summary, the cooling assembly consists of a second compressor 71, a heat exchanger 72, and a fan 73 connected in sequence. The fan 73 draws in external air and blows it onto the heat exchanger 72 to enhance heat exchange. The heat exchanger 72 forms a closed loop with the adjacent compressor through an expansion valve. The first exhaust end of the expansion valve of the tail assembly is connected to the second diversion jet box 51 of the cooling box 5, and the main air pipe is connected to the air inlet pipe 411 of the first sealed cavity 42. On the one hand, this avoids the low cooling efficiency caused by insufficient cooling capacity of a single unit. Multiple units connected in series form a stepped cooling system, which can accurately match the different temperature requirements of the cooling box 5 and the first sealed cavity 42. On the other hand, the fan 73 enhances heat exchange and improves heat exchange efficiency, reducing energy waste. At the same time, through pipeline diversion, it provides cooling medium for the cooling box 5 and delivers temperature-controlled gas to the roller changing cavity, simplifying the structure while improving energy utilization.

[0078] The air inlet pipe 411 (connected to the main air pipe), exhaust pipe 412, and air exchange pipe 413 (connected to the vacuum pump and nitrogen tank) on the sealing cover 41 work together: before changing the roll, the air exchange pipe 413 is used to evacuate the vacuum and remove nitrogen, and inject air to balance the pressure. After changing the roll, air is evacuated and nitrogen is injected to reduce the oxygen content. The air inlet pipe 411 delivers temperature-controlled gas to maintain the temperature inside the cavity. The temperature sensor monitors and provides feedback for adjustment in real time. Through precise evacuation and replacement, the cavity is kept low in oxygen and the pressure is stable. This avoids insufficient preheating or slow cooling of the spare hot press roll 46 due to lack of temperature control, which would affect the roll changing efficiency. In addition, the linkage between the temperature-controlled gas and the sensor can maintain the temperature inside the cavity and match the working position, ensuring rapid adaptation to production after the roll change.

[0079] The second sealed cavity 74 of the third installation box 7 extracts nitrogen gas after heat exchange and cooling in the preheating box 2 and sends it to the first compressor to participate in the cooling cycle; the first compressor 61 of the second installation box 6 extracts nitrogen gas after heat absorption in the cooling box 5, and after heating, sends it to the preheating box 2 through the first split jet box 23 (the first split jet box 23 enhances the uniformity of preheating), avoiding the waste of resources caused by the single use of nitrogen gas, realizing the reuse of nitrogen gas in a closed loop and reducing operating costs; and the nitrogen gas is evenly blown onto the steel surface through the split box (first / second jet split box), improving the uniformity of preheating and cooling, avoiding the impact of local temperature deviation on the performance of steel, and realizing the full-link recovery of cooling waste heat and preheating energy, further reducing additional energy consumption.

[0080] The temperature sensor on the expansion valve monitors the gas temperature, and the sensor on the sealing cover 41 monitors the temperature inside the first sealing cavity 42. The two work together to adjust the opening of the expansion valve, precisely controlling the gas temperature entering the second diversion jet box 51 (cooling box 5) and the air inlet pipe 411 (roller changing cavity). This solves the problem of large differences in temperature requirements under different working conditions (cooling of the cooling box 5 and heat preservation of the roller changing cavity) and difficulty in synchronous control. The linkage mechanism can match the cooling rate and the preheating temperature of the roller changing cavity respectively, and the precise temperature control ensures that the temperature deviation of each link is within the allowable range of the process, thus ensuring product quality and production continuity.

[0081] When replacing the hot press roller 46, the temperature sensors on the first sealing chamber 42 and the expansion valve provide real-time feedback on temperature data. Based on this, the flow rate and temperature of the low-temperature nitrogen gas (processed by the cooling component) entering the chamber are adjusted to achieve gradient cooling of the hot press roller 46 after use—avoiding thermal stress cracking of the roller body caused by traditional sudden cooling and extending the service life of the hot press roller 46. At the same time, the nitrogen gas that has absorbed heat and heated up is transported to the first compressor 61 through the exhaust pipe 412. After being compressed and heated up, it participates in the preheating again, which not only avoids the waste of resources caused by direct nitrogen emission, but also recovers the heat during the cooling process, further reducing the system energy consumption.

[0082] During roll changing, low-temperature nitrogen gas creates a low-oxygen, temperature-controlled closed environment within the first sealed chamber 42: the low-oxygen atmosphere prevents the hot press roll 46 from oxidizing and rusting due to contact with air at high temperatures (solving the problem of roll surface oxidation in traditional open environment roll changing); the temperature sensor linkage control ensures that the cooling rate matches the material characteristics of the hot press roll 46, avoiding roll deformation caused by uneven cooling (affecting subsequent forming accuracy); at the same time, nitrogen, as an inert gas, combined with the pressure balance design of the ventilation pipe 413, eliminates the safety hazards that may be caused by air participation in high-temperature environments (such as local high temperature igniting impurities), providing safety assurance for roll changing operations and further adapting to the stability requirements of continuous production.

[0083] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-described technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention are within the scope of the present invention.

Claims

1. A heating and rolling production line for ultra-high strength steel, comprising, from left to right, a feeding rack (1), a preheating box (2), a heating box (3), a rolling box (4), and a cooling box (5), characterized in that, The bottom of the preheating box (2) is fixedly installed with a third mounting box (7), and a gas cooling component is provided inside the third mounting box (7). The bottom of the cooling box (5) is fixedly installed with a second mounting box (6), and a gas heating section is provided inside the second mounting box (6). The roller press box (4) is provided with an upper roller press module and a lower roller press module. Both the upper roller press module and the lower roller press module include a sealing cover (41). The two sets of sealing covers (41) are symmetrically arranged. A mounting seat (43) is rotatably mounted on the sealing cover (41). Two sets of symmetrically arranged sliding seats (45) are slidably connected on each mounting seat (43). A hot press roller (46) is rotatably mounted on the sliding seat (45). A transmission housing (44) is rotatably mounted on the side wall of the roller press (4). Splined shafts (441) are fixedly mounted on both output ends of the transmission housing (44). The two sets of splined shafts (441) are symmetrically arranged. The rotation ratio of the two sets of splined shafts (441) is 1:1, and the rotation direction is the same. A coupling sleeve (451) is rotatably mounted on the sliding seat (45). The coupling sleeve (451) is connected to the splined shaft (441). A drive handle (442) is fixedly mounted on the side wall of the transmission housing (44). The input shaft of the transmission housing (44) passes through the drive handle (442) and extends to the outside of the roller press (4). A drive shaft (443) is fixedly mounted thereon. The multiple drive shafts (443) in the upper roller pressing die group rotate synchronously through the first pulley group, and the multiple drive shafts (443) in the lower roller pressing die group rotate synchronously through the second pulley group. The first pulley group is connected to the second motor (48) fixedly installed on the top of the heating box (3). One of the drive shafts (443) in the upper roller pressing die group and one of the drive shafts (443) in the lower roller pressing die group are connected through the gear transmission module. A sealing plate (47) is fixedly installed on the side wall of the roller press (4). The sealing plate (47), the sealing cover (41), the box body of the roller press (4) and the mounting base (43) cooperate to form the first sealing cavity (42). An air inlet pipe (411), an exhaust pipe (412) and a ventilation pipe (413) communicating with the first sealing cavity (42) are fixedly installed on the sealing cover (41). The ventilation pipe (413) is connected to the vacuum pump and nitrogen tank outside the device through a control valve, and is used for vacuum exhaust and replenishing nitrogen to reduce the oxygen content in the first sealing cavity (42).

2. The ultra-high strength steel heating roll forming production line according to claim 1, characterized in that, The preheating box (2), heating box (3), roller pressing box (4) and cooling box (5) are all equipped with a conveying assembly (21). The conveying assembly (21) includes a transmission roller (211) that rotates in the preheating box (2), heating box (3), roller pressing box (4) and cooling box (5) respectively. A first mounting box (212) is fixedly installed on the side wall of the preheating box (2) and the cooling box (5). A first motor (215) is fixedly installed on the end of each of the two first mounting boxes (212). A drive shaft (213) is rotatably installed in the first mounting box (212). The drive shaft (213) is connected to the transmission roller (211) through a bevel gear set (214).

3. The ultra-high strength steel heated roll forming production line according to claim 2, characterized in that, It also includes a pressing assembly (22) set on the top of the preheating box (2). The pressing assembly (22) includes an electric hydraulic cylinder (221) fixedly installed on the top of the preheating box (2). A connecting arm (222) is slidably installed on the preheating box (2). A mounting bracket (223) is fixedly installed on one end of the connecting arm (222) extending into the preheating box (2). A pressing roller (224) is rotatably installed on the mounting bracket (223). One end of the connecting arm (222) extending into the top of the preheating box (2) is fixedly connected to the output end of the electric hydraulic cylinder (221).

4. The ultra-high strength steel heating roll forming production line according to claim 1, characterized in that, An electromagnetic heater (31) is fixedly installed inside the heating box (3).

5. The ultra-high strength steel heated roll forming production line according to claim 1, characterized in that, A feeding plate (11) is slidably installed on the feeding rack (1). The feeding plate (11) is magnetically fixed and sealed to the feeding rack (1). The feeding plate (11) is provided with a feeding groove (12) that matches the cross-section of the ultra-high strength steel plate during feeding. A first sealing plate (13) is rotatably installed on one side of the feeding plate (11) inside the preheating box (2).

6. The ultra-high strength steel heated roll forming production line according to claim 1, characterized in that, The discharge end of the cooling box (5) is slidably installed with a discharge plate (8). The discharge plate (8) is magnetically fixed and sealed to the cooling box (5). The discharge plate (8) is provided with a discharge groove (82) that matches the cross section of the steel part after hot roll forming. A second sealing plate (81) is rotatably installed on the side of the discharge plate (8) outside the cooling box (5). The second sealing plate (81) is magnetically fixed to the discharge plate (8).

7. The ultra-high strength steel heating roll forming production line according to claim 1, characterized in that, The third mounting box (7) is fixedly installed with multiple sets of cooling components connected in sequence. The cooling components include a second compressor (71) and a heat exchanger (72) fixedly installed on the inner wall of the bottom of the third mounting box (7). A fan (73) is fixedly installed in the third mounting box (7). The fan (73) is located above the second compressor (71) and the heat exchanger (72). The third mounting box (7) is provided with a second sealed cavity (74) that communicates with the preheating box (2), and the air inlet of the second compressor (71) located at the first end is connected to the second sealed cavity (74); The heat exchanger (72) has its inlet end connected to the outlet end of the second compressor (71) on one side. The outlet end of the heat exchanger (72) is connected to the inlet end of the second compressor (71) on the other side through an expansion valve. The second outlet ends of multiple sets of expansion valves are all connected to the same main air pipe, which is connected to the inlet end of the inlet pipe (411).

8. The ultra-high strength steel heating roll forming production line according to claim 7, characterized in that, The gas heating section inside the second mounting box (6) includes a first compressor (61). The inlet of the first compressor (61) is connected to the outlet of the cooling box (5). The outlet of the cooling box (5) is located at one end near the roller press box (4). The preheating box (2) is provided with a first split jet box (23) at one end near the heating box (3). The inlet of the first split jet box (23) is connected to the output end of the first compressor (61). The cooling box (5) is fixedly installed with a second split jet box (51). The first exhaust end of the expansion valve of the tail cooling component is connected to the second split jet box (51). The exhaust end of the first compressor (61) is connected to the first split jet box (23). The exhaust end of the exhaust pipe (412) is connected to the intake end of the first compressor (61).

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