A rolling forming device and processing control method for a steel frame of a battery pack for a vehicle

Abstract

The application discloses a kind of battery package steel frame of vehicle battery package steel frame and processing control method of rolling forming device, including rolling base, with the conveying direction of steel sheet as X axis direction, with the width direction of steel sheet as Y axis direction, multiple rolling forming units are arranged in parallel along X axis direction on rolling base, and the end of rolling base opposite to X axis direction is provided with auxiliary platform, surface detection device and synchronous positioning unit are installed on auxiliary platform, finished product detection unit is installed on the other end of rolling base, and rolling forming unit includes frame and the upper rolling die and lower rolling die arranged in the frame, the distance between upper rolling die and lower rolling die is adjusted by servo cylinder on the upper end of frame to drive upper rolling die to lift.This application can solve the problem that existing rolling equipment cannot adapt to the characteristics of martensitic steel sheet, resulting in low machining precision and being unable to apply to high-precision forming of battery package steel frame.

Description

Technical Field

[0001] This invention relates to the field of automotive battery pack processing technology, specifically to a roll forming apparatus and processing control method for a steel frame of an automotive battery pack. Background Technology

[0002] With the rapid development of the new energy vehicle industry, battery packs, as core energy storage components, face increasingly stringent requirements regarding structural strength, dimensional accuracy, and large-scale production capabilities. Many automotive battery packs use martensitic steel plates for their steel frames. Martensitic steel plates possess advantages such as high strength and high wear resistance, effectively improving the impact resistance and lifespan of the battery pack. However, their high strength also presents numerous challenges to the roll forming process.

[0003] In existing technologies, the steel frame of a battery pack is typically made by sequentially rolling steel sheets through multiple sets of roll forming units. The steel sheets pass through rows of roll forming units along the conveying direction, and a preset cross-section (such as a H-shape) is formed by the extrusion of upper and lower roll forming dies. However, existing roll forming devices and control methods have the following technical defects:

[0004] Martensitic steel sheet raw materials are prone to irregular protrusions, depressions and other uneven defects on the surface. In addition, they have high strength and obvious elastic rebound. Traditional rolling equipment uses rolling molds with fixed parameters for processing, which cannot adaptively adjust to the uneven parts of the surface. This results in uneven force on the uneven areas and uncontrollable forming, ultimately causing the frame size accuracy deviation. The conventional deviation can reach more than ±0.1mm, which cannot meet the high precision requirements of battery pack assembly.

[0005] In addition, the existing equipment mainly conducts post-production sampling inspections, which cannot feed the inspection data back to the rolling control process in real time. This makes it difficult to form a closed-loop optimization and continuously correct the rolling parameters to adapt to the differences in characteristics of different batches of steel plates, further limiting the stability of dimensional accuracy.

[0006] Therefore, there is an urgent need for a rolling equipment and control method that is adapted to the characteristics of martensitic steel plates and can solve the problems of low dimensional accuracy, poor adaptability and insufficient stability in large-scale production in existing technologies, so as to meet the high-precision processing requirements of steel frames for new energy vehicle battery packs. Summary of the Invention

[0007] This invention provides a roll forming device and processing control method for steel frames of automotive battery packs, which can solve the problem that existing roll forming equipment cannot adapt to the characteristics of martensitic steel plates, resulting in low processing accuracy and inability to meet the high-precision forming requirements of steel frames for battery packs.

[0008] To achieve the above objectives, in a first aspect, the present invention provides the following technical solution: a roll forming device for a steel frame of an automotive battery pack, comprising a roll forming base, with the conveying direction of the steel sheet as the X-axis and the width direction of the steel sheet as the Y-axis. Multiple roll forming units are arranged side-by-side along the X-axis on the roll forming base. An auxiliary platform is provided at one end of the roll forming base opposite to the X-axis. A surface inspection device for detecting surface unevenness of the conveyed steel sheet and a synchronous positioning unit for dividing the conveyed steel sheet into unit areas are installed on the auxiliary platform. A finished product inspection unit is installed at the other end of the roll forming base. Each roll forming unit includes a frame and an upper roller disposed inside the frame. The system includes a pressing die and a lower rolling die. The upper rolling die is driven by a servo electric cylinder at the top of the frame to raise and lower, adjusting the distance between the upper and lower rolling dies. The lower rolling die is driven by a drive motor to rotate. The surface inspection device, synchronous positioning unit, finished product inspection unit, servo electric cylinder, and drive motor are all electrically connected to the control unit, realizing integrated linkage of surface inspection, unit positioning, rolling forming, and finished product inspection. The servo electric cylinder drives the upper die adjustment, solving the problem that traditional devices cannot adapt to uneven surfaces. The lower rolling die is driven by the drive motor to rotate, and the upper rolling die can be raised and lowered for adjustment, balancing rolling efficiency and forming accuracy. All components are electrically connected to the control unit, providing a hardware foundation for automated closed-loop control.

[0009] Preferably, the synchronous positioning unit is located between the surface detection device and the rolling base, and includes a laser positioning sensor and an encoder; the laser positioning sensor can accurately capture the edge position of the steel plate, and the encoder collects the conveying speed in real time. The two work together to establish a two-dimensional coordinate system to achieve accurate division and traceability of the steel plate positioning unit.

[0010] Preferably, the surface detection device uses a laser profile sensor array, with 3-5 laser profile sensors evenly arranged along the Y-axis. The laser profile sensors can achieve full coverage scanning of the width of the steel plate, avoiding blind spots in single sensor scanning, improving the integrity and accuracy of surface unevenness detection, and providing reliable data input for subsequent adjustment calculation.

[0011] Preferably, the finished product inspection unit includes a ring-shaped or C-shaped laser scanning sensor and at least one visual inspection camera. The finished steel frame product is conveyed through the laser scanning sensor, which can realize 360° full-dimensional size inspection of the finished product. The visual inspection camera is used to supplement the detailed inspection, which solves the limitations of traditional sampling inspection or single-sided inspection and ensures that the size deviation of the finished product is fully captured.

[0012] Preferably, the upper rolling die in the rolling forming unit is provided with upper lifting sliders at both ends that match the frame, and the output shaft of the servo electric cylinder is connected to the corresponding upper lifting slider. The upper lifting slider is adapted to the frame to provide a stable lifting guide for the upper rolling die, avoid the upper die from shifting or tilting during the adjustment process, ensure the parallelism between the upper and lower dies, improve the dimensional consistency of the rolling forming, and reduce the load loss of the servo electric cylinder.

[0013] Preferably, the lower rolling die is further provided with lower lifting sliders at both ends that match the frame. The lower end of the lower lifting slider is connected to a lifting screw. A worm gear is sleeved on the outer side of the lifting screw. A transverse worm is meshed on one side of the worm gear. The two transverse worms are connected by a coupling. An adjusting handwheel is installed at one end of any one of the transverse worms. The worm gear, worm, and lifting screw form a manual adjustment mechanism, which can precisely adjust the reference height of the lower rolling die to adapt to the processing requirements of steel plates of different thicknesses and frame sizes, taking into account both reference stability and process flexibility. The two transverse worms are connected by a coupling to ensure that the two ends of the lower die rise and fall synchronously, avoiding forming deviations caused by the tilting of the lower die.

[0014] Preferably, the auxiliary platform is provided with vertical guide wheel sets and horizontal limiting guide wheel sets on both sides of the surface inspection device. The steel plate passes through the vertical guide wheel sets and the horizontal limiting guide wheel sets in sequence. The vertical guide wheel sets correct the vertical posture of the steel plate to avoid warping. The horizontal limiting guide wheel sets restrict the lateral displacement of the steel plate to ensure that the steel plate is transported smoothly along the X-axis direction, reducing the impact of posture deviation during the transport process on the inspection accuracy and rolling accuracy.

[0015] In a second aspect, the present invention also provides a processing control method for a roll forming apparatus for a steel frame of a vehicle battery pack according to the first aspect, comprising the following steps:

[0016] S1. The control unit drives the upper rolling die of each rolling forming unit to reset to the standard initial height via a servo electric cylinder. The standard initial height for each rolling forming unit is different and needs to be set according to the rolling process and the shape of the steel frame. Taking the edge of the steel sheet feed end as a reference, the synchronous positioning unit is controlled to establish a two-dimensional rectangular coordinate system along the X-axis and Y-axis, dividing the steel sheet into several precise positioning units and assigning a unique coordinate identifier. At the same time, the signal synchronization and zero-point calibration of the surface inspection device, synchronous positioning unit, finished product inspection unit and rolling forming unit are completed to ensure that the coordinate system of each component is consistent.

[0017] S2. During the steel sheet conveying process, the control unit controls the surface detection device to perform a full-coverage three-dimensional scan of the steel sheet surface, collects the surface contour data of each positioning unit and transmits it to the control unit. The control unit filters out the unit to be adjusted based on the preset unevenness judgment threshold, records its coordinates, unevenness amount ΔH and contour characteristics, and synchronously associates it with the rolling forming unit in the corresponding processing area.

[0018] S3. The control unit calculates the adjustment amount ΔS of the rolling die on the corresponding rolling forming unit based on the unevenness amount ΔH of the unit to be adjusted, the imported steel plate material characteristic parameters and the preset frame forming size, and incorporates the material characteristic correction coefficient to simultaneously compensate for the elastic rebound amount of the steel plate.

[0019] S4. When the synchronous positioning unit detects that the precision positioning unit to be adjusted has reached the processing position of the corresponding roll forming unit, it sends a trigger signal to the control unit. The control unit drives the servo electric cylinder of the roll forming unit to drive the upper roll forming mold to complete the lifting and lowering adjustment according to the pre-calculated adjustment amount ΔS.

[0020] S5. The control unit controls the finished product inspection unit to perform full-dimensional dimensional inspection on the processed battery pack steel frame. It binds the inspection positions of the finished product with the coordinates of the front steel plate precise positioning unit and the corresponding roll forming unit to generate dimensional deviation data ΔD. The control unit compares ΔD with the preset qualified threshold. For deviations exceeding the threshold, it analyzes the corresponding upper mold adjustment parameters and corrects them through machine learning algorithms. It updates the parameter database and iteratively optimizes the calculation logic of the upper mold adjustment amount for subsequent processing to form a closed-loop control.

[0021] The above control method uses the unevenness ΔH as the input value, quickly outputs the adjustment trend through the basic proportional coefficient Kp, and then adapts to the strength and thickness differences of the martensitic steel plate through the material property correction coefficient Km, and coordinates with the springback experience correction coefficient Kz to finally obtain the upper die adjustment amount ΔS, ensuring that the adjustment action both offsets the surface unevenness and adapts to the material properties. The position of the steel plate is tracked in real time by the synchronous positioning unit. When the unit to be adjusted reaches the corresponding rolling unit, the adjustment action is triggered to avoid adjustment lag. The finished product size deviation ΔD is bound to the front-end positioning unit and adjustment parameters. The Kp, Km, and Kz parameters are optimized through machine learning algorithms, the database is updated and synchronously applied to subsequent processing, gradually reducing the size deviation and improving the stability of large-scale production.

[0022] Furthermore, the calculation logic for the upper modulus adjustment amount ΔS in step S3 is as follows:

[0023] ΔSup = S0 + Kp × ΔH × Km × Kz; where S0 is the baseline adjustment amount, with a default value of 0, which is only corrected when the preset frame forming size changes; ΔH is the actual unevenness of the unit to be adjusted.

[0024] The proportional coefficient Kp ranges from 4.5 to 6.0, and the springback empirical correction coefficient Kz ranges from 1.05 to 1.2. The material property correction coefficient Km is calculated using the formula Km=E / (αs×h), where E is the elastic modulus of the martensitic steel plate, αs is the yield strength of the martensitic steel plate, and h is the thickness of the steel plate. Km and Kz work together to achieve material property adaptation and springback compensation.

[0025] Furthermore, the size of the precise positioning unit in step S1 is 10mm × 10mm; the preset unevenness judgment threshold in step S2 is ±0.05mm.

[0026] Compared with the prior art, the beneficial effects of the present invention are:

[0027] This system achieves integrated operation of surface inspection, unit positioning, roll forming, and finished product inspection. The upper die is adjusted via a servo electric cylinder, solving the problem of traditional devices being unable to adapt to surface unevenness. The lower roll forming die is driven by a motor for rotation, while the upper roll forming die is adjustable in height, balancing roll forming efficiency and precision. All components are electrically connected to the control unit, providing the hardware foundation for automated closed-loop control. The lower die features a worm gear manual adjustment structure, balancing real-time adaptive adjustment with baseline stability, adapting to different frame specifications. The control method uses the unevenness ΔH as input, quickly outputting the adjustment trend through a basic proportional coefficient Kp. Then, a material property correction coefficient Km is used to adapt to differences in the strength and thickness of martensitic steel plates, and this is further corrected in conjunction with a springback experience correction coefficient Kz, ultimately yielding the upper die adjustment amount ΔS. This ensures that the adjustment action both compensates for surface unevenness and adapts to material properties. Attached Figure Description

[0028] Figure 1 This is a front view structural diagram of the present invention;

[0029] Figure 2 This is a top view of the structure of the present invention;

[0030] Figure 3 for Figure 2 AA-direction sectional view of the structure;

[0031] Figure 4 for Figure 2 BB-directed partial structural diagram;

[0032] Figure 5 This is a three-dimensional structural diagram of the roll forming unit of the present invention.

[0033] Figure label:

[0034] 1. Roll forming base; 11. Synchronous positioning unit; 12. Vertical guide wheel assembly; 13. Horizontal limit guide wheel assembly; 2. Roll forming unit; 20. Translation drive motor; 21. Frame; 22. Servo electric cylinder; 23. Upper rolling die; 24. Upper lifting slider; 25. Lower lifting slider; 26. Drive motor; 27. Adjusting handwheel; 28. Lifting screw; 29. ​​Drive gear; 3. Auxiliary platform; 31. Coupling shaft; 32. Worm gear; 33. Lower rolling die; 4. Surface inspection device; 5. Control unit; 7. Finished product inspection unit; 8. Slide rail; 9. Rack. Detailed Implementation

[0035] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention.

[0036] like Figure 1-5 As shown, this invention addresses the problem that existing rolling equipment cannot adapt to the characteristics of martensitic steel plates, resulting in low processing accuracy and inability to perform high-precision forming of battery pack steel frames. The invention provides the following technical solution: a rolling forming device for automotive battery pack steel frames, comprising a rolling base 1, with the conveying direction of the steel sheet as the X-axis and the width direction of the steel sheet as the Y-axis. Multiple rolling forming units 2 are arranged side-by-side along the X-axis on the rolling base 1. An auxiliary platform 3 is provided at the end of the rolling base 1 opposite to the X-axis. The auxiliary platform 3 is equipped with a surface detection device 4 for detecting surface unevenness of the conveyed steel sheet and a device for... The synchronous positioning unit 11 divides the steel plates being transported into unit areas. The other end of the rolling base 1 is equipped with a finished product inspection unit 7. The rolling forming unit 2 includes a frame 21 and an upper rolling mold 23 and a lower rolling mold 33 disposed inside the frame 21. The upper rolling mold 23 is driven to rise and fall by a servo electric cylinder 22 at the upper end of the frame 21 to adjust the distance between the upper rolling mold 23 and the lower rolling mold 33. The lower rolling mold 33 is driven to rotate by a drive motor 26. The surface inspection device 4, the synchronous positioning unit 11, the finished product inspection unit 7, the servo electric cylinder 22, and the drive motor 26 are all electrically connected to the control unit 5.

[0037] The technical solution in this embodiment establishes a two-dimensional rectangular coordinate system through the synchronous positioning unit 11, dividing the steel plate into standardized positioning units. This unifies the coordinate system of the surface inspection device, the roll forming unit, and the finished product inspection unit, ensuring that any uneven position on the steel plate can be accurately traced to the corresponding roll forming unit, providing a position reference for subsequent adjustment actions. The upper roll forming mold 23 is driven by the servo electric cylinder 22 to achieve high-precision lifting and lowering, with fast response speed and high positioning accuracy, and can adapt to the surface unevenness adjustment requirements in real time. The lower roll forming mold 33 is equipped with a manual adjustment mechanism, which can preset the reference height according to different frame cross-sectional dimensions, taking into account both reference stability and process flexibility, and avoiding forming deviations caused by a single fixed lower mold.

[0038] The front end uses a surface inspection device 4 to scan the entire width of the steel plate, which can quickly capture the location and extent of surface unevenness; the back end uses a finished product inspection unit 7 to realize 360° no-dead-angle size inspection of the finished product, and at the same time binds the inspection data with the front end positioning unit to provide accurate data support for parameter optimization.

[0039] Specifically, the rolling base 1 can be welded from Q235 steel plate, with a length of 5000mm, a width of 800mm, and a height of 1200mm; eight sets of rolling forming units 2 are arranged side by side along the X-axis. The auxiliary platform 3 can be connected to the rolling base 1 or set separately and at intervals from the rolling base 1, which is quite flexible in its setup.

[0040] The control unit 5 uses a PLC controller, model S7-1500, which is connected to each component via a Profinet bus to achieve real-time signal transmission. The upper rolling die 23 is made of Cr12MoV alloy, and the lower rolling die 33 is made of the same material. The drive motor 26 has a power of 1.5kW, which drives the lower rolling die 33 to rotate to realize the conveying and rolling of steel plates.

[0041] To improve the adaptability and flexibility of the rolling device, a rack 9 and a slide rail 8 are installed on the upper side of the rolling base 1 along the X-axis. The frame 21 of the rolling forming unit 2 is mounted on the slide rail 8, and a translation drive motor 20 is installed at the bottom of the frame 21. A drive gear 29 that meshes with the rack 9 is installed on the main shaft of the translation drive motor 20. By driving the drive gear 29 to rotate through the translation drive motor 20, the horizontal position of the rolling forming unit 2 can be adjusted, thereby adjusting the spacing between adjacent rolling forming units 2 to accommodate battery pack frames of different specifications and shapes, without the need for manual adjustment.

[0042] In this embodiment, the synchronous positioning unit 11 is positioned between the surface detection device 4 and the rolling base 1, and includes a laser positioning sensor and an encoder. The laser positioning sensor can accurately capture the edge position of the steel plate, and the encoder collects the conveying speed in real time. The two work together to establish a two-dimensional coordinate system to achieve accurate division and traceability of the steel plate positioning unit. Specifically, the synchronous positioning unit 11 is installed between the surface detection device 4 and the rolling base 1, 50mm away from the output end of the surface detection device 4. The laser positioning sensor is a Keyence IL-1000 with a measurement accuracy of ±0.001mm. Two sensors are arranged along the Y-axis and are respectively aligned with the two sides of the steel plate edge. The encoder is an incremental encoder, model E6B2-CWZ6C, coaxially connected to the conveying roller shaft, with a resolution of 1024 lines. It collects the steel plate conveying speed in real time and feeds it back to the control unit 5.

[0043] In this embodiment, the surface detection device 4 employs a laser profile sensor array. Three to five laser profile sensors are evenly arranged along the Y-axis. These sensors enable full-coverage scanning of the steel plate's width, avoiding blind spots in single-sensor scanning, improving the completeness and accuracy of surface unevenness detection, and providing reliable data input for subsequent adjustment calculations. Specifically, the surface detection device 4 uses four Keyence LJ-V7000 laser profile sensors, evenly arranged along the Y-axis with an 80mm spacing between adjacent sensors. The scanning frequency is 500Hz, the measurement range is 0-50mm, and the accuracy is ±0.002mm. The sensors are installed 150mm above the steel plate surface, with the scanning direction perpendicular to the steel plate's conveying direction. This allows for simultaneous acquisition of profile data from the upper surface of the steel plate, and data fusion eliminates errors in overlapping scanning areas.

[0044] In this embodiment, the finished product inspection unit 7 includes a ring-shaped or C-shaped laser scanning sensor and at least one visual inspection camera. The finished steel frame is conveyed through the laser scanning sensor, enabling 360° full-dimensional size inspection of the finished product. The visual inspection camera supplements the detailed inspection, overcoming the limitations of traditional sampling or single-sided inspection and ensuring that the dimensional deviations of the finished product are fully captured. Specifically, the finished product inspection unit 7 can use a ring-shaped laser scanning sensor, model Hexagon RS-Series, with an inner diameter of 200mm, adapted to the outer diameter of the battery pack steel frame, and a scanning accuracy of ±0.003mm. Two visual inspection cameras, model Baslerac A2500-14gm, with a lens focal length of 25mm and a shooting frame rate of 30fps, are evenly arranged along the circumference of the ring sensor to focus on inspecting the size and flatness of key positions such as frame corners and welds. The finished steel frame passes through the center of the ring sensor, and the inspection data is transmitted to the control unit 5 in real time for analysis.

[0045] In this embodiment, the upper rolling die 23 in the rolling forming unit 2 is provided with upper lifting sliders 24 at both ends that match the frame 21. The output shaft of the servo electric cylinder 22 is connected to the corresponding upper lifting slider 24. The upper lifting slider is adapted to the frame to provide a stable lifting guide for the upper rolling die 23, avoiding deviation or tilting of the upper die during adjustment, ensuring the parallelism between the upper and lower dies, improving the dimensional consistency of the rolling forming, and reducing the load loss of the servo electric cylinder 22. The servo electric cylinder 22 is an EC60 electric cylinder with a rated thrust of 50kN and a positioning accuracy of ±0.001mm. The output shaft is connected to the upper lifting slider 24 through a ball joint, which can compensate for minor installation deviations and ensure smooth lifting of the upper die.

[0046] Meanwhile, in this embodiment, both ends of the lower rolling die 33 are also provided with lower lifting sliders 25 that match the frame 21. The lower end of the lower lifting slider 25 is connected to a lifting screw 28. A worm gear 32 is sleeved on the outer side of the lifting screw 28. A transverse worm is meshed on one side of the worm gear 32. The two transverse worms are connected by a coupling 31. An adjusting handwheel 27 is installed at one end of any one of the transverse worms. The worm gear, the lifting screw and the worm wheel form a manual adjustment mechanism, which can precisely adjust the reference height of the lower rolling die to adapt to steel plates of different thicknesses and frames of different cross-sectional sizes. The machining requirements are balanced with both baseline stability and process flexibility. The two transverse worm gears are connected by a coupling to ensure synchronous lifting of both ends of the lower mold, avoiding forming deviations caused by mold tilting. The lower lifting slider 25 is fitted with the guide rail of the frame 21 with clearance. The lifting screw 28 adopts a trapezoidal thread with a pitch of 2mm and a precision grade of 5. The worm wheel 32 has a module of 2 and 40 teeth. The coupling 31 is made of No. 45 steel and is 300mm long. Both ends are connected to the transverse worm gear through couplings. The lower mold can be lifted or lowered by 2mm with one rotation of the adjusting handwheel 27. The adjustment amount is precisely controlled by the scale markings, with an adjustment accuracy of ±0.01mm.

[0047] In this embodiment, the auxiliary platform 3 is equipped with vertical guide wheel sets 12 and horizontal limiting guide wheel sets 13 on both sides of the surface detection device 4. The steel plate passes through the vertical guide wheel sets 12 and the horizontal limiting guide wheel sets 13 in sequence. The vertical guide wheel sets 12 correct the vertical posture of the steel plate to avoid warping; the horizontal limiting guide wheel sets 13 restrict the lateral displacement of the steel plate to ensure that the steel plate is transported smoothly along the X-axis direction, reducing the impact of posture deviation during the transport process on the detection accuracy and rolling accuracy. Specifically, the auxiliary platform 3 has two sets of vertical guide wheel sets 12, each set containing two vertically opposite guide wheels, made of polyurethane to avoid scratching the surface of the steel plate; the auxiliary platform 3 has two sets of horizontal limiting guide wheel sets 13, each set containing two horizontally opposite guide wheels, and the spacing between the guide wheels can be adjusted according to the width of the steel plate; the steel plate passes through the vertical guide wheel sets and the horizontal limiting guide wheel sets in sequence, and the transport deviation is controlled within ±0.02mm.

[0048] As a specific implementation example in this embodiment:

[0049] The above-mentioned equipment is used to process a battery pack steel frame with dimensions of 400mm×200mm×3mm. The steel frame has a H-shaped cross-section, and the raw material is a martensitic steel plate with a thickness of 2mm and a width of 200mm. The specific process is as follows:

[0050] 1. Pre-processing and initialization: The martensitic steel sheet roll is installed on the conveying device. The steel sheet passes through the vertical guide wheel group 12 and the horizontal limit guide wheel group 13 of the auxiliary platform 3 in sequence to correct the conveying posture. The control unit 5 starts the initialization program and drives the upper rolling die 23 of each rolling unit to reset to the preset initial height, such as 5mm for the 1st-2nd group, 3.5mm for the 3rd-5th group, and 3mm for the 6th-8th group. The lower rolling die 33 keeps the reference height of 2mm unchanged. The synchronous positioning unit 11 establishes an XY axis two-dimensional coordinate system, divides the steel sheet into 10mm×10mm positioning units, completes the signal synchronization of each component, and controls the calibration error within ±0.005mm.

[0051] 2. Surface Inspection and Positioning: The steel sheet is conveyed at a speed of 0.1 m / s. The surface inspection device 4 scans the upper surface of the steel sheet at a frequency of 500 Hz, collects the contour data of each positioning unit, and compares it with the judgment threshold of ±0.05 mm. Three units to be adjusted are selected, namely coordinate (X5, Y3): ΔH=+0.06 mm (protrusion), coordinate (X12, Y8): ΔH=-0.07 mm (depression), and coordinate (X18, Y15): ΔH=+0.08 mm (protrusion), and are respectively associated with the 3rd, 5th and 7th groups of roll forming units.

[0052] 3. Adjustment Calculation: Control unit 5 imports the parameters of the martensitic steel plate: E=205GPa, αs=1300MPa, h=2mm, calculate Km=205×10 3 / (1300×2)=78.84mm; Kp is taken as 5.0, Kz is matched to 1.1 according to the steel plate parameters; calculate the upper mold adjustment amount of each unit to be adjusted respectively:

[0053] Coordinates (X5, Y3): ΔS = 5.0 × 0.06 × 78.84 × 1.1 ≈ 2.59 mm, that is, the upper mold rises by 2.59 mm;

[0054] Coordinates (X12, Y8): ΔH takes the absolute value of 0.07mm, ΔS=5.0×0.07×78.84×1.1≈3.02mm, that is, the upper mold descends by 3.02mm;

[0055] Coordinates (X18, Y15): ΔS = 5.0 × 0.08 × 78.84 × 1.1 ≈ 3.47 mm, that is, the upper mold rises by 2.59 mm.

[0056] 4. Dynamic Rolling Adjustment: The synchronous positioning unit 11 tracks the position of the steel sheet in real time. When the coordinate (X5, Y3) unit reaches the 3rd rolling unit, the adjustment signal is triggered, and the servo electric cylinder 22 drives the upper die to rise by 2.59mm. During the processing, the pressure sensor feedback pressure value is 45kN, with no deviation, and no fine adjustment is required. After the unit leaves, the upper die returns to the initial height of 3.5mm. Similarly, when the coordinate (X12, Y8) unit reaches the 5th unit, the upper die descends by 3.02mm, and when the coordinate (X18, Y15) unit reaches the 7th unit, the upper die rises by 3.47mm, completing the targeted adjustment.

[0057] 5. Finished Product Inspection and Feedback Optimization: The processed border enters the finished product inspection unit 7. The ring laser scanning sensor scans the dimensions 360°, and the vision camera supplements the inspection of the corner accuracy, generating dimensional deviation data ΔD. Specifically, the finished product position corresponding to coordinates (X5, Y3) is ΔD=+0.01mm, the position corresponding to coordinates (X12, Y8) is ΔD=-0.015mm, and the position corresponding to coordinates (X18, Y15) is ΔD=+0.008mm, all ≤±0.05mm of the qualified threshold. The control unit 5 records the current Kp, Km, and Kz parameters and incorporates them into the database to provide a benchmark for the processing of steel plates in the same batch. If ΔD exceeds the threshold in the future, the Kz value is fine-tuned through a machine learning algorithm to update the parameters and apply them.

[0058] It should be noted that all directional indicators (such as up, down, left, right, front, back, etc.) in the embodiments of the present invention are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indicator will also change accordingly.

[0059] Furthermore, in this invention, descriptions involving "first," "second," etc., are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0060] In this invention, unless otherwise explicitly specified and limited, the terms "connection," "fixed," etc., should be interpreted broadly. For example, "fixed" can mean a fixed connection, a detachable connection, or an integral part; it can mean a mechanical connection or an electrical connection; it can mean a direct connection or an indirect connection through an intermediate medium; it can mean the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0061] Furthermore, the technical solutions of the various embodiments of the present invention can be combined with each other, but only if they are feasible for those skilled in the art. If the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such combination of technical solutions does not exist and is not within the scope of protection claimed by the present invention.

Claims

1. A roll forming device for a steel frame of a vehicle battery pack, comprising a roll forming base (1), with the conveying direction of the steel sheet as the X-axis direction and the width direction of the steel sheet as the Y-axis direction, wherein multiple roll forming units (2) are arranged side by side along the X-axis direction on the roll forming base (1), characterized in that, The rolling base (1) is provided with an auxiliary platform (3) at one end opposite to the X-axis direction. The auxiliary platform (3) is equipped with a surface detection device (4) for detecting unevenness on the surface of the steel plate during transport and a synchronous positioning unit (11) for dividing the steel plate during transport into unit areas. The other end of the rolling base (1) is equipped with a finished product detection unit (7). The rolling forming unit (2) includes a frame (21) and an upper rolling mold (23) and a lower rolling mold (33) set inside the frame (21). The upper rolling mold (23) is driven to rise and fall by a servo electric cylinder (22) at the upper end of the frame (21) to adjust the distance between the upper rolling mold (23) and the lower rolling mold (33). The lower rolling mold (33) is driven to rotate by a drive motor (26). The surface detection device (4), synchronous positioning unit (11), finished product detection unit (7), servo electric cylinder (22) and drive motor (26) are all electrically connected to the control unit (5). During the steel sheet conveying process, the control unit (5) controls the surface detection device (4) to perform a full-coverage three-dimensional scan of the steel sheet surface, collect the surface contour data of each positioning unit and transmit it to the control unit (5). The control unit (5) selects the unit to be adjusted based on the preset unevenness judgment threshold, records its coordinates, unevenness amount ΔH and contour features, and synchronously associates the corresponding rolling forming unit (2) in the processing area. The control unit (5) calculates the adjustment amount ΔS of the rolling die on the corresponding rolling forming unit (2) as follows: ΔSup = S0 + Kp × ΔH × Km × Kz; where S0 is the baseline adjustment amount, with a default value of 0, which is only corrected when the preset frame forming size changes; ΔH is the actual unevenness of the unit to be adjusted. The proportional coefficient Kp ranges from 4.5 to 6.0, and the springback empirical correction coefficient Kz ranges from 1.05 to 1.

2. The material property correction coefficient Km is calculated using the formula Km=E / (αs×h), where E is the elastic modulus of the martensitic steel plate, αs is the yield strength of the martensitic steel plate, and h is the thickness of the steel plate. Km and Kz work together to achieve material property adaptation and springback compensation.

2. The roll forming apparatus for the steel frame of a vehicle battery pack according to claim 1, characterized in that: The synchronous positioning unit (11) is located between the surface detection device (4) and the rolling base (1), and includes a laser positioning sensor and an encoder.

3. The roll forming apparatus for the steel frame of a vehicle battery pack according to claim 2, characterized in that: The surface detection device (4) uses a laser profile sensor array, with 3-5 laser profile sensors evenly arranged along the Y-axis.

4. The roll forming apparatus for the steel frame of a vehicle battery pack according to claim 3, characterized in that: The finished product inspection unit (7) includes a ring-shaped or C-shaped laser scanning sensor and at least one visual inspection camera, through which the finished steel frame is conveyed.

5. The roll forming apparatus for the steel frame of a vehicle battery pack according to claim 4, characterized in that: The upper rolling die (23) in the rolling forming unit (2) is provided with upper lifting sliders (24) that match the frame (21) at both ends, and the output shaft of the servo electric cylinder (22) is connected to the corresponding upper lifting slider (24).

6. The roll forming apparatus for the steel frame of a vehicle battery pack according to claim 5, characterized in that: The lower rolling die (33) is also provided with a lower lifting slider (25) that matches the frame (21) at both ends. The lower end of the lower lifting slider (25) is connected to a lifting screw (28). A worm wheel (32) is sleeved on the outside of the lifting screw (28). A transverse worm is meshed on one side of the worm wheel (32). The transverse worms on both sides are connected by a connecting shaft (31). An adjusting handwheel (27) is installed at one end of any transverse worm.

7. The roll forming apparatus for the steel frame of a vehicle battery pack according to claim 5, characterized in that: The auxiliary platform (3) is provided with vertical guide wheel group (12) and horizontal limiting guide wheel group (13) on both sides of the surface detection device (4), and the steel plate passes through the vertical guide wheel group (12) and the horizontal limiting guide wheel group (13) in sequence.

8. A processing control method for a roll forming apparatus for a steel frame of a vehicle battery pack according to claim 6, characterized in that, Includes the following steps: S1, the control unit (5) drives the upper rolling mold (23) of each rolling forming unit (2) to reset to the standard initial height through the servo electric cylinder (22). The standard initial height of each rolling forming unit (2) is different and needs to be set according to the rolling process and the shape of the steel frame. Taking the edge of the steel plate feed end as the reference, the synchronous positioning unit (11) is controlled to establish a two-dimensional rectangular coordinate system along the X-axis and Y-axis, divide the steel plate into several precise positioning units and assign a unique coordinate identifier; at the same time, the signal synchronization and zero point calibration of the surface detection device (4), synchronous positioning unit (11), finished product detection unit (7) and rolling forming unit (2) are completed to ensure that the coordinate system of each component is consistent. S2. During the steel sheet conveying process, the control unit (5) controls the surface detection device (4) to perform a full-coverage three-dimensional scan of the steel sheet surface, collects the surface contour data of each positioning unit and transmits it to the control unit (5). The control unit (5) selects the unit to be adjusted based on the preset unevenness judgment threshold, records its coordinates, unevenness amount ΔH and contour features, and synchronously associates the corresponding rolling forming unit (2) in the processing area. S3, Control unit (5) calculates the adjustment amount ΔS of the rolling die on the corresponding rolling forming unit (2) based on the unevenness amount ΔH of the unit to be adjusted, the imported steel plate material characteristic parameters and the preset frame forming size, and incorporates the material characteristic correction coefficient to simultaneously compensate for the elastic rebound amount of the steel plate. S4. When the synchronous positioning unit (11) detects that the precision positioning unit to be adjusted has reached the processing position of the corresponding rolling forming unit (2), it sends a trigger signal to the control unit (5). The control unit (5) drives the servo electric cylinder (22) of the rolling forming unit (2) to drive the upper rolling mold (23) to complete the lifting adjustment according to the pre-calculated adjustment amount ΔS. S5, Control Unit (5) controls Finished Product Inspection Unit (7) to perform full-dimensional size inspection on the steel frame of the battery pack after processing, binds the inspection positions of the finished product with the coordinates of the front steel plate precise positioning unit and the corresponding rolling forming unit, and generates size deviation data ΔD; Control Unit (5) compares ΔD with the preset qualified threshold, analyzes the corresponding upper mold adjustment parameters for deviations exceeding the threshold and corrects them through machine learning algorithms, updates the parameter database, iteratively optimizes the upper mold adjustment calculation logic for subsequent processing, and forms closed-loop control.

9. The processing control method of the roll forming device for the steel frame of the vehicle battery pack according to claim 8, characterized in that: The size of the precise positioning unit in step S1 is 10mm×10mm; the preset unevenness judgment threshold in step S2 is ±0.05mm.

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