Mobile phone rear cover and alumite film gold stamping equipment and use method

Abstract

The invention discloses a mobile phone rear cover and alumite film gold stamping device and a using method, the mobile phone rear cover and alumite film gold stamping device comprises a lower rack, a countertop, a gold stamping press-fit module and an alumite film winding and unwinding module, the countertop is installed on the top of the lower rack, the gold stamping press-fit module is vertically installed on the top of the countertop, the alumite film winding and unwinding module is movably installed on the gold stamping press-fit module, and the alumite film winding and unwinding module is vertically installed on the countertop. Through deep coupling of a dynamic pressure compensation algorithm and a PID temperature control algorithm, extremely high hot stamping precision is achieved, the dynamic pressure compensation algorithm analyzes the temperature change rate and the film material speed in real time, the pressing force is dynamically adjusted, plating layer breakage or pattern offset caused by heat lag in a traditional technology is avoided, and meanwhile the hot stamping precision is greatly improved. The PID algorithm dynamically calculates the proportional gain based on the thermal conductivity, density and thickness of the material, the gold stamping effect is greatly improved, and meanwhile, the gold stamping requirements of mobile phone rear covers made of different materials can be met by adjusting the pressing and heating processes.

Description

Technical Field

[0001] The present invention relates to the field of mobile phone component processing equipment, in particular to a mobile phone back cover and electrochemical aluminum film hot stamping equipment and a use method. Background Art

[0002] With the widespread adoption of smartphones, the manufacturing process for phone cases is increasingly focused on high quality, high precision, and aesthetics. To enhance the appearance of phone cases, particularly the metallic finish of phone back covers, hot stamping has become a popular decorative method. Hot stamping combines an anodized aluminum film with the surface of a phone's back cover through heat pressing, creating a decorative metallic sheen. This process is widely used in the design of high-end phones, phone accessories, and other electronic products.

[0003] Traditional hot stamping processes often rely on manual operation or relatively simple automated equipment. These traditional methods have several shortcomings. For example, during the hot stamping process, inaccurate pressure and heat control can lead to uneven contact between the anodized aluminum film and the phone's back cover, affecting the quality and consistency of the final product. Furthermore, existing equipment cannot monitor pressure and temperature changes in real time during operation, resulting in unstable product quality and prone to errors during film changes, affecting production efficiency.

[0004] To address these shortcomings, intelligent automated equipment has emerged in recent years. These devices use sophisticated control systems to monitor and adjust pressure and temperature in real time, ensuring consistent hot stamping results for every product. Existing technology often utilizes mechanized devices to transport, press, and heat anodized aluminum foil. However, most equipment still faces technical bottlenecks, particularly in precision control and material adaptability.

[0005] Therefore, how to design an efficient and precise hot stamping equipment for mobile phone back covers and electrochemical aluminum films that can achieve stable pressure control, temperature control and adaptive processing of film materials under the premise of automation has become a technical problem that needs to be solved urgently in the industry.

[0006] After searching, it was found that a PTP laser electroplated aluminum hot stamping device and method [Application No.: 202311560847.0, Publication No.: CN117507576A] was disclosed in Chinese patent documents. It includes a hot stamping roller and a printing roller for hot pressing laser electroplated aluminum and aluminum foil; a transition unit and a compression transmission unit are provided at the rear ends of the hot stamping roller and the printing roller; the transition unit is provided with a hot pressing plate, a vacuum insulation plate and a cooling plate in sequence in the direction of aluminum foil conveying. Although this device can achieve the hot stamping effect, it cannot meet the high-precision and high-requirement hot stamping requirements of mobile phone shells, and does not meet the requirements of dynamic regulation. Summary of the Invention

[0007] In view of the problems existing in the prior art, the purpose of the present invention is to provide a mobile phone back cover and anodized aluminum film hot stamping device and a method of use.

[0008] A mobile phone back cover and anodized aluminum film hot stamping equipment and a method of use, characterized by comprising a lower frame, a table panel, a hot stamping pressing module and anodized aluminum film retracting and releasing module;

[0009] A table panel is installed on the top of the lower frame, a hot stamping and pressing module is vertically installed on the top of the table panel, and an electrochemical aluminum film retracting and extending module is movably installed on the hot stamping and pressing module;

[0010] The hot stamping and pressing module includes a lower profiling jig, an upper profiling jig, a lower jig fixing plate, a heat-insulating synthetic stone, a guide lifting plate, and a servo motor. The lower profiling jig and the upper profiling jig form an opposing structure. The lower profiling jig is mounted on the surface of the table panel through the lower jig fixing plate, and the upper profiling jig is connected to the guide lifting plate through the heat-insulating synthetic stone.

[0011] The guide lifting plate forms a sliding fit with the four guide shafts through a linear bearing sleeve. The lower end of the guide shaft is fixedly mounted on the table panel, and the upper end of the guide shaft is fixedly mounted on the upper fixed plate. The table panel, the upper fixed plate and the guide shaft form a frame structure. A servo motor is installed on the top of the upper fixed plate. A floating joint is provided on the top of the guide lifting plate, which is connected to the working end of the servo motor through the floating joint.

[0012] The electrochemical aluminum film rewinding and unwinding module includes an unwinding mechanism and a rewinding mechanism;

[0013] The unwinding mechanism includes a magnetic powder brake, an unwinding shaft and an unwinding fixed plate. The unwinding shaft is vertically installed on one side of the unwinding fixed plate, and the magnetic powder brake is installed on the other side of the unwinding fixed plate. The output shaft of the magnetic powder brake passes through the unwinding fixed plate and is connected to the unwinding shaft.

[0014] The winding mechanism includes a stepper motor, a winding shaft, a winding fixed plate, a synchronous pulley 1 and a synchronous pulley 2. The winding shaft and the stepper motor are vertically installed on one side of the winding fixed plate, and the synchronous pulley 1 and the synchronous pulley 2 are installed on the other side of the winding fixed plate. The output shaft of the stepper motor passes through the winding fixed plate and is connected to the synchronous pulley 1. The transmission shaft of the winding shaft passes through the winding fixed plate and is connected to the synchronous pulley 2. The synchronous pulley 1 and the synchronous pulley 2 are driven by a belt.

[0015] A transmission roller 1 and a transmission roller 2 are provided between the unwinding fixed plate and the winding fixed plate. The transmission roller 1 is installed on the unwinding shaft side of the unwinding fixed plate, and the transmission roller 2 is installed on the stepping motor side of the winding fixed plate.

[0016] The unwinding fixed plate and the rewinding fixed plate are installed on the guide lifting plate;

[0017] The lower rack has an integrated control module inside.

[0018] Preferably, the servo motor has a built-in pressure sensor for real-time monitoring of the pressing contact force.

[0019] Through this technical solution, the pressure sensor built into the servo motor monitors the contact force of the hot stamping process in real time and feeds this data back to the control system. This system adjusts the servo motor's output based on the real-time pressure value, ensuring that the pressure applied during the hot stamping process remains within a predetermined range, avoiding product quality instability caused by excessive or insufficient pressure. Furthermore, the pressure sensor's feedback signal can be used to dynamically adjust the hot stamping module's contact state, optimizing the process and improving the equipment's automation and precision.

[0020] Preferably, the thermal insulation synthetic stone is divided into two left-right symmetrical pieces.

[0021] Through the above technical solution, the insulating synthetic stone is designed as two symmetrical structures, which effectively improves the thermal efficiency and stability of the equipment. The two symmetrical insulating synthetic stones not only optimize the uniform distribution of heat, but also effectively reduce heat loss, ensuring that the hot stamping and pressing modules maintain a constant temperature during operation. This precise temperature control enables the equipment to operate stably in different operating environments and with different materials, avoiding uneven hot stamping effects or quality defects caused by temperature fluctuations. The symmetrical insulating synthetic stone structure also has excellent mechanical strength and high-temperature resistance, allowing it to operate in high-temperature environments for long periods of time without deformation or damage, effectively extending the service life of the equipment.

[0022] Preferably, the electrochemical aluminum film rewinding and unwinding module enables the electrochemical aluminum film to form an S-shaped transmission path from the unwinding shaft through the bottom of the transmission roller one, then around the top of the transmission roller two to the rewinding shaft.

[0023] Through the above technical solution, the design of this S-shaped transmission path can effectively control the tension of the anodized aluminum film and the stability during the transmission process, thereby ensuring the smooth transfer of the film material during the hot stamping and laminating process, and avoiding the stretching or twisting of the film material. Specifically, the anodized aluminum film begins to be transmitted through the unwinding shaft and is initially guided by the transmission roller one to ensure that the film material enters the transmission path smoothly. During the transmission process, the design above the transmission roller two further ensures the uniform tension of the film material, so that the film material always maintains a constant tension when it reaches the reel, which is crucial for maintaining the quality of hot stamping. The S-shaped path design also effectively reduces the slippage and wrinkling of the anodized aluminum film, avoids deformation or adhesion of the film material during processing, and ensures the surface quality of the final product.

[0024] Preferably, four parallel heating rods are embedded in the upper profiling jig, and the heating rods are evenly distributed along the hot stamping and pressing area.

[0025] The above technical solution avoids temperature fluctuations caused by uneven local heating. This structural design effectively prevents heat from being concentrated in a specific area, reducing quality defects caused by large temperature differences, such as incomplete hot stamping or blurred patterns. The layout of the heating rods also ensures uniform temperature distribution during the heating process, further improving the process accuracy of the equipment and reducing process defects caused by temperature instability. In addition, this design enhances heating efficiency. The precisely arranged heating rods can quickly transfer heat to the entire pressing area, allowing the temperature to reach the desired value in a shorter time, thereby reducing energy waste during the heating process.

[0026] Preferably, the method of use comprises the following steps:

[0027] Step 1: Workpiece positioning and system calibration

[0028] Place the back cover of the mobile phone in the positioning groove of the lower profiling fixture. Preload the magnetic powder brake with a basic tension of 0.5N·m-3.0N·m. Select the corresponding parameters according to the material of the mobile phone back cover.

[0029] Step 2: Dynamic Pressing Control

[0030] Servo motor starts two-stage pressing:

[0031] Stage 1: Press down at a speed of 20-40 mm / s to a position 3-5 mm away from the workpiece, and set the dynamic pressure compensation value of the servo motor according to the film material model, temperature and other conditions;

[0032] Phase 2: Switch to a speed of 5-10 mm / s and start pressure-displacement dual closed-loop control;

[0033] Step 3: Adaptive hot pressing process

[0034] The heating rod is controlled by an integrated control module to increase its temperature. The temperature increase method is calculated by a dynamic PID parameter formula. The tensile deformation rate of the anodized aluminum film is monitored in real time. When the deformation rate is too large, a compensation mechanism is triggered, including increasing the torque of the magnetic powder brake, reducing the speed of the stepper motor, and lowering the holding pressure of the servo motor.

[0035] Step 4: Precise resetting and membrane material replacement

[0036] After the pressure holding is completed, the servo motor resets along the guide shaft at a speed of 10mm / s-30mm / s, and the reset stroke deviation is ≤±0.03mm; the stepper motor rewinds the waste film at a speed of 0.5m / min-1.5m / min, and the unwinding shaft releases the new film segment.

[0037] Through the above technical solutions, the workpiece positioning and system verification steps ensure the stable positioning of the phone's back cover by preloading the basic tension, providing a solid foundation for subsequent pressing. Then, in the dynamic pressing control, the servo motor ensures accurate pressure distribution and uniform pressing effect through a two-stage pressing mode and pressure-displacement dual closed-loop control, avoiding quality defects. Finally, through the adaptive hot pressing process and precise reset mechanism, the equipment can monitor and dynamically adjust in real time during the heating process, and compensate for deformation during the heating and pressing process to ensure the stability of the film material and the quality of hot stamping. This series of technical solutions effectively improves the automation level and accuracy of the equipment, not only optimizing the entire production process, but also improving production efficiency and product stability.

[0038] Preferably, the dynamic pressure compensation value satisfies the following parameter relationship:

[0039]

[0040] in:

[0041] ΔP: real-time pressure compensation value of the servo motor;

[0042] m: The identifier corresponding to the manually selected material type;

[0043] k1,m: temperature-pressure coupling coefficient of material m;

[0044] k2,m: velocity-pressure coupling coefficient of material m;

[0045] dT / dt: The temperature change rate of the upper profiling fixture, in °C / s, calculated from the temperature difference measurements of the four heating rods;

[0046] dx / dt: The real-time displacement speed of the anodized aluminum film, in mm / s, converted from the movement speed of the take-up shaft.

[0047] Through the above technical solution, the calculation and adjustment of the dynamic pressure compensation value realizes high-precision hot stamping pressing control. The real-time pressure compensation value of the servo motor is dynamically adjusted according to the material type, temperature change rate and displacement speed of the electroplated aluminum film to ensure a stable pressing effect under different operating conditions. Specifically, the corresponding temperature-pressure coupling coefficient and speed-pressure coupling coefficient are selected by the identifier for different material types, so that the mutual influence between temperature and pressure, speed and pressure is accurately modeled and adjusted. Through temperature difference measurement and real-time displacement speed feedback, the system can calculate the temperature change rate and film material displacement speed in real time, and perform pressure compensation based on these data to ensure that the pressure during the pressing process is always maintained within the optimal range.

[0048] Preferably, the PID dynamic parameter formula satisfies the following parameters:

[0049] in:

[0050]

[0051] Kp: proportional coefficient of PID temperature control;

[0052] α m : initial proportional gain of material m, based on thermal response speed;

[0053] β m : attenuation factor of material m;

[0054] γ m : Film velocity-temperature coupling coefficient of material m.

[0055] Through the above technical solution, the application of the PID dynamic parameter formula effectively optimizes the temperature control process and improves the device's temperature control accuracy and response speed. Specifically, the proportional coefficient Kp ensures precise regulation of temperature changes to achieve the set target temperature by adjusting the proportional gain of the PID temperature control. The initial proportional gain of material m is adjusted according to the material's thermal response speed, enabling the control system to quickly respond to temperature changes based on the thermal conductivity characteristics of different materials. The attenuation factor adjusts the smoothness of the temperature response based on the material's characteristics, avoiding quality issues caused by temperature overshoot or excessive oscillation.

[0056] Preferably, the temperature change rate of the upper profiling fixture satisfies the following parameters:

[0057]

[0058] in:

[0059] wi: weighted coefficient, reflecting the contribution of the i-th heating rod to the temperature of the upper profiling fixture. The central heating rod has a high weight and the edge has a low weight.

[0060] Ti(t): real-time temperature of the i-th heating rod at time t;

[0061] Ti(t-Δt): historical temperature of the i-th heating rod at time t-Δt;

[0062] Δt: sampling time interval.

[0063] Through the above technical solution, the calculation method of the temperature change rate of the upper profiling fixture accurately reflects the influence of each heating rod on the temperature change of the upper profiling fixture through the weighted coefficient. The weight of the central heating rod is higher, while the weight of the edge heating rod is lower. This design makes the temperature distribution more uniform and effectively prevents heat loss or uneven hot stamping caused by uneven temperature. Specifically, the temperature change rate is calculated by the difference between the real-time temperature and the historical temperature of the heating rod, which is the sampling time interval. The weighted coefficient is used to represent the contribution of each heating rod to the temperature change to adapt to the temperature influence of heating rods in different positions. The temperature change of the central heating rod has a greater impact on the overall temperature, so its weighted coefficient is also higher, while the edge heating rods use a lower weight to achieve precise control and uniform heating.

[0064] Preferably, the attenuation factor of the upper profiling fixture satisfies the following parameters

[0065]

[0066] in:

[0067] βm: The attenuation factor of material m, reflecting the diffusion rate of heat in the fixture;

[0068] λm: thermal conductivity of material m;

[0069] ρm: density of material m;

[0070] h: The thickness of the upper profiling fixture.

[0071] Through the above technical solution, the attenuation factor of the upper contoured fixture effectively reflects the speed of heat diffusion in the fixture. The attenuation factor is closely related to the thermal conductivity and density of the material and the thickness of the fixture, which enables the system to accurately control the heat diffusion process in the fixture according to the thermal conductivity characteristics of different materials. Specifically, thermal conductivity indicates the ability of the material to conduct heat. The higher the thermal conductivity, the faster the heat diffusion rate; density affects the ability of the material to store heat. The greater the density, the slower the heat diffusion rate; the thickness of the fixture determines the distance of heat conduction. The greater the thickness, the longer the time and path for heat diffusion. Through the combination of these parameters, the attenuation factor can accurately describe the speed at which heat propagates in the fixture, thereby ensuring the uniformity and stability of heat distribution.

[0072] Compared with the prior art, the present invention has the following advantages:

[0073] 1. This hot stamping equipment achieves extremely high hot stamping accuracy through the deep coupling of the dynamic pressure compensation algorithm and the PID temperature control algorithm. The dynamic pressure compensation algorithm analyzes the temperature change rate and film speed in real time, dynamically adjusting the pressing force to avoid coating fracture or pattern offset caused by thermal lag in traditional processes. At the same time, the PID algorithm dynamically calculates the proportional gain based on the material's thermal conductivity, density and thickness, greatly improving the hot stamping effect.

[0074] 2. This hot stamping equipment adapts to the hot stamping needs of mobile phone back covers made of various materials by adjusting the pressing and heating processes. Whether it's the hardness, thickness, or surface treatment of the material, the equipment adjusts operating parameters based on real-time feedback to ensure ideal hot stamping results for all back covers.

[0075] 3. The hot stamping and pressing module features an opposing upper and lower profiling jigs. The precise sliding fit of the guide lift plate and four guide shafts ensures stability during the pressing process. Furthermore, the use of servo and stepper motors ensures smooth operation, reducing vibration and errors in mechanical movement and improving production efficiency. Furthermore, the integrated design and modular structure of the control module simplify commissioning and maintenance. BRIEF DESCRIPTION OF THE DRAWINGS

[0076] Figure 1 It is a three-dimensional schematic diagram of the present invention;

[0077] Figure 2 It is a three-dimensional schematic diagram of the hot stamping and pressing module of the present invention;

[0078] Figure 3 This is a partial enlarged schematic diagram of point A of the present invention;

[0079] Figure 4 Schematic diagram A of the electrochemical aluminum film retractable module of the present invention;

[0080] Figure 5 Schematic diagram B of the electrochemical aluminum film retractable module of the present invention.

[0081] In the figure: 1. Lower frame; 2. Table panel; 3. Hot stamping and pressing module; 4. Anodized aluminum film retracting and unwinding module; 101. Lower profiling jig; 102. Upper profiling jig; 103. Lower jig fixing plate; 104. Thermal insulation synthetic stone; 105. Guide lifting plate; 106. Servo motor; 107. Linear bearing sleeve; 108. Guide shaft; 109. Upper fixing plate; 201. Magnetic powder brake; 202. Unwinding shaft; 203. Unwinding fixing plate; 301. Stepping motor; 302. Rewinding shaft; 303. Rewinding fixing plate; 304. Synchronous pulley 1; 305. Synchronous pulley 2; 401. Drive roller 1; 402. Drive roller 2. DETAILED DESCRIPTION

[0082] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0083] See also Figures 1 to 5 , the present invention provides a technical solution:

[0084] Example 1: Glass mobile phone back cover

[0085] 1. Initial parameter setting:

[0086] Workpiece information: Glass mobile phone back cover

[0087] Anodized aluminum film: PET substrate (thickness 12μm, thermal conductivity λ=0.2W / m·K, density ρ=1400kg / m 3 , specific heat capacity c = 1000 J / kg·K)

[0088] Fixture parameters: Upper profiling fixture thickness h = 20mm

[0089] Calculation of dynamic pressure compensation value:

[0090] According to the formula

[0091]

[0092] Experimental calibration values: k1=1.0, k2=0.7 (glass material adaptation value)

[0093] Real-time data:

[0094] Temperature change rateTemperature change rate

[0095]

[0096] Film speed dx / dt = 10 mm / s;

[0097] ΔP=1.0×29+0.7×10=36N

[0098] Calculation of PID dynamic parameters:

[0099] According to the formula

[0100]

[0101] α value: According to the glass material table, α=100;

[0102] The β value is calculated as follows:

[0103] λ=1.0W / (m·K)

[0104] ρ m =2500kg / m 3

[0105] h=20mm=0.02m

[0106]

[0107] The process of obtaining the γ value is as follows:

[0108] In the hot stamping of glass, the temperature was fixed at 185°C, the pressure was 450N, the film speed was 10mm / s, and the γ value was gradually adjusted to obtain the experimental results shown in Table 1.

[0109] Table 1

[0110]

[0111]

[0112] According to the experimental conclusion, the γ value is selected as 0.1

[0113] The Kp value is calculated as follows

[0114] K p =100×e -0.63×10 +0.1×10=1.53

[0115] 2. Equipment Preparation

[0116] Structural component startup:

[0117] The guide lifting plate 105 is reset to the initial position

[0118] Electrochemical aluminum film threading path: unwinding shaft 202 → below transmission roller 1 401 → above transmission roller 2 402 → rewinding shaft 302

[0119] Step 1: Workpiece positioning and system calibration

[0120] The glass back cover is placed in the positioning groove of the lower profiling fixture 101 , and the magnetic powder brake 201 is preloaded with a basic tension of 0.5 N·m.

[0121] Step 2: Dynamic Press Control

[0122] Stage 1: The servo motor 106 presses down at a speed of 25 mm / s, and the real-time calculation ΔP=36N, the actual pressure=450+36=486N;

[0123] Stage 2: When the distance from the workpiece is 3 mm, the speed is switched to 5 mm / s. The pressure closed-loop control overshoot is +1.1%, and the actual value is 492 N.

[0124] Step 3: Adaptive hot pressing process

[0125] Temperature control: Initial power = 1.53 × 5°C = 7.65% Total power 2000W → 153W;

[0126] Maintain pressure for 50 seconds, actual temperature fluctuation = 185±1.8℃, temperature difference of four heating rods ≤3℃;

[0127] Step 4: Reset and replace membrane material

[0128] The servo motor 106 is reset at a speed of 20 mm / s;

[0129] Stepper motor 301 winding speed 0.8m / min;

[0130] The magnetic powder brake 201 releases the tension to 0.5 N·m, and the unwinding shaft 202 releases a new film segment.

[0131] Example 2: Aluminum alloy mobile phone back cover

[0132] 1. Initial parameter setting:

[0133] Workpiece information: Aluminum alloy mobile phone back cover

[0134] Anodized aluminum film: PET substrate (thickness 12μm, thermal conductivity λ=0.2W / m·K, density ρ=1400kg / m 3 , specific heat capacity c = 1000 J / kg·K)

[0135] Fixture parameters: Upper profiling fixture thickness h = 20mm

[0136] Calculation of dynamic pressure compensation value:

[0137] According to the formula

[0138]

[0139] Experimental calibration value: k1=1.2, k2=1.0 (adaptation value for aluminum alloy material)

[0140] Real-time data:

[0141] Temperature change rateTemperature change rate

[0142]

[0143] Film speed dx / dt = 15 mm / s;

[0144] ΔP=1.2×48+1.0×15=72.6N

[0145] Calculation of PID dynamic parameters:

[0146] According to the formula

[0147]

[0148] α value: According to the aluminum alloy material table, α=150;

[0149] The β value is calculated as follows:

[0150] λ=120W / (m·K)

[0151] ρ m =2700kg / m 3

[0152] h=20mm=0.02m

[0153]

[0154] The process of obtaining the γ value is as follows:

[0155] In the hot stamping of aluminum alloy, the temperature was fixed at 210℃, the pressure was 600N, the film speed was 15mm / s, and the γ value was gradually adjusted to obtain the experimental results shown in Table 2.

[0156] Table 2

[0157] γ value Temperature error (℃) Deformation rate (%) Selection basis 0.0 +3.5 0.25 No compensation, obvious temperature rise lag 0.01 +1.5 0.22 Significantly reduced error (selected value) 0.05 +1.3 0.35 The deformation rate exceeds the standard and the benefit is negative

[0158] According to the experimental conclusion, the γ value is selected as 0.01

[0159] The Kp value is calculated as follows

[0160] K p =150×e -0.81×5 +0.01×15=2.55

[0161] 2. Equipment Preparation

[0162] Structural component startup:

[0163] The guide lifting plate 105 is reset to the initial position

[0164] Electrochemical aluminum film threading path: unwinding shaft 202 → below transmission roller 1 401 → above transmission roller 2 402 → rewinding shaft 302

[0165] Step 1: Workpiece positioning and system calibration

[0166] The aluminum alloy rear cover is placed in the positioning groove of the lower profiling fixture 101 , and the magnetic powder brake 201 is preloaded with a basic tension of 1.8 N·m.

[0167] Step 2: Dynamic Press Control

[0168] Stage 1: The servo motor 106 presses down at a speed of 30 mm / s, and the real-time calculation is ΔP = 72.6 N, and the actual pressure = 600 + 72.6 = 672.6 N;

[0169] Stage 2: When the distance from the workpiece is 3 mm, the speed is switched to 10 mm / s, and the pressure closed-loop control overshoot is -0.6%, and the actual value is 668 N.

[0170] Step 3: Adaptive hot pressing process

[0171] Temperature control: Initial power = 2.55 × 10 ° C = 25.5% Total power 2000W → 510W;

[0172] Maintain pressure for 50 seconds, actual temperature fluctuation = 210±1.5℃, temperature difference of four heating rods ≤2℃;

[0173] Step 4: Reset and replace membrane material

[0174] The servo motor 106 is reset at a speed of 25 mm / s;

[0175] Stepper motor 301 winding speed 1.1m / min;

[0176] The magnetic powder brake 201 releases the tension to 1.8 N·m, and the unwinding shaft 202 releases a new film segment.

[0177] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like to indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0178] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature identified as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, "plurality" means two or more, unless otherwise specifically defined.

[0179] The above is only a preferred specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any technician familiar with this technical field, within the technical scope disclosed by the present invention, who makes equivalent replacements or changes based on the technical solutions and inventive concepts of the present invention, should be covered by the scope of protection of the present invention.

Claims

1. A mobile phone back cover and anodized aluminum film hot stamping device and its use method, characterized by: The machine comprises a lower frame (1), a table panel (2), a hot stamping and pressing module (3) and an electrochemical aluminum film retracting and extending module (4); the table panel (2) is installed on the top of the lower frame (1), the hot stamping and pressing module (3) is vertically installed on the top of the table panel (2), and the electrochemical aluminum film retracting and extending module (4) is movably installed on the top of the table panel; The hot stamping and pressing module (3) comprises a lower profiling jig (101), an upper profiling jig (102), a lower jig fixing plate (103), a heat-insulating synthetic stone (104), a guide lifting plate (105) and a servo motor (106). The lower profiling jig (101) and the upper profiling jig (102) are opposite to each other, the lower profiling jig (101) is fixed to the table panel (2) through the lower jig fixing plate (103), and the upper profiling jig (102) is connected to the guide jacking plate (105) through the heat-insulating synthetic stone (104); the guide jacking plate (105) is slidably matched with four guide shafts (108) through a linear bearing sleeve (107), the lower end of the guide shaft (108) is fixed to the table panel (2), and the upper end is fixed to the upper fixing plate (109), and the table panel (2), the upper fixing plate (109) and the guide shaft (108) constitute a frame structure; the servo motor (106) is installed on the upper fixing plate (109) and is connected to the guide jacking plate (105) through a floating joint; The electrochemical aluminum film unwinding module (4) includes an unwinding mechanism and a winding mechanism: the unwinding mechanism is composed of a magnetic powder brake (201), an unwinding shaft (202) and an unwinding fixed plate (203), and the magnetic powder brake (201) drives the unwinding shaft (202) through the unwinding fixed plate (203); the winding mechanism includes a stepping motor (301), a winding shaft (302), a winding fixed plate (303) and a synchronous pulley group, and the stepping motor (301) drives the winding shaft (302) through a synchronous pulley 1 (304) and a synchronous pulley 2 (305); a transmission roller 1 (401) and a transmission roller 2 (402) are arranged between the unwinding fixed plate (203) and the winding fixed plate (303), and the two are respectively located on the side of the unwinding shaft (202) and the winding shaft (302), and are integrally installed on the guide lifting plate (105); The lower frame (1) is integrated with a control module.

2. The mobile phone back cover and anodized aluminum foil hot stamping device according to claim 1, characterized in that: The servo motor (106) has a built-in pressure sensor for real-time monitoring of the pressing contact force.

3. The mobile phone back cover and anodized aluminum foil hot stamping device according to claim 1, characterized in that: The heat-insulating synthetic stone (104) is divided into two symmetrical pieces.

4. The mobile phone back cover and anodized aluminum foil hot stamping device according to claim 1, characterized in that: The electrochemical aluminum film retracting and unreeling module (4) enables the electrochemical aluminum film to form an S-shaped transmission path from the unreeling shaft (202) through the bottom of the transmission roller (401), and then around the top of the transmission roller (402) to the reeling shaft (302).

5. The mobile phone back cover and anodized aluminum foil hot stamping device according to claim 1, characterized in that: The upper profiling jig (102) is internally embedded with four parallel heating rods, which are evenly distributed along the hot stamping and pressing area.

6. The mobile phone back cover and anodized aluminum foil hot stamping device and method of use according to claim 1, characterized in that: The method of use comprises the following steps: Step 1: Workpiece positioning and system calibration The back cover of the mobile phone is placed in the positioning groove of the lower profiling fixture (101), and the magnetic powder brake (201) is preloaded with a basic tension of 0.5N·m-3.0N·m, and the corresponding parameters are selected according to the material of the back cover of the mobile phone; Step 2: Dynamic Pressing Control The servo motor (106) starts the two-stage pressing: Stage 1: pressing down at a speed of 20-40 mm / s to a position 3-5 mm away from the workpiece, and setting the dynamic pressure compensation value of the servo motor (106) according to the film material model, temperature and other conditions; Phase 2: Switch to a speed of 5-10 mm / s and start pressure-displacement dual closed-loop control; Step 3: Adaptive hot pressing process The heating rod is controlled to increase temperature through an integrated control module. The heating method is calculated through a PID parameter dynamic formula. The tensile deformation rate of the electrochemical aluminum film is monitored in real time. When the deformation rate is too large, a compensation mechanism is triggered, including increasing the torque of the magnetic powder brake (201), reducing the speed of the stepper motor (301), and reducing the holding pressure of the servo motor (106). Step 4: Precise resetting and membrane material replacement After the pressure maintenance is completed, the servo motor (106) resets along the guide shaft (108) at a speed of 10mm / s-30mm / s, and the reset stroke deviation is ≤±0.03mm; the stepper motor (301) rewinds the waste film at a speed of 0.5m / min-1.5m / min, and the unwinding shaft (202) releases the new film segment.

7. The method of use according to claim 5, characterized in that: The dynamic pressure compensation value satisfies the following parameter relationship: in: ΔP: real-time pressure compensation value of the servo motor (106); m: The identifier corresponding to the manually selected material type; k1,m: temperature-pressure coupling coefficient of material m; k2,m: velocity-pressure coupling coefficient of material m; dT / dt: the temperature change rate of the upper profiling fixture (102), in °C / s, calculated from the temperature difference measurements of the four heating rods; dx / dt: real-time displacement speed of the electrochemical aluminum film, in mm / s, converted from the movement speed of the reel (302).

8. The method of use according to claim 5, characterized in that: The PID dynamic parameter formula satisfies the following parameters: in: Kp: proportional coefficient of PID temperature control; α m : initial proportional gain of material m, based on thermal response speed; β m : attenuation factor of material m; γ m : Film velocity-temperature coupling coefficient of material m.

9. The parameter relationship according to claim 7, characterized in that: The temperature change rate of the upper profiling fixture (102) satisfies the following parameters: in: wi: weighted coefficient, reflecting the contribution weight of the i-th heating rod to the temperature of the upper profiling fixture (102), with the central heating rod having a high weight and the edge having a low weight; Ti(t): real-time temperature of the i-th heating rod at time t; Ti(t-Δt): historical temperature of the i-th heating rod at time t-Δt; Δt: sampling time interval.

10. The parameter relationship according to claim 8, characterized in that: The attenuation factor of the upper profiling fixture (102) satisfies the following parameters in: βm: The attenuation factor of material m, reflecting the diffusion rate of heat in the fixture; λm: thermal conductivity of material m; ρm: density of material m; h: thickness of the upper profiling fixture (102).

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