Anti-deviation forming method for in-mold injection molding insert

Abstract

The invention belongs to the technical field of fire-fighting weak current boxes, and particularly relates to an in-mold injection molding insert anti-offset forming method which comprises the following steps: S1, constructing a bionic gradient adsorption and magnetic pre-positioning system: integrating 3-4 micro-nano bionic suckers at the bottom of an insert, and embedding rare earth permanent magnets into the centers of the suckers; an electromagnetic coil array and a vacuum channel are arranged corresponding to the mold positioning surface; s2, a shape memory alloy self-adaptive locking mechanism is designed, specifically, four sets of nickel-titanium alloy SMA locking pins are embedded into the side wall of a mold cavity, and hemispherical protrusions are arranged at the heads of the locking pins and matched with preset positioning grooves of inserts; by means of the composite structure of bionic suction cup negative pressure adsorption, magnetic prepositioning correction and cooperative locking, the problem that traditional rigid positioning is sensitive to the dimensional tolerance of the insert is solved, the resistance to the initial impact of the melt is enhanced through cooperation of multiple acting force, and the positioning precision and stability of the insert in the placement stage are remarkably improved.

Description

Technical Field

[0001] This invention belongs to the field of fire protection low-voltage electrical box technology, specifically a molding method for preventing displacement of in-mold injection molded inserts. Background Technology

[0002] In-mold injection molding technology is a process in which metal, ceramic, or other inserts are pre-placed in a mold cavity and then injected with molten plastic to achieve integrated molding. With its advantages of reducing assembly steps and improving product structural stability, it has become one of the key technologies in the field of precision manufacturing.

[0003] In the consumer electronics field, in-mold injection inserts are used in components such as camera modules and connectors. It is necessary to ensure the coaxiality of the insert and the plastic shell to ensure signal transmission stability and optical performance. In the field of new energy vehicles, inserts such as battery pack terminals and motor end caps are sealed and molded using this technology. The anti-displacement design can avoid safety hazards such as electrolyte leakage and abnormal current conduction.

[0004] Existing in-mold injection molding insert anti-displacement technologies have several limitations: First, the positioning methods are limited. Traditional mechanical positioning relies on rigid clamps, which are difficult to adapt to insert size tolerances. Bionic adsorption or magnetic positioning is mostly used alone and lacks a coordinated locking mechanism, making it susceptible to failure due to melt impact. Second, the control methods are lagging behind. Most technologies only passively prevent displacement by preset injection parameters and do not monitor dynamic data such as melt flow field and insert displacement in real time, making it impossible to intervene in the displacement trend in a timely manner.

[0005] Therefore, the present invention provides a method for preventing displacement of in-mold injection molded inserts. Summary of the Invention

[0006] In order to overcome the shortcomings of the prior art, at least one technical problem raised in the background art is solved.

[0007] The technical solution adopted by this invention to solve its technical problem is: a method for preventing displacement of in-mold injection inserts, comprising the following steps: S1. Construction of biomimetic gradient adsorption and magneto-precision positioning system: 3-4 micro-nano-scale biomimetic suction cups are integrated at the bottom of the insert, and rare earth permanent magnets are embedded in the center of the suction cups; electromagnetic coil arrays and vacuum channels are set on the corresponding mold positioning surfaces. S2. Shape memory alloy adaptive locking mechanism design: Four sets of nickel-titanium alloy SMA locking pins are embedded in the side wall of the mold cavity. The head of the locking pin is provided with a hemispherical protrusion, which matches the positioning groove of the insert. S3. Construction of Multimodal Sensing and Digital Twin Real-time Control System: Fiber Bragg grating sensors are deployed to monitor the strain of the inserts, an infrared thermal imager captures the temperature field distribution at the interface, and a microwave radar scans the three-dimensional position of the inserts in real time to generate real-time data. S4. Melt pulse impact and interface anchoring co-molding process: During the injection stage, the melt is controlled by a servo valve to be injected in a pulsed manner at a frequency of 10-15Hz. The pulse shock wave is used to make the melt more uniformly wrap the insert; at the same time, a micro-anchoring structure is preset on the surface of the insert. S5. Phase change material and water circuit synergistic temperature control and cooling system: A shaped phase change material is embedded in the area around the mold insert to form a composite temperature control system with the traditional cooling water circuit. S6. Full life cycle health assessment and self-maintenance system: The system has a built-in "anti-offset health index" model, which comprehensively evaluates the equipment status based on the following parameters: SMA lock pin fatigue, bionic suction cup wear, and sensor drift value.

[0008] Preferably, the temperature control and cooling system in S5 includes a phase change material energy storage module, a cooling water circuit module, a micro-stirring drive module, and a temperature monitoring and feedback module; The phase change material energy storage module is composed of paraffin-based PCM, a sealed PCM cavity, and high-temperature resistant sealant; the PCM filling rate is ≥95%, and the cavity thermal conductivity is ≥15W / (m・K); The cooling water circuit module consists of a spiral copper cooling water pipe, a water circuit diversion valve, a water temperature controller, and a circulating water pump; the water temperature control range is 20-25℃, the water circuit pressure is 0.3-0.5MPa, and the distance between the cooling water pipe and the PCM cavity is ≤5mm. The micro stirring drive module consists of a micro DC motor, plastic stirring blades, and a motor mounting bracket; the motor operates in a temperature range of -10 to 120°C, and the stirring blades have a service life of ≥10,000 hours. The temperature monitoring feedback module consists of 3 sets of PT100 platinum resistance temperature sensors, a data acquisition unit, and a central controller; the sensor response time is ≤1s and the data transmission delay is ≤100ms.

[0009] Preferably, the sealed cavity of the phase change material energy storage module is directly attached to the cavity wall surface around the mold insert; The spiral water pipes of the cooling water circuit module are arranged around the cavity of the PCM energy storage module. The motor of the micro stirring drive module is embedded in the top of the cavity of the PCM energy storage module through a bracket, and the stirring blades extend into the PCM. The three PT100 sensors of the temperature monitoring feedback module are respectively inserted into: the PCM energy storage module, the mold insert-plastic interface, and the water pipe of the cooling water circuit module; the PT100 sensors of the temperature monitoring feedback module are connected to the data acquisition unit through shielded signal lines, and the acquisition unit then establishes data communication with the central controller through Ethernet to transmit temperature data in real time. The central controller is connected to the water circuit diversion valve and circulating water pump of the cooling water circuit module through the relay output terminal, and controls the start and stop of the water circuit and the water flow rate according to the temperature data; the central controller is connected to the DC motor of the micro stirring drive module through the PWM signal output terminal, and starts stirring when the PCM temperature drops to the phase change point, and stops stirring when the temperature is below 50°C; the central controller has no direct control connection with the PCM energy storage module, and only indirectly judges the working status of the PCM through temperature data.

[0010] Preferably, the core formula of the biomimetic gradient adsorption and magnetostrictive prepositioning system consists of the following: Formula for calculating the total adsorption force of a bionic suction cup: The biomimetic suction cup's adsorption force is jointly formed by negative pressure adsorption force and biomimetic ring-pattern surface tension, as shown in the following formula: ; in, The total adsorption force of the bionic suction cup must meet the following requirements. ; : Suction cup adsorption efficiency coefficient; Vacuum degree, range of values; The effective adsorption area of ​​the suction cup is determined by the diameter of the suction cup. Calculated ; : Surface tension coefficient of the ring pattern; : Circumference of a single ring; : The interfacial tension between the plastic melt and the suction cup surface, 0.035-0.045 for PP / ABS materials; Formula for calculating magnetostrictive prepositioning correction: The displacement of the magnetic torque driven insert for correction satisfies: ; in, Magnetostricted displacement must meet the following requirements. ; : Magnetic moment; Calibration time; Insert mass is calculated from the insert volume and density; : The distance from the point of application of the magnetic torque to the centroid of the insert.

[0011] Preferably, the shape memory alloy adaptive locking core formula consists of the following: Formula for calculating the thermal elongation of shape memory alloy lock pins: The elongation of shape memory alloys (SMA) at the phase transformation temperature satisfies: ; in, The elongation of the SMA lock stop pin must be equal to the depth of the insert positioning groove; Original length of SMA lock pin; Maximum thermal strain during SMA austenitic phase transformation; SMA operating temperature; SMA martensitic phase transformation temperature; SMA austenitic phase transformation temperature; Formula for calculating the locking force of shape memory alloys: The locking force must be greater than the component of the lateral pressure exerted by the melt on the insert: ; in, SMA locking force: 50-80N for nickel-titanium alloy SMA; : Lateral pressure of the melt on the insert; The lateral area of ​​the insert subjected to molten impact is calculated from the insert's height and width. : The angle between the melt flow direction and the side of the insert.

[0012] Preferably, the core formula for multimodal sensing and digital twin control consists of the following: Insert displacement prediction formula: Based on the coupled effects of pressure and temperature on insert displacement, the predicted displacement satisfies: ; in, The insert's predicted displacement must meet the following requirements. ; Pressure displacement coefficient, determined experimentally; The deviation between the actual pressure in the cavity and the preset pressure; Temperature displacement coefficient; The deviation between the actual temperature of the cavity and the preset temperature; Injection speed displacement coefficient; The deviation between the actual injection speed and the preset speed; Formula for process parameter correction: when The hot runner temperature or injection speed needs to be adjusted. or ; in, : Hot runner temperature correction amount; Injection speed correction amount; Adjust the safety factor.

[0013] Preferably, the core formula for melt pulse impact and interface anchoring consists of the following: Pulse injection pressure time-domain formula: The pulsed pressure follows a sinusoidal periodic variation, ensuring that the melt uniformly coats the insert. ; in, : The pulse pressure at any given moment; : Pulse pressure reference value; : Pulse pressure amplitude; Pulse frequency; : Pulse injection time; Formula for calculating interfacial bonding strength: The interfacial shear strength is determined by both the pulse energy and the anchoring structure. ; in, Shear strength at the interface between the insert and the plastic; : The weld strength of the plastic melt itself; : Anchoring structure reinforcement coefficient; : Melt energy injected by a single pulse; The total volume of the anchoring groove is determined by the diameter of the pit. and depth Calculated .

[0014] Preferably, the core formula for the synergistic cooling of the phase change material and the water circuit consists of the following: Formula for calculating synergistic cooling rate: The cooling rate needs to be controlled between 0.6-0.8℃ / s, as shown in the following formula: ; in, Product cooling rate; The latent heat released by PCM; The heat carried away by the cooling water system; Injection molded product quality; Product specific heat capacity; Cooldown time; Temperature gradient control formula: The temperature gradient at the interface between the insert and the plastic needs to be reduced by 50%, as shown in the following formula: ; in, Temperature gradient for synergistic cooling; : Temperature at the interface between the insert and the plastic; : Product outer surface temperature; Product thickness; Temperature gradient of traditional water cooling system.

[0015] Preferably, the core formula for assessing health throughout the entire life cycle consists of the following: Formula for calculating the anti-deviation health index: Health Index The score is obtained by weighting the status of key components, with a maximum score of 100. ; in, Health Index This is normal. Maintenance triggered; , , Weighting coefficient; The SMA locking pin has been cycled a certain number of times. For SMA fatigue life; Vacuum leakage of the bionic suction cup The maximum permissible leakage rate; Sensor drift amount Maximum allowable drift; Maintenance priority calculation formula: Maintenance priority Positively correlated with component failure risk: ; in, Component maintenance priority; : No. Sub-health of each component; : No. Failure impact coefficient of each component.

[0016] The beneficial effects of this invention are as follows: 1. The present invention provides a method for preventing displacement of in-mold injection inserts. Through a composite structure of "bionic suction cup negative pressure adsorption + magnetostrictive pre-positioning correction + synergistic locking", it not only solves the problem of traditional rigid positioning being sensitive to insert size tolerance, but also enhances the resistance to the initial impact of the melt through the synergistic effect of multiple forces, thus significantly improving the positioning accuracy and stability during the insert placement stage.

[0017] 2. The present invention provides a method for preventing displacement of in-mold injection inserts. By utilizing the thermally induced phase change characteristics of SMA, the locking pin can achieve precise expansion and contraction. This not only matches the locking force according to the characteristics of the insert groove to ensure no lateral displacement of the insert during injection molding, but also automatically shrinks and unlocks after cooling, avoiding the demolding resistance problem of traditional mechanical locking. At the same time, the high cycle life of SMA material extends the equipment maintenance cycle. Attached Figure Description

[0018] The invention will now be further described with reference to the accompanying drawings.

[0019] Figure 1 This is a flowchart of the biomimetic gradient adsorption and magneto-induced prepositioning system in this invention; Figure 2 This is a flowchart of the shape memory alloy adaptive locking system in this invention; Figure 3 This is a flowchart of the multimodal sensing and digital twin real-time control system of the present invention; Figure 4 This is a flowchart of the melt pulse impact and interface anchoring co-forming process in this invention; Figure 5 This is a flowchart of the phase change material and water circuit synergistic temperature control and cooling system in this invention; Figure 6 This is a flowchart of the full life cycle health assessment and self-maintenance system in this invention. Detailed Implementation

[0020] To make the technical means, creative features, objectives and effects of this invention easier to understand, the invention will be further described below in conjunction with specific embodiments.

[0021] like Figures 1 to 6 As shown in the embodiment of the present invention, a method for preventing displacement of in-mold injection inserts includes the following steps: S1. Construction of a biomimetic gradient adsorption and magnetostrictive prepositioning system: 3-4 micro-nano-scale biomimetic suction cups (2-5mm in diameter, with 0.1mm-level annular structures on the inner wall of the suction cups to simulate the negative pressure enhancement effect of octopus suction cups) are integrated at the bottom of the insert. A rare-earth permanent magnet (remanence 1.2-1.4T) is embedded in the center of the suction cup. An electromagnetic coil array and a vacuum channel are set on the corresponding mold positioning surface. After the insert is placed, a gradient magnetic field (magnetic field strength 0.3-0.5T) is generated first through the electromagnetic coils. The magnetic torque is used to coarsely position the insert within ±0.05mm. Then, the vacuum system (vacuum degree -0.095~-0.09MPa) is activated to make the biomimetic suction cup produce a "flexible deformation-tight fit" effect. The adsorption force is increased by 40%-60% compared with traditional planar suction cups, solving the problem of unstable positioning of inserts on smooth surfaces. S2. Shape Memory Alloy Adaptive Locking Mechanism Design: Four sets of nickel-titanium alloy SMA locking pins (diameter 1-2mm, phase transformation temperature 50-60℃) are embedded in the sidewall of the mold cavity. The head of the locking pin has a hemispherical protrusion (radius 0.5-1mm) to match the pre-set positioning groove of the insert. Before injection molding, the SMA is in the austenitic state (length shrinkage 1.5%-3%). After the insert is placed, the preheating device is triggered (heating to 60℃ within 30s). The SMA undergoes phase transformation, elongates, and locks into the groove to achieve mechanical locking (locking force 50-80N). After injection molding, the temperature is reduced to below 30℃ through the mold cooling system. The SMA returns to the martensitic state and automatically shrinks and unlocks, avoiding the demolding jamming problem of traditional mechanical locking. The response time of this mechanism is ≤1s, the cycle life is ≥100,000 times, and it is suitable for locking requirements of inserts of different materials. S3. Construction of a multimodal sensing and digital twin real-time control system: Fiber optic grating sensors (5mm spacing) are deployed to monitor insert strain (accuracy ±1). An infrared thermal imager (640×512 resolution) captures the interface temperature field distribution (temperature measurement range 20-300℃), and a microwave radar (operating frequency 24GHz) scans the three-dimensional position of the insert in real time (positioning accuracy 0.001mm), generating real-time data. The data is then transmitted to a digital twin platform to construct a coupled dynamic model of "insert-melt-mold". The insert offset trend is predicted through real-time finite element calculation (computation efficiency ≥1 million elements / s). When the model predicts an offset ≥0.015mm, the hot runner zone temperature (±5℃) and injection screw speed (±10r / min) are automatically adjusted to form a "prediction-intervention" proactive control, which improves the response speed by 60% compared to traditional feedback control. S4. Melt Pulse Impact and Interface Anchoring Co-molding Process: During the injection stage, the melt is pulsed at a frequency of 10-15Hz (pulse pressure fluctuation range ±5MPa) controlled by a servo valve. The pulse shock wave makes the melt more uniformly encapsulate the insert. At the same time, micro-anchoring structures (such as inverted conical pits with a diameter of 0.3-0.5mm and a spacing of 2-3mm) are preset on the surface of the insert. The pulsed melt forms a "vortex-filling" effect in the pits, and after cooling, it forms a mechanical interlocking node, which improves the interface bonding strength by 30%-50%. For high-flow plastics (such as PP and PE), a 0.5s holding pressure section is inserted between pulses to prevent the melt backflow from impacting the insert, thus solving the problem of uneven interface bonding caused by traditional continuous injection. S5. Phase Change Material and Water Circuit Synergistic Temperature Control Cooling System: A shaped phase change material (such as paraffin-based PCM, phase change temperature 80-100℃, latent heat ≥200kJ / kg) is embedded in the periphery of the mold insert, forming a composite temperature control system with the traditional cooling water circuit. In the initial cooling stage (0-5s), the PCM absorbs heat from the melt to maintain the interface temperature above the plastic melting point, avoiding stress concentration caused by rapid cooling. When the temperature drops to the PCM phase change point, forced cooling of the water circuit is activated (water temperature 20-25℃). Through the synergistic effect of the PCM and the water circuit, the cooling rate around the insert is controlled at 0.6-0.8℃ / s, reducing the temperature gradient by 50% compared to traditional water circuit cooling. Simultaneously, a micro-stirring device (300-500r / min) is installed in the PCM cavity to prevent local solidification of the PCM from affecting heat exchange efficiency. S6. Full Lifecycle Health Assessment and Self-Maintenance System: The system incorporates an "Anti-Offset Health Index" model, comprehensively assessing equipment status based on the following parameters: SMA lock pin fatigue (monitored via resistance change), bionic suction cup wear (vacuum leak rate detection), and sensor drift value (periodic calibration data). When the index falls below a threshold (e.g., 80 points), maintenance commands are automatically triggered: plasma repair of the suction cup (restoring surface microstructure), annealing of the SMA (restoring phase change performance), and automatic sensor calibration. Simultaneously, blockchain records each batch of molding data (e.g., offset, process parameters), forming an immutable quality traceability chain. This solves the offset fluctuation problem caused by equipment condition degradation in traditional processes, ensuring a stable offset pass rate of over 99.5% in long-term production.

[0022] The temperature control and cooling system in the S5 mentioned above includes a phase change material (PCM) energy storage module, a cooling water circuit module, a micro-stirring drive module, and a temperature monitoring and feedback module; The aforementioned phase change material (PCM) energy storage module consists of paraffin-based PCM (phase change temperature 80-100℃, latent heat ≥200kJ / kg), a sealed PCM cavity (fitted to the periphery of the mold insert, with cavity volume matching the heat dissipation requirements of the insert), and high-temperature resistant sealant (to prevent PCM leakage); the PCM filling rate is ≥95%, and the cavity thermal conductivity is ≥15W / (m・K) (the cavity material is aluminum alloy); it passively absorbs the heat of the melt in the early stage of cooling, maintaining the temperature of the insert-plastic interface above the melting point of the plastic, avoiding stress concentration caused by rapid cooling; after the temperature drops to the phase change point, it releases the stored heat, and works with the water circuit to achieve uniform temperature control; The aforementioned cooling water circuit module consists of a spiral copper cooling water pipe (diameter 8-12mm, wall thickness 1.5mm), a water circuit diversion valve (electromagnetically controlled, response time ≤0.5s), a water temperature controller (accuracy ±1℃), and a circulating water pump (flow rate 5-8L / min); the water temperature control range is 20-25℃, the water circuit pressure is 0.3-0.5MPa, and the distance between the cooling water pipe and the PCM cavity is ≤5mm; forced cooling is initiated after the PCM phase change to quickly remove heat from the mold and product, control the overall cooling rate, and prevent the insert from shifting due to local overheating or overcooling; The aforementioned micro stirring drive module consists of a micro DC motor (power 10-15W, speed 300-500r / min), plastic stirring blades (blade diameter matched to the PCM cavity, material is PPS high temperature resistant plastic), and a motor mounting bracket (integrated design with the PCM cavity); the motor's operating temperature range is -10-120℃, and the stirring blades have a service life of ≥10,000 hours; it prevents local solidification and agglomeration of the PCM during the cooling process, ensures uniform heat exchange of the PCM, and avoids interface temperature fluctuations caused by uneven heat conduction of the PCM; The temperature monitoring and feedback module consists of three PT100 platinum resistance temperature sensors (temperature range -20-200℃, accuracy ±0.5℃), a data acquisition unit (sampling frequency 10Hz), and a central controller; the sensor response time is ≤1s, and the data transmission delay is ≤100ms; it collects PCM temperature, insert-plastic interface temperature, and cooling water temperature in real time, providing data support for the start-up, shutdown, and parameter adjustment of each module.

[0023] The sealed cavity of the aforementioned phase change material (PCM) energy storage module is directly attached to the cavity wall around the mold insert (fixed by bolts, and the contact surface is coated with thermally conductive silicone grease to enhance heat conduction). The spiral water pipes of the above-mentioned cooling water circuit module are arranged around the cavity of the PCM energy storage module (the distance between the water pipes and the outer wall of the PCM cavity is 3-5mm, and they are fixed by the water channel preset inside the mold). The motor of the aforementioned micro stirring drive module is embedded in the top of the cavity of the PCM energy storage module through a bracket, and the stirring blade extends into the PCM (the gap between the blade and the inner wall of the cavity is ≥1mm to avoid friction). The three PT100 sensors of the temperature monitoring feedback module are respectively inserted into: the PCM energy storage module (depth of 1 / 2 of the cavity height), the mold insert-plastic interface (close to the insert surface), and the water pipe of the cooling water circuit module (upstream of the water flow); the PT100 sensors of the temperature monitoring feedback module are connected to the data acquisition unit through shielded signal lines, and the acquisition unit then establishes data communication with the central controller through Ethernet to transmit temperature data in real time. The aforementioned central controller is connected to the water circuit diversion valve and circulating water pump of the cooling water circuit module through the relay output terminal, and controls the start and stop of the water circuit and the water flow rate according to the temperature data (increase the flow rate when the water temperature is higher than 25℃, and decrease the flow rate when it is lower than 20℃); the aforementioned central controller is connected to the DC motor of the micro stirring drive module through the PWM signal output terminal, and starts stirring when the PCM temperature drops to the phase change point (80℃), and stops stirring when the temperature is lower than 50℃; the aforementioned central controller has no direct control connection with the PCM energy storage module, and only indirectly judges the working status of the PCM through temperature data (if the PCM temperature is higher than 100℃ for a long time, the PCM is judged to be faulty and an alarm is triggered).

[0024] The core formula of the above-mentioned biomimetic gradient adsorption and magnetostrictive prepositioning system consists of the following: Formula for calculating the total adsorption force of a biomimetic suction cup: (initial impact of the equilibrium melt) The biomimetic suction cup's adsorption force is jointly formed by negative pressure adsorption force and biomimetic ring-pattern surface tension, as shown in the following formula: ; in, The total adsorption force of the bionic suction cup (unit: N) must meet the following requirements. ( (The initial impact force of the melt is taken as 50-100N). : Suction cup adsorption efficiency coefficient (0.92-0.98 due to the biomimetic ring pattern enhancing the seal). Vacuum degree (unit: Pa), range of values; Effective suction area of ​​the suction cup (unit: ), by the diameter of the suction cup (2-5mm) calculated ; : Surface tension coefficient of rings (related to the number of rings) Positive correlation , Take 3-5). Circumference of a single ring (unit: m). ( (The average diameter of the ring is 1.8-4.8 mm). Interfacial tension between the plastic melt and the suction cup surface (unit: N / m), 0.035-0.045 for PP / ABS materials; Formula for calculating magnetostrictive pre-positioning correction (to achieve coarse positioning of ±0.05mm) The displacement of the magnetic torque driven insert for correction satisfies: ; in, Magnetostricted displacement (unit: mm) must meet the following requirements. ( (Initial offset of the insert); Magnetic torque (unit: N·mm) ( The magnetic field strength of the electromagnetic coil is 0.3-0.5T; For rare earth permanent magnet magnetic moments, 5-8A. ; (The angle between the magnetic moment and the magnetic field, 0-90°). Calibration time (unit: s), ranging from 0.1 to 0.3 s; The mass of the insert (unit: kg) is calculated from the volume and density of the insert (e.g., 8900 kg / m³ for brass inserts). ); : Distance from the point of application of the magnetic torque to the center of mass of the insert (unit: mm), take 2-5 mm; By using a composite structure of "bionic suction cup negative pressure adsorption + magnetostrictive pre-positioning correction + synergistic locking", the problem of traditional rigid positioning being sensitive to insert size tolerances is solved. Furthermore, the synergistic effect of multiple forces enhances the resistance to the initial impact of the melt, significantly improving the positioning accuracy and stability during the insert placement stage.

[0025] The above-mentioned shape memory alloy adaptive locking core formula consists of the following: Formula for calculating the thermal elongation of shape memory alloy lock stop pins: (matching insert positioning grooves) The elongation of shape memory alloys (SMA) at the phase transformation temperature satisfies: ; in, The elongation of the SMA lock stop pin (unit: mm) must be equal to the depth of the insert positioning groove (0.5-1 mm). Original length of SMA lock pin (unit: mm), take 10-15mm; Maximum thermal strain of SMA austenitic phase transformation (1.5%-3% for nickel-titanium alloys, i.e., 0.015-0.03%). SMA operating temperature (unit: °C), take 50-60 °C (phase change temperature range); SMA martensitic phase transformation temperature (unit: °C), taken as -20 to 0 °C; SMA austenitic phase transformation temperature (unit: °C), take 40-50 °C; Formula for calculating the locking force of shape memory alloys (resistance to molten side pressure): The locking force must be greater than the component of the lateral pressure exerted by the melt on the insert: ; in, SMA locking force (unit: N), 50-80 N for nickel-titanium alloy SMA; Lateral pressure of melt on insert (unit: MPa), take 30-50 MPa; : Lateral area of ​​insert subjected to molten material impact (unit: ), calculated from the height and width of the insert; : The angle between the melt flow direction and the side of the insert (unit: °), which is 30-60°; By utilizing the thermally induced phase change properties of SMA, precise expansion and contraction of the locking pin can be achieved. This not only matches the locking force according to the characteristics of the insert groove, ensuring no lateral displacement of the insert during injection molding, but also automatically shrinks and unlocks after cooling, avoiding the demolding resistance problem of traditional mechanical locking. At the same time, the high cycle life of SMA material extends the equipment maintenance cycle.

[0026] The core formula for multimodal sensing and digital twin control mentioned above consists of the following: Insert displacement prediction formula: (displacement model under multi-field coupling) Based on the coupled effects of pressure and temperature on insert displacement, the predicted displacement satisfies: ; in, Predicted displacement of insert (unit: mm) must meet the following requirements: ; Pressure displacement coefficient (unit: mm / MPa), determined experimentally, ranging from 0.0005 to 0.001; : Deviation between actual cavity pressure and preset pressure (unit: MPa), take -5-5; Temperature displacement coefficient (unit: mm / ℃), ranging from 0.0003 to 0.0008; : Deviation between actual cavity temperature and preset temperature (unit: °C), take -3-3; Injection speed displacement coefficient (unit: mm / (mm / s)), taken as 0.0002-0.0005; : Deviation between actual injection speed and preset speed (unit: mm / s), take -5-5; Formula for process parameter correction: (based on predicted displacement control) when The hot runner temperature or injection speed needs to be adjusted. or ; in, : Hot runner temperature correction (unit: °C), take -3 to -3; Injection speed correction (unit: mm / s), take -5 to -5; Adjust the safety factor (to avoid overcorrection, take 0.7-0.9); By constructing a closed-loop system of "real-time monitoring - digital twin prediction - active correction of process parameters" using multimodal sensors, the offset trend of inserts can be predicted in advance and timely adjustment can be made, overcoming the lag of traditional feedback control and significantly reducing the offset risk caused by dynamic disturbances.

[0027] The above formula for melt pulse impact and interface anchoring core consists of the following: Time-domain formula for pulse injection pressure: (periodic impact pressure) The pulsed pressure follows a sinusoidal periodic variation, ensuring that the melt uniformly coats the insert. ; in, : Pulse pressure at any given moment (unit: MPa); : Pulse pressure reference value (unit: MPa), take 40-60; : Pulse pressure amplitude (unit: MPa), take 5-10; Pulse frequency (unit: Hz), take 10-15; Pulse injection time (unit: s), take 0.5-1.5; Formula for calculating interfacial bond strength: (mechanical interlocking + melt bonding) The interfacial shear strength is determined by both the pulse energy and the anchoring structure. ; in, Shear strength at the interface between the insert and the plastic (unit: MPa) must be ≥25; : Weld strength of the plastic melt itself (unit: MPa), 15-20 for PP / ABS; Anchoring structure reinforcement factor (and the number of pits) Positive correlation , Take 4-6). : Melt energy injected by a single pulse (unit: J). ( The volume of the melt in a single pulse. (Single pulse duration); Total volume of anchoring groove (unit: ), by the diameter of the pit (0.3-0.5mm) and depth (0.2-0.4mm) Calculated ; Through the synergistic effect of pulsed melt injection and micro-anchoring structure on the insert surface, the pulse energy can be used to make the melt more uniformly wrap the insert, and the interfacial bonding strength can be enhanced through mechanical interlocking, which fundamentally reduces the loosening or displacement of the insert caused by insufficient interfacial bonding force.

[0028] The above-mentioned phase change material (PCM) and water-cooled synergistic cooling core formula consists of the following: Synergistic cooling rate calculation formula: (balancing PCM heat storage and water cooling) The water cooling system carries away the product. The cooling rate needs to be controlled between 0.6-0.8℃ / s, as shown in the following formula: ; in, Product cooling rate (unit: ℃ / s), take 0.6-0.8; Latent heat released by PCM (unit: J). ( For PCM quality, (Latent heat of phase transition of PCM, ≥200kJ / kg). Heat carried away by the cooling water circuit (unit: J). ( The specific heat capacity of water is 4200 J / (kg・℃); For circulating water quality; (Temperature difference between water inlet and outlet) Mass of injection molded products (unit: kg); Product specific heat capacity (unit: J / (kg・℃), PP is 1900, ABS is 1800); Cooling time (unit: seconds), take 5-15; Temperature gradient control formula: (to reduce shrinkage stress) The temperature gradient at the interface between the insert and the plastic needs to be reduced by 50%, as shown in the following formula: ; in, Temperature gradient of synergistic cooling (unit: °C / mm); : Temperature of the interface between the insert and the plastic (unit: °C), take 80-100; Product outer surface temperature (unit: °C), take 40-60; Product thickness (unit: mm), range from 2 to 10; Temperature gradient of traditional water cooling (unit: ℃ / mm), take 2-4; By combining the heat storage buffer of phase change material (PCM) with forced water cooling, the interface temperature can be kept stable in the early stage of cooling to reduce stress concentration, and rapid heat dissipation can be achieved in the later stage to ensure molding efficiency. This effectively balances the cooling rate and temperature uniformity, and significantly reduces the risk of deviation during the cooling stage.

[0029] The core formula for assessing health throughout the entire life cycle consists of the following: Anti-deviation health index calculation formula: (multi-parameter weighted score) Health Index The score is obtained by weighting the status of key components, with a maximum score of 100. ; in, Health Index (unit: points) This is normal. Maintenance triggered; , , Weighting coefficients (satisfying) SMA locking is the core technology; adsorption is the foundation; and sensors provide assurance. ); The SMA locking pin has been cycled a certain number of times. The fatigue life of SMA (≥100,000 cycles); Vacuum leakage of bionic suction cup (unit: Pa). The maximum permissible leakage rate (≤500Pa); Sensor drift (unit: mm) Maximum allowable drift (≤0.001mm); Maintenance priority calculation formula: (determines the components to be maintained first) Maintenance priority Positively correlated with component failure risk: ; in, Component maintenance priority (higher value, higher priority); : No. Sub-health of individual components (e.g., SMA sub-health) ); : No. Failure impact coefficient of individual components (SMA failure has the greatest impact; suction cup) ;sensor ); By constructing a health assessment model, the status of key components is monitored in real time and maintenance is automatically triggered. At the same time, blockchain is used to achieve traceability of quality data, which not only avoids batch deviation problems caused by hidden component failures, but also extends the overall life of the equipment and ensures the stability of long-term production.

[0030] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claimed invention.

Claims

1. A method for preventing displacement of in-mold injection molded inserts, characterized in that: The method includes the following steps: S1. Construction of the biomimetic gradient adsorption and magneto-precision positioning system: Multiple micro-nano-scale biomimetic suction cups are integrated at the bottom of the insert, and rare earth permanent magnets are embedded in the center of the suction cups; electromagnetic coil arrays and vacuum channels are set on the corresponding mold positioning surfaces. S2. Shape memory alloy adaptive locking mechanism design: Multiple sets of nickel-titanium alloy SMA locking pins are embedded in the side wall of the mold cavity. The head of the locking pin is provided with a hemispherical protrusion, which matches the positioning groove of the insert. S3. Construction of Multimodal Sensing and Digital Twin Real-time Control System: Fiber Bragg grating sensors are deployed to monitor the strain of the inserts, an infrared thermal imager captures the temperature field distribution at the interface, and a microwave radar scans the three-dimensional position of the inserts in real time to generate real-time data. S4. Melt pulse impact and interface anchoring co-molding process: During the injection stage, the melt is controlled by a servo valve to be injected in a pulsed manner at a frequency of 10-15Hz. The pulse shock wave is used to make the melt more uniformly wrap the insert; at the same time, a micro-anchoring structure is preset on the surface of the insert. S5. Phase change material and water circuit synergistic temperature control and cooling system: A shaped phase change material is embedded in the area around the mold insert to form a composite temperature control system with the traditional cooling water circuit. S6. Full life cycle health assessment and self-maintenance system: The system has a built-in anti-displacement health index model, which comprehensively evaluates the equipment status based on the following parameters: SMA lock pin fatigue, bionic suction cup wear, and sensor drift value.

2. The method for preventing displacement of in-mold injection molded inserts according to claim 1, characterized in that: The temperature control and cooling system in S5 includes a phase change material energy storage module, a cooling water circuit module, a micro-stirring drive module, and a temperature monitoring and feedback module. The phase change material energy storage module is composed of paraffin-based PCM, a sealed PCM cavity, and high-temperature resistant sealant; the PCM filling rate is ≥95%, and the cavity thermal conductivity is ≥15W / (m・K); The cooling water circuit module consists of a spiral copper cooling water pipe, a water circuit diversion valve, a water temperature controller, and a circulating water pump; the water temperature control range is 20-25℃, the water circuit pressure is 0.3-0.5MPa, and the distance between the cooling water pipe and the PCM cavity is ≤5mm. The micro stirring drive module consists of a micro DC motor, plastic stirring blades, and a motor mounting bracket; the motor operates in a temperature range of -10 to 120°C, and the stirring blades have a service life of ≥10,000 hours. The temperature monitoring feedback module consists of 3 sets of PT100 platinum resistance temperature sensors, a data acquisition unit, and a central controller; the sensor response time is ≤1s and the data transmission delay is ≤100ms.

3. The method for preventing displacement of in-mold injection molded inserts according to claim 2, characterized in that: The sealed cavity of the phase change material energy storage module is directly attached to the cavity wall surface around the mold insert; The spiral water pipes of the cooling water circuit module are arranged around the cavity of the PCM energy storage module. The motor of the micro stirring drive module is embedded in the top of the cavity of the PCM energy storage module through a bracket, and the stirring blades extend into the PCM. The three PT100 sensors of the temperature monitoring feedback module are respectively inserted into: the PCM energy storage module, the mold insert-plastic interface, and the water pipe of the cooling water circuit module; the PT100 sensors of the temperature monitoring feedback module are connected to the data acquisition unit through shielded signal lines, and the acquisition unit then establishes data communication with the central controller through Ethernet to transmit temperature data in real time. The central controller is connected to the water circuit diversion valve and circulating water pump of the cooling water circuit module through the relay output terminal, and controls the start and stop of the water circuit and the water flow rate according to the temperature data; the central controller is connected to the DC motor of the micro stirring drive module through the PWM signal output terminal, and starts stirring when the PCM temperature drops to the phase change point, and stops stirring when the temperature is below 50°C; the central controller has no direct control connection with the PCM energy storage module, and only indirectly judges the working status of the PCM through temperature data.

4. The method for preventing displacement of in-mold injection molded inserts according to claim 1, characterized in that: The core formula of the biomimetic gradient adsorption and magnetostrictive prepositioning system consists of the following: Formula for calculating the total adsorption force of a bionic suction cup: The biomimetic suction cup's adsorption force is jointly formed by negative pressure adsorption force and biomimetic ring-pattern surface tension, as shown in the following formula: ； in, The total adsorption force of the bionic suction cup must meet the following requirements. ; : Suction cup adsorption efficiency coefficient; Vacuum degree, range of values; The effective adsorption area of ​​the suction cup is determined by the diameter of the suction cup. Calculated ; : Surface tension coefficient of the ring pattern; : Circumference of a single ring; : The interfacial tension between the plastic melt and the suction cup surface, 0.035-0.045 for PP / ABS materials; By integrating the negative pressure adsorption force of the biomimetic suction cup with the surface tension of the ring pattern, the total adsorption force that can balance the initial impact of the melt is quantitatively calculated, ensuring that the insert is not displaced by the impact of the melt in the early stage of injection molding. Formula for calculating magnetostrictive prepositioning correction: The displacement of the magnetic torque driven insert for correction satisfies: ； in, Magnetostricted displacement must meet the following requirements. ; : magnetic square; Calibration time; Insert mass is calculated from the insert volume and density; : The distance from the point of application of the magnetic torque to the center of mass of the insert; By using parameters such as magnetic torque, correction time, and insert mass, the correction displacement of the insert under magnetostrictive drive is quantitatively calculated, enabling precise adjustment of the insert from "initial offset" to "coarse positioning qualified".

5. A method for preventing displacement of in-mold injection molded inserts according to claim 1, characterized in that: The adaptive locking core formula of the shape memory alloy consists of the following: Formula for calculating the thermal elongation of shape memory alloy lock pins: The elongation of shape memory alloys (SMA) at the phase transformation temperature satisfies: ； in, The elongation of the SMA lock stop pin must be equal to the depth of the insert positioning groove; Original length of SMA lock pin; Maximum thermal strain during SMA austenitic phase transformation; SMA operating temperature; SMA martensitic phase transformation temperature; SMA austenitic phase transformation temperature; Based on the phase change characteristics, operating temperature and original length of SMA, the thermal elongation of the locking pin is quantitatively calculated to ensure that the locking pin can be accurately embedded into the positioning groove of the insert to form a mechanical lock. Formula for calculating the locking force of shape memory alloys: The locking force must be greater than the component of the lateral pressure exerted by the melt on the insert: ； in, SMA locking force: 50-80N for nickel-titanium alloy SMA; : Lateral pressure of the melt on the insert; The lateral area of ​​the insert subjected to molten impact is calculated from the insert's height and width. The angle between the melt flow direction and the side of the insert; By using parameters such as melt side pressure and insert side area, the minimum locking force required by the SMA locking pin is quantitatively calculated to ensure that the insert can resist melt side pressure and not shift laterally during injection molding.

6. The method for preventing displacement of in-mold injection molded inserts according to claim 1, characterized in that: The core formula for multimodal sensing and digital twin control consists of the following: Insert displacement prediction formula: Based on the coupled effects of pressure and temperature on insert displacement, the predicted displacement satisfies: ； in, The insert's predicted displacement must meet the following requirements. ; Pressure displacement coefficient, determined experimentally; The deviation between the actual pressure in the cavity and the preset pressure; Temperature displacement coefficient; The deviation between the actual temperature of the cavity and the preset temperature; Injection speed displacement coefficient; The deviation between the actual injection speed and the preset speed; By integrating multiple parameters such as melt pressure, cavity temperature, and injection speed, the potential displacement of inserts during injection molding can be quantitatively predicted, and displacement risks can be identified in advance. Formula for process parameter correction: when The hot runner temperature or injection speed needs to be adjusted. or ; in, : Hot runner temperature correction amount; Injection speed correction amount; Adjusting the safety factor; When the predicted displacement exceeds the safety threshold, the correction amount for the hot runner temperature or injection speed is quantitatively calculated to ensure that the insert offset can be pulled back to the safe range through parameter adjustment.

7. A method for preventing displacement of in-mold injection molded inserts according to claim 1, characterized in that: The core formula for melt pulse impact and interface anchoring consists of the following: Pulse injection pressure time-domain formula: The pulsed pressure follows a sinusoidal periodic variation, ensuring that the melt uniformly coats the insert. ； in, : The pulse pressure at any given moment; : Pulse pressure reference value; : Pulse pressure amplitude; Pulse frequency; : Pulse injection time; Determine the periodic change pattern of pressure during pulse injection to ensure that the melt uniformly encapsulates the insert in a pulsed impact manner, while avoiding continuous high pressure impact on the insert; Formula for calculating interfacial bonding strength: The interfacial shear strength is determined by both the pulse energy and the anchoring structure. ； in, Shear strength at the interface between the insert and the plastic; : The weld strength of the plastic melt itself; : Anchoring structure reinforcement coefficient; : Melt energy injected by a single pulse; The total volume of the anchoring groove is determined by the diameter of the pit. and depth Calculated ; By integrating the melt weld strength with the reinforcing effect of the anchoring structure, the interfacial shear strength between the insert and the plastic is quantitatively calculated to ensure a firm bond between the two and avoid insert displacement due to interfacial separation in the later stage.

8. A method for preventing displacement of in-mold injection molded inserts according to claim 1, characterized in that: The core formula for the synergistic cooling of phase change materials and water channels consists of the following: Formula for calculating synergistic cooling rate: The cooling rate needs to be controlled between 0.6-0.8℃ / s, as shown in the following formula: ； in, Product cooling rate; The latent heat released by PCM; The heat carried away by the cooling water system; Injection molded product quality; Product specific heat capacity; Cooldown time; By integrating the latent heat released by the PCM and the heat carried away by the water circuit, the cooling rate of the product is quantitatively calculated to balance the needs of rapid cooling for efficiency improvement and slow cooling for stress reduction. Temperature gradient control formula: The temperature gradient at the interface between the insert and the plastic needs to be reduced by 50%, as shown in the following formula: ； in, Temperature gradient for synergistic cooling; : Temperature at the interface between the insert and the plastic; : Product outer surface temperature; Product thickness; Temperature gradient in traditional water cooling; Quantitatively calculate the temperature gradient between the insert and the plastic interface and the product surface to ensure uniform temperature distribution during cooling and reduce shrinkage stress caused by excessive temperature difference (shrinkage stress will pull the insert off-center).

9. A method for preventing displacement of in-mold injection molded inserts according to claim 1, characterized in that: The core formula for assessing health throughout the entire life cycle consists of the following: Formula for calculating the anti-deviation health index: Health Index The score is obtained by weighting the status of key components, with a maximum score of 100. ； in, Health Index This is normal. Maintenance triggered; , , Weighting coefficient; The SMA locking pin has been cycled a certain number of times. For SMA fatigue life; Vacuum leakage of the bionic suction cup The maximum permissible leakage rate; Sensor drift amount Maximum allowable drift; By integrating SMA fatigue status, bionic suction cup wear degree, and sensor drift, the anti-deviation health of the system is quantitatively calculated to determine whether the system still possesses stable anti-deviation capabilities. Maintenance priority calculation formula: Maintenance priority Positively correlated with component failure risk: ； in, Component maintenance priority; : No. Sub-health of each component; : No. Failure impact coefficient of each component; When the health status is not up to standard, the maintenance priority of each failed component is quantitatively calculated to determine the repair sequence of the components and avoid prolonged downtime caused by disordered maintenance.

Images