A foaming and shaping production control system and production line for refrigerator insulation boards

Abstract

This application relates to the field of industrial automation control and discloses a foaming and shaping production control system and production line for refrigerator insulation panels. The system includes a physical execution unit and a logic control unit. The logic control unit collects the initial temperature deviation of the mold and uses a multi-dimensional enthalpy compensation algorithm to control the injection machine to simultaneously adjust the mixing pressure and injection quality, achieving adaptive compensation of source heat energy. A virtual curing integral tracking model is established to calculate the cumulative curing degree of the mold in the oven in real time, and combined with the production line speed clamping coordination module, the guide rail running speed is dynamically adjusted according to the slowest curing requirement. At the oven exit, the product status is determined by the quality arbitration module, and the offline curing mechanism is controlled to physically divert and remedy under-cured molds. This invention solves the problem of curing quality fluctuation caused by differences in mold thermal state and achieves a dynamic balance between production efficiency and foaming quality.

Description

Technical Field

[0001] This invention relates to the field of industrial automation control, specifically to a foaming and shaping production control system and production line for refrigerator insulation boards. Background Technology

[0002] In the manufacturing process of refrigerators, the quality of polyurethane foaming in the insulation layer directly determines the product's energy efficiency rating and structural strength. Existing foaming production lines typically employ a circular, circulating layout, with the mold sequentially passing through the injection station, tunnel oven curing zone, and demolding station. The production control system usually sets the production line speed, injection volume, and oven temperature to fixed values ​​based on a preset process formula to maintain continuous production.

[0003] However, this fixed-parameter control mode heavily relies on the consistency of the initial thermal state of the mold. In actual production, due to variations in ambient temperature, temporary production line shutdowns, or fluctuations in mold turnover cycles, molds arriving at the injection station often exhibit significant surface temperature differences. When the mold temperature is too low, its metal body absorbs a large amount of heat from the initial stage of the polyurethane chemical reaction, leading to slow foaming, excessively high skin density, and even shrinkage deformation. Because traditional injection equipment can only perform a single quantitative output, it cannot dynamically compensate for the enthalpy deficiency of individual molds, resulting in poor product consistency. Furthermore, since tunnel ovens are enclosed heating spaces, the control system cannot know the real-time curing process of the molds within the oven. It often has to reduce the overall line speed to extend the heating time to ensure that even the most difficult-to-cured molds meet the demolding requirements. This "lower is better" speed control strategy greatly limits the overall economic capacity of the production line. At the same time, once under-curing occurs, the existing production process lacks a targeted diversion and remedial mechanism, usually requiring the demolded deformed products to be scrapped directly, resulting in high production cost losses.

[0004] Therefore, this invention proposes a foaming and shaping production control system and production line for refrigerator insulation boards to overcome the shortcomings of the prior art. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides a foaming and shaping production control system and production line for refrigerator insulation boards, which solves the problems of poor foaming quality consistency and low production line operating efficiency caused by differences in the initial thermal state of the molds and fixed process parameter modes in existing refrigerator foaming production lines.

[0006] To achieve the above objectives, the present invention provides the following technical solution: a foaming and shaping production control system for refrigerator insulation boards, comprising a physical production execution unit and a logic control unit;

[0007] The physical production execution unit includes a ring-shaped circulating conveyor rail, a mold transport trolley, an intelligent variable pressure and variable flow injection machine, a tunnel-type constant temperature curing oven, and an offline curing and demolding arbitration execution mechanism.

[0008] The logic control unit includes a central control module, which is configured with:

[0009] The thermal state data acquisition module is used to collect the surface temperature of the mold and generate an initial state data package for the mold.

[0010] The multidimensional enthalpy compensation calculation module is used to calculate the injection pressure correction value and injection quality correction value based on the initial temperature deviation, and control the intelligent variable pressure and variable current injection machine to perform physical and chemical thermal energy gain compensation.

[0011] The virtual curing integral tracking module is used to construct a virtual mapping queue and calculate the current cumulative degree of curing in the oven mold;

[0012] The production line speed clamping coordination module is used to calculate the theoretical line speed based on the remaining curing requirements of the mold and generate the running speed command of the annular circulating conveyor rail in combination with the minimum economic production capacity speed.

[0013] The export quality arbitration module is used to compare the final curing degree value with the standard demolding threshold and control the offline curing and demolding arbitration execution mechanism to perform the mold opening permission or forced mold closing offline action.

[0014] Preferably, the thermal state data acquisition module collects the measured surface temperature of the mold to be foamed in a non-contact manner using an infrared thermal state sensing sensor, and calculates the difference between the measured surface temperature and the preset standard process reference temperature to obtain the initial temperature deviation; the thermal state data acquisition module also binds the initial temperature deviation with the identification mark and timestamp of the mold transport trolley to generate the initial state data package of the mold.

[0015] Preferably, the multidimensional enthalpy compensation calculation module performs the following control based on the initial temperature deviation when it determines that the mold of the cold cabinet to be foamed is in a cold mold state: based on the principle of fluid dynamics energy conversion, it calls the pressure compensation algorithm to calculate the mixing pressure setpoint, and adjusts the back pressure by controlling the position of the throttling valve core of the intelligent variable pressure and variable flow injection machine to increase the physical shear heat; based on the principle of exothermic chemical reaction, it calls the mass compensation algorithm to calculate the injection mass setpoint, and increases the total amount of reactant by controlling the operation of the metering pump of the intelligent variable pressure and variable flow injection machine to increase the chemical reaction heat.

[0016] Preferably, the virtual curing integral tracking module establishes a virtual shift register queue in the controller's memory that maps to the length of the tunnel-type constant temperature curing oven; the virtual curing integral tracking module reads the physical position coordinates of the mold transport trolley in real time, and indexes the corresponding microenvironment temperature value in the pre-stored oven temperature field map, and converts the microenvironment temperature value into the simulated reaction temperature of the mold cavity through a thermal conductivity correction algorithm.

[0017] Preferably, the virtual curing integral tracking module adopts discrete integral logic based on the Arrhenius model, takes the controller's scan cycle as the time step, uses the simulated reaction temperature to iteratively calculate the curing increment generated in each scan cycle, and adds the curing increment to the current cumulative curing degree value until the mold to be foamed is removed from the tunnel constant temperature curing oven.

[0018] Preferably, the production line speed clamping coordination module performs a full queue scan and uses inverse kinematics to obtain the theoretical allowable speed of each monomer that meets the condition of complete curing upon exiting the furnace; the production line speed clamping coordination module performs minimum value screening logic to select the lowest quality priority theoretical speed from all the theoretical allowable speeds of monomers in the furnace.

[0019] Preferably, the production line speed clamping coordination module compares and arbitrates the quality-priority theoretical speed with the preset minimum economic production capacity speed, and selects the larger value as the final running speed command sent to the annular circulating conveyor rail; when the quality-priority theoretical speed is less than the minimum economic production capacity speed, the system forces the system to run at the minimum economic production capacity speed and generates an under-ripening warning sign which is transmitted to the export quality arbitration module.

[0020] Preferably, the export quality arbitration module triggers a verification when the mold to be foamed in the cold cabinet reaches the exit of the tunnel-type constant temperature curing oven; if the final curing degree value is greater than or equal to the standard demolding threshold, it is determined to be an online qualified product and a mold opening permission signal is sent; if the final curing degree value is less than the standard demolding threshold, it is determined to be a product to be remedied, a forced mold closing alarm signal is sent, and the mold to be foamed in the cold cabinet is diverted to the offline curing buffer station.

[0021] Preferably, for the foamed refrigerator mold determined to be a product requiring remediation, the export quality arbitration module calculates the offline remediation time based on the current factory workshop ambient temperature and the amount of curing deficiency through inverse reaction kinetics calculation; the system locks the offline curing and demolding arbitration execution mechanism until the static time of the foamed refrigerator mold in the offline state reaches the offline remediation time, after which the lock is released and manual mold opening is allowed.

[0022] Preferably, the infrared thermal state sensing sensor is located upstream of the intelligent variable pressure and variable flow injection machine, the tunnel-type constant temperature curing oven is located downstream of the intelligent variable pressure and variable flow injection machine and covers the straight section of the annular circulating conveyor rail, and the offline curing and demolding arbitration execution mechanism is located at the outlet of the tunnel-type constant temperature curing oven.

[0023] This invention provides a foaming and shaping production control system and production line for refrigerator insulation boards. It has the following beneficial effects:

[0024] 1. This invention acquires the initial temperature deviation of the mold through a thermal state data acquisition module and directly correlates it with the execution parameters of the intelligent variable pressure and variable flow injection molding machine using a multi-dimensional enthalpy compensation calculation module. During the injection and mixing stage, the system increases physical shear heat by increasing the mixing pressure and simultaneously increases the injection mass to compensate for the heat of chemical reaction. This adjustment mechanism compensates for the heat sink effect caused by the low-temperature mold. This design allows the system to begin production without waiting for mold preheating, ensuring that molds under different thermal states can obtain a relatively consistent foaming and expansion curve, effectively improving quality defects such as excessively high skin density or foam shrinkage caused by mold temperature fluctuations.

[0025] 2. This invention utilizes a virtual curing integral tracking module to establish a mapping of the curing state inside the oven, solving the technical problem of difficulty in real-time monitoring of the internal curing progress in closed ovens. Combined with a production line speed clamping and coordination module, the system can identify the mold with the highest curing demand in the current queue and adjust the running speed of the circular conveyor rail accordingly to ensure that the curing process requirements of that mold are met; simultaneously, a minimum economic production capacity speed is introduced as a lower limit clamping to prevent the overall line speed from being too low due to individual operating conditions. This control logic transforms a fixed production cycle into a variable cycle that is dynamically adjusted based on the curing state, improving the overall operating efficiency of the production line while ensuring the quality of foaming and curing.

[0026] 3. This invention optimizes the handling of under-cured products on traditional production lines by coordinating the export quality arbitration module with the offline curing execution mechanism. When increasing production line speed to maintain capacity leads to insufficient curing of some molds, the system can calculate the required natural recovery time for the product under the workshop ambient temperature based on the reaction kinetic model and guide physical diversion. This mechanism decouples the strict chemical curing time from the physical production cycle, transforming potentially scrapped products into controlled qualified products, significantly reducing the production scrap rate. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of the overall structure of the present invention;

[0028] Figure 2 This is a schematic diagram of the system architecture of the present invention;

[0029] Figure 3 This is a flowchart of the injection control logic based on multidimensional enthalpy compensation of the present invention.

[0030] Figure 4 This is a schematic diagram of the virtual solidified integral tracking logic of the present invention;

[0031] Figure 5 This is a flowchart of the production line speed clamping collaborative control logic of the present invention;

[0032] Figure 6 This is a flowchart of the export diversion decision and offline remediation process of the present invention.

[0033] Among them, 1. Circular circulating conveyor rail; 2. Mold transport trolley; 3. Mold for foaming freezer; 4. Intelligent variable pressure and variable flow injection machine; 5. Tunnel-type constant temperature curing oven;

[0034] 101. Thermal state data acquisition module; 102. Multidimensional enthalpy compensation calculation module; 103. Virtual solidification integral tracking module; 104. Production line speed clamping coordination module; 105. Export quality arbitration module. Detailed Implementation

[0035] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0036] See attached document Figure 1 The present invention provides a production system capable of adaptive dynamic compensation and quality arbitration for molds with different initial thermal states. The system includes two main parts: a physical production execution unit and a logic control unit.

[0037] The main structure of the physical production execution unit is composed of a ring-shaped circulating conveyor rail 1. The ring-shaped circulating conveyor rail 1 is laid on the floor of the production workshop to form a closed circular logistics path. Multiple mold transport trolleys 2 are arranged at intervals on the ring-shaped circulating conveyor rail 1. The bottom of the mold transport trolley 2 is equipped with a set of walking wheels and a drive mechanism that cooperate with the guide rail, which are used to carry the molds 3 of the refrigerator to be foamed to move along the process route. The ring-shaped circulating conveyor rail 1 is divided into a feeding area, a filling area, a curing area and a discharging area in sequence.

[0038] An intelligent variable pressure and variable flow injection machine 4 is installed on one side of the injection area. The intelligent variable pressure and variable flow injection machine 4 is equipped with a dual-component independent metering pump group for black and white materials and a mixing head. Its hydraulic drive system and flow regulating valve are controlled by electrical signals and can receive external commands to change the output mixing pressure value and injection flow rate value. An infrared thermal state sensing sensor is installed upstream of the intelligent variable pressure and variable flow injection machine 4, directly opposite the running path of the mold transport trolley 2. The infrared thermal state sensing sensor is used to collect the surface temperature data of the mold 3 to be foamed before injection in a non-contact manner.

[0039] A tunnel-type constant temperature curing oven 5 is installed in the middle section of the production line. The tunnel-type constant temperature curing oven 5 has a long and narrow channel structure, covering most of the length of the annular circulating conveyor rail 1, forming a closed heating and insulation space. Temperature acquisition probes and heating actuators are arranged inside the tunnel-type constant temperature curing oven 5 to maintain the constant ambient temperature required for foaming and curing. At the outlet of the tunnel-type constant temperature curing oven 5, i.e., the unloading area, an offline curing and demolding arbitration execution mechanism is set up. The offline curing and demolding arbitration execution mechanism includes an audible and visual alarm indicator and a mold opening and closing locking device, which is used to perform physical actions to grant mold opening permission or force mold closing offline.

[0040] The logic control unit is centered on the central control module. Its electrical input terminals are electrically connected to the infrared thermal state sensing sensor, the temperature probe inside the tunnel-type constant temperature curing oven 5, and the encoder used to detect the position and speed of the mold transport trolley 2, respectively. Its electrical output terminals are electrically connected to the controller of the intelligent variable voltage and variable current injection machine 4, the heating controller of the tunnel-type constant temperature curing oven 5, the frequency converter of the annular circulating conveyor rail 1, and the offline curing and demolding arbitration execution mechanism, respectively.

[0041] See attached document Figure 2 The central control module is internally divided into multiple modules based on functional logic, including:

[0042] The thermal state data acquisition module 101 is configured to receive the mold surface temperature signal from the infrared thermal state sensing sensor in real time, and simultaneously acquire the ambient temperature data and the internal temperature data of the oven. The thermal state data acquisition module 101 converts the acquired analog quantity into a digital quantity signal, and establishes a unique one-to-one correspondence index relationship with the specific mold 3 to be foamed in the cold cabinet that passes through the position on the time axis, and generates a mold initial state data packet with an independent ID.

[0043] The multidimensional enthalpy compensation calculation module 102 calculates the injection pressure correction value and injection quality correction value for the specific mold based on the initial temperature deviation of the mold through a preset compensation algorithm. The correction command is directly sent to the intelligent variable pressure and variable flow injection machine 4, so that when the intelligent variable pressure and variable flow injection machine 4 performs injection on the mold, it outputs a polyurethane mixture with specific physical shear heat and chemical reaction heat increment.

[0044] The virtual curing integral tracking module 103 is configured to establish a virtual shift register queue mapped to the physical production line. When the mold 3 to be foamed enters the tunnel-type constant temperature curing oven 5, the virtual curing integral tracking module 103 periodically updates and calculates the current cumulative curing degree value of each mold in the oven based on the real-time ambient temperature and time integral algorithm, and predicts the remaining time required to achieve complete curing.

[0045] The production line speed clamping coordination module 104 scans the remaining curing requirements of all molds in the queue in real time and calculates the theoretical linear speed of the mold that meets the slowest curing requirements. At the same time, the production line speed clamping coordination module 104 introduces the minimum economic production capacity speed as the clamping lower limit and generates the final running speed command of the annular circulating conveyor rail 1 under the premise of ensuring that the production efficiency is not lower than the preset threshold.

[0046] The export quality arbitration module 105 is configured in the end logic of the production line. When the mold 3 of the cold cabinet to be foamed reaches the outlet of the tunnel constant temperature curing oven 5, the export quality arbitration module 105 reads the final curing degree value of the mold in the virtual curing integral tracking module 103. The export quality arbitration module 105 compares the value with the standard demolding threshold. If the value is greater than or equal to the threshold, it sends a demolding opening signal to the offline curing and demolding arbitration execution mechanism. If the value is less than the threshold, it sends a forced mold closing alarm signal, calculates the time required for offline reheating, and prompts manual offline processing.

[0047] Through the coordinated operation of the above modules, the system achieves closed-loop control of the entire process, from material injection source compensation to process speed adjustment and final quality control.

[0048] See attached document Figures 1-2 This invention proposes a foaming and shaping production control system for refrigerator insulation panels. The physical execution terminal and logic control center of the system are constructed into a real-time closed-loop architecture through an industrial fieldbus network. A circular conveyor rail 1 serves as the basic logistics carrier, laid on the floor of the industrial production workshop, its path forming a racetrack-shaped or rectangular loop structure. Multiple mold transport trolleys 2 are mounted on the circular conveyor rail 1 via mechanical guide wheel sets. A refrigerator mold 3 to be foamed is rigidly connected above the mold transport trolley 2. Radio frequency identification tags or barcode labels are installed on the sides of the mold transport trolley 2 to store static attribute characteristic data including mold model, mold wall thickness, and polyurethane design filler quantity.

[0049] The intelligent variable pressure and variable flow feeder 4 is arranged on the process start side of the annular circulating conveyor rail 1. The intelligent variable pressure and variable flow feeder 4 integrates an isocyanate (black material) metering pump group and a polyether (white material) metering pump group. Both metering pumps are driven by independent high-response servo motors. This servo drive mechanism forms the basis for the injection flow rate regulation. By changing the speed of the servo motor, the output mass flow rate of each component is directly controlled. The end of the intelligent variable pressure and variable flow feeder 4 is connected to a mixing head device. The mixing head device is equipped with a hydraulically driven throttle valve core. The stroke position of the throttle valve core determines the nozzle flow cross-sectional area when the black and white materials collide and mix. By jointly controlling the metering pump speed and the throttle valve core position, the intelligent variable pressure and variable flow feeder 4 has the decoupled control capability to change the mixing pressure under the same injection volume or change the injection flow rate under the same mixing pressure.

[0050] The tunnel-type constant temperature curing oven 5 extends along the straight section of the annular circulating conveyor rail 1, creating a physically isolated heating space. The inner wall of the tunnel-type constant temperature curing oven 5 is equipped with infrared radiation heating tubes or hot air circulation vents in sections, and multiple temperature thermocouples are distributed at intervals at different lengths to collect the temperature distribution gradient along the inside of the oven.

[0051] In terms of communication topology, the system adopts an Ethernet-based industrial real-time communication protocol (such as PROFINET, EtherCAT, or EtherNet / IP). The thermal state data acquisition module 101, the multi-dimensional enthalpy compensation calculation module 102, the virtual curing integral tracking module 103, the production line speed clamping coordination module 104, and the export quality arbitration module 105 actually reside in the memory of the central programmable logic controller (PAC) or industrial control computer (IPC), and execute the corresponding logic through the processor. This controller establishes full-duplex digital communication connections via fieldbus with the infrared thermal state sensing sensor installed beside the circular conveyor rail 1, the PLC controller of the intelligent variable pressure and variable flow injection machine 4, the temperature control instrument of the tunnel-type constant temperature curing oven 5, and the absolute encoder used for positioning the mold transport trolley 2.

[0052] The thermal state data acquisition module 101, as the front-end sensing unit of the system, does not operate by simply reading data, but by executing a composite sensing method that includes identity recognition, environmental calibration, and thermal defect quantification. Specifically, it includes the following execution steps:

[0053] S101, when the mold transport trolley 2 carrying the foaming refrigerator mold 3 travels to the preset station near the intelligent variable pressure and variable flow injection machine 4, the RFID reader arranged next to the track reads the identification tag on the mold transport trolley 2 to obtain the unique serial number of the current mold. and the corresponding standard process reference temperature The standard process reference temperature It is a constant based on 25℃ or the optimal foaming reaction initiation temperature set by the process.

[0054] S102, the infrared thermal state sensing sensor starts the measurement program; to eliminate measurement errors caused by the emissivity of the metal mold surface, the thermal state data acquisition module 101 has a preset emissivity correction coefficient. The infrared thermal state sensing sensor performs multi-point scanning on the outer surface and inner cavity surface of the mold 3 to be foamed, and collects a set of raw surface temperature values. After arithmetic averaging or weighted averaging, the effective surface temperature of the mold is generated. .

[0055] S103, Thermal state data acquisition module 101 synchronously reads the ambient air temperature at the inlet of tunnel-type constant temperature curing oven 5. And the temperature of the black material in the four tanks of the intelligent variable pressure and variable flow feeder. With white material temperature This type of environmental and raw material temperature data belongs to auxiliary thermodynamic parameters and is used for subsequent system verification to determine whether the limits of permissible operation are exceeded.

[0056] S104, the thermal state data acquisition module 101 calculates the current mold based on the acquired valid data. The thermal deviation relative to the standard process conditions; instead of directly using a simple temperature difference, a quantitative index of enthalpy loss is introduced to calculate the initial temperature deviation of the mold. Its calculation method follows the following logical relationship:

[0057] ;

[0058] In the formula, This is the standard process reference temperature. For the first Measured effective surface temperature of the mold.

[0059] S105, the thermal state data acquisition module 101 calculates the initial temperature deviation. With mold serial number Binding generates an initial state data packet containing a timestamp, which is written to the controller's shared data block area as the sole input reference for subsequent feedforward control calculations by the multidimensional enthalpy compensation calculation module 102; when When this occurs, it indicates that the mold surface temperature is lower than the standard process reference temperature, and the system determines that positive enthalpy compensation is required; when When the temperature is within or above the standard, the system determines that no compensation is needed or that only standard injection parameters need to be maintained. This logic eliminates the risk of over-reaction caused by mold overheating, ensuring that subsequent algorithms only perform targeted corrections for thermal defects.

[0060] See attached document Figure 3 This invention implements an active control method based on a multi-dimensional enthalpy compensation calculation module 102 at the injection station of a foaming production line. This method quantifies the thermal defects of the mold and converts them into incremental compensation for the injection process parameters, thereby achieving source control of foaming quality. The multi-dimensional enthalpy compensation calculation module 102 is built into the core processor of the control system, and its specific control logic and execution process include the following steps:

[0061] S201, the multidimensional enthalpy compensation calculation module 102 receives the thermal state data acquisition module 101, which includes the initial temperature deviation. The data package; the multidimensional enthalpy compensation calculation module 102 has a preset enthalpy compensation threshold band for the current production formula system, when When the temperature is within the preset positive deviation range (i.e., the mold temperature is lower than the standard temperature but has not reached the rejection limit), the system activates the dual-gain calculation program. This program aims to solve the problems of reaction lag and excessively high skin density in the foaming system caused by the low temperature mold interface by artificially introducing additional physical and chemical heat energy to achieve balance.

[0062] S202, Perform physical enthalpy compensation calculation. This step is based on the energy conversion principle in fluid mechanics, utilizing the physical property of converting kinetic energy into internal energy through shear friction heat generated by high-pressure jet impact; the multidimensional enthalpy compensation calculation module 102 calls the pressure compensation algorithm to calculate the required mixing pressure setpoint of the intelligent variable pressure and variable flow injection machine 4. To overcome the rapid cooling effect of the low-temperature mold on the mixture flow, it is necessary to increase the initial internal energy of the mixture the instant it leaves the mixing head. The specific pressure control model is as follows:

[0063] ;

[0064] In the formula, Indicates that for the first The modified mixing injection pressure command value for each mold; Indicates the reference mixing pressure under standard process conditions; This represents the initial temperature deviation of the mold. The pressure-enthalpy conversion coefficient is derived experimentally from the viscosity-temperature characteristics of polyurethane material and the throttling characteristic curve of the mixing head nozzle. It characterizes the pressure gain ratio that needs to be compensated per unit temperature difference.

[0065] S203, Perform chemical enthalpy compensation calculation. This step is based on the chemical thermodynamic principle that polyurethane foaming is an exothermic reaction. When the mold absorbs heat too quickly, leading to effective heat loss, the system increases the total mass of the reactants, utilizing the additional total heat generated by the increased reactants to offset the heat sink effect of the mold. The multidimensional enthalpy compensation calculation module 102 calls the mass compensation algorithm to calculate the required injection mass setpoint. This quality correction is not a simple increase in volume filler, but rather a measure to ensure sufficient reaction core temperature is maintained during curing. The specific quality control model is as follows:

[0066] ;

[0067] In the formula, Indicates that for the first The corrected total mass instruction value for injection molding of each mold; Indicates the baseline injection quality under standard process conditions; It is the chemical enthalpy compensation coefficient, which is related to the reaction heat value of the black and white material system and the specific heat capacity of the mold material. It is used to quantify the proportion of additional reactants that need to be added under a unit temperature difference.

[0068] S204 generates low-level execution instructions and drives hardware actions. The multi-dimensional enthalpy compensation calculation module 102 calculates the... and The signal is converted into a servo control signal recognizable by the intelligent variable pressure and variable flow feeder 4. To achieve decoupled control of pressure and flow (mass), the system controls the hydraulic throttle valve core on the mixing head to move in the direction of reducing the flow cross-sectional area, thereby maintaining or increasing the pumping flow while building higher back pressure. The physical heat compensation target is achieved; simultaneously, the system controls the integral speed or action time of the metering pump servo motor to ensure that the total material output within a single filling cycle reaches the target. To achieve the goal of chemical heat compensation.

[0069] Through the above steps, the system actively counteracts the "cold effect" of the mold at the moment of injection, so that the foam mixture injected into the mold cavity has a higher initial energy density than the standard state. This ensures that even when the mold temperature is low, the foaming reaction can still proceed according to the expected foaming curve, avoiding quality defects such as insufficient material, hollow areas, or loose skin.

[0070] See attached document Figure 4This invention incorporates a virtual curing integral tracking module 103 within the logic control unit. This module aims to address the technical challenge of the tunnel-type constant temperature curing oven 5 being essentially a black box, making it impossible to directly measure the foaming and curing state. The virtual curing integral tracking module 103 does not rely on physical sensors directly contacting the mold. Instead, it constructs a virtual mapping data queue synchronized with the physical production line and performs real-time calculations using rheological and chemical reaction kinetic principles. Its specific operation and data processing logic include the following steps:

[0071] S301, construct a virtual shift register queue. The virtual curing integral tracking module 103 allocates a first-in-first-out (FIFO) shift register space in the controller's memory stack. The length of this register space is mapped to the effective station length of the tunnel-type constant temperature curing oven 5. When the sensor detects that the mold 3 to be foamed actually enters the oven entrance, the system generates a virtual data object at the head of the register queue. This object inherits the mold's ID information, the timestamp of the entry time, and sets the initial curing degree parameter of the mold to zero.

[0072] S302, performs spatiotemporal mapping of position and temperature. Because the tunnel-type constant temperature curing oven 5 is divided into a heating zone, a constant temperature zone, and a gradient cooling zone, the ambient temperature varies in each zone. The virtual curing integral tracking module 103 reads the pulse encoder values ​​of the annular circulating conveyor rail 1 in real time and calculates the physical position coordinates of the mold 3 to be foamed within the current calculation cycle. Based on these coordinates, the system indexes the current micro-environmental temperature value of the mold in the pre-stored oven temperature site map. For polyurethane foam systems, the actual reaction temperature is affected by both ambient temperature and exothermic reaction. The module uses a thermal conductivity correction algorithm to convert the ambient temperature into a simulated reaction temperature within the mold cavity. .

[0073] S303 performs real-time integration calculations based on the Arrhenius model. This is the core processing logic of the virtual curing integration tracking module 103, designed to transform the invisible cross-linking curing reaction process into quantifiable values. The polyurethane reaction rate is exponentially related to temperature. The virtual curing integration tracking module 103 iteratively calculates the curing increment generated in each scan cycle using the controller's scan cycle (e.g., 100ms to 500ms) as the time step, and accumulates it into the total degree of curing.

[0074] Regarding the first A mold in the furnace, its Cumulative solidification index over time The update calculation is performed based on the following discrete integral model:

[0075] ;

[0076] In the formula: This indicates the end of the current calculation cycle, the first... The cumulative curing index of a mold is a dimensionless normalized parameter, typically set to 0 to 1 (or 0% to 100%). This represents the accumulated solidification index value from the previous calculation period; It is a frequency factor (or pre-exponential factor), determined by the reactivity of the foaming raw material system, and is a constant. The activation energy is the energy threshold required for the crosslinking reaction to occur in the foaming system; it is a constant. It is the ideal gas constant; The simulated thermodynamic temperature of the mold cavity reaction (unit: Kelvin) is obtained based on position mapping during the current calculation cycle. This represents the discrete computation time step of the controller.

[0077] S304, Data Update and Visualization Mapping. After completing a full queue scan calculation, the virtual fixed integral tracking module 103 updates all virtual objects in the register. The system maps these values ​​onto an oven simulation diagram on the human-machine interface (HMI), visually displaying the current curing progress of each mold within the oven using different colors (e.g., red-yellow-green gradient). This calculation process repeats until the mold is physically removed from the oven, at which point it is finally locked. The numerical value serves as the final foaming quality criterion for the mold and is transmitted to downstream modules. This process transforms a complex chemical reaction process, dynamically influenced by temperature, speed, and position, into a linearly monitorable single numerical indicator, providing a quantitative basis for subsequent speed coordination and quality arbitration.

[0078] See attached document Figure 5 To address the issues of uneven curing or wasted capacity caused by fixed production line cycles, the system implements dynamic cycle optimization through a production line speed clamping coordination module 104. The core function of this module 104 is to balance the conflicting variables of "foaming quality" and "production efficiency" in real time. Its specific control strategy and algorithm implementation include the following steps:

[0079] S401, Full queue scan and remaining demand calculation. The production line speed clamping coordination module 104 accesses the data stack of the virtual curing integral tracking module 103 at a preset communication cycle (e.g., once per second) to obtain the status information of all the molds 3 in the tunnel-type constant temperature curing oven 5 that are currently in the oven. For each mold in the oven... The production line speed clamping collaboration module 104 extracts its current cumulative curing index. Current physical location coordinates and remaining physical path length from the oven outlet. .

[0080] S402, Inverse kinematics calculation of the limiting velocity of a single component. The system assumes that each mold must reach or exceed a preset full curing threshold exactly upon reaching the exit. (For example, 0.95 or 1.0). Based on the current curing reaction rate, the system reverse-engineers the maximum allowable linear speed for each mold, i.e., the "theoretical allowable speed of the monomer". The calculation logic essentially converts the remaining time required for a chemical reaction into the upper limit of the velocity allowed by physical motion.

[0081] ;

[0082] In the formula: For the first Each mold is designed to achieve the maximum permissible production line operating speed to ensure complete curing upon exiting the oven; For the first The remaining effective length of the current position of the mold from the oven outlet; For the first The predicted average curing rate of each mold in the remaining path is obtained by querying historical reaction kinetic curves or taking the current instantaneous rate; The standard demolding and curing threshold set for the process; This represents the cumulative curing index of the mold at the current moment.

[0083] It should be noted that when When this occurs, it indicates that the mold has met the curing requirements, and the system will then... Set to infinity or the mechanical limit speed allowed by the system, and do not participate in subsequent bottleneck constraints.

[0084] S403, system bottleneck identification based on the short-board effect. This involves calculating the theoretically permissible speed set for all individual furnace molds. Subsequently, the production line speed clamping coordination module 104 executes the minimum value screening logic. Based on the "barrel effect" principle, the operating speed of the entire circular conveyor rail 1 is limited by the mold with the most urgent demand, i.e., the one requiring the slowest speed (usually the mold with the thickest wall or the latest material injection). This minimum value extracted by the system is defined as the "quality-priority theoretical speed". .

[0085] S404, Capacity Clamping and Maximum Arbitration. Fully Compliant This could lead to excessively low production line speeds, even below the factory's break-even point. Therefore, the system has a preset "minimum economic production speed." This parameter is set by the production management team based on the daily production schedule and energy costs, serving as the baseline speed for the production line operation. The production line speed clamping coordination module 104 will... and Logical arbitration is performed, and the final speed command is generated through a maximum selection algorithm. :

[0086] ;

[0087] In the formula: The final speed setting value sent to the servo drive system of the annular circulating conveyor rail 1; This is the preset minimum economic production rate clamping value; That is, the aforementioned quality-first theoretical speed based on the weakest link effect. ,in This represents the collection of all molds currently inside the oven.

[0088] S405, instruction execution and closed-loop feedback. The production line speed clamping coordination module 104 will calculate the... The speed of the production line is smoothly adjusted by sending signals to the frequency converter or servo drive of the traction motor via a bus.

[0089] This arbitration mechanism led to two possible operating conditions:

[0090] when At that time, the production line was operating at a speed that met the curing requirements of all molds, and the production capacity was higher than the minimum requirement. All molds were qualified products when they came out of the oven.

[0091] when At that time, the system forced to use This means that the "short-board" mold will be forced to accelerate through the oven, reaching its destination at the exit. The value will inevitably be lower than At this point, the production line speed clamping coordination module 104 will trigger an under-curing warning, notifying the downstream export quality arbitration module 105 to perform offline processing on the specific mold. This strategy, while ensuring the basic output of the entire line, transforms quality risks into a controllable offline remedial process, achieving a dynamic balance between capacity and quality.

[0092] See attached document Figure 6 This invention includes an export quality arbitration module 105 at the end of the production line, which constitutes the final quality verification stage of the system. Its core function is to establish a hybrid management model combining online production and offline curing, allowing the production line to sacrifice some online curing time under specific operating conditions to increase capacity, and eliminating quality risks through precisely calculated remedial measures. Its specific judgment logic and execution steps include the following:

[0093] S501, trigger exit synchronization verification. When the mold transport trolley 2 moves to the physical exit position of the tunnel-type constant temperature curing oven 5, the photoelectric switch or limit sensor is triggered. The exit quality arbitration module 105 immediately responds to the interrupt signal, locks the current time, and extracts the specific mold from the data stack of the virtual curing integral tracking module 103. The final process data. This data includes two core indicators: the final cumulative curing index of the mold at the moment of removal from the furnace. And the actual skin temperature currently recorded by the mold.

[0094] S502, Perform quality threshold comparison and judgment. Export quality arbitration module 105 reads the standard demolding and curing threshold set by the system. The system performs logical comparison operations:

[0095] like The mold is determined to be an "online qualified product." The export quality arbitration module 105 sends a release signal to the production line diversion mechanism, and the mold directly enters the subsequent demolding, cleaning, and packaging processes along the main conveyor line. At this time, the system automatically releases the PID control of the mold and archives its data to the historical database.

[0096] S503, activate the offline recovery calculation program. If The mold is determined to be a "repairable product". This situation usually occurs when the aforementioned production line speed clamping coordination module 104 triggers the "minimum economic production capacity speed" clamping, resulting in insufficient physical residence time of the mold in the oven. In this case, the system does not classify the product as scrap, but immediately starts offline remedial time calculation.

[0097] S504 calculates the time required for offline natural curing. Once the mold leaves the oven, the ambient temperature changes from high to room temperature, significantly decreasing the chemical reaction rate, but not stopping it. The system, based on the inverse of the Arrhenius equation, calculates the additional physical time required to fill the remaining curing gaps under these low-temperature conditions. Offline remediation time. The calculation model is as follows:

[0098] ;

[0099] In the formula: For the first Each mold needs to be placed in the offline buffer for the shortest possible recovery time; The standard demolding and curing threshold; This is the actual cumulative curing index when the mold exits the oven; , , These are the frequency factor, activation energy of the reaction, and ideal gas constant, respectively, which are consistent with the parameters used in the online calculation; The current ambient temperature in the factory workshop is provided in real time by an ambient temperature sensor installed in the off-line area. This is a cooling correction factor (an empirical constant, typically 0.8-0.95), used to correct the hysteresis difference between the core temperature and the ambient temperature caused by the thermal inertia of the mold itself.

[0100] S505 performs physical diversion and information binding. After calculation, the export quality arbitration module 105 sends instructions to the pneumatic switch or transfer robot on the conveyor rail to divert the mold transport trolley 2 to the "offline curing buffer station". Simultaneously, the system will calculate... The value is written to the RFID tag on the mold trolley or the associated Manufacturing Execution System (MES) entry. On the information display screen above the buffer station, the system counts down the remaining settling time for the mold. Only when the countdown reaches zero is the settling time satisfied. Only after the logical conditions are met can the system unlock the warning light, allowing the operator to perform the mold opening operation.

[0101] Through this mechanism, the system can transfer the final curing stage, which originally had to be completed in an expensive oven, to a low-cost room temperature environment when necessary. This not only solves the risk of under-curing caused by production line acceleration, thereby reducing production losses while ensuring product quality, but also effectively decouples the rigid binding between production cycle time and chemical reaction time, significantly improving the flexible scheduling capability of the production line.

[0102] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A foamed and shaped production control system for a cold cabinet insulation panel, characterized by, The physical production execution unit and the logic control unit are included; The physical production execution unit includes a ring-shaped circulating conveying guide rail, a mold carrying trolley, an intelligent variable-voltage and variable-current material injection machine, a tunnel-type constant-temperature curing oven, and an offline curing and demolding arbitration execution mechanism. The logic control unit includes a central control module, which is configured with: a thermal state data acquisition module for acquiring mold surface temperature and generating mold initial state data package; a multi-dimensional heat content compensation calculation module for calculating injection pressure correction value and injection quality correction value according to initial temperature deviation, and controlling the intelligent variable-voltage and variable-current material injection machine to perform gain compensation of physical heat energy and chemical heat energy; a virtual curing integral tracking module for building a virtual mapping queue and calculating the current cumulative curing degree value of the oven mold; a line speed clamping coordination module for calculating the theoretical line speed according to the remaining curing demand of the mold and generating the running speed instruction of the ring-shaped circulating conveying guide rail in combination with the minimum economic production speed; an outlet quality arbitration module for comparing the final curing degree value with the standard demolding threshold, and controlling the offline curing and demolding arbitration execution mechanism to perform mold opening permission or forced mold closing offline action.

2. The foamed and shaped production control system of a cold storage cabinet insulation board according to claim 1, characterized in that, The thermal state data acquisition module non-contact acquires the measured surface temperature of the to-be-foamed refrigerator mold through an infrared thermal state sensing sensor, and performs difference operation on the measured surface temperature and the preset standard process reference temperature to obtain the initial temperature deviation; the thermal state data acquisition module also binds the initial temperature deviation with the identification of the mold carrying trolley and the time stamp to generate the mold initial state data package.

3. The foamed and shaped production control system of a cold cabinet insulation panel according to claim 2, characterized in that, The multi-dimensional heat content compensation calculation module performs the following control when determining that the to-be-foamed refrigerator mold is in a cold mold state according to the initial temperature deviation: Based on the principle of fluid mechanics energy conversion, a pressure compensation algorithm is called to calculate the mixed pressure set value, the back pressure is adjusted by controlling the position of the throttle valve core of the intelligent variable-voltage and variable-current material injection machine, and the physical shear heat is increased; Based on the principle of chemical reaction heat release, a quality compensation algorithm is called to calculate the injection quality set value, the total amount of reactants is increased by controlling the action of the metering pump of the intelligent variable-voltage and variable-current material injection machine, and the chemical reaction heat is increased.

4. The foamed and shaped production control system of a cold storage cabinet insulation board according to claim 1, characterized in that, The virtual curing integral tracking module establishes a virtual shift register queue mapped with the length of the tunnel-type constant-temperature curing oven in the memory of the controller; the virtual curing integral tracking module reads the physical position coordinates of the mold carrying trolley in real time, indexes the corresponding micro-environment temperature value in the pre-stored oven temperature field map, and converts the micro-environment temperature value into the simulated reaction temperature of the mold cavity through a thermal conductivity correction algorithm.

5. The foamed and shaped production control system of a cold cabinet insulation panel according to claim 4, characterized in that, The virtual curing integral tracking module uses a discrete integral logic based on the Arrhenius model, takes the scanning period of the controller as the time step, iteratively calculates the curing increment generated in each scanning period using the simulated reaction temperature, and adds the curing increment to the current cumulative curing degree value until the to-be-foamed refrigerator mold moves out of the tunnel-type constant-temperature curing oven.

6. The foamed and shaped production control system of a cold storage cabinet insulation board according to claim 1, characterized in that, The line speed clamp coordination module performs full queue scanning, and obtains a single theoretical allowable speed of each in-furnace mold satisfying the condition of complete solidification upon discharge through inverse operation; the line speed clamp coordination module performs minimum value screening logic to screen a quality priority theoretical speed with the smallest value from the single theoretical allowable speed of all in-furnace molds.

7. The foamed and shaped production control system of a cold cabinet insulation panel according to claim 6, characterized in that, The line speed clamp coordination module compares and arbitrates the quality priority theoretical speed with a preset minimum economic production speed, selects a larger value of the two as a final running speed instruction sent to the ring-shaped circulating conveying guide rail; when the quality priority theoretical speed is smaller than the minimum economic production speed, the system is forced to run at the minimum economic production speed, and an under-curing early warning flag is generated and transmitted to the outlet quality arbitration module.

8. The foamed and shaped production control system of a cold storage cabinet insulation board according to claim 1, characterized in that, The outlet quality arbitration module triggers verification when the foaming refrigerator mold reaches the outlet of the tunnel type constant temperature curing oven; if the final solidification degree value is greater than or equal to the standard demolding threshold, it is determined as an online qualified product, and a demolding signal is sent; If the final solidification degree value is less than the standard demolding threshold, it is determined as a product to be remedied, a forced mold closing alarm signal is sent, and the foaming refrigerator mold is diverted to an offline curing buffer station.

9. The foamed and shaped production control system of a cold cabinet insulation panel according to claim 8, characterized in that, For the foaming refrigerator mold determined to be a product to be remedied, the outlet quality arbitration module calculates the offline remediation time through reaction kinetics inverse operation according to the current factory workshop environment temperature and the solidification degree deficiency; the system locks the offline curing and demolding arbitration execution mechanism until the standing time of the foaming refrigerator mold in the offline state reaches the offline remediation time, then the lock is released and manual demolding is allowed.

10. A foamed profiled production line for freezer insulation panels, applied to the system according to any one of claims 1-9, characterized in that, The infrared thermal state sensing sensor is arranged at an upstream position of the intelligent variable voltage and current injection machine, the tunnel type constant temperature curing oven is arranged downstream of the intelligent variable voltage and current injection machine and covers the linear segment of the ring-shaped circulating conveying guide rail, and the offline curing and demolding arbitration execution mechanism is arranged at the outlet position of the tunnel type constant temperature curing oven.

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