A tire dynamic equivalent vulcanization method and system based on real-time temperature feedback

Abstract

The present application relates to a tire vulcanization control method, in particular to a tire dynamic equivalent vulcanization method and system based on real-time temperature feedback. The present application arranges double-buried depth temperature measuring points with the normal line at key positions such as the shoulder, sidewall and bead, collects temperature in real time and extrapolates to obtain interface or near-interface temperature; based on the temperature, the equivalent vulcanization progress is calculated and integrated to obtain the cumulative equivalent vulcanization time of each position, and the remaining vulcanization time is further calculated to online identify the key position that is most difficult to meet the standard; combined with the equipment execution delay, the advance compensation is carried out, the termination instruction is output when the target equivalent vulcanization condition is reached to complete the steam exhaust, pressure relief and mold opening and tire ejection, and the whole process data is recorded for tracing. The scheme can reduce the risk of under-vulcanization and over-vulcanization, improve the vulcanization consistency and shorten the vulcanization cycle.

Description

Technical Field

[0001] This invention relates to a method for controlling tire vulcanization, and more particularly to a method and system for dynamic equivalent vulcanization of tires based on real-time temperature feedback. Background Technology

[0002] Tire vulcanization is one of the key processes in tire manufacturing that determines the physical and mechanical properties and structural stability of the finished product. In the vulcanizing machine, the green tire undergoes a cross-linking reaction of the rubber compound under specific temperature and pressure conditions via heating media such as steam / heat transfer oil and mold, forming the prescribed tread pattern and shape. Because tires are multi-material, multi-thickness, and multi-part composite structures, the heat capacity, heat conduction paths, and heat dissipation boundary conditions of the tread, shoulder, sidewall, and bead vary significantly. This results in a non-uniform spatial distribution of the temperature field and reaction rate during vulcanization. On the one hand, some areas may experience under-vulcanization due to slow heating or poor heat dissipation, leading to insufficient adhesion, premature fatigue cracking, and reduced durability. On the other hand, some areas may experience over-vulcanization due to rapid heating or heat accumulation, causing the rubber compound to become brittle, reduce springback, and increase hysteresis, thus affecting overall performance such as rolling resistance, wear resistance, and heat aging resistance. In addition, there are other disturbances in the production site, such as differences in mold temperature, fluctuations in tire loading time, changes in cooling / mold cooling time, fluctuations in steam pressure, and differences in batches of rubber materials. These factors make it difficult for traditional control methods that rely on fixed vulcanization time and experience-based corrections to simultaneously ensure sufficient vulcanization and consistency. This can easily lead to increased batch-to-batch fluctuations in tires of the same specification, and may even cause quality risks and rework costs.

[0003] To improve vulcanization quality and stability, the industry has proposed various intelligent vulcanization control technologies based on online monitoring and model calculation. Chinese patent document (CN115416192A) discloses an intelligent control rubber vulcanization process / method / system. This system sets several temperature measuring holes on the mold and uses thermocouples to acquire real-time temperature data. It collects the real-time temperature of each measuring hole at a set cycle and automatically calculates the equivalent vulcanization time. When the calculated equivalent vulcanization time reaches the standard equivalent vulcanization time, vulcanization stops, and a control command is sent to the vulcanizing machine to achieve automatic demolding. Furthermore, the document proposes using three-dimensional software to simulate the vulcanization temperature field to determine the most difficult vulcanization point and use this point as the location of the temperature measuring holes. This type of solution represents a significant improvement over simply fixing the vulcanization time, but it may still have the following shortcomings in engineering applications: First, the temperature of the temperature measuring hole usually reflects the temperature at a certain depth inside the mold or the local thermal state, and may not accurately characterize the true temperature at the tire-mold contact interface or near the rubber compound interface. Therefore, when the temperature gradient is large and the local heat transfer conditions change significantly, the calculation of the equivalent vulcanization time may produce systematic deviations. Second, the standard equivalent vulcanization time is mostly obtained through pre-experiment / experience optimization. When facing differences in the thermal inertia of different batches of rubber compounds or molds, or on-site disturbances, it may be necessary to frequently recalibrate or adjust, otherwise local under-vulcanization or over-vulcanization may still occur. Third, although the location of the temperature measuring point can be determined through simulation, in actual production, factors such as changes in tire specifications and differences in tire mounting conditions can cause the most difficult vulcanization point to drift between different cycles. Relying solely on fixed measuring points determined offline may not be able to maintain effective constraints on critical parts.

[0004] Chinese patent document (CN105538564B) discloses a tire intelligent vulcanization control system. It simulates the tire vulcanization process using CAE methods and compares it with the actual vulcanization process to form a database. During the vulcanization process, it collects real-time on-site process parameters such as vulcanization temperature, pressure, and cooling time, and interacts with the database data to adjust the vulcanization time in real time. The document also mentions adopting the idea of ​​the Arrhenius equation, treating the degree of vulcanization as a function of time and temperature, and obtaining a relatively accurate degree of vulcanization by methods such as the area under the curve, so as to issue a command to end the vulcanization action when the positive vulcanization is reached. The advantage of this type of solution lies in the introduction of a closed-loop adjustment approach involving models, databases, and field parameters. However, it may still have limitations: First, field-collected parameters are often macroscopic process quantities such as cavity temperature and steam pressure, which are difficult to directly characterize the local temperature history and crosslinking reaction differences of different structural layers and parts of the tire. Second, the reliability of CAE simulation and database is highly dependent on the consistency of material parameters, boundary conditions, and production status. When changes occur in mold heat transfer status, tire fitting, venting, etc., model errors may accumulate and affect the reliability of vulcanization termination criteria. Third, the vulcanization termination action objectively has a delay in the equipment execution chain (e.g., venting, depressurization, mold opening, etc.). If the control strategy does not compensate for this delay, overshoot may still occur after the threshold is reached, leading to the risk of local over-vulcanization.

[0005] In addition, there are technical approaches that focus on monitoring the degree of crosslinking / vulcanization. Chinese patent document (CN114786933B) discloses a vulcanization process and equipment for tires. Its monitoring device includes a thermal detection probe located inside the wall of the vulcanization mold, the probe being less than 5 mm away from the inner surface of the mold. An electronic control unit works in conjunction with the monitoring device to interrupt the heating supply when the average degree of crosslinking reached in the detection area of ​​the green tire reaches a predetermined reference value, thereby achieving control of the vulcanization process. This type of approach improves the ability to sense the near-surface thermal state of the mold by placing sensors in areas close to the inner surface of the mold. However, the following problems may still exist: First, the degree of crosslinking usually needs to be calculated from temperature history, material kinetic parameters, or empirical models. If the conversion model does not match the actual rubber compound / working conditions, it will affect the accuracy of the crosslinking degree threshold criterion. Second, Reference 3 uses the average crosslinking degree of the detection area as the control basis. The averaging process may mask the risk of under-curing in the weakest local parts (such as the tire shoulder or tire bead, which are the slowest to heat up), especially in thick-walled structures with significant spatial non-uniformity of temperature field. Third, relying solely on thermal information obtained from a single burial depth or a single probe position may still make it difficult to accurately deduce the true temperature at the tire-mold contact interface, thus leading to criterion bias when there is a significant temperature gradient.

[0006] In summary, while existing intelligent tire vulcanization control technology has evolved from fixed-time control to real-time temperature measurement combined with equivalent vulcanization time / degree calculation and automatic termination, it still faces common challenges in practical applications. These include insufficient representativeness of temperature information (especially the difficulty in accurately obtaining interface or near-interface temperatures), insufficient identification and drift of key components in different vulcanization cycles, and vulcanization termination overshoot caused by equipment execution delays. These issues limit the potential for further reduction in vulcanization time and improvement in vulcanization uniformity. Therefore, it remains necessary to propose a dynamic equivalent vulcanization control scheme for tires that can more accurately characterize the vulcanization temperature history of key components and possess stronger adaptability and robustness, in order to reduce the risk of under-vulcanization / over-vulcanization and improve batch-to-batch consistency and production efficiency. Summary of the Invention

[0007] The technical objective of this invention is to address the problems of uneven temperature fields in various parts during tire vulcanization, difficulty in accurately reflecting the thermal state of the tire-mold contact interface at temperature measurement points, and batch-to-batch fluctuations caused by equipment execution delays. This invention provides a dynamic equivalent vulcanization method and system for tires based on real-time temperature feedback. By acquiring near-interface temperatures at multiple locations online and adaptively identifying key locations, combined with real-time calculation of equivalent vulcanization time and delay compensation control, the invention aims to shorten the vulcanization cycle, reduce the risk of over-vulcanization, and improve the consistency of finished products while ensuring sufficient vulcanization.

[0008] Firstly, in order to achieve the above-mentioned objectives, the present invention adopts the following technical solution:

[0009] A dynamic equivalent vulcanization method for tires based on real-time temperature feedback, comprising the following steps:

[0010] S1. Set temperature acquisition points at at least two locations corresponding to the tire shoulder, sidewall, and bead on the tire vulcanizing mold. For each temperature acquisition point, arrange a first temperature sensor and a second temperature sensor along the normal direction of the inner surface of the mold cavity. Set a reference temperature, target equivalent vulcanization time, sampling period, execution delay, and switching hysteresis threshold. S2. During the vulcanization process, collect the first and second embedment temperatures at each temperature acquisition point in real time, and perform temperature correction, noise reduction, and outlier removal. S3. Based on the temperature difference between the first and second embedment temperatures and the embedment depth difference between the two sensors, adjust the temperature at the interface or near the interface between the mold and the tire. S4. Perform linear extrapolation estimation and calculate the equivalent vulcanization rate factor and cumulative equivalent vulcanization time for each temperature acquisition point; S5. Determine the temperature acquisition point with the largest remaining time required to reach the target equivalent vulcanization time as the key part, and combine the switching hysteresis threshold to suppress frequent switching of the key part. Add the current cumulative equivalent vulcanization time of the key part to the estimated increase in equivalent vulcanization time during the execution delay period to obtain the predicted equivalent vulcanization time; S6. When the predicted equivalent vulcanization time reaches the target equivalent vulcanization time, output the vulcanization termination command, so that the vulcanizing machine performs steam exhaust, depressurization and mold opening to end the vulcanization, and record the process traceability data.

[0011] As a further improvement, in step S1, the first temperature sensor and the second temperature sensor are thermocouples, and the thermocouples are type K thermocouples or type N thermocouples; the burial depth of the first temperature sensor is greater than 0 mm and does not exceed 1 mm, the burial depth of the second temperature sensor is 2 mm to 8 mm, and the burial depth of the second temperature sensor is greater than the burial depth of the first temperature sensor.

[0012] As a further improvement, in step S2, the outlier removal includes: judging the degree of deviation of the first burial depth temperature or the second burial depth temperature from the window mean within the sliding window; when the deviation exceeds 3 times the window temperature standard deviation, the corresponding temperature data is judged as an outlier and replaced with the valid temperature data of the previous sampling time.

[0013] As a further improvement, in step S3, the extrapolation estimation of the interface or near-interface temperature is obtained based on the thermal gradient relationship between the first burial depth temperature, the second burial depth temperature, the burial depth of the first temperature sensor, and the burial depth of the second temperature sensor at the same temperature acquisition point; the equivalent sulfidation rate factor is determined based on the reference temperature, the interface or near-interface temperature, the apparent activation energy of the sulfidation reaction, and the gas constant; the cumulative equivalent sulfidation time is obtained by accumulating the change of the equivalent sulfidation rate factor over time.

[0014] In step S3, the apparent activation energy of the vulcanization reaction is retrieved from the vulcanization formula database by the rubber compound formula identifier, which is used to distinguish different tire rubber compound formulas; the sampling period is any value in the range of 0.1 seconds to 2 seconds.

[0015] As a further improvement, in step S4, the remaining equivalent vulcanization time is determined based on the target equivalent vulcanization time, the current cumulative equivalent vulcanization time, and the current equivalent vulcanization rate factor; the key part is the tire part corresponding to the temperature sampling point with the largest remaining equivalent vulcanization time; when the difference between the remaining equivalent vulcanization time of the candidate key part and the key part at the previous sampling time does not reach the switching hysteresis threshold, the key part at the previous sampling time remains unchanged.

[0016] In step S4, the online identification of key components is performed at least once within a predetermined identification window after the start of vulcanization. The predetermined identification window is a time interval of a preset length starting from the start of vulcanization. The switching hysteresis threshold is used to suppress frequent switching of key components within adjacent sampling cycles, and the switching hysteresis threshold is any value within the range of 0.1 minutes to 3 minutes. Preferably, the predetermined identification window can be 1 to 5 minutes after the start of vulcanization, or the heating stage before reaching the reference temperature, specifically preset according to the tire specifications and the thermal inertia of the mold.

[0017] As a further improvement, in step S4, the execution delay is the equivalent delay time from the output of the vulcanization termination command to the substantial decrease in the heat input of the mold cavity, and is calibrated by the step response test of the vulcanizing machine's mold opening, steam exhaust, and pressure relief execution link; the target equivalent vulcanization time is calculated by converting the rubber compound's T90 at the reference temperature, where T90 is the vulcanization time corresponding to when the rubber compound's torque reaches 90% of the maximum torque.

[0018] Secondly, the present invention also provides a tire dynamic equivalent vulcanization system based on real-time temperature feedback, the system being used to implement the method, comprising:

[0019] A temperature acquisition component is used to arrange a first temperature sensor and a second temperature sensor along the normal direction at each temperature acquisition point of multiple key thermal parts of the vulcanizing mold to obtain the first burial depth temperature and the second burial depth temperature.

[0020] The data preprocessing component is used to perform temperature correction, noise reduction, and outlier removal on the first and second burial depth temperatures.

[0021] An interface temperature estimation component is used to obtain the estimated temperature of the interface or near-interface based on the first burial depth temperature, the second burial depth temperature and their burial depth difference.

[0022] The equivalent vulcanization calculation component is used to calculate the equivalent vulcanization rate factor and cumulative equivalent vulcanization time based on the estimated temperature at the interface or near the interface, the reference temperature, and the vulcanization reaction parameters of the rubber compound.

[0023] The critical component identification and decision-making component is used to calculate the remaining equivalent vulcanization time, identify critical components, and generate a vulcanization termination command in conjunction with the execution delay.

[0024] The equipment interface component is used to send the vulcanization termination command to the vulcanizing machine to execute the end of vulcanization and mold opening and tire ejection;

[0025] Data storage components are used to store temperature acquisition data, estimated temperature at or near the interface, equivalent vulcanization calculation data, key component identification results, and termination event data.

[0026] Preferably, the device interface component is a PLC interface or an industrial Ethernet interface; the critical part identification and decision component includes a hysteresis control unit, which is used to perform critical part switching suppression according to the switching hysteresis threshold; the temperature acquisition component is set at three locations: tire shoulder, tire sidewall, and tire bead, and there are no fewer than three temperature acquisition points.

[0027] Thirdly, the present invention also provides a computer-readable storage medium having a computer program or instructions stored thereon, which, when executed by a processor, implement the steps of the method.

[0028] Fourthly, the present invention also provides a computer program product, including a computer program or instructions that, when executed by a processor, implement the steps of the method.

[0029] This invention employs multi-point temperature acquisition at key thermal components such as the tire shoulder, sidewall, and bead, and uses dual-depth temperature measurement along the same normal direction to estimate the temperature at the tire-mold contact interface or near-interface. This elevates vulcanization control from the internal temperature / cavity temperature of the mold to a temperature input closer to the actual reaction environment of the rubber compound, significantly reducing the system error in equivalent vulcanization calculation caused by temperature gradients, thermal inertia, and tire assembly differences. Furthermore, based on the cumulative equivalent vulcanization time and remaining equivalent vulcanization time of each component, online adaptive identification and dynamic switching of key components are achieved, enabling control criteria to automatically adjust with the thermal drift of each tire and each mold cycle. This invention targets the most difficult-to-curing areas, effectively suppressing the risks of insufficient adhesion, reduced durability, and early cracking caused by localized under-curing. Simultaneously, it introduces advance compensation for equipment execution delays, ensuring that the curing termination time can offset the thermal input inertial overshoot caused by exhaust, depressurization, and mold opening, reducing rubber embrittlement, hysteresis, and performance degradation caused by localized over-curing. Therefore, this invention achieves more stable curing consistency and smaller batch-to-batch fluctuations while ensuring sufficient curing, further shortening the actual curing cycle, reducing energy consumption and rework / scrap rates, and generating traceable temperature-equivalent curing data records, providing a basis for process optimization and quality closed-loop management. Attached Figure Description

[0030] Figure 1 This is a schematic diagram of the tire dynamic equivalent vulcanization system based on real-time temperature feedback according to the present invention.

[0031] Figure 2This is a schematic diagram of the tire dynamic equivalent vulcanization method based on real-time temperature feedback according to the present invention.

[0032] Figure 3 This is a cross-sectional schematic diagram of a double-buried-depth temperature measurement structure along the same normal for key thermal components of a mold.

[0033] Figure 4 This is a schematic diagram of the online identification and switching vibration suppression logic for key components.

[0034] Figure 5 A schematic diagram of the vulcanization termination criterion for implementing delay advance compensation.

[0035] Figure 6 This is a diagram illustrating data recording and process traceability.

[0036] Figure 7 A schematic diagram comparing the curves of the first burial depth temperature, the second burial depth temperature, and the extrapolated interface / near interface temperature at different measuring points.

[0037] Figure 8 The cumulative equivalent vulcanization time at each measuring point varies with time.

[0038] Figure 9 Index the key parts with step curves and corresponding graphs that change over time.

[0039] Figure 10 A comparison chart of the predicted equivalent vulcanization time and the target equivalent vulcanization time.

[0040] Figure 11 This is a statistical comparison chart of the equivalent sulfurization dispersion between different locations at the termination time.

[0041] Figure 12 This is a statistical comparison chart of the total vulcanization time and the equivalent vulcanization overshoot of key parts under different control strategies. Detailed Implementation

[0042] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present invention.

[0043] I. Terminology Explanation

[0044] Temperature acquisition point: A temperature measurement location is set at a key thermal component of the tire vulcanizing mold (such as the tire shoulder, sidewall, and bead), and is denoted as index. .

[0045] Burial depth: The distance between the sensitive end of the temperature sensor along the normal direction of the inner surface of the mold cavity and the inner surface of the cavity. The first burial depth is... The second burial depth is and .

[0046] Interface / near-interface temperature: The equivalent temperature at or near the interface between the tire rubber compound and the inner surface of the mold cavity, denoted as It is used to characterize the actual vulcanization reaction environment of rubber compounds.

[0047] Sampling period: The time interval during which the system samples signals such as temperature, denoted as . .

[0048] Equivalent vulcanization time: Converting any temperature history to a reference temperature. The equivalent reaction time is denoted as . .

[0049] Equivalent vulcanization rate factor: A factor that maps temperature to relative reaction rate using the Arrhenius relation, denoted as .

[0050] Remaining equivalent vulcanization time: the time required to reach the target equivalent vulcanization time The estimated remaining time required is denoted as .

[0051] Key areas: The areas where the target degree of vulcanization is most difficult to achieve at the current vulcanization stage; corresponding index. .

[0052] Execution delay: The equivalent time delay from the system outputting the vulcanization termination command to the substantial decrease in mold cavity heat input (or the vulcanization state entering the termination stage), denoted as .

[0053] Hysteresis threshold: A threshold parameter used to suppress frequent switching of indexes in critical parts, denoted as .

[0054] II. System Structure of the Invention

[0055] like Figure 1 As shown, the system of this invention can be deployed on an industrial computer or embedded controller next to the vulcanizing machine and communicate with the vulcanizing machine's PLC / control system. The system includes at least the following modules:

[0056] Temperature acquisition component: used to set temperature acquisition points in multiple key thermal components. At each sampling point, a first temperature sensor and a second temperature sensor are arranged along the normal direction of the inner surface of the cavity, and output respectively. and .

[0057] The sensor can be a thermocouple (such as type K or type N) or a platinum resistance thermometer; to adapt to the high temperature and high pressure environment of sulfidation, a high temperature resistant thermocouple is preferred.

[0058] like Figure 3 As shown, the two sensors at the same collection point are preferably arranged in the same temperature measuring hole or the same mounting sleeve structure to ensure that they are in the same normal direction and the same lateral position, thereby reducing the error caused by the lateral temperature difference.

[0059] Data acquisition and synchronization components: used for sampling periods Synchronous sampling is performed on each channel, and cold junction compensation, A / D conversion, and timestamp alignment are completed to form a discrete sequence. .

[0060] Data preprocessing component: Corrects, denoises, removes outliers and handles missing data for temperature data, outputting valid temperature data. , (For ease of description, the following text will still use the same characters.) , This represents valid data after preprocessing.

[0061] Interface / near-interface temperature estimation component: based on temperature measurement data and burial depth parameters at the same location at two different depths. , Calculate the interface / near-interface temperature estimation This module is one of the innovative aspects of this invention, used to solve the problem that the internal temperature of the temperature measuring hole is not equal to the true interface temperature.

[0062] Equivalent vulcanization calculation component: based on reference temperature Apparent activation energy With gas constant calculate And integrate to obtain .

[0063] Key component identification and decision-making component: computation And determine At the same time, the hysteresis threshold is utilized. Suppress frequent switching of critical components; further introduce execution latency. Lead time compensation generates a vulcanization termination command.

[0064] Equipment interface component: Outputs vulcanization termination command to the vulcanizing machine through PLC interface or industrial Ethernet interface, and can receive vulcanizing machine status (mold closing, pressure increase, steam exhaust, mold opening, etc.) as decision constraints.

[0065] Data storage and traceability components: such as Figure 6As shown, the original temperature, estimated temperature, equivalent vulcanization, and event records are associated and stored with tire specifications, rubber batches, mold numbers, vulcanizing machine numbers, shifts, etc., supporting traceability and process optimization.

[0066] III. Specific Technical Route for Implementing the Method of the Invention

[0067] like Figure 2 As shown, the method of the present invention generally adopts the following route: multi-site same-normal double-depth temperature measurement → extrapolation of interface / near-interface temperature → real-time integration of Arrhenius equivalent sulfurization → online identification of key parts → delay compensation triggering termination → data traceability.

[0068] Step S1: Set at least two locations on the tire vulcanizing mold corresponding to the tire shoulder, sidewall, and bead. Temperature measurement points Two sensors are arranged at each temperature measurement point along the normal to the inner surface of the cavity, with a burial depth of [missing information]. , and ,in, ;

[0069] Step S2, during the vulcanization process, with sampling period Real-time data collection at various temperature points of and , The sampling sequence number is used, and the collected data is temperature-corrected and outlier-removed to obtain the effective temperature data for calculation.

[0070] Step S3, for each temperature measurement point Based on the burial depth of the first temperature sensor and the second temperature sensor and Extrapolate the temperature at or near the interface between the mold and the tire to obtain the estimated interface or near-interface temperature. and based on reference temperature Calculation of equivalent sulfurization rate factor according to Arrhenius relation The cumulative equivalent vulcanization time is obtained by integration. ;

[0071] Step S4: Calculate the remaining equivalent vulcanization time. And identify key parts According to the switching hysteresis threshold Determine whether to switch critical components, taking into account execution delays. Predicted equivalent vulcanization time ,when Output a termination command. The target equivalent vulcanization time;

[0072] Step S5: The vulcanizing machine performs steam exhaust, depressurization, mold opening, and vulcanization ends.

[0073] IV. Specific Implementation of Method Steps

[0074] The following detailed explanation proceeds step-by-step from S1 to S5. The description below uses discrete sampling times. This is a time index; temperature is expressed in absolute temperature (K) by default. If the temperature measured on-site is in degrees Celsius (°C), it needs to be converted to K before entering the Arrhenius calculation.

[0075] (I) Step S1: Arrangement and parameter configuration of temperature measurement at double depth with the same normal for multiple key parts

[0076] 1) Collection point layout principles

[0077] In tire vulcanization molds, the tire shoulder and bead are typically thermally and structurally sensitive areas: the tire shoulder is affected by tread blocks and grooves, resulting in complex local rubber thickness and heat dissipation conditions; the bead area has a large thickness, a composite of metal skeleton and rubber, and a long heat transfer path, making it prone to becoming the slowest heating area. To cover the non-uniformity of the temperature field, this invention sets temperature sampling points in at least two key thermally sensitive areas. Ideally, the tire should cover the shoulder, sidewall, and bead simultaneously. .

[0078] 2) Achieving double-buried-depth structure with the same normal

[0079] like Figure 3 As shown, temperature measuring holes or mounting holes are machined at the corresponding locations on the mold, with the hole axes arranged along the normal direction of the inner surface of the mold cavity. The sensitive end of the first temperature sensor is located at the embedment depth. At this location, the sensitive end of the second temperature sensor is located at a depth of [insert depth here]. place, and .

[0080] To ensure thermal contact and pressure-resistant sealing, the following structural combinations can be used:

[0081] Install a metal mounting sleeve (such as stainless steel or heat-resistant alloy) inside the hole;

[0082] A high thermal conductivity and temperature-resistant filler material (such as temperature-resistant thermally conductive adhesive or thermally conductive ceramic filler) is filled between the sensor's sensitive end and the mounting sleeve to reduce contact thermal resistance.

[0083] A heat-resistant seal and a clamping structure are installed at the orifice to prevent steam / medium leakage and lead wire wear.

[0084] The lead wire is led out along the pre-reserved wiring groove in the mold to the junction box, and then connected to the data acquisition module.

[0085] 3) Parameter configuration and initialization

[0086] Configure and initialize the following parameters after system startup or each specification change:

[0087] Reference temperature The reference temperature used for equivalent vulcanization calculation;

[0088] Target equivalent vulcanization time :exist To achieve the target degree of vulcanization (e.g., the corresponding rubber compound) The equivalent time (or the degree of goal confirmation in the project);

[0089] Sampling period :For example to ;

[0090] Apparent activation energy It can be retrieved from the database according to the rubber compound formula;

[0091] Execution delay Configure according to the equipment's calibration values;

[0092] Hysteresis threshold Used for switching vibration suppression in critical parts;

[0093] Initial equivalent vulcanization time: for all set up ;

[0094] Initial key components: can be set It can be determined from the tire bead or the initial temperature rise slope measured during the preheating stage.

[0095] (II) Step S2: Real-time acquisition, correction, noise reduction and anomaly handling

[0096] The purpose of step S2 is to provide a stable and reliable input temperature sequence to avoid misjudgment of critical parts or jitter at the termination time caused by noise / transient anomalies.

[0097] 1) Synchronous sampling

[0098] Data acquisition module with Simultaneous sampling of all channels yields... , The significance of synchronous sampling is that the extrapolation in step S3 depends on the temperature difference between the two burial depths, and if they are not synchronized, phase error will be introduced.

[0099] 2) Temperature correction

[0100] Perform cold junction compensation and zero-point correction on the thermocouple signal. Assume the correction bias is... and The corrected temperature is:

[0101] ;

[0102] in, , The corrected temperature; , This is the channel offset calibration value.

[0103] 3) Noise Reduction and Anomaly Removal

[0104] Sliding window mid-range filtering or low-pass filtering can be used. Taking sliding window mid-range filtering as an example, the window length is... :

[0105] Take a window for each channel The median as Similarly, we can obtain .

[0106] like Then determine This is an anomaly, so we use... Substitute; This represents the temperature anomaly threshold.

[0107] 4) Missing and Degradation Strategies

[0108] When any collection point Any channel consecutively missing for more than Degradation can be triggered during each sampling period:

[0109] The remaining data collection points are retained for control purposes; or

[0110] Switch to fixed vulcanization time The strategy is to ensure a safe delivery.

[0111] in, This is the threshold for missing item counts; For safe vulcanization time.

[0112] (III) Step S3: Extrapolation estimation of interface / near interface temperature and real-time integration of equivalent sulfidation

[0113] Step S3 is the first key innovation of this invention: it is obtained by extrapolation through the temperature at two burial depths along the same normal. This makes the equivalent vulcanization calculation input closer to the actual reaction temperature environment of the rubber compound, fundamentally reducing the systematic deviation caused by insufficient representativeness of the temperature measurement orifice; and on this basis, real-time calculation is performed. and This provides a calculable quantity for subsequent online identification of key components and termination criteria.

[0114] 1) Extrapolation estimation Physical basis and applicable conditions

[0115] Within the mold steel body, the local region near the inner surface of the cavity can be approximated as a one-dimensional steady-state or quasi-steady-state heat conduction process: within a sufficiently small thickness range (e.g., a few millimeters), the temperature distribution along the normal direction can be approximately linear or nearly linear. Especially during vulcanization, the mold is heated by the heating medium, and the cavity surface comes into contact with the rubber material, forming boundary heat transfer, resulting in a temperature gradient on the mold surface. Single-point burial depth temperature measurement can only obtain the temperature at a certain depth and cannot be directly equated to the interface temperature; while dual-burial depth temperature measurement can obtain local gradient information, thus extrapolating to the vicinity of the interface.

[0116] Therefore, the present invention sets up at each collection point , Two temperature measurement points are arranged along the same normal to satisfy... And the difference between the two burial depths Within the range of manufacturability and measurability, in order to ensure numerical stability of extrapolation.

[0117] 2) Extrapolation formula and parameter definition for interface / near-interface temperature

[0118] At discrete time Temperature at the first burial depth was collected. With the second burial depth temperature Subsequently, interface / near-interface temperature estimation It can be obtained by extrapolation using linear gradient:

[0119] ;

[0120] in, Number the temperature acquisition points; The sampling time sequence number; For the first The temperature (absolute temperature) measured by the first temperature sensor. For the first The temperature (absolute temperature) measured by the second temperature sensor. The burial depth of the first temperature sensor; The burial depth for the second temperature sensor; Estimate the temperature (absolute temperature) of the interface or near-interface obtained by extrapolation.

[0121] Engineering Explanation: When When the temperature is higher near the surface, the extrapolation will further increase the estimated temperature to approximate the interface; conversely, the same applies. This extrapolation avoids... It can be directly treated as a deviation in interface temperature.

[0122] 3) Numerical stability and constraint handling of extrapolation (preferred implementation)

[0123] To prevent Too small a value will amplify the noise through extrapolation; the optimal setting is:

[0124] ;

[0125] ;

[0126] and ,in This is the minimum burial depth difference threshold.

[0127] In addition, it is possible to Set physical range constraints:

[0128] , and These are the acceptable minimum / maximum absolute temperature boundaries, used to suppress abnormal extrapolated values.

[0129] 4) Equivalent vulcanization rate factor Calculation

[0130] This invention uses the Arrhenius form to convert temperature to a reference temperature. Calculate the equivalent vulcanization rate factor based on the equivalent reaction rate. :

[0131] ;

[0132] in, For the first Point at time The equivalent vulcanization rate factor; This represents the apparent activation energy of the sulfidation reaction. It is the gas constant; Reference temperature (absolute temperature); Estimate the temperature (absolute temperature) for the interface / near interface. When hour, This indicates that the reaction is faster at higher temperatures; when hour, This indicates a slower response.

[0133] 5) Cumulative equivalent vulcanization time Discrete integral

[0134] by The sampling period is the instantaneous equivalent rate factor. By performing discrete integration, the cumulative equivalent vulcanization time is obtained:

[0135] ;

[0136] in, For the first Deadline The cumulative equivalent vulcanization time; This is the cumulative equivalent vulcanization time at the previous sampling time; This is the equivalent vulcanization rate factor; The sampling period.

[0137] During initialization, set During each sampling cycle of the vulcanization process, the system samples all... Parallel update .

[0138] 6) Why extrapolate first? Reintegration can improve control

[0139] If single-point burial depth temperature is used directly conduct and Calculations show that when there is a significant temperature gradient on the surface of the mold, It can systematically underestimate or overestimate the interface temperature, leading to Deviations accumulate over time. The engineering consequences of accumulated deviations typically manifest as follows:

[0140] Premature triggering of termination criteria: leading to undersulfurization;

[0141] The termination criterion was triggered too late, leading to oversulfurization.

[0142] Misjudgment of critical parts: causing the controlled object to deviate from its true weakest part.

[0143] This invention uses local gradient information to obtain a more interface-like result through extrapolation of double burial depths along the same normal. ,make and The calculation is closer to the actual temperature environment of rubber reaction, thus significantly improving the representativeness and robustness of equivalent vulcanization calculation in an engineering-feasible manner without increasing the complexity of the heat transfer model.

[0144] 7) Optional extensions: multi-point extrapolation and least squares (preferred but not required)

[0145] When manufacturing allows for the placement of sensors at three or more burial depths at the same acquisition point, the least squares fit of the temperature gradient can be used and extrapolated to the interface to further suppress the amplification effect of noise extrapolation.

[0146] (iv) Step S4: Online identification of key components, hysteresis vibration suppression and termination of execution delay compensation

[0147] Step S4 no longer relies on offline simulation to fix the most difficult vulcanization point, but instead identifies the key parts that are most difficult to achieve the target in real time based on the equivalent vulcanization state calculated in real time. Meanwhile, equipment execution delays should also be considered. The termination is triggered by advance compensation, reducing the risk of oversulfurization caused by overshoot.

[0148] 1) Remaining equivalent vulcanization time Calculation and meaning

[0149] At any moment Each collection point Already obtained and To estimate how long it will take to reach the target, the remaining equivalent vulcanization time is defined. :

[0150] ;

[0151] in, For the first Point at time Estimate of the remaining equivalent vulcanization time; The target equivalent vulcanization time; To accumulate equivalent vulcanization time; It is the equivalent vulcanization rate factor.

[0152] molecular This indicates how much equivalent time is still needed at the reference temperature; then divide by the current rate factor. This yields the magnitude of the actual time required under current temperature conditions. This quantity comprehensively reflects both the current temperature level and the degree of vulcanization completed, providing a more accurate estimate than relying solely on temperature or solely on... It is more suitable for online key component recognition. When near hour, Approaching zero; when a certain part heats up slowly or has insufficient sulfurization, Relatively large.

[0153] 2) Key online components The determination

[0154] like Figure 4 As shown, the system identifies the part with the longest remaining time as the current critical part:

[0155] ;

[0156] in, For a moment Key component index; Indicates to make Index to get the maximum value .

[0157] The critical areas should be the most difficult to meet the standards for. Defined as maximum, it is equivalent to selecting the part that is furthest from the target if the current state is maintained. It can be updated in real time with changes in temperature field and material state, thereby realizing a one-size-fits-all approach.

[0158] 3) Switching vibration damping in key components

[0159] In actual vulcanization, the temperature signal may fluctuate slightly. and It will also fluctuate accordingly, leading to Frequent switching (jitter) between adjacent sampling cycles. Jitter has two types of adverse effects:

[0160] The decision-making objects are unstable, making it difficult to reach a consensus on termination criteria;

[0161] The event log is complex and may introduce the risk of control command jitter (especially when approaching the termination threshold).

[0162] Therefore, the present invention introduces a hysteresis threshold. One feasible vibration suppression rule is: if the remaining time difference between the old and new critical parts is insufficient to prove that a switch is indeed necessary, then the old critical parts should be retained.

[0163] This can be expressed logically as follows:

[0164] First calculate the candidate key parts ;

[0165] like Then update ;

[0166] Otherwise keep .

[0167] in, Candidate key parts; This refers to the key area in the previous moment; This is the hysteresis threshold.

[0168] This hysteresis mechanism is a key means of achieving stable online identification in engineering. It can ensure that the identification of key parts can reflect the most difficult parts in reality, and is not frequently switched due to minor noise.

[0169] 4) Execution delay Source and labeling

[0170] like Figure 5 As shown, vulcanization termination does not mean the reaction stops immediately upon issuing a command. Typically, a vulcanizing machine involves steps such as venting steam, depressurizing, mold opening, and tire ejection, and there is thermal inertia between the mold and the rubber compound. At the system level, the time from the output of the termination command to the actual decrease in heat input to the mold cavity can be equated to an execution delay. . This can be obtained through equipment calibration: for example, recording the time of the termination command output under standard operating conditions. When the mold temperature / cavity heating status drops significantly Then there is Alternatively, the parameters provided by the equipment manufacturer can be used to determine the method based on on-site verification.

[0171] 5) Criteria for Termination of Delay Compensation

[0172] To offset The overshoot caused by this invention is not included in this invention. Just reached It doesn't terminate at a specific time, but rather is triggered after advance compensation. Define the predicted equivalent vulcanization time:

[0173] ;

[0174] in, The predicted equivalent vulcanization time after delay compensation; The cumulative equivalent vulcanization time for key components; The equivalent vulcanization rate factor for key components; Execution is delayed.

[0175] The termination criterion is: when the following conditions are met. At that time, the system outputs a vulcanization termination command. Among them, The target equivalent vulcanization time. In the future Even if heating is stopped within a certain timeframe, the reaction will continue due to inertia. Estimate the equivalent cumulative amount during this period to achieve early triggering, thereby reducing supersulfurization.

[0176] 6) Delayed compensation in critical areas can reduce the risk of under-sulfurization / over-sulfurization.

[0177] If only fixed measurement points or average values ​​are used as criteria, the following may occur: some areas may meet the standard while critical weak points may not—under-sulfurization; if the execution delay is not considered and the process only terminates after reaching the threshold, the delay and thermal inertia will cause critical points to continue reacting—over-sulfurization; this invention uses... The largest value is used as the key component to ensure that the criterion always targets the most difficult-to-achieve area; then... The advance compensation trigger makes the termination time closer to the ideal target point, thereby shortening the vulcanization cycle, reducing the probability of over-sulfurization, and improving batch-to-batch consistency under the same safety margin.

[0178] (v) Step S5: Terminate execution, open mold and produce tire, and trace data.

[0179] Once the criterion in step S4 is met, the system outputs a vulcanization termination command to the vulcanizing machine via the device interface component. The vulcanizing machine then performs actions such as venting steam, depressurizing, mold opening, and tire ejection. The system records the following simultaneously:

[0180] Termination instruction output time ;

[0181] Key Parts Index ;

[0182] At the time of termination, each data collection point , , wait.

[0183] like Figure 6 As shown, data storage can adopt a structure of batch master table, process sequence table, and event table:

[0184] Batch master form: tire specifications, rubber compound formula identification, mold number, vulcanizing machine number, shift, etc.;

[0185] Process timing table: by Record , , , , , ;

[0186] Event table: critical component switching events, termination command events, abnormal / degradation events, etc.

[0187] This record is not only used for traceability, but also provides a basis for subsequent process optimization and quality diagnosis.

[0188] V. Specific Implementation Examples and Comparative Examples

[0189] The following describes specific embodiments and comparative examples of the present invention. It should be understood that the following embodiments are used to illustrate specific implementations of the present invention and are not intended to limit the scope of protection of the present invention. Without departing from the concept of the present invention, those skilled in the art can adaptively adjust the number of measuring points, sampling cycle, target equivalent vulcanization time, execution delay, and switching hysteresis threshold according to tire specifications, rubber compound formulation, vulcanizing machine type, and mold structure.

[0190] (I) Experimental Objective

[0191] This embodiment is used to verify the technical effectiveness of the present invention compared to fixed-time vulcanization control, single-depth temperature control, fixed key component control, and control without execution delay compensation. The verification focuses on: whether temperature measurement at dual burial depths along the same normal can improve the representativeness of interface or near-interface temperature estimation; whether online identification of key components based on the remaining equivalent vulcanization time can reduce vulcanization differences between components; whether execution delay compensation can reduce equivalent vulcanization overshoot at key components; and whether the total vulcanization time can be shortened while ensuring stable finished product performance.

[0192] (II) Test apparatus and test objects

[0193] This embodiment uses a laboratory tire vulcanizing machine for verification. The vulcanizing machine has functions for mold heating, mold closing and pressurization, steam venting and depressurization, and mold opening and tire ejection, and has a PLC control interface. The temperature acquisition system uses a multi-channel thermocouple acquisition module, and each channel has cold junction compensation, sampling synchronization, and timestamp recording functions. An industrial computer is used to perform data preprocessing, interface or near-interface temperature estimation, equivalent vulcanization calculation, key component identification, execution delay compensation, and termination criterion determination.

[0194] The test subjects were tire samples of the same specification and from the same batch of rubber compound. Except for the different control strategies, the tire specifications, rubber batch, mold number, initial mold temperature, vulcanization pressure, vulcanizing machine, environmental conditions, and operators were kept consistent across all groups. Ten tires from each group were used for statistical analysis to minimize the impact of fluctuations in individual samples on the evaluation results.

[0195] (III) Layout of measuring points and parameter settings

[0196] like Figure 3 As shown, temperature acquisition points are set at key thermal locations on the vulcanizing mold corresponding to the tire shoulder, sidewall, and bead. At each temperature acquisition point, a first temperature sensor and a second temperature sensor are arranged along the normal direction of the mold cavity's inner surface. The first temperature sensor is positioned close to the inner surface of the cavity, while the second temperature sensor is located deeper along the same normal direction. K-type thermocouples are preferred for both sensors, but N-type thermocouples can also be used.

[0197] In this embodiment, there are three temperature sampling points, corresponding to the tire shoulder, sidewall, and bead, respectively; the first temperature sensor is buried at a depth of 1.0 mm, and the second temperature sensor is buried at a depth of 5.0 mm; the sampling period is 0.5 seconds; the reference temperature is 170 degrees Celsius; the target equivalent vulcanization time is 12.0 minutes; the execution delay is 6 seconds; and the switching hysteresis threshold is 0.3 minutes. These parameters can be adjusted based on the rubber compound formulation, tire specifications, and the vulcanizing machine's execution link calibration results.

[0198] The execution delay was obtained through a step response test of the vulcanizing machine's exhaust, depressurization, and mold opening execution links. Specifically, under standard vulcanizing conditions, a termination command was output to the vulcanizing machine, and the time difference between the output of the termination command and the start of a substantial decrease in the heat input to the mold cavity was recorded as the execution delay. To reduce random errors, the test was repeated 5 times, and the average value was taken as the execution delay in this embodiment.

[0199] (iv) Calculation method

[0200] At each sampling moment, the system synchronously collects the first and second burial depth temperatures of each temperature sampling point, and performs temperature correction, noise reduction, and outlier removal. Outlier removal adopts a sliding window method. When a temperature value deviates from the window mean by more than 3 times the standard deviation of the window temperature, the temperature value is judged as an outlier and replaced by the valid temperature value of the previous sampling moment.

[0201] The interface or near-interface temperature is linearly extrapolated based on the first burial depth temperature, the second burial depth temperature at the same temperature acquisition point, and the difference in burial depth between the two sensors. The calculation method is as follows:

[0202] ;

[0203] In the formula, Estimate the temperature at the interface or near the interface for the i-th temperature acquisition point at time t; The temperature at the first burial depth of the i-th temperature acquisition point; The second burial depth temperature of the i-th temperature acquisition point; The burial depth of the first temperature sensor; The burial depth for the second temperature sensor.

[0204] The equivalent vulcanization rate factor is calculated according to the Arrhenius relation:

[0205] ;

[0206] In the formula, Let be the equivalent sulfidation rate factor of the i-th temperature acquisition point at time t; The apparent activation energy of the vulcanization reaction is retrieved from the vulcanization formulation database by the rubber compound formulation identifier. It is the gas constant; For reference temperature; Estimate the temperature at or near the interface. Convert the temperature to absolute temperature before entering the above calculations.

[0207] The cumulative equivalent vulcanization time is obtained using discrete integration:

[0208] ;

[0209] In the formula, Let be the cumulative equivalent vulcanization time of the i-th temperature acquisition point at the k-th sampling time; This is the cumulative equivalent vulcanization time at the previous sampling time; The sampling period.

[0210] To identify the most critical areas that are currently most difficult to meet the standards, the remaining equivalent vulcanization time at each temperature sampling point is calculated:

[0211] ;

[0212] In the formula, Let be the remaining equivalent vulcanization time at time t for the i-th temperature sampling point; The target equivalent vulcanization time; To accumulate equivalent vulcanization time; It is the equivalent vulcanization rate factor.

[0213] The system identifies the temperature sampling point with the largest remaining equivalent vulcanization time as the candidate critical location:

[0214] ;

[0215] In the formula, This is the index of the critical part at time t. To suppress frequent switching of critical parts due to temperature fluctuations within adjacent sampling periods, the system sets a switching hysteresis threshold. When the remaining equivalent vulcanization time difference between the candidate critical part and the critical part at the previous sampling time does not reach the switching hysteresis threshold, the critical part at the previous sampling time remains unchanged; when the switching hysteresis threshold is reached, the candidate critical part is updated to the current critical part.

[0216] To compensate for the thermal input inertia of the vulcanizing machine's execution link, the system calculates the predicted equivalent vulcanizing time after delay compensation:

[0217] ;

[0218] In the formula, To predict the equivalent vulcanization time; This refers to the cumulative equivalent vulcanization time of the current critical components; This is the equivalent vulcanization rate factor for the current key components; To implement a delay, when the predicted equivalent vulcanization time reaches the target equivalent vulcanization time, the system outputs a vulcanization termination command, which the vulcanizing machine then performs steam venting, pressure relief, and mold opening.

[0219] (v) Examples and Comparative Examples

[0220] Example 1

[0221] Example 1 employs the dynamic equivalent vulcanization control method of the present invention.

[0222] First, according to Figure 1 Build a control system, according to Figure 3 Temperature acquisition points with the same normal and double embedment depth are set at the tire shoulder, sidewall, and bead positions. The first and second temperature sensors at each measuring point are connected to a multi-channel temperature acquisition module, which is connected to an industrial computer. The industrial computer communicates with the vulcanizing machine through a PLC interface.

[0223] Secondly, according to Figure 2The vulcanization control process is executed. After vulcanization begins, the system synchronously collects the first and second burial depth temperatures of each measuring point on the tire shoulder, sidewall, and bead at a sampling period of 0.5 seconds, and performs cold end compensation, sliding window filtering, and outlier removal.

[0224] Next, the system calculates the interface or near-interface temperature for each measuring point, and calculates the equivalent vulcanization rate factor and cumulative equivalent vulcanization time based on the interface or near-interface temperature estimate. Figure 7 Used to display the difference between the first burial depth temperature, the second burial depth temperature, and the estimated temperature at or near the interface; Figure 8 Used to display the change of cumulative equivalent vulcanization time at each measuring point over time.

[0225] Then, the system identifies key parts online based on the remaining equivalent vulcanization time at each measuring point, and determines whether to switch key parts based on the switching hysteresis threshold. Figure 4 This is used to illustrate the online identification and switching vibration damping logic of key components. Figure 9 Used to display the changes in the index of key parts over time and the corresponding changes in the remaining equivalent vulcanization time.

[0226] Finally, the system calculates and predicts the equivalent vulcanization time based on the cumulative equivalent vulcanization time of the current critical parts, the equivalent vulcanization rate factor, and the execution delay. When the predicted equivalent vulcanization time reaches the target equivalent vulcanization time, the system outputs a vulcanization termination command. Figure 5 This is used to explain the termination criteria for implementing advance compensation for delays. Figure 10 Used to display a comparison between the predicted equivalent vulcanization time and the target equivalent vulcanization time. After vulcanization is complete, the system... Figure 6 Record raw temperature data, estimated temperature at or near the interface, equivalent vulcanization calculation results, key component identification results, and termination event data.

[0227] Comparative Example 1

[0228] Comparative Example 1 employs fixed-time vulcanization control. This comparative example does not enable real-time temperature feedback control, does not calculate interface or near-interface estimated temperatures, does not calculate equivalent vulcanization rate factors and cumulative equivalent vulcanization time, and does not perform online identification of critical components or execute delay compensation. The vulcanizing machine completes vulcanization according to a preset fixed total vulcanization time. Except for the different control strategy, the tire specifications, rubber batch, mold number, vulcanizing machine, and other process conditions are the same as in Example 1.

[0229] This comparative model is used to evaluate the total vulcanization time, equivalent vulcanization dispersion between parts, and overshoot of key parts under the traditional fixed-time vulcanization method.

[0230] Comparative Example 2

[0231] Comparative Example 2 employs a single-depth fixed-point equivalent vulcanization control. This comparative example uses only the temperature at the first burial depth collected by the first temperature sensor as the temperature input, without performing dual-depth extrapolation; key parts use pre-determined offline fixed measuring points that do not dynamically change with the vulcanization process; the termination criterion does not include execution delay compensation.

[0232] Specifically, the most difficult-to-curing areas among the tire shoulder, sidewall, and bead, determined through offline simulation or empirical judgment, are selected as fixed key areas. The system calculates the equivalent curing process based on the first burial depth temperature of these fixed key areas. When the cumulative equivalent curing time of the fixed key areas reaches the target equivalent curing time, a termination command is output. The remaining conditions are the same as in Example 1.

[0233] This comparative example is used to evaluate the control deviation caused by insufficient representativeness of temperature at single burial depth and the inability of fixed key components to adapt to actual thermal drift.

[0234] Comparative Example 3

[0235] Comparative Example 3 employs a control strategy that uses dual-depth extrapolation but does not perform online identification of critical components. This comparative example is the same as Example 1, both setting temperature acquisition points with the same normal and dual-depth at the tire shoulder, sidewall, and bead, and calculating the estimated temperature at the interface or near the interface; the difference is that Comparative Example 3 still uses a pre-determined fixed critical component as the control object for the curing termination criterion, and does not switch the critical component online based on the remaining equivalent curing time.

[0236] The termination criterion for this comparison includes execution delay compensation, which involves calculating and predicting the equivalent vulcanization time based on the cumulative equivalent vulcanization time of the fixed key parts, the equivalent vulcanization rate factor, and the execution delay, and outputting a termination command when the predicted equivalent vulcanization time reaches the target equivalent vulcanization time. The remaining conditions are the same as in Example 1.

[0237] This comparative example is used to distinguish the contribution of the two technical features, "double-depth extrapolation of interface or near-interface temperature" and "online identification of key parts," to the uniformity of vulcanization.

[0238] Comparative Example 4

[0239] Comparative Example 4 employs dual-depth extrapolation and online identification of key components, but does not perform execution delay compensation. This comparative example is the same as Example 1, both extrapolating and estimating the interface or near-interface temperature and identifying key components online based on the remaining equivalent vulcanization time; the difference is that Comparative Example 4 does not consider the execution delay between the output of the termination command and the substantial decrease in the thermal input of the mold cavity when determining whether to terminate vulcanization.

[0240] Specifically, when the cumulative equivalent vulcanization time of the current critical part reaches the target equivalent vulcanization time, the system outputs a termination command. The remaining conditions are the same as in Example 1.

[0241] This comparative model is used to evaluate the effect of performance delay compensation on suppressing equivalent vulcanization overshoot in critical areas.

[0242] (vi) Evaluation indicators

[0243] The following indicators were used in this embodiment to evaluate the control effect of each group.

[0244] 1. Total vulcanization time, denoted as This refers to the time from the start of mold closing to the completion of the termination instruction.

[0245] 2. The equivalent vulcanization dispersion between locations at the termination point, denoted as... This is used to evaluate the uniformity of vulcanization in key areas, and the calculation method is as follows:

[0246] ;

[0247] In the formula, This represents the cumulative equivalent vulcanization time at the i-th temperature sampling point when vulcanization terminates. The smaller this value, the closer the vulcanization degree is between different key parts.

[0248] 3. Equivalent vulcanization overshoot in critical areas, denoted as It is used to evaluate the degree of overshoot in the termination control, and is calculated as follows:

[0249] ;

[0250] In the formula, This represents the cumulative equivalent vulcanization time at critical locations when vulcanization is terminated. The smaller this value, the closer the termination time is to the target equivalent vulcanization time, and the lower the risk of over-vulcanization.

[0251] 4. Finished product performance indicators, including Shore A hardness, tensile strength, stress at 300% elongation, tear strength, and dynamic loss factor at 60 degrees Celsius. Samples should be taken from the same location during testing and conducted according to the company's inspection procedures or relevant national standards.

[0252] (vii) Process data results

[0253] Figure 7 The results show that, during the same vulcanization process, there are differences between the first embedment temperature, the second embedment temperature, and the extrapolated estimated interface or near-interface temperature. Taking the tire bead measuring point as an example, in the middle and later stages of vulcanization, the first embedment temperature is higher than the second embedment temperature, indicating that the temperature near the inner surface of the cavity is more representative of the heated state of the tire rubber compound; the extrapolated estimated interface or near-interface temperature further reflects the temperature gradient on the mold surface. These results suggest that using only a single embedment temperature as the input for equivalent vulcanization calculations may underestimate or overestimate the actual interfacial thermal state.

[0254] Figure 8The results show that the cumulative equivalent vulcanization time at different measuring points gradually increases with vulcanization time, but the growth rate differs among the tire shoulder, sidewall, and bead. This difference indicates that the thermal history and vulcanization process of different critical parts are not consistent, and if a fixed vulcanization time or fixed critical part control is used, it may not be possible to simultaneously take care of all critical parts.

[0255] Figure 9 The results show that in Example 1, the index of key components can switch during the vulcanization process according to the remaining equivalent vulcanization time, and will not frequently fluctuate within adjacent sampling periods under the action of the switching hysteresis threshold. This result demonstrates that the present invention can determine the most difficult-to-achieve components online based on actual thermal changes, avoiding deviations caused by relying solely on offline simulation or fixed key points based on experience.

[0256] Figure 10 As shown, the predicted equivalent vulcanization time in Example 1 triggers a termination command when the target equivalent vulcanization time is reached. Since the predicted equivalent vulcanization time already includes the equivalent vulcanization amount that may continue to increase during the execution delay, termination can be triggered in advance before the actual heat input has completely decreased, reducing termination overshoot.

[0257] (viii) Statistical data results

[0258] Table 1 shows the statistical results of the equivalent vulcanization dispersion between different control strategies at the termination point. Each group contains 10 samples.

[0259] Table 1. Statistical results of equivalent vulcanization dispersion between different control strategies at the termination point.

[0260]

[0261] As shown in Table 1, the equivalent vulcanization dispersion between different locations at the termination point of Example 1 was lower than that of the comparative examples. Compared with Comparative Example 1, the dispersion of Example 1 was significantly reduced, indicating that fixed-time control is insufficient to adapt to the differences in thermal history of different key locations. Compared with Comparative Example 2, Example 1 improved the representativeness of temperature input through dual-depth extrapolation. Compared with Comparative Example 3, Example 1 further reduced the vulcanization differences between different locations through online identification of key locations. These statistical results are consistent with... Figure 11 The trends shown are consistent.

[0262] Table 2 shows the statistical results of total vulcanization time and equivalent vulcanization overshoot in key areas under different control strategies. Each group has 10 samples.

[0263] Table 2. Statistical results of total vulcanization time and equivalent vulcanization overshoot in key areas under different control strategies.

[0264]

[0265] Table 2 shows that Example 1 shortened the total vulcanization time and reduced the equivalent vulcanization overshoot at critical parts compared to Comparative Example 1. Although Comparative Example 4 used online identification of critical parts, resulting in a slightly shorter total vulcanization time, its equivalent vulcanization overshoot at critical parts was higher than that of Example 1 due to the lack of execution delay compensation. This result indicates that online identification of critical parts alone is insufficient to eliminate the thermal input inertia effect caused by the termination of the execution chain; further introducing execution delay compensation based on online identification of critical parts can more stably control the termination time. These statistical results are consistent with... Figure 12 The trends shown are consistent.

[0266] (ix) Performance results of finished products

[0267] Table 3 shows the key performance test results of the finished products of Comparative Example 1, Comparative Example 2, and Example 1. Each group has 10 samples, and the test samples were taken from the corresponding key parts.

[0268] Table 3. Key performance test results of the finished products of Comparative Example 1, Comparative Example 2, and Example 1

[0269]

[0270] As shown in Table 3, Example 1, while shortening the total vulcanization time and reducing equivalent vulcanization overshoot in key areas, maintained stable finished product hardness, tensile strength, 300% elongation stress, and tear strength, with a slightly lower dynamic loss factor at 60 degrees Celsius. These results indicate that the present invention does not shorten vulcanization time through under-vulcanization, but rather reduces the risk of over-vulcanization and maintains the overall performance of the finished product by more accurately identifying key thermal components and more rationally controlling the termination time.

[0271] (x) Technical Effect Analysis

[0272] A comparison of Example 1 and Comparative Example 1 shows that the fixed-time control does not consider the actual thermal differences of each tire and each cycle. This can easily lead to setting a large time margin to ensure sufficient vulcanization in the slowest parts, resulting in a longer total vulcanization time and greater overshoot in critical areas. Example 1, through real-time temperature feedback and equivalent vulcanization calculation, can output a termination command when the target equivalent vulcanization conditions are reached, thereby reducing unnecessary vulcanization time.

[0273] A comparison of Example 1 and Comparative Example 2 shows that single-depth temperature measurement only reflects the temperature at a certain depth inside the mold and cannot fully reflect the temperature state at the interface or near-interface between the mold and the tire. Example 1 obtains the local temperature gradient through dual-depth temperature measurement along the same normal and estimates the temperature at the extrapolated interface or near-interface based on this, making the equivalent vulcanization calculation input closer to the actual heating state of the rubber compound, thereby reducing the calculation deviation caused by insufficient representativeness of the temperature input.

[0274] A comparison of Example 1 and Comparative Example 3 shows that even with double-depth extrapolation, if the key components are still fixed at their offline determined positions, it may not be able to adapt to the drift of key components caused by changes in tire condition, mold temperature, rubber batch, and local heat transfer conditions during vulcanization. Example 1 identifies key components online using the remaining equivalent vulcanization time, enabling the termination criterion to continuously align with the component most difficult to reach the target vulcanization state, thereby reducing the equivalent vulcanization dispersion between components at termination.

[0275] A comparison of Example 1 and Comparative Example 4 shows that, without execution delay compensation, even if the current critical part has reached the target equivalent vulcanization time, the vulcanizing machine still has thermal input inertia during steam exhaust, depressurization, and mold opening, which may cause continued reaction and overshoot. Example 1 reduces the equivalent vulcanization overshoot of critical parts by incorporating the expected increase in equivalent vulcanization amount during the execution delay period into the predicted equivalent vulcanization time and outputting a termination command in advance before reaching the target condition.

[0276] In summary, Example 1 achieves closed-loop control of the dynamic equivalent vulcanization process of tires by combining dual-depth temperature measurement along the same normal, extrapolation of interface or near-interface temperatures, online identification of key components, switching hysteresis suppression, and execution delay compensation. Compared with the comparative examples, this invention can reduce vulcanization differences between parts, reduce overshoot at key components, and shorten the total vulcanization time while ensuring stable finished product performance.

[0277] The foregoing description of embodiments of the present invention, through which those skilled in the art are able to implement or use the present invention, will be readily apparent to those skilled in the art. Various modifications to these embodiments will be readily apparent to those skilled in the art. The general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the present invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novelty disclosed herein.

[0278] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product embodied on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0279] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart... Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0280] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0281] These computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable apparatus for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0282] In a typical configuration, a computing device includes one or more processors (CPU), input / output interfaces, network interfaces, and memory.

[0283] Memory may include non-persistent memory in computer-readable media, such as random access memory (RAM) and / or non-volatile memory, such as read-only memory (ROM) or flash RAM. Memory is an example of computer-readable media.

[0284] Computer-readable media includes both permanent and non-permanent, removable and non-removable media that can store information using any method or technology. Information can be computer-readable instructions, data structures, modules of programs, or other data. Examples of computer storage media include, but are not limited to, phase-change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technologies, CD-ROM, digital versatile optical disc (DVD) or other optical storage, magnetic tape, magnetic disk storage or other magnetic storage devices, or any other non-transferable medium that can be used to store information accessible by a computing device. As defined herein, computer-readable media does not include transient computer-readable media, such as modulated data signals and carrier waves.

Claims

1. A method for dynamic equivalent vulcanization of tires based on real-time temperature feedback, characterized in that, The steps include the following: S1, set at least two temperature acquisition points at the tire shoulder, sidewall and bead corresponding to the tire vulcanization mold. Each temperature acquisition point is arranged with a first temperature sensor and a second temperature sensor along the normal direction of the inner surface of the cavity, and set the reference temperature, target equivalent vulcanization time, sampling period, execution delay and switching hysteresis threshold. S2, during the vulcanization process, collects the first and second burial depth temperatures at each temperature collection point in real time, and performs temperature correction, noise reduction, and outlier removal. S3. Based on the temperature difference between the first burial depth temperature and the second burial depth temperature and the burial depth difference between the two sensors, the temperature of the contact interface or near interface between the mold and the tire is linearly extrapolated and estimated, and the equivalent vulcanization rate factor and cumulative equivalent vulcanization time of each temperature acquisition point are calculated. S4. The temperature sampling point with the largest remaining time required to reach the target equivalent vulcanization time is identified as the key part. The switching hysteresis threshold is used to suppress frequent switching of the key part. The current accumulated equivalent vulcanization time of the key part is added to the estimated increase in equivalent vulcanization time during the execution delay to obtain the predicted equivalent vulcanization time. S5 outputs a vulcanization termination command when the predicted equivalent vulcanization time reaches the target equivalent vulcanization time, causing the vulcanizing machine to perform steam exhaust, depressurization, and mold opening to end the vulcanization process, and records process traceability data.

2. The method according to claim 1, characterized in that, In step S1, the first temperature sensor and the second temperature sensor are thermocouples, and the thermocouples are type K thermocouples or type N thermocouples; the burial depth of the first temperature sensor is greater than 0 mm and does not exceed 1 mm, the burial depth of the second temperature sensor is 2 mm to 8 mm, and the burial depth of the second temperature sensor is greater than the burial depth of the first temperature sensor.

3. The method according to claim 1, characterized in that, In step S2, the outlier removal includes: determining the degree of deviation of the first burial depth temperature or the second burial depth temperature from the window mean within the sliding window; when the deviation exceeds 3 times the window temperature standard deviation, the corresponding temperature data is determined to be an outlier and replaced with the valid temperature data from the previous sampling time.

4. The method according to claim 1, characterized in that, In step S3, the extrapolation estimation of the interface or near-interface temperature is obtained based on the thermal gradient relationship between the first burial depth temperature, the second burial depth temperature, the burial depth of the first temperature sensor, and the burial depth of the second temperature sensor at the same temperature acquisition point; the equivalent sulfidation rate factor is determined based on the reference temperature, the interface or near-interface temperature, the apparent activation energy of the sulfidation reaction, and the gas constant; the cumulative equivalent sulfidation time is obtained by accumulating the change of the equivalent sulfidation rate factor over time. In step S3, the apparent activation energy of the vulcanization reaction is retrieved from the vulcanization formula database by the rubber compound formula identifier, which is used to distinguish different tire rubber compound formulas; the sampling period is any value in the range of 0.1 seconds to 2 seconds.

5. The method according to claim 1, characterized in that, In step S4, the remaining equivalent vulcanization time is determined based on the target equivalent vulcanization time, the current cumulative equivalent vulcanization time, and the current equivalent vulcanization rate factor; the key part is the tire part corresponding to the temperature sampling point with the largest remaining equivalent vulcanization time; when the difference between the remaining equivalent vulcanization time of the candidate key part and the key part at the previous sampling time does not reach the switching hysteresis threshold, the key part at the previous sampling time remains unchanged. In step S4, the online identification of key parts is performed at least once within a predetermined identification window after the start of vulcanization. The predetermined identification window is a time interval of a preset length starting from the start of vulcanization. The switching hysteresis threshold is used to suppress frequent switching of key parts in adjacent sampling periods, and the switching hysteresis threshold is any value in the range of 0.1 minutes to 3 minutes.

6. The method according to claim 1, characterized in that, In step S4, the execution delay is the equivalent delay time from the output of the vulcanization termination command to the substantial decrease in the heat input of the mold cavity, and is obtained by step response test of the vulcanizing machine's mold opening, steam exhaust, and pressure relief execution link; the target equivalent vulcanization time is calculated from the T90 of the rubber compound at the reference temperature, where T90 is the vulcanization time corresponding to when the rubber compound torque reaches 90% of the maximum torque.

7. A tire dynamic equivalent vulcanization system based on real-time temperature feedback, characterized in that, To implement the method according to any one of claims 1 to 6, comprising: A temperature acquisition component is used to arrange a first temperature sensor and a second temperature sensor along the normal direction at each temperature acquisition point of multiple key thermal parts of the vulcanizing mold to obtain the first burial depth temperature and the second burial depth temperature. The data preprocessing component is used to perform temperature correction, noise reduction, and outlier removal on the first and second burial depth temperatures. An interface temperature estimation component is used to obtain the estimated temperature of the interface or near-interface based on the first burial depth temperature, the second burial depth temperature and their burial depth difference. The equivalent vulcanization calculation component is used to calculate the equivalent vulcanization rate factor and cumulative equivalent vulcanization time based on the estimated temperature at the interface or near the interface, the reference temperature, and the vulcanization reaction parameters of the rubber compound. The critical component identification and decision-making component is used to calculate the remaining equivalent vulcanization time, identify critical components, and generate a vulcanization termination command in conjunction with the execution delay. The equipment interface component is used to send the vulcanization termination command to the vulcanizing machine to execute the end of vulcanization and mold opening and tire ejection; Data storage components are used to store temperature acquisition data, estimated temperature at or near the interface, equivalent vulcanization calculation data, key component identification results, and termination event data.

8. The system according to claim 7, characterized in that, The device interface component is a PLC interface or an industrial Ethernet interface; the critical part identification and decision component includes a hysteresis control unit, which is used to perform critical part switching suppression according to the switching hysteresis threshold; the temperature acquisition component is set at three locations: tire shoulder, tire sidewall, and tire bead, and there are no fewer than three temperature acquisition points.

9. A computer-readable storage medium having a computer program or instructions stored thereon, characterized in that, When the computer program or instructions are executed by a processor, they implement the steps of the method according to any one of claims 1-6.

10. A computer program product, comprising a computer program or instructions, characterized in that, When the computer program or instructions are executed by a processor, they implement the steps of the method according to any one of claims 1-6.

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