A rubber numerical control electrothermal cyclic vulcanizing machine and control system

Abstract

The present invention discloses a rubber numerical control electrothermal cyclic vulcanizer and a control system. The present invention relates to the technical field of rubber processing equipment. The present invention uses a thermal imager to collect the temperature distribution image of the vulcanization chamber in real time and divides the area, identifies the temperature range of each area and calculates the area. Based on the key temperature range of the rubber material, a three-stage intelligent control strategy is constructed: in the heating stage, the heating power and pressure compensation are dynamically adjusted according to the temperature range distribution; in the constant temperature stage, the heating power and pressure parameters are optimized through temperature stability; in the cooling stage, the pressure dynamic compensation is implemented according to the cooling rate. The system uses RFID to record process parameters such as temperature and time in each stage of vulcanization, and realizes product classification storage and regular quality inspection through an intelligent warehousing management system. The present invention significantly reduces energy consumption, improves the vulcanization uniformity of rubber products, reduces the defective rate, and provides an efficient and energy-saving solution for the rubber processing industry through multi-parameter collaborative control.

Description

Technical Field

[0001] The present invention relates to the technical field of rubber processing equipment, and particularly to a rubber numerical control electrothermal circulating vulcanizer and a control system thereof. Background Art

[0002] In the process of rubber vulcanization production, traditional vulcanizers have many drawbacks. On the one hand, heating elements usually operate at a constant power. Regardless of the internal temperature state of the vulcanizer, the thermal power cannot be reasonably adjusted according to the stage where the heating element is located, resulting in a large amount of electrical energy waste. On the other hand, when applying pressure to rubber products, a unified standard is often adopted, ignoring the temperature differences in different parts of the rubber, making the vulcanization degree of different parts of the rubber product inconsistent, seriously affecting the product quality and increasing the defective rate. In addition, in the traditional production mode, it is difficult to trace and manage product quality, and it is difficult to effectively monitor and analyze the quality changes of products during production and storage. Summary of the Invention

[0003] Aiming at the deficiencies of the prior art, the present invention provides a rubber numerical control electrothermal circulating vulcanizer and a control system thereof, which solve the problems that the pressure applied to different parts of the rubber cannot be adjusted according to the internal temperature distribution of the vulcanizer and the quality of rubber products cannot be effectively monitored.

[0004] To achieve the above objectives, the present invention is realized through the following technical solutions: A control system for a rubber numerical control electrothermal circulating vulcanizer, comprising:

[0005] A thermal imaging monitoring and area division module, which uses a thermal imager to monitor the temperature distribution inside the vulcanizer, divides the thermal imaging pictures into n regions according to the shape of the rubber product inside the vulcanizer, the mold structure, and the temperature field distribution, and transmits the thermal imaging pictures of the divided regions to the temperature range identification and area calculation module;

[0006] A temperature range identification and area calculation module, which collects the pixels of each region of the thermal imaging picture, determines the temperature range existing in each region according to the color or gray value of the pixels corresponding to different temperatures, calculates the area of different temperature ranges, and transmits the temperature range and area corresponding to each region of the calculated thermal imaging picture to the temperature rising stage regulation module;

[0007] A temperature rising stage regulation module, which determines the key temperature range according to the characteristics of the rubber material, and adjusts the pressure applied to the region according to the number and total area of the alternative temperature range, general temperature range, and alternative key temperature range in different regions;

[0008] The constant temperature stage control module calculates the stability of the key temperature range of the area within the key temperature range, adjusts the applied pressure on the area within the key temperature range according to the stability and the magnitude of the average temperature in the adjacent time period. For the area outside the key temperature range, it calculates the distance from it to the area within the surrounding key temperature range, and finds the pressure change amount of the area within the key temperature range with the smallest corresponding distance to adjust the applied pressure;

[0009] The cooling stage control module adjusts the applied pressure according to the cooling rates of the areas within the key temperature range and the areas outside the key temperature range.

[0010] As a further solution of the present invention, after the cooling stage control module, there is also a product management and quality monitoring module. After the rubber product is initially inspected and qualified, the product management and quality monitoring module attaches an RFID tag to each rubber product, stores the rubber products in the warehouse according to the first-in, first-out storage principle. For the rubber products that have not been shipped out, an inspection cycle is set, and machine vision inspection software is used to automatically inspect the appearance of the rubber products. If it is found that the appearance of the product has changed, the key production information of the abnormal rubber product is read through a fixed RFID scanner, and the duration intervals [ai, bi] and the temperature mean sequence Temi in different stages are obtained. For the newly produced qualified rubber products, the system automatically compares the time tti used in the three vulcanization stages of the product with [ai, bi]. If tti ∈ [ai, bi], then the product is marked as a product to be observed. The temperature change sequence Wai of the three vulcanization stages of the product to be observed is extracted, and the similarity Si between the sequence Wai and Temi is calculated respectively. A similarity threshold Sth is set, and the number num of those satisfying Si > Sth is counted. If num >= 2, it is marked as a product requiring key attention.

[0011] As a further solution of the present invention, the area corresponding to each temperature range is calculated according to the formula Sij = Nij / k, where Nij is the number of pixel points in each temperature range, and k is the pixel-area conversion coefficient of the thermal imager.

[0012] As a further solution of the present invention, the distance dij between each temperature range in area i and the key temperature range is calculated as dij = |Tij_min - Keymax|. If dij ∈ [dmin, dmax], it is marked as an alternative temperature range. If dij > dmax, it is marked as a general temperature range. If |Tij_max - Keymax| <= dij < dmin, it is marked as an alternative key temperature range. If dij < |Tij_max - Keymax|, it is marked as a key temperature range, where Keymax is the upper limit of the key temperature range of the rubber material, dmin and dmax are distance thresholds, and Tij_min and Tij_max are the lower and upper limits of the jth temperature range in area i.

[0013] As a further solution of the present invention, the specific steps for adjusting the pressure in different regions i during the heating stage are as follows:

[0014] Count the numbers of alternative temperature intervals, general temperature intervals, and alternative critical temperature intervals contained in different regions i as num1, num2, num3, and the total areas as Sai, Sbi, Sci;

[0015] If num2≠0 and num1 = 0, num3 = 0 in region i, then construct a pressure adjustment formula according to the average value of the distances between the general temperature intervals and the critical temperature intervals. The specific formula is as follows: Pi = P0 + k1*avg(di) + k2*avg(di)^2;

[0016] If num1≠0 and num2≠0, num3 = 0, then construct a pressure adjustment formula according to the ratio of the total area of the alternative temperature intervals to the total area of the general temperature intervals. The specific formula is as follows: Pi = P0*(1 + k3*(Sai / Sbi) + k4*sqrt(Sai / Sbi));

[0017] If num3≠0, when Sci / Stotali >= 0.5, apply a pressure of Sbest. When Sci / Stotali < 0.5, construct a pressure adjustment formula according to the total area of the alternative critical temperature intervals. The specific formula is as follows: Pi = Sbest*(1 - k5*(0.5 - Sci / Stotali));

[0018] Among them, P0 is the currently applied pressure, di is the distance between the general temperature interval and the critical temperature interval, avg() is the average function, sqrt() is the square root function, Sbest is the best applied pressure when the rubber is in the critical temperature interval, Stotali is the total area of different regions i, and k1, k2, k3, k4, k5 are pressure adjustment coefficients.

[0019] As a further solution of the present invention, during the constant temperature stage, if (area of the critical temperature interval in region i / total area of region i) > β, then this region is called a region within the critical temperature interval; otherwise, it is called a region within the non-critical temperature interval, where β is the area threshold.

[0020] As a further solution of the present invention, the specific steps for adjusting the pressure in different regions i during the constant temperature stage are as follows:

[0021] Calculate the temperature stability index of the critical temperature interval of the regions within the critical temperature interval , if σ > σmax and , appropriately reduce the regional pressure. The specific pressure adjustment formula is as follows: Pnew = Pcurrent * (1 - h1 * (σ - σmax) * ( ));

[0022] If σ > σmax and , it is necessary to appropriately increase the regional pressure. The specific pressure adjustment formula is as follows: Pnew = Pcurrent * (1 + h2 * (σ - σmax) * ( ));

[0023] For the region within the non-critical temperature range, calculate the distance dnear to the nearest region within the critical temperature range around it. If dnear <= dth, then adjust its own pressure according to the pressure change amount of the region within the critical temperature range. The specific pressure adjustment formula is: Pnew = Pcurrent + h3 * △Pkey * (Scurrent / Stotal), otherwise, maintain the current pressure unchanged;

[0024] Among them, σmax is the temperature stability threshold, △Pkey is the pressure adjustment amount of the region within the critical temperature range, Scurrent is the area of the current region within the non-critical temperature range, Stotal is the total area, Pcurrent is the current regional pressure, 、 is the average value of the temperatures within the time t and t + △t, and h1, h2, h3 are the pressure adjustment coefficients.

[0025] As a further solution of the present invention, the specific steps for pressure adjustment of different regions i during the cooling stage are as follows:

[0026] Calculate the cooling rate vT of each region = (T t+△t - T t ) / △t;

[0027] For the region within the critical temperature range, if vT < vTmax, it is necessary to increase the pressure. The specific pressure adjustment formula is Pnew = Pcurrent * (1 + h4 * (vTmax - vT));

[0028] If vT ∈ [vTmax, 0], the pressure should be appropriately reduced. The specific pressure adjustment formula is: Pnew = Pcurrent * (1 - h5 * (1 - Pp / Pr));

[0029] For the region within the non-critical temperature range, the specific pressure adjustment formula is: Pnew = Pcurrent * (1 + h6 * (vT - vTth) / vTth);

[0030] Among them, vTmax is a negative number, Pp is the proportion of pixels where obvious temperature changes actually occur within the critical temperature range, Pr is the reference value of the proportion of pixels where corresponding obvious temperature changes occur within the critical temperature range under the ideal vulcanization state, vTth is the target cooling rate of the area within the preset non-critical temperature range, and h4, h5, and h6 are pressure adjustment coefficients.

[0031] As a further solution of the present invention, key attention is paid to a specific area in the warehouse where the product is placed. This area is equipped with more intensive environmental monitoring equipment, and at the same time, the inspection frequency is increased, and the inspection frequency is the minimum value in the storage time series.

[0032] A rubber numerically controlled electrothermal cycle vulcanizer, which includes:

[0033] A main frame structure, which is composed of a four-column type or frame type bracket, includes an upper mold that can move up and down and a fixed lower mold. The upper mold and the lower mold are driven to close by a hydraulic or pneumatic device. A pressure sensor and a displacement sensor are arranged between the upper mold and the lower mold to monitor the deformation of the mold and the pressure distribution in real time, and are linked with the temperature range identification and area calculation module of the control system to realize multi-parameter collaborative control of pressure-temperature-displacement;

[0034] An electrothermal cycle heating system, including resistance wires or electromagnetic induction heating elements embedded inside the mold, a spiral coil type heat transfer medium channel surrounding the mold, and an independent temperature control module. The main heating module and the auxiliary circulation module are linked through the circulation of heat transfer oil or water medium to realize rapid temperature rise and uniformity control of the mold temperature, and communicate with the heating-up stage regulation module, the constant temperature stage regulation module, and the cooling-down stage regulation module of the control system to dynamically adjust the heating power;

[0035] A multi-region pressure dynamic adjustment system, including multiple hydraulic cylinders or pneumatic cylinders distributed below or on the side of the mold. Each cylinder corresponds to an independent pressure adjustment unit. The pressure adjustment unit is communicatively connected to the heating-up stage regulation module, the constant temperature stage regulation module, and the cooling-down stage regulation module of the control system, and dynamically adjusts the local pressure based on the pressure compensation instruction sent by the control system to support differential pressure control in different regions during the vulcanization process;

[0036] A thermal imaging integrated monitoring module, including a high-temperature resistant infrared transparent window, an electric zoom thermal imager, and a robotic arm positioning device installed on the side or top of the mold. The thermal imager collects the temperature field data of the vulcanization process in real time through the infrared window and transmits it to the thermal imaging monitoring and area division module of the control system to realize real-time monitoring and area division of the temperature field;

[0037] The intelligent control interface realizes data interaction with the control system through an industrial computer or PLC, supports the coordinated control of the control system over the electric heating cycle heating system, the multi-region pressure dynamic adjustment system, and the thermal imaging integrated monitoring module. Moreover, the intelligent control interface is built-in with an edge computing module, which can analyze the vulcanization parameters in real time and trigger early warnings, and is linked with the product management and quality monitoring module of the control system to realize the storage of vulcanization data and quality traceability.

[0038] The present invention provides a rubber numerically controlled electric heating cycle vulcanizing machine and a control system. Compared with the prior art, it has the following beneficial effects:

[0039] (1) According to the temperature of different parts of the rubber, the present invention precisely adjusts the applied pressure, making the vulcanization degree of each part of the rubber product more uniform, improving the product quality and reducing the defective rate.

[0040] (2) The present invention records the detailed data of the product vulcanization process through RFID tags, and combines with the warehouse management system and the quality monitoring mechanism to realize the effective traceability and management of the rubber product quality, timely discover potential quality problems, and reduce the quality risk of the rubber product. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 It is a system principle block diagram of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0042] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than 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 efforts shall fall within the protection scope of the present invention.

[0043] As Figure 1 , the present invention provides a control system for a rubber numerically controlled electric heating cycle vulcanizing machine, including:

[0044] A thermal imaging monitoring and area division module, which uses a thermal imager to monitor the temperature distribution inside the vulcanizing machine in real time and dynamically.

[0045] The thermal imager takes pictures of the inside of the vulcanizing machine at a fixed frame rate. The setting of the frame rate needs to be determined according to the actual requirements and change speed of the vulcanization process. For the vulcanization stage with rapid temperature changes, the frame rate can be appropriately increased to capture temperature change information more accurately. For example, when vulcanizing some special rubber materials, the temperature changes rapidly during the heating-up stage. At this time, the frame rate can be set to 5 frames per second, so that the temperature change details can be obtained in time. During the constant temperature stage, the temperature is relatively stable, and the frame rate can be adjusted to 2 frames per second to reduce the data processing volume.

[0046] After obtaining the thermal imaging pictures, the thermal imaging pictures are divided into n regions according to the shape of the rubber products in the vulcanizer, the mold structure, and the temperature field distribution. For the shape characteristics of the rubber products, during vulcanization, the heat transfer and vulcanization reaction rates are different in different parts. For example, for rubber products in the shape of automobile tires, there are obvious differences in shape and function in parts such as the tread, sidewall, and shoulder. The tread part is in contact with the ground and needs to withstand greater friction and pressure during actual use. Therefore, more precise temperature and pressure control are required during vulcanization and can be divided into a separate region; the sidewall is relatively thin and dissipates heat quickly, and can be divided into another region; the shoulder part connects the tread and the sidewall, and its temperature and vulcanization conditions are also unique and can be divided into another region. For the mold structure characteristics, factors such as the material, thickness of the mold, and the layout of the internal cooling channels will cause the temperatures of different parts of the rubber product to be inconsistent. If a certain part of the mold is thicker, the heat transfer is relatively slower, and the temperature of the corresponding rubber region will also rise slower, and it can be divided into a separate region for key monitoring. The temperature field distribution characteristic refers to the temperature gradient and distribution law naturally formed inside the vulcanizer during the vulcanization process. By comprehensively considering these factors for regional division, the rubber products and the vulcanization environment can be subdivided according to temperature characteristics, and the regions after subdivision of each thermal imaging picture are transmitted to the temperature range identification and area calculation module.

[0047] The temperature range identification and area calculation module identifies the temperature range and calculates the area within each region. This process is mainly achieved by means of image recognition algorithms. The image recognition algorithms can analyze the pixels in the thermal imaging pictures and determine the temperature range existing within each region according to the color or gray value of the pixels corresponding to different temperatures;

[0048] Accurately calculating the area of the temperature range is crucial for subsequent pressure and power adjustment. Temperature ranges of different areas have different degrees of influence on the overall vulcanization effect during the vulcanization process. Temperature ranges with larger areas may have a greater impact on the overall performance of the rubber products, so more precise control is required;

[0049] For example, for the tread area demarcated during the vulcanization of automobile tires, through an image recognition algorithm, three temperature ranges are identified within this area: [100°C, 110°C], [110°C, 120°C], [120°C, 130°C]. The number of pixel points Nij within each temperature range is counted. Combining with the pixel - area conversion coefficient k (pixels per square meter) of the thermal imager, the area corresponding to each temperature range is calculated according to the formula Sij = Nij / k. k is an important parameter of the thermal imager, which is related to factors such as the resolution and shooting distance of the thermal imager, and needs to be accurately calibrated before use to ensure the accuracy of area calculation. If k = 100 pixels per square meter, after statistics, the number of pixel points within the above - mentioned three temperature ranges are 500, 800, and 300 respectively, then the areas of these three temperature ranges are 5 square meters, 8 square meters, and 3 square meters respectively.

[0050] The heating - up stage control module, which precisely adjusts the applied pressure and heating power according to the characteristics of the rubber material and the requirements of the vulcanization process;

[0051] Determine the critical temperature range [Kaymin, Keymax] of the rubber material. This range is the optimal temperature range for the vulcanization reaction of the rubber. Different types of rubber materials correspond to different critical temperature ranges. For example, the critical temperature range of natural rubber may be in [130°C, 150°C], while the critical temperature range of nitrile rubber may be in [150°C, 170°C];

[0052] Calculate the distance dij = |Tij_min - Keymax| between each temperature range in the calculation region i and the key temperature range, and set the distance thresholds dmin and dmax. If dij ∈ [dmin, dmax], mark this temperature range as an alternative temperature range; if dij > dmax, mark it as a general temperature range; if |Tij_max - Keymax| <= dij < dmin, mark it as an alternative key temperature range; if dij < |Tij_max - Keymax|, mark it as a key temperature range, where dmin and dmax are distance thresholds, and Tij_min and Tij_max are the lower and upper limits of the j-th temperature range in region i. If all temperature ranges in region i belong to general temperature ranges, the distance between the k-th general temperature range and the key temperature range is dit, t ∈ [1, m1]. Calculate the average value avg(di) of the distances between all general temperature ranges and the key temperature range: avg(di) = sum(dit) / m1. Construct the pressure application formula for this i region: Pi = P0 + k1 * avg(di) + k2 * avg(di)^2. If some of the temperature ranges in region i belong to general temperature ranges and some belong to alternative temperature ranges, if the total area of the alternative temperature ranges is Sai and the total area of the general temperature ranges is Sbi, construct the pressure application according to the formula Pi = P0 * (1 + k3 * (Sai / Sbi) + k4 * sqrt(Sai / Sbi)). If region i contains alternative key temperature ranges and the area of the alternative key temperature ranges is Sci, when Sci / Stotali >= 0.5, apply the most suitable pressure Sbest corresponding to the key temperature range of this rubber material; when Sci / Stotali < 0.5, the pressure application formula is Pi = Sbest * (1 - k5 * (0.5 - Sci / Stotali)), where k1, k2, k3, k4, and k5 are all pressure adjustment coefficients.

[0053] After performing thermal imaging shooting on the inside of the vulcanizer and dividing the regions, count the number M1 of general temperature ranges, the number M2 of alternative temperature ranges, and the number M3 of alternative key temperature ranges in all regions of each thermal imaging picture, and set the independent variable parameter ɑ = (M2 + M3) / M1. This parameter reflects the proportion of temperature ranges close to or in the key vulcanization state relative to general temperature ranges in the thermal imaging picture. Adjust the heating power in real time according to this independent variable. The specific formula is , where Q0 is the initial heating power of the heating element, and r is the heating power adjustment coefficient in the temperature rise stage. Adding the e-based function is mainly to control the situation where ɑ appears as an extreme value;

[0054] For example, for the three temperature ranges [100°C, 110°C], [110°C, 120°C], and [120°C, 130°C] identified in the tread area of the above-mentioned car tire, calculate their distances d1 = 50, d2 = 40, and d3 = 30 from the critical temperature range [130°C, 150°C] respectively. The distance thresholds are dmin = 15 and dmax = 30. The first two temperature ranges belong to the general temperature range, and the third temperature range belongs to the alternative temperature range. Then the total area of the general temperature range is Sbi = 5 + 8 = 13 square meters, and the area of the alternative temperature range is Sai = 3 square meters. The area ratio a1i = 3 / 13 ≈ 0.23. The pressure adjustment coefficients are k3 = 0.1 and k4 = 0.05, and P0 = 10. Then the adjusted pressure is Pi = 10*(1 + 0.1*0.23 + 0.05*sqrt(0.23)) = 10.47 MPa. If Q0 = 100 kW, r = 0.2, and ɑ = 1 / 2 = 0.5, then the heating power Q = 100.05 kW.

[0055] Constant temperature stage control module. This module needs to keep the temperature in the vulcanization chamber stable near the critical temperature range to ensure that the rubber product can be fully vulcanized. Continuously monitor the internal temperature distribution of the vulcanizer through a thermal imager, and divide the area into the area within the critical temperature range and the area outside the critical temperature range according to the proportional relationship between the area of the critical temperature range and the total area of the region.

[0056] If (area of the critical temperature range / total area of the region) > β, then this region is called the region within the critical temperature range; otherwise, it is called the region outside the critical temperature range. Calculate the temperature stability index of the critical temperature range of the region within the critical temperature range. , if σ > σmax and the temperature has an upward trend, that is , to prevent over-vulcanization of the rubber, appropriately reduce the regional pressure. The specific pressure transformation formula is as follows: Pnew = Pcurrent*(1 - h1*(σ - σmax)*( )); if σ > σmax and the temperature has a downward trend, that is , to ensure that the vulcanization reaction continues to proceed fully, it is necessary to appropriately increase the regional pressure. The specific pressure transformation formula is as follows: Pnew = Pcurrent*(1 + h2*(σ - σmax)*( )); For the regions within the non-critical temperature range, calculate the distance dnear between it and the nearest region within the critical temperature range. If dnear <= dth, adjust its own pressure according to the pressure adjustment amount of the region within the critical temperature range. The specific formula is: Pnew = Pcurrent + h3 * △Pkey * (Scurrent / Stotal), where △Pkey is the pressure adjustment amount within the critical temperature range, Scurrent is the area of the region within the current non-critical temperature range, and Stotal is the total area. Otherwise, keep the current pressure unchanged;

[0057] Focus on the temperature deviation of each region from the target temperature. The target temperature Ttar is the average temperature value of the critical temperature range. The actual average temperature of the critical temperature range of region i is Tiavg, and the temperature deviation △Ti = Tiavg - Ttar. The region weight is wi. Different regions have different importance for vulcanization. According to the formula Adjust the heating power;

[0058] For example, taking the sidewall area of a car tire as an example, after a period of monitoring, part of this area is within the critical temperature range, and the critical temperature range is [130°C, 150°C]. The target temperature Ttar = 140°C. After calculation, the temperature stability index σ of the critical temperature range of this area is 3°C, and the set threshold σmax = 2°C. It is monitored that the temperature has an upward trend. The current pressure of this area is Pcurrent = 12 MPa, and the pressure adjustment coefficient h1 = 0.1. Since σ > σmax, to prevent over-vulcanization of the rubber, it is necessary to appropriately reduce the regional pressure. The adjusted pressure is Pnew = 12 * (1 - 0.1 * (3 - 2) * 0.5) = 11.4 MPa;

[0059] If there is a small area within the non-critical temperature range in the sidewall area, and its distance dnear from the nearest region within the critical temperature range is 5, the set distance threshold dth = 8, the pressure adjustment amount △Pkey of the region within the critical temperature area is 0.6, the area Scurrent of the region within the current non-critical temperature range is 2 square meters, the total area Stotal where this region is located is 10 square meters, and the pressure adjustment coefficient h3 = 0.2. Because dnear < dth, adjust its own pressure according to the pressure adjustment amount of the region within the critical temperature range. The current pressure Pcurrent = 10 MPa, then the adjusted pressure Pnew = 10 + 0.2 * 0.6 * (2 / 10) = 10.024 MPa;

[0060] If the actual average temperatures of three key temperature intervals in the sidewall region are T1avg = 151 °C, T2avg = 148 °C, and T3avg = 153 °C, and the temperature deviations are calculated as △T1 = 1 °C, △T2 = -2 °C, and △T3 = 3 °C, with the regional weights being w1 = 0.2, w2 = 0.3, and w3 = 0.5, and the heating power adjustment coefficient e1 = 5 kW / °C during the constant temperature stage, and the current heating power Q0 = 80 kW, then the adjusted heating power Q = 80 + 5 * (0.2 - 0.6 + 1.5) = 85.5 kW.

[0061] During the cooling stage, the regulation module continuously monitors the temperature of each region using a thermal imager and calculates the cooling rate vT = (T t+△t - T t ) / △t for each region. For the regions within the key temperature intervals, if the cooling is too fast, i.e., vT < vTmax, where vTmax is a negative number, it may cause stress concentration inside the rubber and affect the product performance. In this case, the pressure needs to be increased. The specific pressure adjustment formula is Pnew = Pcurrent * (1 + h4 * (vTmax - vT)); when the cooling rate is within the normal range, i.e., vT ∈ [vTmax, 0], the pressure should be appropriately reduced to prevent the rubber product from deforming or the internal structure from being damaged due to excessive pressure. The specific pressure adjustment formula is: Pnew = Pcurrent * (1 - h5 * (1 - Pp / Pr)), where Pp is the proportion of pixels with significant temperature changes actually occurring within the key temperature interval, and Pr is the reference value of the proportion of pixels with significant temperature changes corresponding to the key temperature interval in the ideal vulcanization state; for the regions outside the key temperature intervals, Pnew = Pcurrent * (1 + h6 * (vT - vTth) / vTth), where vTth is the preset target cooling rate for the regions outside the key temperature intervals.

[0062] The cooling rate of the key temperature interval in region i is vTkeyi, the target cooling rate is vTtar, the cooling rate deviation △vi = vTtari - vTkeyi, and the regional weight is wi. The specific formula for adjusting the heating power is: ;

[0063] For example, for the shoulder region of an automobile tire, if the current temperature T t = 150 °C within the key temperature interval of this region and the temperature T t+10 = 130 °C after 10 minutes, then the cooling rate vT = -2 °C / min, and the cooling rate threshold vTmax = -1 °C / min, indicating that the cooling is too fast and the pressure needs to be increased. Pcurrent = 10 MPa, and the pressure adjustment coefficient h4 = 0.2. The adjusted pressure is Pnew = 10 * (1 + 0.2 * (-1 + 2)) = 12 MPa;

[0064] If the cooling rate of another area is vT = -0.5 °C / min, within the normal range, the current pressure Pcurrent = 8 MPa, the proportion of pixels with significant temperature changes actually occurring within the critical temperature range is Pp = 0.6, and the reference value of the proportion of pixels with significant temperature changes corresponding within the critical temperature range in the ideal vulcanization state is Pr = 0.8, and the pressure adjustment coefficient h5 = 0.1, then the adjusted pressure is Pnew = 8 * (1 - 0.1 * (1 - 0.6 / 0.8)) = 7.8 MPa;

[0065] If the cooling rates of the critical temperature ranges of three areas are vTkey1 = -0.6 °C / min, vTkey2 = -0.4 °C / min, vTkey3 = -0.3 °C / min respectively, vTtar1 = -0.5 °C / min, vTtar2 = -0.6 °C / min, vTtar3 = -0.2 °C / min, △v1 = 0.1 °C / min, △v2 = -0.2 °C / min, △v3 = 0.1 °C / min, the heating power adjustment coefficient e2 during the cooling stage is 10 °C / min, the current heating power Q0 = 60 kW, and the area weights are w1 = 0.7, w2 = 0.2, w3 = 0.1 respectively, then Q = 60 * (10 * (max(0.1, -0.2, -0.1, 0) / (0.35 + 0.12 + 0.02))) = 122 kW.

[0066] Product management and quality monitoring module. This module mainly conducts comprehensive management and quality monitoring on rubber products from production completion to storage. After the rubber products are vulcanized and initially inspected as qualified, RFID tags are attached to each product;

[0067] Taking automobile tires as an example, RFID tags have the advantages of large storage capacity, convenient reading and writing, and reusable. It can record the basic information of the product, such as the tire model is 205 / 55R16, the batch number is 20250305 - 001, the production date is March 5, 2025, etc. It focuses on recording the detailed data of the three stages of vulcanization heating, constant temperature, and cooling. For example, during the heating stage, it takes 20 minutes to rise from room temperature to 140 °C, and the temperature change sequence is to record the temperature every △t minutes, where △t can take 1, 2,... During the constant temperature stage, it maintains at 140 °C - 160 °C for 30 minutes, and the temperature fluctuation range is ±2 °C. During the cooling stage, it takes 40 minutes to drop from 160 °C to room temperature, and the temperature is recorded every △t1 minutes;

[0068] Qualified products are warehoused in the order of inspection time, adopting the principle of first-in, first-out storage. The purpose of doing this is to ensure the freshness and quality stability of the products, and avoid the performance decline caused by long-term storage of the products. For example, the tires warehoused first in the warehouse will be given priority to be arranged for outbound sales to ensure that consumers can buy products produced relatively recently;

[0069] For qualified rubber products that have not been shipped out, set an inspection cycle. For example, according to the product characteristics and storage environment, conduct an appearance inspection on general rubber products every 30 days, and shorten it to 15 days for products that are prone to aging or are highly precise.

[0070] Use machine vision inspection software to achieve automatic inspection of the appearance of rubber products through algorithms such as image preprocessing, feature extraction, and pattern recognition, including whether there are abnormal changes such as color change, deformation, and cracking on the product appearance. If it is found that the product appearance has changed, read the key production information of the abnormal product through a fixed RFID scanner, including the storage time, time and temperature change data in the three stages of vulcanization. The system calculates the duration interval [ai, bi] of different stages based on the time series of the three stages of product vulcanization. For example, the time series of the heating stage of 10 products with appearance changes is [30, 32, 28, 31, 33, 29, 30, 34, 31, 27] (unit: minute). By calculating the maximum and minimum values of this series, determine the duration interval [27, 34].

[0071] Calculate the average temperature sequence Temi of each stage based on the temperature change data, i ∈ [1, 3]. For example, the temperatures of 10 products at the 10th second of the heating stage are 100°C, 102°C, 98°C, 101°C, 103°C, 99°C, 100°C, 104°C, 101°C, 97°C respectively. Then the average temperature at this time point is (100 + 102 + 98 + 101 + 103 + 99 + 100 + 104 + 101 + 97) ÷ 10 = 100.5°C. Calculate the average sequence Tem1 of the entire heating stage in this way.

[0072] For newly produced qualified rubber products, the system automatically compares the time tti used in the three stages of its vulcanization with [ai, bi]. If tti ∈ [ai, bi], mark the product as a product to be observed. Extract the temperature change sequence Wai of the three stages of vulcanization of the product to be observed, and calculate the similarity Si between the sequence Wai and Temi respectively. i = 1 corresponds to the heating stage, i = 2 corresponds to the constant temperature stage, and i = 3 corresponds to the cooling stage. Set the similarity threshold Sth, and count the number num that satisfies Si > Sth. If num >= 2, it indicates that the temperature change sequences of the product and the product with quality changes are similar in at least two stages, and mark it as a key attention product.

[0073] Key attention products are placed in a specific area of the warehouse, which is equipped with more intensive environmental monitoring equipment, such as temperature and humidity sensors, light sensors, etc. At the same time, increase the inspection frequency, and the inspection frequency is the minimum value in the storage time series.

[0074] A numerical control electrothermal cycle vulcanizer for rubber, the vulcanizer includes:

[0075] The main frame structure is composed of a four-column type or frame type bracket, including an upper mold that can move up and down and a fixed lower mold. The upper mold and the lower mold are driven to close by a hydraulic or pneumatic device. A pressure sensor and a displacement sensor are arranged between the upper mold and the lower mold, which are used to monitor the deformation of the mold and the pressure distribution in real time, and are linked with the temperature range identification and area calculation module of the control system to realize the coordinated control of multiple parameters of pressure-temperature-displacement;

[0076] The electrothermal cycle heating system includes resistance wires or electromagnetic induction heating elements embedded in the mold, a spiral coil type heat conduction medium channel surrounding the mold, and an independent temperature control module. The main heating module and the auxiliary circulation module are linked through the circulation of heat conduction oil or water medium to realize the rapid temperature rise and uniformity control of the mold temperature, and communicate with the heating-up stage regulation module, the constant temperature stage regulation module and the cooling-down stage regulation module of the control system to dynamically adjust the heating power;

[0077] The multi-region pressure dynamic adjustment system includes multiple hydraulic cylinders or pneumatic cylinders distributed under or on the side of the mold. Each cylinder corresponds to an independent pressure adjustment unit. The pressure adjustment unit is communicatively connected with the heating-up stage regulation module, the constant temperature stage regulation module and the cooling-down stage regulation module of the control system, and dynamically adjusts the local pressure based on the pressure compensation instruction sent by the control system to support the differential pressure control in different regions during the vulcanization process;

[0078] The thermal imaging integrated monitoring module includes a high-temperature resistant infrared transparent window installed on the side or top of the mold, an electric zoom thermal imager and a robotic arm positioning device. The thermal imager collects the temperature field data of the vulcanization process in real time through the infrared window and transmits it to the thermal imaging monitoring and area division module of the control system to realize the real-time monitoring and area division of the temperature field;

[0079] The intelligent control interface realizes data interaction with the control system through an industrial computer or PLC, supports the coordinated control of the electrothermal cycle heating system, the multi-region pressure dynamic adjustment system and the thermal imaging integrated monitoring module by the control system, and the intelligent control interface is built-in with an edge computing module, which can analyze the vulcanization parameters in real time and trigger an alarm, and is linked with the product management and quality monitoring module of the control system to realize the storage of vulcanization data and quality traceability.

[0080] Some of the data in the above formula are numerically calculated after removing their dimensions, and the content not described in detail in this specification belongs to the prior art well known to those skilled in the art.

[0081] The above embodiments are only used to illustrate the technical method of the present invention and not to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the technical method of the present invention can be modified or equivalently replaced without departing from the spirit and scope of the technical method of the present invention.

Claims

1. A rubber CNC electric heating cycle vulcanizer control system, characterized in that: include: Thermal imaging monitoring and area division module, which uses a thermal imager to monitor the temperature distribution inside the vulcanizer, divides the thermal imaging image into n areas according to the shape of the rubber product in the vulcanizer, the mold structure and the temperature field distribution, and transmits the thermal imaging image of the divided area to the temperature range recognition and area calculation module; Temperature interval recognition and area calculation module, which collects pixels from each area of ​​the thermal imaging image, determines the temperature interval in each area according to the color or gray value of the pixel corresponding to different temperatures, calculates the area of ​​different temperature intervals, and transmits the calculated temperature interval and area corresponding to each area of ​​the thermal imaging image to the temperature rise stage control module; A temperature rise control module, which determines the critical temperature range according to the characteristics of the rubber material, and adjusts the applied pressure of the area according to the alternative temperature ranges, general temperature ranges, number of alternative critical temperature ranges and total area of ​​different areas; Constant temperature stage control module, which calculates the stability of the key temperature interval of the area within the key temperature interval, adjusts the applied pressure of the area within the key temperature interval according to the stability and the size of the average temperature in the adjacent time period, and for the area within the non-critical temperature interval, calculates its distance from the surrounding areas within the key temperature interval, finds the pressure change of the area within the key temperature interval with the smallest distance to adjust the applied pressure; The cooling stage control module adjusts the applied pressure according to the cooling rate of the areas within the critical temperature range and the areas within the non-critical temperature range.

2. A rubber CNC electric heating cycle vulcanizing machine control system according to claim 1, characterized in that: The temperature reduction stage control module is followed by a product management and quality monitoring module. After the rubber product passes the preliminary inspection, the product management and quality monitoring module attaches an RFID tag to each rubber product, and uses the first-in-first-out storage principle to put the rubber product into storage. For rubber products that have not been shipped out, an inspection cycle is set, and the appearance of the rubber product is automatically inspected using machine vision inspection software. If the appearance of the product changes, the key production information of the abnormal rubber product is read by a fixed RFID scanner, and the duration interval [ai, bi] and the temperature mean sequence Temi of different stages are calculated. For newly produced qualified rubber products, the system automatically compares the time tti used in the three vulcanization stages with [ai, bi]. If tti∈[ai, bi], the product is marked as a product to be observed, and the temperature change sequence Wai of the three vulcanization stages of the product to be observed is extracted. The similarity Si between the sequence Wai and Temi is calculated respectively, and a similarity threshold Sth is set. The number num that satisfies Si>Sth is counted, and if num>=2, it is marked as a key product.

3. A rubber CNC electric heating cycle vulcanizing machine control system according to claim 1, characterized in that: The area corresponding to each temperature interval is calculated according to the formula Sij=Nij / k, where Nij is the number of pixels in each temperature interval and k is the pixel-area conversion coefficient of the thermal imager.

4. A rubber CNC electric heating cycle vulcanizing machine control system according to claim 1, characterized in that: Calculate the distance dij = |Tij_min - Keymax| between each temperature interval in region i and the key temperature interval. If dij ∈ [dmin, dmax], it is marked as an alternative temperature interval. If dij > dmax, it is marked as a general temperature interval. If |Tij_max - Keymax| <= dij < dmin, it is marked as an alternative key temperature interval. If dij < |Tij_max - Keymax|, it is marked as a key temperature interval. Here, Keymax is the upper limit of the key temperature interval of the rubber material, dmin and dmax are distance thresholds, and Tij_min and Tij_max are the lower and upper limits of the j-th temperature interval in region i.

5. A rubber CNC electric heating cycle vulcanizing machine control system according to claim 1, characterized in that: The specific steps for pressure adjustment of different regions i during the heating stage are as follows: Count the number of alternative temperature intervals, general temperature intervals, and alternative key temperature intervals in different regions i as num1, num2, and num3 respectively, and the total areas are Sai, Sbi, and Sci; If num2 ≠ 0 and num1 = 0, num3 = 0 in region i, then construct a pressure adjustment formula based on the average value of the distance between the general temperature interval and the key temperature interval. The specific formula is as follows: Pi = P0 + k1 × avg(di) + k2 × avg(di)^2; If num1 ≠ 0 and num2 ≠ 0, num3 = 0, then construct a pressure adjustment formula based on the ratio of the total area of the alternative temperature interval to the total area of the general temperature interval. The specific formula is as follows: Pi = P0 × (1 + k3 × (Sai / Sbi) + k4 × sqrt(Sai / Sbi)); If num3 ≠ 0, when Sci / Stotali >= 0.5, the applied pressure is Sbest. When Sci / Stotali < 0.5, construct a pressure adjustment formula based on the total area of the alternative key temperature interval. The specific formula is as follows: Pi = Sbest × (1 - k5 × (0.5 - Sci / Stotali)); Here, P0 is the currently applied pressure, di is the distance between the general temperature interval and the key temperature interval, avg() is the average function, sqrt() is the square root function, Sbest is the best applied pressure when the rubber is in the key temperature interval, Stotali is the total area of different regions i, and k1, k2, k3, k4, k5 are pressure adjustment coefficients.

6. A rubber CNC electric heating cycle vulcanizing machine control system according to claim 1, characterized in that: During the constant temperature stage, if (area of the key temperature interval in region i / total area of region i) > β, then this region is called a region within the key temperature interval. Otherwise, it is called a region outside the key temperature interval. Here, β is the area threshold.

7. A rubber CNC electric heating cycle vulcanizing machine control system according to claim 1, characterized in that: The specific steps for pressure adjustment of different regions i during the constant temperature stage are as follows: Calculate the temperature stability index of the critical temperature interval for the area within the critical temperature interval , if σ>σmax and , appropriately reduce the regional pressure. The specific pressure adjustment formula is as follows: Pnew = Pcurrent × (1-h1 × (σ-σmax) × ( )); If σ>σmax and , the regional pressure needs to be appropriately increased. The specific pressure adjustment formula is as follows: Pnew=Pcurrent×(1+h2×(σ-σmax)×( )); For the regions within the non-critical temperature range, calculate the distance dnear to the nearest region within the critical temperature range around it. If dnear <= dth, adjust its own pressure according to the pressure change of the region within the critical temperature range. The specific pressure adjustment formula is: Pnew = Pcurrent + h3 × △Pkey × (Scurrent / Stotal). Otherwise, keep the current pressure unchanged; Among them, σmax is the temperature stability threshold, △Pkey is the pressure adjustment amount of the area in the critical temperature range, Scurrent is the area of ​​the current non-critical temperature range, Stotal is the total area, and Pcurrent is the current regional pressure. , is the average temperature between time t and t+△t, and h1, h2, and h3 are pressure adjustment coefficients.

8. A rubber CNC electric heating cycle vulcanizing machine control system according to claim 1, characterized in that: The specific steps for pressure adjustment of different regions i during the cooling stage are as follows: Calculate the cooling rate vT of each area = (T t+△t -T t ) / △t; For the regions within the critical temperature range, if vT < vTmax, the pressure needs to be increased. The specific pressure adjustment formula is Pnew = Pcurrent × (1 + h4 × (vTmax - vT)); If vT ∈ [vTmax, 0], the pressure should be appropriately decreased. The specific pressure adjustment formula is: Pnew = Pcurrent × (1 - h5 × (1 - Pp / Pr)); For the regions within the non-critical temperature range, the specific pressure adjustment formula is: Pnew = Pcurrent × (1 + h6 × (vT - vTth) / vTth); Among them, vTmax is a negative number, Pp is the proportion of pixels with obvious temperature changes within the critical temperature range actually, Pr is the reference value of the proportion of pixels with obvious temperature changes within the critical temperature range under the ideal vulcanization state, vTth is the preset target cooling rate of the regions within the non-critical temperature range, and h4, h5, h6 are pressure adjustment coefficients.

9. A rubber CNC electric heating cycle vulcanizing machine control system according to claim 2, characterized in that: Focus on the specific area where the product is placed in the warehouse. This area is equipped with more intensive environmental monitoring equipment, and at the same time, increase the inspection frequency, which is the minimum value in the storage time series.

10. A rubber numerical control electric heating cycle vulcanizer, used to execute a rubber numerical control electric heating cycle vulcanizer control system according to any one of claims 1 to 9, characterized in that: This vulcanizer includes: The main frame structure, which is composed of a four-column or frame-type bracket, includes an upper mold that can move up and down and a fixed lower mold. The upper mold and the lower mold are driven to close by a hydraulic or pneumatic device. A pressure sensor and a displacement sensor are arranged between the upper mold and the lower mold to monitor the mold deformation and pressure distribution in real time, and are linked with the temperature range identification and area calculation module of the control system to realize multi-parameter collaborative control of pressure-temperature-displacement; The electrothermal circulation heating system, including resistance wires or electromagnetic induction heating elements embedded in the mold, spiral coil-type heat transfer medium channels surrounding the mold, and an independent temperature control module. The main heating module and the auxiliary circulation module are linked through the circulation of heat transfer oil or water medium to realize rapid temperature rise and uniformity control of the mold temperature, and communicate with the heating-up stage regulation module, constant temperature stage regulation module and cooling-down stage regulation module of the control system to dynamically adjust the heating power; The multi-region pressure dynamic adjustment system, including multiple hydraulic cylinders or pneumatic cylinders distributed under or on the side of the mold. Each cylinder corresponds to an independent pressure adjustment unit. The pressure adjustment unit is communicatively connected with the heating-up stage regulation module, constant temperature stage regulation module and cooling-down stage regulation module of the control system, and dynamically adjusts the local pressure based on the pressure compensation instruction sent by the control system to support differential pressure control in different regions during the vulcanization process; The thermal imaging integrated monitoring module includes a high temperature resistant infrared transparent window installed on the side or top of the mold, an electric zoom thermal imager and a mechanical arm positioning device. The thermal imager collects temperature field data of the vulcanization process in real time through the infrared window and transmits it to the thermal imaging monitoring and area division module of the control system to realize real-time monitoring of the temperature field and area division; The intelligent control interface realizes data interaction with the control system through an industrial computer or PLC, and supports the coordinated control of the electric heat circulation heating system, the multi-zone pressure dynamic adjustment system and the thermal imaging integrated monitoring module. The intelligent control interface has a built-in edge computing module, which can analyze the vulcanization parameters in real time and trigger early warnings, and work with the product management and quality monitoring modules of the control system to realize vulcanization data storage and quality traceability.

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