A method and system for optimizing process parameters applied to wire and cable conductors

Abstract

The application relates to the technical field of material processing, in particular to a method for optimizing process parameters of a wire and cable conductor. The method comprises the following steps: real-time measurement of surface temperatures before the conductor enters an annealing furnace and after the conductor exits the annealing furnace, recording the running speed of the conductor and the diameter of the conductor; when the conductor passes through the annealing furnace, a temperature detection device contacts the surface of the conductor and measures the actual temperature, so that temperature distribution data of the conductor in the annealing furnace are obtained; the heat capacity characteristic value of the conductor is calculated according to the running speed of the conductor and the diameter of the conductor, and the temperature change rate between adjacent temperature detection devices is calculated in combination with the temperature distribution data; the heating power of each temperature zone of the annealing furnace is reversely adjusted according to the deviation of the surface temperature after the conductor exits the annealing furnace from a preset target temperature. The application realizes optimization of the process parameters of the wire and cable conductor, and can effectively avoid product quality problems caused by unstable process parameters.

Description

Technical Field

[0001] This invention relates to the field of materials processing technology, and in particular to a method and system for optimizing process parameters of wire and cable conductors. Background Technology

[0002] In ultra-fine enameled wire production workshops, the process stability of the conductor annealing process directly determines the matching degree between the conductivity and mechanical properties of the finished product. Current mainstream processes employ segmented annealing furnaces, using a combination of multiple temperature zones to control the copper wire crystallization process. Operators typically set baseline values ​​for each temperature zone based on experience, and then fine-tune them based on offline sampling test results. This control mode is sufficient for the production of conventional wire specifications, but when dealing with ultra-fine specifications with a wire diameter less than 0.05mm, the temperature gradient effect between the conductor surface and the core significantly affects the recrystallization process.

[0003] Current technology relies on fixed thermocouples mounted on the annealing furnace wall for temperature monitoring, but this measurement method has inherent limitations. Because the ultrafine conductor passes through the annealing furnace at high speed (typically a linear velocity of 200-300 m / min), its actual temperature deviates significantly from the value detected on the furnace wall. Summary of the Invention

[0004] Therefore, it is necessary for the present invention to provide a method and system for optimizing process parameters of wire and cable conductors to solve at least one of the above-mentioned technical problems.

[0005] To achieve the above objectives, a method for optimizing process parameters of wire and cable conductors includes the following steps:

[0006] Step S1: Measure the surface temperature of the conductor before it enters the annealing furnace and the surface temperature after it exits the annealing furnace in real time, and record the conductor's running speed and conductor diameter at the same time;

[0007] Step S2: When the conductor passes through the annealing furnace, a temperature detection device is used to contact the surface of the conductor and measure the actual temperature to obtain the temperature distribution data of the conductor inside the annealing furnace;

[0008] Step S3: Calculate the thermal capacity characteristic value of the conductor based on its running speed and diameter, and calculate the temperature change rate between adjacent temperature detection devices by combining the temperature distribution data.

[0009] Step S4: Based on the deviation between the surface temperature after exiting the annealing furnace and the preset target temperature, adjust the heating power of each temperature zone of the annealing furnace in reverse.

[0010] Step S5: Adjust the contact pressure of the adjustable thermocouple according to the product of the temperature change rate and the thermal capacity characteristic value;

[0011] Step S6: Repeat steps S1 to S5 until the surface temperature after exiting the annealing furnace falls within the target temperature range in three consecutive measurements and the fluctuation range of the temperature change rate is less than the allowable error. Finally, determine the optimal heating power parameters for each temperature zone.

[0012] Preferably, the present invention also provides a system for optimizing process parameters of wire and cable conductors, used to execute the method for optimizing process parameters of wire and cable conductors as described above, the system for optimizing process parameters of wire and cable conductors comprising:

[0013] The temperature measurement module is used to measure the surface temperature of the conductor before it enters the annealing furnace and after it exits the annealing furnace in real time, while also recording the conductor's running speed and diameter.

[0014] The temperature detection module is used to contact the conductor surface with a temperature detection device and measure the actual temperature when the conductor passes through the annealing furnace, so as to obtain the temperature distribution data of the conductor inside the annealing furnace.

[0015] The heat capacity calculation module is used to calculate the heat capacity characteristic value of the conductor based on the conductor's running speed and conductor diameter, and to calculate the temperature change rate between adjacent temperature detection devices by combining temperature distribution data.

[0016] The power adjustment module is used to adjust the heating power of each temperature zone of the annealing furnace in reverse according to the deviation between the surface temperature after exiting the annealing furnace and the preset target temperature.

[0017] The pressure adjustment module is used to adjust the contact pressure of the adjustable thermocouple according to the product of the temperature change rate and the thermal capacity characteristic value.

[0018] The optimization loop module is used to repeat steps S1 to S5 until the surface temperature after exiting the annealing furnace falls within the target temperature range in three consecutive measurements and the fluctuation range of the temperature change rate is less than the allowable error, and finally the optimal heating power parameters for each temperature zone are determined.

[0019] The beneficial effects of this invention are:

[0020] On the one hand, by measuring the actual temperature by contacting the conductor surface with a temperature detection device, compared with the measurement method of relying on fixed thermocouples installed on the annealing furnace wall in the existing technology, the actual temperature of the conductor can be obtained more accurately. This effectively solves the problem of significant deviation between the actual temperature and the furnace wall detection value when the ultra-fine conductor passes through the annealing furnace at high speed, and provides a more reliable data basis for the optimization of subsequent process parameters.

[0021] On the other hand, based on the deviation between the surface temperature after exiting the annealing furnace and the preset target temperature, the heating power of each temperature zone of the annealing furnace is adjusted in reverse, and the contact pressure of the adjustable thermocouple is adjusted by combining the product of the temperature change rate and the heat capacity characteristic value, so that the adjustment of heating power is more precise and can better adapt to conductors of different diameters and operating speeds, effectively improving the stability and controllability of the annealing process.

[0022] On the other hand, by repeatedly measuring and adjusting until the surface temperature after exiting the annealing furnace falls within the target temperature range in three consecutive measurements and the fluctuation range of the temperature change rate is less than the allowable error, the optimal heating power parameters for each temperature zone are finally determined. This achieves the optimization of the process parameters for wire and cable conductors, effectively avoids product quality problems caused by unstable process parameters, and improves product quality and consistency. Attached Figure Description

[0023] Other features, objects, and advantages of the present invention will become more apparent from the following detailed description taken in conjunction with the accompanying drawings:

[0024] Figure 1 A flowchart illustrating the steps of an embodiment of a method for optimizing process parameters of wire and cable conductors is shown.

[0025] Figure 2 A detailed flowchart illustrating the steps of a method for calculating the heat capacity characteristic value according to an embodiment is shown.

[0026] Figure 3 A schematic diagram of the contact control system structure of a temperature detection device according to an embodiment is shown.

[0027] Figure 4 A schematic diagram of a physical conductor of an embodiment of a wire and cable is shown. Detailed Implementation

[0028] The technical method of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0029] Furthermore, the accompanying drawings are merely illustrative of the invention and are not necessarily drawn to scale. The same reference numerals in the drawings denote the same or similar parts, and therefore repeated descriptions of them will be omitted. Some block diagrams shown in the drawings are functional entities and do not necessarily correspond to physically or logically independent entities. These functional entities can be implemented in software, in one or more hardware modules or integrated circuits, or in different network and / or processor methods and / or microcontroller methods.

[0030] It should be understood that although the terms "first," "second," etc., may be used herein to describe various units, these units should not be limited by these terms. These terms are used merely to distinguish one unit from another. For example, without departing from the scope of the exemplary embodiments, a first unit may be referred to as a second unit, and similarly, a second unit may be referred to as a first unit. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0031] To achieve the above objectives, please refer to Figures 1 to 4 This invention provides a method for optimizing process parameters of wire and cable conductors, comprising the following steps:

[0032] Step S1: Measure the surface temperature of the conductor before it enters the annealing furnace and the surface temperature after it exits the annealing furnace in real time, and record the conductor's running speed and conductor diameter at the same time;

[0033] Step S2: When the conductor passes through the annealing furnace, a temperature detection device is used to contact the surface of the conductor and measure the actual temperature to obtain the temperature distribution data of the conductor inside the annealing furnace;

[0034] Step S3: Calculate the thermal capacity characteristic value of the conductor based on its running speed and diameter, and calculate the temperature change rate between adjacent temperature detection devices by combining the temperature distribution data.

[0035] Step S4: Based on the deviation between the surface temperature after exiting the annealing furnace and the preset target temperature, adjust the heating power of each temperature zone of the annealing furnace in reverse.

[0036] Step S5: Adjust the contact pressure of the adjustable thermocouple according to the product of the temperature change rate and the thermal capacity characteristic value;

[0037] Step S6: Repeat steps S1 to S5 until the surface temperature after exiting the annealing furnace falls within the target temperature range in three consecutive measurements and the fluctuation range of the temperature change rate is less than the allowable error. Finally, determine the optimal heating power parameters for each temperature zone.

[0038] Preferably, the locking conditions for the optimal process parameters also include:

[0039] If the surface temperature and temperature change rate after exiting the annealing furnace meet the preset standards in three consecutive tests, then a conductor sample is taken from the current operating section of the production line and immediately placed in a constant temperature and humidity environment to cool to 25±1℃.

[0040] In one implementation of this invention, assuming that in three consecutive tests, the surface temperatures after exiting the annealing furnace are 200℃, 201℃, and 200.5℃, respectively, with temperature change rates of 0.05℃ / s, 0.06℃ / s, and 0.05℃ / s, respectively, all meeting the preset standard (the preset surface temperature range is 195℃-205℃, and the allowable error for the temperature change rate is ±0.07℃ / s). At this time, a 1-meter-long conductor sample is cut from the current operating section of the production line and placed in a constant temperature and humidity chamber. The target temperature is set to 25℃, and the humidity to 50%RH. The cooling program is started, and after 10 minutes of cooling, the temperature of the conductor sample stabilizes at 25℃.

[0041] Tensile tests were performed on the conductor samples, and the maximum tensile strength value before fracture was recorded. The conductivity of the samples was measured simultaneously.

[0042] The measured tensile strength value is compared with the preset standard strength value, and the relative deviation percentage of the tensile strength value is calculated.

[0043] The measured conductivity value is compared with the preset standard conductivity value, and the percentage of relative deviation of the conductivity value is calculated.

[0044] In this embodiment of the invention, a tensile test is performed on the conductor sample, and the maximum tensile strength value before fracture is recorded. Simultaneously, the conductivity of the sample is measured. Specifically, the tensile test is performed on a standard material testing machine, following the test method specified in international standards (such as ISO 6892-1). A gradually increasing tensile force is applied to the conductor sample until the sample fractures, and the maximum tensile strength value before fracture is recorded. The conductivity measurement is performed in a constant temperature and humidity environment using a conductivity meter to measure the conductor sample.

[0045] In one implementation of this invention, after a tensile test, the maximum tensile strength of the conductor sample before fracture was measured to be 220 MPa, and the conductivity was 58 MS / m. Assuming a preset standard strength value of 210 MPa and a preset standard conductivity of 60 MS / m, the relative deviation percentage of the tensile strength value is calculated as follows: The percentage of relative deviation of conductivity values ​​is Since the relative deviation percentage of tensile strength values ​​does not exceed 5% and the relative deviation percentage of conductivity values ​​does not exceed 3%, the preset standards are met.

[0046] If the relative deviation percentage of the tensile strength value does not exceed 5% and the relative deviation percentage of the conductivity value does not exceed 3%, a process parameter locking command is generated, and the power parameters, thermocouple contact pressure and detection cycle parameters of each temperature zone are written into the non-volatile memory.

[0047] If either the relative deviation percentage of the tensile strength value or the relative deviation percentage of the conductivity value exceeds the tolerance range, the most recent three test data are cleared, the annealing furnace power is reset to the initial default value, and the process is returned to step S1 to restart the optimization process.

[0048] In one implementation of this invention, based on the tensile test and conductivity measurement results, since the relative deviation percentage of the tensile strength value is 4.76% and the relative deviation percentage of the conductivity value is 3.33%, both within the tolerance range, a process parameter locking command is generated. This command writes the power parameters, thermocouple contact pressure, and detection cycle parameters for each temperature zone into a non-volatile memory. Assuming the current power parameters for each temperature zone are 150kW, 120kW, and 100kW, the thermocouple contact pressures are 0.5N, 0.6N, and 0.7N, and the detection cycle is 10 seconds, these parameters are successfully written into the non-volatile memory, completing the locking of the optimal process parameters.

[0049] In another implementation of this invention, suppose that in a certain test, the relative deviation percentage of the measured tensile strength value is 6%, and the relative deviation percentage of the conductivity value is 4%, exceeding the preset standard. At this time, the data of the three most recent tests are cleared, the annealing furnace power is reset to the initial default value (assumed to be 100kW, 80kW, and 60kW), and the process is returned to step S1 to restart the optimization process.

[0050] Preferably, the temperature detection device in step S2 includes adjustable thermocouples symmetrically distributed on both sides of the furnace wall, and the contact control of the adjustable thermocouples includes:

[0051] The contact pressure of each adjustable thermocouple is set to the initial pressure value, and the conductor diameter is calibrated by a laser diameter gauge before the conductor enters the annealing furnace to generate the calibrated conductor diameter.

[0052] In one implementation of this invention, the initial pressure value is assumed to be set to 0.3 N. Before the conductor enters the annealing furnace, a laser diameter gauge measures the conductor diameter to be 0.045 mm, generating a calibrated conductor diameter of 0.045 mm. The control system sets the contact pressure of each adjustable thermocouple to 0.3 N based on the preset initial pressure value.

[0053] When the conductor passes through, if the diameter of the calibrated conductor is less than the preset first threshold, the contact pressure of the adjustable thermocouple is maintained at the initial pressure value. If the diameter of the calibrated conductor is within the range of the preset first threshold to the preset second threshold, the contact pressure increases by 0.1 N for every 0.01 mm increase in diameter, up to a maximum preset maximum pressure value.

[0054] If the diameter of the calibrated conductor exceeds the preset second threshold, the contact pressure of the adjustable thermocouple will be fixed to the preset maximum pressure value.

[0055] In one implementation of this invention, a first preset threshold is 0.05 mm, a second preset threshold is 0.07 mm, and a maximum preset pressure value is 0.8 N. When the conductor passes through the annealing furnace, a laser diameter gauge measures the conductor diameter in real time to be 0.06 mm. According to a preset rule, for every 0.01 mm increase in diameter, the contact pressure increases by 0.1 N. Therefore, the contact pressure increases from the initial 0.3 N to 0.5 N (0.3 N + 0.2 N = 0.5 N). If the conductor diameter is 0.08 mm, exceeding the second preset threshold, the contact pressure will be fixed at 0.8 N.

[0056] Most importantly, adjusting the contact pressure of the adjustable thermocouple also includes:

[0057] The response time of the adjustable thermocouple is recorded synchronously. If the response time exceeds 50 milliseconds, the current detection is stopped, the adjustable thermocouple is controlled to retract to the initial position, the compressed air injection device is started, and the contact end of the adjustable thermocouple is cleaned for 1 second. After cleaning, the adjustable thermocouple is extended again and the contact pressure is reset to the initial pressure value.

[0058] In one implementation of this invention, assuming that in a certain test, the adjusted contact pressure is 0.5 N and the thermocouple response time is 60 milliseconds, exceeding the preset 50 milliseconds, the control system stops the current test, controls the adjustable thermocouple to retract to its initial position, and activates the compressed air jet device to clean the thermocouple contact end for 1 second. After cleaning, the adjustable thermocouple is re-extended, and the contact pressure is reset to the initial pressure value of 0.3 N.

[0059] If the response time still exceeds the limit after three consecutive self-cleaning cycles, the adjustable thermocouple is marked as faulty and the backup detection unit is activated.

[0060] In one implementation of this invention, it is assumed that after three consecutive cleanings, the thermocouple response times are 65 milliseconds, 62 milliseconds, and 68 milliseconds, respectively, all exceeding the preset 50 milliseconds. The control system marks the adjustable thermocouple as faulty and activates the backup detection unit to continue temperature detection.

[0061] Preferably, the triggering conditions for contact pressure adjustment in step S5 include:

[0062] When the product of the rate of temperature change and the thermal capacity characteristic value exceeds the preset first product threshold, the current contact pressure value of the adjustable thermocouple is increased by a preset ratio, and the adjusted contact pressure value is recorded; at the same time, real-time contact pressure monitoring is started. If the adjusted contact pressure value exceeds the preset upper limit, a pressure over-limit alarm is triggered and the process parameter optimization process is paused.

[0063] In one implementation of this invention, assuming that in a certain detection, the temperature change rate is 0.08℃ / s and the heat capacity is 15J / (kg·℃), then the product is 1.2. A preset first product threshold is 1.2, a preset ratio is 10%, and a preset upper limit is 1.0 N. The current contact pressure is 0.8 N. According to the triggering condition, the contact pressure increases by 10%, i.e., by 0.08 N, resulting in an adjusted contact pressure of 0.88 N. The control system records the adjusted contact pressure value and initiates real-time contact pressure monitoring. If the adjusted contact pressure value exceeds 1.0 N, a pressure over-limit alarm is triggered, and the process parameter optimization process is paused.

[0064] When the product of the rate of temperature change and the thermal capacity characteristic value is lower than the preset second product threshold, the current contact pressure value of the adjustable thermocouple is reduced by a preset ratio, and the adjusted contact pressure value is recorded; if the adjusted contact pressure value is lower than the preset lower limit, an insufficient pressure alarm is triggered and the contact pressure is automatically reset to the initial pressure value.

[0065] In this embodiment of the invention, when the product of the temperature change rate and the thermal capacity characteristic value is lower than a preset second product threshold, the current contact pressure value of the adjustable thermocouple is reduced by a preset percentage, and the adjusted contact pressure value is recorded. If the adjusted contact pressure value is lower than a preset lower limit, an insufficient pressure alarm is triggered, and the contact pressure is automatically reset to the initial pressure value. Crucially, after each contact pressure adjustment, it also includes verifying whether the adjusted contact pressure value is within the effective range of 0.2 N to 1.0 N. If it exceeds the effective range, the current process parameters are locked, and an anomaly log is generated. If it is within the effective range, the process parameter optimization process in step S6 continues. Specifically, the preset second product threshold is 0.8, the preset percentage is 10%, and the preset lower limit is 0.2 N. The control system calculates the product of the temperature change rate and the thermal capacity characteristic value in real time and adjusts the contact pressure of the thermocouple according to this product value.

[0066] In one implementation of this invention, assuming that in a certain detection, the temperature change rate is 0.04℃ / s and the heat capacity is 10J / (kg·℃), then the product is 0.4. A preset second product threshold is 0.8, a preset ratio is 10%, and a preset lower limit is 0.2 N. The current contact pressure is 0.6 N. According to the triggering condition, the contact pressure is reduced by 10%, i.e., reduced by 0.06 N, resulting in an adjusted contact pressure of 0.54 N. The control system records the adjusted contact pressure. If the adjusted contact pressure is lower than 0.2 N, an insufficient pressure alarm is triggered, and the contact pressure is automatically reset to the initial pressure value of 0.3 N. After adjustment, the control system verifies whether the contact pressure is within the effective range of 0.2 N to 1.0 N. If it exceeds the effective range, the current process parameters are locked and an anomaly log is generated; if it is within the effective range, the process parameter optimization process in step S6 continues.

[0067] Most importantly, after each contact pressure adjustment, it also includes:

[0068] Verify whether the adjusted contact pressure value is within the effective range of 0.2 N to 1.0 N; if it exceeds the effective range, lock the current process parameters and generate an exception log; if it is within the effective range, continue to execute the process parameter optimization process in step S6.

[0069] Preferably, the method for calculating the heat capacity characteristic value in step S3 includes:

[0070] The reference table for heat capacity coefficients is consulted based on the conductor diameter and operating speed. The reference table is generated by calibrating steady-state thermal balance data of conductors of different diameters at typical operating speeds in the laboratory, and matching the closest diameter and speed setting to obtain the reference heat capacity value.

[0071] In one implementation of this invention, it is assumed that the current conductor diameter is 0.06 mm and the operating speed is 250 m / min. A heat capacity coefficient lookup table records reference heat capacity values ​​for different diameters (0.05 mm, 0.06 mm, 0.07 mm, etc.) and operating speeds (200 m / min, 250 m / min, 300 m / min, etc.). The system matches a reference heat capacity value of 0.08 J / (kg·℃) for a diameter of 0.06 mm and an operating speed of 250 m / min.

[0072] Extract the maximum temperature difference between adjacent detection devices from the temperature distribution data, and when the maximum temperature difference exceeds the preset threshold temperature difference;

[0073] If the maximum temperature difference is located in the high-temperature zone of the annealing furnace, the quotient of the maximum temperature difference divided by the reference temperature difference value of the high-temperature zone is used as the first correction value.

[0074] If the maximum temperature difference is located in the low-temperature zone of the annealing furnace, the quotient of the maximum temperature difference divided by the reference temperature difference value of the low-temperature zone is used as the second correction value.

[0075] In this embodiment of the invention, the preset threshold temperature difference is 5°C. If the maximum temperature difference is located in the high-temperature zone of the annealing furnace, the quotient of the maximum temperature difference divided by the reference temperature difference value of the high-temperature zone is used as the first correction value; if the maximum temperature difference is located in the low-temperature zone of the annealing furnace, the quotient of the maximum temperature difference divided by the reference temperature difference value of the low-temperature zone is used as the second correction value. The reference temperature difference value for the high-temperature zone is 10°C, and the reference temperature difference value for the low-temperature zone is 8°C.

[0076] In one implementation of this invention, it is assumed that the temperature distribution data shows a maximum temperature difference of 6°C between adjacent detection devices, and this maximum temperature difference is located in the high-temperature zone of the annealing furnace. The reference temperature difference value for the high-temperature zone is 10°C, therefore the first correction value is... If the maximum temperature difference is 7℃ and it is located in the low-temperature zone, and the reference temperature difference value for the low-temperature zone is 8℃, then the second correction value is... .

[0077] Multiply the reference heat capacity value by the first correction value or the second correction value to obtain the final heat capacity characteristic value; wherein, the reference temperature difference value of the high temperature section is the maximum allowable temperature difference of the high temperature section of the annealing furnace under standard operating conditions, and the reference temperature difference value of the low temperature section is the maximum allowable temperature difference of the low temperature section of the annealing furnace under standard operating conditions.

[0078] In this embodiment of the invention, the reference heat capacity value is multiplied by either a first correction value or a second correction value to obtain the final heat capacity characteristic value. Specifically, the corresponding correction value is selected based on the segment where the maximum temperature difference occurs, and multiplied by the reference heat capacity value to obtain the final heat capacity characteristic value.

[0079] In one implementation of this invention, assuming a baseline heat capacity of 0.08 J / (kg·℃) and a first correction value of 0.6 (maximum temperature difference located in the high-temperature range), the final heat capacity characteristic value is 0.08 × 0.6 = 0.048 J / (kg·℃). If the maximum temperature difference is located in the low-temperature range, the second correction value is 0.875, and the final heat capacity characteristic value is 0.08 × 0.875 = 0.07 J / (kg·℃).

[0080] Preferably, the specific rules for reverse adjustment of heating power in step S4 include:

[0081] If the surface temperature deviation after exiting the annealing furnace is positive and the temperature change rate exceeds the preset first change rate, then the power of the high-temperature zone of the annealing furnace will be reduced by a preset first proportion, while the power of the low-temperature zone will be increased by a preset second proportion. Here, the surface temperature deviation is the difference between the actual surface temperature of the conductor after exiting the annealing furnace and the median of the preset target temperature range.

[0082] In one implementation of this invention, assuming the preset target temperature range is 200°C, the actual surface temperature of the conductor after exiting the annealing furnace is 205°C, with a surface temperature deviation of +5°C. Simultaneously, the temperature change rate is 0.12°C / s, exceeding the preset first change rate of 0.1°C / s. According to the rules, the power in the high-temperature zone of the annealing furnace is reduced by 10%, and the power in the low-temperature zone is increased by 5%. Assuming the initial power in the high-temperature zone is 150kW and the initial power in the low-temperature zone is 100kW, the adjusted power will be 135kW and 105kW, respectively.

[0083] If the surface temperature deviation after exiting the annealing furnace is negative and the temperature change rate is lower than the preset second change rate, then the power of the high-temperature zone of the annealing furnace will be increased by a preset third proportion, while the power of the low-temperature zone will be decreased by a preset fourth proportion.

[0084] Among them, the preset first rate of change is greater than the preset second rate of change, and after each adjustment, a stable running time of at least 30 seconds must be waited, during which all detection and adjustment operations are paused;

[0085] In this embodiment of the invention, if the surface temperature deviation after exiting the annealing furnace is negative and the temperature change rate is lower than a preset second change rate, the power of the high-temperature zone of the annealing furnace is increased by a preset third proportion, while the power of the low-temperature zone is decreased by a preset fourth proportion. Specifically, the preset second change rate is 0.05℃ / s, the preset third proportion is 15%, and the preset fourth proportion is 10%. The control system automatically adjusts the heating power of each temperature zone based on real-time data of the surface temperature deviation and the temperature change rate.

[0086] In one implementation of this invention, assuming the median of the preset target temperature range is 200°C, the actual surface temperature of the conductor after exiting the annealing furnace is 195°C, with a surface temperature deviation of -5°C. Simultaneously, the temperature change rate is 0.04°C / s, lower than the preset second change rate of 0.05°C / s. According to the rules, the power in the high-temperature zone of the annealing furnace is increased by 15%, and the power in the low-temperature zone is decreased by 10%. Assuming the initial power in the high-temperature zone is 150kW and the initial power in the low-temperature zone is 100kW, the adjusted power is 172.5kW and 90kW, respectively.

[0087] When the rate of temperature change is between the preset second rate of change and the preset first rate of change, the power of each temperature zone remains unchanged.

[0088] In one implementation of this invention, assuming that in a certain detection, the temperature change rate is 0.08℃ / s, which is between a preset second change rate of 0.05℃ / s and a preset first change rate of 0.1℃ / s, the control system maintains the power of each temperature zone unchanged. Assuming the current power of the high-temperature zone is 150kW and the power of the low-temperature zone is 100kW, these powers remain unchanged for the next 30 seconds, during which the control system suspends all detection and adjustment operations to ensure stable operation after the heating power adjustment.

[0089] Preferably, the method for setting the allowable error in step S6 includes:

[0090] The basic error threshold is determined based on the conductor diameter;

[0091] In this embodiment of the invention, the allowable error setting method in step S6 includes determining a basic error threshold based on the conductor diameter. Specifically, the basic error threshold is preset based on the conductor diameter, and different conductor diameters correspond to different basic error thresholds. These values ​​are stored in the system's database, and the system automatically matches the corresponding basic error threshold by inputting the current conductor diameter.

[0092] In one implementation of this invention, it is assumed that the current conductor diameter is 0.06 mm. The system database has preset basic error thresholds as follows: ±1.0 degrees Celsius for a diameter of 0.05 mm, ±1.2 degrees Celsius for a diameter of 0.06 mm, and ±1.4 degrees Celsius for a diameter of 0.07 mm. Therefore, the system matches a basic error threshold of ±1.2 degrees Celsius for a diameter of 0.06 mm.

[0093] If the running speed increases by a preset speed increment threshold, the basic error threshold will be tightened by 0.1 degrees Celsius to generate a correction error threshold.

[0094] If the operating speed decreases by a preset speed reduction threshold, the basic error threshold is relaxed by 0.1 degrees Celsius to generate a correction error threshold; the correction error threshold must meet the minimum allowable error of ±0.5 degrees Celsius and the maximum allowable error of ±3 degrees Celsius.

[0095] In one implementation of this invention, assuming the current operating speed is 250 m / min, the preset speed increment threshold is 50 m / min, and the preset speed decrement threshold is 50 m / min, the basic error threshold is ±1.2 degrees Celsius. If the operating speed increases to 300 m / min (an increase of 50 m / min), the basic error threshold tightens by 0.1 degrees Celsius, and the correction error threshold becomes ±1.1 degrees Celsius. If the operating speed decreases to 200 m / min (a decrease of 50 m / min), the basic error threshold loosens by 0.1 degrees Celsius, and the correction error threshold becomes ±1.3 degrees Celsius.

[0096] If the surface temperature after exiting the annealing furnace falls within the correction error threshold range in three consecutive tests, the process parameter optimization is considered complete.

[0097] In this embodiment of the invention, the correction error threshold must meet the minimum permissible error of ±0.5 degrees Celsius and the maximum permissible error of ±3 degrees Celsius. If the surface temperature after exiting the annealing furnace falls within the correction error threshold range in three consecutive tests, the process parameter optimization is deemed complete. Specifically, after each adjustment of the error threshold, the control system checks whether the minimum and maximum permissible error ranges are met, and records whether the surface temperature is within the correction error threshold range in three consecutive tests.

[0098] In one implementation of this invention, it is assumed that the adjusted correction error threshold is ±1.1 degrees Celsius, satisfying the requirements of a minimum permissible error of ±0.5 degrees Celsius and a maximum permissible error of ±3 degrees Celsius. In three consecutive tests, the surface temperatures after exiting the annealing furnace are 200.3°C, 200.4°C, and 199.8°C, respectively. The preset target temperature is 200°C. Therefore, the surface temperatures in these three tests are all within the correction error threshold range of ±1.1 degrees Celsius. Thus, the control system determines that the process parameter optimization is complete.

[0099] Preferably, step S1 includes:

[0100] An infrared thermometer is installed at the entrance of the annealing furnace. Its optical axis forms a first angle with the direction of conductor travel to measure the surface temperature of the conductor before it enters the annealing furnace in real time. The first angle is in the range of 25 degrees to 35 degrees.

[0101] In one implementation of this invention, it is assumed that the first included angle is set to 30 degrees. A first infrared thermometer is installed at the inlet of the annealing furnace, with its optical axis forming a 30-degree angle with the direction of conductor travel. Before the conductor enters the annealing furnace, the first infrared thermometer measures the surface temperature of the conductor in real time, and the measurement result shows that the surface temperature of the conductor is 180°C.

[0102] A second infrared thermometer is installed at the outlet of the annealing furnace. Its optical axis forms a second angle with the direction of the conductor's travel to measure the surface temperature after exiting the annealing furnace in real time. The range of the second angle is 40 degrees to 50 degrees.

[0103] In one implementation of this invention, it is assumed that the second included angle is set to 45 degrees. A second infrared thermometer is installed at the outlet of the annealing furnace, with its optical axis forming a 45-degree angle with the conductor's travel direction. After the conductor exits the annealing furnace, the second infrared thermometer measures the conductor's surface temperature in real time, and the measurement result shows that the conductor's surface temperature is 205°C.

[0104] The conductor's running speed is collected in real time by an encoder installed on the inlet side of the annealing furnace;

[0105] In one implementation of this invention, it is assumed that the encoder is installed on the conductor drive device at the inlet side of the annealing furnace. When the conductor enters the annealing furnace, the encoder collects the conductor's running speed in real time, and the measurement result shows that the conductor's running speed is 250 meters per minute.

[0106] Before the conductor enters the annealing furnace, the conductor diameter is measured three times consecutively using a laser diameter gauge, and the average value of the three measurements is taken as the conductor diameter.

[0107] In one implementation of this invention, it is assumed that the laser diameter gauge is installed at the inlet of the annealing furnace. Before the conductor enters the annealing furnace, the laser diameter gauge measures the conductor diameter three times consecutively, with measurement results of 0.061 mm, 0.060 mm, and 0.062 mm, respectively. The average of these three measurement results is taken to calculate the conductor diameter as 0.061 mm.

[0108] Preferably, an exception handling step is included after step S6:

[0109] If the fluctuation of the rate of temperature change exceeds 150% of the allowable error threshold twice in a row, the conductor feeding will be suspended and the power parameters of each temperature zone of the annealing furnace will be locked.

[0110] In this embodiment of the invention, an anomaly handling step is included after step S6: when the fluctuation amplitude of the temperature change rate is detected to exceed 150% of the allowable error threshold twice consecutively, the conductor feeding is suspended and the power parameters of each temperature zone of the annealing furnace are locked. Specifically, the control system monitors the fluctuation amplitude of the temperature change rate in real time and compares it with the allowable error threshold. Once it is found that the fluctuation amplitude exceeds 150% of the allowable error threshold twice consecutively, the suspension and locking operations are immediately executed.

[0111] In one implementation of this invention, it is assumed that the allowable error threshold is ±0.5℃ / s. In two consecutive detections, the fluctuation range of the temperature change rate is 0.8℃ / s and 0.9℃ / s, respectively, both exceeding 150% of the allowable error threshold (i.e., 0.75℃ / s). At this time, the control system suspends conductor feeding and locks the power parameters of each temperature zone of the annealing furnace to ensure that the system is in a safe state.

[0112] Start the auxiliary heater to preheat the annealing furnace under no-load conditions. The preheating temperature is the upper limit of the current conductor target temperature range plus 50 degrees Celsius, and the preheating time is 5 minutes.

[0113] In one implementation of this invention, it is assumed that the upper limit of the target temperature range for the conductor is 250°C. The preheating temperature is set to 250°C + 50°C = 300°C. The auxiliary heater is started to preheat the annealing furnace under no-load for 5 minutes. During the preheating process, the control system monitors the furnace temperature in real time to ensure that the preheating temperature reaches 300°C.

[0114] During the preheating process, the following self-test steps are performed on each temperature detection device in sequence:

[0115] Perform blackbody calibration on the non-contact infrared thermometer; the calibration temperature is the preheating temperature.

[0116] In one implementation of this invention, the preheating temperature is assumed to be 300°C. During the preheating process, a blackbody calibration is performed on the non-contact infrared thermometer at 300°C. A contact pressure cyclic test is performed on the adjustable thermocouples, with a test range of 0.2 N to 1.0 N and a test interval of 0.1 N. The test results show that the contact pressure of all adjustable thermocouples is within the effective range, and the self-test step is completed.

[0117] The adjustable thermocouple was subjected to a contact pressure cycle test, with a test range of 0.2 N to 1.0 N and a test interval of 0.1 N.

[0118] After preheating, all detection devices are reinitialized and conductor feeding is resumed. The process parameter optimization process is restarted with the initial contact pressure value.

[0119] In this embodiment of the invention, after preheating, the control system automatically reinitializes all detection devices, including infrared thermometers and adjustable thermocouples, to ensure that all equipment is in normal working condition. Conductor feeding is then resumed, and the process parameter optimization process restarts with the initial contact pressure value.

[0120] In one implementation of this invention, the initial contact pressure is assumed to be 0.3 N. After preheating, the control system reinitializes all detection devices, including the infrared thermometer and the adjustable thermocouple. After confirming that all equipment is functioning correctly, conductor feeding is resumed, and the contact pressure of the adjustable thermocouple is set to 0.3 N, restarting the process parameter optimization process.

[0121] Preferably, the present invention also provides a system for optimizing process parameters of wire and cable conductors, used to execute the method for optimizing process parameters of wire and cable conductors as described above, the system for optimizing process parameters of wire and cable conductors comprising:

[0122] The temperature measurement module is used to measure the surface temperature of the conductor before it enters the annealing furnace and after it exits the annealing furnace in real time, while also recording the conductor's running speed and diameter.

[0123] The temperature detection module is used to contact the conductor surface with a temperature detection device and measure the actual temperature when the conductor passes through the annealing furnace, so as to obtain the temperature distribution data of the conductor inside the annealing furnace.

[0124] The heat capacity calculation module is used to calculate the heat capacity characteristic value of the conductor based on the conductor's running speed and conductor diameter, and to calculate the temperature change rate between adjacent temperature detection devices by combining temperature distribution data.

[0125] The power adjustment module is used to adjust the heating power of each temperature zone of the annealing furnace in reverse according to the deviation between the surface temperature after exiting the annealing furnace and the preset target temperature.

[0126] The pressure adjustment module is used to adjust the contact pressure of the adjustable thermocouple according to the product of the temperature change rate and the thermal capacity characteristic value.

[0127] The optimization loop module is used to repeat steps S1 to S5 until the surface temperature after exiting the annealing furnace falls within the target temperature range in three consecutive measurements and the fluctuation range of the temperature change rate is less than the allowable error, and finally the optimal heating power parameters for each temperature zone are determined.

[0128] Therefore, the embodiments should be considered as exemplary and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of the equivalents of the application are intended to be included within the invention.

[0129] The above description is merely a specific embodiment of the present invention, enabling those skilled in the art to understand or implement the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and 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 novel features of the invention herein.

Claims

1. A method for optimizing process parameters applied to a conductor of an electrical wire or cable, characterized by, Includes the following steps: Step S1: Measure the surface temperature of the conductor before it enters the annealing furnace and the surface temperature after it exits the annealing furnace in real time, and record the conductor's running speed and conductor diameter at the same time; Step S2: When the conductor passes through the annealing furnace, a temperature detection device is used to contact the surface of the conductor and measure the actual temperature to obtain the temperature distribution data of the conductor inside the annealing furnace; The temperature detection device in step S2 includes adjustable thermocouples symmetrically distributed on both sides of the furnace wall. The contact control of the adjustable thermocouples includes: The contact pressure of each adjustable thermocouple is set to the initial pressure value, and the conductor diameter is calibrated by a laser diameter gauge before the conductor enters the annealing furnace to generate the calibrated conductor diameter. When the conductor passes through, if the diameter of the calibrated conductor is less than the preset first threshold, the contact pressure of the adjustable thermocouple is maintained at the initial pressure value. If the diameter of the calibrated conductor is within the range of the preset first threshold to the preset second threshold, the contact pressure increases by 0.1 N for every 0.01 mm increase in diameter, up to a maximum preset maximum pressure value. If the diameter of the calibrated conductor exceeds the preset second threshold, the contact pressure of the adjustable thermocouple will be fixed to the preset maximum pressure value. Step S3: Calculate the thermal capacity characteristic value based on the conductor's running speed and diameter, and combine this with temperature distribution data to calculate the temperature change rate between adjacent temperature detection devices; the calculation method for the thermal capacity characteristic value in step S3 includes: The reference table for heat capacity coefficients is consulted based on the conductor diameter and operating speed. The reference table is generated by calibrating steady-state thermal balance data of conductors of different diameters at typical operating speeds in the laboratory, and matching the closest diameter and speed setting to obtain the reference heat capacity value. Extract the maximum temperature difference between adjacent detection devices from the temperature distribution data, and when the maximum temperature difference exceeds the preset threshold temperature difference; If the maximum temperature difference is located in the high-temperature zone of the annealing furnace, the quotient of the maximum temperature difference divided by the reference temperature difference value of the high-temperature zone is used as the first correction value. If the maximum temperature difference is located in the low-temperature zone of the annealing furnace, the quotient of the maximum temperature difference divided by the reference temperature difference value of the low-temperature zone is used as the second correction value. Multiply the reference heat capacity value by the first correction value or the second correction value to obtain the final heat capacity characteristic value; wherein, the reference temperature difference value of the high temperature section is the maximum allowable temperature difference of the high temperature section of the annealing furnace under standard operating conditions, and the reference temperature difference value of the low temperature section is the maximum allowable temperature difference of the low temperature section of the annealing furnace under standard operating conditions. Step S4: Based on the deviation between the surface temperature after exiting the annealing furnace and the preset target temperature, adjust the heating power of each temperature zone of the annealing furnace in reverse; the specific rules for adjusting the heating power in reverse in step S4 include: If the surface temperature deviation after exiting the annealing furnace is positive and the temperature change rate exceeds the preset first change rate, then the power of the high-temperature zone of the annealing furnace will be reduced by a preset first proportion, while the power of the low-temperature zone will be increased by a preset second proportion. Here, the surface temperature deviation is the difference between the actual surface temperature of the conductor after exiting the annealing furnace and the median of the preset target temperature range. If the surface temperature deviation after exiting the annealing furnace is negative and the temperature change rate is lower than the preset second change rate, then the power of the high-temperature zone of the annealing furnace will be increased by a preset third proportion, while the power of the low-temperature zone will be decreased by a preset fourth proportion. Among them, the preset first rate of change is greater than the preset second rate of change, and after each adjustment, a stable running time of at least 30 seconds must be waited, during which all detection and adjustment operations are paused; When the rate of temperature change is between the preset second rate of change and the preset first rate of change, the power of each temperature zone remains unchanged. Step S5: Adjust the contact pressure of the adjustable thermocouple based on the product of the temperature change rate and the thermal capacity characteristic value; the triggering conditions for contact pressure adjustment in step S5 include: When the product of the rate of temperature change and the thermal capacity characteristic value exceeds the preset first product threshold, the current contact pressure value of the adjustable thermocouple is increased by a preset ratio, and the adjusted contact pressure value is recorded; at the same time, real-time contact pressure monitoring is started. If the adjusted contact pressure value exceeds the preset upper limit, a pressure over-limit alarm is triggered and the process parameter optimization process is paused. When the product of the rate of temperature change and the thermal capacity characteristic value is lower than the preset second product threshold, the current contact pressure value of the adjustable thermocouple is reduced by a preset ratio, and the adjusted contact pressure value is recorded; if the adjusted contact pressure value is lower than the preset lower limit, an insufficient pressure alarm is triggered and the contact pressure is automatically reset to the initial pressure value. Step S6: Repeat steps S1 to S5 until the surface temperature after exiting the annealing furnace falls within the target temperature range in three consecutive measurements and the fluctuation range of the temperature change rate is less than the allowable error. Finally, determine the optimal heating power parameters for each temperature zone. The allowable error setting method in step S6 includes: The basic error threshold is determined based on the conductor diameter; If the running speed increases by a preset speed increment threshold, the basic error threshold will be tightened by 0.1 degrees Celsius to generate a correction error threshold. If the operating speed decreases by a preset speed reduction threshold, the basic error threshold is relaxed by 0.1 degrees Celsius to generate a correction error threshold; the correction error threshold must meet the minimum allowable error of ±0.5 degrees Celsius and the maximum allowable error of ±3 degrees Celsius. If the surface temperature after exiting the annealing furnace falls within the correction error threshold range in three consecutive tests, the process parameter optimization is deemed complete. The conditions for locking in the optimal process parameters also include: After the surface temperature and temperature change rate after exiting the annealing furnace meet the preset standards in three consecutive measurements, a conductor sample is taken from the current operating section of the production line and immediately placed in a constant temperature and humidity environment to cool to 25±1℃. Tensile tests were performed on the conductor samples, and the maximum tensile strength value before fracture was recorded. The conductivity of the samples was measured simultaneously. The measured tensile strength value is compared with the preset standard strength value, and the relative deviation percentage of the tensile strength value is calculated. The measured conductivity value is compared with the preset standard conductivity value, and the percentage of relative deviation of the conductivity value is calculated. If the relative deviation percentage of the tensile strength value does not exceed 5% and the relative deviation percentage of the conductivity value does not exceed 3%, a process parameter locking command is generated, and the power parameters, thermocouple contact pressure and detection cycle parameters of each temperature zone are written into the non-volatile memory. If either the relative deviation percentage of the tensile strength value or the relative deviation percentage of the conductivity value exceeds the tolerance range, the most recent three test data are cleared, the annealing furnace power is reset to the initial default value, and the process is returned to step S1 to restart the optimization process.

2. The method for process parameter optimization applied to the conductor of electrical wire and cable according to claim 1, characterized in that, Step S1 includes: An infrared thermometer is installed at the entrance of the annealing furnace. Its optical axis forms a first angle with the direction of conductor travel to measure the surface temperature of the conductor before it enters the annealing furnace in real time. The first angle ranges from 25 degrees to 35 degrees. A second infrared thermometer is installed at the outlet of the annealing furnace. Its optical axis forms a second angle with the direction of the conductor's travel to measure the surface temperature after exiting the annealing furnace in real time. The range of the second angle is 40 degrees to 50 degrees. The conductor's running speed is collected in real time by an encoder installed on the inlet side of the annealing furnace; Before the conductor enters the annealing furnace, the conductor diameter is measured three times consecutively using a laser diameter gauge, and the average value of the three measurements is taken as the conductor diameter.

3. The method for process parameter optimization applied to electrical wire and cable conductors according to claim 1, characterized in that, The exception handling steps are also included after step S6: If the fluctuation of the rate of temperature change exceeds 150% of the allowable error threshold twice in a row, the conductor feeding will be suspended and the power parameters of each temperature zone of the annealing furnace will be locked. Start the auxiliary heater to preheat the annealing furnace under no-load conditions. The preheating temperature is the upper limit of the current conductor target temperature range plus 50 degrees Celsius, and the preheating time is 5 minutes. During the preheating process, the following self-test steps are performed on each temperature detection device in sequence: Perform blackbody calibration on the non-contact infrared thermometer; the calibration temperature is the preheating temperature. The adjustable thermocouple was subjected to a contact pressure cycle test, with a test range of 0.2 N to 1.0 N and a test interval of 0.1 N. After preheating, all detection devices are reinitialized and conductor feeding is resumed. The process parameter optimization process is restarted with the initial contact pressure value.

4. An electrical wire and cable conductor process parameter optimization system, comprising: For performing the method for optimizing process parameters of wire and cable conductors as described in claim 1, the system for optimizing process parameters of wire and cable conductors includes: The temperature measurement module is used to measure the surface temperature of the conductor before it enters the annealing furnace and after it exits the annealing furnace in real time, while also recording the conductor's running speed and diameter. The temperature detection module is used to contact the conductor surface with a temperature detection device and measure the actual temperature when the conductor passes through the annealing furnace, so as to obtain the temperature distribution data of the conductor inside the annealing furnace. The heat capacity calculation module is used to calculate the heat capacity characteristic value of the conductor based on the conductor's running speed and conductor diameter, and to calculate the temperature change rate between adjacent temperature detection devices by combining temperature distribution data. The power adjustment module is used to adjust the heating power of each temperature zone of the annealing furnace in reverse according to the deviation between the surface temperature after exiting the annealing furnace and the preset target temperature. The pressure adjustment module is used to adjust the contact pressure of the adjustable thermocouple according to the product of the temperature change rate and the thermal capacity characteristic value. The optimization loop module is used to repeat steps S1 to S5 until the surface temperature after exiting the annealing furnace falls within the target temperature range in three consecutive measurements and the fluctuation range of the temperature change rate is less than the allowable error, and finally the optimal heating power parameters for each temperature zone are determined.

Images