CN-121972574-A - Method for predicting correlation of alcohol consumption and cooling capacity in nickel sheet stamping process

CN121972574ACN 121972574 ACN121972574 ACN 121972574ACN-121972574-A

Abstract

The application provides a method for predicting the relation between the consumption of alcohol and cooling capacity in a nickel sheet stamping process, which comprises the steps of extracting the temperature difference between a nickel sheet surface temperature value and an alcohol initial contact temperature value according to temperature acquisition records, carrying out temperature difference superposition on continuous acquisition points to determine an interface temperature difference total value, analyzing the maximum temperature difference in an interface temperature difference accumulation amount, evaluating the maximum temperature difference compared with film boiling trigger temperature to obtain a boiling trigger mark and a current stamping stage number, carrying out cooling heat exchange mode classification identification on the boiling trigger mark, the stamping stage number and historical stamping stage data through a support vector machine algorithm to obtain boiling critical temperature differences in each stamping process stage, evaluating the formation risk of a steam interlayer based on the adjustment range of alcohol spraying amount to obtain an alcohol spraying amount cutting value, generating a spraying control signal and sending the spraying control signal to an adjusting module.

Inventors

ZHANG XINSHU
HUANG SHENGFENG

Assignees

惠州市精工精金属制品有限公司

Dates

Publication Date: 20260505
Application Date: 20260128

Claims (8)

1. A method for predicting the relation between alcohol consumption and cooling capacity in the process of stamping nickel plates includes such steps as collecting the surface temp of nickel plates, synchronously recording the temp at the moment of alcohol spraying contact, obtaining the real-time surface temp value of nickel plates and the initial contact temp value of alcohol, obtaining the temp collecting record with time stamp, extracting the temp difference between the surface temp value of nickel plates and the initial contact temp value of alcohol, overlapping the temp difference between continuously collected points, determining the total temp difference value of interface, analyzing the maximum temp difference, comparing it with film boiling trigger temp to obtain boiling trigger mark and current number, classifying the boiling trigger mark, the number of stamping stages and the data of historical stamping stages by support vector machine, obtaining the boiling critical temp difference, updating alcohol spraying quantity judge threshold, evaluating the temp difference range of current stamping stage, determining the alcohol spraying quantity, regulating amplitude, generating the temp difference value, and cooling.
2. The method for predicting the correlation of the alcohol consumption and the cooling capacity in the nickel sheet stamping process according to claim 1 is characterized by comprising the steps of collecting the surface temperature of a nickel sheet, synchronously recording the temperature at the moment of alcohol spraying contact, obtaining a real-time surface temperature value of the nickel sheet and an initial alcohol contact temperature value, and obtaining a temperature collection record with a time mark.
3. The method for predicting the relation between the alcohol consumption and the cooling capacity in the nickel sheet stamping process according to claim 1 is characterized by comprising the steps of extracting the temperature difference between the nickel sheet surface temperature value and the alcohol initial contact temperature value according to the temperature acquisition record, carrying out temperature difference superposition on continuous acquisition points to determine an interface temperature difference total value, extracting a nickel sheet surface temperature sequence and an alcohol contact temperature sequence from the temperature acquisition record, aligning two groups of data according to a time stamp, calculating the difference value between the nickel sheet surface temperature and the alcohol contact temperature at the same moment to obtain an instant interface temperature difference sequence, carrying out accumulation summation on the instant interface temperature difference sequence according to a time sequence, recording the accumulated temperature difference value of the point if the difference value between the current accumulated value and the previous accumulated value exceeds a preset threshold value to obtain a temperature difference accumulation curve, adopting a sliding window method to process the temperature difference accumulation curve, taking the average value of the temperature difference accumulation values in a window as a representative value of the window, summing all window representative values, dividing the window quantity, and determining the interface temperature difference total value.
4. The method for predicting the correlation between the alcohol consumption and the cooling capacity in the nickel sheet stamping process according to claim 1 is characterized in that the analyzing of the maximum temperature difference in the total interface temperature difference value is compared with film boiling trigger temperature to obtain a boiling trigger mark and a current stamping stage number, wherein the method comprises the steps of scanning the temperature difference value point by point in an interface temperature difference accumulation curve, classifying the temperature difference value according to the size by adopting a decision tree classification algorithm, identifying the maximum temperature difference value and the time position of the maximum temperature difference value in the stamping period to obtain temperature difference peak value data, comparing the maximum value in the temperature difference peak value data with a preset film boiling trigger temperature threshold value, generating the boiling trigger mark as true if the maximum value is higher than the threshold value, otherwise, generating the boiling trigger mark as false, and obtaining the boiling trigger mark with a timestamp, and determining the current stamping stage number according to the proportion of the time position of the temperature difference peak value data in the whole stamping period.
5. The method for predicting the correlation of the alcohol consumption and the cooling capacity in the nickel sheet stamping process according to claim 1 is characterized by comprising the steps of carrying out cooling heat exchange mode classification identification on the boiling trigger mark, the stamping stage number and the historical stamping stage data through a support vector machine algorithm to obtain boiling critical temperature difference of each stamping process stage, constructing a training data set containing positive and negative samples to obtain a marked heat exchange mode sample library, training the heat exchange mode sample library through the support vector machine algorithm, mapping feature vectors into a high-dimensional space through a radial basis function, searching a classification hyperplane of nucleate boiling and film boiling to obtain a heat exchange mode classifier of each stage, inputting real-time data of current stamping into the heat exchange mode classifier, judging whether the current stamping belongs to the nucleate boiling mode or the film boiling mode according to classification results, extracting a temperature difference value corresponding to a classification boundary as a critical point of the stage to obtain a boiling critical temperature difference of the current process stage, carrying out time sequence recording on the boiling critical temperature difference, and updating the training data set and retraining the classifier if critical temperature difference values of a plurality of periods exceed a preset threshold.
6. The method for predicting the relation between the alcohol consumption and the cooling capacity in the nickel sheet stamping process according to claim 1 is characterized in that the alcohol spray quantity judging threshold is updated according to the boiling critical temperature difference, a decision tree algorithm is adopted to evaluate the boiling critical temperature difference region where the current stamping stage number is located, the alcohol spray quantity adjusting amplitude of a high temperature region is determined, the method comprises the steps of multiplying each critical temperature difference value by a preset safety coefficient according to the boiling critical temperature difference of each stamping process stage to obtain an upper limit value, dividing the safety coefficient to obtain a lower limit value, taking the upper limit value and the lower limit value as a new alcohol spray quantity judging threshold to obtain a dynamically adjusted spray quantity judging threshold set, the decision tree algorithm is adopted to divide the spray quantity judging threshold set into sections, a corresponding threshold subset is selected according to the current stamping stage number, the upper limit value and the lower limit value in the current real-time temperature difference and the threshold subset are compared, the specific section position where the current temperature difference is located is determined, the deviation is calculated according to the specific section position, and the temperature difference value is multiplied by the preset adjusting step length to obtain the increasing and decreasing value of the alcohol spray quantity.
7. The method for predicting the association of the alcohol consumption and the cooling capacity in the nickel sheet stamping process according to claim 1 is characterized in that the method comprises the steps of evaluating the formation risk of a steam interlayer based on the alcohol spraying amount adjusting amplitude to obtain an alcohol spraying amount cutting value, generating a spraying control signal and sending the spraying control signal to an adjusting module, calculating the accumulation amount of alcohol on the surface of the nickel sheet in unit time according to the product of the alcohol spraying amount adjusting amplitude and the current spraying rate, judging that the risk level is high if the accumulation amount exceeds the preset multiple of the evaporation amount of the unit area of the nickel sheet, otherwise, judging that the risk level is low to obtain the formation risk level of the steam interlayer, performing association judgment on the risk level and the current nickel sheet surface temperature, multiplying the current spraying amount by a preset cutting coefficient to obtain a cutting value if the risk level is high and the temperature exceeds the film boiling critical temperature, setting the cutting value to be zero if the risk level is low, obtaining the alcohol spraying amount cutting value, calculating the adjusted spraying amount according to the alcohol spraying amount cutting value, converting the adjusted spraying amount into a corresponding valve opening percentage, and sending the digital control signal comprising the target opening and the execution time according to the preset communication code to the adjusting module.
8. The method for predicting the correlation between the alcohol consumption and the cooling capacity in the nickel sheet stamping process according to claim 1 is characterized in that the spraying control signal is executed through the adjusting module, the temperature feedback value of the nickel sheet after execution is obtained and compared with the expected cooling temperature, the method comprises the steps of driving an electromagnetic valve to execute alcohol spraying according to a specified opening degree after receiving the control signal, acquiring the surface temperature of the nickel sheet again through an infrared probe after the spraying is finished to obtain the temperature feedback value after the spraying is finished, comparing the temperature feedback value with the expected temperature obtained by subtracting the preset cooling amplitude from the temperature before spraying, inputting the temperature feedback value as the initial temperature of the next period if the difference value is within an allowable deviation, and circularly entering the nickel sheet surface temperature acquisition flow.

Description

Method for predicting correlation of alcohol consumption and cooling capacity in nickel sheet stamping process Technical Field The invention relates to the technical field of information, in particular to a method for predicting the association of alcohol consumption and cooling capacity in a nickel sheet stamping process. Background In the field of nickel sheet stamping processing, accurate control of the temperature of a workpiece in the stamping process is a core link for ensuring product quality and die life. Nickel sheet is used as high heat conduction material, can produce a large amount of heat when high-speed punching press, if the temperature is out of control, not only can lead to the material deformation inefficacy, can also accelerate the mould wearing and tearing, directly influence production efficiency and cost. In current industry practice, alcohol spraying is commonly used as a cooling means to remove heat by increasing the amount of spraying. This approach is indeed effective at lower temperatures, but problems begin to develop when the surface temperature of the nickel sheet continues to rise and the contact state of the alcohol with the high temperature surface changes essentially. The alcohol is originally in direct contact with the surface of the workpiece in the form of liquid drops to be rapidly vaporized, a layer of heat-insulating steam film is formed to wrap the contact interface, and the steam film blocks the direct contact between the liquid drops and the solid surface, so that heat transfer is converted from efficient convection heat exchange to low-efficiency radiation and small-quantity conduction, and the cooling effect is drastically reduced. This phenomenon is called film boiling, and unlike ordinary nucleate boiling, the latter still has direct contact with the liquid phase, and the vapor layer persists under film boiling, and the heat flux decreases instead. This abnormal performance of cooling efficiency brings about a sharp technical contradiction, namely, in a high temperature region, the higher the temperature of the nickel plate is, the more the alcohol spray amount is needed to be increased to strengthen heat dissipation, but in practice, when the surface temperature exceeds the boiling point of the alcohol by about 80 ℃ and enters a film boiling region, the spray amount is continuously increased to promote instant vaporization of more liquid drops, the thickness of a steam layer is increased, the heat-conducting capacity is further weakened, and the local temperature is suddenly out of control. For example, in continuous stamping operation, the temperature of a high-temperature area at the edge of a workpiece can reach 300 ℃, the thickness of a steam film is increased to tens of micrometers, and the cooling efficiency is reduced to a fraction of the original cooling efficiency. Particularly, in different stages of a stamping cycle, the difference between the heat load and the surface temperature distribution is remarkable, for example, the heat input is less and the temperature is uniform in the initial stage of stamping, the temperature peak value of a plastic deformation zone in the middle stage is high, the heat accumulated in a contact zone of a die at the end stage forms hot spots, and if the alcohol consumption is regulated according to a single increment logic all the time, the cooling failure is triggered at a high-temperature key moment easily, so that the surface of a workpiece is burnt, the dimensional accuracy is out of tolerance or the die is scrapped early. Therefore, how to accurately judge whether the nickel sheet is currently in a film boiling triggering interval according to the real-time surface temperature of the nickel sheet and the interface temperature difference at the moment of alcohol contact, and dynamically adjust the alcohol spraying quantity judgment standard in different stamping stages, so that the problem that the cooling capacity is reduced due to the blind increase of the consumption is solved, and the problem of realizing stable and efficient cooling is solved. Disclosure of Invention The invention provides a method for predicting the association of alcohol consumption and cooling capacity in a nickel sheet stamping process, which mainly comprises the following steps: The method comprises the steps of collecting nickel sheet surface temperature, synchronously recording the temperature at the moment of alcohol spraying contact, obtaining a nickel sheet real-time surface temperature value and an alcohol initial contact temperature value, obtaining a temperature collection record with a time mark, extracting the temperature difference between the nickel sheet surface temperature value and the alcohol initial contact temperature value according to the temperature collection record, carrying out temperature difference superposition on continuous collection points to determine an interface temperature difference total value, analyzing