Production detection method, equipment, device and system for a metal magnetic powder core

Abstract

This application relates to the field of quality inspection technology, and specifically relates to a production inspection method, equipment, device and system for metal magnetic powder cores, specifically including: constructing a pore confidence level based on the change of the effective magnetic permeability of the metal magnetic powder core at different frequencies; constructing a dosage discomfort coefficient based on the difference between the change trends of the hysteresis loss and the eddy current loss of the metal magnetic powder core and the numerical value of the hysteresis loss; constructing a defect confidence level of the metal magnetic powder core based on the pore confidence level and the dosage discomfort coefficient of the metal magnetic powder core; constructing the defect confidence level of each metal magnetic powder core based on the difference between the defect confidence levels of each metal magnetic powder core and other metal magnetic powder cores in the same batch, and performing production quality inspection on each metal magnetic powder core based on the defect confidence level, avoiding the problem that the existing production inspection technology only relies on visual methods to detect the production quality of metal magnetic powder cores, resulting in misdetection because only the surface can be detected, and improving the detection accuracy of production quality.

Description

Technical Field

[0001] This application relates to the technical field of quality inspection, and specifically relates to a production inspection method, equipment, device and system for metal magnetic powder cores. Background Art

[0002] A metal magnetic powder core is a composite magnetic material prepared by insulating coating, pressing and annealing of ferromagnetic alloy powders. The metal magnetic powder core not only retains the high saturation magnetization intensity of the metal magnetic material, but also has a high resistivity, enabling it to be used at higher frequencies. If the preparation effect of the metal magnetic powder core is good, the internal density of the finished metal magnetic powder core after annealing treatment is relatively high, with fewer and smaller pores; if the preparation effect is not good, a large number of air gaps will exist inside the final metal magnetic powder core, thereby increasing power loss and reducing magnetic properties. Therefore, it is necessary to conduct quality inspection on the finished metal magnetic powder core after annealing treatment to avoid affecting the use of its carrier and causing greater economic losses.

[0003] The existing method for quality inspection of the pressed metal magnetic powder core is usually a visual inspection method to detect its pressing density; however, the visual inspection method can only detect surface defects, is difficult to find internal structure problems, cannot comprehensively reflect the pressing effect of the magnetic powder core, the detection method is not comprehensive enough, and misjudgment is likely to occur. Summary of the Invention

[0004] In order to solve the above technical problems, the purpose of this application is to provide a production inspection method, equipment, device and system for metal magnetic powder cores, and the technical solutions adopted are as follows:

[0005] In the first aspect, an embodiment of this application provides a production inspection method for metal magnetic powder cores, and the method includes the following steps:

[0006] Collect the inductance values and power losses of the metal magnetic powder core at each frequency, obtain the effective magnetic permeability of the metal magnetic powder core at each frequency through the inductance value, obtain the hysteresis loss and eddy current loss of the metal magnetic powder core at each frequency through the power loss, and construct a magnetic permeability sequence, a hysteresis loss sequence and an eddy current loss sequence;

[0007] Construct a decline difference index of the magnetic permeability sequence based on the differences between the degrees of change of the magnetic permeability within different frequency ranges, and combine the data change trend in the magnetic permeability sequence and the differences between adjacent elements in the magnetic permeability sequence to construct the pore confidence of the metal magnetic powder core;

[0008] Construct a hysteresis ratio sequence based on the proportion of hysteresis losses at each frequency in the corresponding power losses; based on the difference between the data change trends in the hysteresis loss sequence and the eddy current loss sequence, and combining the data change trend in the hysteresis ratio sequence and the data range in the hysteresis loss sequence, construct a dosage inappropriateness coefficient for the metal magnetic powder core; based on the pore confidence level and the dosage inappropriateness coefficient, construct a suspected index for the metal magnetic powder core;

[0009] Cluster the suspected indices of each metal magnetic powder core in the same production batch to obtain each cluster; based on the difference between each cluster and other clusters, and combining the suspected indices of each metal magnetic powder core and the number of elements in each cluster, construct a defect confidence level for each metal magnetic powder core;

[0010] Conduct production quality inspection of each metal magnetic powder core based on the defect confidence level.

[0011] In one embodiment, the process for obtaining the decrease difference index is as follows:

[0012] Divide the permeability sequence into two subsequences through a sequence segmentation algorithm; calculate the mean value of all elements in the first-order difference sequence of each subsequence, denoted as the first mean value; denote the absolute value of the difference between the first mean values of the two subsequences as the decrease difference index of the permeability sequence.

[0013] In one embodiment, the process for obtaining the pore confidence level is as follows:

[0014] Take the permeability sequence as the input of the linear fitting algorithm, and take the absolute value of the slope of the output fitting line as the change index of the permeability sequence, denoted as B;

[0015] Denote the ratio of the number of elements with negative values in the first-order difference sequence of the permeability sequence to the total number of elements in the first-order difference sequence of the permeability sequence as the decrease ratio; denote the absolute value of the product of the mean value of the elements in the first-order difference sequence of the permeability sequence and the decrease ratio as C; denote the pore confidence level of the metal magnetic powder core as A, and the expression of A is:

[0016] where D is the decrease difference index of the permeability sequence; is the mean value of all elements in the permeability sequence.

[0017] In one embodiment, the process for obtaining the dosage inappropriateness coefficient is as follows:

[0018] Based on the hysteresis loss sequence, eddy current loss sequence, and hysteresis ratio sequence respectively, and using the same acquisition method as the change index of the permeability sequence, calculate the change indices of the hysteresis loss sequence, eddy current loss sequence, and hysteresis ratio sequence respectively; Denote the absolute value of the difference between the change indices of the hysteresis loss sequence and the eddy current loss sequence as G; Denote the dosage inappropriateness coefficient of the metal magnetic powder core as F, and the expression of F is:

[0019] , where H is the change index of the hysteresis ratio sequence; L is the range of the hysteresis loss sequence.

[0020] In one embodiment, the calculation method of the suspected index is:

[0021] , where Y is the suspected index of the metal magnetic powder core; A is the pore confidence of the metal magnetic powder core; F is the dosage inappropriateness coefficient of the metal magnetic powder core; is a normalization function.

[0022] In one embodiment, the process of obtaining the defect confidence is:

[0023] Take the suspected indices of all metal magnetic powder cores in the same production batch as the input of the clustering algorithm, and the output is each clustering cluster; Denote the mean value of all elements in each clustering cluster as the mean suspected index; Denote the clustering cluster where the metal magnetic powder core to be currently detected is located as the detection clustering cluster;

[0024] Calculate the absolute value of the difference between the mean suspected index of the detection clustering cluster and the mean suspected index of each other clustering cluster, and denote it as the first absolute value of the difference; Denote the product of the mean value of all the first absolute values of the differences and the mean suspected index of the detection clustering cluster as K; Denote the ratio of the maximum value of the suspected indices among all metal magnetic powder cores in the same production batch to the suspected index of the metal magnetic powder core to be currently detected as Z; Denote the defect confidence of the metal magnetic powder core to be currently detected as Q, and the expression of Q is:

[0025] , where is the suspected index of the metal magnetic powder core to be currently detected; S is the ratio of the number of metal magnetic powder cores in the detection clustering cluster to the number of all metal magnetic powder cores in the same production batch.

[0026] In one embodiment, the production quality inspection of each metal magnetic powder core based on the defect confidence is specifically:

[0027] For each metal magnetic powder core in the same production batch, if the normalized value of the defect confidence of the metal magnetic powder core is greater than or equal to the preset defect threshold, the production quality of the metal magnetic powder core is unqualified; otherwise, the production quality of the metal magnetic powder core is qualified.

[0028] In a second aspect, an embodiment of the present application further provides a production detection system for metal magnetic powder cores, including:

[0029] A data acquisition module: acquiring the inductance value and power loss of the metal magnetic powder core at each frequency, obtaining the effective magnetic permeability of the metal magnetic powder core at each frequency through the inductance value, obtaining the hysteresis loss and eddy current loss of the metal magnetic powder core at each frequency through the power loss, and constructing a magnetic permeability sequence, a hysteresis loss sequence, and an eddy current loss sequence;

[0030] A pore detection module: constructing a decline difference index of the magnetic permeability sequence based on the difference between the degrees of change in magnetic permeability within different frequency ranges, and combining the data change trend in the magnetic permeability sequence and the difference between adjacent elements in the magnetic permeability sequence to construct the pore confidence level of the metal magnetic powder core;

[0031] A preparation effect analysis module: constructing a hysteresis ratio sequence based on the ratio of the hysteresis loss at each frequency to the corresponding power loss; based on the difference between the data change trends in the hysteresis loss sequence and the eddy current loss sequence, combining the data change trend in the hysteresis ratio sequence and the data change range in the hysteresis loss sequence to construct a dosage discomfort coefficient for the metal magnetic powder core; constructing a suspected index for the metal magnetic powder core based on the pore confidence level and the dosage discomfort coefficient;

[0032] A defect analysis module: clustering the suspected indices of each metal magnetic powder core in the same production batch to obtain each clustering cluster; based on the difference between each clustering cluster and other clustering clusters, combining the suspected indices of each metal magnetic powder core and the number of elements in each clustering cluster to construct the defect confidence level of each metal magnetic powder core;

[0033] A production quality detection module: performing production quality detection on each metal magnetic powder core based on the defect confidence level.

[0034] In a third aspect, an embodiment of the present application further provides a production detection device for metal magnetic powder cores, including a memory, a processor, and a computer program stored in the memory and running on the processor. When the processor executes the computer program, the steps of the method described in the first aspect above are implemented.

[0035] In a fourth aspect, an embodiment of the present application further provides a production detection device for metal magnetic powder cores. A computer program is stored in the device, and when the computer program is executed by a processor, the production detection method described in the first aspect above is implemented.

[0036] The embodiments of the present application have at least the following beneficial effects:

[0037] The pore confidence is constructed based on the change of the effective permeability of the metal magnetic powder core at different frequencies, which reflects the internal structure quality of the metal magnetic powder core, so as to preliminarily evaluate the production quality of the metal magnetic powder core; the dosage discomfort coefficient is constructed based on the difference between the change trends of the hysteresis loss and the eddy current loss of the metal magnetic powder core and the numerical value of the hysteresis loss, which reflects the accuracy of the dosage of the insulation coating agent in the preparation process of the metal magnetic powder core, so as to further evaluate the production quality of the metal magnetic powder core; the defect confidence of the metal magnetic powder core is constructed based on the pore confidence and the dosage discomfort coefficient of the metal magnetic powder core; the defect confidence of each metal magnetic powder core is constructed based on the difference between the defect confidence of each metal magnetic powder core and other metal magnetic powder cores in the same batch, so as to comprehensively evaluate the production quality of the metal magnetic powder core; the production quality of each metal magnetic powder core is detected based on the defect confidence, which avoids the problem that the existing production detection technology only relies on the visual method to detect the production quality of the metal magnetic powder core, resulting in misdetection because only the surface can be detected; by evaluating the internal quality of the metal magnetic powder core and the difference from other magnetic powder cores in the same batch, the production quality of the metal magnetic powder core can be comprehensively detected; compared with the existing technology, the detection accuracy of the production quality can be improved and misdetection can be avoided. Brief Description of the Drawings

[0038] In order to more clearly illustrate the technical solutions and advantages in the embodiments of the present application or the prior art, the drawings required for use in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0039] Figure 1 It is a flowchart of the steps of a production detection method for a metal magnetic powder core provided by an embodiment of the present application;

[0040] Figure 2 It is a schematic diagram of the acquisition process of the pore confidence;

[0041] Figure 3 It is a schematic diagram of the structure of a production detection system for a metal magnetic powder core. Detailed Embodiments

[0042] In order to further elaborate on the technical means and effects adopted by the present application to achieve the predetermined invention purpose, the following describes in detail the specific embodiments, structures, features and effects of a production detection method, equipment, device and system for a metal magnetic powder core proposed according to the present application in conjunction with the drawings and preferred embodiments. In the following description, different "one embodiment" or "another embodiment" do not necessarily refer to the same embodiment. In addition, the specific features, structures or characteristics in one or more embodiments can be combined in any suitable form.

[0043] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the technical field to which this application belongs.

[0044] The following specifically describes the specific solutions of a production detection method, device, apparatus, and system for a metal magnetic powder core provided by this application in conjunction with the accompanying drawings.

[0045] Please refer to Figure 1 , which shows a step flowchart of a production detection method for a metal magnetic powder core provided by an embodiment of this application. The method includes the following steps:

[0046] Step S1, collect the inductance value and power loss of the metal magnetic powder core at each frequency, obtain the effective magnetic permeability of the metal magnetic powder core at each frequency through the inductance value, obtain the hysteresis loss and eddy current loss of the metal magnetic powder core at each frequency through the power loss, and construct a magnetic permeability sequence, a power loss sequence, a hysteresis loss sequence, and an eddy current loss sequence.

[0047] Since the performance of the metal magnetic powder core changes at different frequencies, this application obtains the inductance value of the metal magnetic powder core within the range of 1V voltage and 1 - 1000 kHz frequency through a precision LCR digital bridge, and calculates the effective magnetic permeability based on the inductance value; under the condition that the magnetic flux density is T = 20 mT, the power loss of the metal magnetic powder core at 1 - 400 kHz frequency is collected through a broadband power analyzer, and the power loss is separated into hysteresis loss and eddy current loss through the Bertotti loss model. Among them, the calculation of the effective magnetic permeability and the Bertotti loss model are both well-known technologies, and the specific process will not be elaborated.

[0048] It should be noted that for the value settings of the voltage and frequency range of the digital bridge, and the magnetic flux density and frequency range of the broadband power analyzer, this application only provides one setting method. Implementers can set the value of the voltage and frequency range of the digital bridge, and the value of the magnetic flux density and frequency range of the broadband power analyzer according to the actual situation. This application does not make specific restrictions.

[0049] In this embodiment, data is collected every 1 kHz. According to the collected effective magnetic permeability, power loss, hysteresis loss, and eddy current loss in ascending order of the collection frequency, a magnetic permeability sequence, a power loss sequence, a hysteresis loss sequence, and an eddy current loss sequence of the metal magnetic powder core are constructed respectively.

[0050] In order to eliminate the influence of the dimension between data, all data is processed by Z-score standardization. Among them, Z-score standardization is a well-known technology, and the specific process will not be elaborated.

[0051] Step S2: Construct a decline difference index of the permeability sequence based on the differences between the degrees of change in permeability within different frequency ranges, and construct the pore confidence of the metal powder core by combining the data change trend in the permeability sequence and the differences between adjacent elements in the permeability sequence.

[0052] If the preparation effect of the metal powder core is good, the density inside the metal powder core is high, the air gaps are few and small, then the eddy current loss between powder particles is small, so that the initial effective permeability of the metal powder core is larger and the stability degree is higher. If the preparation effect is not good, the annealing treatment cannot eliminate the internal stress remaining after high-pressure pressing of the metal powder core, resulting in film cracking and increased pores, and the dosage of the added insulating coating agent is not appropriate and does not reduce the pore size between powder particles. Then, although at a lower frequency, the eddy current effect is not obvious and the permeability of the metal powder core does not decrease significantly, but as the frequency gradually increases, the eddy current effect will be very significant, the eddy current loss is large, and it will cause the effective permeability to decrease rapidly. Therefore, compared with the metal powder core with good preparation effect, the metal powder core with poor preparation effect not only has a lower initial effective permeability, but also the number of times of its permeability decline is more and the decline degree is larger as the frequency increases.

[0053] (1) Use the permeability sequence as the input of the least squares method for linear fitting, and record the absolute value of the slope of the output fitting line as the change index of the permeability sequence of the metal powder core. Among them, the least squares method is a well-known technology, and the specific process will not be elaborated. The smaller the change index, the more stable the elements of the permeability sequence and there is no obvious change trend.

[0054] (2) Construct the sharp decline index of the permeability sequence of the metal powder core based on the differences between adjacent elements in the permeability sequence:

[0055] Obtain the first-order difference sequence of the permeability sequence, and record the ratio of the number of elements with negative element values in the first-order difference sequence to the number of all elements in the first-order difference sequence as the decline ratio. Among them, the acquisition of the first-order difference sequence is a well-known technology, and the specific process will not be elaborated. Since the effective permeability of the well-prepared metal powder core is relatively stable at low frequencies and only begins to decline continuously and slowly in the high-frequency range with fewer decline times, its decline ratio is very small. For the metal powder core with poor preparation effect, due to the significant eddy current loss, the effective permeability will decline in advance, with more decline times and a larger decline amplitude, and the decline ratio is very large.

[0056] Record the absolute value of the product of the decline ratio of the permeability sequence and the mean value of the elements in the first-order difference sequence of the permeability sequence as the sharp decline index of the metal powder core. The larger the sharp decline index, the more serious the decline degree of the permeability reflects.

[0057] (3) Furthermore, if the preparation effect is good, the degree of decrease after the frequency increases is still consistent with the degree of decrease when the frequency is small; if the preparation effect is poor, there are more pores inside the metal magnetic powder core, and the degree of decrease in effective magnetic permeability increases with the increase of frequency. Therefore, the production quality of the metal magnetic powder core can be evaluated by calculating the difference between the degree of decrease at different frequencies.

[0058] The magnetic permeability sequence is divided into two subsequences by using the PELT sequence segmentation algorithm, wherein the PELT sequence decomposition algorithm is a well-known technology, and the specific process is not repeated here.

[0059] It should be noted that, for the segmentation of the magnetic permeability sequence, this application only provides a sequence segmentation method. There are many existing sequence segmentation methods, and implementers can also use other sequence segmentation algorithms to segment the magnetic permeability sequence. This application does not make specific restrictions.

[0060] The mean of all elements in the first-order difference sequence of each subsequence is calculated and recorded as the first mean. The absolute value of the difference between the first means of the above two subsequences is recorded as the decline difference index of the magnetic permeability sequence of the metal magnetic powder core. The larger the decline difference index, the greater the decline difference of the effective magnetic permeability of the metal magnetic powder core in different frequency ranges.

[0061] (4) The porosity confidence of the metal magnetic powder core is calculated based on the change index, drop severity index, drop difference index and the mean value of all elements in the magnetic permeability sequence of the metal magnetic powder core. The expression is:

[0062] , where A is the porosity confidence of the metal magnetic powder core; B is the change index of the magnetic permeability sequence of the metal magnetic powder core; C is the decline drastic index of the magnetic permeability sequence of the metal magnetic powder core; D is the decline difference index of the magnetic permeability sequence of the metal magnetic powder core; It is the mean value of all elements in the magnetic permeability series of the metal magnetic powder core.

[0063] The change index reflects the rate of change of the effective permeability with the increase in frequency. The larger the change index, the greater the degree of decrease in the effective permeability and the more obvious the downward trend as the frequency increases. The sharp decrease index reflects the amplitude and frequency of the decrease in the permeability as the frequency increases. The larger the sharp decrease index, the less stable the permeability sequence, the more times of decrease, and the greater the overall decrease amplitude. If the decrease difference index is larger, it indicates that the difference in the effective permeability of the metal magnetic powder core between the low-frequency range and the high-frequency range is greater, and the degree of change in the effective permeability is more intense. If the average value of the elements in the permeability sequence is smaller, it reflects that the overall permeability of the metal magnetic powder core is lower, and the possibility of poor preparation effect is greater. Therefore, if the pore confidence level is larger, it indicates that the overall permeability of the metal magnetic powder core is lower, the degree of decrease is greater, and the number of decreases is more, reflecting that the eddy current loss presented by the metal magnetic powder core is more significant, and the possibility of more pores and poorer preparation effect is greater.

[0064] Step S3: Construct a hysteresis ratio sequence based on the proportion of the hysteresis loss at each frequency in the corresponding power loss; based on the difference between the data change trends in the hysteresis loss sequence and the eddy current loss sequence, combined with the data change trend in the hysteresis ratio sequence and the data change range in the hysteresis loss sequence, construct a dosage discomfort coefficient of the metal magnetic powder core; construct a suspected index of the metal magnetic powder core based on the pore confidence level and the dosage discomfort coefficient.

[0065] Furthermore, the power loss of the metal magnetic powder core is mainly composed of hysteresis loss and eddy current loss. During the preparation process of the metal magnetic powder core, adding an insulating coating agent and an adhesive can, to a certain extent, reduce the eddy current loss and thus increase the effective permeability. If the preparation effect of the metal magnetic powder core is good and the dosage of the insulating coating agent is appropriate, the overall eddy current loss is small. However, since both the hysteresis loss and the eddy current loss increase with the increase in frequency, and at the same magnetic flux density, the increase degree of the hysteresis loss is still less than that of the eddy current loss, the proportion of the hysteresis loss in the power loss will still slowly decrease with the increase in frequency.

[0066] If the preparation effect is not good and the dosage of the insulating coating agent is small, it cannot effectively reduce the eddy current loss between the powder particles, and its eddy current loss will still be large and increase rapidly with the increase in frequency. At this time, the proportion of the hysteresis loss in the power loss will rapidly decrease with the increase in frequency. If the dosage of the insulating coating agent is too much, although it will reduce the eddy current loss and the rising speed of the eddy current loss, it will increase the demagnetizing field of the metal magnetic powder core, causing the hysteresis loss of the metal magnetic powder core to increase rapidly, which will instead increase the power loss. At this time, the proportion of the hysteresis loss in the power loss will increase significantly with the increase in frequency. Therefore, the preparation effect of the metal magnetic powder core can be further reflected by calculating the change in the hysteresis loss.

[0067] (1) Calculate the ratio between each element in the hysteresis loss sequence and the element of the corresponding power in the power loss sequence, record it as the hysteresis ratio, arrange all the hysteresis ratios in order from small to large according to the corresponding power, and the resulting sequence is recorded as the hysteresis ratio sequence.

[0068] Based on the hysteresis loss series, eddy current loss series and hysteresis ratio series, the variation indexes of the hysteresis loss series, eddy current loss series and hysteresis ratio series are calculated respectively in the same way as that of the variation index of the permeability series.

[0069] The change index of the hysteresis ratio series reflects the change of the relative proportion of hysteresis loss in power loss with frequency. The larger the value, the more drastic the change of the proportion of hysteresis loss in power loss with the increase of frequency, which reflects that the possibility of rapid increase or decrease of hysteresis loss ratio is greater, indicating that the possibility of inappropriate dosage of insulating coating agent is greater.

[0070] (2) Calculate the absolute value of the difference between the change index of the hysteresis loss sequence and the eddy current loss sequence as the loss change difference index of the metal magnetic powder core. If the amount of insulating coating agent used is small, the eddy current loss will still increase rapidly with the increase of frequency, while the hysteresis loss will still increase slowly; if the amount used is too much, the eddy current loss will change less, while the hysteresis loss will increase faster. Therefore, the larger the loss change difference index, the greater the difference between the growth degree of the hysteresis loss sequence and the eddy current loss sequence with the increase of frequency, and the greater the possibility that the amount of insulating coating agent used is inappropriate.

[0071] (3) Based on the above analysis, the dosage inappropriateness coefficient of the metal magnetic powder core is constructed, and the expression is:

[0072] , where F is the dosage incompatibility coefficient of the metal magnetic powder core; G is the loss change difference index of the metal magnetic powder core; H is the change index of the hysteresis proportion sequence; and L is the extreme value of the hysteresis loss sequence.

[0073] If the loss change difference index is larger, it means that after adding the insulating coating agent, the growth change difference between the hysteresis loss and the eddy current loss of the metal magnetic powder core is larger; if the change index H of the hysteresis ratio sequence is larger, it reflects that the proportion of hysteresis loss in power loss is more likely to increase or decrease rapidly; if the extreme difference is larger, it reflects that the overall increase in hysteresis loss is greater, and the possibility of excessive use of insulating coating agent is greater. Therefore, if the dosage inappropriate coefficient is larger, it means that the addition amount of insulating coating agent in the preparation process of the metal magnetic powder core is more likely to be inappropriate, reflecting that the preparation effect of the metal magnetic powder core is worse.

[0074] (4) Further, a suspected index of the metal magnetic powder core is constructed based on the porosity confidence level and the dosage discomfort coefficient of the metal magnetic powder core, and the expression is:

[0075] , where Y is the suspected index of the metal magnetic powder core; A is the porosity confidence level of the metal magnetic powder core; F is the dosage discomfort coefficient of the metal magnetic powder core; is a normalization function to eliminate the dimensional influence between parameters.

[0076] The larger the suspected index, the greater the possibility that problems occur in the preparation process of the metal magnetic powder core, and the greater the possibility that there are defects in the production quality of the metal magnetic powder core.

[0077] Step S4: Obtain each clustering cluster by clustering the suspected indexes of the metal magnetic powder cores in the same production batch; based on the differences between each clustering cluster and other clustering clusters, and combining the suspected indexes of the metal magnetic powder cores and the number of elements in each clustering cluster, construct the defect confidence level of each metal magnetic powder core.

[0078] Through the above steps, obtain the suspected indexes of each metal magnetic powder core in the same production batch as the currently to-be-detected metal magnetic powder core, use the suspected indexes of all the metal magnetic powder cores in the same production batch as the input of the DPC density mean clustering algorithm for clustering, and use the cross-validation method to obtain the cut-off distance of the DPC clustering algorithm, and the output is each clustering cluster. Among them, DPC density clustering and the cross-validation method are both well-known technologies, and the specific process will not be elaborated.

[0079] It should be noted that for the clustering of the suspected indexes of all metal magnetic powder cores, the present application only provides a clustering method. There are many existing clustering methods, and implementers can also use other clustering methods to cluster the suspected indexes of all metal magnetic powder cores, and the present application does not make specific restrictions.

[0080] Calculate the mean value of all elements in each clustering cluster, denoted as the mean suspected index.

[0081] Denote the clustering cluster where the currently to-be-detected metal magnetic powder core is located as the detection clustering cluster. Calculate the absolute value of the difference between the mean suspected index of the detection clustering cluster and the mean suspected index of each other clustering cluster, denoted as the first absolute difference value; calculate the mean value of all the first absolute difference values, and denote the product of this mean value and the mean suspected index of the detection clustering cluster as the relative difference index of the detection clustering cluster. The larger the relative difference index, the greater the difference between the detection clustering cluster and other clustering clusters, and the larger the suspected indexes of the elements within the detection clustering cluster.

[0082] The ratio of the maximum value of the suspected index among all metal powder cores in the same batch to the suspected index of the currently tested metal powder core is denoted as the normal confidence level of the currently tested metal powder core. The smaller the normal confidence level, the greater the suspected index of the currently tested metal powder core compared to other metal powder cores, and the greater the likelihood that there are problems with the production quality of the currently tested metal powder core.

[0083] Based on the above analysis, the defect confidence level of the currently tested metal powder core is constructed, and the expression is:

[0084] , where Q is the defect confidence level of the currently tested metal powder core; is the suspected index of the currently tested metal powder core; K is the relative difference index of the detection cluster; S is the ratio of the number of metal powder cores in the detection cluster to the number of all metal powder cores in the same production batch; Z is the normal confidence level of the currently tested metal powder core.

[0085] If the suspected index is larger, it indicates that the likelihood of problems with the production quality of the currently tested metal powder core is greater; if the relative difference index is larger, it reflects that the difference between the detection cluster where the currently tested metal powder core is located and other clusters is greater; since the preparation parameters are the same in the same production batch, the detection results should be relatively consistent. Therefore, if S is smaller, it reflects that the elements in the detection cluster are more likely to be metal powder cores with better or worse preparation effects, and the likelihood of not meeting the general preparation quality is greater; if the normal confidence level Z is smaller, it means that the suspected index of the currently tested metal powder core is closer to the maximum value of the suspected index, and the likelihood that the currently tested metal powder core has the worst preparation effect in the same batch is greater. Therefore, if the defect confidence level is larger, it reflects that the likelihood of problems occurring during the preparation process and poor production quality of the currently tested metal powder core is greater.

[0086] Step S5, perform production quality detection on each metal powder core based on the defect confidence level.

[0087] Take each metal powder core as the currently to-be-detected metal powder core in turn, obtain the defect confidence levels of each metal powder core in the same production batch, and perform normalization processing through the maximum-minimum normalization algorithm. If the normalized defect confidence level is greater than or equal to the defect threshold, it is determined that there is a problem in the preparation process of this metal powder core, and the production quality is unqualified, and it needs to be processed in time; if the normalized defect confidence level is less than the defect threshold, it is determined that the production quality of this metal powder core is qualified and can be used. Preferably, in the embodiments of the present application, the defect threshold is set to 0.5. As other embodiments of the present application, the implementer can set the defect threshold according to the actual situation. Among them, the maximum-minimum normalization algorithm is a well-known technology, and the specific process will not be elaborated.

[0088] It should be noted that for the normalization of the defect confidence levels of all metal powder cores, the present application only provides one normalization algorithm. There are many existing normalization algorithms, and the implementer can also use other normalization algorithms to normalize the defect confidence levels of all metal powder cores. The present application does not make specific restrictions.

[0089] The schematic diagram of the process for obtaining the pore confidence level is as Figure 2 shown.

[0090] Please refer to Figure 3 , Figure 3 which is the schematic structural diagram of a production detection system for metal powder cores provided by the embodiments of the present application. In this embodiment, each unit included in the terminal is used to execute each step in the corresponding embodiment of a production detection method for metal powder cores. Refer to Figure 3 , the production detection system includes:

[0091] Data acquisition module: Collect the inductance value and power loss of the metal powder core at each frequency, obtain the effective magnetic permeability of the metal powder core at each frequency through the inductance value, obtain the hysteresis loss and eddy current loss of the metal powder core at each frequency through the power loss, and construct a magnetic permeability sequence, a hysteresis loss sequence, and an eddy current loss sequence;

[0092] Pore detection module: Construct a decline difference index of the magnetic permeability sequence based on the difference between the degrees of change of the magnetic permeability in different frequency ranges, and combine the data change trend in the magnetic permeability sequence and the difference between adjacent elements in the magnetic permeability sequence to construct the pore confidence level of the metal powder core;

[0093] Preparation effect analysis module: Construct a hysteresis ratio sequence based on the ratio of the hysteresis loss at each frequency to the corresponding power loss; based on the difference between the data change trends in the hysteresis loss sequence and the eddy current loss sequence, combine the data change trend in the hysteresis ratio sequence and the data change range in the hysteresis loss sequence to construct the dosage discomfort coefficient of the metal powder core; construct the suspected index of the metal powder core based on the pore confidence level and the dosage discomfort coefficient;

[0094] Defect analysis module: obtaining each clustering cluster by clustering the suspected indexes of each metal magnetic powder core in the same production batch; based on the differences between each clustering cluster and other clustering clusters, combining the suspected indexes of each metal magnetic powder core and the number of elements in each clustering cluster, constructing the defect confidence of each metal magnetic powder core;

[0095] Production quality detection module: performing production quality detection on each metal magnetic powder core based on the defect confidence.

[0096] Based on the same inventive concept as the above method, an embodiment of the present application further provides a production detection device for metal magnetic powder cores, including a memory, a processor, and a computer program stored in the memory and running on the processor. When the processor executes the computer program, the steps of any one of the above production detection methods for metal magnetic powder cores are implemented.

[0097] Based on the same inventive concept as the above method, an embodiment of the present application further provides a production detection device for metal magnetic powder cores. A computer program is stored in the device, and when the computer program is executed by a processor, the steps of any one of the above production detection methods for metal magnetic powder cores are implemented.

[0098] In summary, an embodiment of the present application provides a production detection method for metal magnetic powder cores. By constructing the pore confidence based on the change of the effective magnetic permeability of the metal magnetic powder core at different frequencies, the internal structure quality of the metal magnetic powder core is reflected, thereby preliminarily evaluating the production quality of the metal magnetic powder core; based on the difference between the change trends of the hysteresis loss and the eddy current loss of the metal magnetic powder core and the numerical value of the hysteresis loss, a dosage discomfort coefficient is constructed, which reflects the accuracy of the dosage of the insulating coating agent in the preparation process of the metal magnetic powder core, thereby further evaluating the production quality of the metal magnetic powder core; based on the pore confidence and the dosage discomfort coefficient of the metal magnetic powder core, the defect confidence of the metal magnetic powder core is constructed; based on the difference between the defect confidence of each metal magnetic powder core in the same batch and the defect confidence of other metal magnetic powder cores, the defect confidence of each metal magnetic powder core is constructed, thereby comprehensively evaluating the production quality of the metal magnetic powder core; based on the defect confidence, production quality detection of each metal magnetic powder core is performed, avoiding the problem that the existing production detection technology only relies on visual means to detect the production quality of metal magnetic powder cores, resulting in misdetection because only the surface can be detected; by evaluating the internal quality of the metal magnetic powder core and the difference from other magnetic powder cores in the same batch, the production quality of the metal magnetic powder core can be comprehensively detected; compared with the prior art, the detection accuracy of the production quality can be improved, and misdetection can be avoided.

[0099] It should be noted that: The above sequence of the embodiments of the present application is only for description and does not represent the superiority or inferiority of the embodiments. Moreover, the specific embodiments of the present application have been described above. Additionally, the processes depicted in the drawings do not necessarily require the specific order or sequential order shown to achieve the desired results. In some embodiments, multitasking and parallel processing are also possible or may be advantageous.

[0100] Each embodiment in the present application is described in a progressive manner. For the same or similar parts among the embodiments, reference can be made to each other, and the key points of each embodiment are the differences from other embodiments.

[0101] The above are only the preferred embodiments of the present application and are not intended to limit the present application. Any modifications, equivalent replacements, improvements, etc. made within the principles of the present application shall be included within the protection scope of the present application.

Claims

1. A production and testing method for metal magnetic powder cores, characterized in that: The method comprises the following steps: The inductance value and power loss of the metal magnetic powder core at each frequency are collected, and the effective magnetic permeability of the metal magnetic powder core at each frequency is obtained through the inductance value, and the hysteresis loss and eddy current loss of the metal magnetic powder core at each frequency are obtained through the power loss, and a magnetic permeability sequence, a hysteresis loss sequence and an eddy current loss sequence are constructed; Based on the difference between the degree of change of magnetic permeability in different frequency ranges, the decline difference index of the magnetic permeability sequence is constructed, and the porosity confidence of the metal magnetic powder core is constructed by combining the data change trend in the magnetic permeability sequence and the difference between adjacent elements in the magnetic permeability sequence. A hysteresis ratio sequence is constructed based on the ratio of the hysteresis loss of each frequency in the corresponding power loss; based on the difference between the data change trends in the hysteresis loss sequence and the eddy current loss sequence, combined with the data change trend in the hysteresis ratio sequence and the data change range in the hysteresis loss sequence, the dosage inappropriateness coefficient of the metal magnetic powder core is constructed; based on the porosity confidence and the dosage inappropriateness coefficient, a suspected index of the metal magnetic powder core is constructed; Each cluster is obtained by clustering the suspected index of each metal magnetic powder core in the same production batch; based on the difference between each cluster and other clusters, combined with the suspected index of each metal magnetic powder core and the number of elements in each cluster, the defect confidence of each metal magnetic powder core is constructed; The production quality of each metal magnetic powder core is inspected based on the defect confidence level.

2. A production and testing method for a metal magnetic powder core as claimed in claim 1, characterized in that: The process of obtaining the decline difference index is as follows: The magnetic permeability sequence is divided into two subsequences by a sequence segmentation algorithm; the mean of all elements in the first-order difference sequence of each subsequence is calculated and recorded as the first mean; the absolute value of the difference between the first means of the two subsequences is recorded as the decline difference index of the magnetic permeability sequence.

3. A production and testing method for a metal magnetic powder core as claimed in claim 1, characterized in that: The process of obtaining the pore confidence is as follows: The permeability sequence is used as the input of the straight line fitting algorithm, and the absolute value of the slope of the output fitting line is used as the variation index of the permeability sequence, denoted as B; The ratio of the number of elements with negative element values ​​in the first-order difference sequence of the magnetic permeability sequence to the number of all elements in the first-order difference sequence of the magnetic permeability sequence is recorded as the decline ratio; the absolute value of the product of the mean value of the element in the first-order difference sequence of the magnetic permeability sequence and the decline ratio is recorded as C; the porosity confidence of the metal magnetic powder core is recorded as A, and the expression of A is: , where D is the decline difference index of the magnetic permeability series; is the mean of all elements in the permeability series.

4. A production and testing method for a metal magnetic powder core as claimed in claim 3, characterized in that: The process of obtaining the dosage incompatibility coefficient is as follows: Based on the hysteresis loss sequence, eddy current loss sequence and hysteresis ratio sequence, the variation index of the hysteresis loss sequence, eddy current loss sequence and hysteresis ratio sequence is calculated respectively in the same way as the variation index of the magnetic permeability sequence; the absolute value of the difference between the variation index of the hysteresis loss sequence and the eddy current loss sequence is recorded as G; the dosage incompatibility coefficient of the metal magnetic powder core is recorded as F, and the expression of F is: , where H is the variation index of the hysteresis ratio series; L is the range of the hysteresis loss series.

5. The production and testing method of a metal magnetic powder core according to claim 1, characterized in that: The calculation method of the suspected index is: , where Y is the suspected index of the metal magnetic powder core; A is the porosity confidence of the metal magnetic powder core; F is the dosage inappropriateness coefficient of the metal magnetic powder core; is the normalization function.

6. A production and testing method for a metal magnetic powder core as claimed in claim 1, characterized in that: The process of obtaining the defect confidence is as follows: The suspected indexes of all metal magnetic powder cores of the same production batch are used as the input of the clustering algorithm, and the output is each cluster; the mean of all elements in each cluster is recorded as the suspected index mean; the cluster where the metal magnetic powder core to be tested currently belongs is recorded as the detection cluster; Calculate the absolute value of the difference between the mean of the suspected index of the detection cluster and the mean of the suspected index of each other cluster, and record it as the first absolute value of the difference; record the product of the mean of all the first absolute values ​​of the difference and the mean of the suspected index of the detection cluster as K; record the ratio of the maximum value of the suspected index of all metal magnetic powder cores in the same production batch to the suspected index of the metal magnetic powder core to be tested as Z; record the defect confidence of the metal magnetic powder core to be tested as Q, and the expression of Q is: , where is the suspected index of the metal magnetic powder core to be tested; S is the ratio of the number of metal magnetic powder cores in the detection cluster to the number of all metal magnetic powder cores in the same production batch.

7. A method for producing and testing a metal magnetic powder core according to claim 1, characterized in that: The production quality inspection of each metal magnetic powder core based on the defect confidence level is specifically as follows: For each metal magnetic powder core of the same production batch, if the normalized value of the defect confidence of the metal magnetic powder core is greater than or equal to the preset defect threshold, the production quality of the metal magnetic powder core is unqualified; otherwise, the production quality of the metal magnetic powder core is qualified.

8. A production and testing system for metal magnetic powder cores, implementing the method as claimed in claim 1, characterized in that: The system comprises: Data acquisition module: collects the inductance value and power loss of the metal magnetic powder core at each frequency, obtains the effective magnetic permeability of the metal magnetic powder core at each frequency through the inductance value, obtains the hysteresis loss and eddy current loss of the metal magnetic powder core at each frequency through the power loss, and constructs the magnetic permeability sequence, hysteresis loss sequence and eddy current loss sequence; Porosity detection module: Based on the difference between the degree of change of magnetic permeability in different frequency ranges, the decline difference index of the magnetic permeability sequence is constructed, and the porosity confidence of the metal magnetic powder core is constructed by combining the data change trend in the magnetic permeability sequence and the difference between adjacent elements in the magnetic permeability sequence; Preparation effect analysis module: construct a hysteresis ratio sequence based on the ratio of hysteresis loss of each frequency in the corresponding power loss; construct the dosage inappropriateness coefficient of the metal magnetic powder core based on the difference between the data change trends in the hysteresis loss sequence and the eddy current loss sequence, combined with the data change trend in the hysteresis ratio sequence and the data change range in the hysteresis loss sequence; construct the suspected index of the metal magnetic powder core based on the porosity confidence and the dosage inappropriateness coefficient; Defect analysis module: cluster the suspected indexes of each metal magnetic powder core in the same production batch to obtain each cluster; based on the difference between each cluster and other clusters, combined with the suspected index of each metal magnetic powder core and the number of elements in each cluster, the defect confidence of each metal magnetic powder core is constructed; Production quality inspection module: performs production quality inspection of each metal magnetic powder core based on the defect confidence level.

9. A production and testing device for metal magnetic powder cores, comprising a memory, a processor, and a computer program stored in the memory and running on the processor, characterized in that: When the processor executes the computer program, the steps of the method according to any one of claims 1 to 7 are implemented.

10. A production and testing device for metal magnetic powder cores, wherein a computer program is stored in the device, characterized in that: When the computer program is executed by a processor, the production detection method according to any one of claims 1 to 7 is implemented.

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