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

Abstract

The invention relates to the technical field of quality detection, in particular to a production detection method, equipment, device and system for a metal magnetic powder core, and the method specifically comprises the steps: constructing a pore confidence coefficient according to the effective magnetic conductivity change condition of the metal magnetic powder core under different frequencies; based on the difference between the variation trends of the magnetic hysteresis loss and the eddy current loss of the metal magnetic powder core and the numerical value of the magnetic hysteresis loss, a use amount discomfort coefficient is constructed; building the defect confidence coefficient of the metal magnetic powder core based on the pore confidence coefficient and the use amount discomfort coefficient of the metal magnetic powder core; the defect confidence coefficient of each metal magnetic powder core is constructed based on the difference between the defect confidence coefficient of each metal magnetic powder core and the defect confidence coefficient of other metal magnetic powder cores in the same batch, and the production quality of each metal magnetic powder core is detected based on the defect confidence coefficient. The problem that the production quality of the metal magnetic powder core is detected only by depending on a visual mode in an existing production detection technology and only the surface can be detected, so that false detection is caused is solved, and the detection precision of the production quality is improved.

Description

Technical Field

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

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

[0003] The existing method of quality inspection of pressed metal magnetic powder cores is usually a visual inspection method to detect its pressing density; however, the visual inspection method can only detect surface defects, it is difficult to find internal structural problems, and it cannot fully reflect the pressing effect of the magnetic powder core. The inspection method is not comprehensive and is prone to misjudgment. Summary of the invention

[0004] In order to solve the above technical problems, the purpose of this application is to provide a production and detection method, equipment, device and system for metal magnetic powder cores. The technical solutions adopted are as follows: In a first aspect, an embodiment of the present application provides a production and detection method for a metal magnetic powder core, the method comprising 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.

[0005] In one embodiment, the process of obtaining the drop 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.

[0006] In one embodiment, the process of obtaining the pore confidence is: 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.

[0007] In one embodiment, 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.

[0008] In one embodiment, 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.

[0009] In one embodiment, the defect confidence level is obtained 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.

[0010] In one embodiment, the production quality inspection of each metal magnetic powder core based on the defect confidence level is specifically performed 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.

[0011] In a second aspect, the present application also provides a production and detection system for metal magnetic powder cores, including: 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.

[0012] In a third aspect, an embodiment of the present application further provides a production and testing device for a metal magnetic powder core, comprising a memory, a processor, and a computer program stored in the memory and running on the processor, wherein the processor implements the steps of the method described in the first aspect when executing the computer program.

[0013] In a fourth aspect, an embodiment of the present application further provides a production inspection device for a metal magnetic powder core, wherein a computer program is stored in the device, and when the computer program is executed by a processor, the production inspection method described in the first aspect is implemented.

[0014] The embodiments of the present application have at least the following beneficial effects: The porosity confidence level is established through the change of effective magnetic permeability of metal powder core at different frequencies, which reflects the internal structure quality of metal powder core, so as to preliminarily evaluate the production quality of metal powder core. The dosage incompatibility coefficient is established based on the difference between the change trends of hysteresis loss and eddy current loss of metal powder core and the numerical value of hysteresis loss, which reflects the accuracy of the dosage of insulating coating agent in the preparation process of metal powder core, so as to further evaluate the production quality of metal powder core. The defect confidence level of metal powder core is established based on the porosity confidence level and dosage incompatibility coefficient of metal powder core. The defect confidence level of metal powder core is established based on the porosity confidence level and dosage incompatibility coefficient of metal powder core. The difference between the defect confidence levels of the magnetic powder cores is used to construct the defect confidence level of each metal magnetic powder core, thereby comprehensively evaluating the production quality of the metal magnetic powder cores; the production quality of each metal magnetic powder core is inspected based on the defect confidence level, thereby avoiding the problem that the existing production inspection technology only relies on visual methods to inspect the production quality of the metal magnetic powder core, which can only inspect the surface and cause false detection; by evaluating the internal quality of the metal magnetic powder core and the difference between the metal magnetic powder core and other magnetic powder cores in the same batch, the production quality of the metal magnetic powder core can be comprehensively inspected; compared with the existing technology, the inspection accuracy of the production quality can be improved and false detection can be avoided. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] 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 embodiments or the prior art descriptions are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0016] Figure 1 A flowchart of a method for producing and testing a metal magnetic powder core provided in one embodiment of the present application; Figure 2 Schematic diagram of the process of obtaining pore confidence; Figure 3 It is a structural schematic diagram of a production and detection system for metal magnetic powder cores. DETAILED DESCRIPTION

[0017] In order to further explain the technical means and effects adopted by the present application to achieve the predetermined invention purpose, the following is a detailed description of the production and detection method, equipment, device and system of a metal magnetic powder core proposed in the present application, its specific implementation method, structure, characteristics and effects, in combination with the accompanying drawings and preferred embodiments. In the following description, different "one embodiment" or "another embodiment" does not necessarily refer to the same embodiment. In addition, specific features, structures or characteristics in one or more embodiments may be combined in any suitable form.

[0018] Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs.

[0019] The specific scheme of the production and testing method, equipment, device and system of the metal magnetic powder core provided by the present application is described in detail below with reference to the accompanying drawings.

[0020] See also Figure 1 , which shows a flowchart of a production and testing method for a metal magnetic powder core provided by an embodiment of the present application, the method comprising the following steps: Step S1, collecting 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 power loss sequence, a hysteresis loss sequence, and an eddy current loss sequence.

[0021] Since the performance of the metal magnetic powder core will change at different frequencies, this application uses a precision LCR digital bridge to obtain the inductance value of the metal magnetic powder core in the range of 1V voltage and 1-1000kHz frequency, and calculates the effective magnetic permeability based on the inductance value; under the condition of magnetic flux density T=20mT, the power loss of the metal magnetic powder core at a frequency of 1-400kHz is collected by a wide-band power analyzer, and the power loss is separated into hysteresis loss and eddy current loss by the Bertotti loss model. Among them, the calculation of effective magnetic permeability and the Bertotti loss model are both well-known technologies, and the specific process will not be repeated.

[0022] It should be noted that, for the voltage and frequency range values ​​of the digital bridge, as well as the magnetic flux density and frequency range values ​​of the wide-band power analyzer, this application only provides one setting method. The implementer can set the voltage and frequency range values ​​of the digital bridge, as well as the magnetic flux density and frequency range values ​​of the wide-band power analyzer according to actual conditions. This application does not impose any specific restrictions.

[0023] In this embodiment, data is collected every 1 kHz, and the magnetic permeability sequence, power loss sequence, hysteresis loss sequence and eddy current loss sequence of the metal magnetic powder core are constructed respectively according to the collected effective magnetic permeability, power loss, hysteresis loss and eddy current loss in the order of the collection frequency from small to large.

[0024] In order to eliminate the dimensional influence between the data, all the data are subjected to Z-score normalization, wherein Z-score normalization is a well-known technology, and the specific process is not repeated here.

[0025] Step S2, constructing a decline difference index of the permeability sequence based on the difference between the degrees of permeability changes in different frequency ranges, and constructing the porosity confidence of the metal magnetic powder core in combination with the data change trend in the permeability sequence and the difference between adjacent elements in the permeability sequence.

[0026] If the preparation effect of the metal magnetic powder core is good, the density inside the metal magnetic powder core is high, and the air gap is small and small, the eddy current loss between the powder particles is small, so that the initial effective magnetic permeability of the metal magnetic powder core is larger and the stability is greater. If the preparation effect is not good, the annealing treatment cannot eliminate the internal stress of the metal magnetic powder core after high-pressure pressing, resulting in cracking of the film layer and increased pores, and the amount of insulating coating agent added is not appropriate, and the pore size between the powder particles is not reduced. Although the eddy current effect is not obvious at lower frequencies, the magnetic permeability of the metal magnetic powder core has not decreased significantly, but as the frequency gradually increases, the eddy current effect will be very significant, and the eddy current loss will be large, which will cause the effective magnetic permeability to drop rapidly. Therefore, compared with the good metal magnetic powder core, the metal magnetic powder core with poor preparation effect not only has a lower initial effective magnetic permeability, but also with the increase of frequency, the number of times its magnetic permeability decreases and the degree of decrease are greater.

[0027] (1) The permeability sequence is used as the input of the least squares method for straight line fitting, and the absolute value of the slope of the output fitting straight line is recorded as the change index of the permeability sequence of the metal magnetic powder core. The least squares method is a well-known technology, and the specific process is not repeated here. The smaller the change index, the more stable the change of the elements of the permeability sequence is, and there is no obvious change trend.

[0028] (2) The decline drastic index of the magnetic permeability sequence of the metal magnetic powder core is constructed based on the difference between adjacent elements in the magnetic permeability sequence: The first-order difference sequence of the magnetic permeability sequence is obtained, and 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 is recorded as the decline percentage. Among them, the acquisition of the first-order difference sequence is a well-known technology, and the specific process is not repeated here. Since the effective magnetic permeability of a well-prepared metal magnetic powder core is relatively stable under frequency, it will only begin to decline slowly and continuously in the high-frequency range, and the number of declines is small, so its decline percentage is very small. For metal magnetic powder cores with poor preparation effects, the effective magnetic permeability will decline in advance due to the more significant eddy current loss, and the number of declines will be large and the decline will be large, and the decline percentage is large.

[0029] The absolute value of the product of the decline ratio of the magnetic permeability sequence and the mean value of the elements in the first-order difference sequence of the magnetic permeability sequence is recorded as the decline severity index of the metal magnetic powder core. The larger the decline severity index, the more serious the decline in magnetic permeability.

[0030] (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.

[0031] 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.

[0032] 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.

[0033] 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.

[0034] (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: , 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.

[0035] The variation index reflects the rate of change of the effective magnetic permeability with the increase of frequency. The larger the variation index, the greater the decrease of the effective magnetic permeability with the increase of frequency, and the more obvious the decrease trend; the decrease drastic index reflects the amplitude and frequency of the decrease of magnetic permeability with the increase of frequency. The larger the decrease drastic index, the more the magnetic permeability sequence is not stable, the more the number of decreases, and the greater the overall decrease. If the decrease difference index is larger, the difference between the effective magnetic permeability of the metal magnetic powder core in the low frequency range and the high frequency range is greater, and the degree of change of the effective magnetic permeability is more drastic. If the element mean of the magnetic permeability sequence is smaller, it reflects that the overall magnetic permeability of the metal magnetic powder core is lower, and the possibility of poor preparation effect is greater. Therefore, if the porosity confidence is larger, it means that the overall magnetic 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 of the metal magnetic powder core is more significant, and the possibility of more porosity and poor preparation effect is greater.

[0036] Step S3, constructing a hysteresis proportion sequence based on the proportion of hysteresis loss at each frequency in the corresponding power loss; constructing a 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 proportion sequence and the data change range in the hysteresis loss sequence; constructing a suspected index of the metal magnetic powder core based on the porosity confidence and the dosage inappropriateness coefficient.

[0037] Furthermore, the power loss of the metal magnetic powder core is mainly composed of hysteresis loss and eddy current loss. In the preparation process of the metal magnetic powder core, adding insulating coating agents and adhesives can reduce eddy current loss to a certain extent, thereby improving the effective magnetic permeability. If the preparation effect of the metal magnetic powder core is good and the amount of insulating coating agent is appropriate, the overall eddy current loss is small; however, since both hysteresis loss and eddy current loss will increase with the increase of frequency, and at the same magnetic flux density, the increase in hysteresis loss is still less than that of eddy current loss, the proportion of hysteresis loss to power loss will still slowly decrease with the increase of frequency.

[0038] If the preparation effect is not good, and the amount of insulating coating agent used is small, the eddy current loss between powder particles cannot be effectively reduced. The eddy current loss will still be large and increase rapidly with the increase of frequency. At this time, the proportion of hysteresis loss in power loss will decrease rapidly with the increase of frequency. If the amount of insulating coating agent used is too much, although it will reduce the eddy current loss and the rate of increase of eddy current loss, it will increase the demagnetization field of the metal magnetic powder core, causing the hysteresis loss of the metal magnetic powder core to increase rapidly, which will increase the power loss. At this time, the proportion of hysteresis loss in power loss will increase significantly with the increase of frequency. Therefore, the preparation effect of the metal magnetic powder core can be further reflected by calculating the change of hysteresis loss.

[0039] (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.

[0040] 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.

[0041] 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.

[0042] (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.

[0043] (3) Based on the above analysis, the dosage inappropriateness coefficient of the metal magnetic powder core is constructed, and the expression is: , 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.

[0044] 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.

[0045] (4) Furthermore, the suspected index of the metal magnetic powder core is constructed based on the porosity confidence and dosage incompatibility coefficient of the metal magnetic powder core, and the expression 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 a normalization function to eliminate the dimensional influence between parameters.

[0046] The larger the suspected index is, the greater the possibility that problems will occur in the preparation process of the metal magnetic powder core, and the greater the possibility that the production quality of the metal magnetic powder core will be defective.

[0047] Step S4, clustering the suspected indexes of the metal magnetic powder cores in the same production batch to obtain clusters; based on the differences 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, constructing the defect confidence of each metal magnetic powder core.

[0048] Through the above steps, the suspected index of each metal magnetic powder core belonging to the same production batch as the metal magnetic powder core currently to be tested is obtained, and the suspected index of all metal magnetic powder cores of the same production batch is clustered as the input of the DPC density mean clustering algorithm, and the cross-validation method is used to obtain the cutoff distance of the DPC clustering algorithm, and the output is each cluster cluster. Among them, the DPC density clustering and cross-validation method are both well-known technologies, and the specific process will not be repeated.

[0049] It should be noted that for the clustering of suspected indexes of all metal magnetic powder cores, this application only provides one 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. This application does not make specific restrictions.

[0050] Calculate the mean of all elements in each cluster and record it as the suspected index mean.

[0051] The cluster where the metal magnetic powder core to be tested is located is recorded as the detection cluster. Calculate the absolute value of the difference between the suspected index mean of the detection cluster and the suspected index mean of each other cluster, and record it as the first absolute value of difference; calculate the mean of all the first absolute values ​​of difference, and record the product of the mean and the suspected index mean of the detection cluster as the comparative difference index of the detection cluster. The larger the comparative difference index, the greater the difference between the detection cluster and other clusters, and the suspected index of the internal elements of the detection cluster is also larger.

[0052] The ratio of the maximum suspected index of all metal powder cores in the same batch to the suspected index of the metal powder core to be tested is recorded as the normal confidence of the metal powder core to be tested. The smaller the normal confidence, the greater the suspected index of the metal powder core to be tested compared with other metal powder cores, and the greater the possibility of production quality problems of the metal powder core to be tested.

[0053] Based on the above analysis, the defect confidence of the metal magnetic powder core to be tested is constructed, and the expression is: , where Q is the defect confidence of the metal magnetic powder core to be tested; is the suspected index of the metal magnetic powder core to be tested; K is the comparative difference index of the detection cluster; 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; Z is the normal confidence of the metal magnetic powder core to be tested.

[0054] If the suspected index is larger, it means that the production quality of the metal magnetic powder core to be tested is more likely to have problems; if the relative difference index is larger, it means that the difference between the cluster of the metal magnetic powder core to be tested and other clusters is larger; since the preparation parameters are consistent in the same production batch, the test results should be relatively consistent, so if S is smaller, it means that the element in the test cluster is more likely to be a metal magnetic powder core with better or worse preparation effect, and the possibility of not meeting the ordinary preparation quality is greater; if the normal confidence Z is smaller, it means that the suspected index of the metal magnetic powder core to be tested is closer to the maximum value of the suspected index, and the possibility that the metal magnetic powder core to be tested is the worst in the same batch is greater. Therefore, if the defect confidence is larger, it means that the metal magnetic powder core to be tested has problems in the preparation process and the production quality is poor.

[0055] Step S5: performing production quality inspection of each metal magnetic powder core based on the defect confidence level.

[0056] Take each metal magnetic powder core as the metal magnetic powder core to be tested in turn, obtain the defect confidence of each metal magnetic powder core of the same production batch, and perform normalization processing through the maximum and minimum normalization algorithm. If the normalized defect confidence is greater than or equal to the defect threshold, it is determined that there is a problem in the preparation process of the metal magnetic powder core, the production quality is unqualified, and timely processing is required; if the normalized defect confidence is less than the defect threshold, it is determined that the production quality of the metal magnetic powder core is qualified and can be used. Preferably, in the embodiment 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 and minimum normalization algorithm is a well-known technology, and the specific process will not be repeated.

[0057] It should be noted that for the normalization of the defect confidence of all metal magnetic powder cores, this application only provides one normalization algorithm. There are many existing normalization algorithms, and implementers can also use other normalization algorithms to normalize the defect confidence of all metal magnetic powder cores. This application does not make specific restrictions.

[0058] The schematic diagram of the process of obtaining pore confidence is as follows: Figure 2 shown.

[0059] See also Figure 3 , Figure 3 is a structural diagram of a production and detection system for a metal magnetic powder core provided in an embodiment of the present application. In this embodiment, each unit included in the terminal is used to execute each step in an embodiment corresponding to a production and detection method for a metal magnetic powder core. Figure 3 , the production inspection system includes: 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.

[0060] Based on the same inventive concept as the above method, an embodiment of the present application also provides a production and inspection device for a metal magnetic powder core, comprising a memory, a processor, and a computer program stored in the memory and running on the processor, wherein when the processor executes the computer program, the steps of any one of the above-mentioned methods for producing and inspecting a metal magnetic powder core are implemented.

[0061] Based on the same inventive concept as the above method, an embodiment of the present application also provides a production and inspection device for a metal magnetic powder core, wherein 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-mentioned methods for producing and inspecting a metal magnetic powder core are implemented.

[0062] In summary, the embodiments of the present application provide a production inspection method for metal magnetic powder cores, which constructs a porosity confidence through the change of the effective magnetic permeability of the metal magnetic powder core at different frequencies, reflecting the internal structure quality of the metal magnetic powder core, thereby preliminarily evaluating the production quality of the metal magnetic powder core; constructs a dosage unsuitability coefficient based on the difference between the changing trends of the hysteresis loss and the eddy current loss of the metal magnetic powder core and the numerical value of the hysteresis loss, reflecting 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; constructs the defect confidence of the metal magnetic powder core based on the porosity confidence and dosage unsuitability coefficient of the metal magnetic powder core; and constructs the defect confidence of the metal magnetic powder core based on the same 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 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, thereby avoiding the problem that the existing production detection technology only relies on visual methods to detect the production quality of the metal magnetic powder core, and can only detect the surface and cause false detection; by evaluating the internal quality of the metal magnetic powder core and the difference between it and 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 production quality can be improved to avoid false detection.

[0063] It should be noted that the above-mentioned sequence of the embodiments of the present application is only for description and does not represent the advantages and disadvantages of the embodiments. The above-mentioned specific embodiments of the present application are described. In addition, the processes depicted in the accompanying drawings do not necessarily require the specific order or continuous order shown to achieve the desired results. In some embodiments, multitasking and parallel processing are also possible or may be advantageous.

[0064] The various embodiments in the present application are described in a progressive manner, and the same or similar parts between the various embodiments can be referenced to each other, and each embodiment focuses on the differences from other embodiments.

[0065] The above description is only a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent substitutions, improvements, etc. made within the principles of the present application should be included in 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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