Differentiation design method of inductor prefabricated submodules

Abstract

The invention discloses a differentiated design method of an inductor prefabricated submodule. The method comprises the following steps: constructing a stress model; carrying out stress analysis on the stress model to obtain stress data; constructing a plurality of sub-models according to the stress data; generating a processing index for each sub-model; and processing to obtain a plurality of prefabricated sub-modules based on the sub-models and the corresponding processing indexes. Compared with a conventional prefabricated sub-module designed according to coil positioning or powder filling, the method has the advantages that the deformation condition of each area of the coil and the blank in the die-casting process is obtained based on the overall stress analysis of the inductor, the plurality of sub-models are divided and disassembled, and the pre-die-casting is carried out according to the sub-models to obtain the pre-cast sub-module which is uniform in stress and pressure bearing; the prefabricated sub-module with low damage rate in the die-casting process is formed, and the defective rate is greatly reduced.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of inductance design, and particularly relates to a differential design method of an inductance precast sub-module. BACKGROUND

[0002] In the production process of inductance production, in addition to directly adopting powder casting molding, in the case of increasingly diversified coil winding configurations, in order to avoid cavities in the powder filling due to the shielding of the coil structure, pre-cast sub-modules are used. Each sub-module is assembled with the coil to form an assembly that eliminates cavities, and then the assembly is subjected to secondary pressure casting to tightly combine it into an inductance blank. In addition, sub-modules of specific shapes can also serve as positioning for the coil, so that the coil can be accurately positioned during the pressure casting process without the need for additional equipment structures.

[0003] However, although the precast sub-modules solve the problems of filling gaps and coil positioning, in the actual production process, due to the precision of pre-casting, there are several irregular contact points or contact surfaces between the coil and the sub-modules, and between different sub-modules, and during pressure casting, the sub-modules and the coil will inevitably deform to varying degrees. In extreme cases, the coil and the pre-cast sub-modules may deform or even break due to uneven stress and pressure, thus inevitably producing defective products. SUMMARY

[0004] The first aspect of the embodiment of the present application discloses a differential design method of an inductance precast sub-module, comprising:

[0005] 101, constructing a stress model;

[0006] 102, performing stress analysis on the stress model to obtain stress data;

[0007] 103, constructing a plurality of sub-models according to the stress data;

[0008] 104, generating processing indicators for each sub-model;

[0009] 105, based on the sub-models and their corresponding processing indicators, a plurality of precast sub-modules are processed.

[0010] Preferably, the stress model comprises at least a first solid model and a second solid model;

[0011] The first solid model is constructed based on the outer shape parameters of the coil, and the second solid model is constructed based on the outer shape parameters of the inductance.

[0012] Preferably, the construction of the stress model comprises:

[0013] The first solid model is substituted into the second solid model.

[0014] Eliminating the overlapping portion between the first three-dimensional model and the second three-dimensional model to obtain a blank model;

[0015] Processing the blank model using a bilateral filtering algorithm to obtain the third three-dimensional model;

[0016] The third three-dimensional model is used to represent a plurality of blanks covering the coil.

[0017] Preferably, performing force analysis on the force model to obtain force data includes:

[0018] Acquiring material data of the coil and the blank, as well as pressure data of the die-casting process;

[0019] Determining the pressure state of each area of ​​the coil according to the calibrated position of the coil, wherein the pressure state includes at least a pressure area, a pressure direction, and a pressure threshold;

[0020] Furthermore, based on the pressure-bearing state of the coil, the deformation state of the blank is analyzed, where the deformation state at least includes a deformation area and a deformation threshold thereof.

[0021] Preferably, constructing a plurality of sub-models according to the force data includes:

[0022] For areas where the pressure threshold or deformation threshold exceeds the standard threshold, mark the exceeding limit area;

[0023] The out-of-limit areas on the same die-casting axis are calibrated, and the third three-dimensional mold is divided and disassembled into the plurality of sub-models accordingly.

[0024] Preferably, when the die-casting process is hot die-casting, the method further comprises:

[0025] Based on the temperature control curve of hot die casting, the pressure bearing state and the deformation state are adjusted.

[0026] Preferably, the method further comprises:

[0027] The third three-dimensional model has an overlapping space relative to the first three-dimensional model, and the overlapping space is used to represent the compression margin of the blank material.

[0028] Preferably, the method further comprises:

[0029] The prefabricated submodule has an enlarged space relative to its corresponding third three-dimensional model, and the enlarged space is used to represent the finishing margin of the prefabricated submodule after the secondary die-casting.

[0030] Preferably, the method further comprises:

[0031] If the interference control submodule is assembled with the coil, a combination is obtained;

[0032] The assembly is subjected to secondary die casting to obtain an inductor blank;

[0033] The inductor blank is finely processed to obtain an inductor.

[0034] Compared with the prior art, the embodiments of the present invention have the following beneficial effects:

[0035] Compared with the conventional prefabricated sub-modules designed based on coil positioning or powder filling, this method is based on the overall force analysis of the inductor to obtain the deformation conditions of each area of ​​the coil and the blank during the die-casting process, and split and disassemble it into several sub-models. Based on this, the pre-die-casting obtains a prefabricated sub-module with uniform force and pressure, and a low breakage rate during the die-casting process, which greatly reduces the defective rate. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0037] Fig. 1 It is a flow chart of a differentiated design method of an inductor prefabricated submodule disclosed in the present invention;

[0038] Fig. 2 It is a schematic diagram of the coil shape of the first three-dimensional model constructed in the differentiated design method of the inductor prefabricated sub-module disclosed in the present invention;

[0039] Fig. 3 It is a schematic diagram of the inductor appearance of the second three-dimensional model constructed in the differentiated design method of the inductor prefabricated sub-module disclosed in the present invention;

[0040] Fig. 4 This is a schematic diagram of a partial structure of an inductor in a differentiated design method for an inductor prefabricated submodule disclosed in the present invention;

[0041] Fig. 5 It is a schematic diagram of the three-dimensional structure of a die-casting device for die-casting an inductor in a differentiated design method for an inductor prefabricated sub-module disclosed in the present invention;

[0042] Fig. 6 It is a schematic top view of a die-casting cavity of a die-casting device in a differentiated design method for an inductor prefabricated sub-module disclosed in the present invention. DETAILED DESCRIPTION

[0043] With reference to the drawings of the embodiments of the present application, the technical solutions in the embodiments of the present application will be clearly and completely described. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments of the present application, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the scope of the present application.

[0044] Please refer to Figs. 1-6 The differential design method of the inductance prefabricated sub-module can include the following contents.

[0045] 101, construct a stress model.

[0046] In this embodiment, the stress model at least includes a first solid model and a second solid model;

[0047] The first solid model is constructed based on the shape parameters of the coil, and the second solid model is constructed based on the shape parameters of the inductance.

[0048] It should be understood that the prefabricated sub-module is not only obtained by pre-pressing casting, but also assembled and subjected to secondary pressure casting when the inductance is formed, so that the volume is subjected to secondary compression, and a design allowance needs to be reserved.

[0049] As an optional implementation, the first solid model and the second solid model should be based on the actual profile of the coil and the inductance, based on the ratio of the powder and the material characteristics, and a certain amount of compression allowance is reserved for subsequent processing.

[0050] As an optional implementation, the stress model is constructed, including:

[0051] The first solid model is substituted into the second solid model;

[0052] The overlapping part of the first solid model and the second solid model is eliminated to obtain a blank body model;

[0053] The blank body model is processed by using a bilateral filtering algorithm to obtain a third solid model.

[0054] Specifically, the third solid model is used to represent a plurality of blank bodies covering the coil, that is, the inductance blank body outside the coil, and the space filled by the powder, so that the irregular space that may be generated by the coil bending part can be directly obtained, and the prefabricated sub-module that is convenient to fill the pores and convenient to produce can be designed accordingly.

[0055] The bilateral filtering algorithm is used to eliminate the extremely thin edges and pores generated after the coil is bent. This part of the edge and the pore will be filled during the subsequent secondary pressure casting, so it is eliminated here to reduce the complexity of the third solid model, which is beneficial to subsequent stress analysis.

[0056] Here, the powder usually includes iron powder and insulating material, and the weight of the insulating material usually accounts for 1% to 3% of the weight of the iron powder.

[0057] The iron powder is a common name in the industry, which is not pure iron powder, but mainly composed of carbonyl powder and alloy powder. According to different product characteristics, the weight ratio of carbonyl powder to alloy powder is adjusted in the range of 10:0 to 0:10.

[0058] For example, when the inductor needs to have stronger saturation electrical characteristics, the proportion of carbonyl powder is increased; when the inductor needs to have stronger inductance electrical characteristics, the proportion of alloy powder is increased.

[0059] As an optional implementation, when the inductor blank is directly made of iron powder, the pressure range of the die casting is usually 400 to 650 MPa.

[0060] If there is a hot die casting requirement, the hot die casting temperature range is usually 150 to 190°C.

[0061] Further, in the process of using pre-die casting to make a pre-submodule, and then using secondary die casting to make an inductor blank, the pressure range of the pre-submodule made of iron powder is usually 650 to 900 MPa, which is higher than the pressure range of the inductor blank directly made of iron powder, to ensure that the structural strength of the pre-submodule meets the standard and to avoid structural damage as much as possible during the secondary die casting process.

[0062] When the combination of the pre-submodule is subsequently die cast, the pressure range is controlled at 400 to 650 MPa, which can ensure effective aggregation of each pre-submodule.

[0063] 102, stress analysis is performed on the stress model to obtain stress data.

[0064] As an optional implementation, the material data of the coil and the blank, and the pressure data of the die casting process are obtained; according to the calibrated position of the coil, the pressure state of each region of the coil is determined, and the pressure state at least includes the pressure area, the pressure direction and the pressure threshold; and based on the pressure state of the coil, the deformation state of the blank is analyzed, and the deformation state at least includes the deformation region and its deformation threshold.

[0065] Specifically, the coil is usually a metal conductor with good plasticity, and different bending styles are used to achieve inductance performance. It can be an arc style or a multi-turn style, and the terminals need to be extended at both ends, so there may be many twisted deformation regions in the same pressure direction.

[0066] Similarly, the blank also deforms along with the deformation process of the coil. Since the blank is a pre-pressing cast preform sub-module, rigid friction may occur between the blank and the coil, causing damage to the coil or unexpected rupture of the blank, ultimately affecting the performance of the inductor.

[0067] Here, by establishing a digital stress model for stress analysis, the area of concentrated stress during secondary pressure casting is obtained for subsequent segmentation and processing.

[0068] It should be understood that in addition to pressure casting at room temperature, there is also a hot pressure casting process to make the blank sinter better.

[0069] As an optional implementation, when the pressure casting process is hot pressure casting, the pressure bearing state and the deformation state are adjusted based on the temperature control curve of the hot pressure casting.

[0070] Here, in addition to considering the changes in the properties of the coil and the powder under the hot pressure casting process, the actual processing process is also taken into account, and the material parameters are correspondingly added or deleted to ensure the accuracy of the stress analysis.

[0071] This embodiment does not limit the range of material parameters.

[0072] 103. Constructing a plurality of sub-models according to the stress data.

[0073] As an optional implementation, the area where the pressure bearing threshold or the deformation threshold exceeds the standard threshold is marked as an overrun area.

[0074] The same pressure casting axis is marked on the same pressure casting axis, and the third solid model is segmented and disassembled into a plurality of sub-models.

[0075] Specifically, the area where the stress analysis exists is marked as an overrun area, and the segmentation and disassembly are performed according to the overrun area, to ensure that the overrun area on the same pressure casting axis is split into different sub-models, avoiding the reduction of structural strength due to the existence of multiple overrun areas on the same pressure casting axis in the same sub-model.

[0076] 104. Generating processing indicators for each sub-model.

[0077] It can be understood that when the preform sub-module is pre-press cast from the powder, the volume of the powder is reduced; when the inductor blank is secondary pressure cast from the preform sub-module, the volume of the preform sub-module is reduced; when the inductor blank is surface finished, the volume of the inductor blank is reduced.

[0078] As an optional implementation, the third solid model has an overlapping space relative to the first solid model, and the overlapping space is used to represent the compression margin of the blank material.

[0079] And, the prefabricated sub-module has an expanded space relative to the third solid model corresponding thereto, and the expanded space is used to represent a finishing allowance of the prefabricated sub-module after the secondary die casting.

[0080] Therefore, each process flow retains a material allowance, thereby ensuring the processing allowance of the next process flow.

[0081] 105. Based on the sub-model and the corresponding processing index, a plurality of prefabricated sub-modules are processed.

[0082] Further, the plurality of prefabricated sub-modules are assembled with the coil to obtain an assembly.

[0083] The assembly is subjected to secondary die casting to obtain an inductor blank.

[0084] The inductor blank is subjected to finishing to obtain an inductor.

[0085] Compared with the prior art, the embodiments of the present application have the following beneficial effects:

[0086] Compared with the conventional prefabricated sub-module designed according to the coil positioning or powder filling, the present method is based on the overall stress analysis of the inductor to know the deformation conditions of the coil and the blank in the die casting process, and a plurality of sub-models are segmented and disassembled, thereby obtaining the prefabricated sub-module with uniform stress bearing pressure and low damage rate in the forming die casting process through pre-die casting, and greatly reducing the scrap rate.

Claims

1. A differentiated design method for an inductor prefabricated submodule, characterized in that: The method comprises:

101. Construct a force model; 102. Perform force analysis on the force model to obtain force data; 103. Constructing a plurality of sub-models according to the force data; 104. Generate processing indicators for each sub-model; 105. Based on the sub-models and their corresponding processing indicators, obtain several prefabricated sub-modules through processing.

2. The differentiated design method for an inductor prefabricated submodule according to claim 1, characterized in that: The force model at least includes a first three-dimensional model and a second three-dimensional model; The first three-dimensional model is constructed based on the external parameters of the coil, and the second three-dimensional model is constructed based on the external parameters of the inductor.

3. The differentiated design method for prefabricated inductor submodule according to claim 2, characterized in that: The structural force model includes: Substituting the second three-dimensional model into the first three-dimensional model; Eliminating the overlapping portion between the first three-dimensional model and the second three-dimensional model to obtain a blank model; Processing the blank model using a bilateral filtering algorithm to obtain the third three-dimensional model; The third three-dimensional model is used to represent a plurality of blanks covering the coil.

4. The differentiated design method for prefabricated inductor submodule according to claim 3, characterized in that: The performing force analysis on the force model to obtain force data includes: Acquiring material data of the coil and the blank, as well as pressure data of the die-casting process; Determining the pressure state of each area of ​​the coil according to the calibrated position of the coil, wherein the pressure state includes at least a pressure area, a pressure direction, and a pressure threshold; Furthermore, based on the pressure-bearing state of the coil, the deformation state of the blank is analyzed, where the deformation state at least includes a deformation area and a deformation threshold thereof.

5. The differentiated design method for prefabricated inductor submodule according to claim 4, characterized in that: The constructing of a plurality of sub-models according to the force data includes: For areas where the pressure threshold or deformation threshold exceeds the standard threshold, mark the exceeding limit area; The out-of-limit areas on the same die-casting axis are calibrated, and the third three-dimensional mold is divided and disassembled into the plurality of sub-models accordingly.

6. The differentiated design method for prefabricated inductor submodule according to claim 4, characterized in that: When the die-casting process is hot die-casting, the method further comprises: Based on the temperature control curve of hot die casting, the pressure bearing state and the deformation state are adjusted.

7. The differentiated design method for prefabricated inductor submodule according to claim 3, characterized in that: The method further comprises: The third three-dimensional model has an overlapping space relative to the first three-dimensional model, and the overlapping space is used to represent the compression margin of the blank material.

8. The differentiated design method for prefabricated inductor submodule according to claim 7, characterized in that: The method further comprises: The prefabricated submodule has an enlarged space relative to its corresponding third three-dimensional model, and the enlarged space is used to represent the finishing margin of the prefabricated submodule after the secondary die-casting.

9. The differentiated design method for prefabricated inductor submodules according to claim 8, characterized in that: The method further comprises: If the interference control submodule is assembled with the coil, a combination is obtained; The assembly is subjected to secondary die casting to obtain an inductor blank; The inductor blank is finely processed to obtain an inductor.

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