Preparation method of vehicle-mounted iron-based amorphous powder core boost inductor, inductor and automobile

Abstract

The invention discloses a preparation method of a vehicle-mounted iron-based amorphous powder core boost inductor, the inductor and an automobile, and relates to the technical field of new energy automobile power driving boost power. The method comprises the following steps: pressing iron-based amorphous powder; the pressed and formed iron-based amorphous powder core is engraved, and multiple sections of strip-shaped magnetic blocks are engraved on the iron-based amorphous powder core; the engraved iron-based amorphous powder core is annealed; the annealed iron-based amorphous powder core and accessories are assembled, and the size of an air gap after assembly is regulated and controlled by the thickness of a ceramic heat-conducting fin; carrying out integrated injection molding on the assembled inductor; and welding the inductor prototype with a copper bar terminal, and testing and packaging after ultrasonic cleaning to obtain the final inductor. The iron-based amorphous powder core small boost inductor with low loss is prepared, can achieve low working temperature and is suitable for a vehicle-mounted environment.

Description

Technical Field

[0001] The present invention relates to the field of new energy vehicle power drive boosting power technology, and in particular to a method for preparing a vehicle-mounted iron-based amorphous powder core boosting inductor, an inductor and a vehicle. Background Art

[0002] The statements in this section merely provide background information related to the present invention and do not necessarily constitute prior art.

[0003] Boost inductors have the advantages of small size, high temperature resistance, and low magnetic leakage. They are usually used in boost circuits, which are widely used in electric drive systems of new energy vehicles. Automotive-grade boost inductors are mainly composed of magnetic cores, winding coils, and skeletons. As new energy vehicles develop towards 800V high-voltage systems, the demand for the number of boost inductors has increased, because high-voltage systems require more boost inductors to improve efficiency. At the same time, higher performance indicators or technical requirements also come with it, such as magnetic flux density, insulation performance, and temperature stability. This requires magnetic materials to have higher magnetic permeability, lower loss, higher insulation performance, and higher temperature stability. At present, the volume of boost inductors produced at home and abroad is relatively large. Since there is no breakthrough in materials, in order to match performance requirements, the volume cannot be reduced. The commonly used material is low-loss iron-silicon material as the magnetic core. A few manufacturers choose iron-nickel material, but the loss of iron-silicon material is still high, and the cost of iron-nickel is higher. The amorphous powder core material has lower loss and can be used as a better choice for boost inductors.

[0004] At present, most new energy vehicles still use iron silicon with high loss as the magnetic core, which places high requirements on heat dissipation. In addition, since the 800V boost has higher requirements on insulation and reliability, and the working current is larger, how to make the boost inductor adapt to the high voltage environment of the vehicle, reduce the loss of the battery core, and reduce the overall volume has become a technical problem that needs to be solved urgently in the existing technology. Summary of the invention

[0005] In view of the shortcomings of the prior art, the purpose of the present invention is to provide a method for preparing a vehicle-mounted iron-based amorphous powder core boost inductor, an inductor and a vehicle, and to prepare a small iron-based amorphous powder core boost inductor with low loss, which can achieve a low operating temperature and adapt to the vehicle-mounted environment.

[0006] In order to achieve the above object, the present invention is implemented through the following technical solutions:

[0007] A first aspect of the present invention provides a method for preparing a vehicle-mounted iron-based amorphous powder core boost inductor, comprising the following steps:

[0008] The iron-based amorphous powder is pressed to obtain an iron-based amorphous powder core;

[0009] The pressed iron-based amorphous powder core is engraved, wherein the iron-based amorphous powder core is engraved into a plurality of strip-shaped magnetic blocks;

[0010] Annealing the engraved iron-based amorphous powder core;

[0011] The annealed iron-based amorphous powder core is assembled with accessories to obtain an assembled inductor, and an air gap is formed between each two adjacent strip-shaped magnetic blocks after bonding through a ceramic heat conductive sheet. After assembly, the size of the air gap is controlled by the thickness of the ceramic heat conductive sheet;

[0012] Performing one-piece injection molding on the assembled inductor to obtain an inductor prototype;

[0013] The inductor prototype is welded to the copper busbar terminal, and after ultrasonic cleaning, the package is tested to obtain the final inductor.

[0014] Furthermore, the iron-based amorphous powder used is composed of: Fe (100-a-b-c-x-y) Si a B b P c Nb x Mn y , among which, 7≤a≤10, 4≤b≤8, 0.2≤c≤2.0, 0.1≤x≤3.5, 0.5≤y≤1.0.

[0015] Furthermore, the magnetic block is engraved at the bonding position during the assembly process with the accessories, and 3 or 4 sections of magnetic blocks are engraved at each bonding position.

[0016] Furthermore, the accessories include a ceramic thermal conductive sheet, a prefabricated frame and a coil. The annealed iron-based amorphous powder core is bonded to the ceramic thermal conductive sheet and the prefabricated frame. The coil is a prefabricated coil, and the prefabricated coil is sleeved on the iron-based amorphous powder core.

[0017] Furthermore, the coil is a flat coil.

[0018] Furthermore, when the engraved iron-based amorphous powder core is annealed, the pressing pressure range of the iron-based amorphous powder core is 20T / cm 2 ~22T / cm 2 , the annealing temperature range is 400℃~460℃.

[0019] Furthermore, the preheating temperature range of the assembled inductor before one-piece injection molding is 110°C to 130°C, the resin molding processing temperature range is 160°C to 270°C, the vacuum range in the mold is 15kpa to 25kpa; the injection pressure range is 40Mp to 100Mpa, and the holding time range is 20s to 30s.

[0020] Furthermore, the cleaning time of the ultrasonic cleaning process ranges from 6 minutes to 10 minutes; the drying temperature ranges from 80° C. to 100° C., and the drying time ranges from 10 minutes to 30 minutes.

[0021] A second aspect of the present invention provides an inductor, which is prepared by the method for preparing the vehicle-mounted iron-based amorphous powder core boost inductor described in the first aspect.

[0022] A third aspect of the present invention provides a car equipped with the inductor according to the second aspect.

[0023] One or more of the above technical solutions have the following beneficial effects:

[0024] The present invention provides a method for preparing a vehicle-mounted iron-based amorphous powder core boost inductor, an inductor and a vehicle. The temperature of the iron-silicon powder core boost inductor rises, requiring harsh heat dissipation conditions or water cooling conditions, which is not conducive to the miniaturization of the boost inductor. The present invention uses iron-based amorphous powder with lower loss to press the magnetic powder core, so it has a lower operating temperature and solves the problem of high-cost heat dissipation devices or thermal pads. Compared with the iron-silicon powder core, the amorphous powder core has poorer DC bias resistance, so the present invention sets multiple narrower air gaps to balance the disadvantage of bias capability.

[0025] In the step-up inductor forming method of the present invention, PBS resin with good insulation and withstand voltage is used for thermoplastic integral forming, which not only has high structural stability but also has better PBS heat dissipation effect, is suitable for full automation, and can reduce the production cost of the step-up inductor.

[0026] Advantages of additional aspects of the present invention will be given in part in the following description, and in part will become obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The accompanying drawings in the specification, which constitute a part of the present invention, are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0028] Figure 1 This is a flow chart of a method for preparing a vehicle-mounted iron-based amorphous powder core boost inductor in Embodiment 1 of the present invention;

[0029] Figure 2 is an overall structural diagram of a boost inductor in Embodiment 1 of the present invention;

[0030] Figure 3 is a cross-sectional view of a boost inductor in Embodiment 1 of the present invention;

[0031] Among them, 1. Iron-based amorphous powder core, 2. Ceramic thermal conductive sheet, 3. Coil, 4. Insulation frame, 5. Copper busbar terminal, 6. Nut hole. DETAILED DESCRIPTION

[0032] It should be noted that the following detailed descriptions are exemplary and are intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used herein have the same meanings as those commonly understood by those skilled in the art to which the present invention belongs.

[0033] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present invention. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "include" and / or "include" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or their combinations;

[0034] Embodiment 1:

[0035] Embodiment 1 of the present invention provides a method for preparing a vehicle-mounted iron-based amorphous powder core boost inductor, specifically for preparing a vehicle-mounted power factor correction (PFC) boost inductor, such as Figure 1 As shown, the boost inductor is formed through the steps of pressing the block iron-based amorphous powder core, carving the iron-based amorphous powder core, annealing the iron-based amorphous powder core, assembling the iron-based amorphous powder core and accessories, integrated PBS vacuum injection molding, copper bus terminal welding, ultrasonic cleaning and testing packaging. The inductor structure is shown in FIG. Figure 2 and Figure 3 shown.

[0036] The specific steps include:

[0037] Step 1: Press the iron-based amorphous powder to obtain the iron-based amorphous powder core 1. The iron-based amorphous powder is pressed into a U shape.

[0038] In a specific implementation, the traditional iron-silicon is replaced with an iron-based one. This embodiment uses an iron-based amorphous powder core 1 as the magnetic core of the inductor, which can effectively reduce the heat generation under high current, reduce the heat dissipation requirements, and reduce costs. The iron-based amorphous powder used is composed of: Fe (100-a-b-c-x-y) Si a B b P c Nb x Mn y , where 7≤a≤10, 4≤b≤8, 0.2≤c≤2.0, 0.1≤x≤3.5, 0.5≤y≤1.0, and the remainder is Fe. The magnetic permeability is around 60, and its DC bias capability is 66% to 75% μe@100Oe.

[0039] Step 2: Carve the pressed iron-based amorphous powder core, wherein the iron-based amorphous powder core is carved into multiple strip-shaped magnetic blocks. The magnetic blocks are still connected to the main body of the iron-based amorphous powder core, and gaps are left between each adjacent magnetic block.

[0040] Wherein, an air gap is formed between each two adjacent strip-shaped magnetic blocks after being bonded together by a ceramic heat-conducting sheet with a high thermal conductivity, and the air gap can prevent the inductor from being easily saturated when a large current is applied.

[0041] Step 3: Annealing the engraved iron-based amorphous powder core.

[0042] In a specific embodiment, when the engraved iron-based amorphous powder core is annealed, the pressing pressure of the iron-based amorphous powder core is in the range of 20T / cm 2 ~22T / cm 2 The annealing temperature range is 400°C to 460°C. Preferably, the pressing pressure of the iron-based amorphous powder core is 21T / cm 2 , the annealing temperature is 430℃.

[0043] Step 4: Assemble the annealed iron-based amorphous powder core and accessories to obtain an assembled inductor. An air gap is formed between each two adjacent strip-shaped magnetic blocks after bonding through a ceramic heat conductive sheet. The air gap formed after assembly is controlled by the thickness of the ceramic heat conductive sheet. In this embodiment, the general air gap thickness is designed to be between 0.4 mm and 2 mm.

[0044] In a specific embodiment, the accessories include a ceramic thermal conductive sheet 2, a prefabricated insulating skeleton 4 and a coil 3, and the annealed iron-based amorphous powder core 1 is bonded to the ceramic thermal conductive sheet 2 and the prefabricated insulating skeleton 4. The ceramic thermal conductive sheet used is an aluminum nitride ceramic thermal conductive sheet, and the bonding method is glue bonding. The prefabricated coil 3 is sleeved on the iron-based amorphous powder core, and the coil 3 is a flat coil, which can adapt to the high current environment and the volume that can be accommodated in the vehicle. A nut hole 6 is left on the prefabricated insulating skeleton 4, and the inductor is fixed by a nut through the nut hole.

[0045] The magnetic blocks are engraved at the bonding points during the assembly process with the accessories, and 3 or 4 magnetic blocks are engraved at each bonding position. The multi-segment narrow air gap design adopted in this embodiment can make up for the shortcoming of poor amorphous DC bias capability, and the U-shaped design at both ends of the iron-based amorphous powder core reduces the leakage flux, which is conducive to the uniform distribution of high-heating sections and increases the overall magnetic properties of the inductor. The operating temperature can be below 120°C under high current and high voltage conditions. Although multiple air gaps help to adjust the DC bias capability of the boost inductor, and the more air gap segments, the narrower the air gap, and the more uniform the distribution of high-heating sections, the more air gap segments are, but the more air gap segments, the better, and it is necessary to comprehensively consider the assembly cost and the current surface area capacity of the inductor. Therefore, this embodiment sets the number of engraved magnetic blocks at each bonding point to 3 or 4 segments.

[0046] Step 5: Perform one-piece injection molding on the assembled inductor to obtain the inductor prototype.

[0047] In a specific embodiment, one-piece PBS vacuum injection molding is adopted, which has a stable structure and excellent heat dissipation, and is conducive to automated production and cost reduction. The preheating temperature range of the assembled inductor before one-piece injection molding is 110℃~130℃, the resin molding processing temperature range is 160℃~270℃, and the vacuum degree in the mold range is 15kpa~25kpa; the injection pressure range is 40Mp~100Mpa, and the holding time range is 20s~30s. Preferably, the preheating temperature of the assembled inductor is 120℃, and the vacuum degree in the mold is 20kpa.

[0048] Step 6: Solder the inductor prototype to the copper busbar terminal 5, and test the package after ultrasonic cleaning to obtain the final inductor.

[0049] In a specific implementation, the copper busbar terminal 5 is welded by argon arc welding technology, requiring the solder joint to be bright without burrs, black spots, and the welding depth to be greater than 1.3 to 3.2 mm. In this embodiment, ultrasonic cleaning is performed by air shower ultrasonic cleaning, and the cleaning time of the ultrasonic cleaning process ranges from 6 minutes to 10 minutes; the drying temperature ranges from 80°C to 100°C, and the drying time ranges from 10 minutes to 30 minutes. Preferably, the drying time is 20 minutes.

[0050] In order to better illustrate the superiority of the method described in this embodiment, the following experiment was conducted, and the experimental parameters and performance parameters are shown in Table 1:

[0051] Table 1 Comparison of experimental parameters and performance parameters

[0052]

[0053] From the table above, we can see that different core materials are used to prepare boost inductors. The core magnetic permeability and core loss are different. The integrated boost inductor will have certain differences in inductance and temperature rise. It can be seen that the choice of core material will affect the temperature rise of the inductor. The material selection of the automotive inductor core is particularly important. It can be found from the examples and comparative examples that the operating temperature of the boost inductor using an iron-based amorphous powder core is about 10°C lower than that of the iron-silicon boost inductor.

[0054] Embodiment 2:

[0055] A second embodiment of the present invention provides an inductor, which is prepared by using the method for preparing the vehicle-mounted iron-based amorphous powder core boost inductor described in the embodiment.

[0056] Embodiment three:

[0057] A third embodiment of the present invention provides a car, which is a new energy car and is equipped with the inductor described in the second embodiment.

[0058] The steps involved in the above embodiments 2 and 3 correspond to the method embodiment 1. For the specific implementation methods, please refer to the relevant description part of embodiment 1.

[0059] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for preparing a vehicle-mounted iron-based amorphous powder core boost inductor, characterized in that: The following steps are involved: The iron-based amorphous powder is pressed to obtain an iron-based amorphous powder core; The pressed iron-based amorphous powder core is engraved, wherein the iron-based amorphous powder core is engraved into a plurality of strip-shaped magnetic blocks; Annealing the engraved iron-based amorphous powder core; The annealed iron-based amorphous powder core is assembled with accessories to obtain an assembled inductor, and an air gap is formed between each two adjacent strip-shaped magnetic blocks after bonding through a ceramic heat conductive sheet. After assembly, the size of the air gap is controlled by the thickness of the ceramic heat conductive sheet; Performing one-piece injection molding on the assembled inductor to obtain an inductor prototype; The inductor prototype is welded to the copper busbar terminal, and after ultrasonic cleaning, the package is tested to obtain the final inductor.

2. The method for preparing the vehicle-mounted iron-based amorphous powder core boost inductor according to claim 1, characterized in that: The iron-based amorphous powder used is composed of: Fe (100-a-b-c-x-y) Si a B b P c Nb x Mn y , Among them, 7≤a≤10, 4≤b≤8, 0.2≤c≤2.0, 0.1≤x≤3.5, 0.5≤y≤1.

0.

3. The method for preparing the vehicle-mounted iron-based amorphous powder core boost inductor according to claim 1, characterized in that: The magnetic block is engraved at the bonding position during the assembly process with the accessories, and 3 or 4 sections of magnetic blocks are engraved at each bonding position.

4. The method for preparing the vehicle-mounted iron-based amorphous powder core boost inductor according to claim 1, characterized in that: The accessories include a ceramic heat conductive sheet, a prefabricated frame and a coil. The annealed iron-based amorphous powder core is bonded to the ceramic heat conductive sheet and the prefabricated frame. The coil is a prefabricated coil, which is sleeved on the iron-based amorphous powder core.

5. The method for preparing the vehicle-mounted iron-based amorphous powder core boost inductor according to claim 4, characterized in that: The coil is a flat coil.

6. The method for preparing the vehicle-mounted iron-based amorphous powder core boost inductor according to claim 1, characterized in that: When the engraved iron-based amorphous powder core is annealed, the pressing pressure range of the iron-based amorphous powder core is 20T / cm 2 ~22T / cm 2 , the annealing temperature range is 400℃~460℃.

7. The method for preparing the vehicle-mounted iron-based amorphous powder core boost inductor according to claim 1, characterized in that: The preheating temperature range of the assembled inductor before one-piece injection molding is 110℃~130℃, the resin molding processing temperature range is 160℃~270℃, the vacuum range in the mold is 15kpa~25kpa; the injection pressure range is 40Mp~100Mpa, and the holding time range is 20s~30s.

8. The method for preparing the vehicle-mounted iron-based amorphous powder core boost inductor according to claim 1, characterized in that: The cleaning time of the ultrasonic cleaning process ranges from 6 minutes to 10 minutes; the drying temperature ranges from 80°C to 100°C, and the drying time ranges from 10 minutes to 30 minutes.

9. An inductor, wherein the inductor is prepared by the method for preparing a vehicle-mounted iron-based amorphous powder core boost inductor according to any one of claims 1 to 8.

10. A car equipped with the inductor according to claim 9.

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