Inductor with adjustable shockproof strength

Abstract

The invention relates to the technical field of power electronic components, and discloses an inductor with adjustable shockproof strength, comprising: a composite inductor assembly comprising a magnetic core assembly and a coil winding wound on the magnetic core assembly; according to the magnetic core assembly, a first E-shaped magnetic core body and a second E-shaped magnetic core body are spliced face to face to form a closed magnetic circuit, and a middle column butt joint air gap is formed between the spliced middle column end faces of the first E-shaped magnetic core body and the second E-shaped magnetic core body. And the magnetic sensitive rigidity adjusting medium is filled outside the composite inductor assembly. And an edge leakage magnetic field under a large-current working condition is used for driving MRE magnetic hardening, so that self-adaptive rigidity enhancement is realized. When a vehicle jolts or accelerates urgently, the inductor and the shell are in rigid connection through the magnetic sensitive rigidity adjusting medium, mechanical impact is effectively resisted, and fatigue fracture of pins is prevented; the piezoelectric actuator of the active base is used for generating anti-phase mechanical waves, and active noise counteracting is achieved.

Description

Technical Field

[0001] This invention relates to the field of power electronic components technology, specifically to an inductor with adjustable shock resistance. Background Technology

[0002] Inductors are core components in power electronic devices. During operation, inductors face two major sources of vibration:

[0003] External mechanical shocks, such as the bumps experienced by an electric vehicle while driving, are mainly low-frequency (<100Hz) and large-amplitude vibrations. This requires the inductor to be mounted with extremely high rigidity to prevent the leads from breaking.

[0004] Internal electromagnetic noise: The magnetostriction effect generated by the magnetic core under an alternating magnetic field and the Lorentz force on the coil will produce high-frequency (2kHz-20kHz), small-amplitude vibrations, forming a piercing "whistling". This requires the fixed structure to have low stiffness and high damping to cut off the noise propagation path.

[0005] Existing technologies typically employ epoxy resin potting processes. Hard potting provides shock resistance but transmits noise; soft potting provides sound insulation but cannot withstand mechanical impact. Therefore, there is an urgent need for a new structure that can automatically adjust its stiffness according to operating conditions and actively eliminate noise. Summary of the Invention

[0006] This invention provides an inductor with adjustable shock resistance, which solves the problems mentioned in the background art.

[0007] This invention provides the following technical solution: an inductor with adjustable shock resistance, comprising:

[0008] A composite inductor assembly includes a magnetic core assembly and a coil winding wound around the magnetic core assembly; the magnetic core assembly consists of a first E-shaped magnetic core and a second E-shaped magnetic core facing each other to form a closed magnetic circuit, and a central column abutment air gap is formed between the face-to-face end faces of the facing cores.

[0009] A magnetic stiffness regulating medium filled outside the composite inductor assembly;

[0010] A rigid container with an insulated rigid housing housing the composite inductor assembly and the magnetic stiffness regulating medium; and

[0011] The active base assembly disposed below the insulating rigid shell includes an active base PCB board, a piezoelectric actuator, a flexible hinge structure, and a vibration pickup unit.

[0012] The magnetic stiffness adjusting medium is configured to reversibly change its shear modulus in response to the intensity change of the edge leakage magnetic field generated at the air gap of the middle column.

[0013] The active base PCB board generates a reverse vibration damping force by driving the piezoelectric actuator based on the vibration signal detected by the vibration pickup unit.

[0014] As a preferred embodiment of the present invention, the magnetic stiffness adjustment medium is a magnetorheological elastomer, which completely encloses the air gap between the central column and the coil winding. When current is applied to the coil winding, the leakage magnetic field at the air gap causes the medium to harden, locking the composite inductor assembly within the insulating rigid shell.

[0015] As a preferred embodiment of the present invention, the flexible hinge structure includes an elastic metal plate, with dividing lines at the four corners of the elastic metal plate, and elastic support portions separated by the dividing lines.

[0016] As a preferred embodiment of the present invention, the bottom of the insulating rigid shell is connected to the top center of the elastic metal plate;

[0017] The top of the piezoelectric actuator is connected to the bottom of the elastic support, and the bottom of the piezoelectric actuator is connected to the top of the active base PCB board;

[0018] The vibration pickup unit is located at the top center of the active base PCB board.

[0019] As a preferred embodiment of the present invention, a Z-axis suspension gap is provided between the flexible hinge structure and the vibration pickup unit to allow the elastic metal plate to generate controlled displacement in the Z-axis direction.

[0020] As a preferred embodiment of the present invention, the flexible hinge structure is integrally cut from spring steel or beryllium copper alloy, and its stiffness in the Z-axis direction is less than its stiffness in the X-axis and Y-axis directions.

[0021] As a preferred embodiment of the present invention, the piezoelectric actuator includes four sets of piezoelectric ceramic stacks arranged in a rectangular symmetrical pattern, which respectively support the four corners of the flexible hinge structure; the vibration pickup unit is located at the geometric center of these four sets of piezoelectric actuators and coincides with the geometric center of the elastic metal plate in the Z-axis direction.

[0022] As a preferred embodiment of the present invention, a non-magnetic insulating gasket is provided in the air gap between the middle columns. The gasket is made of polyimide or mica and has a thickness of 0.5 mm to 2.0 mm. The magnetic stiffness adjusting medium enveloping the air gap between the middle columns has a thickness of not less than 3.0 mm.

[0023] As a preferred technical solution of the present invention, the inductor has two cooperative working modes:

[0024] In the adaptive passive mode, under low-frequency and large-amplitude operating conditions, the characteristic of the magnetic stiffness adjustment medium becoming harder as the load current increases is utilized to improve the system stiffness and avoid mechanical resonance points.

[0025] In the active mode, under high-frequency howling conditions, the active base assembly generates a mechanical force that is opposite in phase to the magnetostrictive vibration of the inductor, thereby canceling the residual vibration transmitted to the external circuit board.

[0026] As a preferred embodiment of the present invention, the active mode further includes a controller, which is configured to perform the following steps:

[0027] The real-time vibration signal acquired by the vibration pickup unit is received as an error signal;

[0028] Obtain a signal that is in phase with the inductor's operating current as a reference signal;

[0029] Update the filter weight coefficients using an adaptive filtering algorithm;

[0030] An inverted drive signal is generated and applied to the piezoelectric actuator.

[0031] The present invention has the following beneficial effects:

[0032] 1. This adjustable shock-resistant inductor utilizes the edge leakage magnetic field under high current conditions to drive MRE magnetostriction, achieving "adaptive stiffness enhancement." During vehicle bumps or rapid acceleration, a rigid connection is formed between the inductor and the housing through a magnetic stiffness adjustment medium, effectively resisting mechanical shock and preventing lead fatigue breakage.

[0033] Active noise cancellation is achieved by generating antiphase mechanical waves through a piezoelectric actuator on an active base. This addresses the high-frequency micro-amplitude vibrations that are difficult to completely isolate in MREs by actively controlling their cancellation at the source or along the transmission path, significantly reducing noise in the sensitive frequency range and outperforming the sound transmission characteristics of traditional hard potting.

[0034] 2. This adjustable vibration damping inductor achieves functional decoupling through the adoption of a "dual-mode collaborative architecture." Low-frequency, large-amplitude vibrations are handled by a passive variable stiffness layer, while high-frequency, small-amplitude vibrations are handled by an active vibration damping layer. This "rigid-flexible" design overcomes the shortcomings of traditional single-material potting, which cannot simultaneously meet the requirements of high stiffness and high damping, and achieves vibration management across all operating conditions and frequency bands. Attached Figure Description

[0035] Figure 1 This is a schematic diagram of the installation state of the present invention;

[0036] Figure 2 This is a schematic diagram showing the structural position between the composite inductor assembly and the insulating rigid housing of the present invention;

[0037] Figure 3 This is a schematic diagram of the composite inductor assembly structure of the present invention;

[0038] Figure 4 This is a schematic diagram of the flexible hinge structure of the present invention;

[0039] Figure 5 This is a block diagram illustrating the active control principle of the active vibration damping base of the present invention;

[0040] Figure 6 This is a schematic diagram comparing the microscopic states of the magnetic stiffness adjustment medium of the present invention under different currents;

[0041] Figure 7 This is a response curve of the equivalent stiffness of the inductor system of the present invention as a function of coil current.

[0042] In the diagram: 1. Active base PCB board; 2. Piezoelectric actuator; 3. Flexible hinge structure; 4. Insulating rigid shell; 5. Composite inductor assembly; 6. Magnetic stiffness adjustment medium; 7. Vibration pickup unit;

[0043] 301. Flexible metal plate; 302. Dividing line; 303. Flexible support part;

[0044] 501. First E-shaped magnetic core; 502. Second E-shaped magnetic core; 503. Coil winding; 504. Air gap between the center column and the coil. Detailed Implementation

[0045] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0046] Please see Figure 1 - Figure 7 An inductor with adjustable shock resistance, comprising:

[0047] The composite inductor assembly 5 includes a magnetic core assembly and a coil winding 503 wound around the magnetic core assembly; the magnetic core assembly consists of a first E-shaped magnetic core 501 and a second E-shaped magnetic core 502 facing each other to form a closed magnetic circuit, and a central column abutment air gap 504 is formed between the central column end faces of the two facing each other.

[0048] Magnetic stiffness adjusting medium 6 is filled outside the composite inductor assembly 5;

[0049] A rigid container with an insulating rigid housing 4 housing the composite inductor assembly 5 and the magnetic stiffness regulating medium 6; and

[0050] The active base assembly located below the insulating rigid housing 4 includes an active base PCB board 1, a piezoelectric actuator 2, a flexible hinge structure 3, and a vibration pickup unit 7.

[0051] Among them, the magnetic stiffness adjustment medium 6 is configured to reversibly change its shear modulus in response to the intensity change of the edge leakage magnetic field generated at the air gap 504 of the middle column.

[0052] Among them, the active base PCB board 1 generates a reverse vibration damping force by driving the piezoelectric actuator 2 based on the vibration signal detected by the vibration pickup unit 7.

[0053] Vibration pickup unit 7 uses a MEMS accelerometer.

[0054] Composite inductor assembly 5: Composed of a first E-shaped magnetic core 501 and a second E-shaped magnetic core 502, perpendicularly joined together face to face. The preferred material is iron-silicon-aluminum or manganese-zinc ferrite. The coil winding 503 is wound on the center column.

[0055] The magnetic stiffness adjustment medium 6 fills the cavity between the composite inductor assembly 5 and the insulating rigid shell 4, and completely encloses the composite inductor assembly 5 with a thickness of not less than 3mm.

[0056] The MRE (Medium Resonance Equipment) is driven by the leakage magnetic field generated by the inductor's own current, eliminating the need for additional electromagnets or energy sources. The high-frequency response characteristics of the inverse piezoelectric effect are utilized to address the high-frequency howling caused by magnetostriction, resolving the contradiction between "low-frequency shock resistance" and "high-frequency sound insulation" that traditional single-encapsulation structures cannot simultaneously achieve. This enables vibration management across the entire frequency range.

[0057] In a preferred embodiment: the magnetic stiffness adjustment medium 6 is a magnetorheological elastomer, which completely encloses the air gap 504 between the central column and the air gap; according to electromagnetic field theory, the magnetic resistance at the air gap is the greatest, causing the magnetic field lines to spread to the surrounding area to form an edge leakage magnetic field, which has the strongest magnetization effect on the magnetic particles, ensuring that the MRE can respond quickly and undergo "magnetic hardening" when the inductor's operating current increases, and can achieve adaptive locking without external sensors, preventing mechanical shaking under high current impact.

[0058] When current is applied to the coil winding 503, the leakage magnetic field at the air gap causes the dielectric to harden, locking the composite inductor assembly 5 inside the insulating rigid housing 4.

[0059] The magnetic stiffness adjustment medium 6 adopts a magnetorheological elastomer (MRE).

[0060] The matrix is ​​a two-component addition-type silicone rubber with a Shore hardness of A20, accounting for 70% by volume; the dispersed phase is carbonyl iron powder with an average particle size of 5μm, accounting for 30% by volume.

[0061] Iron powder is mixed into liquid silicone rubber, and after vacuum degassing, it is thermo-cured at 100°C for 1 hour in a magnetic field-free environment to obtain an isotropic initial state.

[0062] When the coil current is 0, the iron powder is randomly distributed, the MRE modulus is low, and it acts as a vibration isolation agent. When the coil carries a rated large current, the leakage magnetic field strength at the air gap can reach 300mT. The iron powder particles are magnetized along the magnetic lines of force and form a chain structure. The MRE shear modulus rapidly increases to over 2.0MPa, which secures and locks the inductor.

[0063] In a preferred embodiment, the flexible hinge structure 3 includes an elastic metal plate 301, with dividing lines 302 at the four corners of the elastic metal plate 301, and elastic support portions 303 separated by the dividing lines 302.

[0064] The flexible hinge structure 3 is integrally cut from spring steel or beryllium copper alloy. This structure has low stiffness in the Z-axis direction, allowing for slight vertical movement, while it has extremely high stiffness in the X / Y plane direction, preventing lateral swaying.

[0065] In a preferred embodiment: the bottom of the insulating rigid housing 4 is connected to the top center of the elastic metal plate 301;

[0066] The bottom of the insulating rigid housing 4 is rigidly connected to the upper surface of the elastic metal plate 301 by epoxy resin glue or screws. The vibration pickup unit 7 is located at the center of the active base PCB board 1, and a Z-axis suspension gap of 0.2mm-0.5mm is maintained between its upper part and the lower surface of the elastic metal plate 301 to ensure sufficient vibration damping stroke and prevent mechanical collision.

[0067] The top of the piezoelectric actuator 2 is connected to the bottom of the elastic support 303, and the bottom of the piezoelectric actuator 2 is connected to the top of the active base PCB board 1.

[0068] In a preferred embodiment, a Z-axis suspension gap is provided between the flexible hinge structure 3 and the vibration pickup unit 7 to allow the elastic metal plate 301 to generate controlled displacement in the Z-axis direction.

[0069] In a preferred embodiment: the piezoelectric actuator 2 includes four sets of piezoelectric ceramic stacks arranged in a rectangular symmetrical pattern, which respectively support the four corners of the flexible hinge structure 3; the vibration pickup unit 7 is located at the geometric center of these four sets of piezoelectric actuators and coincides with the geometric center of the elastic metal plate 301 in the Z-axis direction.

[0070] In a preferred embodiment: a non-magnetic insulating gasket is provided inside the air gap 504 between the middle columns. The gasket is made of polyimide or mica and has a thickness of 0.5 mm to 2.0 mm. The magnetic stiffness adjustment medium 6 surrounds the air gap 504 between the middle columns with a thickness of not less than 3.0 mm.

[0071] In a preferred embodiment, the inductor has two cooperative operating modes:

[0072] In the adaptive passive mode, under low-frequency and large-amplitude operating conditions, the magnetic stiffness adjustment medium 6 is used to increase the stiffness of the system by increasing the load current, thereby avoiding the mechanical resonance point.

[0073] In active mode, under high-frequency howling conditions, the active base component generates a mechanical force that is opposite in phase to the magnetostrictive vibration of the inductor, thereby canceling the residual vibration transmitted to the external circuit board.

[0074] Active vibration damping workflow and control logic

[0075] A. Principles and system logic, such as Figure 5 As shown

[0076] The active mode is designed to counteract residual vibrations transmitted to the external circuit board by generating a mechanical force opposite in phase to the magnetostrictive vibration of the inductor under high-frequency whistling conditions using an active base assembly. Its system hardware logic is as follows:

[0077] Detection: Vibration pickup unit 7, i.e., MEMS accelerometer, collects the vertical vibration acceleration signal of the inductor in real time as an error signal. .

[0078] Processing: The signal is input to the controller (MCU microcontroller unit or DSP digital signal processor). The controller has a built-in F-LMS adaptive filtering algorithm and obtains a signal in phase with the inductor's operating current as a reference signal. .

[0079] Drive and Execution: The controller generates an inverse drive voltage based on an algorithm, which is then amplified and applied to the piezoelectric actuator 2. The piezoelectric actuator 2 drives the elastic metal plate 301 and the inductor assembly above it to produce an inverse motion, thereby achieving vibration cancellation in physical space.

[0080] B. Controller Configuration and Algorithm Implementation Steps: In a preferred embodiment, the controller is configured to perform the following core steps, including offline channel identification and online real-time control:

[0081] Step 1: Secondary Channel Identification (Offline Initialization Phase)

[0082] Before system startup or in calibration mode, the piezoelectric actuator 2 is excited using white noise, and the vibration pickup unit 7 acquires the response. An algorithm is used to identify the physical transfer function from the actuator to the sensor. (i.e., secondary channel), establish a control model .

[0083] Step 2: Real-time Control Loop (Online Operation Phase) The system operates real-time closed-loop control at a sampling rate of 50kHz:

[0084] Receive real-time error signal and reference signal ;

[0085] Filtering the reference signal using a secondary channel model: Calculation ;

[0086] Update the adaptive filter weights using gradient descent: To minimize the mean square value of the error signal;

[0087] Generate an inverted drive signal and output it to the drive circuit: .

[0088] To better understand the passive adjustment mechanism of this invention, the adaptive state of the inductor under different operating conditions is illustrated using the application of an on-board charger (OBC) in an electric vehicle as an example:

[0089] Trickle charging or standby mode: The battery is almost fully charged, and the OBC operates at a low current. ).

[0090] At this time, the coil current is small, and the leakage magnetic field generated at the air gap 504 between the middle column and the air gap is very weak. ).

[0091] MRE state: Magnetic particles in magnetic stiffness adjustment medium 6 are randomly distributed, and the material exhibits a "soft state" (shear modulus). ).

[0092] The soft MRE provides excellent vibration isolation and damping, effectively cutting off the transmission path of high-frequency micro-vibrations of the inductor to the housing, thus achieving silent operation.

[0093] Constant current fast charging or rapid acceleration mode: When the vehicle is accelerating rapidly or the OBC is in the maximum power fast charging stage ( ).

[0094] The large current causes a sharp increase in the leakage flux density at the air gap, enhancing the edge leakage magnetic field. ) Penetrates the MRE layer.

[0095] MRE state: Magnetic particles rapidly align into chains along magnetic field lines, and the MRE undergoes magnetohardening, instantly transforming into a "hard state" (shear modulus). ).

[0096] The hardened MRE securely locks the composite inductor assembly 5 within the insulated rigid housing 4, greatly enhancing the overall rigidity of the system. This allows it to withstand low-frequency mechanical shocks from road bumps and electromagnetic attraction from high currents, preventing pins from breaking due to significant shaking.

[0097] By utilizing the physical characteristics of the inductor itself, a passive self-closed loop of "current → leakage magnetic field → MRE stiffness" is established, which can realize intelligent adjustment of stiffness without the need for external sensors.

[0098] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0099] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. An inductor with adjustable shock resistance, characterized in that, include: The composite inductor assembly (5) includes a magnetic core assembly and a coil winding (503) wound around the magnetic core assembly; the magnetic core assembly is formed by the first E-shaped magnetic core (501) and the second E-shaped magnetic core (502) facing each other to form a closed magnetic circuit, and a central column abutment air gap (504) is formed between the central column end faces of the two opposing magnetic cores. Magnetic stiffness adjustment medium (6) filled outside the composite inductor assembly (5); A rigid container insulated rigid housing (4) housing the composite inductor assembly (5) and the magnetic stiffness regulating medium (6); and The active base assembly located below the insulating rigid shell (4) includes an active base PCB board (1), a piezoelectric actuator (2), a flexible hinge structure (3), and a vibration pickup unit (7). The magnetic stiffness adjusting medium (6) is configured to reversibly change its shear modulus in response to the intensity change of the edge leakage magnetic field generated at the air gap (504) of the middle column. The active base PCB board (1) generates a reverse vibration damping force by driving the piezoelectric actuator (2) based on the vibration signal detected by the vibration pickup unit (7).

2. An inductor with adjustable shock absorption strength according to claim 1, characterized in that: The magnetic stiffness adjustment medium (6) is a magnetorheological elastomer, which completely encloses the air gap (504) between the central column and the air gap. When current is applied to the coil winding (503), the leakage magnetic field at the air gap causes the medium to harden, locking the composite inductor assembly (5) inside the insulating rigid shell (4).

3. An inductor with adjustable shock absorption strength according to claim 1, characterized in that: The flexible hinge structure (3) includes an elastic metal plate (301), with dividing lines (302) at the four corners of the elastic metal plate (301), and an elastic support part (303) separated by the dividing lines (302).

4. An inductor with adjustable shock resistance according to claim 3, characterized in that: The bottom of the insulating rigid shell (4) is connected to the top center of the elastic metal plate (301); The top of the piezoelectric actuator (2) is connected to the bottom of the elastic support (303), and the bottom of the piezoelectric actuator (2) is connected to the top of the active base PCB board (1). The vibration pickup unit (7) is located at the top center of the active base PCB board (1).

5. An inductor with adjustable shock absorption strength according to claim 4, characterized in that: A Z-axis suspension gap is left between the flexible hinge structure (3) and the vibration pickup unit (7) to allow the elastic metal plate (301) to generate controlled displacement in the Z-axis direction.

6. An inductor with adjustable shock absorption strength according to claim 5, characterized in that: The flexible hinge structure (3) is integrally cut from spring steel or beryllium copper alloy, and its stiffness in the Z-axis direction is less than its stiffness in the X-axis and Y-axis directions.

7. An inductor with adjustable shock resistance according to claim 6, characterized in that: The piezoelectric actuator (2) includes four sets of piezoelectric ceramic stacks arranged in a rectangular symmetrical pattern, which respectively support the four corners of the flexible hinge structure (3); the vibration pickup unit (7) is located at the geometric center of these four sets of piezoelectric actuators and coincides with the geometric center of the elastic metal plate (301) in the Z-axis direction.

8. An inductor with adjustable shock absorption strength according to claim 1, characterized in that: The central column connection air gap (504) is provided with a non-magnetic insulating gasket, the gasket is made of polyimide or mica and has a thickness of 0.5mm to 2.0mm; the magnetic stiffness adjustment medium (6) surrounds the central column connection air gap (504) with a thickness of not less than 3.0mm.

9. An inductor with adjustable shock resistance according to claim 8, characterized in that: The inductor has two cooperative operating modes: In the adaptive passive mode, under low-frequency and large-amplitude conditions, the system stiffness is improved by utilizing the characteristic that the magnetic stiffness adjustment medium (6) becomes harder as the load current increases, so as to avoid the mechanical resonance point. In the active mode, under high-frequency howling conditions, the active base assembly generates a mechanical force that is opposite in phase to the magnetostrictive vibration of the inductor, thereby canceling the residual vibration transmitted to the external circuit board.

10. An inductor with adjustable shock absorption strength according to claim 9, characterized in that: The active mode also includes a controller configured to perform the following steps: The vibration signal collected by the vibration pickup unit (7) is received as an error signal; Obtain a signal that is in phase with the inductor's operating current as a reference signal; Update the filter weight coefficients using an adaptive filtering algorithm; An inverted drive signal is generated and applied to the piezoelectric actuator (2).

Images