Spiral coil structure with magnetic core and hollow inductor

Abstract

The utility model relates to the field of inductors, in particular to a spiral coil structure with a magnetic core and a hollow inductor, the spiral coil structure comprises a spiral coil and a hollow magnetic core unit, the magnetic core unit is located on the inner side of the spiral coil, and a hollow area in the magnetic core unit penetrates through the magnetic core unit in the extending direction of the center line of the spiral coil. The spiral coil structure adopted by the inductor is provided with the magnetic core unit, the sensitivity of the inductor is guaranteed, the magnetic core unit is hollow, and a certain space can be provided for installation and implantation of other electronic components in the application of the small-size inductor, so that various functional requirements of the inductor are met; and compared with a solid magnetic core, the processing and using cost of a magnetic core material is greatly saved.

Description

Technical Field

[0001] This application relates to the field of inductors, and particularly to a spiral coil structure with a magnetic core and an air-core inductor. Background Art

[0002] An inductor is a component that can convert electrical energy into magnetic energy and store it. Through the magnetic field coupling between inductors, it can be used for contactless wireless power supply or to achieve functions such as magnetic positioning and navigation.

[0003] In actual application scenarios, with the increasing demand for miniaturization of electronic products, the size of electronic components is getting smaller and smaller, and the size of inductors is also getting smaller. For example, in implantable medical electronic systems, in order to reduce damage to human tissues, the size of implant devices should be designed as small as possible, and the inductor components used also have the characteristics of small size.

[0004] Regarding the prior art, the inventor found that when the size of the inductor component is small, the sensitivity is poorly balanced, and due to the limitation of the overall size of the inductor, other cooperating electronic components (such as chips, etc.) cannot be implanted, resulting in limitations in the functions of the corresponding electronic products. Summary of the Utility Model

[0005] This application provides a spiral coil structure with a magnetic core and an air-core inductor to solve the problems of poor sensitivity and limited functions of small-sized inductor components.

[0006] A spiral coil with a magnetic core provided by this application adopts the following technical solutions:

[0007] A spiral coil structure with a magnetic core includes:

[0008] A spiral coil, and;

[0009] A hollow magnetic core unit, the magnetic core unit is located inside the spiral coil, and the hollow area in the magnetic core unit extends through the magnetic core unit along the central line extension direction of the spiral coil.

[0010] By adopting the above technical solutions, a magnetic core unit is arranged in the spiral coil. The setting of the magnetic core can improve the induced voltage and sensitivity of the spiral coil. In addition, the magnetic core unit is hollow, providing a certain space for installing other electronic components (such as chips, etc.), and can also meet the usage function requirements under the small-sized spiral coil structure.

[0011] Further preferably, the magnetic core unit includes a magnetic core rod, and a hollow area is arranged on the magnetic core rod, and the hollow area extends through the magnetic core rod along the central line direction of the magnetic core rod.

[0012] By adopting the above technical solution, the magnetic core unit uses a hollow magnetic core rod, and the connection between the magnetic core rod and the spiral coil can be completed through one installation, which is convenient and fast.

[0013] Further preferably, the magnetic core unit includes more than two magnetic core rods, and all the magnetic core rods enclose a hollow area of the magnetic core unit at one end close to the center line of the spiral coil.

[0014] By adopting the above technical solution, more than two magnetic core rods are provided to form the magnetic core unit, and the hollow area of the magnetic core unit is enclosed by all the magnetic core rods at a section close to the center line of the spiral coil, reducing the use and processing costs of the magnetic core material.

[0015] Further preferably, the magnetic core rod is fixedly pasted to the inner wall of the spiral coil.

[0016] By adopting the above technical solution, the magnetic core rod and the spiral coil are fixedly installed by pasting, which is simple and convenient.

[0017] Further preferably, the center line of the magnetic core rod is parallel to, coincides with, or intersects the center line of the spiral coil.

[0018] By adopting the above technical solution, the center line of the magnetic core rod is parallel to, coincides with, or intersects the center line of the spiral coil, and the setting method is diverse, which can meet the installation requirements and also reduce the installation requirements.

[0019] Further preferably, along the length direction of the magnetic core rod, the cross section of the magnetic core rod is non-circular.

[0020] By adopting the above technical solution, the magnetic core rod can adopt a non-circular cross section to meet the requirements of improving the induced voltage and sensitivity of the spiral coil, and reduce the processing requirements for the magnetic core rod.

[0021] Further preferably, the width d of the magnetic core rod in the direction perpendicular to the center line of the spiral coil is ≤ 50 μm.

[0022] By adopting the above technical solution, the width d of the magnetic core rod in the direction perpendicular to the center line of the spiral coil is ≤ 50 μm to meet the installation requirements of small size.

[0023] Further preferably, there are more than three magnetic core rods, and the magnetic core rods are evenly distributed along the circumferential direction of the inner side of the spiral coil.

[0024] By adopting the above technical solution, when there are more than three magnetic core rods, the magnetic core rods are evenly distributed along the circumferential direction of the inner side of the spiral coil, so that the distribution of magnetic induction lines is more uniform.

[0025] This application also provides a technical solution as follows:

[0026] A hollow inductor includes a spiral coil structure with a magnetic core as described above.

[0027] By adopting the above technical solution, the spiral coil structure with a magnetic core is applied to an inductor to form a hollow inductor, which can ensure the sensitivity and space utilization effect even when the size of the inductor is small.

[0028] Further preferably, it further includes a first PI tube and a second PI tube. The spiral coil structure with a magnetic core is located inside the first PI tube, the second PI tube is located in the hollow area of the magnetic core unit, and an adhesive layer is filled between the first PI tube and the second PI tube.

[0029] By adopting the above technical solution, the spiral coil with a magnetic core is arranged in the gap between the two PI tubes, and the gap is filled with an adhesive layer. The adhesive layer generally uses epoxy resin, which plays a role in connection and insulation, ensuring the reliability of the hollow inductor. And the second PI tube is located in the hollow area of the magnetic core unit, which can also separate other electronic components installed in the hollow area from the magnetic core unit in the future to eliminate the potential use hazards of contact between other electronic components and the magnetic core unit.

[0030] In summary, the present application has at least the following beneficial effects: In the present application, the spiral coil structure adopted by the inductor has a magnetic core unit, which ensures the sensitivity of the inductor. The magnetic core unit is hollow, and in the application of small-sized inductors, it can also provide a certain space for the installation and implantation of other electronic components to meet various functional requirements of the inductor, and greatly saves the processing and use costs of the magnetic core material compared with a solid magnetic core. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 is an exploded schematic view of the spiral coil structure with a magnetic core in Embodiment 1;

[0032] Figure 2 is a front view schematic view of the spiral coil structure with a magnetic core in Embodiment 1, where the cross-section of the magnetic core rod and the cross-section of the hollow area are both circular;

[0033] Figure 3 is a front view schematic view of the spiral coil structure with a magnetic core in Embodiment 1, where the cross-section of the magnetic core rod and the cross-section of the hollow area are both rectangular;

[0034] Figure 4 is a three-dimensional structure schematic view of the spiral coil structure with a magnetic core in Embodiment 2;

[0035] Figure 5 is an exploded schematic view of the spiral coil structure with a magnetic core in Embodiment 2;

[0036] Figure 6It is a front view schematic diagram of the spiral coil structure with a magnetic core in the second embodiment, where the cross-section of the magnetic core rod is circular and the width is in the range of less than or equal to 50 μm;

[0037] Figure 7 It is a side view sectional schematic diagram of the second embodiment, where the two magnetic core rods are respectively arc-shaped and width-gradual;

[0038] Figure 8 It is a front view schematic diagram when the cross-section of the magnetic core rod in the second embodiment is rectangular;

[0039] Figure 9 It is a front view schematic diagram when the width of the magnetic core rod in the second embodiment is in the range greater than 50 μm;

[0040] Figure 10 It is a front view schematic diagram of the spiral coil structure with a magnetic core in the third embodiment, where several magnetic core rods are evenly arranged;

[0041] Figure 11 It is a front view schematic diagram of the spiral coil structure with a magnetic core in the third embodiment, where several magnetic core rods are unevenly arranged;

[0042] Figure 12 It is an explosion schematic diagram of a hollow inductor;

[0043] Figure 13 It is a side view sectional drawing of a hollow inductor;

[0044] Figure 14 It is a front view schematic diagram of a hollow inductor.

[0045] Explanation of reference numerals: 1, spiral coil; 2, magnetic core unit; 3, magnetic core rod; 4, first PI tube; 5, second PI tube; 6, lead; S, hollow area. Detailed implementation manners

[0046] The following will further describe the present application in detail with reference to the attached Figure 1 - attached Figure 14 drawings.

[0047] The embodiments of the present application disclose a spiral coil structure with a magnetic core and a hollow inductor applying the spiral coil structure, where: as shown in the attached Figure 1 drawings, the spiral coil structure includes a spiral coil 1 and a magnetic core unit 2 located inside the spiral coil 1, and the setting of the magnetic core unit 2 is used to ensure the induced voltage and sensitivity of the spiral coil 1.

[0048] First, the principle of the setting of the magnetic core unit 2 to improve the induced voltage and sensitivity of the spiral coil 1 will be described:

[0049] Based on Faraday's law of electromagnetic induction: V i= dΦ / dt, V i is the induced voltage in the coil, and Φ is the magnetic flux in the coil.

[0050] The coil generates an induced voltage V under an alternating magnetic field, and its quantitative relationship with the apparent magnetic permeability μa is: v s (t) = -μ a NωcosωtB0·nA c .

[0051] The coil sensitivity Ks, and its quantitative relationship with the apparent magnetic permeability μa is:

[0052] k s = 2πNA c μ a .

[0053] Where: N is the number of turns of the coil, μa is the apparent magnetic permeability, B0 is the magnetic field amplitude, Ac is the cross-sectional area of the coil, n is the unit vector perpendicular to the cross-sectional area Ac of the coil, ω is the angular frequency of the received magnetic field, and Π is the constant of the circumference ratio.

[0054] In summary, when there is no magnetic core in the spiral coil 1, μa = 1; when the spiral coil 1 has a magnetic core, μa > 1. Therefore, the magnetic core unit 2 is provided to increase the apparent magnetic permeability to achieve the effect of increasing the induced voltage and sensitivity of the spiral coil 1.

[0055] The magnetic core unit 2 is integrally hollow, and the hollow area in the magnetic core unit 2 extends through the magnetic core unit 2 along the extension direction of the center line of the spiral coil 1. The hollow magnetic core unit 2 facilitates the installation of other electronic components such as implanted chips in the hollow area therein, so as to meet more functional requirements when applied to inductors or other electronic devices.

[0056] For the magnetic core unit 2, the present application provides the following embodiments:

[0057] Embodiment 1

[0058] Combined with the attached Figure 2 and the attached Figure 3 , the magnetic core unit 2 includes a magnetic core rod 3. The magnetic core rod 3 is hollow. In this embodiment, the hollow area inside the magnetic core rod 3 is the hollow area of the magnetic core unit 2 for implanting electronic components such as chips. In this embodiment, the cross-section of the hollow area is preferably circular, and in other embodiments, the cross-section of the hollow area can also be non-circular to meet more usage requirements.

[0059] The magnetic core rod 3 is installed on the inner wall of the spiral coil 1 by gluing and fixing to improve the stability of the overall structure. The common adhesive for electronic components is epoxy resin. In other embodiments, the radial outer contour of the magnetic core rod 3 can be processed to match the radial inner contour of the spiral coil 1, and the connection between the magnetic core rod 3 and the spiral coil 1 can also be completed by insertion. Along the extension direction of the center line of the spiral coil 1, the length of the magnetic core rod 3 is generally greater than the length of the spiral coil 1, which is convenient for connection. The magnetic core rod 3 is also installed on other external components, so that the magnetic core rod 3 and the spiral coil 1 can be interlaced and assembled in space.

[0060] In addition, in order to meet the small-size installation requirements, there are certain requirements for the width of the magnetic core rod 3 along the center line direction of the vertical spiral coil 1. In this embodiment, the width d of the magnetic core rod 3 along the center line direction of the vertical spiral coil 1 is within the range of 50 μm. In other practical application scenarios, the width d of the magnetic core rod 3 along the center line direction of the vertical spiral coil 1 is ≤50 μm. The larger the width of the magnetic core rod 3, the smaller the enclosed hollow area. In practical applications, a magnetic core rod 3 of appropriate width should be selected.

[0061] Embodiment 2

[0062] The difference from the first embodiment is that: Figure 4 To Attachment Figure 6 The magnetic core unit 2 includes two magnetic core rods 3, and the magnetic core rods 3 are close to the center line of the spiral coil 1 to form a hollow area of ​​the magnetic core unit 2. Figure 6 As shown by the dotted line in .

[0063] In this embodiment, the magnetic core rod 3 uses less magnetic core material, which can save costs and reduce the processing cost and difficulty of the magnetic core rod 3.

[0064] Combined with Figure 7 To Attachment Figure 9 After the magnetic core rod 3 is connected to the spiral coil 1, its center line is parallel to, overlapped with, or at an angle to the center line of the spiral coil 1, and the preferred solution is to make the center line of the magnetic core rod 3 parallel to the center line of the spiral coil 1. Of course, the center line of the magnetic core rod 3 coinciding with or at an angle to the center line of the spiral coil 1 can also meet the function of the magnetic core, and the installation requirements for the magnetic core rod 3 are relatively low.

[0065] The shape and cross section of the magnetic core rod 3 may also make its center line non-parallel to the center line of the spiral coil 1, such as the magnetic core rod 3 has a certain curvature along the length direction, the diameter of the magnetic core rod 3 changes gradually along its own length direction, the cross section of the magnetic core rod 3 along its length direction is non-circular, etc. In this embodiment, a cylindrical magnetic core rod 3 is used, which is easy to manufacture and can also keep the center line of the magnetic core rod 3 parallel to the center line of the spiral coil 1 as much as possible.

[0066] The magnetic core rod 3 can be a solid magnetic core rod 3, and its width d in the direction perpendicular to the center line of the spiral coil 1 is ≤ 50 μm, that is: the diameters of the two magnetic core rods 3 can be unequal, and the dimensional requirements for the two magnetic core rods 3 are relatively low.

[0067] Embodiment III

[0068] The difference from Embodiment II is that: in combination with Attached Figure 10 and Attached Figure 11 , the magnetic core rod 3 unit includes more than three magnetic core rods 3, and the magnetic core rods 3 are arranged uniformly in the cross-section along the center line direction of the spiral coil 1. The number of magnetic core rods 3 can be reasonably set according to the required value of the apparent magnetic permeability, and the uniform arrangement can also make the distribution of magnetic induction lines more uniform.

[0069] In other embodiments, the installation positions of several magnetic core rods 3 can also adopt a non-uniform manner, reducing the installation requirements for the magnetic core rods 3 and the spiral coil 1.

[0070] In the embodiments of the present application, a hollow inductor is also disclosed, which applies the above-mentioned spiral coil structure with a magnetic core. Specifically, as shown in Attached Figure 12 to Attached Figure 14 , it includes a first PI tube 4 and a second PI tube 5. The spiral coil structure is arranged in the above-mentioned manner of Embodiment III, and the spiral coil structure is located in the first PI tube 4, and the second PI tube 5 is located in the hollow region of the magnetic core unit 2. Epoxy resin is filled between the first PI tube 4 and the second PI tube 5. As a commonly used adhesive in electronic components, epoxy resin plays a good connecting role and can also play an insulating role. In addition, the second PI tube 5 can isolate the space area again to facilitate the installation of other electronic components such as chips and prevent the magnetic core rods 3 from contacting other electronic components.

[0071] In addition, two leads 6 are also provided on the spiral coil 1 for welding twisted pairs so that the spiral coil 1 can be energized.

[0072] In the present application, the corresponding structural dimensions of a hollow inductor actually applied to the scenario of electromagnetic navigation and positioning are provided. Specifically: the package size OD of the hollow inductor is less than 1 mm, the outer diameter of the internal channel (i.e., the inner diameter of the second PI tube 5) is greater than 0.3 mm, and the length does not exceed 2 mm. The overall size is small, and it can achieve high-precision positioning under a weak magnetic field with a strength within 0.6 mT and a frequency in the range of 50 Hz to 10 kHz, with an error of ±1 mm, and can meet the functional requirements in implantable medical electronic systems.

[0073] The above are all the preferred embodiments of the present application. The protection scope of the present application is not limited thereby. Therefore, all equivalent changes made according to the structure, shape, and principle of the present application should be covered within the protection scope of the present application.

Claims

1. A spiral coil structure with a magnetic core, characterized in that: include: A helical coil (1); and A hollow magnetic core unit (2), the magnetic core unit (2) being located inside the spiral coil (1), and a hollow area in the magnetic core unit (2) penetrating the magnetic core unit (2) along the extension direction of the center line of the spiral coil (1).

2. The spiral coil structure with a magnetic core according to claim 1, characterized in that: The magnetic core unit (2) comprises a magnetic core rod (3), the hollow region being arranged on the magnetic core rod (3), and the hollow region penetrating the magnetic core rod (3) along the center line direction of the magnetic core rod (3).

3. The spiral coil structure with a magnetic core according to claim 1, characterized in that: The magnetic core unit (2) comprises more than two magnetic core rods (3), and all of the magnetic core rods (3) are close to one end of the center line of the spiral coil (1) to form a hollow area of ​​the magnetic core unit (2).

4. The spiral coil structure with a magnetic core according to claim 2 or 3, characterized in that: The magnetic core rod (3) is glued and fixed to the inner wall of the spiral coil (1).

5. The spiral coil structure with a magnetic core according to claim 2 or 3, characterized in that: The center line of the magnetic core rod (3) is parallel to, coincides with, or intersects with the center line of the spiral coil (1).

6. The spiral coil structure with a magnetic core according to claim 2 or 3, characterized in that: Along the length direction of the magnetic core rod (3), the cross section of the magnetic core rod (3) is non-circular.

7. The spiral coil structure with a magnetic core according to claim 2 or 3, characterized in that: The width d of the magnetic core rod (3) in a direction perpendicular to the center line of the spiral coil (1) is ≤50 μm.

8. The spiral coil structure with a magnetic core according to claim 1, characterized in that: The magnetic core unit (2) comprises magnetic core rods (3), the number of the magnetic core rods (3) being more than three, and the magnetic core rods (3) being evenly distributed along the circumference of the inner side of the spiral coil (1).

9. An air-core inductor, characterized in that: The invention comprises a spiral coil structure with a magnetic core as claimed in any one of claims 1 to 8.

10. The air-core inductor according to claim 9, characterized in that: It also comprises a first PI tube (4) and a second PI tube (5), wherein the spiral coil structure with the magnetic core is located in the first PI tube (4), and the second PI tube (5) is located in the hollow area of ​​the magnetic core unit (2), and an adhesive layer is filled between the first PI tube (4) and the second PI tube (5).

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