Magnetic shielding device for transformer and magnetic shielding transformer

Abstract

The utility model relates to a magnetic shielding device for a transformer and a magnetic shielding transformer. The magnetic shielding device comprises an uncovered metal shell, an insulating central column, an insulating spacer and a metal cover plate. The insulating central column is located in the uncovered metal shell, and the uncovered metal shell is fixedly connected with the metal cover plate through the insulating central column; one end of the insulating central column is fixedly connected with the bottom of the uncovered metal shell, and the other end of the insulating central column is fixedly connected with the metal cover plate. And the insulating spacer is arranged between the metal cover plate and the uncovered metal shell. According to the magnetic shielding device disclosed by the utility model, the uncovered metal shell, the insulating spacer and the metal cover plate form an approximately totally-enclosed internal space, so that the transformer can be magnetically shielded to the maximum extent. In addition, the metal sealing structure can be separated by adding the insulating central column and the insulating spacer, and the inductance value of the transformer can be shielded while magnetic shielding can be avoided.

Description

Technical Field

[0001] The utility model relates to the technical field of magnetic leakage shielding, in particular to a magnetic shielding device for a transformer and a magnetic shielding transformer. Background Art

[0002] With the miniaturization and integration of electronic equipment, as well as the increase in operating frequency, the problem of electromagnetic interference has become increasingly prominent and has gradually become one of the important factors affecting the normal operation of equipment. Electromagnetic interference not only comes from external sources, such as power lines, wireless communication equipment, etc., but also from the mutual influence between components inside the equipment, especially components that generate strong magnetic fields, such as transformers.

[0003] A transformer is a device that uses the principle of electromagnetic induction to change AC voltage. It will generate a magnetic field in the surrounding environment, causing magnetic leakage in the transformer during operation, interfering with surrounding components. In the prior art, copper or semi-enclosed metal casings are generally wrapped around the outside of the transformer to provide magnetic shielding for the transformer.

[0004] In some demanding circuits, such as precision measuring instruments, low-noise amplifiers, and other devices that are sensitive to the magnetic field in the environment, smaller magnetic interference may also lead to measurement errors or performance degradation of the device. In high-density integrated circuits, the distance between different functional modules is small, and the problem of magnetic field interference is more prominent.

[0005] In the above-mentioned circuits with strict requirements, the current method of magnetically shielding the transformer by wrapping it in copper or a semi-enclosed metal casing can only partially reduce the leakage magnetic field, and will still cause magnetic interference to the components in the circuit that are close to the transformer, causing the transformer to fail to meet the use requirements.

[0006] Therefore, it is necessary to strengthen the magnetic shielding effect of the transformer and reduce the magnetic interference to other surrounding components during the use of the transformer. Utility Model Content

[0007] 1. Technical issues to be resolved

[0008] In order to solve the problem in the prior art that copper skin or semi-enclosed metal casing has poor shielding effect on magnetic shielding of transformers and still generates magnetic interference to components in similar positions, the utility model provides a magnetic shielding device for transformers and a magnetic shielding transformer.

[0009] (II) Technical solution

[0010] In order to achieve the above object, the utility model provides a magnetic shielding device for a transformer, comprising a coverless metal shell, an insulating center column, an insulating gasket and a metal cover plate;

[0011] The insulating central column is located inside the uncovered metal shell, and the uncovered metal shell and the metal cover are fastened together via the insulating central column; one end of the insulating central column is fixedly connected to the bottom of the uncovered metal shell, and the other end of the insulating central column is fastened together to the metal cover;

[0012] The insulating gasket is arranged between the metal cover plate and the uncovered metal housing.

[0013] In the magnetic shielding device as described above, preferably, the thickness of the insulating gasket is 0.5-1 mm; the thickness of the uncovered metal shell and the metal cover plate is 0.75-1.5 mm.

[0014] In the magnetic shielding device as described above, preferably, the insulating central column is threadedly connected to the bottom of the uncovered metal shell, and the other end of the insulating central column is fastened to the metal cover plate by screws.

[0015] In the magnetic shielding device as described above, preferably, the coverless metal shell is an aluminum alloy shell, a copper alloy shell or a Permalloy shell;

[0016] The metal cover plate is an aluminum alloy plate, a copper alloy plate or a Permalloy plate.

[0017] In the magnetic shielding device as described above, preferably, the insulating gasket is a polyimide gasket or an epoxy resin gasket;

[0018] The insulating central column is a polyimide column or an epoxy resin column.

[0019] As for the magnetic shielding device as described above, preferably, the insulating gasket and the metal cover plate also have wire holes.

[0020] As for the magnetic shielding device as described above, preferably, a protrusion is further provided on the uncovered metal shell, and a groove is further provided on the insulating gasket and the metal cover plate, and the protrusion is matched with the groove in a concave-convex manner.

[0021] As for the magnetic shielding device as described above, preferably, the coverless metal shell is also provided with a hanging ear.

[0022] The utility model also provides a magnetic shielding transformer, comprising a transformer body and the magnetic shielding device mentioned above;

[0023] The transformer body is fixedly arranged on the bottom of the uncovered metal shell through a potting glue layer.

[0024] As for the magnetic shielding transformer as described above, preferably, the bottom of the transformer body contacts the bottom of the uncovered metal shell, and the insulating center column passes through the inner ring of the transformer body and is not in contact with the transformer body.

[0025] (III) Beneficial effects

[0026] The beneficial effects of the utility model are:

[0027] The magnetic shielding device of the utility model forms a nearly fully enclosed internal space through a uncovered metal shell, an insulating gasket and a metal cover plate, which can maximize the magnetic shielding of the transformer. Compared with the existing technology of magnetic shielding through copper wrapping or semi-enclosed metal shell, the magnetic shielding device of the utility model can ensure that other components in similar positions will not be disturbed by the magnetic field of the transformer in the circuit with high requirements for electromagnetic interference, and achieve the effect of small residual magnetism in the working area and low magnetic field noise.

[0028] In addition, the insulating center column and the insulating gasket in the utility model can also separate the metal sealing structure, so that the inductance of the transformer can remain unchanged during use, avoiding shielding the inductance of the transformer itself while magnetically shielding, avoiding causing the transformer performance to shift and affecting its normal use. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is a schematic diagram of the overall structure of the magnetic shielding device for transformers in the utility model;

[0030] Figure 2 It is a front view of the magnetic shielding device for transformer in the utility model;

[0031] Figure 3 It is a top view of the magnetic shielding device for transformer in the utility model;

[0032] Figure 4 It is a schematic diagram of the connection state between the uncovered metal housing and the insulating center column;

[0033] Figure 5 This is a schematic diagram of the structure of the metal housing without a cover in the utility model;

[0034] Figure 6 This is a schematic diagram of the structure of the uncovered metal housing from another angle;

[0035] Figure 7 It is a structural schematic diagram of the metal cover plate in the utility model;

[0036] Figure 8 It is a structural schematic diagram of the insulating gasket in the utility model.

[0037] [Description of Reference Numerals]

[0038] 1: Uncovered metal casing; 2: Insulating center column; 3: Insulating gasket; 4: Metal cover; 5: Screws; 6: Wire hole; 7: Protrusion; 8: Groove; 9: Mounting ear. DETAILED DESCRIPTION

[0039] In order to better explain the present invention and facilitate understanding, the present invention is described in detail below through specific implementation modes in conjunction with the accompanying drawings.

[0040] like Figure 1-8 As shown, the utility model provides a magnetic shielding device for a transformer, comprising an uncovered metal shell 1, an insulating center column 2, an insulating gasket 3 and a metal cover plate 4. The insulating center column 2 is located inside the uncovered metal shell 1, and the uncovered metal shell 1 and the metal cover plate 4 are fastened together through the insulating center column 2. Specifically, one end of the insulating center column 2 is fixedly connected to the bottom of the uncovered metal shell 1, and the other end of the insulating center column 2 is fastened together with the metal cover plate 4. The insulating gasket 3 is arranged between the metal cover plate 4 and the uncovered metal shell 1.

[0041] In the utility model, the uncovered metal shell 1 and the metal cover plate 4 form a fastening structure through the insulating central column 2, and the insulating gasket 3 is located between the uncovered metal shell 1 and the metal cover plate 4 and is clamped by the uncovered metal shell 1 and the metal cover plate 4.

[0042] The magnetic shielding device of the utility model forms an almost fully enclosed internal space through the uncovered metal shell 1, the insulating gasket 3 and the metal cover plate 4, which can maximize the magnetic shielding of the transformer. Compared with the prior art of magnetic shielding through copper wrapping or semi-enclosed metal shell, the magnetic shielding device of the utility model can ensure that in circuits with high requirements for electromagnetic interference, such as precision measuring instruments, low-noise amplifiers or high-density integrated circuits, other components close to the transformer position will not be disturbed by the magnetic field of the transformer, achieving the effect of small residual magnetism in the working area and low magnetic field noise.

[0043] In addition, the provision of the insulating center column 2 and the insulating gasket 3 in the utility model can also separate the metal sealing structure composed of the metal cover plate 4 and the uncovered metal shell 1, so that the inductance of the transformer can remain unchanged during use, avoiding shielding the inductance of the transformer itself while magnetically shielding, and avoiding causing the transformer performance to shift and affect its normal use. After actual testing, the magnetic shielding device of the utility model can maintain the inductance of the transformer 100% during use. If the insulating center column 2 and the insulating gasket 3 are not provided, the full metal structure formed by the metal cover plate 4 and the uncovered metal shell 1 will shield the inductance of the transformer itself while shielding the leakage magnetic field, causing a significant shift in the electrical performance of the transformer and affecting its use.

[0044] like Figure 1 As shown, the uncovered metal housing 1 may be in a cylindrical shape, the insulating gasket 3 may be in a ring shape, and the metal cover plate 4 may be in a circular shape.

[0045] Preferably, in order to ensure both the magnetic shielding effect and the inductance retention effect, the thickness of the insulating gasket 3 in the utility model is 0.5-1 mm. If the thickness of the insulating gasket 3 is less than 0.5 mm, the inductance of the transformer may be shielded by the uncovered metal housing 1 and the metal cover plate 4, affecting the normal use of the transformer. If the thickness of the insulating gasket 3 is higher than 1 mm, the magnetic shielding effect of the transformer may be affected, causing it to generate electromagnetic interference to other components in similar positions in the circuit. In addition, the thickness of the uncovered metal housing 1 and the metal cover plate 4 in the present invention can be 0.75-1.5 mm.

[0046] Further preferably, the fixed connection between the insulating central column 2 and the bottom of the uncovered metal shell 1 in the utility model can be a threaded connection, and the bottom of the insulating central column 2 can be provided with an external thread, which cooperates with the thread provided on the inner bottom of the uncovered metal shell 1. The other end of the insulating central column 2 can be fastened to the metal cover plate 4 by means of a screw 5 or the like. Specifically, a threaded hole can be provided on the metal cover plate 4, and an internal thread can be provided on the upper end of the insulating central column 2, and the metal cover plate 4 and the internal thread of the insulating central column 2 are connected together by means of the screw 5. In the present invention, in order to ensure the connection strength, the screw 5 can be made of stainless steel.

[0047] Aluminum alloy, copper alloy and Permalloy can shield the magnetic field of the transformer. Therefore, preferably, the coverless metal shell 1 in the present invention can be an aluminum alloy shell, a copper alloy shell or a Permalloy shell, and the metal cover plate 4 can also be an aluminum alloy plate, a copper alloy plate or a Permalloy plate.

[0048] Polyimide and epoxy resin both have good insulation effects, so, more preferably, the insulating gasket 3 can be a polyimide gasket or an epoxy resin gasket, and the insulating central column 2 is a polyimide column or an epoxy resin column.

[0049] In order to prevent the metal cover plate 4 from shifting and rotating relative to the uncovered metal shell 1 and the insulating gasket 3, preferably, a protrusion 7 is further provided on the uncovered metal shell 1 in the utility model, and a groove 8 is further provided on the insulating gasket 3 and the metal cover plate 4, and the protrusion 7 and the groove 8 are matched with each other.

[0050] Preferably, if Figure 1-6 As shown, a plurality of hanging ears 9 can be further provided on the coverless metal housing 1 of the present invention to facilitate installation of the transformer in a corresponding circuit.

[0051] like Figure 1 , Figure 3 , Figure 6 as well as Figure 8 As shown, the insulating gasket 3 and the metal cover plate 4 also have a wire hole 6. Figure 6As shown, a wire hole may also be provided at the bottom of the uncovered metal housing 1, and a lead terminal connected to the transformer may pass through the wire hole 6 or the wire hole to be connected to other external structural components.

[0052] In addition, the utility model also provides a magnetic shielding transformer, including a transformer body and the above-mentioned magnetic shielding device. The above-mentioned transformer body includes a toroidal iron core, a primary coil, and a secondary coil. The transformer body can be fixedly arranged at the bottom of the uncovered metal shell 1 by a potting layer. Specifically, the bottom of the transformer body contacts the bottom of the uncovered metal shell 1, and the insulating center column 2 passes through the inner ring of the transformer body and is in a non-contact relationship with the transformer body. The potting layer fills the entire uncovered metal shell.

[0053] The setting of the potting glue layer can enhance the mechanical stability of the magnetic shielding device and the magnetic shielding transformer. The potting glue selected can be epoxy resin, special magnetic shielding glue, high thermal conductivity potting glue, etc. These glues have good thermal conductivity, insulation, temperature resistance and bonding strength, can effectively fill the gap inside the magnetic shielding device, reduce the vibration of the transformer body, and help dissipate heat.

[0054] In the description of this specification, the description of the terms "one embodiment", "some embodiments", "embodiment", "example", "specific example" or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the utility model. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, unless they are contradictory.

[0055] Although the embodiments of the present invention have been shown and described above, it can be understood that the above embodiments are illustrative and cannot be understood as limitations of the present invention. Ordinary technicians in the field can change, modify, replace and modify the above embodiments within the scope of the present invention.

Claims

1. A magnetic shielding device for a transformer, characterized in that: It comprises a coverless metal shell (1), an insulating central column (2), an insulating gasket (3) and a metal cover plate (4); The insulating central column (2) is located inside the uncovered metal shell (1), and the uncovered metal shell (1) and the metal cover plate (4) are fastened together via the insulating central column (2); one end of the insulating central column (2) is fixedly connected to the bottom of the uncovered metal shell (1), and the other end of the insulating central column (2) is fastened together to the metal cover plate (4); The insulating gasket (3) is arranged between the metal cover plate (4) and the uncovered metal housing (1).

2. The magnetic shielding device according to claim 1, characterized in that: The thickness of the insulating gasket (3) is 0.5-1 mm; the thickness of the uncovered metal housing (1) and the metal cover plate (4) is 0.75-1.5 mm.

3. The magnetic shielding device according to claim 1, characterized in that: The insulating central column (2) is threadedly connected to the bottom of the uncovered metal housing (1), and the other end of the insulating central column (2) is fastened to the metal cover plate (4) via screws (5).

4. The magnetic shielding device according to claim 1, characterized in that: The coverless metal housing (1) is an aluminum alloy housing, a copper alloy housing or a Permalloy housing; The metal cover plate (4) is an aluminum alloy plate, a copper alloy plate or a Permalloy plate.

5. The magnetic shielding device according to claim 1, characterized in that: The insulating gasket (3) is a polyimide gasket or an epoxy resin gasket; The insulating central column (2) is a polyimide column or an epoxy resin column.

6. The magnetic shielding device according to claim 1, characterized in that: The insulating gasket (3) and the metal cover plate (4) are also provided with wire holes (6).

7. The magnetic shielding device according to claim 1, characterized in that: A protrusion (7) is also provided on the coverless metal shell (1), and a groove (8) is also provided on the insulating gasket (3) and the metal cover plate (4), and the protrusion (7) and the groove (8) are matched in a concave-convex manner.

8. The magnetic shielding device according to claim 1, characterized in that: The coverless metal shell (1) is also provided with a hanging ear (9).

9. A magnetic shielding transformer, characterized in that: It comprises a transformer body and the magnetic shielding device according to any one of claims 1 to 8; The transformer body is fixedly arranged on the bottom of the uncovered metal casing (1) via a potting glue layer.

10. The magnetic shielding transformer according to claim 9, characterized in that: The bottom of the transformer body contacts the bottom of the uncovered metal shell (1), and the insulating central column (2) passes through the inner ring of the transformer body and is not in contact with the transformer body.

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