Oil tank magnetic shielding structure and transformer

Abstract

This utility model discloses a magnetic shielding structure for an oil tank and a transformer, relating to the field of transformer technology. The magnetic shielding structure includes a magnetic shielding assembly, an oil tank, and a fastening assembly. The magnetic shielding assembly includes a shielding group, a mounting plate, and at least one set of mounting frames. The shielding group comprises multiple layers of silicon steel sheets and is mounted within a mounting frame formed by the mounting frames. The mounting plate is mounted on the shielding group, and / or mounted on the mounting frame. The mounting plate is perpendicular to the silicon steel sheets. Along the length of the mounting plate, its length is greater than the distance between the outer walls of the mounting frame. Mounting portions are provided at both ends of the mounting plate. The oil tank includes sidewalls perpendicular to the silicon steel sheets and threaded seats corresponding to the mounting portions. The fastening assembly includes a pressure member that threadedly engages with the threaded seats to press the mounting plate against the sidewalls. This solution can eliminate the magnetic hysteresis resonance phenomenon of the magnetic shielding assembly and the discharge phenomenon at the connection with the sidewalls.

Description

Technical Field

[0001] This utility model relates to the field of transformer technology, and in particular to a magnetic shielding structure for an oil tank and a transformer. Background Technology

[0002] To reduce losses caused by leakage flux in transformers, magnetic shielding components are typically installed on the transformer tank walls. Currently, there are two main methods for installing magnetic shielding components on the tank walls: snap-fit ​​and welding. When using snap-fit, the clips are first welded to the tank wall, and then the magnetic shielding component is snapped onto the clips. During the connection, the clips are bent by hammering to secure the magnetic shielding component. When using welding, the magnetic shielding component is directly welded to the tank wall. However, snap-fit ​​connections are prone to causing the magnetic shielding component to wobble and generate hysteresis resonance under the influence of leakage flux, resulting in significant noise during transformer operation. Welding connections can easily lead to weld slag becoming trapped between the tank wall and the magnetic shielding component. As a conductive metallic impurity, the weld slag forms sharp conductors under the influence of magnetic and electric fields, causing sharp-angle discharge phenomena. Over long-term operation, this can gradually damage the weld seams, creating potential quality issues. Utility Model Content

[0003] The main purpose of this utility model is to propose a magnetic shielding structure for an oil tank and a transformer, which aims to eliminate the magnetic hysteresis resonance phenomenon in the magnetic shielding component and the discharge phenomenon at the connection between the magnetic shielding component and the oil tank wall.

[0004] To achieve the above objectives, this utility model proposes a magnetic shielding structure for an oil tank, comprising:

[0005] A magnetic shielding assembly includes a shielding group, a mounting plate, and at least one set of mounting frames. The shielding group includes multiple layers of silicon steel sheets, and the mounting frames are provided with mounting frames. The mounting frames are connected to the shielding group along the circumference of the shielding group.

[0006] The mounting plate is mounted on the shielding assembly, and / or the mounting plate is mounted on the mounting frame;

[0007] The mounting plate is perpendicular to the silicon steel sheet. Along the length of the mounting plate, the length of the mounting plate is greater than the distance between the outer walls of the mounting frame. Mounting portions are provided at both ends of the mounting plate.

[0008] The fuel tank includes a side wall and threaded seats that are corresponding to the mounting portions. The silicon steel sheet is perpendicular to the side wall, the mounting plate is parallel to the side wall, the threaded seats are perpendicularly disposed on the side wall, and the threaded seats pass through the mounting portions.

[0009] The fastening assembly includes a pressure member that is threadedly engaged with the threaded seat to press the mounting plate against the sidewall.

[0010] In one embodiment, the mounting frame includes two end plates and two side clamps arranged opposite to each other. The side clamps are parallel to the silicon steel sheet. The end plates and the side clamps are alternately connected along the circumference of the shielding assembly and enclose to form the mounting frame. The shielding assembly is connected to the end plates and the side clamps on all four sides respectively.

[0011] In one embodiment, there are multiple mounting plates. The direction from one end plate to another is defined as the first direction, and the multiple mounting plates are arranged in parallel along the first direction.

[0012] In one embodiment, the mounting part is a through groove with an opening for the threaded seat to pass through, and the mounting plate is mounted on the threaded seat through the through groove.

[0013] In one embodiment, all of the openings are arranged in the same direction along the first direction;

[0014] Alternatively, some of the openings may be positioned opposite to the remaining openings.

[0015] In one embodiment, both the end plate and the side clamp have rounded corners at the ends away from the sidewall.

[0016] In one embodiment, the fuel tank further includes at least one support block, which is mounted on the side wall and the side of the support block away from the side wall is fitted with the shielding assembly.

[0017] In one embodiment, the fastening assembly further includes a shielding cap, the shielding cap including a connected connecting piece and a cap body, the connecting piece having a through hole, the threaded seat passing through the through hole, the pressure member for pressing the connecting piece against the mounting plate, and the cap body covering at least a portion of the pressure member.

[0018] In one embodiment, the fastening assembly further includes a pressure pad, which is fitted onto the side of the connecting piece away from the sidewall, and the pressure member presses the connecting piece against the mounting plate through the pressure pad.

[0019] This utility model also proposes a transformer, including the oil tank magnetic shielding structure as described in any of the above embodiments.

[0020] According to the technical solution provided by this utility model, the magnetic shielding structure of the oil tank includes a magnetic shielding assembly, an oil tank, and a fastening assembly. The magnetic shielding assembly includes a shielding group, a mounting plate, and at least one set of mounting frames. The shielding group includes multiple layers of silicon steel sheets. The mounting frames are provided with mounting frames that are connected to the shielding group circumferentially. The mounting plate is mounted on the shielding group, and / or mounted on the mounting frame. The mounting plate is perpendicular to the silicon steel sheets. Along the length of the mounting plate, the length of the mounting plate is greater than the distance between the outer walls of the mounting frames. Mounting portions are provided at both ends of the mounting plate. The oil tank includes side walls and threaded seats corresponding to the mounting portions. The silicon steel sheets are perpendicular to the side walls, the mounting plates are parallel to the side walls, and the threaded seats are perpendicularly disposed on the side walls and pass through the mounting portions. The fastening assembly includes a pressure member that is threadedly engaged with the threaded seats to press the mounting plate against the side walls. This design allows the shielding assembly to form a unified whole under the support of the mounting bracket. During installation, the mounting plate is first attached to the threaded seat, and then pressed against the side wall by clamping components, thus enabling the entire magnetic shielding assembly to be installed on the side wall. Simultaneously, because the silicon steel plate is perpendicular to the side wall, leakage magnetic lines of force can enter the silicon steel plate along its side, providing a low magnetic resistance path for leakage magnetic flux and reducing the magnetic flux density on the surface of the shielding assembly. Therefore, the magnetic shielding assembly provided in this solution can both securely connect to the side wall and reduce the magnetic force of leakage magnetic flux on the shielding assembly. Furthermore, the non-welded connection between the magnetic shielding assembly and the side wall prevents hysteresis resonance and discharge phenomena at the connection point between the magnetic shielding assembly and the side wall. Attached Figure Description

[0021] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0022] Figure 1 This is a schematic diagram of the magnetic shielding structure of the fuel tank provided in an embodiment of the present invention;

[0023] Figure 2 for Figure 1 A top-view structural diagram;

[0024] Figure 3 This is a schematic diagram of the structure of a magnetic shielding assembly provided in an embodiment of the present invention;

[0025] Figure 4 for Figure 3 A top-view structural diagram;

[0026] Figure 5 for Figure 3 A schematic diagram of the side structure;

[0027] Figure 6 This is a partial structural schematic diagram of an embodiment of the fuel tank provided by the present utility model;

[0028] Figure 7 for Figure 6 A schematic diagram of the side structure;

[0029] Figure 8 This is a schematic diagram of the magnetic shielding structure for an oil tank provided in another embodiment of the present invention;

[0030] Figure 9 This is a schematic diagram of the structure of the fastening assembly after installation according to an embodiment of the present invention;

[0031] Figure 10 A front structural schematic diagram and a side structural cross-sectional view of the shielding cap provided in an embodiment of this utility model.

[0032] Explanation of icon numbers:

[0033] 100. Magnetic shielding structure for fuel tank;

[0034] 1. Magnetic shielding assembly; 11. Shielding group; 111. Silicon steel sheet; 12. Mounting plate; 121. Mounting part; 121a. Through groove; 13. Mounting bracket; 131. End plate; 132. Side clamping plate;

[0035] 2. Oil tank; 21. Side wall; 22. Threaded seat; 23. Support block;

[0036] 3. Fastening assembly; 31. Pressure component; 32. Shielding cap; 321. Connecting piece; 322. Cap body; 33. Pressure pad;

[0037] X, the first direction.

[0038] The realization of the purpose, functional features and advantages of this utility model will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0039] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present utility model.

[0040] It should be noted that if the embodiments of this utility model involve directional indicators (such as up, down, left, right, front, back, etc.), the directional indicators are only used to explain the relative positional relationship and movement of the components in a specific posture. If the specific posture changes, the directional indicators will also change accordingly.

[0041] Furthermore, if the embodiments of this utility model involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the use of "and / or" or "and / or" throughout the text includes three parallel solutions. For example, "A and / or B" includes solution A, solution B, or a solution where both A and B are satisfied simultaneously. Furthermore, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this utility model.

[0042] In the design of oil-immersed transformers, when the incident magnetic flux density on the surface of the transformer tank reaches a certain value, a magnetic shielding component needs to be laid on the tank surface to reduce leakage flux entering the tank and avoid stray losses. There are two traditional methods for installing the magnetic shielding component in the tank. One method uses clips to connect it to the tank; the clips are first welded to the tank wall, and then the magnetic shielding component is attached to the clips. The clips are then bent by tapping, preventing them from falling off. The other method uses welding, directly welding the magnetic shielding component to the tank wall.

[0043] However, according to the applicant's observations, the clips have a certain degree of resilience. After the magnetic shielding component is combined with the clips, the installation of the magnetic shielding component is not secure and is prone to shaking. In this case, due to the influence of magnetic leakage, the magnetic shielding component is prone to magnetic hysteresis resonance, causing the transformer to generate significant noise during operation. When using welding connections, the magnetic shielding component needs to be welded as a whole to the tank wall. This process generates a large welding area, and due to manufacturing precision limitations, the magnetic shielding component cannot be completely fitted to the tank wall. Therefore, during welding, weld slag inevitably gets trapped between the magnetic shielding component and the tank wall, or trapped in the weld seam. In this case, multiple slag removal operations are required after the welding operation, which consumes a lot of manpower and is difficult to remove the weld slag. Since the weld slag is usually an irregularly shaped conductive metallic impurity, it is easy to form sharp conductors under the action of magnetic and electric fields, causing sharp-angle discharge phenomena. After the transformer has been running for a long time, the weld seam is easily gradually damaged, causing potential quality problems.

[0044] In view of this, the present invention proposes a magnetic shielding structure for fuel tanks to solve or at least alleviate the above-mentioned problems.

[0045] Please see Figures 1 to 10 In one embodiment of this utility model, the oil tank magnetic shielding structure 100 includes a magnetic shielding assembly 1, an oil tank 2, and a fastening assembly 3. The magnetic shielding assembly 1 includes a shielding group 11, a mounting plate 12, and at least one set of mounting frames 13. The shielding group 11 includes multiple layers of silicon steel sheets 111. The mounting frame 13 includes two opposing end plates 131 and two side clamping plates 132. The side clamping plates 132 are parallel to the silicon steel sheets 111. The end plates 131 and side clamping plates 132 are alternately connected along the circumference of the shielding group 11 and enclose it to form a mounting frame. The shielding group 11 is mounted on the mounting frame. The mounting plate 12 is mounted on the shielding group 11 between the two end plates 131, and / or, the mounting plate 12 is mounted on the side clamping plates 132. Mounting plate 12 is perpendicular to silicon steel sheet 111. The length of mounting plate 12 is greater than the distance between the two side clamping plates 132. Mounting portions 121 are provided at both ends of mounting plate 12 along its length. Oil tank 2 includes side wall 21 and threaded seats 22 that correspond one-to-one with mounting portions 121. Silicon steel sheet 111 is perpendicular to side wall 21. Threaded seats 22 are perpendicularly arranged on side wall 21 and pass through mounting portions 121. Fastening assembly 3 includes pressure member 31. Pressure member 31 is threadedly engaged with threaded seat 22 to press mounting plate 12 against side wall 21.

[0046] Specifically, silicon steel sheet 111 is a silicon-containing soft magnetic alloy, mainly composed of iron and silicon. It possesses excellent electromagnetic properties, particularly high permeability and low magnetic reluctance, effectively guiding magnetic field lines to form a closed magnetic circuit and significantly reducing magnetic leakage. Therefore, in this embodiment, silicon steel sheet 111 is used to form shielding group 11. Shielding group 11 includes one of stacked magnetic shielding and rolled magnetic shielding. Stacked magnetic shielding is made from multiple silicon steel sheets 111 through processes such as overlapping, extrusion, and fixing. Rolled magnetic shielding is formed by rolling strip silicon steel sheets 111 from one end to the other and extruding them into a racetrack shape, having both length and width directions. When using stacked magnetic shielding, the side clamps 132 are arranged parallel to the multiple silicon steel sheets 111; when using rolled magnetic shielding, the side clamps 132 are parallel to the silicon steel sheets 111 along the length direction of the rolled magnetic shielding. The shielding assembly 11 is mounted around the mounting frame, and the connection method includes bonding and welding. In this embodiment, the shielding assembly 11 is welded to the mounting frame 13. Specifically, spot welding is performed at the connection points between the shielding assembly 11 and the side clamping plate 132 and between the shielding assembly 11 and the end plate 131. This process ensures the connection strength between the shielding assembly 11 and the mounting frame 13 without creating large areas of weld seams that could cause metal slag to be trapped in the weld seams. In the mounting frame 13, adjacent end plates 131 and side clamping plates 132 are also welded together, and the weld seams are ground. By mounting the shielding assembly 11 to the mounting frame 13, the mounting components can constrain the shielding assembly 11, preventing it from loosening during operation, thereby improving the overall strength of the shielding assembly 11.

[0047] In this embodiment, please refer to Figure 3 and Figure 4 The mounting plate 12 is a long strip that spans the shielding assembly 11 along its length, with both ends extending out to facilitate connection between the mounting portion 121 and the threaded seat 22. In this embodiment, the mounting plate 12 can be connected only to the shielding assembly 11, only to the two side clamping plates 132, or simultaneously to both the shielding assembly 11 and the side clamping plates 132, specifically by welding. In this embodiment, the threaded seat 22 includes either a threaded rod with external threads or a threaded platform with internal threads. When a threaded rod is used, the clamping member 31 is a nut, which, through its engagement with the threaded rod, presses the mounting plate 12 near the mounting portion 121 against the side wall 21. When the threaded seat 22 uses a threaded platform, the clamping member 31 is a screw with a nut, which can be screwed into the threaded platform, while the nut presses the mounting plate 12 near the mounting portion 121 against the side wall 21. The specific implementation of the threaded seat 22 and the clamping member 31 can be determined according to actual design requirements.

[0048] According to the technical solution of this embodiment, the shielding assembly 11 is formed as a whole under the action of the mounting bracket 13. When the magnetic shielding assembly 1 is installed, the mounting plate 12 can first be hung on the threaded seat 22, and then the mounting plate 12 is pressed tightly against the side wall 21 by the pressure member 31, so that the magnetic shielding assembly 1 can be installed as a whole on the side wall 21. At the same time, since the silicon steel plate is perpendicular to the side wall 21, the leakage magnetic field lines can enter the silicon steel plate along the side of the silicon steel plate, thereby providing a low magnetic resistance path for the leakage magnetic field and reducing the magnetic density on the surface of the shielding assembly 11. In this way, the magnetic shielding assembly 1 provided by this solution can be firmly connected to the side wall 21, and the magnetic force effect of leakage magnetic field on the shielding assembly 11 can be reduced. Moreover, the magnetic shielding assembly 1 and the side wall 21 adopt a non-welded connection method, so that the magnetic shielding assembly 1 in this solution will not produce magnetic hysteresis resonance phenomenon and discharge phenomenon at the connection between the magnetic shielding assembly 1 and the side wall 21.

[0049] Furthermore, in one embodiment of this utility model, please refer to... Figure 3 , Figure 3 An embodiment of a vertically mounted magnetic shielding assembly 1 is provided, comprising multiple mounting plates 12. Let the direction from one end plate 131 to another end plate 131 be defined as the first direction X. The multiple mounting plates 12 are arranged parallel to each other along the first direction X. By providing multiple mounting plates 12, the magnetic shielding assembly 1 is made more stable when mounted on the threaded seat 22, facilitating the installation of the clamping member 31. Simultaneously, the multiple mounting plates 12 can distribute the load transmitted by the shielding assembly 11 or the side clamping plate 132, preventing stress concentration in any single mounting plate 12. Furthermore, the cooperation of multiple threaded seats 22 and clamping members 31 to press the multiple mounting plates 12 together also improves the stability of the magnetic shielding assembly 1 during installation.

[0050] There are various ways to implement the mounting part 121. In one embodiment of this utility model, the mounting part 121 is a circular hole or an elliptical hole. During installation, the threaded seat 22 is directly inserted into the circular hole or elliptical hole, and then the pressure member 31 is engaged with the threaded seat 22 to press the mounting plate 12 tightly.

[0051] In another embodiment, please refer to Figure 3 The mounting section 121 is a through groove 121a with an opening for the threaded seat 22 to pass through. The mounting plate 12 is mounted on the threaded seat 22 via the through groove 121a. The through groove 121a is U-shaped. During the installation of the magnetic shielding assembly 1, it is positioned such that... Figure 3In the embodiment shown, the through groove 121a is mounted on the threaded seat 22 from top to bottom. During this process, the threaded seat 22 enters the through groove 121a through the opening and finally abuts against the top wall of the through groove 121a. This arrangement reduces the requirements for the machining accuracy of the through groove 121a and avoids the situation where one of the mounting parts 121 cannot be aligned with the threaded seat 22, thus improving the installation efficiency of the magnetic shielding assembly 1.

[0052] To adapt to various operating conditions, the magnetic shielding assembly 1 can be installed in both vertical and horizontal directions. In one embodiment of this invention, please refer to... Figure 3 When the magnetic shielding component 1 is installed vertically, all the openings in the mounting plate 12 are set downwards. Considering the effect of gravity, the magnetic shielding component 1 will not move upwards after installation. Therefore, setting all the openings downwards in the same direction can improve the installation efficiency of the magnetic shielding component 1.

[0053] In another embodiment, please refer to Figure 8 When the magnetic shielding assembly 1 is installed horizontally, at least one opening in the mounting plate 12 is positioned opposite to the openings in the other mounting plates 12. Since the magnetic shielding assembly 1 may still move horizontally even when the clamping member 31 and the threaded seat 22 press the mounting plate 12 against the side wall 21 during horizontal installation, this arrangement, where some openings are opposite to others, allows some through slots 121a to mutually limit each other, ensuring that no horizontal displacement occurs after the magnetic shielding assembly 1 is installed.

[0054] In one embodiment of this utility model, please refer to Figure 6 and Figure 7 The oil tank 2 also includes at least one support block 23, which is installed on the side wall 21, with the side of the support block 23 away from the side wall 21 abutting against the shielding assembly 11. The support block 23 is specifically a long strip or a square block, and is connected to the side wall 21 by welding. Multiple support blocks 23 can be installed, distributed along the first direction X on the side wall 21. By providing the support blocks 23, on the one hand, when the magnetic shielding assembly 1 is mounted, the support blocks 23 can provide support to the magnetic shielding assembly 1, preventing it from tipping over when not secured by the clamping member 31, thus facilitating installation. On the other hand, the support blocks 23 can provide support to the shielding assembly 11. Since the shielding assembly 11 is made of stacked silicon steel sheets 111, it may deform under magnetic force in a direction perpendicular to the side wall 21. Therefore, by providing the support blocks 23, a certain degree of resistance to deformation can be provided to the shielding assembly 11.

[0055] Please see Figure 9 and Figure 10In one embodiment of this utility model, the fastening assembly 3 further includes a shielding cap 32. The shielding cap 32 includes a connected connecting piece 321 and a cap body 322. The connecting piece 321 has a through hole, through which a threaded seat 22 passes. A pressing member 31 is used to press the connecting piece 321 against the mounting plate 12. The cap body 322 covers at least a portion of the pressing member 31. Taking a threaded seat 22 as a screw and a pressing member 31 as a nut as an example, the connecting piece 321 is installed on the side of the mounting plate 12 away from the side wall 21. The screw passes through the through hole, and the nut can press the connecting piece 321 tightly against the mounting plate 12. After installation, the cap body 322 is manually placed on the nut. In this way, the sharp corners in the nut can be shielded by the cap body 322 to avoid sharp corner discharge in the nut.

[0056] In one embodiment of this utility model, the fastening assembly 3 further includes a pressure pad 33, which is fitted onto the side of the connecting piece 321 away from the sidewall 21. The pressure member 31 presses the connecting piece 321 against the mounting plate 12 through the pressure pad 33. The pressure pad 33 includes at least one of a metal pad and an elastic pad. By providing the pressure pad 33, damage to the connecting piece 321 caused by the pressure member 31 directly pressing it is avoided. At the same time, the pressure pad 33 generates reverse tension through elastic deformation, continuously pressing the pressure member 31 to counteract the loosening tendency caused by vibration and prevent the connection between the pressure member 31 and the threaded seat 22 from becoming loose.

[0057] In one embodiment of the utility model, please refer to Figure 4 and Figure 5 Both the end plate 131 and the side clamp plate 132 have rounded corners at the ends away from the side wall 21. The ends of the end plate 131 and the side clamp plate 132 away from the side wall 21 usually face the iron core and coil in the transformer. The leakage flux in this part is relatively large, so rounding the corners at this part can avoid the occurrence of sharp corner discharge.

[0058] In one embodiment of this utility model, the magnetic shielding assembly 1 further includes at least one central pull plate, which is arranged parallel to the mounting plate 12, perpendicular to the silicon steel sheet 111, and its length is less than or equal to the distance between the two side clamping plates 132. The central pull plate is welded to the shielding assembly 11. The middle part of the central pull plate is welded to the shielding assembly 11, and its two ends are respectively welded to the two side clamping plates 132. Multiple central pull plates can be provided and arranged parallel to each other along the first direction X. In this way, the central pull plate can secure the silicon steel sheet 111 in the shielding assembly 11, reduce the probability of the silicon steel sheet 111 becoming loose, and improve the overall strength of the shielding assembly 11.

[0059] This utility model also proposes a transformer, which includes an oil tank magnetic shielding structure 100. The specific structure of the oil tank magnetic shielding structure 100 is as described in the above embodiments. Since this transformer adopts all the technical solutions of all the above embodiments, it has at least all the beneficial effects brought about by the technical solutions of the above embodiments, which will not be described in detail here.

[0060] The above description is merely an exemplary embodiment of the present utility model and does not limit the scope of protection of the present utility model. Any equivalent structural transformations made based on the technical concept of the present utility model and the contents of the present utility model specification and drawings, or direct / indirect applications in other related technical fields, are included within the scope of protection of the present utility model.

Claims

1. An oil tank magnetic shielding structure, characterized by, include: A magnetic shielding assembly includes a shielding group, a mounting plate, and at least one set of mounting frames. The shielding group includes multiple layers of silicon steel sheets, and the mounting frames are provided with mounting frames. The mounting frames are connected to the shielding group along the circumference of the shielding group. The mounting plate is mounted on the shielding assembly, and / or the mounting plate is mounted on the mounting frame; The mounting plate is perpendicular to the silicon steel sheet. Along the length of the mounting plate, the length of the mounting plate is greater than the distance between the outer walls of the mounting frame. Mounting portions are provided at both ends of the mounting plate. The fuel tank includes a side wall and threaded seats that are corresponding to the mounting portions. The silicon steel sheet is perpendicular to the side wall, the mounting plate is parallel to the side wall, the threaded seats are perpendicularly disposed on the side wall, and the threaded seats pass through the mounting portions. The fastening assembly includes a pressure member that is threadedly engaged with the threaded seat to press the mounting plate against the sidewall.

2. The oil tank magnetic shielding structure according to claim 1, characterized by The mounting frame includes two end plates and two side clamps arranged opposite to each other. The side clamps are parallel to the silicon steel sheet. The end plates and the side clamps are alternately connected along the circumference of the shielding group and enclose it to form the mounting frame. The shielding group is connected to the end plates and the side clamps on all four sides respectively.

3. The magnetic shielding structure for the fuel tank as described in claim 2, characterized in that, The number of mounting plates is multiple. Let the direction from one end plate to another end plate be the first direction. Then the multiple mounting plates are arranged in parallel along the first direction.

4. The magnetic shielding structure for the fuel tank as described in claim 3, characterized in that, The mounting part is a through groove with an opening for the threaded seat to pass through. The mounting plate is mounted on the threaded seat through the through groove.

5. The magnetic shielding structure for the fuel tank as described in claim 4, characterized in that, All of the openings are arranged in the same direction along the first direction; Alternatively, some of the openings may be positioned opposite to the remaining openings.

6. The magnetic shielding structure for the fuel tank as described in claim 2, characterized in that, Both the end plate and the side clamping plate have rounded corners at the ends away from the side wall.

7. The magnetic shielding structure for the fuel tank as described in claim 1, characterized in that, The oil tank also includes at least one support block, which is installed on the side wall, and the side of the support block away from the side wall is fitted with the shielding assembly.

8. The magnetic shielding structure for the fuel tank as described in claim 1, characterized in that, The fastening assembly further includes a shielding cap, which includes a connecting piece and a cap body. The connecting piece has a through hole, and the threaded seat passes through the through hole. The pressure member is used to press the connecting piece against the mounting plate, and the cap body covers at least a portion of the pressure member.

9. The magnetic shielding structure for the fuel tank as described in claim 8, characterized in that, The fastening assembly further includes a pressure pad, which is fitted onto the side of the connecting piece away from the sidewall, and the pressure member presses the connecting piece against the mounting plate through the pressure pad.

10. A transformer, characterized in that, Includes the oil tank magnetic shielding structure as described in any one of claims 1 to 9.

Images