Magnetic field shielding structure and transient electromagnetic detection device

Abstract

The invention relates to a magnetic field shielding structure and a transient electromagnetic detection device, and relates to the technical field of transient electromagnetic detection, the magnetic field shielding structure comprises a shielding member, the shielding member comprises a plurality of shielding structures, the plurality of shielding structures are arranged along the circumferential direction of the shielding member, each shielding structure comprises a shielding part and an isolation part, and in two adjacent shielding structures, the isolation part is arranged along the circumferential direction of the shielding member. The shielding part and the isolation part are arranged in a staggered manner, the isolation part is made of an insulating material, the magnetic field intensity radiated by the transmitting coil in non-detection directions such as the upward direction and the lateral direction can be effectively weakened through the arrangement of the shielding part, invalid interference signals can be reduced, and meanwhile, the shielding part and the insulating isolation part are arranged in a staggered manner, so that the shielding effect is improved. Therefore, generation of eddy current in the shielding part can be inhibited, superposition of an additional secondary magnetic field formed by the eddy current and an effective secondary magnetic field signal generated by the underground target body can be avoided, the accuracy of detection data can be greatly improved, and the problem of detection distortion caused by eddy current interference of an existing shielding structure is solved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of transient electromagnetic detection, in particular to a magnetic field shielding structure and a transient electromagnetic detection device. BACKGROUND

[0002] The transient electromagnetic method is an important geophysical detection method, which sends a pulse magnetic field to the underground through a transmitting coil, and uses a receiving coil to observe the secondary decay field induced by the underground medium, so as to analyze and infer the electrical distribution of the underground geological structure and target body. In practical application, especially in urban or industrial areas with complex interference bodies, in order to suppress the magnetic field radiated by the transmitting coil in the non-detection direction (such as upward and lateral), reduce the interference coupling generated by the low-resistance body on the ground and in the air, a magnetic field shielding structure is often introduced into the detection device.

[0003] At present, the existing electromagnetic field shielding method usually uses high-conductivity metal parts (such as metal plates, metal covers, etc.) for shielding, which uses the counter-magnetic field generated by eddy current to attenuate the magnetic field strength in a specific direction, so as to achieve overall shielding of the space magnetic field. However, in the transient pulse magnetic field environment of the transient electromagnetic method, the eddy current itself will generate an additional secondary magnetic field, which will be collected by the receiving coil together with the effective secondary magnetic field signal generated by the underground target body, forming interference that is difficult to separate, seriously confusing the identification of the real underground anomaly signal, and finally leading to distortion of the detection data and decrease of the accuracy of the interpretation result. SUMMARY

[0004] In order to solve the problem that the magnetic field shielding structure of the existing transient electromagnetic device will generate induced eddy current and interfere with the signal while shielding the magnetic field, resulting in distortion of the detection result, the present application provides a magnetic field shielding structure.

[0005] In the first aspect, the magnetic field shielding structure provided by the present application adopts the following technical scheme: A magnetic field shielding structure for a transient electromagnetic detection device, the magnetic field shielding structure comprising a shielding member, the shielding member comprising a plurality of shielding structures, the plurality of shielding structures being arranged along the circumference of the shielding member, each of the shielding structures comprising a shielding part and an isolation part, the shielding part and the isolation part of adjacent two of the shielding structures being arranged in an interlaced manner, and the isolation part being made of an insulating material.

[0006] By adopting the technical scheme, the shielding part is arranged to effectively weaken the magnetic field intensity radiated by the transmitting coil to the upper and side directions and other non-detection directions, reduce the possibility of coupling interference between the magnetic field and the shallow water layer on the ground, metal pipelines, low-altitude cables, metal structures and other low-resistance bodies, help to reduce invalid interference signals, and the shielding part and the insulating isolation part are arranged in an interleaved manner to suppress the generation of eddy current in the shielding part, avoid superposition of the additional secondary magnetic field formed by the eddy current and the effective secondary magnetic field signal generated by the underground target body, ensure that the signal collected by the receiving coil is closer to the real situation underground, and greatly improve the accuracy of the detection data, thereby solving the problem of detection distortion caused by eddy current interference of the existing shielding structure.

[0007] Optionally, the material of the shielding part is permalloy, manganese-zinc ferrite or nickel-iron soft magnetic alloy; and / or, The material of the isolation part is epoxy glass cloth or polytetrafluoroethylene.

[0008] By adopting the technical scheme, the shielding part with high magnetic permeability and low electrical conductivity can improve the shielding ability of the magnetic field in the non-detection direction, effectively block the radiation of useless magnetic field, further reduce the coupling interference with external low-resistance bodies, and on the other hand, the shielding part can generate less eddy current interference while achieving efficient shielding, and can form a synergistic effect with the insulating isolation part to greatly improve the purity of the effective secondary magnetic field signal; at the same time, the isolation part is made of epoxy glass cloth and polytetrafluoroethylene, which can stably block the current, effectively avoid the formation of a continuous conductive loop, significantly improve the eddy current suppression effect and stability, further reduce the probability of generating additional interference magnetic field, and make the shielding part adapt to the environmental requirements of complex detection scenes such as urban or industrial areas, reduce the risk of damage to the isolation part caused by vibration, collision or environmental corrosion, thereby helping to prolong the service life of the shielding structure.

[0009] Optionally, at the periphery of the shielding part, the width of the isolation part is L1, wherein 0.5mm≤L1≤2mm; and / or, At the periphery of the shielding part, the width of the shielding part is L2, wherein 1.5cm≤L2≤2cm.

[0010] By adopting the technical scheme, the width of the isolation part is limited to 0.5-2 mm, which can ensure that the isolation part has sufficient insulation blocking area, effectively blocks the current path to suppress eddy current, avoids excessive space occupation, ensures that the shielding part can be normally arranged to realize efficient magnetic field shielding, and realizes the performance balance of insulation isolation and magnetic field shielding; meanwhile, the width of the shielding part is limited to 1.5-2 cm, which can ensure that the shielding part has sufficient magnetic field shielding area, efficiently guides and blocks the magnetic field in the non-probing direction, and reduces interference coupling; meanwhile, the width range is matched with the peripheral width of the isolation part, which can form uniform shielding and isolation alternating arrangement in the circumferential direction of the shielding piece, avoids the appearance of shielding blind area or isolation invalid area, and guarantees the stability of the overall structure.

[0011] Optionally, the shielding piece includes a shielding body and an isolation body, the shielding body includes a plurality of shielding parts arranged at intervals in the circumferential direction thereof, and the isolation body includes a plurality of isolation parts arranged at intervals in the circumferential direction thereof, and the shielding body and the isolation body are connected in plug-in connection.

[0012] By adopting the technical scheme, the shielding piece is divided into a shielding body and an isolation body, which can process the shielding parts and the isolation parts in batches, and improve the processing precision and efficiency. Meanwhile, the shielding body and the isolation body are connected in plug-in connection, which can ensure that the plurality of shielding parts on the shielding body and the plurality of isolation parts on the isolation body are strictly arranged at intervals in the circumferential direction and staggered after assembly, avoids shielding or isolation invalidity caused by assembly deviation, and is convenient for later maintenance and component replacement.

[0013] Optionally, the shielding part and the isolation part each include a main body segment and a guide segment, the main body segment extends in the horizontal direction, and one end of the guide segment is connected to the main body segment and the other end extends downward.

[0014] By adopting the technical scheme, the shielding structure not only blocks the radiation magnetic field from above, but also effectively guides and blocks the diffusion magnetic field from the side, which can greatly expand the spatial range of shielding, further reduce the probability of coupling interference with the ground and low-resistance bodies in the air, guide more magnetic fields to the underground probing direction, improve the magnetic field strength of the transmitting coil radiated to the underground, help to enhance the induced secondary magnetic field signal of the underground target body, and improve the signal-to-noise ratio of the signal.

[0015] Optionally, the length of the guide segment is L3, and 3 cm≤L2≤7 cm.

[0016] By adopting the above technical solution, the length of the guide section is limited to between 3 cm and 7 cm. This ensures that the guide section has sufficient length to guide and block the lateral diffusion of the magnetic field, enhance the shielding effect, and concentrate the magnetic field in the detection direction. It also helps to reduce the volume of the magnetic field shielding structure, making it convenient to carry and transport.

[0017] Optionally, multiple shielding components are provided, and the multiple shielding components are stacked in the vertical direction.

[0018] By adopting the above technical solution, it is possible to block and weaken the magnetic field in the non-detection direction step by step, thereby improving the overall shielding efficiency. It is also possible to make the energy of the magnetic field gradually decay during the penetration process, thereby reducing the risk of eddy current generation.

[0019] Optionally, the isolation portions of two adjacent shielding members are staggered; and / or, An isolation element is provided between two adjacent shielding elements, and the isolation element is made of an insulating material.

[0020] By adopting the above technical solution, the isolation sections of two adjacent shielding components are staggered. On the one hand, this fills the shielding blind spots between upper and lower layers, enabling the multi-layer shielding structure to form a continuous and complete shielding coverage. On the other hand, it further breaks the continuity of the conductive circuit, further suppressing the generation and conduction of eddy currents and preventing eddy currents from forming superimposed interference in the multi-layer structure. Simultaneously, an isolation component made of insulating material is provided between two adjacent shielding components. This not only forms an insulating barrier between adjacent shielding components, blocking the conductive path between layers and preventing eddy currents from conducting between different shielding components, but also ensures a stable distance between adjacent shielding components, preventing deformation of the shielding structure due to contact compression and ensuring the original layout and stable performance of each shielding component.

[0021] Optionally, the magnetic field shielding structure further includes a protective cover, which is disposed above the shielding component.

[0022] By adopting the above technical solution, physical protection can be provided for the shielding component. This can prevent the shielding and isolation components from being damaged by collisions or from being corroded by the environment, thus avoiding performance degradation. It can also prevent debris falling from above or conductive particles suspended at low altitudes from contacting the shielding component to a certain extent, thus preventing these debris from forming additional conductive loops and affecting the eddy current suppression effect.

[0023] Secondly, the transient electromagnetic detection device provided in this application adopts the following technical solution: A transient electromagnetic detection device includes a magnetic field shielding structure, the magnetic field shielding structure includes a shielding component, the shielding component includes multiple shielding structures, the multiple shielding structures are arranged circumferentially along the shielding component, each shielding structure includes a shielding part and an isolation part, in two adjacent shielding structures the shielding part and the isolation part are staggered, the isolation part is made of an insulating material.

[0024] In summary, this application includes at least one of the following beneficial technical effects: 1. By adopting a structure in which a high-permeability shielding part and an insulating isolation part are arranged alternately along the circumference, the magnetic field radiated by the coil to the non-detection direction is effectively weakened and the external interference coupling is reduced. At the same time, the large-scale induced eddy current generated by the shielding structure itself in the transient magnetic field is fundamentally suppressed, thereby avoiding the additional secondary magnetic field interference introduced by the shielding body and significantly improving the signal-to-noise ratio and detection accuracy of the received signal. 2. By selecting specific high-permeability materials such as permalloy and manganese-zinc ferrite as shielding parts, and specific insulating materials such as epoxy glass cloth and polytetrafluoroethylene as isolation parts, while achieving efficient magnetic field guidance and attenuation, the stable and reliable insulation performance of the isolation parts is ensured, making the eddy current suppression effect more thorough and longer-lasting, and enhancing the structure's adaptability to complex outdoor environments. 3. By employing a method of stacking multiple shielding components in the vertical direction with staggered isolation sections of adjacent shielding components, the leakage magnetic field can be attenuated step by step, significantly improving the overall shielding effectiveness and further blocking the conductive path that may be formed in the vertical direction, thus enhancing the suppression effect on eddy currents and achieving a doubling and optimization of shielding performance. Attached Figure Description

[0025] Figure 1 This is an exploded structural diagram of the transient electromagnetic detection device provided in this application; Figure 2 yes Figure 1 A three-dimensional structural diagram of the transient electromagnetic detection device in the image; Figure 3 yes Figure 1 A three-dimensional structural diagram of the shielding component in the image; Figure 4 yes Figure 1 A three-dimensional structural diagram of the shielding body of the shielding component in the diagram; Figure 5 yes Figure 1 A three-dimensional structural diagram of the shielding component's isolation body. Figure 6 yes Figure 1 A schematic diagram of the coil assembly in the transient electromagnetic transceiver integrated coil structure; Figure 7 yes Figure 1A three-dimensional structural diagram of the support for the transient electromagnetic transceiver coil structure in the image; Figure 8 yes Figure 1 A top view of the support structure of the transient electromagnetic transceiver coil structure.

[0026] Explanation of reference numerals in the attached figures: 1000. Transient electromagnetic detection device; 100. Magnetic field shielding structure; 110. Shielding component; 111. Shielding structure; 1111. Shielding part; 1112. Isolation part; 112. Shielding main body; 1121. Main body section; 1122. Guide section; 113. Isolation main body; 120. Isolation component; 130. Protective cover; 200. Transient electromagnetic transceiver coil structure; 210. Support; 211. Bracket; 2111. First mounting slot; 2112. Second mounting slot; 2113. Third mounting slot; 212. Base; 2121. Receiving slot; 2122. Operating part; 220. Coil assembly; 220a. First power connection part; 220b. Second power connection part; 220c. Third power connection part; 220d. Fourth power connection part; 221. Transmitting coil; 2211. Second transmitting end; 222. Receiving coil; 2221. Second receiving end; 223. Connecting coil; 2231. First connecting end; 2232. Second connecting end. Detailed Implementation

[0027] The following is in conjunction with the appendix Figure 1 -Appendix Figure 8 This application will be described in further detail below.

[0028] In one embodiment of this application, please refer to Figures 1 to 3 A magnetic field shielding structure 100 is used in a transient electromagnetic detection device 1000. The magnetic field shielding structure 100 includes a shielding member 110, which includes a plurality of shielding structures 111. The plurality of shielding structures 111 are arranged circumferentially along the shielding member 110. Each shielding structure 111 includes a shielding part 1111 and an isolation part 1112. In two adjacent shielding structures 111, the shielding part 1111 and the isolation part 1112 are staggered. The isolation part 1112 is made of an insulating material.

[0029] It should be noted that the shielding component 110 can have various shapes, such as circular, square, or polygonal, etc., and the embodiments of this application do not limit this. Further, please refer to... Figures 3 to 5 The staggered arrangement of shielding part 1111 and isolation part 1112 means that shielding part 1111 is located between two adjacent isolation parts 1112, and isolation part 1112 is located between two adjacent shielding parts 1111.

[0030] Understandably, when the coil of the transient electromagnetic detection device 1000 is operating, it radiates a magnetic field in directions other than the detection direction. The shielding part 1111 can block this part of the magnetic field, reducing coupling interference with low-resistivity bodies on the ground and in the air. The insulating material of the isolation part 1112 disrupts the conductive continuity of the shield 110, and the staggered arrangement of adjacent shielding structures 111 can further optimize the connection effect of shielding and isolation, avoiding the formation of a continuous conductive loop. When a changing transient pulse magnetic field acts on the shield 110, the insulating isolation part 1112 will block the current flow path, thereby suppressing the generation of eddy currents and preventing eddy currents from forming additional secondary magnetic fields that interfere with the effective signal.

[0031] In this embodiment, by setting the shielding part 1111, the magnetic field intensity radiated by the transmitting coil 221 in non-detection directions such as upward and side can be effectively weakened, reducing the possibility of coupling interference between the magnetic field and low-resistivity bodies such as shallow water layers, metal pipes, low-altitude cables, and metal structures. This helps to reduce invalid interference signals. At the same time, the shielding part 1111 and the insulating isolation part 1112 are staggered to suppress the generation of eddy currents in the shielding part 110. This avoids the superposition of the additional secondary magnetic field generated by the eddy currents with the effective secondary magnetic field signal generated by the underground target, ensuring that the signal collected by the receiving coil 222 is closer to the actual underground situation. This can significantly improve the accuracy of the detection data, thereby solving the problem of detection distortion caused by eddy current interference in the existing shielding structure 111.

[0032] In one embodiment of this application, the shielding part 1111 is made of permalloy, manganese-zinc ferrite, or nickel-iron soft magnetic alloy. Since the magnetic field shielding requirements for transient electromagnetic detection not only require blocking the magnetic field but also minimizing its own interference with the detection signal, permalloy, manganese-zinc ferrite, and nickel-iron soft magnetic alloy all possess the characteristics of high permeability and low conductivity. On the one hand, they can provide a low magnetic reluctance path for the magnetic field, efficiently guiding the magnetic field in the non-detection direction through the shielding part 1111, thereby enhancing the shielding effect. On the other hand, they have low eddy current losses, and compared to ordinary metal materials, they are less likely to generate strong eddy currents in changing transient magnetic fields, further assisting in suppressing interference. Thus, by employing a shielding part 1111 with high magnetic permeability and low electrical conductivity, on the one hand, the shielding capability against magnetic fields in non-detection directions can be improved, effectively blocking the radiation of useless magnetic fields and further reducing coupling interference with external low-resistivity bodies. On the other hand, while achieving efficient shielding, the shielding part 1111 can reduce the eddy current interference it generates to a lower level, and can form a synergistic effect with the insulating isolation part 1112, greatly improving the purity of the effective secondary magnetic field signal.

[0033] In one embodiment of this application, the isolation part 1112 is made of epoxy glass cloth or polytetrafluoroethylene (PTFE). Since the shielding component 110 needs to withstand the magnetic field and certain environmental stresses for a long time when the transient electromagnetic detection device 1000 is working, both epoxy glass cloth and PTFE have excellent insulation properties, effectively blocking current paths and significantly suppressing the generation of eddy currents. At the same time, these two materials also have good mechanical strength and environmental resistance, maintaining structural stability in complex detection environments and preventing isolation failure due to material damage. Therefore, the use of epoxy glass cloth and PTFE in the isolation part 1112 not only enables the isolation part 1112 to stably block current and effectively avoid the formation of continuous conductive loops, significantly improving the effect and stability of eddy current suppression and further reducing the probability of generating additional interfering magnetic fields, but also allows the shielding component 110 to adapt to the environmental requirements of complex detection scenarios such as urban or industrial areas, reducing the risk of damage to the isolation part 1112 due to vibration, collision, or environmental corrosion, thereby helping to extend the service life of the shielding structure 111.

[0034] It is understood that the two related technical features mentioned above, namely, "the material of the shielding part 1111 is permalloy, manganese zinc ferrite or nickel iron soft magnetic alloy" and "the material of the isolation part 1112 is epoxy glass cloth or polytetrafluoroethylene", can be selected or provided simultaneously. The embodiments of this application do not limit this.

[0035] In one embodiment of this application, please refer to Figure 5 At the periphery of the shielding component 110, the width of the isolation portion 1112 is L1, where 0.5mm ≤ L1 ≤ 2mm. Since the width of the isolation portion 1112 directly affects the insulation blocking effect and the structural compactness of the shielding component 110, if the width of the isolation portion 1112 is too small, the insulation blocking area will be insufficient, potentially failing to completely cut off the conductive circuit and causing eddy current suppression failure; if the width of the isolation portion 1112 is too large, it will occupy too much space, compressing the layout space of the shielding portion 1111 and reducing shielding efficiency. Therefore, the width of the isolation portion 1112 is limited to between 0.5 mm and 2 mm. This ensures that the isolation portion 1112 has sufficient insulation blocking area to effectively block the current path and suppress eddy currents, while avoiding excessive space occupation, ensuring that the shielding portion 1111 can be properly laid out to achieve efficient magnetic field shielding, thereby achieving a performance balance between insulation isolation and magnetic field shielding. Furthermore, the isolation portion 1112 can be of uniform width or gradually increasing in width outwards; the embodiments of this application do not limit this.

[0036] In one embodiment of this application, please refer to Figure 4At the periphery of the shielding component 110, the width of the shielding portion 1111 is L2, where 1.5cm ≤ L2 ≤ 2cm. Since the width of the shielding portion 1111 directly determines its ability to block magnetic fields, a larger width results in better magnetic field guidance and blocking. However, an excessively wide shielding portion 1111 would lead to an excessively large overall volume of the shielding component 110 and may increase the risk of eddy current generation. Therefore, limiting the width of the shielding portion 1111 to between 1.5cm and 2cm ensures that the shielding portion 1111 has sufficient magnetic field shielding area, effectively guiding and blocking magnetic fields in directions other than the detection direction, and reducing interference coupling. Simultaneously, this width range is compatible with the periphery width of the isolation portion 1112, enabling a uniform alternating layout of shielding and isolation around the shielding component 110, avoiding shielding blind spots or isolation failure areas, and ensuring the stability of the overall structure. Furthermore, from the center of the shield 110 toward its periphery, the width of the shielding portion 1111 gradually increases, so that each shielding portion 1111 converges at the center of the shield 110.

[0037] It is understood that the two related technical features mentioned above, "0.5mm≤L1≤2mm" and "1.5cm≤L2≤2cm", can be set either one or both, and the embodiments of this application do not limit this.

[0038] In one embodiment of this application, please refer to Figure 4 and Figure 5 The shielding component 110 includes a shielding body 112 and an isolation body 113. The shielding body 112 includes a plurality of shielding parts 1111 spaced apart circumferentially thereon, and the isolation body 113 includes a plurality of isolation parts 1112 spaced apart circumferentially thereon. The shielding body 112 and the isolation body 113 are connected by a plug-in joint. Thus, by dividing the shielding component 110 into two parts, the shielding body 112 and the isolation body 113, the shielding parts 1111 and the isolation parts 1112 can be processed in batches, improving processing accuracy and efficiency. At the same time, the plug-in connection between the shielding body 112 and the isolation body 113 ensures that the plurality of shielding parts 1111 on the shielding body 112 and the plurality of isolation parts 1112 on the isolation body 113 strictly adhere to the requirements of circumferential spacing and adjacent staggering after assembly, avoiding shielding or isolation failure due to assembly deviations, and facilitating later maintenance and component replacement.

[0039] In one embodiment of this application, please refer to Figure 4 and Figure 5Both the shielding section 1111 and the isolation section 1112 include a main body section 1121 and a guide section 1122. The main body section 1121 extends horizontally, and one end of the guide section 1122 is connected to the main body section 1121, while the other end extends downward. The horizontal extension of the main body section 1121 forms a horizontal shielding barrier above the transmitting coil 221, directly blocking the upward-radiated magnetic field. The downward extension of the guide section 1122 guides some of the magnetic field that diffuses to the side, making the magnetic field more inclined to converge towards the underground detection direction, while further preventing the coupling of the side magnetic field with the external low-resistivity body. Thus, by setting the downward-extending guide section 1122, the shielding structure 111 can not only block the radiated magnetic field above, but also effectively guide and block the diffused magnetic field on the side. This can greatly expand the shielding space range, further reduce the probability of coupling interference with low-resistivity bodies on the ground and in the air, and guide the magnetic field, causing more magnetic fields to converge in the direction of underground detection. This is beneficial to increasing the magnetic field strength radiated by the transmitting coil 221 to the underground, which helps to enhance the induced secondary magnetic field signal of the underground target and improve the signal-to-noise ratio.

[0040] In one embodiment of this application, the length of the guide segment 1122 is L3, where 3cm ≤ L2 ≤ 7cm. Since the length of the guide segment 1122 directly affects the range and effect of magnetic field guidance, an excessively long length, while expanding the range of magnetic field guidance and shielding, increases the volume of the transient electromagnetic detection device 1000, making it inconvenient to move; an excessively short length fails to fully utilize the guiding function, limiting the shielding range. Therefore, limiting the length of the guide segment 1122 to between 3cm and 7cm ensures that the guide segment 1122 has sufficient length to guide and block laterally diffused magnetic fields, enhancing the shielding effect and converging the magnetic field in the detection direction, while also helping to reduce the volume of the magnetic field shielding structure 100, facilitating carrying and transportation.

[0041] In one embodiment of this application, please refer to Figure 1 Multiple shielding elements 110 are provided and stacked vertically. In this way, by stacking multiple shielding elements 110, a multi-layer shielding barrier is formed, which can not only block and weaken the magnetic field in the non-detection direction step by step, improving the overall shielding efficiency, but also make the energy of the magnetic field gradually attenuate during the penetration process, thereby reducing the risk of eddy current generation.

[0042] Furthermore, when multiple shielding components 110 are stacked, if the isolation portion 1112 is aligned vertically, a magnetic field penetration channel may be formed in the area corresponding to the isolation portion 1112, i.e., a shielding blind zone. Therefore, in this embodiment, the isolation portions 1112 of two adjacent shielding components 110 are staggered. On the one hand, this can fill the shielding blind zone between the upper and lower layers, so that the multi-layer shielding structure 111 forms a continuous and complete shielding coverage. On the other hand, it can further break the continuity of the conductive circuit. Even if a shielding component 110 has a weak current path due to local structural problems, the isolation portion 1112 of the lower shielding component 110 can block it, further suppressing the generation and conduction of eddy currents and avoiding the superposition of eddy currents in the multi-layer structure.

[0043] Please continue reading. Figure 1 When multiple shielding components 110 are stacked, conductive paths may form between adjacent shielding components 110 due to contact, causing eddy currents to conduct and diffuse between layers, exacerbating interference. Therefore, in this embodiment, an isolation component 120 is provided between two adjacent shielding components 110. The isolation component 120 is made of insulating material, which can form an insulating barrier between adjacent shielding components 110, blocking the conductive paths between layers and preventing eddy currents from conducting between different shielding components 110. It can also ensure a stable spacing between adjacent shielding components 110, preventing deformation of the shielding structure 111 due to contact compression, and ensuring the original layout and stable performance of each shielding component 110.

[0044] During actual detection, the shielding component 110 may be affected by external physical impacts, dust, moisture, and other environmental factors. Therefore, in one embodiment of this application, please refer to... Figure 1 The magnetic field shielding structure 100 also includes a protective cover 130, which is located above the shielding component 110. Thus, by providing the protective cover 130, physical protection is provided for the shielding component 110. This prevents the shielding part 1111 and the isolation part 1112 from being damaged by impact or experiencing performance degradation due to environmental corrosion. It also prevents falling debris or low-altitude suspended conductive particles from contacting the shielding component 110, thus avoiding the formation of additional conductive loops that could affect the eddy current suppression effect.

[0045] To achieve the above objectives, this application also provides a transient electromagnetic detection device 1000, which includes a magnetic field shielding structure 100. It is understood that the specific structure of the magnetic field shielding structure 100 is the same as described in the above embodiments. Since this transient electromagnetic detection device 1000 adopts all the technical solutions of all the above embodiments, it possesses at least all the beneficial effects brought about by the technical solutions of the above embodiments, which will not be elaborated upon here.

[0046] In one embodiment of this application, please refer to Figure 6 andFigure 7 The transient electromagnetic detection device 1000 also includes a transient electromagnetic transceiver integrated coil structure 200. The transient electromagnetic transceiver integrated coil structure 200 includes a support 210, a coil assembly 220, and a switching assembly. The coil assembly 220 is disposed on the support 210 and includes a transmitting coil 221, a receiving coil 222, and a connecting coil 223. The transmitting coil 221 is used to transmit a magnetic field, and the receiving coil 222 is disposed inside the transmitting coil 221 to receive a magnetic field. The connecting coil 223 can be connected to either the transmitting coil 221 or the receiving coil 222. The switching assembly is disposed between the transmitting coil 221, the receiving coil 222, and the connecting coil 223 so that the connecting coil 223 can switch between the transmitting coil 221 and the receiving coil 222. When transmitting a magnetic field, the connecting coil 223 is connected to the receiving coil 222 to transmit a ring magnetic field. When receiving a magnetic field, the connecting coil 223 is connected in series with the receiving coil 222 to increase the equivalent area.

[0047] It should be noted that the support 210 can have various shapes, such as circular, square, or polygonal, and the embodiments of this application do not limit this. In addition, the support 210 is provided with an operating part 2122 to facilitate the user to pick up or move the detection device. Furthermore, two operating parts 2122 are provided, and the two operating parts 2122 are arranged at intervals along the circumference of the support.

[0048] It should also be noted that during the magnetic field transmission phase, the switching assembly controls the connection between the connecting coil 223 and the receiving coil 222. At this time, the receiving coil 222 and the connecting coil 223 work together to transmit a ring-shaped magnetic field, eliminating the primary field inside the receiving coil and helping to eliminate primary field interference. During the magnetic field reception phase, the switching assembly switches the connection state, connecting the connecting coil 223 and the receiving coil 222 in series. The increased equivalent area of ​​the series-connected coil enhances the ability to capture the secondary magnetic field signal induced by underground targets, thereby increasing the strength and signal-to-noise ratio of the received signal.

[0049] In this embodiment, by setting up the connecting coil 223, it can cooperate with the transmitting coil 221 to form a ring magnetic field, so that there is no primary field inside the receiving coil, which helps to eliminate primary field interference; it can also be connected in series with the receiving coil 222 to increase the equivalent receiving area, improve the signal acquisition capability, make the received effective signal clearer, and help reduce the difficulty of signal analysis. Furthermore, through the switching function of the switching component, the time-division efficient operation of transmitting and receiving can be achieved, which can avoid mutual interference between the transmitting and receiving coils, thereby helping to further improve the accuracy of the detection data.

[0050] In one embodiment of this application, please refer to Figure 6The switching assembly includes a first switch element (not shown) and a second switch element (not shown). The first and second switch elements are respectively connected to the two ends of the connecting coil 223, so that the connecting coil 223 can be connected to the transmitting coil 221 or the receiving coil 222 respectively. The fact that switch elements are respectively provided at both ends of the connecting coil 223 enables synchronous switching of the connection state from both ends of the circuit, avoiding switching failure due to the malfunction of a single switch element and improving the reliability of circuit switching. During the transmission phase, the first and second switching devices operate synchronously, effectively connecting both ends of the connecting coil 223 to the receiving coil 222. This results in the magnetic field of the connecting coil 223 being opposite to that of the receiving coil 222, forming a circular magnetic field. This eliminates the primary field inside the receiving coil 222, reducing its impact on the detection results. During the reception phase, the two switching devices switch again, connecting both ends of the connecting coil 223 in series with the receiving coil 222 to form a complete circuit. This effectively increases the effective area of ​​the receiving antenna. According to the law of electromagnetic induction, this allows for the induction of a larger amplitude secondary magnetic field voltage signal. Thus, by setting the first and second switching devices, the connecting coil 223 can be connected to either the transmitting coil 221 or the receiving coil 222. This allows the coil assembly 220 to reduce the influence of the primary field during transmission and increase the equivalent area during reception without increasing the overall size, thereby capturing weak secondary magnetic field signals and improving the deep detection capability and signal resolution of the detection device. Of course, in other embodiments, the number of switching devices can be three or four, etc., and the embodiments of this application are not limited to this. Furthermore, there are various types of first and second switching devices, such as single-pole single-throw switches or single-pole double-throw switches, etc. The embodiments of this application do not limit this.

[0051] In one embodiment of this application, please refer to [the relevant documentation]. Figure 6 The electromagnetic detection component has a first power-on part 220a, a second power-on part 220b, a third power-on part 220c, and a fourth power-on part 220d that can be connected to an external circuit. The transmitting coil 221 has a first transmitting end and a second transmitting end 2211. The receiving coil 222 has a first receiving end and a second receiving end 2221. The connecting coil 223 has a first connecting end 2231 and a second connecting end 2232. The first transmitting end is connected to the first power-on part 220a, and the first receiving end is connected to the second connecting end 2221. The first switching element has a first wiring terminal and a first switching end. The first wiring terminal is connected to the first connecting end 2231, and the first switching end can be connected to the second receiving end 2221 or the fourth power-on part 220d respectively. The second switching element has a second wiring terminal and a second switching end. The wiring terminal is connected to the second connecting end 2232, and the second switching end can be connected to the second transmitting end 2211 or the third power-on part 220c respectively.

[0052] It should be noted that the first contact part 220a and the second contact part 220b are both connected to the positive terminal of the external power supply, and the third contact part 220c and the fourth contact part 220d are both connected to the negative terminal of the external power supply. Furthermore, both the first and second switching components are single-pole double-throw switches to reduce the number of switching components and save costs. In addition, there are various winding methods for the transmitting coil 221, the receiving coil 222, and the connecting coil 223. They can all be wound clockwise, all counterclockwise, or a portion can be wound clockwise and another portion counterclockwise, etc. The embodiments of this application do not limit this. However, the winding method of the coils is related to the wiring method and can be adjusted according to actual needs. For example, the transmitting coil 221, the receiving coil 222, and the connecting coil 223 are all wound clockwise to reduce wiring difficulty and facilitate wiring.

[0053] It should also be noted that during the transmission phase, the first switching terminal of the first switch is connected to the fourth power-on part 220d, and the second switching terminal of the second switch is connected to the second transmitting end 2211, so that the tail end of the transmitting coil 221 is connected to the tail end of the connecting coil 223, so that the magnetic field direction of the transmitting coil 221 is opposite to the magnetic field direction of the receiving coil 222, forming a ring-shaped transmitting magnetic field. At this time, the receiving coil 222 is in an open state to avoid affecting the transmitting magnetic field of the coil assembly 220. During the receiving phase, the first switching terminal of the first switch is connected to the second receiving end 2221, and the second switching terminal of the second switch is connected to the third power-on part 220c, so that the tail end of the receiving coil 222 is connected to the head end of the transmitting coil 221, forming a series receiving circuit of the connecting coil 223 and the receiving coil 222. At this time, the transmitting coil 221 is in an open state to avoid affecting the receiving magnetic field of the coil assembly 220.

[0054] In this embodiment, by providing a first power-connecting part 220a, a second power-connecting part 220b, a third power-connecting part 220c, and a fourth power-connecting part 220d, a clear external interface is provided for the coil assembly 220, facilitating connection with external circuits. At the same time, by switching the first and second switching elements, the transmission and reception are electrically isolated, so that the current loop during transmission is completely separated from the high-sensitivity signal loop during reception, thereby helping to avoid crosstalk between the transmitting and receiving circuits.

[0055] In one embodiment of this application, please refer to Figure 7 and Figure 8The support 210 is provided with a first mounting groove 2111 and a second mounting groove 2112 located inside the first mounting groove 2111. The transmitting coil 221 is mounted in the first mounting groove 2111, and the receiving coil 222 is mounted in the second mounting groove 2112. In this way, by setting the first mounting groove 2111 and the second mounting groove 2112, it is possible to avoid the coil from shifting due to vibration or movement during the detection process, ensuring that the magnetic field emitted by the transmitting coil 221 can be accurately radiated into the ground, and the receiving coil 222 can accurately capture the secondary magnetic field signal. It also provides a certain degree of protection for the coil, reducing the damage to the coil caused by external collisions. At the same time, the second mounting groove 2112 is located inside the first mounting groove 2111 to form an inner and outer nested layout, so that the transmitting coil 221 and the receiving coil 222 are concentrically arranged, which helps to improve the uniformity of the transmitted magnetic field and the symmetry of the received signal.

[0056] Furthermore, the connecting coil 223 is mounted in the second mounting slot 2112. This arrangement ensures that the connecting coil 223 and the receiving coil 222 are of equal diameter, eliminating the primary field within the receiving coil 222 and aligning the magnetic field-free region with the region of the receiving coil 222, thereby reducing the influence of the primary field during transmission. Of course, in other embodiments, the connecting coil 223 may also be spaced apart within the receiving coil 222, allowing the diameter of the connecting coil 223 to be smaller than the diameter of the receiving coil 222; this embodiment does not limit this.

[0057] In one embodiment of this application, the ratio of the number of turns of the transmitting coil 221 to the number of turns of the receiving coil 222 is inversely proportional to the ratio of the diameter of the transmitting coil 221 to the diameter of the receiving coil 222, so that the magnetic flux of the transmitting coil 221 can be equal to the magnetic flux of the connecting coil 223, thereby enabling the coil assembly 220 to emit a ring magnetic field.

[0058] In one embodiment of this application, the distance between the first mounting groove 2111 and the second mounting groove 2112 is H, where 5cm ≤ H ≤ 15cm. If the distance between the transmitting coil 221 and the receiving coil 222 is too close, the annular transmitting magnetic field will be too small, resulting in a too short detection distance. Conversely, if the distance between the transmitting coil 221 and the receiving coil 222 is too far, the receiving coil 222 will be too small, affecting the coil's signal acquisition capability. Therefore, limiting the distance between the transmitting coil 221 and the receiving coil 222 to between 5cm and 15cm ensures both the detection distance of the detection device and the signal acquisition capability of the receiving coil 222, thereby enabling the coil assembly 220 to achieve a balance between detection distance and signal acquisition. In one embodiment of this application, multiple second mounting slots 2112 are provided, and the multiple mounting slots are arranged sequentially and at intervals from the periphery of the support 210 toward its center. Thus, by providing multiple second mounting slots 2112, the installation positions of the receiving coil 222 and the connecting coil 223 are selectable, allowing adjustment of the number and position of the coils installed according to different detection depths and accuracy requirements. For example, when detecting shallower strata, the second mounting slot 2112 near the outer edge can be used to install the coil; when detecting deeper strata, the second mounting slot 2112 near the center can be used.

[0059] In one embodiment of this application, the support 210 includes a base 212 and a bracket 211 detachably mounted on the base 212. The base 212 has a receiving groove 2121, and the bracket 211 is disposed within the receiving groove 2121. The coil assembly 220 is disposed on the bracket 211. Thus, by disassembling the support 210 into the base 212 and the bracket 211, it can be disassembled during transportation, reducing the overall volume and lowering transportation difficulty and cost. Furthermore, the bracket 211, as the direct load-bearing component of the coil assembly 220, has a detachable design that facilitates the installation, debugging, and maintenance of the coil assembly 220. When the coil assembly 220 malfunctions, the bracket 211 can be removed from the base 212 for individual repair without moving the entire base 212, improving maintenance efficiency. Simultaneously, the receiving groove 2121 prevents the coil assembly 220 from being damaged by impact or experiencing performance degradation due to environmental corrosion.

[0060] In one embodiment of this application, please refer to Figure 8 The support 210 is provided with a third mounting slot 2113, which is located between the first mounting slot 2111 and the second mounting slot 2112, for mounting the switch assembly. Thus, the precise positioning of the third mounting slot 2113 ensures the stability of the switch assembly's installation position, preventing loosening of the wiring or switch failure due to vibration. Simultaneously, mounting the switch assembly between the first and second mounting slots 2112 minimizes the distance between the switch assembly and each coil, reducing wiring length, lowering signal transmission loss and line interference, and improving circuit stability.

[0061] The embodiments described in this specific implementation are preferred embodiments of this application and are not intended to limit the scope of protection of this application. Identical components are represented by the same reference numerals. Therefore, all equivalent changes made to the structure, shape, and principle of this application should be covered within the scope of protection of this application.

Claims

1. A magnetic field shielding structure for a transient electromagnetic detection device, characterized in that, The magnetic field shielding structure includes a shielding component (110), which includes multiple shielding structures (111). The multiple shielding structures (111) are arranged circumferentially along the shielding component (110). Each shielding structure (111) includes a shielding part (1111) and an isolation part (1112). In two adjacent shielding structures (111), the shielding part (1111) and the isolation part (1112) are staggered. The isolation part (1112) is made of an insulating material.

2. The magnetic field shielding structure according to claim 1, characterized in that, The shielding part (1111) is made of permalloy, manganese-zinc ferrite, or nickel-iron soft magnetic alloy; and / or, The isolation part (1112) is made of epoxy glass cloth or polytetrafluoroethylene.

3. The magnetic field shielding structure according to claim 1, characterized in that, At the periphery of the shielding member (110), the width of the isolation portion (1112) is L1, wherein 0.5mm ≤ L1 ≤ 2mm; and / or, At the periphery of the shielding member (110), the width of the shielding part (1111) is L2, wherein 1.5cm≤L2≤2cm.

4. The magnetic field shielding structure according to claim 1, characterized in that, The shielding component (110) includes a shielding body (112) and an isolation body (113). The shielding body (112) includes a plurality of shielding parts (1111) spaced apart along its circumference. The isolation body (113) includes a plurality of the isolation parts (1112) spaced apart along its circumference. The shielding body (112) and the isolation body (113) are plugged into each other.

5. The magnetic field shielding structure according to claim 1, characterized in that, Both the shielding part (1111) and the isolation part (1112) include a main body section (1121) and a guide section (1122). The main body section (1121) extends horizontally, and one end of the guide section (1122) is connected to the main body section (1121), while the other end extends downward.

6. The magnetic field shielding structure according to claim 5, characterized in that, The length of the guide segment (1122) is L3, where 3cm≤L2≤7cm.

7. The magnetic field shielding structure according to claim 1, characterized in that, Multiple shielding elements (110) are provided, and the multiple shielding elements (110) are stacked in the vertical direction.

8. The magnetic field shielding structure according to claim 7, characterized in that, The isolation portions (1112) of two adjacent shielding members (110) are staggered; and / or, An isolation member (120) is provided between two adjacent shielding members (110), and the isolation member (120) is made of insulating material.

9. The magnetic field shielding structure according to claim 1, characterized in that, The magnetic field shielding structure also includes a protective cover (130), which is located above the shielding component (110).

10. A transient electromagnetic detection device, characterized in that, Includes the magnetic field shielding structure according to any one of claims 1 to 9.

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