A remanence detection chamber

Abstract

The present application relates to the technical field of material residual magnetism detection, and discloses a residual magnetism detection room. The residual magnetism detection room comprises a support main body, a passive shielding layer, at least two pairs of magnetic shielding doors, a demagnetization system and a residual magnetism testing system. The passive shielding layer is arranged on the support main body, comprises a magnetic conducting layer and encloses a detection space. The at least two pairs of magnetic shielding doors are arranged oppositely. The demagnetization system comprises a demagnetization coil wound on the magnetic conducting layer and a single multi-channel synchronous power modulation system, and is used for synchronously reducing the magnetism of the magnetic conducting layer. The residual magnetism testing system is arranged in the detection space. The present application increases the testing capacity through the room body structure, ensures the low magnetic environment in the detection space through the passive shielding and the demagnetization system, improves the accuracy of the residual magnetism testing, integrates the magnetic shielding, demagnetization and residual magnetism testing functions, and sets the at least two pairs of magnetic shielding doors oppositely, so that the detection object can be conveniently put in and taken out, the testing process is optimized, and the convenience and efficiency of the residual magnetism testing are improved.

Description

Technical Field

[0001] This invention relates to the field of residual magnetism detection technology, and in particular to a residual magnetism detection chamber. Background Technology

[0002] In the field of low-magnetic buildings, such as geomagnetic stations, demagnetization stations, chip manufacturing plants, and precision laboratories, strict requirements must be placed on the residual magnetic level of building materials during the early construction and formal operation processes to avoid magnetic pollution during construction and operation, which could affect the stability of the experimental low-magnetic environment.

[0003] However, existing residual magnetism testing equipment, such as conventional barrel-type shielded equipment, has limited testing capabilities, capacity, and efficiency, which are far from meeting the needs for rapid, large-scale residual magnetism testing of building materials and other materials. Summary of the Invention

[0004] The technical problem solved by this invention is to provide a residual magnetism detection chamber to address the issues of small testing capacity and low testing efficiency of existing residual magnetism testing equipment, which cannot meet the needs of large-scale material residual magnetism testing.

[0005] In a first aspect, the present invention provides a residual magnetism detection room, comprising: The main support structure is located on the ground. A passive shielding layer is disposed on the supporting body. The passive shielding layer includes at least one magnetic conductive layer and the passive shielding layer encloses the space to be tested. At least two pairs of magnetic shielding doors are rotatably connected to the supporting body and are arranged opposite to each other on the supporting body; A demagnetizing system, comprising a demagnetizing coil and a single-unit multi-channel synchronous power modulation system, wherein the demagnetizing coil is wound on the magnetic conductive layer, and the single-unit multi-channel synchronous power modulation system is electrically connected to the demagnetizing coil for synchronously reducing the magnetism of the magnetic conductive layer; A residual magnetism testing system is installed within the space to be tested and is used to detect the residual magnetism of the object to be tested within the space.

[0006] Beneficial Effects: By constructing a room-like magnetic shielding structure, a sufficiently large testing space is created, capable of accommodating large-sized objects or conducting large-volume material testing. This solves the problems of small testing capacity and low efficiency of existing barrel-type shielding equipment, meeting the needs for rapid, large-volume residual magnetism testing. Furthermore, by setting up a passive shielding layer, a stable low-magnetic background environment is provided for residual magnetism testing. Simultaneously, by setting up a demagnetization system and using a single-unit multi-channel synchronous power modulation system to synchronously drive the demagnetizing coil, the magnetization state of the magnetic materials is made consistent, thus preventing the residual magnetism testing room itself from becoming a source of magnetic pollution and ensuring a low-magnetic environment within the testing space, thereby improving the accuracy of residual magnetism testing. By integrating magnetic shielding, demagnetization, and residual magnetism testing functions into one unit, and setting up at least two pairs of opposing magnetic shielding doors, the entry and exit of objects under test are facilitated, the testing process is optimized, and the overall convenience and efficiency of residual magnetism testing are improved.

[0007] In some alternative embodiments, a groove is formed by recessing inward along the ground surface, and a plurality of insulating pads are arranged at intervals in the groove. The support body and / or the passive shielding layer at least partially extend into the groove and are disposed on the insulating pads. The groove is filled with a lightweight material, which is filled at least between two adjacent insulating pads; The space to be tested is equipped with a floor, which is located at the bottom of the residual magnetism detection room, and the floor and the ground are on the same plane.

[0008] In some alternative embodiments, a sealing assembly is also included, disposed on the magnetic shielding door; the sealing assembly includes a drive element, a baffle, a slide rail, a slider, and an eccentric wheel; the slide rail is mounted on the magnetic shielding door, the slider is slidably connected to the slide rail, the baffle is mounted on the slider and fixedly connected to the eccentric wheel, and the end of the eccentric wheel away from the baffle is drively connected to the output shaft of the drive element; the baffle extends at least partially into the groove.

[0009] In some optional embodiments, the magnetic shielding door includes a first door body and a second door body, both of which include a plurality of plates, which are stacked in a stepped manner. Each of the plates of the first door body is provided with a sealing element, which seals the gap between the first door body and the second door body when the magnetic shielding door is in the closed state.

[0010] In some optional embodiments, both the passive shielding layer and the magnetic shielding door are provided with a plurality of through holes, which are spaced apart along the outer periphery of the passive shielding layer and along the outer periphery of the magnetic shielding door, and the demagnetizing coil is inserted into the through holes.

[0011] In some alternative embodiments, the diameter of the through hole is less than or equal to 25 mm; The shortest distance H1 from the through hole to the edge of the passive shielding layer satisfies 80mm≤H1≤100mm; The distance H2 between two adjacent through holes on the passive shielding layer satisfies 500mm≤H2≤600mm; The distance H3 between two adjacent through holes on the magnetic shielding door satisfies 150mm≤H3≤200mm.

[0012] In some optional embodiments, the passive shielding layer includes a first magnetic layer, a second magnetic layer, and a third magnetic layer, which are arranged in sequence at intervals. The first magnetic layer is located on the side of the passive shielding layer away from the space to be tested, the third magnetic layer is located on the side of the passive shielding layer closer to the space to be tested, and the second magnetic layer is located between the first magnetic layer and the third magnetic layer.

[0013] In some alternative embodiments, each of the magnetically conductive layers is formed of at least one of non-oriented silicon steel, oriented silicon steel, permalloy, and amorphous nanocrystals.

[0014] In some alternative embodiments, the magnetic conductive layer comprises a plurality of single plates, which are stacked and staggered.

[0015] In some optional embodiments, the length of the internal space of the residual magnetism detection room is L1, which satisfies 3m≤L1≤5m, the width is W1, which satisfies 3m≤W1≤5m, and the height is H4, which satisfies 3m≤H4≤5m. The length of the outer envelope space of the residual magnetism detection room is L2, which satisfies 4m≤L2≤6m; the width is W2, which satisfies 4m≤W2≤6m; and the height is H5, which satisfies 4m≤H5≤6m. Attached Figure Description

[0016] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0017] Figure 1 This is a schematic diagram of the structure of a residual magnetism detection room according to an embodiment of the present invention; Figure 2 This is another structural schematic diagram of a residual magnetism detection room according to an embodiment of the present invention; Figure 3 This is another structural schematic diagram of a residual magnetism detection room according to an embodiment of the present invention; Figure 4 This is another structural schematic diagram of a residual magnetism detection room according to an embodiment of the present invention; Figure 5 This is another structural schematic diagram of a residual magnetism detection room according to an embodiment of the present invention; Figure 6 for Figure 5 A magnified view of part A in the image; Figure 7 This is another structural schematic diagram of a residual magnetism detection room according to an embodiment of the present invention; Figure 8 This is another structural schematic diagram of a residual magnetism detection room according to an embodiment of the present invention; Figure 9 for Figure 8 A magnified view of part B in the image; Figure 10 This is a schematic diagram of the passive shielding layer in a residual magnetism detection room according to an embodiment of the present invention; Figure 11 This is a schematic diagram of the structure of a magnetic shielding door in a residual magnetism detection room according to an embodiment of the present invention.

[0018] Figure label: 10. Support body; 20. Ground; 21. Groove; 100. Passive shielding layer; 110. First magnetic conductive layer; 120. Second magnetic conductive layer; 130. Third magnetic conductive layer; 140. Through hole; 200. Magnetic shielding door; 210. First door body; 211. Plate body; 212. Sealing element; 220. Second door body; 230. Hinge; 241. Drive element; 242. Baffle; 243. Slide rail; 244. Slider; 245. Eccentric wheel; 300. Residual magnetism testing system; 400. Insulating pad; 500. Lightweight material; 600. First wall panel; 700. Second wall panel; 800. Object to be tested. Detailed Implementation

[0019] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0020] In the description of this invention, it should be understood that the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, unless otherwise stated, "a plurality of" means two or more. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0021] The following is combined with Figures 1 to 11 The following describes embodiments of the present invention.

[0022] According to embodiments of the present invention, such as Figures 1 to 5 As shown, a residual magnetism detection chamber is provided, comprising: a supporting body 10 located on the ground 20; a passive shielding layer 100 disposed on the supporting body 10, the passive shielding layer 100 including at least one magnetic conductive layer, the passive shielding layer 100 enclosing a space to be tested; at least two pairs of magnetic shielding doors 200, all rotatably connected to the supporting body 10 and disposed opposite to each other on the supporting body 10; a demagnetizing system, the demagnetizing system including a demagnetizing coil and a single multi-channel synchronous power modulation system, the demagnetizing coil being wound on the magnetic conductive layer, the single multi-channel synchronous power modulation system being electrically connected to the demagnetizing coil for synchronously reducing the magnetism of the magnetic conductive layer; and a residual magnetism testing system 300 disposed within the space to be tested for detecting the residual magnetism of an object 800 within the space to be tested.

[0023] In this embodiment, the residual magnetism detection room includes a support body 10 located on the ground 20. The support body 10 can be formed by several aluminum alloy rods to provide basic mechanical support and positioning for the entire structure. Several passive shielding layers 100 are provided on the support body 10, and the several passive shielding layers 100 enclose a detection space for residual magnetism measurement, i.e., the residual magnetism detection room. Each passive shielding layer 100 is formed by at least one magnetically conductive layer; the magnetically conductive layer shields the magnetic shunt of the DC or extremely low frequency magnetic field, causing the magnetism to attenuate step by step, so as to achieve full coverage of the static magnetic field and the low frequency magnetic field, thereby achieving a better magnetic shielding effect.

[0024] To facilitate the entry and exit of the object 800 to be tested, at least two pairs of magnetic shielding doors 200 are provided in the residual magnetism detection chamber. Each pair of magnetic shielding doors 200 is rotatably connected to the support body 10 via hinges 230 or similar structures, and is arranged opposite to each other on the support body 10 to form a passage through the residual magnetism detection chamber. When the residual magnetism of an object needs to be tested, only one magnetic shielding door 200 on one side of the residual magnetism detection chamber can be opened, and then closed during testing. After the residual magnetism detection is completed, the object to be tested can be transported out through that magnetic shielding door 200. Alternatively, after testing, the other magnetic shielding door 200 on the other side of the residual magnetism detection chamber can be opened, allowing the object to be tested to be transported out from the other side. This enables a streamlined testing process where the object 800 can enter from one end of the residual magnetism detection chamber and exit from the other, significantly improving batch testing efficiency.

[0025] When the magnetic shielding door 200 is closed, the magnetic shielding door 200 and the passive shielding layer 100 together form a complete closed shielding shell. By constructing a room-type magnetic shielding structure, a sufficiently large testing space is formed, which can accommodate large-sized testing objects 800 or conduct large-batch material testing. This solves the problems of small testing capacity and low efficiency of existing barrel-type shielding equipment, and meets the needs of fast, large-batch residual magnetism testing.

[0026] However, the high-permeability material constituting the passive shielding layer 100, while shielding external magnetic fields, is also easily magnetized, generating residual magnetism. This residual magnetism becomes a new source of magnetic contamination in the space to be tested, thus affecting the test accuracy. Therefore, a demagnetizing system is introduced, which includes a demagnetizing coil and a single-unit multi-channel synchronous power modulation system. The demagnetizing coil is wound on the magnetic permeable layer, applying a gradually decaying alternating magnetic field to the magnetic permeable layer, allowing the magnetic shielding material to first saturate and then slowly reach magnetic equilibrium with the environment, ensuring the shielding device is in optimal condition. The single-unit multi-channel synchronous power modulation system is electrically connected to the multi-channel demagnetizing coil. The single-unit multi-channel synchronous power modulation system may include a central control unit, multiple power drive channels, and a synchronization mechanism; each of the multiple power drive channels corresponds to a demagnetizing coil on a magnetic permeable layer.

[0027] Because the magnetic field distribution and magnetization state of the magnetically conductive layers on each surface of the residual magnetism detection chamber are different, a single multi-channel synchronous power modulation system can achieve synchronous control of multiple outputs. This allows for matching the corresponding drive current to the demagnetizing coils at different locations, thereby matching different amplitudes and decay periods based on different materials and positions. Through demagnetization, magnetic balance is achieved, resulting in optimal shielding. This avoids the problems of inconsistent and asynchronous magnetization states that occur with single-channel independent control, effectively improving the magnetic shielding performance of the residual magnetism detection chamber.

[0028] By setting up a passive shielding layer 100, a stable low magnetic background environment is provided for the residual magnetism test. At the same time, by setting up a demagnetization system and using a single multi-channel synchronous power modulation system to synchronously drive the demagnetization coil, the magnetization state of the magnetic materials can be made consistent, thereby avoiding the residual magnetism detection room itself becoming a source of magnetic pollution, ensuring a low magnetic environment in the space to be tested, and thus improving the accuracy of the residual magnetism test.

[0029] The residual magnetism testing system 300 is placed within the testing space, directly detecting the magnitude and distribution of residual magnetism on the object 800 placed within the space. The residual magnetism testing system 300 can be a magnetometer, fluxgate magnetometer, or permeability meter. A handheld magnetometer or permeability meter is used to perform residual magnetism testing on the material under test, allowing for convenient access to the object 800. By integrating magnetic shielding, demagnetization, and residual magnetism testing functions into one unit, and setting up two opposing magnetic shielding gates 200 to facilitate the entry and exit of the object 800, the testing process is optimized, and the overall convenience and efficiency of residual magnetism testing are improved.

[0030] In one embodiment, the passive shielding layer 100 includes a first magnetically conductive layer 110, a second magnetically conductive layer 120, and a third magnetically conductive layer 130. The first magnetically conductive layer 110, the second magnetically conductive layer 120, and the third magnetically conductive layer 130 are arranged in sequence at intervals. The first magnetically conductive layer 110 is located on the side of the passive shielding layer 100 away from the space to be tested, the third magnetically conductive layer 130 is located on the side of the passive shielding layer 100 close to the space to be tested, and the second magnetically conductive layer 120 is located between the first magnetically conductive layer 110 and the third magnetically conductive layer 130. Further, each magnetically conductive layer is formed of at least one of non-oriented silicon steel, oriented silicon steel, permalloy, and amorphous nanocrystals.

[0031] In this embodiment, non-oriented silicon steel has good initial magnetic permeability, low cost, extremely high saturation magnetic flux density, strong anti-magnetic saturation ability, good processing, bending and welding performance, extremely low mass production cost, and low remanence.

[0032] Oriented silicon steel has extremely high permeability in the rolling direction, and its cost is slightly higher than that of non-oriented silicon steel. However, its permeability along the rolling direction is far greater than that of non-oriented silicon steel. It also has lower low-frequency loss, strong anti-saturation ability, and good machinability.

[0033] Permalloy has extremely high initial permeability and extremely high cost. It has high permeability in weak magnetic environments, extremely strong shielding ability for very low frequency magnetic fields, and narrow hysteresis loop, making it suitable for nT-level zero magnetic environments.

[0034] Amorphous nanocrystals have high initial permeability, extremely low loss at the kHz level, and a cost between silicon steel and permalloy. They balance high permeability with moderate saturation flux density, and their loss in the mid-to-low frequency range is much lower than that of silicon steel and permalloy, resulting in balanced performance across the entire frequency range.

[0035] The first magnetically conductive layer 110, the second magnetically conductive layer 120, and the third magnetically conductive layer 130 can be made of the same material; for example, they can be formed from one of the following: non-oriented silicon steel, oriented silicon steel, permalloy, and amorphous nanocrystals. Alternatively, different materials can be selected, such that the first magnetically conductive layer 110, the second magnetically conductive layer 120, and the third magnetically conductive layer 130 are all made of one of the following: non-oriented silicon steel, oriented silicon steel, permalloy, and amorphous nanocrystals.

[0036] Furthermore, the first magnetically conductive layer 110 can be made of non-oriented silicon steel, the second magnetically conductive layer 120 can be made of oriented silicon steel, and the third magnetically conductive layer 130 can be made of permalloy. The first magnetically conductive layer 110, the second magnetically conductive layer 120, and the third magnetically conductive layer 130 are arranged alternately. The first magnetically conductive layer 110 attenuates most of the external geomagnetic and power frequency strong magnetic fields. Then, the insufficient shielding effectiveness of the second magnetically conductive layer 120 under strong directional magnetic fields creates a more stable weak magnetic working environment for the inner third magnetically conductive layer 130. Finally, the third magnetically conductive layer 130 attenuates the residual magnetic field to the nT level, achieving a near-zero magnetic field environment within the residual magnetic detection room. This compensates for the performance shortcomings of the first and second magnetically conductive layers 110 and 120 under extremely low-frequency weak magnetic fields, ensuring the shielding performance of the residual magnetic detection room and the stability of the spatial magnetic field within the room.

[0037] In other possible approaches, to improve the internal environment of the residual magnetism detection room and clarify the testing methods, such as... Figure 3 and Figure 4 As shown, a first wall panel 600 can be attached inside the residual magnetism detection chamber, and a second wall panel 700 can be attached outside the chamber. Both the first wall panel 600 and the second wall panel 700 are connected to the supporting body 10. The first wall panel 600 is located on the side closer to the third magnetic conductive layer 130, and the second wall panel 700 is located on the side closer to the first magnetic conductive layer 110. By setting the first wall panel 600 and the second wall panel 700 inside and outside the residual magnetism detection chamber respectively, the passive shielding layer 100 is protected, and a certain degree of sound and heat insulation is achieved. Furthermore, the interior and exterior of the residual magnetism detection chamber are decorated, improving its aesthetics.

[0038] In one embodiment, a groove 21 is formed by recessing inward along the ground 20. A plurality of insulating pads 400 are arranged at intervals in the groove 21. The support body 10 and / or the passive shielding layer 100 extend at least partially into the groove 21 and are disposed on the insulating pads 400. The groove 21 is filled with a lightweight material 500, which is filled at least between two adjacent insulating pads 400. A floor is provided in the space to be tested. The floor is located at the bottom of the residual magnetism detection room, and the floor and the ground 20 are on the same plane.

[0039] In this embodiment, a groove 21 is formed by recessing downwards on the ground 20 where the residual magnetism detection room is installed. The groove 21 provides a recessed installation space for the passive shielding layer 100, allowing the passive shielding layer 100 and / or the supporting body 10 to extend below the ground 20, forming a complete six-sided closed magnetic shielding circuit, reducing the risk of the geomagnetic field leaking from the bottom of the residual magnetism detection room into the space to be tested.

[0040] A plurality of insulating pads 400 are arranged at intervals within the groove 21, specifically in a grid-like arrangement. When the passive shielding layer 100 extends into the groove 21, the passive shielding layer 100 located at the bottom of the residual magnetism detection chamber is supported on the insulating pads 400. The insulating pads 400 provide uniformly distributed support for the passive shielding layer 100, reducing the risk of localized subsidence and deformation. Furthermore, the insulating pads 400 also achieve electrical insulation from the ground 20, preventing ground potential fluctuations or electromagnetic interference conducted from the ground 20 from affecting the shielding performance of the residual magnetism detection chamber.

[0041] Meanwhile, lightweight material 500 is filled in the groove 21, and the lightweight material 500 is filled between at least two adjacent insulating pads 400. The lightweight material 500 can be foamed concrete or expanded perlite, etc., to further reduce vibration and fill the gaps. By filling the insulating pads 400 with lightweight material 500, displacement of the insulating pads 400 during long-term use or when heavy workpieces are placed can be prevented, ensuring the reliability of the insulation isolation. Moreover, the insulating pads 400 and the lightweight material 500 share the weight, distributing the stress on the passive shielding layer 100 and reducing the risk of bending deformation of the passive shielding layer 100 at the gaps between the insulating pads 400.

[0042] When the passive shielding magnetic layer has multiple magnetic conductive layers, for example, the passive shielding layer 100 is formed by splicing a first magnetic conductive layer 110, a second magnetic conductive layer 120 and a third magnetic conductive layer 130; then, lightweight material 500 can be filled in the groove 21 between the first magnetic conductive layer 110 and the second magnetic conductive layer 120 and between the second magnetic conductive layer 120 and the third magnetic conductive layer 130, so as to effectively support each magnetic conductive layer, disperse the force on the passive shielding layer 100, and reduce the risk of bending deformation of the passive shielding layer 100 under force.

[0043] To facilitate the entry and exit of personnel and equipment, a floor is installed in the testing space, laid on top of the bottom passive shielding layer 100. The surface of the floor is at the same level as the external ground 20, so that there is no threshold or height difference at the connection between the floor and the ground 20, which allows the transport vehicle to drive directly into the testing space and eliminates the height barrier for the object 800 to enter the testing space. Moreover, the stable ground 20 can reduce the vibration of the object 800 and prevent stress magnetization from occurring inside the object 800. At the same time, it can achieve seamless docking between the transport vehicle and the residual magnetism detection room, which is suitable for the assembly line testing of batches of objects 800, thereby improving the testing efficiency of the object 800.

[0044] like Figures 7 to 9 As shown, in one embodiment, a sealing assembly is also included, disposed on the magnetic shielding door 200; the sealing assembly includes a drive member 241, a baffle 242, a slide rail 243, a slider 244, and an eccentric wheel 245; the slide rail 243 is mounted on the magnetic shielding door 200, the slider 244 is slidably connected to the slide rail 243, the baffle 242 is mounted on the slider 244 and fixedly connected to the eccentric wheel 245, and the end of the eccentric wheel 245 away from the baffle 242 is drively connected to the output shaft of the drive member 241; the baffle 242 extends at least partially into the groove 21.

[0045] In this embodiment, the sealing component can be installed on the bottom inner side of the magnetic shielding door 200, that is, the side facing the space to be tested; the groove 21 is located at the position corresponding to the magnetic shielding door 200, without being filled with lightweight material 500, and a slot with a width slightly larger than the thickness of the baffle 242 and a depth consistent with the extension of the baffle 242 is reserved; after the magnetic shielding door 200 is closed, the baffle 242 extends out and extends into the groove 21 through the slot to seal the gap between the magnetic shielding door 200 and the ground 20.

[0046] The sealing assembly includes a drive unit 241, an eccentric wheel 245, a slider 244, a slide rail 243, and a baffle 242. The drive unit 241 can be a DC geared motor or a pneumatic rotary cylinder, providing power for sealing or unlocking. At least two sets of slide rails 243 and sliders 244 are provided, respectively located at both ends of the door body along its width direction. The slide rails 243 are fixed to the door body, and the sliders 244 are slidably connected to the slide rails 243 and fixedly connected to the baffle 242 to ensure that the baffle 242 can only move in a direction perpendicular to the ground 20.

[0047] One end of the eccentric wheel 245 is fixedly connected to the output shaft of the drive component 241, and the other end is fixedly connected to the baffle 242. When the drive component 241 drives the eccentric wheel 245 to move in a circular motion around the output shaft, the baffle 242 is restricted by the slide rail 243 to slide vertically, so the circular motion of the eccentric wheel 245 is converted into the vertical linear motion of the baffle 242. When the eccentric wheel 245 rotates to the lowest point, the baffle 242 extends at least partially and inserts into the groove 21; when the eccentric wheel 245 rotates to the highest point, the baffle 242 retracts to the door body, so that the bottom of the baffle 242 is at least flush with the ground 20, thus not affecting the opening and closing of the magnetic shielding door 200.

[0048] The baffle 242 is composed of at least one magnetically conductive layer. The material of the baffle 242 can be any one or a combination of materials such as non-oriented silicon steel, oriented silicon steel, permalloy, amorphous nanocrystals, and nanocrystals. For example, when the baffle 242 is composed of one magnetically conductive layer, the material of the baffle 242 can be any one of non-oriented silicon steel, oriented silicon steel, permalloy, amorphous nanocrystals, and nanocrystals. When the baffle 242 is composed of two or more magnetically conductive layers, the material of the baffle 242 can be any one of non-oriented silicon steel, oriented silicon steel, permalloy, amorphous nanocrystals, and nanocrystals, or a combination of materials.

[0049] In the specific working process of the sealing assembly, when the magnetic shielding door 200 is in the open state, the baffle 242 is retracted to the door body, so that the bottom of the baffle 242 is at least flush with the ground 20. After the magnetic shielding door 200 is closed and locked, a signal indicating that the door is closed is sent to the control system. The control system controls the drive unit 241 to start, and the output shaft of the drive unit 241 drives the eccentric wheel 245 to rotate. The eccentric wheel 245 drives the baffle 242 to slide down along the slide rail 243 to insert into the reserved slot of the groove 21. When the baffle 242 is inserted into the target position, the position sensor set at the target position is triggered and transmits the signal that the baffle 242 has moved into place to the control system, thereby controlling the drive unit 241 to stop moving, so that the baffle 242 seals the gap between the magnetic shielding door 200 and the ground 20. After the residual magnetism detection of the object 800 is completed, the control system sends an unlocking signal to the drive component 241, causing the drive component 241 to rotate in the opposite direction, which drives the eccentric wheel 245 to rotate, thereby causing the baffle 242 to move upward, so that the baffle 242 retracts to the door body; after the baffle 242 retracts into place, the magnetic shielding door 200 can be opened normally.

[0050] By setting a sealing component, without affecting the opening and closing of the magnetic shielding door 200 and the smooth entry and exit of the object to be detected 800, the baffle 242 can seal the gap between the magnetic shielding door 200 and the ground 20, so that the magnetic shielding door 200 and the bottom passive shielding layer 100 form a continuous magnetic circuit, ensuring electromagnetic continuity and thus effectively suppressing the leakage of magnetic field from the door gap.

[0051] like Figure 6 As shown, in one embodiment, the magnetic shielding door 200 includes a first door body 210 and a second door body 220. Both the first door body 210 and the second door body 220 include a plurality of plates 211, which are stacked in a stepped manner. Each plate 211 of the first door body 210 is provided with a sealing element 212. When the magnetic shielding door 200 is in the closed state, the sealing element 212 seals the gap between the first door body 210 and the second door body 220.

[0052] In this embodiment, the magnetic shielding door 200 includes a first door body 210 and a second door body 220. Both the first door body 210 and the second door body 220 are rotatably connected to the support body 10 via hinges 230, so that the first door body 210 and the second door body 220 are arranged opposite each other. Furthermore, the first door body 210 and the second door body 220 adopt a complementary concave-convex step structure, with each step corresponding to a magnetic conductive layer of the passive shielding layer 100, so as to achieve the continuous layer-by-layer magnetic circuit. Each door body is composed of magnetic conductive plates 211 with the same number of layers as the passive shielding layer 100, and the material of the plates 211 is the same as that of the magnetic conductive layer of the wall at the corresponding position. Taking the three-layer magnetic conductive passive shielding layer 100 as an example, both the first door body 210 and the second door body 220 are composed of three layers of plates 211, and the materials of the three layers of plates 211 from the outside to the inside can be non-oriented silicon steel, oriented silicon steel, and permalloy.

[0053] The multi-layered plates 211 of the first door body 210 and the second door body 220 are staggered and stacked, so that the shape of the first door body 210 and the second door body 220 away from the hinge 230 is stepped. The steps of the first door body 210 and the second door body 220 cooperate with each other. When the magnetic shielding door 200 is in the closed state, the contact surface of the first door body 210 and the second door body 220 forms a tortuous and non-straight gap, which increases the path and magnetic resistance of magnetic field leakage and effectively reduces the amount of magnetic leakage.

[0054] To further seal the gap, a sealing element 212, such as a conductive gasket, is provided on each plate 211 of the first door body 210. A portion of the sealing element 212 is located on each plate 211 of the first door body 210, and another portion extends beyond the edge of the plate 211. Simultaneously, the sealing element 212 is installed along the entire vertical direction of the plate 211, with both ends extending to the top and bottom of the first door body 210. When the magnetic shielding door 200 is in the closed state, after the plates 211 of the second door body 220 are aligned with the plates 211 of the first door body 210, each plate 211 of the second door body 220 abuts against the sealing element 212 extending from the first door body 210, thereby sealing the gap between the first door body 210 and the second door body 220 and effectively suppressing magnetic field leakage from the door gap.

[0055] By combining multi-stage steps and multiple seals, the magnetic leakage at the joints can be effectively reduced, meeting the requirements of nanotesla-level testing environments. Moreover, even if a single seal fails, it does not affect the overall shielding performance of the residual magnetism testing chamber, giving it high sealing reliability.

[0056] It is understood that the magnetic shielding door 200 has a first door body 210 and a second door body 220 that open outwards; therefore, a set of sealing components is provided on both the first door body 210 and the second door body 220, and the length of the baffle 242 is basically the same as the width of the door body. When the baffle 242 extends into the groove 21, it can effectively seal the gap between the magnetic shielding door 200 and the ground 20, thereby effectively suppressing the leakage of magnetic field from the gap.

[0057] like Figure 10 and Figure 11 As shown, in one embodiment, both the passive shielding layer 100 and the magnetic shielding door 200 are provided with a plurality of through holes 140. The plurality of through holes 140 are arranged at intervals along the outer periphery of the passive shielding layer 100 and along the outer periphery of the magnetic shielding door 200, and the demagnetizing coil is inserted into the through holes 140.

[0058] In this embodiment, the through holes 140 are evenly spaced along the outer periphery of the passive shielding layer 100 and the outer periphery of the magnetic shielding door 200, and are arranged linearly at equal intervals to form a closed wiring loop around the entire residual magnetism detection room, ensuring that the demagnetizing magnetic field covers the entire passive shielding layer 100 without any dead angles. It can be understood that each magnetic conductive layer of the passive shielding layer 100 and each plate 211 of the magnetic shielding door 200 are provided with an independent array of through holes 140; and the aperture of the through holes 140 is larger than the outer diameter of the demagnetizing coil to facilitate the insertion of the demagnetizing coil.

[0059] Each magnetically conductive layer corresponds to an independent demagnetizing coil. The demagnetizing coil is threaded through the through-hole 140 of the magnetically conductive layer, so that the demagnetizing coil is wound around the edge of the magnetically conductive layer, forming a closed loop around the magnetically conductive layer. Specifically, the demagnetizing coil can be inserted from a corner through-hole 140 in the residual magnetism detection room, passing through all through-holes 140 sequentially along the wall edge, and finally returning to the starting corner through-hole 140 to exit, forming a complete rectangular closed loop. By directly threading the demagnetizing coil through the through-hole 140, a stable and accurate wiring path is provided for the coil, ensuring the uniformity of the distance and relative position between the coil and the magnetically conductive layer, which is beneficial for generating a uniform demagnetizing magnetic field.

[0060] When the demagnetizing coil is inserted into the through-hole 140 of the magnetically conductive layer, the distance between the coil and the magnetically conductive layer is almost zero; under the same demagnetizing effect, the required demagnetizing power and time are effectively reduced. Each magnetically conductive layer has an independent coil and through-hole 140, and the demagnetizing magnetic field can directly act on the interior of each magnetically conductive layer, so that the magnetically conductive material in the passive shielding layer 100 can be saturated as much as possible, which is beneficial to making the magnetization state of the magnetically conductive material uniform. By arranging the through-holes 140 along the outer periphery of the passive shielding layer 100, the edges of the passive shielding layer 100 are the easiest to magnetize and the areas with the most concentrated residual magnetism. This wiring method can strengthen the demagnetization of the edge areas, ensuring that the residual magnetism of the entire passive shielding layer 100 is uniform.

[0061] In one embodiment, the diameter of the through hole 140 is less than or equal to 25 mm; the shortest distance H1 from the through hole 140 to the edge of the passive shielding layer 100 satisfies 80 mm ≤ H1 ≤ 100 mm; the distance H2 between two adjacent through holes 140 on the passive shielding layer 100 satisfies 500 mm ≤ H2 ≤ 600 mm; and the distance H3 between two adjacent through holes 140 on the magnetic shielding door 200 satisfies 150 mm ≤ H3 ≤ 200 mm.

[0062] In this embodiment, the diameter of the through-hole 140 can be any value from 5mm, 7mm, 10mm, 12mm, 15mm, 17mm, 20mm, 22mm, and 25mm, or a value between any two of these. Since the through-hole 140 on the magnetic permeable layer forms a magnetic leakage window, the magnetic field leakage is related to the diameter of the through-hole 140. If the diameter of the through-hole 140 is too large, such as exceeding 25mm, the magnetic leakage of a single through-hole 140 will be relatively high. The superposition of multiple through-holes 140 will lead to an increase in the overall magnetic field in the remanence detection area, which is detrimental to the high-requirement detection requirements of materials with extremely low remanence characteristics.

[0063] Furthermore, the distance H1 from the through-hole 140 to the edge of the passive shielding layer 100 can be any value among 80mm, 82mm, 85mm, 87mm, 90mm, 92mm, 95mm, 97mm, and 100mm, or a value between any two of these. Since the edge region of the passive shielding layer 100 is where residual magnetism is concentrated and magnetic field leakage is severe, and it is also where structural stress is high, if the distance from the through-hole 140 to the edge of the passive shielding layer 100 is too small, such as less than 80mm, the connection between the through-hole 140 and the passive shielding layer 100 is prone to breakage under external force or thermal expansion and contraction, thus posing a risk of structural failure.

[0064] If the distance from the through-hole 140 to the edge of the passive shielding layer 100 is too large, such as greater than 100mm, the magnetic field generated by the demagnetizing coil will rapidly attenuate when it reaches the outermost edge of the passive shielding layer 100, thus failing to effectively eliminate residual magnetism in the edge region and forming a demagnetizing blind zone at the edge. Insufficient demagnetizing magnetic field strength in the edge region will lead to uneven residual magnetism distribution throughout the passive shielding layer 100, resulting in uneven magnetic field in the space to be detected and affecting the accuracy of residual magnetism detection.

[0065] By appropriately setting the distance from the through hole 140 to the edge of the passive shielding layer 100, the structural reliability of the connection section from the edge region of the passive shielding layer 100 to the through hole 140 can be ensured. Furthermore, it ensures that the edge of the passive shielding layer 100 has sufficient demagnetizing magnetic field strength, guaranteeing a uniform distribution of residual magnetism in the passive shielding layer 100. This results in a uniform magnetic field distribution within the space to be tested, thus ensuring the accuracy of residual magnetism detection.

[0066] Furthermore, the distance H2 between two adjacent through holes 140 on the passive shielding layer 100 can be any value or a value between any two of the following: 500mm, 510mm, 520mm, 530mm, 540mm, 550mm, 560mm, 570mm, 580mm, 590mm, and 600mm. If the distance between two adjacent through holes 140 on the passive shielding layer 100 is too small, such as less than 500mm, the density of the through holes 140 will be too high, thereby disrupting the magnetic continuity of the magnetic conductive layer. This will lead to a decrease in the overall shielding effectiveness of the passive shielding layer 100, making it unable to meet the high requirements for testing the extremely low remanent magnetization characteristics of the material.

[0067] If the distance between two adjacent through holes 140 on the passive shielding layer 100 is too large, such as greater than 600mm, the magnetic field strength at the midpoint between the two adjacent through holes 140 will be lower than that in other areas, resulting in a large difference in the demagnetizing magnetic field strength in different areas. This increases the risk of uneven residual magnetism distribution in the passive shielding layer 100 after demagnetization, which is not conducive to meeting the requirements of high-precision residual magnetism detection.

[0068] By reasonably setting the distance between two adjacent through holes 140 on the passive shielding layer 100, the coverage density and uniformity of the demagnetizing magnetic field on the passive shielding layer 100 can be reasonably set, and the magnetic continuity of the magnetic conductive layer is ensured, so as to meet the requirements of high-precision residual magnetism detection.

[0069] Furthermore, the distance H3 between two adjacent through holes 140 on the magnetic shielding door 200 can be any value or a value between any two of the following: 150mm, 155mm, 160mm, 165mm, 170mm, 175mm, 180mm, 185mm, 190mm, 195mm, and 200mm. The magnetic shielding door 200 is a moving part, and each opening and closing of the door is subject to mechanical stress. Simultaneously, the magnetic field at the door seams changes repeatedly, making the door more easily magnetized than the wall. Moreover, to reduce the weight of the door and facilitate the opening and closing of the magnetic shielding door 200, the thickness of the magnetic conductive plate 211 is usually no thicker than the magnetic conductive layer of the passive shielding layer 100; therefore, the demagnetizing magnetic field attenuates faster inside the door, requiring denser coils to ensure sufficient magnetic field strength. At the same time, the magnetic leakage at the edges and seams of the magnetic shielding door 200 is relatively severe, requiring denser demagnetizing coils to enhance demagnetization and ensure that residual magnetism at the seams is completely eliminated.

[0070] By appropriately setting the distance between two adjacent through holes 140 on the magnetic shielding door 200, making H3 greater than or equal to 150mm, it is possible to avoid insufficient structural strength of the door due to excessive density of through holes 140, and at the same time prevent the magnetic fields of adjacent coils from canceling each other out. Furthermore, by making H3 less than or equal to 200mm, it is ensured that the demagnetizing magnetic field strength at any point on the door surface exceeds the coercivity of the magnetic conductive material, so as to eliminate the demagnetizing blind zone.

[0071] In one embodiment, the magnetic conductive layer includes a plurality of single plates, which are stacked and spliced ​​in a staggered manner.

[0072] In this embodiment, the material of the magnetic conductive layer possesses both magnetic permeability and electrical conductivity. When an alternating magnetic field passes through it, eddy currents are induced within the material. These eddy currents generate a reverse magnetic field, which cancels out the magnetic flux within the magnetic conductive material, thereby weakening the magnetic shunt capability. By stacking multiple single-board units, the eddy currents can be confined to a very small loop within each single-board unit, thereby reducing the eddy current loop area and intensity, and suppressing eddy current losses.

[0073] Furthermore, if the seams of two adjacent layers of single-layer boards are perfectly aligned, a magnetic leakage channel will be formed that runs through the entire magnetically conductive layer, allowing external magnetic fields to penetrate directly into the residual magnetism detection chamber. By splicing several single-layer boards with staggered seams, so that the seam of one layer corresponds to the seamless surface of another layer, the continuous magnetic leakage channel is cut off. Even if a small amount of magnetic field lines leak out at the seam of one layer, they will be captured and diverted by the magnetically conductive single-layer board of the other layer, thus preventing them from penetrating further into the residual magnetism detection chamber, effectively improving the shielding performance of the residual magnetism detection chamber; at the same time, there is no need to compensate for the performance loss caused by magnetic leakage and eddy currents by stacking material thickness, further reducing the amount of high-cost, high-permeability materials used.

[0074] In one embodiment, the length of the internal space of the residual magnetism detection chamber is L1, which satisfies 3m≤L1≤5m, the width is W1, which satisfies 3m≤W1≤5m, and the height is H4, which satisfies 3m≤H4≤5m; the length of the external envelope space of the residual magnetism detection chamber is L2, which satisfies 4m≤L2≤6m, the width is W2, which satisfies 4m≤W2≤6m, and the height is H5, which satisfies 4m≤H5≤6m.

[0075] In this embodiment, the X direction is the length direction of the residual magnetism detection chamber, the Y direction is the width direction of the residual magnetism detection chamber, and the Z direction is the height direction of the residual magnetism detection chamber. The internal length L1 of the residual magnetism detection chamber can be any value of 3m, 3.5m, 4m, 4.5m, 5m, or any value between any two of these values; the internal width W1 of the residual magnetism detection chamber can be any value of 3m, 3.5m, 4m, 4.5m, 5m, or any value between any two of these values; and the internal height H4 of the residual magnetism detection chamber can be any value of 3m, 3.5m, 4m, 4.5m, 5m, or any value between any two of these values.

[0076] If the cavity dimensions inside the residual magnetism testing chamber are too small, when the length, width, and height of the chamber approach the interlayer spacing of the passive shielding layer 100, the magnetic reluctance at the corners of the chamber will decrease relatively, and magnetic field lines will leak from the seams and corners of the passive shielding layer 100, leading to a decline in the shielding performance of the residual magnetism testing chamber. By ensuring that the length and width of the residual magnetism testing chamber are greater than or equal to 3m, the stable low-frequency shielding performance of the chamber is guaranteed; it also facilitates the accommodation of testing equipment and maintains an effective safe distance between the testing equipment and the inner walls of the chamber. By ensuring that the height of the residual magnetism testing chamber is greater than or equal to 3m, operators can stand normally and operate the testing equipment inside the chamber, while also meeting the vertical installation requirements of vertical testing equipment.

[0077] If the cavity size within the residual magnetism detection chamber is too large, the risk of structural deformation and stress accumulation in the large-size passive shielding layer 100 increases. High-permeability materials such as permalloy are highly sensitive to stress; even slight deformation can lead to a significant decrease in permeability, resulting in irreversible degradation of the shielding effectiveness of the magnetic layer. By ensuring that the length, width, and height of the residual magnetism detection chamber are all less than or equal to 5m, the overall structural strength of the chamber is guaranteed, reducing the risk of structural deformation and stress accumulation in the passive shielding layer 100, thereby ensuring the shielding effectiveness of the magnetic layer. Simultaneously, this allows the residual magnetism detection chamber to meet various application scenarios, such as single-person medical testing and magnetobiological research.

[0078] Furthermore, the length L2 of the outer envelope space of the residual magnetism detection room can be any value of 4m, 4.5m, 5m, 5.5m, 6m or any value between any two of them; the width W2 of the outer envelope space of the residual magnetism detection room can be any value of 4m, 4.5m, 5m, 5.5m, 6m or any value between any two of them; and the height H5 of the outer envelope space of the residual magnetism detection room can be any value of 4m, 4.5m, 5m, 5.5m, 6m or any value between any two of them.

[0079] By ensuring that the external length, width, and height of the residual magnetism detection chamber are all greater than or equal to 4m, the internal space requirements of the residual magnetism detection chamber are met. By ensuring that the external length, width, and height of the residual magnetism detection chamber are all less than or equal to 6m, the internal usable space of the residual magnetism detection chamber can be maximized while ensuring its shielding performance, making it suitable for more application scenarios.

[0080] In the specific implementation of the above embodiments, the technical features can be combined in any non-contradictory way. For the sake of brevity, not all possible combinations of the above technical features are described. However, as long as the combination of these technical features is not contradictory, it should be considered to be within the scope of this specification.

[0081] The specific embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are detailed, they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention. Therefore, the scope of protection of this patent should be determined by the appended claims.

Claims

1. A residual magnetism detection room, characterized in that, include: The supporting body (10) is located on the ground (20); A passive shielding layer (100) is disposed on the support body (10), the passive shielding layer (100) includes at least one magnetic conductive layer, and the passive shielding layer (100) encloses to form a space to be tested; At least two pairs of magnetic shielding doors (200) are rotatably connected to the support body (10) and are arranged opposite to each other on the support body (10); A demagnetizing system, comprising a demagnetizing coil and a single-unit multi-channel synchronous power modulation system, wherein the demagnetizing coil is wound on the magnetic conductive layer, and the single-unit multi-channel synchronous power modulation system is electrically connected to the demagnetizing coil for synchronously reducing the magnetism of the magnetic conductive layer; A residual magnetism testing system (300) is installed in the space to be tested and is used to detect the residual magnetism of the object (800) to be tested in the space to be tested.

2. The residual magnetism detection room according to claim 1, characterized in that, A groove (21) is formed by recessing inward along the ground (20), and a plurality of insulating pads (400) are arranged at intervals in the groove (21). The supporting body (10) and / or the passive shielding layer (100) extend at least partially into the groove (21) and are disposed on the insulating pads (400). The groove (21) is filled with a lightweight material (500), and the lightweight material (500) is filled between at least two adjacent insulating pads (400); The space to be tested is provided with a floor, which is located at the bottom of the residual magnetism detection room, and the floor and the ground (20) are on the same plane.

3. A residual magnetism detection room according to claim 2, characterized in that, It also includes a sealing assembly disposed on the magnetic shielding door (200); the sealing assembly includes a drive member (241), a baffle (242), a slide rail (243), a slider (244), and an eccentric wheel (245); the slide rail (243) is mounted on the magnetic shielding door (200), the slider (244) is slidably connected to the slide rail (243), the baffle (242) is mounted on the slider (244) and fixedly connected to the eccentric wheel (245), and one end of the eccentric wheel (245) away from the baffle (242) is drively connected to the output shaft of the drive member (241); the baffle (242) extends at least partially into the groove (21).

4. A residual magnetism detection room according to claim 1, characterized in that, The magnetic shielding door (200) includes a first door body (210) and a second door body (220). Both the first door body (210) and the second door body (220) include a plurality of plates (211), which are stacked in a stepped manner. Each of the plates (211) of the first door body (210) is provided with a sealing element (212), and when the magnetic shielding door (200) is closed, the sealing element (212) seals the gap between the first door body (210) and the second door body (220).

5. A residual magnetism detection room according to claim 1, characterized in that, Both the passive shielding layer (100) and the magnetic shielding door (200) are provided with a plurality of through holes (140). The plurality of through holes (140) are arranged at intervals along the outer periphery of the passive shielding layer (100) and along the outer periphery of the magnetic shielding door (200), and the demagnetizing coil is inserted into the through holes (140).

6. A residual magnetism detection room according to claim 5, characterized in that, The diameter of the through hole (140) is less than or equal to 25 mm; The shortest distance H1 from the through hole (140) to the edge of the passive shielding layer (100) satisfies 80mm≤H1≤100mm; The distance H2 between two adjacent through holes (140) on the passive shielding layer (100) satisfies 500mm≤H2≤600mm; The distance H3 between two adjacent through holes (140) on the magnetic shielding door (200) satisfies 150mm≤H3≤200mm.

7. A residual magnetism detection room according to claim 1, characterized in that, The passive shielding layer (100) includes a first magnetically conductive layer (110), a second magnetically conductive layer (120), and a third magnetically conductive layer (130). The first magnetically conductive layer (110), the second magnetically conductive layer (120), and the third magnetically conductive layer (130) are arranged in sequence at intervals. The first magnetically conductive layer (110) is located on the side of the passive shielding layer (100) away from the space to be tested. The third magnetically conductive layer (130) is located on the side of the passive shielding layer (100) close to the space to be tested. The second magnetically conductive layer (120) is located between the first magnetically conductive layer (110) and the third magnetically conductive layer (130).

8. A residual magnetism detection room according to claim 1, characterized in that, Each of the magnetically conductive layers is formed of at least one of non-oriented silicon steel, oriented silicon steel, permalloy, and amorphous nanocrystals.

9. A residual magnetism detection room according to claim 1, characterized in that, The magnetic conductive layer comprises several single plates, which are stacked and spliced ​​together in a staggered manner.

10. A residual magnetism detection room according to claim 1, characterized in that, The length of the internal space of the residual magnetism detection room is L1, which satisfies 3m≤L1≤5m; the width is W1, which satisfies 3m≤W1≤5m; and the height is H4, which satisfies 3m≤H4≤5m. The length of the outer envelope space of the residual magnetism detection room is L2, which satisfies 4m≤L2≤6m; the width is W2, which satisfies 4m≤W2≤6m; and the height is H5, which satisfies 4m≤H5≤6m.

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