A zero-magnetic shielding device and its usage method

Abstract

This invention discloses a zero-magnetic shielding device and its usage method. The zero-magnetic shielding device includes a magnetic shielding cylinder composed of a shielding cylinder body and a detachably connected shielding cover, and a non-magnetic multifunctional test frame installed inside the magnetic shielding cylinder, consisting of an arc-shaped seat, a lifting mechanism, a test platform, a track, a shelf, a Helmholtz coil, and a foldable nylon magnetic sensing component. This invention eliminates the need to replace the non-magnetic multifunctional test frame when performing magnetic flux and remanence switching tests on the object under test inside the magnetic shielding cylinder, thus improving the efficiency of magnetic flux and remanence switching tests and offering the advantage of convenient switching tests. It also boasts advantages such as high measurement accuracy and a wide range of applications.

Description

Technical Field

[0001] This invention relates to the field of magnetic shielding, and in particular to a zero magnetic shielding device and its method of use. Background Technology

[0002] Magnetic shielding cylinders achieve magnetic field shielding through the high permeability of permalloy. Since the permeability of permalloy is thousands of times that of air, its magnetic reluctance is much lower than that of the internal space. The magnetic field lines of the external magnetic field are mainly conducted along the cylinder wall, with only a very small amount entering the internal space. This magnetic flux diversion effect creates a near-zero magnetic field environment inside the cylinder, effectively blocking interference from the Earth's magnetic field. This provides a near-zero magnetic field testing environment for related instruments performing near-zero or weak magnetic field tests. Its disadvantage is that existing magnetic shielding cylinders require the installation of different test frames inside to perform magnetic flux or remanence tests on the object under test. Switching between test frames is inconvenient and affects testing efficiency. Summary of the Invention

[0003] The purpose of this invention is to provide a zero-magnetic shielding device and its usage method to solve the problem that traditional magnetic shielding cylinders require switching between test frames with different structures when conducting magnetic flux and residual magnetism tests, which leads to inconvenience in switching and affects test efficiency.

[0004] To solve the above-mentioned technical problems, the present invention provides a zero-magnetic shielding device, comprising:

[0005] A magnetic shielding cylinder, including a shielding cylinder body and a detachably connected shielding cover;

[0006] A non-magnetic multifunctional test fixture, installed inside a magnetic shielding cylinder, includes an arc-shaped base installed inside the magnetic shielding cylinder, a test platform located on a horizontal plane above the arc-shaped base, a lifting mechanism hinged between the arc-shaped base and the test platform, a track arranged along the length of the test platform, a shelf slidably arranged on the track, and a Helmholtz coil placed on the shelf for measuring the magnetic flux of an object placed inside the Helmholtz coil. It also includes a foldable nylon magnetic sensing component mounted on the arc-shaped base. When unfolded, the foldable nylon magnetic sensing component passes through an opening in the test platform and is positioned above the shelf for measuring the remanence of the object placed on the shelf. During magnetic flux testing, when folded, the foldable nylon magnetic sensing component retracts from the opening in the test platform onto the arc-shaped base.

[0007] Furthermore, the zero-magnetic shielding device provided by the present invention includes an inner cylinder and an outer cylinder. The inner cylinder is composed of five layers of permalloy cylinders, with a demagnetizing coil wound around the outer wall of the innermost permalloy cylinder. The two ends of the demagnetizing coil extend beyond the shielding cylinder for connection to a demagnetizing machine. The outer cylinder is an aluminum cylinder, and adjacent cylinders are separated by foam filling. The shielding cover includes an embedded inner shielding cover and a protective outer cover. The inner shielding cover consists of two embedded permalloy covers, and the protective outer cover is an aluminum cover. The protective outer cover has two symmetrically arranged handles, and adjacent covers are separated by foam filling. The protective outer cover is enclosedly installed on the outer cylinder, and the inner shielding cover is sealed within the cavity between any three permalloy cylinders between the innermost and outermost layers of the inner cylinder. A sealing ring is arranged around the cavity between any two adjacent permalloy cylinders at the end where the inner shielding cover is installed.

[0008] Furthermore, in the zero magnetic shielding device provided by the present invention, the lifting mechanism is a scissor-type lifting frame, and the test platform is provided with a handle for controlling the scissor-type lifting frame to rise and fall relative to the arc-shaped seat by lifting the test platform.

[0009] Furthermore, the zero-magnetic shielding device provided by the present invention includes a foldable nylon magnetic sensing assembly comprising a support fixedly mounted on an arc-shaped base, an adjusting rod hinged to the support, a nylon magnetic sensor connected to the upper end of the adjusting rod, and a pull rod hinged to the adjusting rod near the support. One end of the pull rod extending out of the arc-shaped base is connected to a handle. When the pull rod is pulled outward by the handle, the adjusting rod and the nylon magnetic sensor connected thereto flip to a horizontal state. When the pull rod is pushed inward by the handle, the adjusting rod and the nylon magnetic sensor connected thereto flip to a vertical state.

[0010] Furthermore, the zero-magnetic shielding device provided by the present invention further includes:

[0011] The support includes a movable frame and a cylindrical frame connected thereto, wherein the magnetic shielding cylinder is detachably connected to the cylindrical frame.

[0012] To address the aforementioned technical problems, the present invention also provides a method for using a zero-magnetic shielding device, including a magnetic flux testing method and a remanence testing method.

[0013] The magnetic flux testing method includes:

[0014] Open the shielding cover installed on the shielding cylinder body to make the magnetic shielding cylinder open. Place the Helmholtz coil on the shelf and place the object to be tested inside the Helmholtz coil. Slide the shelf, the Helmholtz coil on it, and the object to be tested inside it along the track to the predetermined area of ​​the shielding cylinder body. Measure the magnetic flux of the object to be tested through the Helmholtz coil.

[0015] The residual magnetism testing method includes:

[0016] Open the shielding cover installed on the shielding cylinder body of the magnetic shielding cylinder, take out the Helmholtz coil on the shelf, place the object to be tested on the shelf, control the foldable nylon magnetic sensing component to be in the unfolded state, slide the shelf and the object to be tested on it along the track to the detection area of ​​the foldable nylon magnetic sensing component, close the shielding cover to make the magnetic shielding cylinder in the closed state, and measure the residual magnetism of the object to be tested on the shelf through the foldable nylon magnetic sensing component.

[0017] To address the aforementioned technical problems, the present invention also provides a method for using a zero-magnetic shielding device, including a demagnetization method for the zero-magnetic shielding device, a magnetic flux testing method, and a residual magnetism testing method.

[0018] The demagnetization method of the zero-magnetic shielding device includes:

[0019] The innermost permalloy cylinder of the shielding cylinder is demagnetized by connecting a power source to a demagnetizing coil wound around the outer wall of the innermost permalloy cylinder.

[0020] The magnetic flux testing method includes:

[0021] Open the shielding cover installed on the shielding cylinder body to make the magnetic shielding cylinder open. Place the Helmholtz coil on the shelf and place the object to be tested inside the Helmholtz coil. Slide the shelf, the Helmholtz coil on it, and the object to be tested inside it along the track to the predetermined area of ​​the shielding cylinder body. Measure the magnetic flux of the object to be tested through the Helmholtz coil.

[0022] The residual magnetism testing method includes:

[0023] Open the shielding cover installed on the shielding cylinder body of the magnetic shielding cylinder, take out the Helmholtz coil on the shelf, place the object to be tested on the shelf, control the foldable nylon magnetic sensing component to be in the unfolded state, slide the shelf and the object to be tested on it along the track to the detection area of ​​the foldable nylon magnetic sensing component, close the shielding cover to make the magnetic shielding cylinder in the closed state, and measure the residual magnetism of the object to be tested on the shelf through the foldable nylon magnetic sensing component.

[0024] Furthermore, the method of using the zero magnetic shielding device provided by the present invention involves demagnetizing the innermost permalloy cylinder of the shielding cylinder before performing magnetic flux or residual magnetism tests on the object to be tested.

[0025] Furthermore, in the method of using the zero magnetic shielding device provided by the present invention, before measuring the residual magnetism of the object to be tested on the shelf, the height of the test platform and its track, shelf and object to be tested are adjusted by adjusting the height of the lifting mechanism so that the object to be tested enters the recognition area of ​​the nylon magnetic sensor of the foldable nylon magnetic sensing component.

[0026] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0027] The zero-magnetic shielding device and its method of use provided by this invention, when testing the magnetic flux of an object under test inside a magnetic shielding cylinder, involves removing the shielding cover, placing the object under test inside a Helmholtz coil, and sliding the shelf, the Helmholtz coil, and the object under test along a track to a predetermined area within the shielding cylinder. This allows for measurement of the magnetic flux of the object under test via the Helmholtz coil when the magnetic shielding cylinder is open. When performing a residual magnetism test, the Helmholtz coil is removed from the shelf, the object under test is placed on the shelf, and the foldable nylon magnetic sensing component is unfolded. The object under test is then slid along a track to the detection area of ​​the foldable nylon magnetic sensing component. This allows for measurement of the residual magnetism of the object under test via the foldable nylon magnetic sensing component when the magnetic shielding cylinder is closed. Therefore, when performing magnetic flux and residual magnetism switching tests on an object under test inside the magnetic shielding cylinder, there is no need to replace the non-magnetic multi-functional test rack, thus improving the efficiency of switching tests and offering the advantage of convenient switching.

[0028] The zero-magnetic shielding device and its usage method provided by this invention, the non-magnetic multifunctional test rack installed in the magnetic shielding cylinder is suitable for testing the magnetic flux and remanence of the object under test, without the need for switching, and has universality. It avoids the cumbersome process of repeatedly positioning and installing different test racks in the magnetic shielding cylinder when performing magnetic flux and remanence switching tests in the traditional magnetic shielding cylinder, thereby improving the efficiency of magnetic flux and remanence switching tests.

[0029] The zero-magnetic shielding device and its usage method provided by this invention, a non-magnetic multifunctional test rack, can adjust its height inside a magnetic shielding cylinder via a lifting mechanism. On the one hand, this allows the object under test to enter the detection area for residual magnetism testing, thereby improving the accuracy of residual magnetism measurement of the object under test; on the other hand, it is applicable to magnetic shielding cylinders of different diameters, and has the advantage of wide applicability.

[0030] The zero-magnetic shielding device and its usage method provided by this invention feature an arc-shaped base for the non-magnetic multifunctional test fixture, which improves the stability of the entire non-magnetic multifunctional test fixture when installed inside the magnetic shielding cylinder.

[0031] The zero-magnetic shielding device and its usage method provided by this invention allow the shelf of the non-magnetic multifunctional test rack to slide along the track, enabling the object to be tested carried by the shelf to be slid into the test area inside the magnetic shielding cylinder for corresponding measurement, thereby improving the measurement accuracy.

[0032] The zero-magnetic shielding device and its method of use provided by this invention, when performing magnetic flux testing on the object under test, control the foldable nylon magnetic sensing component to be in a folded state, thereby retracting the foldable nylon magnetic sensing component onto the arc-shaped base, avoiding interference and other adverse effects of the foldable nylon magnetic sensing component on the magnetic flux measurement of the object under test; when performing remanence testing on the object under test, control the foldable nylon magnetic sensing component to be in an unfolded state, thereby pushing the object under test into the detection area of ​​the foldable nylon magnetic sensing component to perform remanence measurement. During the remanence testing, the Helmholtz coil is removed to avoid interference with the remanence testing of the object under test. Attached Figure Description

[0033] Figure 1 This is a schematic diagram of the three-dimensional combined structure of the magnetic shielding cylinder;

[0034] Figure 2 This is a schematic diagram of the three-dimensional exploded structure of the magnetic shielding cylinder;

[0035] Figure 3 This is a partial cross-sectional structural diagram of the shielding cylinder and shielding cover in a closed installation state;

[0036] Figure 4 This is a three-dimensional structural diagram of a demagnetizing coil wound on the innermost layer of the inner cylinder;

[0037] Figure 5 This is a three-dimensional structural diagram of an inner cylinder consisting of five layers of permalloy alloy embedded in the cylinder.

[0038] Figure 6 This is a three-dimensional structural diagram of the magnetic shielding cylinder and the bracket in the installation state;

[0039] Figure 7 This is a schematic diagram of the three-dimensional structure of the support frame;

[0040] Figure 8 This is a partial cross-sectional view of the non-magnetic multifunctional test fixture installed inside a shielded cylinder in a residual magnetism test state.

[0041] Figure 9 This is a partial cross-sectional view of a non-magnetic multifunctional test fixture installed inside a shielded cylinder in a magnetic flux testing state.

[0042] Figure 10 This is a three-dimensional structural diagram of a non-magnetic multifunctional test fixture in the residual magnetism test state;

[0043] Figure 11 This is a three-dimensional structural diagram of a non-magnetic multifunctional test fixture in magnetic flux testing mode.

[0044] Figure 12 This is a schematic diagram of the structure of a foldable nylon magnetic sensing component;

[0045] As shown in the figure:

[0046] 100. Magnetic shielding cylinder; 110. Shielding cylinder body; 111. Inner cylinder body; 112. Outer cylinder body; 113. Expanding foam; 114. Sealing ring; 115. Demagnetizing coil; 120. Shielding cover; 121. Shielding inner cover; 122. Protective outer cover; 123. Handle.

[0047] 200. Non-magnetic multi-functional test rack; 210. Arc-shaped base; 220. Lifting mechanism; 230. Test platform; 231. Opening; 232. Handle; 240. Track; 250. Shelf; 260. Helmholtz coil; 270. Foldable nylon magnetic sensing assembly; 271. Support; 272. Adjusting rod; 273. Nylon magnetic sensor; 274. Pull rod; 275. Handle; 280. Object to be tested.

[0048] 300, support frame; 310, mobile frame; 320, tube frame. Detailed Implementation

[0049] The present invention will now be described in detail with reference to the accompanying drawings. The advantages and features of the present invention will become clearer from the following description. It should be noted that the drawings are all in a very simplified form and use non-precise proportions, and are only used to facilitate and clarify the illustration of the embodiments of the present invention.

[0050] This invention provides a zero-magnetic shielding device, comprising at least a magnetic shielding cylinder 100 and a non-magnetic multifunctional test frame 200. Wherein:

[0051] Please refer to Figures 1 to 5The magnetic shielding cylinder 100 includes a shielding cylinder body 110 and a detachably connected shielding cover 120. The shielding cylinder body 110 comprises an inner cylinder body 111 and an outer cylinder body 112. The inner cylinder body 111 consists of five layers of permalloy alloy cylinders, with a demagnetizing coil 115 wound around the outer wall of the innermost permalloy alloy cylinder. The two ends of the demagnetizing coil 115 extend beyond the shielding cylinder body 110 for connection to a demagnetizing machine. The outer cylinder body 112 is an aluminum cylinder used to protect the magnetic shielding cylinder 100, offering the advantage of low cost. Adjacent cylinder layers are separated by foam 113. The shielding cover 120 includes an embedded multi-layered shielding inner cover 121 and a protective outer cover 122. The shielding inner cover 121 can be two embedded permalloy alloy covers, and the protective outer cover 122 is an aluminum cover. The protective outer cover 122 has two symmetrically arranged handles 123, facilitating the installation and removal of the shielding cover 120 relative to the shielding cylinder body 110. Adjacent covers (including the space between the inner shielding cover 121 and the space between the inner shielding cover 121 and the outer protective cover 122) are separated by foam 113. The outer protective cover 122 is enclosedly installed on the outer cylinder 112, and the inner shielding cover 121 is sealed within the cavity between any three layers of permalloy cylinder body 111, between the innermost and outermost layers. The sealed connection between the inner shielding cover 121 and the inner cylinder 111 provides the magnetic shielding cylinder 100 with excellent overall shielding performance. The outer protective cover 122 protects the shielding cover 120 while reducing costs. A sealing ring 114 is provided around the cavity between any two adjacent layers of permalloy cylinder body 111 at the end where the inner shielding cover 121 is installed. This sealing ring 114 provides a dustproof seal. The shielding cover 120 is a cylindrical shape with one end open, similar to a mineral water bottle cap. After it is sealed and installed with the shielding cylinder 110, it can improve the axial shielding effect of the magnetic shielding cylinder 100.

[0052] Please refer to Figures 8 to 12A non-magnetic multifunctional test fixture 200, installed inside the magnetic shielding cylinder 100, includes an arc-shaped base 210 installed inside the magnetic shielding cylinder 100, a test platform 230 located on a horizontal plane above the arc-shaped base 210, a lifting mechanism 220 hinged between the arc-shaped base 210 and the test platform 230, a track 240 arranged along the length of the test platform 230, a shelf 250 slidably arranged on the track 240, and a Helmholtz coil 260 placed on the shelf 250 for measuring the magnetic properties of a coil placed on the test platform 230. The test fixture 200 measures the magnetic flux of the test object 280 within the coil 260. It also includes a foldable nylon magnetic sensing component 270 mounted on the arc-shaped base 210. When unfolded, the foldable nylon magnetic sensing component 270 passes through an opening 231 in the test platform 230 and is positioned above the shelf 250, used to measure the remanence of the test object 280 placed on the shelf 250. During magnetic flux testing, the foldable nylon magnetic sensing component 270 retracts from the opening 231 in the test platform 230 back onto the arc-shaped base 210 when folded. The lifting mechanism 220 can be a scissor-type lifting frame, and the test platform 230 is equipped with a handle 232 for controlling the lifting mechanism 220 relative to the arc-shaped base 210 by lifting the test platform 230. The components of the non-magnetic multifunctional test fixture 200 can be made of ceramic, plastic, or a combination of both. For example, the bearings, tracks, and shelves of the scissor-type lifting frame are made of ceramic materials, while the remaining parts are made of plastic. To enable the switching between folded and unfolded states of the foldable nylon magnetic sensing assembly 270, the foldable nylon magnetic sensing assembly 270 includes a support 271 fixedly mounted on an arc-shaped base 210, an adjusting rod 272 hinged to the support 271, a nylon magnetic sensor 273 (such as a magnetoresistive sensor or Hall effect sensor) connected to the upper end of the adjusting rod 272, and a pull rod 274 hinged to the adjusting rod 272 near the support 271. A handle 275 is connected to one end of the pull rod 274 extending out of the arc-shaped base 210. When the handle 275 pulls the pull rod 274 outwards, the adjusting rod 272 and its connected nylon magnetic sensor 273 flip to a horizontal state, i.e., the folded state. When the handle 275 pushes the pull rod 274 inwards, the adjusting rod 272 and its connected nylon magnetic sensor 273 flip to a vertical state, i.e., the unfolded state. The lever 274 may be provided with a zigzag shape so that when the lever 274 is pushed or pulled by the handle 275, the adjusting lever 272 and the nylon magnetic sensor 273 thereon are in an unfolded or folded state, avoiding the lifting mechanism 220 and preventing interference between the two.

[0053] Please refer to Figure 8 and Figure 9The present invention also provides a method for using a zero magnetic shielding device, including a magnetic flux testing method and a remanence testing method.

[0054] Please refer to this carefully. Figure 9 Magnetic flux measurement methods include:

[0055] Open the shielding cover 120 on the shielding cylinder 110 of the magnetic shielding cylinder 100, so that the magnetic shielding cylinder 100 is in an open state. Place the Helmholtz coil 260 on the shelf 250, and place the object to be tested 280 inside the Helmholtz coil 260. Slide the shelf 250, the Helmholtz coil 260, and the object to be tested 280 along the track 240 to the predetermined area of ​​the shielding cylinder 110. Measure the magnetic flux of the object to be tested 280 through the Helmholtz coil 260. At this time, the foldable nylon magnetic sensing assembly 270 is in a folded state. The Helmholtz coil 260 needs to be connected to a magnetic flux testing device to measure the magnetic flux of the object to be tested 280. The magnetic flux testing device adopts known technology, including but not limited to a magnetometer or Hall sensor connected to the signal output terminal of the Helmholtz coil 260, and a constant current power supply that provides a stable current to the Helmholtz coil. At this time, the magnetic shielding cylinder 100 can be provided with a wire harness hole for a magnetic flux testing device connected to the Helmholtz coil 260.

[0056] Please refer to this carefully. Figure 8 Remanence testing methods include:

[0057] Open the shielding cover 120 on the shielding cylinder body 110 of the magnetic shielding cylinder 100, remove the Helmholtz coil 260 from the shelf 250, place the object to be tested 280 on the shelf 250, control the foldable nylon magnetic sensing component 270 to be in the unfolded state, slide the shelf 250 and the object to be tested 280 on it along the track 240 to the detection area of ​​the foldable nylon magnetic sensing component 270, close the shielding cover 120 to make the magnetic shielding cylinder 100 closed, and measure the residual magnetism of the object to be tested 280 on the shelf 250 through the foldable nylon magnetic sensing component 270. Before the residual magnetism measurement, the foldable nylon magnetic sensing component 270 needs to be connected to a residual magnetism testing device known in the art, which includes, but is not limited to, a computer or microcontroller connected to the nylon magnetic sensor 273 and its connected display screen. In the residual magnetism testing method, in order to improve the measurement accuracy, before measuring the residual magnetism of the object 280 to be tested on the shelf 250, the height of the test platform 230 and its track 240, shelf 250 and object 280 to be tested are adjusted by adjusting the height of the lifting mechanism 220, so that the object 280 to be tested enters the recognition area of ​​the nylon magnetic sensor 273 of the foldable nylon magnetic sensing component 270.

[0058] Please refer to Figures 3 to 4, Figures 8 to 9 This invention also provides a method for using a zero-magnetic shielding device, and further includes a method for demagnetizing the zero-magnetic shielding device. The method for demagnetizing the zero-magnetic shielding device includes:

[0059] The innermost layer of the shielding cylinder 110 is demagnetized by a demagnetizing coil 115 wound around the outer wall of the innermost permalloy cylinder. This eliminates the background magnetic field. The demagnetizing coil 115 needs to be connected to a demagnetizer. The demagnetizer controls the coil 115 to generate an alternating magnetic field attenuation or to repeatedly apply positive and negative magnetic fields (with decreasing amplitude) to achieve the purpose of demagnetizing the shielding cylinder 110. The demagnetizer can employ any known technology in the art. To improve measurement accuracy, the innermost layer of the shielding cylinder 110 is demagnetized before performing magnetic flux or residual magnetism tests on the object 280. The demagnetizing coil 115 can be optionally equipped with a cross-sectional area of ​​2.5 mm². 2 The copper enameled wire is wound into several turns of coil according to the length of the inner cylinder 111, and the demagnetizing coil 115 can be led out from the reserved through hole of the magnetic shielding cylinder 100.

[0060] The zero-magnetic shielding device and its usage method provided in this embodiment of the invention, when testing the magnetic flux of an object 280 inside a magnetic shielding cylinder 100, involves removing the shielding cover 120, placing the object 280 inside a Helmholtz coil 260, and sliding the shelf 250, the Helmholtz coil 260, and the object 280 inside it along the track 240 into a predetermined area of ​​the shielding cylinder 110. This allows the magnetic flux of the object 280 to be measured through the Helmholtz coil 260 while the magnetic shielding cylinder 100 is open. When performing a residual magnetism test, the Helmholtz coil 260 is removed from the shelf 250, and the object 280 is placed on the shelf. On shelf 250, by controlling the foldable nylon magnetic sensing component 270 to be in the unfolded state, the object to be tested 280 on shelf 250 is slid along track 240 to the detection area of ​​foldable nylon magnetic sensing component 270. In the closed magnetic shielding cylinder 100, the residual magnetism of the object to be tested 280 is measured by foldable nylon magnetic sensing component 270. Thus, when performing magnetic flux and residual magnetism switching tests on the object to be tested 280 inside magnetic shielding cylinder 100, there is no need to replace the non-magnetic multifunctional test rack 200, thereby improving the efficiency of switching tests on magnetic flux and residual magnetism of the object to be tested 280 inside magnetic shielding cylinder 100 and having the advantage of convenient switching tests.

[0061] The zero-magnetic shielding device and its usage method provided in this embodiment of the invention, wherein the non-magnetic multifunctional test rack 200 installed inside the magnetic shielding cylinder 100 is suitable for testing the magnetic flux and remanence of the object 280 under test, without the need for switching, and has universality, avoids the cumbersome process of repeatedly positioning and installing different test racks inside the magnetic shielding cylinder 100 when performing magnetic flux and remanence switching tests in the traditional magnetic shielding cylinder 100, thereby improving the efficiency of magnetic flux and remanence switching tests.

[0062] The zero-magnetic shielding device and its usage method provided in this embodiment of the invention allow the non-magnetic multifunctional test rack 200 to adjust its height within the magnetic shielding cylinder 100 via a lifting mechanism 220. This enables the test object 280 to enter the detection area for residual magnetism testing, thereby improving the accuracy of residual magnetism measurement of the test object 280. Furthermore, it is applicable to magnetic shielding cylinders 100 of different diameters, thus having the advantage of wide applicability.

[0063] The zero-magnetic shielding device and its usage method provided in this embodiment of the invention have an arc-shaped base 210 for the non-magnetic multifunctional test frame 200, which improves the stability of the non-magnetic multifunctional test frame 200 as a whole installed in the magnetic shielding cylinder 100.

[0064] The zero magnetic shielding device and its usage method provided in this embodiment of the invention allow the shelf 250 of the non-magnetic multifunctional test rack 200 to slide along the track 240, enabling the object 280 to be tested carried by the shelf 250 to be slid into the test area within the magnetic shielding cylinder 100 for corresponding measurement, thereby improving the measurement accuracy.

[0065] The zero-magnetic shielding device and its usage method provided in this embodiment of the invention, when performing magnetic flux testing on the object under test 280, control the foldable nylon magnetic sensing component 270 to be in a folded state, thereby retracting the foldable nylon magnetic sensing component 270 onto the arc-shaped base 210, avoiding interference and other adverse effects of the foldable nylon magnetic sensing component 270 on the magnetic flux measurement of the object under test 280; when performing remanence magnetism testing on the object under test 280, control the foldable nylon magnetic sensing component 270 to be in an unfolded state, thereby pushing the object under test 280 into the detection area of ​​the foldable nylon magnetic sensing component 270 to perform remanence magnetism measurement. During the remanence magnetism test, the Helmholtz coil 260 is removed to avoid interference with the remanence magnetism test of the object under test 280.

[0066] Please refer to Figures 6 to 7 The zero-magnetic shielding device and its usage method provided in the embodiments of the present invention may further include:

[0067] The support 300 includes a movable frame 310 and a cylindrical frame 320 connected thereto, with the magnetic shielding cylinder 100 detachably connected to the cylindrical frame 320. When the magnetic shielding cylinder 100 is connected to the support 300, the magnetic shielding cylinder 100 can be moved to the test environment by controlling the movement of the movable frame 310, facilitating the handling of the magnetic shielding cylinder 100. The cylindrical frame 320 improves the reliability of the connection to the magnetic shielding cylinder 100. The cylindrical frame 320 is provided with an arc-shaped groove that matches the magnetic shielding cylinder 100. The cylindrical frame 320 can be bolted to the extension plate or ear plate on the magnetic shielding cylinder 100 through through holes or threaded holes. The support 300 also supports the load of the magnetic shielding cylinder 100. To reduce costs, the cylindrical frame 320 can be a grid structure or a hollow structure.

[0068] This invention is not limited to the specific embodiments described above. Obviously, the embodiments described above are only a part of the embodiments of this invention, not all of them. All other embodiments obtained by those skilled in the art based on the described embodiments of this invention are within the scope of protection of this invention. Those skilled in the art can make other modifications and variations to this invention. Therefore, if these modifications and variations of this invention fall within the scope of the claims of this invention, then this invention also intends to include these modifications and variations.

Claims

1. A zero-magnetic shielding device, characterized in that, include: A magnetic shielding cylinder, including a shielding cylinder body and a detachably connected shielding cover; A non-magnetic multifunctional test fixture, installed inside a magnetic shielding cylinder, includes an arc-shaped base installed inside the magnetic shielding cylinder, a test platform located on a horizontal plane above the arc-shaped base, a lifting mechanism hinged between the arc-shaped base and the test platform, a track arranged along the length of the test platform, a shelf slidably arranged on the track, and a Helmholtz coil placed on the shelf for measuring the magnetic flux of an object placed inside the Helmholtz coil. It also includes a foldable nylon magnetic sensing component mounted on the arc-shaped base. When unfolded, the foldable nylon magnetic sensing component passes through an opening in the test platform and is positioned above the shelf for measuring the remanence of the object placed on the shelf. During magnetic flux testing, when folded, the foldable nylon magnetic sensing component retracts from the opening in the test platform onto the arc-shaped base.

2. The zero-magnetic shielding device according to claim 1, characterized in that, The shielding cylinder includes an inner cylinder and an outer cylinder. The inner cylinder is composed of five layers of permalloy alloy cylinders. A demagnetizing coil is wound around the outer wall of the innermost permalloy alloy cylinder. The two ends of the demagnetizing coil extend beyond the shielding cylinder for connection to a demagnetizing machine. The outer cylinder is an aluminum cylinder, and adjacent cylinder layers are separated by foam. The shielding cover includes an embedded inner shielding cover and a protective outer cover. The inner shielding cover consists of two embedded permalloy alloy covers, and the protective outer cover is an aluminum cover. The protective outer cover has two symmetrical handles, and adjacent covers are separated by foam. The protective outer cover is sealed onto the outer cylinder, and the inner shielding cover is sealed within the cavity between any three permalloy alloy cylinder layers between the innermost and outermost layers of the inner cylinder. A sealing ring is arranged around the cavity between any two adjacent permalloy alloy cylinder layers at the end where the inner shielding cover is installed.

3. The zero-magnetic shielding device according to claim 1, characterized in that, The lifting mechanism is a scissor-type lifting frame, and the test platform is equipped with a handle for controlling the scissor-type lifting frame to rise and fall relative to the arc-shaped seat by lifting the test platform.

4. The zero-magnetic shielding device according to claim 1, characterized in that, The foldable nylon magnetic sensing assembly includes a support fixedly mounted on an arc-shaped base, an adjusting rod hinged to the support, a nylon magnetic sensor connected to the upper end of the adjusting rod, and a pull rod hinged to the adjusting rod near the support. A handle is connected to one end of the pull rod extending out of the arc-shaped base. When the pull rod is pulled outward by the handle, the adjusting rod and the nylon magnetic sensor connected to it flip to a horizontal state. When the pull rod is pushed inward by the handle, the adjusting rod and the nylon magnetic sensor connected to it flip to a vertical state.

5. The zero-magnetic shielding device according to claim 1, characterized in that, Also includes: The support includes a movable frame and a cylindrical frame connected thereto, wherein the magnetic shielding cylinder is detachably connected to the cylindrical frame.

6. A method of using a zero-magnetic shielding device according to any one of claims 1-5, characterized in that, This includes methods for testing magnetic flux and methods for testing remanence. The magnetic flux testing method includes: Open the shielding cover installed on the shielding cylinder body to make the magnetic shielding cylinder open. Place the Helmholtz coil on the shelf and place the object to be tested inside the Helmholtz coil. Slide the shelf, the Helmholtz coil on it, and the object to be tested inside it along the track to the predetermined area of ​​the shielding cylinder body. Measure the magnetic flux of the object to be tested through the Helmholtz coil. The residual magnetism testing method includes: Open the shielding cover installed on the shielding cylinder body of the magnetic shielding cylinder, take out the Helmholtz coil on the shelf, place the object to be tested on the shelf, control the foldable nylon magnetic sensing component to be in the unfolded state, slide the shelf and the object to be tested on it along the track to the detection area of ​​the foldable nylon magnetic sensing component, close the shielding cover to make the magnetic shielding cylinder in the closed state, and measure the residual magnetism of the object to be tested on the shelf through the foldable nylon magnetic sensing component.

7. A method of using the zero-magnetic shielding device according to claim 2, characterized in that, This includes demagnetization methods for zero-magnetic shielding devices, magnetic flux testing methods, and residual magnetism testing methods. The demagnetization method of the zero-magnetic shielding device includes: The innermost permalloy cylinder of the shielding cylinder is demagnetized by connecting a power source to a demagnetizing coil wound around the outer wall of the innermost permalloy cylinder. The magnetic flux testing method includes: Open the shielding cover installed on the shielding cylinder body to make the magnetic shielding cylinder open. Place the Helmholtz coil on the shelf and place the object to be tested inside the Helmholtz coil. Slide the shelf, the Helmholtz coil on it, and the object to be tested inside it along the track to the predetermined area of ​​the shielding cylinder body. Measure the magnetic flux of the object to be tested through the Helmholtz coil. The residual magnetism testing method includes: Open the shielding cover installed on the shielding cylinder body of the magnetic shielding cylinder, take out the Helmholtz coil on the shelf, place the object to be tested on the shelf, control the foldable nylon magnetic sensing component to be in the unfolded state, slide the shelf and the object to be tested on it along the track to the detection area of ​​the foldable nylon magnetic sensing component, close the shielding cover to make the magnetic shielding cylinder in the closed state, and measure the residual magnetism of the object to be tested on the shelf through the foldable nylon magnetic sensing component.

8. The method of using the zero-magnetic shielding device according to claim 7, characterized in that, Before performing magnetic flux or residual magnetism tests on the object under test, the innermost permalloy cylinder of the shielding cylinder is demagnetized.

9. The method of using the zero-magnetic shielding device according to claim 7, characterized in that, In the residual magnetism testing method, before measuring the residual magnetism of the object to be tested on the shelf, the height of the test platform and its track, shelf and object to be tested are adjusted by adjusting the height of the lifting mechanism so that the object to be tested enters the recognition area of ​​the nylon magnetic sensor of the foldable nylon magnetic sensing component.

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