A magnetic shielding cavity, a measuring system and a measuring method

Abstract

An embodiment of the present invention relates to a magnetic shielding cavity, a measurement system and a measurement method. The magnetic shielding cavity is used to form a zero magnetic field environment, and includes an inner cavity, an outer cavity, a first extension plate and a second extension plate. The inner cavity has a first opening; the outer cavity has a second opening; the outer cavity is covered on the outside of the inner cavity, and the second opening corresponds to the first opening; the first extension plate is connected to the edge of the second opening and extends outward; the second extension plate is connected to the edge of the second opening, and is arranged opposite to the first extension plate, and extends outward; a translation channel is formed between the first extension plate and the second extension plate; wherein external objects can enter the inner cavity through the translation channel, the second opening and the first opening in sequence through a translation movement.

Description

Technical Field

[0001] The present invention relates to the technical field of magnetic field morphology scanning, and in particular to a magnetic shielding cavity, a measurement system and a measurement method. Background Art

[0002] In magnetic field morphology scanning, the most commonly used device is the Hall effect sensor. The voltage output of the Hall effect sensor is directly proportional to the size of the spatial magnetic field, that is, the higher the magnetic field, the greater the output voltage of the Hall effect sensor.

[0003] When the magnetic field strength is zero, the voltage output value of the Hall effect sensor should theoretically be zero. However, in practice, the voltage output of the Hall effect sensor cannot be zero. Generally speaking, when the magnetic field strength is zero, the voltage output of the Hall effect sensor is an inherent bias voltage of the millivolt or microvolt level, which will introduce errors in the magnetic field measurement. In high-precision magnetic field measurement, the bias voltage must be accurately measured and eliminated through data processing methods.

[0004] In order to accurately measure the bias voltage of the Hall effect sensor, the Hall effect sensor needs to be placed in a zero magnetic field space that is not disturbed by the magnetic field of the external space. However, the design of the magnetic shielding cavity that can form a zero magnetic field environment in the related art is not good enough, resulting in a cumbersome measurement process. Summary of the invention

[0005] The embodiments of the present invention provide a magnetic shielding cavity, a measuring system and a measuring method for simplifying the measuring process.

[0006] The magnetic shielding cavity of the embodiment of the present invention is used to form a zero magnetic field environment, and the magnetic shielding cavity includes: an inner cavity, an outer cavity, a first extension plate and a second extension plate, the inner cavity has a first opening; the outer cavity has a second opening; the outer cavity is covered on the outside of the inner cavity, and the second opening corresponds to the first opening; the first extension plate is connected to the edge of the second opening and extends outward; the second extension plate is connected to the edge of the second opening, and is arranged opposite to the first extension plate, and extends outward; a translation channel is formed between the first extension plate and the second extension plate; wherein, external objects can pass through the translation channel, the second opening and the first opening in sequence through a translation movement to enter the inner cavity.

[0007] According to some embodiments of the present invention, the external object is a Hall sensor;

[0008] Wherein, the Hall sensor is moved along a direction opposite to the direction of the translational motion, and the Hall sensor can be moved out of the inner cavity to measure the magnetic field strength of the magnet being measured.

[0009] According to some embodiments of the present invention, the inner cavity and the outer cavity are both cylindrical structures.

[0010] According to some embodiments of the present invention, the inner cavity comprises an inner side wall, an inner top wall connected to one end of the inner side wall, and an inner bottom wall connected to the other end of the inner side wall;

[0011] The first opening includes a first sub-opening and a second sub-opening, the first sub-opening is arranged on the inner side wall, the second sub-opening is arranged on the inner bottom wall, and the first sub-opening is communicated with the second sub-opening.

[0012] According to some embodiments of the present invention, the first sub-opening is arranged along the axial direction of the inner cavity, and the second sub-opening is arranged along the radial direction of the inner cavity.

[0013] According to some embodiments of the present invention, the length of the first sub-opening is greater than half of the height of the inner side wall, so that the foreign object can move to the center of the inner cavity along the axial direction.

[0014] According to some embodiments of the present invention, the length of the second sub-opening is greater than the radius of the inner bottom wall, so that the foreign object can move to the center of the inner cavity along the radial direction.

[0015] According to some embodiments of the present invention, the outer cavity comprises an outer side wall, an outer top wall connected to one end of the outer side wall, and an outer bottom wall connected to the other end of the outer side wall;

[0016] The second opening includes a third sub-opening and a fourth sub-opening. The third sub-opening is arranged on the outer side wall and corresponds to the first sub-opening. The fourth sub-opening is arranged on the outer bottom wall and corresponds to the second sub-opening. The third sub-opening is connected to the fourth sub-opening.

[0017] The measuring system of the embodiment of the present invention is used to detect the bias voltage of the Hall sensor and measure the magnetic field strength of the magnet to be measured, and the measuring system includes:

[0018] The magnet to be tested;

[0019] A magnetic shielding cavity as described in any one of the above items; at least part of the first opening and at least part of the second opening of the magnetic shielding cavity are both facing the magnet to be measured; and

[0020] The motion platform is used to drive the Hall sensor to generate translational motion so that the Hall sensor can enter and exit the magnetic shielding cavity.

[0021] The measuring method of the embodiment of the present invention is used to detect the bias voltage of the Hall sensor and measure the magnetic field strength of the magnet to be measured, and the measuring method comprises the following steps:

[0022] Providing a magnet to be measured and a Hall sensor, wherein the Hall sensor is located on the center line of the magnet to be measured;

[0023] Providing a magnetic shielding cavity as described in any one of the above items, wherein the magnetic shielding cavity is located on the center line of the magnet to be measured, and at least part of the first opening and at least part of the second opening of the magnetic shielding cavity face the magnet to be measured;

[0024] Driving the Hall sensor to generate translational motion, so that the Hall sensor can enter and exit the magnetic shielding cavity through the translation channel, the second opening and the first opening of the magnetic shielding cavity;

[0025] Wherein, when the Hall sensor is located inside the magnetic shielding cavity, a bias voltage of the Hall sensor is obtained;

[0026] When the Hall sensor is located outside the magnetic shielding cavity, the Hall sensor is used to measure the magnetic field strength of the magnet to be measured.

[0027] One embodiment of the above invention has the following advantages or beneficial effects:

[0028] By adopting the technical means that the first extension plate is connected to the edge of the second opening and extends outward, the second extension plate is connected to the edge of the second opening, and is arranged opposite to the first extension plate and extends outward, and a translation channel is formed between the first extension plate and the second extension plate, the first opening and the second opening of the magnetic shielding cavity of the embodiment of the present invention can be oriented toward the magnet to be measured, so that it is convenient for external objects to enter the interior of the magnetic shielding cavity only through translation movement. Compared with the technical solution of multiple movements in the related art, the magnetic shielding cavity of the embodiment of the present invention only needs to move once, which simplifies the operation. In addition, although the first opening and the second opening are oriented toward the magnet to be measured, by setting the first extension plate and the second extension plate to extend outward, the shielding space of the magnetic shielding cavity is extended outward, ensuring that the zero magnetic field environment in the magnetic shielding cavity is not affected. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The above and other features and advantages of the present invention will become more apparent by describing in detail exemplary embodiments thereof with reference to the attached drawings.

[0030] Figure 1 Shown is a top view of a measurement system in the related art.

[0031] Figure 2 Shown is a structural schematic diagram of a magnetic shielding cavity according to an embodiment of the present invention.

[0032] Figure 3 Shown is another structural schematic diagram of the magnetic shielding cavity according to an embodiment of the present invention.

[0033] Figure 4 Shown is another structural schematic diagram of the magnetic shielding cavity according to an embodiment of the present invention.

[0034] Figure 5 It is shown that Figure 4 Sectional view of AA.

[0035] Figure 6 Shown is a top view of a measurement system according to an embodiment of the present invention.

[0036] Figure 7 Shown is a diagram of magnetic field distribution at different positions inside the magnetic shielding cavity according to an embodiment of the present invention.

[0037] The reference numerals are described as follows:

[0038] 110. Hall sensor

[0039] 120. Magnet under test

[0040] 130. Sports Platform

[0041] 140. Support

[0042] 150. Magnetic shielding cavity

[0043] 200. Magnetic shielding cavity

[0044] 210, Inner cavity

[0045] 211. Inner wall

[0046] 212. Inner bottom wall

[0047] 213. Inner roof wall

[0048] 214. First Opening

[0049] 220. External cavity

[0050] 221. Outer wall

[0051] 222. Outer bottom wall

[0052] 223. External top wall

[0053] 224, Second Opening

[0054] 231. First extension plate

[0055] 232. Second extension plate

[0056] 240. Translation Channel

[0057] D. Translational motion DETAILED DESCRIPTION

[0058] Example embodiments will now be described more fully with reference to the accompanying drawings. However, example embodiments can be implemented in a variety of forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that the present invention will be comprehensive and complete and fully convey the concepts of the example embodiments to those skilled in the art. The same reference numerals in the figures represent the same or similar structures, and thus their detailed description will be omitted.

[0059] like Figure 1 As shown, Figure 1 The figure shows a top view of a measurement system in the related art. The measurement system in the related art includes a Hall sensor 110, a magnet 120 to be measured, a motion platform 130, a support 140 and a magnetic shielding cavity 150, wherein the support 140 is connected to the motion platform 130, the Hall sensor 110 is arranged on the support 140, and the motion platform 130 can drive the support 140 and the Hall sensor 110 to move.

[0060] The magnetic shielding cavity 150 in the related art is a cylindrical structure, one side of the cylindrical structure is closed, and the other side of the cylindrical structure ( Figure 1 The cylindrical structure has an opening (as indicated by the arrow in the middle). The Hall sensor 110 can enter and exit the cylindrical structure through the opening.

[0061] In order to detect the magnetic field strength of the measured magnetic field, the Hall sensor 110 needs to be located near the center line of the measured magnet 120 so as to better map the magnetic field shape. Therefore, the initial position of the Hall sensor 110 needs to be set on one side of the measured magnet 120 and near the center line of the measured magnet 120.

[0062] In addition, the central area of ​​the magnetic shielding cavity 150 also needs to be located on one side of the magnet 120 to be measured, and the central area is located near the center line of the magnet 120 to be measured. In this way, the magnetic field strength in the central area can be close to zero to obtain a zero magnetic field environment. Therefore, when the Hall sensor 110 is inserted into the magnetic shielding cavity 150 and moved to the central area, the bias voltage of the Hall sensor 110 can be accurately measured. Therefore, the initial position of the magnetic shielding cavity 150 also needs to be set near the center line of the magnet 120 to be measured.

[0063] In order to obtain the bias voltage of the Hall sensor 110 in a zero magnetic field environment, the Hall sensor 110 needs to be moved from the initial position to the central area inside the magnetic shielding cavity 150. Specifically, the motion platform 130 first drives the support 140 and the Hall sensor 110 to move along the positive direction of the Z axis, then moves along the negative direction of the X axis to the bottom of the magnetic shielding cavity 150, and finally moves along the negative direction of the Z axis, so that the Hall sensor 110 moves to the central area inside the magnetic shielding cavity 150.

[0064] As can be seen from the above, in order to move the Hall sensor 110 to the central area inside the magnetic shielding cavity 150, the Hall sensor 110 needs to be moved three times. Conversely, the process of moving the Hall sensor 110 out of the magnetic shielding cavity 150 also requires moving the Hall sensor 110 three times. This makes the measurement process cumbersome.

[0065] Based on this, an embodiment of the present invention provides a magnetic shielding cavity that can simplify the measurement process.

[0066] like Figures 2 to 5 As shown, Figure 2 FIG. 2 is a schematic structural diagram of a magnetic shielding cavity 200 according to an embodiment of the present invention. Figure 3 FIG. 2 is another schematic structural diagram of a magnetic shielding cavity 200 according to an embodiment of the present invention. Figure 4 FIG. 2 shows another structural schematic diagram of the magnetic shielding cavity 200 according to an embodiment of the present invention. Figure 5 It is shown that Figure 4 Sectional view of AA.

[0067] The magnetic shielding cavity 200 of the embodiment of the present invention is used to form a zero magnetic field environment. The magnetic shielding cavity 200 includes an inner cavity 210, an outer cavity 220, a first extension plate 231 and a second extension plate 232. The inner cavity 210 has a first opening 214, the outer cavity 220 has a second opening 224, the outer cavity 220 is covered on the outside of the inner cavity 210, and the second opening 224 corresponds to the first opening 214. The first extension plate 231 is connected to the edge of the second opening 224 and extends outward. The second extension plate 232 is connected to the edge of the second opening 224, and is arranged opposite to the first extension plate 231, and extends outward. A translation channel 240 is formed between the first extension plate 231 and the second extension plate 232. Among them, external objects can enter the interior of the inner cavity 210 by passing through the translation channel 240, the second opening 224 and the first opening 214 in sequence through a translation movement D.

[0068] When in use, the Hall sensor 110 passes through the translation channel 240, the second opening 224 and the first opening 214 from the outside of the magnetic shielding cavity 200 through a translation movement D in sequence and enters the interior of the inner cavity 210. Under the common shielding effect of the inner cavity 210, the outer cavity 220, the first extension plate 231 and the second extension plate 232, the internal space of the inner cavity 210 roughly forms a zero magnetic field environment. At this time, in the zero magnetic field environment, the bias voltage value of the Hall sensor 110 can be accurately measured.

[0069] In addition, after obtaining the bias voltage of the Hall sensor 110, the Hall sensor 110 can be moved in a direction opposite to the direction of the translational motion D to remove the Hall sensor 110 from the magnetic shielding cavity 200. After the Hall sensor 110 is removed, the magnetic field strength of the magnet 120 under test can be directly measured.

[0070] By adopting the technical means that the first extension plate 231 is connected to the edge of the second opening 224 and extends outward, the second extension plate 232 is connected to the edge of the second opening 224 and is arranged opposite to the first extension plate 231 and extends outward, and a translation channel 240 is formed between the first extension plate 231 and the second extension plate 232, the first opening 214 and the second opening 224 of the magnetic shielding cavity 200 of the embodiment of the present invention can be oriented toward the magnet 120 to be measured, and it is convenient for external objects to enter the inside of the magnetic shielding cavity 200 only through translation movement D. Compared with the technical solution of multiple movements in the related art, the magnetic shielding cavity 200 of the embodiment of the present invention only needs to move once, which simplifies the operation. In addition, although the first opening 214 and the second opening 224 are oriented toward the magnet 120 to be measured, the shielding space of the magnetic shielding cavity 200 is extended outward by setting the first extension plate 231 and the second extension plate 232 to extend outward, ensuring that the zero magnetic field environment in the magnetic shielding cavity 200 is not affected.

[0071] In one embodiment, the external object may be a Hall sensor 110. After the Hall sensor 110 is translated into the magnetic shielding cavity 200, a bias voltage of the Hall sensor 110 in a zero magnetic field environment may be obtained. After the Hall sensor 110 is moved out of the magnetic shielding cavity 200, the magnetic field strength of the magnet 120 under test may be measured.

[0072] Please continue reading Figures 2 to 5, the inner cavity 210 and the outer cavity 220 can both be cylindrical structures. Specifically: the inner cavity 210 includes an inner side wall 211, an inner top wall 213 connected to one end of the inner side wall 211, and an inner bottom wall 212 connected to the other end of the inner side wall 211. The first opening 214 includes a first sub-opening and a second sub-opening, the first sub-opening is provided on the inner side wall 211, the second sub-opening is provided on the inner bottom wall 212, and the first sub-opening is connected to the second sub-opening. In other words, the first sub-opening and the second sub-opening together form a roughly L-shaped opening.

[0073] In one embodiment, the first sub-opening may face the magnet 120 to be measured, and the second sub-opening may face the motion platform 130. When the motion platform 130 drives the support member 140 and the Hall sensor 110 to translate, the Hall sensor 110 enters and exits the inner cavity 210 through the first sub-opening, and the support member 140 enters and exits the inner cavity 210 through the first sub-opening and the second sub-opening.

[0074] like Figure 2 and Figure 4 As shown, the first sub-opening is arranged along the axial direction of the inner cavity 210 , and the second sub-opening is arranged along the radial direction of the inner cavity 210 .

[0075] By designing the first sub-opening to be along the axial direction and the second sub-opening to be along the radial direction, when the motion platform 130 drives the support member 140 and the Hall sensor 110 to translate, the support member 140 and the Hall sensor 110 can enter and exit the inner cavity 210 along the radial direction of the inner cavity 210.

[0076] like Figure 4 As shown, the length of the first sub-opening is greater than half the height of the inner cavity 210. That is, one end of the first sub-opening starts from the inner bottom wall 212, and the other end of the first sub-opening extends toward the inner top wall 213 and ends at a point more than half of the inner side wall 211. With such a design, the Hall sensor 110 can reach the central area of ​​the inner cavity 210 along the axial direction when it is translated.

[0077] The length of the second sub-opening is greater than the radius of the inner bottom wall 212. That is, one end of the second sub-opening starts at the inner side wall 211, and the other end of the second sub-opening ends at a point more than half of the inner bottom wall 212. With such a design, the Hall sensor 110 can reach the center of the inner cavity 210 in the radial direction when it is translated.

[0078] By designing that the length of the first sub-opening is greater than half the height of the inner cavity 210 and the length of the second sub-opening is greater than the radius of the inner bottom wall 212 , the Hall sensor 110 can reach the central area of ​​the inner cavity 210 .

[0079] Please continue reading Figures 2 to 5 The outer cavity 220 may include an outer wall 221, an outer top wall 223 connected to one end of the outer wall 221, and an outer bottom wall 222 connected to the other end of the outer wall 221. The second opening 224 includes a third sub-opening and a fourth sub-opening, the third sub-opening is provided on the outer wall 221 and is corresponding to the first sub-opening, the fourth sub-opening is provided on the outer bottom wall 222 and is corresponding to the second sub-opening; the third sub-opening is connected to the fourth sub-opening. The third sub-opening and the fourth sub-opening together form a substantially L-shaped opening.

[0080] In one embodiment, the third sub-opening may face the magnet 120 to be measured, and the fourth sub-opening may face the motion platform 130. When the motion platform 130 drives the support member 140 and the Hall sensor 110 to translate, the Hall sensor 110 enters and exits the outer cavity 220 through the third sub-opening, and the support member 140 enters and exits the outer cavity 220 through the third sub-opening and the fourth sub-opening.

[0081] like Figure 2 and Figure 4 As shown, the third sub-opening is arranged along the axial direction of the outer cavity 220 , and the fourth sub-opening is arranged along the radial direction of the outer cavity 220 .

[0082] By designing the third sub-opening to be along the axial direction and the fourth sub-opening to be along the radial direction, when the motion platform 130 drives the support member 140 and the Hall sensor 110 to translate, the support member 140 and the Hall sensor 110 can enter and exit the outer cavity 220 along the radial direction of the outer cavity 220.

[0083] The extension lengths of the third sub-opening and the fourth sub-opening may be similar to those of the first sub-opening and the second sub-opening. Specifically:

[0084] like Figure 4 As shown, the length of the third sub-opening is greater than half the height of the outer cavity 220. That is, one end of the third sub-opening starts from the outer bottom wall 222, and the other end of the third sub-opening extends to the outer top wall 223 and ends at more than half of the outer side wall 221. With such a design, the Hall sensor 110 can reach the central area of ​​the outer cavity 220 along the axial direction when it is translated.

[0085] The length of the fourth sub-opening is greater than the radius of the outer bottom wall 222. That is, one end of the fourth sub-opening starts from the outer side wall 221, and the other end of the fourth sub-opening ends at a point more than half of the outer bottom wall 222. With such a design, the Hall sensor 110 can reach the center of the outer cavity 220 in the radial direction when translated.

[0086] By designing that the length of the third sub-opening is greater than half the height of the outer cavity 220 and the length of the fourth sub-opening is greater than the radius of the outer bottom wall 222 , the Hall sensor 110 can reach the center area of ​​the outer cavity 220 .

[0087] Of course, it is understandable that the inner cavity 210 and the outer cavity 220 may also be in other shapes, such as a spherical shape, a cubic shape, etc.

[0088] In one embodiment, the inner cavity 210 and the outer cavity 220 are coaxially arranged. The inner cavity 210, the outer cavity 220, the first extension plate 231 and the second extension plate 232 can all be made of a high magnetic permeability material, such as an iron-nickel alloy.

[0089] The first extension plate 231 and the second extension plate 232 can be connected to the inner cavity 210 and the outer cavity 220 by argon arc welding.

[0090] In one embodiment, the diameter of the outer cavity 220 may be 150 mm, and the diameter of the inner cavity 210 may be 50 mm. The distance between the first extension plate 231 and the second extension plate 232 may be 33.6 mm. The size of the first extension plate 231 may be 170 mm*120 mm, and the size of the second extension plate 232 may be 170 mm*120 mm.

[0091] In one implementation, the magnetic shielding cavity 200 of the embodiment of the present invention may also be a three-layer structure, a four-layer structure, etc.

[0092] Another aspect of the present invention provides a measurement system for detecting a bias voltage of a Hall sensor 110 and measuring a magnetic field strength of a magnet 120 to be measured.

[0093] like Figure 6 As shown, Figure 6 The top view of the measuring system of the embodiment of the present invention is shown. The measuring system of the embodiment of the present invention comprises a Hall sensor 110, a magnet to be measured 120, a motion platform 130, a support 140 and a magnetic shielding cavity 200 of any of the above embodiments. At least part of the first opening 214 and at least part of the second opening 224 of the magnetic shielding cavity 200 are both facing the magnet to be measured 120. The motion platform 130 is used to drive the Hall sensor 110 to generate translational movement so that the Hall sensor 110 can enter and exit the magnetic shielding cavity 200.

[0094] When measuring the bias voltage of the Hall sensor 110 in a zero magnetic field environment, the Hall sensor 110 passes through the translation channel 240, the second opening 224 and the first opening 214 from the outside of the magnetic shielding cavity 200 through a translation movement D in sequence and enters the interior of the inner cavity 210. Under the common shielding effect of the inner cavity 210, the outer cavity 220, the first extension plate 231 and the second extension plate 232, the internal space of the inner cavity 210 roughly forms a zero magnetic field environment. At this time, in a zero magnetic field environment, the bias voltage value of the Hall sensor 110 can be accurately measured.

[0095] When measuring the magnetic field strength of the measured magnet 120, after obtaining the bias voltage of the Hall sensor 110, the Hall sensor 110 can be moved in a direction opposite to the direction of the above-mentioned translational motion D to move the Hall sensor 110 out of the magnetic shielding cavity 200. After the Hall sensor 110 is moved out, the magnetic field strength of the measured magnet 120 can be directly measured.

[0096] Therefore, the measuring system of the embodiment of the present invention can combine the detection of the bias voltage of the Hall sensor 110 and the measurement of the magnetic field strength of the measured magnet 120 by adopting the magnetic shielding cavity 200 of any of the above embodiments, and the above operation can be completed with only two translation movements D. Compared with the technical solution of multiple movements in the related art, the measuring system of the embodiment of the present invention greatly simplifies the operation and significantly improves the measurement efficiency.

[0097] In one embodiment, the magnet under test 120 may be an accelerator magnet or an insert magnet.

[0098] In another aspect of the present invention, a measurement method is provided for detecting the bias voltage of the Hall sensor 110 and measuring the magnetic field strength of the magnet 120 to be measured. The measurement method comprises the following steps:

[0099] A magnet 120 to be measured and a Hall sensor 110 are provided, wherein the Hall sensor 110 is located on the center line of the magnet 120 to be measured;

[0100] A magnetic shielding cavity 200 according to any of the above embodiments is provided, wherein the magnetic shielding cavity 200 is located on the center line of the magnet 120 to be measured, and at least a portion of the first opening 214 and at least a portion of the second opening 224 of the magnetic shielding cavity 200 face the magnet 120 to be measured;

[0101] The Hall sensor 110 is driven to generate a translational motion D, so that the Hall sensor 110 can enter and exit the magnetic shielding cavity 200 through the translation channel 240 , the second opening 224 , and the first opening 214 of the magnetic shielding cavity 200 ;

[0102] When the Hall sensor 110 is located inside the magnetic shielding cavity 200 , a bias voltage of the Hall sensor 110 is obtained;

[0103] When the Hall sensor 110 is located outside the magnetic shielding cavity 200 , the Hall sensor 110 is used to measure the magnetic field strength of the magnet 120 to be measured.

[0104] It is worth mentioning that the Hall sensor 110 is located on the center line of the measured magnet 120. It should be understood that the center of the Hall sensor 110 can be located on the center line of the measured magnet 120, or can be offset from the center line of the measured magnet 120 by a certain distance. Of course, the offset distance will not be too large, and it can be located within the good field range.

[0105] Combine the following Figure 7 , illustrating the magnetic field distribution of the magnetic shielding cavity 200 according to an embodiment of the present invention.

[0106] like Figure 7 As shown, Figure 7 FIG. 2 shows the magnetic field distribution diagram at different positions inside the magnetic shielding cavity 200 according to an embodiment of the present invention. Figure 2 and Figure 6 In the coordinate system shown, the origin of the coordinate system is set at the center of the magnetic shielding cavity 200, that is, the origin is located at the center of the inner cavity 210 and the outer cavity 220. When Y=0, the magnetic field distribution at different positions along the radial direction of the inner cavity 210 on the axis (i.e., the Z axis) can be obtained.

[0107] Figure 7 In the figure, the horizontal axis represents the X-axis, wherein the 0 point of the X-axis is located on the center line of the inner cavity 210 and the outer cavity 220. The positive direction of the X-axis (i.e., X is between 0 mm and 25 mm) is the direction gradually extending from the 0 point along the radial direction toward the translation channel 240. The negative direction of the X-axis (i.e., X is between -5 mm and 0 mm) is the direction extending from the 0 point along the radial direction away from the translation channel 240. The positive direction of the Z-axis is the direction extending from the 0 point toward the opening direction. The vertical axis represents the magnetic field strength.

[0108] The geomagnetic field is usually around 0.5Gs (Gauss). Under the influence of the geomagnetic field, 12 different points are selected in the positive direction of the Z axis, and 12 different curves are drawn when the X value is between -5mm and 25mm, such as Figure 7 shown.

[0109] It can be seen from the figure that most of the curves are almost equal to 0 when X is in the range of 0mm to 10mm, that is, the magnetic field strength in most of the curves in the region where X is between 0mm and 10mm tends to 0, and only two curves do not tend to 0 in the range of X = 0mm to 10mm. In other words, in the range of X being 0mm to 10mm, the magnetic field strength in most regions in the positive direction of the Z axis is 0. It can be seen that the magnetic shielding cavity 200 of the embodiment of the present invention not only simplifies the measurement process, but also can well shield the earth's magnetism and achieve a zero magnetic field environment.

[0110] The inventor of the present invention has proved through experiments that the magnetic shielding cavity 200 of the embodiment of the present invention can shield the magnetic field in the central area to 10 -8 T (Tesla) level.

[0111] In summary, the advantages and beneficial effects of the magnetic shielding cavity 200, the measurement system and the measurement method according to the embodiment of the present invention are:

[0112] By adopting the technical means that the first extension plate 231 is connected to the edge of the second opening 224 and extends outward, the second extension plate 232 is connected to the edge of the second opening 224, and is arranged opposite to the first extension plate 231 and extends outward, and a translation channel 240 is formed between the first extension plate 231 and the second extension plate 232, the first opening 214 and the second opening 224 of the magnetic shielding cavity 200 of the embodiment of the present invention can be oriented toward the magnet 120 to be measured, and it is convenient for external objects to enter the magnetic shielding cavity 200 only through translation movement. Compared with the technical solution of multiple movements in the related art, the magnetic shielding cavity 200 of the embodiment of the present invention only needs to move once, which simplifies the operation. In addition, although the first opening 214 and the second opening 224 are oriented toward the magnet 120 to be measured, the shielding space of the magnetic shielding cavity 200 is extended outward by setting the first extension plate 231 and the second extension plate 232 to extend outward, ensuring that the zero magnetic field environment in the magnetic shielding cavity 200 is not affected.

[0113] The measuring system of the embodiment of the present invention can combine the detection of the bias voltage of the Hall sensor 110 and the measurement of the magnetic field strength of the measured magnet 120 by adopting the magnetic shielding cavity 200 of any of the above embodiments, and the above operations can be completed with only two translation movements. Compared with the technical solutions of multiple movements in the related art, the measuring system of the embodiment of the present invention greatly simplifies the operation and significantly improves the measurement efficiency.

[0114] In the embodiments of the invention, the terms "first", "second", and "third" are used for descriptive purposes only and are not to be understood as indicating or implying relative importance; the term "plurality" refers to two or more, unless otherwise clearly defined. The terms "installed", "connected", "connected", "fixed", etc. should be understood in a broad sense. For example, "connected" can be a fixed connection, a detachable connection, or an integral connection; "connected" can be a direct connection or an indirect connection through an intermediate medium. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the invention can be understood according to the specific circumstances.

[0115] In the description of the embodiments of the invention, it is necessary to understand that the directions or positional relationships indicated by the terms "up", "down", "left", "right", "front", "back", etc. are based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the embodiments of the invention and simplifying the description, rather than indicating or implying that the device or unit referred to must have a specific direction, be constructed and operated in a specific orientation, and therefore, cannot be understood as a limitation on the embodiments of the invention.

[0116] In the description of this specification, the description of the terms "one embodiment", "some embodiments", "specific embodiments", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the invention embodiment. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0117] The above are only preferred embodiments of the invention embodiments, and are not intended to limit the invention embodiments. For those skilled in the art, the invention embodiments may have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the invention embodiments shall be included in the protection scope of the invention embodiments.

Claims

1. A measuring system for detecting the bias voltage of a Hall sensor and measuring the magnetic field strength of a magnet under test, characterized in that: The measuring system comprises: The magnet to be tested; A magnetic shielding cavity, used to form a zero magnetic field environment, the magnetic shielding cavity comprises an inner cavity, an outer cavity, a first extension plate and a second extension plate, the inner cavity has a first opening; the outer cavity has a second opening; the outer cavity is covered on the outside of the inner cavity, and the second opening corresponds to the first opening; at least part of the first opening and at least part of the second opening are both facing the magnet to be measured; the first extension plate is connected to the edge of the second opening and extends outward; the second extension plate is connected to the edge of the second opening, and is arranged opposite to the first extension plate, and extends outward; a translation channel is formed between the first extension plate and the second extension plate; wherein the Hall sensor can pass through the translation channel, the second opening and the first opening in sequence through a translation movement to enter the inner cavity; the inner cavity and the outer cavity are both cylindrical structures; and A motion platform, used for driving the Hall sensor to generate translational motion, so that the Hall sensor can enter and exit the magnetic shielding cavity; When the Hall sensor is located inside the magnetic shielding cavity, the bias voltage of the Hall sensor is obtained; when the Hall sensor is moved in a direction opposite to the direction of the translational motion and the Hall sensor can be moved out of the inner cavity and located outside the magnetic shielding cavity, the Hall sensor is used to measure the magnetic field strength of the magnet being measured.

2. The measuring system according to claim 1, characterized in that The inner cavity comprises an inner side wall, an inner top wall connected to one end of the inner side wall, and an inner bottom wall connected to the other end of the inner side wall; The first opening includes a first sub-opening and a second sub-opening, the first sub-opening is arranged on the inner side wall, the second sub-opening is arranged on the inner bottom wall, and the first sub-opening is communicated with the second sub-opening.

3. The measuring system according to claim 2, characterized in that The first sub-opening is arranged along the axial direction of the inner cavity, and the second sub-opening is arranged along the radial direction of the inner cavity.

4. The measuring system according to claim 3, characterized in that The length of the first sub-opening is greater than half of the height of the inner side wall, so that the Hall sensor can be moved to the center of the inner cavity along the axial direction.

5. The measuring system according to claim 3, characterized in that The length of the second sub-opening is greater than the radius of the inner bottom wall, so that the Hall sensor can move to the center of the inner cavity in the radial direction.

6. The measuring system according to claim 2, characterized in that The outer cavity comprises an outer side wall, an outer top wall connected to one end of the outer side wall, and an outer bottom wall connected to the other end of the outer side wall; The second opening includes a third sub-opening and a fourth sub-opening. The third sub-opening is arranged on the outer side wall and corresponds to the first sub-opening. The fourth sub-opening is arranged on the outer bottom wall and corresponds to the second sub-opening. The third sub-opening is connected to the fourth sub-opening.

7. A measurement method for detecting the bias voltage of a Hall sensor and measuring the magnetic field strength of a magnet under test, characterized in that: The measuring method comprises the following steps: Providing a magnet to be measured and a Hall sensor, wherein the Hall sensor is located on the center line of the magnet to be measured; A magnetic shielding cavity is provided, the magnetic shielding cavity is located on the center line of the magnet to be measured, the magnetic shielding cavity comprises an inner cavity, an outer cavity, a first extension plate and a second extension plate, the inner cavity has a first opening; the outer cavity has a second opening; the outer cavity is covered on the outside of the inner cavity, and the second opening corresponds to the first opening; the first extension plate is connected to the edge of the second opening and extends outward; the second extension plate is connected to the edge of the second opening, and is arranged opposite to the first extension plate, and extends outward; a translation channel is formed between the first extension plate and the second extension plate; at least part of the first opening and at least part of the second opening of the magnetic shielding cavity face the magnet to be measured; Driving the Hall sensor to generate translational motion, so that the Hall sensor can enter and exit the magnetic shielding cavity through the translation channel, the second opening and the first opening; Wherein, when the Hall sensor is located inside the magnetic shielding cavity, a bias voltage of the Hall sensor is obtained; When the Hall sensor is located outside the magnetic shielding cavity, the Hall sensor is used to measure the magnetic field strength of the magnet to be measured.

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