Method and device for detecting magnetizing saturation of permanent magnet

Abstract

The method comprises the following steps that S1, a plurality of permanent magnets magnetized according to the same standard are tightly attracted to form a permanent magnet queue, when the magnetizing saturation of all the permanent magnets is normal, the permanent magnet queue is equivalent to a single long-strip magnet, and when the magnetizing saturation of all the permanent magnets is normal, the permanent magnet queue is equivalent to a single long-strip magnet; most of magnetic flux flows through the interior of the permanent magnet queue; when the magnetizing saturation of any permanent magnet is abnormal, part of magnetic flux leaks into the air from two magnetic poles of the magnet with the abnormal magnetizing saturation, and a closed loop is formed in the nearby air; s2, a magnetic induction device is fixedly arranged, the to-be-detected permanent magnet queue is moved to enable each permanent magnet to pass through the magnetic induction device, and whether the magnetizing saturation of the corresponding permanent magnet is abnormal or not is judged through magnetic force change induction of the magnetic induction device. According to the technical scheme, continuous detection can be carried out when the to-be-detected permanent magnet queue moves, the permanent magnet queue does not need to be damaged, and the beneficial effect of high detection efficiency is achieved.

Description

Technical Field

[0001] The present invention belongs to the technical field of magnetism, and in particular relates to a method and device for detecting the magnetization saturation of a permanent magnet. Background Art

[0002] The continuous batch magnetization of permanent magnets is typically implemented in the following manner. Using a chute or conveyor belt, the permanent magnets to be magnetized are neatly arranged in a long queue and fed in from one end of a solenoid and out from the other end. Simultaneously, a pulsed power supply discharges the solenoid at a certain frequency, generating a strong pulsed magnetic field that instantly magnetizes the permanent magnets in the solenoid, achieving magnetization. In the actual production process, due to occasional fluctuations in factors such as the processing quality of the permanent magnets, the queue movement speed, and the frequency of pulse discharges, the magnetic flux density of individual magnets in the queue may not reach saturation. With increasingly stringent quality control standards, the accurate and efficient removal of these magnets with low magnetization saturation from the queue is a common requirement in the magnetic material production industry.

[0003] Traditional inspection methods require workers to use tools or automated mechanisms to remove mutually attracted permanent magnets from the test queue one by one. The workers then use a fluxmeter to measure the magnetic moment of each magnet, or a gaussmeter to measure the surface flux density of each magnet. By comparing the measured results with standard values, the magnetization saturation of each magnet is determined to be within the specified range. After inspection, the magnets that meet the standard must be neatly assembled into strips for packaging. This traditional inspection method is therefore inefficient and difficult to adapt to the quality control requirements of large-scale production.

[0004] Therefore, in view of the technical defects of the existing technology, it is necessary to propose a solution to solve the technical problems of the existing technology. Summary of the Invention

[0005] The present invention provides a method and device for detecting the magnetization saturation of permanent magnets. By detecting fluctuations in magnetic attraction near a queue of magnetized permanent magnets, the method locates individual unsaturated permanent magnets within the queue. Compared to traditional detection schemes, the present invention can quickly locate magnets with abnormal magnetization saturation without disrupting the queue, facilitating their individual removal. This eliminates the need to individually peel off individual magnets and then re-adsorb qualified magnets into a queue, significantly improving detection efficiency and reducing the complexity and design and installation difficulty of the automated mechanism. This makes it easier to incorporate continuous magnetization quality monitoring into existing automated magnetization lines.

[0006] In order to solve the technical problems existing in the prior art, the technical solutions of the present invention are as follows: A method for detecting the magnetization saturation of a permanent magnet comprises the following steps: Step S1: Multiple permanent magnets magnetized according to the same standard are tightly attracted to each other to form a permanent magnet array. When the magnetization saturation of all permanent magnets is normal, the permanent magnet array is equivalent to a single long magnet, and most of the magnetic flux flows through the permanent magnet array. When the magnetization saturation of any permanent magnet is abnormal, part of the magnetic flux leaks into the air from the two poles of the magnet with abnormal magnetization saturation, forming a closed loop in the nearby air. Step S2: a fixed magnetic induction device is set, and the queue of permanent magnets to be tested is moved so that each permanent magnet passes through the magnetic induction device. The magnetic induction device senses the magnetic change to determine whether the magnetization saturation of the corresponding permanent magnet is abnormal.

[0007] As a further improvement, in step S2, when all permanent magnets passing near the magnetic induction device are saturated with magnetization, the magnetic attraction force on the magnetic induction device is essentially zero; when there is an abnormal magnetization saturation near the magnetic induction device, the magnetic induction device can sense the magnetic flux leaked from the permanent magnet array, thereby exerting a significant magnetic attraction on it.

[0008] As a further improvement, in step S2, the magnetic induction device is arranged below or on the side of the permanent magnet array.

[0009] As a further improvement, the magnetic induction device includes a magnetic induction sheet, a cantilever beam, a force sensor and a fixed base, wherein: The magnetic sensing piece is fixed to one end of the cantilever beam and is used to sense the magnetic field changes of the permanent magnet array; The other end of the cantilever beam is connected to one end of the force sensor; The other end of the force sensor is connected to a fixed base for sensing the magnitude of the magnetic force.

[0010] As a further improvement, the magnetic sensing piece is close to but not in contact with the permanent magnet array to be measured; When the permanent magnet array to be tested moves relative to the component along the array direction, the magnetic sensing sheet can sense the change of magnetic attraction; The cantilever beam amplifies the magnetic attraction force and transmits it to the force sensor; The force sensor is connected to a post-processing circuit, which is used to measure and store the magnitude of the magnetic attraction force to determine whether the magnetization saturation of the permanent magnet is abnormal.

[0011] As a further improvement, the magnetic sensing sheet is made of a ferromagnetic material with low coercivity, and is made of any one of pure iron, iron alloy, cobalt alloy, nickel alloy, manganese-zinc ferrite and nickel-zinc ferrite; The cantilever beam is made of non-magnetic material, and is made of any one of aluminum alloy, magnesium alloy, copper alloy, non-magnetic stainless steel, glass fiber composite board, carbon fiber composite board, plastic, resin and wood; The force sensor is made of non-magnetic material, and is made of any one of aluminum alloy, magnesium alloy and copper alloy.

[0012] The present invention also discloses a device for detecting the magnetization saturation of a permanent magnet. A magnetic force sensing device is fixedly arranged near a permanent magnet array. The magnetic force sensing device is used to sense the magnetic flux changes of each permanent magnet in the permanent magnet array to be tested, and to determine whether the magnetization saturation of the corresponding permanent magnet is abnormal by sensing the magnetic force changes. When the permanent magnets passing near the magnetic induction device are all saturated with magnetization, the magnetic attraction force on the magnetic induction device is basically zero; when there is an abnormal magnetization saturation near the magnetic induction device, the magnetic induction device can sense the magnetic flux leaked from the permanent magnet array, and then produce a significant magnetic attraction effect on it.

[0013] As a further improvement, the magnetic induction device includes a magnetic induction sheet, a cantilever beam, a force sensor and a fixed base, wherein: The magnetic sensing piece is fixed to one end of the cantilever beam and is used to sense the magnetic field changes of the permanent magnet array; The other end of the cantilever beam is connected to one end of the force sensor; The other end of the force sensor is connected to a fixed base for sensing the magnitude of the magnetic force.

[0014] As a further improvement, the magnetic sensing piece is close to but not in contact with the permanent magnet array to be measured; When the permanent magnet array to be tested moves relative to the component along the array direction, the magnetic sensing sheet can sense the change of magnetic attraction; The cantilever beam amplifies the magnetic attraction force and transmits it to the force sensor; The force sensor is connected to a post-processing circuit, which is used to measure and store the magnitude of the magnetic attraction force to determine whether the magnetization saturation of the permanent magnet is abnormal.

[0015] Preferably, the magnetic sensing sheet is made of a ferromagnetic material with low coercivity, including: pure iron, iron alloy, cobalt alloy, nickel alloy, manganese zinc ferrite and nickel zinc ferrite; Preferably, the cantilever beam is made of non-magnetic materials, including: aluminum alloy, magnesium alloy, copper alloy, non-magnetic stainless steel, glass fiber composite board, carbon fiber composite board, plastic, resin and wood; Preferably, the force sensor is made of non-magnetic materials, including aluminum alloy, magnesium alloy and copper alloy; Preferably, the fastening accessories in the assembly for detecting the magnetization saturation of the permanent magnet array, including the fixing base, screws and gaskets, are all made of non-magnetic materials.

[0016] Compared with the existing technology, the above-mentioned configuration of the present invention produces the following beneficial effects: when the magnets near the magnetic sensing plate are all saturated, the vast majority of the magnetic flux flows through the magnets, and the magnetic attraction force on the magnetic sensing plate is essentially zero. However, when a magnet with a lower saturation passes near the magnetic sensing plate, the magnetic flux leaking from the permanent magnet array will pass through the magnetic sensing plate, exerting a significant magnetic attraction on it. By monitoring and recording the fluctuations in the magnetic attraction force as the array moves, magnets with abnormal saturation can be detected and located. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 A schematic structural diagram of an embodiment of the present invention; Figure 2 is the magnetic flux distribution diagram in the XZ plane when all magnets in the permanent magnet array are saturated; Figure 3 The magnetic flux distribution diagram in the XZ plane when there is a magnet in the permanent magnet array that is not saturated; Figure 4 The distribution diagram of the magnitude of the Z-direction component along the X-direction when there is a magnet in the permanent magnet array that is not saturated; Figure 5 The distribution diagram of the magnetic attraction force of the magnetic sensing piece in the Z direction along the X direction when there is a magnet in the permanent magnet array that is not saturated Figure 6 The magnetic flux distribution diagram in the XZ plane when there are two magnets in the permanent magnet array that are not saturated; Figure 7 The distribution diagram of the magnitude of the Z-direction component along the X-direction when there are two magnets in the permanent magnet array that are not saturated; Figure 8 The distribution diagram of the magnetic attraction force in the Z direction on the magnetic sensing piece along the X direction when there are two magnets in the permanent magnet array that are not saturated; Figure 9 The figure is a flow chart of a method for detecting the magnetization saturation of a permanent magnet according to the present invention. DETAILED DESCRIPTION

[0018] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0019] On the contrary, the present invention covers any alternatives, modifications, equivalents, and solutions that fall within the spirit and scope of the present invention as defined by the claims. Furthermore, to facilitate a better understanding of the present invention, certain specific details are described in detail below in the detailed description of the present invention. Those skilled in the art will be able to fully understand the present invention without these details.

[0020] See also Figure 9 , which is a flow chart of a method for detecting the magnetization saturation of a permanent magnet according to the present invention, comprising the following steps: Step S1: Multiple permanent magnets magnetized according to the same standard are tightly attracted to each other to form a permanent magnet array. When the magnetization saturation of all permanent magnets is normal, the permanent magnet array is equivalent to a single long magnet, and most of the magnetic flux flows through the permanent magnet array. When the magnetization saturation of any permanent magnet is abnormal, part of the magnetic flux leaks into the air from the two poles of the magnet with abnormal magnetization saturation, forming a closed loop in the nearby air. Step S2: a fixed magnetic induction device is set, and the queue of permanent magnets to be tested is moved so that each permanent magnet passes through the magnetic induction device. The magnetic induction device senses the magnetic change to determine whether the magnetization saturation of the corresponding permanent magnet is abnormal.

[0021] In the above technical solution, when the magnetization saturation of all permanent magnets in the permanent magnet array is normal, the magnetic flux distribution of the permanent magnet array is similar to that of a single long magnet, that is, most of the magnetic flux flows in and out from the front and rear ends of the array, and only a small amount of magnetic flux leaks into the air from the sides of the array. When the magnetization saturation of any permanent magnet is abnormal, some magnetic flux leaks into the air from the two poles of the magnet with abnormal magnetization saturation, forming a closed loop in the nearby air. Therefore, when all permanent magnets passing near the magnetic induction device are saturated, the magnetic attraction force on the magnetic induction device is essentially zero. When the magnetization saturation near the magnetic induction device is abnormal, the magnetic induction device can sense the magnetic flux leaking from the permanent magnet array, thereby exerting a significant magnetic attraction on it.

[0022] Figure 1 The figure shows the structure of the magnetic induction device of this embodiment, which includes a magnetic induction sheet 1, a cantilever beam 2, a force sensor 3, a fixed base 4, a connecting bolt 5, and a permanent magnet array 6, wherein: The magnetic sensing sheet 1 is a thin sheet made of a ferromagnetic material with low coercivity. The cantilever beam 2 is a long strip, connected to the magnetic sensing sheet 1 at one end and to the force sensor 3 at the other. The force sensor 3 is connected to the cantilever beam 2 and the fixed base 4 at each end. The force sensor 3 shown in the figure is a resistance strain gauge type, but other types such as piezoelectric ceramic, electromagnetic, and fiber optic can also be used. The cantilever beam 2, force sensor 3, fixed base 4, and connecting bolts 5 are all made of non-magnetic materials. The permanent magnet array 6 is composed of multiple magnetized permanent magnets of the same specifications, positioned end to end, with their magnetization direction along the length of the array. For ease of illustration, this is shown along the positive half-axis in the figure. The permanent magnet array 6 is typically supported by a chute, conveyor belt, or other device and driven by a push rod, roller, or other device, which is not shown in the above device diagram. The arrow on the permanent magnet array 6 indicates that the permanent magnet array moves along the X-axis.

[0023] The specific implementation method for detecting the magnetization saturation of a permanent magnet array using a magnetic sensing device is as follows: The component is positioned below or to the side of the permanent magnet array, with the magnetic sensing plate 1 positioned close to but not in contact with the permanent magnet array 6. The plane of the magnetic sensing plate 1 is parallel to the axis of the array, allowing it to sense the magnetic attraction in the Z-axis direction. When a magnet with abnormal magnetization saturation in the array passes through the magnetic sensing plate, the magnetic attraction fluctuates and is amplified by the cantilever beam 2 and transmitted to the force sensor 3, where it is detected and recorded by the back-end processing circuitry connected to the sensor. At this point, the magnet corresponding to the location of the force sensor 3 is the magnet with abnormal magnetization saturation.

[0024] For example, consider a permanent magnet array with one magnet that is not saturated. Finite element simulation can be used to compare and display the magnetic flux distribution patterns in the area near the permanent magnet array. The simulation parameters are as follows: the permanent magnet array contains 59 permanent magnets, each of which is 10 mm long, 10 mm wide, and 5 mm thick. They are magnetized along the thickness direction. The residual magnetic flux density after saturation magnetization is 1.44 T, while the residual magnetic flux density after saturation is 0.72 T. See [1]. Figure 2 If all magnets in the permanent magnet array 6 are saturated, the magnetic flux distribution in the XZ plane is similar to that of a single long magnet, that is, most of the magnetic flux flows in and out from the head and tail of the array, and only a small amount of magnetic flux leaks into the air from the sides of the array. Figure 3 If there is a magnet in the permanent magnet array 6 that is not saturated, the magnetic flux distribution in the XZ plane will be severely distorted, and part of the magnetic flux will leak into the air from the two poles of the magnet with abnormal magnetization saturation, and form a closed loop in the nearby air.

[0025] Finite element simulation can be used to further compare and display the magnetic flux density in the vicinity of the permanent magnet array. A point 8 mm from the center axis of the magnet array is selected to examine the distribution curve of the Z-direction component of the magnetic flux density vector along the X-direction. Figure 4If all magnets in the permanent magnet array 6 are saturated and magnetized, the Z-direction component of the magnetic flux density vector is basically zero; if there is a magnet in the permanent magnet array 6 that is not saturated, the magnitude and direction of the Z-direction component of the magnetic flux density vector fluctuate violently at this magnet, indicating that a large amount of magnetic flux penetrates into and out of the magnet and forms a closed loop in the nearby air.

[0026] Finite element simulation can be used to further compare and demonstrate the magnitude of the magnetic attraction applied to the magnetic sensing piece 1. The simulation parameters are as follows: the magnetic sensing piece 1 is 10 mm long, 5 mm wide, and 2 mm high, made of pure iron, and the center of the magnetic sensing piece 1 is 8 mm from the center axis of the magnet array. Figure 5 If all magnets in permanent magnet array 6 are saturated, the Z-direction magnetic attraction force on magnetic sensing plate 1 is approximately zero. If one magnet in permanent magnet array 6 is not saturated, when this abnormal magnet moves near magnetic sensing plate 1, the magnetic flux leaking into the air from that location will interact with magnetic sensing plate 1. As a result, the Z-direction magnetic attraction force on magnetic sensing plate 1 exhibits a sharp peak at that location, while remaining approximately zero at other locations, demonstrating excellent positional resolution for magnets with abnormal saturation.

[0027] For example, consider a permanent magnet array with two unsaturated magnets. Finite element simulation can be used to compare the magnetic flux distribution patterns in the vicinity of the permanent magnet array. The simulation parameters are as follows: the permanent magnet array contains 59 permanent magnets, each of which is 10 mm long, 10 mm wide, and 5 mm thick. They are magnetized along the thickness direction. The residual magnetic flux density after saturation magnetization is 1.44 T, while the residual magnetic flux density after unsaturation is 0.72 T. See [1]. Figure 6 If the 21st and 36th permanent magnets from left to right in the permanent magnet array are not saturated, the magnetic flux distribution in the XZ plane will be severely distorted, and part of the magnetic flux will leak into the air from the two poles of the saturation-abnormal magnet and form a closed loop in the nearby air.

[0028] Finite element simulation can be used to further compare and display the magnetic flux density in the vicinity of the permanent magnet array. A point 8 mm from the center axis of the magnet array is selected to examine the distribution curve of the Z-direction component of the magnetic flux density vector along the X-direction. Figure 7 If all magnets in permanent magnet array 6 are saturated and magnetized, the Z-direction component of the magnetic flux density vector is basically zero; if the 21st and 36th permanent magnets from left to right in the permanent magnet array are not saturated, the magnitude and direction of the Z-direction component of the magnetic flux density vector fluctuate violently at the 21st and 36th permanent magnets, indicating that a large amount of magnetic flux enters and exits the magnets and forms a closed loop in the nearby air.

[0029] Finite element simulation can be used to further compare and demonstrate the magnitude of the magnetic attraction applied to the magnetic sensing piece 1. The simulation parameters are as follows: the magnetic sensing piece 1 is 10 mm long, 5 mm wide, and 2 mm high, made of pure iron, and the center of the magnetic sensing piece 1 is 8 mm from the center axis of the magnet array. Figure 8 If all magnets in permanent magnet array 6 are saturated, the Z-direction magnetic attraction force on magnetic sensing plate 1 is approximately zero. If the 21st and 36th permanent magnets (counted from left to right) in the permanent magnet array are not saturated, when these two abnormal magnets move near magnetic sensing plate 1, the magnetic flux leaking into the air from these locations will interact with magnetic sensing plate 1. As a result, the Z-direction magnetic attraction force on magnetic sensing plate 1 exhibits sharp peaks at the 21st and 36th permanent magnets, while remaining approximately zero at all other locations, demonstrating excellent positional resolution for magnets with abnormal saturation.

[0030] It should be pointed out that by using a Gaussmeter to measure the fluctuations of magnetic flux density near a permanent magnet array, it is theoretically possible to find magnets with abnormal saturation. However, it is difficult to adsorb the actual permanent magnet array very neatly. Even if all magnets are saturated and magnetized, the size and direction of the magnetic flux density vector at the magnet joints will also fluctuate violently. Since the Gaussmeter detects the component of a certain specific direction of the magnetic flux density vector, and the sensitive area of ​​the probe is usually only tens of microns, it is more sensitive to the above fluctuations, so there is a high probability of misjudgment, which makes it difficult to apply in practice. The magnetic detection component used in the present invention has a magnetic field sensitive area of ​​several millimeters in width, and has no specific requirements for the direction of the magnetic flux density vector. Therefore, it can have both high anti-interference ability and position resolution ability. In actual practice, the size, shape and measurement spacing of the magnetic sensing piece can be adjusted and optimized according to the specifications of the permanent magnet to be measured to achieve better detection effect.

[0031] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A method for detecting the magnetization saturation of a permanent magnet, characterized in that: The following steps are involved: Step S1: Multiple permanent magnets magnetized according to the same standard are tightly attracted to each other to form a permanent magnet array. When the magnetization saturation of all permanent magnets is normal, the permanent magnet array is equivalent to a single long magnet, and most of the magnetic flux flows through the permanent magnet array. When the magnetization saturation of any permanent magnet is abnormal, part of the magnetic flux leaks into the air from the two poles of the magnet with abnormal magnetization saturation, forming a closed loop in the nearby air. Step S2: a fixed magnetic induction device is set, and the queue of permanent magnets to be tested is moved so that each permanent magnet passes through the magnetic induction device. The magnetic induction device senses the magnetic change to determine whether the magnetization saturation of the corresponding permanent magnet is abnormal.

2. The method for detecting the magnetization saturation of a permanent magnet according to claim 1, wherein: In step S2, when all permanent magnets passing near the magnetic induction device are saturated with magnetization, the magnetic attraction force on the magnetic induction device is basically zero; when there is an abnormal magnetization saturation near the magnetic induction device, the magnetic induction device can sense the magnetic flux leaked from the permanent magnet array, thereby exerting a significant magnetic attraction on it.

3. The method for detecting the magnetization saturation of a permanent magnet according to claim 2, wherein: In step S2, the magnetic induction device is arranged below or on the side of the permanent magnet array.

4. The method for detecting the magnetization saturation of a permanent magnet according to claim 3, wherein: The magnetic induction device includes a magnetic induction sheet, a cantilever beam, a force sensor and a fixed base, wherein: The magnetic sensing piece is fixed to one end of the cantilever beam and is used to sense the magnetic field changes of the permanent magnet array; The other end of the cantilever beam is connected to one end of the force sensor; The other end of the force sensor is connected to a fixed base for sensing the magnitude of the magnetic force.

5. The method for detecting the magnetization saturation of a permanent magnet according to claim 4, wherein: The magnetic sensing piece is close to but not in contact with the permanent magnet array to be tested; When the permanent magnet array to be tested moves relative to the component along the array direction, the magnetic sensing sheet can sense the change of magnetic attraction; The cantilever beam amplifies the magnetic attraction force and transmits it to the force sensor; The force sensor is connected to a post-processing circuit, which is used to measure and store the magnitude of the magnetic attraction force to determine whether the magnetization saturation of the permanent magnet is abnormal.

6. The method for detecting the magnetization saturation of a permanent magnet according to claim 4, wherein: The magnetic sensing sheet is made of a ferromagnetic material with low coercivity, and is made of any one of pure iron, iron alloy, cobalt alloy, nickel alloy, manganese zinc ferrite and nickel zinc ferrite; The cantilever beam is made of non-magnetic material, and is made of any one of aluminum alloy, magnesium alloy, copper alloy, non-magnetic stainless steel, glass fiber composite board, carbon fiber composite board, plastic, resin and wood; The force sensor is made of non-magnetic material, and is made of any one of aluminum alloy, magnesium alloy and copper alloy.

7. A device for detecting the magnetization saturation of a permanent magnet, characterized in that: A magnetic sensing device is fixedly arranged near the permanent magnet array, and is used to sense the magnetic flux changes of each permanent magnet in the permanent magnet array to be tested, and to determine whether the magnetization saturation of the corresponding permanent magnet is abnormal by sensing the magnetic changes; When the permanent magnets passing near the magnetic induction device are all saturated with magnetization, the magnetic attraction force on the magnetic induction device is basically zero; when there is an abnormal magnetization saturation near the magnetic induction device, the magnetic induction device can sense the magnetic flux leaked from the permanent magnet array, and then produce a significant magnetic attraction effect on it.

8. The device for detecting the magnetization saturation of a permanent magnet according to claim 7, characterized in that: The magnetic induction device includes a magnetic induction sheet, a cantilever beam, a force sensor and a fixed base, wherein: The magnetic sensing piece is fixed to one end of the cantilever beam and is used to sense the magnetic field changes of the permanent magnet array; The other end of the cantilever beam is connected to one end of the force sensor; The other end of the force sensor is connected to a fixed base for sensing the magnitude of the magnetic force.

9. The device for detecting the magnetization saturation of a permanent magnet according to claim 8, characterized in that: The magnetic sensing piece is close to but not in contact with the permanent magnet array to be tested; When the permanent magnet array to be tested moves relative to the component along the array direction, the magnetic sensing sheet can sense the change of magnetic attraction; The cantilever beam amplifies the magnetic attraction force and transmits it to the force sensor; The force sensor is connected to a post-processing circuit, which is used to measure and store the magnitude of the magnetic attraction force to determine whether the magnetization saturation of the permanent magnet is abnormal.

10. The device for detecting the magnetization saturation of a permanent magnet according to claim 8, characterized in that: The magnetic sensing sheet is made of a ferromagnetic material with low coercivity, and is made of any one of pure iron, iron alloy, cobalt alloy, nickel alloy, manganese zinc ferrite and nickel zinc ferrite; The cantilever beam is made of non-magnetic material, and is made of any one of aluminum alloy, magnesium alloy, copper alloy, non-magnetic stainless steel, glass fiber composite board, carbon fiber composite board, plastic, resin and wood; The force sensor is made of non-magnetic material, and is made of any one of aluminum alloy, magnesium alloy and copper alloy.

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