A micro-nano device for detecting micro defects in metal sheets under production conditions

Abstract

The present invention relates to a micro-nano device for detecting micro defects of metal sheets under production conditions, comprising a micro-nano device, the micro-nano device comprising a housing, the upper portion of the housing being a mounting opening, a printed circuit board being provided at the bottom of the housing, pads being symmetrically provided on both sides of the housing, the lower ends of the pads being connected to the printed circuit board, spring beam assemblies being symmetrically provided on the other two sides of the housing corresponding to the mounting opening, a mass block being horizontally fixedly mounted between the two spring beam assemblies, a groove being provided at the center of the mass block for limiting the installation of a permanent magnet, movable parallel plates being arranged at equal intervals in the middle of both sides of the mass block relative to the liner, the movable parallel plates, the mass block and the permanent magnet forming a movable body, and fixed parallel plates being arranged at equal intervals on the side walls relative to the liner, the other ends of the fixed parallel plates being inserted into the gaps between the movable parallel plates. The present invention can detect micro defects of metal sheets under production conditions with high detection accuracy.

Description

Technical Field

[0001] The present invention belongs to the technical field of metal sheet micro-defect detection, and in particular to a micro-nano device for detecting metal sheet micro-defects under production conditions. Background Art

[0002] Metal materials are indispensable in our daily lives, playing a crucial role in numerous applications, including lithium-ion batteries, automotive panels, electrical components, and medical devices. However, during the actual production process, numerous surface defects, such as surface or near-surface pinholes, dents, wrinkles, and tiny inclusions, often occur. These micro-defects significantly impact the quality and performance of metal materials. To ensure product quality and effectively reduce production costs, companies must monitor the number, size, and type of material defects during the production process.

[0003] Currently, there are five main types of non-destructive testing methods for metal materials: ultrasonic, radiographic, eddy current, magnetic powder, and penetration. These methods have been used to detect the structure, quantity, and location of defects inside or on the surface of metal samples. However, these methods also have limitations, such as poor real-time performance, low detection confidence, and unsuitability for harsh production environments. In recent years, the rapid development of artificial intelligence technology has enabled image processing to be applied in the field of metal surface defect detection. However, in the application process, this technology requires the metal plate to remain stationary or move at a low speed during the inspection process, and cannot be applied in actual production processes.

[0004] The existing technology mostly uses eddy current technology, but the sensors used in this technology often have reduced detection accuracy because the sensors themselves cannot effectively support the mass of small permanent magnets and do not consider the impact of the mass of the permanent magnets themselves. Therefore, there is an urgent need for a micro-nano device that can detect micro-defects in metal sheets under production conditions, and can better support small permanent magnets and prevent the position of permanent magnets from shifting.

[0005] No patent documents related to this application were found through the search. Summary of the Invention

[0006] The purpose of the present invention is to overcome the shortcomings of the existing technology and provide a micro-nano device for detecting micro-defects in metal sheets under production conditions. The system performs real-time detection of the nanonewton-level Lorentz force generated by micro-defects and / or micro-inclusions inside the metal sheet being tested under actual production conditions, thereby alleviating the technical problem of insufficient detection accuracy of current sensors.

[0007] The present invention solves the technical problem by adopting the following technical solutions:

[0008] A micro-nano device for detecting micro defects of metal sheets under production conditions, comprising a micro-nano device, which is arranged below the metal sheet to be tested in a moving state; the micro-nano device is used to fix a permanent magnet, and the metal sheet to be tested and the permanent magnet move relative to each other, so that the micro-nano device can detect the metal sheet to be tested, characterized in that: the micro-nano device comprises a shell, a mass block, a movable parallel plate, a fixed parallel plate, a pad and a spring beam assembly, the upper part of the shell is a mounting port, a printed circuit board is provided at the bottom of the shell, pads are symmetrically provided on both sides of the shell, the lower ends of the pads are connected to the printed circuit board, and the other two sides of the shell corresponding to the mounting port position are connected to the printed circuit board. Spring beam assemblies are symmetrically arranged inside, and a mass block is horizontally fixed between the two spring beam assemblies to ensure that the mass block is located in the center of the installation opening of the shell, and a groove is made at the center of the mass block for limiting the installation of a permanent magnet. Movable parallel pole plates are arranged at equal intervals in the middle of both sides of the mass block relative to the lining. The movable parallel pole plates, the mass block and the permanent magnet constitute a movable body, and fixed parallel pole plates are arranged at equal intervals on the opposite side walls of the lining, and the other end of the fixed parallel pole plate is inserted in the gap between the movable parallel pole plates; the movable body is driven by the Lorentz force to cause displacement between the movable parallel pole plate and the fixed parallel pole plate, thereby forming a capacitance change.

[0009] Moreover, the movable parallel plates and the fixed parallel plates are parallel to each other.

[0010] Moreover, the spring beam assembly includes two symmetrically arranged support beams, each support beam includes a mounting column and a spring piece that provides a restoring force to the lateral movement of the movable body under the action of the Lorentz force. The mounting column is installed on the inner wall of the shell, and a spring piece is horizontally installed on one side of the mounting column. The other end of the spring piece is fixed at the corner position of the mass block to achieve a stable and centered setting of the mass block. The spring piece is made as a whole and includes a bow-shaped structure with multiple turns or bends.

[0011] Moreover, the permanent magnets are neodymium iron boron permanent magnets, aluminum nickel cobalt permanent magnet alloys, iron chromium cobalt permanent magnet alloys, barium ferrites, strontium ferrites and rare earth cobalt permanent magnets.

[0012] Moreover, the magnetization direction of the permanent magnet is perpendicular to the upper surface of the mass block.

[0013] Moreover, the length of the movable parallel pole plates is the same as the length of the permanent magnets arranged on the mass block.

[0014] Moreover, the shell includes a silicon-based shell, a silicon nitride shell, and a III-V semiconductor shell.

[0015] Moreover, the thickness of the metal sheet being measured is 0-0.1 mm, and the value is not 0.

[0016] Moreover, the diameter of the micro defects or micro inclusions in the metal sheet being tested is 20 μm.

[0017] The advantages and positive effects of the present invention are:

[0018] A groove is formed at the center of the upper surface of the mass block of the present invention for limiting the placement of the permanent magnet, and movable parallel pole plates are set on both sides of the mass block, and the mass block is installed at the center position of the mounting opening of the shell through a spring beam assembly to form a stable integral movable body, and the movable parallel pole plates of the movable body are arranged parallel and cross-wise with the fixed parallel pole plates, which effectively reduces the longitudinal displacement of the mass block caused by the mass of the small permanent magnet, ensuring the stability of the micro-nano device. When the micro-nano device detects a 20μm defect in the metal sheet under actual working conditions, it can generate sufficient lateral displacement for detection, significantly improving the sensitivity of the micro-nano device. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 Schematic diagram of the structure of an embodiment of the present invention;

[0020] Figure 2 A partial schematic diagram provided for an embodiment of the present invention;

[0021] Figure 3 A schematic diagram of the position relationship provided by an embodiment of the present invention;

[0022] Figure 4 This is a simulation diagram of the capacitance change when detecting a 25nN force caused by a 20μm defect on a 100μm thin plate according to an embodiment of the present invention;

[0023] Figure 5 This is a simulation diagram of the capacitance change when detecting a 25nN force caused by a 20μm defect on a 100μm thin plate in a comparative example of the present invention;

[0024] Figure 6 Schematic diagram of the pulse signal of the comparative example. DETAILED DESCRIPTION

[0025] The present invention will be further described in detail below with reference to the accompanying drawings and through specific embodiments. The following embodiments are merely illustrative and non-restrictive, and the scope of protection of the present invention cannot be limited thereto.

[0026] A micro-nano device for detecting micro-defects of metal sheets under production conditions includes a micro-nano device 1, which is arranged below a metal sheet 9 to be tested in a moving state; a permanent magnet 3 is provided on the micro-nano device, and the metal sheet to be tested and the permanent magnet move relative to each other, so that the micro-nano device can detect the metal sheet to be tested. The micro-nano device includes a shell, a mass block 5, a movable parallel plate 7, a fixed parallel plate 8, a pad 2 and a spring beam assembly. The upper part of the shell is a mounting port, and a printed circuit board is provided at the bottom of the shell. Pads are symmetrically provided on both sides of the shell, and the lower end of the pad is connected to the printed circuit board. Spring beam assemblies are symmetrically provided on the other two sides of the shell corresponding to the mounting port position. A mass block is fixed horizontally between the two spring beam assemblies so that the mass block is located at the exact center of the mounting opening of the shell, and a groove is formed at the center of the mass block for limiting the installation of a permanent magnet. Movable parallel pole plates are arranged at equal intervals in the middle of both sides of the mass block relative to the lining plate. The movable parallel pole plates, the mass block and the permanent magnet constitute a movable body, and fixed parallel pole plates are arranged at equal intervals on the opposite side walls of the lining, and the other end of the fixed parallel pole plate is inserted in the gap between the movable parallel pole plates; and the movable parallel pole plate and the fixed parallel pole plate are parallel to each other. The movable body is driven by the Lorentz force to cause displacement between the movable parallel pole plate and the fixed parallel pole plate, thereby forming a capacitance change.

[0027] The spring beam assembly includes two symmetrically arranged support beams 6, each support beam includes a mounting column and a spring clip, the mounting column is installed on the inner wall of the shell, a spring clip is horizontally installed on one side of the mounting column, and the other end of the spring clip is fixed at the corner position of the mass block, thereby realizing the central setting of the mass block, the spring clip is made as a whole, and includes a plurality of turning or curved bow-shaped structures, which are used to reduce the stiffness and provide a restoring force to the lateral movement of the movable body under the action of the Lorentz force, further ensuring that the micro-nano device has sufficient stiffness to support the small permanent magnet.

[0028] In a specific implementation of the present invention, the permanent magnet is used to provide a stable external magnetic field and receive the force of the Lorentz force, and adopts neodymium iron boron permanent magnet, aluminum nickel cobalt permanent magnet alloy, iron chromium cobalt permanent magnet alloy, barium ferrite, strontium ferrite and rare earth cobalt permanent magnet; and the magnetization direction of the permanent magnet is perpendicular to the upper surface of the mass block.

[0029] The length of the movable parallel pole plate is the same as the length of the permanent magnet provided on the mass block;

[0030] In a specific implementation of the present invention, the shell includes a silicon-based shell, a silicon nitride shell, or a III-V semiconductor shell;

[0031] The micro-nano device provided in this embodiment can detect the nanonewton-level Lorentz force generated by micro defects and / or micro inclusions contained in the metal sheet, thereby understanding the defect situation of the metal sheet and further evaluating whether the quality and performance of the metal sheet meet the standards.

[0032] The thickness of the metal sheet to be tested is 0-0.1 mm, and the value is not 0; the diameter of the micro defects / micro inclusions in the metal sheet to be tested is 20 μm.

[0033] Example

[0034] Specifically, in order to verify that the micro-nano device provided in this application can detect defects in the metal sheet under test, a simulation experiment was conducted;

[0035] A small permanent magnet with a side length of 500 μm is placed on a mass block with a size of 1100x700 μm. When the small permanent magnet is subjected to a force of 25 nN generated by a 20 μm defect inside the metal sheet, Figure 3 As shown, the small permanent magnet will drive the mass block to undergo lateral displacement of 6.5nm;

[0036] When the mass is driven by a small permanent magnet to cause a lateral displacement, the distance between the movable plate array and the fixed plate array changes, causing the capacitance to change.

[0037] When the defect passes, the anchor support structures at both ends will provide a restoring force to the mass block through the support beam, causing it to undergo a lateral displacement equal to and in the opposite direction to the lateral displacement caused by the Lorentz force, returning the mass block to its initial position.

[0038] The mass block is affected by the gravity of the small permanent magnet and will undergo a downward displacement of 95nm. The spring beam assembly and the grooves on the surface of the mass block ensure that the permanent magnet is firmly set, forming a complete movable body.

[0039] The sensitivity of the capacitance sensor is related to the lateral displacement of the movable parallel plate. The greater the lateral displacement of the movable parallel plate, the greater the corresponding capacitance change. The calculation formula is:

[0040]

[0041] Where ΔC is the capacitance change, C1 is the capacitance between the left plate, C2 is the capacitance between the right plate, ε0 is the space constant, A is the area of ​​the capacitor plates, d is the distance between the initial fixed plate and the moving plate, Δd is the distance the moving plate moves, and n is the logarithm of the comb capacitance.

[0042] Calculated by the above formula

[0043]

[0044] Under the design parameters of the sensor given above, the capacitance change caused by the distance change is calculated to be on the order of 10e-15F, which can be measured by the existing circuit. Figure 4 .

[0045] Comparative Example

[0046] A small permanent magnet with a side length of 500μm is placed on a mass block with a size of 1100x700μm. When the small permanent magnet is subjected to a 25nN force generated by a 20μm defect inside the metal sheet;

[0047] The existing sensor cannot detect it. Specifically, the pulse signal in the patent of the comparative embodiment 202111089441X is shown in the attached diagram. Figure 6 , it can be found that the signal of a 0.5mm defect is close to the original signal generated during the movement of the metal sheet, and cannot be accurately seen. Therefore, this invention cannot detect defects in metal sheets below 0.5mm;

[0048] Calculated by the above formula

[0049]

[0050] Under the design parameters of the sensor given in the patent document, the capacitance change caused by the distance change is calculated to be on the order of 10e-17F, which is almost impossible to measure with existing circuits. Figure 5 .

[0051] In summary, the present invention provides a micro-nano device for detecting micro defects in metal sheets under production conditions. This is because existing micro-nano devices cannot effectively support the mass of small permanent magnets and cannot achieve high-sensitivity measurements. The micro-nano device of this application has been developed. Through structural adjustment, the longitudinal displacement of the mass block caused by the mass of small permanent magnets is effectively reduced, ensuring the stability of the micro-nano device. While detecting a 20μm defect in a metal sheet under actual working conditions, the micro-nano device can generate sufficient lateral displacement for detection, significantly improving the sensitivity of the micro-nano device.

[0052] The micro-nano device is a capacitive micro force sensor.

[0053] The capacitance change detection principle of this system is as follows: based on the Lorentz force micro-particle detection principle, the reaction force of the Lorentz force on the permanent magnet is detected in real time, and the force signal is amplified, filtered and rectified. The number and amplitude of the final output pulse signal are used to determine the number and size of micro-defects and / or micro-inclusions in the metal being tested. This enables long-term, uninterrupted, real-time online monitoring of micro-defects and / or micro-inclusions in the high-speed moving metal being tested to evaluate whether the product meets the standards.

[0054] Although the embodiments and drawings of the present invention are disclosed for illustrative purposes, those skilled in the art will understand that various substitutions, changes and modifications are possible without departing from the spirit and scope of the present invention and the appended claims. Therefore, the scope of the present invention is not limited to the contents disclosed in the embodiments and drawings.

Claims

1. A micro-nano device for detecting micro-defects on metal sheets under production conditions, comprising a micro-nano device disposed below a moving metal sheet to be detected; a permanent magnet is fixed to the micro-nano device, and the metal sheet to be detected and the permanent magnet move relative to each other, enabling the micro-nano device to detect the metal sheet to be detected. The device is characterized by: The micro-nano device includes a shell, a mass block, a movable parallel electrode plate, a fixed parallel electrode plate, a gasket and a spring beam assembly. The upper part of the shell is a mounting port, and a printed circuit board is provided at the bottom of the shell. Gaskets are symmetrically provided on both sides of the shell, and the lower ends of the gaskets are connected to the printed circuit board. Spring beam assemblies are symmetrically provided on the other two sides of the shell corresponding to the mounting port position. A mass block is horizontally fixed between the two spring beam assemblies to ensure that the mass block is located at the exact center of the mounting port of the shell, and a groove is provided at the center of the mass block for limiting the installation of a permanent magnet. Movable parallel electrodes are arranged at equal intervals in the middle of both sides of the mass block relative to the lining plate. The movable parallel electrodes, the mass block and the permanent magnet constitute a movable body, and fixed parallel electrodes are arranged at equal intervals on the opposite side walls of the gasket, and the other end of the fixed parallel electrode plate is inserted in the gap between the movable parallel electrodes. The movable body is driven by the Lorentz force to cause displacement between the movable parallel electrode plate and the fixed parallel electrode plate, thereby forming a capacitance change.

2. The micro-nano device for detecting micro defects in metal sheets under production conditions according to claim 1, characterized in that: The movable parallel plates and the fixed parallel plates are parallel to each other.

3. The micro-nano device for detecting micro defects in metal sheets under production conditions according to claim 1, characterized in that: The spring beam assembly includes two symmetrically arranged support beams, each support beam includes a mounting column and a spring piece that provides a restoring force to the lateral movement of the movable body under the action of the Lorentz force. The mounting column is installed on the inner wall of the shell, and a spring piece is horizontally installed on one side of the mounting column. The other end of the spring piece is fixedly mounted at the corner position of the mass block to achieve a stable and centered setting of the mass block. The spring piece is made as a whole and includes a bow-shaped structure with multiple turns or bends.

4. The micro-nano device for detecting micro defects in metal sheets under production conditions according to claim 1, characterized in that: The permanent magnets are neodymium iron boron permanent magnets, aluminum nickel cobalt permanent magnet alloys, iron chromium cobalt permanent magnet alloys, barium ferrites, strontium ferrites and rare earth cobalt permanent magnets.

5. The micro-nano device for detecting micro defects in metal sheets under production conditions according to claim 1, characterized in that: The magnetization direction of the permanent magnet is perpendicular to the upper surface of the mass block.

6. The micro-nano device for detecting micro defects in metal sheets under production conditions according to claim 1, characterized in that: The length of the movable parallel pole plates is the same as the length of the permanent magnets arranged on the mass block.

7. The micro-nano device for detecting micro defects in metal sheets under production conditions according to claim 1, characterized in that: The shell includes a silicon-based shell, a silicon nitride shell, and a III-V semiconductor shell.

8. The micro-nano device for detecting micro defects in metal sheets under production conditions according to claim 1, characterized in that: The thickness of the metal sheet being measured is 0-0.1 mm, and the value is not 0.

9. The micro-nano device for detecting micro defects in metal sheets under production conditions according to claim 1, characterized in that: The diameter of the micro defects or micro inclusions in the metal sheet being tested is 20 μm.

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