Stress sensor based on magnetostrictive effect
By using a stress sensor based on the magnetostrictive effect, GMM Terfenol-D rods and Hall effect sensors, the low sensitivity and poor heat dissipation problems of traditional stress sensors are solved, and high-precision, real-time stress monitoring is achieved, which is suitable for high-temperature and high-stress environments.
Patent Information
- Application Number
- CN202421745785.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-07-23
- Publication Date
- 2025-10-03
- Estimated Expiration
- 2034-07-23
AI Technical Summary
Traditional stress sensors have problems such as low sensitivity, complex structure, high maintenance cost and poor heat dissipation, and are difficult to operate stably, especially in high temperature and strong magnetic field environments.
A stress sensor based on the magnetostrictive effect is used. Utilizing GMM Terfenol-D rods and Hall effect sensors, a permanent magnet sleeve provides a constant bias magnetic field. The magnetic flux changes of the GMM rod are monitored to achieve stress measurement. Real-time data acquisition is achieved by combining with a signal processing circuit.
It realizes stress monitoring with simple structure, good heat dissipation and high sensitivity, is suitable for high temperature and high stress environments, provides real-time monitoring functions, and improves the accuracy and reliability of structural health monitoring.
Smart Images
Figure CN223412850U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of stress sensor devices, in particular to a stress sensor based on magnetostrictive effect. Background Art
[0002] In modern industry and aircraft, health monitoring of critical structures is crucial to ensuring safety and extending equipment life. Traditional stress sensors often use strain gauges or fiber optic technology, but these methods suffer from low sensitivity, complex structures, and high maintenance costs.
[0003] Magnetostrictive materials, due to their high sensitivity and excellent mechanical properties, have shown great potential for application in stress sensing. Existing magnetostrictive force sensors require a constant internal bias magnetic field, generated by a powered coil. However, prolonged power supply can lead to internal overheating, resulting in poor heat dissipation in many enclosed applications. Adding a heat sink would further complicate the internal structure of the device.
[0004] Therefore, the current aircraft health monitoring market requires a stress monitoring sensor with simple structure, high precision, good environmental adaptability and real-time monitoring capabilities. Utility Model Content
[0005] In order to overcome the technical defect that the coil inside the traditional magnetostrictive force sensor is energized for too long, which may cause overheating inside the entire device, the utility model provides a stress sensor based on the magnetostrictive effect.
[0006] The utility model provides a stress sensor based on the magnetostrictive effect, comprising an outer shell cylinder, an upper circular magnetic conductive block, a GMM rod, a lower circular magnetic conductive block, a permanent magnet sleeve and a magnetic isolation sleeve; the top end of the outer shell cylinder is provided with a first annular edge extending inwardly in the horizontal direction, the bottom end of the outer shell cylinder is provided with a second annular edge extending outwardly in the horizontal direction, and the bottom of the second annular edge is fastened to the outer shell bottom plate; the top of the magnetic isolation sleeve is provided with an annular magnetic isolation edge extending inwardly in the horizontal direction, an annular groove coaxial with the outer shell cylinder is provided on the inner wall of the outer shell cylinder, and the annular groove extends to the bottom of the outer shell cylinder for embedding the magnetic isolation sleeve; the permanent magnet sleeve is coaxially assembled to the inner side of the magnetic isolation sleeve, a first sleeve fastener is provided between the magnetic isolation sleeve and the permanent magnet sleeve, a magnetic isolation bottom plate is assembled between the bottom of the first sleeve fastener and the outer shell bottom plate, and the magnetic isolation bottom plate and the magnetic isolation sleeve are connected. The inner wall is adapted, the GMM rod is assembled to the inner side of the permanent magnet sleeve, and a second sleeve fastener is assembled between the permanent magnet sleeve and the GMM rod. The input shaft passes through the first annular edge and its lower end is located in the outer shell cylinder. The lower end of the input shaft is abutted against the upper end of the GMM rod through the upper circular magnetic block. The middle through hole of the annular magnetic isolation edge is used to avoid the input shaft. An upper annular magnetic sheet is sandwiched between the top surface of the permanent magnet sleeve and the bottom surface of the annular magnetic isolation edge. The upper circular magnetic block is located in the middle of the upper annular magnetic sheet. A lower circular magnetic sheet is sandwiched between the bottom surface of the permanent magnet sleeve and the top surface of the magnetic isolation bottom plate. A lower circular magnetic block is provided at the lower end of the GMM rod, and a stainless steel cylinder pad is supported between the lower circular magnetic block and the lower circular magnetic sheet. A Hall effect sensor is installed in the middle of the stainless steel cylinder pad. The upper circular magnetic block and the lower circular magnetic block are respectively fitted with the inner wall of the second sleeve fastener.
[0007] The input shaft is the main drive shaft of the device. A permanent magnet sleeve surrounds the GMM rod and Hall effect sensor, providing a constant bias magnetic field. Made of high-coercivity material, the permanent magnet sleeve maintains a stable magnetic field strength under high temperatures and strong magnetic fields. The upper circular magnetic block, upper annular magnetic sheet, lower circular magnetic block, and lower circular magnetic sheet serve as connectors between the permanent magnet sleeve and the GMM rod, creating a regular magnetic circuit and ensuring a stable and sensitive magnetic field through the sensitive GMM rod. The GMM rod, specifically a GMM Terfenol-D rod, has a high saturation magnetostriction coefficient, high magnetic permeability, and high mechanical strength. It can operate stably in high-stress environments and is an ideal material for stress sensing. Its working principle, which utilizes the inverse magnetostrictive effect, is that when the volume and shape of the Terfenol-D rod change, its magnetic permeability changes, causing the magnetic field in the space to change. When the GMM rod deforms, the inverse magnetostrictive effect causes a change in the rod's magnetic permeability, altering the magnetic flux passing through it. The Hall-effect sensor monitors this change and converts it into a change in output voltage. The principle is that the Hall-effect sensor and the GMM rod are located in the same magnetic field, and the magnetic flux density between them is proportional. By monitoring the changes in the Hall-effect sensor's magnetic flux, changes in the GMM rod's magnetic flux can be indirectly monitored. Furthermore, the voltage signal output by the Hall-effect sensor reflects the stress on the GMM rod, that is, the magnitude of the external stress. The upper and lower circular magnetic conductive sheets are thin sheets that secure the upper and lower circular magnetic blocks. A stainless steel cylindrical washer secures the Hall-effect sensor. A gap is left between the second sleeve fastener and the GMM rod. The outer shell, magnetic shielding sleeve, first sleeve fastener, permanent magnet sleeve, second sleeve fastener, upper circular magnetic block, lower circular magnetic block, upper annular magnetic plate, lower circular magnetic plate, and GMM rod are all coaxially arranged and tightly assembled radially. The input shaft, upper circular magnetic block, GMM rod, lower circular magnetic block, stainless steel cylindrical gasket, lower circular magnetic plate, magnetic shielding base plate, and outer shell base plate are tightly assembled axially along the central axis. The magnetic shielding sleeve and base plate prevent magnetic flux leakage from the permanent magnet sleeve, enabling the enclosed GMM rod to operate more efficiently. When the input shaft transmits tensile and compressive loads, the GMM rod changes in volume and shape, and its magnetic permeability changes. This changes the magnetic flux passing through the GMM rod. A Hall effect sensor placed at one end of the GMM rod detects this change in magnetic flux density, generating a corresponding, precise electrical signal based on the Hall effect.
[0008] Preferably, a preload bolt with a through hole is threadedly engaged in the through hole of the first annular edge, and the input shaft is inserted into the through hole of the preload bolt. A flange extends circumferentially from the lower end of the input shaft, and a buffer spring is mounted on the input shaft body between the flange and the preload bolt. The buffer spring cushions the tensile and compressive loads transmitted by the input shaft, providing a certain preload force.
[0009] Preferably, the bottom surface of the upper circular magnetic conductive block and the top surface of the lower circular magnetic conductive block are respectively provided with a slot adapted to the GMM rod. This arrangement is to make the GMM rod connection more secure.
[0010] Preferably, the lower circular magnetic conductive sheet, the magnetic isolation base plate, and the housing base plate are provided with threading holes from top to bottom. The wires of the Hall effect sensor are passed through the threading holes and connected to a signal processing circuit and a data processing system. The signal processing circuit includes an amplifier, a filter, and an analog-to-digital converter. The signal processing circuit is connected to the Hall effect sensor driver via wires. The driver reads the level signal at the output of the Hall effect sensor. The signal processing circuit converts the analog signal output by the Hall effect sensor into a digital signal and transmits it to the data processing system. The data processing system is connected to the signal processing circuit to convert the digital signal into a corresponding load value. The signal processing circuit uses a high-precision operational amplifier and a low-noise filter to ensure signal accuracy and stability.
[0011] Preferably, the second annular edge is connected to the bottom plate of the housing by at least two fastening screws, which facilitates disassembly and provides a secure connection.
[0012] Compared with the prior art, the technical solution provided by the present invention has the following technical effects: 1. Simple structure and good heat dissipation: The stress sensor of the present invention adopts a built-in permanent magnet. The advantages of this are: it can reduce the volume and weight of the sensor, improve the flexibility of installation and the convenience of maintenance, and reduce costs. 2. High sensitivity: Utilize the high magnetic permeability change characteristics of magnetostrictive materials to achieve high-precision stress measurement. Due to the high sensitivity of GMM Terfenol-D material to deformation, it can achieve accurate monitoring of small stress changes. 3. Wide applicability: It is suitable for structural stress monitoring in harsh environments such as high temperature and high stress. In addition, the stress sensor is not a fixed structure. The shape and size of the sensor inside the monitoring device can be flexibly designed according to the monitored object and the spatial environment to achieve multi-scenario application. 4. Real-time monitoring: Real-time stress data acquisition and analysis are realized through signal processing circuits to improve the accuracy and reliability of structural health monitoring. The real-time monitoring function can promptly detect potential problems in the structure and provide important data support for maintenance and safety. BRIEF DESCRIPTION OF THE DRAWINGS
[0013] The accompanying drawings are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present invention, and together with the description, serve to explain the principles of the present invention.
[0014] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.
[0015] Figure 1 Schematic diagram of a stress sensor based on magnetostrictive effect according to an embodiment of the present invention.
[0016] In the figure: 1. Pre-tightening bolt; 2. Outer shell cylinder; 3. Upper annular magnetic conductive sheet; 4. Magnetic isolation sleeve; 5. Permanent magnet sleeve; 6. Second sleeve fastener; 7. Fastening screw; 8. First sleeve fastener; 9. Outer shell bottom plate; 10. Magnetic isolation bottom plate; 11. Lower annular magnetic conductive sheet; 12. Hall effect sensor; 13. Stainless steel cylinder gasket; 14. Lower annular magnetic conductive block; 15. GMM rod; 16. Upper annular magnetic conductive block; 17. Buffer spring; 18. Input shaft; 19. First annular edge; 20. Second annular edge; 21. Annular magnetic isolation edge. DETAILED DESCRIPTION
[0017] In order to more clearly understand the above-mentioned purpose, features and advantages of the present invention, the scheme of the present invention will be further described below. It should be noted that, in the absence of conflict, the embodiments of the present invention and the features therein can be combined with each other.
[0018] In the description, it should be noted that the terms "first" and "second" are used for descriptive purposes only and should not be understood to indicate or imply relative importance. It should be noted that, unless otherwise expressly specified or limited, the terms "installed," "connected," and "connected" should be understood broadly. For example, they can refer to fixed connections, removable connections, or integral connections; mechanical connections, electrical connections; direct connections, indirect connections through an intermediate medium, and internal connections between two components. Those skilled in the art will understand the specific meanings of the above terms based on specific circumstances.
[0019] In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention may also be implemented in other ways different from those described herein; it is obvious that the embodiments in the specification are only part of the embodiments of the present invention, rather than all of the embodiments.
[0020] The specific embodiments of the present invention are described in detail below with reference to the accompanying drawings.
[0021] In one embodiment, Figure 1 As shown, a stress sensor based on the magnetostrictive effect is disclosed, comprising a shell cylinder 2, an upper circular magnetic conductive block 16, a GMM rod 15, a lower circular magnetic conductive block 14, a permanent magnet sleeve 5 and a magnetic isolation sleeve 4; the top of the shell cylinder 2 extends inwardly along the horizontal direction with a first annular edge 19, the bottom of the shell cylinder 2 extends outwardly along the horizontal direction with a second annular edge 20, and the bottom of the second annular edge 20 is fastened to the shell bottom plate 9; the top of the magnetic isolation sleeve 4 extends inwardly along the horizontal direction with a first annular edge 19, and the bottom of the second annular edge 20 extends outwardly along the horizontal direction with a second annular edge 20. An annular magnetic isolation edge 21 extends inward, and an annular groove coaxial with the outer shell cylinder 2 is provided on the inner wall of the outer shell cylinder 2, and the annular groove extends to the bottom of the outer shell cylinder 2 for embedding the magnetic isolation sleeve 4; the permanent magnet sleeve 5 is coaxially assembled to the inner side of the magnetic isolation sleeve 4, and a first sleeve fastener 8 is set between the magnetic isolation sleeve 4 and the permanent magnet sleeve 5. A magnetic isolation bottom plate 10 is assembled between the bottom of the first sleeve fastener 8 and the outer shell bottom plate 9, and the magnetic isolation bottom plate 10 is adapted to the inner wall of the magnetic isolation sleeve 4, GMM rod 15 is assembled to the inner side of the permanent magnet sleeve 5, and a second sleeve fastener 6 is assembled between the permanent magnet sleeve 5 and the GMM rod 15. The input shaft 18 passes through the first annular edge 19 and its lower end is located in the outer shell cylinder 2. The lower end of the input shaft 18 is in contact with the upper end of the GMM rod 15 through the upper circular magnetic conductive block 16. The middle through hole of the annular magnetic isolation edge 21 is used to avoid the input shaft 18. An upper annular magnetic conductive sheet 3 is sandwiched between the top surface of the permanent magnet sleeve 5 and the bottom surface of the annular magnetic isolation edge 21. The upper circular magnetic conductive sheet 3 is sandwiched between the top surface of the permanent magnet sleeve 5 and the bottom surface of the annular magnetic isolation edge 21. The circular magnetic conductive block 16 is located in the middle of the upper annular magnetic conductive sheet 3, and a lower circular magnetic conductive sheet 11 is sandwiched between the bottom surface of the permanent magnet sleeve 5 and the top surface of the magnetic isolation base plate 10. A lower circular magnetic conductive block 14 is provided at the lower end of the GMM rod 15, and a stainless steel cylinder pad 13 is supported between the lower circular magnetic conductive block 14 and the lower circular magnetic conductive sheet 11. A Hall effect sensor 12 is installed in the middle of the stainless steel cylinder pad 13, and the upper circular magnetic conductive block 16 and the lower circular magnetic conductive block 14 are respectively fitted with the inner wall of the second sleeve fastener 6.
[0022] The input shaft 18 is the main drive shaft of the device. The permanent magnet sleeve 5 surrounds the GMM rod 15 and Hall effect sensor 12, providing a constant bias magnetic field. The permanent magnet sleeve 5 is made of high-coercivity material, capable of maintaining a stable magnetic field strength under high temperature and strong magnetic field environments. The upper circular magnetic conductive block 16, upper annular magnetic conductive sheet 3, lower circular magnetic conductive block 14, and lower circular magnetic conductive sheet 11, as connectors between the permanent magnet sleeve 5 and the GMM rod 15, organize the magnetic circuit and ensure the magnetic field passing through the sensitive unit GMM rod 15 is stable and sensitive. The GMM rod 15 is specifically a GMM Terfenol-D rod, which has a high saturation magnetostriction coefficient, high magnetic permeability, and high mechanical strength. It can operate stably in high-stress environments and is an ideal material for stress sensing. Its working principle, which utilizes the inverse magnetostrictive effect, is that when the volume and shape of the Terfenol-D rod change, its own magnetic permeability changes, thereby causing the magnetic field in the space to change. When the GMM rod 15 is deformed, the magnetic permeability of the GMM rod 15 itself changes due to the inverse magnetostrictive effect, and the magnetic flux passing through it will change. The Hall effect sensor 12 will monitor this change and convert the changing magnetic field into a change in the output voltage. The specific principle is as follows: the Hall effect sensor 12 and the GMM rod 15 are located in the same magnetic field, and the magnetic flux density between the two is in a certain proportional relationship. By monitoring the change in the magnetic flux of the Hall effect sensor 12, the change in the magnetic flux of the GMM rod 15 can be indirectly monitored. In addition, the voltage signal output by the Hall effect sensor 12 can reflect the stress condition of the GMM rod 15, that is, the magnitude of the stress applied by the outside world. The upper annular magnetic conductive sheet 3 and the lower circular magnetic conductive sheet 11 are thin sheet structures, and their function is to fix the position of the upper circular magnetic conductive block 16 and the lower circular magnetic conductive block 14. The function of the stainless steel cylinder pad 13 is to fix the Hall effect sensor 12. A gap is left between the second sleeve fastener 6 and the GMM rod 15. The outer shell cylinder 2, magnetic shielding sleeve 4, first sleeve fastener 8, permanent magnet sleeve 5, second sleeve fastener 6, upper circular magnetic conductive block 16, lower circular magnetic conductive block 14, upper annular magnetic conductive sheet 3, lower circular magnetic conductive sheet 11, and GMM rod 15 are all coaxially arranged and tightly assembled radially. The input shaft 18, upper circular magnetic conductive block 16, GMM rod 15, lower circular magnetic conductive block 14, stainless steel cylinder gasket 13, lower circular magnetic conductive sheet 11, magnetic shielding bottom plate 10, and outer shell bottom plate 9 are tightly assembled axially along the central axis. The function of the magnetic shielding sleeve 4 and magnetic shielding bottom plate 10 is to prevent magnetic leakage from the permanent magnet sleeve 5, allowing the sealed GMM rod 15 to work more efficiently. When the input shaft 18 transmits tensile and compressive loads, the volume shape of the GMM rod 15 changes, and its own magnetic permeability changes. At this time, the magnetic flux passing through the GMM rod 15 material changes. The Hall effect sensor 12 placed at one end of the bottom of the GMM rod 15 can capture the change in the magnetic field flux density, and thus obtain the corresponding accurate electrical signal change based on the Hall effect.
[0023] Based on the above embodiment, in a preferred embodiment, a preload bolt 1 with a through hole is threadedly engaged in the through hole of the first annular edge 19, and the input shaft 18 is inserted into the through hole of the preload bolt 1. A flange extends circumferentially from the lower end of the input shaft 18, and a buffer spring 17 is mounted on the body of the input shaft 18 between the flange and the preload bolt 1. The buffer spring 17 buffers the tensile and compressive loads transmitted by the input shaft 18, providing a certain preload force.
[0024] Based on the above embodiment, in a preferred embodiment, the bottom surface of the upper circular magnetic conductive block 16 and the top surface of the lower circular magnetic conductive block 14 are respectively provided with a slot adapted to the GMM rod 15. This is provided to make the connection of the GMM rod 15 more secure.
[0025] In a preferred embodiment, based on the above-described embodiment, the lower circular magnetic conductive plate 11, the magnetic shielding base plate 10, and the housing base plate 9 are provided with threading holes from top to bottom. The wires of the Hall effect sensor 12 are passed through the threading holes and connected to a signal processing circuit and a data processing system. The signal processing circuit includes an amplifier, a filter, and an analog-to-digital converter. The signal processing circuit is connected to the driver of the Hall effect sensor 12 via wires. The driver reads the level signal at the output of the Hall effect sensor 12. The signal processing circuit converts the analog signal output by the Hall effect sensor 12 into a digital signal and transmits it to the data processing system. The data processing system is connected to the signal processing circuit to convert the digital signal into the corresponding load value. The signal processing circuit uses a high-precision operational amplifier and a low-noise filter to ensure signal accuracy and stability.
[0026] Based on the above embodiment, in a preferred embodiment, the second annular edge 20 is connected to the housing bottom plate 9 by at least two fastening screws 7. This arrangement facilitates disassembly and provides a secure connection.
[0027] The above description is only a specific embodiment of the present invention, which enables those skilled in the art to understand or implement the present invention. Although detailed descriptions have been made with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents; and such modifications or replacements do not deviate from the essence of the corresponding technical solutions within the scope of the technical solutions of the embodiments, and they should all be covered by the scope of protection of the claims.
Claims
1. A stress sensor based on magnetostrictive effect, characterized in that: The invention comprises an outer shell cylinder (2), an upper circular magnetic conductive block (16), a GMM rod (15), a lower circular magnetic conductive block (14), a permanent magnet sleeve (5) and a magnetic isolation sleeve (4); the top of the outer shell cylinder (2) is provided with a first annular edge (19) extending inwardly in the horizontal direction, the bottom of the outer shell cylinder (2) is provided with a second annular edge (20) extending outwardly in the horizontal direction, and the bottom of the second annular edge (20) is fastened to the outer shell bottom plate (9); the top of the magnetic isolation sleeve (4) is provided with an annular magnetic isolation edge (21) extending inwardly in the horizontal direction, and the outer shell cylinder ( 2) is provided on the inner wall of the outer shell cylinder (2) with an annular groove coaxial with the outer shell cylinder (2), and the annular groove extends to the bottom of the outer shell cylinder (2) for embedding the magnetic isolation sleeve (4); the permanent magnet sleeve (5) is coaxially assembled to the inner side of the magnetic isolation sleeve (4), a first sleeve fastener (8) is set between the magnetic isolation sleeve (4) and the permanent magnet sleeve (5), a magnetic isolation bottom plate (10) is assembled between the bottom of the first sleeve fastener (8) and the outer shell bottom plate (9), the magnetic isolation bottom plate (10) is adapted to the inner wall of the magnetic isolation sleeve (4), and the GMM rod (15) is assembled to the permanent magnet sleeve (5) On the inner side, a second sleeve fastener (6) is assembled between the permanent magnet sleeve (5) and the GMM rod (15), the input shaft (18) passes through the first annular edge (19) and its lower end is located in the shell cylinder (2), the lower end of the input shaft (18) is abutted against the upper end of the GMM rod (15) through the upper circular magnetic conductive block (16), the middle through hole of the annular magnetic isolation edge (21) is used to avoid the input shaft (18), the upper annular magnetic conductive sheet (3) is sandwiched between the top surface of the permanent magnet sleeve (5) and the bottom surface of the annular magnetic isolation edge (21), the upper circular magnetic conductive block (16) is connected to the upper end of the GMM rod (15), and the upper circular magnetic conductive block (16) is connected to the upper end of the GMM rod (15). 6) is located in the middle of the upper annular magnetic conductive sheet (3), a lower circular magnetic conductive sheet (11) is sandwiched between the bottom surface of the permanent magnet sleeve (5) and the top surface of the magnetic isolation bottom plate (10), a lower circular magnetic conductive block (14) is provided at the lower end of the GMM rod (15), a stainless steel cylindrical pad (13) is supported between the lower circular magnetic conductive block (14) and the lower circular magnetic conductive sheet (11), a Hall effect sensor (12) is installed in the middle of the stainless steel cylindrical pad (13), and the upper circular magnetic conductive block (16) and the lower circular magnetic conductive block (14) are respectively fitted with the inner wall of the second sleeve fastener (6).
2. The stress sensor based on the magnetostrictive effect according to claim 1, characterized in that: A pre-tightening bolt (1) with a through hole is threadedly engaged in the through hole of the first annular edge (19), the input shaft (18) is inserted into the through hole of the pre-tightening bolt (1), the lower end of the input shaft (18) is provided with a flange extending in the circumferential direction, and a buffer spring (17) is sleeved on the shaft body of the input shaft (18) between the flange and the pre-tightening bolt (1).
3. The stress sensor based on magnetostrictive effect according to claim 2, characterized in that: The bottom surface of the upper circular magnetic conductive block (16) and the top surface of the lower circular magnetic conductive block (14) are respectively provided with a card slot adapted to the GMM rod (15).
4. A stress sensor based on magnetostrictive effect according to any one of claims 1 to 3, characterized in that: The lower circular magnetic conductive sheet (11), the magnetic isolation bottom plate (10) and the housing bottom plate (9) are provided with threading holes from top to bottom. The wires of the Hall effect sensor (12) are passed through the threading holes and are connected to a signal processing circuit and a data processing system. The signal processing circuit includes an amplifier, a filter and an analog-to-digital converter.
5. The stress sensor based on magnetostrictive effect according to claim 4, characterized in that: The second annular edge (20) is connected to the housing bottom plate (9) via at least two fastening screws (7).