Stress sensor

Abstract

The invention provides a stress sensor. The stress sensor comprises a fixing part, a contact part and a measuring part, the fixing part is connected with a strain area of an object to be measured; the contact part is connected with a non-strain area of the object to be measured; the measuring part comprises sensing modules, a first lever structure and a second lever structure, the first lever structure and the second lever structure are connected with each other, the first lever structure is connected with the fixing part, the second lever structure is connected with the contact part, and the sensing modules are arranged at the ends of the first lever structure and the second lever structure; wherein when the object to be measured generates strain, the first lever structure and the second lever structure generate relative displacement to generate a displacement distance, and the sensing module outputs a strain value according to the displacement distance. According to the invention, the sensitivity during stress detection can be improved.

Description

Technical Field

[0001] This invention relates to the field of stress detection technology, and specifically to a stress sensor. Background Technology

[0002] Stress sensors are primarily used to detect anomalies or faults in structures or equipment by monitoring changes in structural strain, such as monitoring structural abnormalities or mechanical failures in buildings, roads, and machinery. Among these, fiber Bragg grating stress sensors are devices that achieve distributed strain sensing by distributively etching Bragg reflector units within an optical fiber. These Bragg reflector units selectively reflect light of specific wavelengths propagating in the fiber while transmitting other wavelengths. When deformation occurs at a specific location in the fiber, the Bragg reflector units undergo minute deformation, causing a shift in the wavelength of the reflected light. By monitoring this wavelength shift, fiber Bragg grating stress sensors can accurately measure the distributed strain on the surface to which they are attached. However, traditional fiber Bragg grating stress sensors suffer from low detection sensitivity due to structural limitations, making them unsuitable for scenarios requiring high sensitivity. Summary of the Invention

[0003] This invention provides a stress sensor designed to address the problem of low detection sensitivity in current stress sensors.

[0004] This invention provides a stress sensor, comprising a fixing part, a contact part, and a measuring part; the fixing part is connected to the strain region of the object to be measured; the contact part is connected to the non-strain region of the object to be measured; the measuring part includes a sensing module and a first lever structure and a second lever structure connected to each other, the first lever structure being connected to the fixing part, the second lever structure being connected to the contact part, and the sensing module being provided at the ends of both the first lever structure and the second lever structure; wherein, when the object to be measured generates strain, the first lever structure and the second lever structure undergo relative displacement to generate a displacement distance, and the sensing module outputs a strain value based on the displacement distance.

[0005] Furthermore, the first lever structure includes a first suspension beam, a first support leg, a first connecting part, and a second support leg; one end of the first suspension beam is connected to the fixing part, the other end of the first suspension beam is connected to one side of the first support leg, one end of the first support leg is connected to the second lever structure, the other end of the first support leg is connected to one end of the first connecting part, one end of the first connecting part is connected to one end of the second support leg, the other end of the second support leg is disposed opposite to the second lever structure, and the other end of the second support leg is provided with the sensing module.

[0006] Furthermore, the second lever structure includes a second suspension beam, a third leg, a second connecting portion, and a fourth leg; one end of the second suspension beam is connected to the contact portion, the other end of the second suspension beam is connected to one side of the third leg, one end of the third leg is connected to one end of the first leg, the other end of the third leg is connected to one end of the second connecting portion, the other end of the second connecting portion is connected to one end of the fourth leg, the other end of the fourth leg is opposite to the other end of the second leg, and the other end of the fourth leg is provided with the sensing module.

[0007] Furthermore, a hollow area is provided at the connection between the first leg and the third leg, and the central axis of the measuring part is provided in the hollow area.

[0008] Furthermore, a first included angle is provided between the first leg and the central axis, and between the second leg and the central axis, and the first included angle is less than 90°.

[0009] Furthermore, a second angle is formed between the extension line of the first leg and the extension line of the second leg.

[0010] Furthermore, the second leg extends toward the fourth leg with a first extension portion, and the fourth leg extends toward the second leg with a second extension portion; the end of the first extension portion extends downward with a first protrusion, and the end of the second extension portion extends upward with a second protrusion, and the first protrusion and the second protrusion are arranged opposite to each other; wherein, when the object under test generates strain, relative displacement occurs between the first extension portion and the second extension portion, relative displacement occurs between the first protrusion and the second protrusion, and the displacement direction between the first extension portion and the second extension portion is opposite to the displacement direction between the first protrusion and the second protrusion.

[0011] Furthermore, the sensing module includes a first sensor and a second sensor connected to each other; the first sensor is disposed between the first protrusion and the second protrusion, and the second sensor is disposed between the first extension and the second extension; wherein, when the object under test generates strain, a relative displacement occurs between the first protrusion and the second protrusion, the first sensor detects a first strain change, a relative displacement occurs between the first extension and the second extension, and the second sensor detects a second strain change, and the first strain change and the second strain change are opposite strain changes.

[0012] Furthermore, it also includes a reference sensor, which is disposed on the contact portion and connected to the first sensor.

[0013] Furthermore, both the fixing part and the contact part are provided with at least one fixing hole.

[0014] This invention discloses a stress sensor comprising a fixing part, a contact part, and a measuring part. The fixing part is connected to the strain region of the object to be measured, and the contact part is connected to the non-strain region of the object to be measured. The measuring part includes a sensing module and a first lever structure and a second lever structure connected to each other. When the object to be measured generates strain, the first lever structure and the second lever structure undergo relative displacement, thereby amplifying the strain change of the object to be measured. The sensing module then converts the displacement distance between the first lever structure and the second lever structure into a strain value, thereby realizing strain detection of the object to be measured and improving the sensitivity of the detection. Attached Figure Description

[0015] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the following description of the embodiments will be briefly introduced. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0016] Figure 1 This is an overall structural diagram of a stress sensor provided in an embodiment of the present invention;

[0017] Figure 2 This is an overall structural diagram of a stress sensor provided in an embodiment of the present invention when subjected to a first force;

[0018] Figure 3 This is an overall structural diagram of a stress sensor provided in an embodiment of the present invention when subjected to a second force.

[0019] Figure Descriptions: 100, Stress sensor; 10, Fixing part; 20, Contact part; 30, Measuring part; 31, Sensing module; 311, First sensor; 312, Second sensor; 32, First lever structure; 321, First cantilever beam; 322, First leg; 323, First connecting part; 324, Second leg; 325, First extension part; 326, First protrusion; 33, Second lever structure; 331, Second cantilever beam; 332, Third leg; 333, Second connecting part; 334, Fourth leg; 335, Second extension part; 336, Second protrusion; 34, Hollowed-out area; 40, Reference sensor; 50, Fixing hole. Detailed Implementation

[0020] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0021] It should be understood that, when used in this specification and the appended claims, the terms “comprising” and “including” indicate the presence of the described features, integrals, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, integrals, operations, elements, components and / or collections thereof.

[0022] It should also be understood that the terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to limit the invention. As used in this specification and the appended claims, the singular forms “a,” “an,” and “the” are intended to include the plural forms unless the context clearly indicates otherwise. It should also be understood that the term “and / or” as used in this specification and the appended claims refers to any combination and all possible combinations of one or more of the associated listed items, and includes such combinations.

[0023] Furthermore, the directional terms used in this invention, such as "up," "down," "front," "back," "left," "right," "inner," "outer," and "side," are merely for reference to the accompanying drawings and the product's usage state. Therefore, the directional terms used are for illustrating and understanding this invention, and not for limiting it. Additionally, in the accompanying drawings, structures that are similar or identical are indicated by the same reference numerals.

[0024] See Figures 1 to 3 , Figure 1 This is an overall structural diagram of a stress sensor 100 provided in an embodiment of the present invention; Figure 2 This is an overall structural diagram of the stress sensor 100 provided in an embodiment of the present invention when subjected to a first force; Figure 3 This is an overall structural diagram of a stress sensor 100 provided in an embodiment of the present invention when subjected to a second force. Figure 1As shown, the stress sensor 100 includes a fixing part 10, a contact part 20, and a measuring part 30; the fixing part 10 is connected to the strain region of the object to be measured; the contact part 20 is connected to the non-strain region of the object to be measured; the measuring part 30 includes a sensing module 31 and a first lever structure 32 and a second lever structure 33 connected to each other. The first lever structure 32 is connected to the fixing part 10, and the second lever structure 33 is connected to the contact part 20. The sensing module 31 is provided at the ends of both the first lever structure 32 and the second lever structure 33. When the object to be measured generates strain, the first lever structure 32 and the second lever structure 33 undergo relative displacement to generate a displacement distance, and the sensing module 31 outputs a strain value based on the displacement distance.

[0025] Specifically, the stress sensor 100 may include a fixing part 10, a contact part 20, and a measuring part 30. The fixing part 10 may be fixed to the strain region of the object to be measured, and the contact part 20 may be located in the non-strain region of the object to be measured and in close contact with the object.

[0026] A measuring part 30 is provided between the fixing part 10 and the contact part 20. The measuring part 30 may include a sensing module 31 and a first lever structure 32 and a second lever structure 33 connected to each other. The first lever structure 32 is connected to the fixing part 10, and the second lever structure 33 is connected to the contact part 20. The first lever structure 32 and the second lever structure 33 are also connected to each other, so the fixing part 10 and the contact part 20 can be connected through the first lever structure 32 and the second lever structure 33. At the same time, a sensing module 31 is provided on the first lever structure 32 and the second lever structure 33 respectively. The sensing module 31 may be a fiber Bragg grating sensing module 31.

[0027] When the object under test is subjected to strain, the stress sensor 100 will be subjected to a force that causes a stress change. The force can include compressive force and tensile force. The compressive force refers to squeezing the fixed part 10 and the contact part 20 of the stress sensor 100, thereby compressing the measuring part 30 and causing the measuring part 30 to deform. The tensile force refers to stretching the fixed part 10 and the contact part 20 of the stress sensor 100, thereby expanding the measuring part 30 and causing the measuring part 30 to deform.

[0028] When the measuring unit 30 deforms, the first lever structure 32 and the second lever structure 33 amplify the force and cause displacement, thereby generating a displacement distance. The sensing module 31 provided on the first lever structure 32 and the second lever structure 33 can convert the displacement distance into a wavelength change, and then obtain the stress value based on the wavelength change, thereby realizing the stress detection of the object under test.

[0029] As a further embodiment, the first lever structure 32 includes a first suspension beam 321, a first support leg 322, a first connecting part 323, and a second support leg 324; one end of the first suspension beam 321 is connected to the fixing part 10, the other end of the first suspension beam 321 is connected to one side of the first support leg 322, one end of the first support leg 322 is connected to the second lever structure 33, the other end of the first support leg 322 is connected to one end of the first connecting part 323, one end of the first connecting part 323 is connected to one end of the second support leg 324, the other end of the second support leg 324 is disposed opposite to the second lever structure 33, and the other end of the second support leg 324 is provided with the sensing module 31.

[0030] The first lever structure 32 may include a first suspension beam 321, a first support leg 322, a first connecting part 323, and a second support leg 324. One end of the first suspension beam 321 is connected to the fixing part 10, and the other end of the first suspension beam 321 is connected to one side of the first support leg 322. The connection point between the first suspension beam 321 and the first support leg 322 is designated as the first connection point. Adjusting the position of the first connection point can adjust the amplification effect of the first lever structure 32. For example, the closer the first connection point is to the top of the first support leg 322, the stronger the amplification effect and the greater the strain. The closer the first connection point is to the other end of the first support leg 322, the weaker the amplification effect. The connection position of the first connection point can be set according to actual needs. One end (top) of the first support leg 322 is connected to the second lever structure 33, and the other end of the first support leg 322 is connected to one end of the first connecting part 323. The other end of the first connecting part 323 is connected to one end of the second support leg 324, and the other end of the second support leg 324 is provided with a sensing module 31.

[0031] like Figure 2 As shown, when the stress sensor 100 is subjected to compressive force, the fixing part 10 will compress the first support leg 322 through the first suspension beam 321, thereby causing the structure formed by the first support leg 322, the first connecting part 323 and the second support leg 324 to deform, thereby changing the relative distance between the second support leg 324 and the second lever structure 33. Figure 2 (d1 and d2 in the figure). Sensing module 31 can convert displacement changes into wavelength changes, thereby realizing the detection of corresponding forces.

[0032] As a further embodiment, the second lever structure 33 includes a second suspension beam 331, a third support leg 332, a second connecting part 333, and a fourth support leg 334; one end of the second suspension beam 331 is connected to the contact part 20, the other end of the second suspension beam 331 is connected to one side of the third support leg 332, one end of the third support leg 332 is connected to one end of the first support leg 322, the other end of the third support leg 332 is connected to one end of the second connecting part 333, the other end of the second connecting part 333 is connected to one end of the fourth support leg 334, the other end of the fourth support leg 334 is opposite to the other end of the second support leg 324, and the other end of the fourth support leg 334 is provided with the sensing module 31.

[0033] The second lever structure 33 may include a second suspension beam 331, a third support leg 332, a second connecting part 333, and a fourth support leg 334. One end of the second suspension beam 331 is connected to the contact part 20, and the other end of the second suspension beam 331 is connected to one side of the third support leg 332. The connection point between the second suspension beam 331 and the third support leg 332 is designated as the second connection point. Adjusting the position of this second connection point can adjust the amplification effect of the second lever structure 33. For example, the closer the second connection point is to the top of the third support leg 332, the stronger the amplification effect and the greater the strain. The closer the second connection point is to the other end of the third support leg 332, the weaker the amplification effect. The connection position of the second connection point can be set according to actual needs. One end (top) of the third support leg 332 is connected to one end of the first support leg 322, and the other end of the third support leg 332 is connected to one end of the second connecting part 333. The other end of the second connecting part 333 is connected to one end of the fourth support leg 334, and the other end of the fourth support leg 334 is equipped with a sensing module 31.

[0034] like Figure 2 As shown, when the stress sensor 100 is subjected to compressive force, the fixing part 10 will compress the first leg 322 through the first suspension beam 321, and the contact part 20 will compress the third leg 332 through the second suspension beam 331. This causes the structure formed by the first leg 322, the first connecting part 323, and the second leg 324 to deform, and also causes the structure formed by the third leg 332, the second connecting part 333, and the fourth leg 334 to deform, thereby changing the relative distance between the second leg 324 and the fourth leg 334. Figure 2 (d1 and d2 in the figure). Sensing module 31 can convert displacement changes into wavelength changes, thereby realizing the detection of corresponding forces.

[0035] In addition, the lengths of the first suspension beam 321 and the second suspension beam 331 can also affect the magnification effect. That is, the longer the lengths of the first suspension beam 321 and the second suspension beam 331, the better the magnification effect; the shorter the lengths of the first suspension beam 321 and the second suspension beam 331, the weaker the magnification effect.

[0036] As a further embodiment, a hollow area 34 is provided at the connection between the first leg 322 and the third leg 332, and the central axis of the measuring part 30 is provided in the hollow area 34.

[0037] The hollow area 34 can be a circular area. The magnification effect of the first lever structure 32 and the second lever structure 33 can be adjusted by adjusting the diameter of the circular area. For example, the larger the diameter of the hollow area 34, the stronger the magnification effect, and the smaller the diameter of the hollow area 34, the weaker the magnification effect.

[0038] As mentioned above, the positions of the first connection point and the second connection point can affect the magnification effect. Specifically, the distance between the first connection point and the hollow area 34 and the distance between the second connection point and the bracket of the hollow area 34 can affect the magnification effect. That is, the closer the first connection point and the second connection point are to the hollow area 34, the stronger the magnification effect. The farther the first connection point and the second connection point are from the hollow area 34, the weaker the magnification effect.

[0039] As a further embodiment, a first included angle is provided between the first leg 322 and the central axis, and between the second leg 324 and the central axis, and the first included angle is less than 90°.

[0040] Among them, such as Figure 2 As shown, Figure 2 In the first angle, θ1 is greater than 0° and less than 90°. The amplification effect, i.e. the sensitivity, can be adjusted by adjusting the size of the first angle. For example, the larger the first angle, the stronger the amplification effect, i.e. the greater the strain change caused by the same force. The smaller the first angle, the weaker the amplification effect.

[0041] As a further embodiment, a second angle is formed between the extension line of the first leg 322 and the extension line of the second leg 324.

[0042] Among them, such as Figure 2 As shown, Figure 2 θ2 is the second included angle, which can be a specific angle used to ensure that the displacement trajectories of d1 and d2 are close to linear, thereby improving the linearity of strain measurement.

[0043] As a further embodiment, the second leg 324 extends toward the fourth leg 334 with a first extension 325, and the fourth leg 334 extends toward the second leg 324 with a second extension 335; the end of the first extension 325 extends downward with a first protrusion 326, and the end of the second extension 335 extends upward with a second protrusion 336, and the first protrusion 326 and the second protrusion 336 are disposed opposite to each other; wherein, when the object under test is subjected to strain, relative displacement occurs between the first extension 325 and the second extension 335, and relative displacement occurs between the first protrusion 326 and the second protrusion 336, and the displacement direction between the first extension 325 and the second extension 335 is opposite to the displacement direction between the first protrusion 326 and the second protrusion 336.

[0044] Among them, the second leg 324 extends towards the fourth leg 334 with a first extension 325, and the first extension 325 extends downward with a first protrusion 326. Simultaneously, the fourth leg 334 extends towards the second leg 324 with a second extension 335, and the second extension 335 extends upward with a second protrusion 336. Figure 1 As shown, the positional relationship between the first protrusion 326 and the second protrusion 336 is approximately a snap-fit ​​relationship. That is, it can be approximately understood that the first protrusion 326 is snapped onto the second extension 335, and the second protrusion 336 is snapped onto the first extension 325. Figure 1 It can be seen that there is no direct contact between the first protrusion 326 and the second extension 335, nor between the second protrusion 336 and the first extension 325, but rather a certain gap is left. A sensing module 31 is provided between the first protrusion 326 and the second protrusion 336, and between the first extension 325 and the second extension 335.

[0045] like Figure 2 As shown, when subjected to compressive force, the gap between the first protrusion 326 and the second protrusion 336 increases, i.e., d1 increases, while the gap between the bottom of the first extension 325 and the bottom of the second extension 335 decreases, i.e., d2 decreases. Figure 3 As shown, when subjected to tensile force, the gap between the first protrusion 326 and the second protrusion 336 decreases, i.e., d1 decreases, and the gap between the bottom of the first extension 325 and the bottom of the second extension 335 increases, i.e., d2 increases.

[0046] As a further embodiment, the sensing module 31 includes a first sensor 311 and a second sensor 312 connected to each other; the first sensor 311 is disposed between the first protrusion 326 and the second protrusion 336, and the second sensor 312 is disposed between the first extension 325 and the second extension 335; wherein, when the object under test generates strain, a relative displacement occurs between the first protrusion 326 and the second protrusion 336, the first sensor 311 detects a first strain change, a relative displacement occurs between the first extension 325 and the second extension 335, and the second sensor 312 detects a second strain change, and the first strain change and the second strain change are opposite strain changes.

[0047] The sensing module 31 may include multiple sensors, such as a first sensor 311 and a second sensor 312. Both the first sensor 311 and the second sensor 312 may be fiber Bragg grating sensors. The first sensor 311 is located between the first protrusion 326 and the second protrusion 336, and the second sensor 312 is located between the bottom of the first extension 325 and the bottom of the second extension 335. The first sensor 311 and the second sensor 312 are connected by an optical fiber. Figure 1 As shown, the first sensor 311 and the second sensor 312 are connected via optical fiber, allowing the first sensor 311 to be placed in... Figure 1 The second sensor 312 is placed at the position shown. Figure 2 The positions shown, i.e., the first sensor 311 and the second sensor 312, are designed as separate units from the first lever structure 32 and the second lever structure 33. In actual manufacturing, the fixing part 10, the contact part 20, the first lever structure 32, and the second lever structure 33 can be manufactured separately, and then the sensing module 31 can be placed at the designated position. Alternatively, the fixing part 10, the contact part 20, the first lever structure 32, and the second lever structure 33 can be integrally formed, meaning they can be printed using 3D printing, thus enabling rapid mass production.

[0048] The first sensor 311 is used to detect the displacement change between the first protrusion 326 and the second protrusion 336, and the second sensor 312 is used to detect the displacement change between the bottom of the first extension 325 and the bottom of the second extension 335. Let the wavelength change of the first sensor 311 be d1 and the wavelength change of the second sensor 312 be d2, then the stress value can be calculated using formula (1):

[0049] ε=k1(d1-d2)(1)

[0050] Where ε is the stress value, k1 is the wavelength change-strain conversion coefficient, d1 is the reflected wavelength of the first sensor 311, and d2 is the reflected wavelength of the second sensor 312.

[0051] As a further embodiment, a reference sensor 40 is also included, which is disposed on the contact portion 20 and is connected to the first sensor 311.

[0052] The reference sensor 40 can also be a fiber Bragg grating sensor, which is disposed on the contact portion 20. That is, the reference sensor 40 will not change according to the change of the applied force, but will only be affected by environmental factors, such as temperature changes. In other words, the reflected wavelength of the reference sensor 40 will change according to the temperature. After introducing the reference sensor 40, the stress change caused by temperature change can be eliminated, thereby making the detection result more accurate. After introducing the reference sensor 40, the formula for calculating the stress value can be obtained from formula (2):

[0053] ε=k1(d1-d2)-k2d3(2)

[0054] Where ε is the stress value, k1 is the wavelength change-strain conversion coefficient, d1 is the reflected wavelength of the first sensor 311, d2 is the reflected wavelength of the second sensor 312, k2 is the temperature compensation coefficient, and d3 is the reflected wavelength of the reference sensor 40.

[0055] Temperature fluctuations synchronously affect d1 and d2, and the changes in the two signals are similar. Therefore, the differential signal d1-d2 can be used as the first compensation term for temperature compensation. The output d3 of the reference sensor 40 is not affected by strain, but only by temperature. Therefore, -k2d3 is used as the second compensation term for temperature compensation. The first and second compensation terms can further improve the measurement accuracy and avoid the interference of temperature on the measurement results.

[0056] As a further embodiment, both the fixing part 10 and the contact part 20 are provided with at least one fixing hole 50.

[0057] At least one fixing hole 50 may be provided on the fixing part 10 and the measuring part 30 respectively for connecting with the object to be measured. For example, two fixing holes 50 may be provided on the fixing part 10 and the contact part 20 respectively.

[0058] The present invention discloses a stress sensor in which the fixing part is connected to the strain region of the object to be measured, the contact part is connected to the non-strain region of the object to be measured, and the measuring part includes a sensing module and a first lever structure and a second lever structure connected to each other. When the object to be measured generates strain, the first lever structure and the second lever structure undergo relative displacement, thereby amplifying the strain change of the object to be measured. The sensing module then converts the displacement distance between the first lever structure and the second lever structure into a strain value, thereby realizing strain detection of the object to be measured and improving the sensitivity of the detection.

[0059] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in the present invention, and these modifications or substitutions should all be covered within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A stress sensor, characterized in that, The stress sensor includes: A fixing part, which is connected to the strain region of the object to be measured; A contact portion, wherein the contact portion is connected to the non-strain region of the object under test; The measuring unit includes a sensing module and a first lever structure and a second lever structure connected to each other. The first lever structure is connected to the fixing part, and the second lever structure is connected to the contact part. The sensing module is provided at the ends of both the first lever structure and the second lever structure. When the object under test generates strain, the first lever structure and the second lever structure undergo relative displacement to generate a displacement distance, and the sensing module outputs a strain value based on the displacement distance.

2. The stress sensor as described in claim 1, characterized in that, The first lever structure includes a first cantilever beam, a first leg, a first connecting part, and a second leg; One end of the first suspension beam is connected to the fixed part, the other end of the first suspension beam is connected to one side of the first support leg, one end of the first support leg is connected to the second lever structure, the other end of the first support leg is connected to one end of the first connecting part, one end of the first connecting part is connected to one end of the second support leg, the other end of the second support leg is opposite to the second lever structure, and the other end of the second support leg is provided with the sensing module.

3. The stress sensor as described in claim 2, characterized in that, The second lever structure includes a second cantilever beam, a third leg, a second connecting part, and a fourth leg; One end of the second suspension beam is connected to the contact portion, and the other end of the second suspension beam is connected to one side of the third leg. One end of the third leg is connected to one end of the first leg, and the other end of the third leg is connected to one end of the second connecting portion. The other end of the second connecting portion is connected to one end of the fourth leg, and the other end of the fourth leg is opposite to the other end of the second leg. The other end of the fourth leg is provided with the sensing module.

4. The stress sensor as described in claim 3, characterized in that, A hollow area is provided at the connection between the first leg and the third leg, and the central axis of the measuring part is provided in the hollow area.

5. The stress sensor as described in claim 4, characterized in that, A first included angle is provided between the first leg and the central axis, and between the second leg and the central axis, and the first included angle is less than 90°.

6. The stress sensor as described in claim 3, characterized in that, The extension line of the first leg and the extension line of the second leg form a second angle.

7. The stress sensor as described in claim 3, characterized in that, The second leg extends toward the fourth leg by a first extension portion, and the fourth leg extends toward the second leg by a second extension portion. The first extension extends downward to form a first protrusion, and the second extension extends upward to form a second protrusion, with the first protrusion and the second protrusion being disposed opposite to each other. When the object under test is subjected to strain, a relative displacement occurs between the first extension and the second extension, and a relative displacement occurs between the first convex portion and the second convex portion. The displacement direction between the first extension and the second extension is opposite to the displacement direction between the first convex portion and the second convex portion.

8. The stress sensor as described in claim 7, characterized in that, The sensing module includes a first sensor and a second sensor that are interconnected. The first sensor is disposed between the first protrusion and the second protrusion, and the second sensor is disposed between the first extension and the second extension; When the object under test is subjected to strain, a relative displacement occurs between the first protrusion and the second protrusion, the first sensor detects a first strain change, a relative displacement occurs between the first extension and the second extension, the second sensor detects a second strain change, and the first strain change and the second strain change are opposite strain changes.

9. The stress sensor as described in claim 8, characterized in that, It also includes a reference sensor, which is disposed on the contact portion and connected to the first sensor.

10. The stress sensor as claimed in claim 1, characterized in that, Both the fixing part and the contact part are provided with at least one fixing hole.

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