Strain sensor

Abstract

The utility model discloses a strain sensor. The strain sensor comprises a housing, a flexible bonding layer and a resistance strain gauge. A circuit board is mounted in the shell; the flexible bonding layer is connected to one side of the shell, and a mounting groove is formed in one surface of the flexible bonding layer; the resistance strain gauge is arranged in the mounting groove and electrically connected with the circuit board, the resistance strain gauge is located on one side of an opening of the mounting groove to form an induction surface, and the induction surface is flush with one surface of the flexible adhesive layer and is used for being adhered to an object to be measured through strain glue. When the strain sensor provided by the scheme is installed, an operation object is a flat shell with a larger plane size, so that the operation difficulty is remarkably reduced, redundant sealing steps in the installation process are reduced, the strain sensor provided by the scheme is simple, convenient and rapid to install, and the technical requirements on installation personnel are greatly reduced.

Description

Technical Field

[0001] This utility model relates to the field of measurement technology, specifically to a strain sensor. Background Technology

[0002] A resistance strain gauge is an electronic component used to detect strain. In application, the resistance strain gauge is tightly attached to a specific measuring point on a structural component. When the structural component is subjected to external force, strain is generated at the measuring point, and the sensitive grid on the strain gauge will also deform accordingly, causing a corresponding change in its resistance value. Subsequently, this resistance change is detected by a dedicated measuring instrument and converted into a corresponding strain value.

[0003] The existing strain sensor installation process mainly includes the following steps: First, the resistance strain gauge is adhered to the surface to be measured using strain adhesive; next, the leads of the resistance strain gauge are connected to the signal lines one by one; finally, sealant is applied to ensure that the resistance strain gauge and its leads are completely wrapped and sealed. Strain sensors require complex steps to adhere the resistance strain gauge to the surface of the object being measured, and the installation process is relatively demanding, time-consuming, and prone to errors. Utility Model Content

[0004] The purpose of this invention is to overcome the above-mentioned technical deficiencies and propose a strain sensor that solves the technical problems of cumbersome installation procedures and high requirements for installation technology in the existing strain sensor.

[0005] To achieve the above-mentioned technical objectives, the present invention adopts the following technical solution:

[0006] This utility model provides a strain sensor, including: a housing, a flexible adhesive layer, and a resistance strain gauge; a circuit board is installed inside the housing; the flexible adhesive layer is connected to one side of the housing, and a mounting groove is provided on one side of the flexible adhesive layer; the resistance strain gauge is disposed in the mounting groove and electrically connected to the circuit board, and the resistance strain gauge is located on one side of the opening of the mounting groove to form a sensing surface, the sensing surface being flush with one side of the flexible adhesive layer, for bonding to the object to be measured by strain adhesive.

[0007] In some embodiments, the flexible adhesive layer has a peelable first film layer on the side where the resistance strain gauge is mounted, the first film layer covering the opening of the mounting groove.

[0008] In some embodiments, the sensing surface of the resistance strain gauge is provided with a second film layer, which is embedded in the mounting groove to isolate the resistance strain gauge from the object to be measured during installation.

[0009] In some embodiments, a collar is fitted around the outside of the resistance strain gauge, and the second film layer is fixed by the collar to cover the sensing surface of the resistance strain gauge, and the outside of the collar is tightly fitted to the inner wall of the mounting groove.

[0010] In some embodiments, the depth of the mounting groove is less than the thickness of the flexible adhesive layer.

[0011] In some embodiments, the flexible adhesive layer is polyacrylate double-sided adhesive or polyurethane double-sided adhesive.

[0012] In some embodiments, the mounting groove is disposed on the side of the flexible adhesive layer opposite to the housing.

[0013] In some embodiments, the housing is filled with insulating adhesive.

[0014] In some embodiments, the outer shell has a plurality of through holes on the side connected to the flexible adhesive layer, so that the insulating adhesive and the flexible adhesive layer can be bonded to each other through the through holes.

[0015] In some embodiments, the outer shell has two mutually perpendicular marking lines on the side opposite to the flexible adhesive layer, and the intersection of the two marking lines coincides with the center of the resistance strain gauge.

[0016] Compared with existing technologies, the strain sensor provided by this invention, through its housing, flexible adhesive layer, and resistance strain gauge, allows for easier installation. The strain gauge is pre-fixed to the housing via the flexible adhesive layer. During installation, the object of the bonding and pressing operations is a flat housing with a larger planar dimension, significantly reducing the difficulty of operation. The strain gauge is completely encased in the flexible adhesive layer, which forms a seal with the strain adhesive during installation, reducing unnecessary sealing steps and effectively preventing contamination or damage to the strain gauge from the external environment, further ensuring measurement accuracy. This makes the strain sensor provided by this solution simple and quick to install, greatly reducing the technical requirements for installers.

[0017] The flexible adhesive layer design allows it to adhere tightly to the surface of the test object before the strain adhesive cures, thus fixing the overall position of the strain sensor and preventing slippage or displacement caused by the weight of the strain sensor. After the strain adhesive cures, the flexible adhesive layer protects the cured strain adhesive layer, preventing peeling and failure of the cured strain adhesive layer due to the weight of the sensor or the pulling of the signal lines. Attached Figure Description

[0018] Figure 1 This is a schematic cross-sectional view of the strain sensor provided in this embodiment of the present invention.

[0019] Figure 2 yes Figure 1 Enlarged view of point A in the middle;

[0020] Figure 3 This is a schematic diagram of the bottom structure of the housing of the strain sensor provided in this embodiment of the present invention;

[0021] Figure 4 This is a schematic diagram of the top surface structure of the housing of the strain sensor provided in this embodiment of the present invention;

[0022] Figure 5 This is a side view of the housing of the strain sensor provided in this embodiment of the present invention.

[0023] Explanation of reference numerals in the attached figures:

[0024] 1. Outer shell; 11. Housing; 12. Outer cover; 121. Raised sheet; 13. Insulating adhesive; 14. Through hole; 2. Circuit board; 3. Flexible adhesive layer; 4. Resistance strain gauge; 41. Strain gauge lead wire; 5. First film layer; 6. Second film layer; 7. Collar; 8. Sensor power signal line. Detailed Implementation

[0025] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present utility model and are not intended to limit the present utility model.

[0026] To address the technical challenges of complex installation procedures and demanding installation techniques for strain sensors, this invention provides a strain sensor that utilizes a flat outer shell with a larger planar dimension when installing the resistance strain gauge. This significantly reduces the operational difficulty and eliminates unnecessary sealing steps during installation, making the strain sensor provided by this solution easy and quick to install and greatly reducing the technical requirements for installers.

[0027] Please see Figures 1 to 5 The strain sensor includes: a housing 1, a circuit board 2, a flexible adhesive layer 3, and a resistance strain gauge 4; the circuit board 2 is installed inside the housing 1; the flexible adhesive layer 3 is connected to one side of the housing 1, and one side of the flexible adhesive layer 3 has a mounting groove; the resistance strain gauge 4 is disposed in the mounting groove and is electrically connected to the circuit board 2, and the resistance strain gauge 4 is located on one side of the opening of the mounting groove to form a sensing surface, the sensing surface being flush with one side of the flexible adhesive layer 3, for bonding to the object to be measured by strain adhesive.

[0028] In this device, circuit board 2 is installed inside housing 1, and a flexible adhesive layer 3 is provided on housing 1. The flexible adhesive layer 3 has mounting grooves for mounting resistance strain gauges 4. The resistance strain gauges 4 are stably fixed to the flexible adhesive layer 3 through the mounting grooves, while simultaneously achieving electrical connection with the circuit board 2. This design not only ensures the accurate installation position of the resistance strain gauges 4 but also improves the stability and reliability of its measurements. The design of the flexible adhesive layer 3 allows the device to flexibly adapt to various surface shapes of the objects being measured, ensuring good fit and measurement accuracy. The design of the sensing surface being flush with the flexible adhesive layer 3 facilitates the secure adhesion of the resistance strain gauges 4 to the object being measured using strain adhesive, thereby achieving accurate measurement of the object's strain.

[0029] For ease of strain gauge installation, please refer to [link / reference needed]. Figure 1 In this embodiment, the mounting groove is located on the side of the flexible adhesive layer 3 opposite to the outer shell 1, allowing the operator to directly operate from the surface of the flexible adhesive layer 3 when installing the resistance strain gauge 4, without the need for flipping or adjusting the device, greatly improving installation efficiency. Of course, in other possible embodiments, the position of the mounting groove can be adjusted according to actual conditions; for example, it can be located on the side of the flexible adhesive layer 3 closer to the outer shell 1, as long as it meets the requirements for stable installation and accurate measurement of the resistance strain gauge 4.

[0030] To further improve the stability and durability of the device, in some possible embodiments, the flexible adhesive layer 3 is a polyacrylate double-sided adhesive or a polyurethane double-sided adhesive to ensure that the device can be attached to the object to be tested stably for a long time without being affected by the external environment.

[0031] To protect the resistance strain gauge 4 before installation, please refer to [link / reference]. Figure 2 In some possible embodiments, the flexible adhesive layer 3 has a first film layer 5 on the side opposite to the outer casing 1. The first film layer 5 covers the opening of the mounting groove and can be torn off. Before the device is used, the first film layer 5 provides protection, preventing dust and impurities from entering the mounting groove and affecting the performance of the resistance strain gauge 4. When it is necessary to attach the device to the object to be measured, the user only needs to peel off the first film layer 5 to expose the resistance strain gauge 4 in the mounting groove, facilitating subsequent strain adhesive application.

[0032] To enable the resistance strain gauge 4 to be detachable and reusable, please refer to [link / reference]. Figure 2In some possible embodiments, the sensing surface of the strain gauge 4 is equipped with a second film layer 6, such as a polyimide film. A collar 7 is fitted around the outside of the strain gauge 4, and the second film layer 6 is fixed by the collar 7, thereby embedding it in the mounting groove and covering the sensing surface of the strain gauge 4. The second film layer 6 serves to isolate the strain gauge 4 from the object being measured during installation. Disassembly only requires peeling off the second film layer 6 without damaging the strain gauge 4 itself, achieving detachability and reusability of the strain gauge 4, reducing usage costs. Simultaneously, the presence of the second film layer 6 can also protect the sensing surface of the strain gauge 4 to a certain extent, preventing damage during installation, further improving the durability and measurement accuracy of the device. The outer side of the collar 7 is tightly fitted to the inner wall of the mounting groove to ensure the stability and positional accuracy of the strain gauge 4 within the groove. The thickness of the second film layer 6 should be as thin as possible to reduce its impact on strain transmission; typically, a film with a thickness of less than 0.05 mm is chosen.

[0033] Preferably, please refer to Figure 1 and Figure 2 In this embodiment, the depth of the mounting groove is less than the thickness of the flexible adhesive layer 3, so that after the resistance strain gauge 4 is installed, the flexible adhesive layer 3 still has a certain thickness, which can provide better buffering and bonding effect.

[0034] To ensure the sealing effect of the strain sensor, please refer to... Figure 1 In some possible embodiments, the housing 1 is filled with insulating adhesive 13, and the strain gauge leads 41 of the resistance strain gauge 4 are connected to the circuit board 2 through the flexible adhesive layer 3 and the insulating adhesive 13. The circuit board 2 is connected to the sensor power signal line 8. This design effectively prevents moisture, dust and other impurities from entering the housing 1, avoiding affecting the normal operation of the circuit board 2 and the resistance strain gauge 4, and also enhances the overall structural strength of the device, improving its impact and vibration resistance.

[0035] Further, please refer to Figure 1 and Figure 2 In some possible embodiments, the outer shell 1 is provided with a plurality of through holes 14 on the side connected to the flexible adhesive layer 3. When the insulating adhesive 13 is filled, it can overflow from these through holes 14 and connect to the flexible adhesive layer 3 to further enhance the bonding force between the outer shell 1 and the flexible adhesive layer 3 and ensure the overall stability of the device.

[0036] To ensure the accurate installation of this strain sensor, please refer to [link / reference]. Figure 3In some possible embodiments, the outer shell 1 has two mutually perpendicular marking lines on the side facing away from the flexible adhesive layer 3, and the intersection of the two marking lines coincides with the center of the resistance strain gauge 4. This allows installers to quickly locate the resistance strain gauge 4 during installation, enabling precise installation based on the measuring point position of the strain gauge 4. This ensures that the resistance strain gauge 4 is accurately adhered to the predetermined position on the object to be measured, thereby improving measurement accuracy. Simultaneously, the auxiliary positioning of the marking lines simplifies the installation process, reduces the possibility of installation errors, and makes the entire installation process more efficient and convenient.

[0037] For easier inspection and repair of circuit board 2, please refer to [link / reference]. Figure 5 In this embodiment, the outer casing 1 includes a housing 11 and an outer cover 12. The housing 11 has a through hole 14 and an opening at a position opposite to the flexible adhesive layer 3. The outer cover 12 can cover the opening. Protrusions 121 are provided on both sides of the outer cover 12, and latches are provided on the protrusions 121. A detachable connection can be achieved by the latches engaging with the latches on the housing 11. When the circuit board 2 needs to be inspected or repaired, the circuit board 2 can be easily accessed simply by opening the outer cover 12, without disassembling the entire device, greatly improving maintenance convenience. Furthermore, a sealing strip is provided between the housing 11 and the outer cover 12 to ensure the device's waterproof and dustproof performance in the closed state, protecting the circuit board 2 from external environmental interference and further extending the device's service life.

[0038] This invention utilizes a housing 1, a flexible adhesive layer 3, and a resistance strain gauge 4. The strain gauge 4 is pre-fixed to the housing 1 via the flexible adhesive layer 3. During installation, the object of the adhesive and pressing operations is the flat housing 1 with a larger planar dimension, significantly reducing the difficulty of operation. The strain gauge is completely enclosed by the flexible adhesive layer 3, which forms a seal with the strain gauge adhesive during installation, reducing unnecessary sealing steps and effectively preventing the strain gauge from being contaminated or damaged by the external environment during installation, further ensuring the accuracy of the measurement. This makes the strain sensor provided by this solution easy and quick to install, greatly reducing the technical requirements for installers.

[0039] The flexible adhesive layer 3 is designed to adhere tightly to the surface of the object under test before the strain adhesive cures, so as to fix the overall position of the strain sensor and prevent slippage or displacement caused by the weight of the strain sensor. After the strain adhesive cures, the flexible adhesive layer 3 protects the cured strain adhesive layer and prevents the cured strain adhesive layer from peeling off due to the weight of the sensor or the pulling of the signal line.

[0040] In the description of this application, it should be noted that the terms "upper" and "lower," etc., indicating the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application. Unless otherwise expressly specified and limited, the terms "installed," "connected," and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication between two elements. For those skilled in the art, the specific meaning of the above terms in this application can be understood according to the specific circumstances.

[0041] It should be noted that in this application, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0042] The specific embodiments of this utility model described above do not constitute a limitation on the scope of protection of this utility model. Any other corresponding changes and modifications made based on the technical concept of this utility model should be included within the scope of protection of the claims of this utility model.

Claims

1. A strain sensor, characterized in that, include: A housing, in which a circuit board is installed; A flexible adhesive layer is attached to one side of the outer casing, and one side of the flexible adhesive layer is provided with a mounting groove; as well as, A resistance strain gauge is disposed in the mounting groove and electrically connected to the circuit board. The resistance strain gauge forms a sensing surface on one side of the opening of the mounting groove. The sensing surface is flush with one side of the flexible adhesive layer and is used to adhere to the object to be measured by strain adhesive.

2. The strain sensor according to claim 1, characterized in that, The flexible adhesive layer has a peelable first film layer on the side where the resistance strain gauge is mounted, and the first film layer covers the opening of the mounting groove.

3. The strain sensor according to claim 1, characterized in that, The sensing surface of the resistance strain gauge is equipped with a second film layer, which is embedded in the mounting groove to isolate the resistance strain gauge from the object to be measured during installation.

4. The strain sensor according to claim 3, characterized in that, A collar is fitted around the outside of the resistance strain gauge, and the second film layer is fixed by the collar to cover the sensing surface of the resistance strain gauge, and the outside of the collar is tightly fitted to the inner wall of the mounting groove.

5. The strain sensor according to claim 1, characterized in that, The depth of the mounting groove is less than the thickness of the flexible adhesive layer.

6. The strain sensor according to claim 1, characterized in that, The flexible adhesive layer is polyacrylate double-sided adhesive or polyurethane double-sided adhesive.

7. The strain sensor according to claim 1, characterized in that, The mounting groove is located on the side of the flexible adhesive layer opposite to the outer shell.

8. The strain sensor according to claim 1, characterized in that, The outer casing is filled with insulating adhesive.

9. The strain sensor according to claim 8, characterized in that, The outer shell has several through holes on one side connected to the flexible adhesive layer, so that the insulating adhesive and the flexible adhesive layer can be bonded to each other through the through holes.

10. The strain sensor according to claim 1, characterized in that, The outer shell has two perpendicular marking lines on the side opposite to the flexible adhesive layer, and the intersection of the two marking lines coincides with the center of the resistance strain gauge.

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