Fiber grating light weight strain sensor

Abstract

The utility model relates to sensor technical field, concretely relates to a kind of optical fiber grating light weight strain sensor.It mainly aims at the problem that sensor will be stressed unbalanced due to the order of two ends installation when sensor is installed, it is easy to cause damage to optical fiber, and it is difficult to guarantee that sensor will not be bent when installing, and the following technical scheme is proposed: including intermediate tube, intermediate tube is the core component of grating optical fiber strain sensor, the both ends of intermediate tube are respectively sleeved with connecting base.The optical fiber grating light weight strain sensor, when installing in order at two ends, because of the connecting spring between mounting support and fixed frame, therefore, the one end of sensor not being fixed has enough activity space, and the light pipe itself is made of high-strength material, therefore, the both ends of sensor can be supported, avoid the intermediate tube to be bent due to uneven stress, protect the safety of optical fiber grating sensor.

Description

Technical Field

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

[0002] Fiber Bragg grating sensors are a type of commonly used physical sensor, often used in building structure monitoring, power equipment monitoring, and machinery manufacturing monitoring. Their core principle is based on Bragg's law of reflection, which determines changes in physical quantities by detecting the change in the Bragg wavelength after a broadband light source passes through a fiber Bragg grating. They have the core advantages of adapting to harsh environments and distributed measurement.

[0003] Existing sensors are typically used to detect temperature and structural strain, so fiber optic sensors need to be mounted on the surface of the structural components. However, during installation, the sensors may experience unbalanced stress due to the sequential installation of the two ends, which can easily damage the fiber optic cable. Furthermore, it is difficult to ensure that the sensor will not bend during installation. Utility Model Content

[0004] In view of the above-mentioned shortcomings of the existing technology, the present invention provides a lightweight fiber Bragg grating strain sensor, which can effectively solve the problems in the existing technology where the sensor is subjected to unbalanced force during installation due to the sequential installation of the two ends, which can easily damage the optical fiber, and it is difficult to ensure that the sensor will not bend during installation.

[0005] To achieve the above objectives, this utility model provides the following technical solution: This utility model provides a lightweight fiber Bragg grating strain sensor, including a middle tube, with connecting bases sleeved at both ends of the middle tube. The end of the connecting base away from the middle tube is used to connect an optical fiber, and a fixing mechanism is also provided on the side of the connecting base. The fixing mechanism includes a fixing frame sleeved on the side of each connecting base, a mounting tube fixedly installed on the top of each fixing frame, a light-transmitting tube slidably installed on the inner wall of each mounting tube, and a connecting tube installed on the side of each light-transmitting tube away from the mounting tube. A reflective component for changing the light path is provided in the middle portion of one of the light-transmitting tubes. Furthermore, a limiting spring is fixedly installed on both sides of the bottom of each of the fixed frames, and a mounting bracket is fixedly installed at the end of the limiting spring away from the fixed frame. A screw cylinder is fixedly installed on both sides of the top of the mounting bracket, and a screw hole is opened on both sides of the top of the fixed frame.

[0006] Furthermore, the limiting spring is arranged around the side of the screw cylinder, and a screw is threaded onto the inner wall of each screw hole. The mounting bracket is used to connect with the surface of the structural component.

[0007] Furthermore, a laser lamp is fixedly installed on the inner wall of one of the mounting tubes, and the switch of the laser lamp passes through the end of the mounting tube away from the light-transmitting tube.

[0008] Furthermore, a limiting groove is formed on the inner wall of each of the mounting tubes, and a limiting block is fixedly provided on one side of each of the light-transmitting tubes near the mounting tube, the limiting block being shaped to fit the limiting groove.

[0009] Furthermore, each of the light-transmitting tubes has a rotating tube rotatably disposed on the side near the connecting tube, and a screw cylinder is fixedly disposed at each end of the connecting tube. The inner wall of each screw cylinder is threadedly connected to the side of the rotating tube. The inner wall of the connecting tube is connected to the screw cylinder on the side near the reflective component, and a marking block is fixedly disposed on the side of the inner wall of the connecting tube away from the reflective component.

[0010] Furthermore, the reflective assembly includes a right-angle folded tube, the two ends of which are fixedly connected to the ends of the light-transmitting tube, and a reflector is fixedly installed at each bend of the inner wall of the right-angle folded tube.

[0011] Furthermore, the reflective component and the laser lamp are located on the same side of the connecting tube, and the light from the laser lamp illuminates the light-transmitting tube and can pass through different ends of the right-angle folded tube via a reflector.

[0012] Beneficial effects The technical solution provided by this utility model has the following advantages compared with the known prior art: 1. When the lightweight fiber Bragg grating strain sensor is installed in sequence at both ends, the end of the sensor that is not fixed has sufficient room to move because of the spring connecting the mounting bracket and the fixing frame. In addition, the light tube itself is made of high-strength material, so it can support both ends of the sensor and prevent the middle tube from bending due to uneven force on the sensor, thus protecting the safety of the fiber Bragg grating sensor. Second, in the case of this lightweight fiber Bragg grating strain sensor, if the light-transmitting tube is bent during sensor installation, the laser light will not be able to accurately illuminate the center of the marker block. However, when installing the sensor, the worker can observe the relative position of the marker block and the laser light through the connecting tube, so as to determine in time whether the light-transmitting tube is bent, and further determine whether the two ends of the sensor are on the same straight line, ensuring that the sensor is in a straight state after installation and is not subject to unnecessary pressure from external structural components. Attached Figure Description

[0013] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0014] Figure 1 This is a schematic diagram of the entire utility model; Figure 2 This is a schematic diagram of the fixing frame of this utility model; Figure 3 This utility model Figure 2 A magnified structural diagram of A in the middle; Figure 4 This is a schematic diagram of the light-transmitting tube of this utility model; Figure 5 This utility model Figure 4 A magnified structural diagram of B in the diagram; Figure 6 This utility model Figure 4 A magnified structural diagram of C; Figure 7 This is a schematic diagram of the reflective component of this utility model.

[0015] Reference numerals in the attached drawings: 1. Intermediate tube; 2. Connecting base; 3. Fixing mechanism; 31. Fixing frame; 311. Limiting spring; 312. Mounting support; 32. Mounting tube; 321. Laser light; 322. Limiting groove; 323. Limiting block; 33. Light-transmitting tube; 331. Rotating tube; 34. Connecting tube; 341. Marking block; 35. Reflecting component; 351. Right-angle folded tube; 352. Reflector. Detailed Implementation

[0016] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model 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 this utility model. All other embodiments obtained by those skilled in the art based on the embodiments of this utility model without creative effort are within the scope of protection of this utility model.

[0017] The present invention will be further described below with reference to the embodiments.

[0018] See attached document Figure 1-7A lightweight fiber Bragg grating strain sensor includes a central tube 1, which is the core component of the fiber Bragg grating strain sensor. The central tube 1 contains a Bragg grating for filtering light. Connecting bases 2 are respectively fitted at both ends of the central tube 1. The connecting bases 2 are mainly used to connect optical fibers and are divided into an input end and an output end. The optical fiber at the input end emits a broadband light source, which is reflected from the optical fiber at the output end after passing through the grating. The end of the connecting base 2 away from the central tube 1 is used to connect the optical fiber. The sensor also includes a fixing mechanism 3 located on the side of the connecting base 2. The fixing mechanism 3 is mainly used to install the fiber Bragg grating strain sensor on a flat surface of the structural component.

[0019] The fixing mechanism 3 includes a fixing frame 31 sleeved on the side of each connecting base 2, a mounting tube 32 fixedly installed on the top of each fixing frame 31, a light-transmitting tube 33 slidably installed on the inner wall of each mounting tube 32, the light-transmitting tube 33 itself is made of alloy material with high strength, a connecting tube 34 is installed on the side of each light-transmitting tube 33 away from the mounting tube 32, and a reflection component 35 for changing the light path is provided in the middle part of one of the light-transmitting tubes 33.

[0020] Each mounting bracket 31 has a limiting spring 311 fixedly installed on both sides of its bottom. A mounting support 312 is fixedly installed at the end of the limiting spring 311 away from the mounting bracket 31. A screw cylinder is fixedly installed on both sides of the top of the mounting support 312. A screw hole is opened on both sides of the top of the mounting bracket 31. The limiting spring 311 is arranged around the side of the screw cylinder. A screw is threaded into the inner wall of each screw hole. The mounting support 312 is used to connect with the surface of the structural component. The screw can be threaded into the screw cylinder on the surface of the mounting support 312 to connect the mounting bracket 31 and the mounting support 312 together.

[0021] A laser lamp 321 is fixedly installed on the inner wall of one of the mounting tubes 32. The switch of the laser lamp 321 passes through the end of the mounting tube 32 away from the light transmission tube 33. The laser lamp 321 can be turned on by the switch, and the light source emitted by the laser lamp 321 will directly enter the light transmission tube 33.

[0022] Each mounting tube 32 has a limiting groove 322 on its inner wall, and each light-transmitting tube 33 has a limiting block 323 fixedly installed on one side of its end near the mounting tube 32. The limiting block 323 fits the shape of the limiting groove 322, and the light-transmitting tube 33 is inserted into the limiting groove 322 of the mounting tube 32 through the limiting block 323 to prevent the light-transmitting tube 33 from rotating radially.

[0023] Each light-transmitting tube 33 has a rotating tube 331 rotatably mounted on the side near the connecting tube 34. A screw cylinder is fixedly mounted at each end of the connecting tube 34. The inner wall of each screw cylinder is threadedly connected to the side of the rotating tube 331. The rotating tube 331, the light-transmitting tube 33, and the screw cylinders on the side of the connecting tube 34 are all in a connected state. The optical fiber of the laser lamp 321 can enter the rotating tube 331 from the light-transmitting tube 33, then enter the screw cylinder, and finally enter the interior of the connecting tube 34. The inner wall of the connecting tube 34 is connected to the screw cylinder on the side near the reflecting component 35. A marker block 341 is fixedly mounted on the inner wall of the connecting tube 34 away from the reflecting component 35. A circular array of uniformly arranged notches is opened on the side of the connecting tube 34, allowing a view of the interior of the connecting tube 34. The marker block 341 is used to receive the light from the laser lamp 321.

[0024] The reflective assembly 35 includes a right-angle bend tube 351, with both ends of the right-angle bend tube 351 fixedly connected to the ends of the light-transmitting tube 33. A reflector 352 is fixedly installed at each bend of the inner wall of the right-angle bend tube 351. The bends of the right-angle bend tube 351 are all 90° bends, and each reflector 352 is placed at an angle at the bend of the right-angle bend tube 351. The angle of inclination of the reflector 352 is 45° to the axis of each segment of the right-angle bend tube 351. The reflective assembly 35 and the laser lamp 321 are located on the same side of the connecting tube 34. The light from the laser lamp 321 shines into the light-transmitting tube 33 and can pass through different ends of the right-angle bend tube 351 through the reflector 352.

[0025] Working principle: The fiber optic strain sensor needs to be placed on the surface of the structural component. First, holes are drilled on the surface of the structural component, and the hole positions must match the positions of the mounting holes of different mounting brackets 312. Then, the mounting brackets 312 are fixed to the surface of the structural component by means of screws or rivets. It should be noted that the screws of the fixing bracket 31 need to be separated from the screws of the mounting bracket 312, while the light transmission tube 33 needs to be connected to the fixing bracket 31 throughout the installation process.

[0026] When the staff connects one of the mounting supports 312 to the surface of the structural component, the other mounting support 312, being unfixed, will cause uneven force on both ends of the fiber Bragg grating sensor. However, because the mounting support 312 is connected to the fixing frame 31 by a spring, the unfixed end of the sensor has sufficient room to move. Furthermore, the light tube 33 itself is made of high-strength material, which can support both ends of the sensor and prevent the middle tube 1 from bending due to uneven force, thus protecting the safety of the fiber Bragg grating sensor.

[0027] Furthermore, during installation, workers can turn on the laser light 321 via a switch. The optical fiber of the laser light 321 passes through the light-transmitting tube 33 to reach the inside of the right-angle bend tube 351, and then reaches the inside of the connecting tube 34 through the reflection of the reflector 352. Due to the multiple reflections by the reflectors 352, the change in the direction of the laser light 321 is amplified. Therefore, if the light-transmitting tube 33 is bent during installation, the laser light 321 cannot accurately illuminate the center of the marker block 341. When installing the sensor, workers can observe the relative position of the marker block 341 and the laser light 321 through the connecting tube 34, thereby promptly determining whether the light-transmitting tube 33 has bent, and further determining whether the two ends of the sensor are on the same straight line. This ensures that the sensor is in a straight state after installation and is not subject to additional pressure from external structural components.

[0028] After installation, in order to avoid the light tube 33 affecting the sensor's sensing of the structural strain, it is necessary to rotate the rotating tube 331 at the end of each light tube 33 so that the rotating tube 331 drives the light tube 33 closer to the connecting tube 34 through the thread until the end of the light tube 33 is brought out of the mounting tube 32. At this time, the light tube 33 and the connecting tube 34 can be taken out as a whole and can be reused.

[0029] The above embodiments are only used to illustrate the technical solutions of this utility model, and are not intended to limit it. Although this utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions will not cause the essence of the corresponding technical solutions to deviate from the protection scope of the technical solutions of the embodiments of this utility model.

Claims

1. A lightweight fiber Bragg grating strain sensor, comprising a central tube (1), wherein connecting bases (2) are respectively fitted at both ends of the central tube (1), and the end of the connecting base (2) away from the central tube (1) is used to connect an optical fiber, characterized in that: It also includes a fixing mechanism (3) located on the side of the connecting base (2); The fixing mechanism (3) includes a fixing frame (31) sleeved on the side of each connecting base (2), an installation tube (32) fixedly installed on the top of each fixing frame (31), a light-transmitting tube (33) slidably installed on the inner wall of each installation tube (32), and a connecting tube (34) installed on the side of each light-transmitting tube (33) away from the installation tube (32). A reflection component (35) for changing the light path is provided in the middle part of one of the light-transmitting tubes (33).

2. The lightweight fiber Bragg grating strain sensor according to claim 1, characterized in that, Each of the fixed frames (31) has a limiting spring (311) fixedly installed on both sides of its bottom. The end of the limiting spring (311) away from the fixed frame (31) is fixedly installed with a mounting bracket (312). The top two sides of the mounting bracket (312) are fixedly installed with a screw cylinder. The top two sides of the fixed frame (31) are respectively provided with a screw hole.

3. The lightweight fiber Bragg grating strain sensor according to claim 2, characterized in that, The limiting spring (311) is arranged around the side of the screw barrel, and a screw is threaded to the inner wall of each screw hole. The mounting bracket (312) is used to connect with the surface of the structural component.

4. A lightweight fiber Bragg grating strain sensor according to claim 1, characterized in that, A laser lamp (321) is fixedly installed on the inner wall of one of the mounting tubes (32), and the switch of the laser lamp (321) passes through the end of the mounting tube (32) away from the light-transmitting tube (33).

5. A lightweight fiber Bragg grating strain sensor according to claim 1, characterized in that, Each of the mounting tubes (32) has a limiting groove (322) on its inner wall, and each of the light-transmitting tubes (33) has a limiting block (323) fixedly installed on one side of the end near the mounting tube (32), and the limiting block (323) fits the shape of the limiting groove (322).

6. A lightweight fiber Bragg grating strain sensor according to claim 1, characterized in that, Each of the light-transmitting tubes (33) has a rotating tube (331) rotatably disposed on the side near the connecting tube (34). A screw cylinder is fixedly disposed at each end of the connecting tube (34). The inner wall of each screw cylinder is threadedly connected to the side of the rotating tube (331). The inner wall of the connecting tube (34) is connected to the screw cylinder on the side near the reflective component (35). A marking block (341) is fixedly disposed on the side of the inner wall of the connecting tube (34) away from the reflective component (35).

7. A lightweight fiber Bragg grating strain sensor according to claim 1, characterized in that, The reflective assembly (35) includes a right-angle fold tube (351), both ends of which are fixedly connected to the ends of the light-transmitting tube (33), and a reflector (352) is fixedly installed at each bend of the inner wall of the right-angle fold tube (351).

8. A lightweight fiber Bragg grating strain sensor according to claim 7, characterized in that, The reflective component (35) and the laser lamp (321) are located on the same side of the connecting tube (34). The light from the laser lamp (321) enters the light-transmitting tube (33) and can pass through the different ends of the right-angle folded tube (351) through the reflector (352).

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