Contact type optical fiber deformation sensor

Abstract

The invention relates to the technical field of optical fiber sensors, in particular to a contact type optical fiber deformation sensor which comprises a shell, a contact assembly and an optical fiber, a cavity is formed in the shell, the contact assembly comprises an ejector rod and an elastic piece, the ejector rod is arranged at one end of the cavity, the optical fiber is fixed to the other end of the cavity, and the elastic piece is arranged in the cavity. One end of the ejector rod is in sliding fit with the cavity, the ejector rod and the optical fiber are arranged at intervals, the elastic piece is arranged on the outer side of the other end of the ejector rod in a sleeving mode, a step column is arranged on the outer wall of the ejector rod, and the two ends of the elastic piece abut against the step column and the shell respectively. The ejector rod is in contact with the measured object, the measured object deforms to push the ejector rod to move towards the other end of the cavity and compresses the elastic piece, and the elastic piece compresses to provide elastic force for resetting of the ejector rod; the ejector rod generates displacement, so that the gap between the ejector rod and the optical fiber is changed, the wavelength of the returned light is further changed, and the deformation quantity of the measured object can be accurately obtained by demodulating and calculating the change of the wavelength.

Description

Technical Field

[0001] The present invention relates to the technical field of optical fiber sensors, and in particular to a contact-type optical fiber deformation sensor. Background Art

[0002] With the advancement of globalization and the continuous development of industrialization, people's demand for energy is also increasing. The nuclear power industry is developing rapidly. In order to be able to apply nuclear technology safely, stably and efficiently, it is particularly important to obtain accurate parameters during nuclear testing, such as the deformation parameters of the test piece. However, during nuclear testing, conventional deformation sensors cannot accurately measure deformation parameters in high temperature, high pressure, strong radiation and confined space environments.

[0003] Fiber optic sensors are currently experiencing rapid development. With advantages such as high sensitivity, strong anti-interference capabilities, and stable operation in extreme environments, they have been widely used in fields such as energy, transportation, civil engineering, environmental monitoring, and healthcare, becoming a vital component of modern sensing technology. However, their application in the nuclear power industry is very limited, especially in areas with harsh working environments. Acquiring deformation parameters during irradiation testing requires complex and cumbersome mechanical mechanisms and circuit measurements. Due to these harsh working environments and confined spaces, these conditions often lead to unexpected accidents, inaccurate measurement data, and insufficient measurement accuracy. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a contact-type optical fiber deformation sensor that can accurately measure deformation parameters in complex environments such as high temperature, high pressure, strong radiation, and confined space during nuclear testing.

[0005] The technical solution of the present invention to solve the above-mentioned technical problems is as follows: A contact-type optical fiber deformation sensor comprises a shell, a contact assembly and an optical fiber, a cavity being provided inside the shell, the contact assembly comprising a push rod and an elastic member, the push rod being provided at one end of the cavity, the optical fiber being fixed at the other end of the cavity, one end of the push rod slidingly fitting with the cavity and being spaced apart from the optical fiber, the elastic member being sleeved on the outside of the other end of the push rod, the outer wall of the push rod having a step column, and the two ends of the elastic member respectively abutting against the step column and the shell.

[0006] The beneficial effects of the present invention are as follows: the push rod contacts the object to be measured, and the object to be measured is deformed, thereby pushing the push rod to move toward the other end of the cavity. During the process, the push rod relies on elastic force to keep the push rod close to the object to be measured, so that it moves with the deformation of the object to be measured. At the same time, the push rod compresses the elastic part, and the elastic part compresses and accumulates force to provide elastic force for the subsequent reset of the push rod; the displacement of the push rod causes the gap between the push rod and the optical fiber to change, and the change in the gap in turn changes the return wavelength of the light in the optical fiber. By demodulating and calculating the change in wavelength, the deformation amount of the object to be measured can be accurately obtained.

[0007] On the basis of the above technical solution, the present invention can also be improved as follows.

[0008] Furthermore, one end surface of the push rod is a plane, and the other end surface of the push rod is a curved surface.

[0009] The beneficial effect of adopting the above further solution is: setting the end surface of one end of the push rod to a plane, and setting the end surface of the other end of the push rod to an arc surface, the contact area between the arc surface and the object to be measured is small, and the feedback is more sensitive, thereby accurately converting the deformation of the object to be measured into the displacement of the push rod.

[0010] Furthermore, it also includes a protection component, the optical fiber passes through the protection component, and the protection component is fixedly connected to the shell.

[0011] The beneficial effect of adopting the above further solution is: by providing a protective component to protect the optical fiber, the contact optical fiber sensor can operate in environments such as high temperature, high pressure and strong radiation, thereby improving the service life and applicability of the contact optical fiber sensor.

[0012] Furthermore, the ports at both ends of the cavity are respectively fixedly provided with a first baffle and a second baffle, the first baffle abuts against the step column, and the second baffle is fixedly connected to the protection component.

[0013] The beneficial effect of adopting the above further solution is that the first baffle is provided and abuts against the step column, thereby limiting the displacement of the push rod and its reset. The second baffle fixes the protective assembly, thereby making the contact-type optical fiber deformation sensor more stable and ensuring more accurate data measurement.

[0014] Furthermore, the protective component includes a ceramic core and an armored sheath, the ceramic core and the armored sheath are fixedly connected and fixedly sleeved on the outside of the optical fiber, the ceramic core is arranged at the other end of the cavity, and one end of the armored sheath is fixedly connected to one end of the outer shell.

[0015] The beneficial effects of adopting the above further solution are: protecting and fixing the optical fiber, thereby improving the service life of the contact optical fiber deformation sensor. At the same time, the setting of the ceramic core and armored sheath makes the contact optical fiber deformation sensor suitable for harsh environments such as high temperature, high pressure, and strong radiation.

[0016] Furthermore, one end of the optical fiber is flush with one end surface of the ceramic core.

[0017] The beneficial effect of adopting the above further solution is: ensuring that the gap between the optical fiber and the top rod is accurately measurable, and the change in the gap causes the wavelength of the returned light detected by the optical fiber to change accordingly, thereby accurately obtaining the deformation of the object being measured based on subsequent demodulation and calculation.

[0018] Furthermore, the protection component also includes a sleeve, which is fixedly sleeved on the outside of the optical fiber, and one end of the sleeve is fixedly connected to the other end of the armored sheath.

[0019] The beneficial effect of adopting the above further solution is that the provision of the sleeve further protects the optical fiber from being broken.

[0020] Furthermore, it also includes a mounting frame, which is sleeved on the outside of the shell and connected to the shell.

[0021] The beneficial effect of adopting the above further solution is that the mounting frame and the housing are detachably connected, and the fixing frame for fixing the sensor is connected to the mounting frame, thereby fixing the sensor and facilitating measurement.

[0022] Furthermore, the outer side of the shell is provided with an external thread, one end of the mounting frame is provided with a mounting hole, and the other end of the mounting frame is provided with a threaded hole, and the shell and the mounting frame are threadedly connected through the threaded hole and the external thread.

[0023] The beneficial effect of adopting the above further solution is: the housing and the mounting frame are connected through the threaded hole and the external thread, and the fixing frame is connected to the mounting frame through the mounting hole, thereby fixing the sensor and facilitating the measurement of the deformation variable of the object being measured.

[0024] Furthermore, it also includes a bolt, a locking hole is provided on one side of the mounting frame, the bolt is threadedly connected to the locking hole and abuts against the side wall of the shell, and the axis of the locking hole is perpendicular to the axis of the threaded hole.

[0025] The beneficial effect of adopting the above further solution is: after adjusting the position of the mounting bracket on the housing, the mounting bracket and the fixing bracket are connected by screwing together through the bolts and locking holes, thereby stabilizing the sensor, making it more stable during measurement and the measurement data more accurate. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 is a cross-sectional view of the contact-type optical fiber deformation sensor of the present invention;

[0027] Figure 2 Schematic diagram of the contact-type optical fiber deformation sensor of the present invention;

[0028] Figure 3 Schematic diagram of the contact type optical fiber deformation sensor mounting bracket of the present invention.

[0029] In the accompanying drawings, the components represented by the reference numerals are as follows:

[0030] 100, housing; 200, contact assembly; 210, push rod; 220, elastic member; 300, optical fiber; 400, protective assembly; 410, ceramic core; 420, armored jacket; 430, sleeve; 500, stepped column; 600, mounting bracket; 610, mounting hole; 620, threaded hole; 630, locking hole; 700, first baffle; 800, second baffle. DETAILED DESCRIPTION

[0031] The principles and features of the present invention are described below. The examples given are only used to explain the present invention and are not used to limit the scope of the present invention.

[0032] like Figure 1-Figure 3 As shown, this embodiment provides a contact-type optical fiber deformation sensor, including a housing 100, a contact assembly 200 and an optical fiber 300. A cavity is provided inside the housing 100, and the contact assembly 200 includes a push rod 210 and an elastic member 220. The push rod 210 is provided at one end of the cavity, and the optical fiber 300 is fixed to the other end of the cavity. One end of the push rod 210 slides with the cavity and is spaced apart from the optical fiber 300. The elastic member 220 is sleeved on the outside of the other end of the push rod 210. The outer wall of the push rod 210 has a step column 500, and the two ends of the elastic member 220 are respectively in contact with the step column 500 and the housing 100.

[0033] In this embodiment, the top rod 210 contacts the object to be measured, and the object to be measured is deformed, thereby pushing the top rod 210 to move toward the other end of the cavity. During this process, the top rod 210 relies on elastic force to keep the top rod 210 close to the object to be measured, so that it moves as the object to be measured deforms. At the same time, the top rod 210 compresses the elastic part 220, and the elastic part 220 compresses and accumulates force to provide elastic force for the subsequent reset of the top rod 210; the displacement of the top rod 210 causes the gap between the top rod 210 and the optical fiber 300 to change, and the change in the gap in turn changes the return wavelength of the light in the optical fiber 300. By demodulating and calculating the change in wavelength, the deformation of the object to be measured can be accurately obtained.

[0034] Specifically, the elastic member 220 is a spring or elastic material.

[0035] Specifically, the housing 100 is formed in one piece.

[0036] Specifically, the outer surface of the push rod 210 and the inner cavity of the housing 100 are polished.

[0037] By performing a polishing process, the friction of the push rod 210 when moving in the inner cavity is reduced, so that the displacement is more accurate and the deformation of the measured object is accurately obtained; at the same time, the wear resistance of the push rod 210 is improved, ensuring the service life of the sensor.

[0038] On the basis of any of the above solutions, one end surface of the push rod 210 is a plane, and the other end surface of the push rod 210 is a curved surface.

[0039] One end surface of the push rod 210 is set as a plane, and the other end surface of the push rod 210 is set as an arc surface. The contact area between the arc surface and the object to be measured is small, and the feedback is more sensitive. The arc surface contacts the object to be measured and then pushes the push rod 210 to move, and the deformation of the object to be measured is accurately converted into the displacement of the push rod 210.

[0040] Specifically, both ends of the push rod 210 are mirror-polished.

[0041] The arc surface is polished to make it more sensitive to the contact with the object being measured, so that the deformation of the object being measured can be obtained through the accurate displacement of the push rod 210; the flat surface is polished to facilitate light signal reflection and signal sensitivity, thereby making the measurement data more accurate.

[0042] On the basis of any of the above solutions, a protection component 400 is further included, the optical fiber 300 passes through the protection component 400, and the protection component 400 is fixedly connected to the housing 100.

[0043] By providing the protection component 400 , the optical fiber 300 is protected, so that the contact optical fiber sensor can operate in environments such as high temperature, high pressure and strong radiation, thereby improving the service life and applicability of the contact optical fiber sensor.

[0044] Alternatively, the optical fiber 300 and the housing 100 are directly fixed, such as by bonding.

[0045] Based on any of the above schemes, the ports at both ends of the cavity are respectively fixed with a first baffle 700 and a second baffle 800, the first baffle 700 abuts against the step column 500, and the second baffle 800 is fixedly connected to the protection component 400.

[0046] By setting the first baffle 700 and the first baffle 700 abutting against the step column 500, the top rod 210 is limited when it moves to generate displacement and reset, and the setting of the second baffle 800 fixes the protective component 400, thereby making the contact optical fiber deformation sensor more stable as a whole and making the data measurement more accurate.

[0047] Specifically, the first baffle 700 and the second baffle 800 are welded to the ports at both ends of the cavity by laser welding.

[0048] Specifically, the first blocking piece 700 and the ejector pin 210 are clearance-fitted.

[0049] In a specific example, in the initial state, one end of the step column 500 abuts against one end of the first baffle 700, and the other end of the step column 500 abuts against one end of the elastic member 220, and the top rod 210 and the first baffle 700 are loosely fitted, and the top rod 210 can freely pass through the first baffle 700.

[0050] Based on any of the above schemes, the protective component 400 includes a ceramic core 410 and an armored sheath 420, the ceramic core 410 and the armored sheath 420 are fixedly connected and fixedly sleeved on the outside of the optical fiber 300, the ceramic core 410 is arranged at the other end of the cavity, and one end of the armored sheath 420 is fixedly connected to one end of the outer shell 100.

[0051] The setting of the protection component 400 protects and fixes the optical fiber 300, thereby improving the service life of the contact optical fiber deformation sensor. At the same time, the setting of the ceramic core 410 and the armored sheath 420 makes the contact optical fiber deformation sensor suitable for harsh environments such as high temperature, high pressure, and strong radiation.

[0052] Specifically, one end of the ceramic core 410 and one end of the armor sheath 420 are fixed by welding using high-temperature glass solder.

[0053] Based on any of the above solutions, one end of the optical fiber 300 is flush with one end surface of the ceramic core 410 .

[0054] By aligning one end of the optical fiber 300 with one end of the ceramic core 410, the gap between the optical fiber 300 and the top rod 210 is ensured to be accurately measurable. The change in the gap causes the wavelength of the returned light detected by the optical fiber 300 to change accordingly, thereby accurately obtaining the deformation of the object being measured based on subsequent demodulation and calculation.

[0055] Specifically, the initial gap between the ceramic core 410 and the push rod 210 is determined by the material of the object being measured and the ambient temperature. Accordingly, the maximum length of the arc end of the push rod 210 extending out of the housing 100 can be increased or decreased according to actual needs.

[0056] Based on any of the above solutions, the protection component 400 further includes a sleeve 430 , which is fixedly sleeved on the outside of the optical fiber 300 , and one end of the sleeve 430 is fixedly connected to the other end of the armored jacket 420 .

[0057] The provision of the sleeve 430 further protects the optical fiber 300 from being broken.

[0058] Specifically, one end of the sleeve 430 and the armored sheath 420 are fixed by laser welding.

[0059] In one specific example, the coating of optical fiber 300 is polyimide, which is resistant to radiation and high temperatures. Optical fiber 300 passes through sleeve 430, which is secured to armored jacket 420 via laser welding. Optical fiber 300 then passes through ceramic core 410, which is then welded to the end using high-temperature glass solder. The end of ceramic core 410, near the ejector pin 210, is polished and smoothed to serve as the probe end face of optical fiber 300, thereby detecting the position of ejector pin 210.

[0060] Specifically, the sleeve 430 is a stainless steel tube.

[0061] On the basis of any of the above solutions, a mounting bracket 600 is further included. The mounting bracket 600 is sleeved on the outer side of the housing 100 and connected to the housing 100 .

[0062] The mounting bracket 600 and the housing 100 are detachably connected. The fixing bracket (not shown in the figure) is connected to the mounting bracket 600 to fix the contact-type optical fiber deformation sensor, thereby facilitating measurement of the object to be measured.

[0063] Specifically, the mounting bracket 600 and the housing 100 are detachably connected.

[0064] Based on any of the above schemes, the outer side of the shell 100 is provided with an external thread, one end of the mounting frame 600 is provided with a mounting hole 610, and the other end of the mounting frame 600 is provided with a threaded hole 620, and the shell 100 and the mounting frame 600 are threadedly connected through the threaded hole 620 and the external thread.

[0065] The housing 100 and the mounting bracket 600 are threadedly connected via the threaded hole 620 and the external thread, and the fixing bracket is connected to the mounting bracket 600 via the mounting hole 610, thereby fixing the contact optical fiber deformation sensor to facilitate the measurement of the deformation of the object being measured.

[0066] Based on any of the above schemes, it also includes a bolt, and a locking hole 630 is provided on one side of the mounting frame 600. The bolt and the locking hole 630 are threadedly connected and abut against the side wall of the shell 100. The axis of the locking hole 630 is perpendicular to the axis of the threaded hole 620.

[0067] After adjusting the position of the mounting bracket 600 on the housing 100 , the mounting bracket 600 is connected to the fixing bracket by screwing the bolts and the locking holes 630 , thereby making the measurement more stable and the measurement data more accurate.

[0068] In one specific example, the outer surface of the housing 100 features an M4 external thread, allowing the mounting bracket 600 to be adjusted using the threaded adjustment. Once adjusted to the desired position, it can be secured with bolts engaging the locking holes 630. The mounting bracket 600 and the housing 100 are then laser welded. The housing 100 has a maximum outer diameter of 4 mm, allowing the sensor to operate in confined spaces. The push rod 210 is made of Kovar 4J29, a material with a low coefficient of expansion that improves the sensor's measurement accuracy in high-temperature environments. The initial gap between the push rod 210 and the ceramic core 410 is 2.7 mm. The sensor is connected to a mounting bracket (not shown) via the mounting holes 610 in the mounting bracket 600, securing the sensor and bracket. The object being measured is placed on one end of the curved surface of the push rod 210, with the curved surface in contact with the object. When the push rod 210 senses the object's deformation, it pushes it toward the ceramic core 410, while a compression spring provides the force for the push rod 210 to return to its original position. As the push rod 210 moves, the gap between the push rod 210 and the ceramic core 410 becomes smaller, and the deformation of the object being measured is converted into the displacement of the push rod 210. The optical fiber 300 probe senses the change in the gap, and the change in the gap will change the return wavelength of the light in the optical fiber 300. Through back-end demodulation and calculation of the wavelength change, the deformation of the object can be accurately measured and transmitted to the back-end system through the optical fiber 300. After completing the measurement of the deformation of the object being measured, the spring provides elastic force for the push rod 210 to reset, and the push rod 210 resets and waits for the next operation. The sensor can operate in complex environments such as high temperature, high pressure, strong radiation, and confined space, and can accurately measure the deformation of the object being measured.

[0069] In the description of the present invention, it should be understood that the terms "length", "up", "down", "top", "bottom", "inside", "outside", "axial", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, they cannot be understood as limiting the present invention.

[0070] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In the description of the present invention, "plurality" means at least two, such as two, three, etc., unless otherwise specifically defined.

[0071] In the present invention, unless otherwise specified or limited, the terms "mounted," "connected," "connect," "fixed," etc. should be understood in a broad sense. For example, they may refer to fixed connection, detachable connection, or integration; they may refer to direct connection or indirect connection through an intermediate medium; they may refer to internal communication between two components or interaction between two components, unless otherwise specified. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0072] In the present invention, unless otherwise expressly specified or limited, when a first feature is "above" or "below" a second feature, it may mean that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediary. Furthermore, when a first feature is "above," "above," or "above" a second feature, it may mean that the first feature is directly above or diagonally above the second feature, or simply means that the first feature is at a higher level than the second feature. When a first feature is "below," "below," or "below" a second feature, it may mean that the first feature is directly below or diagonally below the second feature, or simply means that the first feature is at a lower level than the second feature.

[0073] In the description of this specification, the reference terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" mean that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art can combine and combine different embodiments or examples described in this specification and features of different embodiments or examples without contradiction.

[0074] Although the embodiments of the present invention have been shown and described above, it will be understood that the above embodiments are illustrative and are not to be construed as limitations on the present invention. A person skilled in the art may change, modify, replace and modify the above embodiments within the scope of the present invention.

Claims

1. A contact optical fiber deformation sensor, characterized in that: The invention comprises a shell (100), a contact assembly (200) and an optical fiber (300), wherein a cavity is arranged inside the shell (100), and the contact assembly (200) comprises a push rod (210) and an elastic member (220), wherein the push rod (210) is arranged at one end of the cavity, and the optical fiber (300) is fixed at the other end of the cavity, and one end of the push rod (210) is slidably matched with the cavity and is spaced apart from the optical fiber (300), and the elastic member (220) is sleeved on the outer side of the other end of the push rod (210), and the outer wall of the push rod (210) has a step column (500), and the two ends of the elastic member (220) are respectively in contact with the step column (500) and the shell (100).

2. A contact optical fiber deformation sensor according to claim 1, characterized in that: One end surface of the push rod (210) is a plane, and the other end surface of the push rod (210) is a curved surface.

3. The contact optical fiber deformation sensor according to claim 1, characterized in that: It also comprises a protection component (400), the optical fiber (300) passes through the protection component (400), and the protection component (400) is fixedly connected to the housing (100).

4. A contact optical fiber deformation sensor according to claim 3, characterized in that: The ports at both ends of the cavity are respectively fixedly provided with a first baffle (700) and a second baffle (800); the first baffle (700) abuts against the step column (500), and the second baffle (800) is fixedly connected to the protection component (400).

5. The contact optical fiber deformation sensor according to claim 3, characterized in that: The protection component (400) comprises a ceramic core (410) and an armored jacket (420); the ceramic core (410) and the armored jacket (420) are fixedly connected and fixedly sleeved on the outside of the optical fiber (300); the ceramic core (410) is arranged at the other end of the cavity; one end of the armored jacket (420) is fixedly connected to one end of the outer shell (100).

6. The contact optical fiber deformation sensor according to claim 5, characterized in that: One end of the optical fiber (300) is flush with an end surface of one end of the ceramic core (410).

7. The contact optical fiber deformation sensor according to claim 5, characterized in that: The protection component (400) further comprises a sleeve (430), wherein the sleeve (430) is fixedly sleeved on the outside of the optical fiber (300), and one end of the sleeve (430) is fixedly connected to the other end of the armored jacket (420).

8. A contact optical fiber deformation sensor according to any one of claims 1 to 7, characterized in that: It also includes a mounting frame (600), wherein the mounting frame (600) is sleeved on the outside of the housing (100) and connected to the housing (100).

9. The contact optical fiber deformation sensor according to claim 8, characterized in that: The outer side of the housing (100) is provided with an external thread, one end of the mounting frame (600) is provided with a mounting hole (610), and the other end of the mounting frame (600) is provided with a threaded hole (620), and the housing (100) and the mounting frame (600) are threadedly connected via the threaded hole (620) and the external thread.

10. The contact optical fiber deformation sensor according to claim 9, characterized in that: It also includes a bolt, and a locking hole (630) is provided on one side of the mounting frame (600). The bolt and the locking hole (630) are threadedly connected and abut against the side wall of the housing (100). The axis of the locking hole (630) is perpendicular to the axis of the threaded hole (620).

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