Radial fixing structure for fiber displacement sensor and fiber displacement sensor

Abstract

The present disclosure provides a radial fixing structure for fiber displacement sensor and a fiber displacement sensor. The sensor comprises an inner sleeve and an outer sleeve, the outer sleeve is sleeved outside the inner sleeve and can slide relative to the inner sleeve, and the central axes of the two sleeves coincide. The fixing structure body has a radial matching surface bonded with the outer sleeve and a mounting end surface for fitting the measured object; the radial matching surface is provided with a radial matching groove, the central axis of which coincides with the central axis of the outer sleeve, and the groove wall is provided with a radial glue storage groove for accommodating the adhesive overflowing between the outer wall of the outer sleeve and the groove wall during bonding. The present disclosure effectively accommodates the overflowing glue through the glue storage groove, avoids pollution, and improves the installation quality and reliability.

Description

Technical Field

[0001] This application relates to the field of fiber optic sensing technology, specifically to a radial fixing structure for a fiber optic displacement sensor and a fiber optic displacement sensor, and more particularly to an installation and fixing structure that collects adhesive overflowing during bonding by setting a radial adhesive storage groove on the groove wall of the radial mating surface of the fixing structure. Background Technology

[0002] White light phase-shifting interferometry (PSI) is a high-precision displacement measurement method that requires extremely high optical path stability. It requires two interferometric mirrors to be strictly parallel and have a relative orientation accuracy at the sub-arcsecond level.

[0003] When this technology is packaged into a fiber optic displacement sensor for field applications, the sensor typically includes a relative motion component comprising an inner sleeve and an outer sleeve. The outer sleeve is fitted over the inner sleeve and can slide relative to it. A mating groove is provided on the radial mating surface of the fixed structure, and one end of the outer sleeve extends into the groove and is fixed by adhesive. Because the outer wall of the outer sleeve is essentially in contact with the groove wall, the gap between them is extremely limited.

[0004] However, existing installation methods have the following drawbacks: Firstly, there is a serious problem with excess adhesive. To ensure bonding strength, operators usually apply a sufficient amount of adhesive into the mating groove. However, there is nowhere to contain the excess adhesive, so it overflows outwards along the groove opening, which may stick to other parts of the sensor or cause other parts that do not need to be bonded to be accidentally bonded and fixed.

[0005] Secondly, there is a lack of adhesive overflow collection structure. In traditional designs, the walls of the mating tank are flat and do not have the function of accommodating excess adhesive. The flow direction of the overflowing adhesive is uncontrollable, increasing the risk of contaminating optical components or sticking to moving parts.

[0006] Third, poor installation consistency. Differences in the amount of adhesive applied by different operators can lead to varying degrees of adhesive overflow. Furthermore, the volume shrinkage of the adhesive after curing may have unpredictable effects on the internal optical path of the sensor, compromising the consistency and reliability of measurements.

[0007] Therefore, there is an urgent need in the field for a radial fixing structure for fiber optic displacement sensors that can effectively contain adhesive overflowing during the bonding process.

[0008] It should be noted that the above introduction to the technical background is only for the purpose of providing a clear and complete explanation of the technical solutions of this application and facilitating understanding by those skilled in the art. It should not be assumed that these technical solutions are known to those skilled in the art simply because they have been described in the background section of this application. Utility Model Content

[0009] To address one or more of the aforementioned technical problems, this utility model provides a radial fixing structure for fiber optic displacement sensors and a fiber optic displacement sensor. The core objective is to provide a radially extending radial adhesive storage groove on the groove wall of the radial mating surface of the fixing structure, so that excess adhesive during the bonding process can be collected in the radial adhesive storage groove, thereby preventing adhesive from overflowing along the groove opening and contaminating other components, and improving the installation quality and reliability of the fiber optic displacement sensor.

[0010] In a first aspect of this disclosure, a radial fixing structure for a fiber optic displacement sensor is provided. The fiber optic displacement sensor includes a relative motion assembly comprising an inner sleeve and an outer sleeve. The outer sleeve is configured to be fitted over the inner sleeve. The inner wall of the outer sleeve abuts against the outer wall of the inner sleeve to form a relatively sliding structure, and the central axis of the inner sleeve coincides with the central axis of the outer sleeve. The fixing structure includes a fixing structure body having a radial mating surface for fixed connection with the outer sleeve and a surface for contact with the object being measured. The mounting end face is fitted to the body surface; a radial mating groove is provided on the radial mating surface, the radial mating groove is configured to be bonded and fixed to the outer wall of the outer sleeve near the cable outlet end by adhesive, and the central axis of the radial mating groove coincides with the central axis of the outer sleeve; a radial adhesive reservoir is provided on the groove wall of the radial mating groove, the radial adhesive reservoir is configured to extend outwardly in the radial direction of the radial mating groove, and the radial adhesive reservoir is configured to collect the adhesive that overflows from the outer wall of the outer sleeve and the groove wall of the radial mating groove during the bonding process.

[0011] Furthermore, in some embodiments, the radial adhesive reservoir is configured to extend from the opening of the radial mating groove to the bottom of the radial mating groove.

[0012] Furthermore, in some embodiments, the cross-sectional shape of the radial adhesive reservoir is any one of U-shape, semi-circular, V-shape or rectangular.

[0013] Furthermore, in some embodiments, the radial adhesive reservoirs are configured as a plurality, distributed at circumferential intervals along the radial mating grooves.

[0014] Furthermore, in some embodiments, the radial adhesive reservoirs are configured as 2N, distributed in pairs at intervals along the circumference of the radial mating grooves, and symmetrically distributed with respect to the central axis of the radial mating grooves, where N is a positive integer.

[0015] Furthermore, in some embodiments, the depth of the radial mating groove is 0.5 mm to 2 mm, and the depth of the radial adhesive reservoir is 0.2 mm to 0.8 mm.

[0016] Furthermore, in some embodiments, the fixing structure body is made of a metal material or an engineering plastic, wherein the metal material includes any one of stainless steel and aluminum alloy; and the engineering plastic includes any one of PEEK and polycarbonate.

[0017] A second aspect of this disclosure also provides an optical fiber displacement sensor comprising the fixing structure as described above.

[0018] Furthermore, in some embodiments, the fiber optic displacement sensor is a white light interferometric MEMS fiber optic displacement sensor.

[0019] The beneficial effects of this disclosure are as follows: In some embodiments, the system effectively collects excess adhesive, preventing contamination. For example, by providing a radially extending radial adhesive reservoir on the wall of the mating groove of the fixed structure's radial mating surface, excess adhesive during bonding is squeezed into the radial adhesive reservoir under pressure, preventing adhesive from overflowing outwards along the groove opening and avoiding adhesive adhering to other sensor components or causing unnecessarily bonded areas to be accidentally fixed. In some embodiments, the system is easy to manufacture and inexpensive. For example, the radial adhesive reservoir is provided along the radial direction of the mating groove and can be directly processed from the groove opening along its wall, simplifying the manufacturing process without adding extra parts or assembly steps, making it suitable for mass production. In some embodiments, the system improves installation quality and consistency. For example, the radial adhesive reservoir provides a fixed storage space for excess adhesive, reducing the impact of differences in adhesive application by different operators and improving the consistency and reliability of fiber optic displacement sensor installation. In some embodiments, the system is compact and does not increase volume. For example, the radial adhesive reservoir is located on the groove wall of the mating groove, without increasing the external dimensions of the fixed structure, which is beneficial for miniaturized sensor design. Attached Figure Description

[0020] The above and other features, advantages and aspects of the embodiments of this disclosure will become more apparent from the accompanying drawings and the following detailed description, wherein: Figure 1 A schematic diagram of a white light interferometric MEMS fiber optic displacement sensor according to an embodiment of the present disclosure is shown; Figure 2 A three-dimensional structural schematic diagram of a fixing structure according to an embodiment of the present disclosure is shown; Figure 3 A schematic diagram of the mounting structure according to an alternative embodiment of the present disclosure is shown; In the various figures, the same or corresponding reference numerals indicate the same or corresponding parts, including: fixed structure body 100; radial mating surface 110; mounting end face 120; radial mating groove 130; groove wall 140; radial glue storage groove 150; inner sleeve 200; outer sleeve 300; fixed structure at the cable outlet 400; and fixed structure at the tail end 500. Detailed Implementation

[0021] Embodiments of this disclosure will now be described in more detail with reference to the accompanying drawings. While some embodiments of this disclosure are shown in the drawings, it should be understood that this disclosure can be implemented in various forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided to provide a more thorough and complete understanding of this disclosure. It should be understood that the accompanying drawings and embodiments of this disclosure are for illustrative purposes only and are not intended to limit the scope of protection of this disclosure.

[0022] In the description of embodiments of this disclosure, the term "comprising" and similar terms should be understood as open-ended inclusion, i.e., "including but not limited to". The term "based on" should be understood as "at least partially based on". The term "one embodiment" or "the embodiment" should be understood as "at least one embodiment". The terms "first", "second", etc., may refer to different or the same objects. Other explicit and implicit definitions may also be included below.

[0023] In view of the urgent need in the field for a radial fixing structure for fiber optic displacement sensors that can effectively contain adhesive spilled during the bonding process and prevent adhesive from contaminating other components.

[0024] This disclosure will be explained in more detail with reference to the accompanying drawings. It should be noted that in the embodiments of this disclosure, the term "outgoing cable end" refers to the end closest to the optical fiber or cable or the cable fixing structure, while "tail end" refers to the other end opposite the outgoing cable end.

[0025] First, regarding the basic structure.

[0026] like Figure 1 As shown, the fiber optic displacement sensor of this embodiment includes a relative motion component. The relative motion component includes an inner sleeve 200 and an outer sleeve 300. The outer sleeve 300 is fitted over the inner sleeve 200, and the inner wall of the outer sleeve 300 abuts against the outer wall of the inner sleeve 200 to form a relatively sliding structure. The central axis of the inner sleeve 200 coincides with the central axis of the outer sleeve 300. In some embodiments, the fiber optic displacement sensor further includes a fixing structure 400 at the cable exit end and a fixing structure 500 at the tail end; wherein the fixing structure 400 at the cable exit end is used for fixed connection with the outer wall of the outer sleeve, and the fixing structure 500 at the tail end is used for fixed connection with the outer wall of the inner sleeve, both of which are coaxially arranged with the outer sleeve 300.

[0027] like Figure 2 As shown, the fixing structure includes a fixing structure body 100. The fixing structure body 100 has a radial mating surface 110 and a mounting end face 120. The radial mating surface 110 is used for fixed connection with the outer sleeve 300, and the mounting end face 120 is used for contact with the surface of the object being measured. The mounting end face 120 and the radial mating surface 110 are not on the same plane.

[0028] A radial mating groove 130 is provided on the radial mating surface 110. For example... Figure 2 As shown and referenced Figure 1 and Figure 3 The radial fitting groove 130 is configured to be bonded and fixed to the outer wall of the outer sleeve 300 by adhesive. During installation, one end of the outer sleeve 300 extends into the radial fitting groove 130, and the central axis of the radial fitting groove 130 coincides with the central axis of the outer sleeve 300. The outer wall of the outer sleeve 300 is bonded to the groove wall 140 of the radial fitting groove 130 by adhesive, thereby achieving a fixed connection between the fixing structure and the outer sleeve 300.

[0029] A radial adhesive reservoir 150 is provided on the wall 140 of the radial mating groove 130. The radial adhesive reservoir 150 extends outward in the radial direction of the radial mating groove 130 (that is, an additional small groove is provided on the wall 140 that is recessed inward, and this small groove extends from the opening of the radial mating groove 130 to the bottom of the radial mating groove 130 in a direction parallel to the central axis of the radial mating groove 130), and is used to collect the adhesive that overflows from the outer wall of the outer sleeve 300 and the wall 140 of the radial mating groove 130 during the bonding process.

[0030] It should be understood that during the adhesive application process, the operator applies adhesive to the radial mating groove 130 or the outer wall of the outer sleeve 300, and then inserts the outer sleeve 300 into the radial mating groove 130. During insertion and pressing, excess adhesive is squeezed out from the gap between the outer wall of the outer sleeve 300 and the groove wall 140. At this time, the radial adhesive reservoir 150 provides a storage space for this overflowing adhesive, preventing the adhesive from overflowing outward along the groove opening of the radial mating groove 130, thereby preventing the adhesive from sticking to other components of the sensor or causing other parts that do not need to be bonded to be accidentally bonded. Furthermore, the radial mating groove 130 includes a bottom, and although a slot is provided at the bottom, the radius of the slot should be smaller than the radius of the outer wall of the outer sleeve 300. This not only prevents the outer sleeve 300 from excessively extending into the optical precision part of the cable end, but also ensures that any adhesive overflowing during the process remains within the radial adhesive reservoir 150 and does not overflow into the optical precision part of the cable end along the slot. It should also be understood that the radial adhesive reservoir 150 begins at the opening of the radial mating groove 130 towards the tail end, extends radially (e.g., along the central axis of the radial mating groove 130), and terminates at the bottom of the radial mating groove 130.

[0031] Furthermore, regarding the location and shape of the radial adhesive reservoir.

[0032] like Figure 2 As shown, in some embodiments, the radial adhesive reservoir 150 is disposed on the wall 140 of the radial mating groove 130. This arrangement allows the adhesive to flow more easily into the radial adhesive reservoir 150 under gravity, resulting in better storage. Simultaneously, because the radial adhesive reservoir 150 is located on the wall 140, the adhesive can be effectively contained, preventing excessive overflow.

[0033] The cross-sectional shape of the radial adhesive reservoir 150 can be any one of U-shape, semi-circular, V-shape or rectangular. U-shaped or semi-circular radial adhesive reservoirs facilitate the flow and filling of adhesive, avoid dead corners, and ensure that adhesive can flow fully into the radial adhesive reservoir 150.

[0034] In some embodiments, alternatively, the depth of the radial mating groove 130 is 0.5 mm to 2 mm (preferably 1 mm). It should be understood that the depth of the radial mating groove 130 can refer to the distance extending radially from the opening facing the outer sleeve side to the bottom of the groove. Similarly, the depth of the radial glue reservoir 150 is 0.2 mm to 0.8 mm (preferably 0.5 mm). The depth of the radial glue reservoir 150 can refer to the distance extending radially from the opening facing the central axis of the radial mating groove 130 to the bottom of the groove. The width of the radial glue reservoir 150 is 0.3 mm to 1.0 mm. It should be understood that the width of the radial glue reservoir 150 can refer to the distance between the sidewalls on the left and right sides of the radial glue reservoir 150.

[0035] Furthermore, regarding the arrangement of the radial adhesive storage tanks.

[0036] like Figure 2 As shown, in some embodiments, multiple radial adhesive reservoirs 150 are provided, distributed circumferentially at intervals along the radial mating grooves 130. The arrangement of multiple radial adhesive reservoirs 150 can collect overflowing adhesive from multiple directions, further improving the collection effect.

[0037] In a preferred embodiment, there are 2N radial adhesive reservoirs 150, arranged in pairs and spaced apart along the circumference of the radial mating groove 130, and symmetrically distributed with respect to the central axis of the radial mating groove 130, where N is a positive integer. For example, when N=2, there are 4 radial adhesive reservoirs 150, evenly distributed circumferentially and symmetrically arranged in pairs; when N=3, there are 6 radial adhesive reservoirs 150, evenly distributed circumferentially and symmetrically arranged in pairs. The symmetrically arranged radial adhesive reservoirs 150 ensure that the adhesive is evenly collected in all directions of the circumference of the radial mating groove 130, avoiding insufficient fixation between the adhesive reservoir and the outer sleeve 300 due to uneven collection on one side.

[0038] Further explanation regarding the processing method.

[0039] The radial glue reservoir 150 is arranged along the radial direction of the radial mating groove 130 and can be directly machined from the opening of the radial mating groove 130 along its groove wall 140. Specifically, after machining the radial mating groove 130, a corresponding tool is inserted from the opening of the radial mating groove 130 to radially mill or turn the radial glue reservoir 150 along the groove wall 140. This machining method is simple and convenient, does not require complex processes and equipment, and is suitable for mass production.

[0040] Furthermore, regarding the materials and connection methods of the fixed structure.

[0041] The fixed structure body 100 can be made of metallic materials (such as stainless steel or aluminum alloy) or engineering plastics (such as PEEK or polycarbonate). Metallic materials offer high strength and durability, making them suitable for long-term monitoring scenarios; engineering plastics offer advantages such as light weight and low cost, making them suitable for weight-sensitive applications. Those skilled in the art should understand from existing technology that metallic materials include stainless steel or aluminum alloy. Stainless steel is preferably austenitic stainless steel (such as SUS304 or SUS316L), with a yield strength ≥200MPa, suitable for humid, weakly acidic or alkaline, or medical disinfection environments, and possesses excellent corrosion resistance and ductility; aluminum alloy is preferably 6-series (such as 6061-T6) or 7-series (such as 7075-T6) aerospace-grade hard aluminum alloy, with a tensile strength of up to 300MPa and a density ≤2.8g / cm³, suitable for dynamic fixing scenarios requiring lightweight construction and resistance to moderate alternating loads. It should also be understood that engineering plastics include polyetheretherketone (PEEK) or polycarbonate (PC). PEEK is preferably glass fiber or carbon fiber modified and reinforced grade, with a long-term operating temperature up to 160℃, a flexural modulus ≥4GPa, and X-ray permeability, making it suitable for non-magnetic interference-free fixing structures requiring high-temperature sterilization or medical imaging monitoring. Polycarbonate (PC) is preferably flame-retardant grade (UL94 V-0), with a notched impact strength ≥600J / m and light transmittance ≥85%, making it suitable for protective fixing shells requiring transparent observation of internal components or high impact toughness. Therefore, those skilled in the art can rationally select one from the aforementioned set as the body material based on the specific load-bearing capacity, operating temperature range, media corrosivity, and manufacturing cost. Specifically, when the fixing structure needs to withstand a dynamic torque ≥100N·m and the ambient temperature ≥120℃, metallic materials (especially stainless steel) are preferred to ensure creep resistance; when the fixing structure needs insulation, wave transmission, or weight reduction (40%~60% weight reduction compared to metal) and the operating temperature ≤120℃, PEEK or PC are preferred. When metal materials are selected, the body is integrally formed by precision casting, CNC milling (CNC) or powder metallurgy injection molding (MIM), and after forming, it is subjected to solution-aging heat treatment to eliminate internal stress. When engineering plastics are selected, the body is formed by injection molding or 3D fused deposition modeling, and after forming, it needs to be stress-relief annealed at 150℃~200℃ to ensure dimensional stability.

[0042] The main body 100 and the outer sleeve 300 are bonded together with adhesive. During installation, the operator applies an appropriate amount of adhesive to the radial mating groove 130 or the outer wall of the outer sleeve 300, then inserts one end of the outer sleeve 300 into the radial mating groove 130 and applies appropriate pressure to ensure a tight fit. Excess adhesive is squeezed into the radial adhesive reservoir 150 during the pressing process. Once the adhesive has cured, the fixing is complete.

[0043] Furthermore, regarding fiber optic displacement sensors.

[0044] This disclosure also provides a fiber optic displacement sensor, which includes the fixed structure as described above. Specifically, this fiber optic displacement sensor can be a white light interferometric MEMS fiber optic displacement sensor. By providing a radial adhesive reservoir on the wall of the radial mating groove of the fixed structure, the sensor can effectively collect adhesive overflowing during the bonding process, preventing adhesive contamination of other components, thereby ensuring the sensor's measurement accuracy and long-term reliability.

[0045] It should be understood that the above embodiments illustrate a MEMS fiber optic displacement sensor, but other types of fiber optic displacement sensors are also possible, as long as the fixed structure needs to be bonded and fixed to the outer tube.

[0046] In some alternative embodiments, such as Figure 3 As shown, both the output and tail ends of the fiber optic displacement sensor are equipped with the fixing structures mentioned in the above embodiments (not just at the output end). However, it should be noted that since the output end of this application has a large number of precision optical components, the fixing structure at the output end adopts a radial fixing method. This method actually has high processing requirements and is difficult to apply adhesive for bonding and fixing. It is generally only suitable for fixing small sections, for example, if the length to be fixed is only 3mm, that is, the depth of the radial mating groove is 3mm. In this case, such a short section to be bonded requires a sufficiently large bonding area. Therefore, a radial mating groove method that does not damage the bonding area is adopted, along with a corresponding radially arranged adhesive reservoir. It should also be understood that since the tail end fixing structure does not need to accommodate a large number of optical functional components, a sufficiently long inner sleeve can be arranged to fix the tail end fixing structure. Therefore, in this case, the radial mating groove scheme is not preferred, but it can be implemented if cost is not a concern.

[0047] The various embodiments of this disclosure have been described above. These descriptions are exemplary and not exhaustive, nor are they limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments. The terminology used herein is chosen to best explain the principles, practical application, or technical improvements to the embodiments in the market, or to enable others skilled in the art to understand the embodiments disclosed herein.

[0048] The above description is merely an optional embodiment of this disclosure and is not intended to limit this disclosure. Various modifications and variations can be made to this disclosure by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this disclosure should be included within the scope of protection of this disclosure.

Claims

1. A radial fixing structure for an optical fiber displacement sensor, the optical fiber displacement sensor including a relative motion component, the relative motion component including an inner sleeve and an outer sleeve; the outer sleeve is configured to be fitted over the outside of the inner sleeve; the inner wall of the outer sleeve and the outer wall of the inner sleeve abut against each other to form a relatively sliding structure, and the central axis of the inner sleeve coincides with the central axis of the outer sleeve; Its features are, The fixing structure includes a fixing structure body, which has a radial mating surface for fixed connection with the outer sleeve and an mounting end face for contact with the surface of the object being measured. A radial mating groove is provided on the radial mating surface. The radial mating groove is configured to be bonded and fixed to the outer wall of the outer sleeve near the cable outlet end by adhesive, and the central axis of the radial mating groove coincides with the central axis of the outer sleeve. A radial adhesive reservoir is provided on the wall of the radial mating groove. The radial adhesive reservoir is configured to extend outwardly in the radial direction of the radial mating groove and is configured to collect adhesive that overflows from between the outer wall of the outer sleeve and the wall of the radial mating groove during the bonding process.

2. The radial fixing structure for the fiber optic displacement sensor according to claim 1, characterized in that, The radial adhesive reservoir is configured to extend from the opening of the radial mating groove to the bottom of the radial mating groove.

3. The radial fixing structure for the fiber optic displacement sensor according to claim 1, characterized in that, The cross-sectional shape of the radial glue storage tank can be any one of U-shape, semi-circular, V-shape or rectangular.

4. The radial fixing structure for the fiber optic displacement sensor according to claim 1, characterized in that, The radial adhesive storage tanks are configured as a plurality of those, which are distributed at circumferential intervals along the radial mating grooves.

5. The radial fixing structure for the fiber optic displacement sensor according to claim 1, characterized in that, The radial adhesive storage tanks are configured as 2N, which are distributed in pairs at intervals along the circumference of the radial mating grooves and are symmetrically distributed with respect to the central axis of the radial mating grooves, where N is a positive integer.

6. The radial fixing structure for the fiber optic displacement sensor according to claim 1, characterized in that, The depth of the radial mating groove is 0.5 mm to 2 mm, and the depth of the radial adhesive storage groove is 0.2 mm to 0.8 mm.

7. The radial fixing structure for the fiber optic displacement sensor according to claim 1, characterized in that, The fixed structure body is made of metal or engineering plastic, wherein the metal material includes any one of stainless steel and aluminum alloy; and the engineering plastic includes any one of PEEK and polycarbonate.

8. A fiber optic displacement sensor, characterized in that, Includes the fixed structure as described in any one of claims 1 to 7.

9. The fiber optic displacement sensor according to claim 8, characterized in that, The fiber optic displacement sensor is a white light interferometric MEMS fiber optic displacement sensor.

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