KR100941227B1 - A fixture for an optical fiber sensor and a method for fixing an optical fiber sensor by using a fixture - Google Patents

Abstract

The present invention relates to a fixture for attaching an optical fiber sensor to an optical fiber sensor package and a method of attaching the optical fiber sensor to an optical fiber sensor package using the stator.

The stator 300 of the present invention is used to attach the optical fiber sensor 100, which is made to function as an optical fiber sensor, in the optical fiber sensor package 200, and has a cylindrical body portion 370; Adhesive filling hole 320 formed to flow the liquid adhesive 360 from the circular outer surface of the middle of the upper body portion 370 to the center of the body portion; Two cylindrical light-diameter through-holes 330 formed on both sides of the upper body 370 to penetrate the optical fiber sensor; Is formed between the two wide-bore hole 330 is connected to the two wide-bore hole 330 and the narrow-hole through-hole 340 to allow the optical fiber sensor to penetrate the two wide-bore hole 330; And the optical fiber sensor is prevented from being bent or broken at the end of the boundary surface of the wide-area through-hole 330 and the narrow-area through-hole 330 by being inserted into the inside of the wide-area through-hole 330. And characterized in that it comprises a protective jacket 350 to protect.

And the method for attaching the optical fiber sensor to the object according to the present invention, the step of stripping the acrylic coating of the corresponding portion of the optical fiber sensor to be attached to the optical fiber sensor package by a desired width (S10); Passing the stripped portion of the optical fiber sensor through the optical fiber sensor insertion hole formed in the center of the stator for attaching the optical fiber sensor to adjust the middle portion of the stripped optical fiber sensor portion to coincide with the adhesive filling hole located in the center of the stator. (S20); Injecting the adhesive into the adhesive filling hole of the stator having the position adjusted above (S30); The adhesive injected above flows through the adhesive filling hole of the stator to coat around the cladding part of the stripped part of the optical fiber sensor, and then flows continuously to coat the empty space and protective jacket of the wide-area section formed at both ends of the stator. Step S40; And solidifying the coated adhesive (S50).

By implementing the present invention, it is possible to prevent the slip phenomenon of the acrylic coating, to prevent the cutting of the strip part of the optical fiber sensor, and to reuse the optical fiber sensor even if the optical fiber sensor package is lost, thereby reducing the repair cost. In addition, since only the damaged package part needs to be repaired, the time required for repair can be shortened.

Fiber optic, stator, fiber optic sensor, slip phenomenon, deformation, fiber grating sensor, fiber optic sensor package, attachment method.

Description

A fixture for an optical fiber sensor and a method for fixing an optical fiber sensor by using a fixture}

The technical field of the present invention relates to a technique for attaching an optical fiber sensor to an optical fiber sensor package for measuring various physical deformations in order to measure physical deformation of an object such as a building or civil structure (hereinafter referred to as "object").

1 is an internal configuration diagram of a general optical fiber. Such optical fibers are generally glass fibers composed of a core portion of 8 to 10 μm and a cladding portion of about 125 μm having a different refractive index. If the grating is carved in a special way to such an optical fiber, the optical fiber can be used as an optical fiber grating sensor. The method of making the optical fiber grating sensor corresponds to the background art of the present invention and is not the content of the present invention, so a description thereof will be omitted. At this time, the grating is formed in the core and the cladding portion. In addition, the glass fiber is acrylic coated about 245 ~ 250㎛ because of the risk of its own breakage.

The acrylic coating has the advantage of protecting the optical fiber or the optical fiber grating sensor, but when the optical fiber grating sensor is directly attached to the object, slip occurs between the acrylic coating part and the cladding part, resulting in accurate deformation. ) Difficulty in measuring. Figure 2 shows an example of fixing the optical fiber according to the prior art.

Therefore, in order to accurately measure the physical deformation of the object, the cladding portion of the object and the optical fiber grating sensor must be fixedly attached. For this purpose, the acrylic coating of the attachment point optical fiber sensor must be peeled off. 3 illustrates an example of a state in which a part of the acrylic coating of the optical fiber sensor is removed to fix the optical fiber to the sensor package according to the related art.

However, at this time, the optical fiber sensor of the stripped portion is generally lower in strength than the optical fiber sensor of the other portion, and when the deformation occurs, the stripped portion is easily broken or difficult to attach the optical fiber sensor to the sensor package. Here, the optical fiber sensor package is a device installed at one end of the object to measure the degree of physical deformation of the object, together with a jig for fixing the optical fiber sensor to the object, the optical fiber sensor is fixed inside the sensor package and subjected to external impact. It has a protective function. Commonly used fiber optic sensor packages include pore-strain gauges, inclinometers, stress gauges, displacement gauges, strain gauges, underground displacement gauges, and rock bolt axisometers.

It is a first object of the present invention to provide a stator for an optical fiber sensor in order to solve the problems of the prior art described above, and to provide a method of attaching an optical fiber sensor to an optical fiber sensor package using the stator.

A second object of the present invention is to provide a means for protecting the strength of the strip portion of the optical fiber sensor from being lowered when attaching the optical fiber sensor to the sensor package.

It is a third object of this invention to provide a means for facilitating adhesive filling by placing holes for adhesive filling in the stator.

The fourth object of the present invention is to reuse the optical fiber sensor package and the optical fiber sensor when the case of the optical fiber sensor package is lost or when the optical fiber sensor inside the optical fiber sensor package is lost, thereby reducing the repair cost, Repairing only the package part provides a means for reducing the time required for repair.

Other objects and advantages of the present invention will become more apparent from the following detailed description of the invention and the accompanying drawings.

The problem solving means of this invention is a stator. That is, the stator 300 of the present invention is used to attach the optical fiber 100 made to function as the optical fiber sensor to the optical fiber sensor package 200, and has a cylindrical body portion 370; Adhesive filling hole 320 formed to flow the liquid adhesive 360 from the circular outer surface of the middle of the upper body portion 370 to the center of the body portion; Two cylindrical light-diameter through-holes 330 formed on both sides of the upper body 370 to penetrate the optical fiber sensor; Is formed between the two wide-bore hole 330 is connected to the two wide-bore hole 330 and the narrow-hole through-hole 340 to allow the optical fiber sensor to penetrate the two wide-bore hole 330; And the optical fiber sensor bent or broken at the end of the boundary surface of the wide-area passage 330 and the narrow-area passage 340 by being inserted into the inner side of the wide-area passage 330. It characterized in that it comprises a protective jacket 350 for preventing and protecting.

And another problem solving means of this invention is a method of attaching an optical fiber sensor to an object using the stator. The method comprises the steps of: stripping the acrylic coating of the corresponding portion of the optical fiber sensor to be attached to the optical fiber sensor package by a desired width (S10); Passing the corresponding part of the stripped optical fiber sensor through the optical fiber sensor insertion hole formed at the center of the stator for attaching the optical fiber so that the middle part of the stripped optical fiber sensor part coincides with the adhesive filling hole located at the center of the stator (S20); Injecting the adhesive into the adhesive filling hole of the stator having the position adjusted above (S30); The adhesive injected above flows through the adhesive filling hole of the stator to coat the cladding around the stripped portion of the optical fiber sensor, and then continuously flows into the empty space and the protective jacket 350 formed at both ends of the stator. Coating to step (S40); It characterized in that it comprises a step (S50) to harden the coated adhesive.

Stripping the acrylic coating of the corresponding portion of the optical fiber sensor to be attached to the optical fiber sensor package by a desired width; Passing the stripped optical fiber portion through the optical fiber sensor insertion hole formed in the center of the optical fiber attachment stator to adjust the middle portion of the stripped portion to coincide with the epoxy filling hole located at the center of the stator; Injecting epoxy into the epoxy filling hole of the stator with the above position adjusted; Epoxy injected above flows through the epoxy filling hole of the stator to coat the cladding around the stripped portion of the optical fiber sensor (S40); And hardening the coated epoxy.

The effects expected by the practice of this invention are as follows:

First, when fixing the optical fiber sensor in the optical fiber sensor package, it is possible to prevent the acrylic coating portion fixing portion of the optical fiber sensor is deformed to generate a slip phenomenon.

Second, when peeling the part to be attached from the acrylic coating of the optical fiber sensor, the peeled part is sharply dropped, so there is a high risk of breaking the optical fiber sensor. However, the stator can protect the peeled part of the acrylic coating and reinforce the strength. .

Third, the adhesive filling hole in the center of the stator to facilitate the injection of the adhesive.

Fourth, the shape and size of the stator can be varied according to the shape / attachment method of the sensor package or the surface shape / use of the object, so that the fiber optic sensor is fixed and attached to the inside of every package regardless of the type of the fiber optic sensor package. can do.

Fifth, if the optical fiber sensor is directly attached to the inside of the optical fiber sensor package with adhesive, the case of the optical fiber sensor package is lost or the optical fiber sensor inside the optical fiber sensor package is lost. By fixing and attaching the optical fiber sensor inside the optical fiber sensor package, the fiber optic sensor package and the optical fiber sensor can be reused, and the repair cost can be reduced. It can be shortened.

<Description of Configuration and Operation of Preferred Embodiment>

A preferred embodiment of the present invention will be described below with reference to the drawings. First, the configuration and operation principle of the stator 300 used in the present invention will be described. 4 is an internal configuration diagram of a preferred embodiment of the stator 300 for an optical fiber sensor used in the present invention.

The stator 300 having the configuration as shown in FIG. 4 is preferably made of a metal material (or may be made of another material). The stator 300 is used to attach the grating engraved optical fiber 100 inside the optical fiber sensor package 200 to function as an optical fiber sensor.

4A of FIG. 4 is a perspective view showing the appearance of the stator 300. The stator 300 has a cylindrical shape as a whole, and an adhesive filling hole 320 is formed at an intermediate position of the cylinder. And both sides of the stator 300 is formed with a circular wide-bore hole 330. 4A shows a state in which the optical fiber 100 penetrates into the optical fiber 130 in a state in which it is not stripped through the optical hole passage 310.

4B of FIG. 4 is an internal cross sectional view of FIG. 4A. Looking at this cross section, the adhesive filling hole 320 is formed in funnel shape. That is, the outer diameter of the filling hole 320 is larger and narrower as you go inward.

And the wide-bore aperture 330 is formed to have a specific radius by a predetermined depth in each end surface of the stator 300 of the cylindrical shape. In this embodiment, the depth of the wide-bore passage 330 is 5 cm. However, this value can be adjusted as needed. And although the diameter of the wide-bore passage 330 is set to 900 to 1000 μm in this embodiment, this value can also be adjusted as necessary. Between the two wide-bore port 330 is an elongated narrow-hole through-hole 340 is located, the diameter of the narrow-hole through-hole 340 is determined in consideration of the diameter of the optical fiber 100 sensor, this implementation In the example, the diameter of the narrow narrow passage 340 is 250 to 500 µm. However, it is obvious to those skilled in the art that this value can be adjusted as needed.

The boundary surface of the photosphere aperture 330 and the narrow aperture tube 340 and the end portion of the photosphere aperture 330 are relatively sharp, so that the interface 100 and the optical fiber 100 sensor directly contact the optical fiber 100 sensor. Of the optical fiber 100 sensor is broken by inserting a protective jacket 350 of a soft material (for example, rubber) into the wide-bore port opening 330 and filling and fixing with an adhesive 100 because the risk of breakage or damage is very high. It does not cause loss or damage. The protective jacket 350 is preferably made of a material having at least rubbery toughness and softness. At this time, the outer diameter of the protective jacket 350 is preferably about 900 ~ 1000㎛. It is obvious to those skilled in the art that this value can be adjusted as needed.

Meanwhile, the optical fiber 100 sensor penetrates through the wide-diameter passage 330 and the narrow-diameter passage 340 and then the adhesive 360 in the liquid state with the adhesive filling hole 320 of the stator 300. When blowing, the adhesive 360 flows through the filling hole 320 to cover the stripped portion of the optical fiber sensor first, and then flows from side to side along the narrow-bore passage 340 to the wide-bore passage 330. The adhesive flows into the empty space and the protective jacket 350 of the narrow aperture through hole 340 and the wide aperture through hole 330 and gradually hardens. Epoxy is preferable as the adhesive 360 used at this time. Especially thermosetting epoxy is more preferable as an adhesive agent. This is because the epoxy is excellent in the ability to bond the metal (stator body portion) 370 and the glass (optical fiber sensor) 100, and the strength of the adhesion does not fall even with temperature changes.

5 illustrates a method of injecting adhesive 360 to a preferred embodiment of a stator 300 for an optical fiber sensor used in the present invention. 5A illustrates a case where the adhesive 360 is filled by the adhesive filling hole 320 of the stator 300, and FIG. 5B illustrates the wide-area section 330 and the narrow-angle section in FIG. 5A. 340 is an enlarged state diagram.

In Figure 5b it can be seen that the optical fiber 100 sensor inside the stator 300 is largely divided into three parts. Section C is a case where the acrylic coating 130 of the optical fiber 100 is peeled off so that only the core part 110 and the cladding part 120 remain, and the adhesive 360 is between the cladding part 120 and the narrow diameter section 340. It is confirmed in Figure 5e that the filling.

On the contrary, the section B is a section in which the optical fiber 100 in which the acrylic coating 130 is not stripped exists, and the adhesive 360 fills the space between the acrylic coating 130 and the narrow diameter section 340 in FIG. 5D. It is confirmed.

In addition, the section A is also a section in which the optical fiber 100 sensor, in which the acrylic coating 130 is not peeled, similar to the section B is present. The difference is that in the A section, the adhesive 360 is filled between the acrylic coating 130 of the optical fiber 100 sensor and the light aperture 330, and the protective jacket 350 is located outside the light aperture 330. It is confirmed in FIG. 5C.

5C is a cross-sectional view of section A-A 'of FIG. 5B, FIG. 5D is a cross-sectional view of section B-B' of FIG. 5B, and FIG. 5E is a cross-sectional view of section C-C 'of FIG. 5B.

FIG. 6 is a flowchart illustrating a preferred embodiment of a method of attaching an optical fiber sensor to the optical fiber sensor package 200 using the stator 300 for the optical fiber sensor according to the present invention.

The present invention, the core portion 110 is located in the center; A cladding unit 120 having a different refractive index than the core unit 110 and surrounding the core unit 110; And an optical fiber sensor made by engraving a lattice in a specific method on the optical fiber 100 which is a glass fiber composed of an acrylic coating part 130 covering the cladding part 120, and the optical fiber made in this way on an object to grasp the degree of deformation. The sensor is attached to and measured through various optical fiber sensor packages 200 (not shown) using the stator 300 of the present invention.

According to the present invention, a method of attaching an optical fiber sensor to the optical fiber sensor package 200 is as follows. First, stripping the acrylic coating 130 of the corresponding portion of the optical fiber sensor to be attached to the optical fiber sensor package 200 by a desired width (S10), and the above stripped optical fiber sensor portion 160 stator 300 for attaching the optical fiber sensor Penetration through the optical fiber insertion hole 310 formed in the middle of the) is adjusted so that the middle portion of the stripped portion 160 coincides with the adhesive filling hole 320 located in the center of the stator 300 (S20).

The adhesive 360 is injected into the adhesive filling hole 320 of the stator 300 whose position is adjusted above (S30).

The adhesive 360 injected above flows through the adhesive filling hole 320 of the stator 300, and the cladding portion 120 and the acrylic coating 130 of the stripped portion 160 of the sensor 100 of the optical fiber 100 and After the periphery is coated, it continues to flow to coat the empty space and the protective jacket 350 of the wide-area section 330 formed on both ends of the stator 300 (S40). And harden the coated adhesive 360 (S50). According to the present invention, the optical fiber sensor is fixed to the stator 300 through a series of processes mentioned above, and the optical fiber sensor is fixed inside the optical fiber sensor package to be firmly attached to the object.

As such, the present invention may be variously modified and may take various forms, and only the specific embodiments thereof are described in the detailed description of the present invention. It is to be understood, however, that the present invention is not limited to the specific forms mentioned in the detailed description of the invention, but rather includes all modifications, equivalents, and substitutions within the spirit and scope of the invention as defined by the appended claims. It should be understood to do.

This invention is applicable in most fields where an optical fiber sensor is used. For example, the optical fiber sensor can be used in the case of providing a hole displacement gauge, inclinometer, stress gauge, displacement gauge, strain gauge, ground displacement gauge, rock bolt axial force gauge, and the like. In addition, since the technology can be used in various fields, the present invention has a great industrial applicability.

1 is an internal configuration diagram of a typical optical fiber.

2 is an exemplary view of fixing the optical fiber sensor directly to the optical fiber sensor package according to the prior art.

Figure 3 is an illustration of a state in which a portion of the acrylic coating of the optical fiber sensor is removed to fix the optical fiber sensor according to the prior art.

Figure 4 is an internal configuration of a preferred embodiment of a fiber optic sensor attachment stator (Fixture) used in the present invention.

Figure 5 is an exemplary view showing a method of injecting an adhesive to a preferred embodiment of the optical fiber sensor attachment stator (Fixture) used in the present invention.

Figure 5a is an exemplary view when the adhesive is filled with the adhesive filling hole in the center of the fixture (Fixture).

FIG. 5B is an enlarged view of the wide-area section and the narrow-angle section in FIG. 5A; FIG.

5C is a cross-sectional view taken along the line AA ′ of FIG. 5B.

FIG. 5D is a sectional view taken along the line BB ′ in FIG. 5B.

5E is a cross-sectional view taken along the line CC ′ of FIG. 5B.

Figure 6 is a flow chart of a preferred embodiment of the optical fiber sensor attachment method using a fiber optic sensor attachment stator (Fixture) according to the present invention.

<Description of Symbols for Major Parts of Drawings>

100: optical fiber (optical fiber sensor) 110: core portion

120: cladding portion 130: acrylic coating portion

140: slip part 150: epoxy

160: strip portion 200: optical fiber sensor package

300: Fixture 320: Adhesive filling hole

330: Gwanggu opening through hole 340: Gonggu opening through hole

350: protective jacket 360: adhesive

370: stator body

Claims (8)

In a stator used to attach an optical fiber made to function as an optical fiber sensor inside an optical fiber sensor package, Upper stator, Cylindrical body portion; An adhesive filling hole formed to flow a liquid adhesive from the circular outer surface of the middle of the upper body portion to the center of the body portion; Two cylindrical light-bulb through-holes formed on both sides of the upper body to penetrate the optical fiber sensor; Is formed between the above two wide-bore holes through the narrow hole through-holes that connect the two wide-bore holes and the optical fiber sensor to penetrate the two wide-bore holes; And It is inserted into the inside of the above-mentioned wide-bore port, and it includes a protective jacket to prevent the optical fiber sensor from bending or breaking at the boundary of the wide-bore hole and narrow-hole hole and the end of the hole. , At this time, the optical fiber sensor is characterized in that the optical fiber grating sensor, the stator for attachment inside the optical fiber sensor package of the optical fiber sensor. The stator for attaching the inside of an optical fiber sensor package according to claim 1, wherein the hole for filling the adhesive is formed in a funnel shape so that the outer surface side aperture is larger and the aperture becomes narrower as it goes inward. The method of claim 1, wherein the material of the stator body, the wide-diameter through-hole and the narrow-diameter through-hole is made of metal, the material of the fiber optic sensor is glass, and the protective jacket is made of a material having toughness and softness of rubber or more. , Stator for attachment inside the fiber optic sensor package of the fiber optic sensor. The stator of claim 1, wherein the adhesive is made of a material suitable for bonding metal and glass. The stator for attaching the inside of the optical fiber sensor package of the optical fiber sensor according to claim 1, wherein the adhesive is an epoxy that does not drop in adhesive strength even with temperature change. delete The stator of claim 5, wherein the epoxy is a thermosetting epoxy. A core portion located in the center; A cladding portion that has a different refractive index than the core portion and surrounds the core portion; And The optical fiber sensor made of optical fiber, which is a glass fiber made of an acrylate coating, which surrounds the cladding part, is applied to an object to grasp the degree of strain. In the method of attaching through a variety of optical fiber sensor package by using a fixture for attaching a single optical fiber sensor, Stripping the acrylic coating of the corresponding portion of the optical fiber sensor to be attached to the optical fiber sensor package by a desired width; Passing the corresponding part of the stripped optical fiber sensor through the optical fiber insertion hole formed in the center of the stator for attaching the optical fiber sensor so that the middle part of the stripped optical fiber sensor part coincides with the adhesive filling hole located in the center of the stator ; Injecting adhesive into the adhesive filling hole of the stator adjusted from above; The adhesive injected above flows through the adhesive filling hole of the stator to coat the cladding part and the acrylic coating part and the periphery of the stripped part of the optical fiber sensor, and then flows continuously to form empty spaces between the wide-area sections formed at both ends of the stator. Coating up to a protective jacket; And Method of attaching the optical fiber sensor to the object, characterized in that comprising the step of hardening the coated adhesive.

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