JP2007132824A - Detection device and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a detection device capable of surely fixing an optical fiber, and to provide its manufacturing method. <P>SOLUTION: A groove 14 is formed on the outer surface of a resin tube 12 formed of a polyolefin-based resin, and an optical fiber 16 using the polyolefin-based resin for a shell 20 is fitted into the groove 14. The opening of the groove 14 is blocked by a welding member 18 formed of the polyolefin-based resin, and hot wind from a welding heater is blown against the resin tube 12, the shell 20 and the welding member 18, and the welding member 18 is plunged into the groove 14. As a result, the welding member 18 is fused with the resin tube 12 and the shell 20, respectively, and the optical fiber 16 is fixed to the resin tube 12, to thereby form this detection device 10. Since the welding member 18 is used, the optical fiber 16 can be mounted simply and surely on the resin tube 12. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a detection device and a method for manufacturing the same, and more particularly, to a detection device and a method for manufacturing the same that detect ground behavior such as landslide and distortion of a concrete structure such as a tunnel, or measure distortion of a bridge.

An example of a conventional detection device and a manufacturing method thereof is disclosed in Patent Document 1. The optical fiber strain sensor of Patent Document 1 is formed by wiring an optical fiber in a groove formed on the outer peripheral surface of a fiber fixing member.
JP 2002-107122 A [G01B 11/16, G01D 5/26, G01D 21/00, G01L 1/24, G01M 11/00]

  In the prior art of Patent Document 1, before the optical fiber is fixed to the fiber fixing member, for example, when the optical fiber is temporarily fixed in the groove of the fiber fixing member using a tape or an adhesive, the optical fiber is not bonded due to the poor adhesion. Fixing defects may occur, and there were problems with reliability and workability.

  Therefore, a main object of the present invention is to provide a detection device and a method for manufacturing the same that can securely fix an optical fiber.

  The invention of claim 1 is formed of a polyolefin-based resin that is fused with a rod-shaped member formed of a polyolefin-based resin, a groove formed on the outer surface of the rod-shaped member, an optical fiber fitted into the groove, and a rod-shaped member. It is a detection apparatus provided with a welding member.

  According to the first aspect of the present invention, a groove (14) is provided on the outer surface of the rod-shaped member (12, 58: reference numerals exemplifying corresponding portions in the embodiment; the same shall apply hereinafter), and an optical fiber ( 16). The respective surfaces of the rod-like member (12, 58) and the welding member (18) are melted, and the welding member (18) is pushed into the groove (14). Thereby, the melted part of the welding member (18) is pressed against the melted part of the rod-like member (12, 58), and these are fused.

  As described above, the welding member (18) and the rod-like members (12, 58) are fused, so that the opening (25) of the groove (14) into which the optical fiber (16) is fitted is closed by the welding member (18). Can be removed. For this reason, the optical fiber (16) is securely fixed to the rod-shaped members (12, 58).

  The invention according to claim 2 is the detection device according to claim 1, wherein the outer sheath of the optical fiber is formed of a polyolefin resin, and the welding member is further fused to the outer sheath.

  In the invention of claim 2, the outer sheath (20) of the optical fiber (16) is formed of a polyolefin resin. The surface of the outer skin (20) is melted together with the rod-shaped members (12, 58) and the welded member (18). When the welded member (18) is pushed into the groove (14) in the melted state, the melted portion of the welded member (18) is fused to the melted portions of the rod-shaped member (12, 58) and the outer skin (20). .

  In this way, the welding member (18) is not only fused to the rod-like member (12, 58), but also to the outer skin (20), so that the outer skin (20) and the rod-like member (12, 58) are fused. Are joined via a welding member (18). For this reason, the optical fiber (16) is more firmly fixed to the rod-like members (12, 58).

  The invention of claim 3 provides (a) a rod-shaped member formed with a groove on the outer surface and made of a polyolefin resin, and (b) fitting an optical fiber whose outer skin is made of a polyolefin resin into the groove. And (c) manufacturing a detection device that pushes the welding member into the groove while blowing hot air to the rod-like member, outer skin and welding member so as to cover the opening of the groove with a welding member formed of polyolefin resin. Is the method.

  In the invention of claim 3, the groove (14) is provided on the outer surface of the rod-like member (12, 58), and the optical fiber (16) is fitted into the groove (14). When hot air is blown onto the rod-shaped member (12, 58), the outer cover (20) of the optical fiber (16) and the welding member (18) so as to cover the opening (25) of the groove (14) with the welding member (18), These surfaces melt. When the welded member (18) is pushed into the groove (14) in the melted state, the melted portion of the welded member (18) is pressed against the melted portion of the rod-shaped member (12, 58), and these are fused. In addition, the melted portion of the welding member (18) is pressed against the melted portion of the outer skin (20), and these are fused.

  In this manner, with the opening (25) of the groove (14) covered with the welding member (18), hot air is blown to the rod-like member (12, 58), the outer skin (20) and the welding member (18), When the welding member (18) is pushed into the groove (14), the melted portions of the rod-like member (12, 58), the outer skin (20) and the welding member (18) come into contact with each other, and the welding member (18). Is fused to the rod-like member (12, 58) and the outer skin (20). Further, the opening (25) of the groove (14) in which the optical fiber (16) is fitted is closed by the welding member (18). Thereby, since the rod-shaped members (12, 58) and the outer skin (20) are joined via the welding members (18), the optical fiber is securely fixed to the rod-shaped members (12, 58).

  Moreover, since the welding member (18) is pressed against the rod-shaped member (12, 58) and the outer skin (20) by pushing the welding member (18) into the groove (14), the rod-shaped member (12, 58) By simply melting the surface and the surface of the outer skin (20), the welding member (18) is fused to each of the rod-shaped members (12, 58) and the outer skin (20). Therefore, since the rod-shaped member (12, 58) and the outer skin (20) are melted too much and they are not deformed, the optical fiber is attached to an appropriate position of the rod-shaped member (12, 58).

  According to this invention, an optical fiber can be reliably fixed to the outer surface of a rod-shaped member by using a welding member.

  The above object, other objects, features and advantages of the present invention will become more apparent from the following detailed description of embodiments with reference to the drawings.

  1 and 2, the detecting device 10 according to one embodiment of the present invention fits the optical fiber 16 in the groove 14 of the resin tube 12 shown in FIG. 3, and then attaches the welding member 18 shown in FIG. 4 to the resin tube 12. And by fusing to the outer skin 20 of the optical fiber 16.

  The resin pipe 12 shown in FIGS. 5 and 6, which is an example of a rod-shaped member, is a straight pipe formed of, for example, a polyolefin resin. The outer diameter D of the resin tube 12 is set to 60 mm, for example. When the outer diameter D of the resin tube 12 is too large, the workability of the detection device 10 is deteriorated. On the other hand, when the outer diameter D is too small, the detection capability of the detection device 10 is lowered. For this reason, the outer diameter D of the resin tube 12 is appropriately determined according to the required capacity of the detection device 10.

  The resin tubes 12 are fused together in a state where the end surfaces of the resin tubes 12 are abutted with the end surfaces of the other resin tubes 12. In this way, the plurality of resin pipes 12 are connected in series.

  A groove 14 is provided on the outer surface of the resin tube 12. A plurality of grooves 14 are provided at equal intervals in the circumferential direction of the resin tube 12, and four grooves are provided in this embodiment. Each groove 14 extends in a straight line parallel to the tube axis 12 a of the resin tube 12. The cross-sectional shape of the groove 14 is U-shaped, and its bottom 22 is arcuate.

  However, since these grooves 14 are formed on the outer surface of the resin tube 12 by post-processing or secondary processing, both side portions 24 of the grooves 14 are inclined to the inside of the grooves 14, and the width W1 of the bottom portion 22 of the grooves 14 is the groove. 14 openings 25 are formed to be larger than the width W2. As shown in FIG. 3, the depth H of the groove 14 is larger than the outer diameter E of the outer sheath 20 of the optical fiber 16, and is set to a length 1.5 to 2 times the outer diameter, for example. As shown in FIG. 6, the length of the groove 14 is the same as the length of the resin tube 12, and the groove 14 is provided over the entire length of the resin tube 12. The grooves 14 of the plurality of connected resin tubes 12 are continuous in a straight line, and a hole 26 is provided in the tube wall of the resin tube 12 at a position where the connecting portion of the resin tube 12 and the groove 14 intersect.

  As is well known, the optical fiber 16 shown in FIG. 3 is obtained by coating a fiber core wire with, for example, FRP, and the outer surface of the FRP (not shown) is further covered with a skin 20. The outer skin 20 is made of the same type of resin as that of the resin tube 12. In this embodiment, the same type of polyolefin resin as the resin tube 12 is used. The diameter E of the outer sheath 20 of the optical fiber 16 is set to be equal to or smaller than the width W1 and the depth H of the groove 14 and larger than the width W2 of the opening 25 of the groove 14. As shown in FIG. 2, the length of the optical fiber 16 is set to be longer than the total length of the four grooves 14 in the plurality of connected resin tubes 12, and the four grooves are formed by one optical fiber 16. All 14 are wired.

  The welding member 18 shown in FIG. 3 is a rod-like member, and is formed of the same type as the resin of the resin tube 12. In this embodiment, the same type of polyolefin resin as the resin tube 12 is used. The outer diameter F of the welding member 18 is set equal to or larger than the width W2 of the opening 25 of the groove 14. As shown in FIG. 2, the length of the welding member 18 is set to be the same as the length of the plurality of connected resin pipes 12.

  When manufacturing this detection apparatus 10, first, the resin tube 12 is extrusion-molded with the extruder 28 shown in FIG. The resin tube 12 extruded from the extruder 28 is inserted into the base 32 of the cooling water tank 30 to prepare the outer surface of the resin tube 12. After cooling the resin tube 12, the groove 14 is provided by applying a rotary saw 34 or the like to the outer surface of the resin tube 12. The cross-sectional shape of the groove 14 is U-shaped, and both side portions 24 are formed in parallel. Then, the resin tube 12 is taken up by the take-up machine 36, a predetermined mark is printed on the outer surface of the resin tube 12 by the marking device 38, and then the resin tube 12 is cut to a certain length by the cutter of the cutting machine 40, The pipe discharge device 42 discharges the resin pipe 12 into the rack.

  The formed resin pipe 12 is carried to the construction site. Therefore, as shown in FIG. 8, the end faces of the two resin pipes 12 are brought into contact with each other while the positions of the grooves 14 are aligned, and butt fusion is performed. Thereby, the resin pipes 12 are connected. However, the portion fused by butt fusion rises from the outer surface of the resin tube 12 and the bead 44 closes the groove 14, so that the groove 14 is blocked by the bead 44 and the optical fiber 16 cannot be fitted into the groove 14. . Therefore, as shown in FIG. 6, a hole 26 is drilled in the tube wall of the resin tube 12 at a position where the bead 44 and the groove 14 intersect, and the bead 44 closing the groove 14 is removed and connected. The grooves 14 of the resin pipe 12 are made continuous. If the diameter of the hole 26 is equal to or greater than the width W1 of the groove 14 and the depth of the hole 26 is equal to or greater than the depth H of the groove 14, the hole 26 extends through the tube wall of the resin pipe 12. It may or may not penetrate.

  Then, the plurality of resin tubes 12 are connected by the same method as described above so that the required length is obtained, and the grooves 14 of the connected resin tubes 12 are continued. Then, as shown in FIG. 9, an optical fiber 16 having a required length is fitted into the groove 14.

  When the optical fiber 16 is fitted into the groove 14, the opening 25 of the groove 14 is slightly pushed wide. That is, stress remains in the resin tube 12 during the extrusion process shown in FIG. By utilizing this property, as shown in FIG. 9, both side portions 24 of the groove 14 are inclined to the inside of the groove 14 so that the width W2 of the opening 25 of the groove 14 is narrower than the width W1 when the groove 14 is formed, and the opening is opened. The width W2 of 25 is made the same as or slightly narrower than the outer diameter E of the outer skin 20 of the optical fiber 16.

  In this way, by utilizing the residual stress of the resin tube 12, the width W <b> 2 of the opening 25 is made the same as or slightly narrower than the outer diameter E of the outer skin 20, so that the opening 25 is slightly expanded, and the optical fiber 16. Easily enters the groove 14, and the optical fiber 16 once fitted does not easily come off from the groove 14, so that it is not necessary to temporarily fix the optical fiber 16 to the resin tube 12.

  Next, a welding heater 46 shown in FIG. 10 is prepared, and the welding member 18 is attached to the welding heater 46. The welding heater 46 has a blowout port 50 and a delivery pipe portion 48, and blows hot air from the blowout port 50. As a result, the hot air is blown out from the outlet 50 and at the same time, a part of the hot air is also blown out to the delivery pipe portion 48 to heat the side of the welding member 18 facing the groove 14.

  Using such a welding heater 46, for example, hot air of 250 to 400 ° C. is blown from the outlet 50 to the groove 14 so as to close the opening 25 of the groove 14 with the welding member 18. The portion of the welding member 18 facing the groove 14 and the resin pipe 12 and the outer skin 20 near the opening 25 of the groove 14 are heated by hot air, and the vicinity of the surface of the heated portion is melted.

  Then, as shown in FIG. 3, when the welding member 18 is pushed into the groove 14 while blowing hot air, the welding member 18 is pressed against the resin pipe 12 and the outer skin 20. As a result, the melted portion of the weld member 18 comes into contact with the melted portion of the resin tube 12 and is fused, and the melted portion of the weld member 18 comes into contact with and melts the melted portion of the outer skin 20. When the fused portion is cooled, the resin tube 12 and the outer skin 20 are joined via the welding member 18, and the optical fiber 16 is firmly fixed to the resin tube 12.

  Then, as shown in FIGS. 1 and 2, the optical fiber 16 is wired over the entire length of the four grooves 14 using, for example, one optical fiber 16. Thereby, the detection apparatus 10 is formed.

  The detection device 10 is inserted into a casing tube 52 buried in advance in the ground shown in FIG. 11, and a filler such as cement 54 is filled around the detection device 10 in the casing tube 52. When the tip of the optical fiber 16 is connected to an optical strain analyzer (not shown) or the like, the movement in the ground can be measured by the detection device 10.

  In this way, by welding the welding member 18 and the rod-shaped member 12 and fusing the welding member 18 and the outer skin 20, the outer skin 20 and the rod-shaped member 12 are joined via the welding member 18, and The opening 25 of the groove 14 into which the optical fiber 16 is fitted is closed by the welding member 18. Therefore, since the optical fiber 16 is securely fixed to the rod-shaped member 12, the optical fiber 16 can follow the movement of the resin tube 12 without being detached from the resin tube 12, and the detection accuracy of the detection device 10 is reduced. It can be suppressed.

  Further, in a state in which the opening 25 of the groove 14 is covered with the welding member 18, the welding member 18 is pushed into the groove 14 while blowing hot air to the groove 14 by the welding heater 46. It is possible to melt only a portion necessary for fusing 20 and the welding member 18 and to bring the portion into contact with each other for fusing. For this reason, problems such as deformation and poor adhesion due to heating of the resin tube 12 and the outer skin 20 do not occur, and workability is excellent.

  In addition, the processing accuracy is good by processing the groove 14 when the resin tube 12 is manufactured. In addition, the position of the optical fiber 16 does not shift due to deformation of the resin tube 12 or the outer sheath 20 due to heating. Therefore, the fiber 16 can be attached at an accurate position, and the detection device 10 can have high detection accuracy.

  Further, by setting the depth H of the groove 14 to 1.5 to 2 times the outer diameter E of the outer skin 20 of the optical fiber 16, the optical fiber 16 can be easily attached and fixed. That is, if the depth of the groove 14 is too shallow, the inclination of the groove 14 is reduced, and the optical fiber 16 is easily detached from the groove 14. On the other hand, when the depth of the groove 14 is too deep, it becomes difficult to fuse the outer sheath 20 of the optical fiber 16 and the welding member 18 together.

  Although the polyolefin resin is used for the outer skin 20 and the welding member 18 is fused to the rod-shaped member 12 and the outer skin 20, the outer skin 20 is formed of a resin other than the polyolefin resin, and the welding member 18 is fused to the outer skin 20. Instead, it can be fused to the rod-shaped member 12. Even in this case, since the opening 25 of the groove 14 into which the optical fiber 16 is fitted is closed by the welding member 18, the optical fiber 16 is fixed to the rod-shaped member 12.

  Moreover, although the cross-sectional shape of the bottom part 22 of the groove | channel 14 of the resin pipe 12 was made into circular arc shape, as shown in FIG. 12, you may change the cross-sectional shape of the bottom part 56 into linear form. Further, as shown in FIG. 13, the cross-sectional shape of the bottom 58 of the groove 14 may be changed to a V shape.

  Although the groove 14 is provided in the resin tube 12 after the extrusion molding, the groove 14 can be provided in the process of extrusion molding the resin tube 12. In this case, without using the rotary saw 34, for example, the die head portion of the extruder 28 shaped to form the groove 14, the base portion 20 of the cooling water tank 30, and the like are used to connect the resin pipe 12 to the die head portion of the extruder. A groove 14 is formed in the resin tube 12 by passing through a cap part or the like.

  Further, although four grooves 14 are formed in the resin pipe 12, the number of the grooves 14 may be one or more, and the specific number is the kind of ground deformation or the requirement for the detection purpose of the detection device 10. It is determined arbitrarily depending on accuracy. If the number of the grooves 14 is increased and the optical fiber 16 is attached to each of the grooves 14, the detection accuracy of the detection device 10 is improved.

  Although the hole 14 is made in the tube wall of the resin pipe 12 where the groove 14 and the bead 44 intersect to make the groove 14 continuous, the bead 44 can be shaved without making the hole 26 to make the groove 14 continuous.

  Although the detection device 10 is inserted into the casing tube 52 buried in advance in the ground, the detection device 10 may be buried directly in the ground. Moreover, the detection apparatus 10 can also be installed in structures, such as a tunnel. Thereby, it becomes possible to detect distortion of these structures.

  Furthermore, although the hollow resin tube 12 is used for the rod-shaped member, instead of this, a resin tube having a cross-sectional shape such as a cross shape or a rectangular shape that receives movement of the ground or the like on the surface can also be used for the rod-shaped member. . For example, the solid pipe 58 shown in FIG. 14 is a solid pipe whose cross-sectional shape is a cross shape. Since the solid pipe 58 is substantially the same as the resin pipe 12 except for the cross-sectional shape and the solid pipe 58, the description thereof will be omitted. In this case, the grooves 14 are respectively formed on one side surface or the tip of the four protrusions 60 of the solid tube 58, and the optical fiber 16 is fitted into the groove 14 as shown in FIG. Then, in a state where the optical fiber 16 is held in the groove 14 by the residual stress of the solid tube 58, the outer skin 20 of the optical fiber 16 and the solid tube 58 are fused via the welding member 18.

  Thus, by making the cross-sectional shape of the solid pipe 58 into a cross shape or the like, the solid pipe 58 can receive the movement regardless of the movement of the ground or the like from any direction. Detecting the behavior etc. That is, if the ground moves in the direction indicated by the arrow 62, the ground movement is received by the plane of the solid pipe 58. Further, even when there is a movement of the ground in an oblique direction with respect to the solid pipe 58, the solid pipe 58 causes the movement of the ground in the oblique direction indicated by the arrow 64 to enter between the two protrusions 60. Receive at corner 66. For this reason, the solid pipe 58 has no loss of force with respect to the movement of the ground and the like, and can capture the movement of the ground with high sensitivity.

  Note that the specific numerical values of the angles and dimensions given above are merely examples, and can be appropriately changed as necessary.

It is a cross-sectional view which shows the detection apparatus of one Example of this invention. It is a longitudinal cross-sectional view of the detection apparatus of FIG. It is a cross-sectional view showing a state in which an optical fiber is fitted in a groove of a resin tube and an opening of the groove is closed with a welding member. It is a cross-sectional view which shows the state which welded the welding member to the outer cover of the resin pipe and the optical fiber. It is a cross-sectional view showing a resin tube. It is a top view which shows the state which connected the some resin pipe. It is an illustration figure which shows the extrusion equipment used for manufacture of a resin pipe. It is a top view which shows the state which attached the end surface of the adjacent resin pipe | tube and butt-fused. It is a cross-sectional view which shows the state which fitted the optical fiber in the groove | channel of the resin pipe. It is a top view which shows the state which sprayed a hot air on the outer surface of the welding member, the resin pipe | tube, and the optical fiber using the welding heater, and pushed the welding member into the groove | channel. It is sectional drawing which shows the state which embed | buried the detection apparatus in the ground. It is a cross-sectional view which shows the resin pipe | tube which can be used for the detection apparatus of another Example of this invention. It is a cross-sectional view which shows the resin pipe | tube which can be used for the detection apparatus of another Example of this invention. It is a cross-sectional view which shows the solid pipe | tube which can be used for the detection apparatus of another Example of this invention. FIG. 15 is a cross-sectional view showing a state in which an optical fiber is fitted in the groove of the solid pipe in FIG. 14 and the welding member is fused to the solid pipe and the outer skin.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Detection apparatus 12 ... Resin pipe 14 ... Groove 16 ... Optical fiber 18 ... Welding member 20 ... Outer skin 58 ... Solid pipe

Claims (3)

A rod-shaped member formed of a polyolefin-based resin,
A groove formed on the outer surface of the rod-shaped member,
A detection apparatus comprising: an optical fiber fitted in the groove; and a welding member formed of a polyolefin-based resin and fused to the rod-shaped member. The outer sheath of the optical fiber is formed of a polyolefin resin,
The detection device according to claim 1, wherein the welding member is further fused to the outer skin. (a) preparing a rod-like member formed with a groove on the outer surface and made of a polyolefin-based resin;
(b) fitting an optical fiber whose outer skin is made of a polyolefin resin into the groove; and
(c) Cover the opening of the groove with a welding member formed of a polyolefin-based resin, and push the welding member into the groove while blowing hot air to the rod-shaped member, the outer skin, and the welding member. A method for manufacturing a detection device.

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