JP2015219293A - Liquid light guide and method for manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a liquid light guide in which a gas component in atmospheric air is hard to enter into the light guide liquid even when a resin tube having a low gas barrier property is used.SOLUTION: A light guide liquid 3 to be a core is filled into the hollow section of a resin tube 2 whose one end side is sealed by a light transmissivity plug 5, and the light transmissivity plug 5 is temporarily joined at the other end side while inside of the resin tube 2 is kept in a state of degasification. Then, before the resin tube is sealed, the filling pressure of the light guide liquid 3 is selected so as to be 1100 hPa or more and an engineering proof pressure or less within a use temperature range in a compression process in which the light transmissivity plug 5 is pushed into the resin tube 2 and the light guide liquid 3 is pressurized.

Description

  The present invention relates to a liquid light guide in which a hollow portion of a resin tube is filled with a light guide liquid serving as a core.

The liquid light guide is obtained by filling a light guide liquid serving as a core in a resin tube and sealing both ends with a light-transmitting plug such as a quartz rod. Generally, as a resin tube, FEP, PFA is used. Resins containing fluorine such as are used.
When sealing both ends of the tube, since the light guide liquid is generally incompressible, a wire is inserted between the tube and the translucent plug and the light guide liquid is allowed to flow out of the gap. After the optical plug is pushed in, the wire is extracted and the translucent plug is sealed with a cap or the like, so that the filling pressure of the light guide liquid and the atmospheric pressure become substantially equal.

  However, since the fluorine-containing resin has low gas barrier properties, gas in the atmosphere easily penetrates the tube and enters the light guide, and the tube is filled with the light guide liquid, so bubbles are formed. This causes a problem that the light transmittance is lowered.

  For this reason, conventionally, as shown in FIG. 11, a clad tube 42 made of a fluororesin is filled with a light guide liquid 43, and both ends thereof are sealed with translucent plugs 44. A liquid light guide 41 having a double structure by providing a protective tube 45 made of a material having a high gas barrier property on the outside, and forming a gap 46 between the cladding tube 42 and the protective tube 45 in an airtight manner to block outside air. It has been proposed (see Patent Document 1).

According to this, since the clad tube 42 is not exposed to the outside air, gas components in the atmosphere hardly enter the light guide liquid 43.
However, even if the gap 46 is formed airtight, it is inevitable that the air penetrates the clad tube 42 and enters the light guide liquid 43 because air exists in the gap 46.

  In addition, since the tubes 42 and 45 must be doubled through the gap 46, there is a demerit that not only the rigidity is increased and the flexibility is sacrificed, but also the weight is increased as a whole.

JP-A-8-94872

  Therefore, the present invention provides a gas in the atmosphere even if a tube made of a material having a low gas barrier property is used, even if it is exposed to the atmosphere as it is without providing a protective tube outside the tube and making the tube double. It is a technical problem to provide a liquid light guide in which components do not easily enter the light guide liquid and a method for manufacturing the same.

In order to solve this problem, the present invention provides a liquid light guide in which a hollow portion of a resin tube is filled with a light guide liquid serving as a core, and both ends thereof are sealed with a translucent plug. The filling pressure of the liquid is selected so as to be 1100 hPa or more and the design withstand pressure or less within the operating temperature range.
In addition, the method of the present invention fills the hollow portion of a resin tube whose one end is sealed with a light-transmitting plug with a light guide liquid serving as a core, maintains the inside of the tube in an evacuated state, and moves it to the other end. A method of manufacturing a liquid light guide for sealing a light-transmitting plug after temporarily fixing the light-transmitting plug. After temporarily fixing the light-transmitting plug on the other end and sealing the plug, And a pressurizing step of pressurizing the light guide liquid.
Further, according to another manufacturing method of the present invention, at least one end side is attached with a base capable of inserting and removing the needle in an airtight state, and both end openings are sealed with a light-transmitting plug, and the hollow portion of the resin tube is formed. A method of manufacturing a liquid light guide in which a needle is inserted from the base after the light guide liquid serving as a core is filled and the internal air is vented, and is guided through the venting needle after the venting process is completed. A pressurizing step of pressurizing and filling the optical liquid into the tube is provided.

According to the present invention, the filling pressure of the light guide liquid in the tube is 1100 hPa or more within the operating temperature range, and is selected sufficiently higher than the normal atmospheric pressure.
Therefore, even if a tube made of a material having a low gas barrier property is used, since the pressure in the tube is higher than the atmospheric pressure, it is reliably prevented that gas components in the atmosphere enter the tube.
Moreover, since the filling pressure is selected to be equal to or lower than the design withstand pressure, the translucent plug that seals both ends of the manufactured liquid light guide may fall off due to internal pressure, or the tube may burst. There is nothing.

Explanatory drawing which shows an example of the liquid light guide by this invention. Explanatory drawing which shows the resin-made tubes used for this invention method. Explanatory drawing which shows the process of filling a light guide liquid. Explanatory drawing which shows the process of temporarily fixing a translucent plug. Explanatory drawing which shows the liquid light guide which temporarily fixed the translucent plug. Explanatory drawing which shows the pressurization process by this invention method. Explanatory drawing which shows the process of sealing a translucent plug. Explanatory drawing which shows the process of cut | disconnecting resin-made tubes. Explanatory drawing which shows the resin-made tubes used in the other Example of this invention method. Explanatory drawing which shows the deaeration process and pressurization process by other Example of this invention method. Explanatory drawing which shows the conventional liquid light guide.

Even if a tube made of a material having a low gas barrier property is used, a protective tube is provided on the outside of the tube, and the tube is not doubled. In order to achieve the purpose of making it difficult to enter the light guide liquid,
In a liquid light guide in which a hollow portion of a resin tube is filled with a light guide liquid as a core and both ends thereof are sealed with a light-transmitting plug, the filling pressure of the light guide liquid is set to 1100 hPa within the operating temperature range. It selected above so that it might become below design withstand pressure | voltage.

As shown in FIG. 1, the liquid light guide 1 according to the present invention has a hollow portion of a resin tube 2 filled with a light guide liquid 3 serving as a core.
In this example, the resin tube 2 having an outer diameter of 10.5 mm, an inner diameter of 10 mm, and a length of 1 m formed of FEP was used.
The light guide liquid 3 was filled with a 38% calcium chloride solution at 20 ° C. so as to be atmospheric pressure + 400 hPa (about 1400 hPa).

Collet chuck type caps 4 are externally mounted on both ends of the tube 2, and translucent plugs 5 inserted into both ends of the tube 2 are fixed by the caps.
The base 4 includes a collet 7 in which a spring chuck 6 is formed by a radial dividing groove (not shown), and a lock nut 8 for tightening the spring chuck 6, and a taper screw formed on the outer peripheral surface of the spring chuck 6; By tapering a taper screw formed on the lock nut 8 and reducing the diameter of the spring chuck 6 portion, the resin tube 2 can be pressed against the translucent plug 5 to seal the openings at both ends of the tube 2. It is like that.
A quartz rod is used as the translucent plug 5.

The design operating temperature of the liquid light guide 1 was −10 ° C. to 45 ° C., and it was confirmed that the filling pressure of the light guide liquid 3 did not fall below 1100 hPa within the temperature range.
Further, it was confirmed that the design withstand pressure of the liquid light guide 1 can be safely used for 100 days when the filling pressure of the light guide liquid 3 is increased to 10000 hPa at an air temperature of 20 ° C.

The above is one configuration example of the liquid light guide according to the present invention, and the manufacturing method thereof will be described next.
First, as shown in FIG. 2, a translucent plug 5 inserted on one end side of the resin tube 2 is fixed with a base 4 and a collet 7 is externally provided on the other end side, as shown in FIG. The light guide liquid 3 is submerged in the liquid tank 11 and the hollow portion is filled with the light guide liquid 3.
Next, after the opened other end side is raised and all the bubbles remaining in the tube 2 are discharged, the translucent plug 5 is temporarily fixed to the other end side of the tube 2 as shown in FIG. The light guide liquid 3 is filled without generating bubbles.

In this state, as shown in FIG. 5, the resin tube 2 is taken out from the liquid tank 11, the lock nut 8 is sheathed from the other end side, and the tube 2 is fixed so as not to be displaced. A pressurizing step of pushing the optical plug 5 into the tube 2 is executed.
As a result, the substantial length of the hollow portion filled with the light guide liquid 3 is shortened. However, since the liquid such as the light guide liquid 3 is generally incompressible, the resin tube 2 is expanded by a corresponding amount. As a result, the filling pressure of the light guide liquid 3 is considered to be higher than the atmospheric pressure by the amount of tension acting in the in-plane direction of the resin tube 2.

6 to 7, when the lock nut 8 is tightened while the translucent rod 5 is pushed by the plunger 12, the spring chuck 6 of the collet 7 is reduced in diameter, and the tube 2 is translucent. The tube 2 is sealed by being firmly sandwiched between the rod 5 and the chuck 6.
After the completion of the sealing, if the excess portion of the tip of the resin tube is cut as shown in FIG. 8, the liquid light guide 1 shown in FIG. 1 is completed.

In addition, when manufacturing the liquid light guide 1 by this method, since it is difficult to obtain | require the filling pressure of the light guide liquid 3 correctly, the pushing force of the translucent rod 5 is used as a filling pressure of a light guide liquid. May be.
For more precise control, a sensing rod having the same size as the translucent rod 5 provided with a pressure sensor at the tip is attached to one end of the resin tube 2 instead of the translucent rod 5. In a pressurizing process in which the light guide liquid 3 is filled using the dummy tube and the opening end is temporarily fixed with the light transmissive rod 5 and then the light transmissive rod 5 is pushed in the same process as described above. What is necessary is just to measure beforehand the relationship between the pushing amount of 5 and the pressure detected by the pressure sensor.
And when manufacturing the liquid light guide 1, the filling pressure of the light guide liquid 3 can be controlled by adjusting the pushing amount of the translucent rod 5 with reference to the measured data.

Table 1 shows the liquid light guide 1 manufactured by the same method. By adjusting the pushing amount of the translucent rod 5 in the pressurizing step, the pressure difference ΔP with respect to the atmospheric pressure is changed from 0 to 10,000 hPa. It is the experimental result which observed the bubble generation | occurrence | production state inside the tube 3 after 100 days progress.
In addition, the atmospheric pressure on the date of manufacture was 1014 hPa.
According to this, it was visually confirmed that bubbles produced after 100 days had passed in the product manufactured with a differential pressure ΔP = 0 hPa, and a significant decrease in transmission efficiency was observed.
Although it was confirmed that the product produced with the differential pressure ΔP = 100 hPa had slight bubbles, it was possible to confirm a sufficient advantage over the product produced with the differential pressure ΔP = 0 hPa. There was no significant decrease in transmission efficiency.
The product produced at a differential pressure ΔP = 200 hPa showed almost no generation of bubbles, and a sufficient superiority was confirmed even compared to the product produced at a differential pressure ΔP = 100 hPa.
Furthermore, in the case of the product manufactured with a differential pressure ΔP = 300 hPa or more, generation of bubbles could not be confirmed.

FIG. 9 is an explanatory view showing another liquid light guide 21 according to the present invention.
The liquid light guide 21 of this example has a base part in which a hollow portion of a resin tube 22 having an outer diameter of 11 cm, an inner diameter of 10 cm, and a length of 3 m formed by FEP is filled with a light guide liquid 23 serving as a core. 24, both ends of the tube 22 are sealed with a quartz translucent plug 25.

The resin tube 22 is formed with a flange portion 22a having an enlarged opening at both ends, and the flange portion 22a and the translucent plug 25 are fastened by a base 24.
The base 24 includes an annular base 24A that is sheathed on the tube 22, and an annular plug retainer 24B that is sheathed on the translucent plug 25 and screwed to the base 24A with bolts 26 and nuts 27.

The translucent plug 25 is formed by integrally forming a rod portion 25a serving as a light incident / exit port and a flange portion 25b sandwiched between the annular base 24A and the plug retainer 24B.
Then, in a state where the flange portion 22a of the resin tube 22 and the flange portion 25b of the translucent plug 25 are opposed to each other, a ring-shaped packing 28 is disposed therebetween, and these are the annular base 24A of the base 24 and the plug presser. 24B is sandwiched and firmly fixed.

The packing 28 is made of silicon rubber, and is fixed by the base 24, and an air extraction needle 29 (for extracting air inside the flange portion 25b of the translucent plug 25 and the packing 23 is used. Can be inserted).
In FIG. 9, the base 24 to which the left end side of the resin tube 22 is fixed is shown, and the base 24 to which the right end side is not fixed is shown.

  When the liquid light guide 21 is manufactured, the end portion is sealed by attaching a translucent plug 25 and a packing 28 to one end side of the resin tube 22 and fixing with the base 24, and the light guide liquid is contained inside. Whether or not air remains in the tube 22 in the state in which the tube 23 is injected, the other end side is similarly attached with the translucent plug 25 and the packing 28 and fixed with the base 24 to fix the end. Seal the part.

Next, as shown in FIG. 10, one end side is raised, and an evacuation needle 29 is inserted between the translucent plug 25 and the packing 28 sandwiched between the caps 24 on the upper end side.
An exhaust pipe 30 that discharges the remaining air in the tube 22 and a liquid supply pipe 32 that supplies the light guide liquid 23 from the light guide liquid supply source 31 at a predetermined pressure are connected to the bleed needle 29. Yes.
The exhaust pipe 30 is provided with an on / off valve 33, a superabsorbed liquid storage tank 34, and a vacuum pump 35, and by discharging a small amount of the light guide liquid 23 into the tank 34 when discharging the remaining air. The light guide liquid 23 can be filled in a portion from the needle 29 to the valve 33 of the exhaust pipe 30.
An on / off valve 36, a pressure gauge 37, and a liquid feed pump 38 are interposed in the liquid feed line 32.

Here, an air extraction process for extracting air from the tube 22 is executed.
The venting process is performed by opening the on / off valve 33 while the vacuum pump 35 is in operation. As a result, when the valve 33 is closed when the remaining air in the tube 22 is exhausted and the light guide liquid 23 is sucked into the storage tank 34, the portion from the needle 29 to the valve 33 in the exhaust line 30 is closed. Is filled with the light guide liquid 23.

After the evacuation process, a pressurizing process for pressurizing and filling the light guide liquid 23 into the tube 22 is performed.
If the liquid feed pump 38 is operated by opening the on / off valve 36 of the liquid feed pipe 32, the light guide liquid 23 is pumped from the light guide liquid supply source 31 to the tube 22.
At this time, since the portion from the needle 29 to the valve 33 of the exhaust pipe 30 is filled with the light guide liquid 23, air does not flow back into the tube 22.
If necessary, the deaeration process and the pressurization process may be repeated.
When the pressure gauge 37 is monitored and a predetermined pressure (for example, 1400 hPa) is reached, the on / off valve 36 is closed and the needle 29 is removed. Thus, the liquid light guide 21 is completed.

The method of this example is particularly effective when the diameter of the tube 22 is as thick as several centimeters or more.
In the second embodiment, the case where the bleed needle and the light guide liquid filling needle are used together has been described, but it goes without saying that separate needles may be used.

  The present invention can be applied to a liquid light guide in which a hollow portion of a resin tube is filled with a light guide liquid serving as a core.

1,21 Liquid light guide 2,22 Resin tube 3,23 Light guide liquid 4,24 Cap 5,25 Translucent plug 6 Spring chuck 7 Collet 8 Lock nut

Claims (5)

In a liquid light guide in which a hollow portion of a resin tube is filled with a light guide liquid serving as a core, and both ends thereof are sealed with a translucent plug,
A liquid light guide characterized in that a filling pressure of the light guide liquid is selected so as to be 1100 hPa or more and a design withstand pressure or less within a use temperature range. Fill the hollow part of the resin tube sealed at one end with a translucent plug with the light guide liquid as the core, keep the inside of the tube evacuated, and temporarily fix the translucent plug to the other end After that, a liquid light guide manufacturing method for sealing this,
After the light-transmitting plug on the other end side is temporarily fixed and before sealing, the liquid light guide is provided with a pressurizing step of pressing the light guide liquid by pushing the plug into the tube. Method. A base capable of inserting and removing the needle in an airtight state is attached to at least one end side, and the opening at both ends is sealed with a light-transmitting plug, and the hollow portion of the resin tube is filled with a light guide liquid serving as a core. A method for producing a liquid light guide comprising a venting step for venting internal air by inserting a needle from a base,
A method for producing a liquid light guide, comprising: a pressurizing step of pressurizing and filling the light guide liquid into the tube through a needle after completion of the venting step.   The method for manufacturing a liquid light guide according to claim 2 or 3, wherein a filling pressure of the light guide liquid to be pressurized and filled in the pressurizing step is 1100 hPa or more. The method for producing a liquid light guide according to claim 2 or 3, wherein a filling pressure of the light guide liquid to be pressurized and filled in the pressurizing step is 1400 hPa or more.

Images