JPH01191802A - Coated optical fiber airtight through part - Google Patents

Abstract

PURPOSE:To hold the airtightness extending over a long period of time by forming a through hole of a seal flange to a tapered shape, inserting an optical core fiber through this through hole, filling a seal material having no adhesive property and pressing it. CONSTITUTION:On the center part of a seal flange 4 whose cross section is shaped like T, a tapered hole 5 whose diameter is contracted toward the leg part side is provided, a screw 6 is formed in the outside periphery of the leg part, and an opening part of the leg part side of the tapered hole 5 is formed so as to become a little larger than the diameter of an optical core fiber 3. Between the tapered hole 5 and the optical core fiber which has been inserted through this hole, a rubber-like seal material 2a having no adhesive property is filled, and the fiber abuts on the end face of the seal flange 4 after the seal material 2a has been hardened by a seal material holder 9, tightened with a screw 10 and fixed by pushing in the seal material 2a. As for the seal flange 4 to which the core 3 has been attached airtightly in such a way, its leg part is inserted into a through-hole 1a of a pressure container wall 1 through an O ring 7 from a high pressure side A and screwed with a nut 8 and fixed. The seal material 2a and the seal material holder 9 are always pressed from a low pressure side B, therefore, the core 3 is held airtightly.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an optical fiber core hermetically sealed penetration section, and more specifically, to an optical fiber core used in an environment with a pressure difference or via an environment with a pressure difference. The present invention relates to an optical fiber core hermetic penetration part which is particularly effective in various cases.

[Prior art] Figures 2(a) and 2(b) are for example Utility Model Application No. 1982-142.
FIG. 2 is a vertical cross-sectional view and a side view showing an example of a conventional optical fiber airtight penetration part disclosed in Japanese Patent No. 002. In the figure, (
1) Pressure vessel wall, (la) is a through hole provided in the pressure vessel wall (1), (2) is a sealing material filled in the through hole (la), (3) is an optical fiber (3a) It is an optical fiber coated with a protective coating. Note that A is the high pressure side, B
indicates the low pressure side.

Since the optical fiber (3) is sealed to the pressure vessel wall (1) via the sealing material (2), the penetrating portion of the optical fiber (3) is kept airtight.

[Problems to be Solved by the Invention] According to the conventional optical fiber coated wire hermetic penetration section configured as described above, since the hermeticity is determined by the adhesion ability of the sealing material (2), the optical fiber coated wire (3) and through hole (la
), it was necessary to select a sealing material that was compatible with the sealing material, and there were also problems such as poor long-term reliability.

The present invention was made in order to solve the above-mentioned problems, and aims to provide an optical fiber core hermetic penetration part that can maintain airtightness without relying on the adhesive force of a sealing material and has high reliability. shall be.

[Means for Solving the Problems] The present invention has been made to achieve the above objects, and
A through hole for the optical fiber coated wire provided in the seal flange is formed in a tapered shape, and the optical fiber coated wire is inserted into the through hole, and a non-adhesive sealing material is filled and pressed to create an airtight penetration part for the optical fiber coated wire. This is what we provide.

[Function] For example, if the seal flange is installed so that the large diameter side opening of the tapered through hole is located on the high pressure side, the sealing material will be constantly pressed by high pressure and the optical fiber core will be held airtight. .

[Embodiment of the Invention] FIG. 1(a) is a longitudinal sectional view of an embodiment of the present invention, and FIG. 1(b) is a side view thereof. Note that the same or equivalent parts as in the conventional example shown in FIG. 2 are denoted by the same reference numerals, and the explanation thereof will be omitted. In the figure,
(4) is a seal flange with a T-shaped cross section, a tapered hole (5) that decreases in diameter toward the leg is provided in the center, and a screw (8) is formed on the outer periphery of the leg. has been done. Note that the opening on the leg side of the tapered hole (5) is formed to be slightly larger than the diameter of the optical fiber core (3). (2a)
is a non-adhesive rubber-like sealing material filled between the tapered hole (5) and the optical fiber core (3) inserted into it up to the end face of the sealing flange (4). A mold silicone RTV rubber (trade name KE 1300) was used. (9) is a sealing material presser that comes into contact with the end face of the sealing flange (4) after the sealing material (2a) has hardened, and
Tighten with O) and push in the sealing material (2a) to fix it.

The seal flange (4) to which the optical fiber core (3) is airtightly attached as described above is connected from the high pressure side A through the O-ring (7) so that its legs are connected to the through hole in the pressure vessel wall (1). (
la), and screw the nut (8) onto the leg screw (6) from the low-pressure side to secure it. At this time, the large diameter side of the tapered hole (5), and therefore the side where the sealing material (2a) is pushed, is located on the high pressure side A. As a result, the sealant presser (9)
The sealing material (2a) is always pressed to the low pressure side due to the pressure difference between the high pressure side A and the low pressure side B, and the optical fiber core (3)
is kept airtight.

[Effects of the Invention] As is clear from the above description, according to the present invention, the through hole of the seal flange is tapered and the sealing material is pushed into the through hole using a non-adhesive sealing material. Therefore, the airtightness is not related to the adhesion ability of the sealing material, and a highly reliable airtightness effect can be obtained over a long period of time.

[Brief explanation of the drawing]

FIGS. 1(a) and (b) are a cross-sectional view and a side view thereof showing an embodiment of the present invention, and FIGS. 2(a) and (b) are cross-sectional views showing an example of a conventional optical fiber core hermetic penetration part. FIG. 2 is a diagram and a side view thereof. (2a)...Seal material, (3)...Optical fiber core, (4)...Seal flange, (5)...Tapered through hole, (9)...Seal material holder . In addition, in the figures, the same reference numerals indicate the same or corresponding parts.

Claims (1)

[Scope of Claims] In an optical fiber hermetic penetration portion formed by filling a sealing material into a through hole of a seal flange through which an optical fiber is inserted, the through hole of the seal flange is formed in a tapered shape, and the through hole of the seal flange is formed into a tapered shape. An optical fiber core airtight penetration part characterized in that an optical fiber core is inserted into a through hole, and a non-adhesive sealing material is filled and pressed.