JPS625208A - Optical fiber connector and its production - Google Patents

Abstract

PURPOSE:To decrease the number of parts and to provide a smaller and more economical connector by maintaining the prescribed region including the joint part at the front end of the butt side in a fitting hole of the fitting member of the connector under the air pressure lower than the atm. pressure. CONSTITUTION:The connector for optical fibers 1 is constituted of a pair of cores 20 having the front ends 21 on the butt side formed to a small diameter, a rectangular block-shaped fitting member 30 having the fitting hole 31 provided with a suction hole 32 and a sealing member 40. The ends 21 are fitted into the hole 31 from one end thereof and thereafter a suction device is connected to the port 32 and the air pressure in the space A is so set as to be made lower than the atm. pressure. The force to press the cores 20 to each other is thereby generated and the ends 21 are brought into press contact with each other. Since the cores 20 are axially pressed to each other, the need for a pressing member, etc. is eliminated and the number of parts is decreased.

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Field) The present invention relates to a small and simple optical fiber connector with a small number of parts and a method for manufacturing the same.

(Prior art) A conventional optical fiber connector consists of at least four types of parts as shown below: (1) a core (also called a ferrule) for fixing the optical fiber; (2) a core end face that butts and fits. (3) A pressing member (coil spring) for pressing the end faces of the core axially inward to each other; (4) A waterproof and environmentally resistant member for positioning the pressing member and the sleeve. It is equipped with a housing to ensure the safety.

The basic layout of these parts is shown in FIG.

In the figure, 1 is an optical fiber, 2 is a core, 3 is a fitting member, 4 is a pressing member, and 5 is a housing. Furthermore, a device in which the fitting member 3 and the housing 5 shown in FIG. 1 are integrated is also known.

(Problems to be Solved by the Invention) All conventional optical fiber connectors have a mechanism in which the cores 2 are pressed against each other by respective pressing members, so a housing 5 is required to simultaneously fix a pair of pressing members 4. Met. Therefore, there were drawbacks listed below.

(1) In addition to the pair of cores 2 and the fitting member 3, at least parts equivalent to the pressing member 4 and the housing 5 are required, so the number of parts is large and it is not economical.

(2) The assembly work is complicated when assembling the optical fiber connector.

(3) Due to the presence of the pressing member 4 and the housing 5, the outer diameter and overall length of the optical fiber connector cannot be reduced, and high-density packaging cannot be achieved.

(4) When attaching and detaching the optical fiber connector, in addition to fitting the core 2 and the fitting member 3, it is necessary to fasten the housing 5.

(Object of the Invention) An object of the present invention is to provide an optical fiber connector that solves problems related to economy, workability, and miniaturization by omitting parts corresponding to a pressing member and a housing and reducing the number of parts. and 2. To provide a method for simply and accurately manufacturing such an optical fiber connector.

(Means for Solving the Problems) In order to solve the above problems, the first invention provides a first invention in which two pairs of cores each holding one end of an optical fiber are fixed and the open end portions of the two cores are brought into contact with one another. In an optical fiber connector that is fitted from one end of a fitting hole of a fitting member to position and join their mutual axes, a predetermined area in the fitting hole including at least the joint of the abutting open end portion is heated to atmospheric pressure. The second invention is characterized in that the air pressure is maintained at a lower air pressure than A groove is formed in a suitable position of a fitting member provided with a fitting hole for positioning and joining the axes of each other when the pair of cores are fitted, so that the groove reaches at least a predetermined area including the joint portion from the outside when the pair of cores are in a predetermined fitted state. Alternatively, a hole is provided in advance, the abutting open end portions of the pair of cores are fitted into the fitting hole of the fitting member, and the air pressure in the area is set to be lower than atmospheric pressure by suction means through the groove or hole. Then, the groove or hole is sealed with a sealing member.

(Function) According to the first invention, since the predetermined region in the fitting hole including at least the joint portion of the abutting open end portion is maintained at a pressure lower than atmospheric pressure, the force that presses the pair of cores together is generated, and the force is (p), where the pressure in the predetermined area A is Pi and the pressure outside the optical fiber connector (atmospheric pressure) is PO.
o-Pi)X (cross-sectional area of the core). Therefore, pressing requires no special parts for applying force. Further, according to the second invention, since it is sufficient to provide grooves or holes in advance at appropriate locations on the pair of cores or fitting members, the present invention can be applied without significantly changing the basic structure of the conventional optical fiber connector. Such an optical fiber connector can be manufactured.

(Embodiment) FIG. 1 shows a first embodiment of the optical fiber connector of the present invention, and in the figure, the same components as those of the conventional example are denoted by the same reference numerals. That is, 1 fixes an optical fiber, and 20 fixes one end of the optical fiber 1, respectively.

In the pair of gripped cores, each abutting open end portion 21 is formed to have a small diameter. Reference numeral 30 denotes a rectangular block-shaped fitting member, and a fitting hole 31 is provided in the longitudinal direction of the fitting member, into which the abutting open end portion 21 of the core 20 is fitted from one end to position and connect their axes. There is. 32 is a suction hole that communicates with the inside of the fitting hole 31 from the bottom surface of the fitting member 30 in the middle in the longitudinal direction. 40 is a sealing member that airtightly seals the suction hole 32.

The end portion 21 on the mating side of the core 20 is hermetically fitted into the fitting hole 31 of the fitting member 30, and a space A surrounded by the core 20, the fitting member 30, and the sealing member 40 is formed. The pressure Pi is kept lower than the pressure outside the optical fiber connector (atmospheric pressure>po).

As mentioned above, in the optical fiber connector of the present invention, since the pressure Pi in the space A is smaller than the atmospheric pressure PO, a force is generated that presses the pair of cores 20 against each other, and the abutting side optical end 21 of the cores 20 is pressed against each other. Pressure contact. Therefore, special parts for pressing the cores 20 against each other in the axial direction are not required.

In the embodiment described above, the fitting member 30 is made of a plastic material, but it may be made of a material that maintains airtightness, such as metal or ceramic. Further, airtightness between the outer periphery of the core 20 and the inner periphery of the fitting member 31 may be ensured by interposing an O-ring or the like.

Next, a method of manufacturing the above-mentioned optical fiber connector will be explained. First, as shown in FIG. 2, a fitting member 30 having a fitting hole 31 and a suction hole 32 is prepared.

Next, as shown in FIG. 3, the light end portions 21 of the above-mentioned butt 1 mating side of the core 20 are fitted from one end of the fitting hole 31 of the fitting member 30, respectively. Next, the suction port 51 of the suction device 50 is connected to the suction hole 32 of the fitting member 30, and the suction device 50 is operated to set the air pressure in the air 111A to a pressure lower than atmospheric pressure. Finally, the suction device 50 is removed and the suction hole 32 is sealed. As the suction device 50, a syringe or a small pump is used.

As a result, as mentioned earlier, a pressure difference is created between the inside and outside of the optical fiber connector, and this pressure difference is added to the cross-sectional area of the core 20, in other words, the area of the fitting hole 31 plus the axial direction. Pressing generates force. Actually, an experiment was conducted in the case where the outer diameter of the large diameter portion of the core 20 and the inner diameter of the fitting hole 31 were approximately 2.5 mm in diameter. As a result, the pressing force was approximately 50g,
Calculated value (approximately 490 as atmospheric pressure 1kOf/cm2)
It was confirmed that the pressing force is generated by the pressure difference between the inside and outside of the optical fiber connector.

Furthermore, as a result of measuring the connection loss, it was 0.25 dB when using the pressing part and the housing, and 0.27 dB when using the air pressure difference shown in this example, and there was no difference between the two, indicating good characteristics. I confirmed that there is. As is clear from the results, it was confirmed that compared to the conventional technology, it was possible to obtain good connection characteristics without using parts corresponding to the pressing part or the housing.

FIG. 4 is a diagram showing the tip shape of the core 20 confirmed in an experiment in the case of a single-fiber optical fiber connector in this embodiment, and 1a shows the end surface of the bare optical fiber. In this figure (a) (
In the case of (b) (c) (d), a small diameter part is provided at the tip, but even if the small diameter part is not provided as shown in (a) (+13), the core 20 Due to the limited machining accuracy, there is always a space at the abutted tip, so pressing force is generated even for other shapes. That is, the generation of pressing force does not depend on the shape of the tip of the core 20. This also applies to optical fiber connectors that connect multiple optical fibers.

The fifth figure shows a second embodiment of the optical fiber connector of the present invention, where 30' is a sleeve-like fitting member, 31' is a fitting hole, and 32- is a fitting part @301 in the thickness direction. The provided suction hole 60 is a closure device for the suction hole 32.

In this embodiment, when the optical fiber is connected, the state in which the pressure is reduced by the suction device 50 described above through the suction hole 32' is maintained airtight by the n-closing device 60. Therefore, the inner surface of the obturator 60 and
In order to prevent a gap from forming on the outer surface of the fitting member 30', the obturator 60 is made of a flexible material, or the gap between the obturator 60 and the fitting member 30' is filled with a grease-like or fluid grease. It is necessary to fill it with material. On the other hand, the obturator 60 does not need to cover the entire outer periphery of the fitting member 30;
Any shape is sufficient as long as it seals only ′. Other configurations and functions 1. The effect is similar to that of the previous embodiment.

6 and 7 show a third embodiment of the present invention, in which a suction groove 32'' is provided in the longitudinal direction of the inner surface of the fitting hole 31''. Fig. 7 shows the actual connection state using the wooden surface mating member 30''.As shown in this embodiment, since the suction groove 32'' is not on the side surface of the mating member 30'', it is possible to miniaturize the optical fiber connector. has an advantage. Note that 70 is the groove 3
2''.Other functions and effects of the structure 2 are the same as those of the previous embodiment.

FIG. 8 shows another modified example of the core, in which a hollow 111A is inserted into the outer circumferential surface of the core 20 from the outside while it is in the fitted state with the fitting member.
A suction groove 22 is provided which communicates with the. In this embodiment, there is no need to provide a suction hole in the fitting member, and the fitting member can be manufactured easily. Other configurations.

The action and effect are the same as in the previous embodiment.

FIG. 9 shows a fourth embodiment of the present invention, and 80 is an adhesive for fixing the core 20, the fitting member 30', and the fitting hole 31' provided in the fitting member 30'. , or an adhesive material (hereinafter abbreviated as ``adhesive'' for simplicity). In this embodiment, after the core 20 is pressed by a pressure difference (temporary fixation), the adhesive 80 is applied to the core 20 and the fitting member 30' and cured to perform permanent fixation. In this embodiment, the above-mentioned pressing does not depend on the cross-sectional area of the core 20, and strong fixation is possible. Further, although omitted in FIG. 9, a suction hole closing device 60 mm plate 70 shown in FIGS. 5 and 7 may be used. Furthermore, the suction hole 32' may be provided in the same direction as the axial direction of the fitting hole of the fitting member, as shown in FIGS. 7 and 8, or may be provided in the core 20.

(Effects of the Invention) As explained above, according to the first invention, pressing forces are applied due to the pressure difference between the closed space surrounded by the pair of cores and the fitting member and the outside. As parts of the optical fiber connector, there is no need for parts corresponding to a pressing part and a housing, which has the advantage of reducing the number of parts, making the optical fiber connector smaller, and making it more economical. Therefore, a large number of optical fiber connectors can be accommodated in a narrow space, which has a great advantage in reducing the cost of optical lines. Furthermore, since the pressure difference between the inside and outside of the optical fiber connector is constant, the connection characteristics of the optical fiber connector are stable because a constant pressing force is applied regardless of the skill of the connection worker. be. Further, according to the second invention, there is an advantage that an optical fiber connector having the above-mentioned advantages can be easily and precisely manufactured without significantly changing the basic structure of the conventional optical fiber connector.

[Brief explanation of drawings]

FIG. 1 is a partially vertical front view showing a schematic structure of an optical fiber connector according to a first embodiment of the present invention, and FIG. 2 is a perspective view of a fitting member used in the first embodiment of the present invention. Third
The figure is a partially longitudinal front view showing the first embodiment of the method of the present invention using the fitting member shown in FIG. 2, and FIGS. FIG. 5 is a perspective view of an optical fiber connector showing a second embodiment of the present invention, and FIGS. 6 and 7 are a perspective view of a main part showing a modification of the tip part.
Fig. 6 is a perspective view of the fitting member, Fig. 7 is a partially longitudinal front view showing the connected state, and Fig. 8 shows another modification of the core used in the present invention. FIG. 9 is a partially longitudinal front view of an optical fiber connector showing a fourth embodiment of the present invention, and FIG. 10 is a partially longitudinal front view of a conventional optical fiber connector. DESCRIPTION OF SYMBOLS 1... Optical fiber, 20... Core, 30... Fitting member, 31... Fitting hole, 32... Suction hole, 40...
・Seal part, 5.0...Suction device Fig. 1 Fig. 2 Fig. 3 Fig. 4 (a)

Claims (2)

[Claims] (1) The butt-side tips of a pair of cores, each holding and holding one end of the optical fiber, are fitted from one end of the fitting hole of one fitting member to position and join their respective axes. 1. An optical fiber connector, wherein a predetermined area in the fitting hole including at least the joint portion of the abutting side tip is maintained at a pressure lower than atmospheric pressure. (2) A pair of cores each fixing and gripping one end of the optical fiber or a fitting hole is provided in which the abutting side tips of the pair of cores are fitted from one end to position and join their respective axes. A groove or a hole is provided in advance in a suitable position of the fitting member so that when the pair of cores are in a predetermined fitted state, a predetermined region including at least the joint portion is reached from the outside, and the ends of the abutting side of the pair of cores are Fitting into the fitting hole of the fitting member, setting the air pressure in the area lower than atmospheric pressure by suction means through the groove or hole, and then sealing the groove or hole with a sealing member. A manufacturing method for a featured optical fiber connector.