WO2002097499A1

WO2002097499A1 - Thick-walled thin tube, method of producing the same

Info

Publication number: WO2002097499A1
Application number: PCT/JP2001/004484
Authority: WO
Inventors: Masaru Otsubo; Masahito Nishihara; Kouki Nagashima
Original assignee: Masaru Otsubo; Masahito Nishihara; Kouki Nagashima
Priority date: 2001-05-29
Filing date: 2001-05-29
Publication date: 2002-12-05

Abstract

A novel optical fiber ferrule structure capable of greatly reducing the manufacturing cost by means of a consistent simple production process; a method of producing the same; and a thick-walled thin tube processing method applicable to various uses, it being applicable not only to optical fiber of glass raw material but also to optical fiber of plastic raw material in exactly the same manner. To this end, a metallic thick-walled thin tube such as a ferrule having its contour formed to a predetermined size by forming at least one layer of plating on the outer surface of a pipe base material, and a method of producing the same are employed.

Description

Specification

Thick thin tube and its manufacturing method

The present invention relates to a ferrule used for a connector for connecting a precision thick thin tube, particularly an optical fiber used for optical communication, and a method of manufacturing the ferrule. Background art

Components generally called ferrules used in optical fiber connection connectors are required to have extremely high dimensional accuracy in order to prevent loss of light at the connection portions. In other words, in order to accurately match the axis at the connection between the optical fiber and the optical fiber, it is necessary to realize the displacement of the inner and outer diameters of the inner and outer diameters at the sub-micron level with high accuracy. Must. Further, the outer diameter of the ferrule is generally extremely large compared to its inner diameter, and the outer diameter is typically 1.2 to 2.5 mm, whereas the inner diameter is about 0.125 mm. It has the shape of a capillary.

In addition, it is important for ferrules to have sufficient strength against abrasion and deformation due to many attachments and detachments, and between the optical fiber and ferrule due to temperature changes. The processing method and material must be selected so that the internal stress generated by the process is below a certain value regardless of whether it is being processed or used.

Due to the above requirements for ferrules used for connectors for connecting optical fibers, a typical method for producing ferrules has been injection molding or extrusion molding of ceramic powder, synthetic resin, metal, etc. containing a binder. A manufacturing method is used in which a number of steps are performed after molding such as by firing, cutting into appropriate dimensions through a process such as firing, and polishing and finishing the outer and inner diameters. In particular, wire wrapping or laser processing is used for the inner diameter processing where the optical fiber is inserted, but this requires not only expensive processing equipment and processing costs but also difficult processing in the processing process. There is a problem that the production cost is extremely high due to the poor yield due to the properties, shrinkage and deformation. In particular, several ideas have been devised for the inner diameter machining of Ferrule, and typical ideas are described below.

The first method is a method in which an electric wire is applied to a melting metal core wire having substantially the same outer diameter as the outer diameter of the optical fiber. In other words, when the outer diameter of the electrode is almost equal to or larger than the outer diameter of the ferrule, it is polished to the correct outer diameter by machining, cut, and the ^ -ray is melted and removed to remove the ferrule It is a method of manufacturing. Another method is to apply electric force using a metal core wire whose outer diameter is almost the same as the outer diameter of the optical fiber as the core. Similarly, the outer diameter of the electric mirror is approximately equal to or slightly larger than the outer diameter of the ferrule. In the meantime, a metal core wire used as a core is pulled out, polished to an accurate outer diameter by machining, cut, and the core wire is melted and removed to produce ferrule. There are two ways to pull out the metal core wire: one is to pull out the wire after applying an electric wire, and the other is to pull out the wire from both sides after the metal wire is butt-connected. As described above, in these methods, since the core metal wire of the core is broken or bent, the accuracy of the inner diameter is extremely poor, and the surface roughness is rough and unstable, so finishing is indispensable and the yield is not good. In addition, there were problems such as the thickness of the electric wire used as the material of the ferrule being large, the processing cost being high, and the length of the ferrule being limited.

Still other methods include the invention of Japanese Patent Laid-Open Publication No. 2000-11006, Japanese Patent Publication No. 2001-108686. In other words, a metal pipe with excellent dimensional accuracy and surface quality is integrally formed with high-temperature fluid material by means such as injection molding, and the metal pipe is firmly fixed by the stress during heat shrinkage or solidification shrinkage. This is a device for manufacturing ferrules. However, even in this manufacturing method, there is a situation in which deformation or eccentricity of thin metal pipes due to heat or pressure during injection molding is expected. The present invention solves these problems of the prior art, and enables a novel structure and method for manufacturing a ferrule for an optical fiber that can greatly reduce the manufacturing cost by a consistent and simple manufacturing process. It is intended to provide The present invention is applicable not only to optical fibers made of glass material but also to optical fibers made of plastic material, and it is an object of the present invention to provide a method of processing a thick thin tube applicable to various uses. is there. Disclosure of the invention

The structure of the novel optical fiber ferrule according to the present invention and its manufacturing method will be disclosed below. As described above, an optical fiber used for optical communication passes through a number of connection points in the transmission path, but in order to minimize the loss at the connection point, the distance between the connected optical fibers must be minimized. The axes must be precisely aligned. For this reason, ferrules used as connection parts for optical connectors are required to machine the inner diameter accuracy, outer diameter accuracy, and misalignment of the inner and outer diameter axes with submicron precision. In addition, the outer diameter of ferrule is generally extremely large compared to its inner diameter, and the outer diameter is typically 1.2 to 2.5 mm compared to 0.125 thigh. It has the shape of a thick thin tube. Furthermore, it is important for ferrules to have sufficient strength against abrasion and deformation due to repeated attachment and detachment, and the inner diameter of the ferrule that holds the optical fiber is linear and precise roundness. It is desirable to have a very smooth surface. That is, optical fiber and failure -The processing method and material must be carefully selected during processing and during use, so that the stress caused by temperature changes between the components does not damage the optical fiber. In other words, the most important technical problem in the manufacture of ferrules is to provide a technology that satisfies the requirements for the inner diameter accuracy and inner surface smoothness of the ferrule through which the optical fiber passes. The present invention uses a precision metal pipe whose inner diameter is equal to or slightly larger than the outer diameter of the optical fiber as the base material of the ferrule, and a new process that is not affected by sudden pressure or thermal stress in the processing process. It provides a ferrule with a configuration and a method for manufacturing the ferrule. The technology for manufacturing precision metal pipes has already reached the level where it is possible to stably manufacture mass-produced pipes with an inner diameter equal to the outer diameter of an optical fiber, for example, an inner diameter of 0.125 mm. However, the inner diameter accuracy and inner surface smoothness can sufficiently satisfy the requirements for ferrules. As a typical metal pipe material, various stainless steel materials are suitable. The present invention provides a ferrule having a predetermined outer diameter by forming a thick metal material such as nickel and chromium on the outer surface of the metal pipe by various chemical plating techniques such as electro-mechanical plating or electroless plating. Ferrule is manufactured by processing. In particular, chemical plating such as electroless plating has a higher uniformity of the plating layer than electro-magnetic plating, so if proper process control is performed, ferrules with high outer diameter accuracy can be manufactured in a single process. It is possible. Furthermore, it is also effective to take the process of finishing the outer diameter to the specified dimensional accuracy by grinding the outer diameter in a later process after applying the plating thickness until it is slightly larger than the specified outer diameter. . Furthermore, in order to improve the abrasion resistance of the ferrule against repeated desorption, the surface of a chemically plated material such as an electroplated or an electroless plated is treated with a material having a higher abrasion resistance or hardness. It is effective to harden the surface by means of thermal treatment or heat treatment. As an example, the surface of a stainless steel metal pipe is evenly electroless nickel-plated to the specified outer diameter of the ferrule, and then the surface hardness is increased by hard chrome plating to greatly improve the wear resistance of the ferrule. Things are possible. After such a plating step, the ferrule may be cut to a predetermined length and finished at both end faces to produce a ferrule. Furthermore, during the above-mentioned processing or after the processing step, the inner and outer diameter ends of the ferrule are rounded by adding a chemical polishing step or a machining step, etc., so that the optical fiber can be inserted easily and the ferrule can be assembled. It is also possible to prevent the optical fiber from being damaged by stress concentration at the edge of the ferrule end face.

A ferrule manufactured by such a processing process is based on a metal pipe having high dimensional accuracy and smoothness of an inner diameter as a base material. Since it can be manufactured without applying pressure, heat, etc., it is possible to easily manufacture extremely accurate and high quality ferrules. In addition, the molten metal core described in the conventional example Compared to the electrode method using a metal or the electrode method using a core, the thickness of the metal layer is clearly smaller, so it is obvious that the processing time is shorter and less expensive, and the layer thickness is smaller. Outer diameter accuracy is high. In addition, it is an extremely common manufacturing facility such as an electrode or electroless plating, and can be manufactured in large quantities at one time.Since dimensional control in the manufacturing process is easy, it is stable at extremely low manufacturing cost compared to the conventional technology. It is possible to provide manufacturing technology.

Further, according to the present invention, even if the cross section of the metal pipe is not only circular but also polygonal, it is possible to produce thick thin tubes and ferrules in exactly the same manner. In general, the cross section of an optical fiber is circular, so the cross section of the ferrule is made circular, but the polygonal cross section is good in terms of characteristics or workability. It is also possible to use a polygon or an arbitrary shape in which the optical fiber is inscribed.

Further, the present invention includes a selection of an extremely wide pipe base material and a selection of plating material, and a structure of a thick-walled thin tube or ferrule composed of a combination thereof, and a manufacturing method thereof. In other words, in particular, chemical plating technology, pipe base and plating materials can be made of not only various metal materials but also various oxide materials and non-metallic materials, etc. It is possible to create composite structures. That is, the present invention can be manufactured without applying any external restraining force, external pressure, high heat, etc. to the pipe base material in the manufacturing process of the thick thin tube. Glass pipes ゃ Plastic pipes and other inorganic material pipes ゃ Organic material pipes or composite materials are used to create the optimal combination of materials that match the accuracy, durability and quality of the environment and required characteristics. It is possible to manufacture thick-walled tubing or ferrules by selecting the matching. BRIEF DESCRIPTION OF THE FIGURES

1, 2, 3, and 4 show an example of a manufacturing process of a ferrule according to the present invention. 1 indicates the stainless steel pipe base, 2 indicates the inner diameter of the pipe base, 3 indicates the outer diameter of the pipe base, and 4 indicates the length of the pipe tomb. FIG. 2 shows a state in which an electroless nickel plating 10 is applied to the surface of the outer diameter 3 of the pipe base material shown in FIG. 1 to fill the outer diameter 11 of the ferrule. Fig. 3 shows an example in which hard chrome plating 12 is further applied to the surface of outer diameter 11 to improve wear resistance. FIG. 4 shows a process of manufacturing a ferrule by cutting to a predetermined length 15 after finishing the process of FIG. 2 or 3 and polishing and polishing both end surfaces. In other words, it is possible to manufacture a plurality of ferrules at a time by setting the length 4 of the pipe base material to a value equal to or more than a multiple of the length 15 of the ferrule and cutting the ferrule later.

Fig. 5 shows an example of a ferrule in which the inner and outer diameter end faces of the ferrule are rounded by adding a chemical polishing step during the processing step, thereby improving the penetration and assemblability of the optical fiber. Industrial applicability

The present invention particularly relates to a structure of a ferrule used for a connector for connecting an optical fiber used for optical communication and a method of manufacturing the same. It is possible to mass-produce inexpensive materials at very low cost, and it is extremely effective to spread the application of optical cables to various industrial uses. Further, the present invention may be used as a production technology for micromechanical parts, including thick-walled thin tubes, whose size is expected to increase in the future.

Claims

The scope of the claims

-Based on a metal pipe with the inscribed circle dimension of the hole in the cross section of the pipe equal to or slightly larger than the outer diameter of the optical fiber passing therethrough, there is no at least one layer on the outer surface of the metal pipe tomb. A ferrule integrated with a metal pipe, wherein an outer shape is formed to a predetermined size by plating a metal material by a chemical plating means such as an electrolytic plating, and a method of manufacturing the same. The base of the metal pipe is a metal pipe in which the inscribed circle of the hole in the pipe section is equal to or slightly larger than the outer diameter of the optical fiber passing through it. (4) A ferrule integrated with a metal pipe, wherein an outer shape is formed to a predetermined size by plating a metal material by plating means, and a method of manufacturing the ferrule.

The base of the pipe is a metal pipe in which the inscribed circle of the hole in the cross section of the pipe is equal to or slightly larger than the outer diameter of the optical fiber passing therethrough. A ferrule integrated with a metal pipe, wherein an outer shape is formed to a predetermined size by plating a ceramic material by a chemical plating means such as an electrolytic plating, and a method of manufacturing the same.

The base material is a glass pipe whose inscribed circle of the hole in the cross section of the pipe is equal to or slightly larger than the outer diameter of the optical fiber passing therethrough, and at least one layer of electroless plating is provided on the outer surface of the pipe base. A pi-boo ferrule having an outer shape formed to a predetermined size by applying a metal material by chemical plating means, and a method of manufacturing the ferrule.

The base material is a glass pipe whose inscribed circle of the hole in the cross section of the pipe is equal to or slightly larger than the outer diameter of the optical fiber passing therethrough, and at least one layer of electroless plating is provided on the outer surface of the pipe base. A metal pipe-integrated ferrule characterized in that the outer shape is formed to a predetermined size by plating a ceramic material by chemical plating means, and a method of manufacturing the same.

The pipe base is made of a plastic pipe in which the inscribed circle of the hole in the pipe cross section is equal to or slightly larger than the outer diameter of the optical fiber passing therethrough. A pip-boo shaped ferrule characterized in that the outer shape is finished to predetermined dimensions by plating metal material (1) by chemical plating means such as electrolytic plating, and a method of manufacturing the ferrule.

Claims 1 to 6, characterized in that the outer shape is formed to a predetermined size on the outer surface of the pipe base material by combining a plating method with a chemical plating means such as an electroless plating. Pipe-shaped ferrule and its manufacturing method. H

8. The pie-boo shaped ferrule according to claim 1, wherein the ferrule is formed to have a predetermined outer size by a plating layer made of a plurality of materials, and a method of manufacturing the ferrule.

9. The pipe-integrated filler according to any one of claims 1 to 8, wherein the shape of the hole in the cross section of the pipe base material is circular, and a method for producing the same.

10. The post-processing step according to claim 1 to 9, wherein a material is coated on the outer surface of the pipe base material to form the outer dimensions equal to or slightly larger than the predetermined outer dimensions of the ferrule, and then a grinding process or the like is performed. A ferrule integrated with a pipe, characterized in that the ferrule has been finished to predetermined external dimensions by the method, and a method of manufacturing the same.

11. The pipe according to claim 1, wherein the surface hardness is increased by forming a metal material having a higher hardness on the surface to form a predetermined outer dimension. Body shape ferrule and its manufacturing method.

12. The pipe-integrated file according to any one of claims 1 to 10, wherein the surface thereof is heat-treated or chemically treated to increase the surface hardness, and a method for producing the same.

13. The pipe according to any one of claims 1 to 12, wherein the processing step includes a step of rounding or chamfering at least one end face of the hole of the pipe by chemical treatment, electrolytic treatment, or mechanical processing. An integrated ferrule and a method of manufacturing the same.

14. In Claims 1 to 12, the length of the pipe base material is at least twice as long as the length of the ferrule, and is cut to a predetermined length after plating, or A manufacturing method that manufactures multiple ferrules by cutting to length and then plating.

15. In claim 1, the metal pipe base is made of a stainless steel material, and at least one layer is formed on its outer surface by a nickel layer by electroless nickel plating. A metal pipe-integrated ferrule and a method for manufacturing the same.

1 6. A metal pipe is used as a grave material, and at least one layer is formed on the outer surface of the metal pipe base material by chemical plating such as electroless plating to increase the wall thickness of the pipe so that the outer shape is predetermined. A thick metal thin tube characterized by being formed to dimensions, and a method for producing the same.

17. Metal pipe is used as a base material, and at least one layer of metal material is thickened on the outer surface of the metal pipe base material by electroplating means to increase the wall thickness of the pipe, thereby reducing the outer shape to a predetermined size. A thick metal thin tube characterized by being formed, and a method for producing the same.

18. Metal pipe is used as base material, and at least one layer of ceramic material is thickened on the outer surface of the metal pipe base material by chemical plating means such as electroless plating to increase pipe wall thickness. A thick metal thin tube formed in a predetermined size, and a method for manufacturing the same.

1 9. Based on a glass pipe, at least one layer of electroless A thick-walled thin tube characterized in that the outer shape is finished to predetermined dimensions by increasing the thickness of the pipe by thickening a metal material by means of a chemical sticking means such as wood, and a method of manufacturing the same.

0. Glass pipe as the base material, at least one layer of ceramic material is applied to the outer surface of the pipe base material by chemical plating such as electroless plating to increase the wall thickness of the pipe to make the outer shape to a predetermined size. A thick-walled thin tube characterized by being formed, and a method for producing the same.

1. A plastic pipe is used as a pipe grave material, and at least one layer is formed on the outer surface of the pipe base material by a chemical plating method such as an electroless plating method to increase the wall thickness by increasing the thickness of the metal material. A thick-walled thin tube characterized by being formed to dimensions, and a method for producing the same. 2. In claim 16 to 21, the thickness of the pipe is increased by combining the chemical plating means such as electroless plating and the electroplating means on the outer diameter surface of the pipe base material to make the pipe thicker, A thick-walled thin tube having an outer shape formed to a predetermined size, and a method for producing the same.

3. The thick-walled thin tube according to any one of claims 17 to 22, wherein the thin-walled tube is formed to have predetermined external dimensions by using a metal layer made of two or more kinds of metal materials, and a method for manufacturing the same.

4. The thick thin tube according to claim 16 or 23, wherein the shape of the hole in the cross section of the pipe base material is circular, and a method for producing the same.

5. The thick-walled thin tube according to claim 16, wherein the pipe is formed in an arbitrary shape instead of a straight line, and a method for producing the same.