JP2010044254A - Optical indoor cable and method of laying optical indoor cable - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical indoor cable which enables a multiple thread laying in an existing pipe by reducing friction, and to provide a method of laying using the optical indoor cable, wherein problems existing in a conventional technology are taken into consideration. <P>SOLUTION: The optical indoor cable 91 includes an optical fiber 11 and a coating 12 which covers the outer periphery of the optical fiber 11, and undulations which irregularly rise and fall are provided on the surface of the coating 12. As the undulations irregularly rise and fall, the undulations of the optical indoor cable 91 are not stuck to each other and the contact area of the coating 12 is reduced. Further, the dynamic friction coefficient of the surface of the coating 12 is reduced compared to the flat surface of the coating 12. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a low-friction optical indoor cable that facilitates insertion into an existing pipe of a condominium or the like or pulling out an arbitrary cable, and facilitates multi-laying in an existing pipe space.

  With the spread and expansion of optical communication services, the installation of optical indoor cables indoors such as detached houses, apartment houses such as condominiums, and office buildings is progressing. In particular, with the diversification of optical communication services, it is required to make all houses light in apartment houses such as apartments.

Optical indoor cables suitable for indoor lead-in wiring have been developed (see, for example, Patent Document 1). When laying a new optical indoor cable in a pipe, pass the line machine through the pipe in advance, connect the line machine and the optical indoor cable at the pipe entrance, and connect the line machine from the other pipe outlet. Towing can be laid.
Japanese Patent No. 4040633

  In a conventional optical indoor cable laying method using a wire machine, friction occurs when an existing cable comes into contact with the wire machine and the optical indoor cable. Due to this friction, even if there is enough space for laying optical indoor cables in the piping, the number of cables that can be laid is limited to a few, and there is a problem that it is not possible to accommodate indoor lighting in all units. there were.

  More specifically, taking a 22mmφ pipe as an example, if there is already an 8.8mm diameter metal cable in the pipe and pulling it one by one through the conventional optical indoor cable passer, the first one is Although there is no problem, the traction tension suddenly increases with the increase of the frictional force of the cable in the pipe as the number of lanes increases, and the traction tension reaches 20 kg at only the third line. When pulling out the third line, the pulling tension reaches 37 kg. I couldn't pull the 4th line. In other words, 10 to 30 medium-sized apartments require at least 30 lines, but there is a problem that conventional optical indoor cables cannot do this.

  Accordingly, the present invention has been made in view of the problems of the prior art, and an optical indoor cable that enables multiple laying on existing piping by reducing friction, and an optical indoor cable laying method using the optical indoor cable. The purpose is to provide.

  Conventionally, it has been believed that the friction of the cable can be reduced by eliminating the irregularities on the surface of the optical indoor cable. However, the inventors have discovered that when the surface of the optical indoor cable is rough, the friction on the surface of the optical indoor cable is reduced.

Therefore, in order to solve the above-described problem, an optical indoor cable according to the present invention is an optical indoor cable including an optical fiber and a coating covering an outer periphery of the optical fiber, and the surface of the coating is irregular. It is characterized by providing unevenness on the surface.
Since there are irregularities irregularly undulating on the surface of the coating, the contact area on the surface of the optical indoor cable is reduced, so that the dynamic friction coefficient on the surface of the optical indoor cable can be reduced. According to the present invention, in laying a cable in an existing pipe, it is possible to easily insert or pull out an arbitrary cable and to pull a low tension without affecting the existing cable. As a result, it is possible to lay multiple lines on existing pipes, which has been impossible in the past, to solve the problem of deadlines in existing pipes and to make all the doors light.
Moreover, because of its low friction, it has been necessary to have a wire-passing device by obtaining rigidity, but it can follow the piping space independently with the power of only the cable without using a wire-passing device. Can be inserted. As a result, it is possible to realize a significant reduction in the laying construction time per one line and to realize all-door optical wiring in the optical communication service.

  In the optical indoor cable according to the present invention, it is preferable that the unevenness has a surface roughness of 1 μm or more and 30 μm or less. When the surface roughness is 1 μm or more and 30 μm or less, the dynamic friction coefficient of the optical indoor cable surface can be reduced. Here, the surface roughness refers to the average of the absolute values of the height at the reference length.

  The irregularities preferably have a surface roughness of 1 μm or more and 9 μm or less when measured using a contact-type surface roughness measurement method. In particular, the unevenness preferably has a surface roughness of 1 μm or more and 3 μm or less or 8 μm or more and 9 μm or less when measured using a contact-type surface roughness measurement method. Moreover, it is preferable that the said unevenness | corrugation has a surface roughness of 5 micrometers or more and 30 micrometers or less when measured using a non-contact-type surface roughness measuring method.

  The irregularities have a surface roughness of 5 μm or more and 30 μm or less when measured using a non-contact type surface roughness measuring method, and 1 μm or more when measured using a contact type surface roughness measuring method. It is preferable to have a surface roughness of 3 μm or less. Further, it has a surface roughness of 5 μm or more and 30 μm or less when measured using a non-contact type surface roughness measuring method, and is 8 μm or more and 9 μm or less when measured using a contact type surface roughness measuring method. It is preferable to have a surface roughness of

In the optical indoor cable according to the present invention, it is preferable that the coating includes fine particles having an average particle diameter substantially equal to the surface roughness of the unevenness on the surface material.
When the surface material contains fine particles having a surface roughness, the surface of the optical indoor cable can be provided with irregularities having a surface roughness.

In the optical indoor cable according to the present invention, the fine particles are preferably made of crosslinked polyethylene.
Cross-linked polyethylene has excellent pressure resistance and heat resistance and is hard, and therefore, wear due to friction with other cables is small. Thereby, even when there is repeated friction with the cable, an increase in the friction coefficient of the coating surface can be prevented.

In the optical indoor cable according to the present invention, it is preferable that the coating includes fluorine or silicon as a surface material.
Fluorine or silicon is relatively stiff and has high friction resistance compared to other materials. For this reason, by including fluorine or silicon on the surface of the coating, the optical indoor cable itself can be independently inserted and pulled out without using a wire machine.

In the optical indoor cable according to the present invention, the fluorine or silicon is preferably a powder having an average particle diameter smaller than the unevenness.
Fluorine or silicon is relatively stiff and has high friction resistance compared to other materials. For this reason, it discovered that the friction on the surface of an optical indoor cable could be reduced by including a fluorine-type or silicon-type powder.

The optical indoor cable laying method according to the present invention is characterized by having a step of pushing the optical indoor cable into a pipe with the end in the longitudinal direction of the optical indoor cable according to the present invention as the head.
Since the optical indoor cable according to the present invention has a small friction coefficient on the surface, resistance due to friction with the existing cable is small. Therefore, by providing a certain degree of rigidity, laying can be performed by pushing without using a line machine.

  ADVANTAGE OF THE INVENTION According to this invention, the laying method using the optical indoor cable which enables the multi-laying to existing piping by low friction, and the said optical indoor cable can be provided.

  Embodiments of the present invention will be described with reference to the accompanying drawings. The embodiment described below is an example of the configuration of the present invention, and the present invention is not limited to the following embodiment.

  FIG. 1 is a schematic configuration diagram of an optical indoor cable according to the present embodiment. The optical indoor cable 91 according to this embodiment includes an optical fiber 11 and a coating 12 that covers the outer periphery of the optical fiber. The optical fiber 11 includes a core for propagating light and a clad for reflecting light incident from the core. In the present embodiment, the number of optical fibers 11 may be one, or two or more.

  FIG. 2 shows a cross-sectional view of a pipe when an existing cable is inserted into an existing pipe and a new optical indoor cable is inserted into the empty space. Since the existing cable 92 is located at the bottom of the pipe 30, the newly installed optical indoor cable 91 has three linear contact portions parallel to the longitudinal direction of the optical indoor cable 91 between the adjacent three existing cables 92. Will have. The actual existing cable 92 does not have a circular cross section as shown in the figure, and may be close to a rectangular cross section. However, the dynamic friction generation site with the adjacent existing cable 92 is not a surface but the longitudinal direction of the optical indoor cable 91. It becomes a line parallel to. 1 and 2, the optical indoor cable 91 is described as having a circular cross section, but the cross sectional shape of the optical indoor cable 91 is not limited to a circular shape, and includes a rectangular shape and an elliptical shape. Further, the optical indoor cable 91 may be in the form of a tape.

  If the friction on the surface of the optical indoor cable 91 is reduced to the utmost limit, the number of optical indoor cables 91 to be inserted into the limited empty space in the pipe 30 can be maximized. Accordingly, the optical indoor cable 91 is identified by specifying the critical area of the surface roughness of the optical indoor cable 91 and the covering material that can minimize the dynamic friction generated between adjacent cables when the optical indoor cable 91 is inserted. The dynamic friction at the time of insertion was reduced, and it was possible to lay 30 or more of the conventional cables that could not be laid on 4 or more.

  The surface of the coating 12 shown in FIG. 1 is provided with irregularities that irregularly undulate. Since the irregularities undulate irregularly, the irregularities of the optical indoor cable 91 do not get stuck, and the contact area of the coating 12 can be reduced. 3 and 4, the dynamic friction coefficient on the surface of the coating 12 can be reduced as compared to when the surface of the coating 12 is flat.

  The unevenness preferably has a surface roughness of 1 μm or more and 30 μm or less. Here, the surface roughness refers to the average of the absolute values of the height at the reference length. When the surface roughness is 1 μm or more and 30 μm or less, the dynamic friction coefficient on the surface of the optical indoor cable can be made smaller than the results of the examples shown in FIGS. At this time, since the dynamic friction coefficient is less than 0.2, the optical indoor cable can be inserted. When the surface roughness was less than 1 μm, the dynamic friction coefficient obtained by the contact-type and non-contact-type surface roughness measurement methods exceeded 0.2, and the dynamic friction coefficient increased as the unevenness disappeared. When the surface roughness exceeds 30 μm, the dynamic friction coefficient obtained by the non-contact type surface roughness measuring method tends to exceed 0.2.

  The surface roughness evaluation index will be described. For example, in a commercially available contact-type surface roughness measurement method, when a stylus scans the actual surface of a sample, the vertical axis represents the curve (measurement curve) created by the locus of the tip of the cone (tip sphere center). The curve obtained by plotting the coordinates on the horizontal axis and sampling (digitizing) at regular intervals is called the measurement cross-section curve, and the length (reference length) of a portion obtained by extracting a certain length from the measurement cross-section curve The surface roughness is defined by the average of the absolute values of height at JIS, and is defined as a JIS standard. For example, the arithmetic average roughness Ra specified in JIS B 0601: 2001. The specification may be another standard such as JIS B 0651.

  When measured using a contact-type surface roughness measurement method, the irregularities preferably have an arithmetic average roughness of 1 μm or more and 9 μm or less. At this time, since the dynamic friction coefficient is less than 0.2 from the result of the embodiment shown in FIGS. 3 and 4, the optical indoor cable can be inserted. In particular, the irregularities preferably have a surface roughness of 1 μm or more and 3 μm or less, or 8 μm or more and 9 μm or less. With these surface roughnesses, the dynamic friction coefficient can be minimized from the results of the examples shown in FIGS. In the contact-type surface roughness measurement method, the surface of a sample is traced with a stylus and the vertical movement of the stylus is detected.

  When measured using a non-contact type surface roughness measurement method, the irregularities preferably have a surface roughness of 5 μm or more and 30 μm or less. At this time, since the dynamic friction coefficient is less than 0.2 from the result of the embodiment shown in FIGS. 3 and 4, the optical indoor cable can be inserted. The non-contact type surface roughness measurement method is a measurement method that uses light instead of a stylus, for example, a confocal method or a white interference method.

  FIG. 5 shows an example of the correlation between the contact-type surface roughness and the non-contact-type surface roughness. It was also found that a positive correlation was established in any of the four types of optical indoor cables A, B, C, and D. If the correlation line is obtained in advance by the least square method for the measured values of the contact-type surface roughness and the non-contact-type surface roughness, the contact-type surface roughness can be calculated from the contact-type surface roughness, regardless of the type of optical indoor cable. The contact type surface roughness can be estimated from the non-contact type surface roughness. Therefore, when an optical indoor cable with a known contact type surface roughness and an optical indoor cable with a known non-contact type surface roughness are mixed and inserted into the same pipe, an adjacent optical indoor is used using a correlation line. The dynamic friction coefficient of the cable can be estimated. This is because the surface roughness varies within an allowable range, so when determining the insertion order of a plurality of optical indoor cables having different surface roughnesses, for example, the optical indoors are inserted in such an insertion order that the dynamic friction force is always minimized. The cable can be inserted.

  When measurement is possible using both contact-type and non-contact-type surface roughness measurement methods, the unevenness is 1 μm to 9 μm arithmetic average roughness when measured using contact-type surface roughness measurement methods. And a surface roughness of 5 μm or more and 30 μm or less when measured using a non-contact type surface roughness measurement method. In particular, the irregularities have an arithmetic average roughness of 1 μm or more and 3 μm or less or 8 μm or more and 9 μm or less when measured using a contact type surface roughness measurement method, and a non-contact type surface roughness measurement method is used. The surface roughness is preferably 5 μm or more and 30 μm or less.

  In order to form the structure having the above-described surface roughness into the coating 12, for example, a method of incorporating a surface roughening process such as sandblasting into the line after extrusion molding, or an arbitrary vertical and horizontal direction in the line after extrusion molding There are a method of roughening the surface of the fiber by transferring the rough surface through a rough roll, and a method of manufacturing a fiber by extrusion molding by mixing fine particles of an arbitrary particle diameter with a coating material. The fine particles are preferably formed of a hard material having excellent pressure resistance and heat resistance, such as crosslinked polyethylene.

  When a fiber is manufactured by extrusion molding by mixing fine particles with the material of the coating 12, the coating 12 preferably includes fine particles having an average particle diameter substantially equal to the surface roughness of the coating 12 on the surface material. At this time, the average particle diameter of the fine particles is preferably such that the surface roughness formed on the surface of the coating 12 is substantially equal to the preferable surface roughness. The coating material is a resin such as polyethylene or polyvinyl chloride.

  In order to reduce the friction on the surface of the optical indoor cable and to provide rigidity, the coating 12 preferably contains fluorine or silicon in the surface material. In addition, fluorine or silicon is preferably a powder having an average particle size smaller than that of irregularities. A material having at least fluorine-based or silicon-based powder is relatively rigid compared to other materials, that is, it has a high friction resistance, so that it can be inserted and pulled independently by the optical indoor cable itself without using a line machine. I found out that

  The optical indoor cable laying method according to the present embodiment has a step of pushing the optical indoor cable 91 according to the present embodiment into the pipe 30 shown in FIG. Since the optical indoor cable 91 has little friction, if the optical indoor cable 91 has a certain degree of rigidity, the optical indoor cable 91 can be passed through the pipe 30 by being pushed in without using a line machine.

  The surface roughness was changed for the polyethylene samples, and the dynamic friction coefficient was measured for each. The surface roughness indicates an arithmetic average roughness Ra specified in JIS B 0601. In this example, the surface roughness was measured using a contact-type surface roughness measurement method. In the measurement of the dynamic friction coefficient, the pulling speed was 10 m / s, the measuring speed was 0.3 mm / s, and the measuring distance was 5 mm.

  FIG. 3 is a plot of the coefficient of dynamic friction versus the surface roughness measured using the contact-type surface roughness measurement method. When measured using the contact-type surface roughness measurement method, the dynamic friction coefficient is 0.2 or less, which allows the insertion of an optical indoor cable within a range having an arithmetic average roughness Ra of 1 μm to about 9 μm. It was. More preferably, it was found that the dynamic friction coefficient is minimized in a range having an arithmetic average roughness Ra of 2 μm to 3 μm or 8 μm to 9 μm.

  Similarly to Example 1, the surface roughness was changed for the polyethylene samples, and the dynamic friction coefficient was measured for each. The surface roughness indicates an arithmetic average roughness Ra specified in JIS B 0601. In this example, the surface roughness was measured using a non-contact type surface roughness measuring method. In the measurement of the dynamic friction coefficient, the pulling speed was 10 m / s, the measuring speed was 0.3 mm / s, and the measuring distance was 5 mm.

  FIG. 4 is a plot of dynamic friction coefficients versus surface roughness measured using a non-contact type surface roughness measurement method. For the non-contact type surface roughness measuring method, an ultra-deep shape measuring microscope of the confocal method was used. It was found that the dynamic friction coefficient was minimized in a range having an arithmetic average roughness Ra of 5 μm to 30 μm when measured using a non-contact type surface roughness measurement method.

  INDUSTRIAL APPLICABILITY The present invention can be used for providing an optical communication service that uses existing piping such as an apartment and performs wiring to all the houses.

It is a lineblock diagram of the optical indoor cable concerning this embodiment. Sectional drawing of piping when an existing cable is inserted in the existing piping and an optical indoor cable is newly inserted in the empty space is shown. The dynamic friction coefficient is plotted against the surface roughness measured using the contact-type surface roughness measurement method. The dynamic friction coefficient is plotted against the surface roughness measured using a non-contact type surface roughness measuring method. It is a graph which shows an example of the correlation of contact type surface roughness and non-contact type surface roughness.

Explanation of symbols

11 Optical fiber 12 Coating 30 Piping 91 Optical indoor cable 92 Existing cable

Claims (9)

Optical fiber,
An optical indoor cable comprising a coating covering an outer periphery of the optical fiber,
An optical indoor cable comprising irregularities that undulate irregularly on the surface of the covering.   The optical indoor cable according to claim 1, wherein the unevenness has a surface roughness of 1 μm or more and 30 μm or less.   2. The optical indoor cable according to claim 1, wherein the unevenness has a surface roughness of 1 μm to 9 μm when measured using a contact-type surface roughness measurement method.   The optical indoor cable according to claim 1, wherein the unevenness has a surface roughness of 5 μm or more and 30 μm or less when measured using a non-contact type surface roughness measurement method.   The optical indoor cable according to any one of claims 2 to 4, wherein the coating includes fine particles having an average particle diameter substantially equal to the surface roughness of the unevenness on the surface material.   The optical indoor cable according to claim 5, wherein the fine particles are made of crosslinked polyethylene.   The optical indoor cable according to any one of claims 1 to 6, wherein the coating includes fluorine or silicon as a material of a surface.   The optical indoor cable according to claim 7, wherein the fluorine or silicon is a powder having an average particle diameter smaller than the unevenness.   An optical indoor cable laying method comprising a step of pushing the optical indoor cable into a pipe with the end portion in the longitudinal direction of the optical indoor cable according to any one of claims 1 to 8 as a head.

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