JP2005257887A - Optical branching box and optical star coupler holding member - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To keep a wiring form of optical fibers constituting an optical star coupler, fixed. <P>SOLUTION: An optical star coupler 42 and a coupler holding member 46 are stored in an optical branching box. The coupler holding member 46 has a holding part 47 formed therein, which has grooves wherein respective optical fibers 43 constituting the optical star coupler 42 are held in a fixed disposition form. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an optical branch box for network connection of nodes such as microcomputers in a vehicle.

  In recent years, the number of microcomputers mounted on one automobile has increased as the functionality of automobiles has increased. As a technology for connecting these microcomputers, for example, a form in which each microcomputer is connected in a star shape using an optical star coupler is conceivable.

  As the optical star coupler used here, one in which intermediate portions of a plurality of plastic optical fibers are mutually welded by ultrasonic welding or the like is assumed. Such an optical star coupler can be multi-branched with low loss.

  Such an optical star coupler is disclosed in Patent Document 1, for example.

JP-A-5-281436

  However, since the optical star coupler itself has a configuration in which plastic optical fibers are fused to each other, when this optical star coupler is mounted on a vehicle or the like as it is, the plastic optical fiber is caused by vibration of the vehicle or the like. There is a risk of bending deformation or the like. For example, if the bending radius becomes smaller than the bending radius inherent in the plastic optical fiber, there is a problem that the bending loss rapidly increases.

  Therefore, an object of the present invention is to keep the wiring configuration of the optical fiber constituting the optical star coupler constant.

  According to a first aspect of the present invention, there is provided an optical branching box including an optical star coupler having a plurality of optical fibers, the optical star coupler holding having a holding portion for holding each optical fiber in a fixed wiring form. An optical branching box comprising a member and a casing for housing the optical star coupler holding member.

  In this case, the optical star coupler further includes an optical connector that connects between each optical fiber of the optical star coupler and an external optical transmission line, and the holding unit guides an end of each optical fiber toward the optical connector. It is good to be formed in the shape to hold.

  The holding section may be formed in a shape that holds each optical fiber with a bending radius that is equal to or larger than a minimum bending radius unique to each optical fiber constituting the optical star coupler.

  Furthermore, the holding part may have a groove for receiving and holding the optical fiber.

  The optical star coupler holding member may be black.

  According to a second aspect of the present invention, there is provided an optical star coupler holding member for holding an optical star coupler having a plurality of optical fibers, wherein a holding portion for holding each optical fiber in a predetermined wiring form is formed. Is.

  According to the first aspect of the present invention, the wiring form of each optical fiber is kept constant by holding each optical fiber by the holding portion.

  In this case, if the holding portion is formed to hold the end portion of each optical fiber so as to guide the optical fiber toward the optical connector, the bending form of the optical fiber is more constant at the introduction portion to each optical connector. Kept in shape.

  In addition, when the holding part is formed in a shape that holds each optical fiber with a bending radius that is greater than or equal to the minimum bending radius inherent to the optical fiber, each optical fiber is held in a form that has a bending radius that is greater than or equal to the minimum bending radius. Is done. Therefore, a large bending loss in the optical fiber can be prevented.

  Further, when the holding portion has a groove for accommodating and holding the optical fiber, the holding portion holds the optical fiber in a more fixed arrangement form and without concentrating the holding force locally. it can.

  Furthermore, when the optical star coupler holding member is black, it can effectively prevent external light from entering the optical fiber by absorbing light.

  Also, according to the second aspect of the present invention, the wiring form of each optical fiber is kept constant by holding each optical fiber in the holding portion.

  Hereinafter, an optical branching box according to an embodiment of the present invention will be described.

  First, an application example of this optical branch box will be described. This optical branching box is used in an optical communication network system for vehicles as shown in FIG. In FIG. 1, the front direction of the vehicle C is indicated by F, and the rear direction is indicated by R.

  This vehicular optical communication network system is applied to a vehicle C, and a plurality of nodes in the vehicle C are network-connected via one or a plurality of optical branch boxes 40.

  In FIG. 1, the microcomputers 30A, 30B, 30C, 30D, 30E, and 30F, which are nodes in the vehicle C, are divided into microcomputers 30A, 30B, and 30C, and microcomputers 30D, 30E, and 30F according to installation locations such as the front or rear of the vehicle C. It is divided into two groups. The front groups of microcomputers 30A, 30B, and 30C are connected to the front optical branch box 40 in a star shape, and the rear groups of microcomputers 30D, 30E, and 30F are connected to the rear optical branch box 40. Are connected in a star shape. Further, the front optical branch box 40 and the rear optical branch box 40 are relay-connected via a predetermined optical transmission line 20. The connection between the optical branch box 40 and the microcomputers 30A, 30B, 30C, 30D, 30E, and 30F, and the connection between the optical branch boxes 40 are, for example, an optical transmission line 32 using two optical fiber cables, 20 through.

  Thereby, each microcomputer 30A, 30B, 30C, 30D, 30E, 30F is network-connected in the aspect which can mutually communicate.

  In addition, the optical branch box 40 may be provided by a single number or three or more depending on the number of nodes to be connected.

  FIG. 2 is a perspective view showing the optical branching box, and FIG. 3 is a view showing a coupler holding member inside the optical branching box 40.

  The optical branch box 40 includes an optical star coupler 42, a coupler holding member 46, a casing 50, and an optical connector 58. The optical branch box 40 also includes an electrical substrate 50 and an electrical connector 62 for electrical wiring branching.

  The optical star coupler 42 distributes or couples optical signals input to a predetermined input port as appropriate and outputs them to other predetermined output ports. The optical star coupler 42 includes a plurality of optical fibers 43 such as plastic optical fibers. ing.

  More specifically, the optical star coupler 42 is formed by mutually welding intermediate portions of a plurality of optical fibers 43 by ultrasonic welding or the like, and includes a plurality of input fiber portions 43a and a plurality of output fibers. The fiber portion 43b and the fused portion 44 are provided. Here, an example in which the coupler 42 having eight input fiber portions 43a and eight output fiber portions 43b is configured using eight optical fibers 43 will be described, but the number thereof is limited to the example. Absent.

  Further, as described above, a plurality of optical fibers 43 are fused together at a single fused portion 44, a plurality of optical fibers are fused at a plurality of locations, a waveguide, and a reflecting mirror. Even if it is used, the present invention can be applied to a configuration in which an optical fiber is partially used.

  The casing 50 is formed in a box shape that can accommodate the optical star coupler 42, the turntable holding member 46, and an electric board 60 described later. A connector disposition hole 52h is formed on one main surface of the casing 50 (the surface on the front side in FIG. 2). Here, eight connector arrangement holes 52h are formed in a horizontal row for optical signals, and two connector arrangement holes 53h are formed for electricity.

  Further, the coupler holding member 46 has a configuration in which a holding portion 47 for accommodating and holding the optical fibers 43 in a fixed arrangement is formed.

  More specifically, the coupler holding member 46 is a substantially square plate-like member made of acetal resin such as Duracon (trademark), for example, and a holding portion 47 is formed on one main surface side thereof.

  Here, the holding part 47 is comprised by the groove | channel which can accommodate and hold the optical fiber 43, and each optical fiber 43 is accommodated and hold | maintained by the fixed arrangement | positioning form as follows.

  That is, the fused portion 44 of the optical star coupler 42 is disposed and fixed at a substantially middle portion on one side of the coupler holding member 46. Further, a plurality (eight in this case) of optical connectors 58 are attached to the other side portion of the coupler holding member 46 at positions and postures that can be arranged in the connector arrangement holes 52h of the casing 50. Yes. Each optical connector 58 is configured to be able to connect the external connector 21 (see FIG. 2) connected to the ends of the external optical transmission lines 32 and 20. Each optical connector 58 is connected to the optical transmission lines 32 and 20 on the external connector side by connecting one end of one input fiber portion 43a and one end of one output fiber portion 43b for input / output of optical signals. On the other hand, it is held so as to be optically connectable.

  The holding portion 47 includes an input fiber holding groove group 48 extending from one end portion of the fused portion 44 toward the respective optical connectors 58 so as to draw a substantially S shape, and each of the light beams from the other end portion of the fused portion 44. And an output fiber holding groove group 49 extending so as to draw a reverse substantially S-shape toward the connector 58.

  The input fiber holding groove group 48 has a plurality of grooves corresponding to the number of input fiber portions 43a.

  In the two curved region portions 48C of the input fiber holding groove group 48, each groove has a concentric arc shape with different diameters. In the curve region portion 48 </ b> C, the radius of curvature of the groove 48 </ b> C <b> 1 located on the innermost peripheral side is set to be larger than the minimum bending radius of the optical fiber 43. Here, the minimum bending radius of the optical fiber 43 is a value determined according to the refractive index of the core and cladding of the optical fiber 43, and when the optical fiber 43 is bent at a radius smaller than this minimum bending radius, This is a value at which the loss of is extremely large.

  Further, in the linear fiber portion 48L connecting the two curved region portions 48C in the input fiber holding groove group 48, the grooves extend so as to draw a substantially parallel shape.

  Further, in the portion from the curved region portion 48C on one side to each optical connector 58, each groove is formed in a shape reaching an optical connector 58 by bending in an arc in the middle of extending linearly.

  The output fiber holding groove group 49 has a plurality of grooves corresponding to the number of output fiber portions 43b.

  In the two curve region portions 49C of the output fiber holding groove group 49, each groove has a target form with the fusion portion 44 sandwiched between the grooves in each of the curve region portions 48C. Further, in the linear region portion 49L of the output fiber holding groove group 49, each groove is shared with each groove of the linear region portion 48L.

  That is, the output fiber holding groove group 49 as a whole has a target shape with the fused portion 44 sandwiched from the input fiber holding groove group 48.

  Each of the grooves constituting the input fiber holding groove group 48 and the output fiber holding groove group 49 is formed in a concave groove shape that can accommodate the optical fiber 43. Preferably, each groove 47g is formed to a depth that can accommodate one or two optical fibers 43, as shown in FIG. 4 (a) or FIG. 4 (b). In particular, in the shared linear region portion 48L, the groove 47g is formed to a depth that can accommodate about two optical fibers 43 (input fiber portion 43a and output fiber portion 43b).

  Each groove constituting the input fiber holding groove group 48 separately guides the input fiber portion 43a toward each optical connector 58. Similarly, each groove constituting the output fiber holding groove group 49 includes Similarly to the input fiber holding groove group 48, the output fiber portions 43 b are separately guided toward the optical connectors 58.

  Each optical connector 58 holds an end portion of one input fiber portion 43a and an end portion of one output fiber portion 43b.

  In addition, an electrical board 60 having an electrical connector 62 is built in the optical branch box 40.

  The electrical board 60 is, for example, a board on which a circuit for power distribution is formed, and a power supply board is attached as an electrical connector 62 on one side thereof. Of course, a predetermined control circuit may be incorporated in the electric board 60 and the electric connector 62 may have terminals for transmitting and receiving electric signals.

  In manufacturing the optical branching box 40, a coupler holding member 46 in which fiber holding groove groups 48 and 49 are formed is prepared, and an optical star coupler 42 in which the optical fibers 43 are mutually fused is prepared. The fused portion 44 is disposed and fixed on the coupler holding member 46, and the input fiber portions 43a and the output fiber portions 43b extending outward from both ends of the fused portion 44 are provided. The fiber holding groove groups 48 and 49 are fitted into the respective grooves. Then, the end portions of the input fiber portions 43 a and the end portions of the output fiber portions 43 b are appropriately combined and held by the optical connectors 58 attached to the coupler holding member 46. Before or after such holding, the optical connector 58 is attached to the coupler holding member 46.

  Separately from this, an electrical board 60 to which an electrical connector 62 is attached is prepared.

  Each optical connector 58 is disposed in each connector disposition hole 52h of the casing 50, and each electrical connector 62 is disposed in the connector disposition hole 53h. The coupler holding member 46 and the electric board 60 are connected to each other. Then, in a state where they are arranged in a superposed manner with a predetermined interval between them, they are fixed in the casing 50 using screwing or an engaging structure.

  In this way, the light branching box 40 is manufactured.

  According to the optical branch box 40 configured as described above, the optical fiber 43 is held by the holding portion 47, whereby the wiring form of each optical fiber 43 is kept constant. For this reason, the optical fiber is prevented from being bent and deformed by the vibration of the vehicle or the like. Therefore, an increase in optical loss due to a large bending deformation can be effectively prevented. Further, the vibration of each optical fiber 43 is also suppressed, and the vibration resistance is excellent.

  In addition, the fiber holding groove groups 48 and 49 of the holding portion 47 of the coupler holding member 46 are formed to hold the end portions of the optical fibers 43 so as to be guided to the optical connectors 58. At the introduction portion, the bending form of the optical fiber 43 is kept more constant.

  In addition, since the optical connector 58 is attached to the coupler holding member 46, the positional relationship between the optical connector 48 and the coupler holding member 46 is kept constant. Thus, the bending form of the optical fiber 43 is kept more constant.

  Further, there is an advantage that the optical star coupler 42 and the optical connector 58 attached to the coupler holding member 46 can be easily assembled in the casing 50 as described above.

  Furthermore, since the holding portion 47 is formed in a shape that holds each optical fiber 43 with a bending radius that is greater than or equal to the minimum bending radius of the optical fiber 43, each optical fiber 43 has a bending radius that is greater than or equal to the minimum bending radius. Held in. Therefore, a large bending loss in the optical fiber 43 can be prevented.

  Further, the optical star coupler 42 that is held by the coupler holding member 46 is accommodated in the casing 50, so that the optical star coupler can be waterproofed.

  In the present embodiment, each groove constituting the holding portion 47 has a substantially S-shape, but this is not always necessary. A groove extending between the fused portion 44 and each optical connector 44 so as to connect with a shortest path while drawing a curve larger than a predetermined minimum bending radius may be used.

  Moreover, in the said embodiment, although the holding | maintenance part 47 is formed in the linear groove | channel which can accommodate and hold | maintain the optical fiber 43, it is not necessarily required. For example, the holding portion 47 may be formed so as to protrude from one main surface of the coupler holding member 46 and sandwich the optical fiber 43 partially or intermittently. In short, various configurations that can hold the optical fiber 43 in a fixed arrangement can be employed.

  However, the holding portion 47 is configured by a groove that accommodates and holds the optical fiber 43, so that the holding force is concentrated locally in a more fixed arrangement form than a partial and intermittent holding structure. There is an advantage that the optical fiber 43 can be held without. Further, since the optical fiber 43 is accommodated in the groove 50 after being accommodated in the casing 50, the heat of the ambient atmosphere is hardly transmitted to the optical fiber 46, and there is an advantage that heat resistance is excellent.

  In this case, three or more optical fibers 43 may be held by one groove. However, in order to suppress vibration of the optical fiber 43 due to vehicle vibration or the like, it is preferable to hold one or two optical fibers 43 in one groove.

  The coupler holding member 46 preferably has at least a black surface. Thereby, external light is absorbed and external light intrusion into the optical fiber 43 can be effectively prevented.

  Further, in this embodiment, a concave portion corresponding to the outer shape of the fused portion 44 is formed in the coupler holding member 46, the fused portion 44 is disposed in the concave portion, and the fused portion 44 is shaped into a predetermined shape. You may make it hold | maintain.

It is a figure which shows the whole structure of the optical communication network system for vehicles which is an application example of an optical branch box. It is a perspective view which shows an optical branch box. It is a figure which shows the state by which the optical star coupler was hold | maintained at the coupler holding member. It is sectional drawing which shows the groove | channel of a holding | maintenance part.

Explanation of symbols

DESCRIPTION OF SYMBOLS 40 Optical branch box 42 Optical star coupler 43 Optical fiber 43a Input fiber part 43b Output fiber part 44 Fusion part 46 Coupler holding member 47 Holding part 48 Input fiber holding groove group 49 Output fiber holding groove group 50 Casing 58 Optical connector

Claims (6)

An optical branch box comprising an optical star coupler having a plurality of optical fibers,
An optical star coupler holding member formed with a holding part for holding each optical fiber in a fixed wiring form;
A casing for housing the optical star coupler holding member;
Light branch box with The optical branch box according to claim 1,
Further comprising an optical connector for connecting between each optical fiber of the optical star coupler and an external optical transmission line,
The said holding | maintenance part is an optical branch box formed in the shape hold | maintained so that the edge part of each said optical fiber may be guide | induced toward the said optical connector. The optical branching box according to claim 1 or 2,
The holding section is an optical branching box formed to hold each optical fiber with a bending radius equal to or larger than a minimum bending radius specific to each optical fiber constituting the optical star coupler. The optical branch box according to any one of claims 1 to 3,
The said holding | maintenance part is an optical branch box which has the groove | channel which accommodates and hold | maintains the said optical fiber. The optical branching box according to any one of claims 1 to 4,
The optical star coupler holding member is an optical branching box exhibiting a black color. An optical star coupler holding member for holding an optical star coupler having a plurality of optical fibers,
An optical star coupler holding member in which a holding part for holding each optical fiber in a predetermined wiring form is formed.

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