JP2019211558A - Optical connector - Google Patents

Abstract

To provide an optical connector which has a few components and favorable assembly work efficiency.SOLUTION: A pair of jacket holding parts 39 are each formed in substantially semiperimeter at positions facing each other, a protrusion 41 with a diameter larger than that of the jacket holding part 39 is formed between the jacket holding parts 39. The jacket 31 at the distal end of the optical cord is divided to be torn along the longitudinal direction. The distal end of the divided jacket 31 is arranged in the jacket holding part 39 formed on the outer periphery of the rear end of a second housing 13. That is, the jacket 31 is arranged in the position other than the protrusion 41. The jacket 31 is pressurized to the jacket holding part 39, and the rotation of the jacket is restricted by the protrusion 41 even when the jacket 31 tries to rotate the outer periphery of the second housing 13 when screwing the fixing member. Therefore, the twisting of the optical fiber inside an optical cord can be suppressed.SELECTED DRAWING: Figure 5

Description

  The present invention relates to an optical connector that is simple in structure and easy to assemble.

  Conventionally, when an optical connector is connected to the tip of the optical cord, the optical fiber of the optical cord and the optical fiber built in the ferrule are connected, and a member such as a housing is assembled so as to accommodate this connecting portion. It was.

  Such an optical connector has a structure in which an optical fiber core wire built in a ferrule and an optical fiber core wire drawn out from an optical cord are fusion-bonded, and the outer sheath of the optical cord is covered behind the housing. There has been proposed a method in which the outer cover of the optical cord is fixed by being pressed by a pressed member, and further by screwing the fixing member and the housing (for example, Patent Document 1).

JP 2011-118348 A

  However, when the fixing member is screwed to fix the outer cover of the optical cord as in Patent Document 1, the outer cover may rotate together with the fixing member when the fixing member is screwed. In such a case, twisting occurred in the optical fiber inside the optical cord, causing damage to the optical fiber and transmission loss.

  Further, in order to fix the outer cover of the optical cord to the rear end portion of the housing, two parts of the cover pressing member and the fixing member are necessary, and the number of parts is large and the structure is complicated.

  The present invention has been made in view of such problems, and an object of the present invention is to provide an optical connector having a small number of parts and good assembly workability.

  In order to achieve the above-described object, the present invention provides an optical connector in which a built-in optical fiber held by a ferrule and an optical fiber in an optical cord are connected, the housing connected to the ferrule, and the housing A fixing member that is screwed and connected to the rear of the optical code, and a jacket of a tip of the optical cord is divided along a longitudinal direction, and a tip of the divided jacket is a rear end portion of the housing Disposed at the outer periphery of the housing, and the front end of the outer cover is sandwiched and fixed between the housing and the fixing member, and a projecting portion protruding in the radial direction is formed in a circumferential section of the rear end portion of the housing, In the optical connector, the outer cover is disposed at a portion other than the protrusion.

  A tube is covered on the outer periphery of the predetermined length of the optical cord exposed from the fixing member, the tube has a two-layer structure, the inner layer is made of a relatively hard resin, and the outer layer is relatively hard. It may consist of a low resin.

  A large diameter portion may be formed at a distal end portion of the tube on the fixing member side, and the large diameter portion may be fitted to a reduced diameter portion of the fixing member so that the tube and the fixing member are connected. .

  According to the present invention, since the jacket of the optical cord can be fixed without using the jacket pressing member, the number of parts can be reduced. Moreover, since the protrusion which protrudes to a radial direction is formed in the rear-end part of a housing, and a cover is arrange | positioned in parts other than a protrusion, even if it tries to rotate a cover, rotation is controlled by a protrusion. For this reason, rotation of the jacket can be suppressed when the fixing member is screwed. For this reason, assembly work is easy.

  Also, if the optical cord exposed from the fixing member is covered with a tube, and the inner layer of the tube is made of a relatively hard resin and the outer layer is made of a relatively low hardness resin, the operation of inserting the optical cord through the tube Is easy and the flexibility when bent can be increased. Moreover, the tube can be easily connected to the fixing member by the large diameter portion by forming the large diameter portion at the distal end portion of the tube.

  According to the present invention, it is possible to provide an optical connector having a small number of parts and good assembly workability.

The perspective view of the optical connector 1. FIG. (A) is a top view of the optical connector 1, (b) is a side view of the optical connector 1. FIG. (A) is the sectional view on the AA line of Fig.2 (a), (b) is the sectional view on the BB line of FIG.2 (b). The disassembled perspective view of the 2nd housing 13, the fixing member 19, and the tube 21. FIG. (A) is CC arrow directional view of FIG. 4, (b) is a figure which shows the state which has arrange | positioned the jacket to (a). Sectional drawing of the tube 21. FIG.

  Hereinafter, an optical connector 1 according to an embodiment of the present invention will be described. FIG. 1 is a perspective view of the optical connector 1, FIG. 2A is a plan view of the optical connector 1, and FIG. 2B is a side view of the optical connector 1. 3A is a sectional view taken along line AA in FIG. 2A, and FIG. 3B is a sectional view taken along line BB in FIG. 2B.

  As shown in FIGS. 3A and 3B, the optical connector 1 is a so-called SC connector, and mainly includes a ferrule 3, a first housing 5, a spring 9, a protective sleeve 11, and a second housing 13. , The fixing member 19, the tube 21 and the like. The optical connector to which the present invention can be applied may be an LC connector.

  The optical connector 1 is formed at the tip of the optical cord 27. The optical cord 27 includes an optical fiber 29 therein. A tensile strength fiber 33 is formed on the outer periphery of the optical fiber 29, and a jacket 31 is formed on the outer periphery thereof.

  A built-in optical fiber 25 is held inside the ferrule 3. The built-in optical fiber 25 is connected to the optical fiber 29 of the optical cord 27. That is, inside the optical connector 1, the built-in optical fiber 25 held by the ferrule 3 and the optical fiber 29 inside the optical cord 27 are connected, and the connection portion is reinforced by the protective sleeve 11.

  The ferrule 3 is accommodated in the first housing 5. The ferrule 3 includes a ferrule body and a flange portion, and the built-in optical fiber 25 described above is held in the ferrule body. A flange portion is connected and fixed to the rear end portion of the ferrule body.

  A spring 9 is disposed behind the ferrule 3 (flange portion). The ferrule 3 is pressed against the first housing 5 by a spring 9. When the ferrule 3 is pushed backward against the spring 9, the ferrule 3 can slide backward with respect to the first housing 5.

  The first housing 5 is accommodated in the knob 15. The knob 15 is a part that performs a detaching operation with respect to an adapter that is a connection target.

  A second housing 13 is joined to the rear of the first housing 5. The connecting portion between the built-in optical fiber 25 of the ferrule 3 and the optical fiber 29 of the optical cord 27 is disposed inside the second housing 13. That is, the ferrule 3 is connected to the second housing 13 via the first housing 5. In the present invention, the first housing 5 and the second housing 13 may be simply referred to as a housing. Details of the second housing 13 will be described later.

  A fixing member 19 is disposed behind the second housing 13. A male screw portion is formed on the outer peripheral portion of the second housing 13, and is screwed with a female screw portion formed on the inner surface of the fixing member 19. That is, the fixing member 19 can be fixed to the second housing 13 by screwing the fixing member 19 behind the second housing 13.

  A tube 21 is joined to the rear of the fixing member 19. The tube 21 is a member that is made of a flexible resin and suppresses rapid bending of the optical cord 27, and is disposed on the outer periphery of the optical cord 27. Details of the tube 21 will be described later.

  Next, the optical cord retaining structure will be described in detail. FIG. 4 is an exploded perspective view of the second housing 13, the fixing member 19, and the tube 21.

  As described above, the external thread portion is formed on the outer peripheral surface of the second housing 13. The male screw portion is screwed with a female screw portion formed on the inner surface of the fixing member 19. At this time, a gap is formed between the external thread portion formed on the outer periphery of the second housing 13 and the internal thread portion formed on the inner surface of the fixing member 19, and the tensile strength fiber 33 of the optical cord 27 is sandwiched. That is, the male thread portion formed on the outer peripheral surface of the second housing 13 becomes the tensile fiber holding portion 37.

  An outer sheath holding portion 39 having a diameter smaller than that of the tensile strength fiber holding portion 37 is provided behind the tensile strength fiber holding portion 37 of the second housing 13. The jacket holding part 39 is a part where the jacket 31 of the optical cord 27 is held. The jacket holding part 39 has an uneven shape that is continuous for a predetermined length in the circumferential direction. That is, the outer casing holding portion 39 is repeatedly uneven in the axial direction (longitudinal direction) of the second housing 13.

  Fig.5 (a) is a CC arrow directional view of FIG. The pair of jacket holding portions 39 is formed in a substantially half circumference at positions facing each other, and a pair of protrusions 41 having a diameter larger than the diameter of the jacket holding portion 39 is formed between the jacket holding portions 39. Is done. That is, in the circumferential cross section of the rear end portion of the second housing 13, a protruding portion 41 that protrudes in the radial direction is formed, and the jacket holding portion 39 is sandwiched in the circumferential direction by the protruding portion 41. In the illustrated example, the protrusions 41 are arranged at two opposing positions, but may be one or three or more.

  As described above, the jacket 31 is disposed in the jacket holding portion 39. FIG. 5B is a conceptual diagram showing a state in which the jacket 31 is arranged on the jacket holding portion 39. The outer jacket 31 at the tip of the optical cord 27 is torn and divided along the longitudinal direction. The front end of the divided outer casing 31 is disposed in an outer casing holding portion 39 formed on the outer periphery of the rear end portion of the second housing 13. That is, the outer jacket 31 is disposed at a portion other than the protrusion 41.

  As shown in FIG. 3B, in this state, the fixing member 19 is screwed into the second housing 13, whereby the tip of the outer cover 31 is sandwiched and fixed between the second housing 13 and the fixing member 19. . At this time, the outer cover 31 is pressed by the outer cover holding part 39, and when the fixing member 19 is screwed, even if the outer cover 31 tries to rotate the outer periphery of the second housing 13, the outer cover 31 is caused by the protrusion 41. Rotation is regulated. For this reason, the twist of the optical fiber 29 inside the optical cord 27 can be suppressed.

  Next, a method for assembling the optical connector will be described. First, in a state in which the protective sleeve 11 is retracted to the optical cord 27, the optical fiber 29 of the optical cord 27 and the built-in optical fiber 25 of the ferrule 3 are set in a fusion machine and fusion-bonded. At this time, a transport cap is connected to the tip of the ferrule 3 as necessary.

  At the end of the optical cord 27, the jacket 31 is previously peeled off for a predetermined length, and the internal tensile strength fiber 33 and the optical fiber 29 are drawn out. At this time, the front end portion of the outer jacket 31 is torn by a predetermined length and is divided into, for example, two in the circumferential direction.

  After the optical fiber 29 and the built-in optical fiber 25 are fused, the protective sleeve 11 is moved to the connecting portion and fixed. The protective sleeve 11 has, for example, a heat-shrinkable member and a core material, and can be fixed to the connecting portion by heating at the connecting portion between the optical fiber 29 and the built-in optical fiber 25.

  Next, the spring 9 and the second housing 13 that have been retracted by the optical cord 27 are moved to join the rear end of the first housing 5 and the second housing 13 together. The 1st housing 5 and the 2nd housing 13 can be joined by the latch etc. which abbreviate | omitted illustration, for example.

  In the state where the second housing 13 is connected to the first housing 5, the outer cover 31 that is torn and divided into two at the end portion of the optical cord 27 is spread at the rear end portion of the second housing 13, as described above. Arranged in the jacket holding part 39. Further, the tensile strength fiber 33 led out from the optical cord 27 passes through the jacket holding portion 39 and is disposed on the tensile strength fiber holding portion 37.

  Next, the fixing member 19 and the tube 21 that have been retracted by the optical cord 27 are moved, and the male screw portion (strength fiber holding portion 37) on the outer peripheral portion of the second housing 13 and the inner surface of the fixing member 19 are formed. The second housing 13 and the fixing member 19 are joined together by screwing the female screw portions. That is, the fixing member 19 can be fixed to the second housing 13 by screwing the fixing member 19 into the second housing 13.

  At this time, as shown in FIG. 5B, the height of the protrusion 41 with respect to the jacket holding portion 39 is lower than the thickness of the jacket 31. For this reason, when the fixing member 19 is screwed into the second housing 13, the outer cover 31 is pressed against the second housing 13 from the outside by the inner surface of the fixing member 19. That is, the outer cover 31 is firmly sandwiched between the fixing member 19 and the second housing 13 so that the outer cover 31 can be fixed.

  In addition, the tensile strength fibers 33 arranged along the outer periphery of the second housing 13 are sandwiched between the male screw portion and the female screw portion between the second housing 13 and the fixing member 19. That is, a slight gap is formed between the male screw portion and the female screw portion between the second housing 13 and the fixing member 19, and the tensile strength fiber 33 is sandwiched between the gaps. For this reason, the tensile strength fiber 33 can be fastened and fixed to the outer periphery of the second housing 13. Thus, the optical connector 1 can be assembled.

  A tube 21 is attached to the rear end of the fixing member 19 in advance. FIG. 6 is an enlarged view of a portion D in FIG. 3A, and is an enlarged cross-sectional view of the tube 21. The tube 21 is put on the outer periphery of a predetermined length of the optical cord 27 exposed from the rear of the fixing member 19.

  As described above, when the optical fiber of the optical cord 27 is fused with the built-in optical fiber 25 of the ferrule 3, the outer jacket 31 having a predetermined length at the tip end portion of the optical cord 27 is torn, and the internal light The fiber 29 needs to be exposed for a predetermined length. The tube 21 covers the optical cord 27 at least in a range where the outer jacket 31 of the optical cord 27 is torn.

  Here, the tube 21 has at least a two-layer structure, and includes an inner resin layer 21a and an outer resin layer 21b provided on the outer periphery of the inner resin layer 21a. The inner resin layer 21a is a resin having a relatively high hardness, such as polytetrafluoroethylene (PTFE) resin, and the outer resin layer 21b is made of a resin having a relatively low hardness. A vinyl acetate copolymer (EVA) resin or the like is applicable.

  Further, an intermediate resin layer 21c is provided between the inner resin layer 21a and the outer resin layer 21b at a part of the distal end portion of the tube 21 on the fixing member side. That is, the part where the intermediate resin layer 21c is provided is a thick part having a larger diameter than other parts. The fixed member 19 is provided with a reduced diameter portion of a hole through which the tube 21 is inserted, and the fixed member 19 and the tube 21 can be connected by fitting the large diameter portion into the reduced diameter portion. .

  When attaching the tube 21 to the optical cord 27, the fixing member 19 is fitted in the optical cord 27 in advance, and then the optical cord 27 is inserted into the tube 21. At this time, if the slippage between the outer jacket 31 of the optical cord 27 and the inner surface of the tube 21 is poor, it is difficult to attach the tube 21.

  On the other hand, if the tube 21 is made of a resin having a certain degree of rigidity and good sliding with the optical cord 27, the bendability of the optical cord 27 is deteriorated. For this reason, the tube 21 is made of a resin having relatively high hardness, rigidity, and slipperiness, ensuring attachment to the optical cord 27, and making the outer layer of a resin having low hardness and being easily bent. Therefore, bendability can be ensured. When the fixing member 19 is moved to the distal end side of the optical cord 27, as described above, the reduced diameter portion of the rear end portion of the fixing member 19 and the large diameter portion of the tube 21 come into contact with each other, and the fixing member 19 and the tube 21 are brought into contact with each other. Can be prevented from coming off.

The external resin layer 21b can be made of a heat shrink resin. After the tube 21 is manufactured, the inner resin layer 21a is passed through a metal rod or the like having the same diameter as the optical cord, the intermediate resin layer 21c is passed, and the outer resin layer 21b is passed through and adjusted to each predetermined position. By heat-shrinking the external resin layer 21b, 21a, 21c, and 21b can be integrated. After integration, the tube 21 is manufactured by pulling out a metal rod or the like.
Here, by making the length of the external resin layer 21b longer than the length of the internal resin layer 21a, the internal resin layer 21a does not protrude beyond the external resin layer 21b behind the tube 21.

  According to the present embodiment, when the fixing member 19 is screwed into the second housing 13, the protrusion 41 is formed between the outer casing holding portions 39 where the outer casing 31 is disposed. The rotation of the outer cover 31 can prevent the outer cover 31 from rotating together with the fixing member 19.

  The jacket 31 is compressed between the jacket holding part 39 of the second housing 13 and the inner surface of the fixing member 19, and is pressed against the uneven shape of the jacket holding part 39 to be fixed. For this reason, other members, such as a jacket pressing member for fixing the jacket 31, are unnecessary, and the number of parts can be reduced.

  Further, even when it is necessary to increase the tear length of the outer jacket 31 at the tip end portion of the optical cord 27 for setting to the fusion machine, the torn outer jacket 31 can be covered by using the tube 21. it can.

  Further, since the tube 21 has a two-layer structure and the inner resin layer 21a is made of a relatively hard resin, an operation of attaching the tube 21 to the optical cord 27 becomes easy. Further, the bendability of the optical cord 27 can be improved by the outer resin layer 21b being made of a relatively soft resin.

  As mentioned above, although embodiment of this invention was described referring an accompanying drawing, the technical scope of this invention is not influenced by embodiment mentioned above. It is obvious for those skilled in the art that various modifications or modifications can be conceived within the scope of the technical idea described in the claims, and these are naturally within the technical scope of the present invention. It is understood that it belongs.

  For example, the shape of each part constituting the optical connector 1 is not limited to the illustrated example.

1 ... optical connector 3 ... ferrule 5 ... first housing 9 ... spring 11 ... protective sleeve 13 ... second housing 15 ... knob 19 ... fixing member 21 ... ... Tube 21a ......... Inner resin layer 21b ......... Outer resin layer 21c ......... Intermediate resin layer 25 ......... Built-in optical fiber 27 ......... Optical cord 29 ......... Optical fiber 31 ......... Coat 33 ... ... Strength fiber 37 ... Strength fiber holder 39 ... Outer jacket holder 41 ... Projection

Claims (3)

An optical connector in which a built-in optical fiber held by a ferrule and an optical fiber inside an optical cord are connected,
A housing connected to the ferrule;
A fixing member screwed and connected to the rear of the housing;
Comprising
The outer jacket of the front end of the optical cord is divided along the longitudinal direction, and the front end of the divided outer jacket is disposed on the outer periphery of the rear end portion of the housing. It is sandwiched and fixed with a fixing member,
An optical connector, wherein a protrusion projecting in a radial direction is formed in a circumferential section of a rear end portion of the housing, and the outer cover is disposed at a portion other than the protrusion. A tube is put on the outer periphery of a predetermined length of the optical cord exposed from the fixing member,
2. The optical connector according to claim 1, wherein the tube has a two-layer structure, an inner layer is made of a resin having a relatively high hardness, and an outer layer is made of a resin having a relatively low hardness.   A large-diameter portion is formed at a distal end portion of the tube on the fixing member side, the large-diameter portion is fitted to a reduced-diameter portion of the fixing member, and the tube and the fixing member are connected. The optical connector according to claim 2, wherein:

Images