JP4324564B2 - Optical connector - Google Patents

Description

  The present invention relates to an optical connector that can easily connect an optical fiber at a construction site without polishing and without bonding.

  Conventionally, as an optical connector having a structure in which the connection state of optical fibers can be changed according to the situation in the field, for example, as disclosed in Patent Document 1, a semicircular shape is formed on a cylindrical ferrule. There is provided a technique for fixing an optical fiber by using a presser having a cutout portion partially formed and a semicircular outer shape corresponding to the cutout portion. At this time, the portion of the ferrule corresponding to the notch is a fixing flat portion, and a fiber fixing concave portion is formed in the fixing flat portion in the axial direction. Then, when connecting the optical fibers, the two optical fiber strands are fitted into the fiber fixing recesses, the ends thereof are butted against each other, and the presser is inserted into the notch for this state. After being overlapped with the part, the presser and the ferrule are covered with a ring-shaped clamp and brought into close contact with each other, thereby fixing the connection state of the optical fiber.

  However, in the conventional optical connector, the flat part for fixing the ferrule and the flat part of the presser are overlapped to press the optical fiber, so that the diameter including the outer skin is about 0.25 mm and the diameter of the strand is 0. In the case of a glass-based optical fiber having a thickness of about 125 mm, there has been a problem that a pressing force stronger than necessary acts and breaks. Moreover, since the optical fiber is firmly pressed down, expansion and contraction of the optical fiber in response to temperature changes is suppressed, and excessive internal stress is generated in the optical fiber, and the optical fiber can be damaged or destroyed over time. Also had problems to do.

In order to solve these problems, the applicant himself proposed an optical connector as disclosed in Patent Document 2. That is, an optical connector that connects two optical fibers by connecting them inside a ferrule, and a surface facing the optical fiber is a convex arc-shaped holding surface and both end portions in the axial direction are tapered. A receiving portion, at least three chuck pins assembled so that one optical fiber can be inserted, and a tapered pressing surface provided inside the ferrule so as to come into contact with one receiving portion; A tapered working surface that is in contact with the other receiving portion is formed, and the chuck pin is held in the assembled state so as to be movable in the axial direction inside the ferrule, and the chuck pin is held. A dish that elastically presses the chuck pin holder to move the chuck pin holder in the axial direction so that the surfaces are brought close to each other to provide a holding force of the optical fiber. Those comprising an operating member having a root-like plurality of buffer springs.
JP-A-9-127371 Japanese Patent Application No. 2003-364115

  However, conventionally, in order to secure the optical fiber fixing and holding force, it is necessary to make the length of the chuck pin sufficiently large, and the force for pressing the chuck pin against the optical fiber corresponds to the length of the chuck pin. It was necessary to set appropriately. For example, in order to shorten the overall length of the chuck pin as much as possible, it is necessary to increase the force of pressing the chuck pin against the optical fiber. However, in an optical connector having a conventional structure, there is no method other than increasing the number of disc spring-shaped buffer springs to increase the elastic force by increasing the force pressed against the optical fiber.

  In addition, since the conventional operation member is formed by a screw-in type presser cover, during the pressing operation of the optical fiber, the rotational force of the presser cover is transmitted to the chuck pin holder through the buffer spring, and further, the working surface of the chuck pin holder Due to the pressure contact with the chuck pin receiving portion, the rotational force is transmitted to the chuck pin itself, which may damage the optical fiber.

  Therefore, the present invention has been made in view of the conventional problems as described above, and it is possible to reduce the length of the holding portion of the optical fiber as much as possible while maintaining the strengthening of the holding force of the optical fiber. In addition, an object of the present invention is to provide an optical connector capable of avoiding the optical fiber from being damaged by the rotational force of the conventional screw-in type presser lid.

  In order to solve the above-described problem, in the present invention, an optical connector that connects two optical fibers by abutting the inside of a ferrule, and a surface facing the optical fiber is a convex arc-shaped holding surface and The front end in the axial direction is a tapered receiving portion so as to come into contact with the tapered pressing surface provided inside the ferrule, and is assembled so that one of the optical fibers can be inserted. Three chuck pins and a ring-shaped tag member that is tightly wound around the rear end portion of the chuck pins to bring the holding surfaces of the assembled chuck pins close to each other and to give a holding force of the optical fiber; A presser lid that can be press-fitted into the ferrule so as to hold the tag member that is tightly wound around the chuck pin is provided.

  The presser lid is formed by a thin cylindrical portion that can be compressed in the inner diameter direction by press-fitting and pushing into the ferrule. After press-fitting, the presser lid is engaged with the engaged portion that is provided around the ferrule. An engagement part may be formed on the outer periphery of the lid.

  In the optical connector according to the present invention configured as described above, a tag member is inserted into the ferrule in advance, and is assembled to each other with the optical fiber inserted from the rear end of the ferrule to the tag member. When the chuck pin is pushed in, the chuck pin moves toward the tip of the ferrule after the optical fiber is completely pressed by the tag member.

  At this time, since the front end portion of the chuck pin in the axial direction is a tapered receiving portion so as to come into contact with the tapered pressing surface provided inside the ferrule, an excessive amount of movement of the chuck pin itself is prevented. Will be. In addition, the taper-shaped pressing surface and the receiving portion each generate the maximum tightening force of the tag member after the chuck pin is pressed and moved in the distal direction.

  Further, when the tag member is inserted into the rear portion of the chuck pin, a force is generated to spread the tip side of the chuck pin, and each of the tapered pressing surface and the receiving portion has such a force to spread. It acts to hold down.

  In addition, the presser lid is a tag member by engaging the engaging portion on the outer periphery of the presser lid with the engaged portion inside the ferrule after the thin cylindrical portion is compressed in the inner diameter direction by press-fitting and pushing into the ferrule. The presser lid is fixed in a state where is held from the rear side. In addition, when the presser lid is forcibly pulled out from the ferrule, the thin cylindrical portion is compressed in the inner diameter direction, the engaging portion on the outer periphery of the presser lid is released from the engaged portion inside the ferrule, and the presser lid is removed.

  According to the present invention, it is possible to reduce the length of the holding portion of the optical fiber as much as possible while maintaining the strengthening of the holding force of the optical fiber, and to the optical fiber by the rotational force of the screw-type holding lid as in the prior art. Can be avoided.

  That is, this is because the present invention has a convex arc-shaped holding surface facing the optical fiber and a tapered front end in the axial direction so as to come into contact with the tapered pressing surface provided inside the ferrule. The holding portion of the assembled chuck pin and the holding surface of the assembled chuck pin are brought close to each other to give a holding force of the optical fiber. Therefore, a ring-shaped tag member that is fastened and wound around the rear end of the chuck pin, and a presser cover that can be press-fitted into the ferrule so as to hold the tag member fastened and wound on the chuck pin. As a result, the maximum tightening force of the tag member is generated after the chuck pin is fully moved in the distal direction while pressing down the chuck pin, and the amount of movement of the chuck pin itself In addition to being small, it can also be expected to reduce the abutting force of the optical fiber, prevent it from breaking against the end face of the optical fiber in field construction, and maintain the strengthening of the optical fiber holding force. However, the length of the holding portion of the optical fiber can be shortened as much as possible.

  The presser lid is formed by a thin cylindrical portion that can be compressed in the inner diameter direction by press-fitting and pushing into the ferrule. After press-fitting, the presser lid is engaged with the engaged portion that is provided around the ferrule. Since the engaging portion is formed on the outer periphery of the lid, it is possible to easily avoid the optical fiber from being damaged by the rotational force of the conventional screw-type presser lid.

  The best mode for carrying out the present invention will be described below with reference to the drawings. Reference numeral 1 shown in the drawing indicates that an optical fiber is connected at a construction site without being polished or bonded. And an optical connector for abutting and connecting two optical fibers inside the ferrule, as shown in FIGS. 1 and 2, a ferrule 4 for connecting the two optical fibers 2 and 3, and a ferrule. 4, a chuck pin 5 housed in the chuck 4, a ring-shaped tag member 6 that is fastened and wound around the rear end of the chuck pin 5, and a presser lid 7 that can be press-fitted into the ferrule 4. ing.

  The ferrule 4 includes a guide sleeve 8, a cylindrical frame 9, a connection sleeve 10, and a sleeve holder 11 that holds the guide sleeve 8 and the connection sleeve 10 coaxially. The corresponding optical fiber 2 or 3 penetrates through these members constituting the ferrule 4 and the chuck pin 5 and the presser lid 7. For this reason, optical fiber through holes are axially provided in all of these constituent members. Is formed.

  The cylindrical frame 9 has a cylindrical outer shape, and holds the guide sleeve 8 at the front part (left part) in the axial direction and holds the chuck pin 5 at the rear part (right part). A sleeve holding hole 9a and a chuck pin holding hole 9b for holding these are formed at corresponding positions.

  The chuck pin holding hole 9b has a cylindrical shape matching the outer shape of the chuck pin 5 and extends in the axial direction. A tapered pressing surface 13 is formed at the insertion tip portion of the chuck pin 5 in the chuck pin holding hole 9b, and is in contact with the tapered receiving portion 5a on the tip side of the chuck pin 5. That is, since the receiving portion 5a has a tapered shape whose diameter gradually decreases toward the axial front end (left direction in FIG. 1), the pressing surface 13 is also formed to have a similar inclined surface.

  The chuck pin 5 holds and fixes one optical fiber 2 in the cylindrical frame 9 (ferrule 4). The chuck pin 5 has a horizontally long shape extending in the axial direction, and three of the chuck pins 5 are used in an assembled state when the optical fiber 2 is held. That is, the chuck pin 5 comes into contact with the optical fiber 2 from three surrounding directions to hold it.

  Each chuck pin 5 is formed by a holding portion 5c and receiving portions 5a and 5b at both ends of the holding portion 5c. As shown in FIG. 3, the holding portion 5 c holds the optical fiber 2 in cooperation with the holding portions 5 c of the other chuck pins 5. That is, the holding portions 5 c of the three chuck pins 5 are each formed with a holding surface 14 that is a convex arcuate curved surface that protrudes toward the opposing optical fiber 2. The optical fiber 2 is inserted into the assembled three chuck pins 5, and in this inserted state, the chuck pin 5 moves in the direction of the optical fiber 2 so that the convex arc-shaped holding surface 14 is in contact with the outer surface of the optical fiber 2. The optical fiber 2 is held by the chuck pin 5 by contacting from three directions.

  The tag member 6 is for applying the holding force of the optical fiber 2 by bringing the holding surfaces 14 of the three chuck pins 5 close to each other, and is fastened and wound around the rear end portion of the chuck pins 5. It is formed by a ring-shaped rigid member. A step-shaped locking portion 9 c is formed along the inner periphery of the ferrule 4 so that the tag member 6 is locked and fixed inside the ferrule 4.

  The presser lid 7 has a cylindrical shape with an annular protrusion 7a on the tip side so that the tag member 6 fastened and wound around the chuck pin 5 is held from the rear side while being locked by the locking portion 9c. And can be press-fitted into the ferrule 4. As shown in FIG. 4, the presser lid 7 becomes a thin cylindrical portion by, for example, increasing the diameter of the through hole of the optical fiber so that it can be compressed by being pressed inwardly into the ferrule 4 and can be compressed. After the press-fitting and pushing into the ferrule 4, for example, a concave annular engaged portion 4 a provided around the ferrule 4, for example, a convex annular engaging portion 7 b formed on the outer periphery of the presser lid 7. Are engaged.

  Next, the operation of this configuration will be described. A tag member 6 is inserted in advance into the ferrule 4 and assembled to the tag member 5 from the rear end of the ferrule 4 with the optical fiber 2 inserted therethrough. The chuck pin 5 is pushed.

  At this time, the chuck pin 5 moves toward the tip of the ferrule 4 after the optical fiber 2 is completely pressed by the tag member 5. Due to this movement, the tapered pressing surface 13 provided in the ferrule 4 and the tapered receiving portion 5a at the front end in the axial direction of the chuck pin 5 come into contact with each other. In addition to being blocked, the taper-shaped pressing surface 13 and the receiving portion 5a generate the maximum tightening force of the tag member 6 after the chuck pin 5 is pressed and moved in the distal direction. Furthermore, when the tag member 6 is fitted into the rear portion of the chuck pin 5, a force is generated to cause the tip side of the chuck pin 5 to spread. However, each of the tapered pressing surface 13 and the receiving portion 5a is Acts to suppress the force of spreading.

  A presser lid 7 inserted in advance into the optical fiber 2 is pushed in and attached by press-fitting from the rear opening side of the ferrule 4. At this time, after the thin cylindrical portion is compressed in the inner diameter direction, the engaging portion 7a on the outer periphery of the presser lid 7 is engaged with the engaged portion 4a inside the ferrule 4, so that the tag member 6 is moved by the annular protrusion 7a. Thus, the presser lid 7 is fixed while being held from the rear side. When the presser lid 7 is forcibly pulled out from the ferrule 4, the thin cylindrical portion is compressed in the inner diameter direction, and the engaging portion 7 b on the outer periphery of the presser lid 7 is released from the engaged portion 4 a inside the ferrule 4. 7 is easily removed.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a partially broken perspective view of an optical connector showing a state where optical fiber core wires are connected in the best mode for carrying out the present invention. It is a disassembled perspective view of an optical connector similarly. In FIG. 1, it is explanatory drawing of a XX cross section. It is an expanded sectional view around a presser lid.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Optical connector 2, 3 Optical fiber 4 Ferrule 4a Engagement part 5 Chuck pins 5a, 5b Reception part 5c Holding part 6 Tag member 7 Presser lid 7a Annular protrusion 7b Engagement part 8 Guide sleeve 9 Cylindrical frame 9a Sleeve holding hole 9b Chuck pin holding hole 9c Locking portion 10 Connection sleeve 11 Sleeve holder 13 Pressing surface 14 Holding surface

Claims (2)

  An optical connector for connecting two optical fibers by abutting two optical fibers inside the ferrule, wherein the surface facing the optical fiber is a convex arc-shaped holding surface and a tapered pressing provided in the ferrule The front end in the axial direction is a tapered receiving portion so as to come into contact with the surface, and at least three chuck pins assembled so that one optical fiber can be inserted, and a holding surface of the assembled chuck pin A ring-shaped tag member that is tightly wound around the rear end of the chuck pin and a tag member that is tightly wound around the chuck pin are held so as to be close to each other and give a holding force of the optical fiber. An optical connector comprising a presser lid that can be press-fitted into the ferrule. The presser lid is formed by a thin cylindrical part that can be compressed in the inner diameter direction by press-fitting and pushing into the ferrule. The optical connector according to claim 1, wherein an engaging portion is formed on the optical connector.

Images