JP4703446B2 - Optical fiber core wire holding structure of optical connector - Google Patents

Description

  The present invention provides an optical connector capable of easily connecting an optical fiber at a construction site in an unpolished and non-adhered state, in a chuck pin holding hole of a ferrule constituting the optical connector. The present invention relates to an optical fiber core wire holding structure of an optical connector provided with a mechanism capable of correcting a shift in the axial direction of a chuck pin when holding an optical fiber.

  Conventionally, as shown in Patent Document 1, the applicant of the present invention himself can shorten 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. An optical connector that can prevent the optical fiber from being damaged by the rotational force of the screw-type presser cover is provided.

That is, according to the present invention, in an optical connector for connecting two optical fibers together inside a ferrule, a surface facing the optical fiber is a convex arc-shaped holding surface, and the ferrule has a cylindrical frame inside. At least three chuck pins assembled so that one front optical fiber can be inserted, and the front end in the axial direction is a tapered receiving portion so as to come into contact with the provided tapered pressing surface. A ring-shaped tag member that is tightened and wound around the rear end of the chuck pin and a chuck pin that is tightened and wound around the chuck pin so that the holding surfaces of the chuck pins are brought close to each other to give a holding force of the optical fiber. And a presser lid that can be press-fitted into the ferrule so as to hold the tag member.
Japanese Patent Application No. 2005-006606

  However, conventionally, the inside of the chuck pin holding hole of the ferrule has to be as wide as possible so as not to hinder the insertion of the core of the optical fiber. For this reason, even if the three chuck pins are aligned with respect to the axial direction inside the chuck pin holding hole, the optical fiber and the chuck pin come into contact with each other when the optical fiber is inserted. On the other hand, it is unavoidable that the axial displacement occurs. Moreover, at the start of pressing and sliding the tag member to the three chuck pins, it can be easily determined by the time difference between the chuck pins and the start of the contact of the tag members due to the inclination due to the difference in the way the two members fit in the cylindrical frame. There was a risk that axial misalignment would occur between the three chuck pins.

  If the chuck pins are pressed against the tapered pressing surface inside the ferrule tip side while being displaced in the axial direction in this way, when the three chuck pins are moved toward each other, this displaced state remains as it is. Therefore, the core of the optical fiber is sandwiched at a position eccentric from the axial center of the ferrule. For this reason, an axial deviation occurs between the optical fiber insertion hole of the connection sleeve held in the sleeve holder in the front part in the ferrule axial direction, and the optical fiber may be broken in some cases.

  Therefore, the present invention is an improvement on the optical connector shown in Patent Document 1 in view of the conventional circumstances as described above, and the chuck pin is inserted into the chuck pin holding hole when the core wire of the optical fiber is inserted. An optical connector that can hold the optical fiber inside the chuck pin holding hole without causing a shift in the axial direction of the chuck pin while ensuring a space larger than the outer coating diameter of the core wire by moving toward the outer wall side An object of the present invention is to provide an optical fiber core wire holding structure.

  In order to solve the above-described problems, in the present invention, at least three chuck pins assembled so that the optical fiber can be inserted and the assembled chuck pins are brought close to each other to increase the holding force of the optical fiber. A ring-shaped tag member that is tightly wound around the chuck pin to be applied, and a presser cover that can be press-fitted into the ferrule so as to hold the tag member that is tightly wound around the chuck pin. An optical fiber core holding structure for an optical connector, which is fitted around the chuck pins so that the chuck pins are held in a radially expanded position with the chuck pins aligned before insertion of the optical fiber. When the insert is inserted, the holding member is pressed and slid by pushing the presser lid, and the gap between the chuck pins is reduced to release this holding. Kkupin are those having a chuck pin holder shall grip the core of the optical fiber.

  In the above-described configuration, each chuck pin can be held by the chuck pin holder by elastic holding protrusions provided on the inner periphery of the chuck pin holder so as to sandwich and hold both end portions of the chuck pin.

  And the flat part for chuck pin shift | offset | regulation can be provided in the inner back part of the said ferrule so that the front-end part side of the chuck pin pushed inside the ferrule may be latched.

  Further, a flat portion for restricting chuck pin misalignment may be provided on the insertion tip side of the presser lid so that the rear end side of the chuck pin pushed into the ferrule is locked.

  According to the present invention, when inserting the core wire of the optical fiber, the chuck pin is moved toward the outer wall side inside the chuck pin holding hole to secure a space larger than the outer coating diameter of the core wire, and to shift the chuck pin in the axial direction. The optical fiber can be securely held inside the chuck pin holding hole without being generated.

  That is, this is inserted around the chuck pins so that the present invention holds the chuck pins in a state where they are aligned in the radial direction before and after insertion of the optical fiber. This is because the chuck member is provided with a chuck pin holder in which each chuck pin grips the core wire of the optical fiber by releasing the holding by pressing and sliding the holding member by pushing the presser lid and narrowing the interval between the chuck pins. As a result, when the core wire of the optical fiber is inserted, the chuck pin is moved toward the outer wall side inside the chuck pin holding hole, and a space larger than the outer sheath diameter of the core wire can be secured. Therefore, the axial displacement of the chuck pin due to the contact between the inserted optical fiber and the chuck pin can be prevented. In addition, after inserting the optical fiber, by pressing and sliding the tag member by pushing the presser lid, the chuck pins held in a mutually aligned state are removed from the chuck pin holder in the inner diameter direction almost simultaneously. . Therefore, the chuck pin can reliably hold the optical fiber inside the chuck pin holding hole without causing any axial displacement.

  In addition, each chuck pin is held by the chuck pin holder by elastic holding protrusions provided on the inner periphery of the chuck pin holder so as to sandwich and hold both side ends of the chuck pin. The pin can be easily detached from the chuck pin holder.

  And, since the front end side of the chuck pin pushed into the ferrule is locked, a flat portion for regulating the chuck pin misalignment is provided in the inner part of the ferrule so that the inserted optical fiber can be pressed by the chuck pin. Even if the chuck pin is misaligned in the axial direction, the tip of the chuck pin presses against the flat portion, so that it is possible to prevent the chuck pin from deviating in the axial direction beyond a certain level.

  In addition, since the rear end side of the chuck pin that is pushed into the ferrule is locked, a flat portion for regulating the chuck pin misalignment is provided on the insertion tip side of the presser lid, so that the chuck pin holding hole of the inserted optical fiber After gripping with the chuck pin inside, when the presser cover is pushed to the center of the chuck pin, the rear end of the chuck pin will press against the flat part of the presser cover. The misaligned chuck pins can be corrected in the direction in which they are aligned. As described above, the front and rear end portions of the chuck pin are held in contact with the flat portions provided on the ferrule and the presser lid, so that the deviation of the chuck pin in the front-rear direction is reliably eliminated.

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 is an optical connector for connecting two optical fibers in a ferrule so that the optical fibers can be connected at a construction site without polishing and without bonding. 1 and 2, the optical connector 1 includes a ferrule 4 for connecting two optical fibers 2 and 3, a chuck pin 5 housed in the ferrule 4, and a chuck pin 5 respectively. Are held in a radially expanded position in a state where they are aligned with each other, a thin disc-shaped chuck pin holder 12 that is fitted around the chuck pin 5, and a tightening winding at the rear end of the chuck pin 5. The ring-shaped tag member 6 and the presser lid 7 that can be press-fitted into the ferrule 4 are generally configured.

  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). The sleeve holding hole 9a and the chuck pin holding hole 9b for holding these are formed so as to communicate with 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 taper-shaped pressing surface 13 and an annular and pin-shaped flat portion 13a connected to the pressing surface 13 are formed at the tip end of the chuck pin 5 in the chuck pin holding hole 9b. The tapered receiving portion 5a on the tip side of the chuck pin 5 is in contact with the pressing surface 13, and the flat portion 13a is in contact with a later-described abutting portion 5d at the tip of the chuck pin 5. That is, since the receiving portion 5a of the chuck pin 5 has a tapered shape whose diameter gradually decreases toward the tip in the axial direction (left direction in FIG. 1), the pressing surface 13 is formed to have a similar inclined surface. Yes. The flat portion 13a for regulating the chuck pin misalignment is such that the center of the inner surface of the chuck pin 5 is just touched to the optical fiber 2 when the chuck pin 5 completes gripping the optical fiber 2 on the central axis of the cylindrical frame 9. It is formed to have such a positional relationship.

  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 has a holding portion 5c, tapered receiving portions 5a and 5b at both ends of the holding portion 5c, and abutment formed at the front end portion of the receiving portion 5a and the rear end portion of the receiving portion 5b. The portions 5d and 5e are formed. 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 shape of the chuck pin 5 does not limit the present invention. For example, the chuck pin 5 formed in a columnar shape may be employed.

  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, that is, the inner diameter direction, and the convex arc-shaped holding surface 14 becomes the optical fiber 2. The optical fiber 2 is held by the chuck pin 5 by being in contact with the outer surface. At the same time, the abutting portion 5d on the front end side of the chuck pin 5 is brought into contact with the flat portion 13a in the inner portion of the chuck pin holding hole 9b, and the abutting portion 5e on the rear end side of the chuck pin 5 The presser lid 7 is press-fitted into the presser lid 7 and is in contact with a flat portion 7c formed on the insertion tip side.

  As shown in FIG. 5, the chuck pin holder 12 has a large opening 12c at the center of the thin disk disk as compared to the total diameter of the three chuck pins 5 bundled. Bifurcated protrusion-like elastic holding projections 12a are formed at three locations along the inner peripheral edge at intervals of 120 degrees and are opposed to each other while being sandwiched between the pair of circular arc cutout portions 12b. The chuck pin holder 12 is held at a position where the chuck pins 5 are aligned with each other in a radially expanded state by sandwiching both end portions of the chuck pins 5 by the elastic holding protrusions 12a which are separated from each other. It is meant to be At this time, the elastic holding projection 12a itself is easily released from the holding force when the gap between the chuck pins 5 is narrowed by pressing and sliding the tag member 6 by pushing the presser lid 7. It has a certain holding pressure holding force.

  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 tightened and wound around the center portion of the chuck pins 5. The ring-shaped rigid member is formed. 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 via the chuck pin holder 12. Note that the tightening force of the tag member 6 with respect to the three chuck pins 5 is set so as to have a force enough to penetrate the outer sheath 2a of the optical fiber 2 and press the optical fiber itself as shown in FIG. ing.

  The presser lid 7 has an annular projection 7a on the tip side via a flat portion 7c so that the tag member 6 tightened and wound around the chuck pin 5 is held from the rear side while being locked by the locking portion 9c. It has a cylindrical shape 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 pressing into the ferrule 4, for example, a concave annular engaged portion 4 a provided around the ferrule 4, and a convex annular engaging portion 7 b formed on the outer periphery of the presser lid 7 are provided. It is designed to engage.

  Further, the flat portion 7c of the presser lid 7 serves as a relief for pushing the tag member 6 to the center portion of the chuck pin 5, and the depth of the flat portion 7c is set at the inner portion of the chuck pin holding hole 9b. Similar to the positioning of the flat portion 13a, when the optical fiber 2 is held on the central axis, the chuck is shifted to the position just before the abutting portion 5e at the rear end of the chuck pin 5 comes into contact with the rear end side. The dimensions are such that the pins 5 can be pushed so as to be corrected. Accordingly, the chuck pin 5 is sandwiched in the longitudinal direction by the flat portion 13a in the inner portion of the chuck pin holding hole 9b and the flat portion 7c of the presser lid 7, thereby correcting the axial displacement.

Next, the effect | action by this structure is demonstrated.
First, as shown in FIG. 5, both end portions of each chuck pin 5 are clamped by both elastic holding protrusions 12a of the chuck pin holder 12 which are separated from each other, and the three chuck pins 5 are aligned with each other. It is held at a position expanded in the radial direction. Then, the chuck pins 5 assembled with each other in a state where the optical fiber 2 is inserted are pushed into the chuck pin holding holes 9b inside the ferrule 4, and then the tag member 6 is inserted from the rear.

  That is, as shown in FIG. 6, at first, the connector is in a state in which the presser lid 7 is temporarily press-fitted into the cylindrical frame 9 in a state where the optical fiber 2 is not inserted (the rear end flange portion 7a of the presser lid 7 and the cylindrical frame). 9 is a state in which a predetermined gap is held between the rear ends. Then, when the optical fiber 2 is connected, the tip of the optical fiber 2 is processed (the outer portion of the optical fiber that enters the guide sleeve 8 is removed) and inserted from the rear of the ferrule 4 so that the tip of the optical fiber 2 is inside the connection sleeve 10. Optical fiber connection is performed by pressing the presser lid 7 until it is in contact with the end until the rear end collar portion 7a is in contact with the rear end portion of the cylindrical frame 9.

  At this time, as shown in FIG. 1, the presser lid 7 is made to slide and slide the rear end receiving portion 5 b of the chuck pin 5 to the substantially center position by the tag member 6, thereby reducing the interval between the chuck pins 5. Therefore, the chuck pin 5 is detached from the elastic holding projection 12a of the chuck pin holder 12, and the core wire of the optical fiber 2 is gripped. At this time, the chuck pins 5 move toward each other in the direction of the optical fiber 2, that is, the inner diameter direction, and the convex arc-shaped holding surface 14 comes into contact with the outer surface of the optical fiber 2 as shown in FIG. It is held by the pin 5.

  Then, the outer pin 2a of the optical fiber 2 is pierced by the clamping force of the chuck pin 5, and the chuck pin 5 moves in the direction of the tip of the ferrule 4 after pressing the optical fiber strand. 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.

  Then, after the thin cylindrical portion is compressed in the inner diameter direction, the engaging portion 7b 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 held by the annular protrusion 7a. The presser lid 7 is fixed in a state of being held from the rear side. At this time, as shown in FIG. 1, the abutting portion 5d on the front end side of the chuck pin 5 is brought into contact with the flat portion 13a in the inner portion of the chuck pin holding hole 9b, and the abutting portion 5e on the rear end side of the chuck pin 5 is provided. Is brought into contact with a flat portion 7c formed on the insertion tip side of the presser lid 7 to be press-fitted and fitted into the ferrule 4.

  As a result, the chuck pin 5 is sandwiched in the longitudinal direction by both the flat portion 13a in the inner part of the chuck pin holding hole 9b and the flat portion 7c of the presser lid 7, and the axial displacement is corrected.

  In addition, 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, the tapered pressing surface 13 and the receiving portion 5a are Acts to suppress the force of spreading. 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 XX sectional drawing. It is an expanded sectional view around a presser lid. The state of use of the chuck pin holder is shown, (a) is a perspective view of the state where the chuck pin is mounted on the elastic holding projection of the chuck pin holder, and (b) is the state where the chuck pin is mounted on the elastic holding projection of the chuck pin holder. It is a partially cutaway perspective view. It is a perspective view of a partially broken optical connector before connecting the optical fiber core wire.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Optical connector 2 Optical fiber 2a Outer skin 3 Optical fiber 4 Ferrule 4a Engagement part 5 Chuck pin 5a, 5b Reception part 5c Holding part 5d, 5e Abutting part 6 Tag member 7 Presser lid 7a Annular protrusion 7b Engagement part 7c Flat Part 8 Guide sleeve 9 Cylindrical frame 9a Sleeve holding hole 9b Chuck pin holding hole 9c Locking part 10 Connection sleeve 11 Sleeve holder 12 Chuck pin holder 12a Elastic holding projection 12b Arc notch part 12c Opening part 13 Pressing surface 13a Flat part 14 Holding part surface

Claims (4)

  At least three chuck pins that are assembled so that the optical fiber can be inserted, and a ring shape that is tightly wound around the chuck pins so as to apply the holding force of the optical fiber by bringing the assembled chuck pins close to each other An optical fiber core wire holding structure for an optical connector, comprising: a tag member; and 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. Prior to insertion, the chuck pins are fitted and inserted around the chuck pins so as to be held in a radially expanded position with the chuck pins aligned, and when the optical fiber is inserted, the tag member is pressed and slid by pressing the presser lid, By reducing the distance between the chuck pins, this holding is released and each chuck pin grips the core of the optical fiber. Optical fiber core retaining structure of the optical connector, characterized in that includes a chuck pin holder.   2. The optical connector according to claim 1, wherein each chuck pin is held by the chuck pin holder by an elastic holding protrusion provided on an inner periphery of the chuck pin holder so as to hold both side ends of the chuck pin. Fiber core holding structure.   The optical fiber core wire holding structure for an optical connector according to claim 1 or 2, further comprising a flat portion for regulating chuck pin misalignment at a deep portion in the ferrule so that a front end portion side of the chuck pin pushed into the ferrule is locked.   The optical connector light according to any one of claims 1 to 3, wherein a flat portion for restricting chuck pin misalignment is provided on the insertion tip end side of the presser lid so that the rear end portion side of the chuck pin pushed into the ferrule is locked. Fiber core holding structure.

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