JP2005128275A - Optical connector - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To conduct optical fiber connection by an optical connector at a site without making discontinuity of an optical fiber. <P>SOLUTION: In an optical connector 1, connection of optical fibers is conducted by abutting two optical fibers 2 and 3 in a ferrule 4. The optical connector 1 is provided with at least three chuck pints 5 in which opposing surfaces with respect to an optical fiber are made into projected circular-arc shaped holding surfaces 14, both tip parts along an axial direction are made into taper shaped receiving sections 5a and 5b so that the optical fiber 2 is inserted and assembled into, a chuck pin holder 6 in which a taper shaped pressure surface 13, that is arranged inside the ferrule 4 so as to contact one of the receiving section 5a, and a taper shaped operating surface 17, that contacts with the other receiving section 5b, are formed and the chuck pins 5 are held in an assembled condition and arranged in a freely movable manner along the axial direction inside the ferrule 4 and an operating member 7 which is used to move holding surfaces 14 of the assembled chuck pins 5 closer and is used to move the chuck pin holder 6 along the axial direction to add holding force of the optical fibers. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an optical connector capable of easily connecting an optical fiber at a construction site.

  When laying an optical fiber, it is necessary to change the connection state according to the situation at the site. For this reason, optical fibers have been developed for easy on-site connection. Japanese Patent Application Laid-Open No. 9-127371 discloses an optical connector having a structure that can be assembled on site in order to connect optical fibers on site.

  In this optical connector, a semicircular cutout is partially formed in a ferrule having a cylindrical outer shape, and an optical fiber is fixed using a presser having a semicircular outer shape corresponding to the cutout. It is. 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.

To connect the optical fiber, two optical fiber strands are fitted into the fiber fixing recess, the end portions are butted against each other, and the presser is inserted into the notch portion against the butted state of the optical fiber strands. Overlay on the flat surface for fixing. Then, the presser and ferrule in an overlapped state are covered with a ring-shaped clamp made of spring steel or the like and the presser and the ferrule are brought into close contact with each other to fix the connection state of the optical fibers.
JP-A-9-127371

  The glass-based optical fiber has a diameter of about 0.25 mm including the outer sheath, and the strand has a diameter of about 0.125 mm. Therefore, the fixing needs to be performed with an appropriate force. However, in the above-described conventional optical connector, since the optical fiber is pressed by overlapping the fixing flat portion of the ferrule and the flat portion of the presser, an optical fiber is subjected to a pressing force stronger than necessary. Has a problem of disconnection. In addition, since the optical fiber is firmly pressed down, expansion and contraction of the optical fiber in response to temperature changes are suppressed, and excessive internal stress is generated in the optical fiber, and the optical fiber is damaged or destroyed over time. It also has a problem.

  The present invention has been made in consideration of such conventional problems, and can be used to fix the optical fiber with a suitable force when connecting the optical fiber in the field, so that the optical fiber can be cut or damaged. An object of the present invention is to provide an optical connector having a structure that can be prevented.

  In order to achieve the above object, an optical connector according to a first aspect of the present invention is an optical connector for connecting an optical fiber by abutting two optical fibers inside a ferrule, and is a surface facing the optical fiber. Is a convex arc-shaped holding surface and both end portions in the axial direction are tapered receiving portions, at least three chuck pins assembled so that one optical fiber can be inserted, and one A tapered pressing surface provided inside the ferrule so as to be in contact with the receiving portion and a tapered working surface that is in contact with the other receiving portion are formed, and the ferrule is held by holding the chuck pin in an assembled state. The chuck pin holder, which is arranged so as to be movable in the axial direction, and the holding surface of the assembled chuck pin are brought close to each other to give a holding force of the optical fiber. Characterized in that an operating member for moving axially Kupinhoruda.

  In the first aspect of the present invention, the chuck pin holder is moved in the axial direction by operating the operating member in a state where the optical fiber is inserted into the assembled chuck pin. By this movement, the tapered receiving portions at both ends of the chuck pin come into contact with the pressing surface of the ferrule and the working surface of the chuck pin, and the holding surfaces of the chuck pin approach each other. Thereby, since the holding surface of the chuck pin holds the optical fiber from the periphery, the two optical fibers are fixed in a connected state. With such a structure, the optical fiber connection operation can be easily performed on site.

  In this invention, the holding surface of the chuck pin has a convex arc shape, and the holding surfaces of the adjacent chuck pins come into contact with each other, so that the access to the optical fiber more than necessary is restricted. Is done. For this reason, it is possible to prevent disconnection of the optical fiber without pressing the optical fiber more than necessary. Further, since the optical fiber is held with an appropriate force, the optical fiber can be freely expanded and contracted due to a temperature change, and internal stress is not generated. For this reason, the optical fiber is not damaged or broken during use, and stable performance can be maintained for a long time.

  A second aspect of the present invention is the optical connector according to the first aspect, wherein the operation member includes a buffer spring that elastically presses the chuck pin holder.

  In the invention of claim 2, since the axial movement force of the chuck pin holder is reduced by the buffer spring provided on the operation member, the holding force of the optical fiber by the chuck pin can be indirectly reduced. For this reason, an excessive holding force does not act on the optical fiber, and the disconnection of the optical fiber can be more reliably prevented.

  A third aspect of the invention is an optical connector according to the first aspect, wherein a connection sleeve to which the other optical fiber is inserted and fixed in a state where the end of the other optical fiber is exposed, and one optical fiber includes A guide sleeve that is inserted and has an end face that abuts the end face of the connection sleeve to connect the two optical fibers, and the end of one of the optical fibers is recessed from the end face of the corresponding sleeve. The tip of the counterpart optical fiber is abutted against the recess.

  According to the third aspect of the present invention, the end surfaces of the connection sleeves and the end surfaces of the guide sleeves are brought into contact with each other, so that the end portions of the optical fibers disposed in these sleeves are brought into contact with each other for connection. In this invention, the end of one of the optical fibers on the connection sleeve side or the guide sleeve side is recessed, and the end of the optical fiber on the other side is abutted against the indented portion. Heart effects occur. For this reason, it is possible to make a connection with a highly accurate coaxiality.

  A fourth aspect of the present invention is the optical connector according to the third aspect, characterized in that the recess is filled with a matching agent.

  As described above, the matching agent is filled in the hollow portion of the optical fiber so that the light is not scattered. For this reason, an optical signal can be transmitted with good efficiency without connection loss.

  According to the optical connector of the present invention, it is possible not only to easily connect the optical fiber in the field, but also to prevent the optical fiber from being pushed more than necessary, so that the disconnection of the optical fiber can be prevented, In addition, the optical fiber is free from expansion and contraction due to temperature changes, and no internal stress is generated. Therefore, the optical fiber is not damaged or broken, and stable performance can be maintained for a long time. .

  1 to 8 show an embodiment of the present invention, FIG. 1 is an exploded perspective view of an optical connector, FIG. 2 is a partially broken perspective view showing the inside of an optical fiber connection state, and FIG. 4 is a half-sectional view of the connection state, FIG. 5 is a front view of the chuck pin, FIG. 6 is an exploded perspective view of a portion for connecting the optical fiber, and FIG. 7 is a cross-sectional view showing the end surface treatment to the connection sleeve. 8 is a cross-sectional view showing a connection state of optical fibers.

  As shown in FIGS. 1 to 4, the optical connector 1 according to this embodiment includes a ferrule 4 that connects two optical fibers 2 and 3, a plurality of chuck pins 5 and chucks disposed in the ferrule 4. A pin holder 6 and a presser lid 7 as an operation member are provided.

  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, the chuck pin holder 6, the presser lid 7, and the buffer spring 18 described later. An optical fiber through hole is formed in all the constituent members in the axial direction.

  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 holder 6 at the rear part (right part). A sleeve holding hole 9a and a holder holding hole 9b for holding these are formed at corresponding positions.

  The holder holding hole 9b has a cylindrical shape matching the outer shape of the chuck pin holder 6 and extends in the axial direction. A pressing surface 13 is formed at an insertion tip portion of the chuck pin holder 6 in the holder holding hole 9b. The pressing surface 13 is in contact with a tapered receiving portion 5a on the distal end side of the chuck pin 5 described later, and therefore has a tapered shape corresponding to the receiving portion 5a. That is, since the receiving portion 5a 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 also formed to have the same inclination.

  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. It should be noted that at least three chuck pins 5 may be used, or more. 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.

  The holding unit 5 c holds the optical fiber 2 in cooperation with the holding unit 5 c of the other chuck pin 5. FIG. 5 shows the front surface of the holding portion 5 c of the chuck pin 5. A holding surface 14 is formed on each of the holding portions 5 c of the three chuck pins 5. The holding surface 14 faces the optical fiber 2 to be held, and is a convex arcuate curved surface that protrudes toward the 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. Contact. As a result, the optical fiber 2 is held by the chuck pin 5. As shown in FIG. 3, the optical fiber 2 is held by the chuck pin 5 in a state in which the outer strand 2b is covered with the fiber strand 2a.

  The radius of curvature R1 of the holding surface 14 of the chuck pin 5 is larger than the radius R2 of the optical fiber 2, and the holding surface 14 comes into contact with the optical fiber 2 when the chuck pins 5 approach and the holding surface 14 comes into contact with each other. The diameter is set so as to be in contact with the outer surface. By setting the radius of curvature R1 of the holding surface 14 to have such a diameter, the holding surfaces 14 of the adjacent chuck pins 5 come into contact with each other and at the same time, the optical fiber 2 is held at the center of each holding surface 14. Can be done.

  The variation in the radius of curvature R1 of the holding surface 14 in the chuck pin 5 can be about 15.5% (R2≈0.155 × R1) of the radius R2 of the optical fiber 2. In such a variation, since the machining accuracy of the chuck pin 5 is not so required, there is an advantage that the mass productivity is improved.

  In this embodiment, as shown in FIG. 5, the holding portion 5 c in each chuck pin 5 is not only the surface facing the optical fiber 2 (holding surface 14), but also the non-facing surface 15 is substantially the same as the holding surface 14. It is formed in a convex arcuate curved surface having the same curvature. That is, the holding portion 5c of the chuck pin 5 is formed so that both the inner and outer surfaces are convex arcuate curved surfaces that protrude outward. In this way, by making the inner and outer surfaces of the holding portion 5c have convex arcuate curved surfaces with substantially the same curvature, it is not necessary to consider the directionality when the chuck pin 5 is assembled, and the chuck pin 5 can be easily assembled. Can be done.

  The receiving portions 5 a and 5 b formed at both ends of the holding portion 14, that is, at both ends in the axial direction of the chuck pin 5, have a tapered shape whose diameter gradually decreases along the axial direction of the chuck pin 5. By making the receiving portions 5a and 5b have such a tapered shape, the chuck pins 5 can be moved in the approaching direction via the receiving portions 5a and 5b, as will be described later.

  The chuck pin holder 6 holds the above chuck pin 5 in the assembled state shown in FIG. 5, and for this reason, a pin hole 6a into which the chuck pin 5 is inserted in the assembled state is formed in the axial direction. . An action surface 17 is continuously provided at the insertion direction end portion (right end portion in FIG. 1) of the pin hole 6a. The working surface 17 corresponds to one receiving portion 5 b of the chuck pin 5, and for this reason, the working surface 17 is formed in a tapered shape whose diameter gradually decreases as the distance from the chuck pin 5 increases.

  When the working surface 17 of the chuck pin holder 6 and the pressing surface 13 of the cylindrical frame 9 are in contact with the receiving portions 5b and 5a at both ends of the chuck pin 5, the assembled chuck pin 5 is moved in the radial direction. It is possible to move in the direction of mutual approach along.

  The presser lid 7 as an operation member is attached by being inserted into the cylindrical frame 9 from the rear side of the chuck pin holder 6 after the chuck pin holder 6 is inserted into the cylindrical frame 9. In this embodiment, a buffer spring 18 is inserted between the presser lid 7 and the chuck pin holder 6.

  The presser lid 7 has a threaded portion (male threaded portion) 7a formed on the outer surface on the cylindrical frame 9 side, and is screwed with a threaded portion (female threaded portion) 9c formed on the corresponding inner surface of the tubular frame 9. It is fixed to the cylindrical frame 9. During the screwing, the presser lid 7 moves in the direction of the chuck pin holder 6. By this movement, the chuck pin holder 6 moves in the cylindrical frame 9 in the direction of the chuck pin 5 along the axial direction.

  Due to the movement of the chuck pin holder 6, the working surface 17 of the holder 9 comes into contact with the receiving portions 5 b of the respective chuck pins 5, and the chuck pins 5 are moved in the same direction by this contact. By this movement, the receiving portions 5 a of the respective chuck pins 5 come into contact with the pressing surface 13 of the cylindrical frame 9. Accordingly, the tapered receiving portions 5a and 5b at both ends in the axial direction are pressed by the pressing surface 13 of the cylindrical frame 9 and the action surface 17 of the chuck pin holder 6, so that the assembled chuck pin 5 is along the radial direction. Approach each other. By this approach, the holding surface 14 of the holding portion 5c of the chuck pin 5 comes into contact with the periphery of the optical fiber 2 from three directions, so that the optical fiber 2 can be held and the optical fiber 2 can be fixed. By fixing the optical fiber 2, the two optical fibers 2 and 3 are brought into contact with each other as described later, and the connection of the two optical fibers 2 and 3 is completed.

  In such a structure, it is only necessary to rotate the presser lid 7 while the optical fiber 2 is inserted, and the optical fibers 2 and 3 can be easily connected in the field.

  When the chuck pins 5 that hold the optical fiber 2 are close to each other, the holding surface 14 of one chuck pin 5 comes into contact with the holding surface 14 of the adjacent chuck pin 5 to prevent further approach. . For this reason, the optical fiber 2 is not pressed down more than necessary, and disconnection of the optical fiber due to pressing down more than necessary can be prevented.

  Further, since the optical fiber 2 can be held with an appropriate force, the optical fiber can be freely expanded and contracted due to a temperature change, and internal stress is not generated in the optical fiber 2. For this reason, the optical fiber is not damaged or broken during use, and stable performance can be maintained for a long time.

  The buffer spring 18 is configured by overlapping a plurality of disc springs along the axial direction. The buffer spring 18 is disposed between the presser lid 7 and the chuck pin holder 6, and acts to elastically relieve the pressing force applied to the chuck pin holder 6 by the presser lid 7. By providing the buffer spring 18 in this way, the moving force in the axial direction of the chuck pin holder 6 is reduced, so that the pressing force applied to the chuck pin 5 by the chuck pin holder 6 can be indirectly reduced. As a result, the holding force of the optical fiber 2 by the chuck pin 5 can be relaxed, an excessive holding force does not act on the optical fiber 2, and disconnection of the optical fiber 2 and the like can be more reliably prevented. Can do.

  The buffer spring 18 also acts to make the holding force of the optical fiber 2 held by the chuck pins 5 uniform. For this reason, the optical fiber 2 can be held without holding force unevenly distributed, and disconnection of the optical fiber 2 caused by uneven holding force can be prevented. Furthermore, even if the pressing force applied to the optical fiber 2 due to the difference in thermal expansion coefficient between the optical fiber 2 and the chuck pin 5 changes due to relaxation and equalization of the holding force by the buffer spring 18 described above, this change is absorbed. The good holding state of the optical fiber 2 can be continued.

  Next, the fiber strand 2a of one optical fiber 2 is inserted and held in the guide sleeve 8, and the fiber strand 3a of the other optical fiber 3 is inserted and held in the connection sleeve 10 ( (See FIG. 3). The opposed end surfaces of the guide sleeve 8 and the connecting sleeve 10 are abutted in the sleeve holder 11 so that the end surfaces of the optical fibers 2 and 3 are abutted with each other, and the optical fibers are connected. Prior to the connection, one of the optical fibers 2 is in a state where the outer skin 2b portion is held by the chuck pin 5 as described above.

  In order to match the guide sleeve 8 and the connection sleeve 10 with high accuracy, the sleeves 8 and 10 have the same outer diameter, and an optical fiber through hole having the same diameter is formed in the center portion. . The sleeve holder 11 has a cylindrical holder portion 11a into which the sleeves 8 and 10 are press-fitted. The holder portion 11a holds the sleeves 8 and 10 so that they are coaxial. For this reason, the inner surface of the holder part 11a is finished with high accuracy.

  FIG. 8 shows a state in which the two optical fibers 2 and 3 are connected by a butt. The optical fibers 2 and 3 are abutted by abutting the end surfaces of the guide sleeve 8 and the connection sleeve 10 press-fitted into the sleeve holder 11. Prior to the butting, the end surfaces of the guide sleeve 8 and the connection sleeve 10 are polished by PC polishing or the like.

  In this embodiment, the end portion of the fiber strand 3a on the connection sleeve 10 side is recessed from the end surface 10a of the sleeve 10, whereby a recess portion 21 is formed as shown in FIG. On the other hand, the optical fibers 2 and 3 are connected by the fiber strand 2a of the optical fiber 2 on the guide sleeve 8 side being abutted against the recess 21 (see FIG. 8). Since the fiber strands 2a and 3a are aligned with each other by the butting to the hollow portion 21, the fiber strands 2a and 3a can be butted with high precision coaxiality, and there is no light loss. The fibers 2 and 3 can be connected.

  Furthermore, in this embodiment, as shown in FIG. 8, the matching agent 23 is filled in the hollow portion 21 formed in the fiber strand 3a. Filling of the matching agent 23 can be easily performed by applying the matching agent 23 to the recess 21 before the fiber strands 2a and 3a are butted together. By filling such a matching agent 23, it is possible to transmit the fiber strands 2a and 3a without scattering light, so that it is possible to transmit an optical signal with good efficiency without connection loss.

  The depression 21 can be easily formed by buffing the end surface 10a of the connection sleeve 10 on the abutting side. That is, the optical fiber is made of glass, whereas the connection sleeve 10 is made of ceramics or the like harder than glass. Therefore, the end face 10a of the connection sleeve 10 is buffed to give priority to the optical fiber. This is because the hollow portion 21 can be formed by polishing. Thereby, while being able to form the hollow part 21 on the spot easily, the formation can be performed in a short time.

  FIG. 9 shows another embodiment of the present invention, and the same members as those in the above-described embodiment are given the same reference numerals and correspond to each other.

  In this embodiment, a coil spring 25 is used as a buffer spring. The coil spring 25 is disposed between the presser lid 7 and the chuck pin holder 6. A cylindrical cover portion 7 b extending in the axial direction is formed at the end of the presser lid 7, and the coil spring is formed. 25 is accommodated inside the cover portion 7b. The chuck pin holder 6 has a contact piece 6d with which the end of the coil spring 25 abuts extending along the radial direction. In order to enable the chuck pin holder 6 to move in the axial direction, the cylindrical frame 9 is formed with a slit 9d through which the contact piece 6d is extracted. In such a structure, since the spring force can be applied to the chuck pin holder 6 by the coil spring 25 coming into contact with the contact piece 6d, the same buffering action as the disc spring shown in FIGS. It is possible to do.

  By using such a coil spring 25 as a buffer spring, the buffer spring can be arranged in the radial direction, so that the axial length of the optical connector 1 can be shortened accordingly, and operability in the field is improved. Will improve.

It is a disassembled perspective view of the optical connector in one embodiment of this invention. It is a partially broken perspective view of the ferrule which shows the fixed state of an optical fiber. It is a fractured perspective view showing the inside of the optical connector. It is a half-cut sectional view showing the inside of an optical connector. It is a front view which shows the effect | action of a chuck pin. It is a disassembled perspective view which shows a connection sleeve and a guide sleeve. It is sectional drawing which shows the end surface part of a connection sleeve. It is sectional drawing which shows the state which faced and connected two optical fibers. It is a half-cut sectional view showing another embodiment of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Optical connector 2, 3 Optical fiber 4 Ferrule 5 Chuck pin 5a, 5b Chuck pin receiving part 5c Holding part 6 Chuck pin holder 7 Pressing lid 8 Guide sleeve 9 Cylindrical frame 10 Connection sleeve 11 Sleeve holder 13 Pressing surface 17 Working surface 18 Buffer spring

Claims (4)

An optical connector for connecting optical fibers by abutting two optical fibers inside a ferrule,
The surface facing the optical fiber is a convex arc-shaped holding surface, and both end portions in the axial direction are tapered receiving portions, and is assembled so that one of the optical fibers can be inserted. A chuck pin, a tapered pressing surface provided inside the ferrule so as to be in contact with one receiving portion, and a tapered working surface that is in contact with the other receiving portion. A chuck pin holder that is held in an assembled state and is disposed so as to be movable in the axial direction inside the ferrule and a chuck pin holder for holding the optical fiber holding force by bringing the holding surfaces of the assembled chuck pins close to each other. An optical connector comprising an operation member that moves the shaft in the axial direction.   The optical connector according to claim 1, wherein the operation member includes a buffer spring that elastically presses the chuck pin holder.   A connection sleeve in which the other optical fiber is inserted and fixed in a state where the end of the other optical fiber is exposed, and one optical fiber is inserted, and an end face is used to connect the two optical fibers. A guide sleeve abutted against the end surface of the connection sleeve, and the end of one of the optical fibers is recessed from the end surface of the corresponding sleeve, and the tip of the counterpart optical fiber abuts against the recess The optical connector according to claim 1, wherein the optical connector is provided. The optical connector according to claim 3, wherein the recess is filled with a matching agent.

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