JP2012220798A - Optical fiber terminal, optical fiber cable with terminal, optical connector, and optical fiber cable with connector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical fiber terminal, an optical fiber cable with the terminal, an optical connector, and an optical fiber cable with the connector, that are capable of realizing an optical connector which is resistant to vibration and shock.SOLUTION: An optical fiber terminal is attached to a tip of an optical fiber cable which includes: an optical fiber element wire that is an optical fiber coated with element wire coating; a tensile strength body disposed along a longitudinal direction of the optical fiber element wire; and a coating part for coating the optical fiber element wire and the tensile strength body. The optical fiber terminal includes: a cylindrical body into which the optical fiber element wire is inserted and around which the tensile strength body is mounted on an outer periphery; and a tensile strength body fixing member for fixing the tensile strength body to the cylindrical body. A flange is formed on the cylindrical body along the outer periphery. The tensile strength body fixing member is fitted to at least a part of the cylindrical body including the flange through the tensile strength body while the fitting portion is caulked to fix the tensile strength body to the cylindrical body and to lock the tensile strength body to the flange.

Description

  The present invention relates to an optical fiber terminal, an optical fiber cable with a terminal, an optical connector, and an optical fiber cable with a connector.

  With the increase in the amount of communication information such as control signals, image signals, and audio signals in vehicles in recent years, optical fiber cables are used instead of conventional metal cables in transmission lines used for transmitting information signals. (See Patent Documents 1 and 2). The optical fiber cable is a signal transmission path suitable for high-speed and large-capacity information communication because there is no problem of releasing noise to the surroundings by increasing the communication speed unlike a metal cable.

  The optical fiber cable has an optical connector at its end. The optical connector includes a terminal (optical fiber terminal) having a ferrule attached to the tip of an optical fiber cable, and a housing having a structure for holding the optical fiber terminal and connecting to another optical connector or the like. Yes. On the other hand, an optical connector is also provided in a device that performs communication, and an optical fiber cable and a device that performs communication can be connected by connecting the optical connectors to each other. The connection between the optical fiber cables is also realized by the optical connector. The connection between optical fiber cables is called a Wire to Wire connection.

  In a conventional optical connector, a back body having a locking portion for locking the stop ring is joined to the rear end of the ferrule, and the back body is connected to the stop ring via a spring. Some have a structure in which a stop ring and a back body are locked by a locking portion while being inserted (see Patent Document 3).

JP 2002-107573 A Japanese Patent No. 381396 Japanese Patent Laid-Open No. 11-218642

  By the way, when applying an optical fiber cable to the wire harness in a vehicle, the apparatus which communicates by a wire harness is arrange | positioned at each structural unit of vehicles, such as a roof part, a floor part, an engine periphery, an instrument panel periphery. Therefore, in the wire harness that connects communication devices arranged in each structural unit, especially the optical connector used for wire-to-wire connection is used in the assembly process, assembly process, inspection and maintenance, etc. during vehicle manufacturing. In some cases, the attachment and detachment is repeated many times, and at that time, a strong impact such as pulling may be applied. In addition, the optical connector is also subjected to vibration, impact, etc. when the vehicle is running. Therefore, particularly optical connectors used in vehicles are required to be resistant to vibration and impact.

  The present invention has been made in view of the above, and an object thereof is to provide an optical fiber terminal, an optical fiber cable with a terminal, an optical connector, and an optical fiber cable with a connector that can realize an optical connector that is resistant to vibration and impact. And

  In order to solve the above-described problems and achieve the object, an optical fiber terminal according to the present invention is arranged along an optical fiber strand in which an optical fiber is coated with a strand, and a longitudinal direction of the optical fiber strand. An optical fiber terminal attached to the tip of an optical fiber cable having a tensile strength member, and an optical fiber cable and a covering portion that covers the tensile strength material, the optical fiber wire being inserted through and the tensile strength member And a tensile strength fixing member that fixes the tensile strength body to the cylindrical body, and a flange is formed along the outer periphery of the cylindrical body, and the tensile strength fixing member is Fitting at least a part of the cylindrical body including the flange through the tensile strength body, and crimping the fitting portion to fix the tensile strength body to the cylindrical body and engage the flange. The features.

  In the optical fiber terminal according to the present invention as set forth in the invention described above, the cylindrical body has the flange at an end portion on the insertion entrance side of the optical fiber.

  Moreover, the optical fiber terminal according to the present invention is characterized in that, in the above invention, the cylindrical body has a protrusion having a protrusion height lower than that of the flange.

  Further, in the optical fiber terminal according to the present invention, in the above invention, the cylindrical body includes an insertion hole for inserting and fixing the optical fiber strand, and a tip surface of the optical fiber inserted through the insertion hole. A ferrule having an exposed front end surface and a pedestal portion for placing the strength member on an end opposite to the front end surface, wherein the flange is formed on the pedestal portion. To do.

  In the optical fiber terminal according to the present invention, in the above invention, the strength member is made of resin fiber, and the strength member fixing member is fitted to at least a part of the pedestal portion including the flange. The tensile strength body on the pedestal portion is caulked together with the mating portion.

  Moreover, the optical fiber terminal according to the present invention is the optical fiber terminal according to the above invention, wherein the ferrule includes an optical fiber fixing member having a groove for gripping the optical fiber, and the side surface is inserted through the optical fiber terminal. An opening hole having a depth at least exposing the optical fiber is formed, the optical fiber fixing member is inserted into the opening hole of the ferrule, and the inserted optical fiber is gripped by the groove. To fix the inserted optical fiber.

  Further, in the optical fiber terminal according to the present invention, in the above invention, the cylindrical body is formed on an insertion hole side for inserting the optical fiber strand and an insertion entrance side of the optical fiber strand in the insertion hole. And a stop ring having a pedestal portion on which the strength member is placed, wherein the flange is formed on the pedestal portion.

  An optical fiber cable with a terminal according to the present invention includes an optical fiber coated with an optical fiber covered with a strand, a tensile body disposed along a longitudinal direction of the optical fiber, and the optical fiber An optical fiber cable having a wire and a covering portion that covers the strength member, and the optical fiber terminal according to any one of the inventions attached to a tip of the optical fiber cable. To do.

  An optical connector according to the present invention includes the optical fiber terminal according to any one of the above inventions, and a housing that holds the optical fiber terminal, and the housing connects the optical connector to another optical fiber. A fixing structure for detachably fixing to the connector is provided.

  In the optical connector according to the present invention as set forth in the invention described above, the fixing structure is a latch structure for locking the optical connector to another optical connector.

  Moreover, the optical connector according to the present invention includes the optical fiber terminal fixing member for fixing the optical fiber terminal to the housing in the above invention, and the ferrule is fitted with the optical fiber terminal fixing member. A groove is provided in the outer peripheral portion.

  In the optical connector according to the present invention as set forth in the invention described above, the housing has a regulating surface that regulates movement of the optical fiber terminal toward the distal end surface of the ferrule.

  Further, the optical connector according to the present invention is the above-described invention, wherein the ferrule is in contact with the restriction surface of the housing to restrict the movement of the optical fiber terminal toward the distal end surface of the ferrule. It is characterized by having.

  An optical fiber cable with a connector according to the present invention includes an optical fiber coated with an optical fiber covered with a strand, a tensile body disposed along a longitudinal direction of the optical fiber, and the optical fiber An optical fiber cable having a wire and a covering portion that covers the strength member, and the optical connector according to any one of the above inventions attached to a tip of the optical fiber cable. .

  According to the present invention, the strength member fixing member is caulked and locked to the flange formed on the cylindrical body through which the optical fiber is inserted and the strength body is placed on the outer peripheral surface. Since the flange and the strength member fixing member are integrated with each other through the strength member, it is possible to realize an optical connector that is resistant to vibration and impact.

FIG. 1 is a diagram schematically showing an optical fiber cable with a terminal in which an optical fiber terminal according to Embodiment 1 is attached to the tip of an optical fiber cable. FIG. 2 is a schematic exploded view of the optical fiber cable with terminal shown in FIG. FIG. 3 is a diagram schematically showing the structure of the optical fiber. FIG. 4 is a cross-sectional view for explaining how the optical fiber fixing member is inserted into the ferrule. FIG. 5 is a partial cross-sectional view illustrating a state in which the strength member is fixed. FIG. 6 is a diagram schematically illustrating a usage state of the optical connector according to the second and third embodiments. FIG. 7 is a diagram schematically illustrating an optical fiber cable with a connector in which the optical connector according to Embodiment 2 is attached to the tip of the optical fiber cable. FIG. 8 is a partial cross-sectional view of the optical connector shown in FIG. FIG. 9 is a diagram schematically showing the structure of the optical fiber terminal fixing member shown in FIG. FIG. 10 is a diagram schematically illustrating an optical fiber cable with a connector in which the optical connector according to Embodiment 3 is attached to the tip of the optical fiber cable. FIG. 11 is a partial cross-sectional view of the optical connector shown in FIG. 12 is a partial cross-sectional view showing a state in which the optical connector shown in FIG. 7 and the optical connector shown in FIG. 10 are connected. FIG. 13 is a schematic cross-sectional view showing the configuration of a modification of the optical fiber terminal according to the embodiment of the present invention.

  Hereinafter, embodiments of an optical fiber terminal, an optical fiber cable with a terminal, an optical connector, and an optical fiber cable with a connector according to the present invention will be described in detail with reference to the drawings. Note that the present invention is not limited to the embodiments.

(Embodiment 1)
First, the optical fiber terminal according to Embodiment 1 of the present invention will be described. FIG. 1 is a diagram schematically showing an optical fiber cable with a terminal in which an optical fiber terminal according to Embodiment 1 is attached to the tip of an optical fiber cable. As shown in FIG. 1, the optical fiber terminal 10 is attached to each end of an optical fiber cable 1 attached to a two-core structure optical connector, and includes a ferrule 2, a caulking ring 3 that is a strength member fixing member, Protective boot 4 is provided. Further, the ferrule 2 includes an optical fiber fixing member 2e. Since the two optical fiber terminals 10 have the same structure, only one optical fiber terminal 10 will be described below.

  FIG. 2 is a schematic exploded view of the optical fiber cable with terminal shown in FIG. As shown in FIG. 2, the optical fiber cable 1 includes an optical fiber 1aa and an optical fiber 1a formed on the outer periphery of the optical fiber 1aa along the longitudinal direction and covering the optical fiber 1aa. 1a, a tensile body 1b arranged along the longitudinal direction on the outer circumference of the optical fiber 1a, and an outer covering portion 1c covering the outer circumference of the tensile body 1b along the longitudinal direction. The tensile body 1b is made of, for example, an aramid resin fiber such as Kevlar (registered trademark), and is disposed so as to surround the outer periphery of the optical fiber 1a. The strand covering portion 1ab is made of, for example, a polyamide resin. Then, the strand covering portion 1ab and the outer covering portion 1c are partially removed at the tip of the optical fiber cable 1, and the optical fiber 1aa, the strand covering portion 1ab, and the strength member 1b are exposed to the outside by a predetermined length. It is supposed to be.

  FIG. 3 is a diagram schematically showing the structure of the optical fiber 1a. As shown in FIG. 3, the optical fiber 1aa includes a core portion 1aaa made of quartz glass, and a clad portion 1aab made of hard plastic having a lower refractive index than the core portion 1aaa, formed on the outer periphery of the core portion 1aaa. This is a so-called HCS (Hard Clad Silica) optical fiber. The core diameter of the core part 1aaa is 200 μm, for example, and the clad diameter of the clad part 1aab is 230 μm, for example, which transmits an optical signal of 850 nm in a low loss, a wide band and a low bending loss, and can be repeatedly bent and pulled. Designed to be strong.

  Returning to FIG. 2, the ferrule 2 has an overall cylindrical shape, and includes a tip end portion 2 a, a flange portion 2 b formed along the outer periphery, a main body portion 2 c, a pedestal portion 2 d, and an optical fiber. And a fixing member 2e. The ferrule 2 is made of, for example, polyphenylene sulfide resin (PPS) excellent in heat resistance, mechanical strength, and moldability. The distal end portion 2a has a distal end surface 2aa. The pedestal portion 2d is located at the end opposite to the tip end surface 2aa, and the convex portion 2da and the flange 2db are formed along the outer periphery, and the surface thereof is uneven. A groove 2g is formed between the main body 2c and the flange 2b along the outer periphery. Further, the ferrule 2 is formed with an insertion hole 2h for inserting the distal end portion of the optical fiber cable 1 so as to penetrate from the distal end surface 2aa to the pedestal portion 2d. The diameter of the insertion hole 2h is set to be substantially the same as or slightly larger than the outer diameter of the optical fiber 1aa at the distal end portion 2a, and the other portion (except for the opening hole 2ca described later) of the optical fiber 1a. It is set to be approximately the same as the outer diameter or slightly larger.

  The optical fiber fixing member 2e has a hook shape and has a groove 2ea for holding the optical fiber 1a. An opening hole 2ca for inserting the optical fiber fixing member 2e is formed on the side surface side of the main body 2c of the ferrule 2. The opening hole 2ca has a shape such that when the optical fiber fixing member 2e is inserted, the inner wall of the opening hole 2ca and the outer wall of the optical fiber fixing member 2e are in contact with each other with almost no gap. Further, the opening hole 2ca communicates with the insertion hole 2h, and is formed to such a depth that the portion of the strand covering portion 1ab of the optical fiber cable 1 inserted through the ferrule 2 is exposed. The structure in the opening hole 2ca of the ferrule 2 will be described in detail later.

  Next, a method for attaching the optical fiber terminal 10 to the tip of the optical fiber cable 1 will be described. First, the optical fiber cable 1 is sequentially inserted into the protective boot 4 and the caulking ring 3. Next, a part of the outer covering portion 1c and the strand covering portion 1ab at the distal end portion of the optical fiber cable 1 are partially removed, and the optical fiber 1aa, the strand covering portion 1ab, and the strength member 1b are respectively externalized by a predetermined length. To expose.

  Next, the tip of the optical fiber cable 1 is inserted from the pedestal 2d side of the ferrule 2 into the insertion hole 2h. At this time, the distal end surface 1aaac (see FIG. 1) of the optical fiber 1aa inserted through the insertion hole 2h is exposed to the distal end surface 2aa of the ferrule 2, and the distal end surface 1aac and the distal end surface 2aa are inserted so as to be substantially in the same plane. To do. At this time, the strand covering portion 1ab of the optical fiber strand 1a is positioned at the position of the opening hole 2ca.

  Next, the optical fiber 1a is fixed to the ferrule 2 by inserting the optical fiber fixing member 2e into the opening hole 2ca and holding the optical fiber 1a. FIG. 4 is a cross-sectional view taken along a plane perpendicular to the longitudinal direction of the ferrule 2, illustrating how the optical fiber fixing member 2 e is inserted into the ferrule 2. As shown in FIG. 4, a support base 2i is formed on the bottom surface of the opening hole 2ca of the ferrule 2 along the insertion direction of the optical fiber 1a. When the optical fiber 1a is inserted, the support base 2i is formed. 2i supported. The upper surface of the support base 2i may be a flat surface or a V-groove or U-groove for positioning the fiber strand 1a.

  Therefore, the optical fiber fixing member 2e is inserted into the opening hole 2ca, and the optical fiber 1a is held by the groove 2ea. Since the concavo-convex portion 2eb is formed in the groove 2ea, when the optical fiber fixing member 2e grips the optical fiber 1a by the groove 2ea, the frictional force between the groove 2ea and the optical fiber 1a is high. Become. Further, as described above, since the inner wall of the opening hole 2ca and the outer wall of the optical fiber fixing member 2e are in contact with each other with almost no gap, the optical fiber fixing member 2e is brought into contact with the ferrule 2 when inserted into the opening hole 2ca. Press contact. Due to this frictional force and pressure, the optical fiber 1a is fixed to the ferrule 2 by the optical fiber fixing member 2e, and the concave portion of the fixing member 2e and the convex portion provided in the opening hole 2ca as shown in FIG. The fitting member 2e prevents the fixing member 2e from coming off the opening hole 2ca. In addition, by fixing the optical fiber 1a to the ferrule 2 using such an optical fiber fixing member 2e, it is possible to attach without waiting for the adhesive to solidify, for example, when fixing with an adhesive. Since the work can be continued, the work process time can be further shortened. Moreover, since the fixing member 2e can be removed, it is easy to adjust the relative positional relationship between the ferrule 2 and the optical fiber 1a. Further, if the inner diameter φ2h of the insertion hole 2h is 1.2 to 1.5 times the outer diameter φ1a of the optical fiber 1a, deflection can occur in the pedestal portion 2d (5 mm to 1.5 mm). In many cases, it is possible to prevent damage caused by pushing the optical fiber 1aa.

  Next, the tensile body 1 b is placed on the pedestal 2 d of the ferrule 2. At this time, it is preferable to place the strength member 1b uniformly over the outer periphery of the pedestal 2d. Next, the caulking ring 3 is fitted into the pedestal portion 2d, and the pedestal portion 2d is caulked together with the tensile body 1b placed on the pedestal portion 2d by the caulking ring 3. Thereafter, the protective boot 4 is attached to the caulking ring 3. Thereby, the optical fiber terminal 10 can be attached to the optical fiber cable 1 to obtain an optical fiber cable with a terminal. The protective boot 4 is made of, for example, rubber or plastic having elasticity, and prevents the connection portion between the optical fiber terminal 10 and the optical fiber cable 1 from being bent at a bending diameter smaller than the allowable radius. This prevents the optical fiber 1a from being broken.

  Here, in the optical fiber terminal 10, the caulking ring 3 fixes the tensile body 1 b to the ferrule 2, and the tensile body 1 b is fixed and integrated with the ferrule 2, so that the structure is strong against vibration and impact. ing.

  FIG. 5 is a partial cross-sectional view illustrating a state where the strength member 1b is fixed. As shown in FIG. 5, the strength member 1 b is directly fixed to the pedestal 2 d of the ferrule 2 by a caulking ring 3.

  Here, as described above, the projecting portion 2da and the flange 2db are formed on the pedestal portion 2d along the outer periphery. The convex part 2da is formed on the outer wall of the pedestal part 2d and on the main body part 2c side (hereinafter referred to as the front side) of the ferrule 2 as compared to the flange 2db. On the other hand, the flange 2db is formed at the rear end of the pedestal 2d.

  As shown in FIG. 5, the outer diameter W2 of the convex portion 2da is larger than the outer diameter W1 of the pedestal portion 2d, and the outer diameter W3 of the flange 2db is larger than the outer diameter W2 of the convex portion 2da. That is, the protruding height of the convex portion 2da from the outer wall of the pedestal portion 2d is lower than the protruding height of the flange 2db, and the relationship between the outer diameters W1 to W3 is W1 <W2 <W3.

  As described above, since the convex portion 2da and the flange 2db are formed along the outer periphery of the pedestal portion 2d, irregularities are formed on the outer surface of the pedestal portion 2d. As shown in FIG. 5, a tensile body 1b is placed on the outer peripheral surface of the pedestal portion 2d having such an uneven shape.

  On the other hand, the caulking ring 3 is fitted through this strength member 1b to at least a part of the ferrule 2 including the flange 2db, that is, the pedestal portion 2d on which the convex portion 2da and the flange 2db are formed, as shown in FIG. Apply external force in the direction of the thick arrow to caulk this fitting part. As a result, the caulking ring 3 is deformed in conformity with the outer surface of the pedestal portion 2d, and the strength member 1b is pressed and fixed to the pedestal portion 2d and locked to the flange 2db. In this case, the caulking ring 3 tightens the flange 2db from at least the upper surface of the flange 2db to the front surface.

  As a result, both are integrated at the connection portion between the optical fiber cable 1 and the optical fiber terminal 10, and the optical fiber cable 1 and the optical fiber terminal 10 are hardly separated even if the optical fiber cable 1 is pulled by vibration or impact. So it is strong against vibration and shock. In particular, since the caulking ring 3 is locked to the flange 2db as described above, when the caulking ring 3 is pulled, the caulking ring 3 is caught by the flange 2db and is not easily pulled out. As a result, the caulking ring 3 is further resistant to pulling. Further, since the strength member 1b caulked by the caulking ring 3 is pulled by the projections 2da and the flange 2db when pulled, it becomes more resistant to pulling. In addition, you may provide the convex part engaged with the groove | channel of the base part 2d in the inner periphery of the crimping ring 3. FIG.

  Further, in the optical fiber terminal 10, the optical fiber 1 a is fixed to the ferrule 2 using an optical fiber fixing member 2 e. As a result, the optical fiber terminal 10 and the optical fiber cable 1 are more firmly connected, and thus are more resistant to vibration and impact. Further, with this structure, an external force applied to the optical fiber cable 1 is applied to the fixed portion, and the influence on the end face side is small. For this purpose, it is convenient if the fixed part has a length of 3 mm to 1.6 mm.

  As described above, in the optical fiber terminal 10 according to the first embodiment, the caulking ring 3 is caulked to the pedestal portion 2d of the ferrule 2 via the tensile strength body 1b, and thereby, the tensile strength body is secured to the uneven portion of the pedestal portion 2d. 1b is pressed and fixed, and the caulking ring 3 is locked to the flange 2db. Therefore, even if the optical fiber cable 1 is pulled by vibration or impact, it is difficult to separate from the optical fiber cable 1, and it is strong against vibration and impact. For example, it can withstand a tensile tension of 100 N.

(Embodiments 2 and 3)
Next, Embodiments 2 and 3 of the present invention will be described. The optical connector according to the second and third embodiments includes the optical fiber terminal according to the first embodiment.

  FIG. 6 is a diagram schematically illustrating a usage state of the optical connector according to the second and third embodiments. FIG. 6 shows the in-vehicle communication system 100. In this in-vehicle communication system 100, a control board 101 and a control board 102 provided in a communication apparatus are connected via optical fiber cables 103 and 104 with connectors, and control signals are communicated with each other.

  The control boards 101 and 102 are equipped with FOT (Fiber Optical Transceiver) 101a and 102a each having a female connector structure. In the optical fiber cable with connector 103, the male optical connector 20 according to the second embodiment is attached to both ends of the optical fiber cable 1 shown in FIG. The optical fiber cable with connector 104 is obtained by attaching the optical connector 20 and the female optical connector 30 according to Embodiment 3 to each end of the optical fiber cable 1. The optical connectors 20 of the optical fiber cables with connectors 103 and 104 are connected to the FOTs 101a and 102a, respectively, and the other optical connector 20 of the optical fiber cable with connectors 103 and the optical connector 30 of the optical fiber cable with connectors 104 are connected. (In other words, wire-to-wire connection), signal transmission paths are formed by the optical fiber cables 103 and 104 with connectors between the control boards 101 and 102, and high-speed and large-capacity communication can be performed.

  Next, the optical connector according to Embodiment 2 will be specifically described. FIG. 7 is a diagram schematically illustrating an optical fiber cable with a connector in which the optical connector according to Embodiment 2 is attached to the tip of the optical fiber cable. 7A is a front view, FIG. 7B is a side view, and FIG. 7C is a plan view. FIG. 8 is a partial cross-sectional view of the optical connector shown in FIG.

  As shown in FIGS. 7 and 8, the optical connector 20 includes an optical fiber terminal 10 according to the first embodiment, a housing 21 that holds the optical fiber terminal 10, and an optical fiber terminal 10 that is fixed to the housing 21. And an optical fiber terminal fixing member 22.

  The housing 21 includes two insertion holes 21 a formed in parallel to each other in the longitudinal direction for inserting two optical fiber terminals 10 attached to the respective ends of the optical fiber cable 1 having a two-core structure, and an upper surface of the housing 21. A slit 21b for penetrating the bottom surface and communicating with the insertion hole 21a, for inserting the optical fiber terminal fixing member 22, and an obliquely upward direction from the front end to the rear end in the longitudinal direction at substantially the center in the width direction An elastic arm portion 21c formed so as to incline, a hook portion 21d for hooking and stopping the tip portion 21ca of the arm portion 21c, a latch protrusion portion 21e formed on the upper portion of the arm portion 21c, It has. The inner wall of the insertion hole 21a is formed with a regulating surface 21f that abuts against the front end surface 2ba of the flange portion 2b of the optical fiber terminal 10 and restricts the movement of the optical fiber terminal 10 toward the front end surface. The housing 21 is made of, for example, PPS or polybutylene terephthalate (PBT). Further, considering use in a vehicle, a resin having a heat resistance and a small coefficient of thermal expansion is preferable.

  FIG. 9 is a diagram schematically showing the structure of the optical fiber terminal fixing member shown in FIG. 9A is a front view, FIG. 9B is a side view, FIG. 9C is a cross-sectional view taken along line AA in FIG. 9A, and an optical fiber terminal fixing member fixes the optical fiber terminal. It shows a state. As shown in FIG. 9, the optical fiber terminal fixing member 22 includes a main body portion 22a, a fitting portion 22b formed so as to protrude from both ends in the width direction of the main body portion 22a, and a substantially center in the width direction of the main body portion 22a. The locking portion 22c and the spring portion 22d are formed so as to protrude from the center. Two gaps 22e are formed between the fitting portion 22b, the locking portion 22c, and the spring portion 22d. The optical fiber terminal fixing member 22 is made of, for example, PPS or PBT.

  The thickness of the fitting portion 22b is set to be substantially the same as or slightly thinner than the width of the groove 2g of the ferrule 2. The locking part 22c is formed slightly in front of the fitting part 22b, and a locking claw 22ca is formed at the tip. Further, as shown in FIGS. 9B and 9C, the spring portion 22d is curved in an arc shape so as to protrude toward the locking portion 22c when viewed from the side, and the arc-shaped portion is The fitting portion 22b is formed so as to protrude from the surface on the locking portion 22c side. In this embodiment, the width of the fitting portion 22b and the groove portion 2g is designed to be substantially equal, but the width of the groove portion 2g is set 0.5 to 1.5 mm larger than the fitting portion 22b, and the spring portion 22d. Is set to be pressed by the spring, the tensile force applied to the optical fiber cable 1 is absorbed by the spring and is prevented from being instantaneously applied to the housing 21, so that damage to the housing 21 can be effectively prevented.

  Next, a method for assembling the optical connector 20 will be described. First, as shown in FIG. 8, the two optical fiber terminals 10 are inserted into the insertion hole 21a of the housing 21 so that the front end surface 2ba of the flange portion 2b of the ferrule 2 is in contact with the regulation surface 21f in the insertion hole 21a. . At this time, the groove 2 g of the ferrule 2 is positioned so as to overlap with the slit 21 b formed in the housing 21.

  Next, the optical fiber terminal fixing member 22 is inserted into the slit 21 b from the bottom surface side of the housing 21. Then, as shown in FIG. 9C, the two fitting portions 22 b of the optical fiber terminal fixing member 22 are inserted into the outer grooves 2 g of the two ferrules 2. The tip of the fitting portion 22b reaches the slit 21b on the upper surface side and is inserted. Therefore, the movement of the optical fiber terminal fixing member 22 in the longitudinal direction is restricted by the slit 21b on the upper bottom surface.

  Moreover, although the spring part 22d is inserted in each of the groove parts 2g of the two ferrules 2, it is inserted in a state where the curved part is pushed back by the flange part 2b. As a result, the spring portion 22d presses the rear end surface 2bb of the flange portion 2b, so that the front end surface 2ba of the flange portion 2b is pressed against the restriction surface 21f of the housing 21 toward the front end surface 2aa side of the ferrule 2. As a result, the ferrule 2 is held against the restriction surface 21 f of the housing 21. The locking portion 22 c passes between the two ferrules 2, and the locking claw 22 ca is locked to the slit 21 b on the upper surface side of the housing 21. As a result, the optical fiber terminal fixing member 22 is fixed to the housing 21. The two ferrules 2 are disposed in the two gaps 22e.

  As described above, the fitting portion 22b of the optical fiber terminal fixing member 22 is fitted into the groove portion 2g of the ferrule 2, and the optical fiber terminal fixing member 22 is fitted into the slit 21b. As a result, since the optical fiber terminal 10 is firmly fixed to the housing 21, the optical connector 20 is further resistant to vibrations and shocks, so that it can withstand, for example, a tensile tension of 100 N and has high connection reliability. Become. Further, in the second embodiment, since the optical fiber terminal fixing member 22 holds the optical fiber terminal 10 against the regulating surface 21f of the housing 21 by the spring portion 22d, the optical fiber terminal 10 moves in the distal end surface direction. Is further regulated, the distal end surface 2aa of the optical fiber terminal 10 can be set at a desired position.

  Next, the optical connector according to Embodiment 3 will be specifically described. FIG. 10 is a diagram schematically illustrating an optical fiber cable with a connector in which the optical connector according to Embodiment 3 is attached to the tip of the optical fiber cable. 10A is a front view, FIG. 10B is a side view, and FIG. 10C is a plan view. FIG. 11 is a partial cross-sectional view of the optical connector shown in FIG.

  As shown in FIGS. 10 and 11, the optical connector 30 includes an optical fiber terminal 10 according to the first embodiment, a housing 31 that holds the optical fiber terminal 10, and an optical fiber terminal 10 that is fixed to the housing 31. An optical fiber terminal fixing member 22 similar to that shown in FIG. 9 is provided.

  The housing 31 has two insertion holes 31a formed in parallel to the longitudinal direction for inserting the two optical fiber terminals 10 attached to the respective ends of the optical fiber cable 1 having a two-core structure, and an upper surface from the bottom surface of the housing 31. The optical connector 20 according to the second embodiment is formed so as to penetrate through the insertion hole 31a and communicate with the slit 31b for inserting the optical fiber terminal fixing member 22 in the distal direction from the insertion hole 31a. And an accommodating portion 31c that is inserted and accommodated. Further, a protrusion 31d is formed on the upper surface of the housing 31. A guide groove 31e for guiding the arm portion 21c when the optical connector 20 is inserted is formed inside the protruding portion 31d so as to be continuous with the accommodating portion 31c. The latch protruding portion 21e is fitted into the protruding portion 31d. A latch hole 31f is formed as a fixing structure for this purpose. In addition, a regulation surface 31g is formed on the inner wall of the insertion hole 31a so as to abut the front end surface 2ba of the flange portion 2b of the optical fiber terminal 10 so as to restrict the forward movement of the optical fiber terminal 10. The housing 31 is made of, for example, PPS or PBT.

  Next, a method for assembling the optical connector 30 will be described. First, as shown in FIG. 11, the two optical fiber terminals 10 are inserted into the insertion hole 31a of the housing 31 so that the front end surface 2ba of the flange 2b of the ferrule 2 abuts on the regulation surface 31g in the insertion hole 31a. . At this time, the groove 2 g of the ferrule 2 is positioned so as to overlap with the slit 31 b formed in the housing 31.

  Next, the optical fiber terminal fixing member 22 is inserted into the slit (insertion hole) 31 b from the upper surface side of the housing 31. Then, as in the case of the optical connector 20, the two fitting portions 22 b of the optical fiber terminal fixing member 22 are inserted into the outer groove portions 2 g of the two ferrules 2. The tip of the fitting portion 22b reaches the slit 21b on the bottom side and is inserted. Accordingly, the movement of the optical fiber terminal fixing member 22 in the longitudinal direction is restricted by the slit 31b on the upper bottom surface.

  Moreover, although the spring part 22d is inserted in each of the groove parts 2g of the two ferrules 2, it is inserted in a state where the curved part is pushed back by the flange part 2b. As a result, the spring portion 22d presses the rear end surface 2bb of the flange portion 2b, so that the front end surface 2ba of the flange portion 2b is pressed against the restriction surface 31g of the housing 31 toward the front end surface 2aa side of the ferrule 2. As a result, the ferrule 2 is held against the regulating surface 31 g of the housing 31. The locking portion 22 c passes between the two ferrules 2, and the locking claw 22 ca is locked to the slit 31 b on the bottom surface side of the housing 31. As a result, the optical fiber terminal fixing member 22 is fixed to the housing 31. The two ferrules 2 are disposed in the two gaps 22e, respectively.

  As described above, the fitting portion 22b of the optical fiber terminal fixing member 22 is fitted in the groove 2g of the ferrule 2, and the optical fiber terminal fixing member 22 is fitted in the slit 31b. As a result, since the optical fiber terminal 10 is firmly fixed to the housing 31, the optical connector 30 is more resistant to vibrations and shocks. For example, it can withstand a tensile tension of 100 N and has high connection reliability. Become. Further, since the optical fiber terminal 10 can be inserted into the housing 21 and the optical fiber terminal 10 can be positioned and fixed by the optical fiber terminal fixing member 22 from the outside of the housing 21, the optical connector assembly can be easily manufactured. Furthermore, in the third embodiment, since the optical fiber terminal fixing member 22 holds the optical fiber terminal 10 against the regulating surface 31g of the housing 31 by the spring portion 22d, the optical fiber terminal 10 moves in the distal direction. Is further regulated, the distal end surface 2aa of the optical fiber terminal 10 can be set at a desired position.

  12 is a partial cross-sectional view showing a state where the optical connector 20 according to the second embodiment shown in FIG. 7 and the optical connector 30 according to the third embodiment shown in FIG. 10 are connected. When connecting the optical connector 20 and the optical connector 30, the optical connector 20 is inserted into the housing portion 31 c of the optical connector 30. Then, the arm portion 21c of the optical connector 20 is guided by the guide groove 31e, and the latch protrusion 21e is fitted into the latch hole 31f and locked. Thereby, the optical connector 20 and the optical connector 30 are connected. When disconnecting this connection, it is possible to release the connection by depressing the distal end portion 21ca of the arm portion 21c of the optical connector 20 and releasing the latch projection 21e from the latch hole 31f.

  When the optical connector 20 and the optical connector 30 are connected, a gap G having a predetermined width is formed between the front end surfaces 2aa of the optical fiber terminals 10 facing each other. By forming the gap G in this manner, even if the optical fiber terminal 10 vibrates due to, for example, vibration or impact, or the optical connector 20 and the optical connector 30 are repeatedly attached and detached in the manufacturing and maintenance processes, the optical fiber The tip surfaces 1aac of the optical fibers 1aa on the same plane as the tip surface 2aa of the terminal 10 do not rub against each other. Accordingly, the tip surface 1aac is prevented from being damaged or scratched.

  The width of the gap G is, for example, 500 μm or less, preferably 30 to 300 μm, and the optical fiber cables 1 are connected with low optical loss according to the core diameter of the optical fiber 1aa, the numerical aperture, and the pistoning of the optical fiber 1aa. To be set. In the optical connectors 20 and 30 according to the present embodiment, the optical fiber terminal 10 moves in the distal direction by the optical fiber terminal fixing member 22 and the flange portion 2b of the optical fiber terminal 10 and the regulating surfaces 21f and 31g. Since the optical fiber terminal 10 is integrally formed and the position of the ferrule 2 and the optical fiber 1aa does not shift, vibration and shock are applied to the optical connectors 20 and 30 connected to each other. Even if added, the gap G is maintained, so that the tip surfaces 2aa of the optical fiber terminals 10 do not contact each other, and the tip surface 1aaac of the optical fiber 1aa is prevented from being damaged or scratched. In order to prevent light loss due to the gap G in the present embodiment, a multimode communication system having a wavelength of 800 to 1300 μm is used as the optical fiber 1aa having a core diameter of 50 to 250 μm, particularly 160 to 220 μm. It is convenient to use in.

(Modification)
Below, the modification of the optical fiber terminal concerning embodiment of this invention is demonstrated. In the above-described embodiment, the flange 2db is formed on the pedestal 2d positioned at the rear of the ferrule 2, the caulking ring 3 is fitted to the pedestal 2d including the flange 2db, and the fitting 2 is caulked to flange 2db. Although the caulking ring 3 is locked, the present invention is not limited to this, and the flange 3 for locking the caulking ring 3 may be formed in a stop ring that is one component of the optical fiber terminal.

  FIG. 13 is a schematic cross-sectional view showing the configuration of a modification of the optical fiber terminal according to the embodiment of the present invention. FIG. 13 shows a cross section of an optical connector 40 including the optical fiber terminal 6 according to this modification.

  As shown in FIG. 13, the optical fiber terminal 6 according to this modification includes an optical fiber cable 1 including an optical fiber 1a, a tensile member 1b, an outer covering portion 1c, and the like, as in the above-described embodiment. A caulking ring 3 and a protective boot 4. Further, the optical fiber terminal 6 includes a stop ring 5 that is a cylindrical body having a through-hole through which the optical fiber strand 1a is inserted, and a ferrule and a stop ring 5 for inserting and fixing the optical fiber strand 1a. And are connected via a spring. The optical fiber 1a passes through the spring and is fixedly inserted into the insertion hole of the ferrule. The tip surface of the optical fiber 1a is exposed to the ferrule tip surface through the ferrule insertion hole. In this case, the tip surface of the optical fiber 1a and the tip surface of the ferrule are substantially flush. On the other hand, the optical connector 40 has a configuration in which the optical fiber terminal 6 is accommodated in a housing having the same function as that of the above-described embodiment. In this case, the stop ring 5 is inserted and fixed to the housing of the optical connector 40 by a locking claw as shown in FIG.

  Here, the stop ring 5 is formed with a pedestal portion for placing the strength member 1b on the insertion entrance side of the optical fiber 1a. The outer wall surface of the pedestal portion has a convex portion 5a and the outer wall surface. A flange 5b having a protrusion height higher than that of the convex portion 5a is formed. That is, the outer diameter of the flange 5b is larger than that of the convex portion 5a, and an uneven shape is formed on the outer surface of the stop ring 5 similarly to the pedestal portion 2d of the ferrule 2 described above. The flange 5b is formed at the rear end of the pedestal portion of the stop ring 5, and the convex portion 5a is formed on the front side of the stop ring 5 with respect to the flange 5b. As shown in FIG. 13, the strength member 1 b is placed on the outer peripheral surface of the pedestal portion of the stop ring 5 having such an uneven shape.

  On the other hand, the caulking ring 3 is fitted through this strength member 1b to at least a part of the stop ring 5 including the flange 5b, that is, the pedestal portion of the stop ring 5 in which the convex portion 5a and the flange 5b are formed, The fitting portion is caulked by applying an external force. As a result, the caulking ring 3 is deformed in conformity with the uneven outer surface of the stop ring 5, and the strength member 1 b is pressed and fixed to the stop ring 5 and locked to the flange 5 b. In this case, the caulking ring 3 fastens the flange 5b from at least the upper surface of the flange 5b to the front surface.

  As a result, both are integrated at the connection portion between the optical fiber cable 1 and the optical fiber terminal 6, and the optical fiber cable 1 and the optical fiber terminal 6 are hardly separated even if the optical fiber cable 1 is pulled by vibration or impact. So it is strong against vibration and shock. In particular, since the caulking ring 3 is locked to the flange 5b as described above, when the caulking ring 3 is pulled, the caulking ring 3 is caught by the flange 5b and is difficult to be pulled out. As a result, the caulking ring 3 becomes more resistant to pulling.

  As described above, in the optical fiber terminal 6 according to this modification, the caulking ring 3 is caulked to the rear portion (pedestal portion) of the stop ring 5 via the tensile body 1b, whereby the tensile strength is applied to the uneven portion of the stop ring 5. Since the body 1b is pressed and fixed, and the caulking ring 3 is locked to the flange 5b, even if the optical fiber cable 1 is pulled by vibration or impact, it is difficult to separate from the optical fiber cable 1 and is strong against vibration and impact. For example, it can withstand a tensile tension of 100 N.

  In the embodiment and the modification described above, one convex portion is formed on the pedestal portion of the ferrule or the pedestal portion of the stop ring. However, the present invention is not limited to this, and a plurality of convex portions may be formed. It is not necessary to form one.

  In the embodiment and the modification described above, the flange is formed at the rear end portion of the ferrule or the rear end portion of the stop ring. However, the flange places the strength member 1b and fits the caulking ring 3 therewith. If it is a part to perform, it may be formed not only in a rear end part but in a desired part, such as a part from the front part rather than the center part or rear end part of a base part or a stop ring. A plurality of flanges may be formed.

  Furthermore, in the above-described embodiment and modification, an optical fiber cable using a resin fiber is used as the tensile body. However, as the optical fiber cable, for example, a wire-shaped tensile body made of metal, FRP, or the like is used. The one used may be used.

  In the embodiment described above, the optical fiber is fixed to the ferrule using the optical fiber fixing member. However, the optical fiber may be bonded and fixed to the ferrule.

  Furthermore, in the optical connector according to the above-described embodiment or modification, if dust, dust, or moisture enters the optical connector during attachment or detachment, the connection light loss of the optical connector may increase. Therefore, it is preferable to provide a dustproof or waterproof structure such as a rubber cover in the optical connector.

  In the above-described embodiments and modifications, the optical fiber terminal and the optical connector of the present invention are applied to a two-core optical fiber cable. However, the present invention is not limited to this, and one or three or more cores are used. This can also be applied to multi-core optical fiber cables.

  Moreover, in the said embodiment, although the fixing | fixed part by an optical fiber fixing member was made into one place of an optical fiber terminal, you may provide in multiple places, such as providing in the other end side of the connection end surface of an optical connector, for example.

  The material of the optical fiber fixing member may be a resin material such as PPS, but may be a metal such as iron, aluminum, or stainless steel.

  As a use in a portion where the tensile force is not so much although the impact resistance is inferior, the fitting portion may be pressed against the end surface as a spring member. Further, if the fitting part is made of a member that is elastically deformed in any of the longitudinal directions, and the distance between the housing and the front end surface of the collar part of the optical fiber terminal is slightly set, the fitting fitted into the groove of the optical fiber terminal It can also be designed to allow longitudinal movement in the longitudinal direction by the joint.

  Further, the present invention is not limited to the above-described embodiment or modification. What was comprised combining each component mentioned above suitably is also contained in this invention.

DESCRIPTION OF SYMBOLS 1 Optical fiber cable 1a Optical fiber strand 1aa Optical fiber 1aaa Core part 1aab Cladding part 1aac Tip end face 1ab Strand covering part 1b Strength member 1c Outer covering part 2 Ferrule 2a Tip end part 2aa Tip end face 2b Front end face 2bb Rear end face 2c body part 2eb uneven part 2ca opening hole 2d pedestal part 2da, 5a convex part 2db, 5b flange 2e optical fiber fixing member 2ea groove 2g groove part 2h, 21a, 31a insertion hole 2i support base 3 caulking ring 4 protective boot 5 stop ring 6 DESCRIPTION OF SYMBOLS 10 Optical fiber terminal 20, 30, 40 Optical connector 21, 31 Housing 21b, 31b Slit 21c Arm part 21ca Tip part 21d Latch part 21e Latch projection part 21f, 31g Restriction surface 22 Optical fiber terminal fixing member 22a Main body part 22 The fitting portion 22c locking portion 22ca locking claw 22d spring portion 22e gap 31c accommodating portion 31d protruding portion 31e guide groove 31f latch hole 100-vehicle communication system 101 control board 103, 104 with connector optical fiber cable G gap

Claims (15)

An optical fiber coated with an optical fiber coating; a tensile body disposed along a longitudinal direction of the optical fiber; and a coating portion covering the optical fiber and the tensile body. An optical fiber terminal attached to the tip of an optical fiber cable,
A cylindrical body through which the optical fiber is inserted and the tensile body is placed on an outer peripheral surface;
A strength member fixing member for fixing the strength member to the cylindrical body;
With
A flange is formed along the outer periphery of the cylindrical body,
The tensile strength fixing member is fitted to at least a part of the cylindrical body including the flange via the tensile strength body, and the fitting portion is caulked to fix the tensile strength body to the cylindrical body and the flange. An optical fiber terminal that is locked to the optical fiber terminal.   2. The optical fiber terminal according to claim 1, wherein the cylindrical body has the flange at an end of the optical fiber strand on the insertion entrance side.   3. The optical fiber terminal according to claim 1, wherein the cylindrical body has a protrusion having a protrusion height lower than that of the flange. The cylindrical body includes an insertion hole for inserting and fixing the optical fiber, a distal end surface at which a distal end surface of the optical fiber inserted through the insertion hole is exposed, and an end portion opposite to the distal end surface. And a pedestal for mounting the tensile body on the ferrule,
The optical fiber terminal according to claim 1, wherein the flange is formed on the pedestal portion. The tensile body is made of resin fibers,
The said tensile strength body fixing member fits at least a part of said base part including the said flange, and caulks the said tensile strength body on the said base part with this fitting part. Optical fiber terminal. The ferrule includes an optical fiber fixing member having a groove for gripping the optical fiber, and an opening hole having a depth at least exposing the inserted optical fiber is formed on a side surface. And
The optical fiber fixing member is inserted into an opening hole of the ferrule, and the inserted optical fiber is fixed by gripping the inserted optical fiber in the groove. Item 6. The optical fiber terminal according to Item 4 or 5. The cylindrical body includes an insertion hole for inserting the optical fiber, and a pedestal portion formed on the insertion entrance side of the optical fiber in the insertion hole for mounting the tensile body. Stop ring,
The optical fiber terminal according to claim 1, wherein the flange is formed on the pedestal portion. An optical fiber coated with an optical fiber coating; a tensile body disposed along a longitudinal direction of the optical fiber; and a coating portion covering the optical fiber and the tensile body. Fiber optic cable,
The optical fiber terminal according to any one of claims 1 to 7, attached to a tip of the optical fiber cable,
An optical fiber cable with a terminal, comprising: The optical fiber terminal according to any one of claims 1 to 6,
A housing for holding the optical fiber terminal;
The optical connector is provided with a fixing structure for detachably fixing the optical connector to another optical connector.   The optical connector according to claim 9, wherein the fixing structure is a latch structure for locking the optical connector to another optical connector.   An optical fiber terminal fixing member for fixing the optical fiber terminal to the housing is provided, and the ferrule is provided with a groove on the outer peripheral portion in which the optical fiber terminal fixing member is fitted. Item 11. The optical connector according to Item 9 or 10.   12. The optical connector according to claim 10, wherein the housing has a regulating surface that regulates movement of the optical fiber terminal toward the distal end surface of the ferrule.   13. The optical connector according to claim 12, wherein the ferrule has a flange portion that abuts on the restriction surface of the housing and restricts movement of the optical fiber terminal toward the distal end surface of the ferrule. . An optical fiber terminal according to claim 7,
A housing for holding the optical fiber terminal;
The optical connector is provided with a fixing structure for detachably fixing the optical connector to another optical connector. An optical fiber coated with an optical fiber coating; a tensile body disposed along a longitudinal direction of the optical fiber; and a coating portion covering the optical fiber and the tensile body. Fiber optic cable,
The optical connector according to any one of claims 9 to 14, which is attached to a tip of the optical fiber cable;
An optical fiber cable with a connector, comprising:

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