JP2012083579A - Ferrule for optical connector, and assembly of optical connector and optical cable - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a ferrule for an optical connector, which allows the reduction of manufacturing costs while being miniaturized in an axial direction.SOLUTION: A cylindrical engagement part 10 with which a counterpart ferrule is to be engaged, an optical fiber positioning hole 20 which connects with the cylindrical engagement part 10 and of which the radial direction an optical fiber is positioned in, and an optical fiber fixing hole 30 which connects with the optical fiber positioning hole 20 and to which the optical fiber is fixed by adhesion are formed in this order along the axial direction from a front end of the ferrule, and an adhesive injection hole 40 connecting with the peripheral surface side of the optical fiber fixing hole 30 is formed to open in an outer peripheral surface.

Description

  The present invention relates to a ferrule for an optical connector and an assembly of an optical connector and an optical cable. Specifically, the ferrule for an optical connector in which a cylindrical engagement portion with which a counterpart ferrule is engaged, and the optical connector for the same The present invention relates to an optical connector / optical cable assembly in which ferrules are arranged.

  In general, an optical cable using an optical fiber (also referred to as an optical fiber cable) is widely used for home and industrial information communication because it enables high-speed communication of a large amount of information. For example, automobiles are equipped with various electrical components (for example, a car navigation system), but are beginning to be used for communication of these electrical components. With the development of such optical communication, optical connectors (optical fibers) for optically connecting optical fiber terminals to each other (connecting so that optical signals can be transmitted) and optically connecting optical fibers and photoelectric conversion elements. Various types of connectors have also been proposed.

  The optical connector is provided with a ferrule that holds the end of the optical fiber. The optical fiber is fixed to the ferrule so as to be flush with the distal end surface of the ferrule, and the distal end surface of the ferrule disposed on the counterpart optical connector (the other party ferrule) is abutted. Thereby, the ends of the optical fibers are optically connected to each other.

  In this type of optical connector, as described in Patent Document 1, for example, a cylindrical member called a split sleeve is used in order to suppress misalignment of a ferrule (optical fiber) to be abutted. FIG. 6B is a schematic view showing a butt structure between ferrules using such a split sleeve. As illustrated, the split sleeve 100 is attached to the outer periphery 1011 of one ferrule 101. When the other optical connector is fitted into one optical connector, the ferrule 90 (shown by a dotted line) of the other optical connector enters the split sleeve 100 and abuts with the ferrule 101 of the one optical connector. Since the split sleeve 100 is formed with a slit along the axial direction thereof, one ferrule 101 and the other ferrule 90 inserted into the split sleeve 100 are held so as to be tightened inward by elastic force. Is done. That is, since one ferrule 101 and the other ferrule 90 are held in the split sleeve 100 without rattling, axial misalignment of the ferrule (optical fiber 81) to be abutted is suppressed.

JP 2006-208631 A

  However, in the above configuration, since the split sleeve 100 is attached to the outer periphery 1011 of the ferrule 101, there is a problem that the ferrule 101 becomes larger in the axial direction (fitting direction of the optical connector). That is, since it is necessary to secure an attachment allowance for attaching the split sleeve 100 to the ferrule 101 (contact allowance between the ferrule and the split sleeve; indicated by X4 in FIG. 6B), the ferrule 101 becomes longer in the axial direction. This is one of the factors that hinder the miniaturization of optical connectors.

  Further, high dimensional accuracy of the outer periphery 1011 of the ferrule 101 to which the split sleeve 100 is attached (high coaxiality between the outer periphery 1011 of the ferrule 101 and the optical fiber fixing hole 1012 to which the optical fiber 81 is fixed, and the outer periphery 1011 of the ferrule 101 It is difficult to ensure a high degree of cylindricity, and there is a problem in that manufacturing costs such as mold costs increase.

  In view of the above circumstances, the present invention provides an optical connector ferrule capable of reducing the manufacturing cost while reducing the size in the axial direction (connecting direction of the connector), and light provided with such an optical connector ferrule. To provide an assembly of a connector and an optical cable.

  In order to solve the above-mentioned problems, an optical connector ferrule according to the present invention is an optical connector ferrule formed integrally, and has a cylindrical shape in which a counterpart ferrule is engaged in order from the tip along the axial direction. An engaging portion, an optical fiber positioning hole that is connected to the space inside the cylindrical engaging portion, the optical fiber is positioned in the radial direction, and an optical fiber that is connected to the optical fiber positioning hole and to which the optical fiber is bonded and fixed The gist of the present invention is that a fiber fixing hole is formed, and an adhesive injection hole that is continuous with the peripheral surface side of the optical fiber fixing hole and opens on the outer peripheral surface is formed.

  The “cylindrical shape” in the present invention includes those other than the configuration having a circular cross section. For example, it includes all hollow shapes such as a so-called rectangular tube having a rectangular or triangular cross section and an elliptical cross section.

  In this case, it is only necessary that the cylindrical engagement portion has slits formed in the axial direction thereof, and two or more slits may be formed in the circumferential direction.

  An optical connector and optical cable assembly according to the present invention is an optical connector in which any one of the above optical connector ferrules is arranged, and the optical cable has an optical fiber. The gist of the invention is that the optical fiber is fixed to an optical connector ferrule disposed on the optical connector.

  The ferrule for an optical connector according to the present invention is such that a cylindrical engagement portion with which a mating ferrule is engaged is integrally formed with an optical fiber positioning hole for positioning an optical fiber and an optical fiber fixing hole for fixing an optical fiber. is there. That is, the ferrule itself is formed with a configuration that suppresses axial misalignment with the counterpart ferrule, which was conventionally achieved by the “split sleeve”. Therefore, it is not necessary to secure a mounting allowance for attaching the split sleeve to the ferrule (contact allowance between the ferrule and the split sleeve) as in the prior art. In other words, the mating ferrule on the tip side of the abutting surface is engaged. Since it is only necessary to form a cylindrical engagement portion having such a length that does not tilt, the size in the axial direction (connecting direction of the connector) can be reduced. Therefore, the size of the optical connector in which the optical connector ferrule is disposed in the axial direction can also be reduced.

  Moreover, since the cylindrical engaging part with which the other party ferrule engages is comprised in ferrule itself, manufacturing cost can be reduced. That is, since the conventional split sleeve is not configured to be attached to the ferrule, and the two members are configured as a single member, the manufacturing cost is reduced.

  Furthermore, in this invention, in order to form the said cylindrical engaging part, the abutting surface with the other party ferrule becomes an inner bottom face of a cylindrical engaging part. Therefore, when the abutting surface with the counterpart ferrule is polished (mirror finish), the cylindrical portion of the cylindrical engaging portion becomes an obstacle, and the polishing operation becomes difficult (impossible). For example, if an optical fiber is injected into the ferrule and then the optical fiber is inserted into the ferrule and bonded and fixed (adhesive is put in first), the adhesive always adheres to the tip surface of the optical fiber. Therefore, polishing the abutting surface with the counterpart ferrule is an indispensable work. On the other hand, in the present invention, since the adhesive injection hole opened on the outer peripheral surface of the ferrule is formed, it is not necessary to polish the abutting surface with the counterpart ferrule. That is, the optical fiber is inserted through the fiber fixing hole and the fiber positioning hole to a position where the abutting surface and the tip of the counterpart ferrule are flush with each other, and then the optical fiber is inserted by the adhesive injected from the adhesive injection hole. Since it can be bonded and fixed in the ferrule fixing hole (after-adhesion of the adhesive becomes possible), polishing of the abutting surface with the counterpart ferrule is unnecessary. That is, in the present invention, the occurrence of problems due to the formation of the cylindrical engagement portion is prevented by the adhesive injection hole opened on the outer peripheral surface of the ferrule.

  Then, if a slit is formed in the cylindrical engagement portion and the counterpart ferrule engaged with the cylindrical engagement portion is engaged so as to expand the slit, the mating counterpart ferrule is in the cylindrical engagement. Since it is tightened inward by the elastic force of the joint portion, the effect of suppressing the axial deviation of the ferrule (optical fiber) to be abutted is high. Moreover, the thickness of the cylindrical engaging part formed in the ferrule itself by integral molding can be freely set. That is, it is possible to ensure strength that is not easily damaged or deformed even when the slit is formed.

  Moreover, since the cylindrical engaging portion is formed on the ferrule itself by integral molding, it can be formed at two or more locations in the circumferential direction. For example, in the case of a conventional split sleeve, if two or more slits are formed, the split sleeve itself is divided into two or more, so that the slit can be formed only in one place. On the other hand, in the present invention, the cylindrical engagement portion is connected to the portion where the optical fiber positioning hole and the optical fiber fixing hole are formed. Therefore, even if two or more slits are formed, the cylindrical engagement portion is not formed. There is no division. That is, by adjusting the number of slits, it is possible to select to firmly engage the counterpart ferrule with the cylindrical engaging portion, and it is also possible to select to loosely engage (make it easy to insert and remove).

  These ferrules for optical connectors can be applied to optical connectors for all uses, and the most suitable uses include in-vehicle optical connectors for connecting multimode optical fibers.

It is an external view of the ferrule for optical connectors concerning one Embodiment of this invention. It is sectional drawing (the AA line cross section in FIG. 1) of the ferrule for optical connectors concerning one Embodiment of this invention. It is sectional drawing (BB sectional view in FIG. 2) of the ferrule for optical connectors concerning one Embodiment of this invention. It is sectional drawing (CC sectional view in FIG. 1) of the cylindrical engaging part in the ferrule for optical connectors concerning one Embodiment of this invention. It is sectional drawing (equivalent to the CC cross section in FIG. 1) which shows the example in which the 2 or more slit was formed in the cylindrical engaging part. It is a figure which compares the length in the axial direction of the ferrule (a) for optical connectors concerning this embodiment, and the ferrule (b) for conventional optical connectors. It is sectional drawing of the assembly of the optical connector and optical cable concerning one Embodiment of this invention. It is an external view (partial sectional view) of a ferrule for optical connectors according to another embodiment of the present invention.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the following description, unless otherwise specified, the front end (front) side refers to the butting surface 1s side (left side in FIGS. 1 to 3) of the optical connector ferrule 1 with the counterpart ferrule, and the rear end side. Means the opposite side. The axial direction simply refers to the axial direction of the optical fiber 81 held by the optical connector ferrule 1 (the horizontal direction in FIGS. 1 to 3), the vertical direction refers to the vertical direction in FIG. 2, and the width direction. The vertical direction in FIG. 1 (direction perpendicular to the axial direction and the vertical direction) is referred to.

  In the present embodiment, the “optical fiber” refers to a fiber that is composed of a “core” that is a portion through which an optical signal propagates and a “cladding” formed outside the core. On the other hand, the “core” and “cladding” coated with a coating material are called “optical fiber strands”. That is, “optical fiber” is a concept including “optical fiber”.

  The optical connector ferrule 1 according to one embodiment of the present invention shown in FIGS. 1 to 3 is integrally formed of a synthetic resin material. The ferrule 1 for an optical connector includes a cylindrical engagement portion 10 located on the most distal side, an optical fiber positioning hole 20 located on the rear end side of the cylindrical engagement portion 10, and the optical fiber positioning hole 20. An optical fiber fixing hole 30 located on the rear end side and an adhesive injection hole 40 opened on the outer peripheral surface (opened in a direction orthogonal to the axial direction) are formed. 2 and 3, for reference, the optical fiber 81 (optical fiber strand 82) and the counterpart ferrule 90 fixed to the optical connector ferrule 1 are indicated by dotted lines.

  The cylindrical engagement part 10 is a cylindrical part with which the other party ferrule 90 engages inside. Specifically, it is a portion in which a cylindrical side wall 11 having a circular cross section extending from the periphery of the butting surface 1s to the counterpart ferrule 90 is formed (in other words, the inner bottom surface of the cylindrical engaging portion 10). Is the butting surface 1s with the counterpart ferrule 90).

  A slit 111 extending in the axial direction is formed on the side wall 11 of the cylindrical engagement portion 10. Therefore, a cross section obtained by cutting the cylindrical engaging portion 10 along a plane orthogonal to the axial direction has a substantially “C” shape (see FIG. 4). The slit 111 makes it easier for the side wall 11 of the cylindrical engagement portion 10 to expand outward. The inner periphery of the cylindrical engagement portion 10 is formed slightly smaller than the diameter of the counterpart ferrule 90 engaged with the cylindrical engagement portion 10, and the cylindrical engagement is achieved by inserting the counterpart ferrule 90. The side wall 11 of the part 10 is slightly expanded. Therefore, the inserted counterpart ferrule 90 is clamped inward by the elastic force of the side wall 11 of the cylindrical engaging portion 10 and is held without rattling inside the cylindrical engaging portion 10. In this state, the butting surface (tip surface) of the mating ferrule 90 is butted against the butting surface 1s of the optical connector ferrule 1 according to the present embodiment. The axial deviation from the optical fiber 81 fixed to the optical connector ferrule 1 is suppressed.

  For example, as shown in FIG. 5, two or more slits 111 may be formed in the circumferential direction of the cylindrical engaging portion 10 (three slits 111 are formed in FIG. 4). The number of slits 111 to be formed may be reduced when the counterpart ferrule 90 is firmly engaged with the cylindrical engaging portion 10, and may be increased when it is loosely engaged (easy to insert and remove). Further, when two or more slits 111 are formed in one cylindrical engaging portion 10, the slits 111 are formed at equal intervals in the circumferential direction of the cylindrical engaging portion 10 as shown in the figure. That's fine. In order to cause the side wall 11 of the cylindrical engagement portion 10 to be evenly expanded in the circumferential direction by the counterpart ferrule 90 inserted into the cylindrical engagement portion 10 (equal pressure in the circumferential direction is applied to the counterpart ferrule 90). To make it hang).

  Note that the “cylindrical shape” in the present embodiment includes other than the configuration having a circular cross section. For example, it includes all hollow shapes such as a so-called rectangular tube having a rectangular or triangular cross section and an elliptical cross section.

  The optical fiber positioning hole 20 is a through-hole formed continuously to the space inside the cylindrical engagement portion 10. Specifically, it is formed from the center of the inner bottom surface (butting surface 1s) of the cylindrical engagement portion 10 toward the rear end side in the axial direction, and is located on the same axis as the cylindrical engagement portion 10 (cylindrical engagement). The central axes of the portion 10 and the optical fiber positioning hole 20 are the same). That is, the distal end side opening of the optical fiber positioning hole 20 faces the space inside the cylindrical engagement portion 10. The diameter of the optical fiber positioning hole 20 is slightly larger than the diameter of the optical fiber 81 fixed to the optical connector ferrule 1. Specifically, the hole diameter is such that the optical fiber 81 can be easily inserted from the rear end side of the optical fiber positioning hole 20 and the inserted optical fiber 81 does not rattle in the optical fiber positioning hole 20. (The hole diameter is a so-called “clearance fit”). In addition, a tapered portion 21 is formed at the rear end of the optical fiber positioning hole 20 so that the diameter of the optical fiber 81 is increased toward the optical fiber fixing hole 30 so that the optical fiber 81 can be easily inserted. The optical fiber 81 is positioned in the radial direction by being inserted into the optical fiber positioning hole 20.

  The optical fiber fixing hole 30 is a through hole formed continuously to the optical fiber positioning hole 20. Specifically, the optical fiber positioning hole 20 has the same diameter as the taper portion 21 and is formed toward the rear end side in the axial direction, and is positioned on the same axis as the cylindrical engagement portion 10 and the optical fiber positioning hole 20 (cylindrical shape). The central axes of the engaging portion 10 and the optical fiber positioning hole 20 and the optical fiber fixing hole 30 are the same). The optical fiber fixing hole 30 is opened at the rear end face of the optical connector ferrule 1. From this opening, the optical fiber 81 is inserted up to the optical fiber positioning hole 20 (until the tip of the optical fiber 81 is flush with the butting surface 1s). As will be described later, in this embodiment, the optical fiber strand 82 in a state of being covered with a coating material is located in the optical fiber fixing hole 30. Therefore, the optical fiber fixing hole 30 is formed to have a diameter through which the optical fiber 82 can be inserted.

  The adhesive injection hole 40 is opened on the outer peripheral surface (upper side surface) of the optical connector ferrule 1, and the adhesive injection hole is formed such that the opposite side of the opening 41 is connected to the peripheral surface side of the optical fiber fixing hole 30. It is. Specifically, the center line (axis line) of the adhesive injection hole 40 is the axis line of the optical connector ferrule 1 (center line of the cylindrical engagement portion 10, the optical fiber positioning hole 20, and the optical fiber fixing hole 30). Orthogonal to The opening 41 of the adhesive injection hole 40 is formed in a tapered shape so that the size of the opening 41 expands outward in order to facilitate injection of the adhesive. The optical fiber 82 including the optical fiber 81 is bonded and fixed in the optical fiber fixing hole 30 by the adhesive injected from the adhesive injection hole 40. That is, the optical fiber 81 (optical fiber strand 82) is inserted from the optical fiber fixing hole 30, and the optical fiber 81 is positioned in the radial direction by the optical fiber positioning hole 20 (the end of the optical fiber 81 is the butted surface 1s). And an optical fiber 81 (optical fiber element) by injecting adhesive from the adhesive injection hole 40 in a state where the optical fiber strand 82 is positioned in the optical fiber fixing hole 30. Line 82) is adhered and fixed to the optical connector ferrule 1 at a predetermined position. At this time, the optical fiber 81 is connected to the optical fiber 81 in a state in which a member that becomes a wall that closes the opening on the distal end side of the optical fiber positioning hole 20 is in contact with the inner bottom surface (butting surface 1s) of the cylindrical engagement portion 10. If inserted into the positioning hole 20, the tip of the optical fiber 81 and the butting surface 1s can be flush with each other.

  Thus, in this embodiment, after inserting the optical fiber 81 in the ferrule 1 for optical connectors, the optical fiber 81 can be fixed by injecting an adhesive. That is, “post-adhesive adhesive” is possible.

  The fixing of the optical fiber 81 to the optical connector ferrule 1 does not necessarily have to be bonded and fixed in the optical fiber fixing hole 30 in the state of the optical fiber strand 82, and the covering material is peeled off. A configuration in which the optical fiber 81 is bonded and fixed may be employed. That is, at least “optical fiber” (regardless of the presence or absence of a covering material) may be configured to be bonded and fixed to the optical connector ferrule 1 in the optical fiber fixing hole 30. Further, the center line of the adhesive injection hole 40 and the axis line of the optical connector ferrule 1 are not necessarily orthogonal to each other. If the opening 41 of the adhesive injection hole 40 is formed on the outer peripheral surface of the optical connector ferrule 1 so that the adhesive can be injected from the outer peripheral surface side of the optical connector ferrule 1 (toward the direction intersecting the axial direction). As long as it is open).

  According to the ferrule 1 for an optical connector according to one embodiment of the present invention described above, the following operational effects are exhibited.

  The ferrule 1 for an optical connector according to the present embodiment includes an optical fiber positioning hole 20 for positioning the optical fiber 81 and an optical fiber fixing hole for fixing the optical fiber 81 by the cylindrical engaging portion 10 with which the counterpart ferrule 90 is engaged. 30 and an integral molding. That is, since the configuration that suppresses axial misalignment with the counterpart ferrule 90, which is conventionally performed by the "split sleeve", is formed as the cylindrical engagement portion 10 on the ferrule itself, the entire ferrule in the axial direction is formed. The size can be reduced.

  This point will be described in detail with reference to FIG. FIG. 6 shows a configuration using a ferrule 1 for an optical connector according to the present embodiment and a conventional split sleeve (a configuration using a split sleeve 100 and a ferrule 101. Hereinafter, it may be simply referred to as a conventional configuration). It is a figure which compares the length in an axial direction. For reference, in FIG. 6, as in FIGS. 2 and 3, the optical fiber 81 (optical fiber strand 82) and the counterpart ferrule 90 are indicated by dotted lines. In both configurations, the counterpart ferrule engagement allowance X1 with which the counterpart ferrule 90 engages (the length of the cylindrical engagement portion 10 in the optical connector ferrule 1), and the optical fiber positioning for positioning the optical fiber 81 in the radial direction. Allowance X2 (the length of the optical fiber positioning hole 20 in the optical connector ferrule 1) and an optical fiber fixing allowance X3 for fixing the optical fiber 81 to the ferrule (in the optical connector ferrule 1, the optical fiber fixing hole 30). Are all set to the same length. In the conventional configuration, the length of the ferrule 101 inserted into the split sleeve 100 is usually set to be the same as the length of the counterpart ferrule 90 inserted into the split sleeve 100. That is, the attachment allowance (contact allowance) X4 for attaching the split sleeve 100 to the ferrule 101 is set to the same length as the counterpart ferrule engagement allowance X1 with which the counterpart ferrule 90 is engaged.

  As shown in FIG. 6A, the length in the axial direction of the optical connector ferrule 1 according to the present embodiment is “X1 + X2 + X3”. On the other hand, as shown in FIG. 6B, the length in the axial direction of the conventional configuration is “X1 + X2 + X3 + X4”. In other words, the conventional configuration is longer in the axial direction by the attachment allowance X4 for attaching the split sleeve 100. As described above, according to the ferrule 1 for an optical connector according to the present embodiment, it is not necessary to secure an attachment allowance for attaching the split sleeve 100, so that the length in the axial direction can be reduced.

  In the conventional configuration, it is also possible to design the region of the attachment allowance X4 of the split sleeve 100 so as to double as the region of the optical fiber positioning allowance X2. However, the mounting allowance X4 requires a length for attaching the split sleeve 100 to the ferrule 101 in a stable state (so as not to tilt), whereas the optical fiber positioning allowance X2 abuts the tip of the optical fiber 81. Since it is sufficient that the length can be positioned at the center of the surface (it is possible to set the length relatively small), the mounting allowance X4 of the split sleeve 100 is more than the optical fiber positioning allowance X2. Usually it must be set longer. That is, even if the region of the mounting allowance X4 is designed to be used as the region of the optical fiber positioning allowance X2, the conventional configuration is still longer in the axial direction.

  In the present embodiment, the cylindrical engagement portion 10 can be configured as a ferrule as described above because the adhesive injection hole 40 that is opened in the outer peripheral surface of the optical connector ferrule 1 is formed. . Specifically, it is as follows. When the cylindrical engagement portion 10 is formed, the abutting surface 1 s with the counterpart ferrule 90 becomes the inner bottom surface of the cylindrical engagement portion 10. Therefore, the side wall 11 of the cylindrical engaging portion 10 becomes an obstacle, and the work of polishing (mirror finish) the butting surface 1s with the counterpart ferrule 90 becomes difficult (impossible). For example, after injecting the adhesive into the ferrule, if the optical fiber is inserted into the ferrule and bonded and fixed (adhesive is put in first), the tip of the optical fiber inserted later Since the adhesive always adheres, polishing the butting surface 1s with the counterpart ferrule is an indispensable operation. Therefore, the difficulty of the polishing operation due to the presence of the cylindrical engagement portion 10 becomes a problem.

  On the other hand, in this embodiment, since the adhesive injection hole 40 in which the opening 41 is located is formed on the outer peripheral surface of the optical connector ferrule 1, it is not necessary to polish the butted surface 1s with the counterpart ferrule 90. That is, the optical fiber 81 is inserted through the optical fiber fixing hole 30 and the optical fiber positioning hole 20 until the tip of the optical fiber 81 is flush with the abutting surface 1s with the counterpart ferrule 90, and then the adhesive is injected. Since the optical fiber 81 can be bonded and fixed in the ferrule fixing hole by the adhesive injected from the hole 40 (adhesion of the adhesive can be performed later), it is not necessary to polish the abutting surface 1s with the counterpart ferrule 90. is there. In other words, in the present embodiment, the formation of the cylindrical engagement portion 10 is prevented by forming the adhesive injection hole 40 that opens on the outer peripheral surface of the ferrule 1 for an optical connector.

  Moreover, according to this embodiment, since the cylindrical engaging part 10 with which the other party ferrule 90 engages is comprised by ferrule itself (it is the structure integrally formed), a split sleeve etc. are unnecessary, and parts processing Lead to easier and fewer parts. That is, the manufacturing cost is reduced.

  In addition, the cylindrical engaging portion 10 is formed with a slit 111 for suppressing an axial deviation with the counterpart ferrule 90 to be abutted, but the cylindrical engaging portion 10 formed by integral molding has its wall thickness. Since the thickness can be set freely, it is possible to ensure strength that does not easily break or deform.

  Moreover, since the cylindrical engaging part 10 is formed in ferrule itself by integral molding, it can be formed in two or more places in the circumferential direction. For example, in the case of a split sleeve used in the conventional configuration, if two or more slits are formed, the split sleeve itself is divided into two or more, and therefore the slit can be formed only in one place. On the other hand, in this embodiment, since the cylindrical engaging part 10 is connected with the part in which the optical fiber positioning hole 20 and the optical fiber fixing hole 30 are formed, it is a cylinder even if two or more slits 111 are formed. The shape engaging portion 10 is not divided. That is, by adjusting the number of the slits 111, it is possible to select to firmly engage the counterpart ferrule 90 with the cylindrical engaging portion 10 or to select loose engagement (to facilitate insertion / removal).

  Next, an application example of the optical connector ferrule 1 will be described. FIG. 7 is a schematic diagram (cross-sectional view) of an in-vehicle optical connector and an optical cable assembly 2 (an optical connector and an optical cable assembly according to an embodiment of the present invention) to which the optical connector ferrule 1 is applied. ).

  The in-vehicle optical connector / optical cable assembly 2 shown in FIG. 7 includes an in-vehicle optical connector 50 and an optical cable 60 assembled thereto. The in-vehicle optical connector 50 includes a connector housing 51 and an optical connector ferrule 1 disposed in the connector housing 51. This in-vehicle optical connector 50 is used as an optical communication connector for various electrical components equipped in an automobile.

  The optical cable 60 includes an optical fiber 61 and a sheath 62 that covers the optical fiber. Note that a reinforcing member (for example, an aramid fiber) that reinforces the optical cable 60 is generally disposed in the sheath 62. The optical fiber 61 included in the optical cable 60 is a so-called multimode optical fiber. The multimode optical fiber 61 is bonded and fixed to the optical connector ferrule 1 with an adhesive as described above. The optical cable 60 is attached to the connector housing 51 so as not to be pulled out even when pulled. The attachment method is not particularly limited. As an example of the attachment method, as shown in FIG. 7, there is a configuration in which the attachment is made to the connector housing 51 via an engagement member 621 fixed to the sheath 62.

  Generally, in-vehicle optical connectors, once the optical connectors are fitted together, the fitting is not canceled unless there are special circumstances such as repair. That is, the number of connector insertions / removals is small. In addition, the multimode optical fiber has a larger core diameter than the single mode optical fiber, and the fibers can be easily connected to each other. The optical connector ferrule 1 described in detail above is particularly effective when used under such conditions.

  Although the embodiments of the present invention have been described in detail above, the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the gist of the present invention.

  For example, FIG. 8 is an example showing another embodiment of the present invention. In one optical connector ferrule 1a, a cylindrical engagement portion 10a, an optical fiber positioning hole 20a, and an optical fiber fixing hole 30a are arranged in the width direction. Two are formed. That is, the optical connector ferrule 1a shown in FIG. 8 is a two-fiber ferrule capable of connecting two optical fibers at a time. Optical communication is often used in two-fiber pairs for transmission and reception, and the number of parts can be reduced by using such a two-fiber ferrule. In this configuration, the adhesive injection hole 40a may be formed as two continuous with the two fiber fixing holes 30a as shown in FIG. 8, or continuous with both of the two fiber fixing holes 30a. One thing may be formed.

DESCRIPTION OF SYMBOLS 1 Optical connector ferrule 2 Vehicle-mounted optical connector and optical cable assembly 10 Cylindrical engagement part 111 Slit 20 Optical fiber positioning hole 30 Optical fiber fixing hole 40 Adhesive injection hole 50 Automotive optical connector 60 Optical cable 61 Optical fiber 81 Light Fiber 90 Counter ferrule

Claims (4)

An optical connector ferrule formed integrally,
In order from the tip along the axial direction,
A cylindrical tubular engaging portion with which the counterpart ferrule is engaged;
An optical fiber positioning hole that is continuous with the space inside the cylindrical engagement portion and in which the optical fiber is positioned in the radial direction;
An optical fiber fixing hole that is connected to the optical fiber positioning hole and to which the optical fiber is bonded and fixed is formed.
A ferrule for an optical connector, characterized in that an adhesive injection hole that is continuous with the peripheral surface side of the optical fiber fixing hole and opens on the outer peripheral surface is formed.   The ferrule for an optical connector according to claim 1, wherein a slit is formed in the cylindrical engagement portion in the axial direction.   The ferrule for an optical connector according to claim 2, wherein the slit is formed at two or more locations in a circumferential direction of the cylindrical engagement portion. An optical connector and an optical cable assembly in which an optical cable is assembled to an optical connector in which the optical connector ferrule according to any one of claims 1 to 3 is disposed,
The optical cable has an optical fiber,
An assembly of an optical connector and an optical cable, wherein the optical fiber is fixed to an optical connector ferrule disposed on the optical connector.

Images