In-vehicle optical connector unit

Abstract

An in-vehicle optical connector unit 10 comprises: optical fibers 111, 121; an optical connector 20 that connects the optical fibers 111, 121 to each other; a case 70 that houses the optical connector 20; a cover 80 that covers the case 70; a cushioning member 91 that is interposed between the optical connector 20 and the case 70; and a cushioning member 92 that is interposed between the optical connector 20 and the cover 80. The optical connector 20 comprises a pair of ferrules 31, 41 that respectively hold the optical fibers 111, 121 and respectively have connection end surfaces 311, 411 where end surfaces of the optical fibers 111, 121 are exposed, and a clamp spring 50 that presses the pair of ferrules 31, 41 against each other during a condition in which the connection end surfaces 311, 411 are in contact with each other.

Description

In-vehicle optical connector unit

[0001] The present invention relates to an in-vehicle optical connector unit. For designated countries where incorporation by reference of documents is permitted, the content of Japanese Patent Application No. 2024-150200, filed in Japan on August 30, 2024, is incorporated by reference into this specification and made a part of the description of this specification.

[0002] A known multi-fiber optical connector for connecting optical fibers together is the MT (Mechanical Transferable) connector, standardized as an "F12-type multi-fiber optical fiber connector" in JIS C5981 (see, for example, Patent Document 1 (paragraphs

[0002] to

[0003] , Figure 4)). This MT connector includes a pair of ferrules, a pair of guide pins, and a clamp spring for mounting the ferrules. The pair of ferrules are brought into contact with each other, and multiple optical fibers exposed at the connecting end surface of one ferrule are respectively opposed to multiple optical fibers exposed at the connecting end surface of the other ferrule, thereby optically connecting the optical fibers together.

[0003] Japanese Patent Application Laid-Open No. 2007-47456

[0004] When the above-mentioned MT connector is used to connect optical fibers inside an automobile, external loads such as shocks and vibrations may be applied to the MT connector during the manufacture of the automobile or while the automobile is running. Such external loads may cause the connecting end faces of the ferrules to become misaligned, making it impossible to maintain a highly accurate opposing state between the optical fibers, which may result in a deterioration of the optical characteristics.

[0005] An object of the present invention is to provide an on-vehicle optical connector unit that can suppress deterioration of optical characteristics.

[0006] [1] Aspect 1 of the present invention is an on-vehicle optical connector unit comprising: a plurality of optical fibers; an optical connector for connecting the optical fibers; a case for accommodating the optical connector; a cover for covering the case; a first buffer member interposed between the optical connector and the case; and a second buffer member interposed between the optical connector and the cover, wherein the optical connector comprises a pair of ferrules that hold the optical fibers, each ferrule having a connection end face at which an end face of the optical fiber is exposed, and a clamp spring that presses the pair of ferrules against each other while the connection end faces are in contact with each other.

[0007] [2] Aspect 2 of the present invention may be an in-vehicle optical connector unit according to aspect 1, wherein the case has a first main surface extending in a direction perpendicular to the thickness direction of the ferrule and includes a bottom plate that holds the optical connector, the cover has a second main surface extending parallel to the first main surface and includes a lid plate that covers the optical connector housed in the case, the first buffer member is a sheet-like member extending between the first main surface and the optical connector, and the second buffer member is a sheet-like member extending between the second main surface and the optical connector.

[0008] [3] Aspect 3 of the present invention may be an in-vehicle optical connector unit according to aspect 1 or 2, wherein the case comprises a bottom plate that holds the optical connector and a pair of first pillar portions provided on the bottom plate so as to face the rear end surface of the ferrule, and the optical fiber passes between the pair of first pillar portions.

[0009] [4] Aspect 4 of the present invention may be an in-vehicle optical connector unit according to aspect 3, wherein the optical connector has the optical fiber inserted therein and a first boot attached to the rear end surface of the ferrule, and the first boot is interposed between the first pillar portion and the ferrule.

[0010] [5] Aspect 5 of the present invention may be an in-vehicle optical connector unit according to aspect 3 or 4, wherein the first pillar portion has an inner surface facing the rear end face of the ferrule and an outer surface opposite the inner surface, and the outer surface has an arc-shaped cross-sectional shape.

[0011] [6] Aspect 6 of the present invention may be an in-vehicle optical connector unit according to any one of aspects 1 to 5, wherein the case comprises a bottom plate that holds the optical connector, a second pillar portion provided on the bottom plate so as to face the central portion of the optical connector, and a first side plate provided on the bottom plate so as to face the end portion of the optical connector, and wherein a first gap between the optical connector and the first side plate is wider than a second gap between the optical connector and the second pillar portion.

[0012] [7] Aspect 7 of the present invention may be an in-vehicle optical connector unit according to aspect 6, wherein the side plate has a protrusion that protrudes toward the outside of the case, the cover has a cover plate that covers the optical connector, and a second side plate provided on the cover plate to correspond to the first side plate, the second side plate has an opening with which the protrusion can engage, and the cover is detachable from the case.

[0013] [8] Aspect 8 of the present invention is an in-vehicle optical connector unit according to any one of aspects 1 to 7, wherein the case comprises a bottom plate that holds the optical connector and a pair of first pillars that are provided on the bottom plate so as to face the rear end surface of the ferrule, the optical fiber passes between the pair of first pillars, and the in-vehicle optical connector unit may be an in-vehicle optical connector unit that comprises a second boot into which the optical fiber is inserted and that is positioned outside the first pillars.

[0014] [9] Aspect 9 of the present invention may be an in-vehicle optical connector unit in any one of aspects 1 to 8, wherein the case has a bottom plate that holds the optical connector, and the bottom plate has an attachment portion for attaching the in-vehicle optical connector unit to a mounting body.

[0015]

[10] Aspect 10 of the present invention may be an in-vehicle optical connector unit according to any one of aspects 1 to 9, wherein the clamp spring is interposed between the first buffer member and the pair of ferrules.

[0016] According to the present invention, an in-vehicle optical connector unit includes a case that houses an optical connector, a cover that covers the case, a first buffer member interposed between the optical connector and the case, and a second buffer member interposed between the optical connector and the cover. This prevents the connection end faces of a pair of ferrules from shifting due to an external load applied to the optical connector unit, and prevents deterioration of the optical characteristics of the optical connector unit.

[0017] Fig. 1 is a side view showing a vehicle equipped with an optical connector unit according to an embodiment of the present invention. Fig. 2 is a perspective view showing the optical connector unit according to an embodiment of the present invention. Fig. 3 is an exploded perspective view of the optical connector unit according to an embodiment of the present invention. Fig. 4 is a perspective view showing an optical connector according to an embodiment of the present invention. Fig. 5 is a cross-sectional view taken along line VV in Fig. 2. Fig. 6 is a plan view showing the optical connector unit according to an embodiment of the present invention with the cover and upper buffer member removed. Fig. 7 is an exploded perspective view showing a modified example of the optical connector unit according to an embodiment of the present invention.

[0018] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0019] FIG. 1 is a side view showing a vehicle 1 equipped with an optical connector unit 10 according to this embodiment.

[0020] 1, the optical connector unit 10 in this embodiment is mounted on a vehicle 1 to connect optical fiber ribbons 11, 12 inside the vehicle 1. Specific examples of the vehicle 1 include electric vehicles such as electric vehicles (EVs) and hybrid electric vehicles (HEVs), and internal combustion engine vehicles that use gasoline or the like as fuel.

[0021] For example, an antenna device 3 is installed on a front bumper 2 of a vehicle 1. An example of the antenna device 3 is, but is not limited to, a millimeter-wave antenna array module. The antenna device 3 includes a circuit board 5 and an optical connector unit 10. The circuit board 5 includes a wiring board 6, an antenna element 7, and a photoelectric conversion element 8. The antenna element 7 and the photoelectric conversion element 8 are mounted on the wiring board 6. The photoelectric conversion element 8 is a circuit element fabricated using, for example, silicon photonics technology. The antenna element 7 and the photoelectric conversion element 8 are electrically connected via electrical wiring 9 on the wiring board 6. The photoelectric conversion element 8 is optically connected to an on-board ECU (Electronic Control Unit) 4 via the optical connector unit 10. Note that the use of the optical connector unit 10 is not particularly limited to the above, as long as it is installed in the vehicle 1.

[0022] The configuration of the optical connector unit 10 in this embodiment will be described below with reference to FIGS.

[0023] Fig. 2 is a perspective view showing the optical connector unit 10 in this embodiment, Fig. 3 is an exploded perspective view of the optical connector unit 10 in this embodiment, Fig. 4 is a perspective view showing the optical connector 20 in this embodiment, and Fig. 5 is a cross-sectional view taken along line VV in Fig. 2. Fig. 6 is a plan view showing the optical connector unit 10 in this embodiment with the cover 80 and the buffer member 92 removed.

[0024] 2 to 6, the optical connector unit 10 of this embodiment includes optical fiber ribbons 11 and 12, an optical connector 20, a case 70, a cover 80, and buffer members 91 and 92. The buffer member 91 corresponds to an example of a "first buffer member" in this aspect of the present invention, and the buffer member 92 corresponds to an example of a "second buffer member" in this aspect of the present invention.

[0025] The optical fiber ribbon 11 includes a plurality of optical fibers 111. The plurality of optical fibers 111 are arranged in a row and collectively coated with a resin material. The plurality of optical fibers 111 may be intermittently continuous with the resin material. Similarly, the optical fiber ribbon 12 includes a plurality of optical fibers 121 arranged in a row and collectively coated with a resin material. The optical fibers 111, 121 correspond to an example of the "optical fiber" in the aspects of the present invention.

[0026] The optical connector 20 connects the optical fiber ribbons 11 and 12. The optical connector 20 includes a pair of optical connector plugs 30 and 40, a clamp spring 50, and a pair of guide pins 60.

[0027] One optical connector plug 30 includes a ferrule 31 and an inner boot 32. One end of the optical fiber ribbon 11 is optically connected to the photoelectric conversion element 8 on the circuit board 5. The ferrule 31 is attached to the other end of the optical fiber ribbon 11.

[0028] The ferrule 31 is a so-called MT (Mechanical Transferable) ferrule. The ferrule 31 is made of, but is not limited to, a hard resin material such as PPS (Poly Phenylene Sulfide). The ferrule 31 has a connecting end surface 311 at its tip that comes into contact with a connecting end surface 411 of a ferrule 41 of a mating optical connector plug 40.

[0029] The connecting end face 311 of the ferrule 31 is an inclined, obliquely polished end face. Although not particularly limited, this connecting end face 311 has an inclination angle of, for example, 8 degrees with respect to a direction perpendicular to the optical axis of the optical fiber 111. Note that the connecting end face 311 of the ferrule 31 may also be a flat, polished end face that is not inclined.

[0030] The ferrule 31 has a plurality of holding holes 312 penetrating the ferrule 31. The plurality of holding holes 312 are arranged at equal intervals in the width direction of the ferrule 31 (the X direction in the drawing) and extend parallel to one another. The plurality of holding holes 312 open at the connection end face 311.

[0031] The coating resin of the optical fiber ribbon 11 is removed from its end, exposing the optical fiber 111. The optical fiber 111 is inserted into each holding hole 312, and the end face of the optical fiber 111 is exposed from the connection end face 311 of the ferrule 31. The optical fiber 111 is fixed to the ferrule 31 with an adhesive.

[0032] The number of optical fibers 111 included in the optical fiber ribbon 11 is not particularly limited. The number of holding holes 312 included in the ferrule 31 can also be set according to the number of optical fibers 111 included in the optical fiber ribbon 11. The arrangement of the holding holes 312 on the connection end face 311 of the ferrule 31 is also not particularly limited to the above. For example, multiple holding hole rows, each having multiple holding holes 312 arranged in the width direction of the ferrule 31, may be arranged at intervals in the thickness direction of the ferrule 31 (Z direction in the figure).

[0033] The ferrule 31 also has a pair of guide holes 313 near both ends thereof. The pair of guide holes 313 penetrate the ferrule 31 and open at the connection end face 311. When connecting the optical connector plugs 30 and 40, guide pins 60 are inserted into the guide holes 313.

[0034] A cylindrical inner boot 32 is attached to the rear end face 314 of the ferrule 31. This inner boot 32 is a so-called MT boot. This inner boot 32 is made of a material that is softer than the material that constitutes the ferrule 31. This inner boot 32 is made of an elastically deformable material, such as rubber. The optical fiber 111 extending from the rear end face 314 of the ferrule 31 is inserted into this inner boot 32. The rear end face 314 of the ferrule 31 is the surface of the ferrule 31 opposite the connection end face 311, and is the surface of the ferrule 31 on the rear end side (the +Y side in the figure).

[0035] The other optical connector plug 40 also includes a ferrule 41 and an inner boot 42. One end of the optical fiber ribbon 12 is optically connected to the ECU 4. The ferrule 41 is attached to the other end of the optical fiber ribbon 12. The ferrule 41 has a configuration basically similar to that of the ferrule 31 of the optical connector plug 30. In this embodiment, the ferrules 31, 41, inner boots 32, 43, and guide pins 60 are the same as those of an existing MT connector, thereby reducing the cost of the optical connector unit 10.

[0036] The connecting end face 411 of this ferrule 41 is also an obliquely polished end face. Note that the connecting end face 311 of one ferrule 31 has an inclination such that the upper end protrudes toward the tip, while the connecting end face 411 of the other ferrule 41 has an inclination such that the lower end protrudes toward the tip. This complementary inclination allows the connecting end faces 311, 411 of the ferrules 31, 41 to come into close contact with each other.

[0037] The ferrule 41 has a plurality of holding holes 412 that penetrate the ferrule 41 and open at the connection end face 411. The plurality of holding holes 412 are arranged to face the holding holes 312 of the ferrule 31. The coating resin of the optical fiber ribbon 12 is removed from its end, exposing the optical fibers 121. The optical fibers 121 are inserted into the respective holding holes 412, and the end faces of the optical fibers 121 are exposed from the connection end face 411 of the ferrule 41. The optical fibers 121 are fixed to the ferrule 41 with an adhesive.

[0038] The ferrule 41 also has a pair of guide holes 413 penetrating the ferrule 41. The pair of guide holes 413 open at the connection end face 411 so as to face the guide holes 313 of the ferrule 31. When connecting the optical connector plugs 30 and 40, guide pins 60 are inserted into the guide holes 413.

[0039] A cylindrical inner boot 42 is attached to the rear end face 414 of the ferrule 41. Like the inner boot 42 of the optical connector plug 30 described above, this inner boot 42 is also made of an elastically deformable material such as rubber. The optical fiber 121 extending from the rear end face 414 of the ferrule 41 is inserted into this inner boot 42. The rear end face 414 of the ferrule 41 is the face of the ferrule 41 opposite the connection end face 411, and is the face of the ferrule 41 on the rear end side (the -Y side in the figure).

[0040] The clamp spring 50 includes a plate portion 51 and four arms 52, 53 protruding from the four corners of the plate portion 51. The clamp spring 50 is made of a metal material and is capable of elastic deformation. When the clamp spring 50 is attached to the ferrules 31, 41 with their connecting end faces 311, 411 butted together, the pair of arms 52 press against the rear end face 314 of one ferrule 31, and the pair of arms 53 press against the rear end face 414 of the other ferrule 41. At this time, by bringing the ferrules 31, 41 close to each other with guide pins 60 inserted into the guide holes 313, 413, the connecting end faces 311, 411 are accurately positioned relative to each other. In addition, the arm portions 52, 53 of the clamp spring 50 block the openings of the guide holes 313, 314 in the rear end faces 311, 411 of the ferrules 31, 41, thereby preventing the guide pins 60 installed in the guide holes 313, 314 of the ferrules 31, 41 from falling out of the rear end faces 311, 411 of the ferrules 31, 41.

[0041] In this manner, with the pair of ferrules 31, 41 pressed against each other, the optical connector plugs 30, 40 are joined by the clamp spring 50. One of the inner boots 32 extends outward (toward the +Y side in the figure) from between the pair of arm portions 52. The other inner boot 42 also extends outward (toward the -Y side in the figure) from between the pair of arm portions 53.

[0042] The optical connector 20 is housed in a case 70. The case 70 includes a bottom plate 71, pillars 72 to 74, and side plates 75 and 76. The case 70 is made of, for example, a thermoplastic resin material with excellent heat resistance and environmental resistance. While not particularly limited, a specific example of the thermoplastic resin material that makes up the case 70 is polybutylene terephthalate (PBT) containing glass fiber. The bottom plate 71, pillars 72 to 74, and side plates 75 and 76 are integrally formed. The pillars 72 and 73 correspond to an example of a "first pillar" in this aspect of the present invention, the pillar 74 corresponds to an example of a "second pillar" in this aspect of the present invention, and the side plates 75 and 76 correspond to an example of a "first side plate" in this aspect of the present invention.

[0043] The bottom plate 71 has a flat plate shape and holds the optical connector 20. An upper surface 711 of the bottom plate 71 is a plane extending in a direction perpendicular to the thickness direction of the ferrules 31 and 41 (the Z direction in the figure). The bottom plate 71 holds the optical connector 20 via a sheet-like buffer member 91. The lower surface of the optical connector 20 (specifically, the lower surfaces of the ferrules 31 and 41) contacts the upper surface of the buffer member 91, and the lower surface of the buffer member 91 contacts the upper surface 711 of the bottom plate 71. The upper surface 711 of the bottom plate 71 corresponds to an example of a "first main surface" in this aspect of the present invention.

[0044] The buffer member 91 is a sheet-like member made of rubber that has excellent shock and vibration absorption properties. A specific example of the rubber that makes up the buffer member 91 is, but is not limited to, vibration-damping rubber such as nitrile rubber. The buffer member 91 is fixed to the upper surface 711 of the bottom plate 71 with, for example, an adhesive. The buffer member 91 absorbs external loads such as shocks and vibrations applied to the optical connector unit 10 during the manufacture of the vehicle 1 or while the vehicle 1 is running, thereby suppressing the transmission of the external loads to the optical connector 20.

[0045] In particular, the MT ferrule 31 (41) has a rectangular cross-sectional shape (i.e., a flat cross-sectional shape) with a high aspect ratio, and the thickness t (see FIG. 3) of the MT ferrule 31 (41) is smaller than the width w (see FIG. 3) of the MT ferrule 31 (41) (t<w). This makes the optical connector 20 more susceptible to bending in its thickness direction (Z direction in the figure). Therefore, the thickness direction (Z direction in the figure) component of the external load applied to the optical connector unit 10 during automobile manufacturing or operation has a greater impact on the optical characteristics of the optical connector 20 than the width direction (X direction in the figure). In contrast, in this embodiment, the buffer member 91 is disposed in the thickness direction (Z direction in the figure) of the optical connector 20, thereby efficiently suppressing degradation of the optical characteristics of the optical connector 20 due to the external load.

[0046] The pillars 72 to 74 and the side plates 75 and 76 are erected on the outer edges of the upper surface 711 of the bottom plate 71 .

[0047] The pair of pillars 72 are provided on one short side (the +Y side in the drawing) of the bottom plate 71. The optical fiber ribbon 11 extending from one optical connector plug 30 passes between the pair of pillars 72 and extends to the outside of the case 70. The spacing S between the pair of pillars 72 is １ is the width W of the optical fiber ribbon 11 １ is larger than (S １ >W １ ) (see Figure 6).

[0048] The pillar portion 72 has an inner surface 721 and an outer surface 722 opposite the inner surface 721. The inner surface 721 faces the rear end surface 314 of the ferrule 31 and has a linear cross-sectional shape. An inner boot 32 is interposed between the inner surface 721 and the ferrule 31. When the optical connector 20 moves inside the case 70 due to an external load, the inner boot 32 can mitigate the impact that the optical connector 20 receives.

[0049] Furthermore, the outer surface 722 of the pillar portion 72 has an arc-shaped cross section. The arc-shaped cross section of the outer surface 722 protrudes convexly toward the outside of the case 70. The outer surface 722 can prevent the optical fiber 111 from being damaged when the optical fiber ribbon 11 comes into contact with the pillar portion 72.

[0050] 5 and 6 , a portion of the optical fiber ribbon 11 located outside the case 70 relative to the column portion 72 may be covered with an outer boot 33. This outer boot 33 is a tubular member made of an elastically deformable material such as rubber, similar to the above-mentioned inner boot 32. This outer boot 33 can suppress damage to the optical fibers 111 caused by contact of the optical fiber ribbon 11 with surrounding members.

[0051] The pair of pillars 73 are provided on the other short side (the -Y side in the drawing) of the bottom plate 71. The optical fiber ribbon 12 extending from the other optical connector plug 40 passes between the pair of pillars 73 and extends to the outside of the case 70. The spacing S between the pair of pillars 73 is２ is the width W of the optical fiber ribbon 12 ２ is larger than (S ２ >W ２ ) (see Figure 6).

[0052] Like the above-described columnar portion 72, the columnar portion 73 also has an inner surface 731 facing the rear end surface 414 of the ferrule 41. An inner boot 42 is interposed between the inner surface 731 and the ferrule 41, and the inner boot 42 can mitigate the impact that the optical connector 20 receives from the case 70.

[0053] Furthermore, like the above-described column portion 72, the column portion 73 has an outer surface 732 with an arc-shaped cross section. The arc-shaped cross section of the outer surface 732 protrudes convexly toward the outside of the case 70. The outer surface 732 can prevent the optical fiber 121 from being damaged when the optical fiber ribbon 12 comes into contact with the column portion 73.

[0054] 5 and 6 , a portion of the optical fiber ribbon 12 located outside the case 70 relative to the column portion 73 may be covered with an outer boot 43. Similar to the inner boot 42 described above, the outer boot 43 is a tubular member made of an elastically deformable material such as rubber. The outer boot 43 can suppress damage to the optical fibers 121 caused by contact of the optical fiber ribbon 12 with surrounding members.

[0055] A pair of pillars 74 are provided on the long sides of the bottom plate 71. The pillars 74 are provided on the bottom plate 71 so as to be located to the sides of the central portion of the optical connector 20. That is, the pillars 74 face the side surfaces of the central portion of the optical connector 20 and restrict movement of the optical connector 20 in the width direction (X direction in the figure). The central portion of the optical connector 20 is a portion of the optical connector 20 that includes the center CP of the optical connector 20 (see FIG. 6 ). In this embodiment, the central portion of the optical connector 20 is a central portion that includes the connection end faces 311, 411 of the pair of ferrules 31, 41 that are in contact with each other.

[0056] Four side plates 75, 76 are also provided on the long sides of the bottom plate 71. These side plates 75, 76 are provided on the bottom plate 71 so as to be located on the sides of the end portions of the optical connector 20 relative to the central portion. In other words, these side plates 75, 76 face the side surfaces of the end portions of the optical connector 20. Note that the end portions of the optical connector 20 are portions of the optical connector 20 closer to the rear end of the optical connector 20 (the +Y side or −Y side in the figure) than the central portion. In this embodiment, the end portions of the optical connector 20 are portions of the pair of ferrules 31, 41 closer to the rear end of the optical connector 20 (the +Y side or −Y side in the figure) than the central portion.

[0057] The four side plates 75, 76 are arranged adjacent to the pillar portion 74. The pair of side plates 75 are arranged to sandwich one pillar portion 74 (the +X side in the figure). On the other hand, the pair of side plates 76 are arranged to sandwich the other pillar portion 72 (the -X side in the figure). The side plates 75, 76 each have protrusions 751, 761 that protrude toward the outside of the case 70.

[0058] Gap C between the optical connector 20 and the side plate 75 １ is the gap C between the optical connector 20 and one of the pillars 74 ３ It is wider than (C １ >C ３ Similarly, the gap C between the optical connector 20 and the side plate 76 ２ is the gap C between the optical connector 20 and the other column portion 74 ４ It is wider than (C ２ >C ４ ). Therefore, rotation of the optical connector 20 within the case 70 (rotation as indicated by arrow R around the center P of the optical connector 20 in FIG. 6 ) is permitted. As a result, even if the optical fiber ribbons 11, 12 are pulled in the X direction in the figure outside the case 70, the optical connector 20 is rotatable, and damage to the optical fibers 111, 121 can be suppressed.

[0059] In this embodiment, the gap C １ is the gap between the ferrule 31 (41) and the side plate 75, and the gap C ３is a gap between the ferrule 31 (41) and one of the pillar portions 74. In this embodiment, the gap C ２ is the gap between the ferrule 31 (41) and the side plate 76, and the gap C ４ is the gap between the ferrule 31 (41) and the other post 74. １ , C ２ corresponds to an example of the "first gap" in the embodiment of the present invention, and the gap C ３ , C ４ corresponds to an example of the "second gap" in this aspect of the present invention.

[0060] Two fixing holes 712 are formed in the bottom plate 71 of the case 70. For example, bolts 77 (see FIG. 1 ) may be inserted into the fixing holes 712, and the case 70 may be directly fixed to the circuit board 5 by the bolts 77. Alternatively, although not specifically shown, the case 70 may be indirectly fixed to the circuit board 5 by fixing the case 70 to a member fixed to the circuit board 5. The fixing holes 712 correspond to an example of a "fixing portion" in this aspect of the present invention, and the circuit board 5 corresponds to an example of a "receiving body" in this aspect of the present invention. Note that the object (receiving body) to which the case 70 is fixed is not limited to the circuit board 5 described above.

[0061] The cover 80 covers the case 70 from above and is supported by the pillars 72 to 74 of the case 70. The cover 80 includes a lid plate 81 and side plates 82 and 83. Like the case 70 described above, the cover 80 is made of, for example, a thermoplastic resin material that has excellent heat resistance and environmental resistance. Although not particularly limited, a specific example of the thermoplastic resin material that makes up the cover 80 is polybutylene terephthalate (PBT) containing glass fiber. The lid plate 81 and the side plates 82 and 83 are integrally formed. The side plates 82 and 83 correspond to an example of a "second side plate" in this aspect of the present invention.

[0062] The cover plate 81 has a flat plate shape and covers the optical connector 20 housed in the case 70. A lower surface 811 of the cover plate 81 is also a plane extending in a direction perpendicular to the thickness direction of the ferrules 31, 41 (the Z direction in the figure). The lower surface 811 extends parallel to the upper surface 711 of the bottom plate 71 of the case 70. The cover plate 81 covers the optical connector 20 via a sheet-like buffer member 92. The lower surface 811 of the cover plate 81 contacts the upper surface of the buffer member 92, and the lower surface of the buffer member 92 contacts the upper surface of the optical connector 20 (specifically, the upper surface of the plate portion 51 of the clamp spring 50). The lower surface 811 of the cover plate 81 corresponds to an example of a "second main surface" in this aspect of the present invention.

[0063] The buffer member 92 is a sheet-like member made of rubber that has excellent shock and vibration absorption properties, similar to the buffer member 91 described above. Specific examples of the rubber that makes up the buffer member 92 include, but are not limited to, vibration-damping rubber such as nitrile rubber. The buffer member 92 is fixed to the lower surface 811 of the cover plate 81 with, for example, an adhesive.

[0064] The buffer member 92 absorbs the external load applied to the optical connector unit 10, thereby suppressing the transmission of the external load to the optical connector 20. Furthermore, since the buffer member 92 is disposed in the thickness direction (Z direction in the figure) of the optical connector 20, it is possible to efficiently suppress the deterioration of the optical characteristics of the optical connector 20 caused by the external load.

[0065] Four side plates 82, 83 are provided on the long sides of the cover plate 81. The pair of side plates 82 are arranged to correspond to the side plate 75 of the case 70. An opening 821 is formed in each of the side plates 82. The pair of side plates 83 are arranged to correspond to the side plate 76 of the case 70. The side plates 83 have basically the same configuration as the side plate 82, and are provided on the cover plate 81 so as to face the side plate 82. An opening 831 is formed in each of the side plates 83.

[0066] When the cover 80 covers the case 70, the projections 751 and 761 on the side plates 75 and 76 of the case 70 engage with the openings 821 and 831 on the side plates 82 and 83, respectively, thereby securing the cover 80 to the case 70. The cover 80 can be removed from the case 70 by releasing the engagement between the projections 751 and 761 and the openings 821 and 831. In other words, the cover 80 is detachably attached to the case 70. The cover 70 and the case 80 may be secured together with screws. Alternatively, the cover 70 and the case 80 may be secured together permanently using an adhesive or the like.

[0067] As described above, in this embodiment, the in-vehicle optical connector unit 10 includes the case 70 that houses the optical connector 20, the cover 80 that covers the case 70, the buffer member 91 that is interposed between the optical connector 20 and the case 70, and the buffer member 92 that is interposed between the optical connector 20 and the cover 80. Therefore, it is possible to prevent the connection end faces 311, 411 of the pair of ferrules 31, 41 from being misaligned due to an external load applied to the optical connector unit 10, and it is possible to prevent deterioration of the optical characteristics of the optical connector 20 (for example, deterioration of insertion loss and return loss) that is caused by an external load applied during the manufacture of the vehicle 1 or while the vehicle 1 is running.

[0068] It should be noted that the above-described embodiments have been described to facilitate understanding of the present invention, and are not intended to limit the present invention. Therefore, the elements disclosed in the above embodiments are intended to include all design modifications and equivalents that fall within the technical scope of the present invention.

[0069] For example, as shown in Fig. 7, the optical connector 20 may be housed in a case 70 so that the clamp spring 50 is located below the optical connector plugs 30, 40. Fig. 7 is an exploded perspective view showing an optical connector unit 10B, which is a modified example of the optical connector unit 10 in this embodiment. In this optical connector unit 10B, a lower buffer member 91 is interposed between the bottom plate 71 of the case 70 and the clamp spring 50, and an upper buffer member 92 is interposed between the lid plate 81 of the cover 80 and the ferrules 31, 41.

[0070] By positioning the clamp spring 50 below the optical connector plugs 30, 40, when assembling the optical connector unit 10, the optical connector plugs 30, 40 can be inserted into the clamp spring 50 with the clamp spring 50 already housed in the case 70. At this time, the optical fiber ribbons 11, 12 are inserted between the pillar portions 72, 73 of the case 70, so that contact between the optical fiber ribbons 11, 12 and the arm portions 52, 53 of the clamp spring 50 can be suppressed, and damage to the optical fibers 111, 121 can be suppressed.

[0071] DESCRIPTION OF SYMBOLS 10, 10B...Optical connector unit 11, 12...Optical fiber ribbon core wire 111, 121...Optical fiber 20...Optical connector 30...Optical connector plug 31...Ferrule 311...Connection end face 314...Rear end face 32...Inner boot 33...Outer boot 40...Optical connector plug 41...Ferrule 411...Connection end face 414...Rear end face 42...Inner boot 43...Outer boot 50...Clamp spring 60...Pin 70...Case 71...Bottom plate 711...Top surface 712...Fixing hole 72, 73...Column portion 721, 731...Inner surface 722, 732...Outer surface 74...Column portion 75, 76...Side plate 751, 761...Protrusion 80...Cover 81...Cover plate 811...Bottom surface 82, 83...Side plate 821, 831...openings 91, 92...buffer members

Claims

1. An on-vehicle optical connector unit comprising: a plurality of optical fibers; an optical connector for connecting the optical fibers; a case for accommodating the optical connector; a cover for covering the case; a first buffer member interposed between the optical connector and the case; and a second buffer member interposed between the optical connector and the cover, wherein the optical connector comprises: a pair of ferrules for holding the optical fibers, each ferrule having a connecting end face at which an end face of the optical fiber is exposed; and a clamp spring for pressing the pair of ferrules against each other with the connecting end faces in contact with each other.

2. An in-vehicle optical connector unit as described in claim 1, wherein the case has a first main surface extending in a direction perpendicular to the thickness direction of the ferrule and comprises a bottom plate that holds the optical connector, the cover has a second main surface extending parallel to the first main surface and comprises a lid plate that covers the optical connector housed in the case, the first buffer member is a sheet-like member that extends between the first main surface and the optical connector, and the second buffer member is a sheet-like member that extends between the second main surface and the optical connector.

3. An on-vehicle optical connector unit according to claim 1 or 2, wherein the case comprises: a bottom plate that holds the optical connector; and a pair of first pillars provided on the bottom plate so as to face the rear end face of the ferrule, and the optical fiber passes between the pair of first pillars.

4. An on-vehicle optical connector unit according to claim 3, wherein the optical connector has the optical fiber inserted therein and comprises a first boot attached to the rear end face of the ferrule, the first boot being interposed between the first pillar portion and the ferrule.

5. An on-vehicle optical connector unit according to claim 3 or 4, wherein the first pillar portion has an inner surface facing the rear end face of the ferrule and an outer surface opposite the inner surface, and the outer surface has an arc-shaped cross section.

6. An in-vehicle optical connector unit as claimed in any one of claims 1 to 5, wherein the case comprises: a bottom plate that holds the optical connector; a second pillar portion provided on the bottom plate so as to face a central portion of the optical connector; and a first side plate provided on the bottom plate so as to face an end portion of the optical connector, and a first gap between the optical connector and the first side plate is wider than a second gap between the optical connector and the second pillar portion.

7. An on-vehicle optical connector unit as claimed in claim 6, wherein the side plate has a protrusion that protrudes towards the outside of the case, the cover has a cover plate that covers the optical connector, and a second side plate provided on the cover plate to correspond to the first side plate, the second side plate has an opening with which the protrusion can engage, and the cover is an on-vehicle optical connector unit that is detachable from the case.

8. An on-vehicle optical connector unit according to any one of claims 1 to 7, wherein the case comprises: a bottom plate that holds the optical connector; and a pair of first pillars provided on the bottom plate so as to face the rear end face of the ferrule; the optical fiber passes between the pair of first pillars; and the on-vehicle optical connector unit comprises a second boot into which the optical fiber is inserted and which is positioned outside the first pillars.

9. An on-vehicle optical connector unit according to any one of claims 1 to 8, wherein the case has a bottom plate that holds the optical connector, and the bottom plate has an attachment portion for attaching the on-vehicle optical connector unit to a mounting body.

10. An on-vehicle optical connector unit according to any one of claims 1 to 9, wherein the clamp spring is interposed between the first buffer member and the pair of ferrules.

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