JP2013057860A - Connector terminal structure part of optical cable - Google Patents

Abstract

PROBLEM TO BE SOLVED: To allow bending restriction at a connector terminal of an optical cable even in a narrower space.SOLUTION: A connector terminal structure part 10 of an optical cable is configured to restrict bending of an optical cable 22. The connector terminal structure part 10 of an optical cable includes: a wiring part 20 including the optical cable 22; an optical connector 30, a base end part of which is connected to one end part of the optical cable 22; and a bending restriction part 40 having a contact part 42 which is provided in a position nearer to the wiring part 20 than the base end part of the optical connector 30 at least partially in a peripheral direction in an outer periphery of the wiring part 20 to be spaced from the outer peripheral part of the wiring part 20.

Description

  The present invention relates to a bending regulation technique in a connector connection terminal of an optical cable.

  Optical cables may be routed in a bent state or bend when routed, but if bent at an excessive bend radius, transmission degradation and damage to the internal optical fiber may occur. For example, the connection end portion of the optical fiber with respect to the optical connector is likely to be bent with a small bending radius as a base point of the bending operation.

  On the other hand, Patent Document 1 discloses a configuration in which a boot surrounding the outer periphery of the optical cable is provided at the base end portion of the connector. Further, Patent Document 1 discloses a bent boot for an optical connector that is inserted into the boot surrounding the outer periphery of the boot and the optical cable extending to the side thereof.

JP 2009-282177 A

  However, the boot and the bent boot for optical connector of Patent Document 1 are long in the extending direction of the optical cable and are difficult to use when the optical connector is disposed in a narrow place. Moreover, since the boot and the bent boot for optical connector in Patent Document 1 are in contact with the outer periphery of the optical cable at the end thereof and bend together with the optical cable, the optical cable extending therefrom is the boot or the bent boot for optical connector. There is also a possibility of bending with a small bending radius from the end of the base.

  Therefore, an object of the present invention is to enable bending regulation at a connector terminal of an optical cable even in a narrow space.

  The first aspect includes a wiring portion including an optical cable, an optical connector in which one end of the optical cable is connected to a base end, and the wiring at a position closer to the wiring portion than the base end of the optical connector. A bending restricting portion having an abutting portion provided at least at a part in the circumferential direction on the outer periphery of the wiring portion with a space from the outer peripheral portion of the wiring portion.

  A 2nd aspect is a connector terminal structure part of the optical cable which concerns on a 1st aspect, Comprising: The said contact part is formed in the cyclic | annular form surrounding the outer periphery of the said wiring part.

  A 3rd aspect is a connector terminal structure part of the optical cable which concerns on a 1st or 2nd aspect, Comprising: The said bending control part is the heat-shrinkable tube provided by being fitted by the base end side part in the said optical connector. It is formed by.

  A 4th aspect is a connector terminal structure part of the optical cable which concerns on any one 1st-3rd aspect, Comprising: The said wiring part has a corrugated tube which covers the outer periphery of the said optical cable.

  A 5th aspect is a connector terminal structure part of the optical cable which concerns on a 4th aspect, Comprising: The said corrugated tube is non-fixed with respect to the said optical connector and the said optical cable in the boundary part of the said optical connector and the said optical cable. It is.

  According to the connector terminal structure portion of the optical cable according to the first aspect, the bending restricting portion is located at a position closer to the wiring portion than the proximal end portion of the optical connector in which one end portion of the optical cable of the wiring portion is connected to the proximal end portion. Since there is an abutting portion provided at least partially in the circumferential direction on the outer periphery of the wiring portion at a distance from the outer peripheral portion of the wiring portion, when the wiring portion is bent, it contacts the bent wiring portion. A contact part can contact | abut and a bending operation can be controlled, and the excessive bending which makes the base end part of the optical connector of a wiring part a base point can be suppressed. Thereby, even in a narrower space, it is possible to restrict bending at the connector end of the optical cable.

  According to the connector terminal structure part of the optical cable according to the second aspect, since the contact part is formed in an annular shape covering the outer periphery of the wiring part, bending in any direction of the wiring part can be restricted.

  According to the connector terminal structure portion of the optical cable according to the third aspect, the bending restricting portion is formed by a heat-shrinkable tube that is provided by being fitted on the proximal end side portion of the optical connector. Even after the optical cable is connected, the bending restricting portion can be formed by inserting the optical connector and performing thermal contraction at the attachment position, and the assembly workability is excellent.

  According to the connector terminal structure portion of the optical cable according to the fourth aspect, since the wiring portion has the corrugated tube that covers the outer periphery of the optical cable, the bending restriction is also applied to the portion beyond the base of the optical cable extending from the optical connector. It can be performed.

  According to the connector terminal structure portion of the optical cable according to the fifth aspect, the corrugated tube of the wiring portion is not fixed to the optical connector and the optical cable at the boundary portion between the optical connector and the optical cable. The load can be reduced and the corrugated tube can be prevented from being broken.

It is a perspective view of the connector terminal structure part of an optical cable. It is a perspective view which shows the state by which the optical cable was connected to the optical connector. It is a figure which shows the example of wiring of an optical cable. It is a top view of the connector terminal structure part of an optical cable. It is a side view of the connector terminal structure part of an optical cable. It is a figure which shows a mode that the wiring part was bent. It is a figure which shows the process of forming a bending control part. It is a figure which shows the process of forming a bending control part. It is a figure which shows the process of forming a bending control part.

  Hereinafter, the connector terminal structure part 10 of the optical cable according to the embodiment will be described (see FIG. 1). The connector terminal structure 10 of the optical cable is configured to suppress excessive bending of the optical cable 22 at the connection end of the optical cable 22 connected to the optical connector 30 with respect to the optical connector 30.

  The connector terminal structure portion 10 of the present optical cable includes a wiring portion 20 including an optical cable 22, an optical connector 30, and a bending restriction portion 40.

  The wiring unit 20 includes an optical cable 22 and a corrugated tube 25 that covers the outer periphery of the optical cable 22.

  The optical cable 22 is a cable having an optical fiber made of glass or plastic inside. One end of the optical cable 22 is connected to the optical connector 30.

  The wiring unit 20 including the optical cable 22 may be routed between a car navigation system 92 and a vehicle body 94 of an automobile, for example (see FIG. 3). That is, one end of the optical cable 22 is connected to the optical connector 30 connected to the car navigation system 92, and the other end is connected to an optical connector or the like connected to a device provided on the vehicle body 94 side. Some car navigation systems 92 are disposed in a housing portion 96 formed on the dashboard of the vehicle body 94. In this case, the distance between the car navigation system 92 and the other connection destination of the optical cable 22 is reduced. . Further, such a car navigation system 92 is disposed in the housing portion 96 after performing connection work in a state where the car navigation system 92 is retracted from the housing portion 96. That is, the wiring portion 20 including the optical cable 22 is highly likely to be bent with a small bending radius when being pushed into the housing portion 96 of the car navigation system 92.

  The corrugated tube 25 is a member for suppressing the bending operation of the optical cable 22 at a small bending radius. The corrugated tube 25 is a member formed in a cylindrical shape in which convex ridges and concave valleys along the circumferential direction are provided alternately and continuously in the extending direction. The corrugated tube 25 is manufactured by extruding a synthetic resin material (for example, PP (polypropylene), PA (polyamide), etc.) into a cylindrical shape and blow molding or vacuum molding. Moreover, it is preferable that the corrugated tube 25 is formed so as to have higher rigidity than the optical cable 22.

  The corrugated tube 25 is preferably provided so as to cover the outer periphery of the bent portion of the optical cable 22. More specifically, the corrugated tube 25 covers a range including a connection end portion of the optical cable 22 with respect to the optical connector 30 (a boundary portion with the optical connector 30 in the extending direction of the optical cable 22). The corrugated tube 25 is not fixed to the optical connector 30 and the optical cable 22 at the boundary portion between the optical connector 30 and the optical cable 22 (see FIG. 4). The end of the corrugated tube 25 opposite to the optical connector 30 is fixed by, for example, winding an adhesive tape 26 around the outer periphery of the optical cable 22.

  The optical connector 30 is a member that is connected to an in-vehicle device such as the car navigation system 92 or a counterpart optical connector while one end of the optical cable 22 is connected to the base end (see FIG. 2). Hereinafter, a male connector is shown as an example of the optical connector 30. The optical connector 30 includes a connection portion 32, a large portion 34, and a small portion 36 in order from the distal end portion toward the proximal end portion.

  The connection unit 32 is a part connected to an in-vehicle device such as the car navigation system 92 or a counterpart optical connector. The small portion 36 located on the proximal end side with respect to the connecting portion 32 with the large portion 34 interposed therebetween is smaller than the large portion 34 in a cross-sectional view orthogonal to the direction connecting the distal end portion and the proximal end portion of the optical connector 30. It is formed into a shape. The optical connector 30 has a cavity 38 in which one end portion of the optical cable 22 is disposed, and the cavity 38 is formed in a shape opened at the proximal end portion of the small portion 36.

  Here, the optical cable 30 in the two wiring parts 20 is connected to the optical connector 30, and two cavities 38 are provided in parallel correspondingly. Since the two optical cables 22 are connected to the optical connector 30 at a relatively narrow interval (here, 3 mm), it is difficult to attach the boot to the optical cable 22 connected to the optical connector 30. . The optical connector 30 includes a connection portion 32, a large portion 34, and a small portion 36 that are substantially different rectangular parallelepipeds. The two cavities 38 are formed in a wide shape in the adjacent direction.

  However, the optical connector 30 is not limited to the shape described above, and other shapes can be employed. Further, the number of optical cables 22 connected to the optical connector 30 is not limited to two, and may be one or more than three. The optical connector 30 is not limited to a male connector, and may be a female connector that can connect a male connector as a mating connector.

  The bending restricting portion 40 is a portion that restricts the bending operation of the wiring portion 20 extending from the base end portion of the optical connector 30 and can be brought into contact with the wiring portion 20 that is bent with the base end portion of the optical connector 30 as a base point. It has the contact part 42 (refer FIGS. 4-6). The contact portion 42 is provided at least at a part in the circumferential direction on the outer periphery of the wiring portion 20 at a position closer to the outer peripheral portion of the wiring portion 20 at a position closer to the wiring portion 20 than the proximal end portion of the optical connector 30. ing. The contact portion 42 is preferably provided on the outer periphery of the wiring portion 20 in a state extending linearly from the optical connector 30 on the side where the wiring portion 20 is bent. Here, the contact part 42 is formed in an annular shape surrounding the outer periphery of the wiring part 20. That is, the bending operation in any direction of the wiring part 20 can be restricted.

  Further, the distance between the contact portion 42 and the outer peripheral portion of the wiring portion 20 and the distance from the base end portion of the optical connector 30 are excessive when the wiring portion 20 is bent with the base end portion of the optical connector 30 as a base point. It is good to set so that it can contact | abut to the outer peripheral part of the wiring part 20 by the attitude | position before becoming a proper bending attitude | position. At least the abutting portion 42 may be able to abut on the wiring portion 20 in a posture before the optical cable 22 is bent with a bending radius smaller than the minimum allowable bending radius. In other words, the abutting portion 42 is spaced from the outer peripheral portion of the wiring portion 20 such that the abutting portion 42 abuts the wiring portion 20 with a bending posture having a bending radius equal to or larger than the minimum allowable bending radius of the optical cable 22 and the optical connector 30. The distance from the base end (for example, 10 mm or more) is set.

  Here, the minimum allowable bend radius is set as a limit bend radius that is assumed that the transmission loss and breakage probability of the optical fiber, which increases as the bend radius decreases, can withstand the use of the optical cable 22. is there. More specifically, the transmission loss (bending loss) is, for example, the degree of loss (dB) when an optical signal having a certain wavelength L is incident on the optical cable 22 wound n times with a certain bending radius. Be evaluated. The fracture probability is evaluated by, for example, the probability that the optical cable 22 wound around m with a certain bending radius will break after t years (for example, an acceleration test may be performed). The minimum allowable bending radius is set so that both the evaluation values of the transmission loss and the fracture probability satisfy the criteria determined according to the actual use situation. For example, the transmission loss is the degree of loss (dB) when an optical signal having a wavelength of 1550 nm is incident on the optical cable 22 wound 100 times at a certain bending radius r, and the fracture probability is 50 at a certain bending radius r. It is good to evaluate with the probability that the optical cable 22 wound around will break after 15 years. In this case, for example, the minimum allowable bending radius can be a bending radius r such that the transmission loss is 0.5 dB / 100 or less and the fracture probability is 1.0 × 10 −6 or less. The bending radius refers to the radius of curvature of the central axis of the optical cable 22.

  Here, the bending restricting portion 40 is formed by a heat-shrinkable tube 41 provided by being fitted around the proximal end portion of the optical connector 30. The bending restricting portion 40 has a cylindrical shape as a whole, and includes an enclosure portion 44 having an abutting portion 42 and an external fitting portion 46.

  The external fitting portion 46 is a portion that is formed in a shape along the outer peripheral portion of the small portion 36 of the optical connector 30 and is externally fitted to the small portion 36. That is, the outer fitting part 46 is formed in a substantially rectangular tube shape. The outer fitting portion 46 may be bonded to the outer peripheral portion of the small portion 36 by an adhesive layer 48 interposed between the outer peripheral portion 46 and the small portion 36 on the inner peripheral side. The adhesive layer 48 may be formed by application of an adhesive, a double-sided adhesive tape, or the like.

  The surrounding portion 44 is a portion that surrounds the outer periphery of the portion of the wiring portion 20 on the optical connector 30 side. The end portion of the enclosure 44 is an annular contact portion 42. The surrounding portion 44 is provided with the two wiring portions 20 on the inner side, and is spaced from the outer peripheral portion of the two wiring portions 20 over the entire circumferential direction. This cross section 44 has a substantially oval shape that is long in the direction in which the two wiring portions 20 are adjacent to each other in a cross-sectional view orthogonal to the penetrating method (a pair of arc-shaped portions are connected by a pair of linear portions, rounded corners). It may be a shape close to a rectangle) (see FIG. 1).

  Further, in the bending restricting portion 40, the enclosure portion 44 may be elastically deformable. However, it is preferable that the bending operation with the base end portion of the optical connector 30 of the wiring portion 20 as a base point can be regulated, that is, at least higher rigidity than the corrugated tube 25 is set. Further, the bending restricting portion 40 has high rigidity capable of preventing the optical cable 22 from being bent with a bending radius smaller than the minimum allowable bending radius in the bending operation of the wiring portion 20 with the base end portion of the optical connector 30 as a base point. It is also important to be.

  The bending restricting portion 40 is formed as follows. First, the adhesive layer 48 is formed on the outer peripheral portion of the small portion 36 of the optical connector 30 (see FIG. 7). Here, the adhesive layer 48 is formed not on the inner peripheral portion of the heat shrinkable tube 41 but on the outer peripheral portion of the small portion 36, so that the adhesive layer 48 is attached to the optical connector when the heat shrinkable tube 41 is mounted. It is possible to improve the workability by preventing sticking to the outer surface of 30. And the heat contraction tube 41 before heat contraction is arrange | positioned in the position which covers the boundary part of the optical connector 30 and the wiring part 20 (refer FIG. 7, FIG. 8). More specifically, the heat shrinkable tube 41 may be disposed at a position where one end portion is located on the outer periphery of the small portion 36 and surrounds the adhesive layer 48.

  Next, the heat shrinkable tube 41 is heat shrunk (see FIGS. 8 and 9). The heat shrinking work can be performed by applying hot air. Thereby, the site | part located in the outer periphery of the small part 36 among the heat contraction tubes 41 deform | transforms into the shape in alignment with the outer peripheral part of the small part 36. FIG. At this time, the heat-shrinkable tube 41 that has been heat-shrinked is bonded to the small portion 36 by the adhesive layer 48. Further, a portion of the heat shrinkable tube 41 located on the outer periphery of the wiring portion 20 is heat-shrinked smaller than a portion located on the outer periphery of the small portion 36 and deforms into a shape similar to the outer peripheral portion of the adjacent small portion 36.

  Here, two methods for forming the heat-shrinkable tube 41 in a shape spaced apart from the outer peripheral portion of the wiring portion 20 will be described. The first is a method for selecting the heat shrinkable tube 41. That is, the heat-shrinkable tube 41 has a shape and size through which the optical connector 30 can be inserted, and is smaller than the external shape of the small portion 36 in the form after heat shrinkage and extends from the proximal end portion of the optical connector 30. It is good to select the thing of the shrinkage | contraction rate used as the magnitude | size spaced apart with respect to the outer peripheral part of the wiring part 20. FIG. The second is a method of adjusting the heating temperature, the heating time, and the like for the shrinking mode at the time of heat shrinking. In the second method as well, the heat shrinkable tube 41 has a shape and size through which the optical connector 30 can be inserted, and a shrinkage rate smaller than the external shape of the small portion 36 in the form after heat shrinkage. Choose one.

  In the connector terminal structure portion 10 of the optical cable, when the wiring portion 20 is bent with the base end portion of the optical connector 30 as a base point, the wiring portion 20 is brought into contact with the contact portion 42 inside the enclosure portion 44 of the bending restriction portion 40. It can be bent to the abutment posture. In this state, the wiring portion 20 bent to the posture to contact the contact portion 42 is restricted from being bent with the base end portion of the optical connector 30 as a base point beyond this bending posture. And when the wiring part 20 is further bent from the said bending attitude | position, it is bent in the part ahead of the contact part 42. FIG. That is, the amount of bending with the base end portion of the optical connector 30 of the wiring portion 20 as the base point remains in the range where bending is restricted, and when there is no bending restricting portion 40, it concentrates on the root portion of the wiring portion 20 on the optical connector 30 side. Bending stress is distributed to other parts. But when the bending control part 40 is formed with the member which can be elastically deformed, it can be bent and deformed in the range of elastic deformation.

  Further, when the wiring part 20 is bent, the corrugated tube 25 is stretched on the outer peripheral side of the bent form. And when a big bending stress acts on the corrugated tube 25 in the state where elongation has occurred, the corrugated tube 25 is more likely to bend than when the bending stress acts on a state where no elongation has occurred. Here, since the end portion of the corrugated tube 25 on the side of the optical connector 30 is not fixed, the end portion moves in the extending direction with respect to the optical cable 22 along with the bending operation so that the extension is suppressed. It is configured.

  According to the connector terminal structure portion 10 of the optical cable according to the above configuration, the bending restricting portion 40 is spaced from the base end portion of the optical connector 30 on the wiring portion 20 side with respect to the outer peripheral portion of the wiring portion 20. Since the contact portion 42 is provided at least at a part in the circumferential direction on the outer periphery of the wiring portion 20, when the wiring portion 20 is bent, the contact portion 42 contacts the bent wiring portion 20 to perform a bending operation. It is possible to restrict the excessive bending with the base end of the optical connector 30 of the wiring portion 20 as a base point. As a result, even in a narrower space, it is possible to regulate the bending of the optical cable 22 at the end of the optical connector 30.

  Moreover, since the contact part 42 is formed in the annular | circular shape which covers the outer periphery of the wiring part 20, it can restrict | limit bending of the wiring part 20 in any direction.

  Further, since the bending restricting portion 40 is formed by the heat-shrinkable tube 41 provided by being fitted around the proximal end portion of the optical connector 30, even after the optical cable 22 is connected to the optical connector 30. The bending restricting portion 40 can be formed by inserting the optical connector 30 and causing the optical connector 30 to be thermally shrunk at the attachment position, and is excellent in assembling workability.

  In addition, since the wiring portion 20 includes the corrugated tube 25 that covers the outer periphery of the optical cable 22, bending restriction can be performed even at a portion beyond the base of the optical cable 22 that extends from the optical connector 30.

  Further, since the corrugated tube 25 of the wiring portion 20 is not fixed to the optical connector 30 and the optical cable 22 at the boundary portion between the optical connector 30 and the optical cable 22, a load applied to the corrugated tube 25 due to the bending operation of the wiring portion 20. Can be reduced to prevent breakage and the like. Moreover, the structure which fixes the corrugated tube 25 in the optical connector 30 can be abbreviate | omitted, and the bending space of the wiring part 20 by that much can be ensured large.

  Moreover, while forming the bending control part 40 using the heat shrinkable tube 41 which can be retrofitted, the optical cable 22 is abbreviate | omitted while omitting the structure for fixing the corrugated tube 25 in the optical connector 30 by fixing the corrugated tube 25 at the other end. Is held at a portion of the optical cable 22 where the bending is desired to be restricted, and the bending restriction at the connection end of the optical connector 30 of the optical cable 22 can be performed using the existing optical connector. Thereby, the design of a new optical connector and the new installation of a manufacturing apparatus (molding mold etc.) can be omitted, and cost and man-hours can be reduced.

  Up to now, the example in which the bending restricting portion 40 is formed by the heat-shrinkable tube 41 has been described. However, the present invention is not limited to this, and the contact portion 42 is located at the position closer to the optical cable 22 than the base end portion of the optical connector 30. It suffices that the wiring part 20 is provided at least partially in the circumferential direction at an interval with respect to the outer peripheral part of the wiring part 20. For example, the bending restricting portion may be configured such that the outer peripheral portion of the base end portion of the optical connector 30 is extended toward the base end side with straw. Moreover, the structure by which the contact part which can be contact | abutted to the wiring part 20 to be bent may be provided only in the circumferential direction part in the outer periphery of the wiring part 20 may be sufficient as a bending control part.

  Further, in the wiring portion 20, a member for bending regulation other than the corrugated tube 25 may be attached to the optical cable 22, or the corrugated tube 25 may be omitted.

DESCRIPTION OF SYMBOLS 10 Connector terminal structure part 20 Wiring part 22 Optical cable 25 Corrugated tube 30 Optical connector 40 Bending control part 41 Heat-shrinkable tube 42 Contact part

Claims (5)

A wiring section including an optical cable;
An optical connector in which one end of the optical cable is connected to the base end;
At a position closer to the wiring portion side than the base end portion of the optical connector, a contact portion provided at least partially in the circumferential direction on the outer periphery of the wiring portion is spaced apart from the outer peripheral portion of the wiring portion. A bending restriction section;
An optical cable connector terminal structure. It is a connector terminal structure part of the optical cable according to claim 1,
The contact portion is a connector terminal structure portion of an optical cable formed in an annular shape surrounding the outer periphery of the wiring portion. It is a connector terminal structure part of the optical cable according to claim 1 or claim 2,
The bend restricting portion is a connector terminal structure portion of an optical cable, which is formed by a heat-shrinkable tube provided by being fitted around a proximal end portion of the optical connector. It is a connector terminal structure part of the optical cable according to any one of claims 1 to 3,
The said wiring part is a connector terminal structure part of an optical cable which has a corrugated tube which covers the outer periphery of the said optical cable. It is a connector terminal structure part of the optical cable according to claim 4,
The corrugated tube is a connector terminal structure portion of an optical cable that is not fixed to the optical connector and the optical cable at a boundary portion between the optical connector and the optical cable.

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