JP2006010865A - Retainer mechanism of optical fiber - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical fiber retainer that is superior in reliability. <P>SOLUTION: A retainer 30 is attached to the front of a light-projecting element. The retainer 30 has a pair of clamps 31, and a fiber hole 34 is provided facing them. A lock 45 having a presser 67A is attached around the retainer 30, to press the clamps 31 in the direction to close them. Thus, the fiber hole 34 is contracted, to retain the end of the optical fiber F. The fiber hole 34 is set smaller than the outside diameter of the optical fiber F, before the fiber F is inserted. The fiber F is deformed as the retainer 30 fastens it, and the reaction of the clamps 31 against the lock 45 becomes smaller. Accordingly, the retaining reliability is increased, since the lock 45 is hard to deform in the direction of loosening the retaining pressure to the fiber F. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a mechanism for holding an end portion of an optical fiber in front of a photoelectric element in a photoelectric switch or the like.

Conventionally, as this type of holding device, there are a holding member having a pair of holding pieces that can be elastically expanded on the front surface of an element block in which a photoelectric element is mounted, and an operation for holding the holding member in a locked state. The thing which arranged the member is known (patent document 1). In this structure, the holding piece of the holding member is formed with a fiber insertion hole for inserting and holding the optical fiber between the opposed surfaces.
On the other hand, the operating member is provided with a pressing portion, and is displaceable between a raised position and a lowered position. In the raised position, the pressing portion of the operating member is separated from the clamping piece, but in the lowered position, the pressing piece abuts on the outer periphery of the clamping piece and elastically displaces the clamping piece in the locking direction. Thus, the end of the optical fiber is held by elastically displacing the holding piece in the direction of reducing the diameter of the fiber insertion hole.
Further, the hole diameter of the fiber insertion hole is set to be larger than the maximum fiber diameter used in the natural state.
JP 2002-296455 A

In the above configuration, since the optical fiber is held by pressing the clamping piece 1 by the lock member 3, the repulsive force received by the lock member 3 in the locked state as shown in FIG. It is a force obtained by adding both the required force and the force required to elastically deform the holding member in the closing direction in addition to the required force.
Therefore, when such a repulsive force is applied over time, the lock member 3 may be deformed, and there is room for improvement in terms of improving the reliability of holding the optical fiber.
The present invention has been completed based on the above-described circumstances, and an object thereof is to provide an optical fiber holding device that is excellent in reliability.

  As means for achieving the above-mentioned object, the invention of claim 1 includes an element block in which a photoelectric element is mounted, and an optical fiber provided in the element block and arranged to face the photoelectric element. A holding member having a pair of holding pieces that can be elastically held, a fiber insertion hole that is formed between opposing surfaces of the pair of holding pieces and through which the optical fiber is inserted, and the fiber insertion hole that connects the pair of holding pieces An optical fiber holding device comprising: a lock position that is pressed in a tightening direction to be reduced in diameter; and a lock member that is displaceable between a release position that releases the pressed state. The diameter of the hole in the pressed state is smaller than the outer diameter of the optical fiber, and the holding member or the locking member is inserted into the holding member or the locking member before or after the optical fiber is inserted. A diameter expanding means is provided for guiding the insertion operation of the optical fiber with respect to the fiber insertion hole by expanding the hole diameter of the optical fiber insertion hole to a hole diameter equal to or larger than the hole diameter in the non-pressed state. The lock member is characterized in that the diameter of the fiber insertion hole expanded by the diameter expansion means is reduced within a range not smaller than a non-pressed hole diameter size at the lock position.

  According to a second aspect of the present invention, there is provided an element block in which a photoelectric element is mounted, and a holding member provided in the element block and having a pair of holding pieces capable of holding an optical fiber disposed facing the photoelectric element. A fiber insertion hole that is formed between the opposing surfaces of the pair of sandwiching pieces and through which the optical fiber is inserted; a lock position that presses the pair of sandwiching pieces in a tightening direction in which the diameter of the fiber insertion hole is reduced; and An optical fiber holding device including a lock member that is displaceable from a release position that is separated from the holding piece and releases the same pressing state, the holding member being formed by both holding pieces formed separately. It is characterized in that the ends are connected to each other through a hinge so as to be freely opened.

  According to a third aspect of the present invention, in the one according to the first or second aspect, the hole edge portion of the fiber insertion hole facing the optical fiber during the insertion operation is directed toward the tip side. It is characterized in that a guide portion serving as the diameter expanding means is provided so that the hole diameter gradually increases.

  According to a fourth aspect of the present invention, in the one according to the first or second aspect, the fiber insertion hole is formed on the lock member by contacting the holding pieces when the lock member is in the release position. An expanding protrusion is formed as the diameter expanding means for expanding the sandwiching piece so as to expand, and the expanding protrusion is displaced from the release position to the lock position of the lock member. Along with this, there is a feature in that the contact state is released by retreating from both the holding pieces.

<Invention of Claim 1>
Since the optical fiber is held by pressing the holding piece with the lock member, the lock member receives a repulsive force from the holding piece. If a large repulsive force acts over time, the lock member may be deformed. In this regard, according to the first aspect of the present invention, the hole diameter size in the non-pressed state of the fiber insertion hole is set smaller than the outer diameter size of the optical fiber. Therefore, if the diameter reduction operation of the fiber insertion hole by the lock member is performed within a predetermined use range (within a range in which the fiber insertion hole after pressing is not smaller than the non-pressed hole size), the lock member The repulsive force received by the optical fiber F is only the force required to press the optical fiber F. In addition, as the time passes, the optical fiber conforms to the holding piece and is somewhat reduced in diameter, but the magnitude of the repulsive force is also reduced by the amount that the optical fiber is reduced in diameter. Therefore, since the magnitude of the repulsive force received by the lock member is reduced, the lock member is less likely to be deformed, and the holding reliability is excellent.

  In addition, if it is used beyond the range of use (if the lock member is pressed until the hole diameter size of the fiber insertion hole becomes smaller than the hole diameter size in the non-pressed state), the repulsive force against the lock member will be increased accordingly. This is because, in order to make the hole diameter of the fiber insertion hole smaller than the hole diameter size in the non-pressed state, in addition to deforming the optical fiber F, it is necessary to elastically displace the holding piece of the holding member in the closing direction. In addition, the repulsive force received by the lock member is increased accordingly.

<Invention of Claim 2>
According to invention of Claim 2, the clamping piece is connected via the hinge and can be opened leg freely. With such a configuration, when the optical fiber is reduced in diameter with the passage of time as in the first aspect of the invention, the repulsive force in the expanding direction of the sandwiching piece is also reduced. Decreases by the amount of Therefore, since the magnitude | size of the force which a lock member receives via a clamping piece becomes small, it becomes a structure where a lock member cannot change easily, and it is excellent also in the reliability of holding | maintenance.

<Invention of Claim 3>
According to the invention of claim 3, since the optical fiber insertion operation to the fiber insertion hole is guided by the guide portion, the assembly workability is excellent.

<Invention of Claim 4>
According to the fourth aspect of the present invention, when the lock member is in the release position, the fiber insertion hole is in an expanded state, so that the optical fiber can be easily inserted into and extracted from the fiber insertion hole.

<Embodiment 1>
A first embodiment of the present invention will be described with reference to FIGS.
In FIG. 1, reference numeral 10 denotes an element block, which is formed in a vertically long shape with a synthetic resin material. The element block 10 itself is attached to a mounting plate 11 protruding from a device or the like with a screw 12 or the like. It has become.
A photoelectric element mounting portion 15 is set on the rear surface side (right side in FIG. 1) of the element block 10, and a mounting portion 16 such as a holding member 30 described later is set on the front surface side.

The mounting portion 15 is formed in a stepped shape with the upper side projecting rearward, and a stepped upper mounting hole 18 having a reduced diameter on the back side opens in the rear surface in the projecting portion 17. Is formed. In the upper mounting hole 18, the light projecting element 20 covered with the casing 20 </ b> A is accommodated facing forward with the reduced diameter portion 18 </ b> A on the back side opened.
On the lower side of the mounting portion 15, a stepped lower mounting hole 19 having a reduced diameter on the back side is formed in the rear surface. In the lower mounting hole 19, the light receiving element 21 is accommodated in the same manner facing forward. The lead wires 22 of both elements 20 and 21 are drawn out backward.

From the center of the front surface of the reduced diameter portion 18 </ b> A in the upper mounting hole 18, a horizontal insertion passage 25 through which the optical fiber F can be inserted is formed in the front surface of the mounting portion 16. However, the inner end of the insertion passage 25 is reduced in diameter so that the tip of the optical fiber F through which the stepped portion 26 is inserted can be abutted.
On the other hand, from the center of the front surface of the lower mounting hole 19, an insertion passage 25 is formed in the front surface of the mounting portion 16 so as to open in the horizontal direction through which the optical fiber F used in the same manner as described above can be inserted. . It should be noted that the upper and lower sides of the mounting portion 16 are retracted by one step to the back side in order to release a lock member 45 described later.

  Two holding members 30 on the upper and lower sides are mounted on the front surface of the mounting portion 16. The holding member 30 is made of synthetic resin, and two pieces are formed in the same shape. In detail, as shown in FIG. 5, the holding member 30 has a shape in which the upper ends of a pair of elastically displaceable holding pieces 31 are connected by a connecting portion 32, and both holding pieces 32 are centered on the connecting portion 32. 31 can be opened and closed. A triangular cutout portion 37 is formed on the outer surface near the lower ends of the sandwiching pieces 31, and a linear contact portion 36 is formed below the triangular cutout portion 37.

  In addition, a fiber insertion hole 34 through which the optical fiber F is inserted is formed at a position near the upper end of the opposing surfaces of the both sandwiching pieces 31. Although described in detail later, the hole diameter of the fiber insertion hole 34 is smaller than the outer diameter of the optical fiber F to be used in a natural state where no force from other members is applied to the sandwiching pieces 31. It is said that. This is a configuration corresponding to “the hole diameter size in the non-pressed state of the fiber insertion hole is smaller than the outer diameter size of the optical fiber” in the present invention.

  Further, as shown in FIG. 9, a guide oblique portion (corresponding to the guide portion of the present invention) 34A is formed at the front edge of the fiber insertion hole 34, and the front (the side facing the optical fiber F). The hole diameter expands toward. Therefore, when the optical fiber F is pressed against the fiber insertion hole 34, the optical fiber F is guided toward the center of the fiber insertion hole 34 by receiving a guide action by the guide inclined portion 34A, and both the sandwiching pieces 31 are optical fibers. A pressing force in the expanding direction is received from F. As a result, the diameter of the fiber insertion hole 34 is smaller than the outer diameter of the optical fiber F before the optical fiber is inserted, but the diameter of the fiber insertion hole 34 increases with the insertion operation. It is possible to smoothly perform the operation of inserting the optical fiber F into the insertion hole 34.

As shown in FIG. 1, a mounting rod 38 is projected on the rear surface of the connecting portion 32 of the holding member 30, and short legs are respectively provided on the rear surface near the lower ends of both sandwiching pieces 31. A body 39 is projected.
On the other hand, a mounting hole 40 into which the mounting rod 38 can be press-fitted is opened at a position above the entrance of each insertion passage 25 formed on the front surface of the mounting portion 16. Specifically, the upper mounting hole 40 is opened on the surface of the mounting portion 16 that is retracted one step, and the lower mounting hole 40 is opened on the front surface of the mounting portion 16. In addition, a horizontally long groove 41 is formed at a position below each insertion passage 25 so that both legs 39 can be inserted with a clearance in the height direction.

  Therefore, the holding member 30 is vertically mounted on the front surface of the mounting portion 16 while the mounting rods 38 are press-fitted into the corresponding mounting holes 40 and both the legs 39 are inserted into the grooves 41. At this time, the center of the fiber insertion hole 34 formed between the holding pieces 31 in each holding member 30 coincides with the axis of the corresponding insertion path 25, that is, the axis of the light projecting element 20 or the light receiving element 21. It is set. Further, both the sandwiching pieces 31 can be opened and closed while swinging the leg 39 in the groove 41.

  A lock member 45 for holding the optical fiber F inserted into the fiber insertion hole 34 in a retaining state is attached to the front surface of the attachment portion 16. The lock member 45 is made of synthetic resin, and as shown in FIG. 3, is formed in a box shape that is slightly longer than the attachment portion 16 and opens rearward, and is a holding member attached to the front surface of the attachment portion 16. 30 to cover the side surface of the mounting portion 16 and can be attached. However, a predetermined clearance is provided in the vertical direction.

  In addition, two longitudinal elongated holes 64 are formed on the front surface of the lock member 45 so that the top and bottom of the lock member 45 can be moved up and down regardless of whether the lock member 45 moves to a lock position or a release position described later. The insertion passage 25 can be opened forward through the corresponding long hole 64.

  On the left and right side plates of the locking member 45, a guide plate 46 projects from the center height position at the rear edge thereof toward the rear. The guide plate 46 can be slidably brought into contact with the left and right side surfaces of the front side of the element block 10, and inward hooks 47 are formed on the upper and lower ends of the projecting edges on the opposing surfaces of the both guide plates 46. . On the other hand, on the left and right side surfaces of the element block 10, as shown in FIG. 2, longitudinal guide grooves 48 into which the hooks 47 are fitted are formed.

  Therefore, the lock member 45 is covered from the front side of the mounting portion 16, and the hooks 47 of both guide plates 46 are fitted into the guide grooves 48, so that the lock members 45 are positioned along the guide grooves 48 (the positions shown in FIG. 7). The holding member 30 is pressed inward to reduce the diameter of the fiber insertion hole 34) and the release position (the position shown in FIG. 6 where the pressure is released) is mounted so as to be movable up and down. Has been.

  More specifically, as shown in FIG. 5, engagement walls 65 having a symmetrical shape are formed from the left and right side surfaces in the lock member 45 so as to protrude toward both sides of the holding member 30. ing. Two sets of upper and lower lock projections 67 are formed at a position substantially opposite to the tip (lower end in the figure) of the sandwiching piece 31 in the engagement wall 65. The lock protrusion 67 includes a pressing portion 67A protruding inward and an inclined portion 67B connected to the pressing portion 67A. Both inclined portions 67B are inclined so that the distance between the opposing wall surfaces expands toward the lower side.

  When the lock member 45 is in the release position shown in FIG. 6, the abutting portion 36 of the clamping piece 31 is in a position retracted below the pressing portion 67 </ b> A, and the both clamping pieces 31 are in any tightening direction from the locking member 45. It remains in a state where it does not receive (inward) pressing force. However, the notch portion 37 and the inclined portion 67B of the sandwiching piece 31 are in contact with each other, so that the sandwiching piece 31 is prevented from being excessively opened and deformed.

  On the other hand, when the lock member 45 is in the lock position shown in FIG. 7, the pressing portion 67 </ b> A rides on the contact portion 36 from the notch portion 37 of the holding piece 31. As a result, the lock member 45 displaces both the holding pieces 31 in the open state in the closing direction in which the diameter of the fiber insertion hole 34 is reduced.

In addition, a fitting portion 35 extending in the vertical direction in FIG. 5 is provided on a side portion of the fiber insertion hole 34 on the outer surface of the both sandwiching pieces 31, while a slightly opposite position of the locking member 45 to the fitting portion 35. A fitted portion 66 is formed on the upper side along the vertical direction. The width dimensions of both the parts 35 and 66 are formed to be substantially the same dimension, and the fitting part 35 is fitted inside the fitted part 66 at the locked position.
And the opposing surfaces of these both parts 35 and 66 are mutually inclined, and both parts 35 and 66 are diagonally fitted in the same fitting state (refer FIG. 9). By adopting such an oblique fitting configuration, the fitting portion 35 receives an inward pressing force from the fitting portion 66 when a force in the pulling direction acts on the optical fiber F, so that the optical fiber F It becomes difficult to remove from the holding member 30.

  Incidentally, as shown in FIG. 8, the natural diameter of the fiber insertion hole 34 is 2.0 mm, whereas the outer diameter φ of the optical fiber F is 2.2 mm. The hole diameter φa of 34 is set smaller than the outer diameter of the optical fiber F. By setting the dimensions as described above, the operation of reducing the diameter of the fiber insertion hole 34 by the lock member 45 is within a predetermined use range (within a range in which the fiber insertion hole 34 after pressing does not become smaller than the hole diameter size in the natural state). ) If performed, the lock member 45 is difficult to deform.

  This is because, as described above, the lock member 45 presses the holding member 30 in the closing direction at the lock position. For this reason, the lock member receives a repulsive force (restoring force) from the holding member 30, but if the repulsive force continues to act over time, the lock member 45 is easily deformed. If the hole diameter φa of the fiber insertion hole 34 is set to 2.2 mm or more, the repulsive force received by the lock member 45 is the force required to press the optical fiber F, and In addition, the force is obtained by adding both of the forces required to elastically deform the holding member 30 in the closing direction.

However, in this embodiment, the hole diameter φa of the fiber insertion hole 34 is set smaller than the outer diameter of the optical fiber F. Therefore, since the repulsive force received by the lock member 45 is only a force required for pressing the optical fiber F, the hole diameter φa of the fiber insertion hole 34 is set to 2.2 mm or more. As a result, the magnitude of the repulsive force is reduced.
In addition, the portion of the optical fiber F that has been tightened is reduced in diameter to the tightened diameter size (2.0 mm in the present embodiment) as time elapses. Accordingly, the magnitude of the repulsive force is also reduced, and the lock member 45 is hardly deformed.

  In addition, if it is used beyond the use range (the lock member 45 is pressed until the hole diameter size of the fiber insertion hole 34 becomes smaller than the hole diameter size in the natural state), the repulsive force against the lock member 45 is increased accordingly. This is because, in order to make the hole diameter of the fiber insertion hole 34 expanded by insertion of the optical fiber F smaller than the natural hole diameter φa, in addition to deforming the optical fiber F, the holding piece 31 of the holding member 30 Must be elastically displaced in the closing direction, and the repulsive force received by the lock member 45 is increased accordingly.

  A support arm 50 is formed on the upper surface of the element block 10 so as to protrude above the mounting portion 16, and a lever 51 for moving the lock member 45 up and down is supported on the support arm 50. The lever 51 is made of synthetic resin, and has an operation portion 52 for hooking a finger on one end side and an engagement portion 53 formed on the other end side. The engaging portion 53 is mounted so as to sandwich the support arm 50, and the pin 56 is inserted over the shaft hole 54 formed in the base portion of the engaging portion 53 and the shaft hole 55 of the support arm 50, so that the lever 51 is rotatably supported between the tilt position shown in FIG. 1 and the standing position shown in FIG.

The lever 51 functions so that the tip of the engaging portion 53 presses the upper plate 45U of the lock member 45. In addition, a pair of flange portions 58 are formed to rise at the rear end portion of the upper surface of the lock member 45, and the outer surface on the front edge side of the engaging portion 53 of the lever 51 is in the flange portion 58. A pull-up portion 59 that can be submerged is formed to project.
That is, when the lever 51 is in the tilted position, the pulling portion 59 is hooked on the collar portion 58 and pulls it up, whereby the lock member 45 is brought to the release position, while the lever 51 rotates to the standing position. Then, when the engaging portion 53 pushes down the upper plate 45U, the lock member 45 is brought to a lock position where the upper plate 45U hits the upper surface of the upper holding member 30. The lever 51 can be held in an upright position by fitting a lock claw 61 (indicated by a chain line in FIG. 4) provided on the element block 10 side into a lock groove 62 formed on the side surface.

  A cover 70 is attached to the front surface of the element block 10. The cover 70 is mounted so as to cover the front surface of the holding member 30 from the pivot support position of the lever 51, and a window hole 71 is opened at a position corresponding to the upper and lower insertion paths 25. In addition, a plurality of protrusions are formed on the front surface of the lock member 45 and are in contact with the back surface of the cover 70, reducing the frictional resistance between the lock member 45 and the cover 70 and smooth sliding. It comes to secure.

This embodiment has the structure as described above, and the operation thereof will be described subsequently.
When mounting the optical fiber F, the lever 51 is rotated to the tilt position of FIG. 1 and the lock member 45 is set to the release position. At this time, the fiber insertion hole 34 of the holding member 30 and the lower side of the long hole 64 of the lock member 45 are aligned, and the optical fiber F can be inserted into the fiber insertion hole 34 from the front. It is like that. In addition, the hole diameter of the fiber insertion hole 34 is set to 2.0 mm before the optical fiber F is inserted.

  From this state, when the optical fiber F is directly opposed to the fiber insertion hole 34 and pushed into the back side, the optical fiber F is guided toward the center of the fiber insertion hole 34 by being guided by the guide oblique portion 34A. Both sandwiching pieces 31 receive a pressing force in the expanding direction from the optical fiber F. As a result, the diameter of the fiber insertion hole 34 is increased in accordance with the insertion operation of the optical fiber F, and the optical fiber F is inserted into the inner side of the fiber insertion hole 34 and eventually into the insertion path 25. Eventually, the upper part hits the step 26 in the back of the insertion passage 25 and the lower part hits the front surface of the light receiving element 21, thereby stopping the insertion. When the insertion operation of the optical fiber F is completed, the diameter of the fiber insertion hole 34 is expanded to 2.2 mm (see FIG. 8B, the diameter of the expanded hole). φb is 2.2 mm).

When both optical fibers F are inserted, a finger is put on the operation unit 52 and the lever 51 is rotated toward the standing position in FIG. During this time, the lever 51 rotates about the pin 56 in the clockwise direction in FIG. 1, and the tip of the engaging portion 53 pushes down the upper plate 45U, so that the lock member 45 is lowered.
Accordingly, each optical fiber F moves relative to the upper side of the long hole 64 of the lock member 45, and the left and right pressing portions 67A of the engagement wall 65 move along the notch portion 37 of the sandwiching piece 31. go. Thereby, both the clamping pieces 31 are pressed inward, and the fiber insertion holes 34 are gradually reduced in diameter in the tightening direction. Eventually, the pressing portion 67A rides on the abutting portion 36 of the clamping piece 31, and the holding member 30 reaches the locked position.

  In this locked position, the fiber insertion hole 34 is in a state where the hole diameter is reduced to 2.0 mm and holds the end portion of the optical fiber F inserted therein (see FIG. 8C, tightening). The hole diameter φc at the time of insertion is 2.0 mm). From the above, the end of the upper optical fiber F is held coaxially with the light projecting element 20, and the end of the lower optical fiber F is held coaxially with the light receiving element 21. Further, in this locked position, the pressing portion 67A is brought into contact with the contact portion 36 of the both sandwiching pieces 31 to prevent the holding member 30 from opening.

  According to the present embodiment, the hole diameter φa of the fiber insertion hole 34 in the natural state (before optical fiber insertion) is set to 2.0 mm, which is smaller than the outer diameter of the optical fiber F. Therefore, as described above, since the repulsive force received by the lock member 45 from the holding member 30 is only a force for pressing the optical fiber F, the hole diameter φa of the fiber insertion hole 34 is set to 2.2 mm or more. The magnitude of the repulsive force is smaller than in the case of. In addition, the portion of the optical fiber F that has been tightened is reduced in diameter to the tightened diameter size (2.0 mm in the present embodiment) as time elapses. Accordingly, the magnitude of the repulsive force is also reduced, and the lock member 45 is hardly deformed.

Further, since the hole diameter φa of the fiber insertion hole 34 in the natural state is set to be smaller than the outer diameter of the optical fiber F, the following effects can also be obtained.
That is, with the above setting, once the optical fiber F is inserted into the fiber insertion hole 34, the optical fiber F always receives an inward pressing force from both the clamping pieces 31 regardless of the pressing by the lock member 45. On the other hand, when the hole diameter φa of the fiber insertion hole 34 is set larger than the outer diameter of the optical fiber F, the optical fiber F is first subjected to a pressing force by pressing by the lock member 45. Therefore, if the pressing force by the lock member 45 is equal, the total pressing force on the optical fiber F increases when the hole diameter φa of the fiber insertion hole 34 is set smaller than the outer diameter of the optical fiber F.

  From the above, by setting the hole diameter φa of the fiber insertion hole 34 before insertion of the optical fiber to be smaller than the outer diameter of the optical fiber F, a stable holding force can be obtained over a long period of time. Predetermined light transmission efficiency can be ensured and high detection accuracy can be obtained without causing a positional shift between the element 20 or the light receiving element 21 and the optical fiber F.

<Embodiment 2>
A second embodiment will be described with reference to FIGS.
In the first embodiment, the diameter increasing means for expanding the fiber insertion hole 34 is formed by the guide inclined portion 34A. However, in the second embodiment, the locking member 45 is provided with the expanding protrusion 75. Since the other configuration is the same as that of the first embodiment, the duplicated portions are denoted by the same reference numerals and the description thereof is omitted.

As shown in FIG. 10, a pair of upper and lower expanding protrusions 75 are formed at the center in the width direction of the side surface (the surface on the side facing the holding member 30) of the lock member 45. The expanding protrusion 75 has a triangular shape, and when the locking member 45 is in the release position, it just enters between the sandwiching pieces 31 to widen the sandwiching piece 31 and thus the fiber insertion hole 34. (See FIG. 11). The lateral width of the expanding protrusion 75 is set to a dimension such that the hole diameter of the fiber insertion hole 34 is φ2.3 mm at the release position.
With such a configuration, it is possible to smoothly insert the optical fiber F into the fiber insertion hole 34, and the pushing force when the optical fiber F is inserted into the fiber insertion hole 34 is also the first embodiment. It becomes possible to hold down compared with the case of.

  In addition, when the lock member 45 is lowered from the release position to the lock position, the expanding protrusion 75 is also lowered toward the distal end side of the holding piece 31, and when the lock member 45 reaches the lock position, the spread member 75 is expanded. The opening protrusion 75 is completely retracted from between both the sandwiching pieces 31 (see FIG. 12). Accordingly, the pressing operation by the lock member 45 is performed without any trouble, and the optical fiber F is held by the holding member 30 at the lock position.

<Embodiment 3>
Next, a third embodiment of the present invention will be described with reference to FIGS.
In the first embodiment, both sandwiching pieces 31 are integrally formed and the ends thereof are connected by the connecting portion 32. However, in the third embodiment, the sandwiching pieces 81 and 82 are formed by individual members and between the opposing surfaces. A fiber insertion hole 34 for inserting the optical fiber F is provided. Further, the upper ends of the sandwiching pieces 81 and 82 are connected to each other by a hinge 85, and both the sandwiching pieces 81 and 82 can be freely opened. A spring member or the like that generates an urging force is not mounted between the sandwiching pieces 81 and 82. Therefore, even when the leg opening operation is performed, when the holding member 80 is in a single state (a state before the optical fiber is inserted into the fiber insertion hole), no restoring force or the like is generated between the both sandwiching pieces 81 and 82. It is configured. Other configurations are the same as those in the first embodiment.
Thus, if it is the structure which connects the clamping pieces 81 and 82 by the hinge 85 and can make a leg open freely, the effect similar to the case of Embodiment 1 will be acquired. That is, the repulsive force received by the lock member 45 is only a force for pressing the optical fiber F.

<Other embodiments>
The present invention is not limited to the embodiments described with reference to the above description and drawings. For example, the following embodiments are also included in the technical scope of the present invention, and further, within the scope not departing from the gist of the invention other than the following. Various modifications can be made.

  (1) In the above embodiment, the holding member 30 is configured separately from the element block 10, but may be configured integrally.

  (2) In the above embodiment, the lock member 45 is operated by the lever 51, but the lever 51 may be abolished and the lock member 45 may be manually operated.

The longitudinal cross-sectional view which shows the state in which the lock member in Embodiment 1 exists in a cancellation | release position The partial bottom view Perspective view of lock member Longitudinal sectional view showing a state where the lock member is in the lock position Sectional view showing the state before inserting the optical fiber Sectional drawing which shows the state which the holding member expanded by optical fiber insertion Sectional drawing which shows the state by which the holding member was pressed by the locking member Diagram showing fluctuation of hole diameter of fiber insertion hole The figure which shows the insertion operation of the optical fiber to the fiber insertion hole The perspective view of the locking member concerning Embodiment 2 (showing the state seen from the back side) Sectional drawing which shows the state by which the holding member was expanded by the expansion protrusion Sectional drawing which shows the state which the expansion protrusion evacuated from the holding member The figure which shows the decomposition | disassembly state of the holding member in Embodiment 3. The figure which shows the state in which the clamping piece was connected by the hinge Figure showing a conventional example

Explanation of symbols

F ... Optical fiber 10 ... Element block 20 ... Projection element (photoelectric element)
21. Light receiving element (photoelectric element)
30 ... Holding member 34 ... Fiber insertion hole 45 ... Lock member

Claims (4)

An element block in which a photoelectric element is mounted;
A holding member having a pair of clamping pieces provided in the element block and capable of elastically clamping an optical fiber arranged facing the photoelectric element;
A fiber insertion hole formed between the opposing surfaces of the pair of sandwiching pieces and through which the optical fiber is inserted;
An optical fiber holding device comprising: a lock position that presses the pair of clamping pieces in a tightening direction in which the diameter of the fiber insertion hole is reduced; and a lock member that is displaceable between a release position that releases the pressed state. A device,
While the hole diameter size in the non-pressed state of the fiber insertion hole is smaller than the outer diameter size of the optical fiber,
The holding member or the lock member is configured to increase the diameter of the optical fiber insertion hole to a diameter larger than the diameter of the non-pressed state with respect to the fiber insertion hole before or after the optical fiber is inserted. A diameter expanding means for guiding the insertion operation of the optical fiber is provided,
Further, the optical fiber holding mechanism is characterized in that the lock member reduces the diameter of the fiber insertion hole expanded by the diameter expansion means within a range not smaller than a non-pressed hole diameter size at the lock position. An element block in which a photoelectric element is mounted;
A holding member having a pair of clamping pieces provided in the element block and capable of clamping an optical fiber disposed facing the photoelectric element;
A fiber insertion hole formed between the opposing surfaces of the pair of sandwiching pieces and through which the optical fiber is inserted;
A lock member that is displaceable between a lock position that presses the pair of clamping pieces in a tightening direction in which the diameter of the fiber insertion hole is reduced, and a release position that is spaced apart from the clamping pieces and releases the same pressing state. An optical fiber holding device comprising:
The holding member is an optical fiber holding mechanism in which ends of both holding pieces formed individually are connected to each other through a hinge so as to be freely opened. In the fiber insertion hole, a guide portion serving as the diameter-expanding means is provided at the hole edge on the side facing the optical fiber during the insertion operation so that the hole diameter gradually increases toward the tip side. The optical fiber holding mechanism according to claim 1, wherein the optical fiber holding mechanism is provided. The locking member is an expansion means that is the diameter-expansion means that expands the clamping piece so that the fiber insertion hole is expanded by abutting both the clamping pieces when the locking member is in the release position. An open protrusion is formed,
2. The expansion protrusion is retracted from the both clamping pieces to release the contact state in accordance with the displacement operation of the lock member from the release position to the lock position. Item 3. The optical fiber holding mechanism according to Item 2.

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