JP2008165003A - Ferrule holding member, optical receptacle, and optical module - Google Patents

Abstract

[PROBLEMS] To easily press-fit another member even after another member is press-fitted into an inner hole, and to easily press-fit another member into the inner hole after being press-fitted into another member. A ferrule holding member that can be provided is provided.
A ferrule holding member comprising a cylindrical body having an inner peripheral surface and an outer peripheral surface, wherein one end of a ferrule 2 is press-fitted into an inner hole of the cylindrical body to hold the ferrule 2.
A plurality of inner circumferential grooves are formed in the inner circumferential surface in the press-fitting direction of the ferrule 2, and inner circumferential abutting surfaces 11a with which the ferrules abut each other are formed between the inner circumferential grooves 11g. An outer peripheral groove 12g was formed at a position corresponding to the inner peripheral contact surface 11a.
[Selection] Figure 3

Description

  The present invention relates to a ferrule holding member, an optical receptacle, and an optical module that are mainly used for an optical receptacle.

  The optical receptacle is a receiving-side optical component connected to the optical fiber connector, and is used, for example, to optically connect an optical fiber held by the optical fiber connector to a light receiving element or a light emitting element. This optical receptacle is configured by fixing a sleeve into which a ferrule is inserted from one end in a case, and the plug ferrule of the optical fiber connector is inserted from the other end of the sleeve so as to contact the end face of the ferrule. The That is, in the optical receptacle, when the plug ferrule of the optical fiber connector comes into contact with the end face of the ferrule, it is necessary to fix the ferrule on the optical receptacle side so as not to be displaced. Therefore, in the optical receptacle, a structure has been proposed in which a ferrule is press-fitted into a sleeve and, for example, a ring member into which a part of the ferrule is press-fitted and the ring member is further press-fitted into a case ( Patent Document 1).

Patent Document 2 discloses an optical receptacle in which a stub corresponding to the ferrule of Patent Document 1 is fixed to a case by a cylindrical member called a bush, and a sleeve is fixed to the case by a ring member. In Patent Document 2, the stub is press-fitted into the inner hole of the bush, the bush is press-fitted into the case, the sleeve is press-fitted into the ring member, and the ring member is press-fitted into the case.
JP 2005-37571 A JP 2005-31515 A

  However, for example, when a holding member such as a ring member or a bush is pressed into another hole and the holding member itself is pressed into another member, the other member is pressed into the inner hole. As a result, the outer shape is deformed (for example, swells). As a result, with this holding member, it becomes difficult to press-fit the holding member itself into another member. Conversely, when the holding member is press-fitted into another member, it is possible to press-fit another member into the inner hole of the holding member. There was a problem that became difficult.

  Therefore, the present invention can easily press-fit another member even after another member is press-fitted into the inner hole, and after inserting the other member into the inner hole, It is an object of the present invention to provide a ferrule holding member that can be easily press-fitted.

  In order to achieve the above object, a ferrule holding member according to the present invention includes a cylindrical body having an inner peripheral surface and an outer peripheral surface, and one end of the ferrule is press-fitted into an inner hole of the cylindrical body. A plurality of inner circumferential grooves formed in the inner circumferential surface in the press-fitting direction of the ferrule, and inner circumferential abutting surfaces on which the ferrules abut each other between the inner circumferential grooves. The outer peripheral groove is formed at a position facing the inner peripheral contact surface on the outer peripheral surface.

  Moreover, the ferrule holding member according to the present invention is characterized in that the inner peripheral contact surface is located on one peripheral surface centered on the inner peripheral axis.

  Furthermore, the ferrule holding member according to the present invention is characterized in that a bottom surface of the outer peripheral groove is a curved surface bulging outward.

  Furthermore, the ferrule holding member according to the present invention is characterized in that the bottom surface of the outer peripheral groove is a curved surface recessed inward.

Moreover, the ferrule holding member according to the present invention is characterized in that the width of the outer peripheral groove is larger than the width of the inner peripheral contact surface.
Here, in this specification, the term “width” refers to the width in the circumferential direction of the inner periphery or outer periphery of the cylinder.

An optical receptacle according to the present invention includes a ferrule holding member according to the present invention,
A ferrule whose one end is press-fitted into the ferrule holding member;
And a cylindrical case in which the ferrule holding member corresponding to the ferrule press-fitting portion of the ferrule holding member is press-fitted in a hole.

  An optical module according to the present invention includes an optical receptacle according to the present invention, an optical element that emits light into the through hole of the ferrule, or receives light through the through hole of the ferrule, And a housing that is connected to the optical receptacle and accommodates the optical element.

The ferrule holding member according to the present invention as described above forms a plurality of inner peripheral grooves on the inner peripheral surface, and forms inner peripheral contact surfaces on which the ferrules contact respectively between the inner peripheral grooves, Since the outer peripheral groove is formed at a position facing the inner peripheral contact surface on the surface, even if the ferrule is press-fitted into the inner hole, deformation of the inner peripheral contact surface caused by the press-fitting (on the bottom of the outer peripheral groove) Deformation) can be accommodated in the outer peripheral groove, so that the ferrule can be press-fitted without deforming the outer peripheral abutment surface of the ferrule holding member that abuts another member.
Therefore, according to the present invention, even after another member is press-fitted into the inner hole of the cylindrical body, it can be easily press-fitted into another member, and the inner hole after being press-fitted into another member. It is possible to easily press-fit other members into.

  Hereinafter, an optical receptacle according to an embodiment of the present invention will be described with reference to the drawings.

First Embodiment FIG. 1 is a cross-sectional view showing a configuration of an optical receptacle according to a first embodiment of the present invention.
The optical receptacle of the first embodiment has a cylindrical case 4, a cylindrical sleeve 3 having a hole into which a plug ferrule on the optical connector side is inserted, and a distal end side disposed in an inner hole of the sleeve 3. It includes a ferrule 2 with which the front end surface of the plug ferrule abuts on the front end surface, and a ferrule holder 1 that holds the ferrule 2 at a predetermined position in the cylindrical case 4. The optical receptacle has a rear end (one end) of the ferrule 2 press-fitted into the ferrule holder 1, and a ferrule holder 1 corresponding to the press-fitted portion of the ferrule 2 of the ferrule holder 1 is press-fitted into the cylindrical case 4. ing.

In the optical receptacle of the first embodiment, as shown in FIG. 2, the ferrule holder 1 has a cylindrical shape having an inner peripheral surface and an outer peripheral surface, and the rear end portion of the ferrule 2 is press-fitted into the inner hole. Then, it is press-fitted into the cylindrical case 4, thereby holding the ferrule 2 at a predetermined position in the cylindrical case 4. That is, the ferrule holder 1 is a cylindrical body having an inner peripheral contact surface with which the outer peripheral surface of the rear end portion of the ferrule 2 contacts and an outer peripheral contact surface with which the inner peripheral surface of the cylindrical case 4 contacts.
In the first embodiment, the ferrule holder 1 is press-fitted into the cylindrical case 4 so that the front end surface of the ferrule holder 1 comes into contact with the rear end surface of the sleeve 3. In addition to being held in position, it also serves as a stopper that holds the sleeve 3 so as not to retract when the plug ferrule is inserted.
The material of the ferrule holder 1 is not particularly limited as long as it can be easily press-fitted with metal, ceramics, etc. For example, SUS-based stainless steel is preferable from the viewpoint of easy shape processing. It is.
The sleeve 3 has a function of holding the distal end portion of the ferrule 2 in a hole on one end side, and is configured in a cylindrical shape, for example. Further, the sleeve 3 is inserted with a plug ferrule (not shown) having an optical fiber in the hole on the other end side, whereby the inner diameter is expanded to hold the ferrule 2 and the plug ferrule. The sleeve 3 aligns the ferrule 2 and the plug ferrule within the hole portion, thereby accurately performing optical coupling between the optical fibers held inside the ferrule 2 and the plug ferrule. It is a member. As a material of the sleeve 3, for example, a ceramic such as zirconia or alumina, or a metal such as copper can be used.
The cylindrical case 4 is formed of a hollow body having an inner diameter into which the sleeve 4 can be inserted and removed, and has a function of covering and protecting the sleeve 4 holding the tip of the ferrule 2. The material of the cylindrical case 4 is preferably a metal material such as stainless steel or copper from the viewpoint of improving the weldability with the casing constituting the optical module.

  Here, in particular, in the first embodiment, the ferrule holder 1 is shaped as follows to facilitate the press-fitting when manufacturing the optical receptacle, and after the press-fitting, the ferrule is securely placed in the cylindrical case. Is held in the position.

  That is, as shown in FIG. 3, the ferrule holder 1 which is a ferrule holding member in the first embodiment has a plurality of inner peripheral grooves 11g formed in the ferrule press-fitting direction on the inner peripheral surface of the cylinder. Moreover, in the ferrule holder 1, it becomes the inner peripheral contact surface 11a with which the outer peripheral surface of the ferrule into which the front end surface of the convex part comprised between the inner peripheral grooves 11g press-fits contacts. And the outer peripheral groove | channel 12g is formed in the outer peripheral surface of the ferrule holder 1 in the position corresponding to the inner peripheral contact surface 11a.

Thus, in the first embodiment, when the rear end portion of the ferrule 2 is press-fitted into the inner hole of the ferrule holder 1 and an outward force is applied to the inner peripheral contact surface 11a, the inner peripheral contact surface Although the portion of the outer peripheral groove 12g formed on the outer peripheral surface facing 11a is deformed, the deformation of the outer peripheral contact surface 12a is suppressed.
Further, in the first embodiment, when the ferrule 2 is press-fitted into the inner hole of the ferrule holder 1, the inner peripheral contact surface 11a expands outward together with the non-contact surface 12b, and the insertion of the ferrule 2 can be facilitated. In addition, the outward spread of the non-contact surface 11b and the outer peripheral contact surface 12a to which no outward pressure is applied can be suppressed. Therefore, the ferrule holder 1 of the first embodiment can easily press-fit the ferrule 2 into its inner hole, and the deformation of the outer peripheral contact surface 12a due to the press-fitting of the ferrule 2 is suppressed, so that the ferrule 2 is press-fitted. In this state, the ferrule holder 1 can be easily press-fitted into the cylindrical case 4.

  Thus, in the ferrule holder 1 of 1st Embodiment, the internal peripheral surface is comprised by the non-contact surface 11b which consists of several inner peripheral contact surfaces 11a extended in the axial direction, and the inner surface of the internal peripheral groove 11g. Thus, the outer periphery of the press-fitted ferrule 2 is not in contact with the entire inner periphery, but is in contact only with the inner peripheral contact surface 11a. Further, the outer peripheral surface of the ferrule holder 1 also includes a plurality of outer peripheral contact surfaces 12a extending in the axial direction and a non-contact surface 12b including the inner surfaces of the outer peripheral grooves 12g. Only the contact surface 12 a is in contact with the inner peripheral surface of the cylindrical case 4.

Hereinafter, the ferrule holder 1 of 1st Embodiment is demonstrated in detail.
In the ferrule holder 1 of the first embodiment, three inner circumferential grooves 11g having a width of 1/6 of the inner circumference are formed on the inner wall of the cylinder, and each of the inner circumference is 1/6 of the inner circumference. Three inner peripheral contact surfaces 11a having a length width are formed.
Since the ferrule holder 1 of the first embodiment configured as described above can hold the press-fitted ferrule 2 in contact with the three inner peripheral contact surfaces 11a of the inner peripheral surface of the inner hole, It can be held while reducing the axial deviation.
Here, since the inner peripheral contact surface 11a is a surface that contacts the outer peripheral surface of the ferrule 2 when the ferrule 2 is press-fitted, the inner peripheral contact surface 11a has one circumference corresponding to the outer periphery of the ferrule. It is formed so as to be located on the surface (first circumferential surface). Specifically, the diameter of the first circumferential surface is preferably 0.002 to 0 with respect to the diameter of the ferrule to be press-fitted. 0.03 mm is set in a smaller range, and more preferably in a range of 0.005 to 0.015 mm. As described above, in the first embodiment, the ferrule holder 1 is configured such that the inner peripheral contact surface 11a is a curved surface that easily contacts the outer peripheral surface of the ferrule 2, so that the inner peripheral contact surface 11a and the outer periphery of the ferrule 2 are Since the contact area with the surface can be increased, the force for holding the ferrule 2 is improved. In the first embodiment, since the inner peripheral contact surface 11a is formed at equal intervals with respect to the circumferential direction of the inner peripheral surface of the ferrule holder 1, the force for holding the ferrule 2 acts evenly. The force for holding the ferrule 2 can be stabilized.
In the first embodiment, as shown in FIG. 3, the groove 11g is formed such that its bottom surface is located on a second circumferential surface having a diameter larger than that of the first circumferential surface.
Here, preferably, the diameter of the second circumferential surface is set to a range larger by 0.1 to 0.5 mm than the diameter of the first circumferential surface.
Thus, in the first embodiment, by making the width of the outer peripheral groove 12a larger than the width of the inner peripheral contact surface 11a, the ferrule 2 is press-fitted into the inner hole of the ferrule holder 1, and the inner peripheral contact is made. Even if an outward force is generated on the surface 11a and the bottom surface of the outer circumferential groove 12a is deformed, the deformed portion can be efficiently stored in the outer circumferential groove 12a.

Further, on the outer peripheral surface of the ferrule holder 1, three grooves 12g having a width of 1/6 of the outer periphery are formed at equal intervals, and each of the three grooves having a width of 1/6 of the outer periphery is formed. An outer peripheral contact surface 12a is formed. In the present embodiment, the three grooves 12g having a width of 1/6 of the outer periphery are used. However, the present invention is not limited to such a form, and when the three grooves 12g are formed, If it is the width | variety of the length of 1/6-1/8, while holding the ferrule 2 firmly, a deformation | transformation of the outer peripheral contact surface 12a can be suppressed.
When the ferrule holder 1 of the first embodiment having such an outer peripheral surface is press-fitted into the cylindrical case 4, the three outer peripheral contact surfaces 12 a come into contact with the inner peripheral surface of the cylindrical case 4. Since it is held, the axial deviation of the ferrule holder 1 can be reduced.
Here, since the outer peripheral contact surface 12a is a surface that contacts the inner peripheral surface of the cylindrical case 4 when the ferrule holder 1 is press-fitted into the cylindrical case 4, the three outer peripheral contact surfaces 12a are: It is formed so as to be located on one circumferential surface (third circumferential surface) corresponding to the inner circumferential surface of the cylindrical case 4, and specifically, the diameter of the third circumferential surface is the cylindrical case. Preferably, it is set in the range of 0.002 to 0.03 mm larger than the inner diameter of 4, more preferably in the range of 0.005 to 0.015 mm.
In the first embodiment, the outer peripheral groove 12g is formed so that its bottom surface is located on the fourth circumferential surface having a smaller diameter than the third circumferential surface.
Here, preferably, the diameter of the fourth circumferential surface is set in a range smaller by 0.1 to 0.5 mm than the diameter of the third circumferential surface.

In the ferrule holder 1 configured as described above, the deformation of the outer peripheral contact surface 12a is suppressed even after the rear end portion of the ferrule 2 is press-fitted into the inner hole of the cylindrical body. 1 can be easily press-fitted into the cylindrical case 4.
Further, since the deformation of the inner peripheral contact surface 11a is suppressed even after the ferrule holder 1 is press-fitted into the cylindrical case 4, the rear end portion of the ferrule 2 can be easily press-fitted.
Therefore, the optical receptacle configured to include the ferrule holder 1 can reduce the axial deviation of the ferrule 2 and simplify the manufacturing process.
The inner peripheral groove 11g and the outer peripheral groove 12g of the ferrule holder 1 are formed on the inner peripheral surface and the outer periphery of a cylindrical body made of a SUS metal that has been prepared in advance if the ferrule holder 1 is made of a SUS metal. The groove can be formed by, for example, milling or wire electric discharge machining of the surface. Further, when the ferrule holder 1 is made of ceramics, the ceramic raw material is put into a mold capable of forming the inner circumferential groove 11g and the outer circumferential groove 12g, and press-molded and then fired.

Further, in the ferrule holder 1 in the first embodiment, the deformation of the outer peripheral contact surface 12a when the rear end portion of the ferrule 2 is press-fitted into the inner hole is suppressed, and the ferrule holder 1 is attached to the cylindrical case 4. Since the deformation of the inner peripheral contact surface 11a when being press-fitted is suppressed, the allowable range of dimensional accuracy can be increased, and the ferrule holder 1 can be manufactured at a low cost.
Moreover, in 1st Embodiment, it is preferable that the ferrule holder 1 is a curved surface where the bottom face of the outer periphery groove | channel 12g swelled outside. According to such a configuration, the outward force generated on the inner peripheral contact surface 11a when the ferrule 2 is press-fitted into the inner hole of the ferrule holder 1 and the bulge direction of the bottom surface of the outer peripheral groove 12g are in the same direction. The force required when press-fitting the ferrule 2 can be reduced.

<Second Embodiment>
Hereinafter, an optical receptacle according to a second embodiment of the present invention will be described with reference to FIG. 4 is a sectional view of the ferrule holder 100 (a sectional view of a section orthogonal to the axis).
The optical receptacle of the second embodiment is the same as the optical receptacle of the first embodiment except that the ferrule holder 100 shown in FIG. 4 is used instead of the ferrule holder 1 shown in FIG. The optical receptacle is configured in the same manner as the optical receptacle of the first embodiment.

The ferrule holder 100 according to the second embodiment is different from the ferrule holder 1 according to the first embodiment in the non-contact surfaces of the outer peripheral surface and the inner peripheral surface.
That is, in the ferrule holder 100 of the second embodiment, the inner peripheral surface of the cylinder is a plurality of (three) located on the first circumferential surface similar to the ferrule holder 1 of the first embodiment. The inner peripheral contact surface 11a and the non-contact surface 110b formed between the inner peripheral contact surface 11a and the shape of the non-contact surface 110b are the same as those of the first embodiment. It is different from the contact surface 11b.

  Moreover, in the ferrule holder 100 of 2nd Embodiment, the outer peripheral surface of a cylinder is a some (3) outer periphery located on the 3rd circumferential surface similar to the ferrule holder 1 of 1st Embodiment. The non-contact surface 120b is formed between the contact surface 12a and the outer peripheral contact surface 12a, and the non-contact surface 120b is a concave surface. This is different from the non-contact surface 12b.

As described above, in the optical receptacle according to the second embodiment, the ferrule holder 100 is formed between the inner peripheral contact surfaces 11a and the inner peripheral contact surfaces 11a in which the inner peripheral surface of the inner hole extends in the axial direction. The outer periphery of the press-fitted ferrule 2 is not in contact with the entire inner periphery, but is in contact only with the inner peripheral contact surface 11a. Further, the outer peripheral surface of the ferrule holder 100 is also composed of a plurality of outer peripheral contact surfaces extending in the axial direction and a non-contact surface 120b formed between the outer peripheral contact surfaces and is press-fitted into the cylindrical case 4 Sometimes, only the outer peripheral contact surface 12a is in contact with the inner periphery of the cylindrical case 4.
Therefore, in the ferrule holder 100 of the second embodiment, since the boundary between the bottom surface and the side surface of the outer circumferential groove 12g is a curved surface, when the ferrule 2 is press-fitted, the stress concentration at the boundary is efficiently reduced. It is possible to reduce breakage of the boundary portion. Further, since the ferrule holder 100 has a concave curved surface in which the non-contact surface 120b constituting the outer peripheral groove 12g is depressed, the groove processing is easier than the outer peripheral groove 12g of the first embodiment.

<Modification>
In the first embodiment and the second embodiment described above, three inner peripheral contact surfaces 11a and three outer peripheral contact surfaces 12a are formed, but the present invention is not limited to this. , At least two or more.
Further, in the first embodiment and the second embodiment, in the ferrule holder 100, the outer peripheral surface including the inner peripheral surface including the inner peripheral contact surface and the non-contact surface, and the outer peripheral contact surface and the non-contact surface. However, the present invention is not limited to this, and the inner peripheral contact surface of the sleeve in which the tip side of the ferrule is press-fitted and is further press-fitted into the cylindrical case. Further, an inner peripheral surface composed of a non-contact surface and an outer peripheral surface composed of an outer peripheral contact surface and a non-contact surface may be formed to facilitate press-fitting.
That is, the present invention can be applied to all ferrule holding members in which the ferrule is press-fitted into the inner hole and is itself press-fitted into the inner hole of another cylindrical member.

Next, an embodiment of an optical module provided with the optical receptacle of the present invention will be described with reference to the drawings. FIG. 5 is a cross-sectional view showing an embodiment of the optical module of the present invention. The optical module includes an optical receptacle according to the first embodiment of the present invention, an optical element 5, a lens 6, and a housing 7 that holds the optical element 5.
The optical element 5 is a light receiving element for receiving light emitted from the optical fiber of the optical receptacle, or a light emitting element that emits light toward the optical fiber of the optical receptacle.
The lens 6 has a function of condensing the light transmitted through the through hole of the ferrule 2 of the optical receptacle and condensing it toward the optical element 5 (light receiving element). For example, glass such as borosilicate glass or quartz glass is used. Composed of materials. The lens 6 also has a function of collecting the light emitted from the optical element 5 (light emitting element) toward the through hole of the ferrule 2 of the optical receptacle. In addition, you may arrange | position an optical fiber in the through-hole of the ferrule 2 from a viewpoint of reducing the reflection by the refractive index difference with air. That is, in the optical module of the present invention, optical coupling with the light emitting element or the light receiving element may be performed via the optical fiber disposed in the through hole of the ferrule 2.
The housing 7 has a function of holding the optical element 5 and the lens 6 and is preferably made of, for example, a stainless material from the viewpoint of being easily weldable.
Since such an optical module 11 includes the ferrule holder 1, the axial deviation of the ferrule 2 can be reduced, and thus the optical coupling with the optical element 5 can be stabilized.

It is a longitudinal cross-sectional view (cross section parallel to an axis | shaft) of the optical receptacle of 1st Embodiment which concerns on this invention. It is a transverse cross section (AA 'section perpendicular to an axis) of the optical receptacle of a 1st embodiment. It is a side view in the end surface of the ferrule holder in 1st Embodiment. It is a side view in the end surface of the ferrule holder used for the optical receptacle of 2nd Embodiment which concerns on this invention. It is a longitudinal cross-sectional view of the optical module which is one Embodiment which concerns on this invention.

Explanation of symbols

100 ferrule holder, 2 ferrule, 3 sleeve, 4 cylindrical case,
5 optical element, 6 lens, 7 housing, 11a inner peripheral contact surface 12a outer peripheral contact surface 11b, 12b, 110b, 120b non-contact surface, 11g inner peripheral groove, 12g outer peripheral groove

Claims (7)

A ferrule holding member comprising a cylindrical body having an inner peripheral surface and an outer peripheral surface, wherein one end of the ferrule is press-fitted into an inner hole of the cylindrical body to hold the ferrule;
A plurality of inner circumferential grooves are formed in the inner circumferential surface in the press-fitting direction of the ferrule, an inner circumferential abutting surface with which the ferrule abuts is formed between the inner circumferential grooves, and the inner circumferential surface A ferrule holding member, wherein an outer peripheral groove is formed at a position corresponding to the contact surface.   The ferrule holding member according to claim 1, wherein the inner circumferential contact surface is located on one circumferential surface.   3. The ferrule holding member according to claim 1, wherein a bottom surface of the outer peripheral groove is a curved surface bulging outward.   3. The ferrule holding member according to claim 1, wherein a bottom surface of the outer peripheral groove is a curved surface recessed inward.   The ferrule holding member according to any one of claims 1 to 4, wherein a width of the outer peripheral groove is larger than a width of the inner peripheral abutting surface. The ferrule holding member according to any one of claims 1 to 5,
A ferrule whose one end is press-fitted into the ferrule holding member;
An optical receptacle comprising: a cylindrical case in which the ferrule holding member corresponding to the ferrule press-fitting portion of the ferrule holding member is press-fitted in a hole. An optical receptacle according to claim 6;
An optical element that emits light into the through-hole of the ferrule, or receives light through the through-hole of the ferrule;
An optical module comprising: a housing connected to the optical receptacle and accommodating the optical element.

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