JP2002267879A - Optical connector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical connector which can satisfactorily connect an optical fiber with the other optical fiber or with the other optical component. SOLUTION: The optical connector is equipped with a ferrule 2 which has at least a positioning hole 2a to position one optical fiber and a pair of guide holes 2c, locking lugs 3a for fitting, and a housing 3 which has grooves 3b to hold back the locking lugs 3a and houses the ferrule 2 therein. In a process for fitting the housings 3 with each other, the largest amount of deformation caused by reactive force after the locking lug 3a is elastically deformed to the side of the ferrule 2 in which the housing 3 is housed is reduced compared with the amount of clearances between the inner wall of the housing 3 and the outer periphery of the ferrule 2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical connector used for connecting an optical fiber to another optical fiber or an optical component.

[0002]

2. Description of the Related Art On an optical transmission line, it is necessary to connect optical fibers to each other or to connect optical fibers to optical components. Although there are various connection methods, it is common practice to connect the ends of the optical fibers into connectors. Examples of such an optical connector include U.S. Pat. No. 6,116,790 and JP-T-2000-515986.
And the like described in Japanese Patent Application Laid-Open Publication No. H10-163, etc. are known. The optical connectors described in these publications include a ferrule for holding an end of an optical fiber and positioning the optical fiber with a mating optical fiber (optical component), and housing the ferrule therein to fit with the mating optical connector. And a housing provided with a mechanism for performing the above. The fitting of the optical connectors is performed by locking the locking projections (claws) and the locking recesses (grooves) formed on the housing. Further, the positioning of the ferrules is performed by a pair of guide pins and guide holes.

[0003]

However, in the above-described optical connector, there is a concern that interference between the housing and the ferrule occurs when the optical connectors are fitted together. If interference between the housing and the ferrule occurs at the time of fitting, there is a possibility that positional accuracy between the opposing ferrule is degraded and connection loss due to misalignment of the optical fiber occurs. Also,
If a shear load acts on the ferrule due to interference between the housing and the ferrule in a state where the connection end surfaces are in contact with each other, there is a possibility that the fiber end surface may be damaged. If the attachment / detachment is repeated in this state, it is feared that the scratch grows and the connection characteristics deteriorate.

Further, when interference between the housing and the ferrule occurs at the time of fitting, the tip of the guide pin is displaced from the guide hole, and the periphery of the guide hole is damaged. The positional accuracy of the optical fiber may be degraded, and a connection loss may occur due to the misalignment of the optical fiber. The present invention has been made in order to solve these problems, and an object of the present invention is to provide an optical connector that can suitably perform connection between an optical fiber and a mating optical fiber or a mating optical component. is there.

[0005]

According to a first aspect of the present invention, there is provided an optical connector having a ferrule having at least one optical fiber positioning hole and a pair of guide holes, a locking claw for fitting, and a locking claw. An optical connector comprising a housing having a groove for retaining and housing a ferrule therein, wherein in a process of fitting the housings together, the housing is housed inside by a reaction force after the locking claw is elastically deformed. It is characterized in that the maximum amount of deformation toward the ferrule side is smaller than the clearance amount between the inner wall of the housing and the outer periphery of the ferrule.

[0006] The optical connector according to the second aspect is the first aspect.
In the invention described in the above, the amount of clearance between the inner wall of the housing and the outer periphery of the ferrule is the maximum amount of deformation of the housing toward the ferrule due to reaction force after the locking claw is elastically deformed in the process of fitting the housings together. When,
It is characterized in that it is larger than the total amount of the positioning accuracy of the guide pin hole with respect to the outer periphery of the ferrule.

[0007] The optical connector according to the third aspect is the first aspect.
In the invention described in the above, the amount of clearance between the inner wall of the housing and the outer periphery of the ferrule is the maximum amount of deformation of the housing toward the ferrule due to reaction force after the locking claw is elastically deformed in the process of fitting the housings together. It is characterized in that it is 0.02 to 0.30 mm wider than that.

The optical connector according to the fourth aspect is the third aspect of the present invention.
In the invention described in the above, the amount of clearance between the inner wall of the housing and the outer periphery of the ferrule is the maximum amount of deformation of the housing toward the ferrule due to reaction force after the locking claw is elastically deformed in the process of fitting the housings together. It is characterized by being 0.05 to 0.20 mm wider than that.
This defines a particularly preferable range among the ranges described in claim 3.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the optical connector according to the present invention will be described with reference to the drawings. 1 shows the upper surface of the optical connector, FIG. 2 shows the side surface, FIG. 3 shows the lower surface, and FIG. 4 shows the connection end surface. 5 is a sectional view taken along line BB in FIG. 2, FIG. 6 is a sectional view taken along line CC in FIG. 2, and FIG. 7 is a sectional view taken along line AA in FIG. However, the optical connector shown in FIGS. 1 to 4 is a type that does not have a guide pin described later. On the other hand, the optical connector shown in FIGS. 5 to 7 is a type having a guide pin. The only difference between the two is the presence or absence of a guide pin.

The optical connector of the present embodiment is an optical fiber
And a housing 3 housing the ferrule 2 therein and having a fitting mechanism. The ferrule 2 is a commonly used MT ferrule. Inside the ferrule 2, an optical fiber positioning hole 2a for accommodating and positioning the distal end of the tape-shaped optical fiber 1 is formed (see FIG. 4). The end face of the distal end of the optical fiber 1 housed in the optical fiber positioning hole 2 a is exposed at the connection end face 2 b of the ferrule 2.

The ferrule 2 is formed with a pair of guide holes 2 c parallel to the optical fiber 1 so as to be located on both sides of the optical fiber 1. Each guide hole 2c is formed to penetrate from the connection end surface 2b to the opposite end surface (referred to as a rear end surface 2d). A pink lamp 4 is pressed by a spring 5 on the rear end face 2 d of the ferrule 2. In the case of the optical connector having the guide pin 6, the pink lamp 4 clamps (clamps) the base end of the guide pin 6. In the case of the optical connector having no guide pin 6, the pink lamp 4 is simply the rear end face 2d of the ferrule 2.
(A hole for attaching the base end of the guide pin 6 may or may not be formed).

A pair of guide pins 6 whose base ends are held by the pink lamper 4 are inserted into the above-described guide holes 2c,
The tip protrudes from the connection end face 2b. The ferrule 2 is housed in a housing 3 which is a cylindrical body having a substantially square cross section. The housing 3 has a stepped portion inside, and the stepped portion narrows the internal space on the distal end side of the housing 3. The flange of the ferrule 2 abuts on the stepped portion so that the ferrule 2 pressed by the spring 5 does not protrude from the housing 3.

A sub-housing 7 is fitted on the base end side of the housing 3 to form a reaction force surface on the base end side of the spring 5. The sub-housing 7 has a hole formed in the center thereof, and the above-described optical fiber 1 is inserted into this hole. A further easily deformable boot 8 made of rubber is attached to the base end of the sub housing 7. Boots 8
The optical fiber 1 is also inserted. Boots 8
Prevents the optical fiber 1 from being sharply bent at the base end side of the optical connector.

On the front end side of the housing 3, a pair of locking claws (locking claws) 3a and a pair of locking recesses (grooves for locking the locking claws) 3b are formed. For convenience of description, the upper surface of the optical connector shown in FIG. 2 will be described as an upper surface, and the lower surface will be described as a lower surface. The locking claw 3a is formed on the upper surface side of the optical connector with the claws facing each other. The locking claw 3a has a claw at the tip of a cantilevered arm, and this arm can be elastically deformed. This locking claw 3
a is formed so as to slightly protrude outside the housing 3 main body. On the other hand, the pair of locking recesses 3b is formed on the lower surface side of the optical connector so as to be adjacent to each locking claw 3a. Each locking recess 3 b is formed on the outer surface of the housing 3.

As described above, the locking claw 3a and the locking recess 3
Since the b is formed, the optical connector having the guide pin 6 and the optical connector having no guide pin 6 can be fitted upside down. At this time,
One of the locking claws 3a is locked by the other locking recess 3b, and the other locking claw 3a is locked by the one locking recess 3b to maintain the fitted state. When the locking claw 3a and the locking recess 3b are locked, the locking claw 3a elastically deforms outward. Along with this, the periphery of the housing 3 where the locking recess 3b is formed is also elastically deformed inward (to the ferrule 2 side) by the elastic restoring force of the locking claw 3a.

There is a strong demand for high density and high integration of optical fibers (optical connectors), and it is necessary to reduce the size of optical connectors as much as possible. Accordingly, each member of the optical connector is made thinner.
The peripheral portion where the locking concave portion 3b is formed is also deformed by the elastic restoring force of the locking claw 3a. In the case of the present embodiment, the portion of the housing 3 where the locking concave portion 3b is formed,
The lower surface of the housing 3 is also continuous and is hardly deformed inward, but still inevitably elastically deforms inward to some extent.

The positioning of the optical connectors in the up-down direction at the time of fitting is performed by a positioning plane 3c formed on the side wall surface of the housing 3. The positioning plane 3c is formed on a side wall surface perpendicular to the arrangement plane of the pair of guide holes 2c, and the extending direction of the plane is parallel to the guide holes 2c. When the optical connectors are fitted to each other, the positioning planes 3c are brought into contact with each other, so that the optical connectors are roughly positioned in the vertical direction. The accurate positioning of the ferrules 2 is performed by the above-described guide holes 2c and the guide pins 6.

Incidentally, a cylindrical adapter (not shown) may be used for facilitating the fitting between the optical connectors. Such an adapter is configured to house the optical connector therein, is attached to the outside of one optical connector in advance, and performs approximate positioning with the other optical connector therein. When the other optical connector is inserted into the adapter attached to one of the optical connectors, the positions of the guide pins 6 and the guide holes 2c substantially match, and the other optical connectors are pushed in as they are, so that the other optical connectors are pushed in. Are fitted.

The connection process between the optical connectors is shown in FIGS.
3 is shown. One (left side in the figure) optical connector does not have the guide pin 6. The other (right side in the figure) optical connector has a guide pin 6. The pair of optical connectors are configured using exactly the same members except for the presence or absence of the guide pins 6. As can be seen from the figure, upon connection, the pair of optical connectors are arranged such that the upper and lower surfaces are upside down. In this state, when the two members are moved forward with respect to each other, first, the tips of the pair of guide pins 6 are inserted into the guide holes 2c of the optical connector (FIG. 9).

When the optical connectors are further advanced with respect to each other, the locking claw 3a comes into contact with the wall near the locking recess 3b (FIG. 10). Elastic deformation of the periphery of 3b starts (FIG. 11).
The peripheral portion of the locking recess 3b is elastically deformed toward the inner ferrule 2 by the reaction force received from the locking claw 3a side, and the locking claw 3a is deformed outward by the reaction force received from the locking claw 3b side. And
Immediately before the locking claw 3a is locked by the locking recess 3b, the amount of elastic deformation of both becomes maximum (FIG. 12).
a and the locking recess 3b are locked (FIG. 13). When the optical connectors are locked with each other, each ferrule 2 has a spring 5
The connection end faces 2b are pressed against each other, and the connection end faces 2b are brought into close contact with each other.

In this embodiment, the maximum deformation of the housing 3 (the periphery of the locking recess 3b) toward the outer surface (outer periphery) of the ferrule 2 when the optical connector is connected is determined by the inner surface of the housing 3. The clearance between the (inner wall) and the ferrule 2 is smaller than the clearance. In other words, the inner surface (inner wall) of the housing 3 and the ferrule 2
Is larger than the maximum deformation of the housing 3 (the periphery of the locking concave portion 3b) toward the ferrule 2 when the optical connector is connected. By doing so, contact between the housing 3 and the ferrule 2 (the ferrule 2 itself and the mating ferrule 2) during connection of the optical connectors is prevented, and damage to the ferrule 2 and the end face of the optical fiber 1 is prevented. be able to.

Furthermore, here, the clearance between the inner surface (inner wall) of the housing 3 and the outer surface (outer periphery) of the ferrule 2 when the optical connector is connected is set to “the locking of the housing 3 (when the optical connector is connected). The maximum amount of deformation of the recess 3b (peripheral portion) toward the ferrule 2 "and" the positioning accuracy of the guide hole 2c with respect to the outer surface of the ferrule 2 "are set to be larger than the total amount. In other words, the total amount of “the maximum amount of deformation of the housing 3 (peripheral portion of the locking recess 3b thereof) toward the ferrule 2 when the optical connector is connected” and “the positioning accuracy of the guide hole 2c with respect to the outer surface of the ferrule 2”. But,
The clearance between the inner surface (inner wall) of the housing 3 and the ferrule 2 is made smaller.

Here, the positioning accuracy of the guide hole 2c and the guide pin 6 is also taken into consideration. For example, it is assumed that the maximum deformation amount of the housing 3 toward the ferrule 2 is α, and the positioning accuracy between the guide hole 2c and the guide pin 6 is ± β. In this case, there is a possibility that the positioning accuracy of the guide hole 2c and the guide pin 6 may approach the inner surface of one housing 3 by β with respect to a certain reference (away from the other inner surface). In anticipation of this, by securing a clearance amount of the maximum deformation amount α of the housing 3 + the positioning accuracy β, the contact between the housing 3 and the ferrule 2 can be more reliably prevented.

As a result, the maximum deformation of the housing 3 toward the ferrule 2 is simply made smaller than the clearance between the housing 3 and the ferrule 2 (the housing 3).
The amount of clearance between the ferrule 2 and the housing 3
Is larger than the maximum deformation of the housing 3 to the ferrule 2 side), and further as described above, it is possible to more reliably connect the housing 3 when connecting the optical connectors.
And the ferrule 2 (the ferrule 2 itself and the ferrule 2 on the other side) can be prevented from contacting the ferrule 2 and the tip end surface of the optical fiber 1.

Alternatively, simply, the maximum deformation amount of the housing 3 toward the ferrule 2 is made smaller than the clearance amount between the housing 3 and the ferrule 2 (the housing 3).
The amount of clearance between the ferrule 2 and the housing 3
Is larger than the maximum deformation of the ferrule 2), and the clearance between the inner surface (inner wall) of the housing 3 and the outer surface (outer periphery) of the ferrule 2 when the optical connector is connected is changed by the optical connector. The maximum deformation amount of the housing 3 (peripheral portion of the locking concave portion 3b) toward the ferrule 2 at the time of connection may be wider by 0.02 to 0.30 mm. The present embodiment also satisfies this condition.

By doing so, the contact between the housing 3 and the ferrule 2 (the ferrule 2 itself and the ferrule 2 on the other side) is prevented when the optical connectors are connected to each other. Damage can be prevented. If the clearance is less than 0.02 mm, contact between the housing 3 and the ferrule 2 is likely to occur. Conversely, if the above-mentioned clearance exceeds 0.30 mm, the center axis of the guide pin is greatly displaced from the center axis of the counterpart guide hole, and a situation in which the guide pin is not inserted into the guide hole is likely to occur. Would.

Even within the above-mentioned range, the clearance between the inner surface of the housing 3 and the outer surface of the ferrule 2 at the time of connection of the optical connector is limited by the amount of clearance around the locking recess 3b of the housing 3 at the time of connection of the optical connector. It is particularly preferable that the maximum deformation amount of the part (2) toward the ferrule 2 is 0.05 to 0.20 mm wider, and this embodiment satisfies this condition. In this manner, the prevention of damage to the optical fiber 1 and the ferrule 2 by suppressing the contact between the ferrule 2 and the housing 3 and the suppression of the enlargement of the optical connector can be realized in a highly balanced manner.

The above-mentioned deformation amount (clearance amount)
Is a case where the connection partner side is an optical connector having the same configuration (only the presence or absence of the guide pin 6 is different), so that it is possible to judge by itself. If the other side is an optical connector having the same configuration (only the presence or absence of the guide pin 6 is different), the deformation amount (clearance amount) at that time is equal to that of itself. That is, by defining the clearance amount of the ferrule 2 itself, the clearance amount between the ferrule 2 and the mating optical connector at the time of fitting is also defined. However, the present invention is applied to an optical connector having the same configuration (only the presence or absence of the guide pin 6 differs)
May be connected. In this case, the locking mechanism should have the same form, and the same effect can be obtained.

Although the ferrule 2 has a structure floating in the housing 3, the above-mentioned preferable value of the clearance amount and the like are determined only by the relationship between the locking claw 3a on one side and the ferrule 2. However, it is assumed that the relationship between the locking claw 3a on the other side and the ferrule 2 is established. That is, even if the above-mentioned preferred clearance is secured only on one side, if the preferred clearance is not secured on the other side, it cannot be said that there is no contact between the ferrule 2 and the housing 3 at all. . For this reason, it is necessary to secure the above-mentioned suitable clearance amount on both sides.

FIG. 14 shows a state in which the housing 3 and the ferrule 2 are in contact with each other. Although not shown in this figure is the optical connector of the present embodiment, each component corresponding to the present embodiment is denoted by the same reference numeral for reference. In the drawing, γ indicates the difference in the horizontal direction between the centers of the corresponding guide holes 2c of the pair of optical connectors.

FIG. 15 shows the positioning of the optical connectors in the vertical direction by the positioning plane 3c described above. As described above, when the optical connectors are connected to each other, the positioning planes 3c abut against each other, so that the optical connectors are roughly positioned in the up-down direction.
However, accurate positioning of the ferrules 2 (that is, positioning of the optical fibers) is performed by the guide holes 2c and the guide pins 6. With such a mechanism, the tip of the guide pin 6 can be more smoothly inserted into the guide hole 2c of the other party, and the tip of the guide pin 6 may damage the connection end face 2b of the other ferrule 2. Can be prevented.

As a comparative example of the configuration of FIG. 15, FIG.
6 shows the configuration of FIG. In FIG. 16, even if there is a clearance between the ferrule and the housing when viewed from the individual connector plug, the clearance between the ferrules may be substantially lost in the fitted state. Further, when the housing is deformed as described above, or the guide hole is misaligned in the ferrule (the amount of misalignment of the guide hole with respect to the outer shape), the interference between the ferrule and the housing becomes more remarkable.

The measured value of the amount of deflection of the housing 3 due to the reaction force of the elastic deformation of the locking claw 3a was 0.05 mm. Prototype connector with clearance set to 0.1mm
As a result of the evaluation of the connection characteristics including the repeated attachment / detachment, the connection characteristics were equivalent to the value of the MT connector ferrule alone (before mounting the housing) (0.2 dB or less), and no damage or deformation of the guide hole occurred. . Scratch on the fiber end face and deterioration of connection characteristics due to repeated attachment and detachment hardly occurred.

The present invention is not limited to the above embodiment. For example, the form of the optical connector is not limited to the embodiment described above. An optical connector comprising a ferrule having at least one optical fiber positioning hole and a pair of guide holes, a locking claw for fitting, a housing having a groove for retaining the locking claw and accommodating the ferrule therein. If there is, the present invention can be applied, and for example, the optical connector described in U.S. Pat.

[0035]

According to the optical connector of the present invention, the contact between the housing and the ferrule can be prevented when the optical connector is connected, and the ferrule and the optical fiber can be effectively prevented from being damaged.

[Brief description of the drawings]

FIG. 1 is a plan view of an embodiment of the optical connector of the present invention.

FIG. 2 is a side view of the optical connector of FIG.

FIG. 3 is a bottom view of the optical connector of FIG. 1;

FIG. 4 is a front view (a front view of a connection end face) of the optical connector of FIG. 1;

FIG. 5 is a sectional view taken along line BB in FIG. 2;

FIG. 6 is a sectional view taken along line CC in FIG. 2;

FIG. 7 is a sectional view taken along line AA in FIG. 1;

8 is a cross-sectional view showing a connection process between the optical connectors of FIG.

9 is a cross-sectional view showing a process of connecting the optical connectors of FIG.

FIG. 10 is a cross-sectional view showing a process of connecting the optical connectors of FIG.

FIG. 11 is a cross-sectional view showing a process of connecting the optical connectors of FIG.

FIG. 12 is a cross-sectional view showing a connection process between the optical connectors of FIG. 1;

13 is a cross-sectional view showing a connection process between the optical connectors of FIG.

FIG. 14 is an enlarged sectional view showing a case where a housing and a ferrule interfere with each other.

15 is a longitudinal sectional view when the optical connectors of FIG. 1 are connected to each other.

FIG. 16 is a diagram corresponding to FIG. 15 of a comparative example.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Optical fiber, 2 ... Ferrule, 2a ... Optical fiber positioning hole, 2b ... Connection end surface, 2c ... Guide hole, 2d ... Rear end surface, 3 ... Housing, 3a ... Locking claw (locking nail), 3
b: locking recess (groove), 3c: positioning plane, 4: pink lamper, 5: spring, 6: guide pin, 8: sub housing, 9: boot.

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Toshiaki Kakii 1-chome, Taya-cho, Sakae-ku, Yokohama-shi, Kanagawa F-term (reference) in Yokohama Works, Sumitomo Electric Industries, Ltd. 2H036 JA02 QA02 QA43 QA49 QA57 QA59

Claims (4)

[Claims] 1. A ferrule having at least one optical fiber positioning hole and a pair of guide holes, a locking claw for fitting, a housing having a groove for retaining the locking claw and accommodating the ferrule therein. In the process of fitting the housings to each other, the maximum amount of deformation of the housing toward the ferrule side where the housing is housed by a reaction force after the locking claw is elastically deformed is provided. An optical connector characterized in that the optical connector is configured to be smaller than a clearance amount between an inner wall of the housing and an outer periphery of the ferrule. 2. The amount of clearance between an inner wall of the housing and an outer periphery of the ferrule is determined by a reaction force after the locking claw is elastically deformed in a process of fitting the housings to each other. The optical connector according to claim 1, wherein the total amount is greater than a total amount of a maximum deformation amount of the ferrule and positioning accuracy of a guide pin hole with respect to an outer periphery of the ferrule. 3. The amount of clearance between the inner wall of the housing and the outer periphery of the ferrule is determined by the reaction force after the locking claw is elastically deformed in the process of fitting the housings together. The optical connector according to claim 1, wherein the optical connector is wider by 0.02 to 0.30 mm than the maximum deformation amount. 4. An amount of clearance between an inner wall of the housing and an outer periphery of the ferrule is determined by a reaction force after the locking claw is elastically deformed in a process of fitting the housings to each other. The optical connector according to claim 3, wherein the optical connector is wider than the maximum deformation amount by 0.05 to 0.20 mm.