JPH01506A - optical connector plug - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an optical connector, and particularly to an optical connector plug that is useful for use in connection areas where large tensile forces are not applied to the connector, such as inside devices. be.

(Prior Art) In recent years, various high-performance optical connectors for optical communications have been developed.

Screw locks, pionet locks, bush-on locks, and the like are used to fasten the adapter and plug of optical connectors. Bushinion lock type optical connectors are non-rotating, requiring plug insertion and removal only in the axial direction, so they require less operating space than screw locks, piellonet locks, etc., and are suitable for high-density mounting. Institute of Electronics and Communication Engineers Technical Report C58
5-128 "Low-Cost, High-Performance Button-On Optical Connectors", conventional bush-on-lock optical connectors have a cantilever-like structure with a protrusion and a locking claw inside the adapter housing. Equipped with an elastic locking piece.

The plug contains a floating ferrule and is slidably mounted on the outer surface of the plug frame and the plug frame, which has four parts that completely lock the locking claws of the elastic locking pieces. It is equipped with a locking pawl that opens and a knob that releases the lock of the recess. Further, the optical fiber is inserted and fixed into the ferrule, and the Kevlar and jacket of the optical cord are fixed to the plug frame.

With this configuration, when the optical cord is pulled while the plug and adapter are connected, the pulling force is passed through Kevlar to the plug frame, the recess of the plug frame, the locking pawl, the elastic locking piece, It is said to be the adapter housing. At this time, since the ferrules are floating within the plug frame, the above-mentioned tensile force is not applied to the ferrules, and the bond between the ferrules is maintained. Therefore, the optical signal does not decrease.

In this way, the bush-on-lock optical connector can maintain stable optical connection characteristics even if a large tensile force (for example, about 10 kg) is applied to the optical cord.

(Problems to be Solved by the Invention) By the way, with the expansion of the application of optical technology, it is thought that optical connectors will be densely packaged inside devices.

In such areas, the push-on lock system is applicable to screw locks, piellonet locks, etc. as described above. However, since a large tensile force is rarely applied to the optical cord, there is no need to design it to withstand a large tensile force as with conventional bush-on-lock type optical connectors. Therefore, the conventional bush-on-lock type optical connector in which the ferrule floats within the plug frame has a problem in that it requires a large number of parts in the above-mentioned application area. In addition, since the ferrule and plug frame are separated, the plug frame, Kevlar, and outer sheath must be adhesively fixed after the ferrule and optical fiber have been adhesively fixed, resulting in the problem of longer assembly time. Ta.

In view of these problems, the object of the present invention is to provide a simple optical connector plug that is suitable for use in connection areas where a large tensile force is not applied to the connector, such as inside a device, is inexpensive with fewer parts, and has a short assembly time. Our goal is to provide the following.

(Means for Solving the Problems) In order to solve the above-mentioned problems, the present invention provides an adapter that is inserted into an adapter having at least one cantilever-shaped elastic locking piece having a protrusion and a locking claw inside the housing. The optical connector plug includes a plug frame including a ferrule, a spring that applies a pressing force to the plug frame in the axial direction of the ferrule, and an outer surface of the plug frame that slides in the axial direction with the spring interposed therebetween. a movably mounted knob, the knob presses the protrusion of the elastic locking piece upwardly to pass through when inserted, and after insertion, pushes the protrusion of the elastic locking piece against the pressing force of the spring. It has a sloped surface that presses the protrusion upward and allows the protrusion to pass when the protrusion is pulled out.

(Function) According to the present invention, since the plug frame includes the ferrule, the number of parts is reduced, and the plug becomes inexpensive. Furthermore, since the ferrule and the optical fiber can be adhesively fixed and the plug frame and the optical cord's Kevlar and jacket can be adhesively fixed at the same time, assembly time is shortened. Further, in the present invention, the ferrule is pushed forward by the spring and brought into contact with the opposing ferrule.

Conversely, since the knob is pushed backward by the spring, the slope of the knob contacts the protrusion of the elastic locking piece, and the force of the spring pushing the knob backward and the force of pulling the knob forward due to the deflection of the elastic locking piece are generated. A lock is made at a point on the slope where the is balanced.

That is, the adapter and the plug are held in a locked state, albeit imperfectly, with each other.

By having the adapter and plug locking method as described above, it is possible to use a common adapter with conventional bush-on optical connectors, and the optical connector is a simple type in which the ferrule is included in the plug frame, yet has stable connection characteristics. realizable.

(Embodiment) Fig. 1 shows an embodiment of the present invention, in which 1 is a plug, 2 is a plug frame, 2a is a ferrule, 2b is a protrusion, 2C is a recess, 2d is a step, 3 is a spring, and 4 is a knob. , 4a, 4b
4c and 4d are sloped portions, 5 is a hood, 6 is an optical fiber, and 7 is an optical cord. The ferrule 2a is integrally molded with the plug frame 2 from plastic. A knob 4 is mounted on the outer surface of the plug frame 2 so as to be slidable back and forth. The protrusion 2b of the plug frame 2 is the knob 4
The plug frame 2 hits the front protrusion 4a of the knob 4.
I'm trying not to get out of it. A spring 3 is provided between the stepped portion 2d of the plug frame 2 and the rear protrusion 4b of the knob 4, which pushes the plug frame 2 forward and applies a pressing force to the ferrule 2a.

There is a recess 2 between the protrusion 2b and the step 2d of the plug frame 2.
There is C.

FIG. 2 is a perspective view showing the knob of FIG. 1 in more detail. The knob 4 has a rectangular cylindrical shape, and openings 4e are formed at the front of the upper and lower surfaces of the knob 4, respectively. Also,
Slope portions 4c and 4d are formed on both sides of the upper and lower surfaces closer to the front.

FIG. 3 shows a sectional view of an optical connector in which two plugs shown in FIG. 1 are inserted into an adapter from both sides and connected. In FIG. 3, 8 is an adapter, 9 is a housing, 9a is a support member extending vertically inside the housing 9, 10 is an elastic locking piece, 11 is an alignment sleeve, and the elastic locking piece 10 is an upper part of the support member 9a. The alignment sleeve 11 is provided in a cantilever shape on both sides of the lower part, and is provided so as to pass through the center of the support member 9a. θ is the inclination angle of the slope portion 4d. The adapter used in this embodiment is the same as that used in conventional bush-on optical connectors.

FIG. 4 is a perspective view showing the elastic locking piece 10 of the adapter 8 of FIG. 3 in more detail. A locking pawl 10b and a protrusion 10a projecting to both sides are formed at the tip of the elastic locking piece lO.

To assemble the optical connector plug of this embodiment, first, the optical fiber 6 is adhesively fixed to the ferrule 2a, the Kevlar and jacket of the optical cord 7 are simultaneously adhesively fixed to the plug frame 2, and the end surface of the ferrule 2a is polished to a mirror finish. Spring 3 from the rear end of the plug frame 2. The knobs 4 are pushed into the plug frame 2 in this order, and the diagonal portion of the protrusion 4a of the knob 4 passes over the stepped portion 2d and the protrusion 2b of the plug frame 2, so that the knob 4 is attached to the plug frame 2. Finally, plug frame 2
Attach a rubber hood 5 to the rear end of the hood.

When inserting the plug 1 into the adapter 8 whose operation will be explained next, the plug 1 is moved forward using the knob 4. As a result, the elastic locking piece 1
0's protrusion 10a climbs along the slope portion 4a of the knob 4,
The elastic locking piece 10 is opened and the plug 1 is inserted into the adapter 8. When further inserted, the protrusion 10a descends the slope portion 4d of the knob 4 and is locked at one point along the way.

FIG. 3 shows this state. This locking point is caused by the force pushing the knob 4 backward by the spring 3 and the deflection of the elastic locking piece 10, and the knob 4 is pushed through the protrusion 10a and the slope 4d.
This is the point where the force pushing forward is balanced.

When pulling out the plug 1 from the adapter 8, hold the knob 4 and move the plug 1 backward so that the protrusion 10 of the elastic locking piece 10
a climbs along the slope portion 4d, the elastic locking piece 10 is opened, and the plug 1 is removed from the adapter 8.

Here, the greater the inclination angle θ of the slope portion 4d, that is, the steeper the slope, the greater the force applied to the slope portion 4d and the knob 4 due to the deflection of the elastic locking piece 10. However, as the inclination angle θ increases, the pulling force when pulling out the plug also increases. For example, at θ-90@, it becomes completely locked and cannot be removed. Therefore, it is desirable to select the inclination angle θ so that the force applied to the plug frame 2 due to the deflection of the elastic locking piece 10 is slightly larger than the repulsive force of the spring (for example, about 1 kg). This maintains the connection between the adapter and the plug. Note that the force applied to the plug frame 2 due to the deflection of the elastic locking piece 10 can be easily determined from a well-known formula expressing the deflection of a cantilever beam. An example of calculating the force applied to the plug frame due to the deflection of the elastic locking piece will be shown below.

The force f applied to the plug frame 2 due to the deflection of the cantilever-shaped elastic locking piece 10 is given by the following equation.

ωEat 3 sin θ + μ cos θ f-2XX () 41a cos θ - μ sin θ FIG. 5 (a) is an explanatory diagram showing a state in which the elastic locking piece 10 is locked to the knob 4, and FIG. 5 (b) is an explanatory diagram showing the elastic locking piece 10 being locked to the knob 4. 10 is a diagram showing a cross section of FIG. As shown in FIGS. 5(a) and 5(b), regarding the elastic locking piece 10, ω is the amount of deflection, E is Young's modulus, and a
is the width, t is the thickness, and g is the length from the root of the elastic locking piece 10 to the point where the protrusion 10a contacts the slope portion 4d.

θ is the inclination angle of the slope portion 4d of the knob 4, and μ is the coefficient of friction between the protrusion 10a of the elastic locking piece 10 and the slope portion 4d of the knob 4. The coefficient of 2 is due to the fact that two elastic locking pieces are locked per plug.

As an example, ω = 0.75 mm, E -200
kg/mm”a -4mm%t -0.9mm, (1
-5.8mm, θ-60°, μm 0.14,
f-2,7 kg is obtained. Also, depending on the material and shape of the elastic locking piece 10, the above-mentioned 1.
A force f of about kg or more can be obtained.

On the other hand, when a tensile force is applied to the optical cord, if the tensile force is as small as the repulsive force of the spring 3 (for example, about 1 kg) or less, the plug frame 2 will not move back, so the connection between the adapter and the plug will be maintained. At the same time, since the ferrule 2a integrated into the plug frame 2 does not move back, the optical connection characteristics are also maintained stably.

When a force larger than the repulsive force of the spring 3 is applied, the plug frame 2 moves backward, but the protrusion 2b of the plug frame 2 is locked by the locking pawl 10b of the elastic locking piece 10, and the minute force shown in FIG. It retreats by a distance d. At this time, since the other connected plug frame 2 moves forward, only an extremely short momentary interruption of several 11 seconds or less, which corresponds to the time for the spring 3 to expand and contract, occurs, and after that, stable optical connection characteristics are maintained. Ru.

In the plug frame 2 of the embodiment shown in FIG. 1, the ferrule 2a is integrally molded with the same plastic material as the plug frame 2, but the ferrule 2a is made of a different material and is integrally formed with the plug frame 2. may be

FIG. 6 shows a second embodiment, in which:
The plug frame 2 consists of a ceramic ferrule 2e and a plastic plug frame base 2f, which are integrated with each other. Such a plug frame 2 is made by integrally molding a well-known ceramic ferrule 2e with a plug frame base 2f during molding by insert molding, or by inserting a ceramic ferrule 2e into a plug frame base 2f and fixing it with adhesive. . Furthermore, a well-known ceramic capillary type ferrule or the like may be used as the ceramic ferrule 2e.

According to the embodiment in which the ferrule 2e in FIG. 6 uses a plug frame 2 made of a different material, ceramic ferrules and ceramic capillary-type ferrules generally have higher dimensional accuracy in hole diameter, outer diameter, eccentricity, etc. than plastic ferrules. Since a ferrule with a higher resistance can be made, the optical connector plug of the present invention can be applied to a wider range of areas.

Incidentally, as shown in this embodiment, the adapter into which the optical connector plug of the present invention is inserted may be the same as the adapter used for the conventional bush-on optical connector.

(Effects of the Invention) As explained above, in the optical connector plug of the present invention, the ferrule is included in the plug frame, and the spring interposed between the plug frame and the knob applies a pressing force in the axial direction of the ferrule. This reduces the number of parts and maintains stable optical connection characteristics as long as the tensile force on the optical cord is less than the repulsive force of the spring. Furthermore, even if the tensile force is greater than the repulsive force of the spring, only a momentary disconnection occurs, and after that, stable optical connection characteristics can be maintained. Therefore, the integration has the advantage that the plug becomes cheaper and the assembly time is shortened because the optical fiber and the ferrule can be adhesively fixed and the optical cord Kevlar, the jacket and the plug frame can be adhesively fixed at the same time.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of a plug shown in one embodiment of the present invention, FIG. 2 is a perspective view showing details of the knob shown in FIG. 1, and FIG. 4 is a sectional view showing a state in which the adapter is inserted from both sides, FIG. 4 is a perspective view showing a main part of the elastic locking piece of the adapter in FIG. 3, and FIG. FIG. 5(b) is a sectional view of the elastic locking piece 10, and FIG. 6 is a sectional view of a plug showing another embodiment of the present invention. 1...Plug, 2...Plug frame,' 2 a
, 2e...ferrule, 2b...protrusion, 2C・
... Recessed portion, 2d... Stepped portion, 2f... Plug frame base, 3... Spring, 4... Knob, 4a, 4b...
・Protrusion, 4C+4d...Slope part, 4e...Opening part,
5...Hood, 6...Optical fiber, 7...Optical cord, 8...Adapter, 9...＼Using, 10...
...Elastic locking piece, 10a...Protrusion, 10b...Latching claw, 11...Alignment sleeve. Patent applicant Nippon Telegraph and Telephone Corporation

Claims (4)

[Claims] (1) In an optical connector plug to be inserted into an adapter having at least one cantilever-like elastic locking piece having a protrusion and a locking claw in the housing, a plug frame including a ferrule, and a a spring that applies a pressing force in the axial direction of the ferrule; and a knob that is mounted on the outer surface of the plug frame so as to be slidable in the axial direction with the spring interposed therebetween; a slope that presses the protrusion of the elastic locking piece upwardly to allow it to pass, locks the protrusion of the elastic locking piece against the pressing force of the spring after insertion, and presses the protrusion upwardly to allow the protrusion to pass when it is pulled out; An optical connector plug characterized in that it has a part. (2) The optical connector plug according to claim 1, wherein the ferrule is integrally molded with the plug frame. (3) The optical connector plug according to claim 1, wherein the ferrule is formed of a material different from that of the plug frame base and is integrated with the plug frame base. (4) The optical connector plug according to claim 3, wherein the ferrule is made of ceramic such as zirconia.