RU2799106C1 - Multichannel optical fibre connector - Google Patents

Abstract

FIELD: detachable connections of optical data transmission lines.

SUBSTANCE: multichannel fibre-optic connector, consisting of a plug and a socket, comprising housings made cylindrical and as a single whole, light guides with tips placed in the openings of the bodies, and optical centralizers of the tips of the light guides of the plug and socket, whereas spring-loaded ferrules for the light guides of the socket are installed in the openings of the socket housing springs. Each tip of the light guide of the socket is rigidly fixed at one end in the ferrule, and at the other end it is inserted into the optical centralizer to ensure mating of the ends of the tips of the light guides of the plug and the socket that match each other, characterized in that each tip of the light guide of the plug at one end is hermetically fixed in the hole of the plug body with the help of an individual glass insulator, and the other end is inserted into the optical centralizer, pressed against the plug body with a nut.

EFFECT: operational reliability under conditions of increased operating pressure while maintaining the reliability of the splicing of the light guides of the multichannel fibre optic connector and simplicity of the design.

1 cl, 1 dwg

Description

SUBSTANCE: invention relates to detachable connectors of optical information transmission lines and can be used as a sealed multichannel optical connector operating under high pressure conditions.

It is known from the field of technology that in optical connectors the most important condition for operability is the minimization of optical losses, the magnitude of which is determined by the reliability of the docking of the detachable connector, i.e. the degree of overlapping of the ends of the joined optical fibers. The misalignment of the fibers in the connector can be affected by a number of factors: misalignment tolerance of the fiber in the optical tip; misalignment tolerance of the optical tip in the ferrule body; misalignment tolerance of the ferrule in the body bore, consisting of the positional tolerance for location relative to the common base; ferrule and housing clearance; misalignment tolerance of two bases (plug, socket), etc. The first two factors can be partially minimized by special optical tips of strict geometry made of metal, ceramics, and glass. Other factors can be minimized both by strict tolerances for the manufacture of the corresponding parts, and by the use of various compensators. And the manufacture of parts of strict geometry with minimum tolerances is a complex technological task that requires specialized metal-cutting equipment, and involves a complex manufacturing process and, as a result, a high cost.

It is known that in the design of optical connectors, strict splicing of the tips of the light guides is ensured by a precision sleeve installed in the optical centralizer. When docking, the tips enter the precision sleeve tightly, with virtually no gap. In the presence of misalignments in the ferrules of plugs, sockets using optical centralizers, the design of a multichannel connector must provide the possibility of radial displacement of at least one of the existing ferrules. For the connector to work, it is necessary to ensure the overall strict alignment of both the stepped holes for the ferrules of the plug and socket, and the optical centralizers of the multichannel connector. When joining the ferrules of the fork, the axes of the precision bushings of the centralizers must be coaxial with the axes of the tips of the fork, then only the precision bushings of the centralizers will fit tightly on the tips of the ferrules of the fork. However, in the case of even a slight misalignment, the lead-in chamfers of the joined elements will rest against each other with their edges, creating a misalignment, and when a significant axial force is applied, the existing misalignment will create significant radial loads in the joined elements, and one of the elements (precision bushing) may collapse.

Known fiber optic connector described in the optical-electrical connector [RF patent No. 2501139, IPC H02G 15/08, G02B 6/36, pub. 10.12.2013], consisting of a plug and a socket containing housings made cylindrical and integral, placed in the holes of the housings ferrules for light guides with tips, and optical centralizers of ferrules that respond to each other. In this device, ferrules for light guides are spring-loaded and installed with radial seals.

The disadvantage of the known connector is the lack of reliability of the joining of optical fibers, as well as the complexity of the design and the associated high complexity of manufacturing connector parts. According to the authors, it can be assumed that the required radial displacement of the ferrules, necessary to compensate for misalignment, in this connector can provide a gap between each ferrule and a stepped hole for it in the body. However, the design of the ferrules is equipped with radial seals, as a rule, made of hard rubber, and when the ferrules are radially displaced (due to misalignment of the ferrule tip in precision bushings), the radial seal is deformed within the specified compensation gap (usually small). If the clearance is too small, the spring-loaded ferrules will "bite" in the stepped hole, creating additional friction against the spring force. Thus, the axial force of ferrule docking in the optical centralizer due to misalignment will increase and may exceed the spring force, which will lead to unreliable docking of ferrules to each other, to breakage of precision bushings of optical centralizers. This drawback is exacerbated under conditions of increased operating pressure in the presence of several radial hard rubber seals in the design. In addition, satisfaction of the condition of interchangeability within the batch required for replacement during routine maintenance or emergency situations, and the condition of ensuring strict manufacturing tolerances can lead to technological elimination (marriage). In this connector, two rows of sealing rings are placed to seal the ferrules (in practice, there may be more). The disadvantage of this type of sealing is the limited service life of the sealing elements (usually hard rubber), the service life of which is less than that of the connector itself and the cable itself. This is due to the fact that the rubber material is subject to aging. The wide operating temperature range (e.g. sea water) and the constant deformation of the seal significantly shorten its service life. Thus, during the operation of the connector, it is necessary to either replace the socket or rebuild the connector with the replacement of rubber products.

Known fiber optic connector, described in the optical-electrical connector and taken as a prototype [RF patent No. 2719771, IPC H02G 15/08, G02B 6/36, pub. 04/23/2020], which partially solves the shortcomings of the previous analogue. This connector consists of a plug and a socket, containing housings made cylindrical and in a single whole, light guides with tips placed in the openings of the housings, and optical centralizers of tips of the light guides of the plug and socket that respond to each other, moreover, ferrules for the light guides of the socket are installed in the openings of the socket housing, spring-loaded springs, wherein each tip of the light guide of the socket is rigidly fixed at one end in the ferrule, and at the other end is inserted into the optical centralizer to ensure mating of the ends of the tips of the light guides of the plug and socket that respond to each other. In this connector, each lug for the fork fiber, as in the previous analogue, is installed in a ferrule, which, in turn, is installed in the hole of the fork body using radial seals. And the ferrules for the light guides of the socket are installed in the openings of the socket housing with floating centering sleeves covering them, which are additional intermediate power elements for joining the tips of the coupled light guides of the plug and the socket. Each optical centralizer is rigidly attached with one end to the ferrule for the fork light guide, and with the other free end is inserted into the specified sleeve.

The disadvantage of the prototype is that, according to the authors, the floating sleeve is an unnecessary and ineffective element, since in order to ensure strict mating of the tips of the plug and socket in the centralizer, it is necessary to ensure the following conditions: strict concentricity of the inner and outer cylindrical surfaces of the optical centralizers of the plug between yourself; strict concentricity of the outer surfaces of the socket light guide tip relative to the outer surfaces of the socket ferrule; strict concentricity of the outer and inner surfaces of the floating coupling; strict alignment of the tips of the light guide of the plug between themselves and the body elements; and it is also necessary to calculate and ensure the ratio of the gaps between the mating surfaces of the floating couplings and optical centralizers, and, accordingly, the couplings and ferrules of the rosette. The fulfillment of all these conditions is laborious and requires special calculations. Thus, the alignment of the tips of the optical fibers of the plug in the hole in the body of the plug depends on the tolerances of the ferrule hole for the specified tip, on the tolerances of the outer diameter of each ferrule in the body of the plug, on the tolerances for the location and diameter of the holes in the body of the plug for the ferrules. It is also necessary to take into account the tolerances for the manufacture of the optical centralizer, since the initial “power” coupling of the coupling takes place along its outer diameter. The presence of rubber rings in the connection sets the ratio of the outer diameter of each ferrule and the size of the holes in the fork body in a special way, characteristic of the design of this type of seals. The coaxiality of the coupling in the socket housing depends on the tolerances for the manufacture of the coupling itself and the tolerances of the holes for them in the socket housing. The gap between the outer diameter of the coupling and the diameter of the holes in the socket housing must compensate for all the tolerances of the plug elements listed above. The manufacture of the above parts requires minimizing tolerances and, accordingly, the use of high-precision equipment.

In addition, the design of the prototype, like the previous analogue, is also complicated, with stepped docking, the number of possible distortions increases, and the operational reliability of the connection decreases.

Also in the known connector, the axial tightness of the ferrules in the plug body is ensured by the adhesive connection of each tip of the plug light guide in the ferrules, as well as by sealing each ferrule in the plug body with radial seals. These sealing methods use materials that have a limited service life. Adhesive joints shrink and are subject to aging, thus pressing and sealing the ceramic tip into the ferrule is unreliable. Radial seals, as a rule, are made in the form of rubber rings, which ensure the tightness of the connection up to 27 MPa of external pressure, which does not ensure operational reliability under conditions of increased operating pressure. The rubber material is subject to aging, a wide operating temperature range and constant deformation of the seal significantly reduce its service life. To ensure the functioning of the connection, it is necessary to constantly carry out its routine maintenance (lubrication, replacement of rings after the warranty or general service life has expired). Replacing rings in subsea connectors is a labor intensive and expensive procedure.

The technical result to which the claimed invention is directed is to ensure operational reliability under conditions of increased operating pressure while maintaining the reliability of splicing of the light guides of the multichannel fiber optic connector with the simplicity of the design.

The technical result is achieved by the fact that a multichannel fiber optic connector, consisting of a plug and a socket, containing housings made cylindrical and integral, placed in the openings of the housings, light guides with tips, and optical centralizers of the tips of the light guides of the plug and socket that respond to each other, while in the holes Ferrules for the light guides of the socket, spring-loaded by springs, are installed on the socket housing, each tip of the light guide of the socket is rigidly fixed at one end in the ferrule, and at the other end is inserted into the optical centralizer to ensure that the ends of the tips of the light guides of the plug and socket that respond to each other are mated, according to the invention, each tip of the light guide of the plug is one its end is hermetically fixed in the hole of the plug body with the help of an individual glass insulator, and the other end is inserted into the optical centralizer pressed against the plug body with a nut.

Hermetic fastening of each tip of the fork fiber with one end in the hole of the plug body using an individual glass insulator, and the introduction of the specified tip with the other end into the optical centralizer, pressed against the plug body with a nut, ensures operational reliability under conditions of increased operating pressure (external hydrostatic pressure up to 100 MPa and above) and strict coaxiality of the tips of the light guides, ensuring the reliability of the splicing of the light guides of the multichannel fiber optic connector with the simplicity of the design. Compared to the prototype, the ferrule in the plug housing, sealed by means of radial seals, is excluded, thereby completely eliminating the dependence of the alignment of the ceramic tip for the plug light guide on intermediate structural elements and the above disadvantages of this connection described in the prototype. The introduction of each fiber of the plug with its free end into the optical centralizer makes it possible to cover the tip with the optical centralizer, thereby orienting the optical centralizer in the radial direction relative to the rigidly fixed tip for the fork fiber. In this case, the axial arrangement of the centralizers assumes the axial arrangement of the indicated tips, providing a strict geometry of the position of the tips of the light guides of the plug and socket included in it. Also, the number of mating surfaces and the number of structural parts are minimized, increasing the reliability of the splicing of the light guides of the multichannel fiber optic connector with the simplicity of the design. As a result of this connection, no special calculation is required when designing and high-precision manufacturing equipment, and the gap between each ferrule of the socket and the corresponding hole in the socket body is determined by the size of the tolerance for the location of the ceramic plug tips fixed in the plug body with a glass insulator. As you know, the minimum tolerances of such connections are determined by the values of radial displacements - 0.03 mm. Manufacturing tolerances for ferrules and holes can be minimized to grade 6 and defined in tens of microns. In this case, the general tolerance of the specified displacement can be determined by a radial displacement of 0.04 mm. Thus, with such displacement fields, the ceramic tip of the socket (diameter 2.5 mm) itself becomes a guide element (pin), which, under the required axial action, docks with the centralizer and the ceramic tip of the plug itself, while the ferrule of the socket, spring-loaded by a spring, has the possibility of radial movement in the opening of the housing, compensating for minor axial displacements of the tips of the plug and socket by the size of the gap.

Thus, the set of essential features of the proposed device ensures operational reliability under conditions of increased operating pressure while maintaining the reliability of splicing of the optical fibers of a multichannel fiber optic connector with a simple design.

The presence in the claimed invention of features that distinguish it from the prototype, allows us to consider it as corresponding to the condition of "novelty".

The new features contained in the distinctive part of the claims are not found in technical solutions of a similar purpose. On this basis, it can be concluded that the claimed invention complies with the "inventive step" condition.

The invention is illustrated in the drawing, which shows an axial section of a multi-channel fiber optic connector.

In FIG. the following designations are accepted.

1 - fork body;

2 - socket housing;

3 - light guide plug;

4 - socket light guide;

5 - tip for the light guide of the plug;

6 - tip for the socket light guide;

7 - glass insulator;

8 - optical centralizer;

9 - rosette ferrule;

10 - spring;

11 - step of the hole in the fork body;

12 - nut;

13 - nut fixing the ferrule.

The device is made as follows.

Multichannel fiber optic connector (Fig.) contains a plug and a socket, housings 1, 2 of which are made cylindrical and integral and have through holes in which the light guides 3 of the plug and the light guides 4 of the socket are placed. The connector also contains optical centralizers 8 tips 5, 6 light guides 3, 4 that respond to each other. to the body 1 by a movable nut 12. The holes in the body 1 of the fork in this particular case are stepped, while each optical centralizer 8 is installed with a stop against the step of the hole in the body 1 of the fork, providing a "power short circuit along the axis" of the centralizer 8 to the body 1 of the plug, as resistance to friction that occurs when it is docked with the tip 6 of the socket, while maintaining the integrity of the glass insulators 7. In the holes of the housing 2, the sockets are installed with a clearance of the ferrule 9, spring-loaded with springs 10. Each ceramic tip 6 of the light guide 4 of the socket is rigidly fixed at one end in the ferrule 9, and the other free end is inserted into the optical centralizer 8 to ensure the mating of the ends of the tips 5, 6 that respond to each other.

The assembly of the device is carried out as follows.

Initially, the plug and socket are assembled separately. The plug is assembled as follows: tips 5 and glass bushings of glass insulators 7 are installed in the holes of the body 1 of the plug, and at the same time, all the tips 5 of the multichannel fiber optic connector are fastened using the technology of metal-to-glass junctions. Then, light guides 3 are glued into the tips 5 by impregnating a deep penetration sealant. The ends of the tips 5 with protruding light guides 3 are ground. The protruding parts of the tips 5 are covered with otic centralizers 8, which are fixed in the body 1 with nuts 12. The socket is assembled as follows: tips 6 are installed in the holes of the body 2 of the socket, pressed with their ends into ferrules 9. Next, light guides 4 are glued into the tips 6, the ends are polished. To ensure radial displacement, each ferrule 9, spring-loaded by springs 10, is installed in the openings of the body 2 of the socket with a gap. Then the ferrules 9 are fixed with nuts 13. The plug and socket are ready for docking.

To implement a multi-channel fiber optic connection, the plug and socket are joined, strictly orienting their bodies 1, 2 relative to each other. At the same time, all the tips 6 of the light guides of the socket, overcoming minor misalignments, are inserted into the centralizers 7, ensuring that the ends of the tips 5, 6 of the light guides 3, 4 that respond to each other are joined. plugs and sockets. To overcome the frictional resistance with minor misalignments of the optical centralizers 8 and tips 6, the ends of the optical centralizers can have lead-in chamfers.

This technical solution minimizes the number of mating surfaces that ensure reliable mating of the ceramic tips of the optical fibers of a multichannel fiber optic connector and ensures operational reliability under conditions of increased operating pressure. The proposed fiber optic connector, in comparison with the prototype, is simple in design due to the exclusion from the design of the device of the plug ferrules with radial seals, as well as floating socket sockets and related parts that require high-precision equipment for manufacturing. At the same time, the claimed design does not contain organic materials (rubber rings, glue), which excludes routine maintenance. The overall service life is greatly increased. The design of the proposed invention allows the manufacture of parts to be carried out on a universal program metal-cutting equipment, which significantly reduces the cost.

In addition, this fiber optic connector can be used in an optical-electrical connector, where electrodes for electrical lines are also soldered using glass-to-metal junction technology. Moreover, the soldering of the electrodes and tips of the light guides of the plug is carried out simultaneously according to a single technological process.

A prototype was made at the enterprise, which confirmed the operability of the proposed device. A multi-channel fiber optic connector was used to connect cable lines connecting the bulkheads of a deep-sea submersible. The test results confirmed, with the simplicity of the design, the provision of operational reliability under conditions of increased operating pressure while maintaining the reliability of fiber splicing.

The presented information testifies to the fulfillment of the following set of conditions when using the claimed invention:

- the inventive multi-channel fiber optic connector refers to detachable connectors of optical information transmission lines;

- the claimed device, when used, is capable of ensuring operational reliability under conditions of increased operating pressure while maintaining the reliability of splicing of the optical fibers of a multi-channel fiber optic connector with a simple design;

- for the claimed device in the form in which it is characterized in the claims, the possibility of its implementation using the means and methods described in the application and known before the priority date is confirmed.

Therefore, the claimed device meets the condition of "industrial applicability".

Claims (1)

Multichannel fiber-optic connector, consisting of a plug and a socket, containing housings made cylindrical and in a single whole, light guides with tips placed in the openings of the bodies, and optical centralizers of the tips of the light guides of the plug and socket, while ferrules for the light guides of the socket, spring-loaded, are installed in the openings of the socket housing springs, wherein each tip of the light guide of the socket is rigidly fixed at one end in the ferrule, and at the other end is inserted into the optical centralizer to ensure that the ends of the tips of the light guides of the plug and the socket match each other, characterized in that each tip of the light guide of the plug is hermetically fixed at one end in the hole of the plug housing with the help of an individual glass insulator, and the other end is inserted into the optical centralizer, pressed against the plug body with a nut.

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