End forming method of splitter-free butterfly-shaped leading-in optical cable and prefabricated end forming assembly

Abstract

The invention discloses a branching device-free butterfly-shaped leading-in optical cable terminating method. The branching device-free butterfly-shaped leading-in optical cable terminating method comprises the following steps of 1, stripping a multi-core butterfly-shaped leading-in optical cable; 2, connecting the optical fiber and the multiple strands of steel stranded wires to the optical cable supporting tube; 3, connecting the bare fiber with the sub-connector; 4, respectively connecting the sub-connector and the optical cable supporting tube with an optical fiber storage box; and step 5, detecting the end face of the ferrule. A prefabricated end forming assembly comprises an optical fiber storage box, a sub-connector, an optical cable supporting tube, a metal pressing tube and a protective sleeve, the sub-connector is arranged at the front end of the optical fiber storage box, the optical cable supporting tube is arranged at the rear end of the optical fiber storage box, the metal pressing tube is arranged on the outer circle of the optical cable supporting tube in a sleeving mode, and the protective sleeve is arranged outside the metal pressing tube in a sleeving mode. According to the invention, the structural principle of the splitter is combined with the structural principle of the optical joint, and a novel multi-core butterfly-shaped drop cable forming method is designed, so that the original splitter structure is omitted, and the optical joint can be quickly manufactured.

Description

Technical Field

[0001] The present invention relates to a termination method for a branchless butterfly-shaped optical fiber cable and a pre-terminated component. Background Art

[0002] The butterfly-shaped optical fiber cable, also known as the drop cable, has a flat structure. On both sides of the cable, metal or non-metal strengthening members are symmetrically and tightly wrapped, and an anti-bending insensitive optical fiber is tightly sheathed in the middle. This makes the overall cable have very good tensile strength and anti-compression ability, and also has a certain anti-rat bite ability. Its application scenarios have expanded from the initial corridor parallel wiring and home wiring to indoor vertical wiring, outdoor overhead wiring, and indoor and outdoor scenarios. Taking an optical fiber cable with a cross-sectional size of 2mm×3mm as an example, it can support up to 4-core wiring. Only a common wire stripper and diagonal pliers are needed to strip and fuse the fiber or add an optical connector. Compared with outdoor optical fiber cables and indoor branch optical fiber cables, which require professional tools for stripping, it is simpler, more economical, and has higher work efficiency. This has made the application of the butterfly-shaped optical fiber cable more and more extensive.

[0003] However, it is found that making optical connectors for butterfly-shaped optical fiber cables is rather troublesome during application. For example, Figure 1 as shown, for multi-core cables, a splitter is needed to branch them into single-core drop cables before making optical connectors, while single-core cables can be directly made into optical connectors. The optical connectors made on-site cannot be fixed on the tensile support strengthening member of the optical fiber cable. Instead, they can only be fixed on the outer sheath of the optical fiber cable. This results in poor tensile strength of the optical connector, and at most, it can only barely achieve a tensile effect of 50N. Factory pre-terminated optical connectors are generally divided into two types. One is to use the method of fixing the optical fiber cable during on-site production, and its tensile strength is the same as the former. The other is to change the structure of the optical connector according to the tight-sheath structure of the optical fiber cable. For example, Figure 3 as shown, the optical fiber and the metal or non-metal strengthening member are inserted into the glue-injected and lengthened ferrule tail handle and hardened at high temperature. In addition, the surface of the single-strand strengthening member is relatively smooth, and the adhesion force after the extrusion of the outer sheath of the optical fiber cable is small. To avoid the outer sheath being scratched and causing fiber breakage due to excessive force on the optical fiber cable, a crimping ring is used to crimp the former to the outer sheath of the optical fiber cable to form an integral part to achieve the tensile effect synchronously.

[0004] For example, Figure 2As shown in the figure, when branching the optical fibers of the multi-core butterfly lead-in optical cable, it is necessary to first strip the outer sheath of the optical cable according to a predetermined length to expose the coated optical fiber. The coated optical fiber is hereinafter referred to as the optical fiber, and the multi-core butterfly lead-in optical cable is hereinafter referred to as the multi-core optical cable; insert the outer sheath of the multi-core optical cable into the input end of the splitter and fasten the optical cable to the splitter with a metal buckle. For the output end, use the same method to fasten the empty butterfly cable tube to the splitter with a metal buckle; then insert the multi-core optical fibers into different empty butterfly cable tubes according to the wire sequence requirements until the optical fibers are exposed and the optical fibers in the splitter are smooth; then use glue to solidify and fix the optical fibers at the optical fiber branch in the middle of the splitter to prevent the optical fibers from being pulled off when making optical connectors, cover the cover plate and heat-shrink the splitter as a whole with a heat-shrinkable tube; then make prefabricated optical connectors respectively according to the factory method; if the length of the branched optical fiber is too long, in order to avoid the optical fiber from retracting when passing through the connector, it is necessary to first use glue to solidify and fix the optical fiber coming out of the empty butterfly cable tube to facilitate fiber threading.

[0005] After the multi-core optical cable is branched through the splitter and then prefabricated at the end, not only is the overall volume too large, but the tensile strength of the cables in the splitter part mainly depends on the tensile strength of the outer sheath of the optical cable, and its tensile force is about between 40N and 50N. If too much force is applied, the splitter is prone to breakage, resulting in the scrapping of the entire product; in addition, the overall length of the optical connector is relatively long, which limits the application of the product in scenarios with small space and short distance. It is also necessary to increase the storage space, and the manufacturing process is troublesome. Summary of the Invention

[0006] The purpose of this part is to outline some aspects of the embodiments of the present invention and briefly introduce some preferred embodiments. In this part, as well as in the abstract and title of the specification of this application, some simplifications or omissions may be made to avoid obscuring the purpose of this part, the abstract of the specification and the title of the invention, and such simplifications or omissions cannot be used to limit the scope of the present invention.

[0007] The technical problem to be solved by the present invention is how to quickly make an optical connector for a multi-core butterfly lead-in optical cable without a splitter.

[0008] To solve the above technical problem, the present invention provides the following technical solution: A method for terminating a butterfly lead-in optical cable without a splitter, comprising the following steps:

[0009] Step 1: Strip the multi-core butterfly lead-in optical cable;

[0010] Step 2: Connect the optical fiber and the multi-strand steel wire to the optical cable support tube;

[0011] Step 3: Connect the bare optical fiber to the sub-connector;

[0012] Step 4: Connect the sub-connector and the optical cable support tube to the optical fiber storage box respectively;

[0013] Step 5: Detect the end face of the ferrule.

[0014] As a preferred solution of the termination method of the branchless butterfly lead-in optical cable according to the present invention, wherein: Step 2 includes: first passing the optical fiber through the inner hole of the optical cable support tube, and then crimping multiple strands of steel stranded wire to the outer circumference of the optical cable support tube through a metal crimping tube.

[0015] As a preferred solution of the termination method of the branchless butterfly lead-in optical cable according to the present invention, wherein: Step 3 includes: after injecting glue into the assembled sub-connector, threading the bare optical fiber into the ferrule assembly.

[0016] As a preferred solution of the termination method of the branchless butterfly lead-in optical cable according to the present invention, wherein: Step 4 includes: installing each single-end sub-connector into the corresponding installation slot at the front end of the storage base according to the wire sequence requirements, installing the optical cable support tube into the corresponding card slot at the rear end of the storage base, and covering the box cover after completion of the installation.

[0017] As a preferred solution of the termination method of the branchless butterfly lead-in optical cable according to the present invention, wherein: Step 5 includes: placing the prefabricated termination assembly into an oven to cure the glue in the ferrule assembly, then cutting the optical fiber at the ferrule end face and sleeving a protective sleeve, then placing it on the grinding disc of a grinding machine for grinding, and finally detecting the ferrule end face, and performing an insertion loss test after passing the inspection.

[0018] As a preferred solution of the termination method of the branchless butterfly lead-in optical cable according to the present invention, wherein: after the sub-connector and the optical cable support tube are respectively installed on the storage base, the optical fiber between the sub-connector and the optical cable support tube in the cavity of the storage base should be in a micro-bent state.

[0019] A prefabricated termination assembly for terminating a multi-core butterfly lead-in optical cable, comprising an optical fiber storage box, a sub-connector, an optical cable support tube, a metal crimping tube and a protective sleeve. The sub-connector is arranged at the front end of the optical fiber storage box, the optical cable support tube is arranged at the rear end of the optical fiber storage box, the metal crimping tube is sleeved on the outer circumference of the optical cable support tube, and the protective sleeve is sleeved outside the metal crimping tube.

[0020] As a preferred solution of the prefabricated termination assembly according to the present invention, wherein: the optical fiber storage box includes a storage base and a box cover. The front end of the storage base is provided with a plurality of installation slots, the left and right sides of the installation slots are symmetrically provided with limit blocks, the bottom of the installation slots is provided with a first arc surface, the rear end of the storage base is symmetrically provided with card slots, the optical cable support tube is symmetrically provided with blocks matching the card slots, the inner surface of the front end of the box cover is provided with bumps, and the storage base is connected to the box cover through a buckle.

[0021] As a preferred embodiment of the prefabricated termination assembly of the present invention, the sub-connector includes a front sleeve, a ferrule assembly, an extension tube, a spring, and a rear sleeve. The front sleeve, the ferrule assembly, the extension tube, the spring, and the rear sleeve are assembled together in sequence to form a miniaturized optical connector. On the left and right sides of the tail of the rear sleeve, side grooves matching the limit blocks are symmetrically arranged. On the bottom end of the tail of the rear sleeve, a second arc surface matching the first arc surface is arranged. On the top end of the tail of the rear sleeve, a plane matching the convex block is arranged.

[0022] As a preferred embodiment of the prefabricated termination assembly of the present invention, a plurality of circular concave and convex surfaces are arranged on the outer circumference of the optical cable support tube.

[0023] The beneficial effects of the present invention are as follows:

[0024] 1. By combining the structural principle of the splitter with the structural principle of the optical connector, a new method for terminating the multi-core butterfly lead-in optical cable is designed, which not only eliminates the original splitter structure but also realizes the rapid production of the optical connector.

[0025] 2. The entire termination assembly is integrally prefabricated, with a small volume, and the length of the single-end prefabricated termination assembly is less than 60 mm, which is convenient for wiring. Description of the Drawings

[0026] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for the description of the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present invention, and those of ordinary skill in the art can obtain other drawings based on these drawings without creative efforts. Among them:

[0027] Figure 1 It is a schematic structural diagram of the termination of the existing double-core butterfly lead-in optical cable.

[0028] Figure 2 It is a schematic internal structure diagram of the splitter.

[0029] Figure 3 It is a schematic structural diagram of the existing double-core optical cable.

[0030] Figure 4 It is a schematic structural diagram of the termination of the butterfly lead-in optical cable without a splitter.

[0031] Figure 5 It is a schematic structural diagram of the prefabricated termination assembly of the butterfly lead-in optical cable without a splitter.

[0032] Figure 6 It is an exploded schematic diagram of the sub-connector.

[0033] Figure 7 It is a schematic structural diagram of the sub-connector after completion of assembly.

[0034] Figure 8 Another perspective structural schematic diagram after the sub-connector is assembled.

[0035] Figure 9 Structural schematic diagram of the storage base.

[0036] Figure 10 Structural schematic diagram of the box cover.

[0037] Figure 11 Structural schematic diagram of the optical cable support tube.

[0038] Figure 12 Structural schematic diagram of the metal pressure tube.

[0039] Figure 13 Structural schematic diagram of the improved dual-core optical cable in Embodiment 1.

[0040] Figure 14 Structural schematic diagram of the multi-strand steel stranded wire placed on the optical cable support tube.

[0041] Figure 15 Structural schematic diagram of the two single-terminal connectors after fiber threading.

[0042] Figure 16 Structural schematic diagram of the optical fiber in the storage base.

[0043] In the figure: 100, dual-core optical cable; 101, optical fiber; 102, single-strand phosphated steel rod; 103, multi-strand steel stranded wire; 200, splitter; 201, branch base; 202, metal buckle; 300, butterfly cable empty tube; 400, single-core connector; 500, prefabricated end assembly; 510, optical fiber storage box; 511, storage base; 5111, installation groove; 5112, limit block; 5113, first arc surface; 5114, card slot; 5115, buckle; 512, box cover; 5121, convex block; 520, sub-connector; 521, front sleeve; 522, ferrule assembly; 523, extension tube; 524, spring; 525, rear sleeve; 5251, side groove; 5252, second arc surface; 5253, flat surface; 530, optical cable support tube; 531, card block; 532, circular concave-convex surface; 540, metal pressure tube; 550, protective sleeve. Detailed implementation manners

[0044] To make the above objects, features and advantages of the present invention more obvious and understandable, the following detailed description of the specific implementation manners of the present invention will be given in conjunction with the accompanying drawings of the specification.

[0045] In the following description, numerous specific details are set forth to provide a thorough understanding of the present invention. However, the present invention may be practiced in other ways different from those described herein. Persons skilled in the art can make similar extensions without departing from the spirit of the present invention. Therefore, the present invention is not limited by the specific embodiments disclosed below.

[0046] Secondly, the so-called "one embodiment" or "embodiment" herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation manner of the present invention. The phrase "in one embodiment" appearing in different places in this specification does not necessarily refer to the same embodiment, nor is it an individual or alternative embodiment that is mutually exclusive with other embodiments.

[0047] Embodiment 1

[0048] Most of the existing multi-core butterfly distribution optical cables are pre-terminated after being branched by a splitter 200. Not only is the overall volume too large, but the tensile strength of some cables of the splitter 200 mainly depends on the tensile strength of the outer sheath of the optical cable, and its tensile force is approximately between 40 N and 50 N. If too much force is applied, the splitter 200 is likely to break, resulting in the scrapping of the entire product. At the same time, the overall length of the splitter 200 plus the optical connector is relatively long, which limits the application of the product in scenarios with small space and short distance, and also requires an increase in storage space, and the manufacturing process is troublesome.

[0049] Such as Figures 1 to 3As shown, in this embodiment, a double-core butterfly-shaped fiber optic cable is taken as an example, hereinafter referred to as the double-core cable 100 or the optical cable for short. The existing method for terminating a double-core butterfly-shaped fiber optic cable is as follows: First, prepare the butterfly cable empty tube 300 and cut it according to the specified size. The conventional cutting size of the butterfly cable empty tube 300 is 0.5 to 0.8 meters. If it is shorter, it will cause difficulties in installation and grinding on the grinding disc of the grinding machine. The strengthening members on both sides of the end of the butterfly cable empty tube 300 should be exposed by no less than 5 mm. Then, peel off the outer skin of the double-core cable 100 according to the fixed length size, and the optical fibers 101 are respectively inserted into and passed through the butterfly cable empty tube 300. Install them into the branch base 201 of the splitter 200 according to the wire sequence requirements and straighten them in the wire groove. After completion, use the metal buckle 202 to tightly clamp the outer sheath of the optical cable in the corresponding wire groove of the branch base 201 of the splitter 200. Fill the optical fiber 101 in the wire groove of the branch base 201 with glue and cure it to avoid excessive bending caused by the movement of the optical fiber 101. After curing, cover the cover plate and tightly shrink it with a heat shrinkable sleeve. Then, apply glue to the other end of the butterfly cable empty tube 300 to fix the protruding optical fiber 101. After complete curing, strip the bare fiber according to the fixed length size and insert it into the single-core connector 400 filled with glue until the bare fiber protrudes from the end face of the ferrule by no less than 2 mm. Then, synchronously insert the strengthening members protruding from both sides of the end of the butterfly cable empty tube 300 into the extended tail handle, put it into the baking oven, take it out after high-temperature curing; cut off the bare fiber exposed from the end face of the ferrule. It should be noted that since the surface of the existing single-strand strengthening member (single-strand phosphated steel rod 102) is relatively smooth and the adhesion after extrusion of the outer sheath of the optical cable is small, in order to avoid the outer sheath from being displaced due to excessive force on the optical cable and causing fiber breakage, a metal compression ring is also used to tightly press and fix the optical cable and the rear end of the extended tail handle. After that, assemble the outer shell and the tail sleeve to complete the prefabrication of the single port. Finally, after grinding, end inspection, and testing are qualified, it is a finished product.

[0050] Referring to Figures 4 to 16 the figure, this embodiment provides a method for terminating a butterfly-shaped fiber optic cable without a splitter, including the following steps:

[0051] Step 1: First, peel the double-core butterfly-shaped fiber optic cable according to the fixed length size. After completion, peel the optical fiber 101 according to the fixed length size to expose the bare fiber;

[0052] Step 2: Then, pass the optical fiber 101 through the inner hole of the optical cable support tube 530 and let it come out. After completion, place the multi-strand steel wire 103 on both sides of the optical fiber 101 on the circular concave-convex surface 532 of the outer circle of the optical cable support tube 530. Push the metal compression tube 540 so that the metal compression tube 540 is sleeved on the outer circle of the optical cable support tube 530, that is, compress the multi-strand steel wire 103 on the optical cable by riveting to achieve rapid compression and fixation of the two-core optical cable 100. During the riveting process, push the opened multi-strand steel wire 103 flat to form a shape similar to aramid fiber to increase the tensile strength of the product. Through experimental verification, a tensile effect of not less than 100 N can be achieved. The tensile characteristics of the product are not less than those of imported aramid fiber, far superior to domestic aramid fiber, and the cost is lower than that of imported aramid fiber. It should be noted that in this embodiment, the traditional smooth single-strand phosphated steel bar 102 that is not easy to fix is replaced with a multi-strand steel wire 103 with a rough surface, so as to fix the optical cable in a way similar to the aramid crimping of a soft optical cable. At the same time, a tight outer sheath is injection-molded outside the multi-strand steel wire 103 to strengthen the adhesion of the optical cable outer skin, so that only by compressing the multi-strand steel wire 103 can the tensile effect be achieved;

[0053] Step 3: Then, after injecting glue into the assembled sub-connector 520, directly pass the optical fiber 101 with the bare fiber stripped into the ferrule assembly 522. The bare fiber needs to extend out of the ferrule end face by not less than 2 mm. Connect the other sub-connector 520 and the optical fiber 101 in the same way;

[0054] Step 4: Install the two single-terminal connectors 520 into the corresponding installation slots 5111 at the front end of the storage base 511 according to the wire sequence requirements, and install the optical cable support tube 530 into the corresponding card slots 5114 at the rear end of the storage base 511. Due to the structural characteristics of the multi-core optical cable, the optical fiber 101 and the optical cable are in a tight-sheath structure. When the sub-connector 520 is coupled with the opposite connector through a coupler, the ferrule assembly 522 will retract under force, causing the optical fiber 101 to move back and forth. Therefore, after installing the sub-connector 520 and the optical cable support tube 530 to the storage base 511 respectively, it is necessary to ensure that the optical fiber 101 between the sub-connector 520 and the optical cable support tube 530 in the cavity of the storage base 511 is in a slightly bent state to avoid fiber breakage, and then cover the box cover 512;

[0055] Step 5: Place the single-end prefabricated end assembly 500 into an oven to cure the glue in the ferrule assembly 522, then cut the fiber at the ferrule end face and sleeve it with a protective sleeve 550, then place it on the grinding disc of a grinding machine for grinding, and finally detect the ferrule end face and perform an insertion loss test. After passing the test, it is a finished product. Connect the other end prefabricated end assembly 500 and the two-core optical cable 100 in the same way.

[0056] In this embodiment, based on the original multi-core optical cable branch structure, the design is further optimized. By combining the structural principle of the splitter 200 with that of the optical connector, a new method for terminating the butterfly-shaped optical fiber cable is designed. Compared with the existing termination methods, the related structures such as the splitter 200 and the butterfly cable empty tube 300 are removed. It not only realizes the rapid production of optical connectors for multi-core butterfly-shaped optical fiber cables without a splitter 200, but also greatly shortens the overall length of the termination assembly, making its length meet the requirement of being less than 60 mm of the industry standard, and reduces the overall volume of the prefabricated termination assembly 500 for easy cabling, enabling the product to be better applied in scenarios with small space and short distance. It should be noted that the new method for terminating the butterfly-shaped optical fiber cable adopted in this embodiment is based on the existing processing method for mass production and cost reduction.

[0057] Embodiment 2

[0058] Referring to Figures 4 to 16 , this embodiment provides a prefabricated termination assembly 500 for the method of terminating the multi-core butterfly-shaped optical fiber cable in Embodiment 1, including an optical fiber storage box 510, a sub-connector 520, an optical cable support tube 530, a metal compression tube 540, and a protective sleeve 550. The sub-connector 520 is arranged at the front end of the optical fiber storage box 510, the optical cable support tube 530 is arranged at the rear end of the optical fiber storage box 510, the metal compression tube 540 is sleeved on the outer circumference of the optical cable support tube 530, and the protective sleeve 550 is sleeved outside the metal compression tube 540.

[0059] The optical fiber storage box 510 in this embodiment serves as the carrier of the entire prefabricated termination assembly 500. A sub-connector 520 for connecting the optical fiber 101 is installed at the front end of the optical fiber storage box 510, and an optical cable support tube 530 for connecting the multi-core optical cable is installed at the rear end of the optical fiber storage box 510. A metal compression tube 540 is sleeved on the outer circumference of the optical cable support tube 530. The multi-strand steel wire 103 placed on the outer circumference of the optical cable support tube 530 is riveted by the metal compression tube 540. A protective sleeve 550 is also sleeved outside the metal compression tube 540 to achieve the integration of the entire prefabricated termination assembly 500. It not only realizes the rapid production of optical connectors for multi-core butterfly-shaped optical fiber cables without a splitter 200, but also greatly shortens the overall length of the termination assembly, making its length meet the requirement of being less than 60 mm of the industry standard, and reduces the overall volume of the prefabricated termination assembly 500 for easy cabling, enabling the product to be better applied in scenarios with small space and short distance.

[0060] Specifically, the optical fiber storage box 510 includes a storage base 511 and a box cover 512. A plurality of mounting grooves 5111 are distributed at the front end of the storage base 511. Limiting blocks 5112 are symmetrically arranged on the left and right sides of the mounting grooves 5111. A first arc surface 5113 is arranged at the bottom of the mounting grooves 5111. Card slots 5114 are symmetrically arranged at the rear end of the storage base 511. Card blocks 531 that cooperate with the card slots 5114 are symmetrically arranged on the optical cable support pipe 530. A convex block 5121 is arranged on the inner surface of the front end of the box cover 512. The storage base 511 is connected to the box cover 512 through a buckle 5115.

[0061] The optical fiber storage box 510 in this embodiment is mainly composed of a storage base 511 and a box cover 512. Two mounting grooves 5111 are symmetrically arranged at the front end of the storage base 511. Limiting blocks 5112 are symmetrically arranged on the left and right sides inside the mounting grooves 5111. A first arc surface 5113 is arranged at the bottom of the mounting grooves 5111 so as to firmly fix the sub-connector 520 at the front end of the storage base 511. Card slots 5114 are symmetrically arranged at the rear end of the storage base 511. Card blocks 531 that cooperate with the card slots 5114 are symmetrically arranged on the left and right sides at the front end of the optical cable support pipe 530 so as to firmly fix the optical cable support pipe 530 at the rear end of the storage base 511. In addition, a convex block 5121 is arranged on the inner surface of the front end of the box cover 512 in this embodiment. The top of the sub-connector 520 is pressed through the convex block 5121, further improving the reliability of the connection between the sub-connector 520 and the optical fiber storage box 510. Buckles 5115 are arranged on the left and right sides of the storage base 511. The storage base 511 is fixedly connected to the box cover 512 through the buckles 5115.

[0062] Specifically, the sub-connector 520 includes a front sleeve 521, a ferrule assembly 522, an extension tube 523, a spring 524 and a rear sleeve 525. The front sleeve 521, the ferrule assembly 522, the extension tube 523, the spring 524 and the rear sleeve 525 are assembled together in sequence to form a miniaturized optical connector. Side grooves 5251 that cooperate with the limiting blocks 5112 are symmetrically arranged on the left and right sides of the tail of the rear sleeve 525. A second arc surface 5252 that cooperates with the first arc surface 5113 is arranged at the bottom end of the tail of the rear sleeve 525. A flat surface 5253 that cooperates with the convex block 5121 is arranged at the top end of the tail of the rear sleeve 525.

[0063] The sub-connector 520 in this embodiment is mainly composed of a front sleeve 521, a ferrule assembly 522, an extension tube 523, a spring 524 and a rear sleeve 525. The front sleeve 521, the ferrule assembly 522, the extension tube 523, the spring 524 and the rear sleeve 525 are assembled together in sequence to form a miniaturized optical connector, so as to shorten the fiber passing distance of the optical fiber 101, facilitate the rapid fiber passing of the thin optical fiber 101, reduce the difficulty of fiber passing, and the front end of the extension tube 523 is sleeved on the end of the tail handle of the ferrule assembly 522, and the rear end of the extension tube 523 is flush with or protrudes from the end of the assembled sub-connector 520, so as to facilitate injecting glue into the assembled sub-connector 520 from this hole and simply threading the optical fiber 101 with the bare fiber stripped into place. Side grooves 5251 that cooperate with the limit blocks 5112 are symmetrically arranged on the left and right sides of the tail of the rear sleeve 525, and a second arc surface 5252 that cooperates with the first arc surface 5113 is arranged at the bottom end of the tail of the rear sleeve 525, so as to firmly fix the sub-connector 520 in the installation groove 5111 at the front end of the storage base 511 through the rear sleeve 525. A flat surface 5253 that cooperates with the convex block 5121 is arranged at the top end of the tail of the rear sleeve 525. When the box cover 512 is fixedly installed on the storage base 511 through the buckle 5115, the convex block 5121 on the box cover 512 squeezes the flat surface 5253 at the top end of the tail of the rear sleeve 525, further improving the connection reliability between the sub-connector 520 and the optical fiber storage box 510.

[0064] Furthermore, a plurality of circular concave-convex surfaces 532 are arranged on the outer circumference of the optical cable support tube 530.

[0065] In this embodiment, circular concave-convex surfaces 532 are also arranged on the outer circumference of the optical cable support tube 530 to increase the friction between the optical cable support tube 530 and the stranded steel wires 103, improve the connection reliability between the optical cable support tube 530 and the optical cable, and further improve the tensile strength of the entire prefabricated end assembly 500.

[0066] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the technical solutions of the present invention can be modified or equivalently replaced without departing from the spirit and scope of the technical solutions of the present invention, and they should all be covered within the scope of the claims of the present invention.

Claims

1. A method for terminating a splitter-free butterfly-shaped optical cable, characterized in that: The following steps are involved: Step 1: Strip the multi-core butterfly-shaped lead-in optical cable; Step 2: Connect the optical fiber and multiple strands of steel wire to the optical cable support tube; Step 3: Connect the bare fiber to the sub-connector; Step 4: The sub-connector and the optical cable support tube are respectively connected to the optical fiber storage box; Step 5: Inspect the ferrule end face.

2. The termination method of the splitter-free butterfly-shaped introduction optical cable according to claim 1, characterized in that: Step 2 includes: firstly passing the optical fiber through the inner hole of the optical cable support tube, and then crimping the multiple strands of steel wire to the outer circle of the optical cable support tube through a metal crimping tube.

3. The method for terminating a splitter-free butterfly-shaped optical cable as claimed in claim 2, characterized in that: Step 3 includes: after the assembled sub-connector is injected with glue, the bare fiber is inserted into the ferrule assembly.

4. The method for terminating a splitter-free butterfly-shaped optical cable as claimed in claim 3, characterized in that: Step 4 includes: installing each single-end sub-connector into the corresponding installation slot at the front end of the storage base according to the line sequence requirements, installing the optical cable support tube into the corresponding card slot at the rear end of the storage base, and closing the box cover after the installation is completed.

5. The method for terminating a splitter-free butterfly-shaped optical cable as claimed in claim 4, characterized in that: Step 5 includes: placing the prefabricated terminal assembly into a drying oven to solidify the glue in the ferrule assembly, then cutting the fiber on the ferrule end face and putting on a protective cover, then placing it on the grinding disc of a grinder for grinding, and finally inspecting the ferrule end face. If it passes the test, an insertion loss test is performed.

6. The method for terminating a splitter-free butterfly-shaped optical cable as claimed in claim 4, characterized in that: After the sub-connector and the optical cable support tube are installed on the storage base respectively, the optical fiber between the sub-connector and the optical cable support tube in the cavity of the storage base should be in a slightly bent state.

7. A prefabricated termination assembly for terminating a multi-core butterfly-shaped lead-in optical cable, characterized in that: It includes an optical fiber storage box, a sub-connector, an optical cable support tube, a metal pressing tube and a protective sleeve. The sub-connector is arranged at the front end of the optical fiber storage box, the optical cable support tube is arranged at the rear end of the optical fiber storage box, the metal pressing tube sleeve is arranged at the outer circle of the optical cable support tube, and the protective sleeve is arranged outside the metal pressing tube.

8. The method for terminating a splitter-free butterfly-shaped introduction optical cable as claimed in claim 7, characterized in that: The optical fiber storage box includes a storage base and a box cover. A plurality of installation grooves are distributed at the front end of the storage base. Limit blocks are symmetrically arranged on the left and right sides of the installation grooves. A first arc surface is arranged at the bottom of the installation grooves. A card slot is symmetrically arranged at the rear end of the storage base. Card blocks matching the card slots are symmetrically arranged on the optical cable support tube. A protrusion is arranged on the inner surface of the front end of the box cover. The storage base is connected to the box cover by a buckle.

9. The method for terminating a splitter-free butterfly-shaped optical cable as claimed in claim 8, characterized in that: The sub-connector includes a front sleeve, a core assembly, an extension tube, a spring and a rear sleeve. The front sleeve, the core assembly, the extension tube, the spring and the rear sleeve are assembled together in sequence to form a miniaturized optical connector. Side grooves that match the limit blocks are symmetrically arranged on the left and right sides of the rear end of the rear sleeve, the bottom end of the rear sleeve is provided with a second arc surface that matches the first arc surface, and the top end of the rear sleeve is provided with a plane that matches the protrusion.

10. The termination method of a splitter-free butterfly-shaped introduction optical cable according to claim 7, characterized in that: The outer circumference of the optical cable support tube is provided with a plurality of circular concave and convex surfaces.

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