A pre-assembled SC type optical fiber connector

Abstract

The present invention discloses a pre-assembled SC type optical fiber connector, which relates to the field of optical fiber communication technology and aims to solve the problem of slow on-site assembly and large optical loss causing unstable optical fiber signals. The pre-assembled SC type optical fiber connector comprises an optical cable, a front shell, a core, a sleeve and a crimping sleeve. The core is provided with a through hole for accommodating the core along the axial direction. The sleeve is fixedly connected with a fixing seat on the side facing the crimping sleeve. A flap is rotatably connected to the fixing seat. A through groove for inserting the optical cable is formed between the fixing seat and the flap. A clamping block for always clamping the optical cable is fixedly connected to the inner wall of the flap. The flap can be replaced and connected to the fixing seat to clamp optical cables of different specifications. The present invention only needs to perform fiber stripping, optical fiber insertion, glue curing and grinding work on site. Other parts are completed in the factory, thereby greatly increasing the on-site assembly efficiency of the optical fiber connector, and at the same time, improving the assembly accuracy, making it more convenient to use, and having reliable performance and reducing the loss of light.

Description

Technical Field

[0001] The present invention relates to the technical field of optical fiber communication, and more particularly to a pre-assembled SC type optical fiber connector. Background Art

[0002] Optical cables are manufactured to meet optical, mechanical or environmental performance specifications. They are communication cable components that use one or more optical fibers placed in a sheath as transmission media and can be used individually or in groups. Optical cables are mainly composed of optical fibers, Kevlar wires (filling layers) and outer sheaths. Optical fibers include optical fibers (cores, glass fibers as thin as hair) and sheaths wrapped around the optical fibers. They are used to transmit optical signals. Optical cables are a light transmission tool that uses the principle of total reflection of light in fibers made of glass or plastic. They are widely used in the field of communications. During the processing of optical cables, the covering layer needs to be removed for the next processing step.

[0003] With the large-scale application of FTTH (Fiber To The Home), a large number of fiber optic connectors suitable for on-site assembly are inevitably needed. Commonly used on-site assembled fiber optic connectors usually include a fiber optic ferrule and a fiber optic clamping mechanism. The fiber optic ferrule is pre-installed with an optical fiber, and then the optical fiber to be terminated on site is inserted into the fiber optic clamping mechanism and docked with the optical fiber in the fiber optic ferrule. In order to reduce the light loss at the fiber optic docking point, matching liquid is generally injected into the fiber optic docking point. Since the volatilization rate of the matching liquid is related to the temperature, humidity and other factors of the environment, the service life of the fiber optic connector is greatly affected by the environment. Moreover, after long-term use, due to the volatilization of the matching liquid or the loosening of the clamping mechanism, it is easy to cause gaps or misalignment in the fiber end faces at the fiber optic docking point, the docking accuracy of the optical fiber is reduced and the light loss is increased. Therefore, straight-through fiber optic connectors have also appeared.

[0004] A Chinese patent with publication number CN105223650A discloses a fused-end type leather cable optical fiber connector, and its technical key points are: it includes a core assembly, a spring, a shell, an outer shell, a key, a tail shell with openings at both ends, and a leather line optical cable. The core assembly includes a core, a box shell, a box cover, and a clamp spring. The core is arranged in the front end of the box shell, one side of the box shell matches and connects to the box cover, and a notch is formed at one end of the box shell and the box cover after the box shell and the box cover are connected. The clamp spring is clamped on the box cover and the box shell, and the spring is sleeved on the cylinder at the rear of the box shell. The end of the cylinder at the rear of the box shell is provided with an annular step. The pin assembly is inserted from the front end of the shell, and a step is provided in the middle part of the shell. A fastening device is provided at the rear end of the shell. The pin assembly is buckled on the step of the shell through the annular step. Holes are provided on the shell and the outer shell, and the shell is sleeved on the shell. The notch is in the same straight line as the holes on the shell and the outer shell, and the key is inserted into the notch. The tail shell and the rear end of the shell are detachably connected, which ensures tensile strength, continues stable performance, and improves service life.

[0005] Although the above solution can fasten the sheathed optical cable and assemble it on site, different types of optical cables need to be assembled on site using connectors of different specifications, which is rather troublesome.

[0006] Therefore, a new solution needs to be proposed to solve this problem. Summary of the invention

[0007] The object of the present invention is to provide a pre-assembled SC type optical fiber connector in order to solve the above-mentioned problems.

[0008] The above technical purpose of the present invention is achieved through the following technical solutions: a preassembled SC type optical fiber connector, comprising an optical cable, a front shell, a core, a sleeve shell and a crimping sleeve, the front shell, the sleeve shell and the crimping sleeve are connected in sequence, the core is provided with a through hole for accommodating the fiber core along the axial direction, the sleeve shell is fixedly connected to a fixing seat facing the crimping sleeve side, a flap is rotatably connected to the fixing seat, a through groove for inserting the optical cable is formed between the fixing seat and the flap, a clamping block for always clamping the optical cable is fixedly connected to the inner wall of the flap, and the flap can be replaceably connected to the fixing seat to clamp optical cables of different specifications.

[0009] By adopting the above technical solution, when in use, since the lengths of the clamping blocks in different flaps are different, the flap can be selected according to the actual specifications of optical cables. When replacing, it is only necessary to detach the clamping points on both sides of the original flap from its hinge, and then re-insert the flap that meets the specification requirements to achieve the hinge. Since the fixing seat and the flap are both made of plastic material and have a certain elasticity, replacement is extremely convenient, which greatly improves the applicability of the optical fiber connector and can improve assembly efficiency.

[0010] The present invention is further configured as follows: a limit column for limiting the left and right sides of the optical cable is fixedly connected to the inner bottom surface of the fixing seat, and the inner side surface of the limit column and the bottom surface of the clamping block are both provided with inclined surfaces so that the thickness of the limit column and the clamping block gradually decreases toward the end away from the housing.

[0011] By adopting the above technical solution, by setting the limit column, the two sides of the optical cable can be clamped and limited to ensure the stability of the optical cable after insertion, and the inclined surface is set on the limit column and the clamping block to play a limiting role when pulling in the reverse direction, thereby further improving the stability of the optical cable after installation and ensuring the stable use of the optical fiber.

[0012] The present invention is further configured as follows: the outer side surfaces of the flip cover and the fixing seat are fixedly connected with a threaded section threadedly connected to the crimping sleeve, and a clamping space for clamping the outer skin of the optical cable is provided between the outer side surfaces of one end of the flip cover and the fixing seat away from the housing and the crimping sleeve.

[0013] By adopting the above technical solution and setting the threaded section and the clamping space, when using the optical fiber connector, the optical cable needs to be stripped first, and after inserting the fiber, the Kevlar wire and the outer skin of the optical cable are flipped to the outside of the flip cover and the fixing seat, and then when the crimping sleeve is threadedly connected, the Kevlar wire of the optical cable will be fixed by the threaded teeth of the threaded section, and the outer skin of the optical cable will be firmly clamped in the clamping space, thereby ensuring the stability of the optical cable after being connected to the optical fiber connector.

[0014] The present invention is further configured as follows: a top surface of one end of the sleeve shell close to the fixing seat is provided with a transfer groove, and the flip cover is rotatably connected to the inner wall of the transfer groove.

[0015] By adopting the above technical solution, the flap is hinged in the adapter slot to achieve an inward buckle effect. Compared with the existing outward buckle situation, it can save space and reduce costs, and can also increase the connection firmness between the flap and the fixed seat.

[0016] The present invention is further configured as follows: the ferrule includes a lead-out head, a limiting portion and a connecting portion, and a spring is installed between the end surface of the limiting portion close to the sleeve and the sleeve to push the ferrule to abut against the front shell and drive the lead-out head to extend out of the front shell.

[0017] By adopting the above technical solution and arranging a spring, the plug core can be pushed into the front shell under the action of the spring, and the lead-out head can be driven to extend out of the front shell along the through slot of the front shell.

[0018] The present invention is further configured as follows: a microtube extending into the casing and sleeved outside the optical fiber of the optical cable is sleeved on the outer side of one end of the connecting portion away from the limiting portion.

[0019] By adopting the above technical solution and setting the microtube, it is possible to guide the optical cable core into the ferrule, strengthen the radial limitation of the optical fiber, improve the blind penetration effect of the fiber core, and improve the on-site assembly effect of the optical fiber connector.

[0020] The present invention is further configured as follows: a ring sleeve which is connected to the through groove and is used for the microtube to extend into is fixedly connected to the axial center of the shell, one end of the spring away from the limiting portion abuts against the end face of the ring sleeve, a plurality of limiting strips for radially positioning the spring are fixedly connected to the outer side face of the ring sleeve, and a limiting groove for the limiting strip to be inserted is opened in the front shell.

[0021] By adopting the above technical solution and setting a limit strip, the spring can be radially limited and fixed, so that the center line of the spring and the center line of the ring sleeve can be kept on the same straight line, thereby ensuring that the spring is easy to assemble and can be used in conjunction with the limit groove, so that after assembly, the outer side of the spring is attached to the inner wall of the front shell, avoiding the situation where the spring bends and affects the optical fiber assembly, thereby improving practicality.

[0022] The present invention is further configured as follows: a plurality of positioning grooves are provided on the side of the limiting portion, and an annular retaining bar for blocking the limiting portion and a positioning block for snapping into the positioning groove are fixedly connected in the front shell.

[0023] By adopting the above technical solution, the circumferential limiting effect of the ferrule can be improved through the positioning groove and the positioning block, the stability of the ferrule can be ensured, and the use effect can be improved.

[0024] The present invention is further configured such that: the ferrule is fixedly connected to the fiber core of the optical cable by glue.

[0025] By adopting the above technical solution and utilizing the glue curing method, the connection reliability and durability between the fiber core and the ferrule can be increased, and the appearance of nodes can be avoided, thereby greatly improving the stability of optical performance.

[0026] The present invention is further configured as follows: a tail sleeve is connected to a side of the crimping sleeve away from the sleeve shell, a plurality of strip holes are provided on the side of the tail sleeve, the insert is made of elastic material, the sleeve shell and the tail sleeve are both provided with a snap-in groove, and the front shell and the crimping sleeve are both fixedly connected with a snap-in block for snapping with the snap-in groove.

[0027] By adopting the above technical solution, the housing and the front housing, the tail housing and the crimping housing are connected by snap-fitting, which can greatly improve the assembly speed and thus the assembly efficiency. In addition, the tail housing is elastic and has a better protective effect on the optical cable.

[0028] In summary, the present invention has the following beneficial effects:

[0029] The present invention only requires fiber stripping, fiber insertion, glue curing and grinding on site, and other parts are completed in the factory, thereby greatly increasing the on-site assembly efficiency of the optical fiber connector, while improving assembly accuracy, making it more convenient to use, reliable in performance, and reducing light loss. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 is a cross-sectional view of Embodiment 3 of the present invention;

[0031] Figure 2 is a cross-sectional view of a fifth embodiment of the present invention;

[0032] Figure 3 is a cross-sectional view of the first embodiment of the present invention;

[0033] Figure 4 is a cross-sectional view of a second embodiment of the present invention;

[0034] Figure 5 The structure of the casing in the present invention is shown in FIG. Figure 1 ;

[0035] Figure 6 The structure of the casing in the present invention is shown in FIG. Figure 2 ;

[0036] Figure 7 It is a structural schematic diagram of the front shell in the present invention;

[0037] Figure 8 It is a structural schematic diagram of the insert in the present invention.

[0038] Figure numerals: 1. Insert; 101. Lead-out head; 102. Limiting part; 103. Connecting part; 104. Positioning groove; 2. Front shell; 21. Annular baffle; 22. Positioning block; 23. Limiting groove; 3. Spring; 4. Optical cable; 5. Microtube; 6. Sleeve; 61. Fixing seat; 611. Limiting column; 62. Flip cover; 621. Clamping block; 622. Anti-slip convex strip; 63. Threaded section; 64. Adapter groove; 65. Ring sleeve; 66. Limiting strip; 7. Crimp sleeve; 8. Tail sleeve; 81. Strip hole; 9. Snap-in block; 10. Snap-in groove; 11. Clamping space. DETAILED DESCRIPTION

[0039] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0040] A pre-assembled SC type fiber optic connector, such as Figure 1 , Figure 5 As shown, it includes an optical cable 4, a front shell 2, a core 1, a sleeve 6 and a crimping sleeve 7. The front shell 2, the sleeve 6 and the crimping sleeve 7 are connected in sequence. The core 1 is provided with a through hole for accommodating the fiber core along the axial direction. The sleeve 6 is fixedly connected to a fixing seat 61 on the side facing the crimping sleeve 7. A flap 62 is rotatably connected to the fixing seat 61. A through groove for inserting the optical cable 4 is formed between the fixing seat 61 and the flap 62. A clamping block 621 for always clamping the optical cable 4 is fixedly connected to the inner wall of the flap 62. The flap 62 can be replaceably connected to the fixing seat 61 to clamp optical cables 4 of different specifications.

[0041] like Figure 1 , Figure 5 As shown, there are two types of flip covers 62 , one type of clamping block 621 is in a shallow state inside the flip cover 62 , and the other type of clamping block 621 is in a thicker state inside the flip cover 62 .

[0042] like Figure 1 , Figure 3As shown, in the first embodiment, when the optical cable 4 is a 2mm*1.6mm square cable, a thicker flap 62 of the clamping block 621 can be selected to achieve a clamping and limiting effect on the square cable.

[0043] like Figure 1 , Figure 4 As shown, in the second embodiment, when the optical cable 4 is a 2mm*3mm square cable, a shallower flip cover 62 of the clamping block 621 can be selected to achieve a clamping and limiting effect on the square cable.

[0044] like Figure 1 As shown, in the third embodiment: when the optical cable 4 is a round cable with a diameter of 0.9 mm, a flap 62 with a shallower clamping block 621 can be selected, and a mounting block can be connected to the outer shell of the round cable. The clamping block 621 can limit the position of the round cable by clamping and limiting the mounting block.

[0045] Embodiment 4: When the optical cable 4 uses a round cable with a diameter of 2 mm, a thicker flap 62 with the same clamping block 621 as in Embodiment 1 can be selected. The clamping block 621 that can clamp the square cable in Embodiment 1 can certainly clamp the round cable, and because the round cable is flexible, it will not affect the internal optical fiber.

[0046] like Figure 1 , Figure 2 As shown, in Example 5: when the optical cable 4 uses a round cable with a diameter of 3 mm, a shallower flip cover 62 of the same clamping block 621 as in Example 2 can be selected. The clamping block 621 that can clamp the square cable in Example 2 can certainly clamp the round cable, and because the round cable is flexible, it will not affect the internal optical fiber.

[0047] Therefore, when in use, the two flip covers 62 have different lengths of the clamping blocks 621 in them, so the flip covers 62 can be selected according to the different specifications of the optical cables 4 actually used. Moreover, when replacing, it is only necessary to detach the clamping points on both sides of the original flip cover 62 from its hinge, and then re-insert the flip cover 62 that meets the specification requirements to achieve the hinge. Because the fixing seat 61 and the flip cover 62 are both made of plastic material and have a certain elasticity, replacement is extremely convenient, which greatly improves the applicability of the optical fiber connector and can improve assembly efficiency.

[0048] like Figure 1 , Figure 5 , Figure 6As shown, the inner bottom surface of the fixing seat 61 is fixedly connected with a limiting column 611 for limiting the left and right sides of the optical cable 4, which can clamp and limit the two sides of the optical cable 4 to ensure the stability of the optical cable 4 after insertion, and the inner side surface of the limiting column 611 and the bottom surface of the clamping block 621 are both provided with inclined surfaces so that the thickness of the limiting column 611 and the clamping block 621 gradually decreases toward the end away from the sleeve 6, which can limit the outer skin of the optical cable 4 when pulled in the reverse direction to prevent the outer skin of the optical cable 4 from being pulled out, and when the flap 62 is closed on the fixing seat 61, the upper end of the limiting column 611 extends into the flap 62, thereby limiting the position of the flap 62, which can better clamp the optical cable 4 and ensure the cooperation between the flap 62 and the fixing seat 61.

[0049] like Figure 1 , Figure 5 As shown, the outer side surfaces of the flip cover 62 and the fixing seat 61 are fixedly connected with a threaded section 63 threadedly connected to the crimping sleeve 7, and the screw teeth on the threaded section 63 can be used to fix the Kevlar wire of the optical cable 4, and a clamping space 11 for clamping the outer skin of the optical cable 4 is provided between the outer side surfaces of the flip cover 62 and the fixing seat 61 at one end away from the sleeve 6 and the crimping sleeve 7, and the outer sides of the flip cover 62 and the fixing seat 61 are fixedly connected with an anti-slip convex strip 622 in the clamping space 11, which can firmly clamp the outer skin of the optical cable 4 and ensure the stability of the optical cable 4 after being connected to the optical fiber connector.

[0050] like Figure 1 , Figure 6 As shown, a transfer groove 64 is provided on the top surface of one end of the shell 6 close to the fixed seat 61, and the flip cover 62 is rotatably connected to the inner wall of the transfer groove 64 to achieve an inner buckle. Compared with the existing outer buckle, it can save space and reduce costs, and can also increase the connection firmness between the flip cover 62 and the fixed seat 61.

[0051] like Figure 1 , Figure 8 As shown, the ferrule 1 is fixedly connected to the fiber core of the optical cable 4 by glue. By utilizing the glue curing method, the connection reliability and durability between the fiber core and the ferrule 1 can be increased, and the occurrence of nodes can be avoided, thereby greatly improving the stability of the optical performance. The ferrule 1 includes a lead-out head 101, a limiting portion 102 and a connecting portion 103. A spring 3 is installed between the end face of the limiting portion 102 close to the sleeve 6 and the sleeve 6 to push the ferrule 1 to abut against the front shell 2 and drive the lead-out head 101 to extend out of the front shell 2. The outer side of one end of the connecting portion 103 away from the limiting portion 102 is sleeved with a microtube 5 that extends into the sleeve 6 and is sleeved on the outside of the optical fiber of the optical cable 4. The microtube 5 can guide the fiber core of the optical cable 4 to enter the ferrule 1, and can strengthen the radial limitation of the optical fiber, improve the blind penetration effect of the fiber core, and improve the on-site assembly effect of the optical fiber connector.

[0052] like Figure 1 , Figure 5, Figure 6 , Figure 7 As shown, the axial center of the sleeve 6 is fixedly connected with a ring sleeve 65 which is connected to the through groove and is used for the microtube 5 to extend into. The end of the spring 3 away from the limiting portion 102 abuts against the end face of the ring sleeve 65. The outer side surface of the ring sleeve 65 is fixedly connected with a plurality of limiting strips 66 for radially positioning the spring 3. A limiting groove 23 for the limiting strips 66 to be inserted is provided in the front shell 2, so that the inner wall of the front shell 2 can radially limit and fix the spring 3, so that the center line of the spring 3 and the center line of the ring sleeve 65 can be kept in the same straight line, thereby ensuring that the spring 3 is easy to assemble and can be used in conjunction with the limiting groove 23, so that after assembly, the outer side of the spring 3 is attached to the inner wall of the front shell 2, avoiding the bending of the spring 3 and affecting the optical fiber assembly, thereby improving practicality.

[0053] like Figure 1 , Figure 7 , Figure 8 As shown, a plurality of positioning grooves 104 are provided on the side of the limiting portion 102, and an annular retaining strip 21 for blocking the limiting portion 102 and a positioning block 22 for snapping into the positioning groove 104 are fixedly connected inside the front shell 2, which can improve the circumferential limiting effect of the ferrule 1, ensure the stability of the ferrule 1, and improve the use effect.

[0054] like Figure 1 As shown, the side of the crimping sleeve 7 away from the casing 6 is connected to the tail sheath 8, and a plurality of strip holes 81 are provided on the side of the tail sheath 8. The ferrule 1 is made of elastic material, and the casing 6 and the tail sheath 8 are both provided with a snap-in groove 10. The front shell 2 and the crimping sleeve 7 are both fixedly connected with a snap-in block 9 for snapping with the snap-in groove 10. The connection by snapping can greatly improve the assembly speed and efficiency, and the tail sheath 8 is elastic and has a better protective effect on the optical cable 4.

[0055] The present invention only requires on-site fiber stripping, fiber insertion, glue curing and grinding, and other parts are completed in the factory, thereby greatly increasing the on-site assembly efficiency of the fiber optic connector, while improving assembly accuracy, making it more convenient to use, reliable in performance, and reducing light loss. When in use, the fiber is stripped first, and then the optical cable 4 is inserted from the axial through hole of the tail sheath 8 and the crimping sleeve 7 and enters the sleeve 6. The optical fiber of the optical cable 4 passes through the microtube 5 and its core is cured with the core 1 through glue. At this time, the flip cover 62 is closed, and part of the outer skin of the optical cable 4 and the Kevlar line are covered on the outside of the flip cover 62 and the fixing seat 61. Thereafter, the crimping sleeve 7 is threadedly connected with the threaded section 63, and the thread on the threaded section 63 is used to The teeth are used to fix the Kevlar wire of the optical cable 4 and the clamping space 11 is used to firmly clamp the outer skin of the optical cable 4, and then the front shell 2 is inserted into the limit groove 23 on the inner wall of the front shell 2 so that the limit groove 23 is inserted into the limit strip 66 and the front shell 2 and the sleeve shell 6 are clamped to achieve the fixation of the two. At this time, the spring 3 pushes the core 1 to abut against the annular baffle 21 of the front shell 2, and finally the tail sheath 8 and the crimping sleeve 7 are clamped, which simplifies the assembly and disassembly of the optical fiber connector and makes the optical fiber connector have higher assembly accuracy. There is no need to pre-install optical fiber in the core 1, which is more convenient to use, has reliable performance, and reduces light loss. The front shell 2 and the sleeve shell 6 of the present invention are both injection molded parts, which can reduce their weight and material costs.

[0056] The above is only a preferred embodiment of the present invention, and the protection scope of the present invention is not limited to the above embodiments. All technical solutions under the concept of the present invention belong to the protection scope of the present invention. It should be pointed out that for ordinary technicians in this technical field, some improvements and modifications without departing from the principle of the present invention should also be regarded as the protection scope of the present invention.

Claims

1. A preassembled SC type optical fiber connector, comprising an optical cable (4), a front shell (2), a core (1), a sleeve (6) and a crimping sleeve (7), wherein the front shell (2), the sleeve (6) and the crimping sleeve (7) are connected in sequence, and the core (1) is provided with a through hole for accommodating the optical core along the axial direction, characterized in that: The housing (6) is fixedly connected to a fixing seat (61) on the side facing the crimping sleeve (7); a flap (62) is rotatably connected to the fixing seat (61); a through slot for inserting the optical cable (4) is formed between the fixing seat (61) and the flap (62); a clamping block (621) for always clamping the optical cable (4) is fixedly connected to the inner wall of the flap (62); the flap (62) can be replaceably connected to the fixing seat (61) to clamp optical cables (4) of different specifications; a limiting column (611) for limiting the left and right sides of the optical cable (4) is fixedly connected to the inner bottom surface of the fixing seat (61); The inner side surface of the limiting column (611) and the bottom surface of the clamping block (621) are both provided with inclined surfaces so that the thickness of the limiting column (611) and the clamping block (621) gradually decreases toward the end away from the casing (6); the outer side surfaces of the flip cover (62) and the fixing seat (61) are fixedly connected with a threaded section (63) threadedly connected to the crimping sleeve (7), and a clamping space (11) for clamping the outer skin of the optical cable (4) is provided between the outer side surfaces of the end of the flip cover (62) and the fixing seat (61) away from the casing (6) and the crimping sleeve (7), and the lengths of the clamping blocks (621) in different flip covers (62) are different.

2. A preassembled SC type optical fiber connector according to claim 1, characterized in that: A transfer groove (64) is provided on the top surface of one end of the sleeve (6) close to the fixing seat (61), and the flip cover (62) is rotatably connected to the inner wall of the transfer groove (64).

3. The preassembled SC type optical fiber connector according to claim 1, characterized in that: The ferrule (1) comprises a lead-out head (101), a limiting portion (102) and a connecting portion (103); a spring (3) is installed between the end surface of the limiting portion (102) close to the sleeve (6) and the sleeve (6) to push the ferrule (1) to abut against the inside of the front shell (2) and drive the lead-out head (101) to extend out of the front shell (2).

4. The preassembled SC type optical fiber connector according to claim 3, characterized in that: A microtube (5) is sleeved on the outer side of one end of the connecting portion (103) away from the limiting portion (102), the microtube (5) extending into the sleeve (6) and sleeved on the outside of the optical fiber of the optical cable (4).

5. The preassembled SC type optical fiber connector according to claim 4, characterized in that: The axial center of the sleeve (6) is fixedly connected with a ring sleeve (65) which is in communication with the through groove and is used for the microtube (5) to extend therein; one end of the spring (3) away from the limiting portion (102) abuts against the end surface of the ring sleeve (65); the outer side surface of the ring sleeve (65) is fixedly connected with a plurality of limiting strips (66) for radially positioning the spring (3); and a limiting groove (23) for the limiting strips (66) to be inserted therein is provided in the front shell (2).

6. The preassembled SC type optical fiber connector according to claim 5, characterized in that: A plurality of positioning grooves (104) are provided on the side of the limiting portion (102), and an annular retaining strip (21) for blocking the limiting portion (102) and a positioning block (22) for snapping into the positioning groove (104) are fixedly connected inside the front shell (2).

7. A preassembled SC type optical fiber connector according to any one of claims 1 to 6, characterized in that: The ferrule (1) and the fiber core of the optical cable (4) are fixedly connected by glue.

8. The preassembled SC type optical fiber connector according to claim 7, characterized in that: The side of the crimping sleeve (7) away from the sleeve shell (6) is connected to a tail sleeve (8), a side of the tail sleeve (8) is provided with a plurality of strip holes (81), the tail sleeve (8) is made of elastic material, the sleeve shell (6) and the tail sleeve (8) are both provided with a snap-fit ​​groove (10), and the front shell (2) and the crimping sleeve (7) are both fixedly connected with a snap-fit ​​block (9) for snapping with the snap-fit ​​groove (10).

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