Bend-resistant multimode optical fiber

Abstract

The present invention relates to a bending-resistant multimode optical fiber applied in the field of optical fibers, comprising an optical fiber core and a reflective coating coated on the outer side of the optical fiber core, wherein the outer side of the reflective coating is wrapped with a core wrapping sleeve, an outer protective sleeve is provided on a movable cover on the outer side of the core wrapping sleeve, a gap is formed between the core wrapping sleeve and the outer protective sleeve, and a movable supporting structure is installed in the gap between the core wrapping sleeve and the outer protective sleeve. By adopting the above structure, the core wrapping sleeve and the outer protective sleeve are connected in an axially slidable manner by utilizing the movable supporting structure installed in the gap between the core wrapping sleeve and the outer protective sleeve. On the one hand, the movable supporting structure itself is utilized to strengthen the overall anti-bending strength of the multimode optical fiber, and on the other hand, the core wrapping sleeve is bent with an arc much smaller than that of the outer protective sleeve, thereby achieving a good anti-bending effect and providing a good anti-bending protection for the optical fiber core.

Description

Technical Field

[0001] The present invention relates to a multimode optical fiber, in particular to a bend-resistant multimode optical fiber applied in the field of optical fibers. Background Art

[0002] Optical cables are manufactured to meet optical, mechanical, or environmental performance specifications. They are communications cable assemblies that utilize one or more optical fibers enclosed in a sheath as the transmission medium and can be used individually or in groups. Optical cables primarily consist of optical fibers (hair-thin glass filaments) protected by a plastic sheath and outer sheath. They contain no metals such as gold, silver, copper, or aluminum and are generally not worth recycling. Optical cables are communications lines that utilize a specific number of optical fibers arranged into a cable core, encased in a sheath and sometimes even an outer sheath, to transmit optical signals. These cables are formed by applying a specific process to the optical fibers (the optical transmission medium).

[0003] During the construction and use of optical cables, optical fiber breakage may occur due to excessive bending angles of the optical cables, affecting the transmission of optical fiber signals. Existing optical cables only have one reinforcement member in the center. Although the reinforcement member in the center can provide a certain degree of support, the effect is not significant.

[0004] Optical fibers are relatively fragile. When optical cables are affected by external forces, the optical fibers inside the cables are easily damaged, causing them to be squeezed, broken, or cracked, thereby affecting the signal transmission of the optical fibers.

[0005] To solve the above problems, the specification of Chinese patent CN219574446U discloses a bend-resistant multimode optical fiber, a bend-resistant multimode optical fiber, comprising multiple groups of optical fibers and a central reinforcement member, each group of optical fibers is covered with a sleeve, the sleeves are arranged in a ring array along the central reinforcement member, an inner protective sleeve is covered on the outer surface of the sleeve, a reinforcement layer is covered on the outer side of the inner sleeve, an outer sleeve is covered on the outer periphery of the reinforcement layer, and an anti-bending strip is connected to the outer surface of the outer sleeve. The bend-resistant multimode optical fiber separates each group of optical fibers by providing a partition on the central reinforcement member, thereby preventing each group of optical fibers from being squeezed against each other, and also playing an impact-proof role, preventing external force from directly impacting the optical fiber and causing the optical fiber to bend. By symmetrically arranging two mounting tubes on the outer surface of the outer sleeve, anti-bending strips are inserted into the mounting tubes to enhance the bending resistance of the entire optical cable.

[0006] Although the above-mentioned bend-resistant multimode optical fiber enhances its anti-bending effect by setting anti-bending strips, it only relies on the strength of the anti-bending strips themselves to resist bending, and its anti-bending effect is limited. At the same time, its inner and outer layers undergo bending deformation with basically the same curvature when bent. When the outer layer structure is bound to bend, the optical fiber core inside cannot be well protected, and its anti-bending effect is poor. Summary of the Invention

[0007] In view of the above-mentioned existing technologies, the technical problem to be solved by the present invention is how to design a bend-resistant multimode optical fiber that can not only improve the overall bending resistance of the multimode optical fiber, but also provide good protection for the inner optical fiber core when the outer protective layer is inevitably bent.

[0008] To solve the above problems, the present invention provides a bend-resistant multimode optical fiber, comprising an optical fiber core and a reflective coating coated on the outer side of the optical fiber core, a core wrapping sleeve wrapped around the outer side of the reflective coating, an outer protective sleeve provided on the outer side of the core wrapping sleeve, and a reinforced wear-resistant layer provided on the outer side of the fixed sleeve;

[0009] A gap is formed between the fiber core wrapping sleeve and the outer protective sleeve;

[0010] A movable support structure is installed in the gap between the fiber core wrapping sleeve and the outer protective sleeve. The movable support structure is slidably connected to the outer side of the fiber core wrapping sleeve and the inner side of the outer protective sleeve. The sliding distance of the movable support structure on the outer side of the fiber core wrapping sleeve is smaller than the sliding distance of the movable support structure on the inner side of the outer protective sleeve.

[0011] The movable support structure slides along the axial direction of the optical fiber core, and the length direction of the movable support structure is the same as the axial direction of the optical fiber core;

[0012] The movable support structure is composed of a plurality of anti-bending support sliders distributed along the circumference of the optical fiber core axis. The sides of the plurality of anti-bending support sliders close to the optical fiber core are slidably connected to the outside of the optical fiber core wrapping sleeve, and the sides of the plurality of anti-bending support sliders away from the optical fiber core are slidably connected to the inside of the outer protective sleeve.

[0013] A reset piece is installed on one side of the plurality of anti-bending support sliders close to the optical fiber core and on one side of the plurality of anti-bending support sliders away from the optical fiber core.

[0014] In the above-mentioned bend-resistant multimode optical fiber, a movable supporting structure installed in the gap between the core wrapping sleeve and the outer protective sleeve is used to form an axially slidable connection relationship between the core wrapping sleeve and the outer protective sleeve. On the one hand, the movable supporting structure itself is used to strengthen the overall bending strength of the multimode optical fiber, so that the multimode optical fiber can resist bending in multiple directions. On the other hand, when the outer protective sleeve is bent under force, the core wrapping sleeve and the internal optical fiber core can generate relative movement with the outer protective sleeve, thereby causing the movable supporting structure to move axially and making the core wrapping sleeve less affected by the outer protective sleeve, that is, while the outer protective sleeve bends a larger arc, the inner side of the core wrapping sleeve bends a smaller arc, thereby making the deformation arc of the optical fiber core smaller, providing a better anti-bending effect.

[0015] As a further supplement to the present application, a first supporting groove is provided on the outside of the fiber core wrapping sleeve, and a second supporting groove is provided on the inside of the outer protective sleeve, and the length of the first supporting groove is less than the length of the second supporting groove;

[0016] There are multiple first supporting grooves and multiple second supporting grooves, the multiple first supporting grooves correspond to the multiple second supporting grooves one by one, and the multiple first supporting grooves and the multiple second supporting grooves are evenly distributed along the axis of the optical fiber core;

[0017] The two sides of the anti-bending support sliding block are respectively slidably embedded in the first support groove and the second support groove.

[0018] As a further supplement to this application, the reset element includes:

[0019] Two first return springs are provided and are respectively fixed to the two ends of the anti-bending support slider close to the optical fiber core, and the ends of the two first return springs away from the anti-bending support slider are respectively fixed to the inner walls of the two sides of the first support groove;

[0020] The second return spring is also provided with two second return springs and is respectively fixed to the two ends of the anti-bending support slider away from the optical fiber core. The ends of the two second return springs away from the anti-bending support slider are respectively fixed to the inner walls on both sides of the second support groove.

[0021] As a further supplement to the present application, the gap between the fiber core wrapping sleeve and the outer protective sleeve is filled with a filling protective body, and the filling protective body is filled between multiple anti-bending support sliders.

[0022] As another improvement of the present application, a sliding sleeve on one side of the anti-bending support slider close to the fiber core wrapping sleeve is provided with a first connecting end seat, and the first connecting end seat is fixed to the outer side wall of the fiber core wrapping sleeve;

[0023] A sliding sleeve on one side of the anti-bending support slider close to the outer protective sleeve is provided with a second connecting end seat, and the second connecting end seat is fixed to the inner side wall of the outer protective sleeve.

[0024] As another improved supplement to the present application, the reset member includes a first reset spring located in the slide groove of the first connecting end seat and a second reset spring located in the slide groove of the second connecting end seat, one end of the first reset spring and one end of the second reset spring are both fixed to one side of the anti-bending support slider, the other end of the first reset spring away from the anti-bending support slider is fixed to the inner side wall of the slide groove of the first connecting end seat, and the other end of the second reset spring away from the anti-bending support slider is fixed to the inner side wall of the slide groove of the second connecting end seat.

[0025] As another improvement of the present application, an anti-bending corner body is further provided in the gap between the fiber core wrapping sleeve and the outer protective sleeve. The anti-bending corner body is made of elastic material. There are multiple anti-bending corner bodies and they are staggered on the circumference with multiple anti-bending support sliders. The anti-bending corner body is an L-shaped plate-like long strip structure. The two ends of the anti-bending corner body are fixed to the inner side of the outer protective sleeve, and the middle bending part of the anti-bending corner body is movably abutted against the outer side of the fiber core wrapping sleeve.

[0026] As a supplement to another improvement of the present application, the middle line of the angle of the anti-bending angle body extends toward the optical fiber core, and the extension direction deviates from the axis of the optical fiber core.

[0027] In summary, the anti-bending support slider installed in the gap between the fiber core wrapping sleeve and the outer protective sleeve is used to form an axially slidable connection relationship between the fiber core wrapping sleeve and the outer protective sleeve. On the one hand, the anti-bending support slider itself is used to strengthen the overall anti-bending strength of the multi-mode optical fiber, so that the multi-mode optical fiber can resist bending in multiple directions. On the other hand, when the outer protective sleeve is subjected to a large bending force, the anti-bending support slider slides in the outer protective sleeve, and similarly, it slides on the fiber core wrapping sleeve. The difference is that the sliding distance of the anti-bending support slider in the outer protective sleeve is large, and the sliding distance on the fiber core wrapping sleeve is small. At this time, even if the outer protective sleeve is bent with a large curvature, the fiber core wrapping sleeve can slide relative to the outer protective sleeve, so that the bending force on the fiber core wrapping sleeve is small, so that the fiber core wrapping sleeve is bent with a curvature much smaller than that of the outer protective sleeve, thereby achieving a good anti-bending effect and providing good anti-bending protection for the optical fiber core.

[0028] In addition, when the external bending force is eliminated, the first return spring and the second return spring work together to make the anti-bending support slider slide in the first support groove and the second support groove and complete the reset, so that the relative position between the fiber core wrapping sleeve and the outer protective sleeve is restored to its original state, and the bent fiber core wrapping sleeve and the outer protective sleeve are reset at the same time, thereby eliminating the bending deformation of the optical fiber core and achieving the purpose of resetting the optical fiber core. It can restore the shape of the optical fiber core after the external bending force is eliminated, thereby ensuring the transmission effect of the optical fiber core. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 This is a structural diagram of the first embodiment of the present application;

[0030] Figure 2 This is a cross-sectional view of the first embodiment of the present application;

[0031] Figure 3 This is a partial enlarged cross-sectional view of the first embodiment of the present application;

[0032] Figure 4 This is an end elevation view of the first embodiment of the present application;

[0033] Figure 5 This is a schematic diagram of another movable support structure according to the second embodiment of the present application;

[0034] Figure 6 This is a structural diagram of the third embodiment of the present application;

[0035] Figure 7 This is an end elevation view of the third embodiment of the present application;

[0036] Figure 8 This is a schematic diagram of the extension direction of the pressure of the anti-bending corner body in the third embodiment of the present application.

[0037] Description of the numbers in the figure:

[0038] 1. Optical fiber core; 2. Reflective coating; 3. Fiber core wrapping sleeve; 301. First support groove; 4. Outer protective sleeve; 401. Second support groove; 5. Reinforced wear-resistant layer; 6. Anti-bending support slider; 601. First return spring; 602. Second return spring; 603. First connection end seat; 604. Second connection end seat; 7. Filling protection body; 8. Anti-bending angle body. DETAILED DESCRIPTION

[0039] The following describes three implementation methods of the present application in detail with reference to the accompanying drawings.

[0040] The first implementation method:

[0041] The present invention provides a bend-resistant multimode optical fiber. Figure 1-Figure 2 , comprising an optical fiber core 1 and a reflective coating 2 coated on the outer side of the optical fiber core 1, a core wrapping sleeve 3 wrapped around the outer side of the reflective coating 2, an outer protective sleeve 4 provided on the outer side of the core wrapping sleeve 3, and a reinforced wear-resistant layer 5 provided on the outer side of the outer protective sleeve 4;

[0042] A gap is formed between the fiber core wrapping sleeve 3 and the outer protective sleeve 4;

[0043] A movable support structure is installed in the gap between the fiber core wrapping sleeve 3 and the outer protective sleeve 4. The movable support structure is slidably connected to the outer side of the fiber core wrapping sleeve 3 and the inner side of the outer protective sleeve 4. The sliding distance of the movable support structure on the outer side of the fiber core wrapping sleeve 3 is smaller than the sliding distance of the movable support structure on the inner side of the outer protective sleeve 4.

[0044] The movable supporting structure slides along the axial direction of the optical fiber core 1 , and the length direction of the movable supporting structure is the same as the axial direction of the optical fiber core 1 .

[0045] Based on the above structure, a movable supporting structure installed in the gap between the core wrapping sleeve 3 and the outer protective sleeve 4 is used to form an axially slidable connection relationship between the core wrapping sleeve 3 and the outer protective sleeve 4. On the one hand, the movable supporting structure itself is used to strengthen the overall bending strength of the multi-mode optical fiber, so that the multi-mode optical fiber can resist bending in multiple directions. On the other hand, when the outer protective sleeve 4 is bent under force, the core wrapping sleeve 3 and the internal optical fiber core 1 can generate relative movement with the outer protective sleeve 4, so that the movable supporting structure moves axially and the core wrapping sleeve 3 is less affected by the outer protective sleeve 4, that is, when the outer protective sleeve 4 bends a larger arc, the inner side of the core wrapping sleeve 3 bends a smaller arc, so that the deformation arc of the optical fiber core 1 is smaller, providing a better anti-bending effect.

[0046] Figure 2 The movable support structure is shown to be composed of multiple anti-bending support sliders 6 distributed circumferentially along the axis of the optical fiber core 1. The sides of the multiple anti-bending support sliders 6 close to the optical fiber core 1 are all slidably connected to the outside of the optical fiber core wrapping sleeve 3, and the sides of the multiple anti-bending support sliders 6 away from the optical fiber core 1 are all slidably connected to the inside of the outer protective sleeve 4;

[0047] Restoring parts are installed on the side of the multiple anti-bending support sliders 6 close to the optical fiber core 1 and the side of the anti-bending support sliders 6 away from the optical fiber core 1.

[0048] By setting the anti-bending support slider 6, when the outer protective sleeve 4 is bent by force, the anti-bending support slider 6 provides an anti-bending support force for the outer protective sleeve, thereby improving the anti-bending performance of the multimode optical fiber;

[0049] At the same time, when the outer protective cover 4 is subjected to a large bending force, the anti-bending support slider 6 slides inside the outer protective cover 4, and similarly, it also slides on the fiber core wrapping cover 3. The difference is that the sliding distance of the anti-bending support slider 6 inside the outer protective cover 4 is larger, and the sliding distance on the fiber core wrapping cover 3 is smaller. At this time, even if the outer protective cover 4 bends with a large curvature, the fiber core wrapping cover 3 will be able to slide relative to the outer protective cover 4, so that the bending force on the fiber core wrapping cover 3 is smaller, thereby making the fiber core wrapping cover 3 bend with a curvature far smaller than that of the outer protective cover 4, thereby achieving a good anti-bending effect and providing good anti-bending protection for the optical fiber core 1.

[0050] Figure 2-Figure 3 It shows that a first supporting groove 301 is opened on the outside of the fiber core wrapping sleeve 3, and a second supporting groove 401 is opened on the inside of the outer protective sleeve 4. The length of the first supporting groove 301 is smaller than the length of the second supporting groove 401;

[0051] There are multiple first supporting grooves 301 and multiple second supporting grooves 401, and the multiple first supporting grooves 301 correspond to the multiple second supporting grooves 401 one by one, and the multiple first supporting grooves 301 and the multiple second supporting grooves 401 are evenly distributed along the axis of the optical fiber core 1;

[0052] The two sides of the anti-bending support slider 6 are respectively slidably embedded in the first support groove 301 and the second support groove 401 .

[0053] When the outer protective cover 4 is bent under force, the outer side of the anti-bending support slider 6 slides in the second support groove 401. At the same time, the inner side of the anti-bending support slider 6 slides in the first support groove 301, so that the fiber core wrapping cover 3 can slide relative to the outer protective cover 4, thereby achieving the purpose of less influence of the bent outer protective cover 4 on the fiber core wrapping cover 3.

[0054] Figure 3 The reset member includes a first reset spring 601. Two first reset springs 601 are provided and are respectively fixed to the two ends of the anti-bending support slider 6 on the side close to the optical fiber core 1. The ends of the two first reset springs 601 away from the anti-bending support slider 6 are respectively fixed to the inner walls of the two sides of the first support groove 301.

[0055] The second return spring 602 is also provided with two second return springs 602 and is respectively fixed to the two ends of the anti-bending support slider 6 away from the optical fiber core 1, and the ends of the two second return springs 602 away from the anti-bending support slider 6 are respectively fixed to the inner walls on both sides of the second support groove 401.

[0056] Through the setting of the first return spring 601 and the second return spring 602, when the external bending force is eliminated, the first return spring 601 and the second return spring 602 work together to make the anti-bending support slider 6 slide in the first support groove 301 and the second support groove 401 and complete the reset, so that the relative position between the fiber core wrapping sleeve 3 and the outer protective sleeve 4 is restored to its original state, and the bent fiber core wrapping sleeve 3 and the outer protective sleeve 4 are reset at the same time, thereby eliminating the bending deformation of the optical fiber core 1 and achieving the purpose of resetting the optical fiber core 1. It can restore the shape of the optical fiber core 1 after the external bending force is eliminated, thereby ensuring the transmission effect of the optical fiber core 1.

[0057] Figure 4 The gap between the fiber core wrapping sleeve 3 and the outer protective sleeve 4 is filled with a filling protective body 7. The filling protective body 7 can be made of an elastic material (such as sponge, flexible fiber, etc.) commonly used in the prior art and suitable for this embodiment. The filling protective body 7 can be granular, strip-shaped, or block-shaped. However, the length, width, and height of the filling protective body 7 are all smaller than the width of the gap between the fiber core wrapping sleeve 3 and the outer protective sleeve 4. The filling protective body 7 is filled between the multiple anti-bending support sliders 6.

[0058] By setting the filling protective body 7, it is possible to fill the gap between the core wrapping sleeve 3 and the outer protective sleeve 4 while ensuring that the core wrapping sleeve 3 and the outer protective sleeve 4 can still form a relatively sliding connection relationship, thereby ensuring its anti-bending effect while avoiding excessive deformation caused by the formation of a cavity between the core wrapping sleeve 3 and the outer protective sleeve 4, thereby avoiding irreversible deformation damage to the core wrapping sleeve 3 or the outer protective sleeve 4 (especially the outer protective sleeve 4) during bending.

[0059] Second implementation method:

[0060] Figure 5 It is shown that the sliding sleeve on one side of the anti-bending support slider 6 close to the fiber core wrapping sleeve 3 is provided with a first connection end seat 603, and the first connection end seat 603 is fixed to the outer wall of the fiber core wrapping sleeve 3;

[0061] A second connection end seat 604 is provided on the sliding sleeve of the anti-bending support slider 6 close to the outer protective sleeve 4 , and the second connection end seat 604 is fixed to the inner side wall of the outer protective sleeve 4 .

[0062] The use of the first connection end seat 603 and the second connection end seat 604 can still achieve a relative sliding connection between the fiber core wrapping sleeve 3 and the outer protective sleeve 4, and at the same time avoid grooving the fiber core wrapping sleeve 3 and the outer protective sleeve 4, thereby ensuring that the structural strength of the fiber core wrapping sleeve 3 and the outer protective sleeve 4 will not be weakened, ensuring that the fiber core wrapping sleeve 3 and the outer protective sleeve 4 can jointly provide stable and reliable protection for the optical fiber core 1, and at the same time can reduce the wear of the fiber core wrapping sleeve 3 and the outer protective sleeve 4 during multiple bending processes, thereby extending the service life of the multimode optical fiber (outer layer) to a certain extent.

[0063] Figure 5 The reset member is shown to include a first reset spring 601 located in the sliding groove of the first connecting end seat 603 and a second reset spring 602 located in the sliding groove of the second connecting end seat 604. One end of the first reset spring 601 and one end of the second reset spring 602 are both fixed to one side of the anti-bending support slider 6. The other end of the first reset spring 601 away from the anti-bending support slider 6 is fixed to the inner side wall of the sliding groove of the first connecting end seat 603. The other end of the second reset spring 602 away from the anti-bending support slider 6 is fixed to the inner side wall of the sliding groove of the second connecting end seat 604.

[0064] The first return spring 601 and the second return spring 602 are arranged in the first connection end seat 603 and the second connection end seat 604, which can also drive the anti-bending support slider 6 to reset, thereby achieving the purpose of driving the multimode optical fiber to return to its original state after the external bending force is removed.

[0065] The third implementation method:

[0066] Figure 6-Figure 7It is shown that an anti-bending angle body 8 is also provided in the gap between the fiber core wrapping sleeve 3 and the outer protective sleeve 4. The anti-bending angle body 8 is made of elastic material (such as rubber, thermoplastic elastomer ‌TPE‌, etc.), so that it has certain anti-bending performance and can be deformed. There are multiple anti-bending angle bodies 8 and they are staggered on the circumference with multiple anti-bending support sliders 6. The anti-bending angle body 8 is an L-shaped plate-like long strip structure. The two ends of the anti-bending angle body 8 are fixed to the inner side of the outer protective sleeve 4, and the middle bending part of the anti-bending angle body 8 is movably abutted against the outer side of the fiber core wrapping sleeve 3.

[0067] By setting the anti-bending angle body 8, it is possible to cooperate with the anti-bending support slider 6 to further enhance the overall structural strength of the multi-mode optical fiber, thereby enhancing the anti-bending strength of the multi-mode optical fiber and achieving a better anti-bending effect.

[0068] Figure 8 It is shown that the midline of the included angle of the anti-bending angle body 8 extends toward the optical fiber core 1, and the extension direction deviates from the axis of the optical fiber core 1;

[0069] This arrangement can prevent the pressure of the anti-bending angle body 8 from directly causing radial extrusion of the optical fiber core 1 when the anti-bending angle body 8 is subjected to force, thereby preventing the optical fiber core 1 from being damaged by the pressure of the anti-bending angle body 8. While ensuring that the overall bending strength of the multi-mode optical fiber is enhanced, it avoids the phenomenon of aggravated damage that may be caused during the bending process, and has a good practical use effect.

[0070] In view of current actual needs, the protection scope of the above-mentioned implementation mode adopted in this application is not limited to this. Various changes made within the knowledge scope of technical personnel in this field without departing from the concept of this application still fall within the protection scope of the present invention.

Claims

1. A bend-resistant multimode optical fiber, comprising an optical fiber core (1) and a reflective coating (2) coated on the outer side of the optical fiber core (1), wherein the outer side of the reflective coating (2) is wrapped with a core wrapping sleeve (3), a movable cover outside the core wrapping sleeve (3) is provided with an outer protective sleeve (4), and a fixed sleeve outside the outer protective sleeve (4) is provided with a reinforced wear-resistant layer (5), characterized in that: A gap is formed between the fiber core wrapping sleeve (3) and the outer protective sleeve (4); A movable support structure is installed in the gap between the fiber core wrapping sleeve (3) and the outer protective sleeve (4), the movable support structure is slidably connected to the outer side of the fiber core wrapping sleeve (3) and the inner side of the outer protective sleeve (4), and the sliding distance of the movable support structure on the outer side of the fiber core wrapping sleeve (3) is smaller than the sliding distance of the movable support structure on the inner side of the outer protective sleeve (4); The movable support structure slides along the axial direction of the optical fiber core (1), and the length direction of the movable support structure is the same as the axial direction of the optical fiber core (1); The movable support structure is composed of a plurality of anti-bending support sliders (6) distributed along the circumference of the axis of the optical fiber core (1); the sides of the plurality of anti-bending support sliders (6) close to the optical fiber core (1) are all slidably connected to the outside of the optical fiber core wrapping sleeve (3); and the sides of the plurality of anti-bending support sliders (6) away from the optical fiber core (1) are all slidably connected to the inside of the outer protective sleeve (4); A reset piece is installed on a side of the plurality of anti-bending support sliders (6) close to the optical fiber core (1) and a side of the anti-bending support sliders (6) away from the optical fiber core (1); The outer side of the fiber core wrapping sleeve (3) is provided with a first supporting groove (301), the inner side of the outer protective sleeve (4) is provided with a second supporting groove (401), and the length of the first supporting groove (301) is smaller than the length of the second supporting groove (401); A plurality of the first supporting grooves (301) and a plurality of the second supporting grooves (401) are provided, the plurality of the first supporting grooves (301) and the plurality of the second supporting grooves (401) correspond one to one, and the plurality of the first supporting grooves (301) and the plurality of the second supporting grooves (401) are evenly distributed along the axis of the optical fiber core (1); The two sides of the anti-bending support sliding block (6) are respectively slidably embedded in the first support groove (301) and the second support groove (401); The reset element comprises: A first return spring (601), wherein two first return springs (601) are provided and are respectively fixed to two ends of the anti-bending support slider (6) close to the optical fiber core (1), and one end of the two first return springs (601) away from the anti-bending support slider (6) is respectively fixed to the inner walls on both sides of the first support groove (301); A second return spring (602), wherein two second return springs (602) are also provided and are respectively fixed to two ends of the anti-bending support slider (6) away from the optical fiber core (1), and one end of the two second return springs (602) away from the anti-bending support slider (6) is respectively fixed to the inner walls on both sides of the second support groove (401); The gap between the fiber core wrapping sleeve (3) and the outer protective sleeve (4) is filled with a filling protection body (7), and the filling protection body (7) is filled between a plurality of anti-bending support sliders (6).

2. A bend-resistant multimode optical fiber, comprising an optical fiber core (1) and a reflective coating (2) coated on the outer side of the optical fiber core (1), the outer side of the reflective coating (2) being wrapped with a core wrapping sleeve (3), the outer movable cover of the core wrapping sleeve (3) being provided with an outer protective sleeve (4), and the outer fixed sleeve of the outer protective sleeve (4) being provided with a reinforced wear-resistant layer (5), characterized in that: A gap is formed between the fiber core wrapping sleeve (3) and the outer protective sleeve (4); A movable support structure is installed in the gap between the fiber core wrapping sleeve (3) and the outer protective sleeve (4), the movable support structure is slidably connected to the outer side of the fiber core wrapping sleeve (3) and the inner side of the outer protective sleeve (4), and the sliding distance of the movable support structure on the outer side of the fiber core wrapping sleeve (3) is smaller than the sliding distance of the movable support structure on the inner side of the outer protective sleeve (4); The movable support structure slides along the axial direction of the optical fiber core (1), and the length direction of the movable support structure is the same as the axial direction of the optical fiber core (1); The movable support structure is composed of a plurality of anti-bending support sliders (6) distributed along the circumference of the axis of the optical fiber core (1); the sides of the plurality of anti-bending support sliders (6) close to the optical fiber core (1) are all slidably connected to the outside of the optical fiber core wrapping sleeve (3); and the sides of the plurality of anti-bending support sliders (6) away from the optical fiber core (1) are all slidably connected to the inside of the outer protective sleeve (4); A reset piece is installed on a side of the plurality of anti-bending support sliders (6) close to the optical fiber core (1) and a side of the anti-bending support sliders (6) away from the optical fiber core (1); A first connection end seat (603) is provided on a sliding sleeve on one side of the anti-bending support slider (6) close to the fiber core wrapping sleeve (3), and the first connection end seat (603) is fixed to the outer side wall of the fiber core wrapping sleeve (3); A sliding sleeve on one side of the anti-bending support sliding block (6) close to the outer protective sleeve (4) is provided with a second connecting end seat (604), and the second connecting end seat (604) is fixed to the inner side wall of the outer protective sleeve (4); The return member comprises a first return spring (601) located in a slide groove of the first connection end seat (603) and a second return spring (602) located in a slide groove of the second connection end seat (604), one end of the first return spring (601) and one end of the second return spring (602) are both fixed to one side of the anti-bending support slider (6), the other end of the first return spring (601) away from the anti-bending support slider (6) is fixed to the inner side wall of the slide groove of the first connection end seat (603), and the other end of the second return spring (602) away from the anti-bending support slider (6) is fixed to the inner side wall of the slide groove of the second connection end seat (604).

3. The bend-resistant multimode optical fiber according to any one of claims 1-2, characterized in that: An anti-bending angle body (8) is also provided in the gap between the fiber core wrapping sleeve (3) and the outer protective sleeve (4), and the anti-bending angle body (8) is made of elastic material; The anti-bending angle body (8) is provided with a plurality of anti-bending support sliders (6) which are staggeredly distributed on the circumference. The anti-bending angle body (8) is an L-shaped plate-like long strip structure. The two ends of the anti-bending angle body (8) are fixed to the inner side of the outer protective sleeve (4). The middle bending portion of the anti-bending angle body (8) is movably abutted against the outer side of the fiber core wrapping sleeve (3).

4. The bend-resistant multimode optical fiber according to claim 3, characterized in that: The midline of the angle of the anti-bending angle body (8) extends towards the optical fiber core (1), and the extending direction deviates from the axis of the optical fiber core (1).

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