Ultrahigh-fiber-number optical fiber bundle preparation method and device

Abstract

The invention discloses a preparation method of an ultra-high-fiber-number optical fiber bundle. The preparation method comprises the following steps: 1) coating a coating layer on a single bare optical fiber drawn by a drawing tower, and then curing the single bare optical fiber; 2) only winding a layer of optical fiber coated with a coating layer on a wire collecting cylinder; (3) pressing each turn of the optical fiber on the wire collecting cylinder on the wire collecting cylinder by adopting a limiting device; (4) cutting the optical fiber on the wire collecting cylinder by adopting a cutter so as to cut off each turn of the optical fiber on the wire collecting cylinder, thereby obtaining a set number of single-bundle optical fibers used for forming an ultrahigh-fiber-number optical fiber bundle; (5) all the single-bundle optical fibers used for forming the ultra-high-fiber-number optical fiber bundle fall on a bundling device, all the optical fibers are bundled through the bundling device, and therefore the ultra-high-fiber-number optical fiber bundle is formed; and (6) the limiting device relieves constraint on the ultra-high-fiber-number optical fiber bundle, and the ultra-high-fiber-number optical fiber bundle is taken down from the wire collecting cylinder. The ultra-high-fiber-number optical fiber bundle prepared by the method is high in consistency of indexes such as length and strength, stable and reliable in quality and high in production efficiency.

Description

Technical Field

[0001] The present invention belongs to the technical field of optical fiber preparation, and more specifically, relates to a method and equipment for preparing an ultra-high fiber count optical fiber bundle. Background Art

[0002] Fiber optic bundles are a physical form of bundling many independent optical fibers together, and then wrapped into a bundle with a large outer sheath. Each optical fiber can transmit light energy independently. Fiber optic bundles are often used in medical fields such as endoscopes, laser surgical equipment, and medical imaging systems. In the field of laser processing, fiber optic bundles can also be used to transmit power to achieve laser processing and laser welding. With the further development of optical fiber applications, fiber optic bundles have performed better in the field of lighting, such as automotive atmosphere lights, interior and exterior decoration of buildings, etc.

[0003] Fiber bundles can contain from a few to tens of thousands of optical fibers depending on the application. For example, an illumination fiber bundle uses a few to dozens of optical fibers, while an imaging fiber bundle often requires hundreds to thousands of optical fibers, and a high-resolution endoscopic imaging fiber bundle may contain up to 100,000 optical fibers.

[0004] Conventional fiber bundle preparation reference Figure 1 , usually the drawn rolled optical fiber is manually divided into fibers, manually cut and bundled according to the required length of the optical fiber bundle, which is not only inefficient, but also the number of fibers can generally only reach dozens or hundreds, and it is impossible to prepare optical fiber bundles with more than a thousand fibers. Moreover, manual cutting and bundling can easily make the lengths of the individual optical fibers in the bundled optical fiber bundles different, and the ends are uneven. Later, the ends of the optical fiber bundles still need to be cut flat to ensure the consistency of the length of the individual optical fibers.

[0005] At present, there are also methods of cutting a single or multiple reels at a fixed length through a fiber splitter, and then manually bundling them into bundles. Although this reduces the manual fiber splitting and cutting steps, the actual efficiency cannot be significantly improved due to the short required length of the fiber bundle itself and the small set fiber splitting speed value. In addition, the number of fiber reels carried on the fiber splitter is relatively limited, and it is difficult to quickly prepare fiber bundles of tens of thousands of fibers. For ultra-high fiber counts of thousands or more, it is often difficult to make them neat and orderly if a single optical fiber is used for manual bundling. Problems such as fiber twisting, relative sliding, and uneven end faces may occur, resulting in abnormal fiber transmission performance and a large difference in the energy distribution of the emitted light spot from the expected requirements.

[0006] For the preparation of ultra-high fiber count optical fiber bundles, a method is adopted in which optical fiber single filaments are bundled into optical fiber multifilaments, and then the optical fiber multifilaments are drawn and manually bundled, such as Chinese patent documents CN104181636A and CN104355533A. The process of bundling optical fiber single filaments into optical fiber multifilaments adopts manual bundling or parallel drawing technology, such as Chinese patent documents CN1286229A and CN1306296C. On the one hand, this ultra-high fiber bundle requires the use of thermoplastic optical fiber organic coatings, which cannot be applied to general photocurable optical fiber coatings. On the other hand, the manual bundling process still cannot avoid the problem of optical fiber transmission performance variation. In addition, the parallel drawing equipment has a complex structure and also has the problem of low consistency. The Chinese patent document CN1286229A discloses multiple independent drawing devices that draw optical fibers in parallel. The optical fibers need to be melted and formed at the same time and then rolled together. This type of equipment requires a huge investment cost. Since the optical fibers come out of multiple drawing devices, it is very difficult to ensure that all independent preform rods are drawn in complete synchronization. It is also difficult to ensure the consistency of diameter and strength indicators of all optical fibers drawn by various drawing devices. The subsequent fiber splitting, cutting and bundling will result in low consistency in diameter, strength, length, etc. of the single bundled optical fibers in the formed optical fiber bundle, which will affect the use of the optical fiber bundle and also require the end to be cut flat. Patent document CN1306296C discloses that a plurality of heating inner liners are arranged in a rectangular orientation in a large graphite furnace, and each liners can hold an independent preform rod. When the graphite furnace is heated, all the preform rods can be melt-drawn and formed at the same time, and then the preform rods are solidified and bundled through densely winding and impregnating the coating layer. In addition to the high investment cost, the synchronous control of the preparation process and wire drawing is also very complicated. Moreover, since multiple optical fibers are drawn at one time, the geometric consistency and strength consistency between the optical fibers cannot be guaranteed. The consistency of the single bundle of optical fibers formed by subsequent fiber splitting, cutting and bundling is low, which will affect the use effect of the optical fiber bundle, and the end portion needs to be cut flat again. Summary of the invention

[0007] In view of the above defects or improvement needs of the prior art, the present invention provides a method and equipment for preparing an ultra-high fiber-count optical fiber bundle. The prepared ultra-high fiber-count optical fiber bundle has high consistency in indicators such as length and strength, stable and reliable quality and high production efficiency, which solves the problems of complex existing optical fiber bundle preparation process, long cycle and poor consistency between fibers, and is particularly conducive to the one-time preparation of ultra-high fiber-count optical fiber bundles with tens of thousands of fibers.

[0008] To achieve the above object, according to one aspect of the present invention, a method for preparing an ultra-high fiber count optical fiber bundle is provided, characterized in that it comprises the following steps:

[0009] 1) A single bare optical fiber drawn by a drawing tower is coated with a coating and then cured;

[0010] 2) Only one layer of coated optical fiber is wound on the receiving drum, and the pitch of the optical fiber wound on the receiving drum is kept consistent;

[0011] 3) A limiting device is used to press each turn of the optical fiber on the receiving drum onto the receiving drum to prevent the cut optical fiber from falling off the receiving drum during subsequent cutting of the optical fiber;

[0012] 4) using a cutter to cut the optical fiber on the receiving drum to cut off each turn of the optical fiber on the receiving drum, thereby obtaining a set number of single-bundle optical fibers for forming an ultra-high fiber count optical fiber bundle;

[0013] 5) allowing all single-bundled optical fibers used to form an ultra-high fiber-count optical fiber bundle to fall onto a bundling device, and bundling all the optical fibers by the bundling device to form the ultra-high fiber-count optical fiber bundle;

[0014] 6) The limiting device releases the restraint on the ultra-high fiber count optical fiber bundle, and the ultra-high fiber count optical fiber bundle is removed from the receiving drum.

[0015] Preferably, in step 1), the drawing tower has the ability to draw preform rods with an outer diameter of 10 mm to 80 mm, and preform rods of different diameters are matched with graphite parts of different inner diameters, and the gap between the graphite parts and the preform rods is 2.5 mm to 10 mm.

[0016] Preferably, a single-layer or double-layer coating device can be used to coat a single optical fiber drawn by a drawing tower, and the coating device includes a coating chamber made of Teflon material or nylon material, a coating mold made of rubber material is provided at the lower end of the coating chamber, and the coating chamber is filled with coating material so that a coating layer is coated on the surface of the optical fiber when the optical fiber passes through the coating mold.

[0017] Preferably, the collecting drum comprises a drum body and a cotton layer covering the drum body, the optical fiber is wound on the cotton layer of the collecting drum, and the cotton layer is made of foam cotton or pearl cotton with a foaming ratio of 20-30.

[0018] Preferably, the outer diameter of the main body of the collecting reel is D, and the length L of the single-bundled optical fiber is changed by changing the thickness t of the cotton layer, and D and L satisfy the relationship: L=π(D+2t).

[0019] Preferably, step 2) further comprises: installing a fiber collection reel wrapped with a layer of optical fiber onto an optical fiber screening machine to perform strength screening on the optical fiber, and the fiber collection reel on the optical fiber screening machine for carrying the screened optical fiber is exactly the same as the fiber collection reel.

[0020] Preferably, the relationship is satisfied: h = n·2d max, where the number of single-bundle optical fibers produced after the optical fibers wound on a single reel are cut is n, the total length of the optical fibers wound on a single reel along the axial direction of the reel is h, and the maximum value of the optical fiber outer diameter specification range is d max .

[0021] Preferably, if the total fiber number N of the ultra-high fiber count optical fiber bundle to be prepared is greater than n, it is achieved by replacing the drawing cylinder multiple times to prepare k optical fiber bundles with n fiber counts, wherein N=k×n, and k can be an integer or a decimal.

[0022] Preferably, the limiting device is a U-shaped rod, and a slot is provided on the wire collecting drum, and both ends of the U-shaped rod are inserted into the slot of the wire collecting drum, so that the U-shaped rod limits each circle of the optical fiber on the wire collecting drum.

[0023] Preferably, the outer diameter of the cladding of the optical fiber drawn by the drawing tower is 40 μm to 125 μm;

[0024] The number of fibers in an ultra-high fiber count optical fiber bundle is more than 1,000.

[0025] According to one aspect of the present invention, there is also provided an ultra-high fiber count optical fiber bundle preparation device, characterized in that it comprises:

[0026] The drawing tower is used to draw a single optical fiber;

[0027] A coating device, used for applying a coating layer on the drawn optical fiber;

[0028] A curing device, used for curing the coating layer;

[0029] The fiber collecting device has a fiber collecting drum, which is used to wind only one layer of optical fiber and keep the pitch of the optical fiber wound on the fiber collecting drum consistent;

[0030] The limiting device is used to press each turn of the optical fiber on the receiving drum onto the receiving drum to prevent the cut optical fiber from falling off the receiving drum when the optical fiber is subsequently cut;

[0031] A cutter, used for cutting the optical fiber on the receiving drum, so as to cut off each turn of the optical fiber on the receiving drum, thereby obtaining a set number of single-bundle optical fibers for forming an ultra-high fiber count optical fiber bundle;

[0032] The bundling device is used to bundle all the optical fibers after the cutter cuts the optical fibers on the fiber collection drum, so as to form the ultra-high fiber count optical fiber bundle.

[0033] In general, the above technical solutions conceived by the present invention can achieve the following beneficial effects compared with the prior art:

[0034] 1) The present invention provides a method for preparing an ultra-high fiber count optical fiber bundle. By only winding a single optical fiber coming out of a drawing tower on a receiving drum, and only winding a layer of optical fiber on the receiving drum, "single-fiber bundle" is achieved. Since the single-bundled optical fibers of the ultra-high fiber count optical fiber bundle come out of the same drawing tower and are prepared from the same optical fiber, the consistency of the diameter, strength and other indicators of the optical fibers in the prepared ultra-high fiber count optical fiber bundle can be ensured, and the optical fiber stress in the optical fiber bundle is consistent, and there are no problems such as kinking and relative sliding, which helps to maintain the consistency of performance during subsequent use. The method for preparing an ultra-high fiber count optical fiber bundle provided by the present invention has good versatility for different optical fiber coatings because single-fiber bundle formation does not require secondary drawing.

[0035] 2) A method for preparing an ultra-high fiber count optical fiber bundle of the present invention limits the position of each turn of the optical fiber by a limiting device. When the optical fiber is subsequently cut by a tool, the optical fiber will not move, and the consistency of the length of each optical fiber can be maintained after cutting. The optical fibers are then bundled together by a bundling device without causing the ends of the optical fibers to be uneven. Therefore, the length of each single-bundled optical fiber can be guaranteed to be consistent and the ends are flush, and there is no need to cut the ends of the ultra-high fiber count optical fiber bundle flat to ensure consistency of length.

[0036] 3) The method for preparing an ultra-high fiber count optical fiber bundle of the present invention can prepare an ultra-high fiber count optical fiber bundle with tens of thousands of fibers by cutting a layer of optical fibers wound on a receiving drum and then bundling them, with high production efficiency.

[0037] 4) The present invention provides a method for preparing an ultra-high fiber count optical fiber bundle, which designs a plastic coating cavity and a rubber coating mold combination, and can significantly reduce the manufacturing cost and maintenance and replacement frequency of existing metal coating devices for drawing thin-diameter optical fibers. At the same time, since thin-diameter optical fibers require smaller inner holes of the coating mold, it is more likely to cause the inner holes of the coating mold to be rubbed due to the shaking of the optical fiber when the drawing tension is small, or the inner holes of the coating mold to be blocked due to abnormal fluctuations in the wire diameter during the wire drawing process, thereby preventing the optical fiber from breaking during the drawing process, poor optical fiber strength, and the scrapping of expensive high-precision coating molds.

[0038] In addition, the rubber coating mold will not scratch the surface of the bare optical fiber and cause poor strength like the metal mold, even if it rubs against the glass bare optical fiber. At the same time, due to the plasticity change of the rubber material, the coating material will not easily block the mold hole. Even if the friction causes the mold aperture to become larger and cannot be used, it is very easy to replace it with a new part. Therefore, this single low-cost rubber coating mold can be used as a one-time investment, and there is no need to worry about the residual solidified paint dandruff in the hole of the metal coating mold that has not been cleaned off, causing poor fiber coating when it is put into use next time.

[0039] 5) The present invention provides a method for preparing an ultra-high fiber count optical fiber bundle. By selecting a collection tube with different outer diameters of a cotton layer within the allowable range of the collection tube, and coating the surface of the collection tube with foam cotton or pearl cotton of different thicknesses, the change in the circumference of a single coil of the collection tube is changed, and then converted into a change in the length of a single fiber bundle. Since a fiber collection tube can collect tens of thousands of coils in one layer, when the cutter is controlled to cut the optical fiber along the axial direction of the collection tube, a fiber bundle with a large number of fibers can be prepared at one time. Compared with the existing manual cutting and bundling, the total number of fibers, manufacturing cost and efficiency are significantly improved.

[0040] 6) The method for preparing an ultra-high fiber count optical fiber bundle of the present invention can firstly carry out offline strength screening and optical fiber testing after the single-tube fiber collection, select another fiber collection tube with the same structure, and then cut and bundle it, so as to ensure the reliable strength of each single optical fiber in the optical fiber bundle.

[0041] 7) The ultra-high fiber count optical fiber bundle preparation device of the present invention can reduce equipment investment, lower manufacturing costs, and improve preparation efficiency, and is particularly suitable for the preparation of ultra-high fiber count optical fiber bundles. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 This is a physical picture of a conventional optical fiber bundle with a small number of fibers;

[0043] Figure 2 It is a schematic diagram of a single-core, thin-diameter optical fiber plastic coating cavity device provided by the present invention;

[0044] Figure 3 is a schematic diagram of a rubber coating mold provided by the present invention;

[0045] Figure 4 It is a schematic diagram of an adjustment platform capable of adjusting the alignment level online for assembling a coating cavity and a coating mold provided by the present invention;

[0046] Figure 5 It is a schematic diagram of a cross section of a wire collecting drum with a variable outer diameter and coating thickness provided by the present invention;

[0047] Figure 6 It is a schematic diagram of the height of the wire collecting drum provided by the present invention;

[0048] Figure 7 is a schematic diagram of a wire collecting device provided by the present invention;

[0049] Figure 8 It is an assembly diagram of a tool for cutting optical fiber and a fiber clip provided by the present invention;

[0050] Fig. 9 This is a physical picture of the ultra-large fiber count optical fiber bundle provided by the present invention;

[0051] Fig.10It is a schematic diagram of the optical fiber bundle provided by the present invention passing through the loose tube;

[0052] Fig.11 yes Figure 3 The enlarged schematic diagram of point Ⅰ in the middle;

[0053] Fig.12 It is a schematic diagram of the bare optical fiber provided by the present invention after being coated with a coating layer. DETAILED DESCRIPTION

[0054] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0055] Referring to the accompanying drawings, a method for preparing an ultra-high fiber count optical fiber bundle is provided. The ultra-high fiber count optical fiber bundle is an optical fiber bundle having a large number of fibers, especially an optical fiber bundle having a fiber count of more than 1,000 cores, and more preferably an optical fiber bundle having a fiber count of more than 10,000 cores. The method for preparing an ultra-high fiber count optical fiber bundle comprises the following steps:

[0056] 1) The single bare optical fiber drawn by the drawing tower is coated with a coating layer and then solidified; the preform rods for preparing the optical fiber bundle can be preform rods with different rod making processes, different core package doping elements, and different core package shapes, and preform rods of different diameters are matched with graphite parts of different inner diameters. The drawing tower includes a graphite heating furnace that can accommodate the drawing capacity of preform rods with an outer diameter of 10mm to 80mm, which is used to heat the preform rods and melt them into filaments. Preform rods of different diameters are matched and replaced with graphite parts of different inner diameters. In order to make the preform rods heated evenly and ensure the stable fluctuation of the bare optical fiber wire diameter, the gap between the inner diameter of the graphite part and the rod diameter of the drawn preform rod is optimally 2.5 to 10mm. A single-layer or double-layer coating device can be used to coat the single optical fiber drawn by the drawing tower, and the coating device includes a coating cavity made of Teflon or nylon material, and a coating mold made of rubber material is arranged at the lower end of the coating cavity. The coating cavity is filled with coating material so that when the optical fiber passes through the coating mold, a coating layer is coated on the surface of the optical fiber.

[0057] In addition, according to the coating diameter requirements of a single optical fiber in the prepared optical fiber bundle, a single-layer or double-layer coating device can be used to coat the single optical fiber drawn by the drawing tower. The coating device 2 is made of Teflon material or nylon material, and the coating device includes a coating cavity 21 made of Teflon material or nylon material, and a coating mold 3 made of rubber material is arranged at the lower end of the coating cavity 21. The coating cavity 21 is filled with a coating material so that when the optical fiber passes through the coating mold 3, a coating layer is coated on the surface of the optical fiber. The coating mold 3 has an inner hole 31. If double-layer coating is required, an additional set of the above-mentioned coating device system can be added. The bare optical fiber of the present invention has a cladding, and the drawing tower can continuously draw optical fibers with a small cladding diameter, so that the cladding diameter of the drawn bare optical fiber is between 40μm and 125μm.

[0058] 2) Only one layer of coated optical fiber is wound on the wire-receiving drum 1, and the pitch of the optical fiber wound on the wire-receiving drum 1 is kept consistent; the turns of the optical fiber on the wire-receiving drum 1 can contact each other and maintain a dense arrangement to increase the fiber count of the ultra-high fiber count optical fiber bundle that can be prepared; the wire-receiving drum 1 has a drum body 11 and a cotton layer 12 coated on the drum body 11, and the optical fiber is wound on the cotton layer 12 of the wire-receiving drum 1, and the cotton layer 12 is replaceable. The outside of the drum body 11 can be coated with foam cotton or pearl cotton of different thicknesses, so that the inner diameter of the drum body 11 of the wire-receiving drum 1 is fixed and the outer diameter is optional. The wire-receiving drum 1 is driven by a first power mechanism to automatically move and rotate to wind the optical fiber. In addition, after the wire-receiving drum 1 is wound with a layer of coated optical fiber, the wire-receiving drum 1 with a layer of optical fiber is installed on an optical fiber screening machine to perform strength screening on the optical fiber, and the fiber-receiving drum on the optical fiber screening machine for carrying the screened optical fiber is exactly the same as the wire-receiving drum 1. The foam cotton or pearl cotton coated on the surface of the tube body 11 are all foam materials, and the foaming ratio is often used to describe their hardness. Due to the high pressure of thin-diameter optical fibers, in order to prevent the foam cotton or pearl cotton from causing poor appearance such as indentation on the optical fiber coating, it is best to select a foaming ratio in the range of 20 to 30. Unless otherwise specified, the foaming ratio in the present invention refers to the volume ratio of the foam cotton or pearl cotton after foaming to the volume ratio before foaming. The foaming ratio of 20 to 30 is agreed to ensure that the foam cotton or pearl cotton material wrapped on the surface of the wire collection tube 1 has a certain hardness, can bear the extrusion stress of the optical fiber bending and winding, prevent the deformation caused by the coating material being too soft and affecting the optical fiber wiring, and is not too hard, so that after contact with the optical fiber, mechanical friction damage or indentation will appear on the surface of the optical fiber coating, affecting the appearance of the optical fiber coating.

[0059] 3) A limiting device is used to press each turn of the optical fiber on the receiving drum 1 onto the receiving drum 1 to prevent the cut optical fiber from falling off the receiving drum 1 when the optical fiber is subsequently cut. The limiting device can be driven by a second power mechanism to press each turn of the optical fiber on the receiving drum 1 to prevent loosening. The pressure is appropriate and the optical fiber cannot be damaged. Alternatively, the limiting device can be detachably mounted on the receiving drum 1. For example, a U-shaped rod can be used, and a slot is provided on the receiving drum 1. The two ends of the U-shaped rod are inserted into the slot of the receiving drum 1, so that the U-shaped rod limits each turn of the optical fiber on the receiving drum 1. After the cutter 6 completes the cutting of the wound optical fiber, the U-shaped rod is removed from the receiving drum 1.

[0060] 4) Use the cutter 6 to cut the optical fiber on the receiving drum 1 to cut off each turn of the optical fiber on the receiving drum 1, so as to obtain a set number of single-bundle optical fibers for forming an ultra-high fiber count optical fiber bundle; the cutter 6 is driven by the cutter driving device 7 to move and cut automatically. For the screened optical fiber or the optical fiber that does not need to be inspected for strength, the switch is manipulated to make the cutter 6 automatically extend and neatly cut the optical fiber. The limit devices at both ends press the optical fiber wound on the receiving drum 1, and then the bundling device 8 wraps and gathers them for bundling to prepare a single-tube ultra-high fiber count optical fiber bundle with a fiber number of n, that is, the number of single-bundle optical fibers prepared by the single-tube receiving drum 1 is n. The bundling device can use an optical fiber bundling machine for automatic bundling, or use an optical fiber bundle or optical fiber tie for manual bundling. The optical fiber bundle or optical fiber tie can preferably be pre-installed on the receiving drum 1.

[0061] 5) All optical fibers used to form an ultra-high fiber-count optical fiber bundle fall onto the bundling device 8, and all optical fibers are bundled by the bundling device 8 to form the ultra-high fiber-count optical fiber bundle; the limiting device limits the position, the cutter 6 cuts, and the bundling device 8 bundles, so that the length of a single bundle of optical fibers in the ultra-high fiber-count optical fiber bundle is consistent and the ends are flush, and there is no need to cut the ends of the ultra-high fiber-count optical fiber bundle flat later, and the ends can be directly placed in a sleeve and fixed together with an adhesive.

[0062] If there are M turns of optical fiber wound on the receiving drum 1, and the tool 6 only cuts at the first position, M single-bundle optical fibers can be formed. If the tool 6 cuts the optical fiber at a position 180° symmetrical to the first position, that is, the tool cuts at two positions, 2M single-bundle optical fibers can be formed. At this time, two limiting devices are required to press the optical fiber at two locations. After cutting is completed, the receiving drum 1 can be rotated, and the optical fiber on the upper part of the receiving drum 1 can be rotated 180° so that it can fall onto the bundling device 8 and then be wrapped.

[0063] 6) The limiting device releases the restraint on the ultra-high fiber count optical fiber bundle, and the ultra-high fiber count optical fiber bundle is removed from the receiving drum 1.

[0064] Furthermore, the outer diameter of the drum body 11 of the collecting drum 1 is D, and the length L of a single single-bundle optical fiber is changed by changing the thickness t of the cotton layer 12, and D and L satisfy the relationship: L=π(D+2t).

[0065] Furthermore, the relationship is satisfied: h = n·2d max , where the number of single-bundle optical fibers produced after the optical fibers wound on a single reel 1 are cut is n, the total length of the optical fibers wound on a single reel 1 along the axial direction of the reel 1 is h, and the maximum value of the optical fiber outer diameter specification range is d max If the diameter of the optical fiber is between 40 μm and 125 μm, then d max =125μm.

[0066] Furthermore, if the total fiber number N of the ultra-high fiber count optical fiber bundle to be prepared is greater than n, it can be achieved by replacing the drawing tube multiple times to prepare k optical fiber bundles with n fiber counts, where N = k × n, and k can be an integer or a decimal. When a single collection tube 1 is full of optical fibers, it can be replaced with another collection tube 1 to continue to reel in the optical fibers. If necessary, it can be transferred to an optical fiber screening machine for strength screening. The outer diameter of the collection tube carrying the screened optical fibers and the thickness of the foam cotton or pearl cotton coated are consistent with the collection tube 1 currently assembled on the drawing tower.

[0067] According to another aspect of the present invention, there is also provided an ultra-high fiber count optical fiber bundle preparation device, comprising:

[0068] The drawing tower is used to draw a single optical fiber;

[0069] The coating device is used to apply a coating layer on the drawn optical fiber. The coating device can perform single-layer or double-layer coating on the optical fiber. If it is a double-layer coating, the inner coating layer is applied first, and then the outer coating layer is applied. The coating device includes an adjustment platform 4 with a circular hole in the middle and adjustable front, back, left, right and horizontal positions. An inverted conical coating device 2 is installed in the circular hole, including a coating cavity 21 and a coating mold 3 made of rubber material that can be equipped with any diameter of the inner hole 31 required for cutting. The aperture z of the inner hole 31 of the cut coating mold 3, the diameter a of the bare optical fiber before coating and the single-sided coating thickness c, meet the relationship: z = a + 2c.

[0070] The present invention adopts a double-layer independently controllable coating device, and each layer of the coating mold is assembled to an adjustment platform 4 with a circular hole in the middle and adjustable front, back, left, right and horizontal positions. An inverted coating device is installed in the circular hole. This online adjustable design ensures the concentricity of the optical fiber coating and reduces unnecessary secondary starting and quality loss.

[0071] In order to prevent the coating device from scratching the thin-diameter optical fiber and causing poor optical fiber strength, in addition to the above-mentioned plastic coating device 2, the coating mold 3 used is made of rubber. This rubber mold can be arbitrarily cut into the required inner hole 31 diameter.

[0072] The curing device is used for curing the coating layer.

[0073] The wire collecting device comprises a wire collecting drum 1, which is used for winding only one layer of optical fiber and keeping the pitch of the optical fiber wound on the wire collecting drum 1 consistent; the wire collecting device preferably has a drum changing function, and after one wire collecting drum 1 is fully wound with optical fiber, it can be switched to another wire collecting drum 1 for winding, and a tool 6 is preferably arranged parallel to the axial direction of the wire collecting drum 1.

[0074] The limiting device is used to press each turn of the optical fiber on the receiving drum 1 onto the receiving drum 1 to prevent the cut optical fiber from falling off the receiving drum 1 when the optical fiber is subsequently cut.

[0075] The cutter 6 is used to cut the optical fiber on the wire collection drum 1, so as to cut off each turn of the optical fiber on the wire collection drum 1, thereby obtaining a set number of single-bundle optical fibers for forming an ultra-high fiber count optical fiber bundle; the cutter 6 is preferably a diamond knife, and the blade direction of the cutter 6 is perpendicular to the optical fiber winding direction. The wire collection drum 1 is provided with a guide rail 5, and the cutter 6 is driven by a cutter driving mechanism 7 to move along the guide rail 5, and the cutter 6 automatically cuts the optical fiber.

[0076] The bundling device 8 is used to bundle all the optical fibers (all the single-bundled optical fibers) after the cutter 6 cuts the optical fibers on the receiving drum 1, thereby forming the ultra-high fiber count optical fiber bundle.

[0077] The ultra-high fiber count optical fiber bundle involved in the present invention is mainly used for intensive transmission applications such as medical energy transmission and side-lighting illumination, which requires high flexibility of the optical fiber bundle, and the number of fibers is at least more than 1,000. If the diameter of a single optical fiber is based on the conventional 240μm size, the physical diameter after being bundled is very large, which will result in excess strength but insufficient toughness. Therefore, the diameter of the cladding layer and the outer diameter of the coating layer of the single core fiber are relatively small.

[0078] According to the existing wet-to-dry or wet-to-wet metal coating device and system drawing, in addition to the frequent tower breakage that may occur, the metal mold hole will be blocked many times, and the glass blockage cannot be properly cleaned out, resulting in the mold being scrapped due to high price, high processing difficulty, and long procurement cycle. The use of a plastic coating cavity 21 and a matching rubber coating mold 3 not only reduces the cost of use, but also does not cause hard scratches on the rubber coating mold 3 when it collides with the bare optical fiber, and can also be used as a one-time investment to ensure a good drawing state of the optical fiber.

[0079] In order to improve the efficiency of optical fiber bundle preparation and reduce the process difficulty and manufacturing cost, the present invention can make an optical fiber bundle with a large number of fibers at one time by modifying the optical fiber collecting device and the collecting drum 1, thereby realizing the preparation capability of a ten-thousand-core optical fiber bundle. Compared with the method provided by foreign counterparts for solving the problem of simultaneously drawing multiple optical fibers through the front end, this process scheme is much easier in terms of cost investment and process control.

[0080] In order to prepare ultra-high fiber count optical fiber bundles with over 1,000 or even 10,000 fibers, and to ensure the consistency of core-to-core geometry and strength reliability, the present invention provides a preparation method and equipment with low investment cost and stable and reliable quality. The method achieves high consistency of all single-bundled optical fibers in ultra-high fiber count optical fiber bundles through single-strand drawing, single-layer winding, pressing and fixing, cutting and bundling of optical fibers, and combines the modification of the coating device and the adjustment of the outer diameter of the wire collection drum 1 to achieve effective coating and precise control of the single-core optical fiber of the optical fiber bundle. The present invention solves the problems of complex preparation process, long cycle, poor consistency between cores, and unreliable strength of existing optical fiber bundles, and is particularly conducive to the one-time preparation of optical fiber bundles with tens of thousands of fibers.

[0081] If implemented according to the double-layer coating requirements, according to the specifications of the single-core optical fiber cladding diameter d, the inner coating diameter d1 and the outer coating diameter d2 of the optical fiber bundle, the following relationship is used:

[0082] d 内 =2d1―d,d 外 =2d2―d1

[0083] According to the above calculation formula, the length of the tapered diameter-changing area of ​​the rubber material coating mold 3 for the upper and lower layers of coating can be cut so that the diameter d of the exposed inner hole 31 is 内 and d 外 Meet the design requirements of optical fiber coating diameter.

[0084] The prepared rubber coating mold 3 is assembled on the coating device 2 on the adjustment platform 4 with adjusted alignment and level. After the optical fiber is threaded onto the tube, the corresponding coating layer materials are added into the inner and outer coating cavities 21 respectively. The height of the added solution shall not exceed two-thirds of the height of the column of the coating cavity 21.

[0085] According to the length L of the optical fiber bundle and the outer diameter D of the wire collection tube 1, the required foam cotton or pearl cotton thickness t is calculated. The calculation formula is as follows:

[0086] L=π(D+2t)

[0087] Then cut the foam cotton or pearl cotton of the corresponding thickness specification t, wrap it on the wire collection drum 1, and carry out the speed-up wire collection work.

[0088] When using the assembled coating device, the thickness of the foam cotton or pearl cotton of the wire collection drum 1 should be confirmed and the coating should be installed before use. Otherwise, the coating mold 3 will be worn due to long wire collection waiting during preparation, resulting in the inner hole 31 having a larger diameter and being unable to be coated with the required thickness as required.

[0089] According to the outer diameter d of a single optical fiber in the optical fiber bundle, the number of optical fiber bundles n prepared by a single fiber collection drum 1, and the height h of the fiber collection drum 1, the following relationship is used:

[0090] h=n·2d

[0091] The number of fibers n in a single barrel can be confirmed. If n is less than the total number of fibers N in the fiber bundle, then another barrel is added, and then the second barrel is cut and collected to prepare the second fiber bundle with the number n, and so on. N and n are adjusted by N=nk, and k can also be a decimal, such as 1.5.

[0092] If there are requirements for the consistency of optical fiber geometry diameter and optical fiber strength, the optical fiber removed from the tube can be screened for strength and tested for geometry at both ends. The optical fiber that meets the requirements can then be cut and bundled. In order to ensure the consistency of the optical fiber bundle length L and the number of fibers n, the screening collection tube 1 is exactly the same size as the drawing collection tube 1 and is coated with foam cotton or quartz cotton of the same thickness t.

[0093] In summary, the optical fiber bundle preparation device and method provided by the present invention adopts a plastic coating cavity 21 and a rubber coating mold 3, which changes the limitations of the existing metal coating mold 3 for thin-diameter optical fibers. By modeling and selecting the outer diameter of the collection tube 1 and coating it with foam cotton or quartz cotton of different thicknesses, an optical fiber bundle with the required length and tens of thousands of fibers can be quickly prepared, solving the problems of complex preparation process platform, huge cost investment, and long production cycle. At the same time, the geometric consistency and reliability of the single-core optical fiber preparation involved in the present invention are also guaranteed.

[0094] In order to more clearly illustrate the benefits of the present invention, the embodiments are described in terms of relatively complex double-layer coating.

[0095] Table 1 Production parameters and test results of Examples 1 to 7

[0096]

[0097] Example 1

[0098] The ultra-high fiber count fiber bundle provided in this embodiment is at the level of more than 10,000 cores. The more fibers there are, the larger the volume after sheathing. In order to control the volume unit and meet the toughness requirements, the cladding diameter of a single optical fiber in the fiber bundle and the matching coating diameter are designed to be smaller. As shown in Table 1, the cladding diameter of the optical fiber is designed to be 40μm, and the coating diameter is matched to be 85μm, which is nearly 90% smaller than the conventional 125 / 250μm geometric structure. The difficulty of controlling the wire drawing process corresponding to optical fibers of this size will be greatly increased. In order to ensure the smooth preparation of single-core optical fibers, reduce the reliance on the high processing accuracy of the thin-diameter coating mold 3, and prevent the mold from being scrapped due to the difficulty in cleaning the bare optical fiber blocking the mold hole, the following design is used. Figure 2 The plastic coating device 2 shown, the coating chamber material can be Teflon or nylon, Figure 3 The rubber coating mold 3 is matched with the coating cavity 21. The lower end of the coating mold 3 is an inner hole 31 with a gradually changing diameter, which is convenient for cutting to a suitable inner diameter according to different cladding diameters and coating diameter requirements. After cutting, the coating mold 3 is assembled into the coating device 2 containing the coating cavity 21. The coating device 2 is fixed to the adjustment platform 4 (such as the one on the drawing tower) that can adjust the horizontal alignment online. Figure 4 ). When the optical fiber is drawn to a diameter smaller than and close to the cladding diameter, the fiber is threaded onto the tube, and the prepared liquid coating is poured from the upper opening of the coating device 2. Under the traction of the optical fiber and the surface tension of the liquid coating layer, the coating layer quickly wraps the bare optical fiber, and after the coating is completed, it is cured and formed.

[0099] In this embodiment, the length of a single bundle of optical fibers is 1m, which is converted to an outer diameter D of the wire collection drum 1 of 320mm. If the outer diameter D of the drum body 11 of the current wire collection drum 1 is less than 320mm, the drum body 11 can be coated with foam cotton or pearl cotton of corresponding thickness t, so that the total value of D+2t is 320mm. Figure 5 According to the axial length of the main body 11 of the wire collection drum 1 ( Figure 6 The number of fibers n that can be prepared from a single-tube wound optical fiber can be calculated by using the outer coating diameter of the optical fiber as shown in the figure. Figure 7 The wire collecting device is supplemented by a cutter 6 and a limit device ( Figure 8 ), to achieve the preparation of an ultra-high fiber count fiber bundle with n single-bundle fibers. If the final fiber bundle fiber count requirement is N=k×n, it is achieved by forming k n.

[0100] Examples 2 to 6

[0101] The parameters listed in Table 1 are customized within the scope of the claims, and the prepared optical fiber bundle meets the actual length and fiber number requirements. Since the fiber number is less than that in Example 1, the corresponding single-core optical fiber cladding diameter and coating diameter can be increased, which is conducive to reducing the process difficulty. At the same time, the flexibility of the optical fiber bundle is not affected by the increase in the geometric size of the single-core optical fiber. Figure 1 is a real picture of an optical fiber bundle with a relatively small number of fibers, compared with an optical fiber bundle with a large number of fibers prepared in the embodiment shown in the present invention ( Fig. 9 ) and ultra-large fiber bundles with loose tubes ( Fig.10 ), which can reflect a clear process complexity. The present invention obviously has higher processing requirements and the process will be more complicated.

[0102] In the embodiment, the slitting requirements of the inner hole 31 of the rubber coating mold 3 and the corresponding cladding diameter and inner coating layer diameter satisfy the engineering relationship: z=a+2c, such as Fig.11 Because the diameters of the cladding and coating of the optical fiber have tolerances, there is a certain tolerance for the inner hole 31 of the cut coating mold 3, so the aperture values ​​of the upper and lower coating molds 3 listed in the embodiment are recommended central values, not fixed and unique requirements.

[0103] In the embodiment, the outer diameter D+2t of the wire collecting drum 1 is related to the length L of the optical fiber bundle. For optical fiber bundles with a longer required length, such as those greater than 2 meters, it is necessary to select a wire collecting drum 1 with a larger outer diameter D, and then match foam cotton or quartz cotton with a thickness t according to the relationship L=π(D+2t). The basic principle of D and t is t≤D / 2. Otherwise, if D is fixed and unchanged, the increase in the length of the optical fiber bundle is achieved only by continuously increasing the thickness t, which will cause the center of gravity of the wire collecting drum 1 to be unstable, and it will tilt after rotating at a high speed, or even cause the coating to separate from the wire collecting drum 1. Usually, the wire collecting system matched with the drawing tower has the ability to select and use a wire collecting drum 1 with a larger outer diameter D, but if the height h of the wire collecting drum 1 is required to be optional, it is necessary to introduce the wire collecting system modification, which will bring about a large investment in equipment cost. Therefore, the embodiment in the table reflects that only D+2t is changed, and h does not need to be changed, so that optical fiber bundles with different cladding diameters and different lengths can be achieved.

[0104] Example 7

[0105] If the cladding diameter of a single-core optical fiber in the optical fiber bundle is greater than 125 μm, such as 200 μm as listed in Example 7 in Table 1.

[0106] According to the approximate formula of bending force and bending radius of an object:

[0107]

[0108] Wherein, R is the target bending radius of the optical fiber, E is the Young's modulus of the quartz glass optical fiber, r is the radius of the optical fiber quartz cladding, and σ is the stress applied when bending to radius R. The smaller R and σ are, the better the processing flexibility. It is assumed that the basic requirement for processing flexibility is that the minimum bending radius can reach 30 mm. When r is taken as 100 μm according to the present embodiment, it can be calculated according to the above formula that the minimum tolerable bending radius at this size is 52 mm, which cannot be met. Of course, if the optical fiber bundle processing does not need to meet a certain smaller bending flexibility, including the preparation device and method mentioned in the present invention, a thicker single-core optical fiber and an optical fiber bundle with fewer fibers can be prepared, such as Example 7, which can also be regarded as qualified.

[0109] It will be easily understood by those skilled in the art that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for preparing an ultra-high fiber count optical fiber bundle, characterized in that: The following steps are involved: 1) A single bare optical fiber drawn by a drawing tower is coated with a coating and then cured; 2) Only one layer of coated optical fiber is wound on the receiving drum, and the pitch of the optical fiber wound on the receiving drum is kept consistent; 3) A limiting device is used to press each turn of the optical fiber on the receiving drum onto the receiving drum to prevent the cut optical fiber from falling off the receiving drum during subsequent cutting of the optical fiber; 4) using a cutter to cut the optical fiber on the receiving drum to cut off each turn of the optical fiber on the receiving drum, thereby obtaining a set number of single-bundle optical fibers for forming an ultra-high fiber count optical fiber bundle; 5) allowing all single-bundled optical fibers used to form an ultra-high fiber-count optical fiber bundle to fall onto a bundling device, and bundling all the optical fibers by the bundling device to form the ultra-high fiber-count optical fiber bundle; 6) The limiting device releases the restraint on the ultra-high fiber count optical fiber bundle, and the ultra-high fiber count optical fiber bundle is removed from the receiving drum.

2. The method for preparing an ultra-high fiber count optical fiber bundle according to claim 1, characterized in that: In step 1), the drawing tower has the ability to draw preform rods with an outer diameter of 10 mm to 80 mm, and preform rods of different diameters are matched with graphite pieces of different inner diameters, and the gap between the graphite piece and the preform rod is 2.5 mm to 10 mm.

3. The method for preparing an ultra-high fiber count optical fiber bundle according to claim 1, characterized in that: A single-layer or double-layer coating device can be used to coat a single optical fiber drawn by a drawing tower, and the coating device includes a coating cavity made of Teflon or nylon material, a coating mold made of rubber material is arranged at the lower end of the coating cavity, and the coating cavity is filled with coating material so that a coating layer is coated on the surface of the optical fiber when the optical fiber passes through the coating mold.

4. The method for preparing an ultra-high fiber count optical fiber bundle according to claim 3, characterized in that: The wire collecting drum comprises a drum body and a cotton layer covering the drum body, the optical fiber is wound on the cotton layer of the wire collecting drum, the cotton layer is made of foam cotton or pearl cotton and the foaming ratio is 20-30.

5. The method for preparing an ultra-high fiber count optical fiber bundle according to claim 4, characterized in that: The outer diameter of the main body of the collecting reel is D. The length L of a single bundle of optical fibers is changed by changing the thickness t of the cotton layer, and D and L satisfy the relationship: L=π(D+2t).

6. The method for preparing an ultra-high fiber count optical fiber bundle according to claim 1, characterized in that: Step 2) also includes: installing the fiber collection reel wrapped with a layer of optical fiber on the optical fiber screening machine to perform strength screening on the optical fiber, and the fiber collection reel on the optical fiber screening machine for carrying the screened optical fiber is exactly the same as the fiber collection reel.

7. The method for preparing an ultra-high fiber count optical fiber bundle according to claim 1, characterized in that: Satisfies the relationship: h = n·2d max , where the number of single-bundle optical fibers produced after the optical fibers wound on a single reel are cut is n, the total length of the optical fibers wound on a single reel along the axial direction of the reel is h, and the maximum value of the optical fiber outer diameter specification range is d max .

8. The method for preparing an ultra-high fiber count optical fiber bundle according to claim 7, characterized in that: If the total fiber number N of the ultra-high fiber count optical fiber bundle to be prepared is greater than n, it can be achieved by replacing the drawing tube multiple times to prepare k optical fiber bundles with n fiber counts, wherein N = k × n, and k can be an integer or a decimal.

9. The method for preparing an ultra-high fiber count optical fiber bundle according to claim 1, characterized in that: The limiting device is a U-shaped rod, and a slot is provided on the wire collecting drum. Both ends of the U-shaped rod are inserted into the slot of the wire collecting drum, so that the U-shaped rod limits each circle of the optical fiber on the wire collecting drum.

10. The method for preparing an ultra-high fiber count optical fiber bundle according to claim 1, characterized in that: The outer diameter of the cladding of the optical fiber drawn by the drawing tower is 40μm to 125μm; The number of fibers in an ultra-high fiber count optical fiber bundle is more than 1,000.

11. An ultra-high fiber count optical fiber bundle preparation device, characterized in that: include: The drawing tower is used to draw a single optical fiber; A coating device, used for applying a coating layer on the drawn optical fiber; A curing device, used for curing the coating layer; The fiber collecting device has a fiber collecting drum, which is used to wind only one layer of optical fiber and keep the pitch of the optical fiber wound on the fiber collecting drum consistent; The limiting device is used to press each turn of the optical fiber on the receiving drum onto the receiving drum to prevent the cut optical fiber from falling off the receiving drum when the optical fiber is subsequently cut; A cutter, used for cutting the optical fiber on the receiving drum, so as to cut off each turn of the optical fiber on the receiving drum, thereby obtaining a set number of single-bundle optical fibers for forming an ultra-high fiber count optical fiber bundle; The bundling device is used to bundle all the optical fibers after the cutter cuts the optical fibers on the receiving drum, so as to form the ultra-high fiber count optical fiber bundle.

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