Optical cable with outer sheath and manufacturing method thereof

Abstract

The invention belongs to the related field of optical communication transmission technology, and discloses an optical cable with an outer sheath, a plurality of grooves are processed on the outer surface of the outer sheath of the optical cable, and the grooves spirally extend along the longitudinal direction of the optical cable and are uniformly distributed along the circumferential direction of the optical cable. The invention further discloses a corresponding manufacturing method. Meanwhile, some key machining parameters of the groove are optimally designed. According to the invention, the rigidity of the optical cable is reduced, the bending performance of the optical cable is improved, the bending radius of the optical cable is properly reduced, and the grooves can reduce the contact area between the optical cable and the pipeline when the optical cable is laid in the pipeline, so that the frictional resistance is reduced, and the laying construction of the optical cable product is greatly facilitated.

Description

Technical Field

[0001] The present invention belongs to the field of optical communication transmission technology, and more specifically, relates to an optical cable with an outer sheath and a manufacturing method thereof. Background Art

[0002] As a light transmission tool, optical cable encapsulates optical fiber in a sheath so that it can be bent without breaking. Optical fiber must be covered by several layers of protective structure before use to prevent various damages to the optical fiber from the surrounding environment. Among them, the optical cable sheath is the outermost protective layer of the optical cable. It is usually made of polyethylene, steel or aluminum bonding materials and has a smooth round surface. It is used to protect the optical cable from physical and chemical damage during laying and transportation. It has the characteristics of waterproof, shear resistance, and tensile resistance.

[0003] In the prior art, technical improvements to the optical cable sheath mainly revolve around how to improve its strength, or focus more on improving flame retardancy or facilitating processing. For example, CN202110297634.8 discloses a high-strength leather-wire optical cable, in which a groove that shrinks from the outside to the inside is provided on the outer surface of the optical cable sheath, and the outer sheath and the inner sheath are made of wear-resistant resin and elastomeric resin, respectively, which can improve the friction resistance and puncture resistance of the optical cable sheath layer to foreign matter or sharp objects. For another example, WO2004 / 079424A and CN201110140506.9 respectively disclose an optical cable and a method for manufacturing the same, in which the sheaths of these optical cables have a textured outer surface, which correspondingly achieves the purpose of increasing the air delivery distance and air delivery speed.

[0004] However, further research shows that the bending performance of optical cable products is also one of the important indicators that affect the installation. Specifically, the sheath material of existing optical cable products has a certain hardness, which will produce torsional resistance when the optical cable is bent, which will have an adverse effect on the bending performance of the optical cable, increase its bending radius, and be unfavorable for the installation of optical cables in bends; in addition, in the scenario of pipeline installation, the friction resistance between the sheath and the pipeline due to the certain contact area will also bring difficulties to the construction. This situation is common in the construction process of air-blown optical cables and other optical cables laid in pipelines.

[0005] Therefore, the technical problem of reducing the bending radius of optical cable products and reducing the friction resistance between them and the pipeline during laying has not been effectively solved, which has had a great impact on the quality and efficiency of optical cable laying. Summary of the invention

[0006] In view of one or more of the above defects or improvement needs in the prior art, the present invention provides an optical cable with an outer sheath and a method for manufacturing the same, wherein a spirally extending groove is provided on the surface of the outer sheath, and the action mechanism and key processing parameters thereof are studied and designed. Accordingly, not only can the spring effect be utilized to improve the bending performance of the optical cable and reduce its bending radius, but also the contact area between the optical cable and the pipeline can be reduced when the optical cable is laid in the pipeline, so that the friction resistance is reduced, thereby greatly facilitating the installation of the optical cable product.

[0007] To achieve the above object, according to one aspect of the present invention, there is provided an optical cable with an outer sheath, characterized in that a plurality of grooves are processed on the outer surface of the outer sheath, the grooves extend spirally along the longitudinal direction of the optical cable and are evenly distributed along the circumference of the optical cable.

[0008] Through the above conception, since the above-mentioned grooves are processed on the surface of the outer sheath of the optical cable, on the one hand, these grooves extend in a spiral shape along the longitudinal direction of the optical cable to form a spring effect, which not only reduces the rigidity of the optical cable, but also helps to improve the bending performance of the optical cable, so that the bending radius of the optical cable is appropriately reduced, thereby better overcoming the influence of the torsional resistance generated when the optical cable is bent on the laying of the bend in the prior art; on the other hand, these grooves can also reduce the contact area between the optical cable and the pipeline when it is laid and installed in the pipeline, so that the friction resistance is reduced, thereby further facilitating the laying construction of the optical cable.

[0009] As a further preferred embodiment of the present invention, the processing parameters of the groove are designed as follows: groove width 1 mm to 3 mm, groove depth 0.5 mm to 1.5 mm, spiral pitch 50 mm to 500 mm.

[0010] As a further preferred embodiment of the present invention, 5 to 50 grooves are evenly distributed along the circumference of the optical cable.

[0011] As a further preferred embodiment of the present invention, the grooves are preferably evenly distributed in 20 strips along the circumference of the optical cable, and have a groove width of 1.5 mm, a groove depth of 1.0 mm, and a spiral pitch of 50 mm.

[0012] As a further preferred embodiment of the present invention, the outer sheath is made of polyethylene material and may include a metal tape, and the number of layers is one or more than two layers.

[0013] As a further preferred embodiment of the present invention, the above-mentioned optical cable comprises a cable core and an outer sheath from the inside to the outside, wherein the cable core comprises a central reinforcement core and a plurality of sleeves twisted around the central reinforcement core, and a plurality of optical fibers are respectively placed in each sleeve; and cable paste for water blocking can be filled between the sleeve and the central reinforcement core and between each of the sleeves.

[0014] As a further preferred embodiment of the present invention, a water blocking layer may be provided between the outer sheath and the cable core, and an inner sheath may be provided between the water blocking layer and the outer sheath.

[0015] According to another aspect of the present invention, a corresponding manufacturing method is also provided, characterized in that it comprises the following steps:

[0016] S1, processing to form a cable core;

[0017] S2. An outer sheath is arranged outside the cable core, and a plurality of grooves are processed on the outer surface of the outer sheath, wherein the grooves extend in a spiral shape along the longitudinal direction of the optical cable and are evenly distributed along the axial direction of the optical cable.

[0018] As a further preferred embodiment of the present invention, the groove is preferably extruded by a mold installed in a rotating head of an extruder, and its processing parameters are designed as follows: groove width 1mm to 3mm, groove depth 0.5mm to 1.5mm, spiral pitch 50mm to 500mm.

[0019] As a further preferred embodiment of the present invention, a water blocking layer may be provided between the cable core and the outer sheath, and an inner sheath may be provided between the water blocking layer and the outer sheath.

[0020] In general, the above technical solution conceived by the present invention has the following technical advantages compared with the prior art:

[0021] (1) The present invention provides multiple grooves on the surface of the outer sheath of the optical cable and makes targeted improvements to the specific shape and distribution of the grooves, which together with other components of the optical cable can form a spring effect, which not only reduces the rigidity of the optical cable, but also helps to improve the bending performance of the optical cable, so that the bending radius of the optical cable is appropriately reduced, and the contact area between the surface of the optical cable and the pipeline is reduced, thereby better and simultaneously overcoming the adverse effects caused by the friction resistance and torsional resistance of the optical cable when the pipeline is laid and bent in the prior art;

[0022] (2) The present invention also makes further optimization designs for some key processing indicators of the above-mentioned spiral grooves, such as spiral pitch, groove width and depth, and circumferential uniform distribution number, by designing some comparative examples and making comparisons, and accordingly can obtain optical cable products with better comprehensive performance; for example, some actual tests show that compared with the optical cable without the above-mentioned spiral grooves, the rigidity of the optical cable of this scheme can be increased from 5.16N·m 2 Reduced to 3.31N·m 2 The bending radius can be reduced from 110mm to about 50mm, and the friction resistance of laying can also be significantly reduced, so it is particularly suitable for air-blown optical cables and other optical cables laid in pipelines;

[0023] (3) The optical cable product of the present invention is easy to process and can be manufactured using existing production equipment. It has good quality controllability and can be used in various complex environments. It helps to improve the overall performance of the optical cable product and greatly facilitates the installation of the optical cable. Therefore, it has good practical value and application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 is a radial structural cross-sectional view of an optical cable with an outer sheath according to a preferred embodiment of the present application;

[0025] Figure 2 is a process flow chart for manufacturing an optical cable with an outer sheath of the present application;

[0026] Throughout the drawings, the same reference numerals are used to denote the same elements or structures, wherein:

[0027] 1-outer sheath; 2-casing; 3-central reinforcing core; 4-water blocking layer; 5-inner sheath. DETAILED DESCRIPTION

[0028] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention. In addition, the technical features involved in each embodiment of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0029] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0030] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0031] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0032] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0033] Figure 1 is a radial structural cross-sectional view of an optical cable with an outer sheath according to a preferred embodiment of the present application, and will be referred to below Figure 1 To explain the present invention in more detail.

[0034] See also Figure 1 According to a preferred embodiment of the present application, the optical cable comprises at least a cable core and an outer sheath from the inside to the outside, wherein the cable core may have a variety of specific structural forms, all of which are applicable to the outer sheath in the present application. Figure 1 As shown in the figure, the cable core may include a central reinforcing core 3 and a plurality of sleeves 2 twisted around the central reinforcing core 3, wherein a plurality of optical fibers are respectively placed in each sleeve 2; a cable paste for water blocking may be filled between the sleeve 2 and the central reinforcing core 3 and between each sleeve 2. In addition, a water blocking layer 4 may be processed and arranged between the cable core and the outer sheath 1, and an inner sheath 5 may be processed and arranged between the water blocking layer 4 and the outer sheath 1.

[0035] As one of the key improvements of the present application, a plurality of grooves are processed on the outer surface of the outer sheath 1, and the grooves extend in a spiral shape along the longitudinal direction of the optical cable and are evenly distributed along the circumference of the optical cable. The outer sheath can be made of polyethylene material only, or it can contain metal belts, etc. as needed, and the number of layers is one or more than two layers. The reason for this design is mainly to solve the adverse effects caused by friction resistance, torsional resistance, etc. when the optical cable is laid in the pipeline and bent in the prior art. This technical problem has not received enough attention and lacks sufficient technical means to solve it.

[0036] More specifically, on the one hand, these grooves extend in a spiral shape along the longitudinal direction of the optical cable to form a spring effect, which not only reduces the rigidity of the optical cable, but also helps to improve the bending performance of the optical cable, so that the bending radius of the optical cable is appropriately reduced, thereby better overcoming the influence of the torsional resistance generated when the optical cable is bent on the laying of the bend in the prior art; on the other hand, these grooves can also reduce the contact area between the optical cable and the pipeline when it is laid and installed in the pipeline, so that the friction resistance is reduced, thereby further facilitating the laying of the optical cable.

[0037] As another key improvement of the present invention, the present invention further studies and optimizes the key processing parameters of the above grooves. According to a preferred embodiment of the present invention, some key processing parameters of the grooves are designed as follows: groove width 1mm to 3mm, groove depth 0.5mm to 1.5mm, spiral pitch 50mm to 500mm. In addition, 5 to 50 grooves are evenly distributed along the circumference of the optical cable.

[0038] To analyze more specifically, the concave grooves can be designed in three forms: transverse, longitudinal and spiral. Among them, the longitudinal concave grooves can reduce the friction resistance between the optical cable and the pipeline during laying, but are insufficient in improving the bending performance of the optical cable; although the transverse concave grooves can improve the bending performance of the optical cable, it is not conducive to reducing the friction resistance during laying, and combined with the actual production of optical cables, the transverse concave grooves are not easy to process, so they are not considered; finally, the present application specifically chooses to design the groove into a spiral shape extending along the longitudinal direction of the optical cable, that is, the axial direction. This not only improves the bending performance of the optical cable, but also reduces the friction resistance during laying, and is easy to implement in production, so it becomes the preferred solution.

[0039] After optimizing the groove distribution of the present application, through testing and comparison between some actual comparative examples, it can be found that some key processing parameters also play a relatively important role. Some specific comparative examples are given below and are uniformly explained in Table 1.

[0040]

[0041]

[0042] Table 1

[0043] Among them, spiral 10*50 means that spiral grooves are opened along the longitudinal direction of the outer sheath of the optical cable, and 10 grooves are evenly distributed in the circumferential direction, and the spiral pitch is 50mm, and so on. In addition, the test of the bending radius can be achieved by using corresponding equipment. Weights of a certain weight are hung on both ends of the optical cable sample passing through the fixed ring. The optical cable bends under the action of the weight. The length of the optical cable sample is certain (for example, 2 meters), the length of both ends is the same, and the weight of the weights is the same to keep the bending force unchanged. The bending radius can be obtained by measuring the distance between the two ends of the optical cable.

[0044] According to the different comparative proportions listed in Table 1 above, taking into account the performance improvement and processing difficulty goals that the optical cable is expected to achieve in this application, the number of spiral grooves should not be too few or too many, and the spiral pitch needs to be as small as possible. In addition, the width and depth of the grooves also affect the improvement of the performance of the optical cable. Therefore, the key parameters of the above grooves are finally designed as follows in this application: the grooves are evenly distributed along the circumference of the optical cable, with a spiral pitch of 50mm to 500mm; the groove width is 1mm to 3mm, and the groove depth is 0.5mm to 1.5mm.

[0045] In addition, in a preferred embodiment, the key parameters of the groove are designed as follows: 20 grooves are evenly distributed along the circumference of the optical cable, the spiral pitch is designed to be 50 mm, the groove width is 1.5 mm, and the groove depth is 1.0 mm. Actual tests have shown that the above processing parameters can achieve a better balance between improving the bending performance of the optical cable and reducing the friction resistance during laying, and are easy to implement in production, so they become the preferred solution.

[0046] The following is a detailed description of a method for manufacturing an optical cable with an outer sheath of the present application, which may include the following steps:

[0047] Processing of the cable core: The cable core can adopt a variety of structures, all of which are suitable for the outer sheath in this application. As an illustrative example, optical fibers with different core numbers can be placed in separate sleeves, and then the sleeves are twisted around the central reinforcing core and fixed with yarn;

[0048] Processing of the outer sheath: an outer sheath is arranged outside the cable core, and at the same time, a plurality of grooves extending in a spiral shape along the longitudinal direction of the optical cable and uniformly distributed along the axial direction of the optical cable are formed on the outer surface of the outer sheath.

[0049] According to a preferred embodiment of the present application, the grooves can be extruded by a die installed in a rotating head of an extruder, and the die is designed according to the size, quantity and other parameters of the required grooves. An inner sheath may be extruded inside the outer sheath. If there is no inner sheath, it is necessary to ensure that the depth of the groove is less than the thickness of the outer sheath through reasonable die design, and the difference is not less than the minimum sheath thickness required for the optical cable.

[0050] According to another preferred embodiment of the present invention, some key processing parameters of the groove are designed as follows: groove width 1mm-3mm, groove depth 0.5mm-1.5mm, spiral pitch 50mm-500mm; 5-50 grooves are evenly distributed along the circumference of the optical cable. In addition, according to a best embodiment of the present invention, 20 grooves are evenly distributed along the circumference of the optical cable, the spiral pitch is designed to be 50mm, the groove width is 1.5mm, and the groove depth is 1.0mm.

[0051] In summary, according to the technical solution of the present invention, by opening a spirally extending groove on the surface of the outer sheath, and studying and designing its mechanism of action and its key processing parameters, etc., it can not only utilize its spring effect to improve the bending performance of the optical cable and reduce its bending radius, but also reduce the contact area between the optical cable and the pipeline when it is laid in the pipeline, so that the friction resistance is reduced, thereby greatly facilitating the installation of the optical cable product. In addition, the optical cable product of the present invention is easy to process, can be manufactured using existing production equipment, has good quality controllability, can be used in various complex environments, and helps to improve the overall performance of the optical cable product, so it has good practical value and application prospects.

[0052] It will be easily understood by those skilled in the art that the above description is only a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present application shall be included in the scope of protection of the present application.

Claims

1. An optical cable having an outer sheath, characterized in that: A plurality of grooves are processed on the outer surface of the outer sheath. The grooves extend in a spiral shape along the longitudinal direction of the optical cable and are evenly distributed along the circumference of the optical cable.

2. The optical cable according to claim 1, characterized in that The processing parameters of the groove are designed as follows: groove width 1mm-3mm, groove depth 0.5mm-1.5mm, spiral pitch 50mm-500mm.

3. The optical cable according to claim 2, characterized in that The grooves are evenly distributed in a number of 5 to 50 along the circumference of the optical cable.

4. The optical cable according to claim 3, characterized in that The grooves are evenly distributed in 20 strips along the circumference of the optical cable, and have a groove width of 1.5 mm, a groove depth of 1.0 mm, and a spiral pitch of 50 mm.

5. The optical cable according to any one of claims 1 to 4, characterized in that: The outer sheath is made of polyethylene material and may include a metal tape, and the number of layers is one or more than two layers.

6. The optical cable according to any one of claims 1 to 5, characterized in that: The above-mentioned optical cable includes a cable core and an outer sheath from the inside to the outside, wherein the cable core includes a central reinforcing core and multiple sleeves twisted around the central reinforcing core, and multiple optical fibers are concentratedly placed in each sleeve; cable paste for water blocking can be filled between each sleeve and between the sleeve and the central reinforcing core.

7. The optical cable according to claim 6, characterized in that A water blocking layer may be arranged between the outer sheath and the cable core, and an inner sheath may be arranged between the water blocking layer and the outer sheath.

8. A method for manufacturing an optical cable having an outer sheath, characterized in that: The following steps are involved: S1, processing to form a cable core; S2. An outer sheath is arranged outside the cable core, and a plurality of grooves are processed on the outer surface of the outer sheath, wherein the grooves extend in a spiral shape along the longitudinal direction of the optical cable and are evenly distributed along the axial direction of the optical cable.

9. The manufacturing method according to claim 8, characterized in that: The groove is preferably formed by extrusion using a mold installed in a rotating head of an extruder, and its processing parameters are designed as follows: groove width 1mm to 3mm, groove depth 0.5mm to 1.5mm, spiral pitch 50mm to 500mm.

10. The manufacturing method according to claim 8 or 9, characterized in that: A water-blocking layer may be disposed between the cable core and the outer sheath, and an inner sheath may be disposed between the water-blocking layer and the outer sheath.

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