Lightweight multi-fiber cable

Abstract

The application belongs to the field of optical cables, and particularly relates to a lightweight multi-core optical cable. The optical cable comprises, from outside to inside, a sheath layer, a pressure-resistant structure layer and a core wire; the sheath layer is provided with a circular inner cavity, and the pressure-resistant structure layer is wrapped outside the core wire and abuts against the inner wall of the inner cavity; the pressure-resistant structure layer comprises a core portion wrapped outside the core wire, and a plurality of support portions formed by extending the core portion radially outward along the optical cable, the plurality of support portions are arranged uniformly in the circumferential direction outside the core portion, and gaps are formed between adjacent support portions; each support portion is composed of two support ribs, the support ribs are extended from the core portion to abut against the inner wall of the inner cavity of the sheath layer, and the two support ribs of the same support portion are bent towards each other and abut against the surface of the inner wall of the inner cavity. Through the improvement of the pressure-resistant structure, the optical cable can be lightweight while ensuring good pressure resistance, and a larger space is formed in the optical cable, which provides the basis for multi-core.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of optical cable, in particular to a lightweight multi-core optical cable. BACKGROUND

[0002] Optical cable is manufactured to meet the performance specifications of optics, mechanics or environment, which is a communication cable assembly using one or more optical fibers placed in a sheath as a transmission medium and can be used alone or in groups, and it is also one of the common and large quantities of infrastructure required items.

[0003] With the increasing popularity and demand for optical communication, the demand for multi-core optical cable in the market is also increasing. Unlike conventional optical cable, multi-core optical cable has a large number of internal optical fibers, and the conventional protective structure is no longer applicable or has poor applicability. For example, the layer-twisted protective structure, with the increase of the number of cores, the layer inner diameter needs to be increased, and with the increase of the inner diameter, in order to ensure that the stainless steel braid can play a good protective effect, the wire diameter of the stainless steel braid or the thickness thereof needs to be increased, resulting in further increase of the specific gravity of the optical cable, which is very inconvenient for use and transportation. SUMMARY

[0004] In order to solve the problems of poor mechanical properties of existing multi-core optical cable, especially poor compression resistance, and many use defects of existing protective structures such as stainless steel braid protective structure, the present application provides a lightweight multi-core optical cable.

[0005] The main purpose of the present application is to:

[0006] I. Ensure that the optical cable has good compression resistance;

[0007] II. Ensure that the optical cable has a lighter specific gravity;

[0008] III. Suitable for multi-core design inside the optical cable.

[0009] A lightweight multi-core optical cable comprises:

[0010] A sheath layer, a compression-resistant structure layer and a core wire are sequentially arranged from outside to inside;

[0011] The sheath layer is provided with a circular inner cavity, and the compression-resistant structure layer is wrapped outside the core wire and abuts against the inner wall of the inner cavity;

[0012] The compression-resistant structure layer comprises a core portion wrapped outside the core wire, and a plurality of support portions formed by extending the core portion outward along the radial direction of the optical cable, the plurality of support portions are uniformly distributed around the outer periphery of the core portion, and a gap is formed between adjacent support portions;

[0013] The support part consists of two support ribs, which extend from the core and abut against the inner wall of the inner cavity of the sheath layer. The two support ribs of the same support part bend towards each other and abut against the inner wall surface of the inner cavity.

[0014] As a preferred option

[0015] The number of support components should be an odd number.

[0016] As a preferred option

[0017] The inner end of the adjacent support rib is connected to the outer surface of the core.

[0018] As a preferred option

[0019] The adjacent support ribs are connected in a cross shape outside the core, and a crack is formed on the surface of the core between the two support ribs.

[0020] As a preferred option

[0021] A metal reinforcing wire is inserted into the crack.

[0022] As a preferred option

[0023] The support portion of the compressive structural layer is also provided with arc-shaped strips.

[0024] As a preferred option

[0025] The two ends of the arc-shaped strip abut against the inner sides of the two support ribs of the same support part, and the middle part arches outward.

[0026] As a preferred option

[0027] The core wire is composed of several optical fibers wrapped in a bundle tube.

[0028] The beneficial effects of this invention are:

[0029] This invention improves the compressive strength structure, enabling the optical cable to be lightweight while maintaining good compressive strength, and also creating a larger space inside the optical cable, providing a basis for multi-core design. Attached Figure Description

[0030] Figure 1 This is one of the structural schematic diagrams of the optical cable of the present invention;

[0031] Figure 2 This is the second schematic diagram of the optical cable structure of the present invention;

[0032] Figure 3 This is a schematic diagram of an existing stranded optical cable structure;

[0033] Figure 4 for Figure 1 The diagram shows the stress deformation of the optical cable of the present invention.

[0034] Figure 5 is Figure 2 The schematic diagram of the stress deformation of the optical cable of the present invention shown

[0035] In the figure: 100 sheath layer, 101 inner cavity, 200 compressive structure layer, 201 core part, 202 support part, 2021 support rib, 2022 "convex" shaped groove, 20221 groove cavity, 20222 groove opening, 203 arc-shaped strip, 204 split hole, 2041 metal strengthening wire, 300 core wire, 301 tube, 302 optical fiber wire Specific embodiments

[0036] The following further clearly and detailedly describes the present invention in combination with specific embodiments and the drawings of the specification. Those of ordinary skill in the art will be able to implement the present invention based on these descriptions. In addition, the embodiments of the present invention involved in the following description are usually only part of the embodiments of the present invention, rather than all of the embodiments. Therefore, all other embodiments obtained by those of ordinary skill in the art without creative efforts based on the embodiments of the present invention should fall within the scope of protection of the present invention

[0037] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "thickness", "upper", "lower", "horizontal", "top", "bottom", "inner", "outer", "circumferential", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present invention. 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, and the meaning of "several" is to represent one or more

[0038] In the present invention, unless otherwise clearly specified and limited, the terms "installation", "connection", "connection", "fixation" and other terms should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or integrated; it can be a mechanical connection, an electrical connection or communication with each other; it can be directly connected, or indirectly connected through an intermediate medium, and can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly limited. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations

[0039] Unless otherwise specified, the raw materials used in the embodiments of the present invention are all commercially available or raw materials that can be obtained by those skilled in the art; unless otherwise specified, the methods used in the embodiments of the present invention are all methods mastered by those skilled in the art

[0040] Embodiment

[0041] A lightweight multi-core optical cable as shown in Figure 1 and Figure 2 specifically includes:

[0042] A sheath layer 100, a compressive structure layer 200, and a core wire 300 arranged in sequence from outside to inside;

[0043] The core wire 300 is composed of a tube 301 wrapping several optical fiber wires 302;

[0044] The sheath layer 100 is provided with a circular inner cavity 101, and the compressive structure layer 200 is wrapped outside the core wire 300 and abuts against the inner wall of the inner cavity 101 to separate the core wire 300 and the sheath layer 100, which can prevent the external force from being directly conducted through the sheath layer 100 and acting on the core wire 300 after the optical cable is stressed;

[0045] In order to further protect the core wire 300 and block the external force conduction, the following compressive structure layer 200 is specifically adopted:

[0046] It includes a core part 201 wrapped outside the core wire 300, and several support parts 202 formed by the core part 201 extending radially outward along the optical cable. The several support parts 202 are evenly distributed circumferentially outside the core part 201. Each support part 202 is composed of two support ribs 2021 in the same direction. The inner end of the support rib 2021 is connected to the core part 201, and the outer end extends to abut against the inner wall of the inner cavity 101 of the sheath layer 100. And the two support ribs 2021 of the same support part 202 are bent towards each other and abut against the inner wall surface of the inner cavity 101, so that each support part 202 presents a "convex"-shaped groove 2022 similar to a "convex" shape in the radial cross-section of the optical cable;

[0047] In addition, the number of the support parts 202 should be an odd number. Considering the setting form and structural characteristics of the support parts 202, gaps will be formed between adjacent support parts 202. Using an odd number of support parts 202 can make the "convex"-shaped groove 2022 of each support part 202 correspond to the gap in the axisymmetric direction of the radial cross-section of the optical cable. A better choice should be three or five;

[0048] The support parts 202 are arranged closely to each other, but the adjacent support parts 202 can adopt the following two connection forms:

[0049] Form 1, the inner ends of the support ribs 2021 of the adjacent support parts 202 are connected to the outer surface of the core part 201 to form a tight connection structure. In this form, when the optical cable shown in Figure 1 is subjected to external forces on the upper and lower sides, as shown in Figure 4As shown, the upper support portion 202's support ribs 2021 open to both sides, generating an approximately tangential force on the inner end of the upper support rib 2021 in the two adjacent support portions 202 (lower left and lower right support portions 202). This causes the stressed support rib 2021 to tend to open due to the downward movement of its inner end. At the same time, the force on the optical cable is usually radially symmetrical. Figure 1 When the lower side of the optical cable shown is subjected to force, as... Figure 4 As shown, the lower notch opens, which actually causes the lower support ribs 2021 of the two support parts 202 on the lower left and lower right sides to retract inward, thus causing the two support parts 202 on the lower left and lower right sides to have an "upward deflection" tendency. In the above process, the deformation of the upper support part 202, the deflection of the two support parts 202 on both sides, and the friction caused by the deformation and displacement of the parts of each support rib 2021 that bend and abut against the wall surface of the inner cavity 101 can greatly offset and buffer the external force, thus producing a very good buffering effect. Specifically, with Figure 3 The existing stainless steel braided protective stranded optical cables are compared under pressure at the same dB (fiber loss) to compare their compressive strength.

[0050] like Figure 1 and Figure 3 As shown, the outer diameter Od1, core wire diameter Od2, and sheath layer thickness Th1 of the optical cable used in this invention are equal to those of the stranded optical cable used in the comparison. The thickness Th2 of the compressive strength layer 200 of this invention is equal to the total thickness (Th3+Th4) of the inner sheath Th3 and the stainless steel braided mesh protective layer Th4 of the stranded optical cable. The materials of the sheath layer 100 and the inner sheath of the cable used in the comparison are the same, the core wire 300 uses the same batch of core wire 300, the compressive strength layer 200 uses commercially available conventional elastic silicone rubber, and the stainless steel braided mesh protective layer uses commercially available 300... 2. Stainless steel braided mesh protective layer. The ratio of the length (1m) of the optical cable of the present invention to that of the stranded optical cable is 0.71 to 0.73:1. After testing, under constant dB conditions (0 to 0.5 dB test, test light wavelengths of 1310nm and 1550nm), the stress on both is basically in a constant ratio. That is, the stress on the present invention is approximately 96 to 98% of that on the stranded optical cable used in comparison. Without adopting a rigid stranded protective structure, it achieves a compressive strength level that is basically equivalent to that of the stranded optical cable, while significantly reducing the specific gravity of the optical cable.

[0051] Form two, such as Figure 2 As shown, adjacent support ribs 2021 of the support portion 202 are connected in a cross-shaped manner outside the core portion 201, and a slit 204 is formed on the surface of the core portion 201 between the two support portions 202. In this configuration, the support ribs 2021 of the support portion 202 on the radial cross section of the optical cable are arranged in a longer columnar form, and, as shown... Figure 2When the optical cable shown is subjected to external forces on its upper and lower sides, such as Figure 5 As shown, when the upper support rib 2021 transmits the supporting force to the adjacent support rib 202, it no longer acts on its inner end, but rather exhibits a squeezing and pushing action. This causes the outer end of the upper support rib 2021 in the two adjacent support ribs 202 (lower left and lower right support ribs 202) to deform and displace downwards under the squeezing and pushing action. At the same time, the force on the optical cable is usually radially symmetrical. Figure 1 When the lower side of the optical cable is subjected to force, the lower notch opens, which actually causes the lower support ribs 2021 of the two support parts 202 on the lower left and lower right sides to shrink inward. This causes the two support parts 202 on the lower left and lower right sides to deform and displace upward, resulting in both the lower left and lower right support parts 202 showing a contraction trend. As the contraction proceeds, the bent parts of the support ribs 2021 of these two support parts 202 may come into contact. After contact, a more effective pressure-resistant structure will be formed. That is, compared with the first form, the second form makes the optical cable more "flexible" and relatively easier to "flatten" and deform, but with stronger ultimate pressure resistance.

[0052] Furthermore, in the crack 204 created by the second configuration, a device such as... Figure 2 The metal reinforcing wire 2041 shown is a common linear reinforcing structure used in optical cables. It is filled with fine wires adapted to the specifications of the slit 204. The setting of the metal reinforcing wire 2041 can further improve the compressive strength of the Type II optical cable.

[0053] like Figure 2 and Figure 4As shown, the outer diameter Od1, core wire diameter Od2, and sheath layer thickness Th1 of the optical cable used in this invention are equal to those of the stranded optical cable used in the comparison. The thickness Th2 of the compressive strength layer 200 of this invention is equal to the total thickness (Th3+Th4) of the inner sheath Th3 and the stainless steel braided mesh protective layer Th4 of the stranded optical cable. The materials of the sheath layer 100 and the inner sheath of the cable used in the comparison are the same. The core wire 300 uses the same batch of core wire 300. The compressive strength layer 200 uses commercially available conventional elastic silicone rubber. The stainless steel braided mesh protective layer uses commercially available 302 stainless steel braided mesh protective layer. The reinforcing wire uses 302 stainless steel metal wire. The length of the optical cable of the second form of this invention (1m) is the same as that of the stranded optical cable. With a specific gravity of 0.76–0.78:1, after testing, under constant dB conditions (0–0.5 dB test, test light wavelengths of 1310 nm and 1550 nm), the forces on the two are basically in a non-constant ratio. That is, when the dB loss is 0–0.1 dB, the force on the optical cable of the present invention is approximately 93–95% of that on the stranded optical cable. However, this ratio increases rapidly during the 0.1–0.2 dB period. During the 0.3–0.5 dB test, the force on the optical cable of the present invention is 102–103% of that on the stranded optical cable. Without using a rigid stranded protective structure, when subjected to a large external force, the optical cable of the present invention reduces the specific gravity of the optical cable and significantly enhances its compressive strength.

[0054] As can be seen from the above, for the optical cable of the present invention, the deformation and displacement buffering of the structure can produce a relatively excellent pressure buffering effect, thereby enabling the optical cable to maintain a relatively good pressure resistance without the use of high-density stainless steel braided mesh, maintaining the lightweight characteristics of the optical cable, and its huge internal space can also be used to accommodate more optical fiber lines 302. The non-solid contact setting between the core wire 300 and the sheath layer 100 can effectively block the direct transmission of external forces.

[0055] Furthermore,

[0056] The support portion 202 of the compressive strength structure layer 200 is also provided with arc-shaped strips 203;

[0057] The "convex"-shaped groove 2022 is composed of two parts, namely a notch 20222 and a cavity 20221 that are interconnected. The notch 20222 is its opening, and the cavity 20221 is the inner layer close to the core 201. The arc-shaped strip 203 is arranged in the cavity 20221. It is arc-shaped in the radial cross-section of the optical cable. Its two ends abut against the inner sides of two support ribs 2021 of the same support part 202, and the middle part arches outwards. After the arc-shaped strip 203 is arranged, the overall compressive threshold of the optical cable can be further improved. For the optical cable arranged in Form 1, since the lower support ribs 2021 of the support parts 202 on the lower left side and the lower right side are the directly stressed parts, their deformation displacements are usually larger than those of the upper support ribs 2021. When the support ribs 2021 of the two support parts 202 on the lower left side and the lower right side produce a deformation displacement difference and a certain degree of "shrinking inwards", the arc-shaped strip 203 can produce a support and secondary deformation buffering effect, forming a secondary deformation buffer. For the optical cable arranged in Form 2, since the support parts 202 on the lower left side and the lower right side both show a trend of "shrinking inwards", the arc-shaped strip 203 can play a good support buffering role, improve the compressive capacity of the optical cable, and reduce the deformation of the optical cable to a certain extent.

Claims

1. A lightweight multi-core optical cable, characterized in that, include: The outermost layer, the compression-resistant structural layer, and the core wire are arranged sequentially from the outside to the inside. The sheath layer has a circular inner cavity, and the pressure-resistant structural layer covers the outside of the core wire and abuts against the inner wall of the inner cavity; The pressure-resistant structural layer includes a core covering the outside of the core wire, and several support parts extending outward from the core along the radial direction of the optical cable. The support parts are evenly distributed around the core, and gaps are formed between adjacent support parts. The support part consists of two support ribs. The support ribs extend from the core and abut against the inner wall of the inner cavity of the sheath layer. The two support ribs of the same support part bend towards each other and abut against the inner wall surface of the inner cavity. The adjacent support ribs are connected in a cross shape outside the core, and a crack is formed on the surface of the core and between the two support ribs. The support portion of the compressive structural layer is also provided with arc-shaped strips; The two ends of the arc-shaped strip abut against the inner sides of the two support ribs of the same support part, and the middle part arches outward.

2. The lightweight multi-core optical cable according to claim 1, characterized in that, The number of support components should be an odd number.

3. The lightweight multi-core optical cable according to claim 1, characterized in that, The inner end of the adjacent support rib is connected to the outer surface of the core.

4. A lightweight multi-core optical cable according to claim 1, characterized in that, A metal reinforcing wire is inserted into the crack.

5. The lightweight multi-core optical cable according to any one of claims 1 to 4, characterized in that, The core wire is composed of several optical fibers wrapped in a bundle tube.

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