Light flame-retardant sensing optical cable capable of rapidly positioning

Abstract

The invention belongs to the related field of optical communication transmission technology, and discloses a light flame-retardant sensing optical cable capable of fast positioning, the sensing optical cable comprises a sensing optical fiber, a waterproof layer, a reinforcing element and a flame-retardant layer from inside to outside, the side surface of the sensing optical cable is provided with a self-adhesive layer, the sensing optical fiber is used for performing real-time sensing on external disturbance, and the flame-retardant layer is provided with a self-adhesive layer. The waterproof layer is arranged on the periphery of the sensing optical fiber and plays a waterproof role, the reinforcing element is used for improving the mechanical performance of the whole sensing optical cable, the flame-retardant layer is arranged on the outermost layer of the sensing optical cable and plays a flame-retardant role, and the self-adhesive layer is used for attaching the sensing optical cable to a target object. According to the sensing optical cable, it is ensured that the sensing optical cable can be installed in a non-underground laying mode in an efficient, reliable and convenient-to-control mode, the sensing optical cable has the advantages of being high in positioning precision, light, good in flame retardance and the like, meanwhile, the later maintenance work is greatly facilitated, and therefore the sensing optical cable is especially suitable for application occasions such as accident positioning of expressways and elevated roads.

Description

Technical Field

[0001] The present invention belongs to the field of optical communication transmission technology, and more specifically, relates to a fast-positioning lightweight flame-retardant sensing optical cable. Background Art

[0002] As an important part of the national transportation road network, highways, elevated roads, etc. play a significant role in improving traffic efficiency, improving regional traffic conditions, and facilitating travel services. Such roads are more prone to traffic accidents due to their own road conditions, design, and high driving speed. Therefore, in order to protect vehicles from falling sideways from the road when there are safety accidents such as vehicle collisions, guardrails are generally installed on both sides of such roads, which mainly play the role of absorbing energy, while also providing good protection for vehicles and drivers and passengers. The requirements for such guardrails are generally that they are not easy to be destroyed, and they need to increase a certain degree of aesthetics, and have the characteristics of anti-corrosion, anti-aging, and anti-sun.

[0003] Due to the widespread use of guardrails on highways, elevated roads or other similar roads, the maintenance of guardrails is critical. At present, the methods of discovering damage, collapse and breakage of guardrails are generally video surveillance, patrols by dedicated personnel, and reports from enthusiastic people, which is difficult to achieve timely and efficient full coverage. Once a traffic accident such as collision with guardrails is discovered, it is difficult to accurately locate the accident site due to the lack of reference objects, which makes it difficult for casualties to receive timely treatment. Therefore, it is also necessary to provide alarm services for collision with guardrails for various roads.

[0004] In response to the above technical problems, the prior art generally chooses to bury vibration sensing optical cables under the guardrails to locate the location of the accident by monitoring the changes in light intensity when the vehicle collides, or, if the guardrail collapses or breaks under the collision, the precise location can be determined by the signal vanishing point. However, further research shows that the prior art still has the following defects or deficiencies: First, since such optical cables are buried underground, the perception of vibration is unclear, and they are easily affected by the vibration interference caused by large vehicles traveling at high speeds, which may lead to insufficient positioning accuracy; second, such sensing optical cables need to be planned in the early stage of road design, otherwise, when they are later laid or maintained, the road surface needs to be dug up, which has a serious impact on the smooth flow of the road and causes great inconvenience to later maintenance.

[0005] Accordingly, it is necessary to make further improvements in this field to better meet the comprehensive needs of positioning various types of road locations. Summary of the invention

[0006] In response to one or more of the above defects or needs in the prior art, the present invention provides a fast-positioning lightweight flame-retardant sensing optical cable, in which the internal structure composition and setting method of the sensing optical cable are re-studied and designed, and targeted improvements are made to some key performance indicators and other aspects. This not only ensures that the sensing optical cable can be installed in a non-underground manner in an efficient, reliable and easy-to-control manner, but also has the advantages of high positioning accuracy, light weight, good flame retardancy, etc., and greatly facilitates subsequent maintenance work. Therefore, it is particularly suitable for application scenarios such as accident location on highways and elevated roads.

[0007] To achieve the above object, according to the present invention, a fast-positioning lightweight flame-retardant sensing optical cable is provided, characterized in that the sensing optical cable comprises a sensing optical fiber, a water-blocking layer, a reinforcing element and a flame-retardant layer from the inside to the outside, and a self-adhesive layer is provided on the side, wherein:

[0008] The sensing optical fiber is used to perform real-time sensing of external disturbances;

[0009] The water-blocking layer is arranged on the periphery of the sensing optical fiber and plays a waterproof role;

[0010] The reinforcing element is used to improve the mechanical properties of the entire sensing optical cable;

[0011] The flame retardant layer is arranged on the outermost layer of the sensor optical cable and plays a flame retardant role;

[0012] In addition, the above-mentioned sensing optical cable is installed on the target object through the self-adhesive layer.

[0013] As a further preferred embodiment of the present invention, the sensing optical fiber may adopt a loose tube structure, wherein the optical fibers are centrally placed in the tube, and then a water-blocking tape is longitudinally wrapped on the outside of the tube and bound with a water-blocking yarn.

[0014] As a further preferred embodiment of the present invention, the sensing optical fiber may be a tight-buffered optical fiber to further reduce the overall size of the sensing optical cable, wherein a water-blocking yarn is placed parallel to the outside of the tight-buffered optical fiber or a water-blocking tape is used to longitudinally wrap the optical fiber.

[0015] As a further preferred embodiment of the present invention, the reinforcing elements are made of fiber-reinforced composite materials and are arranged in parallel on two horizontal sides of the sensing optical fiber.

[0016] As a further preferred embodiment of the present invention, the performance index of the reinforcing element is designed as follows: the bending strength is above 900 MPa, and more preferably 1000 MPa to 1400 MPa.

[0017] As a further preferred embodiment of the present invention, the main component of the flame retardant layer is polyethylene, and an appropriate amount of flame retardant and other blended materials are added; wherein the polyethylene material is preferably cylindrical particles with a diameter of 3mm to 4mm and a height of 3mm to 6mm.

[0018] As a further preference of the present invention, the performance indicators of the flame retardant layer are designed as follows: after 1008H UV aging, the change rate of tensile strength is less than 30%, and more preferably less than 25%; after 1008H UV aging, the change rate of elongation at break is less than 25%, and more preferably less than 20%.

[0019] As a further preferred embodiment of the present invention, the main component of the self-adhesive layer is polyethylene, and 10% to 15% by weight of polyester polyol and 4% to 8% by weight of polybutene are added.

[0020] As a further preference of the present invention, the performance indicators of the self-adhesive layer are designed as follows: the thickness is greater than 20 μm, more preferably 20 μm to 50 μm; the width occupies more than 50% of the width of the region, more preferably 100%.

[0021] As a further preferred embodiment of the present invention, the above-mentioned sensing optical cable is preferably flat and has an elliptical cross-section, wherein the self-adhesive layer is arranged on one side of the non-arc region of the flat structure.

[0022] As a further preferred embodiment of the present invention, the above-mentioned optical sensor cable is used for accident location monitoring on various types of roads.

[0023] In general, the above technical solution conceived by the present invention has the following technical advantages compared with the prior art:

[0024] (1) The present invention redesigns the internal structure of the sensing optical cable and provides a self-adhesive layer on the side, thereby ensuring that the sensing optical fiber has appropriate flame retardant, waterproof and structural strength properties. Only through the self-adhesive layer, it can be adhered to the target object such as the guardrails on both sides of the expressway and the elevated road in an efficient, reliable and easy-to-control manner. This not only greatly facilitates the early construction and later maintenance, but also significantly improves the optical fiber sensing accuracy compared with the existing technology, and effectively avoids the adverse effects of external interference factors;

[0025] (2) The present invention also optimizes the material and key performance indicators of the reinforcing element, an important component: by making the reinforcing element of FRP material and arranging the reinforcing element in parallel on both sides of the sensing optical fiber, and making targeted restrictions on the performance indicators of the bending strength, while ensuring that the entire optical cable has the required mechanical properties, it can also effectively prevent the guardrail from being severely impacted and damaged, exposing the optical cable therein, and causing secondary injuries to the driver;

[0026] (3) The present invention also optimizes the material and key performance indicators of the self-adhesive layer, an important component: by using a material similar to the flame retardant layer as the base resin for the self-adhesive layer and adding appropriate other components, and by making targeted restrictions on performance indicators such as thickness and width, it can not only provide sufficient adhesion and flexibility, but also ensure that the sensor optical cable can be more closely attached to the guardrail, and help improve the response of the sensor optical cable to external disturbances;

[0027] (4) The present invention also optimizes the specific types and mutual arrangement of the sensing optical fiber, the flame retardant layer and the water-blocking layer: the tight-buffered optical fiber can further reduce the overall size of the sensing optical cable; the flame retardant layer uses polyethylene as the main component to better cooperate with the self-adhesive layer, and its performance indicators can ensure that it can still provide sufficient tensile strength and a small elongation at break change rate after long-term use and aging, thereby improving the reliability and environmental adaptability of the sensing optical cable;

[0028] (5) The overall structure of the sensor optical cable of the present invention is light and compact, has good flame retardancy, and has the characteristics of high positioning accuracy, easy installation and subsequent maintenance. Therefore, it is particularly suitable for application occasions such as accident location on highways and elevated roads, and has good practical value and application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 is a structural cross-sectional view of a lightweight flame-retardant sensor optical cable according to a preferred embodiment of the present invention;

[0030] In all drawings, the same reference numerals are used to denote the same elements or structures, specifically:

[0031] 1-flame retardant layer; 2-sensing optical fiber; 3-reinforcement element; 4-water-blocking yarn; 5-water-blocking yarn; 6-self-adhesive layer. DETAILED DESCRIPTION

[0032] 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.

[0033] 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.

[0034] 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.

[0035] 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.

[0036] 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.

[0037] Figure 1 is a structural cross-sectional view of a lightweight flame-retardant sensor optical cable according to a preferred embodiment of the present invention, which will be referred to below. Figure 1 To explain the present invention in more detail.

[0038] See also Figure 1The sensing optical cable of the present invention is flat as a whole and has an elliptical cross-section. It includes a sensing optical fiber 2, a water-blocking layer, a reinforcing element 3 and a flame-retardant layer 1 from the inside to the outside, and a self-adhesive layer 6 is arranged on the side, wherein the sensing optical fiber 2 is used to perform real-time sensing of external disturbances; the water-blocking layer is arranged on the periphery of the sensing optical fiber and plays a waterproof role; the reinforcing element 3 is used to improve the mechanical properties of the entire sensing optical cable; the flame-retardant layer 1 is arranged on the outermost layer of the sensing optical cable and plays a flame-retardant role; in addition, the above-mentioned sensing optical cable is attached to the target object through the self-adhesive layer 6.

[0039] Through the above ideas, compared with the conventional laying methods of optical cables in the prior art, such as direct burial, pipeline, overhead, etc., the sensor optical cable is laid using a self-adhesive method. Compared with direct burial, the original road surface will not be damaged during construction, causing unnecessary costs; compared with the pipeline construction method, the transmission of vibration will be clearer and more specific, reducing the risk of not being identified; compared with the overhead construction method, the overhead laying is generally suspended between two fixed frames, and the distance between the two fixed frames should not be too long, otherwise the optical cable is easily bent due to the influence of gravity, and the overhead method can only rely on the fixed frame to collect vibrations, and there is also a risk of not being able to fully collect signals. Therefore, the advantage of using the self-adhesive method is that the optical cable can fit the object to be monitored more closely and can clearly identify changes; and the self-adhesive method is simple to operate, which can improve construction efficiency and does not require additional costs. In addition, the flat-shaped optical cable preferably designed by the present invention can further increase the direct contact area between the optical cable and the monitored object such as the guardrail, improve the sensitivity of monitoring, and enhance the signal collection capability.

[0040] Specifically, according to a preferred embodiment of the present invention, the sensing optical fiber 2 can adopt a loose tube structure, wherein the optical fibers are centrally placed in the tube. The sensing optical fiber can also adopt a tight tube structure, which can further reduce the overall size of the sensing optical cable. In addition, the number of sensing optical fibers is generally 1 to 12, preferably 2 to 6.

[0041] According to another preferred embodiment of the present invention, for the water-blocking layer, its main function is to prevent water penetration. The main component of the optical fiber is silicon dioxide. When the optical fiber is exposed to water, water molecules will gradually penetrate into the surface of the optical fiber and react with silicon atoms to hydrolyze, resulting in the breakage of the silicon-oxygen bond, thereby causing damage and cracks inside the optical fiber. When using a tight-buffered optical fiber, it is preferred to place a water-blocking yarn or use a water-blocking tape to wrap it longitudinally outside the optical fiber to strengthen the water-blocking performance of the optical cable; and when using a sensor optical cable with a loose sleeve structure, it is preferred to add a water-blocking yarn 4 or fill it with water-blocking powder in the loose sleeve, and place another water-blocking yarn 4 outside the sleeve or use a water-blocking tape to wrap it longitudinally, thereby reducing the impact of water on the performance of the sensing optical fiber.

[0042] According to another preferred embodiment of the present invention, the reinforcing element is preferably designed as two reinforcing elements arranged in parallel and on both sides of the sensing unit to ensure the mechanical properties of the optical cable. The material of the reinforcing element is preferably FRP, which is composed of glass fiber and resin, and the bending strength is required to be ≥900MPa, and the bending strength is further preferably 1000Mpa~1400Mpa, to prevent the guardrail from being severely impacted, the guardrail is damaged and the optical cable therein is exposed, causing secondary damage to the driver.

[0043] According to another preferred embodiment of the present invention, for the flame retardant layer, the flame retardant layer is preferably a blended material with flame retardant properties made of polyethylene as its main component, and a proper amount of flame retardant and other modifying agents are added through mixing, plasticizing and granulation. Considering that the sensor optical cable is laid on the guardrail in a self-adhesive form, its performance index is preferably that the change rate of tensile strength after 1008H UV aging is ≤30%, and more preferably ≤25%; the change rate of elongation at break after 1008H UV aging is ≤25%, and more preferably ≤20%. In addition, the flame retardant polyethylene material used is preferably cylindrical particles with a diameter of 3mm to 4mm and a height of more than 3mm, or other granular shapes of considerable size.

[0044] According to another preferred embodiment of the present invention, the main function of the self-adhesive layer is to enable the sensor optical cable to effectively adhere to the guardrail and play a sensing role. The self-adhesive layer used in the present invention mainly uses polyethylene as the base resin, and a certain amount of tackifier and plasticizer are added thereto to give the self-adhesive layer a certain adhesive force and flexibility. For example, the main component of the self-adhesive layer is polyethylene, and 10% to 15% of polyester polyols and 4% to 8% of polybutene are added by weight, wherein the molecular chain of polybutene is preferably ≤100000. In order to ensure that it can meet the use of various complex working conditions, the thickness of the self-adhesive layer of the sensor optical cable provided by the present invention is required to be ≥20um, and further preferably 30 to 50um; the width of the self-adhesive layer needs to occupy 50% to 100% of the side width of the setting, preferably 100%, in this way to ensure that the optical cable fits the guardrail tightly and further improve the response of the sensor optical cable to external disturbances.

[0045] In order to better understand the product of the present invention, the following specific examples are provided.

[0046] Embodiment 1:

[0047] In this embodiment, a loose tube structure optical fiber is used. There are two sensing optical fibers in the tube. The two optical fibers are different in color. The tube is also filled with a water-blocking yarn. A water-blocking tape is longitudinally wrapped around the outside of the tube and bound with a water-blocking yarn. Two FRPs with a diameter of 1.6 mm are placed on both sides of the optical fiber. The outer layer uses a black flame-retardant sheath material and a self-adhesive layer is attached to one side.

[0048] Example 2

[0049] In this embodiment, a tight-sleeved sensing optical fiber is used, a water-blocking tape is placed parallel to the outside of the optical fiber, two FRPs with a diameter of 1.0 mm are placed on both sides of the optical fiber, the outer layer uses a black flame-retardant sheath material, and a self-adhesive layer is attached to one side.

[0050] The operation of the optical sensor cable according to the present invention will be briefly explained below.

[0051] When the above-mentioned sensor optical cable is subjected to external force or abnormal vibration, the transmitted light wave signal will be disturbed. The main controller monitors the changes in the light wave signal and converts it into fluctuations in the electrical signal, and converts the electrical signal into a digital signal through the main controller. After processing the received signal, the point where the signal abnormality occurs on the line can be accurately located, and the accident point can be quickly located.

[0052] In summary, the sensor optical cable according to the present invention has been re-studied and designed through its internal structure and its setting method, and targeted improvements have been made to some key performance indicators and other aspects. It not only ensures that the sensor optical cable can complete non-underground installation in an efficient, reliable and easy-to-control manner, but also has the advantages of high positioning accuracy, light weight, good flame retardancy, etc., and greatly facilitates the subsequent maintenance work. Therefore, it is particularly suitable for application scenarios such as accident positioning on highways and elevated roads, and has good practical value and application prospects.

[0053] 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 fast-positioning, lightweight, flame-retardant sensor optical cable, characterized in that: The sensing optical cable includes a sensing optical fiber, a water-blocking layer, a reinforcing element and a flame-retardant layer from the inside to the outside, and a self-adhesive layer is provided on the side, wherein: The sensing optical fiber is used to perform real-time sensing of external disturbances; The water-blocking layer is arranged on the periphery of the sensing optical fiber and plays a waterproof role; The reinforcing element is used to improve the mechanical properties of the entire sensing optical cable; The flame retardant layer is arranged on the outermost layer of the sensor optical cable and plays a flame retardant role; In addition, the above-mentioned sensing optical cable is installed on the target object through the self-adhesive layer.

2. The lightweight flame-retardant sensor optical cable according to claim 1, characterized in that: The sensing optical fiber may adopt a loose tube structure, wherein the optical fiber is centrally placed in the tube, and then a water-blocking tape is longitudinally wrapped on the outside of the tube and bound with a water-blocking yarn.

3. The lightweight flame-retardant sensor optical cable according to claim 1, characterized in that: The sensing optical fiber can be a tight-buffered optical fiber to further reduce the overall size of the sensing optical cable, wherein a water-blocking yarn is placed in parallel outside the tight-buffered optical fiber, or a water-blocking tape is used to longitudinally wrap the optical fiber.

4. The lightweight flame-retardant sensor optical cable according to any one of claims 1 to 3, characterized in that: The reinforcing elements are made of fiber-reinforced composite materials and are arranged in parallel on two horizontal sides of the sensing optical fiber.

5. The lightweight flame-retardant sensor optical cable according to claim 4, characterized in that: The performance index of the reinforcing element is designed as follows: the bending strength is above 900 MPa, and more preferably 1000 MPa to 1400 MPa.

6. The lightweight flame-retardant sensor optical cable according to any one of claims 1 to 5, characterized in that: The main component of the flame retardant layer is polyethylene, and an appropriate amount of flame retardant and other blended materials are added; its performance indicators are designed as follows: after 1008H UV aging, the change rate of tensile strength is less than 30%, and more preferably less than 25%; after 1008H UV aging, the change rate of elongation at break is less than 25%, and more preferably less than 20%.

7. The lightweight flame-retardant sensor optical cable according to any one of claims 1 to 6, characterized in that: The main component of the self-adhesive layer is polyethylene, and 10% to 15% by weight of polyester polyol and 4% to 8% by weight of polybutene are added.

8. The lightweight flame-retardant sensor optical cable according to claim 7, characterized in that: The performance indexes of the self-adhesive layer are designed as follows: the thickness is greater than 20 μm, more preferably 20 μm to 50 μm; the width occupies more than 50% of the width of the region, more preferably 100%.

9. The lightweight flame-retardant sensor optical cable according to any one of claims 1 to 8, characterized in that: The above-mentioned sensing optical cable is preferably flat and has an elliptical cross-section, wherein the self-adhesive layer is arranged on one side of the non-circular arc area of ​​the flat structure.

10. The lightweight flame-retardant sensor optical cable according to any one of claims 1 to 9, characterized in that: The above-mentioned optical sensor cables are used for accident location monitoring purposes on various types of roads.

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