Low-smoke halogen-free environment-friendly flame-retardant intrinsic safety type control cable

Abstract

The utility model relates to the technical field of wires and cables, in particular to a low-smoke halogen-free environment-friendly flame-retardant intrinsic safety type control cable, which comprises an inner core layer formed by a plurality of mutually twisted wire cores; a plurality of filling strips and flame-retardant ropes are twisted on the outer layer of the inner core layer to form an outer core layer; the outer wall of the outer core layer is coated with the first shielding layer; the non-woven fabric wrapping layer wraps the outer wall of the first shielding layer; the flame-retardant layer is coated on the outer wall of the non-woven fabric wrapping layer; according to the intrinsic safety type control cable provided by the utility model, the cable core is composed of the inner core layer formed by the plurality of wire cores and the outer core layer formed by the plurality of filling strips, and the filling strips of the outer core layer have elasticity and flame retardance, so that the stress borne by the shielding layer outside the cable core when the cable is bent can be reduced, and the shielding performance of the cable can be maintained; the signal transmission stability and reliability of the cable are improved, and the cable can be used in a high explosion-proof environment where the cable is frequently bent.

Description

Technical Field

[0001] This utility model relates to the field of wire and cable technology, and more specifically to a low-smoke, halogen-free, environmentally friendly, flame-retardant, intrinsically safe control cable. Background Technology

[0002] Intrinsically safe control cables are special cables designed for intrinsically safe circuits. They possess excellent electrical and safety performance and are specifically designed for flammable, explosive, and high-explosion-proof industrial environments, such as petroleum, chemical, and coal industries, as well as industrial automation control systems and safety monitoring systems.

[0003] Intrinsically safe control cables are characterized by limiting the operating current of equipment to below a safe threshold, thereby preventing the generation of electrical sparks or arcs and ensuring that they will not cause fires or explosions in extreme environments. This characteristic is due to the cable's low capacitance and low inductance design, which not only reduces electromagnetic interference but also improves the stability and reliability of signal transmission.

[0004] Intrinsically safe cables typically utilize a shielding layer to resist external electromagnetic interference and prevent internal signal leakage. For example, a metal mesh braid or metal strip is used as the shielding layer to provide excellent electromagnetic shielding. For intrinsically safe cables with high flame retardant requirements, the shielding layer is placed on the outer layer of the fiberglass tape. However, the cable's bending performance is poor, and the shielding layer is easily affected by the pores in the fiberglass tape, reducing the shielding effect. Utility Model Content

[0005] To address the shortcomings of existing technologies, this utility model proposes a low-smoke, halogen-free, environmentally friendly, flame-retardant, intrinsically safe control cable, comprising:

[0006] The inner core layer is formed by multiple twisted wires;

[0007] An outer core layer is formed by filling and twisting multiple filler strips and flame-retardant ropes around the outer layer of the inner core layer;

[0008] The first shielding layer covers the outer wall of the outer core layer;

[0009] A non-woven fabric wrapping layer is applied to the outer wall of the first shielding layer;

[0010] A flame-retardant layer is wrapped around the outer wall of the non-woven fabric wrapping layer;

[0011] The second shielding layer covers the outer wall of the flame-retardant layer;

[0012] The outer sheath is extruded onto the outer wall of the second shielding layer;

[0013] The filler strip is an elastic hollow structure, and the filler strip is made of ceramicized silicone rubber hollow tube. The wall thickness of the ceramicized silicone rubber hollow tube is less than 1 / 3 of the diameter of the hollow tube. The filler strip is placed between two wire cores and is tangent to the wire cores and the first shielding layer. The flame-retardant rope is filled between the filler strip and the wire cores and is wrapped around the outside by the first shielding layer as a whole.

[0014] Preferably, the flame-retardant rope is a ceramicized filler rope, which is made of ceramicized silicone rubber and glass fiber rope through winding and weaving, with a density of 1.45 to 1.50.

[0015] Preferably, the wire core includes an oxygen-free copper conductor, a polyethylene insulation layer extruded onto the outer wall of the oxygen-free copper conductor, and a longitudinally wrapped copper strip layer covering the outer wall of the polyethylene insulation layer.

[0016] Preferably, the first shielding layer includes a copper strip wrapping layer with a copper strip overlap rate greater than 15%, and the second shielding layer includes a braided shielding layer.

[0017] Preferably, the nonwoven fabric wrapping layer comprises two layers of semi-conductive nonwoven fabric wrapping layer, and the wrapping overlap rate of each layer of semi-conductive nonwoven fabric is greater than 30%.

[0018] Preferably, the flame retardant layer includes a first flame retardant layer and a second flame retardant layer, wherein the first flame retardant layer covers the outer wall of the nonwoven fabric wrapping layer, and the second flame retardant layer covers the outer wall of the first flame retardant layer.

[0019] Preferably, the first flame-retardant layer includes a glass fiber tape wrapping layer, and the second flame-retardant layer includes a ceramicized silicone rubber flame-retardant layer.

[0020] Preferably, the outer sheath comprises a halogen-free, low-smoke, flame-retardant polyolefin flame-retardant layer.

[0021] Compared with existing technologies, the significant advantages of this utility model's low-smoke, halogen-free, environmentally friendly, flame-retardant, intrinsically safe control cable are:

[0022] The low-smoke, halogen-free, environmentally friendly, flame-retardant, intrinsically safe control cable proposed in this utility model has a cable core formed by an inner core layer composed of multiple conductors and an outer core layer composed of multiple filler strips. The filler strips of the outer core layer are elastic and flame-retardant, which can reduce the stress on the outer shielding layer of the cable core when the cable is bent, so as to maintain its shielding performance and improve the signal transmission stability and reliability of the cable. Through the flame-retardant structure composed of fiberglass wrapping tape and ceramicized silicone rubber flame-retardant layer, the cable maintains its flame-retardant ability while improving its bending performance, which can meet the requirements of use in high explosion-proof environments where the cable is frequently bent. Attached Figure Description

[0023] The accompanying drawings are not intended to be drawn to scale. In the drawings, each identical or nearly identical component shown in the various figures may be denoted by the same reference numeral. For clarity, not every component is labeled in each figure. Embodiments of various aspects of the present invention will now be described by way of example and with reference to the accompanying drawings, wherein:

[0024] Figure 1 This utility model describes a low-smoke, halogen-free, environmentally friendly, flame-retardant, intrinsically safe control cable. Detailed Implementation

[0025] To better understand the technical content of this utility model, specific embodiments are provided below in conjunction with the accompanying drawings.

[0026] Combination Figure 1 The example of a low-smoke, halogen-free, environmentally friendly, flame-retardant, intrinsically safe control cable shown includes a cable core, a first shielding layer 4, a non-woven fabric wrapping layer 5, a flame-retardant layer, a second shielding layer 8, and an outer sheath 9.

[0027] The cable core is formed by twisting together multiple conductors 1, multiple filler strips 2, and flame-retardant rope 3. The inner core layer is formed by the multiple twisted conductors 1; the outer core layer is formed by filling and twisting the multiple filler strips 2 and flame-retardant rope 3 around the inner core layer.

[0028] As shown in the attached figure, each conductor 1 includes an oxygen-free copper conductor 11, a polyethylene insulation layer 12 extruded on the outer wall of the oxygen-free copper conductor 11, and a longitudinally wrapped copper strip layer 13 covering the outer wall of the polyethylene insulation layer 12.

[0029] Oxygen-free copper conductor 11 has high conductivity and corrosion resistance, which can reduce conductor heating and energy consumption and improve safety.

[0030] Each conductor 1 has a longitudinally wrapped copper strip structure on its outer wall. Due to the excellent shielding performance of the copper strip, the cable can meet the requirements of flammable, explosive, and high explosion-proof industrial environments, further improving the safety performance of the cable.

[0031] Specifically, such as Figure 1 As shown, the inner core layer consists of 7 wire cores 1 (1 in the middle and 6 in the outer layer). A filler strip 2 is filled between every two wire cores 1. Furthermore, flame-retardant rope 3 is filled on both sides of the filler strip 2 to make the cable core more rounded.

[0032] Specifically, the filler strip 2 and the flame-retardant rope 3 are elastic structures.

[0033] The filler strip 2 is a hollow structure made of ceramicized silicone rubber hollow tube, and the wall thickness of the ceramicized silicone rubber hollow tube is less than 1 / 3 of the diameter of the hollow tube. The filler strip 2 is tangent to the wire core 1 and the first shielding layer 4.

[0034] Flame-retardant rope 3 is filled between filler strip 2 and wire core 1, and is wrapped around the outside by the first shielding layer 4 to form the cable core. The first shielding layer 4 includes a copper tape wrapping layer, and the copper tape wrapping overlap rate is greater than 15%.

[0035] In an optional embodiment, the flame-retardant rope 3 is a ceramicized filler rope, which is made of ceramicized silicone rubber and glass fiber rope through winding and weaving, with a density of 1.45 to 1.50. On the one hand, it can increase the tensile strength of the cable, stabilize the relative position of the wire cores in the cable, and ensure that the cable has good roundness. On the other hand, the ceramicized filler rope has excellent electrical and mechanical properties at room temperature, is resistant to bending, bending, and impact, and is environmentally friendly, halogen-free and smokeless. At temperatures above 650°C, it begins to harden and form a ceramic-like shell, which has fireproof and fire-resistant properties and will not cause secondary fires.

[0036] Thus, the outer core layer set outside the inner core layer has good elasticity and good flame retardancy. When the cable is bent, it can provide deformation through deformation. If the inside of the cable catches fire, the ceramicized silicone rubber hollow tube and the flame retardant rope 3 will carbonize to form a char shell, and the first shielding layer 4 will provide physical support for the carbonized char shell to prevent it from falling off and losing its protective function.

[0037] Furthermore, the nonwoven fabric wrapping layer 5 covers the outer wall of the first shielding layer 4, and the flame retardant layer covers the outer wall of the nonwoven fabric wrapping layer 5; the second shielding layer 8 covers the outer wall of the flame retardant layer, and the outer sheath 9 is extruded onto the outer wall of the second shielding layer 8.

[0038] In an optional embodiment, the flame retardant layer includes a first flame retardant layer 6 and a second flame retardant layer 7, wherein the first flame retardant layer 6 covers the outer wall of the nonwoven fabric wrapping layer 5, and the second flame retardant layer 7 covers the outer wall of the first flame retardant layer 6.

[0039] The first flame-retardant layer 6 includes a glass fiber tape wrapping layer, and the second flame-retardant layer 7 includes a ceramicized silicone rubber flame-retardant layer.

[0040] As an optional example, the fiberglass tape wrapping layer specifically includes at least two layers of fiberglass tape, each layer having a wrapping overlap of more than 30%, and the first and second layers being wrapped in opposite directions.

[0041] Therefore, the ceramicized silicone rubber flame retardant layer ensures that the cable has good flame retardancy while maintaining good bending performance, which can meet the needs of frequent cable bending.

[0042] Furthermore, the non-woven fabric wrapping layer 5 provided between the first shielding layer 4 and the flame-retardant layer can improve the tensile strength of the cable in the axial direction, while providing protection for the first shielding layer 4 and preventing the flame-retardant layer from scratching the copper tape shielding layer.

[0043] Preferably, the nonwoven wrapping layer 5 includes two layers of semi-conductive nonwoven wrapping layer, and the wrapping overlap rate of each layer of semi-conductive nonwoven fabric is greater than 30%.

[0044] Furthermore, to improve the bending performance of the cable, the second shielding layer 8 is a braided shielding layer.

[0045] Furthermore, the outer sheath 9 includes a halogen-free, low-smoke, flame-retardant polyolefin flame-retardant layer. This layer has excellent flame-retardant properties and environmental characteristics, especially as it does not contain harmful substances such as halogens. When burning, it does not produce toxic gases or large amounts of smoke, and is harmless to the environment and human health.

[0046] In conjunction with the above embodiments, the intrinsically safe control cable proposed by this utility model has a circular structure formed by an inner core layer composed of multiple wire cores and an outer core layer composed of multiple filler strips. The filler strips of the outer core layer are elastic and flame-retardant, which can reduce the stress on the outer shielding layer of the cable core when the cable is bent, so as to maintain its shielding performance and improve the signal transmission stability and reliability of the cable. The flame-retardant structure composed of fiberglass wrapping tape and ceramicized silicone rubber flame-retardant layer not only maintains the flame-retardant capability of the cable, but also improves the bending performance of the cable, which can meet the requirements of use in high explosion-proof environments where the cable is frequently bent.

[0047] Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Those skilled in the art to which this invention pertains can make various modifications and refinements without departing from the spirit and scope of the present invention. Therefore, the scope of protection of this invention shall be determined by the claims.

Claims

1. A low-smoke, halogen-free, environmentally friendly, flame-retardant, intrinsically safe control cable, characterized in that, include: The inner core layer is formed by multiple twisted wire cores (1); Multiple filler strips (2) and flame-retardant ropes (3) are filled and twisted together to form an outer core layer on the outer layer of the inner core layer; The first shielding layer (4) covers the outer wall of the outer core layer; A non-woven fabric wrapping layer (5) is wrapped around the outer wall of the first shielding layer (4); A flame-retardant layer is wrapped around the outer wall of the nonwoven fabric wrapping layer (5); The second shielding layer (8) covers the outer wall of the flame-retardant layer; The outer sheath (9) is extruded onto the outer wall of the second shielding layer (8); The filler strip (2) is a hollow structure with an elastic structure, using a ceramicized silicone rubber hollow tube. The wall thickness of the ceramicized silicone rubber hollow tube is less than 1 / 3 of the diameter of the hollow tube. The filler strip (2) is placed between two wire cores (1) and is tangent to the wire cores (1) and the first shielding layer (4). The flame-retardant rope (3) is filled between the filler strip (2) and the wire cores (1) and is wrapped around the outside by the first shielding layer (4) as a whole.

2. The low-smoke, halogen-free, environmentally friendly, flame-retardant, intrinsically safe control cable according to claim 1, characterized in that, The flame-retardant rope (3) is a ceramicized filler rope, which is made of ceramicized silicone rubber and glass fiber rope through winding and weaving, with a density of 1.45 to 1.

50.

3. The low-smoke, halogen-free, environmentally friendly, flame-retardant, intrinsically safe control cable according to claim 1, characterized in that, The core (1) includes an oxygen-free copper conductor (11), a polyethylene insulation layer (12) extruded on the outer wall of the oxygen-free copper conductor (11), and a longitudinally wrapped copper strip layer (13) covering the outer wall of the polyethylene insulation layer (12).

4. The low-smoke, halogen-free, environmentally friendly, flame-retardant, intrinsically safe control cable according to claim 1, characterized in that, The first shielding layer (4) includes a copper strip wrapping layer with a copper strip wrapping overlap rate of more than 15%, and the second shielding layer (8) includes a braided shielding layer.

5. The low-smoke, halogen-free, environmentally friendly, flame-retardant, intrinsically safe control cable according to claim 1, characterized in that, The nonwoven wrapping layer (5) includes two layers of semi-conductive nonwoven wrapping layer, and the wrapping overlap rate of each layer of semi-conductive nonwoven fabric is greater than 30%.

6. The low-smoke, halogen-free, environmentally friendly, flame-retardant, intrinsically safe control cable according to claim 1, characterized in that, The flame retardant layer includes a first flame retardant layer (6) and a second flame retardant layer (7). The first flame retardant layer (6) covers the outer wall of the non-woven fabric wrapping layer (5), and the second flame retardant layer (7) covers the outer wall of the first flame retardant layer (6).

7. The low-smoke, halogen-free, environmentally friendly, flame-retardant, intrinsically safe control cable according to claim 6, characterized in that, The first flame-retardant layer (6) includes a glass fiber tape wrapping layer.

8. The low-smoke, halogen-free, environmentally friendly, flame-retardant, intrinsically safe control cable according to claim 6, characterized in that, The second flame retardant layer (7) includes a ceramicized silicone rubber flame retardant layer.

9. The low-smoke, halogen-free, environmentally friendly, flame-retardant, intrinsically safe control cable according to claim 1, characterized in that, The outer sheath (9) includes a halogen-free, low-smoke, flame-retardant polyolefin flame-retardant layer.

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