Fully-shielded non-grounded process field bus cable

Abstract

The utility model discloses a fully-shielded non-grounded process field bus cable, which comprises two oxygen-free copper single wires and two fan-shaped PFA (Polyfluoroalkoxy) resin filling core frames which are arranged in a cross shape to form a cable core, and each oxygen-free copper single wire comprises an oxygen-free copper conductor and a skin-foam-skin insulating layer. An irradiation crosslinking linear low density polyethylene inner sheath layer, a copper wire weaving inner shielding layer, a copper plastic composite wrapping shielding layer and an irradiation crosslinking linear low density polyethylene outer sheath layer are sequentially wrapped outside the cable core, and a tearing rope is arranged between the irradiation crosslinking linear low density polyethylene inner sheath layer and the copper wire weaving inner shielding layer. The outer surface of the irradiation crosslinking linear low density polyethylene outer sheath layer is provided with axial wire stripping grooves which are matched with the tearing ropes along the axial direction, and reinforcing filling strips are embedded in the axial wire stripping grooves. The cable core structure is more balanced and stable, the double-layer shielding structure ensures stable shielding characteristics, grounding processing is not needed, the difficulty of manual wire stripping operation is reduced, and the durability is better.

Description

Technical Field

[0001] This application belongs to the technical field of cables, and particularly relates to a fully shielded non-grounded process fieldbus cable. Background Art

[0002] The process fieldbus can be used as the connecting wire between process automation controls and measuring instruments in the on-site environment of factory basic control to build an open and decentralized digital fieldbus communication system. It can be installed in cable trays and pipes indoors, outdoors, in humid or dry environments. The fieldbus needs to face a very complex electromagnetic environment. The shielding layer of the fieldbus generally adopts a metal braided shielding structure, and a solid tin-plated copper grounding wire is added. Its flexibility and bending resistance are average, and grounding treatment is required, which brings difficulties to line installation and high installation costs. Signal leakage caused by voids in the shielding structure will reduce the shielding characteristics and the durability is poor. Summary of the Utility Model

[0003] Aiming at the deficiencies of the prior art, the technical problem to be solved by this application is to provide a fully shielded non-grounded process fieldbus cable, with a more balanced and stable core structure, better structural strength, a double-layer shielding structure to ensure stable shielding characteristics, no need for grounding treatment, reducing the difficulty of manual wire stripping operation, reducing installation costs, and having better durability.

[0004] The above technical problems are solved by the following technical solutions in this application.

[0005] The fully shielded non-grounded process fieldbus cable includes two oxygen-free copper single wires and two sector-shaped PFA resin filling cores arranged in a cross shape to form a core. The oxygen-free copper single wire includes an oxygen-free copper conductor and a skin-foam-skin insulation layer. The outside of the core is successively coated with an irradiated cross-linked linear low-density polyethylene inner sheath layer, a copper wire braided inner shielding layer, a copper-plastic composite wrapped shielding layer, and an irradiated cross-linked linear low-density polyethylene outer sheath layer. A tearing cord is provided between the irradiated cross-linked linear low-density polyethylene inner sheath layer and the copper wire braided inner shielding layer. The copper-plastic composite wrapped shielding layer is a copper-plastic composite tape spiral overlapping wrapped structure. The copper-plastic composite tape is formed by laminating a copper foil and a PET film. A plurality of slits are equidistantly spaced along the length direction on the surface of the copper foil. A copper-zinc alloy electroplated layer is electroplated on the surface of the copper foil. An axial stripping groove is axially provided on the outer surface of the irradiated cross-linked linear low-density polyethylene outer sheath layer to cooperate with the tearing cord, and a reinforcing filling strip is embedded in the axial stripping groove.

[0006] Preferably, the thickness of the copper foil is 10 μm to 50 μm, the thickness of the copper-zinc alloy electroplated layer does not exceed 2 μm, and the thickness of the PET film is 20 μm to 100 μm.

[0007] Preferably, the diameter of the oxygen-free copper conductor is 0.6 mm to 0.8 mm.

[0008] Preferably, the skin-foam-skin insulation layer is composed of an irradiated cross-linked linear low-density polyethylene inner layer, a foamed polyethylene insulation layer, and an irradiated cross-linked high-density polyethylene outer layer.

[0009] Preferably, the thickness of the skin-foam-skin insulation layer is 0.8 mm to 1 mm.

[0010] Preferably, the copper wire braided inner shielding layer is formed by reverse spiral winding and braiding of a number of polyester fiber copper foil wires and silver-plated copper wires.

[0011] Preferably, the shielding density of the copper wire braided inner shielding layer is not less than 85%.

[0012] Preferably, the included angle between the length direction of the gap and the length direction of the copper foil is 30 degrees to 120 degrees, the width of the gap is 15 μm to 30 μm, and the distance between the gaps is 100 μm to 200 μm.

[0013] Preferably, the depth of the axial stripping groove is 0.2 mm to 0.8 mm.

[0014] Preferably, the thickness of the irradiated cross-linked linear low-density polyethylene outer sheath layer is not less than 1 mm.

[0015] Advantages of the present application:

[0016] 1. A double-layer shielding structure is formed by the copper wire braided inner shielding layer and the copper-plastic composite wrapped shielding layer. The original copper-plastic composite wrapped shielding layer is improved by removing the grounding wire, and a number of gaps are opened at equal intervals along the length direction on the copper foil surface. The included angle between the length direction of the gap and the length direction of the copper foil is 30 degrees to 120 degrees, the width of the gap is 15 μm to 30 μm, and the distance between the gaps is optimized to be 100 μm to 200 μm. After the copper-plastic composite tape is wrapped, grounding treatment is not required, which can effectively prevent the copper foil surface from being charged, ensure stable shielding performance, is beneficial to reducing the laying and installation process difficulty and operation cost, and the line installation flexibility is better.

[0017] Moreover, a copper-zinc alloy electroplating layer is formed by electroplating on the copper foil surface, which has sufficient corrosion resistance, helps to prevent deterioration such as discoloration caused by copper foil oxidation during the wire stripping operation, ensures stable and reliable electrical characteristics of the cable, and improves durability.

[0018] 2. By opening axial stripping grooves on the outer surface of the irradiated cross-linked linear low-density polyethylene outer sheath layer and embedding reinforcing filler strips in the axial stripping grooves, the reinforcing filler strips made of the same material as the sheath can maintain the integrity of the sheath structure, strengthen the mechanical strength of the sheath, and prevent unexpected damage at the axial stripping grooves. During manual wire stripping operation, the sheath can be easily opened at the position corresponding to the axial stripping grooves through the tearing rope, and it will not cause unexpected damage to the sheath, the internal oxygen-free copper single-wire conductor, and the insulating layer. This greatly reduces the difficulty of the manual wire stripping process, is conducive to improving the operation efficiency and quality, reducing the intensity of the manual wire stripping operation, and reducing the installation cost.

[0019] 3. By adding two sector-shaped PFA resin filling cores and cooperating with two oxygen-free copper single wires to form a cross-shaped arrangement, it is beneficial to ensure that the cross-sectional structure of the cable core is more balanced and stable, with better bending resistance. The contact area between the sector-shaped PFA resin filling core and the oxygen-free copper single wire is large, the force is balanced, the strength of the cable core structure is improved, the stability of signal transmission is ensured, and the durability is better. Brief Description of the Drawings

[0020] Figure 1 It is a schematic cross-sectional structure diagram of an embodiment of the present application.

[0021] Description of the Reference Numerals:

[0022] 1 - Oxygen-free copper single wire, 2 - Sector-shaped PFA resin filling core, 3 - Oxygen-free copper conductor, 4 - Skin-foam-skin insulation layer, 5 - Irradiated cross-linked linear low-density polyethylene inner sheath layer, 6 - Copper wire braided inner shield layer, 7 - Copper-plastic composite wrapped shield layer, 8 - Irradiated cross-linked linear low-density polyethylene outer sheath layer, 9 - Tearing rope, 10 - Axial stripping groove, 11 - Reinforcing filler strip. Detailed Embodiments

[0023] To make the objectives, technical solutions, and advantages of the embodiments of the present application clearer, the technical solutions of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are some, but not all, of the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present application.

[0024] See Figure 1, the fully shielded non-grounded type process field bus cable of the embodiment of the present application includes two oxygen-free copper single wires 1 and two sector-shaped PFA resin filling core frames 2 arranged in a cross shape to form a cable core. The oxygen-free copper single wire 1 includes an oxygen-free copper conductor 3 and a skin-foam-skin insulation layer 4. Specifically, the diameter of the oxygen-free copper conductor 3 is 0.6 mm to 0.8 mm. In one embodiment, the skin-foam-skin insulation layer 4 is composed of an irradiated cross-linked linear low-density polyethylene inner skin layer, a foamed polyethylene insulation layer, and an irradiated cross-linked high-density polyethylene outer skin layer. The thickness of the skin-foam-skin insulation layer 4 is 0.8 mm to 1 mm.

[0025] An irradiated cross-linked linear low-density polyethylene inner sheath layer 5, a copper wire braided inner shielding layer 6, a copper-plastic composite wrapped shielding layer 7, and an irradiated cross-linked linear low-density polyethylene outer sheath layer 8 are sequentially coated outside the cable core. A tearing rope 9 is provided between the irradiated cross-linked linear low-density polyethylene inner sheath layer 5 and the copper wire braided inner shielding layer 6. In one embodiment, the copper wire braided inner shielding layer 6 is formed by reverse spiral winding and braiding of a plurality of polyester fiber copper foil wires and silver-plated copper wires. The shielding density of the copper wire braided inner shielding layer 6 is not less than 85%. The copper-plastic composite wrapped shielding layer 7 is a copper-plastic composite tape spiral overlapping wrapped structure. The copper-plastic composite tape is formed by compounding a copper foil and a PET film. A plurality of gaps are equidistantly spaced along the length direction on the surface of the copper foil. Specifically, the included angle between the length direction of the gap and the length direction of the copper foil is 30 degrees to 120 degrees. The width of the gap is 15 μm to 30 μm, and the distance between the gaps is 100 μm to 200 μm. A copper-zinc alloy electroplated layer is electroplated on the surface of the copper foil. Further, the thickness of the copper foil is 10 μm to 50 μm, the thickness of the copper-zinc alloy electroplated layer does not exceed 2 μm, and the thickness of the PET film is 20 μm to 100 μm. An axial stripping groove 10 is provided on the outer surface of the irradiated cross-linked linear low-density polyethylene outer sheath layer 8 in cooperation with the tearing rope 9 along the axial direction. Further, the depth of the axial stripping groove 10 is 0.2 mm to 0.8 mm. A reinforcing filling strip 11 is embedded in the axial stripping groove 10. The thickness of the irradiated cross-linked linear low-density polyethylene outer sheath layer 8 is not less than 1 mm.

[0026] Obviously, those skilled in the art can make various changes and modifications to the present application without departing from the spirit and scope of the present application. Thus, if these modifications and variations of the present application fall within the scope of the claims of the present application and their equivalent technologies, the present application is also intended to include these changes and modifications.

Claims

1. Totally shielded and non-grounded process fieldbus cable, characterized in that: It includes two oxygen-free copper single wires (1) and two sector-shaped PFA resin filling cores (2) arranged in a cross shape to form a cable core. The oxygen-free copper single wire (1) includes an oxygen-free copper conductor (3) and a skin-foam-skin insulation layer (4). The outside of the cable core is sequentially coated with an irradiated cross-linked linear low-density polyethylene inner sheath layer (5), a copper wire braided inner shielding layer (6), a copper-plastic composite wrapped shielding layer (7), and an irradiated cross-linked linear low-density polyethylene outer sheath layer (8). A tearing rope (9) is provided between the irradiated cross-linked linear low-density polyethylene inner sheath layer (5) and the copper wire braided inner shielding layer (6). The copper-plastic composite wrapped shielding layer (7) is a copper-plastic composite tape spiral overlapping wrapped structure. The copper-plastic composite tape is formed by compounding copper foil and PET film. The copper foil surface is equidistantly spaced with a number of slits along the length direction. A copper-zinc alloy electroplating layer is electroplated on the copper foil surface. An axial stripping groove (10) is provided on the outer surface of the irradiated cross-linked linear low-density polyethylene outer sheath layer (8) in cooperation with the tearing rope (9) along the axial direction. A reinforcing filling strip (11) is embedded in the axial stripping groove (10).

2. The fully shielded non-grounded process fieldbus cable according to claim 1, characterized in that: The thickness of the copper foil is 10 μm to 50 μm, the thickness of the copper-zinc alloy electroplating layer does not exceed 2 μm, and the thickness of the PET film is 20 μm to 100 μm.

3. The fully shielded non-grounded type process fieldbus cable according to claim 1, characterized in that: The diameter of the oxygen-free copper conductor (3) is 0.6 mm to 0.8 mm.

4. The fully shielded non-grounded type process fieldbus cable according to claim 1, wherein: The skin-foam-skin insulation layer (4) is composed of an irradiated cross-linked linear low-density polyethylene inner skin layer, a foamed polyethylene insulation layer, and an irradiated cross-linked high-density polyethylene outer skin layer.

5. The fully shielded non-grounded type process fieldbus cable according to claim 1, characterized in that: The thickness of the skin-foam-skin insulation layer (4) is 0.8 mm to 1 mm.

6. The fully shielded non-grounded type process fieldbus cable according to claim 1, characterized in that: The copper wire braided inner shielding layer (6) is formed by reverse spiral winding and braiding a number of polyester fiber copper foil wires and silver-plated copper wires.

7. The fully shielded non-grounded type process fieldbus cable according to claim 1, wherein: The shielding density of the copper wire braided inner shielding layer (6) is not less than 85%.

8. The fully shielded non-grounded type process fieldbus cable according to claim 1, wherein: The included angle between the length direction of the slit and the length direction of the copper foil is 30 degrees to 120 degrees, the width of the slit is 15 μm to 30 μm, and the distance between the slits is 100 μm to 200 μm.

9. The fully shielded non-grounded type process fieldbus cable according to claim 1, characterized in that: The depth of the axial stripping groove (10) is 0.2 mm to 0.8 mm.

10. The fully shielded non-grounded type process fieldbus cable according to claim 1, characterized in that: The thickness of the irradiated cross-linked linear low-density polyethylene outer sheath layer (8) is not less than 1 mm.

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