Multi-core crosslinked polyethylene insulated flexible environment-friendly power cable and processing technology thereof

Abstract

The invention discloses a multi-core cross-linked polyethylene insulated flexible environment-friendly power cable and a processing technology thereof, relates to the technical field of wires and cables, and effectively solves the problem that the minimum bending radius of the cable cannot meet site construction due to the fact that the flexibility of the cable is improved and the minimum bending radius of the cable is reduced. Comprising a conductor and a sheath, the conductor is arranged in the sheath, the conductor is formed by twisting four groups of main lines and a group of grounding wires, insulating layers are extruded on the outer sides of the main lines and the grounding wires, the cross-sectional area of the main lines is 185 mm < 2 >, 37 strands of wires are regularly arranged and twisted in three layers, the cross-sectional area of the grounding wires is 70 mm < 2 >, and the insulating layers are extruded on the outer sides of the main lines and the grounding wires. 19 strands are divided into two layers to be regularly arranged and stranded, the insulating layer is made of a polyolefin elastomer modified crosslinked polyethylene material, and the thickness of the sheath layer is 2.6 mm.

Description

Technical Field

[0001] The invention relates to the technical field of electric wires and cables, in particular to a multi-core cross-linked polyethylene insulated soft and environment-friendly power cable and a processing technology thereof. Background Art

[0002] As infrastructure materials in an information-based and electrified society, wires and cables are widely used in all walks of life. From communications, electricity, transportation and other fields to home and office scenes, wire and cable connections are everywhere and play a key role in ensuring that information transmission, energy supply and other needs are met. Therefore, the safety and reliability of wires and cables during use are particularly important. In addition to the requirements for the quality of the product itself, it also has requirements for our on-site installation and laying environment. In particular, when some large-section cables are installed and laid in lines with many corners and small angles, and the wiring space of the electrical cabinet is small, there are extremely high requirements for the softness and minimum allowable bending radius of our cables.

[0003] The domestic GB / T 12706-2020 standard clearly stipulates the minimum bending radius for the installation of conventional power cables: the minimum bending radius for single-core cable installation is 20D without armor and 15D with armor, and the minimum bending radius near the connection box and terminal is 15D without armor and 12D with armor; the minimum bending radius for multi-core cable installation is 15D without armor and 12D with armor, and the minimum bending radius near the connection box and terminal is 12D without armor and 10D with armor (D is the outer diameter of the cable). In reality, the installation and laying environment of cables is easily restricted by objective conditions. Sometimes the minimum bending radius of cables can meet national standards but cannot meet the requirements of the on-site construction environment. Either the cable is replaced or the on-site construction environment is changed; or the installation is forced, resulting in excessive bending of the cable and the insulating core, wrinkling or cracking of the plastic layer, and affecting the normal operation of the cable. This phenomenon is particularly obvious for large-section multi-core cross-linked polyethylene insulated cables. The outer diameter of the large-section conductor of this type of cable is large, the outer diameter of the finished product after the multi-core combination is large, and the cross-linked polyethylene material is hard, so the overall bending of this type of cable is poor, and the above problems often occur at the installation site. Based on this, the inventor proposes a multi-core cross-linked polyethylene insulated soft and environmentally friendly power cable. Summary of the invention

[0004] The technical problem to be solved by the present invention is: to overcome the defects of the existing technical problems and provide a multi-core cross-linked polyethylene insulated soft and environmentally friendly power cable and its processing technology, the flexibility of the cable is improved, the minimum bending radius is reduced, and the problem that the minimum bending radius of the cable cannot meet the on-site construction is effectively solved.

[0005] In order to solve the above technical problems, the technical solution of the present invention is: a multi-core cross-linked polyethylene insulated soft environmentally friendly power cable, including a conductor and a sheath, wherein the conductor is located in the sheath, and the conductor is twisted by four groups of main wires and one group of ground wires, and an insulating layer is extruded and arranged on the outside of the main wire and the ground wire, and the cross-sectional area of ​​the main wire is 185mm 2 37 strands of wire are twisted in three layers in a regular arrangement. The cross-sectional area of ​​the grounding wire is 70mm. 2 , 19 strands of wire are twisted in two layers in a regular arrangement, the insulation layer is made of cross-linked polyethylene material modified by polyolefin elastomer, and the thickness of the sheath is 2.6mm.

[0006] Furthermore, a non-woven fabric layer is wrapped around the outer side of the conductor.

[0007] Furthermore, a filler is provided at the center of the conductor and between the conductor and the non-woven fabric layer.

[0008] Furthermore, the filler is an environmentally friendly non-hygroscopic PP material.

[0009] Furthermore, the thickness of the insulation layer on the outside of the main line is 1.6 mm, and the thickness of the insulation layer on the outside of the ground line is 1.1 mm.

[0010] Furthermore, the sheath is made of 5V-90PVC material.

[0011] Furthermore, the non-woven fabric layer is two layers of white lightweight environmentally friendly non-woven fabric wrapped around the outside of the conductor.

[0012] Furthermore, a processing technology for a multi-core cross-linked polyethylene insulated soft and environmentally friendly power cable is provided, comprising the following steps:

[0013] Step 1: Wire drawing and stranding: the main wire uses 3mm copper wire and is drawn into a single wire with a wire diameter of 0.49mm on a multi-head wire drawing machine. 24 single wires are twisted into strands in the left direction with a pitch of 65-75mm; the ground wire uses 3mm copper wire and is drawn into a single wire with a wire diameter of 0.39mm on a multi-head wire drawing machine. 28 single wires are twisted into strands in the left direction with a pitch of 55-65mm;

[0014] Step 2: Conductor twisting. The main line adopts 37 strands of wire in three layers of regular arrangement, that is, the arrangement of 1+6+12+18. All three layers are left-handed, and the outer layer twist pitch is 240-260mm. The ground wire adopts 19 strands of wire in two layers of regular arrangement, that is, the arrangement of 1+6+12. All the two layers are left-handed, and the outer layer twist pitch is 150-170mm.

[0015] Step 3: Conductor insulation: The main line is extruded with a Φ70 / 90 extruder to extrude a 1.6mm thick insulation layer on the conductor according to different color separation requirements. The colors of the insulation layer on the outside of the main line are red, white, blue and black respectively; the grounding wire is extruded with a yellow-green two-color insulation layer with a thickness of 1.1mm on the conductor through a Φ70 / 90 extruder. The green side of the two-color line accounts for 60-70%, and the yellow side accounts for 30-40%;

[0016] Step 4: Cable formation, four cross-sectional areas of 185 mm 2 The main line and a cross-sectional area of ​​70 mm 2 The grounding wire is arranged in red, white, blue and black colors, and is filled with environmentally friendly non-hygroscopic PP filling to form a right-hand cable. It is wrapped with two layers of white lightweight environmentally friendly non-woven fabric to form a non-woven fabric layer, and the non-woven fabric overlap is greater than 15%;

[0017] Step 5: Outer sheath: a layer of 2.6mm thick 5V-90PVC material is extruded on the cable to form a sheath.

[0018] By adopting the above technical solution, the present invention has the following beneficial effects: by improving the conductor process and the cross-linked polyethylene insulation material, the flexibility of the cable is improved and the minimum bending radius is reduced. It has been verified in practice that the minimum bending radius of the cable during installation can reach 6D, and the minimum bending radius of the cable near the connection box and the terminal can reach 4D, which is much lower than the corresponding domestic standards of 15D and 12D (D is the outer diameter of the cable), effectively solving the problem that the minimum bending radius of the cable cannot meet the on-site construction. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a schematic structural diagram of the multi-core cross-linked polyethylene insulated soft environment-friendly power cable of the present invention.

[0020] Reference numerals: 1, conductor; 2, sheath;

[0021] 11. Main line; 12. Ground wire; 13. Insulation layer; 14. Non-woven fabric layer; 15. Filling. DETAILED DESCRIPTION

[0022] In order to make the contents of the present invention more clearly understood, the present invention is further described in detail below based on specific embodiments in conjunction with the accompanying drawings.

[0023] like Figure 1As shown, in this embodiment, a multi-core cross-linked polyethylene insulated soft environmentally friendly power cable is provided, including a conductor 1 and a sheath 2, the conductor 1 is located in the sheath 2, the conductor 1 is twisted by four groups of main wires 11 and a group of ground wires 12, and an insulating layer 13 is extruded on the outside of the main wires 11 and the ground wires 12, a non-woven fabric layer 14 is wrapped around the outside of the conductor 1, and a filler 15 is provided in the center of the conductor 1 and between the conductor 1 and the non-woven fabric layer 14.

[0024] In this embodiment, the cross-sectional area of ​​the main line 11 is 185 mm 2 , the cross-sectional area of ​​the grounding wire 12 is 70mm 2 Specifically, the main line 11 uses 3mm copper wire and is drawn into a single wire with a wire diameter of 0.49mm on a multi-head wire drawing machine. Then, 24 single wires are twisted into strands in the left direction with a pitch of 65-75mm; the grounding wire 12 uses 3mm copper wire and is drawn into a single wire with a wire diameter of 0.39mm on a multi-head wire drawing machine. Then, 28 single wires are twisted into strands in the left direction with a pitch of 55-65mm.

[0025] In this embodiment, the main line 11 adopts 37 strands twisted in three layers in a regular arrangement, that is, an arrangement of 1+6+12+18, all three layers are left-twisted, and the outer layer twisting pitch is 240-260mm. The grounding wire 12 adopts 19 strands twisted in two layers in a regular arrangement, that is, an arrangement of 1+6+12, all two layers are left-twisted, and the outer layer twisting pitch is 150-170mm.

[0026] In this embodiment, the outer sides of the four groups of main lines 11 are respectively extruded with an insulating layer 13 of four colors, red RAL3020, white RAL9003, blue RAL5017, and black RAL9005, with a thickness of 1.6 mm, and the outer side of the grounding wire 12 is extruded with a two-color (green RAL6018 / yellow RAL1016) 1.1 mm thick insulating layer 13.

[0027] In this embodiment, the insulating layer 13 adopts a cross-linked polyethylene material modified by a polyolefin elastomer. The cross-linked polyethylene has good heat resistance, chemical corrosion resistance, and insulation performance, and is an excellent insulating material. However, the material is hard and difficult to bend. By adding a polyolefin elastomer to modify it without changing its advantages, the bending modulus of the insulating material is greatly reduced. Before the improvement, the hardness of the material was 98A, and after the improvement, the hardness of the material was 87A, so that the hardness of the modified cross-linked polyethylene is softened, which helps to reduce the minimum bending radius of the cable.

[0028] In this embodiment, the filler 15 is an environmentally friendly non-hygroscopic PP material. The filler 15 ensures the roundness of the cable and does not adversely affect the insulated conductor 1. It is non-hygroscopic, non-shrunk, and corrosion-resistant.

[0029] In this embodiment, the non-woven fabric layer 14 is two layers of white lightweight environmentally friendly non-woven fabric wrapped around the outside of the conductor 1, and the overlap of the wrapping tape is greater than 15%.

[0030] In this embodiment, the sheath 2 is made of 5V-90PVC material, and the thickness of the sheath 2 is 2.6 mm. The 5V-90PVC material has the functions of flame retardancy and UV resistance, which further improves the service life of the cable.

[0031] Based on the above-mentioned multi-core cross-linked polyethylene insulated soft and environmentally friendly power cable, the present invention also provides a processing technology of the multi-core cross-linked polyethylene insulated soft and environmentally friendly power cable, comprising the following steps:

[0032] Step 1: Wire drawing and stranding. Specifically, the main line 11 is made of 3mm copper wire, which is drawn into a single wire with a wire diameter of 0.49mm on a multi-head wire drawing machine, and then 24 single wires are bundled in a left direction and twisted into strands with a pitch of 65-75mm; the ground wire 12 is made of 3mm copper wire, which is drawn into a single wire with a wire diameter of 0.39mm on a multi-head wire drawing machine, and then 28 single wires are bundled in a left direction and twisted into strands with a pitch of 55-65mm;

[0033] Step 2: Conductor twisting. Specifically, the main line 11 adopts 37 strands of wires in three layers of regular arrangement, that is, the arrangement of 1+6+12+18. All three layers are twisted in the left direction, and the outer layer twist pitch is 240-260mm. The ground wire 12 adopts 19 strands of wires in two layers of regular arrangement, that is, the arrangement of 1+6+12. All the two layers are twisted in the left direction, and the outer layer twist pitch is 150-170mm.

[0034] Step 3: Conductor insulation: The main line 11 is extruded with a Φ70 / 90 extruder to extrude a 1.6mm thick insulation layer 13 on the conductor according to different color separation requirements. The colors of the insulation layer 13 on the outside of the main line 11 are red, white, blue and black respectively; the grounding wire is extruded with a yellow-green two-color insulation layer 13 with a thickness of 1.1mm on the conductor by a Φ70 / 90 extruder. The green side of the two-color line accounts for 60-70%, and the yellow side accounts for 30-40%;

[0035] Step 4: Cable formation, four cross-sectional areas of 185 mm 2 The main line 11 and a cross-sectional area of ​​70 mm 2 The grounding wire is arranged in red, white, blue and black colors, and is filled with environmentally friendly non-hygroscopic PP filling to form a right-hand cable, and is wrapped with two layers of white lightweight environmentally friendly non-woven fabric to form a non-woven fabric layer 14, and the non-woven fabric overlap is greater than 15%;

[0036] Step 5: Outer sheath: a layer of 2.6mm thick 5V-90PVC material is extruded on the cable to form a sheath 2.

[0037] Through the improvement of conductor technology and cross-linked polyethylene insulation materials, the flexibility of the cable has been improved and the minimum bending radius has been reduced. It has been verified in practice that the minimum bending radius of the cable during installation can reach 6D, and the minimum bending radius of the cable near the connection box and the terminal can reach 4D, which is far lower than the corresponding domestic standards of 15D and 12D (D is the outer diameter of the cable), effectively solving the problem that the minimum bending radius of the cable cannot meet the on-site construction.

[0038] The specific embodiments described above further illustrate the technical problems, technical solutions and beneficial effects solved by the present invention. It should be understood that the above are only specific embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A multi-core cross-linked polyethylene insulated soft environmentally friendly power cable, characterized by: The invention comprises a conductor (1) and a sheath (2), wherein the conductor (1) is located in the sheath (2), the conductor (1) is formed by twisting four groups of main wires (11) and one group of ground wires (12), and an insulating layer (13) is extruded and provided on the outside of the main wires (11) and the ground wires (12), and the cross-sectional area of ​​the main wires (11) is 185 mm 2 , 37 strands of wire are twisted in three layers in a regular arrangement, and the cross-sectional area of ​​the grounding wire (12) is 70mm 2 , 19 strands of wire are twisted in two layers in a regular arrangement, the insulating layer (13) is made of a cross-linked polyethylene material modified with a polyolefin elastomer, and the thickness of the sheath (2) is 2.6 mm.

2. A multi-core cross-linked polyethylene insulated soft environmentally friendly power cable according to claim 1, characterized in that: The conductor (1) is wrapped with a non-woven fabric layer (14) on the outside.

3. A multi-core cross-linked polyethylene insulated soft environmentally friendly power cable according to claim 2, characterized in that: A filler (15) is provided at the center of the conductor (1) and between the conductor (1) and the non-woven fabric layer (14).

4. A multi-core cross-linked polyethylene insulated soft environmentally friendly power cable according to claim 3, characterized in that: The filler (15) is an environmentally friendly, non-hygroscopic PP material.

5. The multi-core cross-linked polyethylene insulated soft environmentally friendly power cable according to claim 1, characterized in that: The thickness of the insulating layer (13) outside the main line (11) is 1.6 mm, and the thickness of the insulating layer (13) outside the ground line (12) is 1.1 mm.

6. A multi-core cross-linked polyethylene insulated soft environmentally friendly power cable according to claim 1, characterized in that: The sheath (2) is made of 5V-90PVC material.

7. The multi-core cross-linked polyethylene insulated soft environmentally friendly power cable according to claim 1, characterized in that: The non-woven fabric layer (14) is two layers of white lightweight environmentally friendly non-woven fabric wrapped around the outside of the conductor (1).

8. A processing technology for a multi-core cross-linked polyethylene insulated soft and environmentally friendly power cable, applicable to a multi-core cross-linked polyethylene insulated soft and environmentally friendly power cable as claimed in any one of claims 1 to 7, characterized in that: The following steps are involved: Step 1: Wire drawing and stranding: the main wire (11) is made of 3 mm copper wire and is drawn into a single wire with a wire diameter of 0.49 mm on a multi-head wire drawing machine. 24 single wires are then bundled in a left direction and twisted into a strand with a pitch of 65-75 mm; the ground wire (12) is made of 3 mm copper wire and is drawn into a single wire with a wire diameter of 0.39 mm on a multi-head wire drawing machine. 28 single wires are then bundled in a left direction and twisted into a strand with a pitch of 55-65 mm; Step 2: Conductor twisting: the main line (11) is twisted in three layers with 37 strands arranged in a regular manner, i.e., an arrangement of 1+6+12+18. All three layers are twisted in the left direction, and the outer layer twist pitch is 240-260 mm. The grounding wire (12) is twisted in two layers with 19 strands arranged in a regular manner, i.e., an arrangement of 1+6+12. All the second layer is twisted in the left direction, and the outer layer twist pitch is 150-170 mm. Step 3: Conductor insulation: the main line (11) is extruded with a Φ70 / 90 extruder to form an insulating layer (13) with a thickness of 1.6 mm on the conductor according to different color separation requirements. The colors of the insulating layer (13) outside the main line (11) are red, white, blue and black respectively; the grounding line (12) is extruded with a yellow-green two-color insulating layer (13) with a thickness of 1.1 mm on the conductor by a Φ70 / 90 extruder. In the production of two-color wire, the green side accounts for 60-70% and the yellow side accounts for 30-40%; Step 4: Cable formation, four cross-sectional areas of 185 mm 2 The main line (11) and a cross-sectional area of ​​70 mm 2 The grounding wire (12) is arranged in red, white, blue and black colors and filled with environmentally friendly non-hygroscopic PP filling to form a right-hand cable, and is wrapped with two layers of white lightweight environmentally friendly non-woven fabric to form a non-woven fabric layer (14), and the non-woven fabric overlap is greater than 15%; Step 5: Outer sheath: a layer of 5V-90PVC material with a thickness of 2.6 mm is extruded on the cable after cabling to form the sheath (2).

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