An anti-ice insulated wire for electrified railway and its preparation process

Abstract

The present invention discloses an anti-icing insulated conductor for electrified railways, comprising a conductor core containing a magnetic reinforcement element, wherein a non-metallic semi-conductive layer, an insulating layer and an outer protective layer are sequentially arranged outside the conductor core; the present invention also discloses its preparation process, comprising the following steps: twisting aluminum single wires outside the magnetic reinforcement element to form a conductor core, wherein the magnetic reinforcement element is intermittently arranged; extruding a non-metallic semi-conductive layer, an insulating layer and an outer protective layer outside the conductor core; using a magnet to find marks at intervals of the magnetic reinforcement element; dividing the anchor section from the mark, stripping the outer layer at the outer end of each anchor section to expose the conductor core, and sealing and protecting the stripped end with a heat shrinkable insulating sleeve. The preparation method of the present invention is used to prepare anti-icing insulated conductors, so that continuous production of multiple anchor sections and large lengths becomes possible, and the quality of the insulated conductors is effectively improved; the outer layer is stripped at the end of the insulated conductor, and the stripping operation on the construction site is pre-completed in the production factory, thereby improving the efficiency of on-site construction.

Description

Technical Field

[0001] The invention relates to the technical field of insulated wires, and in particular to an ice-resistant insulated wire for electrified railways and a preparation process thereof. Background Art

[0002] Electrified railways have humid environments such as frost, condensation, and freezing rain. Especially under conditions such as tunnel leakage and wet dew, ice is easily attached to the surface of the conductors, and icicles form, causing burns and corrosion of the positive feeder, which causes the tripping and disconnection of the electrified railway power supply line, affecting the normal operation of the railway. Manual ice removal wastes manpower, material and financial resources. During the production of conductors, due to the different expansion coefficients of different metal materials in the conductor core, bulging or lantern flowers often occur when producing longer insulated conductors, affecting the quality of the conductors. During cable construction and installation, the thicker insulating outer layer of the conductor is inconvenient to strip, affecting the installation and construction efficiency. Summary of the invention

[0003] The object of the present invention is to provide an ice-resistant insulated conductor for electrified railways and a preparation process thereof in view of the above-mentioned deficiencies in the prior art.

[0004] To solve the above problems, the technical solution adopted by the present invention is:

[0005] A preparation process of an ice-resistant insulated conductor for an electrified railway comprises the following steps:

[0006] Step 1) Aluminum single wires are twisted outside the magnetic reinforcement element to form a conductor core, and when the aluminum single wires are twisted, the magnetic reinforcement element is intermittently arranged;

[0007] Step 2) extruding a non-metallic semi-conductive layer on the surface of the conductor core;

[0008] Step 3) extruding an insulating layer outside the non-metallic semi-conductive layer;

[0009] Step 4) extruding an outer protective layer outside the insulating layer;

[0010] Step 5) Use a strong magnet to find the magnetic reinforcement element intervals and mark them on the outer protective layer;

[0011] Step 6) The anchor segments are separated from the marked portions. The outer end of each anchor segment is stripped of a section of the outer layer to expose the conductor core, and the stripped end of the conductor is sealed and protected with a heat shrinkable insulating sleeve.

[0012] Furthermore, in the step 1), the distance between two adjacent magnetic reinforcement elements is 50-200 mm.

[0013] Furthermore, in step 6), 2-5 m of the outer end of the wire is stripped.

[0014] Furthermore, in the step 1), a semi-conductive water-repellent tape is tightly wrapped in the same direction on the outer surface of the magnetic reinforcing element.

[0015] Furthermore, in the step 1), a semi-conductive nylon tape is reversely wrapped around the outer surface of the conductor core.

[0016] Furthermore, the thickness of the semi-conductive water-repellent tape is 0.3-0.6mm, and the expansion rate is 10-16mm / min; the thickness of the semi-conductive nylon tape is 0.12-0.15mm, and the longitudinal tensile strength is not less than 120N / cm; the thickness of the non-metallic semi-conductive layer is 0.8-1.0mm; the nominal thickness of the insulating layer is 8.0mm, and the minimum thickness is not less than 0.72mm; the thickness of the outer protective layer is 1.2-2.0mm.

[0017] An ice-resistant insulated conductor for electrified railways manufactured according to the preparation method described above comprises a conductor core containing a magnetic reinforcement element, the conductor core is extruded with a non-metallic semi-conductive layer, the non-metallic semi-conductive layer is extruded with an insulating layer, and the insulating layer is extruded with an outer protective layer.

[0018] Furthermore, the conductor core is formed by twisting a magnetic reinforcement element and an aluminum single wire, the magnetic reinforcement element is located at the center of the conductor core, and the aluminum single wire is twisted outside the magnetic reinforcement element.

[0019] Furthermore, the magnetic reinforcement element is formed by twisting a plurality of magnetic aluminum-clad steel wires or galvanized steel wires.

[0020] Furthermore, the magnetic reinforcement element is wrapped with a semi-conductive water-repellent tape.

[0021] Furthermore, the conductor core is tightly wrapped with a semi-conductive nylon tape.

[0022] Furthermore, after the outer layer is stripped off at one end of the insulated wire, the conductor core is exposed, and a heat shrinkable insulating sleeve is provided at the stripped end.

[0023] The beneficial effects of adopting the above technical solution are:

[0024] The present invention sequentially arranges a semi-conductive nylon belt, a non-metallic semi-conductive layer, an insulating layer and an outer protective layer outside the conductor core. In a humid environment such as frost, condensation and freezing rain on an electrified railway, especially in a tunnel where ice layers and icicles are easily attached to the surface of the conductor due to water leakage and dew, the present invention can reduce the problems of ice adhesion and tripping and disconnection of the electrified railway power supply line caused by burning and erosion of the positive feeder line, reduce the impact of power supply line equipment failure on the normal operation order of the railway, extend the period of artificial deicing, improve the safety factor of artificial deicing, and save a lot of manpower, material and financial resources.

[0025] The magnetic reinforcing elements are arranged at intervals in the present invention, making it possible to continuously produce multiple anchor sections and long lengths, thereby reducing the number of steel core joints produced in long lengths. The intervals of the magnetic reinforcing elements can solve the problem of aluminum layer bulging and lantern flowers caused by incremental changes due to different linear expansion coefficients of steel and aluminum at high temperatures in cross-linked pipes.

[0026] The present invention adopts multiple strands of magnetic steel wire to form a magnetic reinforcing element, which increases the strength and facilitates wrapping with a water-blocking tape. The water-blocking tape can not only prevent moisture (vapor) from migrating and penetrating into the insulating layer along the conductor gap, but can also be used to absorb and eliminate the change in axial stress caused by the different linear expansion coefficients of the reinforcing element and the aluminum single wire during the high-temperature insulation processing and molding, thereby reducing the problems of conductor bulging and lantern flower; the semi-conductive nylon tape is reversely wrapped on the surface of the aluminum single wire, so that all the aluminum single wires are more tightly packed, which can reduce the problems of conductor bulging and lantern flower, and at the same time avoid the extruded non-metallic semi-conductive layer and the insulating layer from being embedded in the conductor core during the cross-linking process;

[0027] The present invention uses a conductor core with a magnetic reinforcement element and utilizes the magnetic attraction principle to accurately find the segmentation point of the anchor section, thereby solving the problem of difficulty in finding the segmentation point due to metering errors.

[0028] In the present invention, the outer layer of the outer end of the anchor section is stripped and protected with a heat shrinkable insulating sleeve, and the stripping operation on the construction site is pre-completed in the production factory, thereby improving the on-site construction efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 is a schematic cross-sectional view of an insulated conductor according to Embodiment 1 of the present invention;

[0030] Figure 2 is a schematic cross-sectional view of an insulated wire according to Embodiment 2 of the present invention;

[0031] Figure 3 is a schematic cross-sectional view of an insulated wire according to Embodiment 3 of the present invention;

[0032] Figure 4 is a schematic cross-sectional view of an insulated wire according to Embodiment 4 of the present invention;

[0033] Figure 5 is a schematic diagram of the end of an insulated wire according to Embodiment 4 of the present invention;

[0034] Figure 6 It is a schematic diagram of the longitudinal section of the insulated wire reinforcement element in Example 4 of the present invention.

[0035] In the figure: 1. Magnetic reinforcement element; 2. Aluminum single wire; 3. Non-metallic semi-conductive layer; 4. Insulation layer; 5. Outer protective layer; 6. Semi-conductive water-retaining tape; 7. Semi-conductive nylon tape; 8. Heat-shrinkable insulating sleeve. DETAILED DESCRIPTION

[0036] The following embodiments of the present invention are described in further detail in conjunction with the accompanying drawings and examples. The following examples are used to illustrate the present invention, but are not intended to limit the scope of the present invention.

[0037] like Figure 1-6 , which is a schematic structural diagram of an anti-ice insulated conductor for electrified railways according to the present invention;

[0038] Example 1

[0039] like Figure 1 As shown, it is a specific embodiment of an ice-resistant insulated conductor for electrified railways of the present invention, which comprises a conductor core containing a magnetic reinforcement element 1, wherein the conductor core is formed by twisting the magnetic reinforcement element 1 and an aluminum single wire 2, wherein the magnetic reinforcement element 1 is located at the center of the conductor core, and a plurality of the aluminum single wires 2 are coaxially tightly twisted outside the magnetic reinforcement element 1 in layers, and preferably 3 layers in this embodiment, wherein the magnetic reinforcement element 1 is formed by twisting 3-7 aluminum-clad steel wires or galvanized steel wires containing magnetism, and preferably 7 aluminum-clad steel wires in this embodiment, 1 The root is in the center, and 6 coaxial cores are twisted outside it; the conductor core is extruded with a non-metallic semi-conductive layer 3, and the non-metallic semi-conductive layer 3 is extruded with an insulating layer 4, and the insulating layer 4 is extruded from a water-tree resistant cross-linked polyethylene material, which can effectively inhibit the initiation and growth of water trees and electrical trees, meet the requirements of resistance to large current impact, heat resistance and moisture conditions, and is more reliable to use; the insulating layer 4 is extruded with an outer protective layer 5, and the outer protective layer 5 is extruded from polyamide or high-density polyethylene material, and has the characteristics of high lubricity, high wear resistance and low friction coefficient.

[0040] Furthermore, after the outer layer is stripped off at one end of the insulated wire, the conductor core is exposed, and a heat shrinkable insulating sleeve 8 is provided at the stripped end, so that the stripping work on the construction site is pre-completed in the production factory, thereby improving the on-site construction efficiency.

[0041] Example 2

[0042] like Figure 2 As shown, it is a second embodiment of the present invention, which is different from the above-mentioned embodiment 1 in that the magnetic reinforcement element 1 is wrapped with a semi-conductive water-blocking tape 6. The water-blocking tape can not only prevent moisture (vapor) from migrating and penetrating into the insulating layer along the conductor gap, but also can be used to absorb and eliminate the axial stress changes caused by different linear expansion coefficients during the high-temperature processing of the insulation between the reinforcement element and the aluminum single wire, thereby reducing the problems of bulging and lantern flowers.

[0043] Example 3

[0044] like Figure 3As shown, it is the third embodiment of the present invention, which is different from the above-mentioned embodiment 1 in that the conductor core is wrapped with a semi-conductive nylon tape 7. The semi-conductive nylon tape 7 makes all the aluminum single wires 2 tighter, which can reduce the problems of wire bulging and lantern flowers, and at the same time avoids the extrusion of the non-metallic semi-conductive layer 4 and the insulating layer 5 into the conductor core during the cross-linking process.

[0045] Example 4

[0046] like Figure 4-6 As shown, it is a fourth embodiment of an anti-ice insulated conductor for electrified railways of the present invention. The difference from the above-mentioned embodiment 1 is that the magnetic reinforcement element 1 is wrapped with a semiconductive water-repellent tape 6. The semiconductive water-repellent tape 6 blocks the possible migration and penetration of moisture (vapor) from the conductor gap to the insulating layer during operation of the insulated conductor, reduces the factors causing water trees, prevents the conductor from being punctured due to the water tree phenomenon, and can also be used to absorb and eliminate the axial stress changes caused by different linear expansion coefficients during the high-temperature processing of the reinforcement element and the aluminum single wire in the insulation, thereby reducing the problems of bulging and lantern flowers; the conductor core is wrapped with a semiconductive nylon tape 7. The semiconductive nylon tape 7 makes all the aluminum single wires tighter, which can reduce the problems of conductor bulging and lantern flowers, and at the same time avoids the non-metallic semiconductive layer and the insulating layer from being embedded in the conductor core during the cross-linking process.

[0047] For the above-mentioned embodiment 4, a process for preparing an ice-resistant insulated conductor for an electrified railway comprises the following steps:

[0048] Step 1) twisting a plurality of magnetic aluminum-clad steel wires or galvanized steel wires into a magnetic reinforcement element 1, and tightly wrapping a semi-conductive water-coated tape 6 around the outer surface of the magnetic reinforcement element 1 in the same direction;

[0049] Step 2) twisting the aluminum single wires 2 outside the magnetic reinforcement element 1 to form a conductor core. When the aluminum single wires 2 are twisted, the magnetic reinforcement elements 1 are intermittently arranged, and the distance between two adjacent magnetic reinforcement elements 1 is 50-200 mm. The outer surface of the conductor core is tightly wrapped with a semi-conductive nylon tape 7 in the reverse direction;

[0050] Step 3) Extruding a cross-linked non-metallic semi-conductive layer 3 on the surface of the semi-conductive nylon belt 7;

[0051] Step 4) Extruding an anti-water-tree cross-linked polyethylene insulation layer 4 outside the non-metallic semi-conductive layer 3;

[0052] Step 5) Extruding an outer protective layer 5 outside the water tree resistant cross-linked polyethylene insulation layer 4;

[0053] Step 6) Use a strong magnet to find the magnetic reinforcement element 1 at intervals and mark it on the outer protective layer 5;

[0054] Step 7) split the anchor segments from the marked positions, peel off a section of the outer layer at the outer end of each anchor segment, peel off 2-5 m of the outer end to expose the conductor core, and seal and protect the stripped end of the insulated wire with a heat shrinkable insulating sleeve 8.

[0055] Furthermore, the non-metallic semi-conductive layer 3 and the water-tree resistant cross-linked polyethylene insulating layer 4 are co-extruded synchronously and cross-linked in a cross-linking pipe at a temperature of 320° C. to 400° C.

[0056] Furthermore, according to production requirements, the magnetic reinforcement element 1 can preferably be formed by twisting 3-7 magnetic aluminum-clad steel wires or galvanized steel wires.

[0057] Furthermore, according to the size, weight and application requirements of the conductor, one, two, three or more layers of aluminum single wires 2 are twisted outside the magnetic reinforcement element 1 .

[0058] Furthermore, the thickness of the semi-conductive water-repellent tape is 0.3-0.6mm, and the expansion rate is 10-16mm / min; the thickness of the semi-conductive nylon tape is 0.12-0.15mm, and the longitudinal tensile strength is not less than 120N / cm; the thickness of the non-metallic semi-conductive layer is 0.8-1.0mm; the nominal (average) thickness of the insulating layer is 8.0mm, and the minimum thickness is not less than 0.72mm; the thickness of the outer protective layer is 1.2-2.0mm.

[0059] The spacing of the magnetic reinforcing elements in the present invention makes it possible to continuously produce multiple anchor sections and long lengths, reducing the number of steel core joints produced in long lengths. The spacing of the magnetic reinforcing elements can solve the problem of bulging and lantern flowers in the aluminum layer caused by incremental changes due to different linear expansion coefficients of steel and aluminum at high temperatures in cross-linked pipes; and the magnetic attraction principle can be used to accurately find the division points of the anchor sections, which can solve the problem of difficulty in finding the division points due to metering errors; before delivering this product to customers, the outer layer of the outer end of the anchor section is stripped, and the wire core is protected with a heat-shrinkable insulating sleeve, and the stripping work on the construction site is pre-completed in the production factory, thereby improving on-site construction efficiency.

[0060] In the preparation process of ice-resistant insulated wires in other embodiments, the process steps are correspondingly deleted according to the different wire layer structures.

[0061] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A process for preparing ice-resistant insulated wire for electrified railways. It is characterized in that The following steps are involved: Step 1) Aluminum single wires (2) are twisted outside the magnetic reinforcement element (1) to form a conductor core, and when the aluminum single wires (2) are twisted, the magnetic reinforcement element (1) is intermittently arranged; Step 2) extruding a non-metallic semi-conductive layer (3) on the surface of the conductor core; Step 3) Extruding an insulating layer (4) outside the non-metallic semi-conductive layer (3); Step 4) Extruding an outer protective layer (5) outside the insulating layer (4); Step 5) Use a strong magnet to find the magnetic reinforcement element (1) at intervals and mark it on the outer protective layer (5); Step 6) The anchor segments are divided from the marked positions, and a section of the outer layer of each anchor segment is stripped off to expose the conductor core, and the stripped end of the insulated wire is sealed and protected with a heat shrinkable insulating sleeve (8).

2. The process for preparing an ice-resistant insulated wire for electrified railway according to claim 1, It is characterized in that In the step 1), the distance between two adjacent magnetic reinforcement elements (1) is 50-200 mm.

3. The process for preparing an ice-resistant insulated wire for electrified railway according to claim 1, It is characterized in that In the step 6), 2-5 m of the outer end of the insulated wire is stripped.

4. The process for preparing an ice-resistant insulated conductor for electrified railway according to claim 1, It is characterized in that In the step 1), a semi-conductive water-repellent tape (6) is tightly wrapped in the same direction on the outer surface of the magnetic reinforcing element (1).

5. A process for preparing an ice-resistant insulated conductor for electrified railway according to any one of claims 1 to 4, It is characterized in that In the step 1), a semi-conductive nylon tape (7) is reversely wrapped around the outer surface of the conductor core.

6. An anti-icing insulated wire for electrified railway, made by the preparation process of an anti-icing insulated wire for electrified railway according to any one of claims 1 to 4, It is characterized in that It comprises a conductor core containing a magnetic reinforcement element (1), the conductor core is extruded with a non-metallic semi-conductive layer (3), the non-metallic semi-conductive layer (3) is extruded with an insulating layer (4), and the insulating layer (4) is extruded with an outer protective layer (5).

7. The ice-resistant insulated wire for electrified railway according to claim 6, It is characterized in that The conductor core is formed by twisting a magnetic reinforcement element (1) and an aluminum single wire (2), wherein the magnetic reinforcement element (1) is located at the center of the conductor core, and the aluminum single wire (2) is twisted outside the magnetic reinforcement element (1).

8. The ice-resistant insulated wire for electrified railway according to claim 6, It is characterized in that The magnetic reinforcement element (1) is formed by twisting a plurality of magnetic aluminum-clad steel wires or galvanized steel wires.

9. The ice-resistant insulated wire for electrified railway according to claim 6, It is characterized in that The magnetic reinforcement element (1) is wrapped with a semi-conductive water-repellent tape (6).

10. An ice-resistant insulated wire for electrified railway according to any one of claims 6 to 9, It is characterized in that The conductor core is wrapped with a semi-conductive nylon tape (7).

11. The ice-resistant insulated wire for electrified railway according to claim 6, It is characterized in that After the outer layer is stripped off at one end of the wire, the conductor core is exposed, and a heat shrinkable insulating sleeve (8) is provided at the stripped end.

Images