Special cable for railway

Abstract

The invention provides a special cable for a railway, and relates to the technical field of cables. The insulating layer is arranged on the outer side of the conductor, the waterproof layer is arranged on the outer side of the insulating layer, the outer sheath is arranged on the outer side of the waterproof layer, a conductor shielding layer is further arranged between the conductor and the insulating layer, an insulating shielding layer and a metal shielding layer are further arranged between the insulating layer and the waterproof layer, and an armor layer is arranged between the waterproof layer and the outer sheath. The waterproof flame-retardant cable has good electrical insulation performance and good waterproof flame-retardant performance.

Description

Technical Field

[0001] The present invention relates to the technical field of cables, and in particular to a special railway cable. Background Art

[0002] With the large-scale construction of passenger dedicated lines and high-speed railways in my country, and the further improvement of construction scale, it is objectively necessary to use a large number of 27.5kV railway-specific cables. On the one hand, the use of 27.5kV switchgear requires cable inlets and outlets. On the other hand, cable inlets and outlets have more advantages than overhead lines in saving space and having beautiful layout.

[0003] Different from the 26 / 35kV cables widely used in my country's current power system, 27.5kV cables, as special cables for my country's electrified railways, have certain uniqueness. 27.5kV cables must have high reliability to meet the complex environmental requirements of railways. High reliability is reflected in the fact that the cables must be waterproof and flame retardant and have good electrical insulation properties. Summary of the Invention

[0004] The purpose of the present invention is to develop a special railway cable with good electrical insulation performance and good waterproof and flame retardant performance.

[0005] The present invention is achieved through the following technical solutions: A railway-specific cable, comprising: conductor; Insulation layer, provided on the outside of the conductor; A waterproof layer, provided on the outside of the insulating layer; Outer sheath, located outside the waterproof layer; A conductor shielding layer is provided between the conductor and the insulating layer, an insulating shielding layer and a metal shielding layer are provided between the insulating layer and the waterproof layer, and an armor layer is provided between the waterproof layer and the outer sheath.

[0006] Optionally, the conductor shielding layer and the insulating shielding layer are both made of semi-conductive materials, the insulating layer is made of XLPE, the waterproof layer is made of polyethylene, the armor layer is made of copper tape, the metal shielding layer includes copper wire and copper tape, the metal shielding layer is in the form of sparsely wound copper wire and reversely tied copper tape, and the outer sheath is made of flame-retardant polyvinyl chloride.

[0007] Optionally, a water-blocking layer is provided between the metal shielding layer and the waterproof layer.

[0008] Optionally, the water-blocking layer includes two layers of water-blocking yarn, and the space between the two layers of water-blocking yarn is filled with water-blocking grease.

[0009] Optionally, the outside of the cable is further provided with a plurality of cylindrical fire-retardant sleeves made of fire-resistant material.

[0010] Optionally, a plurality of fireproof strips and expansion strips are provided at intervals on the inner wall of the fire-blocking sleeve, and the inner diameters of the fireproof strips and expansion strips are adapted to the outer diameter of the cable.

[0011] Optionally, the fireproof strip is ceramic silicone rubber, and the expansion strip is expanded graphite.

[0012] Optionally, a heat dissipation component is provided in the fire-blocking sleeve, and the heat dissipation component includes a heat-conducting tube provided in the fire-blocking sleeve, a plurality of inner heat-conducting rings connected to the heat-conducting tube are coaxially provided on the inner wall of the fire-blocking sleeve, and a plurality of outer heat-conducting rings connected to the heat-conducting tube are coaxially provided on the outer wall of the fire-blocking sleeve, and the inner diameter of the inner heat-conducting ring is adapted to the outer diameter of the cable.

[0013] Optionally, the interior of the fire-stop sleeve is a cavity structure, the heat-conducting tube is arranged in the cavity, and except for the heat-conducting tube, the rest of the interior cavity of the fire-stop sleeve is filled with refractory fibers.

[0014] Optionally, the fire-stop sleeve includes a first ring sleeve and a second ring sleeve, the first ring sleeve and the second ring sleeve are semi-cylindrical with symmetrical shape and structure, and the first ring sleeve and the second ring sleeve are respectively provided with connecting plates arranged parallel to their axial directions at both ends, and the two connecting plates at both ends of the first ring sleeve are respectively bolted to the two connecting plates at both ends of the second ring sleeve.

[0015] The beneficial effects of the present invention are: The present invention has good electrical insulation performance, and also has good waterproof and flame retardant performance. In particular, the fire barrier sleeve can block the fire and prevent the fire from being transmitted axially on the cable. The ceramic silicone rubber fireproof strip forms a hard ceramic shell when encountering a fire, and a closed space is formed between the two adjacent fireproof strips. The expansion strip between the two adjacent fireproof strips expands when encountering a fire, filling the gap between the two fireproof strips to achieve the purpose of extinguishing the fire. The heat dissipation component on the fireproof sleeve timely conducts heat from the inside of the fireproof sleeve through the heat conduction of the inner heat-conducting ring, the heat-conducting tube and the outer heat-conducting ring to prevent the recurrence of the fire. The fireproof sleeve is a detachable structure and can be adaptively adjusted according to the environment in which the cable is located. When the cable is in a high temperature environment or an environment with fire hazards, the arrangement density of the fireproof sleeve on the cable can be increased. The purpose of extending the fireproof structure is achieved by connecting multiple fireproof sleeves in sequence. Correspondingly, for an environment with low working environment temperature or no fire hazards, the arrangement density of the fireproof sleeve on the cable can be reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0017] Figure 1 This is a structural diagram of Example 1; Figure 2 This is a structural diagram of Example 2; Figure 3 This is a structural diagram of Example 3; Figure 4 This is the internal structure diagram of the firestop sleeve; Figure 5 This is the structural diagram of Example 4.

[0018] Figure numerals: 1. conductor; 2. conductor shielding layer; 3. insulation layer; 4. insulation shielding layer; 5. metal shielding layer; 6. waterproof layer; 7. armor layer; 8. outer sheath; 9. water-blocking layer; 10. fire-blocking sleeve; 101. first ring sleeve; 102. second ring sleeve; 103. connecting plate; 11. outer heat-conducting ring; 12. heat-conducting tube; 13. refractory fiber; 14. fire-proof strip; 15. expansion strip; 16. inner heat-conducting ring. DETAILED DESCRIPTION

[0019] Hereinafter, only certain exemplary embodiments are briefly described. As will be appreciated by those skilled in the art, the described embodiments may be modified in various ways without departing from the spirit or scope of the present invention. Therefore, the drawings and description are to be regarded as illustrative in nature and not restrictive.

[0020] The disclosure below provides many different embodiments or examples for realizing different structures of the present invention. In order to simplify the disclosure of the present invention, the components and settings of specific examples are described below. Of course, they are merely examples and are not intended to limit the present invention. In addition, the present invention may repeat reference numbers and / or reference letters in different examples, and such repetition is for the purpose of simplicity and clarity and does not itself indicate the relationship between the various embodiments and / or settings discussed. In addition, the present invention provides examples of various specific processes and materials, but those of ordinary skill in the art will appreciate the application of other processes and / or the use of other materials.

[0021] The embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0022] Example 1

[0023] like Figure 1 As shown, the present invention discloses a railway-specific cable, which comprises, from the inside to the outside, a conductor 1, a conductor shielding layer 2, an insulating layer 3, an insulating shielding layer 4, a metal shielding layer 5, a waterproof layer 6, an armor layer 7, and an outer sheath 8.

[0024] The conductor shielding layer 2 and the insulating shielding layer 4 are both made of semi-conductive materials, the insulating layer 3 is made of XLPE (cross-linked polyethylene), the waterproof layer 6 is made of polyethylene, and the armor layer 7 is made of copper tape.

[0025] The outer sheath 8 is made of low-smoke halogen-free flame-retardant polyolefin sheath material, which can be flame-retardant polyvinyl chloride.

[0026] The metal shielding layer 5 includes copper wires and copper tapes, which are in the form of sparsely wound copper wires and reversely tied copper tapes.

[0027] Example 2

[0028] like Figure 2 As shown, the difference between this embodiment and embodiment 1 is that a water-blocking layer 9 is further provided between the metal shielding layer 5 and the waterproof layer 6 .

[0029] In the event that the waterproof layer 6 is damaged or cracked, or other conditions that may cause water to penetrate the waterproof layer 6, the water-blocking layer 9 acts as a backup measure to prevent water from entering. The water-blocking layer 9 comprises two layers of water-blocking yarn, with water-blocking grease filled between the two layers of water-blocking yarn.

[0030] Example 3

[0031] like Figure 3 and Figure 4 As shown, this embodiment is different from the embodiment 1 in that a plurality of fire-blocking sleeves 10 are provided outside the cable.

[0032] The fire-blocking sleeve 10 is sleeved on the outer wall of the cable. The fire-blocking sleeve 10 is made of fire-resistant material and is cylindrical. The inner diameter of the fire-blocking sleeve 10 is slightly larger than the outer diameter of the cable. A plurality of fire-blocking strips 14 and expansion strips 15 are arranged at intervals on the inner wall of the fire-blocking sleeve 10, that is, an expansion strip 15 is provided between two adjacent fire-blocking strips 14, and a fire-blocking strip 14 is provided between two adjacent expansion strips 15. The plurality of fire-blocking strips 14 and expansion strips 15 are arranged at equal intervals.

[0033] The fire barrier strip 14 is made of ceramic silicone rubber, and the expansion strip 15 is made of a material that expands at high temperatures, such as expanded graphite. The inner diameters of the fire barrier strips 14 and 15 are slightly smaller than the outer diameter of the cable, ensuring that when the fire barrier sleeve 10 is fitted over the outer wall of the cable, the fire barrier strips 14 and 15 are in close contact, securing the fire barrier sleeve 10.

[0034] The interior of the fire-blocking sleeve 10 is a cavity structure, and a heat dissipation component is provided in the fire-blocking sleeve 10. The heat dissipation component includes a heat-conducting tube 12 provided in the fire-blocking sleeve 10. In addition to the heat-conducting tube 12, the rest of the internal cavity of the fire-blocking sleeve 10 is filled with refractory fibers 13. The refractory fibers 13 can be aluminum silicate refractory fibers or polycrystalline mullite fibers.

[0035] A plurality of annular inner heat-conducting rings 16 are coaxially provided on the inner wall of the fire-blocking sleeve 10. The inner heat-conducting rings 16 are arranged at equal intervals in the axial direction of the fire-blocking sleeve 10 and are arranged in the gap between the fireproof strip 14 and the expansion strip 15. The inner diameter of the inner heat-conducting ring 16 is adapted to the inner diameter of the cable. The outer edge of the inner heat-conducting ring 16 extends into the fire-blocking sleeve 10 and is connected to the inner wall of the heat-conducting tube 12.

[0036] Multiple outer heat-conducting rings 11 are coaxially mounted on the outer wall of the firestop sleeve 10. These rings 11 are evenly spaced axially along the sleeve. The inner edges of these rings 11 extend inwardly into the sleeve 10 and connect to the outer wall of the heat-conducting tube 12. The heat-conducting tube 12, inner heat-conducting rings 16, and outer heat-conducting rings 11 are all constructed from highly thermally conductive materials.

[0037] Example 4

[0038] like Figure 5 As shown, in this embodiment, based on the third embodiment, the fire arrester sleeve 10 is improved into a detachable structure.

[0039] In this embodiment, the fire-arresting sleeve 10 includes a first ring sleeve 101 and a second ring sleeve 102. The first ring sleeve 101 and the second ring sleeve 102 are semi-cylindrical with symmetrical shapes and structures. The first ring sleeve 101 and the second ring sleeve 102 are respectively provided with connecting plates 103 arranged parallel to their axial directions at both ends. The two connecting plates 103 at both ends of the first ring sleeve 101 are respectively bolted to the two connecting plates 103 at both ends of the second ring sleeve 102.

[0040] The clamping force of the first and second ring sleeves 101 and 102 on the cable can be adjusted by adjusting the tightening degree of the bolts. After the bolts are loosened, the firestop sleeve 10 can be axially moved on the cable to adjust its position. Tightening the bolts can secure the position of the firestop sleeve 10 on the cable.

[0041] The above embodiments are only preferred embodiments of the present invention and are not limitations on the technical solutions of the present invention. Any technical solution that can be implemented on the basis of the above embodiments without creative work should be deemed to fall within the scope of protection of the patent of the present invention.

Claims

1. A railway-specific cable, characterized in that: include: conductor; Insulation layer, provided on the outside of the conductor; A waterproof layer, provided on the outside of the insulating layer; Outer sheath, located outside the waterproof layer; A conductor shielding layer is provided between the conductor and the insulating layer, an insulating shielding layer and a metal shielding layer are provided between the insulating layer and the waterproof layer, and an armor layer is provided between the waterproof layer and the outer sheath.

2. The railway-specific cable according to claim 1, characterized in that: The conductor shielding layer and the insulating shielding layer are both made of semi-conductive materials, the insulating layer is made of XLPE, the waterproof layer is made of polyethylene, the armor layer is made of copper tape, the metal shielding layer includes copper wire and copper tape, the metal shielding layer adopts the form of sparsely wound copper wire and reversely tied copper tape, and the outer sheath is made of flame-retardant polyvinyl chloride.

3. The railway-specific cable according to claim 1, characterized in that: A water-blocking layer is further provided between the metal shielding layer and the waterproof layer.

4. The railway-specific cable according to claim 3, characterized in that: The water-blocking layer comprises two layers of water-blocking yarns, and the space between the two layers of water-blocking yarns is filled with water-blocking grease.

5. The railway-specific cable according to claim 1, characterized in that: The outside of the cable is also covered with multiple cylindrical fire-retardant sleeves made of refractory material.

6. The railway-specific cable according to claim 5, characterized in that: A plurality of fireproof strips and expansion strips are arranged at intervals on the inner wall of the fireproof sleeve, and the inner diameters of the fireproof strips and expansion strips are adapted to the outer diameter of the cable.

7. The railway-specific cable according to claim 6, characterized in that: The fireproof strip is ceramic silicone rubber, and the expansion strip is expanded graphite.

8. The railway-specific cable according to claim 5, characterized in that: A heat dissipation assembly is provided in the fire-stop sleeve, and the heat dissipation assembly includes a heat-conducting tube provided in the fire-stop sleeve. A plurality of inner heat-conducting rings connected to the heat-conducting tube are coaxially provided on the inner wall of the fire-stop sleeve, and a plurality of outer heat-conducting rings connected to the heat-conducting tube are coaxially provided on the outer wall of the fire-stop sleeve, and the inner diameter of the inner heat-conducting ring is adapted to the outer diameter of the cable.

9. The railway-specific cable according to claim 8, characterized in that: The interior of the fire-stop sleeve is a cavity structure, and the heat-conducting tube is arranged in the cavity. Except for the heat-conducting tube, the rest of the interior cavity of the fire-stop sleeve is filled with refractory fibers.

10. The railway-specific cable according to claim 5, characterized in that: The fire-stop sleeve includes a first ring sleeve and a second ring sleeve. The first ring sleeve and the second ring sleeve are semi-cylindrical with symmetrical shapes and structures. The first ring sleeve and the second ring sleeve are respectively provided with connecting plates arranged parallel to their axial directions at both ends. The two connecting plates at both ends of the first ring sleeve are respectively bolted to the two connecting plates at both ends of the second ring sleeve.

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