CN202093875U - Flexible fireproof cable - Google Patents

Abstract

A flexible fireproof cable comprises a cable core conductor. An insolating layer, an insulating layer and an oversheath are successively arranged at a periphery of the cable core conductor; the insolating layer is formed by wrapping of synthesis mica tapes; the insulating layer and the oversheath are respectively made of ceramic fireproof silicone rubber materials; and the cable core conductor is prepared by bunches made of tin-coated copper filaments in a regular intertwist of left side manner. The flexible fireproof cable has a simple structure, superior fire resistance performance, little smoke and high flexible; and is non-toxic.

Description

A kind of flexible fireproof cable

technical field

The utility model relates to cables, in particular to a flexible fireproof cable belonging to a power system with a rated voltage of 0.6/1kV.

Background technique

At present, the existing ordinary power cables do not have the function of fire prevention, and cannot be used in some occasions that require high temperature resistance, fire resistance, and good flexibility, such as high-rise buildings, large national buildings, subways, urban power grids, etc., while traditional mineral insulation fireproof The production process of cables is extremely complex and expensive.

The patent document with the application number CN200920079117.8 discloses a mineral-insulated flexible fireproof cable, which only has a high-temperature-resistant mineral insulation layer outside the conductor, and does not clearly indicate which mineral insulation layer it is; the application number is CN200820160730.8 The patent document of discloses a metal sheath flexible fireproof cable, including a copper sheath with a cavity, at least one composite cable arranged in the cavity, although the copper sheath of the cable can be fireproof, but The thermal conductivity is very high, and the temperature of the conductor will rise rapidly in the event of a fire, which will destroy the conductivity of the conductor; the patent document with the application number CN200520073944.8 discloses an inorganic insulated flexible fireproof cable. Stratus mica-wrapped refractory insulating layer is wrapped around the refractory insulating layer. On the refractory insulating layer, there are longitudinally wrapped and butt-welded copper alloy tubes and non-spiral corrugated metal sheaths on the copper alloy tubes. The production process of this cable is complicated and the cost is high. Higher, and the use of metal tube wrapping will limit the flexibility of the cable.

Utility model content

Aiming at the above technical problems, the utility model provides a flexible fireproof cable belonging to a power system with a rated voltage of 0.6/1kV. The utility model has the advantages of simple structure, superior fire resistance, low smoke and non-toxicity, and high flexibility.

The technical scheme of the utility model is as follows:

The utility model comprises a cable core conductor, and an isolation layer, an insulation layer and an outer sheath are sequentially arranged on the periphery of the cable core conductor. The isolation layer is composed of synthetic mica tape wrapping, and the mica tape wrapping overlap rate is greater than or equal to 20%. The insulating layer and the outer sheath are respectively made of ceramic refractory silicone rubber; The pitch diameter ratio follows the rule of 9 plus 2 from the outer layer to the inner layer.

The beneficial technical effects of the utility model are:

1. The isolation layer is a synthetic mica tape, which has a small expansion coefficient, high dielectric strength, high resistivity, uniform dielectric constant, especially high heat resistance, and the temperature resistance can be greater than 1000 ° C, reaching the A-level fire resistance level.

2. The insulating layer and the outer sheath are vulcanized elastomers of ceramic refractory silicone rubber. The volume resistivity of ceramic refractory silicone rubber is 2×10 ¹⁶ Ω??cm, and the oxygen index is 42, which not only has very good electrical insulation It also has excellent fire resistance, flame retardant, low smoke, halogen-free, non-toxic and other properties. At the same time, the residue after combustion is a ceramic-like hard shell, which does not melt or drip at high temperatures of 600~1300°C , to ensure the smooth flow of the line in the event of a fire, and play a solid protective role, which can win valuable time for personnel to escape or system control. The mechanical strength of ceramic refractory silicone rubber is greatly improved after vulcanization. Adopting this design can save the difficult process such as filling, copper sheathing and drawing of conventional mineral insulated cables.

3. The cable core conductor is made of tinned copper monofilaments, and the bundled wires made of tinned copper monofilaments are formed according to the left-handed normal twisting. The core conductors have good flexibility, because they are all twisted in one direction. When bending, the sliding margin between the individual wires is relatively large, so the bending performance of the bundled wires is good. The pitch diameter ratio of each layer of the cable core conductor twisted in the utility model follows the rule of 9 plus 2 from the outer layer to the inner layer, and has a moderate pitch diameter ratio. At the same time, the left-hand stranding makes it difficult for the copper wires to scatter. Conversely, if the pitch-diameter ratio is too small, the harness is not easy to form; if the pitch-diameter ratio is too large, the flexibility of the combined cable will be reduced.

Description of drawings

Fig. 1 is the utility model schematic diagram.

In the figure: 1. Cable core conductor; 2. Isolation layer; 3. Insulation layer; 4. Outer sheath.

Specific implementation method

The utility model comprises a cable core conductor 1, and an isolation layer 2, an insulation layer 3 and an outer sheath 4 are sequentially arranged on the periphery of the cable core conductor 1. The isolation layer 2 is composed of a synthetic mica tape wrapping, and the mica tape wrapping overlap rate Greater than or equal to 20%, the insulating layer 3 and the outer sheath 4 are respectively extruded with vitrified refractory silicone rubber; the vulcanization process of the silicone rubber is made by a conventional process. All the materials mentioned above are commercially available raw materials.

The cable core conductor 1 is composed of tinned copper monofilament bundles according to left-hand normal twisting,

Its arrangement structure is: the innermost layer is 1 bundled wire, and the second inner layer is evenly arranged with 6 bundled wires or tinned copper wires, and then 6 bundled wires are added to each layer when going outward, and the twisting method is regular arrangement concentric twisting Combined, the pitch ratio of stranding is 9, 11, 13, 15... from outside to inside. The number of stranded layers of the cable core conductor 1 (or the cross-sectional area of the cable core conductor 1 ) and the diameter of the tinned copper wire or bundled wire are determined by the current capacity of the cable according to the conventional design. The bunching equipment for bundled wires and the multi-twisting equipment for cables are conventional equipment. the

Claims (3)

1. A flexible fireproof cable, comprising a cable core conductor, is characterized in that: an isolation layer, an insulating layer and an outer sheath are sequentially arranged on the periphery of the cable core conductor, and the isolation layer is formed by wrapping a synthetic mica tape, and the insulation The layer and the outer sheath are respectively made of vitrified refractory silicone rubber; the cable core conductor is made of tinned copper monofilament, and the bundled wires are formed by left-hand normal twisting. 2. The flexible fireproof cable according to claim 1, characterized in that the ratio of the pitch diameters of each layer of the core conductor twisted follows the rule of 9 plus 2 from the outer layer to the inner layer. 3. The flexible fireproof cable according to claim 1, characterized in that in the wrapping structure of the isolation layer, the mica tape wrapping overlap rate is greater than or equal to 20%.