CN221766377U - Tin-plated copper-clad aluminum conductor fireproof flexible cable for rail transit - Google Patents

Abstract

The utility model relates to a tin-plated copper-clad aluminum conductor fireproof flexible cable for rail transit, and belongs to the technical field of cables. The technical scheme is as follows: a copper cladding layer and a tin plating layer are sequentially arranged outside the aluminum core to form a tin-plated copper-clad aluminum conductor (1); a plurality of tinned copper-clad aluminum conductor bundles are twisted together and then are externally wrapped with a calcined muscovite fire-resistant layer (2), a low-smoke halogen-free flame-retardant crosslinked polyolefin insulating layer (3) is extruded outside the calcined muscovite fire-resistant layer to form a wire core, a plurality of wire cores are twisted to form a cable core, and a flame-retardant filler is arranged in the cable core; the cable core is sequentially provided with a reinforced fireproof mica layer, a tinning braided shielding layer and a crosslinked low-smoke halogen-free flame-retardant polyolefin sheath layer. The utility model improves the flexibility of the cable, reduces the broken wires of the cable conductor, reduces the weight of the cable conductor, ensures the integrity of the circuit of the cable during flame propagation, ensures the high strength, excellent flame retardant property and low temperature resistance of the cable, improves the comprehensive protective properties of wear resistance, corrosion resistance, fire resistance and the like of the cable, and prolongs the service life of the cable.

Description

A fire-resistant flexible cable with tinned copper-clad aluminum conductor for rail transit

Technical Field

The utility model relates to a fire-resistant soft cable with tinned copper-clad aluminum conductor for rail transportation, belonging to the technical field of cables.

Background Art

Rail transit refers to a means of transportation that runs on a specific track. Rail transit can be divided into subways, trams, light rails and high-speed railways. In recent years, with the continuous development of social economy, the national rail transit has shown a leapfrog development, and the demand for low-smoke halogen-free flame-retardant rail transit cables has also increased significantly. In the face of the ever-increasing rail transit control equipment, higher requirements are put forward for cables. Ordinary low-smoke halogen-free flame-retardant rail transit cables are not fire-resistant, the conductor is heavy, the flexibility is poor, it is easy to age, the life is short, and the mechanical properties are not high. They can no longer fully meet the technical requirements under specific conditions. In order to reduce the weight of the conductor, the existing technology uses aluminum wires. The biggest problem with aluminum is that it cannot provide a reliable and stable connection. At the same time, from the performance of aluminum, its strength is very low, and the aluminum wire of a small conductor is easy to break, so aluminum wire is not allowed to be used when the CSA requirement is less than 0.75 square. The combination of copper terminals and aluminum wires is relatively common, but there are still some problems with the traditional crimping technology. When exposed to the external atmosphere, the surface of aluminum tends to oxidize quickly and form a resistance layer. This surface layer deteriorates the metal-to-metal contact. Using traditional crimping technology, the insulating layer will prevent the flow of current, thus, generating higher contact resistance and higher heat. A big problem is the chemical reaction caused by the mechanical bonding of the two materials, followed by the high thermal expansion coefficient of aluminum itself, so there is still some uncertainty in the traditional way of connection.

Utility Model Content

The utility model aims to provide a fire-resistant flexible cable with tinned copper clad aluminum conductor for rail transit. The cable is twisted with soft tinned copper clad aluminum conductors and wrapped with a calcined muscovite fire-resistant layer on the outside of the tinned copper clad aluminum conductors. A high-strength low-smoke halogen-free flame-retardant cross-linked polyolefin insulation layer and a cross-linked low-smoke halogen-free flame-retardant polyolefin sheath layer are adopted to reduce the weight of the cable conductor. The cable has the characteristics of excellent electrical performance, good flexibility, aging resistance, good comprehensive protection performance, long service life, etc., and solves the problems existing in the background technology.

The technical solution of the utility model is:

A tinned copper clad aluminum conductor fire-resistant flexible cable for rail transit, comprising a tinned copper clad aluminum conductor, a calcined muscovite fire-resistant layer, a low-smoke halogen-free flame-retardant cross-linked polyolefin insulation layer, a flame-retardant filler, a reinforced fire-resistant mica layer, a tinned braided shielding layer and a cross-linked low-smoke halogen-free flame-retardant polyolefin sheath layer; the tinned copper clad aluminum conductor comprises an aluminum core, a copper coating layer and a tin-plated layer, and a copper coating layer and a tin-plated layer are sequentially arranged outside the aluminum core to form a tinned copper clad aluminum conductor; a plurality of tinned copper clad aluminum conductor bundles are twisted together and then wrapped with a calcined muscovite fire-resistant layer, and a low-smoke halogen-free flame-retardant cross-linked polyolefin insulation layer is extruded outside the calcined muscovite fire-resistant layer to form a wire core, and a plurality of wire cores are twisted to form a cable core, and a flame-retardant filler is arranged inside the cable core; a reinforced fire-resistant mica layer, a tinned braided shielding layer and a cross-linked low-smoke halogen-free flame-retardant polyolefin sheath layer are sequentially arranged outside the cable core.

The stranding direction of the plurality of tinned copper clad aluminum conductors is left-handed, and the pitch is 8-14 times of the stranding diameter.

The calcined muscovite refractory layer and the reinforced refractory mica layer are both made of calcined muscovite with a thickness of 0.12 mm, and are double-layered with 50% overlap.

The thickness of the low-smoke, halogen-free, flame-retardant, cross-linked polyolefin insulation layer is 0.4 mm.

The tinned braided shielding layer is woven from tinned copper wires, the single wire of the tinned copper wires is 0.1-0.15 mm, the braiding machine is a 16-spindle braiding machine, the braiding density is 80%, and the braiding angle is 15°-35°.

The number of the wire cores is three, and the wire cores are arranged in a finished product shape.

The tinned copper clad aluminum conductor is a Class 5 tinned soft copper conductor that complies with the EN50306-2 standard.

The beneficial effects of the utility model are:

1. The tinned copper-clad aluminum conductor is used to improve the cable flexibility, reduce the cable conductor breakage, increase the cable service life, and reduce the cable conductor weight;

2. The calcined muscovite refractory layer is double-layered and wrapped with 50% overlap to ensure the integrity of the cable circuit when the flame spreads; the double-layered refractory mica layer is strengthened and wrapped with 50% overlap to enhance the fire resistance of the cable;

3. The low-smoke halogen-free flame-retardant cross-linked polyolefin insulation layer and the cross-linked low-smoke halogen-free flame-retardant polyolefin sheath layer ensure that the cable has high strength, excellent flame retardant properties, and low temperature resistance, improves the cable's comprehensive protection properties such as wear resistance and corrosion resistance, improves the cable's voltage level, improves the cable's safety protection, and increases the cable's service life.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG1 is a schematic diagram of the structure of the tinned copper clad aluminum conductor of the utility model;

Fig. 2 is a schematic diagram of the structure of the utility model;

In the figure: tinned copper clad aluminum conductor 1, aluminum core 11, copper coating layer 12, tinned layer 13, calcined muscovite refractory layer 2, low-smoke halogen-free flame retardant cross-linked polyolefin insulation layer 3, reinforced refractory mica layer 4, tinned braided shielding layer 5, cross-linked low-smoke halogen-free flame retardant polyolefin sheath layer 6, flame retardant filler 7.

DETAILED DESCRIPTION

The present invention will be further described below through examples in conjunction with the accompanying drawings.

A tinned copper clad aluminum conductor fire-resistant flexible cable for rail transit, comprising a tinned copper clad aluminum conductor 1, a calcined muscovite fire-resistant layer 2, a low-smoke halogen-free flame-retardant cross-linked polyolefin insulation layer 3, a flame-retardant filler 7, a reinforced fire-resistant mica layer 4, a tinned braided shielding layer 5 and a cross-linked low-smoke halogen-free flame-retardant polyolefin sheath layer 6; the tinned copper clad aluminum conductor 1 comprises an aluminum core 11, a copper coating layer 12 and a tinned layer 13, and the copper coating layer 12 is sequentially arranged outside the aluminum core 11 and a tinned layer 13 to form a tinned copper clad aluminum conductor 1; a plurality of tinned copper clad aluminum conductors 1 are twisted together and then wrapped with a calcined muscovite refractory layer 2, a low-smoke, halogen-free, flame-retardant, cross-linked polyolefin insulation layer 3 is extruded outside the calcined muscovite refractory layer 2 to form a wire core, a plurality of wire cores are twisted to form a cable core, and a flame-retardant filler 7 is arranged in the cable core; a reinforced fire-resistant mica layer 4, a tinned braided shielding layer 5 and a cross-linked low-smoke, halogen-free, flame-retardant polyolefin sheath layer 6 are arranged in sequence outside the cable core.

The central aluminum core 11 of the tinned copper-clad aluminum conductor 1 meets the cable conductor structure size requirements, greatly reduces the conductor weight, and makes the cable lighter; the copper cladding layer 12 improves the cable electrical performance, and the cable resistance meets the standard requirements. The copper cladding layer solves the problems of poor conductivity that are easy to occur when the aluminum conductor is wired; the tinned layer 3 meets the cable 20 degree conductor resistance requirements, and at the same time protects the copper wire, and the internal integrity of the tinned copper-clad aluminum conductor when it encounters moisture and complex external environment erosion, maintains a stable conductor resistance, and makes the cable safer to use and increases the service life of the cable. The use of the tinned copper-clad aluminum conductor of the utility model reduces the weight of the cable conductor, and the cable is lighter. The use of the tinned copper-clad aluminum conductor can effectively solve various problems encountered in conductor crimping.

The utility model is formed by twisting 5 types of soft tinned copper clad aluminum conductors that meet the EN50306-2 standard. The specific process is to twist a plurality of tinned copper clad aluminum conductors 1 together in a concentric twisting manner, the direction is left-handed, and the pitch is 8 to 14 times the bundle diameter. Compared with traditional soft conductors, the twisting pitch is small, the cable conductor is soft, and it is not easy to break the wire, which is convenient for installation in a small space and increases the service life of the cable.

The plurality of tinned copper clad aluminum conductors are twisted together into a bundle and then wrapped with 0.12 mm thick calcined muscovite in two layers with 50% overlap. The wrapping is smooth and the overlap rate is controlled as required to ensure the wrapping coverage stability and to ensure that a stable and uniform protective shell is formed after external flame combustion to achieve circuit integrity.

The calcined muscovite refractory layer 2 is extruded with a layer of low-smoke, halogen-free, flame-retardant, cross-linked polyolefin insulation layer 3, the thickness of which is controlled at a thin insulation level of 0.4 mm, and the extrusion concentricity is controlled at more than 75%, ensuring that the cable passes the 0.6/1kV cable product standard finished product withstand voltage test. On the basis of ensuring good electrical insulation performance, the insulation's oil resistance, flame retardancy, low temperature resistance, and mechanical strength are enhanced, and the cross-linking not only maintains the cable's softness but also improves and improves the insulation's aging resistance.

The cable core is wrapped with a reinforced fire-resistant mica layer 4 before braiding, namely a double layer of 0.12 mm calcined muscovite with 50% overlap, so as to enhance the fire-resistant performance.

The tinned braided shielding layer 5 is a tinned copper wire braided on the surface of multiple wire cores after being cabled. The diameter of the braided single wire is related to the diameter of the wire core. The braided single wire is 0.1-0.15 mm, the braiding machine uses a 16-spindle braiding machine, the braiding density is 80%, and the braiding angle is 15°-35°. The tinned braided shielding layer reduces the electromagnetic interference of control signals and strong electricity, stabilizes the control line, and maintains the softness of the cable for easy bending.

The cross-linked low-smoke halogen-free flame-retardant polyolefin sheath layer 6 adopts the sheath material of Solvay Pandena, which has good mechanical properties and comprehensive protection performance. The utility model cable is mostly used for wiring in locomotive compartment control cabinets and compartment boxes, and will encounter various harsh use environments. The sheath material has excellent oil resistance, acid and alkali resistance, UV resistance, wear resistance, cold resistance, high strength, toughness and aging resistance, and has excellent long-term aging performance, ensuring the cable has a service life of 30 years.

The utility model not only maintains the characteristics of small cable size, small space occupation and easy installation, but also provides continuous power supply when rail transit encounters fire, ensuring basic lighting and safe braking of various safety door control systems. This is an important electrical safety technical measure and an effective measure to ensure the normal operation of key electrical systems. It not only buys precious time for evacuating passengers, but also can maximize the safety of the people and public property within a certain range.

The utility model is composed of a tinned copper-clad aluminum conductor 1, a calcined muscovite refractory layer 2, a low-smoke halogen-free flame-retardant cross-linked polyolefin insulation layer 3, a flame-retardant filler 7, a reinforced refractory mica layer 4, a tinned braided shielding layer 5 and a cross-linked low-smoke halogen-free flame-retardant polyolefin sheath layer 6. Each part has a compact structure and a strict production process control to ensure that it is suitable for installation and use in narrow spaces of rail transit vehicles. The conductor of the cable adopts Class 5 tinned soft body to ensure that the conductor resistance meets the requirements. The conductor twisting pitch is adjusted to be small enough, and the twisting is kept in a regular arrangement to ensure that the conductor outer diameter value is stable and round. The general conductor specification range is ^0.5mm2 ~ ^4mm2 . The tinned copper clad aluminum conductor is wrapped with 0.12mm thick calcined muscovite, and the two layers are wrapped at 50%. The calcined muscovite refractory layer can ensure that an inorganic protective shell is formed when the high temperature flame occurs. Even if the outer layer of combustibles or the surrounding combustibles burn and catch fire, the power line can still be kept intact, and the control switches of the relevant lines can be controlled and the normal safety lighting can be maintained. A low-smoke, halogen-free, flame-retardant, cross-linked polyolefin insulation layer with a higher insulation grade is used. To ensure the flame retardant performance of the cable, its oxygen index should not be less than 29. Since the insulation is generally controlled to be 0.4mm, in order to ensure its mechanical properties, the insulation layer needs to be irradiated, and the insulation strength after irradiation cross-linking is not less than 25N/ ^mm2 . Flame retardant filler 7 is provided in the cable core to enhance the flame retardant effect of the cable and delay the spread of flames. The cable core is wrapped with 0.12mm calcined muscovite, which not only protects the inner insulating core, but also enhances the fireproof performance. The tinned braided shielding layer reduces the broken wires of the cable conductor, and the braided conductor surface is flat. After stripping the sheath, it is not loose, which is convenient for crimping with terminals and connecting with cable terminals, and is convenient for cable installation and use. The cross-linked low-smoke halogen-free flame-retardant polyolefin sheath layer is adopted. After cross-linking, the strength is improved. It not only has better mechanical properties such as wear resistance and low temperature resistance, but also has comprehensive protective properties such as oil resistance and corrosion resistance, which improves the safety protection of the cable and increases the service life of the cable.

Advantages of the utility model:

1. Use tinned soft copper clad aluminum wire to twist 5 types of conductors, which improves the flexibility of the cable, reduces the breakage of the cable conductor, increases the service life of the cable, reduces the weight of the cable conductor, and ensures the quality of the conductor crimping;

2. The calcined muscovite fire-resistant layer is wrapped with double layers of 50% overlap to ensure the integrity of the cable circuit when the flame spreads; before braiding, the cable core is wrapped with double layers of 0.12mm calcined muscovite with 50% overlap to enhance the fire resistance of the cable;

3. The design of irradiated low-smoke halogen-free flame-retardant cross-linked polyolefin insulation layer and cross-linked low-smoke halogen-free flame-retardant polyolefin sheath layer ensures that the cable has high strength, excellent flame retardant performance, low temperature resistance, improved wear resistance, corrosion resistance and other comprehensive protection performance of the cable, improved the safety protection of the cable, and increased the service life of the cable;

4. The cable has a low-smoke, halogen-free, flame-retardant, cross-linked polyolefin insulation layer with a thickness of 0.4mm, and a concentricity of more than 75%. The rated voltage of the cable is increased from the original standard 300/500V to 0.6/1kV, and the finished cable withstand voltage test is 3.5kV/5 minutes. The cable withstand voltage is higher than the standard EN50306 requirements, and the voltage level is increased, so it can work normally under higher system voltage.

Claims (5)

1. A tin-plated copper-clad aluminum conductor fire-resistant flexible cable for rail transit is characterized in that: the low-smoke halogen-free flame-retardant cross-linked polyolefin insulating layer (3), flame-retardant filler (7), reinforced flame-retardant mica layer (4), tinned woven shielding layer (5) and cross-linked low-smoke halogen-free flame-retardant polyolefin sheath layer (6); the tin-plated copper-clad aluminum conductor (1) comprises an aluminum core (11), a copper cladding layer (12) and a tin plating layer (13), wherein the copper cladding layer (12) and the tin plating layer (13) are sequentially arranged outside the aluminum core (11) to form the tin-plated copper-clad aluminum conductor (1); a plurality of tin-plated copper-clad aluminum conductors (1) are bunched together and then externally wrapped with a calcined muscovite fire-resistant layer (2), the calcined muscovite fire-resistant layer (2) is externally extruded with a low-smoke halogen-free flame-retardant cross-linked polyolefin insulating layer (3) to form a wire core, a plurality of wire cores are stranded to form a cable core, and a flame-retardant filler (7) is arranged in the cable core; the cable core is externally provided with a reinforced fireproof mica layer (4), a tinning braided shielding layer (5) and a crosslinked low-smoke halogen-free flame-retardant polyolefin sheath layer (6) in sequence.

2. A tin-plated copper-clad aluminum conductor fire-resistant flexible cable for rail transit as recited in claim 1, wherein: the direction of the beam twisting of the plurality of tin-plated copper-clad aluminum conductors (1) is left, and the pitch is 8-14 times of the diameter of the beam twisting.

3. A tin-plated copper-clad aluminum conductor fire-resistant flexible cable for railway traffic according to claim 1 or 2, characterized by: the calcined muscovite refractory layer (2) and the reinforced refractory mica layer (4) are both calcined muscovite with the thickness of 0.12 mm.

4. A tin-plated copper-clad aluminum conductor fire-resistant flexible cable for railway traffic according to claim 1 or 2, characterized by: the thickness of the low-smoke halogen-free flame-retardant crosslinked polyolefin insulating layer (3) is 0.4mm.

5. A tin-plated copper-clad aluminum conductor fire-resistant flexible cable for railway traffic according to claim 1 or 2, characterized by: the tinning braided shielding layer (5) is formed by braiding tinned copper wires, wherein monofilaments of the tinned copper wires are 0.1-0.15 mm, the braiding density is 80%, and the braiding angle is 15-35 degrees.