RU2351485C2 - Method of contact steel aluminium wire manufacturing - Google Patents

Abstract

FIELD: electric equipment.

SUBSTANCE: invention concerns electric equipment, particularly constructions and methods of contact steel aluminium wire production for power supply to electrical vehicles. Method involves application of annular pressed-out aluminium layer onto core at aluminium press by processing tool in the form of matrix and moving rod with at least one conical work surface, cooling by water, and winding on receiving spool. Steel core is made out of one round steel wire, moving rod features work surface in the form of two conjugated conical surfaces with cone angle at wire head side larger than sharp cone angle at wire base side, and water cooling is performed in at least 1.5 m distance from aluminium pressing area.

EFFECT: significantly improved electric properties of wire, prevented corrosion, enhanced resistance to stretch loads.

3 cl, 1 dwg

Description

The invention relates to the field of electrical engineering, in particular to designs and methods for the manufacture of contact steel-aluminum wires designed to power the electrified vehicles.

A known method of manufacturing a contact steel-aluminum wire, in which the steel part of the complex profile having the base of the contact part made in radius and the conductive part of the aluminum profile containing the head and neck are connected by cold rolling. (N.I. Belorussov et al. Electrical cables, wires and cords. M: Energoatomizdat, 1988, p. 43-45).

However, this wire has disadvantages:

- leaking contact of the steel and aluminum parts in the manufacturing process, which leads to large transition resistance and significant loss of electricity;

- the presence of delamination of the wire (steel and aluminum parts) in places of deformation during bending, etc., which is normalized and should not be more than 1.2 mm, which also leads to energy losses;

- the presence of corrosion, since both elements of the wire (steel and aluminum parts) are not protected from moisture, which leads to destruction of the wire;

- voltage is removed by current collectors from the steel part of the wire, which leads to additional energy losses in the steel part of the wire due to the high resistivity of steel compared to aluminum;

- the significant complexity of the manufacture of the wire due to the complex steel profile and, accordingly, the complexity of the surrounding aluminum profile.

The prototype is a method for applying aluminum sheaths to cables (wires). According to the method, an annular layer of extruded aluminum is applied to the cable core on an aluminum press using a technological tool in the form of a matrix and a mandrel having at least one conical working surface. The temperature in the aluminum pressing zone is about 460-500 ° C. Immediately after the tool: mandrel and matrix, the cable enters the scrubber so that the cable insulation does not burn. The temperature after cooling with water should be for cables with polyethylene insulation 50 ° C, and for other cables 70 ° C. Then the cable is wound on the receiving drum (Production of cables and wires. Edited by NI Belorussov and IB Peshkov. M.: Energoatomizdat. 1981. Chapter 11.7. The technology of pressing aluminum shells. S.479-485) .

The disadvantage of this method is that the cable (wire) immediately after the tool: mandrel and matrix, enters the choking device, resulting in the separation of the core and extruded aluminum, which reduces the tensile strength of the wire and increases losses. In addition, using a mandrel with one working conical surface, it is impossible to impose a complex aluminum profile with various wall thicknesses on the steel core.

The basis of the present invention is the task to create such a method of manufacturing contact steel-aluminum wire in which a new execution of operations, a new combination of them, a new technological tool, a new temperature regime would make it possible to manufacture a wire of complex profile, increase the resistance of the wire to tensile loads, and reduce the electrical resistance of the wire and losses.

The problem is solved in that according to the method of manufacturing a contact steel-aluminum wire, comprising applying to the core on an aluminum press an annular layer of extruded aluminum using a technological tool in the form of a matrix and a mandrel having at least one conical working surface, water cooling and winding on the receiving drum, according to the invention, the steel core is made of one steel round wire, while the mandrel has a working surface in the form of two mating conical surfaces rhnostey, wherein the cone angle of the head end of wire greater than the acute angle of the cone from the base wire and wire cooling water is carried out at a distance of not less than 1.5 m from the nip aluminum.

The advantages of the proposed method are that the steel core is made of one steel round wire, while the mandrel has a working surface in the form of two mating conical surfaces, the cone angle from the side of the wire head being larger than the acute cone angle from the side of the wire base, the steel part tightly crimped with a continuous layer of aluminum, which ensures reliable electrical contact along the entire length of the wire. In places of deformation and during operation there is no delamination, which reduces losses and increases the reliability of the wire. During long-term operation, there is no penetration of oxygen, harmful gases and substances, as well as moisture to the steel core, as a result of which there is no corrosion, which increases the service life of the wire.

Due to the fact that water cooling of the hot wire is carried out at a distance of at least 1.5 m from the aluminum pressing zone, the steel core actually merges with the extruded aluminum profile at the molecular level, that is, two metals diffuse: steel and aluminum, which increases the resistance of the wire to tensile loads, reduces the transient resistance at their boundary and reduces losses.

The proposed method allows to make a wire of large building lengths. In addition, the extruded aluminum part of the wire is more durable than cast.

The steel core of one steel round wire can be passed through the correct device before applying aluminum, which improves the quality of aluminum on the steel wire, eliminating delamination.

The angle of the cone of the mandrel from the side of the base of the wire can be equal to 45 °, and the angle of the cone of the mandrel from the side of the head of the wire depends on the displacement of the steel core along the axis of symmetry to the base of the wire and can be no more than 60 °, as a result of which the steel core is tightly compressed by a continuous layer of aluminum parts, providing reliable electrical contact along the entire length of the wire.

In the wire, the steel core is displaced along the axis of symmetry of the aluminum profile from the base of its contact part, which significantly reduces electrical losses compared to the prototype, since when the aluminum part is worn in the lower current-collecting part of the wire, current is removed both from the steel central part and from aluminum parts located on the sides.

The proposed method is schematically illustrated in the drawing, which shows in cross section a contact steel-aluminum wire. The drawing shows 1 - a steel core, 2 - a conductive part of aluminum, 3 - a head, 4 - a neck, 5 - the base of the contact part.

The contact steel-aluminum wire consists of a steel part 1 and a conductive part 2 of an aluminum profile connected together and containing a head 3, a neck 4 and a base of the contact part 5, made in radius. In the wire, the steel part is made in the form of a core 1 from one round steel wire directly covered by a continuous layer of extruded aluminum, and the said core is shifted along the symmetry axis of the aluminum profile 2 to the base of its contact part 5.

Example. A method of manufacturing a contact steel-aluminum wire is as follows. Contact steel-aluminum contact wire with a cross-section of 180/28 mm ² consists of a steel core 1 in the form of a round steel wire of low-carbon thermally untreated, second class, high accuracy according to GOST 3282, with a diameter of 6 mm. On top of the steel wire 1, a continuous layer of A7 grade aluminum is pressed on an aluminum press using a technological tool: a matrix and a mandrel, which has two mating conical working surfaces. Moreover, the angle of the cone of the mandrel from the side of the base of the wire is 45 °, and the angle of the cone of the mandrel from the side of the head 3 of the wire depends on the displacement of the steel core along the axis of symmetry to the base 5 of the wire and is 59 °. In this case, the steel core 1 is offset along the axis of symmetry of the aluminum profile 2 by a distance of 0.8 mm from the base of its contact portion 5.

Water cooling of the hot wire (temperature 460-500 ° C) is carried out at a distance of 1.9 m from the aluminum pressing zone. Then conduct the winding of the wire on the receiving drum.

It should be said that the steel wire can be made of various shapes, for example, in the form of a segment with a flat part at the base 5 of the wire.

Claims (3)

1. A method of manufacturing a contact steel-aluminum wire, comprising applying to the core on an aluminum press an annular layer of extruded aluminum using a technological tool in the form of a matrix and a mandrel having at least one conical working surface, water cooling and winding on the receiving drum, characterized in that the steel core is made of one steel wire, while the mandrel has a working surface in the form of two mating conical surfaces, and the angle of the cone from the side of the head p the wire is larger than the acute angle of the cone from the side of the base of the wire, and the wire is cooled with water at a distance of at least 1.5 m from the aluminum pressing zone. 2. The method according to claim 1, characterized in that the steel core of one steel wire is previously passed through the correct device before applying aluminum. 3. The method according to claim 1, characterized in that the angle of the cone of the mandrel from the side of the base of the wire is 45 °, and the angle of the cone of the mandrel from the side of the head of the wire depends on the displacement of the steel core along the axis of symmetry to the base of the wire and is not more than 60 °.