RU2558388C2 - Spiral tension clamp - Google Patents

Abstract

FIELD: electricity.

SUBSTANCE: invention is referred to the electric power industry, in particular to spiral tension clamps for wires of overhead transmission lines. The clamp consists of branches (3, 4) of coiled wire strands and an eye ring (2). Circular or trapezoidal branches are wound to a composite core (1) and the eye ring (2) in inserted to their loop (5). Ends (6, 7) of the loop 5 of coiled wire strands are fixed in inverted cones (8, 9) supported by an insert of a cylindrical barrel tightened in the eye ring fixed to the pole of the overhead transmission line. An inner surface of the branches (3, 4) is coated with an abrasive material with the grain size of 0.1-0.5 mcm and the composite core (1) is coated with a coating having the thickness of 0.5-1.5 mm.

EFFECT: design allows more even distribution of mechanical stress along the clamp length, reducing the length of the coiled wires, reducing its weight and finally increasing the reliability of the clamp in the process of its long-term operation.

2 cl, 2 dwg

Description

The invention relates to the field of electric power and can be used on overhead power lines as spiral tension clamps for attaching wires to anchor supports.

Known tension clamp for anchoring the wires of overhead power lines and fiber optic cables of communication lines, containing a U-shaped strand of wire spirals wound on a wire or cable, consisting of two branches and ending at one end with a mounting loop in which the thimble is inserted, while the clamp is also equipped with an additionally introduced U-shaped strand of wire spirals with a thimble embedded in its loop, wound on top of the first strand and having a winding direction opposite to that of the first row, balancer beam with shoulders of unequal length, each of which through a short and accordingly long articulated link is connected to the thimble so that these U-shaped strands of wire spirals are offset from each other along the longitudinal axis of the wire or cable by 0.5-2 steps coiling [1].

In this technical solution, the applicant set the task to achieve full compensation of the torques created by the strands and acting on the clamp, which led to a significant complication of the design of the clamp; However, in practice, tension clamps with such characteristics are often not widely used.

Also known is a spiral tension clamp for anchoring wires of overhead power lines or cables of overhead communication lines, containing either a U-shaped strand of wire spirals consisting of two branches wound either on a wire or cable or on a protector mounted on a wire or cable one end ending with a mounting loop in which the thimble is embedded; it is made in the form of a two-layer structure with an additionally introduced U-shaped strand of wire spirals consisting of two branches and ending with a fastening loop, while the additionally introduced strand has a winding direction that is opposite to the direction of winding of the first strand so that if the wire spirals of the first strand have a right winding, then the wire spirals of the additionally introduced strand have left winding, and its branches are wound on top of the branches of the first strand, wound on a wire or cable, or on a wire ode or cable protector, and both of the above strands fastening loops embedded in the thimble [2].

This well-known clamp is distinguished by good operational reliability due to the introduction of an additional strand of wire spirals into the design, but only when fixing the clamp on standard wires widely used on overhead power lines. The use of clamps on the new composite core wires that are being quickly introduced at present remains quite problematic, since the technical characteristics of the material of their strands of wire spirals do not correspond to the physical and mechanical characteristics of such wires.

The closest technical solution to the proposed one is a spiral tension clamp for hanging uninsulated wires of overhead power lines, containing a strand of spiral wires whose branches are wound on the wire and a thimble is inserted in its loop [3].

The specified technical solution is not universal, since it is not designed for use on overhead power lines equipped with wires of a new progressive design, namely, wires with a composite core, which are characterized by high physical and mechanical characteristics.

The applicant set himself the task of developing a new design of a tension clamp for attaching wires to the anchor supports of overhead power lines, namely composite wires or wires with a composite core, which are characterized by high physical and mechanical characteristics: operational reliability, high temperature resistance, high current carrying capacity and other positive qualities. The technical result, which consists in ensuring the effective operation of tension clamps on overhead power lines with composite wires or wires with a composite core, is achieved due to a new set of design features of the proposed spiral tension clamp, set forth in the following claims: "spiral tension clamp for hanging bare wires overhead power lines containing a strand of wire spirals, the branches of which are wound on a wire or composite the core of the wire, and a thimble attached to the support is embedded in its loop; a strand of wire spirals is made of a material whose physical and mechanical characteristics are equivalent to the physical and mechanical characteristics of the core material and the wire itself or its composite core, wire spirals of a round or trapezoidal shape are wound onto a wire or composite core with a variable winding pitch and an angle of inclination α of the wire spirals measured from the cross section of the clamp perpendicular to it or the core of the longitudinal axis x, changing according to the following law: α (x) = α ₀ + s (x / l) ^k , where e α ₀ - the initial angle of inclination of the wire spirals relative to the cross section of the clamp or core; l is the length of the clamp; c and k are numerical parameters ranging from: c = 0.2 ÷ 0.8 and k = 1 ÷ 3, the ends of the loop of a strand of wire spirals are clamped in inverse cones, resting on the liner of a cylindrical glass fixed in the thimble, and the angle β of the inverse cones is approximately equal to the angle of inclination α of the wire spirals of the strand, the inner surface of which is covered with a layer of abrasive with a grain size selected in the range 0.1–0.5 μm, while the core of the wire or core and wire made of composite material have a coating whose thickness is equal to 0.5 ÷ 1.5 mm; the angle of inclination of the wire spirals relative to the transverse clamp changed according to the above law with numerical parameters c and k equal to 0.35 and 2.0, respectively; for the option of mounting the clamp on a composite core with a diameter of 6 mm, it has the following physical and mechanical characteristics: spiral wire diameter d = 2.1 mm, number of wires in the clamp n = 7, initial angle of inclination of the wire spirals relative to the cross section of the clamp or core α ₀ = 98 ° or 8 ° from the longitudinal axis x of the clamp, the modulus of elasticity of the wire material is E = 2000 kg / mm ² , the Poisson's ratio is μ = 0.29, the interference fit, i.e. the difference between the radii of the wire spirals in the free state and mounted on the core, ω = 0.1 mm, friction coefficient k _T = 0 , 5, the maximum allowable load on the clamp N = 3500 kg.

The invention is illustrated by drawings, where figure 1 shows a General view of a tension clamp made according to the present invention, a view perpendicular to the wires of an overhead power line; figure 2 is a view along arrow a in figure 1.

The inventive spiral tension clamp for hanging bare wires of overhead power lines, for example, composite wires or wires with a composite core 1 (Fig. 1) consists of a strand of wire spirals and a fastening device in the form of a thimble 2. Branches 3, 4 strands of wire spirals are wound onto a composite the core 1, and a loop 2 is inserted into the loop 5 of the strand of wire spirals, which is attached to the support (not shown) of the overhead power line. The wire spirals of branches 3, 4 of the strand can be made round or trapezoidal and are wound on a composite core 1 with a variable winding pitch, changing according to the following law: α (x) = α ₀ + s (x / l) ^k , where α ₀ - the initial angle of inclination of the wire spirals relative to the cross section of the clamp or core; l is the length of the clamp; c and k are numerical parameters varying in the range: c = 0.2 ÷ 0.8 and k = 1 ÷ 3, for example, a practical option, when the angle of inclination of the wire spirals relative to the transverse clamp changed according to the above law with numerical parameters c and k equal to 0.35 and 2.0, respectively.

The ends 6, 7 of the loop 5 of the strand of wire spirals are fixed in the inverse cones 8, 9, which are supported by the insert 10 of the cylindrical cup 11 fixed in the thimble 2. The angles β of the inverse cones 8, 9 are selected so that they are approximately equal to the angle of inclination α wire spirals strands, which allows you to balance and align the torques that occur during operation of the tension clamp.

The inner surface of the branches of 3, 4 wire spirals of the strand is covered with a layer of abrasive with a precisely selected grain size in the range 0.1 ÷ 0.5 μm, and the composite core 1 of the wire or core and wire with a special coating 12, the thickness of which is 0.5 ÷ 1 5 mm.

A strand of wire spirals is made of a material having physical and mechanical characteristics close to the physical and mechanical characteristics of the core material and the wire itself or its composite core 1.

As an example, for the option of mounting the clamp on a composite core with a diameter of 6 mm, the clamp has the following physical and mechanical characteristics: diameter of the spiral wire d = 2.1 mm, number of wires in the clamp n = 7, the initial angle of inclination of the wire spirals relative to the cross section of the clamp or core α ₀ = 98 ° or 8 ° from the longitudinal axis x of the clamp, modulus of elasticity of the wire material E = 2000 kg / mm ² , Poisson's ratio µ = 0.29, interference, that is, the difference between the radii of the wire spirals in a free state and mounted on the core , ω = 0.1 mm, coefficients ent friction k _T = 0,5, the maximum permissible load on the nip N = 3500 kg.

The clamp is mounted as follows:

The clamp is mounted either on a wire with a composite core, or simply on a composite core 1. In both versions, both the wire and the composite core can have a special coating 12 of a certain thickness, which enhances the adhesion of wire spirals with them. The branches 3, 4 of the wire spirals of the strand are passed through the reverse cones 8, 9, the end 13 of the composite core 1 is inserted into the insert 10 of the cylindrical glass 11, the loop 5 of the wire spirals of the strand is inserted into the thimble 2 and both branches of 3, 4 wire are wound sequentially on the composite core 1 strands of strands, after which the mounted clamp by means of a thimble 2 is fixed to the anchor support of the overhead power line.

The proposed spiral tension clamp belongs to the class of linear fittings, currently being intensively introduced on overhead power lines. These fittings are developed for the use of new wires, such as high-temperature wires or composite wires, which place high demands on the linear fittings used, in particular spiral tension clamps. Due to the execution of a strand of wire spirals from a material similar in characteristics to the characteristics of composite materials from which wires with a composite core are made, winding wire spirals in a specific way, with a variable step described by the mathematical ratio, the fastening device of the clamp to the support reinforced structure and other new technical solutions were able to more evenly distribute forces along the clamp length, reduce the length of the clamp wire spirals, that is, reduce its weight and ultimately develop an efficient, reliable spiral tension clamp for overhead power lines with composite wires.

Information sources

[one]. Description of the invention to patent No. 2315408 "Spiral tension clamp", H02G 7/02, claimed August 30, 2006, published January 20, 2008.

[2]. Description of the invention to patent No. 2291535 "Spiral tension clamp", H02G 7/02, claimed 12.10.2005, published 10.01.2007.

[3]. Description of the invention to patent No. 2272346 "Spiral tension clamp", H02G 7/02, claimed July 29, 2004, published March 20, 2006.

[four]. The monthly production and technical journal “Electric Stations” No. 1, 1998, pp. 3-5, Fig. 2.

[5]. USSR copyright certificate No. 1014083, H02G 7/02, dated 11.08.81

[6]. Description of the invention to patent No. 2035104 "Method for the manufacture of spiral-type tension clamps", H02G 1/04, published 05/10/95.

[7]. US patent No. 4791237, published December 13, 1988

[8]. French Patent No. 2215731, published 08/23/1974

Claims (2)

1. Spiral tension clamp for hanging bare wires of overhead power lines, containing strands of wire spirals, the branches of which are wound on a wire or composite core of the wire, and a thimble mounted on a support, characterized in that the strands of wire spirals are made of material, physical and mechanical characteristics which are identical to the physical and mechanical characteristics of the core material and the wire itself or its composite core, wire spirals of strands of a round or trapezoidal shape you are on a wire or composite core with a variable angle of elevation α of the wire spirals, counted from the cross section of the clamp perpendicular to it or the core of the longitudinal axis x, while the ends of the strands of wire spirals are clamped in the back cones of the thimble, resting on the liner of a cylindrical glass fixed in the thimble, moreover, the angle β of the inverse cones is approximately equal to the angle of elevation α of the wire spirals of the strands, the inner surface of which is covered with a layer of abrasive with a grain size selected in the range 0.1–0.5 mm. 2. The clamp according to claim 1, characterized in that the core of the wire or core and wire made of composite material have a coating whose thickness is 0.5 ÷ 1.5 mm.

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