RU2365008C1 - Slip-type clamp - Google Patents

Abstract

FIELD: electrical engineering.

SUBSTANCE: invention relates to electrical engineering and can be used as ram clamps to connect aluminium, steel-aluminium and protected wires of overhead power lines. Proposed clamp comprises casing (1) and several rams (2) that have flutes (8, 9). Connected wires (6, 7) are laid in aforesaid flutes and bolted together. Casing (1) and rams (2) represent equal-strength horizontal structures with their geometrical sizes specially selected. For example, A=(1.0 to 1.2)·(d_{wire max.}+d_bolt), where A is the distance between flute vertical axes, d_{wire max.} Is the maximum diametre of wire from the set of wires, d_bolt is the diametre of tensioning device bolt, H=(0.3 to 1.2)·A, R=(0.9·1.1)·H, where H is the height of casing and rams, R is the radius of outer curvature of flutes (8, 9). Casing (1) and rams (2) have rectangular flat (10) with width B and height h, their magnitude being determined from the relationship B=(0.8 to 1.1)·D _{dia.circums circ.nut}, where D _{dia.circums circ.nut} is the diametre of circumscribed circle of nut (4) fitted on tensioning device bolt (3), h=(0.1 to 0.3)·H. Surfaces of flutes (8, 9) have triangular ledges (11) with round apices and triangle base.

EFFECT: metal savings, reduced production costs.

3 cl, 4 dwg

Description

The invention relates to the field of electric power and, in particular, to connecting die clamps (type PA), intended for connecting aluminum, steel-aluminum and protected wires in the cables of anchor supports, as well as for branching overhead transmission lines.

Known die clamp for lightning protection cables of overhead power lines, comprising a housing made in the form of two dies with grooves for cables or wires, and a clamping mechanism, for example a bolt type, one of the dies made in the form of a straight plate, and each gutter of the other die is formed by two radii smoothly passing sequentially from one to another so that the tail parts of the grooves of this plate and the ends of the straight plate are made with overlapping free zone for all diameters of the used cables and wires rows, with the absolute value of the radius of rounding exceeds troughs dies absolute value of the second radius twice [1].

This design actually refers to the die loop clamps used on overhead power lines of 35-110 kV for grounding lightning protection cables, which predetermined the design features of the dies: one in the form of a plate, and the other with grooves of different rounding radii. Such a constructive solution leads to a significant complication of the technological process for the production of clamps and to an unjustified increase in material costs for their manufacture and operation.

Also known is a connecting die clamp for connecting wires of an overhead power transmission line, comprising a body made of a shaped profile with grooves for laying connected wires in them, at least one profile cross section die with grooves identical in geometrical dimensions to the body grooves, and a tightening device fastening the case and dies with the line wires laid in their gutters [2].

Of the main disadvantages of this known technical solution, the following can be distinguished:

- the sealing strength of the connected wires does not always exactly comply with the established operating standards due to the presence of large technological gaps between the bolts of the tightening device and the wires, which does not allow to provide the optimal specific metal consumption of the product and the optimal sealing strength of the wires;

- profiles of the body and dies are selected and their characteristics are calculated without taking into account equal strength over the entire cross section, which also leads to an unjustified increase in the metal consumption of the clamp as a whole.

The applicant was given the practical task of developing a connecting die clamp for mass production, which, in industrial use, would provide a positive technical result, which consists in ensuring a normalized sealing strength of the wires in the clamp and reducing its metal consumption. This positive technical result is achieved due to the new set of essential structural features of the proposed clamp, given in the following claims: "connecting die clamp for connecting the wires of an overhead power line, comprising a body made of a shaped profile with grooves for laying connected wires, at least , one die with a profile section with grooves identical in their geometrical dimensions to the grooves of the housing, and a tightening device, with a fixing case and dies with line wires laid in their troughs, moreover, the profiles of the case and dies are made equally strong over their entire cross-section due to the choice of the following relations for the distance A between the vertical axes of the trenches, the height H of the casing and the dies, the radius R of the external curvature of the troughs and the radius r trough ends: A = (1.0 ÷ 1.2) · (d _{ave. max.} + d _bolts ) so that the wire of maximum diameter from the group of mounted wires in the clamp is located without a gap with the bolts of the tightening device, where d _{pr . max} - the maximum th wire diameter of wires of a group mounted in a clamp, d _bolt - diameter of bolt tightening device, H = (0,3 ÷ 1,2) · A , R = (0,9 ÷ 1,1) · H, while the profiles cases and dies are made in the upper part with a rectangular platform, the width B and height h of which are determined from the following relations: B = (0.8 ÷ 1.1) · D _{descript. surround nuts} where D _{des. surround nuts} - the diameter of the described circle of the nut mounted on the bolt of the tightening device, h = (0.1 ÷ 0.3) · N, respectively; the radius r of the ends of the gutters is selected within r = (0.4 ÷ 1.5) mm; along the surface of the grooves of the casing and the dies made triangular protrusions with a height of h ₁ = (0.3 ÷ 0.4) mm, an angle at the apex of the triangle α = (40 ° ÷ 65 °) and the distance between the vertices of the protrusions l = (0,07 ÷ 0.12) · r _yellow , where r _yellow is the radius of rounding of the gutter, while the top and bottom of the triangle of protrusions are rounded in radii: R ₁ = (0.07 ÷ 0.1) mm and R ₂ = 2R ₁ , where R ₁ - the radius of rounding of the top of the triangle of the gutter protrusions, R ₂ - the radius of rounding of the base of the triangle of the gutter protrusions.

The invention is illustrated by drawings, where in Fig.1 is a General view of the connecting die clamp made according to the present invention, a front view (along the connected wires of the line); figure 2 is the same as in figure 1, a top view; figure 3 - profile of the housing (dies) with the main defining its design geometric parameters in figure 1; figure 4 is a view of E in figure 3, an enlarged scale profile of the surface of the gutter.

The inventive connecting die clamp (serial type PA), designed to connect aluminum, steel-aluminum and protected wires (SIP-3) in the cables of anchor supports, as well as for branching overhead power transmission lines, consists of a housing 1, one or more dies 2 and a tightening a device, which is a set of bolts 3 with nuts 4 and washers 5, through which the housing 1 and the dies 2 are fastened together with the connected wires 6, 7. In the housing 1 and the dies 2 grooves 8, 9 are made, which in their geometric the dimensions are the same both in the housing 1 and in the dies 2. The profiles of the housing 1 and dies 2 are made equally strong over their entire cross-section, which is achieved by optimizing their geometric dimensions and parameters so that when mounting a wire with a maximum diameter of the group mounted in the clamp wires 6, 7 was installed without a gap with the bolts 3 of the tightening device. This embodiment of the profiles of the housing 1 and dies 2 is necessary in order to reduce the maximum bending moment in the most dangerous section of the clamp and thereby reduce the height of the profile. At the same time, an increase in the sealing strength of wires 6, 7 is achieved, since when they are pulled together they acquire an oval shape and are pressed into the body of the bolts 3, creating additional friction of the wires 6, 7 with bolts 3.

The calculations and experimentally established the following ratios of geometric dimensions and parameters of the profile structures of the housing 1 and dies 2 of this clamp, namely A = (1.0 ÷ 1.2) · (d _{ave. Maxim} + d _bolts ), where d _{ave. Maxim} - the maximum diameter of the wire from the group of wires mounted in the clamp, d _bolts - the diameter of the bolt of the tightening device; N = (0.3 ÷ 1.2) · A, R = (0.9 ÷ 1.1) · H, r = (0.4 ÷ 1.5) mm, where r is the radius of the ends of the grooves 8, 9. In addition , the profiles of the housing 1 and dies 2 are performed in the upper part with a rectangular platform 10, the width B and height h of which are selected from the following relations:

B = (0.8 ÷ 1.1) · D _{descript. surround nuts} where D _{des. surround nuts} - the diameter of the described circle of the nut 4 mounted on the bolt 3 of the tightening device, h = (0.1 ÷ 0.3) · H, respectively.

Along the surface of the grooves 8, 9 of the housing 1 and the dies 2, protrusions (notches) 11 of a triangular shape (in the form of a triangle) with a height of h ₁ = (0.3 ÷ 0.4) mm, an angle at the apex of the triangle α = (40 ° ÷ 65 °) and the distance between the peaks of the protrusions l = (0.07 ÷ 0.12) · r _yellow , where r _yellow is the radius of rounding of the gutter. The top and bottom of the triangle of protrusions 11 are rounded in radii: R ₁ = (0.07 ÷ 0.1) mm and R ₂ = 2R ₁ , where R ₁ is the radius of rounding of the top of the triangle of the protrusions of the gutters, R ₂ is the radius of rounding of the base of the triangle of protrusions gutters.

The invention works as follows.

The ends of the connected wires 6, 7 must undergo preliminary training directly to the installation of the clamp. To do this, they are cleaned with a metal brush under lubrication, for example, neutral petroleum jelly or other lubricant equivalent in its characteristics. Mounted clamps must be disassembled with unscrewed nuts 4 and removed bolts 3 and also be prepared for installation. The contact surfaces of the housing 1 and dies 2 are also cleaned with a metal brush under lubrication to prevent oxidation of the cleaned surface. Then, the connected ends of the wires 6, 7 are laid in the grooves 8 of the housing 1 so that they exit from the ends of the grooves 8 by 8 ÷ 10 mm, are successively covered by the grooves 9 of the dies 2 and fastened with bolts 3, tightening the nuts by hand. After installing all the nuts 4, the key is tightened with a wrench of all nuts 4 bolts 3 to a controlled torque.

The use of the proposed connecting die clamp, in which the maximum diameter wire from the set of wires installed in it is located without any gap with respect to the bolts of the tightening device, makes it possible to reduce the maximum bending moment in the weakest section (in the area of the bolt holes) of the housing profiles and clamping dies, reduce the height of the profiles and thereby achieve significant savings in material consumption (metal saving). In addition, the additional effect provided by this design of the clamp is reduced to the necessary increase in the strength of the termination of wires, since when tightening the bolts, the wires become oval and, pressing into the body of the bolts, create additional friction between the wires and the contact surface of the bolts. In addition, due to the possibility of using bolts of a tightening device of increased strength, it was possible to reduce their cross section while reducing (optimizing the profiles) the width of the dies and the casing, that is, to preserve the calculated specific pressure in the clamp, and ultimately reduce the metal consumption.

The proposed connecting die clamps are produced in serial batches and are widely used on overhead power lines.

Information sources

[one]. Description of the invention to the patent of the Russian Federation No. 2024140, cl. Н02G 7/05, dated July 28, 1992, published November 30, 1994, bulletin No. 22.

[2]. Finnish patent No. 52641, cl. H01R 7/24, dated 05.12.1975, published 09.02.1978

Claims (3)

1. A connecting die clamp for connecting wires of an overhead power transmission line, comprising a body made of a shaped profile with grooves for laying connected wires in them, at least one profile cross-section die with grooves identical in geometry to the body grooves, and a tightening device fastening the casing and the dies with the line wires laid in their troughs, moreover, the profiles of the casing and the dies are made equally strong over their entire cross section due to the choice of the following ratios A distance A between the vertical axes of troughs, the height H of the housing and the ram, the radius R of curvature of the outer radius of the grooves and ends of launders r A = (1,0 ÷ 1,2) · (d _pr.maksim. + d _bolt) in such a way that the maximum diameter wire from the group of mounted wires in the clamp was located without a gap with the bolts of the tightening device, where d _pr.maxim. - the maximum diameter of the wire from the group of wires mounted in the clamp, d _bolts - the diameter of the bolt of the tightening device, N = (0.3 ÷ 1.2) · A, R = (0.9 ÷ 1.1) · H, while the profiles of the body and dies are made in the upper part with a rectangular platform, the width B and height h of which are determined from the following relations:
B = (0.8 ÷ 1.1) · D _{descript. surround nuts} where D _{des. surround nuts} - the diameter of the described circumference of the nut mounted on the bolt of the tightening device, h = (0.1 ÷ 0.3) · H, respectively. 2. The clamp according to claim 1, characterized in that in it the radius r of the ends of the gutters is selected within r = (0.4 ÷ 1.5) mm. 3. The clamp according to claim 1, characterized in that along it along the surface of the grooves of the casing and the dies are made protrusions of a triangular shape with a height of h ₁ = 0.3 ÷ 0.4 mm, an angle at the apex of the triangle α = 40 ÷ 65 ° and the distance between the peaks of the protrusions l = (0.07 ÷ 0.12) · r _yellow , where r _yellow is the radius of rounding of the gutter, while the top and base of the triangle of the protrusions are rounded in radii R ₁ = 0.07 ÷ 0.1 mm and R ₂ = 2R ₁ , where R ₁ is the radius of rounding of the top of the triangle of the gutter protrusions, R ₂ is the radius of rounding of the base of the triangle of the gutter protrusions.

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