RU2786932C1 - Tensioning wedge-jointed clamp - Google Patents

Abstract

FIELD: electric power industry.

SUBSTANCE: wedge-jointed tension clamp for fixing wires and lightning cables of overhead power lines contains a housing formed by two sidewalls (1), closed from the upper and lower sides by covers (2). In the housing there are upper (3) and lower (4) wedges for installation on a wire or cable, steel tension plates (9) on the sides of the housing, fastened at the other end with a steel threaded finger (10), devices for pre-screed wedges (5) and a device for clamping the wire. The sidewalls (1) are made of a solid hardened aluminum profile at the same time with bosses made by milling and having an annular groove with grooves along the perimeter of the boss, on which steel tension plates (9) are fixed. The device for screed wedges consists of two clamps (5) of an aluminum profile having a rectangular shape, fastened with two stainless non-magnetic bolts (7) at the edges.

EFFECT: invention enables to increase the reliability and strength of the clamp.

8 cl, 12 dwg

Description

The invention relates to the field of electric power industry. It will find application in tensioning and fastening on the supports of high-voltage power transmission lines (power lines) lightning cables with a diameter of 9 ... 9.5 and 11 ...

There are various technical solutions in the area under consideration.

A patent of the Russian Federation for a utility model No. 48439 (IPK H01R 4/38, published on 10.10.2005) is known. The wedge-jointed clamp contains a body formed by two cheeks and two sidewalls fastening the cheeks to each other, each cheek consists of a base and two side surfaces adjacent to the base, the base of each cheek in the longitudinal direction has the shape of a trapezoid, the side surfaces of the cheeks and the sidewall are made with the possibility of forming lock connection between the corresponding sidewall and the side surfaces of the cheeks. Each sidewall and the side surface of each cheek have profiles, while the side surfaces of each cheek serve as guides for the sidewalls, the clamp contains two wedges installed in the body along its longitudinal direction, while each wedge has a shape that ensures its installation in the body with the possibility of contact along of its surface with the inner surfaces of the corresponding sidewall and cheeks, the surfaces of the wedges facing each other are made with grooves designed to receive the wire. The wedges are installed in the body with the formation of protruding sections from the wider side of the body, on the protruding from the body section of each wedge there is an overlap, conjugated with a section oriented along the wedge and having the shape of a curved surface that provides coverage and retention of the wire. The influx is designed to accommodate holes for fasteners, on the base of the cheek there is a boss for attaching the clamp.

A patent of the Russian Federation for a utility model No. 59894 (IPC, published on December 27, 2006) is known. Forged or stamped connecting clamp is made of aluminum alloy, contains clamp fastening elements to the power line, clamp fastening elements are located with the possibility of clamp installation so that the direction of the fibers of the clamp material coincides with the direction of tensile loads acting on the clamp.

There is also a patent of the Russian Federation for a utility model No. 145029 (IPK H02G 7/00, published on September 10, 2014). SUBSTANCE: tension wedge-jointed clamp for fixing wires of overhead power lines contains a body consisting of two sidewalls connected by planks, upper and lower wedges and rods located in the body, made with the possibility of connection with an insulating suspension of a power line. The clamp is mounted on the wire with the formation of a conical contact surface between the inner surface of the housing and the outer conical surface of the upper and lower wedges, while the wedges are made with the possibility of longitudinal movement along the mentioned contact surface at a distance A.

Known clamps made according to patents No. 48439, No. 59894, No. 145029 have the necessary strength, but have the following disadvantages:

- are not designed and are not able to hold the lightning cable;

- for the manufacture of clamps, powerful vertical hydraulic forging presses with great effort are needed;

- workpieces for stamping sidewalls, wedges and other components for these presses are produced by extrusion on horizontal hydraulic presses, which significantly increases metal consumption, the weight yield of suitable products is 20 ... 40%, against 50 ... 70% according to the proposed option;

- a long technological process is required, which increases the complexity of manufacturing and, accordingly, the cost of their production, which leads to an increase in the cost of clamps.

Known patent of the Russian Federation for the invention No. 2368049 (IPC H02G 7/02, published 09/20/2009), which is the closest to the proposed solution in terms of essential features, respectively, taken as a prototype. SUBSTANCE: tension wedge clamp for fastening wires and cables of overhead power transmission lines contains a housing formed during the assembly of the clamp, at least two side plates closed from the upper and lower sides with covers, upper and lower wedges of a rectangular profile with segmented grooves for installation on a wire or cable, steel tension plates of the body, fastened at the other end with a steel threaded pin for connection with an insulating suspension of the line, and devices for pre-tightening of wedges.

Known tension wedge clamp has low reliability, does not withstand the required load, does not provide the necessary strength of the wire clamp, for its manufacture requires a complex process, which greatly increases the cost of products.

Thus, the technical problem in the area under consideration lies in the fact that all currently known tension wedge-jointed clamps either require significant costs for their manufacture, which leads to an unreasonably high cost of products, or have low reliability and strength. It is proposed to solve this technical problem by creating a wedge-jointed tension clamp of an improved design.

So, the technical result of the invention is to increase the strength and reliability of the tension wedge-jointed clamp while simplifying the process, which reduces the weight and cost of the product.

The technical result is achieved by the fact that in the wedge-jointed tension clamp for fixing steel-aluminum wires (hereinafter referred to as AC wires) and lightning cables of overhead power lines, containing a body formed during the assembly of the clamp, at least two sidewalls, closed from the upper and lower sides by covers, placed in the body, upper and lower wedges of a rectangular profile with segment-shaped grooves for installation on a wire or cable, steel tension plates installed at one end on the sidewalls and fastened at the other end with a steel threaded pin for connection with an insulating suspension of the transmission line, and devices for pre-tightening the wedges and wire or cable, it is proposed to make the sidewalls from a solid hardened aluminum profile together with bosses made by milling and having an annular groove with grooves along the perimeter of the boss, on which steel tension plates are put on. The device for preliminary tightening of the wedges and the device for pressing the wire or cable to the lower wedge is proposed to be made from two clamps made of a rectangular aluminum profile and fastened with two stainless non-magnetic bolts at the edges.

Additional differences are:

- a threaded pin for connecting steel tension plates with an insulating suspension of the line is a bolt with a rounded head without a cotter pin;

- wedges made of hardened aluminum profiles with streamlined protrusions with applied corrugation on the inside;

- corrugation is made with non-sharp edges; (Fig. 9)

- to install the clamp on the cable, additional inserts are installed in the grooves of the wedges (Fig. 10), in which the radius R is equal to half the diameter of the lightning cable, made of non-hardened soft corrosion-resistant aluminum and fixed to the wedges with aluminum rivets (Fig. 11):

- sidewalls, covers, wedges, clamps and additional liners are made by extrusion (hot pressing) with subsequent machining:

- tension plates are made with cutouts along the upper and lower edges;

- on the wedges, upper and lower from the flat side in the zone of contact with the housing cover, during assembly before shipment to the consumer, a lubricant containing molybdenum disulfide is applied

The essence of the invention is illustrated by the following graphics presented in the figures:

Fig. 1, which shows a general view of the proposed wedge-jointed tension clamp, Fig. 2 shows a section of the tension wedge-jointed clamp along the line A-A assembled for a lightning cable, in Fig. 3 is a section along the line A-A assembled for AC wires, in Fig. 4 shows a section along the line B-B assembled for preliminary screeding of wedges when equipped for a lightning cable, in Fig. 5 is a section along the B-B line assembled for preliminary tightening of the wedges and also for pressing the AC wire to the lower wedge, in Fig. 6 is a section along the line B-B assembled to press the lightning cable to the lower wedge along the vertical axis, in FIG. 7 is a threaded pin for connecting steel tension plates to the insulating suspension of the transmission line, in FIG. 8 shows the profile of the wedge trough, FIG. 9 shows the profile of the transverse corrugation of the wedge trough, FIG. 10 shows an additional insert in section, in Fig. 11 shows the place of attachment of the additional insert to the wedge with a rivet, in Fig. 12 shows a sketch of cutting tension plates, where:

1 - sidewall;

2 - housing cover;

3 - top wedge;

4 - lower wedge;

5 - clamps;

6 - additional liners

7 - wedge clamp bolts;

8 - clamping bolts of a lightning cable or wire;

9 - tension plates;

10 - threaded finger;

11 - boss;

12 - rivet;

13 - cutout in the tension plate;

14 - lightning cable;

15 - steel-aluminum wire AC

The design of the tension wedge-jointed clamp (see Fig. 1) is a body consisting of two sidewalls 1 and two covers of the body 2, the grooves of which include the sidewalls according to the type of machine grooves, see section A-A of Fig. 2, Fig. 3 An attachment assembly is inserted into the body, consisting of an upper wedge 3 and a lower wedge 4 with additional inserts installed in them (in the case of cable clamping) 6. Steel tension plates 9 are put on the bosses of the sidewalls 1 and connected with a threaded pin 10 to the power line line insulators for wires AC brands, and lightning cables are suspended on a power line support. The body length is selected depending on the wire diameter in the ratio L of the body = (7.0 ... 8.0) dpr.max, where dpr.max is the maximum diameter of the wire mounted in the clamp. Increasing the length of the body allows the use of a wedge-jointed tension clamp with a wide range of difference between the maximum and minimum values of the diameters of wires of the AC brand within up to 4.0 mm. A solid lubricant containing molybdenum disulfide is applied to the flat side of the housing covers 2, which is in contact with the surface of the wedges 3 and 4.

The device for preliminary tightening of wedges, section B-B, consists of two clamps 5, made of aluminum profile, having a rectangular shape, fastened with two stainless non-magnetic bolts 7 at the edges. Similarly, as in section B-B of Fig. 5, a device for pressing the AC wire to the lower wedge is also made. Device for clamping the ground wire to the lower wedge, section В-В Fig. 6, consists of two clamps 5 made of a rectangular aluminum profile and two stainless non-magnetic bolts 8 clamping the wire or cable to the lower wedge along the vertical axis of the clamps.

Aluminum components of the tension wedge-jointed clamp, consisting of sidewalls 1, body covers 2, top wedges 3 and bottom 4 and clamps 5, are made by extrusion (pressing) from high-strength aluminum alloy, which has high corrosion resistance when operating in an atmosphere used in aviation, with subsequent heat treatment. This alloy retains its performance up to a temperature of minus 70°C, which allows the use of wedge-jointed tension clamps in the Far North without strengthening their design.

Additional inserts 6 are made of a similar aluminum alloy of lower strength and are not subjected to heat treatment, therefore, when the cable is tensioned, the metal of the softer additional insert is pressed into the corrugation of the harder wedges of the upper 3 and lower 4, and inside between the turns of the hard steel cable, which allows you to reliably hold it.

The gutter profile of the wedges is made with 5 longitudinal ribs with a height H equal to 0.3 ... 0.5 mm and a width B equal to 2 mm, on which transverse corrugation is applied (see Fig. 9). This design allows at the initial moment to clamp the wire faster, and at the same time less disturbs its upper layers during long-term operation, which has a positive effect on the reliability of the wire-clamp connection.

The corrugation (see Fig. 9) is carried out on five longitudinal edges of the wedges and has blunt edges. The angle between the ribs, within 15 ... 20 ° is selected, depending on the diameter of the AC wire. Corrugation is applied in the transverse direction on five longitudinal ribs with a depth H equal to 0.3 ... 0.5 mm, with a step L equal to 0.8 ... 1.2 mm and an angle of 50 ... 60 °. This design of the corrugation cuts the wire less, which has a positive effect on the reliability of the tension wedge-jointed clamps.

By changing the shape of the tension plates 9 (see Fig. 12) their weight is reduced by 11…15%. When testing tension wedge-jointed clamps for vibration and shaking, the mass of the body assembly is of great importance, as well as the total mass of the clamp assembly with tension plates 9, the smaller the mass, the more cycles the wire can withstand and, accordingly, the reliability of the entire transmission line increases.

The use of a solid lubricant containing molybdenum disulfide improves the working conditions of the tension wedge clamp, allows you to clamp AC wires or lightning wires with better quality and increases the reliability of the connection. Additional inserts 6, obtained by extrusion (pressing), for a cable with a diameter of 9 ... 9.5 mm and 11 mm differ in the radius of the small groove R (see Fig. 10). The radius R is equal to half the diameter of the cable. For cables with a diameter of 9 ... 9.5 mm, the radius R is 4.5 mm, and for cables with a diameter of 11.0 ... 11.5 mm it is 5.5 mm. During assembly, additional liners 6 are riveted to the top 3 and bottom 4 wedges with an aluminum rivet (see Fig. 11). Mounting on the wire is carried out as follows.

1. Unscrew the bolts 7 of the wedge clamping device 5, remove the upper wedge 3 with the clamp 5 from the lower wedge 4.

2. Completely unscrew bolts 7 or 8 and remove the clamping device for the AC wire or ground wire from the lower wedge 4.

3. Attach lower wedge 4 from below to lightning cable 14 or wire 15, lay upper wedge 3 from above with clamp 5 and evenly, without distortion, tighten with a torque of 10-20 Nm using bolts 7.

4. Pull out one of the sidewalls of the housing covers 2 from the grooves to the wide side and put the clamp on the wire. Insert housing cover into side panel 2 in place.

5. Push the closed clamp body onto wedges 3 and 4.

6. Alternately and evenly tighten bolts 7 until the required torque is reached on both bolts: 30-40 Nm.

7. Put tension plates 9 on the bosses of the sidewall 1 at an angle of 90° to the axis of the clamp, turn and connect with the help of a threaded pin 10 with hinged fittings. Tighten the nuts of the 10th threaded pin, the nut and the locknut with a torque of 60-90 Nm. When tightening, ensure a gap between tension plates 9 and hinged fittings of at least 0.5 mm.

8. Lay lightning cable 14 or AC wire 15 along the bend of lower wedge 4, apply clamp 5 of AC wire or lightning cable and evenly tighten clamp bolts 7 or 8 with a torque of 30-40 Nm.

The advantages of the proposed invention, in comparison with existing analogues:

- production of a tension wedge-jointed clamp without the “stamping” operation allows to reduce the technological process of production, to exclude the use of powerful (with a force of 2 ... 5 thousand tons) hydraulic or mechanical presses and the manufacture of expensive forging dies and punching tools for them;

- the consumption of metal, aluminum alloys is reduced due to the absence of the stamping operation and the production of a more accurate workpiece for the manufacture of housing covers, wedges and clamps for tension wedge-jointed clamps by extrusion (pressing);

- the mass of the assembled body with the wedges of the wedge-jointed tension clamp and the entire clamp with lighter tension plates is reduced, which favorably affects the reliability during vibration and dance tests;

- a new design of the upper and lower wedge grooves with five low longitudinal ribs, with corrugations with blunt edges applied to them, allows you to securely hold the wire and at the same time disturb its structure less than sharp corrugation over the entire surface of the wedge groove;

- the use of additional inserts allows you to securely clamp lightning cables with a diameter of 9 and 11 mm and use a tension wedge-jointed clamp both for lightning cables and for wires of AC brands of certain brands without inserts;

- reducing the mass of tension plates by 11 ... 15% has a positive effect on reducing the effect of the tension wedge-jointed clamp on wires and cables during long-term operation, which increases the reliability of the connection.

Thus, the proposed design of the tension wedge-jointed clamp has increased reliability, strength and low cost.

Claims (8)

1. Tension wedge-jointed clamp for fastening wires and lightning cables of overhead power lines, containing a body formed during the assembly of the clamp by at least two sidewalls closed from the upper and lower sides by covers, upper and lower wedges of a rectangular profile with segmented grooves for installation of steel tension plates on the wire or cable, installed at one end on the sidewalls and fastened at the other end with a steel threaded pin for connection to the insulating suspension of the line, a device for pre-tensioning the wedges and a device for pressing the wire, characterized in that the sidewalls are made of solid hardened aluminum profile together with bosses made by milling and having an annular groove with grooves along the perimeter of the boss, on which steel tension plates are put on, each of the devices for pre-tensioning the wedges and for pressing the wire to the lower wedge consists of two clamps, made x from an aluminum profile having a rectangular shape and fastened with two stainless non-magnetic bolts at the edges. 2. The clamp according to claim 1, characterized in that the threaded pin for connecting steel tension plates with an insulating line suspension is a bolt with a round head without a cotter pin. 3. Clamp according to claim 1, characterized in that the wedges are made of hardened aluminum profiles with streamlined protrusions on the inside with corrugations applied with blunt edges. 4. The clamp according to claim 1, characterized in that to install the clamp on the lightning cable, additional inserts are installed in the wedge grooves, made of non-hardened soft aluminum and fixed in the grooves with aluminum rivets, and the radius of the inner groove of the insert R is equal to half the diameter of the cable. 5. Clamp according to claim 1, characterized in that the sidewalls, covers, wedges, clamps and additional liners are made by extrusion followed by machining. 6. Clamp according to claim 1, characterized in that the tension plates are made with cutouts along the upper and lower edges of the plates. 7. The clamp according to claim 1, characterized in that the wedges, upper and lower from the flat side in the zone of contact with the housing cover, during assembly before shipment to the consumer, are coated with a lubricant containing molybdenum disulfide. 8. Clamp according to claim 1, characterized in that the inner profile of the gutter of the wedges is made with 5 longitudinal ribs with a height H equal to 0.3 ... 0.5 mm and a width B equal to 2 mm, on which transverse corrugation with blunt edges.

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