DE102017214120A1 - Composite insulator and method for producing a composite insulator - Google Patents

Abstract

The composite insulator (2) has a support rod (8) on which a plurality of insulating screens (10) are pushed. The insulating screens (10) are connected by an additionally attached connecting seam (16) with the support rod (8) cohesively. This makes it possible to form the insulating screens (10) as flat annular discs with low material costs.

Description

The invention relates to a composite insulator with a support rod and mounted on this insulating screens and a method for producing such a composite insulator.

Such composite insulators are used in particular as high-voltage insulators for overhead lines. Such composite insulators typically comprise a core of high mechanical load fiber composite having an umbrella sheath of an elastomeric material, often a silicone rubber, applied thereto. Composite insulators are characterized by their low weight and other advantages.

From the DE 27 46 870 C2 as well as the EP 0 774 157 B1 In each case, a method for producing such composite insulators can be seen in which individual insulating screens are pushed onto a core with attached coat of an elastomeric material. The core with attached coat is referred to herein as a support bar. The individual insulating screens have a thickened foot area, which is radially expanded before the screens are pushed. The umbrellas are approximately dish-shaped with a thickened, in particular dome-shaped middle region, wherein the central region forms the foot region, via which the insulating shields are connected to the core. This thickened, central foot area is required in order to avoid unwanted deformation and bending of the respective insulating shield during radial spreading and mounting on the support bar. Due to the thickened foot area, the material requirement is increased. This method with the sliding of individual prefabricated insulating screens is also called Modularverfahren.

From the DE 196 12 466 B4 For example, a method for producing such a composite insulator is known, in which the screen cover with a plurality of insulating screens is applied directly to the core by an injection process. For this purpose, a two-part mold is provided, in which the core is inserted and into which the elastomeric molding compound is then injected.

From the WO 02/31838 A2 shows a further method in which each screen is sprayed individually on an injection mold on the core. As a result, individually different screen shapes can be formed and the number of screens can be varied.

However, in such sprayed with injection molds screens form due to the required separation of the mold halves separating seams on the umbrellas, which are prone to dirt deposits, which can affect the operation as detrimental to the electrical properties.

Based on this, the present invention seeks to provide a composite insulator and a method for producing the same, in which the disadvantages of the prior art are at least reduced.

The object is achieved by a composite insulator having the features of claim 1. The composite insulator has a support rod and mounted on this insulating screens, which are spaced apart over the length of the support rod. The insulating screens are integrally connected by means of an additionally attached connecting seam with the support rod.

The essential difference to the previous, conventionally produced composite insulators can be seen in the additional connection seam. This consists of a suitable polymer, in particular an elastomer, especially of a silicone rubber. About the connecting seam a safe and reliable connection of the individual insulating shield is formed with the support rod. In this case, in particular a cohesive connection is formed. The polymer is adhesive when applied.

By this measure, initially can be dispensed with a thickening in the foot of the insulating screens, so that the total cost of materials for the insulating screens is kept low. As a result, composite insulators can be formed with low weight, which also require less energy in the production due to the lower material usage. Due to the reduced energy input, the CO ₂ balance in the production is improved.

At the same time, the advantage of the modular method with the deferred prefabricated individual insulating screens is maintained compared to molded-on insulating screens, since no separating seams run along the insulating screens, which would be susceptible to dirt deposits.

In an expedient embodiment, the support rod in this case has a core, in particular made of a fiber-reinforced plastic, on which a jacket is applied. The jacket again consists of a suitable polymer, in particular an elastomer, especially preferably of a silicone rubber. This jacket is applied in particular by an extrusion process. The jacket therefore forms a polymer shell for the core. It preferably has a material thickness of a few millimeters, preferably from at least three millimeters, for example, three to five millimeters.

The core is, for example, an (epoxy) resin-impregnated fiber rod (FRP rod). If necessary, an adhesive layer, for example of a suitable lacquer, etc. may be applied between the core and the applied shell. The reliable connection between the core and the shell of the polymer material is achieved by a subsequent crosslinking reaction, in particular a vulcanization of the applied polymer material. The material for the sheath is in particular a so-called high-temperature-crosslinking silicone (HTV silicone). The jacket forms together with the insulating screens, the screen cover. This screen cover extends continuously over the entire length of the composite insulator, in particular without longitudinal seam or other separation points. The screen cover is further preferably formed flame retardant.

Fittings are usually attached to the composite insulator usually in a conventional manner. These fittings are typically made of a metallic material and for example on the support rod, especially pressed onto the core of the support rod. These fittings are used in particular for mechanical attachment of the respective composite insulator to the overhead line.

In an expedient embodiment, the insulating screens, the jacket and the connecting seam of an elastomeric material, in particular of a silicone rubber, especially from the already mentioned HTV silicone. Preferably, at least two, preferably all three of these elements are of the identical elastomeric material or at least of a similar elastomeric material to ensure that the desired integral connection between these three elements is reliably formed.

The desired cohesive connection is formed in particular by a crosslinking reaction. Conveniently, the cross-linking of the material of the three elements takes place only after application of the insulating screens and the connecting seam, so that an intensive cohesive connection is formed. In principle, however, even one or two of these elements, especially the insulating screens and / or the jacket, can already be networked when attaching the connecting seam. The crosslinking reaction takes place, for example, at ambient temperature. In a preferred embodiment, however, the crosslinking reaction is started by an elevated temperature, for example with the aid of a corresponding furnace.

With regard to the desired material savings, the insulating screens are furthermore preferably designed as flat annular disks. As already mentioned above, due to the additional connecting seam, no additional thickening in the foot region or even a dome-like tubular extension in the transitional region to the support rod is required and correspondingly not provided. Viewed in the longitudinal direction of the support rod, the annular disks have no formations or thickenings, especially in a hole region, ie in the region of the core.

In a preferred embodiment, the insulating screens generally have an annular configuration with a central hole. Preferably, a rounding of the hole edge of the central hole is provided. In this way, between the jacket and the respective insulating shield, the polymer material of the connecting seam which is adhesive at least during application can penetrate and thus ensures a reliable connection.

Preferably, the insulating screens have a constant thickness over their entire radial extent. Only at the edge, for example, at the outer edge or at the inner edge to the central hole, a variation of the thickness preferably occurs as a result of a rounding. However, these marginal areas affect a maximum of 10% or a maximum of 5% of the diameter of the insulating screens.

The preferably constant thickness of the insulating screens is typically in the range of a few millimeters, for example in the range of 1 mm to 5 mm.

The insulating screens have a screen projection which is typically in the range between 20mm and 120mm. Under Schirmausladung the radial projection of the insulating screens is understood to support bar. The thickness and the diameter depend on the desired application. The thickness increases with larger diameters.

In order to ensure a reliable connection of the insulating shields on the support rod, the connecting seam is attached to both opposite sides of a respective insulating shield in an expedient embodiment.

The respective connecting seam is generally in each case completely encircling and thus annular.

In a preferred embodiment, the connecting seam is formed as a groove. The connecting seam thereby passes on the one hand to the insulating sheds and on the other hand to the support rod in cross-section viewed tapering off, is So always thinner, so that a largely homogeneous and paragraph and edge-free transition is formed on the one hand to the respective insulating shield and on the other hand to the support rod. As a result, the sensitivity to dirt of the composite insulator is improved and thus also the electrical properties.

The object is further achieved according to the invention by a method for producing such a composite insulator. In the method, first of all the support rod is provided, on which then several insulating screens are pushed in each case up to a desired assembly position. Subsequently, a strand of a suitable polymer is applied circumferentially at a seam area between the support rod and the respective insulating screen. Finally, a cohesive connection of the insulating shield with the support rod via the strand, wherein in this case the connecting seam is formed.

The cohesive bonding is preferably carried out by a cross-linking process, wherein for this purpose the composite insulator is preferably subjected to a subsequent heat treatment for applying the strand.

The individual insulating screens each have the already mentioned central hole with a hole diameter and the support rod has an outer diameter. The hole diameter is in a preferred embodiment, the same size or slightly larger than the outer diameter. By this measure, a simple sliding of the respective Isolierschirms is achieved on the support rod. A radial expansion of the insulating shield in the region of the central hole is not required and not provided. As a result, the particularly thin design of the insulating screens and especially their design as flat annular discs in a particularly advantageous manner. The insulating screens are pushed without applying a radial tension. When pushing is therefore no or only a small amount of force required and there is no risk that deform when pushed the insulating screens in an undesirable manner.

Alternatively, the hole diameter is slightly smaller than the outer diameter. When pushing the inner peripheral edge region of the insulating shield is then bent slightly and nestles against the support rod.

The sliding of the individual insulating screens is preferably carried out manually. Alternatively, the insulating screens are pushed by means of a manipulator, for example by means of a slide-on device.

The same applies in a preferred embodiment for the application of the strand. This is optionally applied manually and preferably with the aid of a manipulator, for example with the aid of a (multi-axis) industrial robot.

After application of the strand, finally, in a preferred embodiment, the desired groove is formed. This is done, for example, with the aid of a spatula with suitably designed head geometry (round spatula). This again takes place optionally manually and preferably with the aid of a manipulator.

In a particularly preferred embodiment, the same manipulator is used for the application of the strand and for the production of the groove, which has a machining head with two tools, so that these two processing steps are carried out in a single combined operation. Specifically, the manipulator has a spray head for applying the strand of the polymer material and additionally a round spatula. These two tools, so spray head and round spatula are arranged, for example in the circumferential direction successively.

Preferably, the support rod rotates during manufacture, especially during application of the strand and during formation of the groove about its center axis. When using a manipulator this is fixed, so not arranged rotating. Even with a manual application of the strand and with a manual formation of the groove, a rotating support of the support rod is preferably provided.

Especially when manually sliding the insulating screens a marking device is further provided, via which the respective mounting position of the respective insulating screen is displayed on the support rod. This is, for example, an optical display element, for example a laser. The marking device, in particular the optical display means and, alternatively, the support rod, is preferably movable in the longitudinal direction of the support rod, so that the different mounting positions are displayed successively.

• 1 eine ausschnittsweise Schnittdarstellung durch einen Verbundisolator,
• 2 eine vergrößerte Darstellung des in der 1 mit einem Kreis markierten Bereichs, sowie
• 3 eine weitere Querschnittsdarstellung zur Illustration des Herstellverfahrens.

An embodiment of the invention will be explained in more detail with reference to FIGS. These show in partially simplified representations

• 1 a partial sectional view through a composite insulator,
• 2 an enlarged view of the in the 1 with a circle marked area, as well
• 3 another cross-sectional view illustrating the manufacturing process.

In the figures, like-acting parts are provided with the same reference numerals.

1 shows a fragmentary longitudinal sectional view of a composite insulator 2 , In the sectional representation of the usually end-mounted metal fittings are not shown.

The composite insulator 2 extends along a longitudinal and a central axis 4 longitudinal 6 , The composite insulator 2 has a particular circular support bar 8th on. On these are at predefined mounting positions, so at different length positions each insulating screens 10 appropriate. The support bar 8th again has a core 12 in particular of a fiber-reinforced plastic on which a jacket 14 is applied from an elastomeric plastic, in particular from a silicone rubber. The support bar 8th is preferably through the core 12 and the coat 14 finally formed, so has no further components.

The insulating screens 10 are also preferably made of an elastomeric material, especially of the same or at least a similar material as the jacket 14 , Preferably, the insulating screens are made 10 also made of a silicone rubber. In principle, other known per se materials for such insulating screens 10 as well as for the coat 14 be used.

In the embodiment, the core 12 represented as a massive core. Alternatively, the core 12 be designed as a hollow core.

The individual insulation screens 10 are formed as flat annular discs, in particular with reference to the 3 can be seen. They have a preferably constant thickness over their radial extent d on. This thickness is preferably only a few millimeters.

The individual insulation screens 10 are by means of a circumferential, annular connection seam 16 with the support rod 8th , with the coat 14 cohesively connected.

Specially based on the 2 This is easy to see that each at a top or bottom of a respective insulating shield 10 one connecting seam each 16 is formed, in a seam area between the respective insulating screen 10 and the support bar 8th , The connection seam 16 is from the outside on the top or bottom and on the support bar 8th applied. The connection seam 16 forms a groove, and runs both to the respective top and bottom of the insulating shield 10 as well as the support bar 8th flat out.

The preparation of such in the 1 and 2 Composite insulator shown below is based on the 3 explained in more detail:

In a first step, the support bar 8th provided. This is previously made in a first step by adding to the core 12 the coat 14 with a layer thickness of at least 3 mm and preferably by an extrusion process is applied.

On the support bar thus obtained 8th be the individual designed as annular disks insulating screens 10 postponed. These have a central hole 18 on. The insulating screens 10 have an outer diameter D1 and the hole 18 an inner diameter D2 on. Furthermore, the support bar 8th a rod diameter D3 (Outer diameter). Both an outer edge and in particular a hole edge of the central hole 18 are rounded or possibly also provided with a chamfer. The rounding of the hole edge of the central hole is in particular based on the enlarged view according to 2 refer to.

The inner diameter D2 the central hole 18 is at least the same size as the outer rod diameter D3 or slightly larger than the outer rod diameter D3 , For example, 0.1 - 0.3 mm larger. This allows the insulating screens 10 in a simple manner in the longitudinal direction 6 on the support bar 8th postpone, without a radial expansion would be required. The insulating screens 10 are therefore positioned without or almost no radial stress at the respective mounting position. They are initially preferably (only) by static friction on the jacket 14 fixed. Since, in contrast to the prior art, no radial expansion of the insulating screens is required, easy sliding is made possible either by hand or by a simple Aufschiebemaschine.

Alternatively, the inner diameter D2 slightly smaller than the bar diameter D3 , for example, 0.1mm-0.3mm. Again, this is usually done when pushing no radial expansion but only a bending of the edge region. Since the insulating screens are usually made of a material with a high content of fillers, they are usually not very elastic.

The individual insulating screens are prepared in advance, for example, in SpritzgießVerfahren (injection molding) or in the compression molding process (compression molding).

After pushing either a respective Isolierschirms 10 or all the insulating screens 10 at the intended mounting positions is in a next step at a near point, ie in the connection region between the hole edge of the central hole 18 a respective insulating screen 10 and the support bar 8th , a strand 20 made of an elastomeric polymer material circumferentially and annularly attached. The polymer material is adhesive at least during application. Due to the rounding, polymer material penetrates between the insulating screens and the support bar 8th one. On both sides of the respective insulating screen 10 each becomes a strand 20 appropriate. This is done by means of a suitable application device, such as a spray head. The polymer material of the strand 18 is pasty when applied. The polymer material is initially uncrosslinked. It already has an adhesiveness, so that in this way the insulating screens are fixed at the positions.

With the help of a round spatula 22 then the groove is formed. During the application of the strand 20 as well as during the generation of the groove, the support rod rotates 8th with the insulating screens attached to it 10 around the center axis 4 , The round blade is, for example, mounted directly on a discharge tip of a manipulator, so that the groove is formed immediately after the application of the polymer material.

In a subsequent process step, finally, the polymer material of the strand 20 networked. For this purpose, the entire prepared composite insulator 2 preferably exposed to an elevated temperature. Alternatively, the crosslinking takes place at room temperature.

Furthermore, the fittings not shown here in a conventional manner end to the support rod 8th appropriate. In particular, these are on the core 12 pressed. The coat 14 extends seamlessly over the entire length of the composite insulator 2 between the two (metal) fittings.

Composite insulators produced in this way satisfy the requirements of the electrical test, for example according to IEC61109 / IEC62217.

LIST OF REFERENCE NUMBERS

2

composite insulator

4

mid-axis

6

longitudinal direction

8th

bearing bar

10

insulating screen

12

core

14

coat

16

seam

18

hole

20

strand

22

around Patel

d

Thickness of the insulating screens

D1

Outer diameter of the insulating screens

D2

Inner diameter of the hole

D3

Bar diameter

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 2746870 C2 [0003]
• EP 0774157 B1 [0003]
• DE 19612466 B4 [0004]
• WO 0231838 A2 [0005]

Claims (14)

Composite insulator (2) with a support rod (8) and mounted on this Isolierschirme (10), characterized in that they are connected by means of an additionally attached connecting seam (16) with the support rod (8) cohesively. Composite insulator (2) after Claim 1 in that the support rod (8) has a core (12), in particular of a fiber-reinforced plastic with a jacket (14) mounted thereon. Composite insulator (2) after Claim 2 in which the insulating screens (10), the jacket (14) and the connecting seam (16) consist of an elastomeric material, in particular of a silicone. Composite insulator (2) according to one of the preceding claims, in which the insulating screens (10) are designed as annular discs. Composite insulator (2) according to one of the preceding claims, in which the insulating screens (10) in the initial state have a central hole (18) with a rounded hole edge. Composite insulator (2) according to one of the preceding claims, in which the insulating screens (10) have neither a thickening nor a dome in the region of the connecting seam (16). Composite insulator (2) according to one of the preceding claims, in which the insulating screens (10) have a constant thickness in the radial direction A composite insulator (2) according to any one of the preceding claims, wherein the insulator screens (10) have a thickness (d) in the range of 1mm to 5mm. A composite insulator (2) as claimed in any one of the preceding claims, wherein the seam (16) is attached to two opposite sides of the insulator screens (10). Composite insulator (2) according to one of the preceding claims, wherein the connecting seam (16) is formed as a groove. Method for producing a composite insulator (2) with the following steps - Provision of a support rod (8) - Sliding insulating umbrellas (10) on the support rod (8) each to a desired mounting position - circumferential application of a strand (20) at a seam area between the support rod (8) and the respective insulating screen (10) - Integrally bonding the insulating shield (10) with the support rod (8) via the strand (20), so that a connecting seam (16) is formed. Method according to Claim 11 in which the cohesive connection takes place by means of a crosslinking process. Method according to one of the two Claims 10 to 12 in which the insulating screens (10) are pushed by means of a manipulator and / or the respective strand (20) is applied. Method according to one of the two Claims 10 to 13 in which the manipulator has a spray head for applying the strand (20) and additionally a round spatula (22), so that by means of the manipulator during application of the strand (20) at the same time a groove is produced.

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