EP1147525B1 - Method and device for producing composite insulators - Google Patents

Abstract

Composite insulators can fulfill their task in a manner which is free of interferences only when the protective sheathings do not comprise seams, gaps and ridges. When the casing and the sheath are simultaneously molded in a work process, ridges can result on the surface of the composite insulator due to mold seams and thereby form sources of interference. Moreover, only composite insulators having a predetermined number of annular sheathes can be produced using these molds. The aim of the invention is to produce composite insulators having any number of annular sheaths and having a sheathing without seams, welds or gaps. To this end, the advance of a core (102) is stopped when applying a material (36) of the sheathings (3) to a rod-shaped or tubular core (102) which is transported in the longitudinal direction thereof and which is comprised of a composite material. In addition, an annular sheath (5) is molded using a mold (15), said mold, when viewed in a direction of transport (31), advances the core (102) in front of the system (12) for applying the material (36) of the sheathing (3). The invention also provides that the advance of the core (102) is resumed after the sheathing (5) has been molded, and the application of the material (36) is continued. The material (36) of the sheathing (3) is applied to the core (102) in an uninterrupted manner until the sheathing (3) has been completely produced.

Description

The invention relates to a method for producing composite insulators According to the preamble of the first claim and a device for Production of composite insulators according to the preamble of the nineteenth Claim.

High voltage insulators are out of the conventional materials Porcelain and glass increasingly also manufactured as composite insulators. Composite insulators consist of a rod or tubular core, which is in turn, for example composed of glass fibers reinforced epoxy resin and a screen sheath, divided into a sheath around the core with a number spaced, plate-shaped umbrellas or one or more spiral Umbrellas, wherein the screen cover of a material with insulating properties consists. These materials include elastomeric materials, for example polymeric plastics. With such materials, the core can easily wrap, before by means of a subsequent thermal treatment of the material final obtains its desired mechanical and electrical properties.

The core of a composite insulator serves to absorb the forces generated by the Suspension acting on the insulator, and therefore carries at its ends appropriately designed fittings, usually made of metal. The screen cover should electrical flashovers, usually due to weather conditions prevent. Composite insulators have compared to the conventional insulators made of glass or Porcelain the advantage that they are much lighter. Besides, they have due the dirt and water-repellent material of the shield covers very good Isolation properties and are therefore particularly suitable for areas with strong polluted atmosphere. This property is only achieved if the Coating of the core is not interrupted at any point or lifted off the core, for example, by joints, seams or columns.

From DE 196 29 796 A1 are composite insulators and methods for their Production known. At the same time, the mantle and the shade become in one Operation continuously shaped. However, according to the known methods are only Composite insulators with spiral-shaped screens can be produced. The experiences with Such composite insulators are currently considered too low.

The object of the present invention is a method and a device to imagine with which the manufacture of composite insulators with any Number of annular shields and a continuous screen cover is possible.

The solution of this task is carried out by the method according to the invention with the help the characterizing features of the first claim. An inventive Device for producing the composite insulators is characterized by the Features of claim nineteen.

Compared with the known method for sheathing the cores of Composite insulators it is possible with the method according to the invention, Composite insulators with any number of annular shields and in produce any length in succession, the screen cover is continuous and has no joints, seams or gaps. This is the core, as from the DE 196 29 796 A1 is known, with constant speed in the middle of the Mouthpiece of a device for applying the material of the screens, for example, an extruder or a piston press, led, wherein the material applied on all sides on the core. The shape of the ring-shaped umbrellas However, in contrast to the known method so that, in the feed direction of the Kerns seen after the device for applying the material of this device a mold is delivered. While the core is being stopped, the shape is filled with the Material of the screen cover filled and a screen formed When the screen has reached the intended shape, the mold is opened, the screen released and the advance of the core is initiated again. The supply of the material is so controlled that the order of the material is not interrupted until that Umbrella shell is completely made. As a result, the screen cover at any point of the composite insulator joints, seams or columns.

From DE 42 02 653 A1 it is known, the complete umbrella cover with annular Shield in a form to form the core. Since the shape is divisible in the plane, in which the core is located, the shield shell has two over its entire length opposite ridges on. Burrs have to be removed as far as possible because they are Sources of interference with respect to the insulation are, especially if they are on the top and lie on the perimeter of the umbrellas. Burrs are collection points for dirt, the can significantly reduce the isolation characteristic. In development of the invention can be avoided in particular on the scope of the umbrellas burrs, that the shape with which the shaping of the screens takes place in their radial Extension is greater than the radius of the screen and not completely with the Material of the shield is filled, so that the parting line is not the material is reached. The mold half for shaping the top of the screens should for Avoid burrs in one piece. Due to the advantageous embodiment of the form eliminates a step to remove the burrs.

When opening the mold, the surface of the screens can adhere to the mold walls stay. This makes the umbrellas difficult to shape and it is the Risk of their surface being damaged. The tendency to stick may be due to the material can be, but also by the adhesion of the screen surface to the shaping Surfaces of the mold, the mold walls, are caused when the supply of Air is difficult to the places where the screen surface of the mold walls should solve. To facilitate the shaping of the umbrellas, it is advantageous to have a To use material with a high Williams plasticity. The inclination, up Surface sticking decreases with increasing Williams plasticity. The material Also, a non-stick additive can be added to its sticking tendency decrease.

The risk of sticking the material of the screen cover to the mold walls can continue to be reduced by the fact that the mold walls made of a material exist, which has so-called non-stick properties, such as Polytetrafluoroethylene.

When prone to sticking materials, especially for example silicones, are following steps in forming the umbrellas advantageous: filling the Shape is monitored with at least one pressure sensor on or in the mold. at a certain, the degree of desired filling corresponding pressure the mold opens a given gap. For this purpose, first in Feed direction of the core forward mold half in the feed direction of the core shifted, for example, by about a millimeter to the pressure on the Reduce material and solve its adhesion to the mold walls. Only after the mold is fully opened to release the screen.

However, the adhesion to the shaping surfaces of the mold can be so great be that their overcoming must be supported by further process steps. To ensure a damage-free shaping of the umbrellas, the Detachment of the screen surface by air supply to the screen surface, in particular at particularly endangered areas of the screen such as the umbrella root, supported become. For this purpose, channels are provided in the mold walls, which on the forming surfaces finish. The channels are shaping Surface closed by valves which then open when peeling the screen surfaces of the mold walls creates a negative pressure. The replacement can be assisted with compressed air injected through the valves.

The detachment of the screen surfaces from the mold walls can also be mechanical by rotating at least one mold half opposite the other around the Longitudinal axis of the core are supported, possibly on the mold walls adhering material is released due to the shearing motion.

The seen in the transport direction forward mold half must be at least two parts be formed to by opening in a substantially radial direction, through Pull apart or open, to clear the way for the screen. Both mold halves can also be designed in two parts. When opening the mold the halves of one half of the mold can be offset in time from the halves of the mold other half of the mold to be opened, the part halves turn in a in the substantially radial direction away from the core. Through this Procedure, a deformation of the screen in the opening direction is avoided as they might occur when opening the halves of the part at the same time.

Another way, the sticking tendency of the material of the shielding shell to the To overcome mold walls is to heat the mold. The Heat treatment may be limited to the curing of the surface, so that The umbrella can be easily shaped. The final heat treatment would then take place in a further process step. But the heat treatment can also the entire required process for curing the material of the Cover screen.

At the ends of a core, the faucets are attached, with those at the one Side of the insulator itself and on the other side the electrical conductor is attached. To attach the fittings to the core, the ends of the core must be free from Be the material of the screen cover. In the manufacture of an inventive Composite insulator is first used when the beginning of the core from the Device for applying the material of the screen sheath emerges, the order of the Material exposed as long as that for the attachment of the fitting provided length has left the device. If at the end of the core of the Point is reached, from which he should wear the fitting, the supply of the material interrupted. The coat then tears at the further advancement of the core at the Device for applying the material from and the core remains naked.

Another way to obtain a sheath-free end of the core is to the rod with continuous promotion of the shell material jerkily around the piece to advance, which should remain free. Due to its viscosity ruptures the Sheath material from advancing and is only reapplied when the core with the usual feed rate through the device for Applying the screen cover is transported.

By the method steps described above, a single operation for subsequent removal of the jacket at the ends of the core, where he has the fittings should carry, saved. In addition, this material is saved, the otherwise got lost.

A simplification of the workflow for the production of a composite insulator is achieved, if not each core individually of the device for applying the material the screen cover must be supplied. If provided for the cores rod or the tube of glass fiber reinforced plastic is so long that at least two Composite insulators can be made one after another, can be a finished molded Composite insulator or at least the already finished molded part of the composite insulator be guided by a heater without a support on the still uncured material of the shielding is required. Then the Composite insulator or at least the part of the composite insulator, already the Heat treatment was subjected to the heat treatment Unaiding wearing part, which is the device for applying the Material of the shield has already left.

Instead of producing individual composite insulators, the manufacturing process can also be carried out continuously, if in each case a following core with the previous core to a continuous rod or tube of great length is connected. With a corresponding quality of connection of the rods or Tubes together there is the possibility of composite insulators of different Length to manufacture one after the other. The length of the composite insulators will not more determined by the length of the individually supplied cores, but by the predetermined number of screens. The cores are then separated when the given number of screens and thus the given length of a Composite insulator is achieved. The connection can for example by a Sticking together of the rods or pipes or a thermal bonding done. However, the connection of the rods or tubes should only be used to To produce a continuous rod or a continuous pipe of great length and the joints do not meet the mechanical requirements for the core meet a composite insulator, such a junction as a body for Separating finished composite insulators are set.

In the manufacture of the composite insulators can advantageously be moved so that after the application of the material of the shielding shell already formed parts of the composite insulator to produce the required material properties of finished screen sheath are thermally treated, while the material for Forming of the remaining part of the composite insulator or already for Forming the subsequent composite insulator on the continuous core is applied when due to the supply of long rods or tubes for individual separation of cores continuous production of Composite insulators is provided. In these process variants must, in Contrary to the state of the art, no longer on the complete completion a composite insulator to be serviced before the required thermal Treatment can be done.

In the thermal treatment of composite insulators with heat radiation sources, which act on the composite insulators from the outer periphery, there is a risk Overheating of the thin screen edges. A uniform heating of the Mantels and in particular the umbrellas is advantageously achieved in that the Heating hot air is used. The heating section, which is the composite insulator is equipped with a hot air blower, which ensures a uniform Temperature distribution and thus for a uniform heating of the screen cover provides.

If the material of the shielding shell has a correspondingly high dipole moment, for example, silicone rubber (HTV) or ethylene-propylene copolymer (EPM) also a vulcanization with high-energy radiation, for example with a microwave, possible.

The handling of the composite insulators during their manufacture becomes particular facilitated by the fact that at least one already finished composite insulator that still connected via the core with the following, not yet finished composite insulator is supported by a conveyor. The conveyor is the Heating device downstream. The continuous bar or the continuous one Pipe from which the finished composite insulators are cut off is on one side Side in the drive rollers of the feed device for the rod or tube stored and on the other side by a finished composite insulator supported. This makes it possible, a not yet ready composite insulator without Supporting his still soft umbrella case during its shaping and subsequent thermal treatment to transport. A deformation or Damage to the screen cover is avoided. The conveyor can for example, be a non-driven conveyor belt on which already finished Composite insulators rest with the outer circumference of their screens. The Composite insulators are moved solely by the advance of the core. Of the Feed takes place by means of a feed device through the device for Applying the material of the screen cover through. The conveyor belt is moving only by the composite insulators resting on it. The Conveyor can also be driven. Their drive with the Drive the rod or tube synchronously done.

In the following, the inventive method for the production of Composite insulators explained on a device provided for this purpose.

Figur 1

schematisch den Aufbau eines Verbundisolators,

Figur 2

eine Vorrichtung zur Herstellung von erfindungsgemäßen Verbundisolatoren,

Figur 3

als Detail eine Einrichtung zur Bildung eines durchgehenden Stabs, von dem die Kerne der Verbundisolatoren abgeschnitten werden, und

Figur 4

als Detail weitere Ausführungsbeispiele einer Form zur Formgebung eines Schirms.

Show it:

FIG. 1

schematically the structure of a composite insulator,

FIG. 2

a device for producing composite insulators according to the invention,

FIG. 3

as a detail, means for forming a continuous rod from which the cores of the composite insulators are cut, and

FIG. 4

as a detail, further embodiments of a mold for shaping a screen.

FIG. 1 shows the construction of a composite insulator according to the invention, such as FIG he the inventive device for the production of composite insulators before Separating from the core of the subsequent composite insulator leaves.

The composite insulator 1 consists of a core 2, which is provided with a screen cover. 3 is covered. The shield shell 3 is divided into a shell 4 and annular Screens 5. For the sake of clarity, only one screen 5 is shown here. One Composite insulator has five sections. The section A represents the first end 6. It has no jacket 4. This free end 6 has a dimension 8, the Attachment of a fitting, not shown here is required. In section B is the core 2 coated with a jacket 4. In section C is the annular Screen 5 and in section D, the core 2 is also coated with a jacket 4. The region E comprises the second end 7 of the insulator 1 and has the dimension 9, which is required for attachment of the other, not shown here fitting. At the region E is in turn followed by an area A of the following insulator 101 which is not fully illustrated here and not yet complete should be completed.

As can be further seen from FIG. 1, the core 2 and the core 102 of the subsequent composite insulator 101 in the present embodiment a continuous rod 14. The core can also be formed from tubes. At the Position 10 becomes the already completed composite insulator 1 from composite insulator 101 separated. As can be seen further from FIG. 1, the jacket-free one follows End 7 of the core 2 of the composite insulator 1, to the separation point 10, the first end 106 of the core 102 of the composite insulator 101, on which also a valve should be attached. This end 106 is therefore also free in a length 108 from the jacket 4.

Figure 2 shows schematically an embodiment of an inventive Device 11 for the production of composite insulators. It is only the invention contributing features shown and described.

The apparatus 11 for producing composite insulators comprises in the present Embodiment essentially means 12 for applying the Material of the shield sheaths 3, a feed rod 13 via a long rod 14 is supplied from glass fiber reinforced plastic from which the cores 2, 102 of the Composite insulators 1, 101 are formed. Furthermore, the device 11 includes a Form 15 for shaping the screens 5, in front of the device 12 for application the material of the shield sheaths 3 is arranged. Close to the device 12 in the present embodiment, a heating section 16 for thermal Treatment of the material of the screen cover, a transport device 17 and a Separator 18 for separating the finished composite insulators 1 from the rod 14 on. The rod 14 is made by forming shorter sections 19 is composed. While the cores 2 of the finished composite insulators 1 of the rod 14 are separated before entering the device 12 for Applying the material of the shield covers 3 new sections 19 added, so that a continuous production of composite insulators is possible.

The type of connection of two sections, rods or tubes, depends on the envisaged procedures. If only composite insulators are to be produced exactly As long as the interconnected bars or tubes, each bar forms or every tube a core. These cores only need each other so far to be connected, that a common transport is possible. That's enough For example, already the connection of two at the end faces abutting rods or pipes by means of adhesive tape.

But if the sections are to be connected permanently and resiliently, there are others Connection method required, for example, bonding, thermal bonding, Friction welding or by means of pins.

Of the possible connection methods, only one example will be described here. The Connecting the sections 19 with the end of the rod 14 takes place permanently through Gluing in an adhesive device 21, which is shown in Figure 3. She is the one Device 12 for applying the material of the shield covers 3 connected upstream. The Adhesive device 21 may for example by means of rollers 22 on a suspension rail 23 slidably suspended to during the gluing process the To be able to join feed movement of the rod 14. The adhesive device 21 stops with a fixed gripper 24 the rod 14 during the bonding process firmly. A gripper 25, which in the direction of the longitudinal axis 26 of the rod 14 back and is herverschiebbar, as indicated by the double arrow 27, holds a section 19 to supplement the rod 14. The portion 19 is fed via support rollers 28, whose distance from one another is adjustable to the diameter of the sections. For example, by means of a nozzle 29 adhesive is applied to the end face 20 of the rod 14 applied. Then, the portion 19 by means of the gripper 25 in the direction of arrow 30th with its end face 20 against the wetted with adhesive end face 20 of the rod 14th pressed and held until the adhesive bond is resilient. While this time travels the adhesive device 21 in the feed direction 31 of the rod 14, which is possible by running on the hanging rail 23. After completion of the Bonding process, the grippers 24 and 25 are opened and the adhesive device 12 at the still free end of the just glued portion 19 driven to there the glue next section.

Hereinafter, the production of composite insulators with the in Figure 2 described inventive device described.

The production of composite insulators can be fully automatic, with the Processes in the individual devices by means of a control device 32nd be coordinated with each other. The individual facilities are via signal and Control lines 33 connected to the controller 32.

When starting the device 11 for the production of composite insulators 1 is a rod 14 in the feed direction 31 through the open drive rollers 34 of the Feed device 13 in the spray head 35 of the device 12 for applying the Material of the shield shell introduced. The device 12 is in the present Embodiment an extruder. The material 36 from which the screen covers. 3 are molded in the present embodiment, an HTV silicone rubber. He is as a band of a supply roll in a known manner by a rotating Worm 37 drawn into the extruder 39 and annular by a rod 14 surrounding nozzle in the spray head 35 and in evenly thick layer on the rod 14 applied. Thus, the application of the material 36 for the screen cover 3 occurs evenly, the drive 40 of the screw 37 via a synchronization controller 41 connected to the feed device 13 of the rod 14.

Thus, the screen cover 3 well on the core 102 of the still to be produced Composite insulator 101 adheres, is in a device 42, in the present Embodiment of the feed device 13 is connected upstream and the rod 14th goes through, applied an adhesive. Furthermore, a length measuring device 43 provided, which rests with a Tastrad 44 on the surface of the rod 14. With the length measuring device 43, the feed of the rod 14 is monitored, the length of the Cores 2 and 102 and the distances of the screens measured from each other and the Separator 18 and the order of the material of the screen covers 3 controlled.

The rod 14 is inserted so far into the spray head 35 that its front page with the outlet opening of the annular nozzle, not shown here matches. Then it will be the feed device 13 is turned on, the extruder 12, the means for Applying the material 36 of the screen covers 3, but not yet. Only when the staff 14, which is from now on the future core of a new composite insulator to the the by the attachment of the valve predetermined length 8, section A in Figure 1, from the spray head 35 is exited, the extruder 12 is turned on and the Material 36 applied to form a screen cover 3. This is the first coat 4 formed. After the predetermined by the controller 32 length through the length measuring device 43 has been detected, the feed of the rod 14th stopped. Section B of the composite insulator is thus made. For a through the controller 32 for a predetermined time, the screw 37 continues to promote the Material 36 for forming the screen cover 3 in the area C. This swells the extrudate 45 from the application nozzle concentrically around the rod 14. After the time is the Promotion of the extrudate 45 stopped and formed from a screen 5.

For shaping a screen 5, a mold 15 is used. It consists of two Halves 46 and 47, wherein the first half 46 directly to the front of the Spray head 35 is arranged, at which the rod 14 exits. The second mold half 47 is, seen in the transport direction 31 of the rod 14, behind the first mold half 46th arranged. The two mold halves 46 and 47 are divided in a plane 48 in the is substantially perpendicular to the longitudinal axis 26 of the rod 14, as through the right angle 49 is indicated. While the first mold half 46 fixed to the Spray head 35 is connected, the second mold half 47 along the longitudinal axis 26 of the rod 14 for closing in the direction of the first mold half 46 and to Opening are moved away from her, as indicated by the double arrow 50.

To clear the way for the newly formed screens, the second mold half 47 at least once again divided into two halves 51 and 52, wherein the Dividing plane 53 is perpendicular to the first dividing plane 48 and through the Longitudinal axis 26 of the rod 14 goes. The division of the mold half 47 allows their Partial halves 51 and 52 substantially radially to the longitudinal axis 26 of the rod 14, ie in to move substantially in the division plane 48, as by the double arrow 54 is hinted at. The two halves 51 and 52 of the mold half 47 can by means of a device 55 are opened and closed, as with the double arrow 54th is also indicated. Possible, but not shown here, is also a unfolding the two halves as two wings. In addition, the device takes over 55 even the opening and closing of the two mold halves 46 and 47 for Shaping the screens. The device 55 is connected via a control line 33 with the Control device 32 connected.

For shaping a screen 5, the part halves 51 and 52 of the mold half 47th merged and then moved to the mold half 47 on the mold half 46. there is the intended for the formation of a screen extrudate 45 of the mold 15th enclosed and shaped a screen 5. Since the amount of extrudate 45 so is dimensioned that it does not fill the mold 15 to the parting line, no burr is created on the circumference of a screen 5 at the location where the two mold halves 46 and 47 collide.

The shape of a screen 5 can also be made so that the mold 15 already is closed when the feed of the rod 14 is stopped. That for the Forming a screen provided extrudate 45 is then in the closed Form promoted. Again, the flow rate of the extrudate from the Control device 32 are preset over time. It is also possible Control of the filling quantity via pressure sensors in the form 15 or on the walls the mold halves 46 and 47, as not shown here.

Since the mold half 47 is again divided into two halves 51 and 52, can whose parting line creates a ridge. To avoid this as far as possible by a corresponding shaping of the edges of the partial halves, for example By rounding, the formation of a sharp and thus disturbing ridge avoided become. In addition, the mold half 47 for shaping the bottom of the Umbrellas be provided so that with the one-piece mold half 46, the top of the Umbrellas can be formed completely burr-free.

After the shaping of a screen 5, the mold 15 has the screen without Release damage to its surface. For materials that adhere to the forming surfaces of the mold 15 tend, for example, in particular Silicone rubber, the mold halves 46 and 47 must be carefully opened, so that the screen surface is not damaged. It can be done this way be that filling the mold 15 by means not shown here pressure sensors is monitored. At a given, the degree of desired filling corresponding pressure, the mold is opened a predetermined gap. This will be First, the mold half 47 in total slowly and in the direction of the longitudinal axis 26th of the rod 14 retracted, for example by about one millimeter, to the pressure to reduce the material and to solve its adhesion to the mold walls. First after that, the mold is fully opened to release the umbrella and the two Part halves 51 and 52 radially to the longitudinal axis 26, in the direction of arrow 54, pulled apart. With switching on the feed device 13 and feed the Stabs 14 then the screen 5 is lifted from the mold half 46.

To the sticking tendency of the material of the screen cover to the walls of the mold halves These can also be minimized with a sticking tendency Be coated material, for example with polytetrafluoroethylene. Solving the Surface of the screen from the mold walls can also be mechanical way be supported by twisting the two Formhätften against each other when the Form is still closed. When the shape of the screen 5 is completed, 1, the region C of a composite insulator 1 is produced according to FIG.

With switching on the feed device 13 for advancing the rod 14 is at the same time the extruder 12 is turned on, so that the screen 5 without Interruption of the coating of the jacket connects. The length of the applied Mantels 4 to the formation of another screen is through the Control device 32 determined. After by the length measuring 43, the predetermined length of the shell 4 has been found, the Feed device 13 stopped and composite insulators with multiple screens the shaping of another screen takes place.

As the composite insulator grows, its first end continues to move away from the spray head 35 and immersed in the heating section 16, the extruder 12th is subordinate. In the heating section 16, a thermal treatment of the still soft material of the shield shell 3, so that he required for an insulator obtained mechanical and electrical properties.

The heating section 16 is a continuous furnace in the present embodiment. The Heat treatment of the raw screen covers is done according to the inventive method with hot air. This is a uniform, a local Overheating avoiding heating of the screen covers ensured.

The hot air is generated by means of a blower 56 with a downstream heater 57 and blown evenly into the continuous furnace 16. The temperature and the Air flow rate are controlled by the controller 32. The length of the Continuous furnace 16 and the thermal treatment of the screen cover are on the Material of the screen and the feed rate of the rod 14 tuned.

Seen in the direction of feed 31 leave the already finished areas of the Composite insulator 101, the continuous furnace 16. The umbrellas 5 are now fixed so that they no longer deform when used to support the composite insulator become. The screens 5 of the continuous furnace 16 leaving composite insulator 101st are pushed onto a transport device 17, in the present Embodiment, a non-driven, endless conveyor belt 58, the order Deflection pulleys 59 is wound, of which only one can be seen here. The Conveyor belt 58 is driven solely by the feed on the conveyor belt lying composite insulators 1 moves. The conveyor belt is so long that still at least one further, completely finished composite insulator 1 on it place place. Characterized in that still all cores 2 and 102 of the composite insulators. 1 or 101 form a continuous rod 14, it is possible that in the Emerging conceived composite insulator 101 with its still soft shield shell. 3 without support through the continuous furnace 16 to transport.

Is the core of a composite insulator complete in the designated areas coated with a screen cover, the order is via the controller 32 of the material 36 of the screen cover 3 is stopped while the advancement of the rod 14 continues. By stopping the extruder 12 ruptures during further advancing the Stabs 14 from the shield case 3 and the rod 14 remains naked. The order of the Material of the shield shell remains interrupted until the Length measuring device 43 has determined that the rod 14 by such a distance has been advanced, which corresponds to the length used to attach the fittings on the just finished with the screen cover and the subsequent, still composite insulator to be produced is required. In addition, the thickness of the Saw blade of the separator 18 taken into account. After that, the application of the Material for the shield shell of the following composite insulator again added.

As can be seen from FIG. 2, two finished composite insulators 1 are already on the transport device 17 accumulated. At the transport device 17 is the Separator 18 at such a distance from its beginning, the guide roller 59, arranged that in addition to two completely finished composite insulators 1 also still at least one already fully cured screen 5 one more composite insulator 101 to be finished rests on the conveyor belt 58. Thereby becomes a good support of the still to be finished composite insulator 101 reached. The separator 18 is with respect to the length of the produced Composite insulators can be moved into appropriate positions, as with the double arrow 60 is indicated. For this purpose, the separator 18, for example, with rollers 61 be slidably suspended on a suspension rail 62. To separate a finished composite insulator 1, the separator 18 after a Positioning by the length measuring device 43 from the controller 32 at directs a location of the transport device 17, where on the conveyor belt 58 the Separation point 10 between two composite insulators 1 is located, for separating at the Cut point 10 delivered and retracted after the separation process again, such as indicated by the double arrow 63. The separation of the finished Composite insulators occur whenever a screen is being formed and the Feed device 13 of the rod 14 is. The separator 18 fixed with a the Verbundisolator 1 undeliverable gripper 64 the end 7 of the separated Composite insulator during the separation process. From the still continuous bar 14, the core 2 of the insulator 1 is separated with a saw 65. After this Separation process, the gripper 64 is opened and withdrawn and the Separator 18 returns to its original position. The severed Composite insulator 1 can now be removed for further processing or will when restarting the transport device 17 to a not shown here Transported collection point.

Do not meet the adhesive joints in the rod 14, the requirements of the Strength of the rod, the formation of the rod 14 can be chosen so that each glued rod only as long as the core of a composite insulator. That would be each splice at the same time again a separation point 10 and no core would be a Clipping site included.

In Figure 4, two ways of designing a form are presented. It in each case only half of a section is represented by the shape and the screen. For a complete illustration, a reflection would be on the longitudinal axis 26 of FIG Staff 14 required.

The mold 15a is closed and consists of the mold half 46a, in front of here Not shown spray head is arranged, and the mold half 47a. The two Mold halves 46a and 47a are divided in the dividing plane 48 perpendicular to the Longitudinal axis 26 of the rod 14 is, as indicated by the right angle 49. The dividing plane 48 simultaneously forms the bottom 66 of the screen 5. Die Top 67 of the screen 5 lies in the mold half 46a. The shaping of the screen 5 is already completed. In front of the screen 5 extends on the rod 14 of the Sheath 4 of the screen cover 3.

A ridge formed by the parting line 68 of the two mold halves 46a and 47a is prevented by the following measures: Dosing of the extrudate to form a screen is done so that the Shaping a screen 5 provided molding space 69 of the mold 15 a not to Dividing line 68 is filled. The radial extent R of the mold space 69 is greater than the actually achieved radius r of the screen 5. The parting line 68 is in Edge region 70 of the screen 5 is not closed. The parting line 68 between the Both mold halves 46a and 47a can be either on the entire circumference of the mold 15a be open, so that the two mold halves are spaced from each other, or the two mold halves abut each other, but point radially directed, on the Circumferentially distributed grooves, which form channels in closed form to Escape of the air from the mold cavity 69 during molding of the screen. 5

The shaping surface 72 of the mold half 47 a, the bottom 66 of the Shade forms 5, is smooth in the present embodiment. She can, too concentric be wavy or ribbed. This creates umbrellas with larger Creepage distance. With umbrellas designed in this way, there are fewer compared to smooth umbrellas Umbrellas required per insulator.

The central opening 73 in the mold half 47 a, with the jacket 4 coated core 102 has a larger diameter than 74 Diameter 75 of the core 102 with jacket 4. The difference should be about 0.5 mm be. By so conditioned gap 76 is avoided that when closing and Opening the mold half 47a of the jacket 4 is damaged.

When the shaping of a screen 5 is completed, when opening the Form problems occur because the bottom 66 and the top 67 of the Schirms 5 to the shaping surfaces 73 and 71 of the mold halves 46a and 47a adhere by adhesion due to occurring negative pressure stay. This effect can occur even with the materials of the screen cover, the do not tend to stick. To detach the screen surface from the mold halves To facilitate, it is advantageous if when opening the two mold halves 46 a and 47a the air between the forming surfaces and the screen surface can flow in. The inflow of air promotes the release of the screen surface from the form walls. A negative pressure created when opening the mold halves between screen surface and mold walls is degraded and the suction effect overcome. To flow in the air poppet valves 77 in the mold halves be provided. They are preferred to be arranged in the areas of the mold, in due to the difficult access to air, the risk of sticking the Screen surface is largest, as in the area of the screen root. In the present Embodiment is in the mold half 46a a poppet valve in the region of Umbrella root 78 arranged.

The plate 79 of the valve 77 is flush with the forming surfaces 71 of Mold half 46a from. The valve disk 79 is acted upon by a valve stem 80 Spring 81 is pulled into the valve seat 82. In the present embodiment opens the valve 77 only at self-building negative pressure in the mold space 69 or at Supply of compressed air from the outside via a deliverable nozzle 83, as indicated by the arrow 84 is hinted at. The force of the springs 81 is set so that upon reaching a certain negative pressure, which occurs when opening the mold, the plate 79th of the valve 77 lifts off the valve seat 82. The negative pressure is set so that a Deformation of the screen 5 is avoided. In addition to the inflow of air presses the plate 79 on the screen surface and lifts them from the forming surfaces 71 off.

The detachment of the screen 5 from the mold walls can additionally by the supply be supported by compressed air 84 by means of the nozzle 83. For this purpose, the nozzle 83 with set their conical mouthpiece 85 in the funnel-shaped adapter 86, the over a channel 87 is connected to the poppet valve 77 and above the valve disk 79 opens. If the compressed air supply 84 is initiated, the valve plate 79 is against the Stressed by the spring 81 from the valve seat 82 and gives the supply of air in the Shaping room 69 free. A short-term compressed air supply can also be on the verge of opening the form. This releases the screen surface at the critical points even before opening the two mold halves of the mold walls.

Below the longitudinal axis 26 of the rod 14 is another possible embodiment a mold 15b shown. With the shape 15 a matching features are with the same reference numerals. In the present embodiment are the two mold halves 46b and 47b with a heater for thermal treatment the material of the umbrella cover equipped. In the mold halves 46b and 47b are in at certain distances from each other heating wires 88 inserted, which have connections 89 are connected to a not shown, controllable current source. By Specification of the current and the time can be a predetermined temperature and thus a predetermined state of the material of the shielding shell can be achieved. Either can be a completed thermal treatment until complete curing of the Schirms done or the material is thermally pretreated so far that the Surfaces 66 and 67 of the screen 5 already become so hard that they turn out easily to release the mold. The final thermal treatment would then be in take a continuous furnace.

The last-described embodiment of a mold may additionally, as here not shown and described, with the previously described embodiment with The valves are combined for the supply of air.

Claims (33)

1. Method for producing composite insulators, wherein a rod-shaped or tubular core of composite material, which is conveyed in its longitudinal direction, is covered with a screening sheath of a material with insulation properties in an appliance for applying the material, wherein at least one screen is shaped from this material,
   characterised in that
   the core feed is stopped in order to shape the screen, an annular screen is shaped by means of a mould which, viewed in the transport direction, is delivered to the core after the appliance for applying the material of the screening sheaths, after shaping the screen, the core feed is resumed and the application of the material continued, and the application of the material of the screening sheath to the core is not interrupted until the screening sheath has been completely produced.
2. Method according to Claim 1, characterised in that the mould, which is split substantially in a plane perpendicular to the longitudinal axis of the core, for shaping the screens is not filled completely up to the parting line with the material of the screening sheath in order to prevent the formation of fins.
3. Method according to Claim 1 or 2, characterised in that a material with a high Williams plasticity is used to reduce the tendency of the material of the screening sheath to adhere to the mould walls.
4. Method according to Claim 1 or 2, characterised in that an antiblocking additive is added to the material of the screening sheath to reduce the adhesion tendency.
5. Method according to any one of Claims 1 to 4, characterised in that the level of the material of the screening sheath in the mould is monitored on the basis of the pressure which is produced by the material in the mould, and that the mould is opened by a predetermined gap at a certain pressure which corresponds to the desired filling degree.
6. Method according to any one of Claims 1 to 5, characterised in that the separation of the screen surface from the mould walls is assisted by supplying air to the screen surface.
7. Method according to any one of Claims 1 to 6, characterised in that the separation of the screen surface from the mould walls is assisted by turning at least one mould half with respect to the other about the longitudinal axis of the core.
8. Method according to any one of Claims 1 to 7, characterised in that at least the mould half which, viewed in the direction of feed of the core, lies before the other mould half, is further divided into sub-halves, and that these sub-halves are opened in time-staggered fashion.
9. Method according to any one of Claims 1 to 8, characterised in that the application of the material of the screening sheath is interrupted during the production of a composite insulator at its beginning and after forming the screening sheath at its end on the core in each case over a predetermined length, and that the fittings of the insulator are fastened to these ends.
10. Method according to any one of Claims 1 to 9, characterised in that one core is of a length such that it can be used to produce at least two composite insulators.
11. Method according to any one of Claims 1 to 10, characterised in that each subsequent core is joined to the preceding core to form a long continuous rod or tube in order to continuously produce a plurality of composite insulators in succession.
12. Method according to any one of Claims 1 to 11, characterised in that the parts of the screening sheath which are already shaped after applying the material of the screening sheath are thermally treated to produce the required material properties, while the material for shaping the remaining parts of the screening sheath or even for shaping the screening sheath of the subsequent composite insulator is applied to the core.
13. Method according to any one of Claims 1 to 11, characterised in that the screens are thermally treated while still in the mould.
14. Method according to Claim 13, characterised in that the screens undergo a thermal pretreatment in the mould and then separately a thermal treatment for finally curing the screens.
15. Method according to either Claim 12 or 14, characterised in that the thermal treatment of the material of the screening sheaths takes place in a continuous furnace by means of hot air.
16. Method according to either Claim 12 or 14, characterised in that the thermal treatment of the material of the screening sheaths takes place by means of microwaves.
17. Method according to any one of Claims 10 to 16, characterised in that at least one already finished composite insulator which is still joined via the core to the subsequent composite insulator is supported by a transport appliance, and that the subsequent composite insulator is thereby held without support between the appliance for applying the material of the screening sheaths and the transport appliance.
18. Method according to any one of Claims 1 to 17, characterised in that composite insulators with a different number of screens are produced in succession.
19. Device for producing composite insulators with a feed appliance for the rod-shaped or tubular core, appliances for applying the material of the screening sheaths to the core and for shaping the screens, as well as a heating appliance for thermally treating the material, in particular for carrying out the method according to any one of Claims 1 to 18, characterised in that a mould (15, 15a, 15b) for shaping at least one annular screen (5) from the material of the screening sheaths is disposed downstream of the appliance (12) for applying the material (36) of the screening sheaths (3).
20. Device according to Claim 19, characterised in that the mould (15, 15a, 15b) for shaping a screen (5) can be split in a first plane (48) perpendicularly (49) to the longitudinal axis (26) of the core (102) of the composite insulator (101) to be produced into two halves (46, 47; 46a, 47a; 46b, 47b).
21. Device according to Claim 20, characterised in that the first half (46, 46a, 46b) of the mould (15, 15a, 15b), viewed in the direction of feed (31) of the core (102) of the composite insulator (101) to be produced, is disposed directly at the mouth of the appliance (12) for applying the material (36) of the screening sheaths (3).
22. Device according to Claim 20 or 21, characterised in that the second half (47) of the mould (15), viewed in the transport direction (31) of the core (102) of the composite insulator (101) to be produced, can be split in a second plane (53), that the second plane (53) is substantially perpendicular to the first plane (48), and that the sub-halves (51, 52) of the mould half (47) can move substantially axially (50) and radially (54) to the longitudinal axis (26) of the core (102).
23. Device according to any one of Claims 19 to 22, characterised in that the radial extent (R) of the cavity (69) in the mould (15, 15a, 15b) is greater than the radius (r) of the shaped screens (5).
24. Device according to any one of Claims 19 to 23, characterised in that a heating section (16) is disposed downstream of the appliance (12) for applying the material (36) of the screening sheaths (3) for the thermal treatment of the material (36).
25. Device according to Claim 24, characterised in that the heating section (16) comprises a hot-air recirculation air blower (56, 57).
26. Device according to Claim 24, characterised in that the heating section comprises a high-energy radiation source, preferably of microwaves.
27. Device according to any one of Claims 19 to 26, characterised in that the mould (15b) for shaping the screens (5) comprises a heating appliance (85, 86) at least for the thermal pretreatment of the material (36) of a screening sheath (3).
28. Device according to any one of Claims 19 to 27, characterised in that an appliance (21) is disposed upstream of the appliance (12) for applying the material (36) of the screening sheaths (3) in order to join sub-pieces (19) together to form a long rod (14) or tube which can be delivered to the appliance (12), and that the cores (102) of the composite insulators (101) to be produced can be formed in succession in the respective required length from the rod (14).
29. Device according to any one of Claims 19 to 28, characterised in that the appliance (12) for applying the material (36) of the screening sheaths (3) is operatively connected to a length measuring instrument (43) at the rod (40) or tube, and that the application of the material (36) for forming the screening sheaths (3) can be controlled in accordance with the feed (31) of the rod (14) or tube.
30. Device according to Claim 29, characterised in that the appliance (12) for applying the material (36) for forming the screening sheaths (3) can be controlled in accordance with the feed (31) of the rod (14) or tube so that the end pieces (6, 7; 106) of the composite insulators (1, 101) remain free of the screening sheath (3) over a predeterminable length (8, 9; 108) in order to connect the fastening fittings.
31. Device according to Claim 29, characterised in that the feed (31) of the rod (14) or tube can be controlled in terms of its speed so that the end pieces (6, 7; 106) of the composite insulators (1, 101) remain free of the screening sheath (3) over a predeterminable length (8, 9; 108) in order to connect the fastening fittings.
32. Device according to any one of Claims 28 to 31, characterised in that a separating appliance (18) for separating finished composite insulators (1) of a predetermined length is disposed downstream of the appliance (12) for applying the material (36) of the screening sheaths (3), and that the separating device (18) is actively connected to the length measuring instrument (43) for measuring the length at the delivered rod (14) or tube.
33. Device according to any one of Claims 19 to 32, characterised in that a transport appliance (17) is provided, by means of which appliance the finished composite insulators (1) can be transported while being supported at the circumference of their screens (5), and that the transport appliance (17) is disposed at a distance from the appliance (12) for applying the material (36) of the screening sheaths (3) and optionally the heating section (16) such that the composite insulators (101) which are still to be completed can be transported without support on the as yet uncured screening sheaths (3).

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