CN1238173C

CN1238173C - Method for installing an elastomeric housing around a slender object

Info

Publication number: CN1238173C
Application number: CN 01806360
Authority: CN
Inventors: Y·加米; G·福尔尼尔
Original assignee: Gouillardon Gaudry SA
Current assignee: Gouillardon Gaudry SA
Priority date: 2000-01-11
Filing date: 2001-01-09
Publication date: 2006-01-25
Anticipated expiration: 2021-01-09
Also published as: TNSN01004A1; FR2803558A1; WO2001051268A1; AU2001231858A1; FR2803558B1; CN1416385A; BR0107481A

Abstract

This press casting method consists in: -realising two blanks shaped to fit the distribution of the casing material around the object; positioning a blank inside a concave cavity (14) of an underlying casting element (11), said cavity conforming to the shape imparted to the casing; positioning an intermediate plate or grid (19) on the lower element, on which the blank mould has been mounted, on both of its main surfaces defining the shape and dimensions of the object or part of the object; defining a second said blank on the upper surface of the grid according to size or protrusion; closing the mould, the upper element of which is also equipped with a female cavity (16) and this for a sufficient period to guide the realisation of the two half-shells, the purpose of which is to finally constitute the outer shell of the object; opening the mold and pulling out the intermediate plate or grid; positioning the object in a lower cavity of a lower element of the mould, said lower cavity being equipped with a lower half-shell, which acts as an object centring element; reclosing the mould for the necessary duration to reticulate or vulcanize the casing and thus to push out the desired duration of the coupling of the two half-shells formed by the above-mentioned closure of the mould, thus obtaining a continuous casing; after reticulation and vulcanization, the mould is opened and the object with the casing (5) completely or partially installed is removed.

Description

The method of around slender body, elastomer shell being installed

Technical field

The present invention is implemented in the method for an elastic housing being installed around the object by the technology that is called die casting, this object can be hollow also can be solid: be elongated shape, rotational symmetry is arranged or do not have rotational symmetry.

It relates in distinctive mode installs such shell around a composite insulator.

Background technology

Such insulator generally is installed on the iron tower of supporting electric wire.According to the voltage of the electric current that is transmitted by these lines, these insulators have some characteristics, as size, and mechanical strength and different insulation, this is readily appreciated that.

These insulators have been finished dual-use function, that is to say on the one hand is at described suitable electric wire and the electric insulation functions between the iron tower, simultaneously be the mechanical function that supports on the other hand, so that the weight of supporting electric wire, no matter when, as rock, particularly with snow, frosting, freezing relevant additional weight.

In the insulator that uses, the combined type insulator all typically comprises three parts now, i.e. two joints, and they are positioned at described insulator two ends, play a part respectively and cable and iron tower machinery hook.With a connector in the middle of two joints, the core that this connector is made by insulating materials constitutes, especially the thermosetting material of being strengthened by fiber is made, be preferably in epoxy resin or the polyester center is filled with glass fibre, comprise a rubber sleeve or shell at last, it has very strong dielectric property and extraordinary anti-ageing, ozone, ultraviolet characteristic.

This shell mainly is by rubber EPDM terpolymer-ethylene-propylene-diene, and silicone rubber is particularly used ethylene-propylene copolymer EPR, can be vulcanized or the elastomer of nettedization is realized by any in a word.

From tradition, this shell has some radial annular fin, and purpose is to limit the leakage line that is suitable for avoiding forming any electric arc between two contacts.

In addition, this shell realizes by this way, and it sticks to annular element or type in the heart, also sticks to the bottom of two contacts respectively.

In order to realize such insulator, especially, advised out diverse ways in order to realize the installation of shell.

In these methods, the most outstanding is gunite, for this reason, exposed insulator, that is to say the insulator of forming by some independent joints of rotation shape center ring connection, be positioned in the mould, in complete traditional mode, people inject with the necessary elastomeric material that constitutes this shell and obtain.

If the people is satisfied in addition in this implementation method of technical elements, cause the expensive expense of increase of these insulators on the other hand, also relate to and realize machinery and implement mould.In fact, such method need be used very expensive self-centering's device or the locating ring of annular element or the type heart in mould.Described locating ring is made with thermoplastic material, makes the core local embrittlement.

Therefore, people propose to be realized by pressurization the installation of these shells.The device of in file FR-A-2732155, describing as people, at the installation that realizes shell with pressurization, this device comprises a pair of cast element, is respectively top with following, and each element is determined a cavity that is used for forming the compound inslation body case.One of cast element, especially Shang Mian element is equipped with separating joint, and these joints are positioned at the proximity space of cavity, its objective is the upper surface that is supported at casting second element.The installation purpose of these plates or joint is to reduce the material of forming shell as far as possible and flows to outside the mould when compression casting, also reduced the overlap at the intrinsic die joint place of this casting method simultaneously like this, this also is in order evenly, capacity to be filled in the cavity that make the mould fin inside that especially diameter is bigger in addition.

But, the equipment people of this model is observed some bigger stress be applied on the plug-in unit, and this plug-in unit should guarantee the creep of rubber in this measure.In addition, consider the shape of cavity, more intense stress can local expansion.At last, concerning the technical application of preparation blank, this equipment is worthless, is particularly useful for rotating symmetric element.

In file EP-A-0624446, people propose also to realize the compound inslation body case by compression casting that it is:

At first, around the type heart, be pre-formed a rubber layer;

Then, the type heart that has this layer rubber is positioned between two parts of mould;

Above-mentioned rubber layer is carried out compression casting, be formed on the predetermined shape of cavity inside that the described two parts of mould limit;

Make the polymerization of compression foundry goods form described shell.

According to this file, above-mentioned rubber layer is made by extrusion casint, and in addition, two parts of above-mentioned mould all are equipped with type heart setting element and find the position to reach the type heart in cavity, thereby has guaranteed the correct center adjustment of shell that the type heart will be realized relatively.It is higher that this equipment is proved cost of use, this mainly be because the complexity of tool set and by blank directly to the type heart the implementation phase complexity.In addition, corresponding method is proved very difficult automation.

Summary of the invention

Target of the present invention is to propose realization and a kind of method of making shell with elastomer is installed on an object, and this shell is elongated, and especially the compound inslation body case combines reliability simultaneously, efficient, and save implementation cost.

Of the present inventionly on a slender body periphery, realize it is characterized in that the method for an elastomer shell by compression casting:

At first, the part of slender body or object is wished to realize that with people the used material of shell makes two blanks 23, its shape is suitable for forming the distribution of the material of shell around the part of object or object;

One of described blank is positioned at 14 inside, matrix chamber of bottom foundry goods 11, and said die cavity has and the corresponding shape of described shell;

Below the mould of equipping blank like this, locate an intermediate plate or grid 19 on the element, be respectively the size shape of determining the part of object or object on the upper and lower main surface;

The described second block of blank 23 in location on size on the upper surface of grid or projection;

Closing molding, the top element of described mould is equipped with a matrix chamber 16 equally, through one period sufficiently long time limit to induce the plasticizing of blank, form the distribution of blank material, moulding on described die cavity, so just realize two and half housings or preformed, its objective is the shell of the part of final formation object or object;

Open mould and pull out intermediate plate or grid;

Below mould element below the part of location slender body or object on the die cavity, described below die cavity equipped half housing or following preformed, it plays the effect of object centering device like this;

Again closing molding through nettedization of the composition material that makes shell or the essential time limit of sulfuration, and is reasoned out two and half housings that form when mould was closed last time or the necessary time limit of preformed binding, obtains a continuous shell at last;

Finish in nettedization and sulfuration, open mould, extract all or part of slender body that shell 5 is housed then out.

Another kind of saying, the present invention mainly is to enable an intermediate plate or grid in the element internal design of compression casting, its projection size roughly corresponding the part of the object of covering shell or the object size of occupying, limit by this way and homogenizing when the part of object or object forms blank shape, the stress that produces by the material pressurized of forming shell.The present invention also allows to avoid the directly pressing steps on the part of object or object of blank, just as described in the prior art.At last, the measure of taking in the method for the invention centers and is directly given to guarantee by following preformed, and the present invention has broken away from and implemented any mechanism or similar devices of centering.

Preferably, mould has designed a degasification stage when closing for the first time.Second degasification stage when closing for the second time, mould also arranged equally.These degasification stages guarantee to eliminate bubble by known mode, especially to the shell of structural housing or relative complex shape especially like this.These degasification stages also comprise the device that is called degasification on a plurality of stricti jurises.

Another useful feature according to the present invention, the die cavity of this mould and intermediate plate or grid contain a kind of antiplastering aid or are subjected to anti-stick processing.This antiplastering aid is by the PTFE polytetrafluoroethylene (PTFE)

Another beneficial feature according to the present invention, when the material that uses is rubber EPDM, the mould dwell period first time was at 20 to 40 seconds, mould is closed the time limit for the second time, reach nettedization or the sulfuration of rubber under this feelings, be 6 to 10 minutes, these numerical value are about 170 ℃ to mold temperature and provide.

The present invention also provides the method for being implemented and installing shell by compression casting on composite insulator 1, and described insulator comprises an annular element or the type heart 2, and it is made by a kind of composite, and link two

hook joints

3,4, also comprise a step that makes casing insulation, it is characterized in that

At first,, that is to say, equip two

suspension joints

3,4 and link their the type heart that wish to form the blank 23 that the material of shell is formed by people for two, its shape adapts to sheathing material and distributes around plug-in unit to each naked insulator to each plug-in unit;

One of described blank in location in the matrix chamber 14 of cast element 11 below a compression casting device, the shape of described die cavity and the shape of described shell consistent 5;

Intermediate plate in location or grid 19 above the cast element below blank described is housed,

size

21,22 is being respectively the geomery of determining plug-in unit on two main surfaces of upper and lower it;

Second described blank in location on size on the upper surface of intermediate plate or grid 19 or

projection

21,22;

Closing molding, the top element 12 of described mould is equipped with a matrix chamber 17 simultaneously, and this wants one period enough time limit to cause the plasticizing of blank, the distribution of blank material, processing and forming on described die cavity so just realizes two and half housings, its objective is the shell of final composition insulator;

Open mould, extract intermediate plate or grid 19 out;

Described plug-in unit is positioned on the following die cavity of following element of mould, die cavity has been equipped with half housing or following preformed, and it plays the effect of plug-in unit centering device;

Again one period necessary time limit of closing molding, so that nettedization of composition material of shell or sulfuration, and release thus two and half housings that formed when last time mould was closed are linked, to reach the required time limit of purpose that forms a continuous shell;

Polymerization finishes to open mould, takes out the insulator that shell 5 is housed then.

Can realize that mode of the present invention and the benefit therefrom seen can appear at better and rely on accompanying drawing with not limiting with symbolic but in the example that do not provide.

Description of drawings

Fig. 1 is the profilograph according to the insulator obtaining of method of invention;

Fig. 2 is that the mould of the method for carrying out an invention is opening the schematic diagram of position;

Fig. 3 is the schematic diagram in its closed position;

Fig. 4 is a schematic diagram of seeing following element or top element from above;

Fig. 5 is a schematic diagram of seeing intermediate plate or grid from above;

Fig. 6 is its cross-sectional view; With

Fig. 7 is a blank schematic diagram of realizing shell according to invention.

The specific embodiment

Following description will lay particular emphasis on the formation and the installation of shell around insulator especially.What should emphasize is that this describes the usage range that does not limit invention, and invention is to realizing and install such shell around any type of object, and these objects can be elongated, and are hollow or solid, symmetry without spin arranged, especially to tubing.

Composite insulator 1 purpose according to the inventive method is to realize a shell, has schematically illustrated its vertical section on Fig. 1.

Composite insulator is made up of two

metal joints

3 and 4 basically, is typically by aluminium, steel or zinc-plated cast iron to make, and each joint all is installed with transverse holes and is separately fixed on iron tower and the cable allowing.

Link up by the annular element or the type heart 2 between these two

joints

3 and 4, as saying, use insulating materials, especially the plastic material of strengthening with glass fibre.The base portion of this annular element 2 in

joint

3 and 4 is respectively 7 and 9 and is received, and is fixed on this position by reducing 8,10.

At last, insulator holds a shell 5, also is dielectric, most typically make by rubber EPDM, and be bonded on the annular element respectively and the base portion of

joint

3 and 4 on.

This shell 5 has some fin 6, and the preferred effect of its electric insulation has been previously described.

According to invention, realize at the insulator place and the shell that is in place 5 is finished by compression casting.

The compression casting device that the present invention proposes schematically is shown in Fig. 2 and 3.It comprises the mould of being made up of two cast elements substantially, and they are respectively following element 11 and top element 12, can excite the motion of rising or descending by guide pillar 18 guidings.

In described example, below cast element 11 can excite up or down motion by pressure, 13 people have illustrated this piston by Reference numeral.

Certainly, this mould has enough temperature, and it is adjustable using the temperature of material, on the one hand, as what describe later, in order to reach the plasticizing of forming sheathing material, reaches nettedization sulfuration simultaneously; On the other hand, consider the maximum temperature that the composition material of the insulator annular part or the type heart 2 can be accepted.

Below each 11 and 12 top cast elements all have a cavity or die cavity, and by 14,16 expressions, it reveals in Fig. 4 in more detail respectively.This die cavity is generally half round post, has in addition and shell 5 consistent shapes.From here, people observe the cut-out that allows fin 6 to form emphatically.

A fundamental characteristics according to invention.This device also comprises an intermediate plate or grid 19, its objective is below mould element 11 and above location between the element 12, more particularly it is against on the upper surface 15 of the following element 11 of mould and on the lower surface 17 against the top element 12 of mould.It bores a hole 20 in addition in addition, and purpose is to cooperate with guide posts 18.This piece plate 19, respectively it upper surface and lower surface on comprise the projection its undersized in the size of naked plug-in unit, just do not have the size of the insulator of shell 5.

In fact, this projection comprises, respectively on each face on the upper and lower surface of plate 19, the annular element of one first semicolumn 21 it and insulator or the size of the type heart 2 half length are corresponding; Second semicolumn 22, it respectively and be that the bottom 7 of 3,4 joint is corresponding with 9 outer surfaces.

In addition, people have expressed the vertical section of plate 19, so just these different sizes of perception preferably.

Just as described, when mould is closed this piece plate last 12, locate between 11 elements down, it contacts with two elements, people can observe this point in Fig. 3.

According to the present invention, we will describe this device embodiments in more detail.

Mould is opening the position, and on the die cavity 14 of element, people locate one first blank, have expressed its shape on Fig. 7 below.Blank is made by the material of forming shell, and general this material is rubber EPDM.

This blank is dumbbell shape, and according to the needed size of insulator various piece, the quantity of material has been carried out meticulous distribution.

Certainly, well-known, the quantity of the material that occurs on blank is greater than people for realizing the size of whole casing actual needs.

In case blank is gone into the position, location grid 19, these grid are preferably in the guide rail place and have this function.

People especially on

size

21 and 22, put and first block of second block of blank that blank is the same on grid, then closing molding so that described second block of blank be positioned on second cast element, 12 die cavities 16.

After mould is closed, such as closing by the startup of piston 13, people carry out the degasification first time, heated about 30 seconds, this softens the composition material of blank and it is entered, especially enter the needed time limit in matrix chamber 14 and 16, just provided the shape of the especially fin 6 that last shell has so from this time.

By this method, people have obtained two and half housings or pre-setting, will reach in their binding of next step and realize complete shell 5.

In addition, following pre-setting will play the effect of centering device or carriage mechanism, so just can receive plug-in unit 3 a suitable position.

So people extract grid out and locate plug-in unit, that is to say naked insulator, it is formed by some independent frameworks with the annular element that they couple together in the pre-setting of described bottom, and itself is contained on the following die cavity of element 11 of mould.

Mould is closed again, people carry out the phase I of degasification, air is extruded in expansion by rubber, then, mould has reached temperature desired, considers that the typical temperature of material EPDM of forming shell is 170 ℃, closing molding is 6 to 10 minutes now, so that described material reaches sulfuration and nettedization, make in addition when mould is closed previous step and to implement two and half housings and reach welding and connection, form a continuous shell 5.

In some practicalities, wish that shell is attached on the annular element 2 of joint 3 and the 4 and bottom 7 and 9.In this scheme, plug-in unit just holds one deck in advance and is fit to bonding material when going into.

According to the present invention, consider the uniform characteristics of pressure distribution of the material of formation shell, this method allows with the effective and efficient manner protection type heart or annular element 2.In fact, two and half housings that picture is formed shell were implemented in a stage in advance, in its inside, plug-in unit has been replaced by the grid that are equipped with projection size, exactly the type heart of this plug-in unit is not subjected to the pressure of material, and this point forms stage and sulfuration and nettedization stage at two and half housings and is not always the case.Therefore according to the method for invention, realize that the insulator of big size becomes possibility, typically reach 5 to 6 meters, they use 220000 to 400000 volts in extra-lnigh tension, and this is that people's mode of also not using economy is accomplished so far.

In addition, should also be noted that the automation characteristics of this method, at first can the time limit carry out work in shielding, especially to the implementation procedure of blank, on the other hand, grid be drawn out of with mould in second heat cycles, carry out blank and on grid, locate to realize follow-up shell.Can repair overlap to the insulator that the front circulation obtains in this heating period simultaneously.

Be understood that this method benefit, except that shell that allow to realize the large scale insulator, can have a mind to the free burial ground for the destitute simultaneously reduces the expense that this shell is in place.

Also have, method of the present invention allows on frangible relatively plug-in unit, realizes shape various backed stamper, especially combined type on the particularly hollow or solid pipe.

At last, by the operation of this method, people obtain the self-centering at backed stamper stage plug-in unit, so just allow to save any centralizer, and it is very difficult that the front has illustrated its installation, also the much less high price of finished product.

Claims

1. Method for realizing an elastomeric shell on the periphery of an elongated object by pressure casting, characterized in that:

firstly, two blanks (23) are made of the material from which one wishes to realize the enclosure for the elongated object or part of the object, the shape of which is suitable for the distribution of the material constituting the enclosure around the object or part of the object;

positioning of one of said blanks inside a concave cavity (14) of the lower casting (11), said cavity having a shape corresponding to said shell;

positioning an intermediate plate or grid (19) on the lower element of the mold thus equipped with blanks, defining the size and shape of the object or part of the object on the upper and lower main surfaces respectively;

- Positioning said second blank (23) on a dimension or protrusion on the upper surface of the grid;

Closing the mold, the upper part of which is also equipped with a concave cavity (16), after a period long enough to induce plasticization of the blank, the distribution of the material comprising the blank is formed on said cavity, thus achieving two half-shells or preforms, the purpose of which is to ultimately constitute the outer shell of an object or part of an object;

Open the mold and pull out the middle plate or grid;

positioning of the elongated object or part of the object on the lower cavity of the lower element of the mould, said lower cavity already equipped with a half-shell or lower preform, so that it acts as an object centering element;

re-closing the mold, after the necessary period for reticulation or vulcanization of the constituent materials of the shell, and deducing the necessary period for the joint of the two half-shells or preforms formed at the last closing of the mold, to finally obtain a continuous shell;

• At the end of reticulation and vulcanization, the mold is opened and the elongated body is then withdrawn fully or partially fitted with the shell (5).

2. The method according to claim 1, characterized in that the material realizing the shell (5) is selected from the group of reticulated and vulcanized rubbers, including rubber EPDM, silicone, ethylene-propylene copolymers.

3. The method as claimed in claim 1, characterized in that a degassing phase is carried out beforehand when the mold is closed for the first time.

4. The method according to claim 1, characterized in that a second degassing is carried out when the mold is closed for the second time.

5. The method according to claim 1, characterized in that, when the intermediate plate or grid is pre-installed in the mould, it undergoes an anti-adhesive treatment to accommodate a covering made of PTFE.

6. Method according to one of claims 1 to 5, characterized in that the object covering the housing (5) is a hollow or solid pipe.

7. Method of implementing and mounting an enclosure by pressure casting on a composite insulator (1) comprising a ring or core (2) made of a composite material and joining two hook joints (3, 4), further comprising a step of insulating the housing, characterized in that,

Firstly, for each insert, that is to say for each bare insulator, equip with two suspension joints (3, 4) and cores connecting them, two blanks (23) consisting of the material one wishes to form the shell, Its shape accommodates the distribution of housing material around the insert;

Positioning one of said blanks in a concave cavity (14) of the lower casting element (11) of a pressurized casting device, the shape of said cavity conforming to the shape of said shell (5);

positioning an intermediate plate or grid (19) above said lower casting element containing the blank, the dimensions (21, 22) defining the shape and dimensions of the insert on its two main surfaces, upper and lower, respectively;

Positioning of a second of said blanks on dimensions or protrusions (21, 22) on the upper surface of the intermediate plate or grid (19);

Closing of the mould, the upper element (12) of which is simultaneously equipped with a concave cavity (17), for a period sufficient to cause the plasticization of the blank, the distribution of the mass of the blank, the forming process on said cavity, In this way two half-shells are realized whose purpose is to finally compose the outer shell of the insulator;

Open the mold and pull out the middle plate or grid (19);

positioning of said insert on the lower cavity of the lower element of the mould, which has been filled with a half-shell or lower preform, which acts as the centering element of the insert;

Re-closing the mold for a period of time necessary to reticulate or vulcanize the constituent materials of the shell, and thereby push out the period required to join the two half-shells formed when the previous mold was closed to form a continuous shell ;

At the end of the polymerization the mold is opened and the insulator with the casing (5) taken out.

8. A method according to claim 7, characterized in that the material with which the housing (5) is realized is selected from the group of materials comprising rubber EPDM, silicone resin, ethylene-propylene copolymers.

9. Method according to any one of claims 7 to 8, characterized in that one or more degassing stages are inserted at different closings of the mold.

10. A method according to claim 7, characterized in that the intermediate plate or grid (19) is anti-stick treated before being placed in the mould, housing a covering of PTFE.