DE202006002897U1 - Feed sieve used in casting installations comprises body with wire mesh formed as one layer in edge zone and having partially flattened wires in wire crossing regions of edge zone - Google Patents

Abstract

A feed sieve (1) comprises a body (2) with a wire mesh (12) formed as one layer in an edge zone (3) and having partially flattened wires in the wire crossing regions of the edge zone.

Description

The The present invention relates to a cast-in screen with a flat wire mesh, which for use in or on casting machines or casting devices for casting of devices and components. In particular, the present invention serves for use in low-pressure Kokillengußanlagen, but can also at applied to other casting methods become.

It are known in the prior art Eingusssiebe, the one Hat or pot shape have. The edge of the hat is usually used as a support to safely arrange the wire in the cut of a screen mold, without the risk of slipping. Such sieves are used e.g. in the production of plastic and metal parts in units needed by up to hundreds of thousands or millions or even more. at blocks for machine parts or housing from e.g. Aluminum alloys can for each single component up to five, ten, Twenty or more inlays are needed, which are then after must be replaced every casting process. The technical and in particular the financial expense for every single sieve therefore has to be limited due to the high quantities be.

Basically, such Sieves are made of wire mesh. For this purpose, a roll of wire mesh with the desired Made fabric weave and it will be punched out of matching pieces and further processed accordingly. Ingot sieves made of wire mesh are characterized by a precise Production and a high filter quality. Another advantage is the open cross-sectional area. A significant disadvantage, however, is that at the edges of the only short pieces of wire can solve that then during the casting process in the body to be produced advised. As a result, the properties of the body to be produced in usually negatively changed, so that such castings are useless. Short-bonded wires that only over one, two or three bonds are bound, but can be used on round ingot sieves and when using wire mesh as a sieve in principle not be prevented unless an edging is provided which means more effort in the production. This is especially true if the sieve at casting temperatures of several hundred degrees Celsius should be used in conventional adhesives conditions do not stand up.

A different possibility is the use of sieves of expanded metal mesh. Such expanded metal be out of a thin one Plate made of solid material, by defined holes in the plate are introduced. By introducing the desired Number and size of holes can be the sieving properties be adjusted, with tissue more precise, with tighter tolerances for the mesh can be made. After punching, the plate is still stretched. Due to the principle occurs the disadvantage of falling out short wires not on, since the sieve made of solid material. Another advantage is that the flat surface between the holes baffles for the Form molten cast, which is so torn and the melting process not disabled. The disadvantage, however, is that the proportion of free area relative to the entire screening surface is low. That's because the remaining wall thickness between two holes due to production be greater must, as the wire diameter of a wire mesh.

Compared to the cited Prior art, the object of the present invention, To provide a Eingusssieb with a wire mesh, in which do not solve any parts that can get into a casting to be produced during the casting process.

The The object is achieved by a Eingusssieb solved with the features of claim 1. preferred Further developments and refinements are the subject of the dependent claims.

The Ingot according to the invention for filtering a molten cast has at least one body, which comprises at least one wire mesh. The body points at least one edge zone and at least one filter zone on and is single-layered at least in the marginal zone. The wire cloth has at least in the wire crossing regions of the edge zone at least partially flattened wires or wire crests on.

The Invention has many advantages. In the case of the casting sieve according to the invention are also short-wrapped wires sufficient to ensure a reliable casting process.

Such short-wrapped wires, the e.g. to be held only by two, three or four bonds, can in certain circumstances during the casting process out of the fabric using conventional die-cast screens solved and so on with the filled Melt enter the component to be produced, causing the component usually becomes unusable.

The cast sieve according to the invention offers considerably better protection, since the wires are considerably more firmly integrated. In the case of the cast-in sieve according to the invention, the wires flattened at the crests of the wire crossing regions or at the binding sites of the fabric are not only frictionally but also positively held. This applies in particular but not only if they are produced according to a preferred development by calendering or compaction of the wire mesh.

The Ingot according to the invention can be easy and in high volumes getting produced. An advantage is the cast sieve according to the invention is also the high free flow area. The production is simple and neither time nor material consuming, so that the invention is widely used.

According to one preferred development are the existing contact points at the binding sites the wires flattened by the calendering. As a result, the wires are pressed together, ensuring a good bond of the wires present in the wire mesh.

In preferred developments of the invention is at least the Border zone of the body in Essentially from a single-layer wire mesh. In particular the entire wire fabric is made in one layer. In special advantageous Embodiments consists of the body in particular completely or but essentially complete made of wire mesh. This allows a particularly simple and inexpensive production, because only the wire mesh are produced and shaped accordingly got to. For quantities Thousands or millions of euros are simple yet reliable ingrained sieves required, which can be prepared in this way.

to further increase For safety, the finished cast sieves are preferred after manufacture still over a vibrating grate or the like, and / or e.g. blown out with compressed air. On the vibrating grate the cast filters are exposed to vibrations, so that through the Vibrations of the vibrating grate possibly still existing easily detachable or loose wires already be removed in advance before using the Eingusssiebes. Therefore indicates a finished sieve the entire area sufficiently tightly bonded wires on.

It have to not all wires over one have flattened cross section, it is also sufficient if only part of the wires are flattened in sections or flattened while other areas of the wires are trained around, which is regularly the original Shape of the wires equivalent.

Especially assigns the wire mesh flat the wire intersection areas flattened crests of the wires of the Wire mesh on. In particular, essentially at all wire crossing points the wiretops flattened. This is done in particular via a Calendering of the wire mesh before the production of the sieve, but can also be done by pressing.

One such a sieve has proved to be very advantageous because it has surprisingly shown that the flattened wires form baffles for the melt on which the oxide skin of the melt ruptures. This will be a reliable casting process considerably supported.

Preferably the thickness of the wire mesh is smaller at least in the peripheral zone as twice a typical wire diameter of the wires of the Wire mesh or as the sum of diameter of the warp and the Weft threads.

In all embodiments, in particular calendered wire mesh preferably one 10 to 40 percent, in particular 15 to 30 Percent reduced wire mesh thickness. For a wire mesh lies the thickness normally at about twice the wire diameter. For extra thick wires and / or small mesh sizes, the thickness is slightly larger. By a calendering, the wire mesh is leveled and it is opposite to the Normally a uniform defined and reduced thickness over the area of the wire mesh is created by flattening the crests of the wires become. This creates a positive connection between the wires. Of the free passage cross section changes at a moderate thickness reduction Not.

Preferably consists of the entire body of the Cast wire mesh screen, so that the thickness of the wire mesh Total is reduced. This is beneficial because on the active Screen area the flattened or flattened wires form baffles for the flowing molten casting and so rip open the oxide skin, while on the other hand, the calendering in the edge zone a solid compound the individual wires causes, so the shorter integrated wires be held firmly.

Around short-wired wires even better and / or to provide stronger baffles, can the wire mesh (in addition still). This can be done by pressing or the like respectively. The compression is preferably carried out only in the peripheral zone, but can also be done in the filter zone. By compacting not only are flattened wire crests at the binding sites or at the contact points of the warp and weft wires of the wire fabric, but there are also flattened areas in the other places, where there is no contact between the warp and weft wires.

Depending on the extent of compaction, a flattening may also be present over the entire tissue surface, the deviation from the in The generally round shape of the wires prior to making the wire mesh is stronger at the crossing points than at other points.

In the densified edge zone is preferably one to 40 to 60 percent reduced wire mesh thickness. The additional compression in the edge zone elevated the hold of the wires in the edge area continues, giving an even more reliable grip is achieved. Even short wires are held securely. The additional Compression is preferably generated by compression. Through a Compaction, the free passage area can be reduced.

In preferred developments, the Eingusssieb or the body comprises a Soil zone and a wall zone. Preferably, the bottom zone comprises and / or the wall zone a wire mesh. That offers advantages, because the passage area is increased. Preferably, in particular, the bottom zone, the wall zone and the edge zone of the Eingusssiebes and the body as a whole in one piece.

In In all embodiments, preferably a flat wire mesh as a raw material for the body used, which is then e.g. is deep-drawn by e.g. a hat, cone or hemispherical shape. Then the body includes one or several re wall zones and optionally one or more Soil zones. In deep-drawn wire fabrics can also in particular in the Wall zone thinner wires as present in the soil or edge zone. Also an embossing is possible, to the desired To achieve shape design.

In As a rule, the cast-in screens are rotationally symmetrical, so that the central axis is the perpendicular through the center of the sieve. This applies preferably to three-dimensional cast-in sieves, if the gates are e.g. have a hat, cone or pot shape. In particular, a cup shape or a spherical, hemispherical, Pyramid, truncated pyramid, truncated cone or a cone shape or such more possible.

The lateral surface the Eingusssiebes may be inclined to the central axis of symmetry. The deflection of the flow and the passage through the lateral surface then bring about an advantageous Rip the oxide skin.

In Particularly preferred embodiments, the wall zone at least two wall sections, each different from the central Symmetry axis are aligned.

Especially the wall sections are at different angles to the aligned central axis of symmetry.

Of the Angle of a wall section or the wall zone to the central Symmetry axis can in all embodiments an inclination greater than 15 degrees, especially greater than 20 degrees exhibit. For example, the angle can be 30 degrees. With such Design is an effective casting process achievable. An advantage of this Design is also the less necessary deformation of the wire mesh in the preparation of.

In another preferred embodiment, the wall zone to central axis of symmetry an inclination less than 15 degrees, in particular also less than 10 degrees.

Especially Preferably, the basic shape of the body is pot-shaped, cup-shaped or hemispherical, wherein be provided in all embodiments, the edge zone as an additional ring can, in addition to the basic form is provided. Such forms increase the stability of the sieve and prevent tilting of the sieve during the casting process. Also centered the cast sieve itself in the gate. Especially in the case a shape of a hemisphere or a pyramid etc. can not be a separate Edge zone may be provided, but the edge zone may be part of the hemisphere shape be. In all cases can the edge zone also serve for sieving.

In preferred developments are the bottom zone, the wall zone and the edge zone of a one-piece Wire mesh.

In In all embodiments, the wire mesh is preferably at least partly from a material taken from a group of materials is, the steel, galvanized steel, stainless steel, tin bronze, brass, Copper, titanium, gold, silver and aluminum. Especially preferred The wire mesh is made of steel or galvanized steel.

Especially is a mesh size in the range between 0.5 mm and 3 mm, in particular between 1 and 2.5 mm. The ge exact mesh size depends on the purpose of use and is in the specified range in preferred applications. This will be coarser Impurities effectively filtered out.

The Ingot sieve or the wire mesh is particularly suitable, a Melt at a temperature of 500 ° C, in particular at a temperature from 700 ° C up to 750 ° C to filter. In particular embodiments, high temperature resistant wires are used so that it can be poured at temperatures up to 1200 ° C.

In further embodiments, a wire used fabric whose wires have a triangular, rectangular, square, polygonal, oval or otherwise shaped base cross-section. With the wire cross-sections, the flow conditions on the wire mesh can be influenced in a targeted manner.

• – Herstellen eines einlagigen Drahtgewebes
• – Ausstanzen oder Ausschneiden eines Abschnittes
• – Verringern der Gewebedicke des einlagigen Drahtgewebes wenigstens in der Randzone des Abschnittes
• – Umformen des Drahtgewebes durch Tiefziehen oder dergleichen

The Applicant points out that it reserves the right to apply for a separate protection for a process for the manufacture of a sieve which comprises at least the following steps:

• - Making a single-layer wire mesh
• - punching or cutting a section
• - Reduce the fabric thickness of the single-layer wire mesh at least in the edge zone of the section
• - Forming the wire mesh by deep drawing or the like

When additional Step can be provided, inter alia, still a compression of the edge zone. Furthermore, a blow-off of the finished Eingusssiebes provided be around loosely held wires blow off. Instead of or in addition to this, the Casting sieve over a vibrator be vibrated in order to remove possibly loose loose wires.

In preferred developments, the body comprises a sintered wire mesh.

In In all embodiments, the wire mesh may include wires that at least in sections round, oval, triangular, rectangular and / or polygonal Have cross-sectional shapes. Is possible e.g. the use of different cross-sectional shapes in warp and weft direction.

If e.g. wires with square (triangular) cross-section for the production of Wire mesh are located at the wire crossing points of the sieve in the peripheral zone before cross - sectional shapes of the square (triangular) form while deviating other parts of the tissue nor the square (triangular) cross-sectional shape is present.

According to one In another embodiment, the cast sieve according to the invention comprises one of a Wire mesh existing body for filtering a cast melt, wherein the body has at least one edge zone and a filter zone, wherein the wire cloth at least in sections flattened wires has and is compressed in the edge zone.

Further Features, characteristics and advantages of the present invention result from the following description of the embodiments with reference to the accompanying drawings.

In this demonstrate:

1 a highly schematic side view of a Gebusssiebes invention in a first embodiment;

2 a view of the Eingusssieb after 1 ;

3 a highly schematic side view of a Gebusssiebes invention in a second embodiment;

4 a view of the Eingusssieb after 3 ;

5 a cross-sectional view of a wire in the original state, and in the calendered and calendered and compacted state;

6 a highly schematic side view of a Gebusssiebes invention in a third embodiment;

7 a highly schematic side view of a Gebusssiebes invention in a fourth embodiment;

8th a highly schematic side view of another Gebusssiebes invention; and

9 a further variant of a Eingussssiebes invention.

With reference to the enclosed 1 and 2 Now, a first embodiment of a Gebusssiebes invention 1 described.

This in 1 highly schematically illustrated Eingusssieb invention 1 includes a body 2 , which consists of a one-piece and a total of single-layer wire mesh.

The pouring sieve 1 has here overall a hat or pot shape and is rotationally symmetrical in this example. For production, a single-layer wire mesh is used, which is calendered over the entire surface. As a result, the original thickness has decreased by about 20 percent, so that with the same thickness of the warp and weft wires, as is the case regularly, there is a wire mesh thickness of about 1.60 times the wire diameter. The calendering makes the wire crests 13a . 13b . 13c etc. in the wire crossing areas 13 flattened. In other places remain the round original shape of the wires 6 receive.

Furthermore, in the production of the calendered fabric, a round section is removed, for example, by being cut out, laser cut or punched out. Subsequently, the wall zone 4 of the cylindrical area by deep drawing the bottom zone 5 generated. The angle of inclination between the wall zone and the central axis of symmetry is low here and amounts to a few degrees, here for example 0 degrees. After making the basic shape, the wires become 6 in the border zone 3 additionally compacted in a press, leaving the final thickness of the wire mesh 12 in the border zone 3 is about 50 percent of the original thickness. Thus, the final thickness is about the original thickness of a wire 6 , This is in the presentation after 1 also due to the reduced line width in the marginal zone 3 clearly shown.

Clearly recognizable, with the fabric type selected here, which is generally designed as a plain weave, there are problem areas with four wires offset by 90 degrees with only short wires 6a . 6b . 6c and 6d , While the wires 6c and 6d Here in the example shown are bound by about six to seven transverse wires, it is the wires 6a and 6b only about four bindings.

Depending on the position of the punching tool, the outer wires may also be bound by even fewer transverse wires, as in the embodiment according to 3 and 4 it can be seen in which the wire 6b maximum held only by two bonds.

at the short-wrapped wires In the prior art, there is a problem that the wires come off during the casting process solve and so the casting work piece can make us unusable. According to the invention the flattened at the crests wires here a better bond achieved by the additional Compaction significantly increased is sufficient so that there is sufficient binding, if the wires after the shake test are still included.

The flattened wires 6 in the filter area 15 who is usually here from the fields 4 and 5 composed, cause cracking of the oxide skin of the melt, so that the casting process can proceed satisfactorily. Also the border zone 3 may belong to the filter zone.

In the in the 3 and 4 illustrated embodiment, like parts are provided with the same reference numerals. In contrast to the previous embodiment, the wall zone 4 here between the edges 4a and 4b an angle 10 to the central axis or to the principal direction of flow of the melt, which may be, for example, twenty or thirty degrees.

In 5 are three different cross sections of a wire 6 shown very schematically. The dashed outline 7 shows the cross section 7 a source wire having a round cross-section. After calendering, the wire faces at least in the wire crossing areas 13 or at the wire crossing points 13a . 13b . 13c etc. a flattened or flattened cross-sectional profile 8th on what's in 5 is shown pulled through. The calendered fabric will be in the marginal zone 3 additionally compacted, so that the cross-sectional profile 9 arises, which is shown in phantom.

While after calendering the width 8c of the wire about the diameter 7d of the original wire, the height has been significantly reduced, namely by about 20 percent in height 8d , The flattened surfaces 8a Here are baffles that support the casting process.

By compaction in the edge zone 3 then not just the height of the wire 9 to the heights 9d it also reduces the width 9c of the wire 9 to.

In the in the 6 to 9 illustrated further embodiments of the invention Ingot sieves 1 For the sake of clarity, the same reference numerals are used for the same parts and components.

The embodiment according to 6 shows a hemispherical cast sieve 1 in which the body 2 a protruding edge zone 3 extending from the edge of the semi-spherical filter zone 15 extends out. Here in the example, as in the other examples, the edge zone 3 also made of wire fabric, so that also the edge zone 3 Part of the filter zone 15 is.

In contrast to the previous embodiments, the filter zone 15 hemispherical and not cup-shaped. The radius 14 depends on the application. Also possible is a cast-in sieve which has a cylindrical or frustoconical wall zone 4 has, which is followed by a hemisphere.

As in the previous embodiments, the wire mesh is made a total of one layer and before the three-dimensional shaping, which takes place here by deep drawing, in total velvet calendered. This will make the wires 6 or the wire crests at the wire crossing points 13a leveled and flattened. The warp and weft wires are thereby deformed so that the wires 6 except by adhesion also by positive connection in the wire mesh 12 being held. In addition to calendering, the wire mesh can be particularly in the edge zone 3 additionally be compacted to a firm hold even short wires 6a to ensure.

In contrast to the embodiment according to 6 is in the embodiment after 7 the edge zone 3 not a separate part of the sieve 1 but integrated in the hemisphere shape. Due to the hemispherical shape is also at slightly oblique insertion of the sieve 1 achieved a tight fit in the gate. Such a form may facilitate processing.

In the production of the sieve after 7 becomes the single layer wire mesh 12 initially calendered flat or the like. Subsequently, the edge of the flat planar wire mesh 12 be compacted before the wire mesh 12 is deep-drawn, whereby the Eingusssieb 1 achieved its final design. Likewise, the process can be reversed, so that first the part is formed and then the compression takes place.

It is possible, instead of a hemisphere shape, to have a shape as in 8th is shown. The particular rotationally symmetrical designed Gebusssieb 1 to 8th has two wall areas 4c . 4d which are inclined at different angles to the axis of symmetry. For example, one angle may be 20 degrees and the other 30 or 45 degrees.

Another variant shows 9 where a flat floor surface 5 present, extending over a stretch 12 extends. The wall zone 4 is rounded and has a radius 14 on.

In all embodiments, the sieves 1 be formed half, mirror or rotationally symmetrical. But also possible infusion screens without symmetry.

1

Eingusssieb

2

body

3

border zone

4

Wandungszone

5

soil zone

6 6a, 6b, 6c, 6d

wires

7

round wire

7d

Height, width

8th

calendered wire

8a

width

8b

height

9

compacted wire

9c

width

9d

height

10

angle

11

central axis

12

wire cloth

13

Wire crossing area

13a, 13b, 13c

wire crossing

14

radius

15

filter zone

Claims (20)

Cast-in sieve ( 1 ) for filtering a cast melt, with a wire mesh ( 12 ) comprehensive body ( 2 ), which at least one edge zone ( 3 ) and a filter zone ( 15 ), characterized in that the wire mesh ( 2 ) at least in the peripheral zone ( 3 ) is single-layered and at least in the wire crossing areas ( 13 ) of the border zone ( 3 ) at least partially flattened wires ( 6 ) having. Cast-in sieve ( 1 ) according to claim 1, characterized in that the body ( 2 ) of a single-layer wire mesh ( 12 ) consists. Cast-in sieve ( 1 ) according to claim 1 or 2, characterized in that the wire mesh ( 12 ) calendered flat. Cast-in sieve ( 1 ) according to at least one of the preceding claims, characterized in that the thickness of the wire mesh at least in the edge zone ( 3 ) is less than twice the wire diameter ( 7 ). Cast-in sieve ( 1 ) according to the preceding claim, characterized in that the wire mesh ( 12 ) has a reduced by 10 to 40 percent, in particular by 15 to 30 percent wire mesh thickness. Cast-in sieve ( 1 ) according to at least one of the preceding claims, characterized in that the wire mesh ( 12 ) is compressed. Cast-in sieve ( 1 ) according to the preceding claim, characterized in that the thickness of the wire mesh ( 12 ) at least in the peripheral zone ( 3 ) is less than one and a half times the wire diameter ( 7 ). Cast-in sieve ( 1 ) according to one of claims 6 or 7, characterized in that the compacted edge zone ( 3 ) has a wire mesh thickness reduced by 40 to 60 percent. Cast-in sieve ( 1 ) after at least one of preceding claims, characterized in that the body ( 2 ) at least one soil zone ( 5 ) and a wall zone ( 4 ) having. Cast-in sieve ( 1 ) according to at least one of the preceding claims, characterized in that the body ( 2 ) is deep-drawn. Cast-in sieve ( 1 ) according to the preceding claim, characterized in that the wall zone ( 4 ) at least two differently inclined wall sections ( 4c . 4d ) having. Cast-in sieve ( 1 ) according to at least one of the preceding claims, characterized in that an angle ( 10 ) of the wall zone ( 4 ) to the central axis ( 20 ) is an inclination greater than 15 degrees, in particular greater than 20 degrees. Cast-in sieve ( 1 ) according to at least one of claims 1 to 9, characterized in that an angle ( 10 ) of the wall zone ( 4 ) to the central axis ( 20 ) an inclination is less than 15 degrees, in particular less than 10 degrees. Cast-in sieve ( 1 ) according to at least one of the preceding claims, characterized in that the body ( 2 ) pot, cup, ball, - hemisphere, pyramid, truncated pyramid, truncated cone or cone-shaped. Cast-in sieve ( 1 ) according to claim 3, characterized in that the bottom zone ( 5 ), the wall zone ( 4 ) and the edge zone ( 3 ) are integral. Cast-in sieve ( 1 ) according to at least one of the preceding claims, characterized in that the wire mesh ( 12 ) is at least partially made of a material taken from a group of materials comprising steel, galvanized steel, stainless steel, tin bronze, brass, copper, titanium, gold, silver and aluminum. Cast-in sieve ( 1 ) according to at least one of the preceding claims, characterized in that a mesh size in the range between 0.5 mm and 3 mm, in particular between 1 and 2.5 mm. Cast-in sieve ( 1 ) according to at least one of the preceding claims, characterized in that the wire mesh is suitable to filter a melt at a temperature above 500 ° C, in particular at a temperature of 700 ° C to 750 ° C. Cast-in sieve ( 1 ) according to at least one of the preceding claims, characterized in that the wire mesh is sintered. Cast-in sieve ( 1 ) according to at least one of the preceding claims, characterized in that the wire mesh comprises wires which have at least partially round, oval, triangular, rectangular and / or polygonal cross-sectional shapes.