DE102006005897B4 - Apparatus and method for producing hollow ceramic articles by high pressure casting - Google Patents

Abstract

Apparatus for producing hollow ceramic articles by high-pressure casting, wherein the device (10) has a mold top part (12), a mold bottom part (14) and mold side parts (16, 18) which, in the closed state of the device (10), correspond to a coreless one corresponding to the hollow ceramic article to be produced Determine mold cavity (20), which is fluidly connected to a Schlickereinlass (28) and with a Schlickerauslass (30), wherein in the mold cavity (20) for generating a rotational movement of the coreless mold cavity (20) located in the slip a rotor element (36) is provided , which has at least one stirring blade (40) and can be driven by means of a drive motor (38), characterized in that the at least one stirring blade (40) of the rotor element (36) has side edges (42) which are adjacent to the side wall contour (74) of the coreless one Mold cavity (20) are adapted and from this has a distance which is half the distance between the side wall (7 4) of the mold cavity (20) and the axis of rotation (48) of the at least one stirring blade (40) of the rotor element (36).

Description

The The invention relates to a device according to the preamble of the claim 1 for the production of hollow ceramic articles by high-pressure casting, wherein the device is a mold top, a bottom mold and mold side parts has, in the closed state of the device a the ceramic hollow article corresponding coreless Determine mold cavity, the fluidic connected to a slurry inlet and to a slurry outlet is, wherein in the mold cavity for generating a rotational movement of the in the coreless mold cavity Schlickers a rotor element is provided, which has at least one stirring blade and by means of a drive motor is drivable, and a method according to the preamble of claim 8 for the production of hollow ceramic articles by High pressure casting, wherein in a device of the type mentioned a ceramic slip filled under pressure, the on the inner contour of the coreless mold cavity a broken piece a desired shear thickness forms, after which the residual slip from the coreless mold cavity is emptied.

While at so-called cup pressure casting a device is used, in which the upper mold part or the lower mold part forms a core, becomes during high pressure casting ceramic hollow objects worked without a core. In this case, slip is filled into the mold cavity and put under pressure, so that in the mold cavity of the broken pieces of the ceramic hollow article depending on the printing time with the desired Shear thickness forms. After the shards, the residual slip emptied from the mold cavity. For this purpose, in the mold cavity a gaseous Medium, preferably air, injected and the residual slip by opening a connected to the device emptying valve from the mold cavity pressed. The solidification of the cullet on the inside of the mold cavity happens also with compressed air.

• 1. An der Innenseite der Seitenwandung des Scherbens d. h. des grünen keramischen Hohlgegenstandes ergeben sich sogenannte Schlickerläufer;
• 2. An der Innenseite des Bodens des Scherbens des keramischen Hohlgegenstandes sind Schlickertropfen oftmals nicht vermeidbar, die nach dem Brand des keramischen Hohlgegenstandes deutlich sichtbar sind und – wie die oben erwähnten Schlickerläufer – zu einem Produktionsausschuss führen;
• 3. An hintergriffigen Stellen, wie dem Ausgießer eines keramischen Hohlgegenstandes in Gestalt einer Kanne, kann der Schlicker nicht abfließen, weshalb es bislang erforderlich ist, die Formvorrichtung drehbar auszubilden, um die besagten hintergriffigen Stellen entleeren zu können. Dabei sind jedoch ebenfalls Schlickerläufer nicht vermeidbar, die sichtbar bleiben und zu einem Produktionsausschuss führen;
• 4. Ist der keramische Hohlgegenstand mit einem großen Henkel ausgebildet, so ist nicht zuverlässig vermeidbar, dass der große Henkel beim Entformen aus der Formvorrichtung abreißt, da die Henkelansatzstellen zum keramischen Hohlgegenstand hin hohl bleiben können.

In this prior art, however, the following problems arise:

• 1. On the inside of the side wall of the cullet ie the green ceramic hollow object so-called Schlicker runner arise;
• 2. On the inside of the bottom of the cullet of the ceramic hollow article slip droplets are often unavoidable, which are clearly visible after the firing of the ceramic hollow article and - as the slip skater mentioned above - lead to a production committee;
• 3. At behind grip sites, such as the spout of a ceramic hollow article in the form of a pot, the slip can not drain, which is why it has hitherto been necessary to form the molding device rotatable to be able to empty the said behind grip points. However, slip skaters are also not avoidable, which remain visible and lead to a production committee;
• 4. If the hollow ceramic article is formed with a large handle, it is not reliably avoidable that the large handle breaks off during demolding of the molding device, since the Henkelansatzstellen can remain hollow to ceramic hollow object.

From the WO 92/15 436 A1 a device of the type mentioned for the production of hollow ceramic articles is known, wherein the device in the closed state determines the ceramic hollow article corresponding coreless mold cavity, wherein in the mold cavity for generating a rotational movement of the present in the coreless mold cavity slip a rotor element is provided which at least one Has stirring blade and is driven by a drive motor.

at This known device consists of the rotor element, for example from a shaft with a diameter of 22 mm and from stirring blades, the from a pole similar Diameter are produced. The rotor blades can also be flat or be perforated.

With this known device is the respective mold in a filling station and in a stirring station emotional. The filling the mold and stirring can also take place in the same station. The ones with slip filled mold can after stirring known process steps such as storage, a Emptying, dripping and conditioning are supplied.

Of the Invention is based on the object, an apparatus and a method of the type mentioned, the device being simple trained and the above-mentioned defects or problems and also according to the method to simple Way are eliminated.

These Task is done by device the features of claim 1 d. H. solved by the fact that the at least one stirring blade of the rotor element side edges facing the side wall contour of the coreless mold cavity are adapted and of this has a distance of half the Distance between the side wall of the mold cavity and the axis of rotation the at least one stirring blade of the rotor element corresponds.

With Help of the motor driven rotor element becomes the slip set in rotation in the coreless mold cavity of the molding apparatus, see above that when emptying the slurry from the mold cavity Schlicker runner on the side wall wiped off by the rotating slip become.

The Rotor element has at least one stirring blade and is in the mold cavity provided such that its axis of rotation to the bottom of the produced ceramic hollow article is oriented vertically.

Around on the inside of the bottom of the green ceramic to be produced Hollow object to avoid dripping drops, it is preferable if the at least one stirring blade has a front edge, which is connected to the bottom contour of the coreless mold cavity is adapted and spaced from this. This distance between the end edge of the at least one stirring blade and the bottom contour the coreless mold cavity is preferably at the shear thickness adapted to the green hollow article produced in the mold cavity.

Of the Coreless mold cavity is preferably for upside down production a ceramic hollow article provided. In the ceramic Hollow article may be one with a handle. It is preferred if the lower mold part is formed with a handle support is. This ensures that ceramic hollow objects with a big handle can be safely removed from the mold. When opening the Holding mold the said handle support the handle in position and when removing the ceramic hollow article For example, by means of compressed air, the handle of the porous mold bottom solved and lifted off.

According to the invention of coreless mold cavity for the upside down production of a ceramic Hollow article be provided with a spout, wherein formed the mold base with a spout emptying channel is discharged through the residual slip from the mold cavity. Thereby become slipstreamers prevented at the pouring opening or it is not necessary, the molding device rotatable as a whole train. The design effort is therefore relatively small.

Is appropriate it when the pourer discharge channel an emptying opening which is connected to the spout opening of the spout the ceramic hollow article is adapted in shape because thereby the cleaning effort at the spout or at the spout opening in advantageously substantially reduced.

The The object underlying the invention is by the method the features of claim 8 d. H. solved in that at least during the Emptying the residual slip a provided in the coreless mold cavity Rotor element is set in rotation to the on the side wall of the Hohlgegenstscherbens residual slip during the Emptying into a rotary motion. Through the rotating residual slip become slip emptier when emptying the residual slip the side wall of the green Hollow object wiped and conditioned by such Schlicker runner Production committees avoided.

Appropriately be it when the rotor element already during the pouring of the Schlickers is set into rotation in the coreless mold cavity. As a result, the slip is during the complete casting cycle put in a rotary motion.

It is according to the invention advantageous if the distance of the rotor element to the upper mold part the shaping device to the thickness of the shear of the bottom of the produced green ceramic hollow object is set to on the inside of the Soil of the green to be produced To escape from the ceramic hollow article resulting slip droplets and prevent a corresponding production committee.

According to the invention it can be advantageous if the speed of the rotor element during the entire Cycle of production of ceramic hollow article in coreless Mold cavity changeable is or changed becomes.

Of the Slip is preferred in the process according to the invention in the for provided an inverted ceramic hollow article to be manufactured coreless mold cavity introduced through the lower mold part from below and pressurized. In this case, the pressure level and / or the printing time of the desired Shear thickness of the green ceramic hollow article to be produced be adjusted accordingly.

To the shard formation is used to empty the residual slip in the coreless mold cavity a gaseous Medium, preferably air, blown. The solidification of the broken piece on the inner contour of the coreless mold cavity also takes place with gaseous Medium, preferably with air.

Compared to the prior art, in which the molding device usually rotatable ausgebil det is to be able to emptied at behind grip points of the ceramic hollow article to be produced the residual slip, according to the invention, only one rotor element is provided in the mold cavity, so that according to the invention results in a significant simplification.

Further Details will be apparent from the following description of a in the drawing illustrated embodiment of the device according to the invention to carry out the method according to the invention.

It demonstrate:

1 an embodiment of the device partially cut, and

2 a section along the section line II-II in 1 through the device.

For the preparation of ceramic hollow objects, such as pitchers, vases, cups, cups o. The like., Provided by high-pressure casting device 10 has a form top 12 , a mold base 14 and mold side part 16 and 18 (see also 2 ) on. When closed, determine the top mold 12 , the mold base 14 and the mold side parts 16 and 18 a mold cavity 20 , its inner contour 22 corresponds to the outer contour of the green ceramic hollow article to be produced.

In 1 is a mold cavity 20 drawn for a jug holding a handle 24 and a spout 26 has.

The mold cavity 20 is fluidic with a slurry inlet 28 and with a slurry outlet 30 connected. The slick inlet 28 has an inlet valve 32 and the slurry outlet 30 has an emptying valve 34 on.

In the mold cavity 20 the device 10 is a rotor element 36 provided that with a drive motor 38 connected is. The connection of the drive motor 38 with that of a stirring blade 40 formed rotor element 36 is through a hollow shaft 42 realized, to which a gaseous medium, preferably compressed air, can be connected. Is in 1 by the dot-dashed arrow line 44 indicated. For sealing the hollow shaft 42 against the slip inlet 28 and the slurry outlet 30 serves a sealing element 46 ,

The rotor element 36 is in the mold cavity 20 provided such that its axis of rotation 48 to the ground 50 in the mold cavity 20 the device 10 produced green ceramic hollow article is oriented vertically. The stirring blade 40 of the rotor element 36 is with a front edge 52 trained to the ground contour 54 of the coreless mold cavity 20 is adjusted and from this a small distance 56 has. This little distance 56 corresponds to the shear thickness of the bottom of the mold cavity 20 to be produced or produced green ceramic hollow article.

How out 1 clearly seen is the coreless mold cavity 20 provided for the upside down production of the ceramic hollow article.

The mold base 14 the molding device 10 is with a handle support 58 trained to handle as well 24 safe to demould.

The mold base 14 is with a pourer discharge channel 60 formed, which has an emptying opening 62 which is adjacent to the spout opening 64 the spout 26 the ceramic hollow article is adapted in shape. As a result, the cleaning effort on the spout 26 or at the spout opening 64 the spout 26 be substantially reduced.

To ensure that even large-volume handles 24 can be safely removed from the handle, the handle 24 - As has already been stated - on the mold base 14 or at the handle support 58 supported. That's through a seal 66 feasible, a circumferential sealing cord 68 and a split mating ring 70 (see in particular 2 ) having. The self-contained sealing cord 68 is at the bottom of the mold 14 provided and the split counter ring 70 is on the two form side parts 16 and 18 arranged. The at least one stirring blade 40 of the rotor element 36 has margins 72 on, the to the side wall contour 74 of the coreless mold cavity 20 are approximately adapted and from the side wall contour 74 a big distance 76 have. This distance 76 corresponds to z. B. approximately half the distance between the side wall contour 74 and the rotation axis 48 of the rotor element 36 or the at least one stirring blade 40 of the rotor element 36 ,

10

contraption

12

Form top (from 10 )

14

Molded bottom (from 10 )

16

Form side part (from 10 )

18

Form side part (from 10 )

20

Mold cavity (from 10 )

22

Inner contour (from 20 )

24

handle

26

pourer

28

Sludge inlet (from 10 )

30

Slurry outlet (from 10 )

32

Inlet valve (in 28 )

34

Emptying valve (in 30 )

36

Rotor element (in 20 )

38

Drive motor (for 36 )

40

Stirring blade (from 36 )

42

Hollow shaft (between 38 and 40 )

44

dot-dashed arrow (at 42 )

46

Sealing element (for 42 )

48

Rotation axis (from 36 respectively. 40 )

50

ground

52

Forehead edge (from 40 )

54

Ground contour (at 12 )

56

small distance (between 52 and 54 )

58

Handle support (for 24 at 14 )

60

Pourer emptying channel (in 14 For 26 )

62

Emptying opening (from 60 )

64

Pouring orifice (from 26 )

66

Sealing (between 14 and 16 . 18 )

68

Sealing cord (from 66 at 14 )

70

split counter ring (from 66 at 16 . 18 )

Claims (15)

Device for producing hollow ceramic articles by high-pressure casting, wherein the device ( 10 ) a mold top ( 12 ), a mold base ( 14 ) and mold side parts ( 16 . 18 ), which in the closed state of the device ( 10 ) a coreless mold cavity corresponding to the hollow ceramic article to be produced ( 20 ), which fluidically with a Schlickereinlass ( 28 ) and with a slip outlet ( 30 ), wherein in the mold cavity ( 20 ) for generating a rotational movement of the in the coreless mold cavity ( 20 ) slip a rotor element ( 36 ) is provided, the at least one stirring blade ( 40 ) and by means of a drive motor ( 38 ) is drivable, characterized in that the at least one stirring blade ( 40 ) of the rotor element ( 36 ) Margins ( 42 ), which on the side wall contour ( 74 ) of the coreless mold cavity ( 20 ) and from this has a distance which is half the distance between the side wall ( 74 ) of the mold cavity ( 20 ) and the axis of rotation ( 48 ) of the at least one stirring blade ( 40 ) of the rotor element ( 36 ) corresponds. Device according to claim 1, characterized in that the rotor element ( 36 ) in the mold cavity ( 20 ) is provided such that its axis of rotation ( 48 ) to the ground ( 50 ) of the ceramic hollow article is oriented vertically. Apparatus according to claim 1, characterized in that the at least one stirring blade ( 40 ) of the rotor element ( 36 ) a front edge ( 52 ), which is connected to the ground contour ( 54 ) of the coreless mold cavity ( 20 ) and one of the shear thickness of the soil ( 50 ) has the ceramic hollow article corresponding small distance. Device according to one of claims 1 to 3, characterized in that the coreless mold cavity ( 20 ) is provided for the overhead production of a ceramic hollow article. Device according to one of claims 1 to 4, characterized in that the coreless mold cavity ( 20 ) for the upside-down production of a ceramic hollow article with a handle ( 24 ) is provided, wherein the lower mold part ( 14 ) with a handle support ( 58 ) is trained. Device according to one of claims 1 to 5, characterized in that the coreless mold cavity ( 20 ) for the upside down production of a ceramic hollow article with a spout ( 26 ) is provided, wherein the lower mold part ( 14 ) with a spout discharge channel ( 60 ) is trained. Apparatus according to claim 6, characterized in that the spout emptying channel ( 60 ) an emptying opening ( 62 ), which is connected to the spout opening ( 64 ) of the spout ( 26 ) of the ceramic hollow article is adapted in shape. Method for producing hollow ceramic articles by high-pressure casting, in which a device ( 10 ), which is a form top ( 12 ), a mold base ( 14 ) and mold side parts ( 16 . 18 ), which in the closed state corresponds to a coreless hollow space corresponding to the ceramic hollow article to be produced ( 20 ), a ceramic slip is filled under pressure, on the inner contour ( 74 . 54 ) of the coreless mold cavity ( 20 ) forms a shard of a desired shearing thickness, after which the residual slip from the coreless mold cavity ( 20 ) is emptied, characterized in that at least during the emptying of the residual slip in a coreless mold cavity ( 20 ) provided rotor element ( 36 ) is set in rotation to enable the residual slurry present on the side wall of the hollow article shard to rotate during emptying. Method according to claim 8, characterized in that the rotor elements ( 36 ) already during the pouring of the slip into the coreless mold cavity ( 20 ) is set in rotation. Method according to claim 8 or 9, characterized in that the distance ( 56 ) of the rotor element ( 36 ) to the form top ( 12 ) of the molding device ( 10 ) on the shear thickness of the soil ( 50 ) of the ceramic hollow article to be produced is adjusted. Method according to one of claims 8 to 10, characterized in that the rotational speed of the rotor element ( 36 ) during the entire cycle of production of the hollow ceramic article in the coreless mold cavity ( 20 ) is changed. Method according to one of claims 8 to 11, characterized in that the slip in the intended for a superset hollow ceramic article seedless mold cavity ( 20 ) through the lower mold part ( 14 ) is introduced from below and pressurized. Method according to claim 12, characterized in that that the pressure level and / or the printing time of the desired Shear thickness of the ceramic hollow article to be produced accordingly is set. Method according to one of claims 8 to 13, characterized in that after the body formation for emptying the residual slip from the coreless mold cavity ( 20 ) In this a gaseous medium, preferably air, is blown. Method according to one of claims 8 to 14, characterized in that the solidification of the cullet on the inner contour ( 74 . 54 ) of the coreless mold cavity ( 20 ) Also with gaseous medium, preferably air, takes place.