DE10206656C2 - mold - Google Patents

Description

The invention relates to the use of a mold comprising a container containing a granular filling material and a first fluid with a fluid-tight and at least partly flexible and expandable, at least partly double-walled wall and at least one container fluid passage for pumping the fluid out of the container, the can be filled or evacuated by means of at least one intermediate fluid passage with a second fluid through the double wall enclosed double wall intermediate space, for producing a workpiece, wherein

• a) a model of the workpiece is first produced,
• b) the model is pressed against the flexible and stretchable wall in this way, while the filling material is in the form of a loose fill that the wall adapts to the shape of the Model hugs
• c) the container is evacuated until the filling material loses its flowability,
• d) the model is removed,
• e) the workpiece in the form produced according to method steps a) to d) shaped and
• f) the shaped workpiece is removed from the mold.

Furthermore, the invention relates to a specially designed for use Molding tool comprising a granular filling material and a first fluid Containing container with a fluid-tight and at least partially flexible and stretchable wall and at least one container fluid passage for pumping the Fluids from the container, the wall in the flexible and stretchable area double-walled and one enclosed by the double wall Double wall space with at least one space fluid passage a second fluid can be filled or evacuated.

A use and a molding tool of the aforementioned type are known from DE 22 58 916 A known. There is a training example of the mold disclosed, which has a circumferential double wall, the one of the inner wall surrounded container space and the double wall space in each case  can be evacuated separately via separate fluid passages. The mold according to this prior art is used for the production of molds for the production of Corsets. The model is placed on the outside using the sack-shaped mold placed. When the container surrounded by the inner wall is evacuated, it shrinks its volume, causing the mold to withdraw from the model, d. H. it a relatively large space is created between the inner wall and the model. by virtue of the double wall space is now filled with sand, so that the direct contact with the model is created and the sand is removed by evacuating the Double wall space stiffened.

It may be useful to use several forming tools to produce one workpiece to use the type mentioned above, in particular in a simple manner To fully grasp the model in its scope. Molding tools of the aforementioned Art are also from US 2,472,754, 2,499,324 and US 2,488,922 known.

In the aforementioned prior art, the separation of the mold and Model or workpiece, especially with complex shapes, can be problematic.

It is an object of the present invention, a use and a To provide molding tool of the type mentioned, which can be easily and reliably separates the model or workpiece from the mold.

When using the type mentioned at the outset, this object is achieved by that the model is pressed into the wall when evacuated Double wall space is made to remove the model and / or the molded Workpiece the second fluid pumped into the double wall space and to Forms of the double wall space is evacuated again.

When making an impression of a model or when making one Workpiece, the double wall space is evacuated, i. H. the two wall parts the double wall lie directly on top of each other. If the imprint of a model after  Evacuation of the container fixed or the workpiece after insertion in the Mold is cured, the fluid between the walls of the double wall pumped, filling the double wall space and ejecting the model or the shaped workpiece is forced. After that the Double wall space evacuated again and the molding tool for the first time or repeated forms can be used because the inner wall of the double wall their shape does not change and the outer wall completely changes again when evacuating hugs the inside wall.

Furthermore, the aforementioned task is accomplished by a molding tool mentioned type solved in that the double wall space alone on a Side of the mold is provided.

The molding tool according to the invention can be designed so that both that first as well as the second fluid is air. The use of air is simple and inexpensive. Alternatively, it is conceivable to use other gases or liquids, such as water or oil.

An embodiment of the invention is shown below with reference to a figure.

The single figure shows schematically in a cross section a mold with a container 1 , the granular filler 2 , z. B. from sand or plastic particles. The filling material 2 can also be a mixture of different grain sizes and / or materials. On one side, the molding tool has a double wall consisting of an outer wall 3 and an inner wall 4 . Both the outer wall 3 and the inner wall 4 are made of a flexible, stretchable but air-impermeable material, e.g. B. silicone or rubber.

Fig. 1 shows the mold in a state immediately after ejection of a molded workpiece. A negative pressure prevails in the container 1 , which was generated during the production of the model impression via the container air passage 5 by means of a pump, which is not shown separately here. The inner wall 4 is pressed against the stiffened filling material. Via an intermediate air passage 6 is also not shown pump air between the inner wall 4 and externa ßere wall 3 was applied by a wide reindeer, pumped, then the outer wall that 3 out of the inner wall 4 from stresses and the ejection of the produced and here also force not shown workpiece.

Now the space 7 between the inner wall 4 and the outer wall 3 can be evacuated again via the space air passage 6 , so that the outer wall 3 nestles against the inner wall 4 and a further tool can be formed.

LIST OF REFERENCE NUMBERS

1

container

2

filling material

3

outer wall

4

inner wall

5

Container air passage

6

Between room air passage

7

gap

Claims (2)

1. Use of a molding tool comprising a granular filling material ( 2 ) and a first fluid-containing container ( 1 ) with a fluid-tight and at least partly flexible and expandable, at least partly double-walled wall and at least one container fluid passage ( 5 ) for pumping out the Fluids from the container ( 1 ), the double wall space ( 7 ) enclosed by the double wall ( 3 , 4 ) being able to be filled or evacuated with at least one space fluid passage ( 6 ),
for the production of a workpiece, wherein

• a) a model of the workpiece is first produced,
• b) the model is pressed against the flexible and stretchable wall in such a way that the filling material ( 2 ) is in the form of a loose bed so that the wall conforms to the shape of the model,
• c) the container is evacuated until the filling material ( 2 ) loses its flowability,
• d) the model is removed,
• e) the workpiece is shaped in the form produced according to method steps a) to d) and
• f) the shaped workpiece is removed from the mold,

characterized in that
the model is pressed into the wall when the double-wall space is evacuated, the second fluid is pumped into the double-wall space ( 7 ) to remove the model and / or the shaped workpiece, and is evacuated again to form the double-wall space ( 7 ). 2. A mold specially designed for use according to claim 1, comprising a granular filler material ( 2 ) and a first fluid-containing container ( 1 ) with a fluid-tight and at least partially flexible and expandable wall and at least one container fluid passage ( 5 ) for pumping the fluid out the container ( 1 ), the wall being double-walled in the flexible and expandable area and a double wall space ( 7 ) enclosed by the double wall ( 3 , 4 ) being able to be filled or evacuated with at least one space fluid passage ( 6 ), characterized in that that the double wall space ( 7 ) is provided on one side of the mold alone.