The present invention relates to a feeder element for use in casting metals in casting molds, comprising a first end for placing on a mold model and an opposing second end for connecting to or for carrying an upper feeder part, the feeder element having a passage extending from the first to the second end for liquid metal. The invention also relates to a feeder insert for use in casting metals in casting molds, with a cavity for receiving liquid metal, comprising or consisting of a feeder element according to the invention and an upper feeder part. Further aspects of the invention relate to construction sets for producing a feeder element according to the invention or a feeder insert according to the invention as well as methods for arranging a feeder insert in a casting mold. Further aspects of the invention emerge from the following description and the accompanying claims.
Feeder elements of the type mentioned at the outset are known from the prior art. Reference is made in this connection, in particular, to the document EP 1184104 B1, which discloses a feeder insert with a first mold element, which is a feeder element of the aforementioned type. Reference is also made to the document DE 10142357 A1, which discloses a feeder system with a feeder or feeder head and a tube-like body.
Further documents, which define the technological background of the present invention, are: DE 10200508324 A1, EP 1567294 B1, DE 20118763 U1, DE 19642838 A1, DE 20112425 U1, WO 2005/095020 A3, DE 202004009367 U1, DE 202006011980 U1 as well as DE 202004021109 U1.
The present invention is based on the object of developing a feeder element according to EP 1184104 B1. The feeder elements (first mold elements) disclosed there, which are provided for carrying an upper feeder part (second mold element) have a first end for placing on mold models, the depositing surface in practice being felt to be too large in many cases. Smaller and smaller attachment faces (and setting faces) are desired by the casting industry as the surfaces of cast parts have recently increasingly become more filigree. However, it has to be taken into account here that the passage opening (through-opening) for liquid metal cannot be as small as desired, as otherwise an acceptable feed behavior can no longer be achieved. In addition, it has to be taken into account that a cooling of the feeder neck, such as can occur in a thin-walled configuration of a feeder element at its side facing the mold model, must not become noticeable in a disruptive manner.
From the prior art, in particular from DE 10142357 A1 already mentioned, attempts are already known to disclose feeders with only a small attachment face, which function satisfactorily during casting operation. However, it has been shown in experiments that configurations, in which a thin-walled tube-like element is exposed at its end facing the cast piece, while its end facing the feeder cavity is surrounded on all sides by feeder molding compound, frequently do not ensure the desired configuration of a breaking edge at the first (lower end).
According to the present invention, to achieve the presently disclosed object, a feeder element is disclosed for use when casting metals in casting molds, with a first end for placing on a mold model and an opposing second end for connecting to or for carrying an upper feeder part, the feeder element having a passage extending from the first to the second end for liquid metal, wherein the feeder element is two-part or multi-part and comprises or consists of:
It is surprisingly ensured in this manner that during cleaning, the feeder reliably breaks off in the direct vicinity of the cast piece; in contrast to this, in a configuration in which the tube-like element does not have a free end within the adapter element, an undesired breaking off of the feeder frequently occurs at the edge opposing the first end of the corresponding tube-like element.
A corresponding feeder insert according to the invention for use when casting metals in casting molds, with a cavity for receiving liquid metal, comprises or consists of:
The feeder element according to the invention can advantageously be inserted as described in EP 1184104 B1 for the “first mold element” there. The upper feeder part of a feeder insert according to the invention in this case corresponds to the “second mold element” according to EP 1184104 B1. Feeder inserts, such as are described in EP 1184104 B1 are commercially available under the name “telefeeder” from CHEMEX GmbH, Germany.
In the delivery state of a feeder element according to the invention, the tube-like element can be inserted to different extents into the adapter element. In many cases, it is advantageous if the tube-like element is not inserted to a maximum extent into the adapter element, so can be inserted further into the adapter element at a later time, for example after the arrangement of a corresponding feeder insert in a molding machine and compression of molding material poured into the molding machine, until it is prevented from a further assertion by the path limiter(s). An arrangement of this type is advantageous to prevent breaking of a feeder element according to the invention or a corresponding feeder insert according to the invention, as would otherwise be possible in the molding material compression because of the compressive forces then acting. In particular in combination with an upper feeder part, which is displaceably arranged relative to the feeder element according to the invention, destruction of a feeder according to the invention is reliably prevented.
Alternatively, the tube-like element may, however, also already be inserted to a maximum extent into the adapter element in the delivery state, so that it is prevented from further insertion by the path limiter(s).
In any case, it applies that, in a feeder element according to the invention, the outer face of the edge area opposing the first end, of the tube-like element, with insertion to a maximum extent within the adapter element, is present with its entire periphery or in portions of the periphery exposed, and therefore, during casting operation, allows the admission of liquid metal onto the outer face.
The adapter element preferably forms the second end of the feeder element, in other words the end of the feeder element, which is provided to connect or to carry an upper feeder part. Alternatively, however, one or more intermediate elements may also be provided between the adapter element and upper feeder part.
The tube-like element of a feeder element according to the invention is preferably cylindrical but other configurations may be provided, however, for example rectangular tube cross-sections or tube-like elements with a conical course.
The tube-like element preferably has a length in the region of 10 to 30 mm, in particular if it is cylindrical.
If the tube-like element has a length in the region of 10 to 30 mm and, in the delivery state, is not inserted to a maximum extent into the adapter element, it allows, in the state before the compression of the molding material, a further insertion of at least 4 mm. It has been shown that in an arrangement of this type, the compressive forces occurring during compression of the molding material can be effectively counteracted.
The tube-like element preferably has a substantially uniform cross-section over the entire length. The ratio of the wall thickness to the overall diameter of the tube-like element is preferably between about 1:5 and 1:120 over the entire length thereof, particularly preferably in the range of 1:10 to 1:100. The thickness of the tube-like element is selected by the person skilled in the art in such a way that it has adequate stability and withstands the compressive forces which occur during the molding material compression.
The tube-like element is preferably produced from a material which is selected from the group consisting of: metallic, ceramic or plastics materials and composite materials based on metal, ceramic and/or plastics material. The tube-like element is preferably produced here from iron, an iron alloy such as steel, aluminum, an aluminum alloy, a brass alloy or ceramic.
The adapter element, on the other hand, is preferably produced from an exothermic or insulating molding compound. The same applies in a feeder insert according to the invention for the upper feeder part.
It is obvious that the adapter element of a feeder element according to the invention generally has a wall or a wall portion, the thickness of which is greater in portions or everywhere than the thickness of the tube-like element at the first end of the feeder element. In particular, when producing the adapter element from an exothermic or insulating molding compound, a wall thickness of less than 1.5 mm cannot be produced with the required process reliability in the course of mass production.
It has already been mentioned that a feeder insert according to the invention is advantageously similar in its construction to the feeder inserts, such as are described in EP 1184104 B1, the components described there as the “first mold element” being replaced by a two-part or multi-part feeder element according to the invention. The content of EP 1184104 B1 is a component of the present text by way of reference.
The feeder element and the upper feeder part of a feeder insert according to the invention are preferably arranged so as to be displaceable into one another. In particular in an arrangement of this type of feeder elements in the upper feeder part, in the feeder element according to the invention, the tube-like element is preferably not inserted to a maximum extent into the adapter element, so it can be further inserted into the adapter element until it is prevented from further insertion by the path limiter(s). The compressive forces occurring during the compression of the molding material are then counteracted by two separate relative movements, namely the relative movement of the upper feeder part relative to the feeder element (the feeder element is inserted into the upper feeder part) and the relative movement of the tube-like element relative to the adapter element (the tube-like element is further inserted into the adapter element, until it rests on the path limiters).
The feeder element and the upper feeder part of a preferred feeder insert according to the invention together form a cavity to receive a liquid metal.
To summarize, a feeder element is therefore preferred, which comprises or consists of:
(a) a two-part or multi-part feeder element with a first end for placing on a mold model and an opposing second end, wherein the feeder element has a passage extending from the first to the second end for liquid metal and comprises or consists of:
(b) an upper feeder part, wherein the feeder element is connected by its second end to the upper feeder part and/or carries the latter, wherein the feeder element and the upper feeder part can be displaced into one another and form or enclose a cavity, in many cases, if not preferred, by the formation of a double wall.
The present invention also relates to a construction set for producing a feeder element according to the invention, comprising a tube-like element and an adapter element. With regard to the configuration of the tube-like element and the associated adapter element, that which was stated above applies correspondingly.
The invention also relates to a construction set for producing a feeder insert according to the invention, comprising
To this extent, the above statements also apply to the configuration of the tube-like element, the adapter element and the upper feeder element correspondingly.
The present invention also relates to a method for the arrangement of a feeder insert in a casting mold, comprising the following steps:
(a) is not inserted to a maximum extent into the adapter element, so it can be inserted further into the adapter element, until it is prevented from further insertion by the path limiter(s) or
(b) is inserted to such an extent that it is prevented from further insertion by the path limiter(s),
In a method according to the invention, the upper feeder part and the feeder element are preferably selected in such a way that when placing the upper feeder part on the feeder element, a feeder insert is formed, the feeder element and the upper feeder part being displaceable into one another, the upper feeder part and the feeder element being displaced into one another when the molding material is compressed (optionally after separation or deformation of holding elements).
The molding machine preferably comprises in a method according to the invention, a model plate (in other words a model mechanism for molding machines, generally consisting of a flat plate with cast in or mechanically fastened models) and the feeder element is inserted into the molding machine in such a way that it is in direct contact with the model plate (the model surface) with its first end.
Statements from EP 1184104 B1 apply correspondingly with regard to the method according to the invention.
The invention will now be described in more detail below with the aid of the accompanying figures shown by way of example, in which:
The adapter element 24 has a wall, which, in portions or everywhere, is greater than the thickness of the tube-like element at the first end 14 of the feeder element 10 and, like the upper feeder part 18, consists of an exothermic or insulating molding compound. Path limiters 26, which are designed in the form of ribs, are integrated into the adapter element 24 (cf.
According to
Also proceeding from the lower edge 38, the inner wall of the upper feeder part 18 has a portion 40 which firstly runs parallel to the outer wall 42 of the adapter element 24 and then passes into a conically upwardly tapering wall portion 50, along which the tip of a centering mandrel can be guided when positioning the feeder insert 8. The conical wall portion 50 finally opens into a centering bore 52 located in the rotational axis 48 of the feeder insert 8 to receive the tip of the centering mandrel 36.
The upper feeder part 18 and the adapter element 24 form a cavity made of partial cavities 30 and 42 which are in connection with one another to receive liquid material.
According to
In
When displacing the upper feeder part 18 in the direction of the mold model 12, the tip of the centering mandrel 36 according to
If the tube-like element 22, as shown in
The lower edge 36 of the upper feeder part 18, during the compression process, acts like a die face on the molding material to be compressed between the lower edge 36 and the mold model 12.
Depending on the application area, the tube-like element 22 may already be completely inserted into the adapter element 24 before the compression (cf.
In this alternative case, the compressive forces occurring during the compression of the molding material are counteracted by two separate relative movements, on the one hand, by the relative movement between the upper feeder part 18 relative to the adapter element 24 and, on the other hand, by the relative movement between the adapter element 24 and the tube-like element 22.
According to
An upper feeder part is then placed on the adapter element 24 in such a way that it is carried thereby. For this purpose, holding projections 34 are provided, for example. An assembled feeder insert 8 is now present in a possible starting arrangement.
In a following step illustrated only in
After a compression process not shown in more detail in the figures, the arrangement according to
As the outer wall 38 projecting over the first adapter element 24, of the upper feeder part 18 acts on the . . . between it and the mold model 12 during the compression process like a die, an excellent molding material compression occurs in this region (indicated in
Number | Date | Country | Kind |
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10 2006 055 988.6 | Nov 2006 | DE | national |
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/EP2007/062620 | 11/21/2007 | WO | 00 | 8/25/2009 |