The instant application claims the priority date of Sep. 10, 2015, the filing date of the German patent application DE 20 2015 104 814.9.
The invention relates to a casting flow running system for supplying liquid metal to mold cavities formed in a casting mold, whereby the casting flow runner system comprises respectively joined pipe sections and respectively, at least one ingate pipe is provided for connecting the casting flow runner system with an ingate of the casting model forming the mold cavity, as well as a frame provided for this type of casting flow runner system having a predetermined breaking point for the metallic residue remaining in the pipe system.
In casting technology, so-called casting flow runner systems are used, as described, by way of example, in DE 38 26 010 A1. For supplying the hot, liquid metal melt to a mold cavity formed in a casting mold by means of a casting model formed therein, a casting flow runner system formed by pipe sections that are connected together is installed and commonly molded with the casting model in the casting mold, by means of which the metal filling one or more infeeds are conducted to a component of the ingates forming the mold cavity, that is, molding plugs, and is divided accordingly. The last pipe sections leading to the ingates to the mold cavity are therefore designated as ingate pipes.
With this type of casting flow runner system, generally a problem exists in that after casting in the area of the ingate, respectively, hardened casting material remains in the interior, in particular, of the ingate pipe, which must be removed after the casting piece is removed from the mold. This causes substantial separation and cleaning expense, depending on the respective cross section of the ingate pipe. In the same manner, the removal of the casting piece is made more difficult because of the metallic residue remaining in the pipe sections of the casting flow runner system.
In addition, it is known from DE 29 05 682 C2, for example, to anchor a casting filter in an open casting system with a casting gate or down sprue formed in the mold sand of the casting mold; the casting filer sufficiently filters out foreign bodies in the liquid metal, on the one hand, and on the other hand, separates the stream of the liquid metal cast into the casting gate or down sprue into individual streams, and in this manner, should reduce the existing casting pressure. This technique cannot be used, however, with a casting flow runner system formed from pipes.
The present invention is therefore based on the object of addressing the problems associated with a casting flow runner system with the above-described features, in particular, to maintain to as little as possible the costs for separating and cleaning metallic residue associated with the ingate pipes on the produced casting piece. It is also an object to facilitate removal of the casting piece.
The invention contemplates that a frame made of a heat-resistance material is positioned and secured to the ingate pipe. A netlike webbing made from a fireproof material spans the frame and is tensioned therein. The frame is positioned and secured to the ingate pipe such that the netlike webbing at least partly crosses the cross section of the ingate pipe and is positioned directly near the surface of the casting piece to be formed by filling of the mold cavity.
The netlike webbing mounted in the cross section of the ingate pipe forms a metallic layer interfused and crossed by the webbing, based on the bathing of the net structure by the hot metal after setting, so that a defined metal weakening is formed and a chipping or knocking off of the hardened metallic residue inn the ingate pipe exactly in the flow of the webbing layer occurs. Since simultaneously, the netlike webbing is positioned in the cross section of the ingate pipe so that the netlike webbing is located during the casting process in the direct vicinity of the surface of the casting piece, breaking off or separation of the metallic residue takes place directly on the casting piece surface, so that the necessary cleaning expense is reduced accordingly. In that the present invention further proposes a frame fixed to the ingate pipe for holding the netlike webbing, the advantage is provided that the frame with the netlike webbing is relatively easy to produce and to mount to the ingate pipe. In that a sufficient tensioning of the netlike webbing in the flow path between the mold cavity and the ingate pipe must be ensured, so that the webbing is not pushed into the mold cavity and therewith, into the casting piece structure during the flow-through of the liquid metal during casting, the arrangement of the frame makes possible a corresponding tensioning and holding of the netlike webbing on the frame. The use of a frame comprising a heat-resistance material for holding the tensioned netlike webbing offers the additional advantage that the frame is not melted by the hot metal flowing through the casting flow runner system and thus, combustion gases that could be detrimental to the casting process do not exist.
According to a first embodiment of the invention, for a directly attachment of the frame, it is provided that the frame is made in the form of a displacement sleeve and has a pipe section that engages over the end of the ingate pipe, with which the frame is attachable onto the end of the ingate pipe. Thus, it is especially advantageous if the frame is made from a fireproof material, in particular ceramic. Since the ingate pipe is attached in a suitable manner after molding of the casting model with the casting flow runner system by means of mold sand in the casting mold, the frame is simultaneously also attach dot the ingate pipe; if necessary, a press fit or force fit can be provided via the diametric ratios of the ingate pipe and the frame.
According to another embodiment of the invention, it is provided that the frame has radially projection that extends from the outer circumference of its pipe section. This projection serves on the one hand as an aid in operation and manipulation during mounting of the frame to the ingate pipe and on the other hand, with the casting flow system including the casting model formed in the casting mold, for attachment of the frame in the mold sand that is introduced, since undercuts are formed in the sand because of the projection, which prevent movement of the ingate pipe with the frame attached thereto. The corresponding projection can be formed completely circumferential, or one or more projections can be provided that extend over a partial area of the circumference of the ingate pipe.
It can be provided that the frame comprises two frame parts, preferably made from metal, which are moveable relative to one another, and which are attachable to one another after the necessary tensioning of the netlike webbing is applied, whereby the frame parts can be connected to one another, for example at individual points by spot welding. In this regard, the frame parts can be insertable into one another and the netlike webbing received therebetween and tensioned by insertion of the frame parts into one another. Other forms of connections, such as adhesive or the like, are also possible.
Alternatively, it can be provided that a first inner frame part has a cylindrical shape with an inner flange formed on one of its ends and a second outer frame part has a cylindrical shape that outwardly encompasses the first frame part with the outer lying projection on the one hand and an inner flange, on the other hand, associated with the inner flange of the first frame part, whereby upon insertion of the frame parts, the flanges of the two frame parts receive and tension the netlike webbing therebetween.
As a particular connecting technology for the frame parts for forming of the frame that tensions the netlike webbing, according to one embodiment, clinching according to the so-called TOX® method is proposed. Accordingly, it is provided that the frame parts are connected to one another, with the netlike webbing placed therebetween, via positive-fit and push or snap button connections produced as a result of a cold working process, whereby the punctiform connections of the frame parts, respectively, catch the netlike webbing placed between the frame parts. So that the netlike webbing placed between the frame parts before clinching is fixed by the so-called TOX® points, an improved and more stable clamping of the netlike webbing occurs in the frame in which the webbing is held, also with corresponding demands created by the metal flowing through the netlike webbing. In addition, by means of the various positions on the circumferential of the frame of the TOX® points, the tensioning of the netlike webbing in the frame is improved, and finally, the corresponding connecting technology is simple and cost-effective in serial production of the frame, because no heat treatment or application of additional connecting elements is required.
The object is also solved by a casting flow runner system, in which a frame with a netlike webbing tensioned therein is arranged between individual pipe sections of the casting flow runner system, whereby the frame positioned between individual pipe sections can be provided in addition to a frame arranged on an ingate pipe. It is not necessary, however, that frames also must be mounted on the associated ingate pipes with the arrangement of the frame between individual pipe sections of the casting flow runner system. For improvement of the removal of the casting piece after completion of the casting process, it is sufficient if frames are arranged only between individual pipe sections of the casting flow runner system with the netlike webbings tensioned therein, because in this manner, in development of the metallic residue formed in the pipe sections of the casting flow runner system, further predetermined breaking points are produced. Upon removal or demolding, the formation of corresponding predetermined breaking points between the pipe sections allows the metallic residue in the pipe sections forming the casting flow runner system to be removed in separate parts.
According to one embodiment of the invention, it is provided that the frame has a greater dimension that the ingate pipe or the pipe section of the casting flow runner system and is arranged on the outside of the ingate pipe or the pipe section, and that the netlike webbing extends over the entire cross section of the ingate pipe or the pipe section In this manner, it is ensured that the liquid metal flows only through the netlike webbing and that the frame is not contacted directly by the liquid metal. Thus, no particular thermal stress of the frame occurs, in particular insofar as the frame is made from metal.
For improving the shielding of the frame holding the netlike webbing from the effects of heat from the liquid metal, it can be provided that the frame is held in a special adapter, preferably comprising a fireproof material, such as a ceramic so that the frame is attached in an indirect manner in the casting mold.
In this connection, it can be provided that the adapter comprises two adapter parts that are engageable in one another in a form-locking manner so that the frame is clamped between the two adapter parts, such that the netlike webbing tensioned in the frame extends over a flow-through opening formed in the adapter parts.
It can therefore be provided that the frame parts that are insertable into one another each have a cub-shaped design with a tapered contour that extends slightly conically from an upper end of a side wall of the frame parts to its lower end with the netlike webbing attached thereto and on the upper end of the side wall, a flange projecting therefrom is arranged with the TOX®-points arranged therein.
Regarding arrangement of a frame with a netlike webbing on the ingate pipe, it can be provided that upon connection of the adapter to the ingate pipe, one adapter part has a recess on an outer side of the adapter for insertion into an end of the ingate pipe and the other adapter part has a disk-like design, such that the netlike webbing extends on an outer face of the adapter part in the region of a contact plane of the adapter on the mold cavity of the casting mold. This enables the netlike webbing to be position in the direct area of the surface of the casting piece to be formed by filling of the mold cavity.
With regard to arrangement of the frame with the netlike webbing between individual pipe sections of the casting flow runner system, it can be provided that with arrangement of the adapter between pipe sections of the casting flow runner system, one adapter part has a recess on an outer side of the adapter for insertion of the adapter part into an end of a pipe section of the casting flow runner system, and the other adapter part on the opposite outer side of the adapter has a receiving element for insertion of the end of a further pipe section into the adapter part.
With regard to the netlike webbing, according to the present invention, the netlike webbing can be embodied as a metallic wire webbing or also as a net made from a fireproof webbing or webbing fibers or threads.
In addition, to avoid too great of a flow resistance, it can be provided that the netlike webbing has a through ole for reducing the flow resistance, which has a smaller dimension that the free cross section of the ingate pipe. In this connection, according to the present invention, it can be provided that the through hold has a surface of 5 to 90% of the free cross sectional surface of the ingate pipe, whereby the net width, that is the width of the net openings, is 1 to 20 mm with a width of the fibers forming the net structure being 1 mm to 15 mm.
In the drawings, exemplary embodiments of the invention are shown, which will be described below in greater detail. In the drawings:
As provided in
As can be seen from
With the embodiment that is shown, which is shown in greater detail in
The embodiment shown in
The adapter 25 comprise a first adapter part 26, which has a return 27 for on one of its ends for insertion into or connection to the ingate pipe 13. A second, annular adapter part 28 cooperates with the first adapter part 26 via a form-locking design 31, so that when the adapter parts 26 and 28 are connected, the provided adapter 25 is formed. The adapter part 28 faces the mold cavity with its lower contact plane 29 during casting in the casting mold. Between the adapter parts 26 and 28, the frame 15 is positioned with the netlike webbing 18 tensioned therein, whereby the frame 15 has a design equipped with a form-locking design 31 between the adapter parts 26, 28, so that the frame 15 is fixed between the two adapter parts 26, 28.
As
As discussed, it is sufficient for an improvement of the demolding process after termination of casting when frames are used only between individual pipe sections 12 of the casting flow runner system 11 with webbings 18 tensioned in the frames 15.
Such a casting flow runner system 11 is shown schematically in
The two-part adapter is shown in
The features of the subject matter of this invention set forth in the above description, the patent claims, the abstract and the drawings can be used individually and in any desired combination for the realization of the invention in its various embodiments.
The specification incorporates by reference the disclosure of DE 20 2015 104 814.9, filed Sep. 10, 2015.
The present invention is, of course, in no way restricted to the specific disclosure of the specification and drawings, but also encompasses any modifications within the scope of the appended claims.
Number | Date | Country | Kind |
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20 2015 104 814 U | Sep 2015 | DE | national |
Number | Date | Country |
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3244079 | Jun 1984 | DE |
3836010 | Apr 1990 | DE |
Entry |
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Hitchings et al. “Use Fabric, Breaker Cores to Cut Ductile Iron Finishing Cost”. Reprinted from Feb. 1999 Modern Casting. http://www.comanchetechnologies.com/Documents/De-Gating%20Tech%20Paper%20to%20Revisit.pdf. |
English Machine Translation of DE 3244079. |
Number | Date | Country | |
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20170080482 A1 | Mar 2017 | US |