Patent Application
20240300007
The invention relates to a feeder insert for use in the casting of metals in casting molds, with a feeder body and a feeder element which interacts with the feeder body, which delimit a feeder cavity for receiving liquid metal, the feeder body having a first end with a passage opening for the liquid metal, and a second end which lies opposite the first end and is open, and the feeder element being arranged at this second open end, it being possible for portions of the feeder body and the feeder element to be displaced telescopically inside one another. Furthermore, the invention relates to a kit for producing one or more feeder inserts, and to the use of a feeder insert of this type.
Feeder inserts which are used in the casting of metals in casting molds are known in the prior art. The feeder inserts are surrounded at least in regions by a mold material used for the production of the casting molds such as, for example, molding sand. By means of the mold material which surrounds the feeder insert, the feeder insert is held in a predefined position within the casting mold or a mold part of the casting mold. Here, the feeder body and the feeder element of the feeder insert delimit a feeder cavity for receiving liquid metal used in the casting within the feeder insert. The feeder body has a first end with a passage opening for the liquid metal, by means of which passage opening a connection to regions of a mold cavity of the mold part of the casting mold to be produced is established. A part quantity of the metal which is filled into the mold cavity of the casting mold during the casting passes through the passage opening into the feeder cavity of the feeder insert. When the metal solidifies in the casting mold, the metal which is situated in the feeder insert and is kept in the liquid state can flow back into the casting mold.
The feeder body has a second end which lies opposite the first end, is open, and is closed by way of the feeder element which is arranged at the second open end. As a result, a virtually closed feeder cavity is configured. In order for it to be possible for the high pressures which acted during the compaction operation on the mold material used to produce the casting mold to be countered, feeder inserts are used which can be changed in terms of their overall height during the compaction operation of the mold material to form a finished mold part.
The German Patent and Trade Mark Office has identified the following prior art in respect of the priority application DE 10 2020 132 342.5: DE 101 56 571 C1, DE 10 2005 025 701 A1, EP 1 184 104 A1 and EP 1 920 859 A1.
The publication EP 1 184 104 A1 has disclosed a feeder insert for use in the casting of metals, which feeder insert has a feeder body and a feeder element, it being possible for portions of the feeder body and the feeder element to be displaced telescopically inside one another. During the compaction operation, the feeder body and the feeder element are therefore moved relative to one another. This feeder insert has proven itself in practice.
It has been determined, however, that over-compaction of the mold material can occur below the feeder element which moves toward the feeder body in a manner which is dependent on the geometry of the feeder inserts which are used. This occasionally leads to damage to the model plate, or water is pressed out of the mold material, as a result of which various problems can occur during the casting method.
Proceeding from the above-described problems, the invention is therefore based on the object of specifying a feeder insert which firstly withstands high compaction pressures during the production of the casting mold and, during its use, the risk of excessive compaction of the mold material below the feeder element which moves toward the feeder body is moreover reduced or in the best case avoided.
The invention achieves the object, on which it is based, in a feeder insert with the features as claimed in claim 1. In particular, portions of the feeder body and the feeder element can be displaced telescopically inside one another, with the result that the feeder cavity can be compressed down to a minimum volume VK, the feeder body defining at least a proportion of 40% of this minimum volume VK.
The invention therefore relates to a feeder insert for use in the casting of metals in casting molds, with a feeder body and a feeder element which interacts with the feeder body, which delimit a feeder cavity for receiving liquid metal, the feeder body having a first end with a passage opening for the liquid metal, and a second end which lies opposite the first end and is open, and the feeder element being arranged at this second, open end, it being possible for portions of the feeder body and the feeder element to be displaced telescopically inside one another, with the result that the feeder cavity can be compressed down to a mini-mum volume VK, the feeder body making up at least a proportion of 40% of this minimum volume VK.
According to the invention, the approach is taken here that the feeder body configures a proportion of at least 40% of the minimum volume VK of the compressed feeder cavity. The feeder body according to the invention has a considerably increased proportion of the minimum volume of the feeder insert which, in particular, is compressed to a maximum extent, in comparison with feeder bodies of known feeders of feeder inserts. Therefore, the feeder body (also called a feeder lower part) is considerably greater in relation to the feeder element (also called a feeder upper part) of a feeder insert according to the invention, than a feeder body of known feeder inserts in relation to its feeder element. It has been assumed until recently that a large feeder upper part was of decisive significance for satisfactory dense feeding during the casting process. In contrast, the size of a feeder body (that is to say, of a feeder lower part) in a feeder insert has a considerably higher influence on effective dense feeding during casting than the size of the feeder element. A feeder cavity which is compressed to a minimum volume VK is to be understood to mean that state of a feeder insert according to the invention, in which it has preferably been compressed to a maximum extent. The maximum compressible minimum volume of the feeder insert defines that state of the feeder insert, in the case of which a further compression of the feeder insert (that is to say, a further displacement of the feeder body and the feeder element relative to one another) would lead to damage to the feeder body (feeder lower part) and/or the feeder element (feeder upper part). During the compression, portions of the feeder body and the feeder element are preferably displaced telescopically inside one another.
One preferred refinement of the feeder insert according to the invention provides that the feeder body de-fines a proportion of 45% or more, preferably 50% or more, particularly preferably 60% or more, with preference 70% or more, with particular preference 80% or more, of the minimum volume VK. The greater the proportion of the feeder body in the minimum volume VK, the further the thermal center of the feeder insert moves in the direction of the cast part to be produced. Here, as the proportion of the feeder body in the minimum volume VK increases, the advantage is enhanced that the feeder element can be of lighter configuration, and a feeder insert according to the invention can be produced with less material consumption in comparison with the known feeder inserts. In the case of a feeder element being reduced in size in comparison with the feeder body, the over-compaction of the mold material below the feeder element is additionally avoided increasingly during the compaction operation of the mold material.
Preferably, the feeder body has a mass mK and the feeder element has a mass mE, and the ratio of the mass mK of the feeder body to the mass mE of the feeder element is 0.5 or greater, preferably 0.85 or greater, particularly preferably 1 or greater, very particularly preferably 2 or greater, with preference 4-5 or greater, with particular preference approximately 5.75. The larger the feeder body is configured in comparison with the feeder element, the greater the ratio also becomes between the mass mK of the feeder body and the mass mE of the feeder element. The mass ratio of the feeder body to the feeder element also has an advantageous influence on the pursued arrangement of the thermal center in the vicinity of the cast part to be produced. The greater the ratio of the masses of the feeder body to the feeder element, the further the thermal center moves in the direction of the cast part to be produced and the better is the dense feeding during the production of the cast part. Here, the mass ratios of the feeder body to the feeder element are also dependent on the materials which are used for the configuration of the feeder body and the feeder element. The preferably highest value of the mass ratio of 5.75 is achieved, in particular, when a heavy exothermic lower part (feeder body) and a light insulating upper part (feeder element) are preferably used in order to configure a feeder insert according to the invention.
One preferred development provides that that proportion of the minimum volume VK which is defined by the feeder body has a sphericity Ψ of 0.75 or greater, preferably of 0.8 or greater, particularly preferably of 0.85 or greater, very particularly preferably 0.9 or greater.
In accordance with one preferred embodiment of the feeder insert according to the invention, it is possible for portions of the feeder element to be pushed into the feeder body, or it is possible for portions of the feeder body to be pushed into the feeder element. The feeder body of the feeder insert according to the invention is preferably a non-deformable feeder lower part. The feeder element is preferably a non-deform-able feeder upper part. During use, the feeder body is usually seated on a mold plate or a mold model and is held in position by way of this. During compaction of the mold material which is used to produce the casting mold or a mold part of the casting mold, in accordance with a first embodiment, the feeder element (that is to say, the feeder upper part) is pushed into the feeder body. Here, surface regions of the feeder element and the feeder body preferably slide on one another. In a second alternative embodiment, the feeder body (that is to say, the feeder lower part) is pushed into the feeder element. Surface regions of the feeder upper part and the feeder lower part preferably also slide on one another in this embodiment. A feeder element which is pushed on the outer side over the feeder body here has greater dimensions and an associated greater mass than a feeder element which can be pushed into the feeder body on the inner side. In the case of a feeder insert, in the case of which the feeder element (feeder upper part) is pushed into the feeder body (feeder lower part) during the compaction of the mold material, higher proportions of the minimum volume VK of the feeder cavity are preferably achieved by way of the feeder body, and/or greater mass ratios of the feeder body to the feeder element are achieved.
It is noted in this context that the proportion of the feeder body in the overall minimum volume VK of the feeder cavity in the case of a feeder insert with a feeder element which is pushed over the feeder body on the outer side, is defined solely by way of the feeder body, and is delimited, in particular, in the direction of the feeder element by way of its second end which is open toward the top. In contrast, in the case of a feeder insert according to the invention, in the case of which the feeder element is pushed into the feeder body on the inner side, the proportion of the feeder body in the minimum volume VK of the feeder cavity is defined by way of that lower end of the feeder element which is pushed into the feeder body; in particular, the lower end of the feeder element then forms the boundary of the minimum volume VK within the feeder body. Only the region between the first end of the feeder body and precisely this boundary is to be taken into consideration for the determination of the proportion of the feeder body in the entire minimum volume VK.
It is preferably provided in accordance with one development of the feeder insert according to the invention that the volume center of gravity of the feeder cavity lies within the volume proportion which is defined by the feeder body when the feeder cavity is compressed down to the minimum volume VK. The thermal center of the feeder insert according to the invention is displaced during the compaction of the mold material together with the volume center of gravity of the feeder cavity in the direction of the cast part to be produced, regardless of the configuration of the feeder insert, that is to say regardless of whether the feeder body is pushed into the feeder element or the feeder element is pushed into the feeder body. It is advantageous if the volume center of gravity of the feeder cavity moves far in the direction of the first end of the feeder body.
In accordance with one preferred refinement, the invention relates to a feeder insert for use in the casting of metals in casting molds, with a feeder body and a feeder element which interacts with the feeder body, which delimit the feeder cavity for receiving liquid metal, the feeder body having a first end with a passage opening for the liquid metal, and a second end which lies opposite the first end and is open, and the feeder element being arranged at this second, open end, it being possible for portions of the feeder element to be pushed into the feeder body, with the result that the feeder cavity can be compressed down to a minimum volume of VK, the feeder body defining at least a proportion of 40% of this minimum volume VK, the feeder body having a mass mK and the feeder element having a mass mE, and the ratio of the mass mK of the feeder body to the mass mE of the feeder element being 0.5 or greater, and the volume center of gravity of the feeder cavity lying within the volume proportion defined by the feeder body when the feeder cavity is compressed down to the minimum volume VK. A feeder insert according to the invention of this type com-bines the features which are essential to the invention, in such a way that a feeder insert of this type achieves at least an unchanged or else higher heating capacity during the refilling operation during casting despite a reduced feed volume and an associated, reduced mass. The feeder insert according to the invention is preferably an inverse tele-feeder, that is to say the feeder element is pushed into the interior of the usually stationary feeder body during the compaction operation of the mold material. The feeder element and the feeder body are usually moved relative to one another in such a way that the feeder insert is compressed to a maximum extent. The feeder cavity in the interior of the feeder insert then has a minimum volume VK, a proportion of at least 40% of which is configured by way of the feeder body. In addition, the feeder body has a mass which corresponds at least to half the mass of the feeder element. In this way, a feeder insert is preferably configured, in the case of which the volume center of gravity of the feeder cavity lies within the volume proportion defined by the feeder body. In one possible refinement of the invention, the feeder element is designed to be pushed, instead of into the feeder body, on the outer side over the feeder body which is as a rule stationary during the compaction operation of the mold material.
One development of the feeder insert according to the invention provides that the feeder body has a wall which extends from the first to the second end, the wall forming, on its inner side which delimits the feeder cavity, a guide for the feeder element which can be pushed along on it into the feeder body. Tilting of the feeder element during the compaction operation in the production of the mold part or the casting mold is counteracted by way of the provision of a guide. The feeder element can be pushed from its starting position at the beginning of the compaction operation into the feeder body to such an extent that the maximum compressible state of the feeder insert is reached. A sliding action between those surfaces of the feeder body and the feeder element which slide on one another is preferably achieved by way of the guide during the movement of the feeder element with respect to the feeder body.
The guide preferably has at least one guide face or a plurality of guide portions which are arranged on the inner side of the wall of the feeder body. In accordance with one preferred refinement of the invention, the guide is configured on the inner side of the wall of the feeder body over its entire extent, as a result of which a large-area sliding effect is brought about. An alternative embodiment of the feeder insert provides that a plurality of guide portions preferably arranged distributed uniformly over the circumference of the feeder body are provided on the inner side of the wall of the feeder body. The individual guide portions extend in the circumferential direction only in a predefined angular range along the inner side of the feeder body. Each guide portion extends in the movement direction of the feeder element, however, preferably from the second open end of the feeder body in the direction of the first end with its passage opening. The feeder element which can be displaced relative to the feeder body is preferably guided during the entire movement of the feeder element from its rest position as far as the maximum compressed state of the feeder insert. The feeder body, just like the feeder element, preferably has guide faces which face one another and overlap one another at least in sections in the movement direction of the feeder element.
The feeder body preferably has a longitudinal axis which extends from the first end to the second end, and, at least along a portion of its longitudinal axis, an inner cross-sectional area which is of substantially rotationally symmetrical configuration about the longitudinal axis. As a result of the preferably rotationally symmetrical cross-sectional area on the feeder body, the feeder element which can preferably be moved along the inner side of the feeder body also has an outer cross-sectional form of substantially rotationally symmetrical configuration. In this way, in relation to the circumferential faces, the feeder body and the feeder element can be joined to one another in any desired orientation. The longitudinal axis of the feeder body runs, in particular, coaxially with respect to the center axis of the passage opening at the first end of the feeder body.
In accordance with one preferred refinement of the feeder insert according to the invention, the feeder body has, starting from its second end in the direction of its first end, an inner, free cross-sectional area which is constant in size and/or decreases along at least one portion of its longitudinal axis. The feeder body is preferably divided into two functional regions in the longitudinal direction. With the aid of the upper functional region which is assigned to the second end of the feeder body, the relative movement between the displaceable feeder element and the usually stationary feeder body is ensured in order to configure the telescopic movement according to the invention. Along a portion of the longitudinal axis of the feeder body, the upper functional region has a free cross-sectional area of substantially constant size. The portion with its substantially constant cross-sectional area has a height in the direction of the longitudinal axis, which height is defined in a manner which is dependent on the size ratios of the feeder body to the feeder element. The height preferably corresponds to at least approximately a third of the overall height of the feeder body according to the invention. This height is preferably approximately half of the overall height of the feeder body.
The second, lower functional region forms an attachment region of the feeder insert according to the invention for attaching to a mold model or a mold plate. The free cross section of the lower functional region preferably decreases from the constant cross section in the direction of the first end of the feeder body. In this way, an attachment region of reduced cross section is produced on the feeder body, which attachment region requires only a small amount of fettling to the finished cast part after the casting operation. The lower functional region preferably has a convexly curved contour along the longitudinal axis. Along a portion of the longitudinal axis of the feeder body, the lower functional region has a contour which preferably approximates the shape of a sphere. As a result, the volume proportion of the feeder body according to the invention in the minimum volume VK of the maximum compressible feeder insert is intended to be increased, and a displacement of the thermal center in the direction of the first end of the feeder body is intended to be brought about.
The feeder element is preferably configured as a feeder cap which can be placed onto the second, open end of the feeder body and closes the latter. The provision of a feeder cap provides a structurally simple possibility for closing the open end of the feeder body, in order to prevent the penetration of mold material into the feeder cavity during the production of the casting mold. In addition to the closure of the open second end of the feeder body, the cap-like configuration of the feeder element brings it about that portions of the feeder body are engaged over or behind, in such a way that the feeder element is locked in the uncompressed state of the feeder insert and therefore in its starting position relative to the feeder body. The feeder element is preferably held in its starting position on the inner side of the wall of the feeder body, in particular in the case of the configuration of the feeder insert as an inverse tele-feeder. To this end, the feeder body and/or the feeder element can have portions which, when brought into contact with one another bring about a positively locking connection.
In accordance with one preferred development of the feeder insert according to the invention, the feeder element has a contact portion which corresponds with the inner side of the wall of the feeder body and is designed to brake the movement of the feeder element during the displacement into the feeder body. By means of the contact portion on the feeder element, controlled braking of the feeder element is brought about during the relative movement, initiated by way of the compaction operation of the mold material, between the feeder body and the feeder element. As a result, the feeder insert according to the invention is not compressed further than as far as its predefined maximum compressible minimum volume. A clamping action for locking the feeder element relative to the feeder body is preferably already achieved in the uncompressed state of the feeder insert between the contact portion on the feeder element and the inner side of the wall of the feeder body. The braking function is preferably achieved by virtue of the fact that the first functional region on the feeder body, starting from the second, open-end, has a free cross section which decreases slightly in the direction of the second functional region, either over the entire circumference or else only in regions. In the case of the displacement of the feeder element during the compaction operation, the contact portion of the feeder element runs increasingly onto the decreasing cross section of the feeder body. The braking action is greater, the further the feeder element is displaced/pushed in relative to, in particular into, the feeder body.
In one possible embodiment of the invention, the feeder element has, on the inner side of its wall, a prefer-ably radially inwardly projecting shoulder which serves as a stop for the feeder element which can preferably be pushed into the feeder body. This projecting shoulder in the form of a material projection on the inner side of the wall of the feeder body limits the pushing of the feeder element into the feeder body. In this way, the maximum possible compression of the feeder insert according to the invention can be limited.
The feeder element preferably has, in relation to the longitudinal axis of the feeder body, at least one bearing web which projects outward in the radial direction via the opening at the second end of the feeder body and preferably lies on the second end of the feeder body along the entire circumference of the opening at this end. The bearing web achieves a situation where, during the production of the casting mold or a mold part of the casting mold, within which the feeder insert is embedded, the penetration of mold material into the interior of the feeder insert is avoided. With the aid of the preferably circumferential bearing web, the gap between the inner side of the wall of the feeder body and the outer face of the feeder element is covered.
One preferred development of the feeder insert according to the invention provides that it is possible for portions of the feeder element to be pushed into the feeder body, and the bearing web is designed such that it is severed when the feeder element is pushed telescopically into the feeder body. In addition to the covering function of the gap between the feeder element and the feeder body, the bearing web has the task of holding the feeder element in its starting position relative to the feeder body. The material thickness of the bearing web, however, is selected in such a way that, after a predefined compaction pressure is reached in the mold material, the bearing web is preferably severed, in particular sheared off, uniformly and, above all, over the full circumference on the feeder element. As a result, the feeder element can then carry out its yielding movement during the production of the casting mold or the mold part of the casting mold, as a result of which damage to the feeder insert or even a fracture of the feeder insert is avoided despite the pressing pressures which prevail.
That contact portion of the feeder element which faces the inner side of the wall of the feeder body prefer-ably has at least one clamping part for holding the feeder element relative to the inner side of the wall of the feeder body. With the aid of the one or plurality of clamping parts on the contact portion of the feeder element, as an alternative to a contact face which bears in a fully circumferential manner against the inner side of the wall of the feeder body, only certain regions of the contact portion are provided for a clamping action with the feeder body. Three or more clamping parts are preferably provided on the contact portion of the feeder element, which clamping parts are configured in one embodiment as a material web and run substantially parallel to the movement direction. The clamping parts preferably project radially outward on the substantially cylindrical outer face of the contact portion.
One preferred development of the feeder insert according to the invention provides that the feeder element has, on that inner side of its wall which delimits the feeder cavity, at least one material web which preferably extends radially and axially with respect to the longitudinal axis of the feeder body. With the aid of the at least one material web which projects on the inner side, for example configured as what is known as a Williams strip or Williams wedge, the formation of a cast skin on the surface of the liquid metal in the feeder cavity and therefore premature solidification of the metal are counteracted. A plurality of material webs are preferably arranged on that inner side of the feeder element which faces the feeder cavity, which material webs divide this region of the feeder cavity in a chamber-like manner. A material web of this type preferably extends in the radial and axial direction, in relation to the longitudinal axis of the feeder body. Two, three, four or more material webs are preferably arranged or configured on the inner side of the wall of the feeder element. The material webs preferably extend in the vertical direction of the feeder element from the inner side of the cover as far as the lower end of the feeder element.
The two, three, four or more material webs are preferably arranged uniformly distributed around the longitudinal axis on the inner-side wall of the feeder element. The metal is kept liquid within the feeder cavity in an improved manner by way of the provision of a plurality of material webs of this type. Two material webs which are directly adjacent to one another are in each case at the same angular spacing from one another, obviously in a manner which is dependent on the number of material webs which are used.
In one preferred refinement of the invention, the feeder element has, on its inner side which faces the feeder cavity, a recess for receiving a centering pin tip. By way of the provision of at least one recess as receptacle for a centering pin tip on the feeder element, the positional stability and/or a desired orientation of the feeder insert relative to a mold model or mold plate which receives the feeder insert can be maintained in a simplified manner. Furthermore, guidance of the feeder element during the compaction operation of the mold material which configures the casting mold is brought about by means of the recess which is provided on the feeder element, in the case of which compaction operation the feeder element is to be moved relative to the feeder body and therefore also relative to the centering pin.
In accordance with one preferred development of the invention, at least portions of the feeder body and/or the feeder element comprise an exothermic heating mass. With the aid of an exothermic heating mass of this type, the solidification behavior of the liquid metal within the feeder cavity can be influenced in a targeted manner. The more the feeder insert consists of an exothermic mass or comprises the latter, the longer the liquid metal which is situated in the feeder insert can be kept liquid by way of the exothermic heating mass, and therefore the longer the operation of refilling into the cast part is possible. The feeder body and/or the feeder element are/is preferably equipped at points or in portions with an exothermic heating mass of this type.
The feeder insert preferably has a modulus in the range from approximately 0.5 cm to 9 cm, preferably from approximately 1.2 cm to 2.6 cm. The indicated ratio of from 0.5 cm to approximately 9 cm between the volume and the heat-outputting surface area preferably specifies the feeder inserts, by way of which satisfactory dense feeding of a cast part to be produced can be achieved. In one preferred embodiment of the invention, the modulus of the feeder insert according to the invention lies in a range from approximately 1.2 to 2.6 cm.
In accordance with one preferred refinement, a feeder insert is provided for use in the casting of metals in vertically separable casting molds, the feeder body and the feeder element being designed for positioning by means of a centering pin which can be positioned along a centering axis, and the feeder cavity being configured in such a way that, in the case of a horizontal arrangement of the centering axis, a predominant volume proportion of the feeder cavity can be positioned above the centering axis. A corresponding feeder insert according to the invention can be used in one preferred embodiment as a side feeder, with the aid of which, instead of customary dense feeding to a casting mold from its upper side, critical regions of the casting mold which lie in a side region of the casting mold can also be refilled. In accordance with one preferred refinement of the feeder insert according to the invention, the feeder body and/or the feeder element which can be displaced relative to the feeder body are/is of asymmetrical configuration with respect to the longitudinal axis of the feeder body and the feeder element, which longitudinal axis is preferably defined by way of the passage opening on the feeder body or a centering pin which protrudes through the passage opening into the feeder cavity.
In accordance with one embodiment of the feeder insert according to the invention, an asymmetrical configuration of the feeder cavity, in relation to the longitudinal axis of the feeder body and the feeder element, is achieved by way of an inhomogeneous configuration of the feeder body and the feeder insert on one side of the longitudinal axis. For corresponding dense feeding using a feeder insert which is configured in this way, it is provided that the feeder insert is positioned with a preferred direction on a mold model or on a mold plate. A further refinement provides that the feeder element has an odd number of material webs on its inner side which defines the feeder cavity, the feeder element then being positioned on the feeder body in such a way that, in the case of a horizontal arrangement of the centering axis, a greater number of material webs are then arranged below the centering axis than above the centering axis.
A feeder insert according to the invention is preferred, the feeder element being formed from exothermic feeder material, or at least portions thereof comprising exothermic feeder material, and/or the feeder body being formed from exothermic feeder material, or at least portions thereof comprising exothermic feeder material. By way of the use of exothermic feeder material, high economic efficiency and, in particular, satisfactory dense feeding during the casting process are achieved, since the metal which is situated in the feeder insert can be kept in a liquid state over a comparatively long time period via the exothermic feeder material. Regions, for example, of the feeder element which are pushed on the outside over or on the inside into the feeder body can also be configured, instead of from an exothermic feeder material, from an insulating feeder material which decreases the output of heat from the feeder insert in an advantageous way. A mold sand, in particular quartz sand, which is bound using a binder can also simply be used as feeder material, however. An exothermic material is frequently preferably used, however, to configure at least parts of the mold elements. Certain regions of the feeder insert can be formed from different materials with different properties (exothermic or insulating). As an alternative, the feed body and the feeder element can be formed in each case from a homogeneous material mixture with exothermic and insulating constituent parts.
For certain purposes, a feeder insert according to the invention is advantageous, in the case of which the feeder body is formed from insulating feeder material or at least portions thereof comprise insulating feeder material and/or the feeder element is formed from an insulating feeder material, or at least portions thereof comprise insulating feeder material. In the case of one alternative embodiment of the feeder insert, it is preferably provided that the feeder body is formed from an exothermic feeder material, or at least portions thereof comprise exothermic feeder material, and/or the feeder body does not comprise exothermic feeder material and is preferably formed from insulating feeder material, or at least portions thereof comprise insulating feeder material, or is formed from a material or containing material which is selected from the group consisting of metals, plastics, cardboards, mixtures thereof and composite materials thereof. In the case of a further alternative refinement of the feeder insert according to the invention, the feeder element is formed from insulating feeder material, or at least portions thereof comprise insulating feeder material, and/or the feeder body is formed from exothermic feeder material, or at least portions thereof comprising exothermic feeder material, or is formed from a material or containing a material which is selected from the group consisting of metals, plastics, cardboards, mixtures thereof and composite materials thereof.
Instead of commercially available feeder materials, the feeder body of a feeder insert according to the invention can also consist of different materials which are preferably selected from the group consisting of metals, plastics, cardboards, mixtures thereof and composite materials thereof.
In the case of a further alternative refinement of the feeder insert according to the invention, the feeder element is formed from an exothermic or insulating feeder material, or at least portions thereof comprise exothermic or insulating feeder material, and/or the feeder body is formed from a material or contains a material which is selected from the group consisting of metals, plastics, cardboards, mixtures thereof and composite materials thereof. Therefore, exothermic or insulating materials such as metals, plastics or card-boards or mixtures or composite materials consisting of metals, plastics and/or cardboards can optionally be used as material for the feeder body.
Exothermic and insulating feeder materials are preferably used to configure the feeder element. The material selection for the feeder body and the feeder element is performed in practice individually and with consideration of the task to be performed in each case. The selection of the material for the feeder body can take place independently of the selection of the material for the feeder element, in so far as the specific intended purpose of the feeder insert according to the invention does not make any balancing necessary.
A further aspect of the present invention relates to a kit for producing one or more feeder inserts in accordance with one of the above-described preferred embodiments, comprising a feeder body or a plurality of feeder bodies, and a feeder element or a plurality of feeder elements which corresponds or correspond to the feeder body or feeder bodies in such a way that, by way of respective assembling of feeder body and feeder element, a feeder insert, as defined in accordance with one of the above-described preferred embodiments, can be produced or a plurality of different feeder inserts, as defined in accordance with one of the above-described preferred embodiments, can be produced with different volumes.
To this extent, the invention is based on the supplementary concept of it being possible for a given feeder body to be assembled with feeder elements of different design or for a given feeder element to be assembled with feeder bodies of different design to form a feeder insert according to the invention. A feeder insert which can accordingly be produced as desired from different feeder bodies and/or feeder elements prefer-ably has in each case one feeder body and feeder element, portions of which can be displaced telescopically into one another in such a way that they configure a feeder cavity which can be compressed down to a minimum volume VK, the feeder body in each case defining at least a proportion of 40% of this minimum volume VK of the feeder cavity. A kit according to the invention provides, for example, a feeder body which can be combined with different feeder elements, it being possible for one of the feeder elements to be pushed on the outer side over the feeder body and for the other feeder element to be pushed on the inner side into the feeder body. With the aid of the feeder element which can be pushed on the outer side over the feeder body, a “classic” tele-feeder is produced and, with the aid of the feeder element which can be pushed into the feeder body, an inverse tele-feeder is produced.
Furthermore, the kit according to the invention preferably comprises a centering pin which corresponds with the passage opening in the or one of the plurality of feeder bodies and preferably with a recess for receiving a centering pin tip in the or one of the plurality of feeder elements. With the aid of the centering pin, a perpendicular orientation of the feeder insert according to the invention with its feeder body and its feeder element with respect to a mold plate or with respect to a mold model preferably takes place. The centering pin preferably has a centering pin base which has a shape which is adapted to the shape of the passage opening. In accordance with one preferred refinement, the passage opening has a non-cylindrical cross section, and the cross section of the centering pin base is of complementary configuration with respect to the cross section of the passage opening. In this refinement, an anti-rotation safeguard between the centering pin and the feeder body which is pushed onto the centering pin is then produced. The centering pin tip can likewise have a non-cylindrical cross section, with the result that a preferred orientation around the centering axis is also brought about in the case of the feeder element which can be brought into contact with the feeder body and the centering pin tip.
In a further aspect, the invention relates to the use of a feeder insert, as defined at least in accordance with one of the above-described preferred embodiments, during the production of a casting mold with a vertical mold separation for dense feeding of a mold cavity present in the casting mold during the casting operation. Reference is made to the above-described embodiments with respect to the feeder insert with regard to the advantages according to the invention and with regard to the preferred embodiments of the kit according to the invention or the use according to the invention which are the same as the advantages and preferred embodiments of the feeder insert according to the invention.
The invention will be described in greater detail in the following text on the basis of one preferred exemplary embodiment with reference to the appended figures, in which:
The feeder body 2 (also called a feeder lower part) has a first end 8, at which a passage opening 10 for the liquid metal is provided. Furthermore, the feeder body 2 has a second end 12 which lies opposite the first end 8, the second end 12 of the feeder body 2 being open. In one preferred embodiment, the feeder element 4 of the feeder insert according to the invention is arranged at the second, open end 12 of the feeder body 2 and closes the latter.
In the present embodiment, portions of the feeder body 2 and the feeder element 4 can be displaced telescopically inside one another. During the telescopic displacement inside one another, portions of the feeder element 4 are pushed into the feeder body 2, surfaces of the feeder body and the feeder element sliding on one another. The feeder body 2 and the feeder element 4 themselves are usually of non-deformable or non-compressible configuration.
By way of the displacement of the feeder body 2 and the feeder element 4, the feeder cavity 6 can be compressed down to a minimum volume VK, the feeder body defining at least a proportion of 40% of this minimum volume VK.
In the embodiment which is shown in
In order to ensure correct positioning of the feeder insert 1 on a model plate or mold model (not shown in greater detail), the feeder insert 1 is received with the aid of a centering pin 14 which, however, is not part of the feeder insert itself. The centering pin 14 serves merely to position the feeder insert 1 during the mold production, and is removed after the production of at least one mold part of the casting mold.
As can be seen from
In one embodiment, on its inner side 22 which delimits the feeder cavity 6, the wall 20 forms or defines a guide for the feeder element 4 which can be pushed in along the inner side of the wall 20. The guide comprises at least one guide face 24 on the inner side 22 of the wall 20 of the feeder body 2. In one possible embodiment, a plurality of guide portions which are arranged on the inner side of the wall can be provided instead of a guide face 24.
The feeder body has a longitudinal axis 26 which extends from the first end 8 to the second end 12. In addition, the feeder body has a cross-sectional area 28 which is of substantially rotationally symmetrical configuration about the longitudinal axis (
The volume center of gravity VS of the feeder cavity 6 lies within that volume proportion of the minimum volume VK which is defined by the feeder body 2. That proportion of the minimum volume VK which is defined by the feeder body has a sphericity of 0.75 or greater.
Furthermore,
Furthermore, the feeder element 4 has a bearing web 32 which projects outward in the radial direction beyond the second open end 12 of the feeder body. In the embodiment which is shown, the bearing web 32 lies along the entire circumference at the second end 12 of the feeder body 2. The bearing web 32 holds the feeder element 4 in position at the second end 12 of the feeder body 2, in order to avoid premature pushing of the feeder element 4 into the feeder body 2. In addition, the bearing web 32 seals the region between the contact portion 30 on the feeder element 4 and the inner side 22 of the wall 20 on the feeder body 2, with the result that no mold material passes between the surfaces which slide on one another.
The bearing web 32 is configured to be severed during the telescopic pushing of the feeder element into the feeder body 2.
In one embodiment of the feeder insert according to the invention, one or more clamping parts are provided on the contact portion 30 of the feeder element 4 in order to hold the feeder element 4 relative to the inner side of the wall 20 of the feeder body 2. In relation to the longitudinal axis 26 of the feeder body 2, the clamping part or parts 34 projects/project approximately radially on the contact portion 30 of the feeder element 4, and therefore face the inner side of the wall 20 of the feeder body 2.
On its inner side 36 of the wall 38 which delimits the feeder cavity 6, the feeder element 4 has a plurality of material webs 40. In the embodiment which is shown, the material webs 40 preferably extend in the radial and axial direction with respect to the longitudinal axis 26 of the feeder body 2. The plurality of material webs 40 which are arranged on the inner side of the wall 38 of the feeder element 4 are arranged distributed uniformly around the longitudinal axis 26.
In one embodiment of the invention, the feeder insert 1 is positioned along a horizontally running centering axis during its use, a predominant volume proportion of the feeder cavity being positioned above the centering axis. This is achieved by the feeder element 4 having an odd number of material webs 40, and the feeder element 4 being positioned relative to the centering axis in such a way that more material webs 38 are arranged below the centering axis than above.
The feeder body 2′ (also called a feeder lower part) has a first end 8, on which a passage opening 10 for the liquid metal is provided. Furthermore, the feeder body 2 has a second end 12 which lies opposite the first end 8, the second end 12 of the feeder body 2′ being open. In the embodiment which is shown, the feeder element 4′ of the feeder insert 1′ according to the invention is arranged at the second, open end 12 of the feeder body 2′ and closes it.
In the present embodiment, portions of the feeder body 2′ and the feeder element 4′ can be displaced telescopically inside one another. During the telescopic displacement inside one another, portions of the feeder element 4′ are pushed on the outer side over the feeder body 2′, faces of the feeder body and the feeder element sliding on one another. The feeder body 2′ and the feeder element 4′ themselves are usually of non-deformable or non-compressible configuration.
By way of the displacement of the feeder body 2′ and the feeder element 4′, the feeder cavity 6 can be compressed down to a minimum volume VK, the feeder body defining at least a proportion of 40% of this minimum volume VK. That embodiment of the feeder body 2′ which is shown in
In order to ensure positioning of the feeder insert 1′ on a model plate or a mold model (not shown in greater detail), a centering pin can likewise be used. The centering pin then corresponds with the passage opening on the feeder body 2′ and a recess 16 on the feeder element 4′ for receiving a centering pin tip of the centering pin.
By way of its outer side 22′, a wall 20 of the feeder body 2′ forms the guide for the feeder element 4′ which can be pushed along the outer side 22′ of the wall 20. The guide comprises at least one guide face 24′ on the outer side 22′ of the wall 20.
As
In one embodiment of the feeder insert 1′ according to the invention, one or more clamping parts 34′ for holding the feeder element 4′ with respect to the outer side 22′ of the wall 20 of the feeder body 2′ are/is provided on the contact portion 30′ of the feeder body 2′. In relation to a longitudinal axis 26 of the feeder body 2′, the clamping part or parts 34′ projects/project approximately radially outward on the contact portion 30′ of the feeder element 4′ and therefore faces/face the inner side of the feeder element 4′.
The feeder element 4′ has a plurality of material webs 40 on its inner side 36, delimiting the feeder cavity 6, of its wall 38. In the embodiment which is shown, the material webs 40 preferably extend in the radial and axial direction with respect to the longitudinal axis 26 of the feeder body 2′. The plurality of material webs 40 which are arranged on the inner side of the wall 38 of the feeder element 4′ are arranged distributed uniformly around the longitudinal axis 26.
In one embodiment of the invention, the feeder element 4′ has, along a portion of the longitudinal axis 26, a cross-sectional area which tapers conically starting from the lower end in the direction of the upper end.
Identical or similar components are denoted by the same designations.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10 2020 132 342.5 | Dec 2020 | DE | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/EP2021/076732 | 9/29/2021 | WO |
