DE102022103215A1 - Method for strengthening a cast component, cast component and core package in certain areas - Google Patents

Abstract

Method for strengthening a cast component in certain areas, comprising the steps of:- creating a multi-part core for forming a cavity in a cast component, wherein at least a first core section is designed as a lost core and at least a second core section is designed as a support core, which is designed and positioned to reinforce the cast component in areas;- arranging the multi-part core in a mold;- casting the cast component;- removing the at least one first core section.

Description

The present invention relates to a method for strengthening a cast component in certain areas, a cast component and a core assembly.

It is known from the prior art to reinforce cavities in components, such as cast components, in certain areas. The WO 99/64287 discloses in this context a method for producing a reinforcement in a cavity of a preferably galvanized motor vehicle component, the cavity being at least partially foamed with a metal foam. The DE 196 50 613 A1 proposes a component with a core made of metal foam, with the metal foam core being encapsulated in a metal cast material and bonded to the cast material. However, it is often not desired or even necessary to completely provide a cavity with a reinforcement. The WO 99/64287 also only discloses a “regional” foaming of a cavity, however, this approach is relatively imprecise from a geometric point of view. The subsequent foaming/reinforcement is also complex in terms of process technology.

It is therefore an object of the present invention to specify a method for strengthening a cast component in certain areas, a cast component and a core package, with the aforementioned disadvantages being eliminated.

This object is achieved by a method according to claim 1, by a cast component according to claim 10 and by a core package according to claim 12. Further advantages and features emerge from the subclaims and the description and the attached figures.

• - Erzeugen eines mehrteiligen Kerns zum Formen eines Hohlraums in einem Gussbauteil, wobei zumindest ein erster Kernabschnitt als verlorener Kern ausgebildet ist und wobei zumindest ein zweiter Kernabschnitt als Stützkern ausgebildet ist, welcher ausgelegt und positioniert wird, das Gussbauteil bereichsweise zu verstärken;
• - Anordnen des mehrteiligen Kerns in einer Gussform;
• - Abgießen des Gussbauteils;
• - Entfernen des zumindest einen ersten Kernabschnitts.

According to the invention, a method for strengthening a cast component in certain areas comprises the steps:

• - Creating a multi-part core for forming a cavity in a cast component, wherein at least a first core section is designed as a lost core and wherein at least a second core section is designed as a support core, which is designed and positioned to reinforce the cast component in some areas;
• - arranging the multi-piece core in a mold;
• - casting of the cast component;
• - removing the at least one first core section.

The multi-part core thus advantageously has an area or section which is removed after casting, cf. the at least one first core section, and an area or section which remains in the component, cf. the aforementioned second core section. Using the multi-part core or using such a “hybrid core”, a cavity can expediently be produced in a cast part in one process step and at the same time be reinforced locally and in a defined manner from the inside. There is no need for a time-consuming, subsequent introduction of a stiffener. An extremely precise arrangement of the support core also advantageously takes place via the multi-part core, in particular also on or in areas which would not be accessible for a subsequent arrangement of a support.

According to one embodiment, the multi-part core comprises a plurality of first core sections and/or a plurality of second core sections. The cavity of the cast component can thus be supported locally or in regions, for example, at a large number of points. Since the supporting cores are all already integrated in the multi-part core, the process as such does not become more complicated.

According to one embodiment, the support core is designed or formed to support or stiffen the respective area completely, in particular over its entire circumference. According to one embodiment, the support core as such can have recesses, holes, channels or the like in order to facilitate and/or enable coring.

• - Ausbilden des zumindest einen zweiten Kernabschnitts als poröse Struktur, insbesondere als Metallschaum.

According to a preferred embodiment, the method comprises the step:

• - Forming the at least one second core section as a porous structure, in particular as a metal foam.

According to a preferred embodiment, the support core is a metal foam core, preferably made of a metallic material, such as in particular a light metal such as aluminum. Suitable plastic foams or metallic foams based on the materials zinc and/or aluminum can also be used. The aforementioned porous structures, in particular the foam materials, are distinguished by their advantageously low specific weight. In addition, they are particularly suitable for use in crash-relevant areas in the automotive sector.

Various methods can be used to produce the porous structure, in particular the metal foam. According to one embodiment, the metal foam core is produced by foaming a melt with the aid of blowing agents or by means of gas injection. Before production by means of sintering is also preferred. The basis for this is suitable metal powder or metal granules.

• - Zumindest teilweise Verwenden von Recyclingmaterial zum Herstellen des zumindest einen zweiten Kernabschnitts.

The method preferably includes the step:

• - At least partially using recycled material to produce the at least one second core section.

• - Zerkleinern von metallischen Reststoffen zum Erzeugen von Ausgangswerkstoff;
• - Verwenden des Ausgangswerkstoffs zum Herstellen des zumindest einen zweiten Kernabschnitts, insbesondere des Metallschaums.

According to one embodiment, the method comprises the steps:

• - Crushing of metallic residues to produce starting material;
• - Using the starting material for producing the at least one second core section, in particular the metal foam.

The metallic residues can preferably be residues from production or else scrap that is or was comminuted in a suitable manner, for example mechanically. According to a preferred embodiment, the aforementioned residues are metallic residues, such as metal chips, production residues, which are comminuted in a more suitable manner, etc. The aforementioned comminution can also be understood to mean melting.

For reasons of sustainability, it is preferable to aim for the largest possible proportion of recycled material/starting material, preferably up to 100%.

• - Herstellen des zumindest einen ersten Kernabschnitts aus Formsand. Bevorzugt ist der zumindest eine Kernabschnitt ein Sandkern. Andere bevorzugte Werkstoffe sind Keramikwerkstoffe oder Salze.

According to one embodiment, the method comprises the step:

• - Manufacturing the at least one first core section from molding sand. The at least one core section is preferably a sand core. Other preferred materials are ceramics or salts.

In the present case, the casting method for casting the cast component is not limited to a specific method. According to a preferred embodiment, the casting of the cast component takes place in gravity die casting. Further preferred embodiments are low-pressure casting, vacuum casting, injector casting or die casting, in which the aforementioned salt cores in particular can be used.

• - Einlegen des zumindest einen zweiten Kernabschnitts in eine Vorrichtung zum Erzeugen von Sandkernen;
• - Anformen des zumindest einen ersten Kernabschnitts.

Zweckmäßigerweise wird der zumindest ein zweiter Kernabschnitt hergestellt und in eine Vorrichtung zum Erzeugen von, insbesondere verlorenen, Kernen, wie insbesondere Sandkernen, beispielsweise in eine Kernschießmaschine, eingelegt. Gemäß einer Ausführungsform wird der zumindest eine zweite Kernabschnitt vorab zumindest abschnittsweise mit einer Beschichtung versehen, welche die Haftung des Materials des ersten Kernabschnitts, wie beispielsweise des Formsands, am ersten Kernabschnitt erhöht.According to one embodiment, the method comprises the steps:

• - Inserting the at least one second core section into a device for producing sand cores;
• - Molding of the at least one first core section.

The at least one second core section is expediently produced and placed in a device for producing cores, in particular lost cores, such as in particular sand cores, for example in a core shooter. According to one embodiment, the at least one second core section is first provided with a coating, at least in sections, which increases the adhesion of the material of the first core section, such as the molding sand, to the first core section.

• - Formen des zumindest einen zweiten Kernabschnitts derart, dass zumindest ein erster Kernabschnitt formschlüssig angeordnet werden kann.

Zweckmäßigerweise umfasst der erste Kernabschnitt zumindest ein Formschlusselement, welches zur formschlüssigen Verbindung mit dem zweiten Kernabschnitt vorgesehen ist. Das Formschlusselement kann als eine Ausnehmung oder als ein Vorsprung ausgebildet sein. Hinsichtlich der Geometrie der Formschlusselemente gibt es insbesondere beim Anformen des zweiten Kernabschnitts große Freiheitsgrade, da das am zweiten Kernabschnitt angeformte oder ausgebildete Formschlusselement beim Anformen mit beispielsweise dem Formsand umspritzt wird. Der erste Kernabschnitt wird also im zweiten Kernabschnitt verankert bzw. umgekehrt. Dies erleichtert insbesondere das spätere Handling des mehrteiligen Kerns.According to one embodiment, the method comprises the step:

• - Shaping the at least one second core section in such a way that at least a first core section can be arranged in a form-fitting manner.

The first core section expediently comprises at least one form-fitting element, which is provided for form-fitting connection with the second core section. The form-fitting element can be designed as a recess or as a projection. With regard to the geometry of the form-fitting elements, there are large degrees of freedom, particularly when molding the second core section, since the form-fitting element molded or formed on the second core section is overmoulded with, for example, the molding sand during molding. The first core section is thus anchored in the second core section and vice versa. In particular, this facilitates later handling of the multi-part core.

• - Separates Herstellen des zumindest einen ersten Kernabschnitts und des zumindest einen zweiten Kernabschnitts;
• - Zusammensetzen der Kernabschnitte zu dem mehrteiligen Kern.

Zweckmäßigerweise sind die an den Kernabschnitten angeformten oder ausgebildeten Formschlusselemente derart geformt, dass eine geeignete formschlüssige Anordnung von zumindest zwei Kernabschnitten ermöglicht wird. Gemäß einer Ausführungsform sind die Formschlusselemente bzw. Kernabschnitte derart ausgebildet, dass ein Zusammenfügen oder Stecken der Kernabschnitte in einer Weise, wie es von Puzzlestücken her bekannt ist, möglich ist.According to one embodiment, the method comprises the steps:

• - separately producing the at least one first core section and the at least one second core section;
• - Assembling the core sections into the multi-part core.

Expediently, the form-locking elements molded or formed on the core sections are shaped in such a way that a suitable form-locking arrangement of at least two core sections is made possible. According to one embodiment, the positive-locking elements or core sections are designed in such a way that the core sections can be joined or plugged in a manner known from jigsaw puzzle pieces.

• - Zumindest bereichsweise stoffschlüssiges Verbinden der Kernabschnitte.

Bevorzugte stoffschlüssige Verbindungsverfahren umfassen insbesondere Kleben. Zweckmäßigerweise werden die verschiedenen Kernabschnitte in geeigneter Weise zusammengeklebt bzw. es wird zumindest teilweise Klebstoff verwendet, um die Formschlusselemente in ihrer Haltefunktion zu unterstützen.According to one embodiment, the method comprises the step:

• - At least in some areas materially bonded connection of the core sections.

Preferred material connection methods include, in particular, gluing. The various core sections are expediently glued together in a suitable manner or at least some adhesive is used to support the form-fitting elements in their holding function.

The invention also relates to a cast component which was produced using the method according to the invention.

According to one embodiment, the cast component is a chassis or structural component of a motor vehicle, such as a passenger car, a motorcycle or a commercial vehicle. The cast component is preferably a light metal cast component, particularly preferably an aluminum die-cast component. A possible chassis component is, for example, a rear axle carrier, which is reinforced at least in some areas, as a result of which, among other things, the crash behavior, in particular the crash rigidity, can be increased locally.

The invention also relates to a core package, comprising a plurality of core sections arranged one on top of the other, with at least a first core section being designed as a lost core, and with at least a second core section being designed as a permanent core, which is designed to act as a supporting core in a cast component .

At this point it should be mentioned that the advantages mentioned in connection with the method apply analogously and correspondingly to the core package, and vice versa.

According to one embodiment, the at least one first core section and the at least one second core section are arranged on one another via a holding structure, wherein the holding structure is designed to position, in particular to fix, the at least two core sections to one another. According to one embodiment, the holding structure is implemented by a separate element or by a plurality of separate elements, such as pins, clamps or the like, which are designed and shaped to hold or fix at least two core sections to one another.

According to an alternative embodiment, the support structure is integrated into the core sections. For this purpose, according to one embodiment, the core sections have suitably designed positive-locking elements, which are designed to engage in one another in such a way that at least two core sections are held together. Depending on the production of the multi-part cores, the interlocking elements can be shaped differently.

If the first core section is molded onto the second core section, i.e. the lost core onto the permanent core, undercuts can be used in the form-fitting elements, for example, whereby two core sections can be positioned or fixed to one another in all spatial directions. Alternatively, if the various core sections are manufactured separately and only attached to one another afterwards, so to speak, there are restrictions with regard to the geometry of the form-fitting elements. These are expediently designed in such a way that there is a degree of freedom in at least one spatial direction in order to enable the core sections to be arranged on one another at all.

According to one embodiment, the multi-part core comprises a multiplicity of first core sections, for example two, three, four or more, and expediently a multiplicity of second core sections, for example two, three, four or more.

Further advantages and features result from the following description of an embodiment of a multi-part core or a method for strengthening a cast component in certain areas with reference to the attached figures.

• 1: eine schematische Ansicht einer Ausführungsform eines mehrteiligen Kerns;
• 2: den aus der 1 bekannten Kern, eingelegt in eine Gießform;
• 3: eine schematische Ansicht des gemäß der 2 hergestellten Gussbauteils.

Show it:

• 1 1: a schematic view of an embodiment of a multi-part core;
• 2 : the one from the 1 known core, placed in a mold;
• 3 : a schematic view of according to FIG 2 manufactured cast component.

1 shows a schematic view of a multi-part core, also known as a hybrid core, see reference number 1. This comprises a plurality of core sections, in particular two first core sections 10 and a second core section 20 arranged between them. for example sand cores. The second core section 20 is a permanent core, according to a preferred embodiment, for example made of a metal foam. Accordingly, the second core section 20 can also be referred to as a metal foam core. A core made of a porous material, which is primarily light, is particularly preferred. The core sections 10 and 20 are connected to one another via holding structures 30 fixed. According to the present embodiment, the holding structures 30 comprise dovetail-shaped interlocking elements 32, which are designed as projections in the first core sections 10, and as congruently designed recesses in the second core section 20. Core sections 10 and 20, as outlined here, can be shifted to one another perpendicularly to the plane of the drawing, but are securely fixed to one another in the plane of the drawing. A like in the 1 The sketched second core section 20 can also be inserted into a core shooter, for example, in order to mold the first core sections 10 on. This enables further degrees of freedom with regard to the geometry of the holding structure 30 and the form-fitting elements 32.

2 shows a schematic view of a mold 50, comprising an upper and a lower mold half, wherein in the cavity formed by the mold halves of the 1 known (hybrid) core is inserted.

3 shows the finished cast component 40. The first core sections 10, cf 1 , are already removed. Only the second core section 20 remains, which remains as a support core in the cast component 40 and locally stiffens or reinforces it from the inside.

Reference List

1

(Hybrid) core, core package

10

first core section

20

second core section, metal foam

30

holding structure

32

interlocking element

40

cast component

50

mold

QUOTES INCLUDED IN DESCRIPTION

This list of documents cited by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent Literature Cited

• WO 9964287 [0002]
• DE 19650613 A1 [0002]

Claims (14)

Method for strengthening a cast component (40) in certain areas, comprising the steps: - Creating a multi-part core (1) for forming a cavity in a cast component (40), wherein at least a first core section (10) is designed as a lost core and at least a second core section (20) is designed as a supporting core, which is designed and positioned is to reinforce the cast component (40) in some areas; - arranging the multi-part core (1) in a mold (50); - casting of the cast component (40); - removing the at least one first core section (10). procedure after claim 1 , comprising the step of: - Forming the at least one second core section (20) as a porous structure, in particular as a metal foam. procedure after claim 1 or 2 , comprising the step of: - at least partially using recycled material to produce the at least one second core section (20). Method according to one of the preceding claims, comprising the steps of: - Crushing of metallic residues to produce starting material; - Using the starting material for producing the at least one second core section (20), in particular the metal foam. Method according to one of the preceding claims, comprising the step: - Manufacturing the at least one first core section (10) from molding sand. Method according to one of the preceding claims, comprising the steps of: - Inserting the at least one second core section (20) in a device for producing cores, in particular lost cores; - Molding of the at least one first core section (10). Method according to one of the preceding claims, comprising the step: - Forming the at least one second core section (20) in such a way that at least one first core section (10) can be arranged in a form-fitting manner. Method according to one of the preceding claims, comprising the steps of: - Separately producing the at least one first core section (10) and the at least one second core section (20); - Assembling the core sections (10, 20) to form the multi-part core (1). procedure after claim 8 , comprising the step of: - at least partially cohesively connecting the core sections (10, 20). Cast component (40) produced by a method according to any one of the preceding claims. Cast component (40) after claim 10 , wherein the cast component (40) is a chassis or structural component of a motor vehicle. Core package (1), comprising a multiplicity of core sections (10, 20) arranged one on top of the other, with at least a first core section (10) being designed as a lost core, and with at least a second core section (20) being designed as a permanent core, which is designed to act as a support core in a cast component (40). core package after claim 12 , wherein the at least one first core section (10) and the at least one second core section (20) are arranged on one another via a holding structure (30), the holding structure (30) being designed to position the at least two core sections (10, 20) in relation to one another , in particular to fix. core package after Claim 13 wherein the holding structure (30) is formed by form-fitting elements (32) which are formed on the core sections (10) and which interlock in such a way that at least two core sections (10, 20) are held together.

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