EP3110581B1 - Method for producing a casting core for manufacturing cylinder heads - Google Patents

Description

The present invention relates to a method for the production of a casting core for the production of cylinder heads, a casting core for the production of cylinder heads and a casting method for the production of at least two cylinder heads.

It is known that cylinder heads are produced by casting. For this purpose, a corresponding outer contour in slides, or in particular in a base plate, is usually formed in a tool mold. In order to be able to form corresponding inner contours, such as water channels, air channels and the combustion chambers in the cylinder head, so-called lost cores are used during casting in the tool mold. These lost cores are usually formed of sand and serve to keep the corresponding cavities free from penetration of the molten melt material. In known molds, the alignment of the cylinder heads is formed from top to bottom, so that the melt from above penetrates with high melting temperature directly on the base plate and distributed there, see for example the CN 101 817 060 A , This leads to high thermal stress on the base plate and the contours formed there for the formation of the corresponding counter contour of the cylinder head.

The EP 0 968 776 A1 describes a method for producing molds in which the mold and / or a core is produced from a thermosetting molding material without prior production of model parts by layer-wise selective solidification of layers of molding material under the action of electromagnetic radiation.

In addition to the thermal load and the corresponding necessary maintenance for the base plate, known casting methods have further disadvantages. In particular, this is the restriction in the freedom of design of Cylinder heads. So must be guaranteed in this orientation from top to bottom demoldability. This also applies and especially with lost cores. In addition, a corresponding manufacturability must be ensured for the insertion and production of these lost cores as casting cores. These two limitations reduce the freedom of design and thus the ability to create even complex cylinder head shapes. Last but not least, the production of cast cores is itself a complicated and expensive process. Also, the alignment and positioning of the same in the tool shape leads to high expenditure of time.

It is an object of the present invention to at least partially overcome the disadvantages described above. In particular, it is the object of the present invention to improve the production of the cast cores and / or the cylinder heads in a cost-effective and simple manner.

The above object is achieved by a method having the features of claim 1, a casting core with the features of claim 7 and a casting method with the features of claim 9. Further features and details of the invention will become apparent from the dependent claims, the description and the drawings , In this case, features and details that are described in connection with the method according to the invention apply, of course, also in connection with the casting core according to the invention and the casting method according to the invention and in each case vice versa, so that with respect to the disclosure of the individual aspects of the invention always reciprocal reference is or can be ,

• Erzeugen wenigstens eines Kernbauteils mit einem aufbauenden Verfahren mit einer Kontur für die Ausbildung von Innenkonturen eines ersten Zylinderkopfes,
• Erzeugen wenigstens eines weiteren Kernbauteils mit einem aufbauenden Verfahren mit einer Kontur für die Ausbildung von Innenkonturen eines weiteren Zylinderkopfes,
• Erzeugen wenigstens eines Anguss-Kernbauteils für die Zufuhr der Schmelze während des Gießverfahrens,
• Verbinden der beiden Kernbauteile mit dem Anguss-Kernbauteil in einer entgegengesetzten Ausrichtung.

An inventive method is used to produce a casting core for the production of cylinder heads. For this purpose, the method comprises the following steps:

• Generating at least one core component with an uplifting method with a contour for the formation of inner contours of a first cylinder head,
• Generating at least one further core component with an uplifting method with a contour for the formation of inner contours of a further cylinder head,
• Producing at least one sprue core component for the supply of the melt during the casting process,
• Connecting the two core members to the sprue core member in an opposite orientation.

An inventive method now builds on a casting core of individual core components. In particular, at least two core components are produced, which are each designed for the formation of the inner contours of a cylinder head. It is thus possible according to the invention to produce two cylinder heads simultaneously in a tool mold with a cast core produced according to the invention. It is already evident here that the production capacity with a mold is doubled or essentially doubled in the same time span.

It can also be seen that the same doubling of the production of the cylinder heads can also be associated with a single casting core and accordingly with the manufacturing effort and the production time of a single casting core.

For the purposes of the present invention, a building-up method is in particular a so-called rapid-prototyping method or the so-called three-dimensional printing. In this case, the respectively desired geometrically three-dimensional shape of the corresponding core component is constructed in a layered structure. In this case, various types of connection between the individual layers can be made available according to the invention. It is preferred if this connection between the individual layers is sufficiently strong to provide the necessary resistance when introducing the melt. At the same time it is necessary that for demolding, a slight dissolution of the material of the casting core can be ensured in order finally to use the cylinder head made accordingly.

Of course, the core components and / or the sprue core component can also be generated at least partially together in a single step. So is It is conceivable that one of the core components will be equipped directly with the functionalities of the sprue core component. Of course, it is also possible that both core components partially have the sprue core component, and accordingly in the assembly an inventive casting core is produced.

By connecting the two core members to the gate core member in an opposite orientation, it will be understood that subsequently within the tool die, the manufacture of the two cylinder heads also occurs in opposite, opposite orientation. While in known molds usually the cylinder heads are aligned with their combustion chambers down in the direction of the base plate, now by a casting core according to the invention rotated by 90 ° alignment can be possible. This results in the two cylinder heads with their combustion chambers being aligned with the direction of the lateral slides in the tool mold. In this case, according to the invention, the orientation of the combustion chambers of the two cylinder heads is oriented opposite to one another. In a side view, this means that one of the two cylinder heads is oriented to the left and the other of the two cylinder heads is oriented to the right. As can be clearly seen here, the complex contour illustrations now no longer need to be provided in the base plate, but rather in the lateral slides of the mold. This leads to a significant reduction of the thermal influence of the base plate during the casting process.

In addition to a longer service life for the base plate so that the cost of time and costs for the maintenance of the base plate and their replacement can be significantly reduced. In addition to the procedural advantages in terms of protection of the base plate and higher capacity of the system, a higher design freedom for the geometric design of the cylinder heads can be ensured by an inventive manufacture of the casting core. Thus, by the lateral alignment of the two core components, a corresponding free design of the inner contours and thus also the closed or partially closed volumes within the cylinder head with higher design freedom possible. Last but not least, a great advantage of a casting core according to the invention is the reduction of the cost of materials for the core. The fact that the sprue core is now used for two cylinder heads, a second sprue core component in Compared to the known solutions in the production of a single cylinder head avoided. In other words, the sprue core component used according to the invention is used in parallel for feeding the tool mold for two cylinder heads. This leads to a reduced cost of materials on the part of the casting core. Since at the same time less sprue material is necessary, costs, time and, above all, material expenditure can also be saved here.

It may be advantageous if, in a method according to the invention, the sprue core component is likewise produced by a constructive method. Under the constructive method is here also a so-called three-dimensional printing or a rapid prototyping process to understand. In particular, the same method and / or the same material composition as for at least one of the two other core components is used for the sprue core component. It is preferred, of course, if the same material and the same constructive method is used for all core components and for the sprue core component. As a result, a significant reduction in the complexity of the entire process and thus also its costs can be achieved.

A method according to the invention can be further developed such that the core components have a connecting section, in particular a form-fitting section, and the sprue core component have counter-connecting sections, in particular counter-form-fitting sections. In this way, the core components can be attached via the connecting portions to the counter-connecting portions of the sprue core member. It is preferred if these are form-fitting and force-transmitting solutions. Thus, a simple nesting of the core components and the sprue core component is possible. For example, the connection interface of the core component may have a corresponding pin-shaped projection. The associated counter-connecting portion of the sprue core component has a corresponding recess, so that the assembly takes place by simply inserting the core member into the associated counter-connecting portion of the sprue core member. This is in particular designed such that the connecting sections and the counter-connecting sections are geometrically aligned with each other. By this is to be understood that a clear orientation of the respective core component only in a single place and is possible on a single orientation at the counter-connecting portion. Thus, the risk of incorrect composition and thus a wrong geometry for the cylinder heads to be produced is avoided with high probability. Last but not least, the connecting sections and the counter-connecting section can also represent a centering aid or a positioning aid in addition to the pure positive and / or non-positive connection. This also leads to achieving the tolerances to be achieved with a higher probability and above all with higher safety. The entire assembly and positioning is thus not easier, but also possible faster.

A further advantage can be achieved if, in a method according to the invention, the core components are connected to the sprue core component with an opposite orientation of approximately 180 °. This orientation is to be understood as meaning, in particular, an orientation angle which is formed between the two main orientations of the two cylinder heads or of the two associated core components. For example, the extrusion axis of a corresponding combustion chamber of the cylinder head may represent such an orientation. It is preferred if the angle between the axis of the combustion chamber of one of the two cylinder heads and the axis of the combustion chamber of the further cylinder head is approximately 180 °. This leads to the most efficient utilization of the necessary Kavitätsraumes within a mold. Thus, the associated tool shape can be made smaller, more compact and less material.

A further advantage can be achieved if, in a method according to the invention, the sprue core component has at least one feeder section and in particular at least one air outlet section. By this is meant that over the feeder section a corresponding melt introduction can take place. Here, too, it is readily apparent that only one single feeder section or a single plurality of feeder sections is necessary for two cylinder heads. Since the melt also solidifies in the feeder section, this inevitably leads to rejects during the casting process, which can be halved accordingly by training and dual use here for two cylinder heads, compared to known solutions. The same applies accordingly to the air outlet section, which serves, during the introduction of the melt, in the Omit cavity located air. Again, a corresponding material savings can be achieved.

It is also advantageous if an inorganic material is used in a method according to the invention for the production of at least one of the core components. This leads in particular to advantages in the production of the casting core, as well as later during removal or insertion of the casting core. This refers in particular to potentially occurring pollutants or odors, which may be unpleasant or even harmful. Accordingly, the use of inorganic material is already preferable in the production of the casting core.

Likewise subject of the present invention is a casting core for the production of cylinder heads, comprising at least two core components, produced with an ancillary method with a contour for the formation of inner contours of each cylinder head. Furthermore, this casting core has a sprue core component for the supply of the melt during the casting process. The core components are connected to the sprue core component in the opposite direction. Preferably, a casting core is produced by means of a method according to the invention. Thus, a casting core according to the invention brings about the same advantages as have been explained in detail with reference to a method according to the invention. In particular, reference should be made to the possible types of connection between the core components and the sprue core component, as have been explained in detail with reference to the connecting portions and the mating connecting portions.

• Zur Verfügung stellen eines Gusskerns mit den Merkmalen der vorliegenden Erfindung,
• Einsetzen des Gusskerns in eine Werkzeugform mit einer seitlichen Ausrichtung der beiden Kernbauteile für die Ausbildung von wenigstens zwei Zylinderköpfen,
• Schließen der Werkzeugform,
• Einbringen der Schmelze durch Speiserkanäle, ausgebildet durch das Anguss-Kernbauteil des Gusskerns.

Another object of the present invention is a casting method for the manufacture of at least two cylinder heads, comprising the following steps:

• Providing a casting core having the features of the present invention,
• Inserting the casting core into a tool mold with a lateral alignment of the two core components for the formation of at least two cylinder heads,
• Closing the mold,
• Introduction of the melt through feeder channels, formed by the sprue core component of the casting core.

A method according to the invention uses in particular a casting core which has been produced by a method according to the invention. Thus, a casting method according to the invention brings about the same advantages as have been explained in detail with reference to a method according to the invention and with reference to a casting core according to the invention.

Fig. 1

eine erste Ausführungsform eines erfindungsgemäßen Gusskerns und zugehöriger Zylinderköpfe,

Fig. 2

die Ausführungsform der Fig. 1 in anderer Perspektive,

Fig. 3

der aufbauende Verfahrensschritt für die Herstellung eines erfindungsgemäßen Gusskerns,

Fig. 4

der Schritt des Verbindens der Kernbauteile mit einem Anguss-Kernbauteil,

Fig. 5

eine Ausführungsform eines erfindungsgemäßen Gusskerns, und

Fig. 6

eine Ausführungsform eines erfindungsgemäßen Gusskerns, eingesetzt in eine entsprechende Werkzeugform.

Further advantages, features and details of the invention will become apparent from the following description in which, with reference to the drawings, embodiments of the invention are described in detail. The features mentioned in the claims and in the description may each be essential to the invention individually or in any desired combination. They show schematically:

Fig. 1

a first embodiment of a casting core according to the invention and associated cylinder heads,

Fig. 2

the embodiment of the Fig. 1 in a different perspective,

Fig. 3

the constructive process step for the production of a casting core according to the invention,

Fig. 4

the step of connecting the core components to a sprue core component,

Fig. 5

an embodiment of a casting core according to the invention, and

Fig. 6

an embodiment of a casting core according to the invention, used in a corresponding tool shape.

The Fig. 1 and 2 show schematically how an inventive casting core 10 acts. Here, it is easy to see how a further core component 20 and 30 is arranged on the left and right via a central sprue core component 40. The two lateral core components 20 and 30 have corresponding contours, which serve for the formation of the respective cylinder head 100 and the associated inner contour 110. Here it is also easy to see how these functions are provided centrally and thus in double use for both cylinder heads 100 via the central sprue core component and the corresponding feeder sections 46 and the air outlet section 48.

Fig. 3 schematically shows a first step of a method according to the invention. Here, in an anabolic manner, for example by means of a rapid prototyping method or a three-dimensional printing method, preferably inorganic material is built up in layers. In this embodiment, two core members 20 and 30 are constructed. Here it is already easy to see that both core components 20 and 30 are formed symmetrically, since they are used for the execution of identical or identical cylinder heads 100. Also, the formation of pin-shaped extensions for the connecting portions 22 and 32 can be seen well in this illustration. The two connecting portions 22 and 32 are formed here as a form-fitting portions 24 and 34.

Fig. 4 shows the assembly of the manufactured core members 20 and 30 and a sprue core member 40. The sprue core member 40 may also be formed here, for example, in a layered construction. Here is well illustrated by the arrows, as the two core members 20 and 30 are inserted into corresponding counter-connecting portions 42 by a simple lateral insertion. Thus, the connection with the connection sections 22 and 32 can be ensured via the correlation of the counter-connection sections 42 or the embodiment as counter-form-fitting sections 44. As a result, after the assembly, the finished casting core 10 looks like the embodiment according to FIG Fig. 5 ,

If the casting core 10 of the embodiment of the Fig. 5 now used in a mold 200, this may for example be a training according to the Fig. 6 be. Here It will be appreciated that a base plate 210 and side slides 220 provide a corresponding cavity in which clearances are left over the casting core 10 for the formation of free volumes in the cylinder heads 100. Thus, according to the invention, the casting process can now be carried out, and two cylinder heads 100 are formed at the same time in lateral offset 180 ° to the left and right of the sprue core component 40.

LIST OF REFERENCE NUMBERS

10

casting core

20

core component

22

connecting portion

24

Form-fitting section

30

core component

32

connecting portion

34

Form-fitting section

40

Sprue core component

42

Against connecting portion

44

Mating interlocking portion

46

feeder section

48

air outlet

100

cylinder head

110

inner contour

200

mold

210

baseplate

220

pusher

Claims (10)

1. A method for producing a casting core (10) for manufacturing cylinder heads (100), having the following steps:

   - producing at least one core component (20) with a building-up method with a contour for forming internal contours (110) of a first cylinder head (100),

   - producing at least one further core component (30) with a building-up method with a contour for forming internal contours (110) of a further cylinder head (100),

   - producing at least one sprue core component (40) for supplying the melt during the casting process,

   - connecting the two core components (20, 30) to the sprue core component (40) in an opposite orientation, wherein an orientation of combustion chambers of the two cylinder heads (100) is oriented in opposite directions to each other for orienting the combustion chambers of the two cylinder heads in the direction of lateral sliders of a mould (200).
2. A method according to Claim 1, characterised in that the sprue core component (40) is likewise produced by a building-up method.
3. A method according to one of the preceding claims, characterised in that the core components (20, 30) have a connecting portion (22, 32), especially a positive-fit portion (24, 34), and the sprue core component (40) has mating connecting portions (42), especially mating positive-fit portions (44), so that the core components (20, 30) are fastened to the mating connecting portions (42) of the sprue core component (40) by way of the connecting portions (22, 34).
4. A method according to one of the preceding claims, characterised in that the core components (20, 30) are connected to the sprue core component (40) with an opposite orientation of approx. 180°.
5. A method according to one of the preceding claims, characterised in that the sprue core component (40) has at least one feeder portion (46) and especially at least one air outlet portion (48).
6. A method according to one of the preceding claims, characterised in that an inorganic material is used for producing at least one of the core components (20, 30).
7. A casting core (10) for manufacturing cylinder heads (100), having at least two core components (20, 30) produced with a building-up method with a contour for forming internal contours (110) of in each case one cylinder head (100) and a sprue core component (40) for supplying the melt during the casting process, wherein the core components (20, 30) are connected to the sprue core component (40) in an opposite orientation, wherein an orientation of combustion chambers of the two cylinder heads (100) is oriented in opposite directions to each other for orienting the combustion chambers of the two cylinder heads in the direction of lateral sliders of a mould (200).
8. A casting core (10) according to Claim 7, characterised in that it is produced by means of a method having the features of one of Claims 1 to 6.
9. A casting method for manufacturing at least two cylinder heads (100), having the following steps:

   - making available a casting core (10) having the features of one of Claims 7 or 8,

   - inserting the casting core (10) into a mould (200) with a lateral orientation of the two core components (20, 30) for forming at least two cylinder heads (100),

   - closing the mould (200),

   - introducing the melt through feeder channels, formed through the sprue core component (40) of the casting core (10).
10. A casting method according to Claim 9, characterised in that the casting core (10) is produced by a method having the features of one of Claims 1 to 6.

Images