EP0704261B1 - Mould with core print and casting piece with closure for core opening - Google Patents

Description

The invention relates to a casting mold with casting core support and a casting with core opening closure, which in Preamble of claim 1 explained type.

In the manufacture of castings with internal cavities Casting cores used, the so-called casting core supports within the casting mold formed by a mold or sand be supported. There is an opportunity to the core itself a number of core supports molding from the core material, which naturally leads to that corresponding openings on the finished casting at these points remain open, which are subsequently called core plugs must be closed.

There are various ways of closing such openings. On the one hand, such openings can occur during processing of the cast part are also processed and e.g. by Machining an internal thread and screwing in a threaded plug be closed.

EP-OS 0 443 720 is a possibility for closing known from core openings. The here through the casting core support formed opening may not need to be machined as the pot-shaped core opening plug used through one in its conical inner opening pressed driver is expanded to the outside so that he has a corresponding outer profile for a provides a secure seal against the opening in the casting.

For castings made of iron material, it is also possible to use so-called to provide lost mold core supports like them are known from DE-PS 674 772, on its outer surface are provided with a corresponding profile, around which during the casting process with the casting material metallurgical forming compound to be increased. To the finished casting there is no opening here, the subsequent must be sealed.

For castings made of aluminum or other skin-forming foundry plugs has this use of lost mold core supports has so far not been successful because there is a difference between lost core support and material of the cast part forms an oxide skin, which is a safe metallurgical Connection not allowed. When the casting shrinks therefore there are micro-cracks at the parting surfaces, which later in the use of the casting for leaks being able to lead.

The object of the invention is to provide a casting mold with casting core support and a casting with core opening closure create a subsequent machining of core openings and the subsequent insertion of core opening plugs can be avoided and replaced by simpler measures.

According to the invention, this object is achieved by a Cast part mold with core support and a casting with core opening closure in the preamble of claim 1 explained type in the characterizing part of the claim 1 and claim 2 features shown.

The fact that in a casting mold for a casting made of aluminum as lost pouring core supports, pot-shaped core opening plugs with a conical inner shape to accommodate a Driver and an already used driver are used, can be caused by the formation of oxide skin and shrinkage of the Casting occurring micro cracks between the casting and the lost casting core support through subsequent driving of the driver can be reliably sealed.

Fig. 1

einen Teilschnitt durch eine Gußteilform für mit einer verlorenen Gießkernabstützung gemäß der Erfindung in seiner Anordnung in der Gießform und

Fig. 2

einen Teilschnitt durch ein Gußteil mit der erfindungsgemäßen verlorenen Gießkernabstützung nach dem Eintreiben des Treibers zur nachträglichen Abdichtung.

The invention is explained in more detail using an exemplary embodiment shown in the accompanying drawings. It shows:

Fig. 1

a partial section through a casting mold for with a lost core support according to the invention in its arrangement in the mold and

Fig. 2

a partial section through a casting with the lost core support according to the invention after driving in the driver for subsequent sealing.

In Fig. 1, a e.g. from a top 1 and a lower part 2 existing casting 3 with a casting cavity 4 formed from that to be cast Casting material, in this case filled with aluminum shall be. To create cavities within the finished casting form, there is still a casting core 5 within the casting mold 3 arranged in different places (of which only one is shown) by casting core supports 6 exactly in its predetermined position is held within the mold 3.

In the present embodiment, the lost one exists Casting core support 6 from a pot-shaped core opening plug 7 made of aluminum, which on its outer surface with the surface increasing corrugations 8 and on its inner surface with a conical recess 9 is formed. The conical Recess 9 receives a tapered driver 10. The order consisting of the core opening plug 7 with the only Driver 10 partially inserted therein is cast into the mold 3 inserted and forms the casting core support for the Casting core 5. Now the casting mold 3 with liquid aluminum filled, this aluminum fills the later casting forming cavity 4 in the mold 3 and searches a connection on the outer surfaces 8 of the core opening plug 7 bring about. However, such a connection is incomplete, because in the case of aluminum casting, there is a lost one Casting core support and the aluminum forms an oxide skin. After the casting has cooled and after demolding the casting shrinks in the usual way and since the connection between the material of the casting and the material of the Core opening plug 7 is not complete, arise this connection point micro cracks, e.g. if the through the casting core 5 formed cavity of the coolant jacket an internal combustion engine is an insufficient seal would result.

In the finished casting 11, which is shown in Fig. 2, is therefore the core opening plug 7 by the in a subsequent Pressing-in process now fully depressed driver 10 so spread that the micro cracks through the plastic Deformation of the core opening plug 7 are closed.

This way you can do without additional machining operations and only without the subsequent insertion of components simple press-in processes an absolute tightness of the used lost core supports can be achieved.

Claims (2)

1. A casting mould with core supporting means, in which a core (5) is arranged within a mould (3) to form a casting cavity (4) and the core (5) is held by means of at least one core support (6) which is profiled on its outer side and subsequently remains cast-in in the cast part,
   characterised in that

   the mould (3) for a cast part of aluminum or like materials has disposed therein a core support in the form of a pot-shaped core opening plug (7) which supports the core (5) and has a drift (10) already at least partly inserted in it.
2. A cast part from a mould according to claim 1,
   characterised in that

   a core opening plug (7) is provided on its outer surface with profiling (8) and on its inner surface with a conical recess (9) into which the conical drift (10) is preinserted, and is completely driven in after the cast part (11) has cooled down.

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