EP0150279B1 - Non-skid chaplets - Google Patents

Description

The invention relates to a core support made of material that can be welded into the casting compound, consisting of a lower and an upper support plate, which are connected to one another by at least one web, which surrounds at least half a height of at least one welded-in body of less thickness than the support plates. Such a core support is known from DE-AS 2258831.

In order to be able to set such core supports in a non-slip manner, in particular on inclined core surfaces, it is known to use perforated support plates and to drive nails into the molding sand of the core through their holes, but this can easily be damaged, quite apart from the disadvantageous additional effort Needlework for nailing and the impossibility of working with typesetting machines.

Instead, it is also known from DE-OS 2 923 702 to glue the core supports on the end face of the core. This has the disadvantage described in the third description paragraph of DE-OS 2923702 that such core supports cannot easily be brought to the core with automatic setting machines because they would previously stick to one another with their glue-coated end faces in the magazine slot of the automatic setting machine. The adhesive application is an additional step.

Finally, it is known to form concentric ribs which are semicircular in cross section in order to increase the friction with respect to the core surface of the end faces of the support plates. However, this is only insufficient because the core support is a small, light object and, with the half-round ribbed support plates, can hardly penetrate the hard molding sand of the core soaked with furan resin. In addition, by forming the semicircular concentric ribs on the support plates, the manufacturing effort for the core support, which is a pronounced mass article, is considerably increased.

Another disadvantage of these allegedly non-slip core supports is that the outermost concentric semicircular rib lies tightly against the molding sand of the core and prevents the penetration of the liquid metal into the cavities between the ribbed support plate and the molding sand during the subsequent casting. The result is unwanted, at least ugly, depressions in the surface of the finished casting, which, however, also impair its strength and dimensional accuracy.

In order to ensure the non-slip fit of core supports of the type mentioned at the outset without these disadvantages, it is proposed according to the invention that all the webs required for supporting a core surface are connected to one another via a common band-shaped weld-in body which fixes the web spacings predetermined by the core surface and the course of the core surface follows. As a result, the holding forces of the interconnected support plates add up. Compared to the mostly uneven core surface, the connection of several webs and support plates by means of a correspondingly pre-bent band-shaped welding body also achieves a form-fitting fixation and a positive centering which facilitates the correct placement of the core supports.

From DE-A 1809883 it is known to connect a plurality of webs via a common strip-shaped support plate made of sheet metal which is adapted to the shaped profile and which can also be perforated. Because of the support function, this sheet has to be correspondingly thick, and because it lies against the mold, it only comes into contact with the incoming casting on one side - despite the perforations - and is cooled by the mold on the other side; the result is poor welding.

Further features form the subjects of the subclaims. The invention is illustrated by the illustrated exemplary embodiments.

• Fig. 1 eine teilweise Seitenansicht,
• Fig. 2 eine Draufsicht dazu,
• Fig. 3 eine Seitenansicht auf ein abgewandeltes Ausführungsbeispiel, für eine gestufte Kernfläche,
• Fig. 3a eine Variante zu Fig. 3
• Fig. 4 eine Draufsicht zu Fig. 3,
• Fig. 5 eine weitere Variante, für eine gerippte Kernfläche, in perspektivischer Schrägansicht und
• Fig. 6 einen Vertikalschnitt dazu.

Show it

• 1 is a partial side view,
• 2 is a plan view of this,
• 3 shows a side view of a modified exemplary embodiment, for a stepped core surface,
• 3a shows a variant of Fig. 3rd
• 4 is a plan view of FIG. 3,
• Fig. 5 shows another variant, for a ribbed core surface, in perspective oblique view and
• Fig. 6 shows a vertical section.

In the simplest case, for an elongated flat core surface, the webs 1 and support plates 2 are connected to one another by a linear weld-in body 3, which may have openings 5 in the area between the support plates 2, which facilitate intimate welding with the casting material, especially if the openings 5 have jagged edges 4.

Some of the support plates 2 can be provided with nail holes 6 known per se in order to give the core supports an additional hold on strongly inclined core surfaces. However, only a few support plates need to be nailed to fix many core supports, the other core supports being set and fixed at the same time.

The exemplary embodiment according to FIGS. 3 and 4 is intended for a stepped, wide core area. The band-shaped welding body 3 a has bends 7, which are stiffened by beads 8, in accordance with the imaginary core surface gradation. In addition, the band-shaped welding body 3a is branched in a network, as can be seen in FIG. 4, and is provided with round openings 5a between adjacent support plates 2. Furthermore, there are additional, closely spaced webs connected by common support plates 2b in a manner known per se.

FIG. 5 shows a perspective top view of a core 8a with a ribbed surface and a correspondingly ribbed and band-shaped branch body 3b.

Fig. 6 shows a vertical section thereof. It can be seen that the support plates 2 are additionally positively secured against excessive displacement.

The welded-in body can be a wire mesh, which has the advantage of a particularly quick, intimate connection with the casting and previously enables the optimal mutual alignment of the adjacent core support elements.

In addition to these measures, the core support elements can be connected by at least one wire made of material that can be welded into the casting compound and which is preferably welded on and runs through the inner surfaces of adjacent support plates. Despite its location near the surface of the later casting, this wire welds reliably and completely into the casting due to its low heat capacity, and it also facilitates the optimal mutual alignment of adjacent core support elements according to a specific production program, even the adaptation to different cores.

Claims (9)

1. Chaplets from a material fusible with the poured metal, consisting of a bottom and a top plate that are connected to each other by at least one shank (1) at about half its height surrounded by at least one weld-in body (3, 3a, 3b) of less thickness than the support plates, characterized in that all shanks (1) needed to support a core surface are connected with each other by a common weld-in strip (3 or 3a or 3b, respectively), fixing the shank distances determined by the core surface, and conforming to the core surface shape.

2. Chaplet according to claim 1, characterized in that the shank (3a) forms at least one closed loop.

3. Chaplet according to claims 1 or 2, characterized in that the shank (3b) forms at least one branch.

4. Chaplet according to one or more of the above claims, characterized in that the shank (3a) exhibits bends and/or kinks between adjacent support plates (2 or 2a, respectively) that are preferably reinforced by beads (8).

5. Chaplet according to one or more of the preceding claims, characterized in that the weld-in strip (3 or 3a or 3b, respectively) exhibits recesses (5) between adjacent support plates.

6. Chaplet according to claim 5, characterized in that the recesses exhibit serrated edges (4).

7. Chaplet according to any one or more of the preceding claims, characterized in that some of the support plates (2a) exhibit known per se nail holes (6).

8. Chaplet according to any one or more of the preceding claims, characterized in that the strip- shaped weld-in body is a wire mesh.

9. Chaplet according to any one or more of the preceding claims, characterized in that the bottom surfaces of adjacent support plates (2b), in addition, are connected to each other by at least one continuous wire (9) fastened thereto - preferably as by welding - of a material fusible with the molten metal.

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