DE549995C - Process for making molds and cores - Google Patents

Description

Method of making molds and cores Mass production of sand cores o. The like. Can be done in such a way that the sand or core mass is blown directly into a molded or core sleeve by means of compressed air. For example, the core box is placed on a printing table that can be raised and lowered, who presses the core box under the sand container bath when he rises, from the opening of which the sand is blown into the can.

Using this method, you can use many sand or mass mixtures Manufacture cores that are hard right from the start for the purposes in question are enough. With some sand mixtures and sometimes when the kernels are green placed in the mold, i.e. not to be dried beforehand, is larger Hardness or strength desired.

According to the invention should for this purpose from a sand container Cores or the like blown into the molding or core boxes by means of repeated pressing of the pressure table carrying the mold or core boxes is compressed against the sand container will. The invention uses pressure pieces or the like placed on or under them for Compression of the sand contained in the core box. The new process can depending on the degree of subsequent compression, the blown kernels one to a large extent Boundaries give different and great hardness.

The particular desired hardness of the cores is ensured that the depth of penetration of the pressure pieces in a suitable manner, so z. B. by a protruding edge, intermediate layers, etc., is limited. Also leave for shaping use the pressure pieces.

In the manufacture of molds and cores by transferring mechanically With pre-compacted sand in mold or core boxes, you have a subsequent one even earlier Compaction of the mass carried out by mechanical means. However, it was done by means of Pounding devices in cumbersome and imperfect ZÄTeise. Evenly dense Shapes could not be obtained and the known devices were proportionate involved. In contrast, the subject of the invention is characterized by an extraordinary great simplicity, and it delivers, since the redensification of the form and the Dimensioning of the thrust pads is determined, consistent results.

To explain the new method, exemplary embodiments are shown in FIG Tools for exercising the same shown in the drawing.

Fig. X illustrates a no-blow molding machine that is being considered here coming art.

Fig. Shows the production and fig. 3 the redensification of a simple cylindrical core.

Abb..l and 5 represent an application of the invention in a remote Core or the like. Fig. 6 and 7 show the redensification by means of strongly conical spines.

The Kemblasmaschine according to Fig. I carries a sand container on a stand a b with lid c. To fill or refill container b, either he himself or his cover c can be pivoted around the column a. At e 'the blow out occurs of the sand from the lower mouth 3 serving compressed air into the container b.

A core box i is on a printing table 2, the piston end in a compressed air cylinder e. In Fig. I this is blowing. the core already finished, the sleeve i is filled with the core mass i '. Between the sleeve i and the muzzle 3 of the sand container b is a pressure piece ¢ for exercising the invention Working method.

In Dep. I, the inside diameter of the core sleeve i is greater than the outer diameter of the mouthpiece 3. For blowing the core you have to go to the place of the Pressure piece q. to introduce a simple disc with a central opening for the passage of sand. The printing table is then raised so far that the core sleeve i with the one lying on it Washer under the mouthpiece, 3 is pressed. After blowing the core, the Printing table 2 lowered, the perforated disc removed and the pressure piece q. .hung up. Now it is only necessary to close the printing table 2 again by means of the piston d lift and press under the sand container. The pressure piece penetrates q. so deep into the core sleeve, as is the protruding edge or flange of the pressure piece q., which limits its depth of penetration.

The process just described is shown schematically in Figures 2 and 3, namely on a core sleeve i and with a mouthpiece 3, in which the interposition of a disk for blowing is not necessary. In Fig.3, the penetration depth is denoted by a. If the core cross-section is _ A, then there is a volume reduction = a # A, which is determined by the dimensioning of the pressure piece q. can be precisely determined beforehand.

According to Dep. Q. stands .auf the printing table 2 is a core sleeve 5 for a profiled core or the like. Here the pressure piece 6 is below the core sleeve 5. At the same time, the extension 6 'of the pressure piece has a recess 6 ″ which is used for shaping. Intermediate layers 7 are located between the sleeve 5 and the edge or flange of the pressure piece 6 when the sand is blown in removed, and the printing table 2 is again pressed against the sand container 3. in this case, the specified in Fig.5 compression # B. obtained by a volume reduction = b in a similar way, one can perform the densification by means of a two-piece (cross split) core box.

In Ab-b. 6, the core sleeve 8 contains a core of relatively large diameter. On the core is a pressure piece g with, for example, three strong and strongly tapered thorns 9 '. By the table carrying the core box 2 is pressed again against the sand container 3, the spikes g 'penetrate the mass and create a compression through their pressure downwards and to the side, the size of which is determined by the volume of the mandrels.

Fig. 7 shows a sleeve i o with a smaller core. The pressure piece i i has only a single mandrel i i 'and is turned on by means of a small cam whose place a dovetail guide or the like can occur, held in its position.

For example, if cores in the form of T-pieces are to be produced, so you can use the compressed air piston for this purpose, which is done in a known manner serves to secure the core sleeve i on the printing table 2 against lateral displacement. Also on this side to be directed against the branch of the T-piece Piston can be attached according to the invention, a pressure piece, which for the purpose of Post compression is pressed into the junction.

Claims (2)

PATENT CLAIMS: i. Process for making molds and cores by blowing the sand into mold or core boxes and then compacting it the mass by mechanical pressure action, characterized in that the one Sand containers blown mass into the mold or core boxes by subsequent pressing of the table carrying the mold or core boxes compacted against the sand container will. 2. The method according to claim i, characterized in that for subsequent Compaction of the molding compound blown into the molding or core boxes on or below suitably designed pressure pieces are placed on the molding or core boxes.