DE2723053A1 - Boxless sand moulds made on core-shooter - followed by transverse compression of sand during gassing via cold box processes - Google Patents

Abstract

Device for mfg. sand moulds and cores on core-shooting machines, where the device includes a carrier (a) for pattern plates. After shooting the sand into a core box, the sand in the box is pressed, esp. at 90 degrees w.r.t. the direction of shooting. The pressure is pref. applied during the gassing of the mould or core. Carrier (a) pref. permits the rapid and simple interchange of pattern plates; and independent gating system is pref. also mounted on the carrier so it is not disturbed during the changing of the pattern plates. One gating system is pref. employed for filling several moulds. Used for mfr. of sand moulds or cores by the cold box or CO2 processes, for casting iron, steel or other metals in foundries. Boxless and moulds can be used with simple wood or metal patterns held by wedges in carrier (a).

Description

Model plate carrier and method of manufacture

of sand cores and boxless sand from coldbox or CO2 sands.

The invention relates to an apparatus for producing Sand molds and cores as used in iron, steel and metal foundries will.

For the production of sand cores, which are inserted into the casting molds core shooters have been developed over the past few decades. These Today machines are so mechanized and technically perfected that one so that not only cores but also forms can be produced. Prerequisite for this However, it is also the further development of the sand binders, which are now known Manufacturing processes such as croning, hotbox, CO2 and coldbox have resulted.

In the molding shop there are the conventional jogger-PreS-turning machines as well as lift-off molding machines, as well as boxless automatic molding machines up to the so-called "Disamatik", in which Stack casting with vertical division is formed and poured.

So we differentiate between the normal forms with lower and upper boxes, as well as stack molding, with the lower and upper parts at the same time with a single molding is formed and placed on top of each other (stacked), several shapes are to be used combined in a package which is cast with just one pouring.

With conventional forms with upper and lower boxes, the transport felt the molding box as a major disadvantage.

It represents a considerable expense factor.

By saving working time, molding sand and liquid iron is included Pile casting the advantage is obvious. However, this procedure is only applicable to flat Castings can be used because the level of difficulty increases with the height of the model and Core-rich cast is difficult or impossible to produce. The practical application this machine is therefore limited to simpler castings in larger series, since changing the model plates also causes a lot of effort.

The boxless automatic molding machine offers advantages; the The usual molding box is dispensed with. (Saving the handling of the molding boxes, such as emptying, Transport etc.) Higher models can be molded up to a certain limit and inserting the core of any kind does not present any difficulties. Disadvantageous However, affects the high sand consumption and the very limited use of the given Measure out the molding surface, because wide walls remain at the edge of the molding ball, so that the boxless form can withstand the pressure of molten iron.

A method is known in which Pormhälften with core shooters or mold parts for batch casting are produced.

Core sand with the common core binders is used as dimensionally stable which harden immediately after gassing in the mold. This way you can in extremely Short cycle time, stack molds are produced with a very high degree of utilization of the mold surface will.

A substantial saving in liquid iron is achieved because only a sprue is required for up to 10 molds.

The sand consumption and the consumption of sand binders are compared the conventional process is greatly reduced, since the cured forms also use thin wall thickness can withstand the casting pressure of the iron. Because of this, too molding boxes can be dispensed with.

However, the method used here also has disadvantages because with complicated models due to insufficient mold filling and with small series The application is limited due to the lengthy work involved in changing the model plates is.

The present invention is based on a device which exploits the advantages mentioned above and avoids the disadvantages.

By installing our model plate carrier, a machine is in its area of application is almost unlimited and it opens up the possibility of the shot shape or core by re-pressing before hardening in addition to condense.

With our model plate carrier, shapes can be made in any Size, length, width and height, which are only limited by the dimensions of the machine, getting produced.

Before the coldbox sand is poured in and priced, the model plate trugel can be adjusted continuously depending on the model height, whereby the molded fabric hose can be limited to a minimum.

Thanks to the short changeover times, even small quantities can still be used can be manufactured profitably, because only the respective model plate is exchanged. The fashion plate carrier and sprue system remain in the machine. They can be high, flat and powerful forms of all kinds can be made.

The aftermath, reswen of the injected Coldboz or CO sand becomes Used for the first time in our model plate carrier and brings significant benefits Advantages: 1. The machine can work with significantly lower shooting pressure, fewer nozzles are required to discharge the shooting air, which protects the model equipment will be raised.

2. It can be made of either delignite wood or metal shaped panels brought to the same size, used and quickly exchanged.

3. By pressing the injected coldbox or C02 sand the mold balls are better compressed, which is significantly cleaner and also very dimensionally stable Results in exhaust gases. The slipstream places often present in higher and more complex forms, which are created by shooting in and cannot be eliminated on their own and also lead to unclean and mineralized areas on the casting surface completely eliminated by pressing.

Shaping on core shooters is improved and up-to-date. The binder manufacturers have new sales opportunities, the cast range to the bulk consumer is improved in quality and cheaper in price.

4. The sand molds can be stored indefinitely and for transportation, Storage, weighting, pouring and cooling do not require a stand track.

Further features of the invention emerge from the attached functional description and based on the drawings.

Fig. 1 shows a view of the device, Fig. 2 shows the plan represent.

In a model plate carrier 1 there are 2 model plates 2 and 3, which by means of the air cylinders 4 and 5 in position under the firing head of the Rern shooting machine to be brought.

The piston in the cylinder 5 has an extension 6 that extends over the end of the cylinder protrudes. When the model plate carrier is in the open position, this extension protrudes 6 in an opening of the backdrop 7. In the closed position, the locking cylinder 8 brought a lock 9 in front of this opening.

The piston in the cylinder 5 is moved back against the lock 9 and stops at this stop.

To fill the cavity between the model plates 2 and 3 is the whole device with the table 10 raised in the usual way and against the shooting head of the machine pressed. After filling, the table is lowered again, the gassing plate inserted and the table raised again.

Cylinder 5 now additionally presses the sand present in the molding device perpendicular to the filling direction. At the same time, the molding material is gassed.

Now the table is lowered, the lock 9 moves back, the two of them Cylinders 4 and 5 open the model plate carrier.

The four bolts must have the hardened core shape for the core impactor 11 hold tight. The grain shape is ejected from the ejector 11.

The model plate change in the recesses in the model plate carrier the model plates are inserted and fixed with two wedges.

Claims (6)

Claims 1. Device for the production of mold balls and Sand cores on core shooters, consisting of a model holder and the associated facilities, characterized in that after filling the Sand content of the core box can also be pressed. 2. Apparatus according to claim 1, characterized in that the pressing pressure acts perpendicular to the direction of filling. 3. Apparatus according to claim 1 and 2, characterized in that the contents of the mold are re-pressed during the gassing process. 4. Modeilpiattträger according to claim 1 to 3, which is a light and quick change of model plates allowed. 5. Model plate carrier according to claims 1 - 4, on which a casting system is mounted, which is independent and unchanged even when changing the model plates remain. 6. Model plate carrier according to claim 5, wherein the casting system the Casting of several forms with one pouring allowed.