FI96583B - Device used in casting process - Google Patents

Description

96583

EQUIPMENT TO BE USED IN THE CASTING PROCESS

The invention relates to a device for use in a casting process, comprising a chamber for a mold and a lid with which the chamber can be closed.

5 The mold used in the manufacture of precision castings, such as jewelery or other similar products, is usually a gypsum alloy. For casting, several molds are made for one casting. In this case, the mold is made by casting it on a model made of wax, which is placed in a metal-10 frame cylinder. Once the gypsum mixture has hardened, the wax is melted away, forming a cavity in the mold for the metal to be cast. Prior to casting, the mold is heated to the desired casting temperature, after which the molten metal is poured into the mold. Once the metal has solidified, the disposable gypsum mold is removed around the casting blank.

There are several steps in making a gypsum mold for the vanishing wax method described above. When the gypsum powder is mixed with water, the gypsum mixture is usually placed in a vacuum chamber to remove the air bubbles in the mixture. The gypsum mixture is then poured onto a model made of wax placed on a metallic one. . kehyssylinteriin. The mold is then placed back under the pressure chamber so that no air bubbles are left in the mold which interfere with metal casting.

25 However, such a method is cumbersome and time-consuming. The air bubbles in the mold must be removed twice. Therefore, a method has been developed in which a gypsum mixture mixed with water is placed in a vacuum chamber which is connected to another chamber 30 via a valve. This second chamber is also a vacuum chamber located below the gypsum alloy container, in which the metal frame cylinder of the mold is placed. Since both the gypsum mixture entering the mold and the mold frame cylinder are under reduced pressure, the gypsum mold can only be filled by opening the bottom valve of the gypsum mixture tank located between the chambers.

Since the production of one gypsum mold at a time is slow, it is known to install several bottom valves in the gypsum alloy tank above, from each of which a flowable gypsum mixture can be poured into the mold at each valve. This makes the production of gypsum molds substantially more efficient and faster.

10 However, several bottom valves and the pipes connected to them make the device complicated and cumbersome to use.

Therefore, carousel-type devices using disappearing model technology have been developed. Such solutions are described, for example, in SU 473.560 (B 22 C 9/04) and EP-A-166.228 (B 22 C 7/02).

It is an object of the present invention to provide a new device which is even more useful than known methods. The device according to the invention is characterized in that the chamber is formed as a multi-purpose chamber so that a first lid, i.e. a gypsum casting lid, and a gypsum container and / or a second lid, i.e. a metal casting lid, connected to the gypsum casting lid can be connected thereto.

The device according to the invention then has a tap from which several molds can be filled. It is assisted by a rotating carousel base placed in the chamber 25, by means of which the desired mold frame can be pivoted at the filling tap. In this case, one or more mold: frame cylinders can be placed in the device so that they can be filled alternately with the gypsum mixture. The bottom of the gypsum tank can be made into a funnel with a filling tap in the middle. The invention makes the production of molds with a simple structure as efficient as with a complex device with several bottom valves.

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The device according to the invention is also versatile, because the lid of the container can be replaced. In this case, the same device can also be used for the casting itself. One way of changing the lid is implemented in such a way that both the container and the lids are placed on 5 columns, around which the desired device combination can be assembled by turning.

The invention will now be described by way of example with reference to the accompanying drawing, in which

Figure 1 shows a perspective view of an apparatus according to the invention for manufacturing a mold.

Figure 2 corresponds to Figure 1 and shows the device seen from the side.

Figure 3 corresponds to Figure 2 and shows the device in a casting situation.

Figure 1 schematically shows an apparatus according to the invention for manufacturing a mold. The device shown in the figure comprises an upper vacuum chamber 10 and a lower vacuum chamber 20. A hose 12 to a vacuum pump is connected to the upper chamber and a flowable gypsum mixture 11 is poured into the chamber.

The desired amount of gypsum mixture can be discharged into the lower chamber 20 via the bottom valve 13.

The lower vacuum chamber 20 has a rotating carousel plate 22 mounted by means of a sealed shaft 21 in the middle, on which one or more metal mold cylinders 25 can be placed. In the exemplary case presented here, two mold cylinders 23a and 22b are drawn on the carousel plate 22, of which at the bottom valve 13 of the upper chamber 10 there is a mold cylinder 23b in the filling turn.

It can be seen from the figure that the mold cylinder 23b is filled with a gypsum mixture 11. When the mold cylinder 23b is full, the bottom valve 13 is closed. The carousel plate 22 is then rotated by the knob 25 so that the second mold cylinder 22a is below it at the bottom valve 13.

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A hose 24 to the vacuum pump is also connected to the lower chamber 20. The hoses 12 and 24 of the chambers are not shown in more detail in the figure, but valves can be connected to both, whereby both chambers 10 and 20 are also made to operate 5 independently.

The figure also schematically shows the support 26 of the lid of the lower chamber 20. The lid 26 is mounted on a rotatable column 14, whereby the lid 26 can be easily moved to the side when the mold cylinders are placed in the lower chamber 20. The upper chamber 10 and the lower chamber 20 can also be hung on the same column 14, so that they can also be rotated to the side. In this case, e.g. the cleaning of the chambers can be easily carried out by passing water through the chamber, which flows into a tank placed below or directly into the drain.

Figure 2 shows the device in a plaster mold manufacturing situation. It can be seen from the figure that the lid 26 of the lower vacuum chamber 20 is in place and locked with quick release pins 27. Before closing the lower vacuum chamber 20, mold frames are placed on the carousel plate, into which the gypsum mixture is discharged from the upper vacuum chamber 10 The lid 26 of the lower vacuum chamber 20, the upper vacuum chamber 10 and the connecting pipe 15 between them with their bottom valves 13 form an assembly which is. , turned around the column 14 at the lower vacuum chamber 20. The lower vacuum chamber 20 is then raised against the cover 26 by means of a cylinder 29 and a piston 30. When one mold sleeve is filled with gypsum mixture, the next mold frame is moved to the connecting pipe 15 by turning the knob 25.

t • 30 Figure 3 shows another mode of operation of the device. In the previous figure, the lid 26 in place has been moved aside and replaced by a casting lid 31 screwed onto the lower vacuum chamber 20. It is locked in place by quick-release pins 27. In the center of the casting lid 31 there is a casting opening 32 from which a metal plate 35 is poured into a central mold. Before the tl 96583 5 is drained, the carousel plate located in the vacuum chamber 20 is raised against the cover 26 by means of a compressed air cylinder 28.

It will be apparent to those skilled in the art that various embodiments of the invention may vary within the scope of the 5 claims below.

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Claims (8)

96583 Device for use in a casting process, comprising a chamber (20) for a mold (23) and a lid (26, 31) with which the chamber can be closed, characterized in that the chamber (20) is formed as a multi-purpose chamber so that a first lid can be connected thereto. (26) i.e. a gypsum casting lid and a gypsum container (10) and / or another lid (31) i.e. a metal casting lid connected to the gypsum casting lid. Device according to Claim 1, characterized in that a gypsum filling tap (13) and a gypsum tank (10) with a bottom funnel, which is formed as a vacuum chamber, are connected to the gypsum casting cover (26) above it. Device according to Claim 1 or 2, characterized in that the multi-purpose chamber (20) can be formed as a vacuum chamber and that a carousel plate (22) is arranged in the multi-purpose chamber, by means of which the desired mold frame (23a, 23b) can be turned over the gypsum filling lid (26). (13). Device according to Claim 1, 2 or 3, characterized in that a casting opening (32) is formed in the metal casting cover (31) and that the cover can be connected to a multi-purpose chamber (20) for casting molten metal into a mold (23). Device according to Claim 4, characterized in that an actuator (28), such as a pneumatic cylinder, is connected to the multi-purpose chamber (20) by means of which the metal carcass plate (26) can be moved vertically to the carousel plate (22) and the mold (23) thereon. against. Device according to one of Claims 1 to 5, characterized in that a lifting device, such as a cylinder (29) and a piston (30), is connected to the multi-purpose chamber (20) by means of which the multi-purpose chamber can be moved vertically. (26), depending on which of the lids (26, 31) is positioned on the multi-purpose chamber. Device according to one of Claims 1 to 6, characterized in that both the gypsum casting lid (26) and the metal casting lid (31) provided with the gypsum tank (10) are connected to a vertical axis, such as a device column (14) around which each lid (26) , 31) is rotatable at the multi-purpose chamber (20) to assemble the desired device combination. Device according to one of Claims 1 to 7, characterized in that the multi-purpose chamber (20) is also connected to the frame post (14) of the device. •. 96583