EP3294477A1

EP3294477A1 - Method for casting metal, adapter unit and device for casting metal comprising such an adapter unit

Info

Publication number: EP3294477A1
Application number: EP16720147.4A
Authority: EP
Inventors: Harald Justus Weis
Original assignee: Ingenieurbuero Weis Inh Dipl-Ing Harald Justus Weis
Current assignee: Ingenieurbuero Weis Inh Dipl-Ing Harald Justus Weis
Priority date: 2015-05-15
Filing date: 2016-05-04
Publication date: 2018-03-21
Anticipated expiration: 2036-05-04
Also published as: WO2016184686A1; EP3294477B1; DE102015208964A1

Abstract

A method for casting metal comprises the method steps of providing molten metal (22) in a casting furnace (2), filling a casting mould (9) with the molten metal (22) from the casting furnace (2), interrupting a fluid connection between the casting furnace (2) and the casting mould (9), venting the casting furnace (2) and actively introducing air into the fluid connection. Also disclosed is an adapter unit (23) for decoupling a casting furnace (2) from a casting mould (9) with an adapter housing (25), which has a housing longitudinal axis (26), and a piston (27), which is movable along the housing longitudinal axis (26) and/or rotatable about the housing longitudinal axis (26), and also a casting device.

Description

Method for casting metal, adapter unit and apparatus for casting metal comprising such an adapter unit

The present patent application claims the benefit of German Patent Application DE 10 2015 208 964.9, the contents of which are incorporated herein by reference.

The invention relates to a method for casting metal, an adapter unit and a device for casting metal comprising such an adapter unit. DE 10 2012 101 055 AI discloses a casting method and a casting plant for the production of workpieces. Several molds are arranged on a rotary table and connectable to a casting furnace. After cooling the melt in the casting mold, the casting furnace can be separated and joined to a next casting mold. A re-compression of the melt in the mold takes place at maximum furnace pressure. During cooling and solidification of the melt, the pressure in the casting mold sinks.

DE 102 33 962 A1 discloses an active power supply adapter in which a piston is provided for pushing melt into the casting mold. In order to avoid blocking of the cast furnace during the Nachdrückens and the solidification of the melt in a mold, additional effort, in particular a heating of the riser is required.

DE 198 21 419 AI discloses a method for increasing low-pressure casting of metal, wherein a controllable piston for pressing the molten metal in the mold is used. DE 198 12 068 AI discloses a casting apparatus and a casting method with recompression by means of a first and a second piston. During the solidification of the melt in the mold, the casting furnace is blocked for further use.

DE 43 32 760 AI discloses a method for low-pressure casting of copper or brass. The molten metal is filled through a riser pipe from the furnace into a mold. After solidification of the melt in the mold, the pressure in the furnace can be lowered. During the solidification of the melt, the mold is thermally coupled to the casting furnace. It is an object of the present invention to improve a method for casting metal, and in particular to reduce the cycle time of a casting, to reduce the energy consumption, to ensure improved material properties of the casting and / or to increase the utilization of the casting furnace.

This object is achieved by a method having the features specified in claim 1. According to the invention, it has been recognized that a fluid connection between a casting furnace and a casting mold is initially interrupted and additionally actively aerated for emptying. The active aeration means that the fluid connection is actively air and / or another gas, in particular targeted, supplied. The active aerating thus takes place, for example, by the supply of air into a standpipe which connects the casting furnace with the casting mold. The invention differs fundamentally from DE 43 32 760 AI, in which aeration of the fluid connection is prevented. Before actively aerating, the casting furnace is vented. The active ventilation of the riser and the venting of the casting furnace can take place simultaneously. It is also conceivable that the protective gas is forced into the riser and the casting furnace is then vented. By aerating the fluid connection molten metal from the fluid connection can get back into the casting furnace, so in particular during the casting furnace is vented. The fluid connection is ensured in particular by a connecting line. The connecting line is designed in particular as a riser. In particular, an adapter unit may be part of the connecting line. In particular, the liquid molten metal may pass back into the casting furnace while the molten metal in the casting mold is solidified and / or pressed. This makes it possible to separate the casting furnace from the mold faster. The cycle time for the casting furnace itself is reduced. There is no waiting time for the casting furnace during the solidification of the molten metal in the casting mold. The utilization of the caster can be increased. In particular, the casting furnace is available for further use after a shorter period of use.

By interrupting and venting the fluid connection, the casting furnace can be thermally and mechanically decoupled from the casting mold. By the thermal and mechanical Decoupling the cast furnace from the casting mold avoids further supply of heat energy to the casting mold, particularly during cooling of the molten metal in the casting mold. This leads directly to a shortening of the cycle time for the casting. The cycle time reduction is thus due to the reduction of the cooling time. The faster a casting cools, the higher its strength values. A cast part with increased strength enables a reduced use of materials and reduced wall thicknesses in the component design. The inventive method allows increased flexibility and diversity in the production of lightweight cast components. A casting cycle is shortened. The overall energy balance of the process is thereby improved. It is possible to use a casting furnace with reduced thermal output. Prior to interrupting fluid communication, molten metal is provided in the casting furnace and filled from the casting furnace into the casting mold. The method relates in particular to casting of light metal, in particular of aluminum and its alloys. The method is applicable to low-pressure casting, particularly with rising molten metal, to counter-pressure casting and vacuum casting. The mold can be a permanent mold, which is also referred to as a mold. The mold may also be a lost mold and is particularly suitable for a sand casting process. The method is particularly suitable for filling a casting mold with low pressure. In the so-called "lost fo am" process, molded parts made of foamed plastic, in particular expanded polystyrene (EPS), known as styrofoam, are embedded in foundry sand After the casting mold is finished, it is filled with the metal melt. The Styrofoam moldings evaporate on contact with the hot molten metal The volume occupied by the styrofoam moldings is filled by the molten metal For additional reduction of the cycle time, several molds can be bundled into a cluster and simultaneously filled with low pressure The material shrinkage can be compensated for and the pressure in the casting during the solidification can be maintained constant in particular by means of an adapter unit, in particular centrally located.The bundling of the casting molds into the grape is particularly applicable to all common sand casting methods.

A method in which an emphasis on the molten metal in the mold by means of an adapter unit, allows the exercise of arbitrarily high pressures, in particular up to 100 bar or more. High pressures are needed in particular for the production of fiber composite materials. The amount of pressure depends in particular on the geometry of the casting mold and / or from the adapter unit, in particular the geometry of individual components of the adapter unit. A workpiece produced in this way has improved material properties and in particular increased strength values. By repressing the material shrinkage is compensated during cooling of the molten metal. Subsequent removal of large feeders is unnecessary. In particular, the subsequent pressing takes place after the fluid connection has been interrupted.

The individual process steps can advantageously be carried out integrated by means of the adapter unit. The adapter unit has an increased functional density. Alternatively, it is possible to include the method steps, in particular the interruption of the fluid connection between the casting furnace and the casting mold, the active aeration of the fluid connection, the forcing onto the molten metal, the demolding of the casting from the casting mold and / or the separation of the casting furnace from the casting mold Mold to accomplish through individual, separate components.

A method in which the pressing is done by displacing a piston in an adapter housing, allows an immediate application of the emphasis on the melt. An axial piston displacement is uncomplicated feasible. The axial lifting movement of the piston can be superimposed on a rotational movement of the piston. In particular, it is possible to variably set the pressure exerted on the molten metal in the casting mold as a function of the pressing time. In particular, it is possible to adjust the pressure so that it is constant during the entire solidification phase. This results in an advantage over the cooling of a molten metal without repressions, ie without active feed, in which the pressure drops during cooling. In particular, repressing no longer takes place directly from the casting furnace.

A method in which an active cooling of the adapter unit is provided, reduces the cycle time of the process, in particular the cooling and solidification of the molten metal in the mold. The cooling of the adapter unit takes place in particular during and / or after the pressing. The cooling of the adapter unit takes place in particular after the fluid connection has been interrupted. In particular, cooling the adapter unit and thus the molten metal in the mold does not adversely affect the heated casting furnace and the therein located molten metal, since the casting furnace after the interruption of the fluid connection thermally and mechanically separated from the adapter unit, that is decoupled, is.

A method in which the molds are bundled and then rotated about a horizontal axis under feeding pressure, allows an advantageous solidification of

Melt. Since the feed volume which can be pressed by the piston stroke could not be sufficient in the case of a bundle of casting molds, it is possible to separate the casting molds from the casting furnace after aerating the riser and to turn them through a horizontally arranged axis of rotation by 180 °, as is described, for example, in DE 10 2004 043 444 B3 is known. The casting molds are turned upside down. The melt volume, which leads to distribution to the individual casting molds, serves as feed volume. When the casting molds are rotated, the melt contained therein can solidify under the action of gravity and / or pressure from above, in particular by means of compressed air, are applied. The advantage over the prior art is then that the melt is pressed into the casting mold via the piston during rotation. Volume shrinkage due to cooling during rotation is compensated. The pressurization counteracts the cavitation.

This procedure, in particular the turning of a filled casting mold, is also possible with individual molds or molds. It is conceivable to position the adapter unit stationary and to leave the molds open. The execution of the method is particularly suitable for a stationary casting furnace and transportable casting molds. The method has a reduced cycle time, since in particular the cooling and / or solidification of the molten metal in the casting mold are not relevant for the cycle time of the casting furnace. A cyclical process sequence, in which the casting furnace is used, is decoupled from the cooling and / or solidification of the molten metal in the casting mold.

A method in which a maximum filling pressure in the casting furnace is provided for filling the molten metal into the casting mold, wherein the maximum filling pressure is less than 0.5 bar, simplifies the design of the casting furnace. The fact that the maximum filling pressure is less than 0.5 bar, the casting furnace is not subject to the pressure vessel regulation. The design and in particular the construction of the caster is thereby simplified. The operation of the caster is simplified. The maximum pressure that must be provided by the casting furnace can be significantly lower. be placed. The pressure must be just so great that the molten metal from the casting furnace, for example, can ascend via a riser into a mold until the mold is filled. The reprints are carried out by means of the adapter unit. The casting furnace can be uncomplicated and, in particular, does not have to be removed according to a pressure vessel regulation. The investment costs and the follow-up costs are reduced. The planning effort is reduced. A potential danger is reduced.

A method of demoulding a casting from the casting mold enables the imaging of a complete process chain of a casting process. In particular, the shaping takes place by means of the adapter unit. The adapter unit has increased functional integration. A separate mold removal tool is unnecessary. The demoulding can be done easily. The demolding is possible immediately after the solidification of the molten metal to the casting. A conversion of a casting method known from the prior art by means of a gravity-casting frame is thereby possible in a particularly advantageous manner.

In a method in which the interruption of the fluid connection is isobaric, the interruption of the fluid connection is independent of the melt pressure feasible. Compared to a slider closure known from the prior art, it is particularly unnecessary to return the displaced melt. The procedure is simplified. Another great advantage is that the shaping in the upper part of the piston in conjunction with the rotational movement of the piston, the melt cross section is cut through the piston, but not squeezed off as in an active feeder according to the prior art, in particular the active feeders from DE 102 33 962 AI or DE 198 12 068 AI are known. In particular, it is ensured that the solidification of the molten metal in the casting mold is decoupled from the interruption of the fluid connection. It is possible to interrupt the fluid connection without an additional increase in pressure on the molten metal. The interruption of the fluid connection is straightforward and error-prone. The risk of production-related material defects in the casting is reduced. In particular, the isobaric interruption of the fluid connection is made by rotating the piston in the adapter housing. This means that the piston performs an axial displacement and a rotation about the longitudinal axis of the adapter housing. The displacements can be carried out independently of each other, ie either an axial displacement, or a rotation or a combined axial-rotational displacement. A method of separating the caster from the mold simplifies thermal and mechanical decoupling of the components. In particular, a separation of a connecting line, which in particular is firmly connected to the casting mold, provided by the casting furnace. The venting of the casting furnace takes place in particular after the thermal decoupling of the furnace from the casting mold. After venting the casting furnace, it is available for connection to other casting molds.

A method in which further molten metal is provided for the following casting cycles during the solidification phase of the casting cycle, in particular by replacement of the at least partially emptied casting furnace by a filled casting furnace and / or by refilling the at least partially emptied casting furnace with molten metal, allows effective use of the Casting furnace, in particular during the solidification of the molten metal. An uninterrupted operation of the method is guaranteed. In the event that sufficient molten metal is still present in the casting furnace for a subsequent casting cycle, the sufficiently filled casting furnace can stay at a position intended for it, in particular at a casting position.

A method in which there is provided an opening spaced along the fluid communication with the mold simplifies active venting of the fluid connection. This ensures that after interrupting the fluid connection molten metal, which is arranged between the mold and the casting furnace, can automatically, in particular due to gravity, flow back into the casting furnace. A so-called pipette effect, according to which the liquid molten metal remains in the riser, is prevented. In particular, the opening serves to vent the fluid connection. For this purpose, the opening is released.

A method in which a storage volume, in particular in the form of a pressurized gas, in particular air, is supplied through the opening of the fluid connection for actively aerating the fluid connection leads to an acceleration of the outflow of the molten metal into the casting furnace. The pressurized gas can be supplied with an aeration pressure of, for example, at least 2 bar, in particular at least 5 bar and in particular at least 10 bar. The storage volume may be advantageous as pressurized gas filled pipe can be provided. A tube can be uncomplicated and in particular not designed as a pressure vessel. When venting the fluid connection, in particular the riser, the gas volume of the storage volume is introduced. The volume of the container and the pressure of the gas cause a quick return of the molten metal from the riser into the casting furnace. It is prevented that the casting furnace is additionally pressurized. Essential for the storage volume so pressure and amount of gas.

As an alternative to active ventilation by supplying pressurized gas, it is also possible to suck the gas, in particular inert gas from a gas storage, which is in particular connected to the opening. In particular, the gas is sucked through the sinking melt column in the compound. The gas storage is in particular a flexible bag in which the gas is under ambient pressure.

A method in which a connection of the casting furnace with at least one second casting mold takes place after the separation of the first casting mold, allows an advantageous utilization of the resources. The casting furnace may be used to fill the second mold while the molten metal in the first mold is being pressed and solidified. This ensures that the molten metal in the casting furnace in a limited time interval, which is in particular at most 90 minutes, can be processed completely. In particular, when the maximum filling pressure is less than 0.5 bar, it is possible to use large-volume casting furnaces. The filling capacity of the caster are set no limits, at least with regard to the pressure vessel regulation.

It is a further object of the present invention to facilitate the practice of the method of casting metal.

This object is achieved by an adapter unit with the features specified in claim 11. It has been recognized that the adapter unit enables the direct, in particular thermal and mechanical, decoupling of the casting furnace from the casting mold. As a result, the implementation of the method is simplified. In particular, the interruption of the fluid connection between see the casting furnace and the mold and the venting of the fluid connection uncomplicated possible. The casting mold has an adapter housing having a housing longitudinal axis and a piston displaceable in the adapter housing. The piston is displaceable along the housing longitudinal axis. The piston is rotatable about the housing longitudinal axis. A control of the piston can be done via various types of drives, for example by means of a hydraulic drive, a pneumatic drive and / or an electric drive.

An adapter unit, wherein the piston has an opening for venting a connectable with the adapter housing connection line, has an increased functionality. Ventilation of the connecting line is possible directly above the piston. In particular, the venting of the adapter housing and in particular the connecting line is made possible by an opening which is arranged at a distance from the casting furnace. It is alternatively conceivable to realize the ventilation via a separate channel, which extends in particular in the interior of the piston. It is also conceivable to realize the ventilation via a separate control unit in the adapter housing. Basically, it is irrelevant how the ventilation takes place in detail. It is essential that the gas used for venting, for example air or another inert gas, at a position, in particular the riser, is supplied so that the molten metal flows back into the riser uncomplicated and completely in the casting furnace, in particular independently. It is also essential that this prevents the formation of metal oxides in the interior of the molten metal and / or on the molten bath surface and / or that gas bubbles remain dissolved in the molten metal. This prevents material defects in the later casting.

An adapter unit is arranged in particular along the fluid connection between the casting furnace and the casting mold. The adapter unit can be retrofitted to existing devices for casting metal. This makes it possible to carry out the method according to the invention with a device known from the prior art, which is retrofitted by the adapter unit according to the invention. This allows a particularly cost-effective upgrading of a known device, the significant advantages by retrofitting the adapter unit such as cycle time reduction of the casting, reduced energy consumption, increasing the strength values of the casting, expanding the product range, especially fiber reinforced castings, maintaining a permanent, uninterrupted casting operation Providing molten metal during the solidification phase of the casting and operating Mehrgießapparaturen with existing air and / or hydraulic networks through the timing of the casting plants.

A device with such an adapter unit is constructed in particular in a modular manner. The modular structure allows in particular a simplification of a central hydraulic supply. Hydraulic travel movements are necessary, for example, for demoulding the casting, ie for opening the casting mold, and / or for closing the casting mold for the mold. Decisive for the size of a hydraulic unit are travel speeds and volumes that are required for, in particular simultaneously occurring, hydraulic travel movements of several hydraulic cylinders in the input or extension direction. With the device, it is possible to successively switch the casting operations of the various modules, so that the hydraulic movements take place in succession. It is sufficient to use one hydraulic unit for all the casting equipment of a module. The size of the hydraulic unit is determined by the size of the casting station. The size of the hydraulic unit corresponds to the size of the casting station. During filling and during the solidification phase, no hydraulic travel is required, with the exception of the hydraulic operation of the adapter unit, which, however, requires only a small flow rate of hydraulic fluid. The low flow rates for the adapter unit can be made available for example via a hydraulic accumulator. It is sufficient to provide a pressure control and an oven temperature control. As a result, compressed air power and power output of the device can be reduced. When purchasing a new device, the system costs are significantly reduced. Due to the fact that, in particular, the adapter unit makes it possible to remove a casting, the design of removal means, such as, for example, a gripping unit for removing a casting from the casting mold, is simplified. In particular, the control and / or regulatory effort and in particular the components required for this purpose is reduced.

The device comprises at least one casting furnace and at least one casting mold. A mutual connection of the at least one casting furnace with a casting mold requires a relative movement between casting furnace and casting mold. This can be done in particular by the fact that the casting mold is suspended in a frame provided for this purpose, that is, it is spatially fixed. In this case, the casting furnace is arranged to be displaceable in space. It is also conceivable that the at least one mold is rotatably arranged, for example, on a carousel arrangement in space, wherein the respective mold to be filled is displaced for connection to the casting furnace relative thereto. It is also conceivable to arrange both the casting furnace and the mold movable in space.

A device with multiple molds allows an increase in efficiency of the device. The method can be designed to be economically effective. In particular, just so many molds are provided that after filling the last mold in a first casting cycle, the first mold to start a second casting cycle is available, since the solidified casting of the first mold of the first casting cycle has been completely removed from the mold. The number of casting molds is therefore dependent in particular on the filling time and the solidification time of the molten metal. In particular, it is conceivable that two casting molds, five or more casting molds are provided. The casting molds can be arranged, for example, grid-like or concentric. In particular, the apparatus includes at least one second casting furnace which provides molten metal when the first casting furnace is deflated. As a result, an essentially uninterrupted operation of the device is ensured, so that at least one casting furnace with molten metal of optimum quality is always available for casting. After providing the molten metal in the first casting furnace remains about a material-dependent processing time, for example, 90 minutes to pour the molten metal in the molds. At the end of this processing time, or when the casting furnace is emptied, a second molten metal furnace may be immediately provided and used for further filling of casting molds. A standstill of the device, in particular interrupting the filling of the molds during the filling of the first casting furnace is thereby avoided. The utilization and the overall efficiency of the device are thereby additionally increased.

A device in which the adapter unit and / or the Verbindungslei-processing are made of ceramic material, has a particularly long service life. The service life of the thermally and / or mechanically highly loaded components, ie the adapter unit and the Verbindungslei-device is increased. In particular, adapter unit and / or the connecting line are made of silicon nitride. It is particularly possible to use the adapter housing and the connection line in one piece, so as a one-piece component to execute. It conceivable to perform highly stressed components as ceramic inserts and / or with ceramic material, in particular zirconia (Zr0 ₂ ) coated material.

Embodiments of the invention will be explained in more detail with reference to the drawing. Show it:

1 shows a device for casting metal with a casting furnace which can be moved between two casting molds,

2 shows a longitudinal section through the casting furnace according to FIG. 1 with the casting mold connected via a riser pipe and an adapter unit, FIG.

3 is an enlarged view of the detail III in Fig. 2,

Fig. 4 is a Fig. 3 corresponding representation of an arrangement of the adapter unit for

Interrupting the fluid connection between casting furnace and casting mold,

Fig. 5 is a Fig. 4 corresponding representation of an arrangement of the adapter unit for

Venting the fluid connection,

Fig. 6 is a representation corresponding to FIG. 5 in an arrangement of the adapter unit for

reprints,

7 is a perspective, enlarged detail view of the piston of the adapter unit,

8 a representation corresponding to FIG. 1 of a further embodiment of a device with a casting carousel, FIG.

9 shows a representation corresponding to FIG. 1 of a further embodiment of a device with a series arrangement of the casting molds, FIG. 10 is a representation corresponding to FIG. 1 of a further embodiment of a device with an extended series system, and FIG. 11 is a representation corresponding to FIG. 10 of a further embodiment of a device with a multiple-line system.

An embodiment of a device 1 shown in FIGS. 1 to 7 is designed as a so-called machine duo. The device 1 is used for low-pressure casting of aluminum.

The apparatus 1 comprises a first casting furnace 2 in which aluminum is heated and the aluminum melt is provided. The first casting furnace 2 can be displaced linearly along a first casting furnace conveying direction 4 by means of a drivable roller conveying device 3. Along the first Gießförderrichtung 4 two mold stations 5 are arranged side by side. The mold stations 5 are designed to be identical. Each casting form station 5 has a frame-like portal 6 with a plurality of vertical supports 7 and horizontal beams 8. At the portal 6, a mold 9 is provided. In a lower column section of the portal 6, the roller conveyor 3 is arranged with the first casting furnace 2. In an upper mold section of the portal 6, the mold 9 is arranged. The vertical distance of the casting mold 9 to the roller conveyor 3 is selected such that the first casting furnace 2 can be coupled to the respectively arranged casting mold 9. In the arrangement shown in FIG. 1, the first casting furnace 2 is coupled to the casting mold 9 of the casting mold station 5 shown on the left. The mold 9 is designed in several parts and has four in one plane relatively displaceable mold side parts 10. The mold side parts 10 are each displaceable in the plane by means of a hydraulic cylinder. Perpendicular to this level, a casting shell 11 is displaceable by means of a lifting portal 12. On an underside of the mold top 11, a mold base 50 is disposed opposite. The mold base 50 is plate-shaped with an access opening for feeding the molten metal. The lower mold part 50 is in particular fixed, in particular immovable, held on the casting mold station 5. To close the casting mold 9, which is also referred to as a mold, the casting mold Side parts 10 and the mold upper part 11 displaced.

In the mold 9 shown on the left in FIG. 1, the side parts 10 and the upper part 11 are in a closed arrangement of the casting mold. In this arrangement, the mold 9 can be filled with molten metal. The casting mold 5 shown on the right in Fig. 1 station 5 shows the mold 9 in the Entformungs- arrangement. The side parts 10 and the upper part 11 are spaced from each other. In this arrangement, a manufactured casting can be removed from the mold.

Adjacent to the roller conveyor 3 and perpendicular to the first Gussförderrichtung 4, a further roller conveyor 13 is provided, which is carried out substantially identical to the first roller conveyor 3. At the roller conveyor 13, a second casting furnace 14 is arranged. The second casting furnace 14 can be displaced along the first casting furnace conveying direction 4 on the roller conveyor 13. According to the arrangement shown in Fig. 1, the second casting furnace 14 is arranged in front of the mold casting station 5 shown on the right. Both the roller conveyor 3 and the roller conveyor 13 allow a change of the casting furnaces 2, 14 perpendicular to the first Gießofenförderrichtung 4, that is along a transverse conveying direction 15. Along the transverse conveying direction 15, a Casting exchange is possible. The first casting furnace 2 has an inner container 16 with an upper cylinder portion and a spherical cap portion formed integrally thereon. The inner container 16 may also be referred to as a crucible. The inner container 16 is also available in other geometric shapes by default. The inner container 16 is surrounded by a thermal insulating layer 17 to reduce the heat loss during the casting process. If the insulating layer 17 of the casting furnace 2 is sufficiently designed, it is conceivable that the casting furnace 2 has no separate heating. Conversely, this means that a separate heating to the casting furnace 2 is provided in order to ensure a sufficient temperature of the molten metal 22. In particular, it is conceivable that the casting furnace is additionally externally heated for every second or third casting. The heating takes place in particular while the casting furnace 2 is arranged in the casting mold station 5. In particular, a connection for heating, in particular for electrical heating, may be provided at the casting mold station 5. The connection for electrical heating is in particular designed such that the casting furnace 2 automatically is coupled with the terminal when it is in the arrangement for filling the mold 9. In addition, an unillustrated air connection for the air supply is provided. At the air connection, a line may be provided for connection to a central air supply. In this case, the control of the filling pressure in the casting furnace 2 is part of the furnace unit, ie the casting furnace 2. It is also possible to provide a regulated air supply above the air connection. In this case, the control of the casting furnace 2 is made stationary.

On an upper side of the inner container 16 with a lid 18 is pressure-tight closed. The lid 18 is insulated on an inner side toward the outside. The casting furnace 2 has a pressure-tight connecting line (not shown) to the outside in order to be able to increase the pressure atmosphere above the melt. The lid 18 has a lid opening 19, which may be arranged in particular centrally on the lid 18. In an upgrade of an existing device, an adapter may be required to compensate for a lateral offset of a riser pipe 24 and / or an adapter housing 25. This makes it possible to use an existing casting furnace immediately. A replacement of the caster is unnecessary. Through the lid opening 19, a removal tube 20 is guided in the inner container 16. The removal tube 20 can be pressed against a spring force of a shaft compensator 21 into the interior of the inner container 16. By means of the spring force of the wave compensator 21, the separation point between the sampling tube 20 and the riser pipe 24 can be pressure-tight manner. The sampling tube 20 is also referred to as oven riser. For improved sealing additional sealing elements can be used in the region of the separation point, which are not shown. The shaft compensator 21 simplifies the replacement of casting furnaces 2. In principle, it is also possible to use a riser pipe arrangement known from the prior art, in which the riser pipe 24 is firmly fixed to the cover 18. In this embodiment, the tightness is guaranteed that the casting furnace 2 is pressed with the casting mold 9 and additional sealing elements are used.

The inner container 16 is filled with a molten metal, in particular with molten aluminum 22. The casting furnace 2, in particular the removal tube 20, is connected to the casting mold 9 via an adapter unit 23. According to the exemplary embodiment shown, the adapter unit 23 has a riser pipe 24, which is arranged substantially concentrically with respect to the removal tube 20, as a connecting line. With the riser pipe 24, an adapter housing 25 is connected, which is a Housing longitudinal axis 26 has. In the adapter housing 25, a piston 27 is arranged.

The riser pipe 24 has a substantially L-shaped flow channel which extends vertically in the extension of the removal tube 20 and at an upper end of the riser pipe 24 has a 90 ° bend. A formed in the adapter housing 25 flow channel is also designed substantially L-shaped. The two flow channels in the riser pipe 24 and in the adapter housing 25 allow a fluid connection between the casting furnace 2 and the mold 9. The flow channels are connected to each other such that the fluid connection is made substantially S-shaped.

The transition from the riser pipe 24 to the adapter housing 25 is conical. This ensures that during the venting the molten metal 22 flows back completely and in particular independently from the riser pipe 24 into the casting furnace 2. In the following, the structure of the adapter unit 23 will be explained in more detail with reference to FIGS. 3 to 7.

According to the embodiment shown adapter housing 25 and riser 24 are designed as separate, independent components. It is also conceivable to carry out the adapter housing 25 in one piece with the riser pipe 24. In particular, it is conceivable to produce a one-piece component made of ceramic material. The production can be simplified. The separate embodiment according to the embodiment shown has the advantage that different materials can be used. In particular, this makes it possible to select a requirement-appropriate selection of the materials for riser pipe 24 and adapter housing 25.

Along the housing longitudinal axis 26, a piston 27 is displaced. The piston 27 is rotatable about the housing longitudinal axis 26 in the adapter housing 25. In the adapter housing 25 is a

Melting reservoir 28 is provided, which faces the mold 9. The Schmelzereservoir 28 is designed as a substantially frusto-conical recess. In this recess melt can be stored during the filling of the mold 9. It is ensured by the melt reservoir 28 that sufficient molten metal 22 is available for repressurization. The adapter housing 25 has a transverse bore 29 which forms a connection of the

Schmelzereservoirs 28 with the fluid channel in the riser 24 allows. The transverse bore 29 is shown in Fig. 3. The adapter housing 25 further has a vent hole 51. The Vent hole 51 is disposed along the housing longitudinal axis 26 at substantially identical height with the transverse bore 29. Based on a rotation angle about the housing longitudinal axis 26, the transverse bore 29 and the vent 51 are spaced from one another. Typically, the transverse bore 29 and vent 51 are not in fluid communication with each other through the piston 27 disposed in the adapter housing 25, particularly during filling of the mold 9.

Concentric with the transverse bore 29 in the piston 27 a streamlined recess is designed as a continuation of the fluid channel. The streamlined recess causes turbulence of the molten metal 22 during filling of the mold 9 can be avoided.

On an outer side of the piston 27, an opening 30 is arranged, which faces the melt channel in the riser pipe 24. The opening 30 can be seen in particular in FIGS. 3, 5 and 6. The opening 30 makes it possible to supply air and / or gas to the riser pipe 24. The opening 30 serves to aerate the fluid connection between the piston 27 and the casting furnace 2.

The opening 30 is embodied on an outer cylinder jacket surface as a groove-shaped depression of the piston 27. The groove-shaped depression extends along the outer cylindrical surface of the piston 27 along a rotation angle range with respect to a longitudinal axis of the piston 27. The rotation angle range is approximately 90 ° in accordance with the exemplary embodiment shown. It is essential that the rotation angle range is large enough that the opening 30 can serve as an air connection channel. In particular, the opening 30 is designed like a blind hole. This means that the opening 30 is no Durchgangsöff and in particular a connection of the Schmelzereservoirs 28 with the riser pipe 24 through the opening 30 is not given. Along a rotational angle about the housing longitudinal axis 26, the opening 30 and the transverse bore 29 are arranged at a distance from one another on an outer side of the piston 27.

The piston 27 is connected to a drive unit, not shown, which allows the displacement of the piston 27 along a Nachdrückrichtung 31, ie along the housing longitudinal axis 26, or rotation about the housing longitudinal axis 26 independently or in combination with each other. In a lower, the mold 9 facing away from the portion of the piston 27 has a cooling bore 32. The cooling hole 32 serves to supply or flow through the lower piston portion with a coolant. The cooling bore 32 can also be used to heat the piston 27 or to temper it in some other way.

A method for casting metal, in particular aluminum, will be explained in more detail below with reference to FIGS. 1 to 7. First, aluminum is provided as molten metal 22 in the first casting furnace 2. The casting furnace 2 is positioned below the mold 9 to be filled, arranged to the left according to FIG. 1, and coupled by means of the adapter unit 23. The coupling takes place in that the riser pipe 24 is placed on an end flange of the sampling tube 20. Once the casting furnace 2 is pressure-tightly connected to the mold 9, the interior of the casting furnace 2 is pressurized. As a result of the pressurization, the molten metal 22 rises via the removal tube 20, the riser pipe 24 and the adapter housing 25 into the casting mold 9. An arrangement of the adapater unit 23 for filling the casting mold 9 is shown in FIGS. 2 and 3. As is apparent in particular from FIG. 3, the piston 27 is arranged at a distance from the transverse bore 29 during the filling of the casting mold 9 with the opening 30. In particular, the transverse bore 29 is separated fluid-tight from the vent 51. A fluid connection between the transverse bore 29 and the vent opening 51 is not present during the filling of the casting mold 9.

After the mold 9 is completely filled with molten metal 22, the piston 27 is rotated about the housing longitudinal axis 26. By turning the melt reservoir 28 is separated from the transverse bore 29. A continuous fluid connection is then not available. The fluid connection is interrupted. This arrangement is shown in FIG.

It is also conceivable that the casting mold 9 is not completely filled with molten metal 22. In this case, the filling of the casting mold 9 takes place by an axial displacement of the piston 27 along the housing longitudinal axis 26, in particular by pressing molten metal 22 from the melt reservoir 28 into the casting mold 9 which is not completely filled.

The fact that the interruption of the fluid connection is effected by a rotation of the cylindrical piston, this process step isobaric. An additional pressurization of Molten metal 22 in the melt reservoir 28 and in particular in the mold 9 does not take place. In the arrangement shown in Fig. 4, there is no direct fluid communication between the casting furnace 2 and the mold 9, in particular not via the molten metal 22. Due to the pipette effect, the molten metal remains in the riser 24 even if the fluid connection is interrupted, although the casting furnace 9 is vented.

By further turning the piston 27 about the housing longitudinal axis 26, the opening 30 is exposed. This means that by turning the piston 27, the groove-shaped recess 30 allows fluid communication between the transverse bore 29 and the vent opening 51. As a result, the fluid connection is ventilated by an end of the riser pipe 24 facing away from the casting furnace 2. For reasons of illustration, in Fig. 6, the molten metal in the adapter housing 25 is not shown and the piston 27 partially cut. For ventilating the riser pipe 24, an air supply opening in the adapter housing 25 is used. Relative to the transverse bore 29, the air supply opening is arranged around the housing longitudinal axis 26 by an angle of rotation of approximately 10 ° to 30 °. The Luftzuführöffhung not shown corresponds to the opening 30, which is designed in particular as an outer groove in the piston 24. The molten metal 22 can automatically flow from the riser pipe 24 back into the casting furnace 2 due to gravity. The casting furnace 2 can be separated from the casting mold 9. In particular, the separation of the casting furnace 2 from the casting mold 9 takes place while the melt 22 in the casting mold 9 is still liquid. By means of the adapter unit, the casting furnace 2 can be thermally and mechanically decoupled from the casting mold 9.

By an axial displacement along the pressing direction 31 of the piston 27, the melt in the mold 9 can be pushed. The casting furnace 2 is decoupled after filling the casting mold 9 in the casting mold station 5 shown on the left and after venting the fluid connection and arranged by means of the roller conveyor 3 below the casting mold 9 of the casting mold station 5 shown on the right. Subsequently, the mold 9 is closed and connected to the casting furnace 2 for filling. The connection is particularly uncomplicated via the adapter unit 23. The closing of the mold 9 and the relocation of the casting furnace 2 takes place independently.

A linear change between the two Gießformstationen 5 takes place until the in the the first casting furnace 2 stockpiled molten metal is no longer processable, for example by the passage of time and / or the molten metal 22 is used up. In this case, the first casting furnace 2 is conveyed via the roller conveyors 3, 13 for refilling and the second casting furnace 14 is conveyed under one of the casting mold stations 5 along the transverse conveying direction 15 for further operation of the apparatus 1.

The device 1 enables uninterrupted operation. Downtimes are minimized and especially excluded. An optimal quality of the molten metal 22 is ensured.

In Fig. 8, a further embodiment of a device is shown, wherein a plurality of mold stations 5, according to the embodiment shown six pieces, are arranged on a rotary indexing table 33 in the form of a casting carousel. The rotary indexing table 33 is rotatable about a vertical axis of rotation 34 such that a respective mold 9 to be filled of a mold station 5 can be arranged above the caster 2 located in a casting position. The Relatiwerlagerung between mold 9 and casting furnace 2 takes place in particular by rotating the rotary index table about the vertical axis of rotation 34 by an angular amount of 60 °. As soon as the casting furnace 2 located in the casting position is emptied, an uninterrupted operation of the device 35 through the second casting furnace 14 can be ensured.

It is conceivable that the casting furnace 2 is arranged on a rotary indexing table 33 and the Gießform- stations 5 are arranged statically.

The replacement of the casting furnaces 2, 14 takes place in the apparatus 35 in the embodiment of FIG. 8 analogous to the first embodiment with the roller conveyors 3, 13. It is alternatively possible to provide other conveyors, the linear and / or rotational promotion of the casting 2 , 14 allow. Continuous conveyors, rail-bound systems and / or driverless transport systems are also possible. In particular, a combination of several of these systems is possible.

In Fig. 9, a further embodiment of a device is shown, wherein the Gießformstationen 5 are designed as a series system. The main difference compared to the first version Form is that four mold stations 5 are arranged side by side in a row.

In principle, it is conceivable that the casting furnace 2 is static and a Relatiwerlage- by a transport of the molds 9 takes place. It is essential that a cyclic method is provided, which means that a filling sequence is predetermined by a filling direction 37 for the device 36 in FIG. 9. This means that the filling molds 9 are filled from left to right as shown in FIG. If the mold 9 shown on the right in FIG. 9 is filled, a new filling cycle begins in the casting mold 9 shown on the left in FIG. 9 of the mold station 5. However, it is also possible that after filling the mold 9 shown on the right in FIG the casting furnace 2 is transported to the adjacent casting mold 9. In this case, the filling direction 37 is oriented from right to left. In principle, it is therefore conceivable that the filling direction 37 can be oriented in both directions along the roller conveyor 3.

Again, a second casting furnace 14 is provided to ensure an uninterrupted flow.

The replacement of cast iron takes place during the cooling phase, so that it is ensured that the casting mold 9 essentially always has the operating temperature and unintentional cooling does not take place. After the last casting mold 9 has been filled, the casting furnace 2 can again be conveyed back to the first casting station 5 and subsequently used for further filling of casting molds 9. In particular, the second casting furnace 14 is only used when the first casting furnace 2 is emptied.

FIG. 10 shows a further embodiment of a device 38. The device 38 essentially corresponds to the device 36 in FIG. 9, wherein a total of eight mold stations 5 are provided. The first casting furnace 2 sequentially fills the casting molds 9 of the casting mold stations 5 arranged in series. If the first casting furnace 2 has reached the end of the row along the filling direction 37, ie has reached the casting mold station 5 shown on the right in FIG Casting cycle started by the second casting furnace 14 from the waiting position on the roller conveyor 13 to the first mold station 5, in Fig., 10 left is shown, is transported along the transverse conveying direction 15. Accordingly, the first casting furnace 2 is transported back by the roller conveyor 3 along the transverse conveying direction 15 on the roller conveyor 13 and positioned against the filling direction 37 on the roller conveyor 13 back to the waiting position in front of the first Gießformstation 5. In the apparatus 38, it is also possible that the first casting furnace 2 and the second casting furnace 14 are simultaneously used on the roller conveyor 3 for filling molds 9. The casting furnaces 2, 14 are operated at a certain distance, which may be defined in terms of time or geometry, to each other. The number of Gießformstationen 5, which are located in this distance, in particular depends on the cycle time of the casting. In addition, a third casting furnace 39 and a fourth casting furnace 40 are provided. The third and fourth casting kilns 39, 40 are made ready to be poured and ready as soon as the first casting furnace 2 and / or the second casting furnace 14 are emptied.

FIG. 11 shows a further embodiment of a device 41 in which several, in particular two, first casting furnaces 2 for filling casting molds are used in parallel. Accordingly, two second casting furnaces 14 are provided in the waiting position and two third casting furnaces 39 for the replacement. Depending on the receiving volume of the caster, the casting weight and the cycle time for filling the mold 9, the number of Gießformstationen 5 and / or the casting furnaces 2 can be set.

The inventive method is suitable for various types of foundries, in particular, the execution of the casting is irrelevant for the application of the method according to the invention. In particular, it is irrelevant whether the core pullers of the casting rack are mounted on a base plate, are designed to be suspended from columns, or move up and down as pinole pullers with the movable clamping plate. The nature of the displaceability of the casting furnaces is also irrelevant for carrying out the method according to the invention. It is conceivable to use roller conveyors or rail-bound and / or driverless transport systems. For the method according to the invention, the execution of the mold for the production of the casting is irrelevant. It is possible to use masonry casting furnaces, which are tempered by ceiling heating elements. It is also possible to use crucible furnaces, which are heated by meander elements. There are also highly insulating pouring conceivable, which are heated for example by means of immersion heaters. In particular, the inventive Method and the device according to the invention are not limited to the specific embodiments in which, as an example, a gantry, the change of casting furnaces via roller conveyors, as a mold a wheel mold and the casting furnace are designed as insulating.

Claims

claims

1 method for casting metal comprising the method steps

Providing molten metal (22) in a casting furnace (2),

Filling the molten metal (22) from the casting furnace (2) into a casting mold (9),

Interrupting a fluid connection between the casting furnace (2) and the casting mold (9),

- venting the caster (2),

- Active venting of the fluid connection.

A method according to claim 1, characterized by pressing on the molten metal

(22) in the casting mold (9) by means of an adapter unit (23), in particular after interrupting the fluid connection, wherein the reprints in particular by axial displacement of a piston (27) in an adapter housing (25), in particular an active cooling of the adapter unit ( 23) is provided, in particular during and / or after the

Reprints.

3. The method according to any one of the preceding claims, characterized by bundling a plurality of molds (9) and rotating the bundled molds under active supply pressure, wherein the axis of rotation is oriented in particular horizontally.

Method according to one of the preceding claims, characterized by a maximum filling pressure in the casting furnace (2) for filling the molten metal (22) into the casting mold (9), the maximum filling pressure being less than 0.5 bar.

Method according to one of the preceding claims, characterized by demoulding a casting from the casting mold (9), in particular by means of the adapter unit (23).

Method according to one of the preceding claims, characterized in that the

Interrupting the fluid connection isobar occurs, in particular isobaric cutting of the melt by rotation of a piston (27) in an adapter housing (25).

Method according to one of the preceding claims, characterized by separating the Casting furnace (2) of the casting mold (9), in particular separating a connecting line (24) from the casting furnace (2), in particular after thermal decoupling of the casting furnace (2) from the casting mold (9).

8. The method according to any one of the preceding claims, characterized by providing additional molten metal for subsequent casting cycles during the solidification phase of the casting cycle, in particular by replacing the at least partially emptied cast furnace (2) by a filled casting furnace (2) and / or by refilling the at least partially emptied Casting furnace (2) with molten metal (22).

9. The method according to any one of the preceding claims, characterized by a along the fluid connection to the casting furnace (2) spaced opening (30) which is released in particular for actively venting the fluid connection, wherein for actively venting in particular a storage volume in the form of a pressurized gas , in particular an inert gas, is supplied through the opening (30) of the fluid connection.

10. The method according to any one of the preceding claims, characterized by connecting the casting furnace (2) with at least one second mold (9) after separating the first mold (9), in particular during the cooling of the molten metal (22) in the first mold (9 ).

11. Adapter unit (23) for decoupling a casting furnace (2) from a casting mold (9) with a housing longitudinal axis (26) having adapter housing (25) and along the housing longitudinal axis (26) displaceable and / or rotatable about the housing longitudinal axis (26) Piston (27).

12. An adapter unit according to claim 11, characterized in that the piston (27) has an opening (30) for actively venting a connectable to the adapter housing (25) connecting line (24).

13. Device for casting metal with

a casting furnace (2) for supplying molten metal (22), at least one casting mold (9),

- At least one adapter unit (23) according to claim 11 or 12.

14. The apparatus according to claim 13, characterized by a plurality of molds (9), in particular in a grid-like or concentric arrangement, wherein in particular at least one second casting furnace (14) is provided for providing molten metal, when the first casting furnace (2) is emptied.

15. The device according to claim 13 or 14, characterized in that the adapter unit (23) and / or the connecting line (24) are made of ceramic material, wherein the adapter housing (25) and the connecting line (24) are in particular made in one piece.