CASTING INSTALLATION FOR CASTING METAL CASTING MATERIAL AND METHOD FOR CASTING METAL CASTING MATERIAL

Description

The invention relates to a casting installation for casting metal casting material, wherein the casting installation comprises a melt-pool container for providing casting material in a liquid state, a casting device, embodied for forcing casting material into a casting die of the casting device, and a dosing container which can be moved from the melt-pool container to the casting device and which, in particular, is embodied as a dosing pipette, in order to use the dosing container to take up a dosable amount of casting material from the melt-pool container into a receiving space of the dosing container and deliver it to the casting device, wherein the dosing container is coupled to an evacuation device of the casting installation, in order to use the evacuation device to evacuate the receiving space to form a negative pressure in the receiving space for the purpose of receiving the amount of casting material into the receiving space.

The invention furthermore relates to a method for casting metal casting material, wherein a dosing container, in particular a dosing pipette, is used to take up a dosed amount of casting material into a receiving space of the dosing container from a melt-pool container with liquid casting material or casting material in a solid state is fed into the receiving space, after which the dosing container is moved from the melt-pool container to a casting device, and casting material from the receiving space is delivered to the casting device, in order to use the casting device to force the casting material delivered to the casting device into a casting die of the casting device, wherein during a taking-up of liquid casting material using the dosing container, the receiving space is evacuated with an evacuation device so that a negative pressure is formed in the receiving space for the purpose of receiving the amount of casting material into the receiving space.

Known are casting installations for casting liquid, metal casting material, wherein a dosing pipette, which can typically be moved by means of robot arm, is used to remove a certain amount of casting material from a crucible with an evacuation of the dosing pipette, after which the dosing pipette is moved to a die casting device using the robot arm and the casting material from the dosing pipette is supplied to a casting chamber of the die casting device, wherein the die casting device is embodied to inject the casting material supplied to the casting chamber into a casting die of the die casting device in order to produce a part by cooling the casting material in the casting die. The purpose of the crucible is normally to provide a melt pool of liquid casting material. The purpose of the dosing pipette is typically to transfer a defined amount of liquid casting material from the crucible to the die casting device with reduced oxidation effects and reduced casting material losses and to deliver it to the casting chamber. In this manner, a measured amount of liquid casting material can be practicably supplied to the die casting device, and parts can be produced by means of the die casting device by injecting liquid casting material into the casting die.

Casting installations for performing thixocasting, also referred to as semi-solid casting, are known as a further type of casting installation. Here, it is normally provided that liquid casting material is scooped from a crucible into a conditioning crucible using a scoop and the casting material in the conditioning crucible is then subjected to a conditioning in order to convert the liquid state into a thixotropic state of the casting material. Typically, the conditioning includes a cooling and stirring of the casting material in the conditioning crucible, frequently involving the use of a stirring tool, in order to realize, normally with a shearing of the casting material, a thixotropic phase or solid-liquid phase of the casting material. Normally, the casting material thereby forms a pulpy casting material body in the conditioning crucible. The thixotropic casting material is then typically poured out of the crucible into a casting chamber of a die casting device, wherein the die casting device is normally designed to force the thixotropic casting material into a casting die without turbulence. With casting installations that are designed for thixocasting, it is normally possible to produce near-net-shape parts with high precision. Compared to a casting installation with liquid die casting, casting installations with thixotropic die casting usually require a complex process route and a space-intensive setup.

This is addressed by the invention. The object of the invention is to specify a casting installation of the type named at the outset which has an improved operational capability.

Furthermore, it is an object of the invention to specify a method for casting metallic casting material of the type named at the outset, which method has an improved operational capability.

According to the invention, the object is attained with a casting installation of the type named at the outset if the casting installation comprises a conditioning station having an induction unit, wherein, before delivery of casting material to the casting device using the dosing container, it is possible, in particular as a matter of choice, to move the dosing container to the conditioning station, in order to electromagnetically stir the casting material using the induction unit for the purpose of converting the casting material into a thixotropic state.

The basis of the invention is the idea of utilizing an embodiment of a casting installation for liquid casting, based a dosing container which can be moved from a melt-pool container to a casting device, wherein the dosing container is embodied to take up a dosed amount of casting material into an evacuable receiving space of the dosing container from the melt-pool container, in order to realize a thixotropic casting, in particular a thixotropic die casting. In this manner, a casting installation for liquid casting can be used with reduced cost, in particular as a matter of choice, for thixotropic casting. This can be achieved if the dosing container is used for a conditioning of the casting material. Conditioning typically denotes a treatment of the casting material for the purpose of converting the casting material, in particular starting from a liquid phase of the casting material, into a thixotropic phase of the casting material. It has been shown that a thixotropic phase of the casting material can be realized by electromagnetic stirring of the, in particular liquid, casting material in the receiving space. The dosing container is preferably a dosing pipette. If the casting installation comprises a conditioning station having an induction unit in order to electromagnetically stir casting material in the receiving space using the induction unit, a thixotropic state of the casting material can be realized in the receiving space. Typically, the dosing container can be moved into a conditioning position relative to the induction unit, in which conditioning position the casting material in the receiving space can be electromagnetically stirred using the induction unit. In this manner, it is rendered possible that, using the dosing container, the casting material be taken up into the dosing container, in particular the receiving space, with reduced interaction with an ambient atmosphere, in particular with reduced oxidation effects; that the casting material then be converted into a thixotropic state; and that the casting material be delivered to the casting device using the dosing container. A high operational capability of the casting installation can thus be achieved.

The melt-pool container, which can be a crucible for example, is typically embodied to accommodate liquid casting material, in particular as a melt pool, or to provide said casting material for a removal using the dosing container. Typically, after the dosing container is used to take up an, in particular dosed, amount of casting material from the melt-pool container and, in particular, after an electromagnetic stirring of the casting material in the receiving space using the induction unit, the dosing container can be moved to the casting device in order to deliver casting material from the receiving space to the casting device. The melt-pool container and the casting device are typically separate objects and/or are arranged such that they are spaced apart from one another. The induction unit is typically controlled, in particular controlled in a closed loop, such that a temperature and/or a solid phase content of the casting material in the receiving space can be adjusted using the induction unit. It has been shown that it is beneficial if the solid phase content is less than 20%, in particular between 0.1% and 20%, preferably between 1% and 15%, particularly preferably between 3% and 10%. With a solid phase content of this type, a particularly disturbance-free working with the thixotropic material, in particular in terms of a handling using the dosing container when thixotropic material is located in the receiving space, can be realized.

It is beneficial if the casting installation comprises an electronic control device for the control, in particular closed-loop control, of the casting installation. For this purpose, the electronic control device typically comprises a microcontroller. The electronic control device can be embodied to control, in particular to control in a closed loop, the casting installation, preferably in an automated manner, in particular depending on a casting material composition.

The casting installation typically comprises a movement apparatus with which the dosing container can be moved, in particular in a controlled manner, preferably with a closed-loop control. In particular, the dosing container can be moved by the movement apparatus from the melt-pool container to the conditioning station and/or to the casting device. The movement apparatus can be embodied to move the dosing container along one or more movement axes, in particular oriented orthogonally to one another. The movement apparatus can be, for example, a swivel arm or portal robot. The dosing container is typically mechanically connected to the movement apparatus, in particular such that it can be detached from the movement apparatus. The movement apparatus can be controlled, in particular controlled in a closed loop, with the electronic control device, and in particular can be coupled accordingly to the electronic control device.

The dosing container typically comprises an evacuable receiving space in order to form a negative pressure in the receiving space by evacuation of the receiving space using the evacuation device. Typically, it is provided that the casting material is suctioned into the receiving space by evacuating the receiving space for the purpose of receiving casting material. The dosing container, in particular the receiving space, is typically embodied such that, for the purpose of receiving casting material into the receiving space, casting material can be supplied to the receiving space from a bottom of the dosing container, in particular of the receiving space, and/or for the purpose of delivering casting material from the receiving space, casting material can be discharged from the receiving space via a bottom of the casting container, in particular of the receiving space. Typically, casting material can be supplied to the receiving space and/or discharged from the receiving space at a lower region, in particular a lowest region, of the receiving space. The dosing container is normally embodied such that, in a state in which the receiving space is partially filled with casting material, an atmosphere volume sealed off from an environment of the dosing container is present above the casting material. Typically, the evacuation device is connected in a gas-conducting manner to the atmosphere volume, in order to discharge gas from the atmosphere volume using the evacuation device. It is beneficial if the evacuation device is connected in a gas-conducting manner to the receiving space at a top of the receiving space, in particular at a highest region of the receiving space. The receiving space typically forms a cavity that can be closed using a closing means of the dosing container. The receiving space is normally formed with receiving space walls which preferably enclose the receiving space essentially entirely. Typically, the receiving space walls of the dosing container are, at least in sections, preferably essentially entirely, formed from a ceramic material. The dosing container can be embodied to take up an, in particular dosed, amount of the liquid casting material into the receiving space by an at least partial dipping of the dosing container into a liquid casting material, or melt pool, accommodated by the melt-pool container. The melt pool is typically formed with liquid casting material. It is expedient if the dosing container comprises outer walls which are embodied, at least in sections, to be inert, so that inertly embodied sections of the outer walls can be dipped into the melt pool, in particular essentially without a chemical reaction between the sections and the melt pool, in order to take up casting material from the melt pool using the dosing container. Typically, the outer walls of the dosing container are, at least in sections, preferably essentially entirely, formed from a ceramic material. The dosing container is typically embodied to take up liquid casting material into the receiving space, in particular from the melt-pool container. The dosing container is typically embodied to deliver free-flowing thixotropic casting material from the receiving space, in particular to the casting device, typically a casting chamber of the casting device.

The dosing container typically comprises a casting material opening for receiving casting material into the dosing container, in particular the receiving space, and/or for delivering casting material from the dosing container, in particular the receiving space, via the casting material opening. Expediently, the dosing container can be embodied to supply casting material to the receiving space via the casting material opening and/or to deliver casting material from the receiving space via the casting material opening. The casting material opening is normally connected in a casting material-conducting manner to the receiving space. The dosing container can comprise a controllable, in particular controllable in a closed loop, closing means for closing and/or opening the casting material opening. The closing means can be controlled, in particular controlled in a closed loop, with the control device, and in particular can be coupled accordingly to the electronic control device. When the casting material opening is open, casting material can be supplied to the receiving space via the casting material opening or delivered from the receiving space via the casting material opening. In particular, when the casting material opening is closed, a passage of casting material through the casting material opening can be essentially prevented by the closing means. The closing means is preferably a closing plug. Accordingly, it is beneficial if the dosing container comprises a casting material opening which can be closed using a controllable closing means, in particular a closing plug that can be moved in a controlled manner, in order to supply casting material to the receiving space via the casting material opening when the casting material opening is open. Expediently, the dosing container can comprise multiple casting material openings. In particular, the dosing container can comprise a first casting material opening for receiving liquid casting material into the receiving space via the first casting material opening and a second casting material opening for delivering free-flowing casting material via the second casting material opening. The first casting material opening and/or the second casting material opening can be embodied as described in relation to the casting material opening. It can be possible to open and close the first casting material opening and the second casting material opening separately from one another, in particular in a controllable manner, preferably with a closed-loop control, typically using one or more closing means, which closing means can be embodied as described in the present document. In particular, a separate closing means can be respectively associated with the first casting material opening and the second casting material opening, in order to open and to close the respective casting material opening using the closing means. The dosing container can be embodied for a dosed taking-up of casting material into the dosing container, in particular the receiving space, and/or for a dosed delivery of casting material from the dosing container, in particular the receiving space.

In order to take up liquid casting material from the melt-pool container using the dosing container, the casting material opening is preferably dipped into a liquid casting material or melt pool provided by the melt-pool container, so that casting material can be taken up into the receiving space via the casting material opening, in particular beneath a melt-pool surface of the melt pool. The dosing container is typically embodied accordingly. In this manner, oxidation effects can be efficiently reduced, in particular prevented. It is beneficial if the casting material opening of the dosing container is arranged in a base region of the dosing container, preferably in a downward orientation. As a result, casting material can be practicably taken up into the receiving space by dipping the base region, in particular the casting material opening, into liquid casting material or a melt pool. It is advantageous if the dosing container is embodied such that, when the casting material opening is open, free-flowing casting material can automatically flow out of the receiving space. The dosing container can be controlled, in particular controlled in a closed loop, with the electronic control device, and in particular can be coupled accordingly to the electronic control device.

The evacuation device typically comprises a vacuum pump in order to evacuate the receiving space, in particular to create a negative pressure in the receiving space. Normally, when the casting material opening is dipped into the melt pool, casting material can be supplied to the receiving space, in particular suctioned into the receiving space, via the casting material opening with an evacuation of the receiving space, in particular a formation of a negative pressure in the receiving space. The evacuation device, in particular vacuum pump, is normally connected in a gas-conducting manner to the receiving space, in particular by an evacuation line. Via the evacuation line, gas can be conducted out of the receiving space, in particular suctioned off using the evacuation device. The evacuation line preferably connects to the receiving space at a top of the receiving space. The evacuation device can be part of the dosing container. The evacuation device can be embodied to variably control, in particular control in a closed loop, a negative pressure in the receiving space, in particular when casting material has been received into the receiving space. In this, a suction force acting on the casting material in the receiving space can be controlled, in particular controlled in a closed loop, specifically for a taking-up and/or delivery of casting material into and from the receiving space, respectively. The evacuation device can be controlled, in particular controlled in a closed loop, with the electronic control device, and in particular can be coupled accordingly to the electronic control device.

It is beneficial if the casting installation comprises a gas supply device in order to supply gas, in particular inert gas, for example argon, to the receiving space using the gas supply device. A gas supply can thereby take place in a controlled manner, in particular with a closed-loop control. The gas supply device can be connected in a gas-conducting manner to the dosing container, in particular the receiving space, via a gas supply line. The gas supply device can be controlled, in particular controlled in a closed loop, with the electronic control device, and in particular can be coupled accordingly to the electronic control device, in particular for a transmission of control signals.

It is expedient if the dosing container comprises a fill level measuring device for determining a fill level, in particular fill volume, of the receiving space with casting material. The fill level measuring device can be embodied to measure a weight and/or a fill height of a casting material in the receiving space. The fill level measuring device can be implemented with one or more measuring sensors. A dipping of the dosing container into a melt pool located in the melt-pool container for the purpose of taking up casting material from the melt pool into the dosing container, in particular into the receiving space, can take place depending on a determination of a fill level of the receiving space using the fill level measuring device. A taking-up and/or delivery of casting material from the dosing container, in particular the receiving space, can take place depending on a determination of a fill level of the receiving space using the fill level measuring device.

It is practicable if the receiving space comprises a first receiving space segment with a cross-sectional area that narrows in a casting material delivery direction of the receiving space. The casting material opening is typically arranged downstream from the first receiving space segment in the casting material delivery direction of the receiving space. Expediently, the first receiving space segment can lead to the casting material opening or a casting material channel forming the casting material opening. Casting material delivery direction of the receiving space typically denotes a flow direction of the casting material in the receiving space when casting material is discharged out of the receiving space for the delivery of the casting material via the casting material opening. The first receiving space segment can be arranged downstream from a second receiving space segment in the casting material delivery direction of the receiving space, wherein the second receiving space segment essentially has a constant cross-sectional area. For example, the second receiving space segment can be formed with wall sections in the shape of cylindrical sleeves, and/or the first receiving segment can be formed with wall segments in the shape of conical sleeves, in particular in the shape of truncated conical sleeves. The wall segments are typically part of the receiving space walls of the receiving space. Typically, the dosing container is, in particular the receiving space walls are and/or an outer surface, preferably sleeve surface, of the dosing container is, predominately, in particular essentially, formed such that it/they comprise(s) or is/are composed of ceramic material.

It is practicable if the casting material opening is formed by a casting material channel, which casting material channel is connected in a casting material-conducting manner to the receiving space. Via the casting material channel, casting material can be supplied to the receiving space and/or discharged from said receiving space. The casting material channel typically has an average cross-sectional area through which casting material can flow, which average cross-sectional area is smaller than an average cross-sectional area of the receiving space, in particular of the receiving space segment. The cross-sectional area of the receiving space, in particular of the receiving space segment, is typically oriented orthogonally to the casting material delivery direction of the receiving space. The casting material channel typically connects to the receiving space in a casting material-conducting manner at a bottom of the receiving space. The casting material channel and/or the casting material opening can be formed by a tubular neck of the dosing container, which neck protrudes away from a base body of the dosing container, in particular downwards. The receiving space is typically located primarily, preferably essentially, in the base body of the dosing container. It is beneficial if the neck has an outer diameter which narrows in a protrusion direction of the neck. The protrusion direction typically denotes a direction in which the neck protrudes outwardly away from the base body. Typically, a longitudinal extension of the neck is oriented parallel to the protrusion direction. The protrusion direction is preferably oriented downwards. Down typically denotes a direction in which the dosing container is, at least partially, dipped into a liquid casting material or melt pool for the purpose of taking up casting material using the dosing container.

It is expedient if the dosing container is embodied for a delivery of free-flowing, thixotropic casting material, in particular to the casting device. It is advantageous if the dosing container is embodied to deliver free-flowing metal casting material, in particular thixotropic casting material, having a solid phase content of more than 0.1%, in particular between 0.1% and 20%, preferably between 1% and 15%, particularly preferably between 3% and 10%, from the receiving space to the casting device, typically via the casting material opening. Thus, casting material in a thixotropic state with a solid phase content of this type can be delivered from the dosing container to the casting device with little disturbance. In particular, a corresponding embodiment of the casting material opening, in particular of the casting material channel, is necessary for a delivery of casting material having a solid phase content of this type from the receiving space. This is particularly relevant, as otherwise clogging with thixotropic casting material can occur in the dosing container, in particular in the region of the casting material opening.

It is advantageous if the casting material opening can be opened in a controllable manner, in particular with a closed-loop control, such that free-flowing metal casting material having a solid phase content of more than 3%, preferably between 3% and 20%, particularly preferably between 3% and 15%, can be delivered to the casting device from the receiving space via the casting material opening. The casting material opening can be controlled, in particular controlled in a closed loop, using the electronic control device.

It is advantageous if a ratio of an average diameter of the receiving space to a diameter of the casting material opening is from 2 to 15, in particular from 3 to 12, preferably from 5 to 10, particularly preferably from 5 to 8. As a result, a low-disturbance working of the dosing container with thixotropic material can be achieved in the dosing container with simultaneously reduced oxidation effects. The diameter of the receiving space is typically measured orthogonally to a casting material delivery direction of the receiving space. The diameter of the casting material opening is typically measured orthogonally to a casting material delivery direction of the casting material opening, in which direction the casting material flows through the casting material opening when casting material is discharged from the receiving space for the delivery of the casting material via the casting material opening. Casting material delivery direction of the receiving space typically denotes a flow direction of the casting material in the receiving space when casting material is discharged from the receiving space for the delivery of the casting material via the casting material opening.

Typically, the induction unit defines a treatment receptacle into which the dosing container can be at least partially inserted for an electromagnetic stirring of the casting material in the receiving space, so that the dosing container is, at least in sections, surrounded by the induction unit. It is expedient if the treatment receptacle and the dosing container are embodied such that the shape thereof corresponds to one another. The treatment receptacle typically defines the conditioning position of the dosing container. The dosing container is normally the conditioning station, in particular the induction unit, insertable into the receiving space in a non-contacting manner. Typically, the dosing container is inserted into the treatment receptacle using the movement apparatus.

It is preferred if the induction unit is formed with one or more inductors, in particular induction coils. The inductors typically define the treatment receptacle. The respective inductor can be an induction coil, comprising multiple coil windings. The electromagnetic induction field is typically generated by means of a flow of electric current through the coil windings. A region covered by the coil windings typically defines the treatment receptacle. The coil windings are normally arranged on an envelope of a rotation body, for example of a cylinder or a cone. For example, the induction unit can be formed by a cylindrical induction coil, comprising multiple coil windings, wherein a region covered, in particular enclosed, by the coil windings is the treatment receptacle. The inductors are normally embodied to generate an electromagnetic induction field in order to electromagnetically stir the casting material in the receiving space in the conditioning position of the dosing container. It is typically provided that, by stirring the casting material, a shearing of the casting material is produced for the purpose of realizing a thixotropic state of the casting material, in particular with a defined solid phase content. It is beneficial if the induction unit is embodied such that the dosing container in the conditioning position is enclosed by the induction unit in all directions orthogonal to an insertion direction of the dosing container into the treatment receptacle.

It is beneficial if the dosing container can be inserted into the treatment receptacle such that at least 20%, in particular at least 50%, preferably at least 65%, of a volume of the receiving space is located inside of the treatment receptacle. As a result, a defined solid phase content of the casting material in the receiving space can be efficiently adjusted. It is thereby particularly beneficial if at least 75%, in particular at least 85%, preferably at least 90%, of a volume of the receiving space is located inside of the treatment receptacle. In particular, essentially the entire receiving space can thereby be located inside of the treatment receptacle. In this manner, a conversion of the casting material into the thixotropic state can be controlled, in particular controlled in a closed loop, with high precision.

It is preferred if the dosing container can be inserted into the treatment receptacle, in particular in a controlled manner, preferably with a closed-loop control, such that at least 20%, in particular at least 50%, preferably at least 65%, of a fill volume of the receiving space is located inside of the treatment receptacle. As a result, a defined solid phase content of the casting material in the receiving space can be efficiently adjusted. It is thereby particularly beneficial if at least 75%, in particular at least 85%, preferably at least 90%, of a fill volume of the receiving space is located inside of the treatment receptacle. In particular, essentially the entire fill volume of the receiving space with casting material can thereby be located inside of the treatment receptacle. The fill volume of the receiving space denotes the volume of the receiving space that is occupied by casting material in the receiving space. The fill volume can be expediently determined using the fill level measuring device. In this manner, a conversion of the casting material into the thixotropic state can be controlled, in particular controlled in a closed loop, with particularly high precision. The insertion into the treatment receptacle can take place in a controlled manner, in particular with a closed-loop control, typically depending on the fill volume of the receiving space. This can occur using the electronic control device.

Normally, with a control, in particular closed-loop control, of the conditioning station, in particular of the induction unit, it is possible to adjust a temperature and/or a solid phase content in the casting material of the receiving space in the conditioning position of the dosing container. Typically, in the conditioning position of the dosing container, the casting material in the receiving space is allowed to cool and/or is actively cooled for the purpose of realizing a thixotropic state of the casting material, in particular simultaneously with the electromagnetic stirring of the casting material. The conditioning station, in particular the induction unit, can be controlled, in particular controlled in a closed loop, with the electronic control device, and can in particular be coupled accordingly to the electronic control device, typically via an electronic control line.

It is advantageous if the conditioning station comprises a cooling device, with which cooling device the casting material in the receiving space can be cooled in the case of a dosing container that has been guided to the conditioning station, or in the conditioning position of the dosing container, in particular simultaneously with the electromagnetic stirring of the casting material using the induction unit. As a result, the thixotropic state of the casting material can be realized with particular efficiency. The cooling with the cooling device can take place in a controlled manner, in particular with a closed-loop control, typically using the electronic control device. The cooling device can be formed with one or more cooling elements through which a cooling fluid can flow, which cooling elements are preferably arranged and embodied such that said elements can surround, at least in sections, the dosing container in a position of the dosing container guided to the conditioning station, or in the conditioning position of the dosing container. The cooling elements can be cooling channels which can in particular be embodied as part of a cooling circuit.

Advantageously, the induction unit can be embodied to be movable, so that the induction unit can, to some extent, be moved in tandem with the dosing container. As a result, a conditioning, in particular an electromagnetic stirring, of the casting material in the receiving space can take place during a movement of the dosing container. The tandem movement can thereby occur when the dosing container has been at least partially inserted into the treatment receptacle. A high efficiency can thus be achieved. The induction unit can be movable with a movement device of the casting installation, in particular in a controlled manner, preferably with a closed-loop control. The movement device can be realized with the movement apparatus. Alternatively, it may be expedient if the induction unit can be passively moved in tandem with the dosing container, for example in that a mechanical connection between the dosing container and the conditioning station, in particular the induction unit, can be realized. It can be possible to activate or deactivate the mechanical connection in a controlled manner, in particular with a closed-loop control.

The casting device typically comprises a casting chamber, to which casting chamber casting material can be delivered using the dosing container. The casting die of the casting device is typically arranged downstream from the casting chamber, so that the casting material can be forced into the casting die from the casting chamber using a pressing element, in particular a plunger, of the casting device. The casting device is typically a die casting device and/or a forming device, in particular a die-forging device. The casting device can be controlled, in particular controlled in a closed loop, with the electronic control device, and in particular can be coupled accordingly to the electronic control device.

A control, in particular closed-loop control, of the dosing container, of the movement apparatus, of the conditioning station, and/or of the casting device can respectively take place with an, in particular separate, electronic control device that is in particular part of the casting installation.

The dosing container, the movement apparatus, the conditioning station, and/or the casting device can be coupled accordingly to the electronic control device for a transmission of control signals, normally via electrical control lines in each case.

According to the invention, the object of the invention is attained with a method for casting metal casting material of the type named at the outset if, before the delivery of the casting material to the casting device, the dosing container is moved, in particular as a matter of choice, to a conditioning station having an induction unit, after which the casting material in the receiving space is electromagnetically stirred using the induction unit in order to convert the casting material into a thixotropic state. The method can be realized with the casting installation described in the present document. By using the dosing container for the conditioning, wherein the casting material in the receiving space of the dosing container is converted into a thixotropic state, it is possible to efficiently, in particular as a matter of choice, realize a casting of thixotropic casting material. In this manner, a high operational capability can be realized. Typically, after conversion of the casting material in the receiving space into the thixotropic state, the casting material is delivered to the casting device by the dosing container, after which the casting material in the thixotropic state is forced into the casting die of the casting device. The forcing typically takes place without any turbulence. The dosing container is typically a dosing pipette which is embodied to suction liquid casting material into the dosing pipette, or the receiving space thereof, with the formation of a negative pressure.

With the dosing container, liquid casting material, in particular in a dosed amount, is preferably taken up into a receiving space of the dosing container from a melt-pool container. Alternatively, mostly in the case of smaller and/or cost-intensive amounts of casting material, it can be beneficial if casting material in a solid state, typically as piece goods, is fed into the receiving space of the dosing container, typically with a dosed amount of casting material. Normally, during or in the case of a taking-up of liquid casting material using the dosing container and/or during or in the case of a taking-up of casting material in a solid state using the dosing container, the receiving space is evacuated using the evacuation device so that a negative pressure is formed in the receiving space for the purpose of receiving the, in particular dosed, amount of casting material into the receiving space.

It is beneficial if, in particular as a matter of choice, in a first method sequence, a conversion of casting material in the receiving space into a thixotropic state takes place with the conditioning station and thixotropic casting material is delivered to the casting device using the dosing container; or alternatively, in a second method sequence, no conversion of casting material in the receiving space into a thixotropic state takes place with the conditioning station, but rather the casting material is delivered to the casting device from the casting container in the liquid state. Typically, the casting material delivered to the casting device is respectively injected into a casting die using the casting device. In the first method sequence, the casting material in a thixotropic state is typically forced into the casting die by the casting device. In the second method sequence, the casting material in a liquid state is typically forced into the casting die by the casting device. The first method sequence and the second method sequence can respectively be realized as described in the present document. The casting installation can be embodied accordingly for carrying out the first method sequence and/or second method sequence. The first method sequence and the second method sequence can take place consecutively. In the first method sequence, in particular in contrast to the second method sequence, the dosing container is typically not moved to the conditioning station or into the conditioning position for an electromagnetic stirring of the casting material in the receiving space. The first method sequence and the second method sequence can be carried out using different casting dies of the casting device. The first method sequence and the second method sequence can have an identical or different composition of the casting material. Expediently, the casting installation can comprise multiple melt-pool containers, wherein the dosing container can be moved to different melt-pool containers in order to take up casting material from the respective melt-pool container. It is expedient if, in various of the melt-pool containers, casting material having a different casting material composition, in particular a different melt-pool composition, is accommodated or provided, typically in a liquid state or as a melt pool in each case.

The method for casting metal casting material can be embodied according to the features and effects which are described, in particular in the foregoing, in the present document within the scope of a casting installation. The same also applies to the casting installation with regard to the method.

It is beneficial if, with the conditioning station, a solid state content of the casting material in the receiving space is adjusted between 0.1% and 20%, in particular between 1% and 20%, preferably between 3% and 15%. With a solid phase content of this type, a particularly disturbance-free working with the thixotropic material, in particular in terms of a handling using the dosing container when thixotropic material is located in the receiving space, can be achieved.

It is advantageous if the casting material in the receiving space is actively cooled simultaneously with the electromagnetic stirring, in order to convert the casting material into the thixotropic state. As a result, the thixotropic state of the casting material in the receiving space can be realized with particular efficiency. This can be realized with a cooling device of the conditioning station.

It is beneficial if the casting installation is controlled, in particular controlled in a closed-loop, in an automated manner. This can be realized with the electronic control device, which can be embodied for this purpose. The control, in particular closed-loop control, can take place depending on an amount of casting material and/or a casting material composition of the casting material. It is particularly beneficial if the conditioning station, in particular the induction unit, is controlled, in particular controlled in a closed loop, in an automated manner depending on a material composition, in particular alloy composition, of the casting material, in order to adjust a thixotropic state of the casting material, in particular with a predefined solid phase content. The electronic control device can be embodied for this purpose. This can be realized efficiently, since a high degree of reproducibility can be achieved through the use of the dosing container for conditioning. In particular, oxidation effects can normally be ignored and/or the receiving space, normally insulated from an environment to the greatest possible extent, enables a precise control of a conversion of the casting material in the receiving space into the thixotropic state.

The casting material is typically a metal alloy, in particular a light metal alloy. Preferably, the casting material is a magnesium-based alloy, aluminum-based alloy, or copper-based alloy.

Liquid casting material typically denotes casting material at a temperature above a liquidus temperature of the casting material. Thixotropic casting material typically denotes casting material in a semi-solid state or at a temperature between a liquidus temperature and a solidus temperature of the casting material. Normally, the melt-pool container, the conditioning station, the casting device, and the dosing container are separate objects and/or are arranged such that they are spaced apart from one another.

Additional features, advantages, and effects of the invention follow from the description of an exemplary embodiment below. In the drawings which are thereby referenced:

FIG. 1 shows a schematic illustration of the casting installation;

FIG. 2 and FIG. 3 show microscopic images of a material structure of parts produced with the casting installation, with and without the use of a conditioning station of the casting installation.

In FIG. 1, a casting installation 1 and a sequence of a method for casting metal casting material are schematically illustrated. The casting installation 1 comprises a melt-pool container 2, a conditioning station 3, a casting device 4, and a dosing container 5 which can be moved using a movement apparatus 6. In FIG. 1, states of an interaction of the dosing container 5 with the melt container, the conditioning station 3, and the casting device 4 are respectively shown. The melt-pool container 2 is embodied to accommodate or for providing liquid casting material. The dosing container 5 can be moved using the movement apparatus 6 from the melt-pool container 2, in particular as a matter of choice, to the conditioning station 3 and to the casting device 4. The movement apparatus 6 can be a swivel arm, for example. It is provided that, with the dosing container 5, an amount of liquid casting material can be taken up from the melt-pool container 2 into a receiving space 8 of the dosing container 5, after which the dosing container 5 is moved, in particular as a matter of choice, to the conditioning station 3 using the movement apparatus 6, in order to electromagnetically stir the casting material in the receiving space 8 using an induction unit 7 of the conditioning station 3 for the purpose of converting the casting material from a liquid state into a thixotropic state. The electromagnetic stirring normally takes place during a cooling of the casting material in the receiving space 8. The dosing container 5 can then be moved to the casting device 4 using the movement apparatus 6, in order to deliver the thixotropic casting material from the receiving space 8 to the casting device 4, typically a casting chamber 9 of the casting device 4. The casting material delivered to the casting chamber 9 can then be pressed into a casting die of the casting device 4 using a pressing element 10, in particular a plunger, of the casting device 4, in order to produce a part by cooling the casting material in the casting die. The dosing container 5 is coupled to an evacuation device 11, with which evacuation device 11 the receiving space 8 can be evacuated, so that a negative pressure can be realized in the receiving space 8 for the purpose of receiving, in particular suctioning, casting material into the receiving space 8. The evacuation device 11 is normally connected to the receiving space 8 in a gas-conducting manner via an evacuation line 12, in order to evacuate the receiving space 8 via the evacuation line 12. The dosing container 5 typically comprises a casting material opening 13 connected in a casting material-conducting manner to the receiving space 8 for receiving casting material into the receiving space 8 via the casting material opening 13 and/or for delivering casting material from the receiving space 8 via the casting material opening 13. Typically, it is provided that the casting material opening 13 is dipped into a liquid casting material located in a melt-pool container 2 in order to take up casting material into the receiving space 8 via the casting material opening 13. In this manner, a dosed amount of casting material can be taken up with reduced oxidation effects using the dosing container 5 and the dosing container 5 can then, in particular as a matter of choice, be used for casting liquid casting material with the casting device 4 or for casting thixotropic casting material with the casting device 4.

The induction unit 7 is normally formed with an induction coil, comprising multiple coil windings. The induction coil forms a treatment receptacle into which the dosing container 5 can be at least partially inserted in order to electromagnetically stir the casting material in the receiving space 8. It is practicable if the dosing container 5 is inserted into the treatment receptacle such that at least 20% of a volume of the receiving space 8, preferably at least 20% of a fill volume of the receiving space 8 with casting material, is located inside of the treatment space. In this manner, a specific, in particular predetermined, solid phase content in the casting material in the thixotropic state can be set.

For the delivery of the thixotropic casting material in the receiving space 8 to the casting device 4, the thixotropic casting material is delivered to the casting device 4, in particular the casting chamber 9 thereof, via the casting material opening 13. For this purpose, it is beneficial if a ratio of an average diameter of the receiving space 8 to a diameter of the casting material 13 is from 2 to 15. Alternatively, preferably cumulatively, it is beneficial if the thixotropic casting material having a solid phase content of more than 3%, in particular between 3% and 20%, is delivered from the receiving space 8 to the casting device 4 via the casting material opening 13. In this manner, a low-disturbance operation with a handling, in particular delivery, of the thixotropic casting material can be achieved using the dosing container 5.

FIG. 2 and FIG. 3 show microscopic images of a material structure of parts produced using the casting installation 1 from FIG. 1, with and without the use of the conditioning station 3 of the casting installation 1. The microscopic images show by way of example a material structure of parts which have been produced with an AlSi7 alloy as casting material using the casting installation 1. FIG. 2 shows a material structure of a part which has been produced without the use of the conditioning station 3, that is, by injecting liquid casting material into the casting die using the casting device 4. FIG. 3 shows a material structure of a part which has been produced with the use of the conditioning station 3, that is, by converting the casting material in the receiving space 8 into a thixotropic state using the conditioning station 3, wherein a solid phase content of 5% was realized, and by subsequently forcing the thixotropic casting material into the casting die using the casting device 4. In the microscopic image from FIG. 2, a dendritic grain structure can be seen. By contrast, a globular corn structure can be seen in the image from FIG. 3.

If, with a dosing container 5, liquid casting material can be taken up into an evacuable receiving space 8 of the dosing container 5, after which the casting material in the receiving space 8 can be electromagnetically stirred in the receiving space 8 using an induction unit 7 of a conditioning station 3 in order to convert the casting material from the liquid state into a thixotropic state and subsequently deliver the thixotropic casting material to a casting device 4 for the purpose of introducing it into a casting die, it is possible to realize a thixotropic casting, or a part produced by thixotropic casting, in a low-cost manner and with reduced oxidation effects. Specifically, the casting installation 1 can, in particular as a matter of choice, be used for casting with liquid casting material and/or casting with thixotropic casting material. As a result, a casting installation 1 with high operational capability can be realized.