Method for producing a cast part
Patent Information
- Authority / Receiving Office
- EP · EP
- Patent Type
- Applications
- Current Assignee / Owner
- FILL GMBH
- Filing Date
- 2024-06-06
- Publication Date
- 2026-04-15
AI Technical Summary
The existing casting method introduces melt into the mold suddenly, leading to air bubbles and oxide inclusions, resulting in defects in the cast workpiece due to turbulence and flashover waves, which reduces the quality of the cast product.
A method involving a casting mold with a sprue and mold cavity, where the sprue is laterally offset and fluidly connected, using a lance with a gas valve to regulate gas entry, and pivoting the mold and lance to control the melt flow, ensuring a smooth and homogeneous introduction of melt into the mold cavity, minimizing turbulence and air inclusions.
This method achieves a homogeneous structure and reduced air inclusions in the cast workpiece, enhancing the quality by controlling the melt flow and minimizing turbulence, resulting in improved casting process efficiency.
Smart Images
Figure AT2024060220_12122024_PF_FP_ABST
Abstract
Description
[0001] METHOD FOR PRODUCING A CAST WORKPIECE
[0002] The invention relates to a method for casting melt.
[0003] DE 102007 011 253 A1 discloses a casting device with a melt container for metallic materials. An injector is arranged on the underside of the melt container, which has an opening for discharging the melt. Furthermore, a closing device is provided, which serves to close the opening.
[0004] The casting device and casting method known from DE 10 2007 011 253 A1 have the disadvantage that the melt is poured into the casting mold in a tumbling motion. This leads to the inclusion of air bubbles and oxides in the cast workpiece, which reduces the quality of the cast workpiece. This effect can be explained as follows: When the melt is poured into the casting mold according to the disclosure of DE 10 2007 011 253 A1, increased turbulence occurs in the melt. During contact of the melt with the lance and the inner walls of the casting mold, the melt tends to collide with the surfaces and flow back in the opposite direction of the flow, which leads to flashover waves on the free surface of the melt. This leads to the folding of the oxide layers formed on the surface of the melt and to the inclusion of air in the metal, which causes defects in the finished castings.
[0005] The object of the present invention was to overcome the disadvantages of the prior art and to provide a method by means of which an improved cast workpiece can be cast.
[0006] This object is achieved by a method according to the claims.
[0007] According to the invention, a method for producing a cast workpiece is provided. The method comprises the following steps:
[0008] - Providing a casting mold with a sprue and a mold cavity, wherein the mold cavity serves to shape the cast workpiece and wherein the sprue is arranged laterally offset from the mold cavity and the sprue and the mold cavity are fluidly connected;
[0009] - Providing a melt container in which a melt receiving space is formed, wherein the melt container has a spout in the form of a lance located at the bottom of the melt container with a spout opening, wherein a gas valve is formed which is fluidly connected to the melt receiving space and wherein the gas valve serves to regulate a gas input into the melt receiving space:
[0010] - Filling the melt container with melt, whereby the melt is introduced into the melt receiving space of the melt container;
[0011] - Pouring the cast workpiece with melt from the melt container, wherein the melt collected in the melt receiving chamber is introduced into the sprue of the casting mold via the pouring opening of the lance, wherein the casting mold is pivoted toward the sprue at a mold pivot angle greater than 0° at least at one point during the pouring process, so that at least a portion of the sprue is lower than the mold cavity. Furthermore, it can be provided that the lance is also pivoted at a lance pivot angle.
[0012] Furthermore, it can be provided that a siphon is arranged on the underside of the lance in the area of the spout opening.
[0013] The method according to the invention has the advantage that the melt is introduced into the casting mold at the sprue and can settle as it runs from the sprue into the mold cavity, so that a homogeneous structure of the cast workpiece can be achieved in the mold cavity. The advantages of this casting method are surprisingly only achieved through the combination of the features according to the invention. One factor is the lance with the pouring opening and the interacting melt container with a gas valve, by means of which the fall height of the melt when introduced into the sprue can be kept as low as possible. A further factor is the design of the casting mold with sprue and mold cavity, whereby the casting mold is pivoted towards the sprue and the melt is poured into the sprue of the casting mold. Because the sprue is the lowest point of the casting system orWhen the mold is formed, a steady flow of the melt from the sprue into the mold cavity can be achieved by increasing the melt level in the sprue. Another factor is that the mold and the lance of the pouring device are pivoted equally. Furthermore, it can be advantageous if the mold is pivoted at a mold pivot angle greater than 0° before the start of pouring. This has the advantage of ensuring a steady pouring process right from the start of the pouring process.
[0014] Furthermore, it can be provided that, even before the bottom of the mold cavity is completely covered with melt, the casting mold is pivoted into a vertical position with a mold pivot angle of 0°. This has the advantage that the cast workpiece can have a homogeneous melt distribution and thus, a homogeneous microstructure can be achieved in the cast workpiece. This is particularly advantageous for rotationally symmetrical cast workpieces.
[0015] Furthermore, the casting mold can be pivoted into a vertical position with a mold tilt angle of 0° at the start of casting, and then pivoted into an inclined position with a mold tilt angle greater than 0° during the casting process. This has the advantage that this measure, adapted to the geometry of the cast workpiece during the casting process, can achieve venting of undercuts in the casting mold. This can be particularly advantageous for pockets in the casting mold that are closed at the top.
[0016] Another advantageous embodiment is one in which the casting mold can be pivoted into a vertical position with a mold pivot angle of 0° before the end of the casting process. This has the advantage that the cast workpiece can have a homogeneous melt distribution and thus, a homogeneous microstructure can be achieved in the cast workpiece. This is particularly advantageous for rotationally symmetrical cast workpieces.
[0017] According to a further development, it is possible to change the mold swivel angle and the lance swivel angle synchronously during casting. This has the advantage of minimizing damage to the lance caused by collision with the sprue.
[0018] Furthermore, the sprue can be provided with a clearance. The clearance can be designed such that the casting mold can be pivoted without the lance having to be pivoted simultaneously. The lance can move within the clearance without colliding with the sprue. This measure has the advantage that the lance does not necessarily have to be pivoted with the casting mold to achieve the advantages of the invention.
[0019] Furthermore, it may be advantageous if the mold tilt angle is, at least temporarily, greater than the lance tilt angle during casting. This has the advantage that this measure allows maximum tilting of the casting mold. In the configuration according to the invention, the maximum possible tilting of the lance is limited by the design of the siphon, since, depending on the design of the siphon, increased tilting of the lance can impair the function of the siphon.
[0020] In addition, it can be provided that when the mold swivel angle is changed during casting, a swivel acceleration is selected such that no area of the mold filled with melt at this time experiences an acceleration higher than 0.1 m / s 2 This has the advantage that this measure can prevent air inclusions in the melt as much as possible.
[0021] Furthermore, it can be provided that the lance pivot angle has a first value greater than 0° at the start of casting, whereby as soon as a melt level in the sprue of the casting mold reaches a certain melt level, the lance pivot angle is increased to a second value, whereby the second value is greater than the first value. This has the advantage that the lance pivot angle can be kept as large as possible during the casting process. The first value of the lance pivot angle can be determined by the maximum possible pivot position of the lance due to the siphon. However, as soon as the melt level is so high that the siphon or a siphon wall of the siphon is completely below the melt level, the tilt can be increased further.
[0022] Furthermore, it can be provided that for pouring the cast workpiece the lance is inserted so deeply into the sprue that the pouring opening lies below a flow channel base. In particular, it can be provided that the pouring opening lies below the flow channel base with a coverage height. Furthermore, it can be provided that the overflow level of the siphon is arranged at a coverage height relative to the flow channel base. This has the advantage that this measure can ensure that the melt can collect in the sprue before it reaches the level of the flow channel base and in doing so rises above the level of the pouring opening. This can ensure that the melt can flow into the flow channel in a calm manner right from the start. The coverage height can be between 1 mm and 200 mm, in particular between 2 mm and 100 mm, preferably between 5 mm and 50 mm.
[0023] According to a particular characteristic, it is possible for the first value to be between 0.1° and 20°, and for the second value to be between the first value and 35°. Tilting within the specified range, in particular, has the advantage of producing a cast workpiece with surprisingly good properties.
[0024] According to an advantageous development, the maximum possible lance pivot angle can be limited by a mechanical stop or a software lock. This has the advantage that this measure can be structurally or procedurally ensured that the functionality of the siphon is not disabled. A software lock is a feature included in the basic programming, according to which the selection of the lance pivot angle is limited when adapting the parameter values to the respective casting mold or the respective casting conditions.
[0025] Furthermore, it is conceivable that a computer-aided simulation could simulate the flow of the melt into the casting mold. This could, in particular, be a CFD simulation. This could, in particular, simulate wave motions of the melt or the dynamic flow behavior of the melt. Furthermore, it is conceivable that the CFD simulation could calculate the venting of the casting mold during the introduction of the melt.
[0026] Furthermore, it is conceivable for the mold swivel angle to change dynamically during casting, becoming larger and smaller. Such a change in the mold swivel angle can also be referred to as rocking or swinging back and forth. By dynamically changing the mold swivel angle, for example, a wave movement of the melt surface, which is caused by the pouring of the melt, can be influenced. This can dampen the wave movement of the melt, so that the melt can no longer hit the walls of the mold cavity. This can increase the quality of the cast workpiece, as inclusions of air bubbles in the cast workpiece can be reduced. In particular, it can be provided that an optimal temporal change in the mold swivel angle is calculated in the computer-aided simulation.
[0027] In particular, it can be advantageous if the casting mold is pivoted into a vertical position with a mold tilt angle of 0° at the start of casting, pivoted into an inclined position with a mold tilt angle greater than 0° during the casting process, and pivoted back into a vertical position with a mold tilt angle of 0° before the end of casting. This has the advantage that this measure, adapted to the geometry of the cast workpiece during the casting process, can achieve venting of undercuts in the casting mold. This can be particularly advantageous for pockets in the casting mold that are closed at the top.
[0028] Furthermore, a computer-implemented method for determining the temporal progression of a mold tilt angle during casting is provided. The method comprises the following steps:
[0029] - Providing a digital model of a melt container which has a spout in the form of a lance located at the bottom of the melt container with a spout opening;
[0030] - Providing a digital model of a casting mold;
[0031] - Carrying out a CFD simulation for casting a cast workpiece, whereby the temporal course of a mold swivel angle of the casting mold is simulated during casting;
[0032] - Determining the temporal progression of the mold swivel angle of the casting mold at which a minimum of air inclusions occurs in the real casting workpiece on the basis of the CFD simulation for casting a casting workpiece;
[0033] - Transferring the calculated time profile of the mold's swivel angle to a digital computer for controlling a casting system. The method according to the invention offers the advantage of improving the quality of the cast workpiece.
[0034] Furthermore, it can be provided that, together with the temporal course of a mold swivel angle of the casting mold, the temporal course of a melt introduction into the casting mold is also simulated, comprising the process steps:
[0035] - Carrying out a CFD simulation for casting a cast workpiece, whereby the temporal course of a mold swivel angle of the casting mold and the temporal course of a melt introduction into the casting mold during casting are simulated;
[0036] - Determining the temporal progression of the mold swivel angle of the casting mold and the temporal progression of melt introduction into the casting mold at which a minimum of air inclusions occurs in the real casting workpiece on the basis of the CFD simulation for casting a casting workpiece;
[0037] - Transferring the calculated time course of the mold swivel angle of the casting mold and the time course of a melt introduction into the casting mold to a digital computer for controlling the casting system.
[0038] For a better understanding of the invention, it is explained in more detail using the following figures.
[0039] They show in a highly simplified, schematic representation:
[0040] Fig. 1 is a schematic representation of a first embodiment of a melt transport device;
[0041] Fig. 2 is a perspective view of a first embodiment of a lance;
[0042] Fig. 3 is a longitudinal sectional view of the first embodiment of the lance;
[0043] Fig. 4 is a schematic representation of a second embodiment of the melt transport device;
[0044] Fig. 5 individual process steps of an embodiment of a casting process.
[0045] By way of introduction, it should be noted that in the variously described embodiments, identical parts are provided with identical reference symbols or component designations. The disclosures contained throughout the description can be applied analogously to identical parts with identical reference symbols or component designations. Furthermore, the positional information chosen in the description, such as top, bottom, side, etc., refers to the directly described and illustrated figure, and these positional information must be applied analogously to the new position in the event of a change in position.
[0046] Fig. 1 shows a first embodiment of a melt transport device 1, which serves to transport melt 2.
[0047] The melt transport device 1 comprises a melt container 3, in which a melt receiving space 4 is formed, which serves to receive the melt 2. Furthermore, the melt transport device 1 can comprise a lance 5, which is coupled to the melt container 3. The lance 5 can be exchangeable with the melt container
[0048] 3. In particular, it is conceivable that the lance 5 is designed as a separate component, which is coupled to the melt container 3. The lance 5 has a pouring opening 6, through which the melt 2 held in the melt container 3 can flow out of the melt transport device 1 into a casting mold 11.
[0049] Furthermore, a gas valve 7 can be formed, which is fluidly connected to the melt receiving space 4 and which is designed to regulate a gas input into the melt receiving space 4.
[0050] Furthermore, it can be provided that a suction line 8 is formed, which can be coupled to a vacuum pump 9. The gas valve 7 can also be arranged in the region of the suction line 8 or be designed to allow gas to flow into the melt receiving chamber 4 in a targeted manner via the suction line 8.
[0051] As can be seen from Fig. 1, it can be provided that the melt transport device 1 has a siphon 10. The siphon 10 can be arranged between the melt receiving space
[0052] 4 and the pouring opening 6.
[0053] In particular, it can be provided that the siphon 10 is arranged on the underside of the lance 5.
[0054] Furthermore, a pressure detection device 12 can be provided, by means of which an internal pressure in the melt receiving chamber 4 can be detected. Thus, the gas pressure in the melt receiving chamber 4 can be specifically adjusted by the gas valve 7.
[0055] As further evident from the embodiment of Fig. 1, the melt transport device 1 can be provided with a fill level sensor 13, which serves to detect an actual fill level 14. The actual fill level 14 can thus be continuously detected and compared with a target fill level 15.
[0056] Figure 2 shows a detailed view of lance 5, with the same reference numerals and component designations used for identical parts as in the previous Fig. 1. To avoid unnecessary repetition, reference is made to the detailed description in the previous Fig. 1. Fig. 2 shows lance 5 in a longitudinal section. The structure of lance 5 will be described below using a combined view of Figs. 1 and 2.
[0057] As can be further seen from Fig. 2, it can be provided that the siphon 10 has a reservoir 16 which is arranged between the melt receiving space 4 and the pouring opening 6.
[0058] The flow channel within the lance 5 can be referred to as a spout 17. In particular, the spout 17 can extend between the melt receiving chamber 4 and the spout opening 6.
[0059] Furthermore, a siphon wall 18 is formed which projects into the reservoir 16 in such a way that, when the reservoir 16 is filled with melt up to an overflow level 20, the melt receiving space 4 is closed in a gas-tight manner with respect to an outer side 19 of the melt container.
[0060] The siphon 10 can be configured such that the reservoir 16 has the overflow level 20, wherein the siphon wall 18 is configured such that it has a siphon wall lower edge 21. The siphon wall 18 protrudes into the reservoir 16 such that a siphon wall lower edge 21 is arranged at a lower level than the overflow level 20.
[0061] As an alternative to the formation of a siphon 10, the lance 5 may also have a different design.
[0062] As further evident from Fig. 1, it can be provided that the melt container 3 is pivotably and displaceably mounted on a manipulation device about a horizontal melt container pivot axis 22. If the melt container pivot axis 22 and the casting mold pivot axis 23 are not congruent, it may be necessary for the melt container 3 and / or the casting mold 11 to be simultaneously displaced during tilting in order to avoid a collision between the melt container 3 and the casting mold 11.
[0063] Furthermore, it can be provided that the casting mold 11 can be pivoted about a horizontal casting mold pivot axis 23. As can also be seen from Fig. 1, it can be provided that a plug 24 is formed, which can serve to reduce an outflow cross-section in the melt container 3. In particular, it can be provided that the plug 24 is designed to be displaceable in a plug axial direction 25 relative to the melt container 3. The plug 24 can be displaced in the plug axial direction 25 by means of an actuator 26. In the illustration according to Fig. 1, the plug 24 is shown in its closed position.
[0064] Furthermore, a digital computer 27 can be provided, by means of which the melt transport device 1 or a casting system can be controlled. In particular, the program for carrying out the method according to the invention can be stored on the digital computer 27.
[0065] As further evident from Fig. 1, the casting mold 11 can be provided with a sprue 28 and a mold cavity 29. The sprue 28 serves to introduce the melt 2 into the casting mold 11, and the mold cavity 29 serves to shape the cast workpiece. In particular, the sprue 28 and the mold cavity 29 can be fluidly coupled to one another by means of a flow channel 30. Furthermore, a depression 31 can be formed in the flow channel 30.
[0066] As can be further seen from Fig. 1, it can be provided that the lance 5 can be introduced into the sprue 28 in order to be able to fill the casting mold 11 with melt 2.
[0067] In particular, it can be provided that the sprue 28 is rotationally symmetrical. Furthermore, it can be provided that the lance 5 is rotationally symmetrical. In particular, it can be provided that the sprue 28 has a sprue diameter 32. Furthermore, it can be provided that the lance 5 has a lance diameter 33. In particular, it can be provided that the sprue diameter 32 is larger than the lance diameter 33. This measure can ensure that the lance 5 can be easily inserted into the sprue 28. Furthermore, this measure can ensure that the lance 5 can be moved or tilted to a small extent relative to the sprue 28 without colliding with the sprue 28.
[0068] As further evident from Fig. 1, it can be provided that, for casting the cast workpiece, the lance 5 is inserted so deeply into the sprue 28 that the pouring opening 6 is located below a flow channel bottom 40. In particular, it can be provided that the pouring opening 6 is located at a coverage height below the flow channel bottom 40. Furthermore, it can be provided that the overflow level 20 of the siphon 10 is arranged at a coverage height 41 relative to the flow channel bottom 40.
[0069] Fig. 3 shows the first embodiment of the melt transport device 1 and the casting mold 11 in a tilted position, wherein again the same reference numerals or component designations are used for the same parts as in the preceding Figs. 1 and 2. To avoid unnecessary repetition, reference is made to the detailed description in the preceding Figs. 1 and 2.
[0070] As can be seen from Fig. 3, the casting mold 11 can be tilted at a mold pivot angle 34. Furthermore, the lance 5 can be tilted at a lance pivot angle 35. In the present embodiment, the mold pivot angle 34 and the lance pivot angle 35 are equal.
[0071] Fig. 3 shows the melt transport device 1 or the casting mold 11 during the casting process. During this process, a melt level 36 of the melt 2 can develop in the casting mold 11. Due to flow conditions or the dynamic viscosity of the melt, the melt level 36 can be somewhat higher in the sprue 28 than in the mold cavity 29. However, due to the physics of the communicating vessels in the sprue 28 and the mold cavity 29, the melt level 36 will generally be at approximately the same level. In particular, it can be provided that the melt level 36 has a melt level height 37. As already explained, the melt level height 37 can be somewhat higher in the sprue 28 than in the mold cavity 29 during the filling process.
[0072] With reference to Figs. 1 and 3, different scenarios of a possible process sequence for pouring the melt 2 into the casting mold 11 or for producing a cast workpiece are now described.
[0073] For all of the process sequences described, it can be provided that the melt container 3 or the lance 5 is filled with melt 2. This can occur in a melting furnace (not shown), wherein the melt 2 can either be sucked into the melt receiving chamber 4 through the pouring openings 6 via the lance 5 or can be filled directly into the melt receiving chamber 4 through a separate opening (not shown). Furthermore, for all of the process variants described further, it can be provided that the lance 5 or the melt container 3 is not tilted during the transport of the melt container 3 from the melting furnace or from the filling station to the casting mold 11.
[0074] In other words, the lance pivot angle 35 can be equal to 0°. This has the advantage that spillage of the melt 2 during transport can be prevented as much as possible. In a further development, it can also be provided that the lance pivot angle 35 is slightly adjusted during transport of the melt container 3, in particular when applying acceleration, so that an acceleration force occurring in the melt 2 due to the acceleration and the resulting displacement of the melt surface can be compensated.
[0075] In a first method variant, the casting mold 11, which is still empty and prepared for casting, can be tilted at a mold tilt angle 34 greater than 0°. The melt container 3 or the lance 5 can be tilted at a lance tilt angle 35 after transport. The lance tilt angle 35 can be the same as the mold tilt angle 34.
[0076] The lance 5 can then be inserted into the sprue 28 of the casting mold 11.
[0077] Subsequently, the negative pressure in the melt receiving chamber 4 can be reduced by means of the gas valve 7, whereby the melt 2 can flow through the pouring opening 6 of the lance 5 into the sprue 28. The melt level 36 will rise in the sprue 28, whereby the melt 2 can also penetrate into the flow channel 30.
[0078] In particular, it can be provided that a filter 42 is arranged in the depression 31, which extends into the flow channel 30. It can be provided that the melt 2 passes through the filter 42, and oxides that are formed at the start of casting are retained in the filter 42.
[0079] If the melt level 36 continues to rise, the melt 2 can flow into the mold cavity 29.
[0080] During the casting process, the melt container 3 and the casting mold 11 can be pivoted into a vertical position according to Fig. 1, in which the mold pivot angle 34 and the lance pivot angle 35 are equal to 0°. In particular, it can be provided that the melt container 3 and the casting mold 11 are pivoted into the vertical position even before a bottom 38 of the mold cavity 29 is completely covered with melt 2.
[0081] The vertical position can then be maintained until the pouring process is completed.
[0082] In a variation of this method, it is also conceivable that the vertical position is not maintained until the end of the casting process, but that upon reaching a certain melt level 36, the melt container 3 or the casting mold 11 is pivoted out of the vertical position again. This renewed pivoting can either be maintained until the end of the casting process or be only temporary, and before the end of the casting process, the melt container 3 and the casting mold 11 can be returned to their vertical position.
[0083] In a second embodiment of the method, it can be provided that at the beginning of the casting process, the melt container 3 and the casting mold 11 are placed in a vertical position with a mold pivot angle 34 and a lance pivot angle 35 equal to 0°, and only when a certain melt level 36 is reached are the melt container 3 and the casting mold 11 tilted. This tilting can, as already described in the first embodiment, either be maintained until the end of the casting process or be only temporary, and before the end of the casting process, the melt container 3 and the casting mold 11 can be returned to their vertical position.
[0084] In both described process variants, the maximum possible lance pivot angle 35 can be limited by the functionality of the siphon 10. In order to achieve a maximum inclined position of the casting mold 11, it can be provided that the mold pivot angle 34 is at least temporarily somewhat larger than the lance pivot angle 35, wherein the difference between the mold pivot angle 34 and the lance pivot angle 35 is selected such that the lance 5 does not collide with the sprue 28.
[0085] As soon as the melt level 36 is above the siphon 10, an increase in the lance pivot angle 35 or an increased tilt of the lance 5 can be enabled. Figure 4 shows the melt transport device 1 in a further and possibly independent embodiment, wherein the same reference numerals as in Figures 1 to 3 are used for the same parts. For the sake of brevity, reference is made here to the detailed description of Figures 1 to 3.
[0086] As can be seen from Fig. 4, the sprue 28 can be provided with a relief 39. The relief 39 can extend the sprue 28 upwards or toward a sprue opening. In a first embodiment, as shown in Fig. 4, the relief 39 can be designed in the form of a slot or in the form of a semicone extending toward the mold cavity 29.
[0087] In a further embodiment variant not shown, it can be provided that the clearance 39 in the sprue 28 is conical.
[0088] Fig. 5 shows a possible process sequence for filling the casting mold 11.
[0089] As can be seen from Fig. 5a, the casting mold 11 can be non-tilted in a first process step, wherein the mold tilt angle 34 can be equal to 0°. In a further process step according to
[0090] Fig. 5b, the casting mold 11 can be tilted and the mold swivel angle 34 can be increased.
[0091] Subsequently, in a further process step according to Fig. 5c, the mold swivel angle 34 can be reduced again.
[0092] Subsequently, in a further process step according to Fig. 5d, the mold swivel angle 34 can be increased again.
[0093] Furthermore, it is conceivable that the mold can be pivoted several times between different pivot angles 34 as shown in Fig. 5c and 5d.
[0094] Subsequently, in a further process step according to Fig. 5e, the mold swivel angle 34 can be brought back to 0°.
[0095] The embodiments show possible embodiments, whereby it should be noted at this point that the invention is not limited to the specifically illustrated embodiments thereof, but rather various combinations of the individual embodiments with each other are also possible and this possibility of variation lies within the skill of the person skilled in the art in this technical field due to the teaching of technical action by means of the objective invention.
[0096] The scope of protection is determined by the claims. However, the description and drawings must be used to interpret the claims. Individual features or combinations of features from the various embodiments shown and described may represent independent inventive solutions. The problem underlying these independent inventive solutions can be derived from the description.
[0097] All information on value ranges in this description is to be understood as including any and all sub-ranges thereof, e.g. the information 1 to 10 is to be understood as including all sub-ranges starting from the lower limit of 1 and the upper limit of 10, ie all sub-ranges begin with a lower limit of 1 or greater and end with an upper limit of 10 or less, e.g. 1 to 1.7, or 3.2 to 8.1, or 5.5 to 10.
[0098] For the sake of clarity, it should finally be pointed out that, in order to better understand the structure, some elements have been shown out of scale and / or enlarged and / or reduced in size.
[0099] Reference symbols
[0100] Melt transport device 32 sprue diameter
[0101] Melt 33 lance diameter
[0102] Melt container 34 mold swivel angle
[0103] Melt receiving space 35 lance swivel angle
[0104] Lance 36 melt level
[0105] Pouring opening 37 Melt level height
[0106] Gas valve 38 bottom
[0107] Suction line 39 exemption
[0108] Vacuum pump 40 flow channel floor
[0109] Siphon 41 Cover height
[0110] Casting mold 42 filter
[0111] Print capture medium
[0112] Level sensor
[0113] Actual filling level
[0114] Target filling level
[0115] reservoir
[0116] spout
[0117] siphon wall
[0118] Melt container outside
[0119] Overflow level
[0120] Siphon wall bottom edge
[0121] Melt container swivel axis
[0122] Casting mold swivel axis
[0123] Plug
[0124] Plug axial direction
[0125] Actuator
[0126] digital computer
[0127] sprue
[0128] mold cavity
[0129] flow channel
[0130] depression
Claims
Patent claims 1. A method for producing a cast workpiece, comprising the process steps: - Providing a casting mold (11) with a sprue (28) and a mold cavity (29), wherein the mold cavity (29) serves to shape the cast workpiece and wherein the sprue (28) is arranged laterally offset from the mold cavity (29) and the sprue (28) and the mold cavity (29) are fluidly connected; - Providing a melt container (3) in which a melt receiving space (4) is formed, wherein the melt container (3) has a spout (17) in the form of a lance (5) located at the bottom of the melt container (3) with a spout opening (6), wherein a gas valve (7) is formed which is fluidly connected to the melt receiving space (4) and wherein the gas valve (7) serves to regulate a gas input into the melt receiving space (4); - filling the melt container (3) with melt (2), wherein the melt (2) is introduced into the melt receiving space (4) of the melt container (3); - Pouring the cast workpiece with melt (2) from the melt container (3), wherein the melt (2) received in the melt receiving space (4) is introduced into the sprue (28) of the casting mold (11) via the pouring opening (6) of the lance (5), wherein the casting mold (11) is pivoted at least at one time during the pouring at a mold pivot angle (34) greater than 0° towards the sprue (28) so that at least a part of the sprue (28) lies lower than the mold cavity (29), in particular that the lance (5) is also pivoted at a lance pivot angle (35).
2. Method according to claim 1, characterized in that the casting mold (11) is pivoted at a mold pivot angle (34) of greater than 0° before the start of casting.
3. Method according to claim 2, characterized in that before the bottom (38) of the mold cavity (29) is completely covered with melt (2), the casting mold (11) is pivoted into a vertical position with a mold pivot angle (34) of 0°.
4. Method according to claim 1, characterized in that the casting mold (11) is moved into a vertical position with a mold swivel angle (34) of 0° at the start of casting. is pivoted and during the casting process is pivoted into an inclined position with a mold pivot angle (34) greater than 0°.
5. Method according to claim 2 or 4, characterized in that the casting mold (11) is pivoted into a vertical position with a mold pivot angle (34) of 0° before the end of the casting.
6. Method according to one of the preceding claims, characterized in that during casting the mold pivot angle (34) and the lance pivot angle (35) are changed synchronously with each other.
7. Method according to one of claims 1 to 5, characterized in that during casting the mold pivot angle (34) is at least temporarily greater than the lance pivot angle (35).
8. Method according to one of the preceding claims, characterized in that when the mold swivel angle (34) changes during casting, a swivel acceleration is selected such that no area of the casting mold (11) filled with melt (2) at this time has an acceleration higher than 0.1 m / s 2 occurs.
9. Method according to one of the preceding claims, characterized in that the lance pivot angle (35) has a first value greater than 0° at the start of casting, wherein as soon as a melt level (36) in the sprue (28) of the casting mold (11) reaches a certain melt level height (37), the lance pivot angle (35) is increased to a second value, wherein the second value is greater than the first value.
10. The method according to claim 9, characterized in that the first value is between 0.1° and 20° and that the second value is between the first value and 35°.
11. Method according to one of the preceding claims, characterized in that the maximum possible lance pivot angle (35) is limited by a mechanical stop or by a software lock.
12. Method according to one of the preceding claims, characterized in that the casting mold (11) is pivoted into a vertical position with a mold pivot angle (34) of 0° at the start of casting and is pivoted into an inclined position with a mold pivot angle (34) greater than 0° during the casting process and is pivoted again into a vertical position with a mold pivot angle (34) of 0° before the end of casting.
13. Method according to one of the preceding claims, characterized in that at the start of casting the melt (2) first flows into a depression (31) arranged between the sprue (28) and the mold cavity (29) and fills this depression before the melt (2) flows into the mold cavity (29).
14. Computer-implemented method for determining a temporal course of a mold swivel angle (34) of a casting mold (11) during casting, comprising the method steps: - Providing a digital model of a melt container (3) which has a spout (17) in the form of a lance (5) located at the bottom of the melt container (3) with a spout opening (6); - providing a digital model of a casting mold (11); - Carrying out a CFD simulation for casting a cast workpiece, wherein the temporal course of a mold swivel angle (34) of the casting mold (11) is simulated during casting; - Determining the temporal progression of the mold swivel angle (34) of the casting mold (11) at which a minimum of air inclusions occurs in the real casting workpiece on the basis of the CFD simulation for casting a casting workpiece; - Transferring the calculated time course of the mold swivel angle (34) of the casting mold (11) to a digital computer (27) for controlling a casting plant.
15. Computer-implemented method according to claim 14, characterized in that together with the temporal course of a mold swivel angle (34) of the casting mold (11), the temporal course of a melt introduction into the casting mold (11) is additionally simulated, comprising the method steps: - Carrying out a CFD simulation for casting a cast workpiece, wherein the temporal course of a mold swivel angle (34) of the casting mold (11) and the temporal course of a melt introduction into the casting mold (11) during casting are simulated; - Determining the temporal progression of the mold swivel angle (34) of the casting mold (11) and the temporal progression of a melt introduction into the casting mold (11) at which a minimum of air inclusions occurs in the real casting workpiece on the basis of the CFD simulation for casting a casting workpiece; - Transferring the calculated time course of the mold swivel angle (34) of the casting mold (11) and the time course of a melt introduction into the casting mold (11) to a digital computer (27) for controlling the casting system.