Casting method and casting machine for metals

Abstract

The invention relates to a casting method for metals, in particular lead and / or zinc, in which at least the following steps are carried out: feeding a metal (2) into a heated cartridge (3); conveying the metal (2) towards the spreading openings (4) of the cartridge (3) by means of a rotational movement of a conveying worm (5) arranged in the cartridge (3); melting the metal (2) and / or holding the metal (2) in a melt in such a way that the metal (2) is substantially completely present in a liquid phase at least in a sub-region at the dispersion opening (4) of the cartridge (3); pushing out the metal (2), which is substantially completely present in the liquid phase, through the dispersion opening (4) of the cartridge (3) by means of an axial piston movement of the feed worm (5), whereby the pushed-out metal (2) at least partially fills the at least one mold cavity (6); and cooling the metal (2) in such a way that the metal is shaped in the at least one mould cavity (6).

Description

Technical Field

[0001] The invention relates to a casting method for metal, in particular lead and / or zinc, and a casting machine having the features of the preamble of claim 15 . Background Art

[0002] In principle, casting methods are known in which molten metal is pushed out of a cartridge or a similar container by means of a piston and filled into a mold cavity, for example in the form of pressure casting.

[0003] The processes disclosed in DE 10 2016 006 917 A1, DE 10 2018 109 322 A1 and DE 10 2019 131 011 A1 also function according to this principle.

[0004] The machines known from the prior art for carrying out the casting method are obviously complex, on the one hand with regard to the design of the barrel or melting container and on the other hand with regard to the sealing of the piston.

[0005] Furthermore, the melt reaching the seal degrades the seal and the sliding surfaces present in this region, so that according to the invention relatively short maintenance intervals must be observed. Summary of the invention

[0006] Against this background, the present invention proposes the object of providing a simpler and / or less maintenance method and machine for casting metal.

[0007] With regard to the casting method, this object is achieved by the features of claim 1 in that at least the following steps are carried out:

[0008] - supplying metal into the barrel,

[0009] - conveying the metal towards the dispensing opening of the barrel by means of the rotational movement of a conveying screw arranged in the barrel,

[0010] - melting the metal and / or keeping the metal in a melt so that the metal is present substantially completely in the liquid phase at least in a subregion at the distribution opening of the cartridge,

[0011] - by means of the axial piston movement of the conveying screw, the metal which is present essentially completely in the liquid phase is pushed out through the distribution opening of the cartridge, whereby the pushed out metal at least partially fills at least one mold cavity, and

[0012] - Cooling the metal so that it takes shape in at least one mold cavity.

[0013] With regard to a casting machine, this object is achieved by the features of claim 15 , namely a casting machine for forming metals, in particular lead and zinc, which is particularly suitable for carrying out the method according to the invention, comprising:

[0014] - Barrel,

[0015] - a supply device for supplying metal into the barrel, and

[0016] a heating device which is configured and arranged to melt the metal present in the cartridge and / or to keep the metal in a melt such that the metal is present substantially completely in the liquid phase at least in a subregion at the distribution opening of the cartridge,

[0017] A conveying screw and a conveying screw drive are provided in the barrel, and the conveying screw drive is designed to set the conveying screw in a rotational motion and an axial piston motion, and the metal which is substantially completely present in the liquid phase is

[0018] - can be conveyed towards the dispensing opening of the cartridge by means of a rotational movement of the conveying worm, and

[0019] - can be pushed out through the dispensing opening of the cartridge by an axial piston movement of the conveying screw in order to at least partially fill at least one mould cavity with metal.

[0020] According to the invention, a complicated seal of a piston in a barrel or a melting container is avoided and replaced by a conveying screw which can convey the molten metal to the casting opening of the barrel on the mold side, so that a seal itself is no longer necessary or can be very simple to implement. At the same time, the conveying screw according to the invention can realize a movement of pushing the metal out of the barrel by an axial piston movement.

[0021] However, it should be noted that the conveying screw in the sense of this document is not a piston, but can only execute piston movements and can therefore assume the function of a piston.

[0022] Surprisingly, it has been found that conveying screws of modern manufacture are subject to an increased thermal load when the conveying screw is subjected to metal melting.

[0023] Of course, axial piston movement is to be understood as axial relative to the center axis of the cartridge. A similar situation applies to the rotational movement of the conveying screw around the center axis of the cartridge.

[0024] In a particularly preferred embodiment of the invention, metals are used whose melting points are below 450° C. and / or 440° C. and / or 430° C., such as, in particular, lead or zinc.

[0025] Suitable metals are, in particular, alkali metals, alkaline earth metals, transition metals, post-transition metals, semimetals, lanthanides and actinides.

[0026] In the sense of the present invention, metal is also understood to mean alloys or mixtures of metals (single-phase or multi-phase). It is also understood to mean material mixtures containing a significant proportion of metal, preferably a material mixture containing more than 25% and / or more than 50% and / or more than 75% and / or more than 90% of metal. For example, metal components with fillers can be realized in this way.

[0027] In a preferred embodiment of the present invention, the metal can be a so-called ZAMAK alloy, ie an alloy of the chemical elements zinc, aluminum, magnesium and copper and optionally other substances. In this particularly preferred embodiment, zinc occupies the largest proportion of the alloy.

[0028] A conveying screw is understood to be a component having a screw geometry, for example in the form of at least one screw thread, such that the material, here metal, is conveyed in a direction in the cartridge by the rotation of the conveying screw.

[0029] The diffusion opening is preferably configured to be selectively opened or closed.

[0030] Therefore, a sealing function is preferably present which ensures that no metal or only small amounts of metal escape from the cartridge when this is undesirable.

[0031] The dispensing opening is preferably provided at one end of the cartridge.

[0032] According to the invention, the subregion of the cartridge in which the metal is present substantially completely in the liquid phase adjoins the scattering opening, so that the axial piston movement causes the metal present substantially completely in the liquid phase to be ejected through the scattering opening.

[0033] The at least one mold cavity can preferably be realized by a casting mold which is separate from the casting machine and which can be mounted on the machine.

[0034] In order to fluidically connect the dispensing opening of the cartridge to the at least one mold cavity, for example, connecting channels and / or channels and / or channel systems can be used in the casting mold containing the at least one mold cavity.

[0035] According to the invention, at least one mold cavity may be partially filled. However, in a preferred embodiment, at least one mold cavity is completely filled.

[0036] Furthermore, protection is claimed for the use of a casting machine according to the invention in a casting method according to the invention.

[0037] Advantageous developments of the invention are defined in the dependent claims.

[0038] Preferably, the metal is supplied to the cartridge in the solid phase.

[0039] Alternatively or additionally, the metal can also be supplied to the cartridge already in the liquid phase.

[0040] The metal may be put into particle form by comminution before being supplied to the barrel.

[0041] Comminution can be achieved, for example, by breaking (for example by means of a cutting wheel) at least one metal wire and / or at least one metal rod or other types of granulation devices.

[0042] Of course, the metal can also already be present in granular form, so that comminution is no longer necessary.

[0043] In a particularly preferred embodiment, the cartridge is brought to a temperature above the melting temperature of the metal, for example by means of a heating device, at least between the supply point of the metal and the distribution opening, and preferably kept there. Thus, melting the metal in the cartridge and / or keeping the metal in the melt can be achieved in a particularly simple manner.

[0044] For melting the metal and / or keeping it in the melt, preferably heating belts and / or induction heating devices and / or infrared radiation devices are used at the barrel, which can be part of a heating arrangement, for example.

[0045] Alternatively or additionally, the barrel can have at least one heating medium channel, for example in the form of a groove (preferably spirally around the barrel), in which a pipe element for the heating medium is preferably arranged, and through which a fluid heating medium, for example oil, is conveyed in order to melt the metal and / or keep the metal in the melt.

[0046] A heating device can be integrated into the barrel.

[0047] In a particularly preferred embodiment, only enough metal can be fed into the cartridge so that there is a partial filling in the cartridge, preferably a partial filling of less than 95%, 90%, 80% and / or 70% (in each case volume fraction).

[0048] On the one hand, this can have the advantage that in the feed region of the conveying screw near the point to which the metal is supplied there is no dense accumulation of metal, for example in the form of particles, which could cause the particles to become jammed between the screw geometry and the cartridge.

[0049] On the other hand, by partial filling, gases and / or moisture evaporating from the metal melt can escape and be sucked away, for example, at the end of the barrel facing away from the dispersing opening or at the filling opening. For example, air streaks and / or bubbles and / or other defects of the molded part can thus be avoided.

[0050] Optionally, the cartridge may contain additional degassing zones and / or degassing openings (separate from the diffusion openings).

[0051] In a particularly preferred embodiment, a backflow prevention mechanism can be used at the guide end of the conveying screw. This has the advantage that a more precisely defined amount of molten metal exits the barrel and enters the at least one mold cavity and / or channel and / or channel system during ejection than would be the case without a non-return valve.

[0052] In a particularly preferred embodiment, an actively actuatable, preferably mechanically actively actuatable backflow prevention mechanism can be used. Reference is made to DE 102012015337 A1, whose technical disclosure regarding a mechanically actively actuatable backflow prevention mechanism is incorporated in its entirety into the present disclosure.

[0053] In a preferred embodiment, a closing nozzle can be used at the dispensing opening of the cartridge for selectively opening the dispensing opening.

[0054] Alternatively or additionally, at least one closing nozzle can be present in the channel and / or in the channel system.

[0055] The metal can be filled into the at least one mold cavity under pressure when being pushed out of the cartridge, wherein the maximum pressure is preferably below 2000 bar and / or 1500 bar and / or 1300 bar.

[0056] A protective gas atmosphere and / or a protective vacuum can be used in the cartridge and / or in the at least one mold cavity and / or in the connecting channel between the cartridge and the mold cavity.

[0057] The connecting channel can be realized by the mentioned channels and / or the mentioned channel systems.

[0058] In this case, a protective vacuum is to be understood in the technical sense as the generation of a negative pressure (compared to the surroundings) in the volume in question.

[0059] Preferably, a pressure accumulator can be used which is operatively connected to the molten metal pressure, preferably in the region of the connecting channel between the cartridge and the mold cavity, fluidically downstream of the conveying screw, preferably fluidically downstream of the backflow prevention device.

[0060] The connecting channel can be realized by the mentioned channels and / or the mentioned channel systems. In terms of terminology, a distinction is made between general connecting channels on the one hand and channels and / or channel systems of the casting on the other hand.

[0061] The pressure accumulator can compensate for pressure peaks that occur when filling the at least one mold cavity due to the incompressibility of the melt.

[0062] In a preferred embodiment, the pressure accumulator can have a piston-cylinder unit and / or a mechanical spring element. Preferably, the chamber of the piston-cylinder unit is operatively connected to the molten metal pressure, and the piston of the piston-cylinder unit can be spring-loaded by means of the mechanical spring element.

[0063] Particularly preferably, the casting mold containing the at least one mold cavity can be temperature-controlled, in particular can be heated and / or cooled during the filling process in order to cool the metal.

[0064] The same applies to the channels and / or channel systems, wherein the channels and / or channel systems are preferably heated substantially continuously in order to keep the metal in the melt here as well (hot channel system).

[0065] Particularly preferably, a conveying screw can be used which has a screw geometry with a compression ratio between 1.0 and 1.4 and / or between 1.1 and 1.3 and / or between 1.15 and 1.25. For example, the compression ratio can be approximately 1.2.

[0066] The compression ratio is understood to be the ratio of the thread volume and / or thread cross-section in the feed region, i.e. the point where the metal is fed, to the thread volume and / or thread cross-section at the end region of the conveying screw (conveying screw tip). This essentially quantifies the degree of compression of the material conveyed by means of the conveying screw.

[0067] Within the scope of the invention, a compression ratio of greater than 1 can be used to evaporate gases and / or moisture from the metal melt, so that these normally undesirable substances do not remain in the metal melt and subsequently in the molded part or react with the metal melt.

[0068] Backflow prevention means, for example in the form of annular or spherical backflow prevention means, as well as closing nozzles, worm geometry, worm drives and hot runner systems are known per se from the field of injection molding and can therefore be taken from another technical field. BRIEF DESCRIPTION OF THE DRAWINGS

[0069] Further advantages and details of the invention are apparent from the drawings and the associated description of the drawings. Here, it is shown:

[0070] Figure 1 An embodiment of a casting machine according to the present invention is shown,

[0071] Figure 2 A further embodiment of a casting machine according to the invention is shown,

[0072] Figure 3 An embodiment according to the invention showing a casting machine in the area of ​​a closing unit, and

[0073] Figure 4 An exemplary embodiment of a pressure accumulator is shown. DETAILED DESCRIPTION

[0074] Figure 1 An exemplary embodiment of a casting machine 1 according to the invention is shown schematically.

[0075] The casting machine comprises a supply device 18 and a barrel 3 .

[0076] The supply device 18 comprises a transport device 21 which, in the present embodiment, comprises rollers for advancing the metal 2 in the form of a lead rod.

[0077] The lead rod is broken up and thus placed in granular form by means of a rotating cutting wheel 6. The metal 2 falls by gravity into a supply opening at a supply position 7 of the barrel 3.

[0078] In addition, in the present exemplary embodiment, the supply device 18 comprises a supply device for a protective gas 14, which likewise enters through a supply opening into the interior of the cartridge 3. The protective gas prevents the metal 2 present in the cartridge 3 from reacting with gas components in the air.

[0079] Alternatively, instead of the protective gas 14 , a suction device can be provided, by means of which a protective vacuum is generated in the cartridge 3 .

[0080] A conveying screw 5 is arranged in the cartridge 3 , which can be moved both rotationally and axially in the cartridge 3 .

[0081] The conveying screw 5 comprises a screw geometry 17 with a screw thread, so that a conveying effect is generated by the rotational movement of the conveying screw 5 , which transports the metal 2 in the direction of the dispensing opening 4 of the cartridge 3 .

[0082] In this embodiment, the worm thread has a constant thread volume so that the compression ratio is 1.

[0083] In an alternative embodiment, the compression ratio may be, for example, approximately 1.2.

[0084] Furthermore, a heating device 19 is provided which, in the present exemplary embodiment, comprises a heating belt 8 .

[0085] The barrel 3 is kept at a temperature above the melting temperature of the metal 2 by means of the heating belt 8 , so that the metal 2 melts in the barrel.

[0086] Furthermore, the metal 2 can also be fed into the cylinder 3 in an already molten state.

[0087] Independently of this, in the present exemplary embodiment it is ensured by the heating band 8 that the metal 2 remains in the melt in the barrel.

[0088] Alternatively or additionally, instead of heating belts, inductive heating and / or heating by means of electromagnetic radiation, preferably infrared radiation, can also be used.

[0089] Alternatively or additionally, the cartridge 3 can have at least one heating medium channel, for example in the form of a groove, through which a fluid heating medium, for example oil, is conveyed in order to melt the metal 2 and / or to keep the metal 2 in the melt.

[0090] In the present embodiment, metal 2 in granular form is supplied into the barrel by means of a supply device 18 and there conveyed by means of a conveying screw 5 toward a distribution opening 4 of the barrel 3, wherein the metal is melted under the action of a heating device 19 and is subsequently present in a substantially completely molten phase in a subregion of the barrel 3, wherein the subregion extends from the distribution opening 4 toward the supply position 7.

[0091] The axial piston movement of the conveying screw 5 can be used to push the molten metal 2 out of the sub-region through the spreading opening 4 and fill it into the mold cavity 12, for which reference is made to Figure 3 .

[0092] A closing nozzle 11 is arranged at the dispensing opening 4 of the cartridge 3 .

[0093] In the present exemplary embodiment, it is provided that the shut-off nozzle 11 is selectively opened simultaneously with the axial piston movement and otherwise remains closed.

[0094] It should be mentioned that within the scope of the present invention, the part or component in which the closing nozzle 11 is arranged is understood to be a part of the cartridge 3. This part of the cartridge 3 can also be understood to be a filling nozzle.

[0095] In the present embodiment, only enough metal is fed into the cartridge so that a partial filling of 50% by volume is present in the cartridge.

[0096] Figure 2 Schematically showing the Figure 1 Another embodiment of a casting machine 1 according to the present invention is similar to the embodiment in FIG.

[0097] The conveying worm drive 20 is shown, which is designed to set the conveying worm 5 not only in a rotational movement but also in an axial piston movement. Figure 1 In the embodiment of FIG. 1 , a conveying worm drive 20 having the described function is also provided.

[0098] and Figure 1 In the embodiment different from Figure 2 In the embodiment of FIG. 1 , a backflow prevention mechanism indicated by a symbol is provided at the leading end 9 of the conveying worm 5 .

[0099] In this case, a mechanically actively actuatable backflow prevention device 10 is preferred.

[0100] Figure 3 The casting machine 1 is shown in the region of a closing unit. The casting machine comprises clamping plates 22 which are movable relative to one another, to which components of the casting mold 16 can be mounted.

[0101] The mold cavity 12 can be opened or closed by a relative movement of the clamping plates 22 .

[0102] One of the clamping plates 22 (usually the fixed clamping plate 22 ) has a through-opening, through which the dispensing opening 4 of the cartridge 3 can be brought into contact with the casting mold.

[0103] For example, the part of the casting machine 1 containing the barrel 3 may be as in Figure 1 or Figure 2 The same is implemented as in the embodiment in.

[0104] Due to the aforementioned axial piston movement, the molten metal 2 enters the connecting channel 13 , which is simply a channel here, and subsequently into the mold cavity 12 .

[0105] Alternatively or additionally, instead of a simple channel, a channel system can be provided, for example for connecting a plurality of mold cavities in a casting mold.

[0106] By selecting the movement profile of the axial piston movement of the conveying screw 5 , the speed with which the molten metal 2 enters the connecting channel 13 and the mold cavity 2 can be set.

[0107] The maximum pressure in the molten metal 2 which occurs here is preferably not higher than 1300 bar. Unwanted pressure peaks can optionally be compensated by means of a pressure accumulator 15, for which purpose Figure 4 A more specific example is shown in FIG.

[0108] In this case, the mold cavity 12 of the casting mold 16 can be temperature-controlled via a temperature-control channel 23, which for reasons of clarity is shown at Figure 3 Not all are provided with reference numerals.

[0109] In the embodiment presented here, it is provided that the mold cavity 12 is heated before filling in order to ensure the fluidity of the molten metal 2 as long as possible. Once the mold cavity 12 is completely filled, the mold cavity 12 is cooled so that the metal 2 cools and hardens at the desired speed.

[0110] During the hardening of the metal 2, a crystalline or amorphous internal structure of the metal 2 can be formed. Of course, mixed forms are also conceivable.

[0111] It should be mentioned that in the region of the mold cavity 12 and / or the connecting channel 13 a protective gas 14 or a protective vacuum can also be used.

[0112] In summary, the exemplary embodiment of the casting machine 1 presented here is suitable for carrying out the casting method according to the invention and is configured to:

[0113] - supplying the metal into the heated barrel,

[0114] - conveying the metal towards the dispensing opening of the barrel by means of the rotational movement of a conveying screw arranged in the barrel,

[0115] - melting the metal and / or keeping the metal in a melt so that the metal is present substantially completely in the liquid phase at least in a subregion at the distribution opening of the cartridge,

[0116] - by means of the axial piston movement of the conveying screw, the metal which is present essentially completely in the liquid phase is pushed out through the distribution opening of the cartridge, whereby the pushed out metal at least partially fills at least one mold cavity, and

[0117] - Cooling the metal so that it takes shape in at least one mold cavity.

[0118] exist Figure 4 A pressure accumulator 15 is shown, which can optionally be used to compensate for pressure peaks during the filling of the mold cavity 12 .

[0119] In the present embodiment, the pressure accumulator 15 is arranged in the area of ​​the connecting channel 13 in the casting mold 16, i.e., the pressure accumulator is effectively connected to the pressure of the molten metal 2 in the area of ​​the connecting channel 13 between the barrel 3 and the mold cavity 12 downstream of the conveying screw 5 in terms of flow technology, in particular downstream of the backflow prevention device 10 in terms of flow technology.

[0120] Alternatively or additionally, a pressure accumulator 15 can also be provided, for example, at the dispensing opening 4 of the cartridge 3 .

[0121] In the present exemplary embodiment, the pressure accumulator comprises a piston-cylinder unit 24 and a mechanical spring element 25 in the form of a helical spring.

[0122] The chamber of the piston-cylinder unit 24 is pressure-operatedly connected to the molten metal 2 , and the piston of the piston-cylinder unit 24 is spring-loaded by means of a mechanical spring element 25 .

[0123] Alternatively or additionally, the spring element 25 can contain a gas pressure spring or a gas bellows (similar to a bladder accumulator).

[0124] If pressure peaks occur during the changing filling process of the mold cavity 12 , for example due to the inertial axial piston movement of the conveying screw 5 , this can be compensated by the pressure accumulator 15 even though the mold cavity and any connecting channels are already filled in volume with molten metal 2 .

[0125] Since in this case the spring element 25 is loaded, a spring movement is performed, whereby a volume relief is obtained in the molten metal 2. The restoring movement of the spring element 25 does not occur until the pressure drops again.

[0126] It should be mentioned that it is not necessary to supply the metal 2 into the cartridge 3 in the solid phase, as is done in accordance with Figure 1 and Figure 2 It is entirely conceivable that the metal 2 is at least partially, preferably completely, melted outside the cartridge 3 and is supplied to the cartridge 3 in the described state.

[0127] Reference numerals list

[0128] 1 Casting Machine

[0129] 2 Metal

[0130] 3 Barrel

[0131] 4 Distribution opening (of barrel)

[0132] 5. Conveying worm gear

[0133] 6 Cutting wheel

[0134] 7 Supply Location

[0135] 8 Heating belt

[0136] 9 Guide end (of conveying worm)

[0137] 10 Backflow Prohibition Agency

[0138] 11 Close the nozzle

[0139] 12 mold cavities

[0140] 13 Connection Channels

[0141] 14 Protective gas

[0142] 15 Accumulator

[0143] 16. Casting

[0144] 17 Worm geometry

[0145] 18 Supply equipment

[0146] 19Heating equipment

[0147] 20 Conveyor worm drive

[0148] 21 Transportation Equipment

[0149] 22 Clamping plate

[0150] 23 Temperature control channels

[0151] 24 Piston cylinder unit (accumulator)

[0152] 25 Spring element

Claims

1. A casting method for metal, in particular lead and / or zinc, wherein at least the following steps are performed: - supplying the metal (2) into a heated cylinder (3), - conveying the metal (2) towards the dispensing opening (4) of the cartridge (3) by means of the rotational movement of a conveying screw (5) arranged in the cartridge (3), - melting the metal (2) and / or keeping the metal (2) in a melt so that the metal (2) is present substantially completely in the liquid phase at least in a subregion at the dispensing opening (4) of the cartridge (3), - by means of the axial piston movement of the conveying screw (5), the metal (2) which is present essentially completely in the liquid phase is pushed out through the dispensing opening (4) of the cartridge (3), whereby the pushed out metal (2) at least partially fills at least one mold cavity (6), and - Cooling the metal (2) so that it takes shape in the at least one mould cavity (6).

2. The casting method according to claim 1, wherein the metal (2) is supplied into the barrel (3) in a solid phase.

3. The casting method according to claim 2, wherein the metal (2) is put into a particle shape by pulverizing before being supplied to the barrel (3).

4. The casting method according to claim 1 , wherein the barrel ( 3 ) is brought to a temperature above the melting temperature of the metal ( 2 ) at least between the supply point ( 7 ) of the metal ( 2 ) and the spreading opening ( 4 ) and preferably is kept there.

5. The casting method according to any one of the preceding claims, wherein a heating belt (8) and / or an induction heating device and / or an infrared radiation device are used at the barrel (3) to melt the metal (2) and / or to keep the metal (2) in the melt.

6. A casting method according to any of the preceding claims, wherein only so much metal (2) is supplied into the barrel (3) that there is a partial filling in the barrel (3), preferably a partial filling of less than 95%, 90%, 80% and / or 70%.

7. Casting method according to any of the preceding claims, wherein a backflow prevention mechanism is used at the leading end (9) of the conveying screw (5).

8. The casting method according to claim 7, wherein an actively actuatable, preferably mechanically actively actuatable, backflow prevention mechanism (10) is used.

9. The casting method according to any of the preceding claims, wherein a closing nozzle (11) is used at the spreading opening (4) of the cartridge (3) for selectively opening the spreading opening (4).

10. A casting method according to any of the preceding claims, wherein the metal (2) is filled into the at least one mold cavity (12) under pressure when it is pushed out of the barrel (3), wherein the maximum pressure is preferably below 2000 bar and / or 1500 bar and / or 1300 bar.

11. A casting method according to any of the preceding claims, wherein a protective gas atmosphere and / or a protective vacuum is used in the barrel (3) and / or in the at least one mold cavity (12) and / or in the connecting channel (13) between the barrel (3) and the mold cavity (12).

12. A casting method according to any of the preceding claims, wherein a pressure accumulator (15) is used, which is fluidically connected to the pressure of the molten metal (2) downstream of the conveying screw (5), preferably fluidically downstream of the backflow prevention device (10), preferably in the area of ​​the connecting channel (13) between the barrel (3) and the mold cavity (12).

13. The casting method according to any of the preceding claims, wherein a casting mold (16) containing the at least one mold cavity (12) is temperature-controlled, in particular heated and / or cooled during the filling process in order to cool the metal (2).

14. The casting method according to claim 1, wherein a conveying screw (5) is used which has a screw geometry (17) with a compression ratio between 1.0 and 1.4 and / or between 1.1 and 1.3 and / or between 1.15 and 1.

25.

15. A casting machine for shaping metal, in particular lead or zinc, which is particularly suitable for carrying out the method according to any one of the preceding claims, comprising: - a barrel (3), - a supply device (18) for supplying the metal (2) into the cartridge (3), and a heating device (19) which is configured and arranged to melt the metal (2) present in the cartridge (3) and / or to keep the metal (2) in a melt such that the metal is present substantially completely in the liquid phase at least in a subregion at the dispensing opening (4) of the cartridge (3), It is characterized in that A conveying screw (5) and a conveying screw drive (20) are arranged in the barrel (3), wherein the conveying screw drive (20) is designed to set the conveying screw (5) into a rotational movement and an axial piston movement, and wherein the metal (2) which is present substantially completely in the liquid phase - can be conveyed towards the dispensing opening (4) of the cartridge (3) by means of the rotational movement of the conveying screw (5), and - can be pushed out through the dispensing opening (4) of the cartridge (3) by an axial piston movement of the conveying screw (5) in order to at least partially fill at least one mould cavity (12) with the metal (2).

16. Use of a casting machine (1) according to claim 15 in a casting method according to any one of claims 1 to 14.

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