Plunger system for die casting machine and casting method

Abstract

The present invention relates to a plunger system for a die casting machine and a casting method. A casting plunger system for a die casting machine, wherein the casting plunger system comprises a stationary system part and a system part, which moves relative to the stationary system part in a corresponding casting cycle to introduce molten material into a casting mold and has a plunger, a plunger rod and a rod drive unit and is configured to decelerate under the action of the pressure on the molten material at the end of the mold filling phase of the casting cycle; and a casting method for a die casting machine having such a plunger system. According to the invention, the moving system part has a mass that can be variably adjusted between different casting cycles, and / or the moving system part consists of a moving main system part and an additional mass unit, which is arranged to be movable relative to the main system part and is configured to decelerate at the end of the mold filling phase of the casting cycle later than the main system part by a predefined delay time. Use in a die casting process.

Description

Technical Field

[0001] The present invention relates to a system and method for evaluating the performance of a driver. A casting plunger system for a die casting machine, wherein the plunger system comprises a stationary system part and a system part which moves relative to the stationary system part during a corresponding casting cycle to introduce molten material into a casting mold, and has a casting plunger, a casting plunger rod and a rod drive unit, and is configured to decelerate under the effect of pressure on the molten material at the end of the mold filling phase of the casting cycle; and a casting method for a die casting machine having such a plunger system. Background Art

[0002] It is known that plunger systems of this type and the associated casting methods are usually used in die casting machines, in particular for the die casting of metal parts. The corresponding casting cycle usually consists of a pre-filling phase in which the molten material is transported or pushed upwards to the inlet of the casting mold, a mold filling phase in which the molten material is pressed into the casting mold and a pressure holding phase in which the holding pressure is applied to the molten material in the casting mold by the plunger. The molten material is transported upwards to the die casting mold and into the die casting mold by a corresponding melt conveying movement of the moving system part relative to the stationary system part of the plunger system. In this case, the stationary system part means, for example, the part of the plunger system that is stationarily held on the associated machine structure of the die casting machine, while the moving system part is the part of the plunger system that moves relative to the stationary system part for this melt transport, i.e. all parts of the plunger system that are moved and decelerated at the end of the mold filling phase. During this deceleration process at the end of the mold filling phase, the forward movement of the moving system part is braked completely or at least to a large extent, thereby compressing the melt into the casting mold, wherein any residual forward movement or a certain degree of rebound or oscillating movement is dissipated at the latest in a subsequent so-called pressure holding phase, if the moving system part has not yet come to a complete standstill at the end of the mold filling phase, it does so at the latest during this pressure holding phase.

[0003] The moving system part usually includes a plunger; a plunger rod; the plunger is connected at the front end of the plunger rod and a rod drive unit, which drives the plunger rod to transport molten material through the plunger and usually includes a drive piston and a plunger coupling, by which the plunger rod is connected to the drive piston at its end opposite to the plunger. The drive piston is usually part of a so-called injection unit, which specifies the drive part of the plunger system. The plunger and the plunger rod are usually part of a so-called casting tool, which specifies the driven part of the plunger system. As another part of the injection unit, optionally, a so-called multiplier unit or pressure translation unit can be connected to the drive piston and is used to provide a holding pressure in the pressure holding phase. The stationary system part of the plunger system specifically includes components for guiding the movement of components of the moving system part, such as a casting cylinder (in which the drive piston is guided) and a casting chamber body, which, for example, defines a cylindrical casting chamber, in which the melt is initially present and the plunger moves in the cylindrical casting chamber.

[0004] At the end of the mold filling phase, during which the casting mold is filled with molten material, the moving system part is braked relatively suddenly, completely or to a large extent to a standstill in its forward movement, wherein a so-called first pressure peak is formed for the molten material in the casting mold. This first pressure peak is important for the first compression of the molten material in the casting mold, in particular in areas of the casting mold or the resulting cast part which are relatively far from the insertion area of ​​the molten material into the casting mold. The pressure multiplication in the pressure holding phase, due to the technically induced time delay and the initial melt solidification, often cannot play an adequate role alone. Thus, for example, in die casting machines of the cold chamber type of small and medium size, the typical mold filling time, i.e. the duration of the mold filling phase, is in the range of 10 ms to 15 ms, while in some cases, due to the design, the pressure multiplication effect in the pressure holding phase is delayed by 15 ms to 35 ms relative to the end of the mold filling phase.

[0005] With regard to the first pressure peak in the casting mold, conventionally conflicting process objectives are considered. On the one hand, the first pressure peak must be high enough to achieve a sufficient first compression of the molten material in the casting mold. On the other hand, too high a first pressure peak in the casting mold can lead to so-called over-ejection of the mold, which means that the melt escapes the mold edge in the mold parting plane (i.e. in the plane separating the movable mold half and the stationary mold half), which leads to undesirable burr formation and necessitates subsequent further machining. Conventionally, the observation of these process objectives with regard to the first pressure peak is considered, wherein a dedicated speed profile is predefined for the development of the speed of the plunger and therefore also for the other components of the moving system part of the plunger system across the casting cycle, in particular during the mold filling phase. However, in order to select the optimal plunger speed, in particular also during the mold filling phase, additional process parameters must be taken into account, such as the flow behavior of the molten material in the casting chamber, the optimization of the duration of the mold filling phase, the minimization of air disturbances and mold wear, as well as the casting mold geometry, the flow resistance of the molten material and the performance of the ejection unit as a drive-related part of the plunger system.

[0006] Patent publication DE 34 33 121 C1 defines a cast plunger system having: a plunger coupling with an integrated hydraulic damping device for a rod drive unit, the hydraulic damping device having a damping chamber and a damping piston displaceable in the damping chamber, and a spring-loaded control piston which, due to inertia, can still move further after the plunger has been decelerated at the end of the mold filling phase and only in this damping situation will the holes running between the damping chamber and the storage chamber be opened, otherwise these holes are blocked.

[0007] In the publication JP 8-300134 A, a plunger system is disclosed, in which the plunger coupling has a pressure chamber containing an explosive medium, which can be exploded during the transition from the pre-filling phase to the mold filling phase to accelerate the advancement of the plunger rod and the plunger relative to the rod drive unit, thereby performing the mold filling phase.

[0008] Publication DE 42 18 556 A1 discloses a cast plunger system comprising a hydraulic dual-circulation cast drive for a pressure piston on the one hand and for a multiplier piston on the other hand, and an associated valve control which uses fast-controllable servo-proportional valves to adjust the required amounts of hydraulic medium acting on the respective pistons in a mutually adjusted manner.

[0009] Patent publication DE 28 33 063 C2 discloses a casting plunger system having a hollow casting piston and a casting piston damping arrangement between the piston rod and the casting piston, so that the piston rod can move to a certain extent into the hollow casting piston together with the internal piston when it is decelerated simultaneously with the casting piston at the end of the mold filling phase. Summary of the invention

[0010] The invention is based on the technical problem of providing a casting plunger system of the initially cited type and a casting method for a die casting machine equipped with such a plunger system which, compared with the above-mentioned prior art, offers advantages in the execution of the casting process with regard to achieving high-quality production castings.

[0011] The invention achieves this object by providing a plunger system having the features of claim 1 and a casting method having the features of claim 10. Advantageous developments of the invention are given in the dependent claims.

[0012] According to one aspect of the invention, the moving system part has a mass which can be variably adjusted between different casting cycles. Here, the variably adjustable mass is to be understood as meaning the so-called solid mass, i.e. the rigid mass, of the moving system part. This means that the mass of the possibly present moving gas and fluid (such as hydraulic fluid) is not considered as part of the variably adjustable mass of the moving system part. Therefore, a change in this mass necessarily requires a change in the solid mass, while the final change in the fluid or gas mass is not taken into account for this. In most cases, the mass of the moving system part corresponds substantially to the sum of the masses of the casting piston, the casting piston rod and the drive rod unit. According to another aspect of the invention, as an alternative to or in addition to the above aspect of the invention, this other aspect can be provided that the moving system part consists of a moving main system part and an additional mass unit, which is arranged to be movable relative to the main system part and is configured to decelerate, i.e. to stop completely or to a large extent in its forward movement at the end of the mold filling phase of the casting cycle, after a predefinable delay time than the main system part. Here, moreover, the additional mass unit is to be understood as meaning one or more solid masses, i.e. rigid masses or solid mass bodies, while any fluid or gas mass is not taken into account for this. For convenience, the mass of a solid is also referred to simply as mass hereinafter.

[0013] A common feature of both inventive aspects is that they allow to modify the momentum inherent in the moving system part before the end of the mold filling phase, independently of the plunger speed or the speed of the moving system part, which momentum acts on the molten material in the casting mold due to the deceleration of the moving system part at the end of the mold filling phase. Momentum is defined in a known manner as the product of mass and velocity, and since the solid mass of the moving system part can be variably adjusted between different casting cycles, by means of the above-mentioned first inventive aspect, the momentum of the moving system part can be variably adjusted, which momentum acts on the molten material in the casting mold by decelerating the moving system part at the end of the mold filling phase of the corresponding casting cycle, so that for different casting cycles it is not necessary to change the velocity profile of the moving system part during the mold filling phase for this purpose. According to another inventive aspect, the action of the momentum of the moving system part on the molten material in the casting mold at the end of the mold filling phase can be modified in the temporal development of its corresponding casting cycle, since the additional mass unit is braked at a later time than the main system part, and thus the momentum action provided by the additional mass unit on the molten material in the casting mold takes effect with a corresponding delay relative to the momentum action due to the deceleration of the moving main system part.

[0014] It has been found that the effect of the momentum of the moving system part (caused by the deceleration of the moving system part at the end of the mold filling phase of the corresponding casting cycle) on the molten material present in the casting mold specifically also determines or in any case substantially influences the first pressure peak of the molten material in the casting mold and thus influences the first compression of the casting caused by the hardening of the molten material in the casting mold and thus influences the properties or quality of the casting. The plunger speed does not need to be changed for this variable change and thus for the optimization of the momentum effect of the moving system part on the molten material in the casting mold and can therefore be optimized in a conventional manner with respect to other criteria, in particular with respect to the flow behavior of the molten material when transported to and into the casting mold and with respect to minimum air disturbances, minimum mold wear and short mold filling times.

[0015] Thus, independently of the development of the plunger speed during the mold filling phase, by variably adjusting the kinetic action of the moving system part on the molten material in the casting mold at the end of the mold filling phase, the plunger system according to the invention allows the corresponding casting process for producing cast parts to be optimized, in particular with regard to casting quality and / or economic optimization. In other words, with the casting method according to the invention, the casting process can be optimized and, therefore, in particular, the quality of the produced cast parts can be optimized, not only by optimizing the speed profile of the plunger during the casting cycle, but also independently of this, by optimizing the kinetic action of the moving system part of the plunger system on the molten material in the casting mold at the end of the mold filling phase.

[0016] The same applies to the casting method according to the invention, which is suitable for a die-casting machine equipped with a casting plunger system according to the invention, wherein, according to the method, at least one casting parameter of the corresponding casting cycle is detected, preferably a casting parameter which substantially determines or jointly determines and / or is indicative of the quality of the casting to be produced and / or a casting parameter which influences the effectiveness of the casting process, and depending on the at least one detected casting parameter, the mass of the movable system part and / or the delay time of a relatively movably arranged additional mass unit can be variably adjusted for one or more future casting cycles.

[0017] In an advantageous embodiment, the plunger system comprises a control unit configured to determine an optimal mass of the mobile system part to be provided for the upcoming casting cycle or cycles and / or an optimal delay time of an additional mass unit (which is arranged to be movable relative to the main system part) to be provided for the upcoming casting cycle or cycles, preferably by evaluating actual values ​​of one or more casting parameters (in particular casting parameters known to a person skilled in the art that influence or represent the quality of the produced casting and / or the effectiveness of the casting process), which actual values ​​were detected by sensors or other means during one or more previous casting cycles. In this way, the control unit is able to automatically optimize the casting process or the casting cycle, such as iteratively applicable and / or by using previously performed computer simulations.

[0018] In a refinement of the invention, the plunger system comprises one or more additional mass bodies, each of which is configured to be releasably attached to the moving system part and to form a component of the moving system part in the attached state. Thus, by selecting one or more of these predefined additional mass bodies for the respective casting cycle and by releasably attaching one or more selected additional mass bodies to the moving system part, the mass and therefore the momentum of the moving system part acting on the molten material in the casting mold at the end of the mold filling phase can be variably selected. If the additional mass body is arranged to be movable relative to the main system part, it can form the additional mass unit. Alternatively, the additional mass body can be an additional mass that is releasably and immovably arranged on other moving system parts.

[0019] In an embodiment of the invention, a plurality of additional mass bodies are provided, at least two of which have different masses. This provides good conditions for minimizing the number of such additional mass bodies to be provided so that the mass of the moving system part can be variably set within a certain predefinable value range. For example, to this end, the additional mass bodies may differ in binary steps, i.e. powers of the number 2, or alternatively be distributed in different steps. Alternatively, for example, the additional mass bodies may all have the same mass, and that is, for example, they can then be produced as the same part. In a corresponding embodiment, the plunger system includes a control unit, which is configured to automatically select the corresponding additional mass body to be attached to the moving system part. For this selection, the control unit preferably uses information about casting parameters related to the casting process of the upcoming casting cycle and / or from one or more previous casting cycles.

[0020] In an embodiment of the invention, the stationary system part has an additional mass storage unit provided for the storage of one or more additional masses. In this way, additional mass can be provided very easily for use on the mobile system part. The additional mass selected for this use is extracted from the storage unit on the stationary system part and coupled to the mobile system part. Alternatively, one or more additional masses can be provided from outside the plunger system or separately therefrom, for example at another location of the machine structure of the die casting machine on which the plunger system is arranged.

[0021] In one embodiment of the invention, the plunger system has an additional mass handling unit configured to automatically attach and remove the corresponding additional mass to and from the moving system part. For example, such a handling unit can be implemented by a fully automatic handling robot or alternatively by a semi-automatic and partially user-actuated handling device.

[0022] In a development of the invention, the plunger system comprises a set of a plurality of casting plungers with predefined different masses, which are configured to be used interchangeably as plungers of the moving system part, so that the mass of the moving system part can be set variably between different casting cycles in this way, wherein the pistons differ in their mass by a predefined mass increment. In order to achieve a corresponding optimal momentum of the plunger system at the end of the mold filling phase, in this case the corresponding most suitable plunger can be selected from a set of several plungers with predefined different masses and used as the plunger of the moving system part. The mass increments can be predefined in any desired way, for example all having the same size or at least some having different sizes.

[0023] In order to be able to keep the casting chamber unchanged, it is preferred if the plungers in this embodiment variant of the invention have the same outer diameter. Also because the choice of suitable materials for the plungers is relatively limited due to the requirements imposed on them with regard to strength and direct melt contact, the achievable mass changes of the plungers are usually correspondingly limited in this case, which makes this embodiment of the invention preferably suitable for smaller mass changes.

[0024] In a refinement of the invention, the plunger system comprises a set of a plurality of cast plunger rods with predefined different masses, which are configured to be interchangeably used as plunger rods of the moving system part, wherein the plunger rods differ in their mass by a predefined mass increment. In order to achieve an optimal momentum of the plunger system at the end of the mold filling phase, in this case, the respective most suitable plunger rod is selected from a set of several plunger rods with predefined different masses and used as the plunger rod of the moving system part. The mass increments can be predefined in any desired way, for example all having the same size or at least partially having different sizes.

[0025] In an advantageous embodiment, cast plunger rods with predefined different masses are configured to be used with the same cast plunger or in any case with a cast plunger of the same outer diameter, and preferably, also configured to be used with the same casting chamber, so that by exchanging the cast plunger rods, the mass of the moving system part can be changed in a desired manner without requiring a different casting chamber or a cast plunger of different outer diameter. For plunger rods with different weights, in this case, an outer diameter that is the same in terms of the insertion depth in the casting chamber is preferably selected. For example, the different masses can be provided by using materials of different weights and / or by different designs of the plunger rod in its axial region in addition to its immersion depth in the casting chamber, in particular with regard to its outer diameter. The insertion depth here means the axial region of the plunger rod through which the plunger rod can be immersed in the casting chamber to the greatest extent, i.e. when the plunger is pushed to the greatest extent at the end of the pressure holding phase. Since the plunger rod constitutes a component of the plunger system, which is generally relatively easy to exchange, but also contributes a large proportion of the total mass of the moving system part, this embodiment of the invention may be particularly advantageous for many applications.

[0026] In a development of the invention, the plunger system comprises a set of multiple cast plunger connectors with predefined different masses, which are configured to be interchangeably used as cast plunger connectors of a rod drive unit of a moving system part, wherein the plunger connectors differ in their mass by a predefined mass increment. In order to achieve a corresponding optimal momentum of the plunger system at the end of the mold filling phase, in this case, the corresponding most suitable plunger connector can be selected from a set of multiple plunger connectors with predefined different masses and used as the plunger connector of the moving system part. The mass increment can be predefined in any desired way, for example all have the same size or at least some have different sizes. The use of plunger connectors of different weights does not require changes to the casting chamber.

[0027] In a development of the invention, the plunger system comprises a set of multiple cast plunger drive pistons with predefined different masses, which are configured to be interchangeably used as cast plunger drive pistons of the rod drive unit of the moving system part, wherein the plunger drive pistons differ in their mass by a predefined mass increment. In order to achieve a corresponding optimal momentum of the plunger system at the end of the mold filling phase, in this case, the corresponding most suitable plunger drive piston can be selected from a set of several plunger drive pistons with predefined different masses and used as the plunger drive piston of the moving system part. The mass increment can be predefined in any desired way, for example all have the same size or at least some have different sizes. The use of plunger drive pistons of different weights does not require changes to the casting chamber.

[0028] In a refinement of the invention, the additional mass unit of the moving system part, which is arranged to be movable relative to the main system part, comprises an additional mass body which is slidably movable on the moving main system part between a starting position and an end position, wherein the starting position is defined by an initial end stop on the moving main system part and / or the end position is defined by an impact end stop on the moving main system part. In this case, after the moving main system part is decelerated at the end of the mold filling phase, the additional mass unit first moves out of the starting position at a substantially constant speed due to its mass inertia and then, on reaching the impact end stop, decelerates in order to invoke its momentum action on the main system part with a corresponding delay and, by this, on the molten material in the casting mold.

[0029] It is to be understood that, depending on requirements and applications, the relatively movable additional mass unit may comprise several individual such additional mass bodies, each of which has an associated, preferably variable, sliding stroke. In a corresponding system embodiment, the sliding strokes of the slidably movable additional mass bodies may be different, whereby they exert their momentum action on the molten material in the casting mould at different times at the end of the mould filling phase, which allows a large variability in the temporal development of the momentum action of the movable system parts on the molten material in the casting mould.

[0030] In an embodiment of the invention, the initial end stop is adjustable on the moving main system part. Alternatively or additionally, the impact end stop is adjustable on the moving main system part. Each of these two measures allows adjusting the sliding stroke of the additional mass unit on the moving main system part and thus adjusting the delay time by which the additional mass unit decelerates later than the main system part at the end of the mold filling phase.

[0031] In an advantageous embodiment variant, provision can also be made, moreover, that the sliding stroke of the additional mass unit can be adjusted variably, manually or automatically, depending on the casting speed at which the mobile system part is moved before deceleration during the mold filling phase. Thus, for example, if necessary, the delay time of the additional mass unit can then remain substantially constant when the casting speed is changed to adapt to other circumstances (for example, the use of different casting molds and / or different casting molten materials).

[0032] In an embodiment of the invention, the plunger system comprises a locking unit for releasably locking the additional mass in a starting position or in an end position or in a predefinable locking position between the starting position and the end position. When the locking unit is activated, this locks the additional mass in the corresponding position and thereby makes it an additional mass that is immovably coupled to the moving main system part and then invokes its momentum action on the molten material in the casting mold at the end of the mold filling phase simultaneously with the other moving system parts. After releasing this locking, the additional mass can again act as an additional mass unit that acts on the molten material in the casting mold with a delay relative to the other moving system parts. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Advantageous embodiments of the invention are depicted in the accompanying drawings. These and other embodiments of the invention are explained in more detail below. In the accompanying drawings:

[0034] Figure 1 A schematic side view of a plunger system according to the invention for a die casting machine, with an additional mass fixed to a plunger drive piston, and an associated casting chamber and a casting mold of the plunger system, is shown,

[0035] Figure 2 FIG. 1 shows an embodiment variant of the plunger system according to the invention without a casting chamber and a casting mold. Figure 1 A view of a plunger system having an additional mass fixed to a plunger coupling,

[0036] Figure 3 A variant embodiment of the plunger system according to the invention is shown. Figure 2 A view of a plunger system having an additional mass fixed to the plunger rod,

[0037] Figure 4 A variant embodiment of the plunger system according to the invention is shown. Figure 2 The piston system has an optional additional mass that can be additionally connected,

[0038] Figure 5 A variant embodiment of the plunger system according to the invention is shown. Figure 2 The plunger system has an additional mass body which is arranged to be slidably movable,

[0039] Figure 6 A variant embodiment of the plunger system according to the invention is shown. Figure 2 The plunger system has a set of several plungers and / or plunger rods and / or plunger couplings and / or plunger drive pistons, each of which has a predefined different mass,

[0040] Figure 7 shows a schematic flow chart for illustrating the steps of interest in the present case of the casting method according to the invention, and

[0041] Figure 8 A characteristic diagram is shown for illustrating the temporal melt pressure development in the casting mold during the casting process for different execution variants of the casting process according to the invention and not according to the invention. DETAILED DESCRIPTION

[0042] Figure 1 A casting plunger system according to the invention for a die casting machine is schematically shown, wherein the plunger system comprises a stationary system part 1 and a mobile system part 2. For example, as shown, the stationary system part 1 comprises a casting chamber 12 and a casting plunger drive cylinder 13, the latter usually being referred to as a casting cylinder for short. The casting chamber 12 usually opens into a casting mold 14, which is formed by a fixed casting mold half and a movable casting mold half of the die casting machine. The mobile system part 2 is movable relative to the stationary system part 1 in order to introduce molten material into the casting mold 14 in a corresponding casting cycle, and therefore it comprises a casting plunger 3, a casting plunger rod 4 and a rod drive unit 5, and is configured to decelerate under the effect of the pressure on the molten material at the end of the mold filling phase of the casting cycle.

[0043] The plunger 3 is arranged fluid-tight and axially movably in, for example, a cylindrical casting chamber 12. In the example shown, the plunger rod 4 carries the plunger 3 on its front face region and is coupled at its rear face region to the rod drive unit 5, in particular to a plunger coupling 9 of the rod drive unit 5. In the example shown, the plunger coupling 9 couples the plunger rod 4 to the front face region of a plunger drive piston 10 of the rod drive unit 5, which is guided so as to be axially movably in a plunger drive cylinder 13. Optionally, the plunger drive piston 10 is coupled to a pressure multiplier unit (not shown).

[0044] According to the invention, the mobile system part 2 has a solid mass which can be variably adjusted between different casting cycles and / or as in Figure 5 As in the exemplary embodiment of the present invention, the mobile main system part 2a and the additional solid mass unit Z E The additional solid mass unit Z E Arranged to be movable relative to the moving main system part 2a and configured to decelerate at the end of the mould filling phase of the casting cycle, after a predefinable delay time than the main system part 2a.

[0045] In a corresponding embodiment, the plunger system according to the invention comprises one or more additional solid masses which are respectively configured to be releasably attached to the mobile system part 2 and which in the attached state form an immovably coupled component of the mobile system part 2 . Figure 1 An embodiment variant is shown in this respect in which such an additional mass ZK is in particular releasably attached to a plunger drive piston 10 of the moving system part 2 . Figure 2 An embodiment variant is shown in this respect, in which such an additional mass ZK is in particular releasably attached to a plunger coupling 9 of the mobile system part 2 . Figure 3 An embodiment variant in this respect is shown, in which such an additional mass ZK is in particular releasably attached to the plunger rod 4 of the mobile system part 2. It is understood that in this case the additional mass ZK is arranged at the axial portion of the plunger rod 4 which is located outside or behind the immersion depth, whereby the front rod portion of the plunger rod 4 is immersed to the greatest extent in the casting chamber 1 in order to advance the plunger 3, so that the additional mass ZK does not hinder the advancement movement of the front immersion depth portion of the plunger rod 4 into the casting chamber 12. Figure 4 An embodiment variant is shown in this respect, in which several such additional masses ZK1, ZK2, ZK3 can be optionally releasably attached to the mobile system part 2, for example to the plunger coupling 9 or the plunger drive piston 10, wherein Figure 4 A situation is shown in which only the first additional mass ZK1 is releasably attached to the mobile system part 2, here in particular to the plunger coupling 9. Preferably, provision is made for the assembly and disassembly of one or more additional masses ZK or ZK1, ZK2, ... to be possible without tools and / or using a quick-change system or a quick clamping system.

[0046] In this embodiment variant with several additional mass bodies ZK1, ZK2, ... which can be releasably attached to the mobile system part 2, it can be advantageous if at least two of the several additional mass bodies ZK1, ZK2, ... have different masses. For example, these additional mass bodies ZK1, ZK2, ... can differ in mass by a power of 2, i.e. the mass of the next heavier additional mass body is twice that of the next lighter additional mass body. With this binary stepping of the masses of the additional mass bodies ZK1, ZK2, ..., any integer multiple of the minimum mass of the lightest additional mass body can be set, wherein a relatively small number of additional mass bodies will be provided for the total mass of all additional mass bodies ZK1, ZK2, ...

[0047] In the corresponding embodiment, Figure 4As shown in the exemplary embodiment of the stationary system part 2, the stationary system part 2 comprises an additional mass storage unit 6, which is used for storing one or more additional mass bodies ZK or ZK1, ZK2, ... For example, Figure 4 An embodiment is shown in which the additional masses ZK1, ZK2, ... are removably suspended on an additional mass holder 6a acting as an additional mass storage unit 6, which in turn is arranged on the stationary system part 1 (e.g. the plunger drive cylinder 13) or alternatively on another stationary fixed component of the corresponding die-casting machine. The additional masses ZK1, ZK2, ... stored in this way can then be extracted from the additional mass storage unit 6 individually or in any combination as required and releasably attached to the mobile system part 2 in order to perform a corresponding casting cycle with the desired total mass of the mobile system part 2.

[0048] In a corresponding embodiment, the plunger system comprises an additional mass handling unit 7, which is configured to automatically attach the corresponding additional mass ZK or ZK1, ZK2, ... to the mobile system part 2 and to automatically remove the corresponding additional mass ZK or ZK1, ZK2, ... from the mobile system part 2. In the exemplary embodiment shown there, such an additional mass handling unit 7 is as follows Figure 4 As shown in the block diagram in . For example, it can include a conventional handling robot, which is specifically configured to perform the necessary handling measures. Alternatively, the additional mass ZK or ZK1, ZK2, ... can be attached to and removed from the mobile system part 2 by a corresponding operator.

[0049] In a corresponding embodiment, the plunger system according to the present invention, such as Figure 6 As shown in FIG. 1 , it comprises: a set of multiple cast plungers 31 to 3 having predefined different masses n1 ,like Figure 6 As shown in the block diagram in FIG. 1 , the cast plungers differ in their mass by a predefined mass increment and are configured to be interchangeably used as plungers 3 of the moving system part 2; and / or a set of multiple cast plunger rods 41 to 4 having predefined different masses n2 ,like Figure 6 As shown in the block diagram in FIG. 1 , the cast plunger rods differ in their mass by a predefined mass increment and are configured to be interchangeably used as plunger rods 4 of the moving system part 2; and / or a set of multiple cast plunger couplings 91 to 9 having predefined different masses n3 ,like Figure 6As shown in the block diagram in FIG. 1 , the cast plunger couplings differ in their mass by a predefined mass increment and are configured to be interchangeably used as plunger couplings 9 of the rod drive unit 5 of the moving system part 2; and / or a set of multiple cast plunger drive pistons 101 to 101 having predefined different masses. n4 ,like Figure 6 As shown in the block diagram in , the cast plunger drive pistons differ in their mass by a predefined mass increment and are configured to be interchangeably used as plunger drive pistons 10 of the rod drive unit 5 of the moving system part 2.

[0050] Depending on the application and the desired total mass of the mobile system part 2, the plungers 3 actually used can be selected from a number n1 of existing plungers 31 to 3 n1 and / or the plunger rod 4 actually used can be selected from a number of plunger rods 41 to 4 of different qualities n2 n2 and / or the plunger coupling 9 actually used can be selected from a number of different qualities of the plunger coupling 91 to 9 n3 n3 and / or the plunger drive piston 10 actually used can be selected from a number of different masses of the plunger drive piston 101 to 10 n4 n4 Select. According to the four groups of plungers 31 to 3 n1 , plunger rod 41 to 4 n2 , plunger connector 91 to 9 n3 and plunger drive piston 101 to 10 n4 Depending on the system design, all four groups may be present for a given plunger system, or only one of the four groups or any two or three of the four groups may be provided.

[0051] In an embodiment of this type of the invention, the mass of the moving system part 2 can be variably adjusted between different casting cycles by selecting different plungers and / or different plunger rods and / or different plunger couplings and / or different plunger drive pistons. If necessary, a releasable attachment of one or more additional masses to the moving system part 2 can additionally be provided, such as Figure 6 As illustrated in the example shown in FIG, by an additional mass body ZK releasably attached to the plunger rod 4. Moreover, if necessary, this type of embodiment can be replaced by the above-mentioned additional mass unit Z E In addition, the additional mass unit is arranged to be movable relative to the mobile main system part 2a.

[0052] The mass increments can be appropriately predefined according to the situation or requirements, the plunger 31 to 3 n1 , plunger rod 41 to 4 n2 , plunger connector 91 to 9 n3 and plunger drive piston 101 to 10 n4Here, it is often convenient to keep the mass increment between each two components with successive masses and / or the total mass difference between the lightest component and the heaviest component of the respective group within predetermined limits. This can be achieved, for example, by predefining suitable threshold values, by which the mass increments of the respective component groups may differ at most and / or by which the mass of the heaviest component of the respective group may be at most greater than the mass of the lightest component of the group, for example given as a percentage.

[0053] In a corresponding embodiment, the additional mass unit Z is arranged to be movable relative to the main system part 2a. E Including the additional mass Z M , the additional mass Z M Arranged on the moving main system part 2 so as to be slidably movable between a starting position and an end position, wherein the starting position is defined by an initial end stop IA on the moving main system part 2a and / or the end position is defined by an impact end stop AA on the moving main system part 2a. Figure 5 A corresponding exemplary embodiment is shown having an initial end stop IA and an impact end stop AA on the moving main system part 2 .

[0054] In an advantageous embodiment, at least the initial end stop IA or the impact end stop AA is adjustable on the mobile main system part 2, wherein the adjustability of both end stops IA, AA may also be provided. The end stops may be adjusted manually as required, for example by means of a manually actuated screw spindle, or automatically by means of a corresponding actuator mechanism. Figure 5 In the exemplary embodiment of , the impact end stop AA is provided on the plunger coupling 9 , while the initial end stop IA is provided by an initial end stop body 8 , which is established to be axially adjustable on the plunger drive piston 10 .

[0055] Therefore, the additional mass Z M The moving main system part 2a can be slidably moved by a sliding stroke or travel H corresponding to the axial spacing between the starting position and the end position relative to the rest of the moving system part, i.e. relative to the moving main system part 2a. If the moving main system part 2a is in contact with the additional mass Z during the mold filling phase M The additional mass Z that can be slidably moved moves at a predefined advancement speed, and the moving main system part 2a is decelerated at the end of the mold filling phase. M This advancement speed is initially maintained until it has covered its travel H from the starting position to the end position and then decelerates upon impact with the end stop AA. At the end of the mold filling phase of the casting cycle, the additional mass ZM It is therefore decelerated, later than the main system part 2a, by a predefined delay time which is obtained by dividing the stroke H by the advancement speed of the moving system part 2 at the end of the mold filling phase immediately before the deceleration of the moving system part 2a.

[0056] In the case of adjustability of at least one of the two end stops IA, AA (which means a corresponding adjustment of the stroke H), the additional mass Z M The delay time for the deceleration later than the main system part 2a can be variably predefined in a desired manner without the propulsion speed of the mobile system part 2 having to be changed.

[0057] exist Figure 5 In an exemplary embodiment, the relatively movable additional mass unit Z E Only the additional mass Z M In an alternative embodiment, the relatively movable additional mass unit Z E The additional mass unit Z comprises one or more additional masses which are arranged to be movable in a desired manner relative to the mobile main system part 2a. E In Figures 1 to 3 The additional mass ZK or Figure 4 One or more additional mass bodies are provided in the form of additional mass bodies ZK1, ZK2, . . . which are configured to be releasably attached to the mobile system part 2 and in the attached state form a component of the mobile system part 2 which is immovably connected to the rest of the mobile system part.

[0058] Although additional mass bodies such as Figures 1 to 3 An additional mass ZK in Figure 4 The immovably coupled attachment of several additional masses ZK1, ZK2, . . . ) in the exemplary embodiment of the embodiment of the present invention results in a corresponding additional momentum transfer to the molten material at the end of the mold filling phase (precisely at the time of the main momentum transfer due to the deceleration of the mobile system part 2 or the mobile main system part 2a), but the additional masses ZK1, ZK2, . . . E The relatively movable connection to the remainder of the moving system part, i.e. the main system part 2a, results in an additional momentum transfer to the molten material, which occurs at the end of the mold filling phase, a predefined delay time later than the main momentum transfer caused by the deceleration of the moving main system part 2a.

[0059] To illustrate this using an example with a drawing, assume, for example, that the advancing speed of the mobile system part 2 towards the end of the mold filling phase is 5 m / s and that the fixed mass of the mobile main system part 2a is 100 kg and the additional mass unit Z E The mass of is 20 kg, and the additional mass unit Z E The sliding stroke H is 50 mm. Then, the additional mass unit Z E An additional momentum of 20% relative to the momentum of the fixed mass of the moving main system part 2a is applied to the molten material, wherein this momentum transfer starts 10 ms after the momentum transfer caused by the deceleration of the moving main system part 2a. The delayed momentum transfer action can advantageously bridge the time period between the first pressure peak (which lags 2 s after the momentum transfer of the fixed mass of the moving main system part at the end of mold filling) and the action of the optional pressure multiplier device (which usually starts only about 20 ms to 35 ms after the end of mold filling), without the first pressure peak being excessively increased, so that over-ejection of the mold can be avoided.

[0060] Depending on the situation or casting parameters, in particular the plunger speed and the structural casting arrangement, the additional mass unit Z E The delayed timing of the additional momentum transfer to the molten material can be influenced in a targeted manner. By adjusting the end stop, i.e. adjusting the sliding stroke H, the delayed momentum transfer can be variably adjusted if necessary in order to optimize the process for the successive casting cycles. Here, if necessary, the additional mass unit Z E The mass of can also be varied, for example by exchanging additional mass units Z E Or by constructing the additional mass unit Z with a variable number of additional mass bodies E , which additional mass may optionally be relatively movably coupled to the mobile main system part 2a. In this way, the intensity and / or timing of this additional momentum transfer to the molten material at the end of the mold filling phase may be adjusted in order to achieve a desired optimal casting quality, which may be determined empirically or by computer simulation, for example.

[0061] In a corresponding embodiment of the invention, the mobile system part 2 comprises several additional mass units Z E , which additional mass unit is arranged to be movable relative to the main system part 2a and, at the end of the mold filling phase of the casting cycle, is decelerated later than the main system part 2a by a corresponding individually predefinable delay time. E, in which case their mass and therefore the intensity of the additional momentum transfer to the molten material can be established individually, as can the time during which they transfer the additional momentum to the molten material by means of their deceleration. If desired, with this embodiment variant, a time-staggered, successive additional momentum transfer to the molten material can be composed of several successively decelerated additional mass units Z E supply.

[0062] In an advantageous embodiment, the plunger system, such as Figure 5 As shown in the exemplary embodiment, the locking unit 11 is used to lock the additional mass body Z M Releasably lockable in a starting position or in an end position or in a predefinable locking position between the starting position and the end position. Figure 5 In the embodiment of the invention, the locking unit 11 is formed by a locking bar device having a locking bar which is pivotally held on the plunger coupling 9 and which is pivotally held when the additional mass Z M When it has reached its end position (ie in this case the impact end stop AA on the plunger coupling 9), it engages the additional mass Z M in the corresponding bar receiver on the

[0063] The locking unit 11 ensures that the additional mass Z M After reaching its impact end stop AA, it is firmly held in place. After completing the casting process, the lock is released so that the additional mass Z M can return to its starting position. Figure 5 As in the example of M The return movement of the Z can optionally be supported by a return spring arrangement 15, which in this example is held in the additional mass Z. M on one side and is held on the other side in a receiver in the plunger coupling 9.

[0064] Figure 7 A schematic flow chart is provided for a die-casting machine (i.e., a die-casting machine) equipped with a plunger system according to the invention. Figures 1 to 6 In one embodiment of the type shown in FIG. 1 , a casting method according to the invention is described, which has only the method steps of interest here. As is known per se, one or more casting parameters originating from one or more previous casting cycles and / or predefined for an upcoming casting cycle are detected in order to execute the corresponding casting cycle. These casting parameters are detected by a machine control system, which is usually coupled to the die casting machine and also forms or comprises a control unit for the plunger system. The control unit for the plunger system (also known per se) is configured to control or adjust the corresponding casting process.

[0065] Characteristically, in the plunger system according to the invention, the control unit determines the mass of the moving system part 2 as an optimal setting for the upcoming casting cycle or cycles and / or determines the delay time as an additional mass unit Z E To optimally set up the upcoming casting cycle or cycles, the additional mass unit Z E is arranged to be movable relative to the main system part 2a. Preferably, for this purpose, the control unit evaluates actual values ​​of one or more casting parameters, in particular casting parameters influencing or representing the quality of the produced casting and / or the effectiveness of the casting process, which actual values ​​are detected by sensors or in other ways and belong to one or more previous casting cycles. Thereby, the control unit is able to automatically optimize the casting cycle purely by control and / or iteratively and / or using previously performed computer simulations and / or by means of real-time control interventions during the corresponding casting process, depending on the design of the control system.

[0066] Therefore, according to the method, Figure 7 As indicated in FIG. 1 , for one or more future casting cycles, the mass of the mobile system part 2 and / or the relatively movably arranged additional mass unit Z E The delay time can be variably adjusted as a function of at least one detected casting parameter. The casting process is then performed using a correspondingly optimized casting process management.

[0067] In a corresponding embodiment, as part of the execution of the casting process according to the method and with the aid of an algorithm appropriately stored therein, the control unit is configured to determine from the plunger position, the plunger speed (i.e. the advancement speed of the moving system part 2) and the mass of the moving system part 2 or the mass of the moving main system part 2a and the slidably movable additional mass unit Z E The mass of the mold can be used to establish an associated momentum or momentum equivalent related to the momentum transfer to the molten material and provide this for further processing. For example, this can also be used to indicate or depict the determined momentum transfer effect visually or by other means as a measure of the compression effect of the first pressure peak occurring in the melt at the end of the mold filling phase.

[0068] Furthermore, in a corresponding embodiment, the control unit is configured to determine the displacement of the mobile system part 2 or the mobile system main part 2a and the relatively movable additional mass unit Z for the expected height of the first pressure peak according to the influencing factors present for a given die casting machine or a given plunger system. EThe necessary mass can be determined by the control unit, or established empirically or by computer simulation using a specific map belonging to the casting to be produced. Additionally or alternatively, the control unit can be configured to determine the optimal additional mass without knowing the actual pressure peak, in which case it is determined empirically from an assessed casting quality, for example, wherein the plunger speed is varied without changing the momentum effect.

[0069] Specifically, the influencing factors are one or more of the following: the preselected or actual plunger speed during the mold filling phase; the absence of a relatively movable additional mass unit Z; E the mass of the mobile system part 2 to be releasably attached without the additional mass bodies ZK, ZK1, ...; the closing force of the mold closing unit of the die casting machine; the impact area of ​​the casting and / or the sprue; the weight of the casting and / or the sprue; the casting characteristics, in particular with regard to the wall thickness; the composition of the molten material; the effective plunger diameter in the casting chamber 12; the dimensions of the plunger drive, in particular with regard to the diameter and the hydraulically effective area; the hydraulic drive pressure of the plunger drive; the parameters of the optional pressure multiplier device, in particular with regard to the dimensions and the hydraulically effective area of ​​the multiplier unit, the predefined pressure curve and the multiplier system pressure; and in the case of the present, relatively movable additional mass unit Z E The actual and / or maximum possible value of the sliding travel H in the case of .

[0070] Furthermore, the control unit can be configured to determine the associated value of the sliding stroke H for the expected height of the first pressure peak in the case where the mass of the present, relatively movable additional mass unit ZE is known, as a function of the influencing factors, or to establish this value from a diagram generated empirically or in particular by a computer simulation for the casting to be produced. In this case as well, if the actual pressure peak is not known, the process may be similar, but the momentum transfer effect has been assessed empirically as being good, and only the plunger speed needs to be changed without changing the momentum transfer effect. If the locking unit 11 is present, an additional influencing factor here may be its locking state, i.e. the relative movable additional mass unit ZE. E or a relatively movable additional mass Z M Whether it is locked by the locking unit 11.

[0071] It is to be understood that the control unit may appropriately take into account a selected mass change of the moving system part 2 for the overall control of the plunger system. Thus, a change in the mass of the moving system part 2 requires a correspondingly changed driving force to accelerate the moving system part 2.

[0072] The detection of the casting parameters is supported by suitable sensors, as will be readily understood by a person skilled in the art when the task of the sensors is known. Here, the sensors may specifically include one or more of the following sensors: sensors for detecting the additional mass bodies ZK, ZK1, ... connected immovably and / or the additional mass units Z that are relatively movable E one or more limit switches for the presence of a piston system; hard-wired and / or wireless identification sensors for identifying individual additional mass bodies and / or assembly components of the piston system, in particular its movable system part 2; acceleration sensors, from which the sensor information can be analyzed together with the sensor data from the casting drive system (in particular regarding position, pressure, etc.) in order to determine the total mass of the movable system part 2; sensors for measuring the relative movement of the additional mass unit Z E Sensor for the actual sliding travel H when present; for detecting the relatively movable additional mass unit Z E or additional mass Z M and for detecting the presence of the locking unit 11 when the relatively movable additional mass unit Z E or additional mass Z M Whether the sensor is in the locked state.

[0073] In the characteristic curve diagram of the exemplary embodiment, Figure 8 The internal mold pressure (i.e., the pressure of the molten material in the mold, P S ) as a function of time t for the last part of the mold filling phase and the subsequent pressure holding phase. Here, a first curve K1 (shown as a dashed line) illustrates the internal mold pressure P of a conventional plunger system without a pressure multiplier device. S The plunger initially moves, for example, at an almost constant advancement speed (i.e. filling speed) and as soon as the end of the mold filling phase is reached at time t E When the pressure in the mold is reached, the pressure in the mold builds up, which in turn causes the pressure in the casting chamber to rise, whereby the plunger is braked to a stop, i.e. the momentum of the plunger or the moving system part of the plunger system is dissipated to zero with a corresponding increase in the internal mold pressure. The liquid molten material in the mold acts to some extent as a compressible spring, i.e. a hydraulic spring. At time t S At , the moving system part of the plunger system stops for the first time and a maximum pressure value, i.e. a first pressure peak, occurs in the mold. Then, due to the corresponding damped oscillating motion of the moving system part of the plunger system, the internal mold pressure p is increased between the compressible molten material on one side and the compressible hydraulic fluid in the driving casting device on the other side. S After a certain damping the oscillation occurs, as is evident from the course of curve K1.

[0074] The second curve K2 illustrates the relationship between the piston system according to the invention and an additional mass that is immovably coupled to the mobile system part 2 (e.g. according to Figures 1 to 3 The additional mass ZK or according to Figure 4 Additional masses ZK1, ZK2, ...) and a typical casting process when used with a pressure multiplier device. According to curve K1, the time t until the end of the mold filling phase with an initial strong pressure rise E , the course of the casting process corresponds to that of the conventional case, and here too, the damped post-oscillation occurs at the transition to the pressure holding phase. However, here, at the time t of the first pressure peak, S Compared with the conventional case at the time, the internal mold pressure p S Higher, that is, here, curve K2 is above curve K1. Moreover, at time t M At this point, the action of the pressure multiplier device begins, which then causes the internal mold pressure p S To reach the desired higher final value p F , the final value p F is significantly higher than the final value p of the conventional case of the first curve K1 without the pressure multiplier device. K At the first pressure peak t S Internal mold pressure p S The rise in is due to the additional momentum transfer from the additional mass to the molten material in the mold, which additional mass is immovably coupled to the moving system part 2 of the plunger system and is formed by one or more of the additional mass bodies ZK, ZK1, ZK2, ... and / or by exchanging corresponding parts of the moving system part 2, such as Figure 6 As explained in , provided by functionally equivalent components having different qualities.

[0075] The third curve K3 illustrates an exemplary casting process using the plunger system according to the invention in an embodiment corresponding to the embodiment described above with respect to the second curve K2, but with the additional presence of an additional mass unit Z arranged so as to be relatively movable. E . Due to this additional mass unit Z E Its momentum transfer effect is called upon to the molten material only after a predefinable delay time of the moving main system part 2a. In this exemplary embodiment, according to curve K3, the internal mold pressure P s The temporal development of V The time development of curve K2 corresponds to the time t V At this point, this delay time has expired and the additional mass unit Z E decelerates and transfers its momentum additionally to the molten material. This results in an internal mold pressure p S At this time t Vrises and in the pressure holding phase until the end pressure p is reached F In the further course of the casting process, the associated curve K3 is higher than the second curve K2 corresponding to the additional pressure. As is evident from the comparison of the curves K2 and K3, due to the additional mass unit Z E The relatively movable arrangement can be used at the time t of the first pressure peak. S The time t when the pressure multiplier starts to work M The period between is the internal mold pressure p S Provides the desired amount of pressure increase.

[0076] As the exemplary embodiments shown and explained above clearly show, the present invention provides an advantageous plunger system for use in a die casting machine, with which the die casting process can be significantly optimized or improved relative to conventional casting processes, in particular in the time period at the end of the mold filling phase and at the transition to the pressure holding phase, which in turn allows the quality of the produced casting to be increased. In particular, the compression, strength, porosity and / or structure formation of the casting can be favorably influenced, since the momentum transmission to the molten material can be varied by varying the mass of the moving system parts without having to change the advancement speed of the moving system parts.

[0077] Independently of one another, the invention allows a targeted influencing of the mold filling time imposed by the advancement speed of the mobile system part 2, i.e. the duration of the mold filling phase, and the pressure value of the internal mold pressure at the time of the first pressure peak, which pressure value can be varied according to the invention by varying the mass of the mobile system part without changing the advancement speed. Thus, for example, the invention allows the use of a plunger system with a minimum mass of the mobile system part (which is in principle advantageous for achieving short mold filling times due to the high predefinable advancement speed) and allows the mass of the mobile system part to be increased by the measures as required, so that the desired pressure level of the first pressure peak and / or the pressure rise in the period after the first pressure peak is achieved by the delayed action of the relatively movable additional mass unit, in particular as a shortening measure until the start of the pressure multiplier action.

Claims

1. A casting plunger system for a die casting machine, the casting plunger system comprising: - a stationary system part (1), and a system part (2) which moves relative to the stationary system part in a respective casting cycle for introducing molten material into a casting mould and has a casting plunger (3), a casting plunger rod (4) and a rod drive unit (5) and is configured to decelerate under the effect of the pressure on the molten material at the end of the mould filling phase of the casting cycle, It is characterized in that - the mobile system part (2) has a mass which can be variably adjusted between different casting cycles, and / or - The mobile system part consists of the mobile main system part (2a) and the additional mass unit (Z E ), the additional mass unit (Z E ) is arranged to be movable relative to the main system part and is configured to decelerate later than the main system part by a predefinable delay time at the end of the mold filling phase of the casting cycle.

2. The casting plunger system according to claim 1, further characterized in that One or more additional masses (ZK, ZK1, ZK2, ...), each of which is configured to be releasably attached to the mobile system part and, in the attached state, forms a component of the mobile system part.

3. The casting plunger system according to claim 2, further characterized in that A plurality of additional masses are provided, at least two of which have different masses.

4. The casting plunger system according to claim 2 or 3, further characterized in that The stationary system part comprises an additional mass storage unit (6) for storage provision of one or more additional masses.

5. The casting plunger system according to claim 2 or 3, further characterized in that An additional mass handling unit (7) is configured to automatically attach and remove a corresponding additional mass to and from the mobile system part.

6. The casting plunger system according to any one of claims 1 to 3, further characterized in that: - a set of a plurality of cast plungers (31, 32, ...) having predefined different masses, said cast plungers differing in their masses by a predefined mass increment and configured to be interchangeable for use as cast plungers of said moving system part, and / or - a set of a plurality of cast plunger rods (41, 42, ...) having predefined different masses, said cast plunger rods differing in their mass by a predefined mass increment and configured to be interchangeably usable as cast plunger rods of said moving system part, and / or - a set of a plurality of cast plunger couplings (91, 92, ...) having predefined different masses, said cast plunger couplings differing in their mass by a predefined mass increment and configured to be interchangeably used as cast plunger couplings (9) of said rod drive unit of said mobile system part, and / or - A set of multiple cast plunger drive pistons (101, 102, ...) having predefined different masses, said cast plunger drive pistons differing in their masses by a predefined mass increment and configured to be interchangeably used as cast plunger drive pistons (10) of said rod drive unit of said moving system part.

7. The casting plunger system according to any one of claims 1 to 3, further characterized in that The additional mass unit arranged relatively movably comprises an additional mass body (Z M ), the additional mass body (Z M ) is arranged on the moving main system part to be slidably movable between a starting position and an end position, wherein the starting position is defined by an initial end stop (IA) on the moving main system part and / or the end position is defined by an impact end stop (AA) on the moving main system part.

8. The casting plunger system of claim 7, further characterized in that: - said initial end stop is adjustable on said moving main system part, and / or - The impact end stop is adjustable on the moving main system part.

9. The cast plunger system of claim 7, further characterized by A locking unit (11) is used to releasably lock the additional mass in the starting position or in the end position or in a predefinable locking position between the starting position and the end position.

10. A casting method for a die casting machine having a casting plunger system according to any one of claims 1 to 9, wherein: at least one casting parameter of the respective casting cycle is detected, and The mass of the mobile system part and / or the delay time relative to the movably arranged additional mass unit is variably adjusted for one or more future casting cycles as a function of at least one detected casting parameter.

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