EP2929957A1 - Die casting machine and method for manufacturing several casting parts - Google Patents

Abstract

The present invention relates to a die-casting machine comprising a movable clamping plate (3) and a fixed clamping plate (2), a mold half (16) arranged on the movable clamping plate (3) and a mold half (16) arranged on the fixed clamping plate (2), characterized in that the die casting machine has at least two, preferably two casting drives (17; 18a, 18b) and an analogous number of casting assemblies (19a, 19b) associated with the casting drives (18a, 18b). The present invention furthermore relates to a method for producing cast parts in a diecasting method, preferably with such a die casting machine, and to a casting mold (25, 27) for a die casting machine and the use of such a die casting machine or casting mold (25, 27) for the production of castings, preferably castings for the automotive sector or the electronics sector.

Description

The present invention relates to a die casting machine and a die casting method for more efficient and economical production of die cast components.

Die casting machines are used for the production of metallic castings such as engine blocks. Is exemplary in the WO 2008/131571 A1 a horizontal two-plate die casting machine described. This two-plate die casting machine comprises a movable clamping plate (BAP) and a fixed clamping plate (FAP), on each of which a mold half is arranged. By moving the movable platen, the die can be opened and closed. In the closed position, the two clamping plates are pressed firmly against each other, so that the two mold halves form a closed mold. In a cavity formed by the closed mold, a molten metal is introduced under pressure and cooled until solidification. The solidified casting can be removed after opening the mold (by moving the movable platen). The movement of the movable platen takes place in the machine according to the WO 2008/131571 A1 above columns, preferably four columns.

The shape formed by the two mold halves can be configured differently. Are known molds with a single cavity or with multiple cavities. In the latter case, the cavities may have the same dimensions (thereby enabling the simultaneous production of components of the same shape), or alternatively the cavities may have different dimensions (whereby the simultaneous production of components of different shape is made possible).

The trend in the automotive industry is to make castings such as structural components, engine blocks or gearbox housing ever larger and thin-walled. The size of a manufacturable in the conventional die casting component but are limited to the extent that during the casting process, the molten metal must be able to flow in cavities in the mold and to be able to fill them completely. For this purpose, the molten metal during the casting process but only a short period available. For larger components, for example, the pressure would have to be increased, with which the molten metal is pressed into the mold, which as explained below but would result in a disadvantageous increase in the closing force to be applied.

In addition, with the size of the component to be produced, the closing pressure required for holding the mold halves together during the casting cycle increases. By pressing the molten metal into the mold, a pressure arises there, the size of which depends, inter alia, on the pressure exerted on the melt during the casting cycle and on the dimensions of the cavity (s). From this pressure results the so-called explosive force which would move the two mold halves apart during the casting cycle, if one did not keep the mold halves closed by applying a closing force exceeding the explosive force. Since the closing force can not be arbitrarily increased but depends on the size of the die casting machine, the dimensions of the cavity (s) are limited in a conventional die casting machine.

So far, the premium segments in the automotive sector have been equipped with structural components, making them lighter and stiffer. However, the need of the automotive industry is also to equip mass vehicles (e.g., compact and upper-middle class vehicles) with structural aluminum and magnesium components. From the point of view of the lightweight construction strategy, much speaks for such an approach. However, the productivity of conventional die casting machines is currently not designed to inexpensively produce the variety of lightweight metal components required for this expansion. Typically, 6 assemblies are now installed in pairs in automotive production: shock tower (shock tower) front and rear, front and rear and side member, end wall and instrument panel.

For an economical production of the required for this approach large number of light metal components, it is necessary to produce several such components simultaneously in a mold with multiple cavities (Multikavitätenform) in a casting cycle, ie for example produce four casts of the component in a casting cycle. However, this requires an increase in the amount of mold cavities. The provision of a cavity in duplicate in one mold means that the cavity dimensions are doubled with the disadvantages described above, in particular an increase in the closing force required during the casting cycle for holding the mold halves together. With conventional die casting machines, the required expansion of the number of pieces of light metal components can not be achieved, since limits are set by the maximum closing force to be applied.

It was the object of the present invention to provide a die casting machine and a die casting method for the economic production of a plurality of components.

The above object is achieved according to the invention by a die casting machine, comprising a movable platen and a fixed platen, arranged on the movable platen mold half and arranged on the fixed platen mold half, characterized in that the die casting machine at least two, preferably two casting drives and an analog Has number of Giessgarnituren assigned to the Giessantrieben.

The present invention is based on the idea not to fill all the cavities of a die-casting mold with a single casting drive, but to use at least two casting drives for filling the cavities.

This has the advantage, on the one hand, that the connecting paths between casting sets and cavities are shortened since the molten metal no longer has to flow into all cavities starting from a casting drive, but can be channeled into different cavities starting from a plurality of casting drives.

In addition, with the aid of the diecasting machine according to the invention, it is possible to carry out the production of castings in different cavities during a casting cycle with such a time delay that the entire casting cycle can be carried out with a lower closing force. The cavities can be filled sequentially by different casting drives, so that the explosive force to be compensated only in the respectively filled Cavities occurs and not the entire explosive force is to compensate, which would occur with simultaneous filling of all existing cavities. This will be explained in detail below.

With the aid of the diecasting machine according to the invention, it is thus possible to produce significantly more castings at the same time within one casting cycle, without an increase in the closing force being required for this purpose. As a result, a significantly higher productivity, typically 80-100%, at least 40-60% increased productivity, can be achieved with the die casting apparatus according to the invention than with conventional die casting machines.

With conventional die casting machines, only as many castings can be produced at the same time, as is possible within the scope of the adjustable maximum closing force. Especially with larger components multiple casting in a casting cycle would be limited because of the strong increasing closing force possible. As a result, a plurality of conventional die casting machines would have to be operated simultaneously in order to achieve comparable productivity with the die casting machine according to the invention. This would have a correspondingly much larger footprint, more operators, etc. result. For this reason, the use of die-cast light metal castings in mass-produced vehicles (e.g., compact and mid-range vehicles) has not been realized.

By means of the present invention, the use of die-cast light metal components in mass-produced vehicles will be economically viable for the first time.

According to the invention, a "casting unit" is understood to mean the entirety of all components of a die-casting machine which are used for the movement of a casting piston and for the pressurization of the molten metal. The "casting drive" is an essential part of a casting unit. A casting drive of a die-casting machine according to the invention comprises a normally hydraulically operated casting cylinder with movable drive pistons disposed therein, a shot valve for controlling the movement of the drive piston in the casting cylinder, and a pressure accumulator. In addition to the casting drive, a casting unit comprises further components such as a guide frame, tie rod, hydraulic tank, and a hydraulic control block.

The "casting drive" is connected to the die casting mold via a "casting set" . A Giessgarnitur consists of a Giesskolbenstange, which is coupled at its one end to the drive piston casting cylinder, a casting piston which is coupled to the mold-side end of the casting piston rod, and a casting chamber in which the casting piston can move and in the casting chamber filled melt through can press its movement into the die casting mold. The casting chamber is connected to at least one mold cavity in the die casting mold. According to the invention, a casting assembly is associated with each casting drive, ie a respective casting assembly is the link between a specific casting drive and the die casting mold.

The skilled person is familiar with casting units, casting drives and casting fittings.

Die casting machines are well known. A distinction is made between the casting assembly between a cold chamber and a hot chamber die casting machine. In a hot chamber die casting machine the casting container is held in a crucible with molten metal. A casting piston moves into the casting container and presses the molten metal through a casting container, which is likewise at least partially arranged in the crucible, into the casting mold. Casting containers and casting pistons are permanently exposed to molten metal in this process. The Giessgarnitur a hot chamber die casting machine is basically designed differently than that of a cold chamber die casting machine.

In a cold chamber die casting machine, the metal is melted in a separate apparatus and kept warm in a molten state in a holding furnace. The amount of molten metal required for producing the desired component is introduced into a cold casting chamber via a filling opening and pressed into the casting mold with the aid of a casting piston movably arranged in the casting chamber.

Cold chamber and hot chamber die casting machines are well known to those skilled in the art. According to the present invention, cold chamber die casting machines are preferred.

The present invention may be practiced with horizontal die casting machines or vertical die casting machines. Horizontal die casting machines are preferred according to the invention.

Die casting machines are designed as so-called 3-plate machines or 2-plate machines. In a 3-plate machine, the movable platen is moved on usually four guide columns by means of a supported on an additional third plate toggle mechanism relative to the fixed platen. The closing force is also generated via the toggle mechanism. In a two-plate machine the movement of the movable platen on usually four guide columns by means of a motor and lock cylinder. The closing force is transferred to the movable platen with the aid of tensioning cylinders, with which the guide columns can be fixed to the movable platen.

According to the present invention, 2-plate die casting machines are preferred. A preferred 2-plate die casting machine is in the WO 2008/131571 A1 described.

The present invention can be carried out both with conventional die casting machines and with vacuum die casting machines or other special designs of die casting machines. The person skilled in the corresponding die casting machines are known.

In a conventional die casting machine, the Giessgarnitur is arranged on the fixed platen and connected via a connecting channel with the cavity in the form formed by the two mold halves in the closed state.

The inventive die casting machine has at least two casting drives. According to a preferred embodiment of the present invention, the die casting machine has exactly two casting drives. If necessary, however, further casting drives may also be present, so that the die-casting machine according to the invention may preferably have from 2 to 10 casting drives. Since, according to the invention, each casting drive is associated with a casting assembly, as described above, the diecasting machine according to the invention has the same number of casting assemblies, ie at least two, preferably two to ten and particularly preferably exactly two casting assemblies.

The Giessgarnituren the die casting machine according to the invention should preferably be arranged on the fixed platen so that the flow paths of the molten metal are kept as short as possible. According to a preferred embodiment, the two or each two Giessgarnituren (and corresponding to the associated Giessantriebe) are arranged horizontally next to each other or vertically above one another or diagonally, preferably symmetrically about the center of the back surface of the fixed platen. More preferably, the two or two sets of each are located close to (i.e., typically 10 to 50 cm apart, depending on the size of the runners) around the center of the back surface of the fixed platen. In principle, however, the Giessgarnituren can also be disposed decentralized on the back surface, preferably within the area between the column nuts on the back surface, the fixed platen, for example in the left or right part of the back surface of the fixed platen.

In order to distribute the load as evenly as possible, it is preferred according to the invention to provide an even number of casting drives (and corresponding casting sets), for example 2, 4, 6, 8 or 10 casting drives, particularly preferably 2 casting drives, which are arranged in pairs around the center of the rear face of the fixed clamping plate are arranged.

According to the present invention, the die casting machine preferably comprises a fixed clamping plate, which has recesses and / or fastening devices for the at least two, preferably two, casting drives.

Typically, in die casting machines the Giessgarnituren are arranged on the fixed platen that part of the Giessgarnitur, usually the casting chamber, arranged in a recess in the fixed platen and fixed there. The arranged in the fixed platen part of the Giessgarnitur may protrude from the side facing away from the casting drive side of the fixed platen and protrude into an opening of the formable on the inside of the fixed platen mold half, or be connected to this opening via a connecting channel. It is also possible to arrange the casting completely outside the fixed platen at the back and secure. In this case, appropriate connecting channels are provided in the fixed clamping plate, via which molten metal can be conveyed from the casting chamber into the casting mold. The Giessgarnituren in this case have an opening which communicate with a corresponding opening of a connecting channel.

Depending on the number of existing Giessantriebe or Giessgarnituren it may be necessary to reinforce the fixed platen or to manufacture a firmer material. Corresponding measures are known to the person skilled in the art and can be routinely implemented.

The Giessgarnituren can be fed from the same container with molten metal. But it is also possible to provide for each Giessgarnitur a separate storage container for molten metal, from which the corresponding Giessgarnitur is charged with molten metal. According to the invention, the molten metal from all conventionally used in die casting metals and metal alloys be prepared. But it can also be used for example salt mixtures for the production of salt cores.

It is basically possible to operate the die casting machine according to the invention by using only one of the existing casting drives, for example with a conventional mold. However, the advantage of the present invention is only achieved by the use of several casting drives during a casting cycle.

According to the present invention, a plurality of cavities provided in a casting mold are preferably filled with the aid of the at least two, preferably two, casting drives.

Molds with multiple cavities are known. One differentiates between so-called multi-cavity forms (as described below in Fig. 4a shown by way of example), in which a certain cavity is present in the mold several times, and so-called combination forms or unit forms (as described below in US Pat Fig. 5a shown by way of example, in which different cavities are provided in the mold. With multi-cavity molds, a particular casting can be made in a single pour cycle in multiple runs. With combination molds or unit molds, different castings can be made in a single pour cycle in duplicate.

In comparison to conventional multi-cavity molds, combination molds or unit molds, casting molds having a larger number of cavities or having larger cavities can be used with the die casting machine according to the invention. The use of such molds is in conventional die casting molds due to the use Such forms associated significant increase in explosive force and to be applied to compensate high closing power not possible.

For example, with conventional die casting machines, only multi-cavity molds can be used which allow the simultaneous casting of two shock towers, i. E. only one mold can be used which provides two corresponding cavities for shock absorber bridges. With the die casting machine according to the invention, however, casting molds can be used, for example, which provide four corresponding cavities for shock absorber bridges. This can double the output per casting cycle (four instead of two shock absorber bridges). Similarly, with the die casting machine according to the invention, it is also possible to achieve a doubling of the output of other components per casting cycle (for example two side members instead of one conventionally castable side member, two panel carriers instead of one conventionally castable panel carrier).

The present invention thus also relates to a casting mold for a die casting machine, constructed from two mold halves, which at least one, preferably several, cavities provides, characterized in that the casting mold comprises at least two, preferably two openings, via which the casting mold can be filled with molten metal.

A casting mold according to the invention comprises, like conventional casting molds, two mold halves which can each be arranged on a movable and a fixed clamping plate of a die casting machine. Each mold half comprises on its inside, ie the side which is not attached to the movable or fixed platen, one or more Recesses, which form the mold cavity (s) in the state of joining the two mold halves. Each mold half also comprises on its inside one or more recesses which form connecting channels in the state of joining the two mold halves, which lead to at least two, for example 2 to 10 and preferably two openings, which is present in the mold half to be arranged on the fixed platen and by which molten metal can be filled into the mold cavity (s).

Compared with conventional casting molds, the casting molds which can be used according to the invention thus have a plurality of openings, so that cavities present in the casting mold can be filled simultaneously by a plurality of different casting drives during a casting cycle. Embodiments of the invention can be used with reference to the Fig. 4b and 5b explained in more detail.

According to a preferred embodiment of the present invention, the mold comprises at least two cavities of the same dimension, which can be filled with molten metal through separate openings. This embodiment is modeled on a conventional multi-cavity mold.

According to a further preferred embodiment of the present invention, the casting mold comprises at least two cavities of different dimensions, which can be filled with molten metal through separate openings. This embodiment is modeled on a conventional combination or unit shape.

The number of cavities provided in the casting mold depends on the size of the castings to be produced and can be, for example, 2 to 10, preferably 2 to 4.

As stated above, a significant advantage of the die casting machine according to the invention is that the casting process in the mold cavities can be carried out sequentially, i. not all existing mold cavities are filled with molten metal at the same time. This ensures that the explosive force during the casting process also arises only sequentially, namely at the positions of the cavities just filled with molten metal.

According to a particularly preferred embodiment of the present invention, a die casting machine is provided in which the movable platen is movable along preferably four guide columns, and additionally preferably on the movable platen fastening devices, preferably clamping cylinders, are preferably arranged for the four guide columns.

A corresponding die casting machine is from the WO 2008/131571 A1 known. In such a die casting machine, the required closing force is provided by the guide columns are fixedly fixed to the movable platen in the closed state, preferably via arranged on the movable platen clamping cylinder. Since preferably the passages for the four guide columns and the corresponding clamping cylinders are located at the four corners of the movable platen, the resulting forces are absorbed evenly by the movable platen and ensures stable operation of the die casting machine.

According to one embodiment of the present invention, it may be sufficient not to provide the closing force at the same time over all clamping cylinders at the same time, but only over those clamping cylinders in the vicinity of the cavity (s) filled with molten metal at the moment. For example, in a first step of the casting cycle, only cavities which are located in the upper part of the casting mold can be filled. In this case, it may be sufficient to provide the closing force only by tensioning the two clamping cylinders at the upper corners of the movable platen. If only cavities are then subsequently filled in a second step of the casting cycle which are located in the lower part of the casting mold, it may be sufficient to provide the closing force required for this purpose only by tensioning the two clamping cylinders at the lower corners of the movable clamping plate.

Similarly, it may be sufficient to tension only the clamping cylinders on the left or right side of the movable platen in the respective step of the casting cycle, if necessary. only there to apply the full closing force.

According to the invention, as stated above, generally lower closing forces are required than in conventional die casting machines. This makes it possible to use according to smaller diameter guide columns and / or larger diameter clamping plates, which in turn allows the use of larger molds. According to the invention, the diameters of the guide columns can be reduced by 20-40%, preferably 20-30%, and the dimensions of the clamping plates by 20-40%, preferably 20-30%, be increased.

For example, it is possible with the present invention, instead of using conventional square clamping plates larger rectangular platens and thereby also to enlarge the shape. Depending on the size of the rectangular platens, it is preferable to use, for example, 6 guide columns instead of 4 to prevent bending of the platens during operation.

1. a) Befüllen eines ersten Teils einer Kavität oder von Kavitäten, welche in einer durch zwei geschlossene Formhälften bereitgestellten Giessform bereitgestellt ist oder sind, mit Metallschmelze mittels eines ersten Giessantriebs;
2. b) Befüllen eines zweiten Teils einer Kavität oder von Kavitäten, welche in einer durch zwei geschlossene Formhälften bereitgestellten Giessform bereitgestellt ist oder sind, mit Metallschmelze mittels eines zweiten Giessantriebs,
3. c) Gegebenenfalls Befüllen eines weiteren Teils einer Kavität oder von Kavitäten, welche in einer durch zwei geschlossene Formhälften bereitgestellten Giessform bereitgestellt ist oder sind, mit Metallschmelze mittels eines weiteren Giessantriebs und
4. d) gegebenenfalls Wiederholung des Schritts c) bis zur vollständigen Befüllung sämtlicher Kavitäten;
   wobei zwischen den Schritten der Befüllung eines Teils der Kavität(en) jeweils eine zeitliche Verzögerung entsprechend im Wesentlichen der Erstarrungszeit des Anschnitts des im vorgängigen Schritt in einem Teil einer Kavität oder von Kavitäten gebildeten Gussstücks eingehalten wird.

The present invention further relates to a process for the production of castings in a die casting process, preferably with a die casting machine described above, comprising the steps

1. a) filling a first part of a cavity or of cavities, which is or are provided in a casting mold provided by two closed mold halves, with molten metal by means of a first casting drive;
2. b) filling a second part of a cavity or of cavities, which is or are provided in a casting mold provided by two closed mold halves, with molten metal by means of a second casting drive,
3. c) optionally filling a further portion of a cavity or cavities, which is provided in a provided by two closed mold halves mold or are, with molten metal by means of another casting drive and
4. d) optionally repeating step c) until the complete filling of all cavities;
   wherein between the steps of filling a portion of the cavity (s) in each case a time delay corresponding to substantially the solidification time of the gate of the casting formed in the previous step in a portion of a cavity or cavities is met.

According to the invention, the term "essentially" is to be interpreted as meaning that deviations of ± 10% from the solidification time of the gating of the casting formed in the previous step in a part of a cavity or cavities.

The above steps are carried out according to the invention in a single casting cycle.

• des Schliessens der Giessform durch Bewegung der beweglichen Aufspannplatte in Schliessstellung, d.h. bis zur Berührung der Formhälften,
• des Spannens der Spannzylinder und dadurch resultierendes Aufbringen von Schliesskraft (wodurch die Maschine in Giessbereitschaft versetzt wird)
• der Dosierung von Metallschmelze in die Giesskammer einer ersten Giessgarnitur,
• des Befüllens eines ersten Teils einer Kavität oder von Kavitäten, welche in der Giessform bereitgestellt ist oder sind, mit Metallschmelze mittels des ersten Giessantriebs,
• der Dosierung von Metallschmelze in die Giesskammer einer zweiten Giessgarnitur, wobei dieser Vorgang vorzugsweise überlappend oder parallel zum Giessvorgang des ersten Giessantriebs erfolgt
• des Befüllens eines zweiten Teils einer Kavität oder von Kavitäten, welche in der Giessform bereitgestellt ist oder sind, mit Metallschmelze mittels des ersten Giessantriebs,
• des Erstarrens oder Abkühlens der Metallschmelze in der Form; hierbei wird so lange Wärme an die Form abgegeben, bis das Gussstück eine für die Entnahme aus der Form ausreichende Festigkeit erreicht hat
• des Öffnens der Giessform durch Bewegung der beweglichen Aufspannplatte in Position zur Entnahme des Gussstücks, und
• der Entnahme des oder der Gussstücke durch typischerweise synchrones Ausstossen und Entnehmen des Gussstücks aus der Form; und
• des Vorbereitens der Form für den nächsten Giesszyklus durch Formsprühen und gegebenenfalls Ausblasen.

According to the present invention, a "casting cycle" is understood to mean a process sequence which begins with the closing of the casting mold by starting the movement of the movable clamping plate in the closed position and with the removal of the casting or castings from the mold opened by movement of the movable clamping plate in the open position ends. A casting cycle according to the invention thus comprises the steps

• the closure of the mold by movement of the movable platen in the closed position, ie until the mold halves touch,
• the tensioning of the clamping cylinders and the resulting application of closing force (whereby the machine is put in readiness for casting)
• the metering of molten metal into the casting chamber of a first casting set,
• the filling of a first part of a cavity or of cavities which is or are provided in the casting mold with molten metal by means of the first casting drive,
• the metering of molten metal in the casting chamber of a second Giessgarnitur, wherein this process is preferably carried out overlapping or parallel to the casting of the first casting drive
• the filling of a second part of a cavity or of cavities which is or are provided in the casting mold with molten metal by means of the first casting drive,
• the solidification or cooling of the molten metal in the mold; In this case, as long as heat is released to the mold until the casting has reached sufficient for removal from the mold strength
• opening the mold by moving the movable platen into position to remove the casting, and
• removing the casting (s) by typically synchronously ejecting and removing the casting from the mold; and
• preparing the mold for the next casting cycle by means of mold spraying and optionally blowing out.

Depending on the number of casting drives used, molten metal must be metered into the casting chambers of further casting sets and from there conveyed by means of the casting or other casting drives into further mold cavities.

The metering of molten metal into a casting chamber of a casting assembly is generally known. In the case of the preferred cold-chamber die casting method, a molten metal is usually produced in a separate container and then filled with suitable aids (for example a ladle or a dosing oven) through an opening in the casting chamber.

The filling of cavities of a mold is also known. A casting piston arranged in a casting cylinder, the other end of which is in the casting chamber in a position that molten metal can be filled through the filling opening in the casting chamber, is moved into the casting chamber by the action of force, preferably hydraulically. The casting piston passes through the filling opening in the casting chamber and closes it against the environment. Typically, the casting piston is moved into the casting chamber in three different phases, applying different pressures and velocities. In the first phase, a slow advance of the casting piston within the casting chamber occurs until the molten metal has been conveyed to the entrance of the mold cavity (i.e., to the gate). In the second phase, the mold cavity is filled very quickly (typically within 10 to 120 ms, depending on the wall thickness and the flow length) by the casting piston is moved forward very quickly. In the third phase, the so-called post-pressure phase, a high pressure (typically greater than 200 bar to 1200 bar) is applied to the casting piston, whereby the volume loss resulting from liquid to solid in the mold cavity during the phase transition of the molten metal is compensated for by feeding molten metal ,

The removal of castings from the mold takes place in a manner known to those skilled in the art, for example with the aid of ejection elements.

With the method according to the invention, several castings are produced in one casting cycle, namely more castings than can be produced in a casting cycle with a conventional die casting machine. The exact number of castings produced in one casting cycle depends on the Size of castings from. The smaller the castings, the more castings can be made in a single casting cycle. With the die casting machine according to the invention, it is possible, for example, to produce four shock absorber bridges which can usually be produced in one casting cycle, two longitudinal beams instead of one conventionally castable longitudinal beam, or two control panel carriers instead of a conventionally castable control panel carrier in one casting cycle.

As stated above, this increase in production is made possible by the fact that the existing cavity spaces are filled sequentially with different casting drives. Between the individual filling steps, a time delay is maintained, which corresponds essentially to the solidification time of the gating of the casting formed in the previous step in a part of a cavity or cavities. According to the invention, this time delay is preferably 2 to 10 seconds, more preferably 3 to 6 seconds.

According to the present invention, a "gate" is understood to mean the interface of the casting between the casting and the connecting channel, which is formed by solidification of the molten metal outside the cavity (s), ie in the connecting channels to the molding cavity or cavities. The gate is removed from the casting at the end of the actual casting cycle.

It should be pointed out that the time for a casting cycle according to the invention does not increase as a result of the time delay to be observed, since the gates occurring in accordance with the invention are generally smaller than conventional gates and solidify faster.

According to the invention, in the period of the time delay between the filling steps, molten metal may be metered into the casting chamber of the next casting composition with the aid of which the filling of the next part of a cavity or cavities is to take place. Particularly preferably, the next dosing step begins at the same time as the "shot" (filling of a portion of cavities) with the aid of the preceding casting drive, so that the method according to the invention can be carried out as quickly and efficiently as possible.

As stated above, in the method according to the invention, it is possible to compensate for the explosive force generated in the steps of filling part of the cavity (s) by a closing force which is applied to the movable platen in the region of the cavity (s) filled in the respective step , In particular, when a die casting machine according to the WO 2008/131571 A1 is used, the required closing force can be provided localized by the guide columns are fixedly fixed to the movable platen in the closed state, preferably on arranged on the movable platen clamping cylinder, but only on those clamping cylinder in the vicinity of the moment filled with molten metal cavity (s). For example, in a first step of the casting cycle, only cavities which are located in the upper part of the casting mold can be filled. In this case, it may be sufficient to provide the closing force only by closing the two clamping cylinders at the upper corners of the movable platen. If only cavities are subsequently filled in a second step of the casting cycle, which are located in the lower part of the mold, it may be sufficient to provide the necessary closing force to provide this only by closing the two clamping cylinder at the lower corners of the movable platen.

Analogously, it may be sufficient to close only the clamping cylinder on the left or right side of the movable platen in the respective step of the casting cycle.

The inventive method is preferably controlled by means of an appropriate software, as sold, for example, by the applicant under the name Dat @ net. Preferably, each casting drive is independently controlled and regulated.

The inventive die casting machine is relatively compact, since only short distances between mold cavities and corresponding casting chambers must be provided. This also reduces the metal consumption (less burnup, less melting) as well as the energy costs associated with melting or burning. The above compact design also ensures that each casting receives the optimum amount of molten metal in the process according to the invention. In contrast to conventional die casting processes, there are no problems with multiple casts in cavities which are far away from the casting system or in an unfavorable position / position.

Due to the significant increase in production die casting machine according to the invention and the inventive method, in particular for the production of large Quantities needed castings are used. The present invention thus also relates to the use of a die-casting machine described above or a casting mold described above for the production of castings, preferably castings for the automotive industry or the electronics sector.

In particular, the present invention is suitable for the production of structural parts in the automotive sector of the compact or upper middle class and can thus make an important contribution to the achievement of CO ₂ goals.

With the present invention, larger and thinner-walled components can be cast, which can meet the automotive industry's need for part integration. In particular, with the present invention, extremely large castings can be produced by casting such a component by means of several casting drives. By way of example, the entire rear part of an automobile, the two side members and a cross-connection for an automobile in one piece or two shock absorber bridges with connecting end wall in a casting called.

Analogously, hard-to-feed, preferably thick-walled castings can also be produced with the present invention by, for example, using a casting drive as the main casting drive and a further casting drive as the feeding aggregate for the thick-walled area.

With the present invention, components can be produced batchwise (ie, a casting and a mirror-image cast piece are produced in a casting cycle, for example, to be installed on the left and right side of a vehicle Components) "just in time" are produced. This reduces the cost of an otherwise required conversion of the die casting machine (in conventional die casting machines for a batch production usually the mold must be changed).

The present invention may also produce castings of various metal alloys in a mold cavity by, for example, fitting a portion of the casting with a metal alloy fed from a first casting drive and another portion of the casting with another metal fed from a second casting drive Alloy is poured. This is particularly advantageous for castings with different requirements in the different component zones (normal strength, high strength, ductile and high ductile in the crash area).

The present invention thus also relates to a casting, preferably produced by the method described above, characterized in that the casting is in one piece and comprises at least two sections which are constructed of different materials, preferably different metals or metal alloys. According to the invention, the casting 2 to 10, preferably have exactly two such different sections. In this context, "integral" is understood to mean that the casting is produced in one working step, for example in a mold cavity during a casting process, and is not produced from two separately manufactured components by subsequent assembly of the separate components.

Fig. 1

eine Druckgiessmaschine entsprechend der WO 2008/131571 A1 .

Fig. 2

eine schematische Ausführungsform der erfindungsgemässen Druckgiessmaschine mit zwei vertikal übereinander angeordneten Giessantrieben und Giessgarnituren

Fig. 3

eine weitere schematische Ausführungsform der erfindungsgemässen Druckgiessmaschine mit zwei horizontal nebeneinander angeordneten Giessantrieben und Giessgarnituren

Fig. 4a

eine schematische Ausführungsform einer herkömmlichen Multikavitäten-Giessform

Fig. 4b

eine schematische Ausführungsform einer erfindungsgemässen Multikavitäten-Giessform

Fig. 5a

eine Ausführungsform einer herkömmlichen Kombinations-Giessform

Fig. 5b

eine Ausführungsform einer erfindungsgemässen Kombinations-Giessform

The present invention will be explained below with reference to non-limiting embodiments and drawings. Show it:

Fig. 1

a die casting machine according to WO 2008/131571 A1 ,

Fig. 2

a schematic embodiment of the inventive die casting machine with two vertically superposed Giessantriebe and Giessgarnituren

Fig. 3

a further schematic embodiment of the inventive die casting machine with two horizontally juxtaposed Giessantrieben and Giessgarnituren

Fig. 4a

a schematic embodiment of a conventional multi-cavity mold

Fig. 4b

a schematic embodiment of an inventive multi-cavity mold

Fig. 5a

an embodiment of a conventional combination mold

Fig. 5b

An embodiment of a combination casting mold according to the invention

In Fig. 1 a conventional die casting machine is shown, as for example in the WO 2008/131571 A1 is described. Such a die casting machine according to the invention preferably equipped with at least two Giessantrieben and correspondingly at least two Giessgarnur and used.

In Fig. 1 a two-plate horizontal die-casting machine is shown, which has a machine bed 1 with a perpendicular thereto arranged fixed platen (FAP) 2 and a movable on the machine bed 1 movably arranged movable platen (BAP) 3.

The BAP 3 has a, preferably closed frame with two feet 7, struts 5 and ribs 6 and an ejector unit 14 for ejecting molded components. At FAP 2 and BAP 3 are each a mold half of a mold 16 are arranged. The BAP 3 is guided in four columns 8, which in turn are stored in the FAP 2. There are two upper and two lower columns 8 are provided. Each column 8 is associated with a tensioning device 9 arranged on the BAP, by means of which the closing force is applied to the respective column 8 during firing. The pillar protection tube 4 integrated into the BAP 3 prevents contamination of the column toothing. Between the lower columns 8 a lock cylinder 10 is provided. Column ejection cylinders 13, which are arranged or fastened to the latch 11 or the BAP 3, are arranged on the column coupling 12. Furthermore, a drive group 15 is provided on the machine bed 1.

In Fig. 1 the casting drive of the die casting machine is not shown.

In Fig. 2 an embodiment of the inventive die casting machine is shown with two vertically superposed Giessantrieben and Giessgarnituren which on a Die casting machine accordingly Fig. 1 are arranged. Same reference numerals in FIG Fig. 1 and 2 denote the same components.

On the formabgewandten side of the fixed platen 2, two casting chambers 19a and 19b are arranged vertically one above the other. The casting chamber 19a contains the end of a casting piston whose other end is arranged in a casting cylinder 18a and can be hydraulically operated there. The casting chamber 19b contains the end of a casting piston whose other end is arranged in a casting cylinder 18b and can be hydraulically operated there. The casting chambers are symmetrically arranged around the center of the fixed platen 2 in this embodiment and secured in corresponding recesses in the fixed platen 2. However, it should be emphasized again that the casting chambers can always be located anywhere on the fixed clamping plate in the area between the guide columns. The exact configuration of the diecasting machine according to the invention can be adapted depending on the casting to be produced. A here only schematically indicated component 17 represents the other components of the casting drives (hydraulic drive).

In Fig. 3 a further embodiment of the inventive die casting machine is shown with two horizontally juxtaposed Giessantrieben and Giessgarnituren, which corresponds to a die casting machine accordingly Fig. 1 are arranged. Same reference numerals in the Fig. 1 to 3 denote the same components.

In Fig. 3 the casting chambers are arranged side by side symmetrically about the center of the fixed platen 2 and fixed in corresponding recesses in the fixed platen 2.

In Fig. 4a a schematic embodiment of a conventional multi-cavity mold 20 is shown. The casting mold has a plurality of (here 6) identical cavities 21 whose dimensions correspond to the dimensions of the castings to be produced. The cavities 21 are connected to one another and to an opening 23 via connection channels 22. The opening 23 is open to the casting drive when the mold 20 is arranged in the die casting machine, and can be filled with molten metal from the casting drive. From the opening 23, the molten metal under pressure flows through the connection channels 22 into the cavities 21.

In Fig. 4b a schematic embodiment of an inventive multi-cavity mold 24 is shown, wherein like reference numerals in the Fig. 4a and 4b denote the same components. The casting mold 24 according to the invention has two openings 23a and 23b, which are in contact with cavities 21a and 21b via respective connecting channels 22a and 22b. Each of the openings 23a and 23b is open to one of the casting drives, when the mold 24 is arranged in the die casting machine, and can be filled with molten metal from these casting drives. From the openings 23a, 23b, the molten metal under pressure flows through the connection channels 22a, 22b into the cavities 21a and 21b.

In the mold 24 according to the invention, more cavities 21a and 21b can be provided than in the case of the conventional casting mold 20. In Fig. 4b are schematically and exemplarily 8 cavities 21a and 21b shown, but as stated above, the number of possible cavities 21a and 21b vary. In the inventive mold 24 according to Fig. 4b can they upper cavities 21a are filled independently of the lower cavities 21b by a separate casting drive, and vice versa.

In Fig. 5a an embodiment of a conventional combination mold 25 is shown. The casting mold has a plurality of (here 3) identical cavities 21 and a cavity 26 different therefrom, the dimensions of which correspond to the dimensions of the castings to be produced. The cavities 21 and 26 are connected to each other and to an opening 23 via connecting channels 22. The opening 23 is open to the casting drive when the mold 25 is arranged in the die casting machine, and can be filled with molten metal from the casting drive. From the opening 23, the molten metal under pressure flows through the connection channels 22 into the cavities 21 and 26.

In Fig. 5b an embodiment of an inventive combination mold 27 is shown, wherein like reference numerals in the Fig. 5a and 5b denote the same components. The inventive casting mold 27 has two openings 23a and 23b which are in contact with cavities 21 and 26 via respective connecting channels 22a and 22b. Each of the openings 23a and 23b is open to one of the casting drives, when the mold 27 is arranged in the die casting machine, and can be filled with molten metal from these casting drives. From the openings 23a, 23b, the molten metal under pressure flows through the connection channels 22a, 22b into the cavities 21 and 26.

In the case of the casting mold 27 according to the invention, more cavities 21 can be provided than in the case of the conventional casting mold 25 Fig. 5b are schematic and exemplary 4 cavities 21st however, as stated above, the number of possible cavities 21 may vary. In addition, the inventive mold 27 has a larger cavity 26 than the conventional mold 25. In the inventive mold 27 according to Fig. 5b the right cavities 21 can be filled independently of the left cavity 26 by a separate casting drive, and vice versa.

Claims (18)

Die casting machine, comprising a movable platen (3) and a fixed platen (2), a mold half (16) arranged on the movable platen (3) and a mold half (16) arranged on the fixed platen (2), characterized in that Die casting machine (19a, 19b) has at least two, preferably two casting drives (17, 18a, 18b) and an analogous number of the Giessantrieben (17, 18a, 18b) zugeordnete. Die casting machine according to claim 1, characterized in that the two or each two casting drives (17, 18a, 18b) are arranged horizontally next to each other or vertically above one another or diagonally one above the other, preferably symmetrically about the center of the rear surface of the fixed platen (2). Die casting machine according to claim 1 or 2, characterized in that the casting mold (25, 27) formed by merging the two mold halves (16) provides at least one, preferably a plurality of cavities (21, 21a, 21b, 26), the casting mold having at least two, preferably comprises two openings (23a, 23b), via which the casting mold (25, 27) through the at least two, preferably two casting drives (18a, 18b) can be filled with molten metal. Die casting machine according to one of claims 1 to 3, characterized in that the fixed clamping plate (2) has recesses and / or fastening devices for the at least two, preferably two Giessgarnituren (19a, 19b). Die casting machine according to one of claims 1 to 4, characterized in that the movable clamping plate (3) along, preferably four, guide columns (8) is movable. Die casting machine according to claim 5, characterized in that on the movable platen (3) fastening devices, preferably clamping cylinder (9), for the, preferably four, guide columns (8) are arranged. Die casting machine according to one of claims 1 to 6, characterized in that the die casting machine is selected from the group consisting of a hot chamber die casting machine, a cold chamber die casting machine, a hot chamber vacuum die casting machine, and a cold chamber vacuum die casting machine, each being a vertical Die casting machine or can act on a horizontal die casting machine. Casting mold (25, 27) for a die casting machine, preferably a die casting machine according to one of claims 1 to 7, constructed from two mold halves (16) which together provide at least one, preferably a plurality of cavities (21, 21a, 21b, 26), characterized in that the casting mold (25, 27) comprises at least two, preferably two openings (23a, 23b), via which the casting mold (25, 27) can be filled with molten metal. Casting mold according to claim 8, characterized in that the casting mold (25, 27) comprises at least two cavities (21a, 21b) of the same dimension, which can be filled with molten metal by separate openings (23a, 23b). Casting mold according to claim 8, characterized in that the casting mold (25, 27) comprises at least two cavities (21, 26) of different dimensions, which can be filled with molten metal by separate openings (23a, 23b). Casting mold according to one of claims 8 to 10, characterized in that for each opening (23a, 23b) a Giessgarnitur (19a, 19b) is provided. A process for the production of castings in a die casting process, preferably with a die casting machine according to one of claims 1 to 7, comprising the steps a) filling a first part of a cavity or cavities (21, 21a, 21b, 26), which is provided in a mold (25, 27) provided by two closed mold halves (16), with molten metal by means of a first casting drive ( 17, 18a, 18b); b) filling a second part of a cavity or cavities (21, 21a, 21b, 26) which is or are provided in a casting mold (25, 27) provided by two closed mold halves (16) with molten metal by means of a second casting drive ( 17, 18a, 18b), c) optionally filling a further portion of a cavity or cavities (21, 21a, 21b, 26) which is or are provided in a mold (25, 27) provided by two closed mold halves (16) with molten metal by means of a further casting drive (17, 18a, 18b) and d) optionally repeating step c) until the complete filling of all cavities (21, 21a, 21b, 26);
wherein between the steps of filling a portion of the cavity (s) (21, 21a, 21b, 26) each a temporal Delay corresponding to substantially the solidification time of the gating of the casting formed in the previous step in a part of a cavity or cavities (21, 21a, 21b, 26) is maintained. A method according to claim 12, characterized in that in the steps of filling a part of the cavity (s) (21, 21a, 21b, 26) resulting explosive force is compensated by a closing force, which at the movable platen (3) at least in the area the filled in each step cavity (s) is created. A method according to claim 13, characterized in that the closing force to the movable platen (3) in the region of the filled in each step cavity (s) (21, 21a, 21b, 26) is applied by fixing guide columns (8) on the movable Clamping plate (3), preferably by clamping cylinder (9). Method according to one of claims 12 to 14, characterized in that the time delay between the respective steps of filling a portion of the cavity (s) (21, 21a, 21b, 26) is 2 to 10 seconds, preferably 3 to 6 seconds. Method according to one of claims 12 to 15, characterized in that castings are produced batchwise, and thus in a casting cycle, a casting and mirror-image casting are produced. Casting, preferably produced by a process according to any one of claims 12 to 16, characterized in that the casting is in one piece and comprises at least two sections made of different materials, preferably different metals or metal alloys, are constructed. Use of a die casting machine according to one of claims 1 to 7 or a casting mold (25, 27) according to one of claims 8 to 11 for the production of castings, preferably castings for the automotive sector or the electronics sector.

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