DE102023105916A1 - Extrusion press - Google Patents

Abstract

In order to achieve a good pressing result despite the use of an electric motor drive to provide the force required for pressing, the inventive basic idea is to take constructive measures which enable the pressing forces to be applied to the material to be pressed as evenly and precisely as possible.

Description

The invention relates to an extrusion press for pressing a material to be pressed through a die with a receiver that receives the material to be pressed and with a press ram that can be displaced with respect to the die (12), wherein at least one component of the extrusion press can be acted upon by an electric motor drive during pressing with a force required for pressing.

From the EN 10 2015 116 002 B4 For example, extrusion presses are known for pressing a material through a die with a receiver that holds the material and with a press ram that can be moved relative to the die, in which the pressing forces are applied via hydraulic drives. Such arrangements have proven to be particularly effective for applying very high pressing forces.

Also from the JP61-43142B1 and the EP 3 470 146 B1 Extrusion presses are known for pressing a material to be pressed through a die with a receiver that receives the material to be pressed and with a press ram that can be moved relative to the die, in which the pressing forces are applied by an electric motor. Such arrangements appear to be particularly suitable for extrusion presses in which lower pressing forces are to be applied and comprise a nut-spindle arrangement in which an electric motor drives a nut in rotation, which in turn acts on a spindle attached to a press ram or to another assembly that can be subjected to a force required for pressing, so that in this way the rotary movement of the electric motor is converted into a linear movement and the pressing forces are applied and the press ram or the corresponding assembly is moved back and forth.

It is an object of the present invention to achieve a good pressing result despite the use of an electric motor drive to provide the force required for pressing.

The object of the invention is achieved by an extrusion press with the features of the independent claims. Further, possibly independent, advantageous embodiments can be found in the subclaims and the following description.

In order to achieve a good pressing result despite the use of an electric motor drive to provide the force required for pressing, the inventive basic idea is to take constructive measures which enable the pressing forces to be applied to the material to be pressed as evenly and precisely as possible.

The most uniform and precise possible application of pressing forces to the material to be pressed and thus good pressing results can be achieved with an extrusion press for pressing a material to be pressed through a die with a receiver that receives the material to be pressed and with an assembly that can be displaced with respect to the die and which can be subjected to a force required for pressing by an electric motor drive during pressing, if the extrusion press is characterized in that the electric motor drive is connected to the assembly that can be displaced with respect to the die by means of a bearing unit that has a play perpendicular to the force.

On the one hand, the bearing unit, which has a play perpendicular to the force, creates a compensation option for any transverse forces that occur perpendicular to the force required for pressing, so that the electric motor drive in particular can work as optimally as possible in terms of its drive power. In particular, any transverse forces that occur perpendicular to the force required for pressing and that could impair the displacement of the displaceable assembly can also be absorbed accordingly. On the other hand, the bearing unit, which has a play perpendicular to the force, has as little impact as possible on the force that the electric motor drive applies to the displaceable assembly or to a stationary assembly against which the electric motor drive is supported, so that the force applied for pressing can be reduced as little as possible.

With a suitable design, this can also relieve the load on the guide of the movable assembly, so that any irregularities during the pressing process, such as unwanted jumps or vibrations, can be reduced to a minimum in order to achieve a good pressing result.

The force required for pressing can be represented by a vector, so that any play in the bearing unit that allows movement perpendicular to this force can improve a uniform and precise application of the pressing forces to the material to be pressed and thus improve the pressing result.

It does not matter whether the game in question has purely translational aspects or also rotational aspects, especially with a rotation axis perpendicular to the force vector. In particular, it appears to be advantageous if both translational and rotational aspects are covered by the play, at least to a certain extent.

Ultimately, any bearing unit that can be used to transmit a force, in this case the force required for pressing, and that has a play perpendicular to this, can be used as a bearing unit that has a play perpendicular to the force. In particular, the bearing unit can therefore comprise a floating bearing, which enables a corresponding play perpendicular to a force with which the floating bearing can be loaded.

The bearing unit can in particular comprise a cardan joint, which - naturally - can transmit a force, in this case the pressing force, along the respective axes of rotation and enables tilting with a component perpendicular to this force. On the other hand, the bearing unit can comprise a joint socket having at least one degree of freedom, preferably at least two degrees of freedom, wherein the degrees of freedom accordingly preferably have at least one component perpendicular to the force required for pressing. In this way, a bearing unit can be provided in a structurally simple manner which has a play perpendicular to the force required for pressing.

The corresponding clearance can be used to relieve the load on the electric motor drive. In particular, the corresponding clearance also allows any gear connections, such as a spindle drive or similar, to be relieved of forces that occur perpendicular to the force required for pressing.

Irrespective of the combination of features mentioned here, an extrusion press for pressing a material to be pressed through a die with a receiver that receives the material to be pressed and with an assembly that can be displaced with respect to the die and that can be subjected to a force required for pressing by an electric motor drive during pressing can be characterized in that the electric motor drive drives shortening means during pressing to shorten a region of a tension element that is under tension, which counteracts the force required for pressing by pulling in order to achieve a good pressing result. This also represents, with a suitable design, a design measure that enables the pressing forces to act on the material to be pressed as evenly and precisely as possible.

An extrusion press usually applies the required pressing force between a die and a punch, which is arranged on a moving beam, in order to press the material through the die. The pressing force is usually applied by moving the moving beam in the pressing direction in relation to the die or vice versa.

In order to prevent the material to be pressed from radially escaping or from escaping past the die in general, a receiver is usually provided which can counteract the radial expansion of the material to be pressed during pressing. The receiver is preferably sealed in a suitable manner against the die or against the moving beam or the punch, so that the material to be pressed can only counteract the pressing force applied by the relative movement of the moving beam in relation to the die by escaping through the die.

Accordingly, in this context, the term receiver is understood to mean any assembly that can hold the material to be pressed and limit the radial expansion of the material to be pressed to a desired extent during pressing. The receiver is preferably sealed against the die and/or the punch or the moving beam, so that no or only very little material to be pressed can escape from the space delimited by the moving beam or punch, the receiver and the die by any means other than through the die.

Finally, there are also extrusion presses that work indirectly, whereby in such extrusion presses the die itself is usually arranged on the punch and the punch is then designed to be hollow so as not to hinder the passage of the material through the die. With such a design, a corresponding sealing plate on the side opposite the punch and the die, i.e. on the moving beam, is sufficient, which only has to ensure a suitable seal against the receiver.

In this embodiment, the punch is also designed in such a way that it penetrates into the receiver due to the movement of the moving beam and in this way reduces the space remaining for the material to be pressed within the receiver during pressing.

It goes without saying that hybrid forms of direct presses and indirect presses are also conceivable, although these are ultimately not or hardly found on the market.

In order to counteract the pressing forces that have to be applied, the extrusion presses usually have a press frame that includes a die beam on the one hand and a counter beam on the other, which are connected to one another by tie rods, so that a corresponding drive, such as the electric motor drive, can be supported on the counter beam and exert the pressing forces on the moving beam. In such a design, a corresponding force is applied between the counter beam and the moving beam by a spindle, by spindles or by one or more shoe pistons, which ultimately leads to the desired movement of the moving beam.

However, since it is not the exertion of a force on the moving beam but its displacement in the direction of the die that ultimately appears to be responsible for the pressing process, it is also conceivable to pull the moving beam directly against the die beam, which can be done in particular via the tie rods. With such a design, it is particularly possible to shorten the tie rods accordingly using shortening means and to apply the pressing forces or the movement of the moving beam via this shortening process.

With such a design, a counter beam can be dispensed with entirely. Depending on the specific implementation, it can be advantageous to use the counter beam, for example, for stabilization purposes or as a bearing body for the tie rods on a part of the tie rods that is no longer subject to tensile force. For example, the counter beam can be provided in the conventional manner at the end of the tie rods that is opposite the die beam. However, if the shortening means are provided on the die beam, for example, so that the tie rods are driven out of the die beam parallel to the material to be pressed out of the die in exactly this direction of movement, it can be advantageous to provide the counter beam or a corresponding stabilization of these driven out ends on the side of the die beam facing away from the receiver in order to stabilize the protruding tie rods.

While the shortening means can shorten an area of a tension element of the extrusion press that is under tension, it is not absolutely necessary for the shortening means to shorten the tension element itself accordingly. Such a shortening would generally be extremely complex in terms of construction, especially since the corresponding shortening of the tension element would have to take place under tension and a new lengthening of the tension element would be necessary for a new pressing process following a current pressing process. Accordingly, it will generally be simpler if the shortening means only shorten the area of the respective tension element that is under tension, which can be implemented structurally easily using cable winches, spindles or linear drives, for example.

In this context, the term "shortening means" refers to any device that is able to shorten a supporting area of a tension element. During a pressing process, this ultimately leads to a shortening of the distance between the assemblies that are connected to one another via the tension element and that exert tension on the tension element. This could then be assemblies that are stationary in relation to the die or assemblies that can be moved in relation to the die, in particular the assembly that can be moved in relation to the die mentioned above.

In particular, regardless of the combination of features mentioned here, an extrusion press for pressing material through a die with a receiver that receives the material to be pressed and with an assembly that can be displaced with respect to the die and that can be subjected to a force required for pressing by an electric motor drive during pressing can be characterized in that the electric motor drive is a linear drive that displaces an assembly that is stationary with respect to the die during pressing and the assembly that can be displaced with respect to the die during pressing against each other during pressing in order to achieve a good pressing result. The use of a linear drive is a design measure that enables the pressing forces to be applied to the material to be pressed as evenly and precisely as possible.

As already explained above, it seems relevant during pressing to displace an assembly with respect to the die in order to exert pressing forces on the material to be pressed and to force the latter through the die.

Accordingly, in the present context, the term "assembly that can be moved relative to the die" refers to any assembly of an extrusion press that can be moved relative to the die. This assembly is then preferably subjected to at least a portion of the pressing forces, preferably all of the pressing forces. In particular, a corresponding movable assembly can be provided by a moving beam. The punch itself or a sealing plate can also represent a corresponding movable assembly.

Preferably, the movable assembly is driven by a drive, in particular by the electric motor drive. It is understood that assemblies of the electric motor drive do not necessarily have to be included in the movable assembly. In particular, for example, a spindle, although it is also moved, can be considered part of the drive or part of a gear between the drive and the movable assembly and not part of the movable assembly.

Ultimately, any assembly of the extrusion press that remains stationary in relation to the die during pressing or can remain stationary can be seen as a stationary assembly in this context. In particular, for example, the die beam can generally be defined as a stationary assembly that is correspondingly stationary in relation to the die. The same applies to the punch in an indirect press. As a rule, the tie rods and the counter beam can also be seen as a stationary assembly of the die during pressing if the drive is supported on the counter beam and has a shifting effect on the beam. On the other hand, it is also conceivable that the counter beam is not a stationary component of the die if, for example, the counter beam itself is displaced during pressing, which can be the case if the counter beam serves as a positioning element for the ends of tie rods, which in turn are also moved in relation to the die, which can be the case, for example, when using the shortening means mentioned above. In direct presses, the receiver will usually also remain stationary in relation to the die during pressing, while in indirect presses the receiver is usually displaced with the beam, so that it cannot then be regarded as a stationary component.

In this context, the term “linear drive” refers to any electric motor drive that can convert electrical energy into a linear movement.

In particular, the linear drive can be a direct drive or comprise a linear actuator, by means of which electrical energy can be converted into a linear movement in a structurally precise manner and in particular using as few additional gear elements as possible or no additional gear elements.

Accordingly, the electric motor drive can also be a direct drive.

Direct drives are characterized by very few gear elements and in particular by no additional gear elements at all, so that the electrical forces can be converted into linear movement or linear forces as directly as possible. In particular, the direct drive will usually still cause a linear movement using a gear or gear elements, such as nuts, worms or spindles, which is preferably not necessary with a linear drive.

Torque motors or motor spindles are particularly suitable as direct drives. Linear actuators or linear motors in particular can be designed as direct drives if necessary. Brushless DC motors can also be used advantageously as electric motor drives or as direct drives.

In particular, the shortening means can comprise the linear drive. Accordingly, the shortening means then preferably displace, via their linear drive, an assembly that is stationary relative to the die during pressing against an assembly that can be displaced relative to the die during pressing, thereby shortening the area of the tension element that is under tension or of all of the assemblies, such as tie rods, of the same. Such a design is extremely compact and in particular makes it possible to distribute the forces to be applied by the linear drive to all of the assemblies or tie rods of the tension element if all of these interact with a linear drive, for example, as long as it is possible to compensate for any tilting moments or different speeds using a suitable control system. In the case of lighter tilting moments or force differences, the bearing unit with play explained above can then be used advantageously if compensation by means of a suitable control system does not appear to be sufficient.

The above-mentioned embodiment is particularly advantageous when the assembly fixed to the die is connected to the assembly displaceable with respect to the die via the tension element during pressing by tension, so that the shortening means or the linear drive belonging to this can become effective immediately.

Ultimately, any motor drive that can convert electrical energy into mechanical energy can be considered an electric motor drive. In particular, conventional electric motors, especially with a gearbox, possibly even with a manual gearbox, can be used accordingly.

Preferably, the electric motor drive is a direct drive, which has already been explained as being particularly advantageous in relation to the linear drive already explained above. On the other hand, the advantages of a direct drive as an electric motor drive can also be used advantageously as an electric motor drive in other arrangements in which a spindle, a gear, a worm or a nut are to be driven in rotation, in order to be able to provide this rotary movement in a manner that requires as little maintenance or loss as possible.

In particular, the electric motor drive can, as already discussed in relation to the linear drive, comprise a linear actuator, which accordingly enables a low-maintenance or low-loss energy conversion of electrical energy into a linear movement or into a linearly directed force. In this case, it does not initially matter whether the linear drive or the linear actuator acts on an assembly, for example on a tie rod, of the tension element or whether a separate device, such as a push rod or similar, is driven by the associated linear actuator.

Preferably, however, the linear actuator acts on a tension element, whereby it appears particularly advantageous if each of the tension rods of the tension element interacts with a corresponding linear actuator. In this way, a relatively compact design of the extrusion press can be realized.

It is particularly advantageous if the tension element has a stator of the linear actuator. In particular, for example, a tie rod of the tension element can be a stator of the linear actuator. In this way, the tension element that is already present can be subjected to a dual use in that it serves as a stator for the linear actuator, which then interacts as a counterpart, for example with a runner that is arranged on the beam or another movable assembly, in order to implement the associated linear movement, and on the other hand serves as a tension element.

The linear drive can include a seal so that the risk of contamination of the linear drive is minimized. Although at first glance extrusion presses should have a relatively low tendency to contaminate their surroundings, it has been found that the high temperatures of the pressed material and various auxiliary units, such as a press waste shear, in particular, can lead to a relatively high level of contamination in the area around an extrusion press. The seal can be used to protect moving components that are involved in applying the pressing forces, such as spindles, nuts, worms or other gear elements, but also rotors and stators of direct drives or linear drives and in particular linear actuators, from such contamination, especially since these components are considered to be extremely sensitive, delicate or susceptible to contamination either due to friction or due to magnetic or electrostatic effects.

These risks can be minimised by sealing.

Preferably, moving components are sealed from the outside, which can be implemented in the form of a bellows or sealing bodies that can be moved relative to one another, such as pipes or hollow bodies that run into one another. Conventional sealing rings or brush rings can also be used for this purpose.

It is understood that, if necessary, additional measures such as overpressure within the sealed space, flushing or additional brushing may be used to further limit contamination if this appears necessary.

The extrusion press can comprise a spindle and a nut that can be moved in relation to the spindle, by means of which the force required for pressing can be provided. Even with such a design, a seal as described above can be advantageous, since the relatively high forces, the relatively large contact area between the spindle and the nut and the relatively high friction that are to be expected with this design make any contamination of the spindle or the nut appear particularly relevant.

In particular, either the spindle or the nut can be rotationally driven by the electric motor drive, which - as already explained above - can be designed in particular as a direct drive.

In an alternative design, the spindle can comprise or represent a tension element. This then enables an extremely compact design, since shortening means can then be provided directly via the spindle and the associated nut.

In particular, it appears advantageous in such a design if each of the tie rods is designed accordingly so that an associated beam can be moved as evenly as possible or subjected to a pressing force.

For structural implementation, it is advantageous if the tension element includes at least one tension rod. This can be designed in different ways depending on the specific implementation. For example, solid rods or slats arranged parallel to one another are known as tension rods. Ropes are also used.

If necessary, support elements, such as the cables or pipes surrounding the slats, are used between the assemblies connected by the tie rod. In this respect, the tie rod can be designed in one piece or in several pieces, depending on the specific implementation. In particular, tensioning elements or tensioning screws or wedges or similar devices can also be components of the tension element in order to ensure a defined distance between the assemblies connected to the tie rod and an adequate possibility of absorbing the tensile forces that occur.

It is already known that the tension element or the tension rod(s) can take on additional functions within the extrusion press. For example, movable components such as the moving beam or a pickup can be guided or even driven on the tension rod. The same applies to a press-off shear, which can also be guided or even driven on the tension element or one or more tension rods for displacements parallel to the direction of the pressing force.

In particular, the tension element can comprise two, three or four tension rods, which are preferably arranged symmetrically to the pressing forces that occur. Point or mirror symmetries are particularly suitable here. In this way, the pressing forces can be distributed as evenly as possible across the tension rods and therefore also across the components subject to the pressing forces.

The tension element can thus pull on a die beam during pressing, particularly if this represents a component that is stationary relative to the die. In particular, the tension rod(s) can pull on the die beam during pressing, so that the forces acting on the die and thus also on the die beam can be passed on in a pulling manner via the tension element or via the tension rod(s).

Cumulatively or alternatively, the tension element can pull on a counter beam during pressing, which is particularly advantageous if the counter beam is a stationary assembly with respect to the die. The same applies to the tension rod(s). This type of design then makes it possible for the counter beam to absorb forces that are directed against the pressing forces and to compensate for them via the tension elements.

In particular, if the tension element works together with a shortening means, it can be advantageous if the tension element acts on the beam as one or the component that can be moved relative to the mattress during pressing. In this way, the beam can be pulled against the die or against the die beam, whereby pressing forces can then be applied against the die via the beam. Such a design proves to be particularly compact.

As already indicated above, the assembly subjected to the force can be guided over at least one travel beam, which is the case, for example, with a stamp of a direct press or with a pressure plate of an indirect press.

As a rule, the beam is guided in a suitable manner on the extrusion press, precisely because it is intended to perform a running function as a beam. Guide rails can be used for this purpose in particular. Components of the tension element, such as tie rods or spacers, such as spacer tubes, often serve as such guides along which the beam can then run. It goes without saying that separate guides can also be provided in different designs. Depending on the specific implementation, these guides can also serve as part of a drive for such components, for example for the targeted relocation of the pickup.

In particular, the assembly subjected to the force can also be the beam itself, whereby it is understood that the beam can also be a component of the assembly subjected to the force if, for example, not only the beam but also the plunger or a sealing plate are defined as components of the assembly subjected to the force.

In particular, the assembly subjected to the force and displaceable with respect to the die can be the press ram or carry the press ram, for example in a direct press, as already indicated above. In an indirect press, the assembly subjected to the force can and displaceable relative to the die, for example, can be the pressure plate or can carry it. Likewise, as already explained above, the press ram or the pressure plate can be a component of the assembly that is subjected to the force and displaceable relative to the die.

Depending on the specific design, the press punch can also be designed as a single piece with the assembly that is subjected to the force and can be displaced with respect to the die.

In particular, the extrusion press can be a metal extrusion press with which a metallic block can be pressed through the die. For example, metallic wires, rods, tubes and/or other prismatic profiles can be produced with an extrusion press.

In this context, an “extrusion press” is understood to mean a press which can be used for primary or forming processes.

Such extrusion presses, in particular metal extrusion presses, can work not only with blocks, for example metallic blocks, but also with powdery materials, for example with powders containing metallic, ceramic and/or hard materials, with graphite powders or with mixtures thereof, whereby corresponding granulates are also equivalent to these and for this purpose the powders or granulates can, if necessary, be sufficiently compacted and pressed beforehand or suitably coated in order to then be able to load them into the receiver of the extrusion press.

It is conceivable that plastic materials can also be processed, whereby the process for pure plastic materials is usually referred to as extrusion. When pressing plastic materials, additional mechanical energy is often introduced, for example through an extruder screw, whereas this is generally not found in extrusion presses.

Preferably, the present extrusion press is used to form or reshape profiles made of stainless steel or aluminum, although it is understood that the application of the extrusion press of the present invention is not limited to this, but can also be used for other products.

The material to be pressed is pressed against and through a die by a press ram, a pressure plate or a similar assembly with the force required for pressing. This is how the forming or primary forming process takes place.

To ensure that the material to be pressed can be pressed through the die and does not move sideways, the material to be pressed is surrounded by a receiver during pressing. Depending on the specific implementation, the receiver usually remains stationary in relation to the press ram or the die during pressing, although in theory mixed forms are also conceivable, as already explained above.

In this respect, the term receiver is understood to mean any assembly that can hold the material to be pressed and prevent it from breaking out sideways during the pressing process. Depending on the specific implementation, seals can also be provided for the moving beam, the punch or the pressure plate or the die in order to force the material to be pressed through the die with as little loss as possible.

Accordingly, the receiver is preferably a block receiver, into which metal blocks or powders or granules compacted, pressed or suitably coated into blocks can be inserted in order to then press them. As a rule, an existing extrusion press is therefore preferably not filled with bulk material or flowable material, but with piece goods, namely the blocks. Depending on the specific process, it goes without saying that the blocks can be preheated in a suitable manner in order to facilitate the subsequent pressing process. It is also possible - depending on the specific implementation - to heat the receiver, a sealing plate or press stamp separately if the heat generated during pressing is not sufficient for the pressed material to flow sufficiently.

Since the extrusion presses in question are preferably filled with blocks or with non-flowable material to be pressed, it is advantageous if the extrusion press operates discontinuously.

In a specific process sequence, the receiver can first be filled with a material to be pressed before pressing or can be filled accordingly. During pressing, the receiver is then emptied or can be emptied accordingly and is then filled with material to be pressed again for a new pressing process.

It is understood that the features of the solutions described above or in the claims can also be combined if necessary in order to be able to implement the advantages cumulatively.

• 1 eine erste Strangpresse mit rotierender Spindel und feststehender Mutter in schematischer Ansicht;
• 2 eine zweite Strangpresse mit rotierender Spindel und feststehender, aber mitwandernder Mutter in schematischer Ansicht;
• 3 eine dritte Strangpresse mit zwei Teilanordnungen sowie mit rotierender Mutter und feststehender Spindel in schematischer Ansicht;
• 4 eine Aufsicht in Pressrichtung auf die Strangpresse nach 3;
• 5 eine exemplarische Darstellung eines Kugelgewindes in perspektivischer Ansicht;
• 6 eine exemplarische Darstellung eines Rollengewindetriebs in perspektivischer Ansicht;
• 7 eine Seitenansicht des Rollengewindetriebs nach 6;
• 8 eine exemplarische Darstellung eines Planetenrollengewindetriebs in perspektivischer Ansicht;
• 9 eine Aufsicht auf das Planetenrollengewindetriebs nach 8;
• 10 eine vierte Strangpresse mit einem kardanischen Gelenk als Lagereinheit;
• 11 eine fünfte Strangpresse mit einer Gelenkpfanne als Lagereinheit; und
• 12 eine sechste Strangpresse mit Verkürzungsmittel, die jeweils einen Lineartrieb umfassen.

Further advantages, objectives and properties of the present invention are explained in the following description of embodiments, which are also shown in particular in the attached drawing. In the drawing:

• 1 a first extrusion press with rotating spindle and fixed nut in schematic view;
• 2 a second extrusion press with rotating spindle and fixed but moving nut in schematic view;
• 3 a third extrusion press with two sub-assemblies and with rotating nut and fixed spindle in schematic view;
• 4 a view in the direction of pressing onto the extrusion press after 3 ;
• 5 an exemplary representation of a ball screw in perspective view;
• 6 an exemplary representation of a roller screw drive in perspective view;
• 7 a side view of the roller screw drive after 6 ;
• 8th an exemplary representation of a planetary roller screw drive in perspective view;
• 9 a view of the planetary roller screw drive according to 8th ;
• 10 a fourth extrusion press with a cardan joint as a bearing unit;
• 11 a fifth extrusion press with a joint socket as a bearing unit; and
• 12 a sixth extrusion press with shortening means, each of which includes a linear drive.

The 1 to 4 and 10 to 12 The extrusion presses 10 shown are each suitable and intended for pressing material 11 through a die 12. In this way, wires, rods, tubes or other prismatic profiles with relatively complex cross-sections can be pressed from the material 11, which can comprise, for example, metallic, ceramic or hard material blocks, possibly also powders or granules.

For pressing, the respective material to be pressed 11 is subjected to a pressing force and pressed through the die 12 in the pressing direction 50.

In order to force the material to be pressed 11 through the die 12, a receiver 13 is provided into which a press ram 14 can be inserted in order to apply the pressing forces.

The extrusion presses 10 shown in the drawing are each direct presses in which the press ram 14 acts directly on the material to be pressed 11 and follows the pressing direction 50 for pressing. Alternatively, the extrusion presses 10 can also be designed as indirect presses in which the press ram 14 carries the die 12 and a pressure plate is displaced together with the receiver 13 against the die 12 and the press ram 14, which accordingly leads to the die 12 and the press ram 14 being immersed in the receiver 13 against the pressing direction for pressing.

In the present embodiments, the respective press stamp 14 is carried by a moving beam 17, which can be displaced together as an assembly 31 with respect to the die 12. It is understood that this displaceable assembly 31 may also have further components, such as a connecting piece 36 and a moving mother beam 35 (see 2 ). In an indirect press, the pressure plate and the moving beam 17 would be combined to form the assembly 31 that can be moved with respect to the die 12, whereby here too, further components, such as the mother beam 35 and the connecting piece 36, may also be included.

The die 12 is supported by a die beam 15, whereby these two form a component group 32 that is stationary with respect to the die 12, which - depending on the desired definition - can also include further components that remain stationary with respect to the die 12 during pressing. In an indirect press, the associated press stamp 14 would also be included in the component group 32 that is stationary with respect to the die 12.

For the actual pressing process, the two assemblies 31, 32 are displaced against each other, so that these two assemblies 31, 32 represent the essentially effective assemblies 30 which must be displaced against each other for pressing.

In the present embodiments, the pressing forces are applied by an electric motor drive 40, which is ultimately supported by a tension element 71 or tension rod 16 on the die spar 15, so that the pressing forces can be counteracted in this way. 1 , 2 , 10 and 11 In the extrusion presses 10 shown, the electric motor drive 40 or a spindle-nut arrangement 20 driven by it is supported on a counter beam 18, on which the tension element 71 or the tension rods 16 act accordingly. 3 and 12 In the embodiments shown, the counter beam 18 has only a stabilizing function. The electric motor drive 40 or a nut 22 is in the extrusion press 10 according to 3 on the running beam 17, so that tensile forces can be transmitted via this nut 22 to the tie rods 16. In the embodiment according to 12 Instead of a nut 22, which interacts with a spindle 21 carried by the tie rods 16, a runner 75 of a linear drive 73 is arranged on the running beam 17 or is designed as such, which can be supported on the tie rod 16, which is designed as a stator 74 of the linear drive 73, so that in this embodiment too the counter beam 18 only serves stabilization purposes.

In order to apply the pressing forces, the 1 to 3, 10 and 11 illustrated embodiments each have spindle-nut assemblies 20 which comprise a spindle 21 and a nut 22.

In the embodiment according to 3 the nut 22 is driven by the electric motor drive 40, while in the embodiments according to 1 , 2 , 10 and 11 the spindle 21 is driven by the electric motor drive 40. It is understood that the corresponding drive types can also be reversed, in the embodiment according to 1 , 10 and 11 the nut 22 is driven in rotation, while in the embodiment according to 3 a rotary drive of the spindle 21 can take place while the nut 22 remains stationary. Ultimately, it depends on a relative movement between these two assemblies, by means of which the rotational movement of the electromotive drive 40 can be converted into a linear movement in the pressing direction 50 or in the opposite direction.

The spindle-nut arrangements 20 are each designed as rolling threads 23 in order to be able to transmit the greatest possible forces with little friction. Depending on the specific design, ball threads 80 or roller threads 90 can be used advantageously, as shown below with reference to the 5 to 9 On the other hand, it is understood that in different embodiments the spindle-nut arrangements 20 can also conventionally provide a frictional interaction between spindle 21 and nut 22, in which case additional lubrication, for example hydrostatic lubrication, can be provided if necessary.

A ball screw 80, as described above, can be used and in 5 shown as an example, comprises the spindle 21 and a nut 22 designed as a ball nut 82, which also comprises a ball return 83 and forms grooves 84 together with the spindle 21. In addition, the ball thread 80 comprises balls 81, which rotate in the grooves 84 and the ball return 83 during a relative rotational movement between the nut 22 and the spindle 21.

An electric motor drive 40 drives the spindle 21 in relation to the nut 22 or vice versa. Between the spindle 21 and the ball nut 82, the balls 81 move in the grooves 84, which move axially when the spindle 21 rotates. The movement of the balls 81 takes place by rolling. The ball return 83 in the ball nut 82 transports the balls 81 back again and thus closes the circuit in which the balls 81 circulate.

While in conventional screw gears with surfaces sliding on one another 50 to 90% of the introduced power is converted into heat, the present ball screw 80 with its ball screw drive has less friction due to the rolling movement of the balls 81. In this way, a lower drive power can be sufficient, which is particularly advantageous when using an electric motor drive 40. In addition, the overall wear and in particular the wear between the spindle 21 and the ball nut 82 is also lower.

It is understood that such ball screws 80 or ball screws of a different design can be used for the spindle-nut arrangement 20 of the other embodiments and also alternative embodiments.

In an alternative embodiment, a roller thread 90 can also be used for the spindle-nut arrangement 20 or, in the present embodiments, as the rolling thread 23.

Such a roller thread 90 could, for example, be designed as a roller screw drive 97, as shown in 6 and 7 is shown.

The roller screw drive 97 comprises a spindle 21 and a nut 22 designed as a roller nut 92. The spindle 21 is surrounded by rollers 91, each of which has circular grooves 99. As the rollers 91 rotate with their grooves 99 around the spindle 21, a relative movement in the axial direction takes place. A correspondingly designed roller nut 92 also comprises a roller return 98. The roller return 98 serves to lift the rollers 91 off the spindle and then return them again.

Because of the radial and axial movement of the rollers 91, the roller nut 92 is designed like a cage to hold the rollers 91 in position.

For the extrusion presses 10 of the present embodiments, the roller thread 90 can also be designed as a planetary roller screw drive 93, as is shown, for example, in 8th and 9 is shown.

The planetary roller screw drive 93 comprises rollers 91 with a thread 94, which rotate in ring-shaped roller nuts 92 around a spindle 21 with its thread 94. This rotation results in an axial relative movement between nut 22 and spindle 21.

The diameters of the spindle 21, the rollers 91 and the roller nut 92 are selected so that the peripheral speeds of the spindle 21 and the rollers 91 match. Synchronization is carried out by a ring 95 with an internal toothing integrated into the roller nut 92, which engages in pinions 96 at the ends of the rollers 91.

In the present planetary roller screw drive 93, the rollers 91 or rolling elements move - in contrast to the embodiments according to 5 and 6 and 7 - in the longitudinal direction not relative to the roller nut 92, so that no return mechanism is necessary. This can enable higher speeds.

Roller threads 90 also enable a corresponding reduction in friction, which also applies to threads with hydrostatic nuts 65. The combination of roller threads 23 with a hydrostatic bearing or in such a way that the nuts of the roller threads 25 are then designed to be hydrostatic can also be used to reduce friction, whereby it is understood that these advantages are already advantageous individually compared to the solutions known from the prior art.

In the 1 , 2 , 10 and 11 In the embodiments shown, the electric motor drive 40 is implemented in each case by a direct drive, which comprises a stator 41 and a rotor 42 rotating with the respective spindle 21. It is understood that in different embodiments, other drives or drive types, in particular, for example, gear drives, which may even be switchable, can also be used.

Since in the embodiment according to 1 , 10 and 11 the spindle 21 is displaced together with the running beam 17, the stator 41 is correspondingly longer in these embodiments than in the embodiment according to 2 , according to which the spindle remains stationary with respect to the die 12, while a corresponding hydrostatic nut 65 runs along with the running beam 17, so that the stator 41 can be made correspondingly shorter.

Here, the hydrostatic nut 65 in the embodiment according to 2 mounted on a mother beam 35 in a floating manner perpendicular to the pressing direction 50, so that in this way a bearing unit 60 is provided which has a play perpendicular to the pressing direction 50 and thus perpendicular to the force required for pressing.

It is understood that, if necessary, a bearing directly on the running beam 17 or an immediate arrangement of the mother beam 35 and the running beam 17 one behind the other is also possible, while in this embodiment a connecting piece 36 with a spacing effect is also provided between the mother beam 35 and the running beam 17.

For lubrication purposes, the hydrostatic nut 65 of the embodiment according to 2 a bearing medium pump 66 and a bearing medium container 67, so that the hydrostatic nut 65 can be sufficiently lubricated both in its contact with the spindle 21 and in the bearing unit 60 with the nut beam 35.

In particular, a hydrostatic nut 65 can be used advantageously both in spindle-nut arrangements 20 with a rotating nut 22 and with a non-rotating nut 22, whereby with a non-rotating nut 22 it appears to be much easier to provide the hydraulic bearing means at the necessary locations, since rotary unions and the like can be dispensed with.

The embodiment also bears 2 in the area of the electric motor drive 40, a further bearing medium pump 66 with a bearing medium container 67, by means of which in particular a hydrostatic bearing 69, which can absorb forces of the spindle 21 on the counter beam 18 directed against the pressing forces, can be lubricated.

The bearing medium pump 66 and the bearing medium tank 67 for the hydrostatic bearings and lubrication systems do indeed mean additional expenditure, in particular additional hydraulic expenditure, which should actually be avoided by using electric motor drives 40. On the other hand, this additional expenditure is not comparable with the expenditure and the risks associated with using hydrostatic drives instead of electric motor drives 40 are considerably lower than the costs and risks associated with using hydrostatic drives.

In addition, the 2 In the embodiment shown, the spindle 21 also has a drive pin 49 which is formed on the side of the spindle 21 which faces the electric motor drive 40 and which carries the rotor 42 so that it can be replaced. Such a design makes it possible to quickly replace the electric motor drive 40 if necessary or to adapt it to specific requirements.

On the other hand, the spindle 21 in the embodiment according to 2 axially supported by a return stroke bearing 26 and two axial bearings 27 in the counter beam 18.

It is understood that the reversal of the effect, which in 2 compared to the embodiment according to 1 , 10 and 11 is shown, can accordingly also be implemented in the latter embodiments if necessary. The same applies to the use of the drive pin 49 in order to increase the flexibility with regard to the electric motor drive 40 ultimately used.

The floating bearing of the hydrostatic nut 65 of the embodiment according to 2 in the embodiment according to 1 , 10 and 11 are used, although these implement alternatives in this regard, which in turn are also used in the embodiment according to 2 can be applied.

The extrusion press uses 10 1 a bearing of the spindle 21 on the running beam 17 by means of an axially effective roller bearing 25 and by means of an axially effective return stroke bearing 26, so that a bearing unit 60 is also provided which allows a play perpendicular to the pressing direction 50 or perpendicular to the force applied for pressing.

The embodiment according to 10 uses a cardanic joint 61 at this point, whereby a sliding bearing of this cardanic joint for tension and compression is not shown separately in this embodiment, but this cardanic joint 61 also requires a play perpendicular to the pressing direction 50 or to the force applied for pressing. Instead of a sliding bearing, rolling bearings can also be used here if necessary.

Especially for the provision of a clearance perpendicular to the pressing direction 50 or to the force applied for pressing, the arrangement according to 11 a suitably shaped joint socket 62 in order to allow a corresponding play perpendicular to the force applied for pressing or to the pressing direction 50. The return stroke is also implemented in this embodiment by a plain bearing (not numbered), whereby roller bearings can also be used instead of the plain bearings. Here too, it is understood that these solutions can also be implemented in a suitable manner in the other embodiments.

In the examples according to 3 and 12 shortening means 70 are provided which shorten the tension elements 71.

In these embodiments, 3 and 12 In each case, it is provided that the individual tie rods 60 are shortened in their effectiveness by shifting the point at which the forces directed against the pressing forces are absorbed closer to the assembly 32 fixed to the die 12.

This can be done in particular by shifting the point of application on the tie rods 16 accordingly, which can be implemented by the shortening means 70 correspondingly having a nut 22 (see 3 ) or a runner 75 (see 12 ) along the tie rods, which then serve as spindle 21 (see 3 ) or as stator 74 (see 12 ) can be trained.

It is understood that in different embodiments the mode of operation of spindle 21 or stator 74 on the one hand and nut 22 and rotor 75 on the other hand can be swapped, for example by rotating spindle 21 and holding nut 22. Also, for example, pull rod 16 can be designed as a rotor of linear drive 73 and conversely a stator of linear drive 73 can be provided on beam 17.

In the examples according to 3 and 12 the shortening means 70 or the individual drive elements of the electric motor drive 40 are provided in sub-arrangements 24 corresponding to the arrangement of the tie rods 16. It is understood that in particular the linear drive 73 may also be used in the arrangements according to 1 , 2 , 10 and 11 can be used, whereby stator 74 and rotor 75 can be used instead of spindle 21 or nut 22 depending on the specific requirement.

In particular, the linear drive 73, as shown in 12 shown, be designed as a linear actuator. Especially with such a design there is a risk that due to the magnetic effects, but possibly also due to electrical or electrostatic effects, increased For this reason, in the embodiment according to 12 a seal 76 in the form of bellows 77 is provided.

It is understood that in different embodiments, instead of a bellows 77, other seals can be provided, as long as they are suitable for sealing the critical areas.

It is also understood that in the other embodiments, corresponding seals can be provided at suitable locations if this is necessary, for example in the case of the electric motor drive 40 designed as direct drives in the embodiments according to 1 , 2 , 10 and 11 or on friction surfaces of the spindles 21 or nuts 22, appears advantageous.

List of reference symbols:

10

Extrusion press

11

Pressed material

12

die

13

Transducer

14

Press stamp

15

Die beam

16

Tie rod

17

Running beam

18

Counter beam

20

Spindle-nut arrangement

21

spindle

22

Mother

23

Rolling thread

24

Partial arrangement

25

Rolling bearings of spindle 21

26

Return stroke bearing

27

Axial bearing of spindle 21

30

module

31

assembly movable relative to the die 12

32

to the matrix 12 stationary assembly

35

Mutterholm

36

Connector

40

electric motor drive

41

stator

42

rotor

49

Drive pin

50

Press direction

60

Storage unit

61

cardanic joint

62

Articular socket

65

hydrostatic nut

66

Bearing pump

67

Storage container

69

hydrostatic bearing

70

Shortening agent

71

Tension element

73

Linear drive

74

Stator of the linear drive 73

75

Runner of the linear drive 73

76

seal

77

Bellows

80

Ball screw

81

Bullet

82

Ball nut

83

Ball return

84

Running grooves

90

Roller thread

91

role

92

Roller nut

93

Planetary roller screw drive

94

thread

95

ring

96

pinion

97

Roller screw drive

98

Roll return

99

Grooves

QUOTES INCLUDED IN THE DESCRIPTION

This list of documents listed by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions.

Cited patent literature

• DE 102015116002 B4 [0002]
• JP 6143142 B1 [0003]
• EP 3470146 B1 [0003]

Claims (10)

Extrusion press (10) for pressing a material to be pressed (11) through a die (12) with a receiver (13) receiving a material to be pressed (11) and with an assembly (31) which is displaceable with respect to the die (12) and which can be acted upon by an electric motor drive (40) during pressing with a force required for pressing, characterized in that the electric motor drive (40) (i) is connected to the assembly (31) which is displaceable with respect to the die (12) by means of a bearing unit (60) which has a play perpendicular to the force; and/or (ii) during pressing, drives shortening means (70) for shortening a region of a tension element (71) which is under tension and which counteracts the force required for pressing by tension, and/or (iii) is a linear drive (73) which displaces an assembly (32) which is stationary with respect to the die (12) during pressing and the assembly (31) which is displaceable with respect to the die (12) during pressing relative to one another during pressing. Extrusion press (10) to Claim 1 , characterized in that the bearing unit (60) comprises a cardanic joint (61) and/or a joint socket (62) having two degrees of freedom. Extrusion press (10) to Claim 1 or 2 , characterized in that the shortening means (70) comprise the linear drive (73) and the assembly (32) which is fixed to the die (12) is connected to the assembly (31) which is displaceable with respect to the die (12) via the tension element (71) during pressing by tension. Extrusion press (10) according to one of the Claims 1 until 3 , characterized in that the electromotive drive (40), in particular the linear drive (73), is a direct drive and/or comprises a linear actuator, wherein the tension element (71) preferably has a stator (74) of the linear actuator. Extrusion press (10) according to one of the Claims 1 until 4 , characterized by a spindle (21) and a nut (22) which is axially displaceable with respect to the spindle (21), wherein preferably the spindle (21) or the nut (22) is rotationally driven by the electric motor drive (40) and/or wherein preferably the spindle (21) is encompassed by the tension element (71) or represents parts thereof. Extrusion press (10) according to one of the Claims 1 until 5 , characterized in that the linear drive (73) comprises a seal (76) which preferably seals moving assemblies from the outside, for example in the form of a bellows (77). Extrusion press (10) according to one of the Claims 1 until 6 , characterized in that the tension element (71) comprises at least one, preferably two, three or four, tension anchors (72). Extrusion press (10) according to one of the Claims 1 until 7 , characterized in that the tension element (71), preferably the tension rod or rods (72), acts in a pulling manner on a die beam (15) as a component (32) fixed to the die (12) and/or on a counter beam or running beam (17) as a component (31) displaceable with respect to the die (12) during pressing. Extrusion press (10) according to one of the Claims 1 until 8th , characterized in that the assembly (31) subjected to the force is guided over at least one running beam (17) or is the running beam (17). Extrusion press (10) according to one of the Claims 1 until 9 , characterized in that the assembly (31) subjected to the force and displaceable with respect to the die (12) is the press stamp (14) or carries the press stamp (14) and is preferably formed integrally therewith.

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