EP2809461B1 - Device and method for producing non-porous profiles from separation residues by means of extrusion - Google Patents

Description

The invention relates to a device and a method for producing pore-free profiles from separating residues by means of extrusion according to the preamble of claims 1 and 8 and to a method for producing property-graded profiles from separating residues according to claim 10.

In the production of workpieces by means of separating manufacturing processes, such as in particular by means of machining manufacturing processes with geometrically determined or also by means of geometrically indeterminate cutting edges, large quantities of chips or similar separating residues inevitably arise in addition to the workpiece that is actually to be produced. Material residues cannot be avoided even in the case of workpiece forming processes such as punching sheet metal or the like. Such material residues are waste with regard to the workpiece produced, however, these separating residues such as chips or the like generally still have the same material properties as the machined blank or the workpiece produced therefrom and are therefore also valuable, if not not be in an immediately usable form. When we talk about separating residues, chips or the like, we should always refer to residues from processing processes such as cutting or other, non-shaping changes in the shape of workpieces.

Separation residues of this type, such as chips, cutting waste and much more, are usually collected with the same type of other material waste, if possible, sorted by type and sent for recycling. For this purpose, chips, for example, are collected separately according to material, for example in containers, and processed further when used metal dealers reach the appropriate quantities.

This further processing usually consists in the fact that larger quantities e.g. of chips, which due to their macro geometry only form a loose heap or a collection of free-flowing smaller particles, are either broken down into smaller particles in appropriate shredders or also compacted in appropriate compactors, so that the volumetric space required for storing and transporting the chips decreases. Subsequently, the usual way of further using such pretreated chips and separating residues is that the recycling companies transport them further to the corresponding melting companies and melt them at high temperatures and thereby recycle them. The problem here is, on the one hand, the high expenditure for the collection, storage, transport and pretreatment of the not yet or not sufficiently compacted separation residues and, on the other hand, the high energy expenditure for melting for recycling.

For compacting metal chips are, for example, from the DE 10 2009 040 491 A1 or the DE 202 10 144 U1 Corresponding briquetting presses are known, in which light metal chips can be compressed by pressing stamps and can be output in the form of briquettes. Although this significantly reduces the volume of chips to be stored and transported, the resulting light metal briquettes still have a high proportion of fluid media such as air and cooling lubricant residues, which are enclosed in the briquette and are very difficult to process directly. The light metal briquettes are only used by melting.

It is also known from powder metallurgy to bake powdered metals or ceramic substances specially produced for this purpose under the action of heat and high pressure, so that a very compact material matrix results, the properties of which, depending on the mixture of the powdered components and the process, are broad Limits can be influenced. Here, however, the starting material, namely the one or more material powders, consists of small, essentially spherical particles, which are produced, for example, from the melt especially for powder metallurgical processing and whose arrangement with respect to one another is very compact and designed with little air inclusions before the thermal pressure treatment. Under the These particles then bake together under pressure and at high temperature and form the very uniform new structure with only a small proportion of pores.

From the US PS 2,391,752 is a process for the production of profiles or tubes or the like. Directly known from metal residues such as chips, in which precompacted and thermally pretreated compacts are introduced into an extrusion device and further pressed therein and extruded into conventional profile shapes. Here, the thermally pretreated compacts are further heated in the extrusion press to temperatures below the melting temperature and pressed through the die in this heated state. The material properties of profiles produced in this way should essentially correspond to those which originate from profiles made from melt materials.

However, it has been found that when processing metal scraps to those in the US PS 2,391,752 Specified manner problems arise in that the profiles produced after the extrusion process have inhomogeneities and defects which allow the use of such profiles at most for subordinate purposes at low loads. Due to the air inclusions in the compacts, air crossings and non-homogeneous material areas are repeatedly formed in the cross sections of the profiles extruded from the compacts, which, under mechanical loads, act as predetermined breaking points already created during manufacture and thus severely restrict the area of use of such profiles. As a result, profiles of this type can only be produced with inferior and rather arbitrary quality, which, moreover, produce only low yields for the economically very complex recycling.

From the US 4,117,703 A , Which forms the basis for the preamble of claim 1, the US 2 967 613 A. and the US 4,059,896 A. Devices, which form the basis for the preamble of claim 8, are known devices for producing profiles from separation residues by means of extrusion, in which chips are pressed in a compression chamber and then extruded. Here, however, there is the problem of safely removing air pockets between the compacted chips before extrusion.

It is therefore an object of the present invention to further extend a generic extrusion process and a generic extrusion device develop that profiles of high quality and resilience can be reliably produced.

The invention is based on a generic device for producing pore-free profiles from separation residues by means of extrusion presses, comprising an extrusion press with a compression chamber consisting of a press ram, a press die and a recipient, into which a pile consisting of manufacturing processes separating separation residues or the like, such as chips or residual materials is fillable. Between the press die and the compression chamber, sealing the compression chamber on the die side, a cover element can be arranged, against which the press ram compresses the heap of separation residues into a compact and thereby removes fluid inclusions remaining in the compression chamber and in the pile, after which the cover element can be removed again and the compressed one Compact can be pushed through the press die as a profile cross section. The arrangement of the cover element, by means of which at least the open cross sections of the die are sealed with respect to the outlet of the compact to be pressed, allows the pile or the compact formed from it to be compressed to a much greater extent than is the case with the method according to the US Pat. PS 2,391,752 was possible. The much stronger compression can be used to selectively drive out the inclusions of fluid media, in particular the inclusions of air in the heap or the compact, and to ensure that no fluid media, such as air in particular, are left in the air before the actual extrusion process Pile or better put in the highly compressed compact. For this purpose, the shape of the stamp and / or cover element ensures that the flow of the fluid medium expelled by the increasing pressure, such as air, is pressed out of the interior of the compact and does not remain in the pores or cavities of the compact, for example can already have negative effects on the extruded profile. Ideally, the fluid medium can be expelled radially from the inside of the heap or compact to the outside, so that the expulsion first begins in the interior of the compact and then progresses further outward. Is the pellet so over one pressed for a certain period of time in the compression chamber between the ram and cover element, the pressure is then briefly relieved and the cover element is moved out between the compression chamber and press die. Immediately afterwards, the pellet produced in this way can then be pressed through the press die in a conventional manner and, because of the pore-free initial state before the extrusion, now also forms defect-free profiles. In this way, the quality of the extruded profiles that can be produced can be significantly increased, for which no further modifications of the extrusion press are necessary except for the addition of the covering element to the cover element and the movement devices required for this. In addition, the compression and the extrusion can be carried out directly in succession in the same extrusion press, whereby additional handling processes of the compact are avoided and the process heat of the compression can also be used directly for the temperature control of the compact for the extrusion. The extrusion of separating residues modified according to the invention can thus be implemented particularly economically and easily in terms of device technology, directly into high-quality profiles.

In a conceivable embodiment, the cover element can be essentially disk-shaped and can be inserted between the compression chamber and the die, preferably pivoted in or pushed in. By means of a disk-shaped cover element of this type, which is pivoted or pushed approximately laterally into the working space of the extrusion press between the compression chamber and the die during the compression of the pile to form the pore-free molding, the extrusion press need only be modified slightly. The cover element can be supported on the press die against the force exerted on the heap or the compact due to the pressure of the press die and therefore only has to be dimensioned such that the press pressures can be reliably introduced into the press die. According to the invention, the press ram has a shape in its end region on the press die side, by means of which a locally different pressure distribution in the pile can be set during compression. Such an uneven pressure distribution, which deviates from the otherwise usual plan configuration of the end face of the press ram, can be used to remove the fluid inclusions in the pile or the compact, in particular to drive the trapped air out of the pile or the compact. In the areas of the cross-section in which the pressure increases first due to the shape of the end face of the press ram in the heap or the compact, for example, the air is pressed away from this area, whereas in neighboring cross-sectional areas no or no so high Pressure is built up by the press ram. Therefore, the air can flow largely unhindered into these areas that are not yet so highly pressurized. If the end face of the press ram is designed in such a way that, for example, starting from the inside of the pile, such as in the area of the longitudinal axis of the compression chamber and thus the pile, higher pressures first arise in the pile and the pressure zone subsequently gradually increases radially outwards, so that A directed outflow and thus a directed expulsion of the air from the heap or the pellet is achieved, whereby the fluid medium such as the air can be removed almost without residue and thus a largely pore-free pellet is produced, which after extrusion then also largely pore-free profile cross sections manufactures.

To this end, in a particularly advantageous embodiment, the end region of the press die on the side of the press die can be bulged in the region of its axis of symmetry in the direction of the press die, preferably at least in sections being conical or spherical or the like. The first contact point or the first contact area of the press ram with the heap or the compact then lies in the area of the axis of symmetry of the press ram and, in the case of an approximately conical configuration of the end face of the press ram, this zone of high pressure expands radially outward in the course of the compression process until the entire cross-section of the pile or pellet is evenly subjected to the high pressure.

In another embodiment, however, it is also conceivable that the design of the end surface creates a non-symmetrical or non-uniform pressure zone, for example by designing the end region of the press ram on the die side in such a way that higher pressures first in a partial region of the cross-section of the compression chamber and thus the pile arise in the pile, after which this area of higher pressures while setting an expulsion direction for those remaining in the pile fluid inclusions successively progressively recorded the entire cross section of the compact. For example, the first contact between the press ram and the heap or compact could take place on one side at one edge of the press ram and could successively propagate across the entire cross section of the press ram to the other edge of the cross-sectional area of the press ram. This would be achievable, for example, by designing the end face obliquely over the entire cross section of the press die and would lead to a one-sided expulsion direction for the fluid medium. It goes without saying that many other end face designs of the press ram are conceivable.

In a further embodiment, it is also conceivable that not only the press ram, but also the substantially disk-shaped cover element on its end face facing the press ram has such a shape that in a partial area of the cross section of the compression chamber, preferably in the area of its axis of symmetry, and thus the Haufwerk first higher pressures arise in the heap. For example, the cover element could in the case of a symmetrically conical press ram have an inverted conical configuration of its end face facing the press ram, which in turn influences the pressure conditions in the heap or compact and the expulsion of the fluid medium, such as the air, can be further improved. Similar to the options described above for the design of the end face of the press die, corresponding variations can also be made in the design of the end face of the cover element, which should be matched to the respective design of the end face of the press die.

Furthermore, it is advantageous if a heating device is provided, by means of which the pre-compacted aggregate can be heated and preferably isostatically pressed to the compact under the action of the press ram. The compaction of the pile towards the pore-free compact can be significantly improved if this compacting takes place under the action of thermal energy, which on the one hand improves the deformability of the separating residues and on the other hand simplifies welding processes of the separating residues forming the pile. Metallurgical and chemical-physical processes within the aggregate or compact will also run faster and more easily, such as flow processes of the fluid medium. In addition, conventional extrusion is carried out at elevated temperatures anyway, so that the preheating when pressing the pile or pellet facilitates the subsequent extrusion. If the compact is placed under maximum pressure after the compacting of the pile, holding the compact in this state of high pressure at the required pressing temperature for a predefinable period improves structuring processes of the matrix of the compact, such as flow processes of the fluid medium or welding processes. In this way, holding the compact in this state of high pressure at the required pressing temperature before the actual extrusion, as is similar to hot isotatic pressing, can significantly improve the quality of the matrix of the compact and thus of the subsequent extrusion profile. Holding the pellet in this state for a few seconds can be sufficient.

It is furthermore advantageous if openings or channels or the like are arranged in the region of the compression chamber in the direction of flow of the directionally expelled fluid inclusions in the heap and / or the compact, through which the expelled fluid inclusions can emerge from the compression chamber. This ensures that the expelled fluids, in particular the expelled air, can actually be completely expelled from the compact and also do not form cavities within the compression chamber on the compact, in which the air then collects and in the subsequent extrusion process again in the cross section of the Profiles can be pressed into it. It is sufficient e.g. to guarantee such an outflow of air through the inevitable annular gaps between the press ram and the recipient. In a further embodiment, however, it is also conceivable that a pressure that is lower than the ambient pressure can be set in the region of the compression chamber, by means of which fluid inclusions in the pile and / or the compact can be removed during the pressing process. Such a vacuum additionally facilitates the outflow of the fluid expelled from the pile or the compact.

The simplest design to implement is the cover element according to the invention when the shearing device of the extrusion press, which is often present on conventional extrusion presses, for separating off press residues Has cover element and / or is designed as a cover element and this cover element is movable into the area between the compression chamber and the die. For example, the knife-like shearing device of the extrusion press, which is inserted between the compression chamber and the die, can be used in a slightly modified design and can also be used as a cover element for the compression of the pile or the compact. In this case, such a cover element can be arranged to be movable mechanically, electrically, pneumatically or hydraulically between the compression chamber and the die.

The invention further relates to a process for the production of pore-free profiles from separation residues by means of extrusion presses, a pile consisting of manufacturing processes separating separation residues or the like, such as chips or residual materials, being filled in an extrusion press into a compression chamber from a press ram, a press die and a recipient. The heap of manufacturing processes separating residual residues is increasingly compressed into a compact in the compression chamber between the press die and a cover element sealing the compression chamber on the press die side while being heated, and the compact is then held under constant hydrostatic pressure over a predeterminable period of time, as a result of which the pile and / remaining fluid inclusions are directed and largely completely expelled, and immediately afterwards the cover element is removed and the compact is pressed through the pressing die into an extruded profile. Due to the increasing and spatially directed compression of the pile or compact, a reliable expulsion of fluid inclusions in the pile or compact is guaranteed, so that a largely pore-free compact is formed even after the compression described in this way, which then immediately follows and in the same extrusion press and can be extruded into high-quality profiles in a single workflow. Keeping the compact, which is loaded at the highest pressure, below a corresponding compression temperature facilitates the shaping and flow processes within the compact and leads to a substantial improvement in the homogeneity of the material of the compact, in particular to a high pore freedom. This means that even non-porous and thus error-free, highly resilient profiles can be produced directly from the appropriate separating residues, without having to melt the separating residues as is common today. The process according to the invention is thus particularly economical and profiles can be produced directly from separating residues, the properties of which are in no way inferior to those of profiles produced from freshly shaped compacts. According to the invention, the fluid inclusions remaining in the pile are directed through the shaping of the pressing die and / or cover element, preferably radially outward, expelled from the pile and / or the compact and removed from the compression chamber. The pore remains in the compact and thus the fluid extracts causing the extruded profile, such as air inclusions, is largely prevented as described above, and a particularly homogeneous matrix of the compact to be extruded results in spite of the very heterogeneous starting material separating residue or chip accumulation.

It is advantageous if the pile consisting of manufacturing processes separating residues or the like, such as chips or residual materials, is fed in precompacted form with a limited degree of compression to the compression chamber of the extrusion press. For example, Part of the compression of the material of the pile takes place in appropriate compacting devices, such as known briquetting presses or the like, and thus materials which can be introduced directly and comfortably into the extrusion press without thermal influence are produced. In the extrusion press operated according to the invention, the pressing of the precompacted pile to the pore-free compact is then carried out under thermal influence before the actual extrusion.

A further simplification and improvement can be achieved in that the compact is compacted with the addition of heat when compressing and expelling the fluid inclusions, preferably similar to hot isostatic pressing over a holding period with constant temperature control, preferably at the temperature required for the extrusion. In this holding period, similar to hot isostatic pressing, flow processes such as the emerging fluid or structuring processes within the compact can take place run completely and undisturbed by changing pressure conditions, whereby the quality of the compact and thus also the quality of the extruded profiles from the compact is significantly improved.

The invention further relates to a method for the production of property-graded profiles from separating residues by means of extrusion molding according to claim 10, wherein a pile consisting of manufacturing processes separating separating residues or the like, such as chips or residual materials, is filled in an extrusion press into a compression chamber from a press ram, a press die and a recipient becomes. Such a method is further developed according to the invention in that the pile is formed from an arrangement of individual layers of manufacturing processes or the like which separate successive layers in the later flow direction in the press die, such as chips or residual materials, the separating residues forming the pile of each layer or the like. Have material properties within each layer which differ from the material properties of the separating residues or the like forming the pile of adjacent layers, and the pile of layers thus layered is processed with the method according to claim 8. The layering of individual layers of separating residues or the like of different material properties according to the invention makes it possible, during the later extrusion of the individual layers, to produce areas within the produced profiles which follow one another in the pressing direction and likewise have correspondingly different material properties. The advantageous properties of different materials with different material properties can be combined in a profile by pressing these layers one after the other and thus also arranging them one after the other in the generated profile. With these innovative processes, both the mechanical properties and the properties such as corrosion resistance, Thermal conductivity, magnetic properties, etc. can be set without restriction. The nature and distribution of these areas within the profile produced makes it possible to adapt the extruded profiles to a wide variety of technical requirements, by not only the mechanical properties but also other properties such as corrosion resistance, thermal expansion, conductivity, weldability or the magnetic properties etc. can be changed over the length of the profile. The profiles extruded with this process are characterized by a better metallurgical connection compared to conventional composite material production. The transitions between the zones are longer and precisely definable. It is also conceivable that a linear change in properties can be guaranteed by continuously increasing additions of other separating residues. The separation residues can be made, for example, of aluminum, magnesium, copper, titanium or their alloys. The use of profiles produced in this way is particularly advantageous, for example for crash boxes in vehicle construction, which should have areas of different deformation resistances in the longitudinal direction of the crash load one behind the other and can be produced particularly simply and inexpensively using the method according to the invention.

In a first embodiment it is e.g. conceivable that the separation residues forming the pile of each layer have essentially homogeneous material properties. Then, in the later extruded profile, the following areas with homogeneous material properties are formed one after the other in the extrusion direction, the longitudinal extent of which can be adjusted by the respective layer thickness of the associated pile.

In another embodiment, however, it is also conceivable that the separating residues forming the pile of each layer have, preferably continuously changing, material properties that change along the later pressing direction. This can be achieved, for example, by the fact that, during the production of the layers, the separating residues forming the pile or the like always have a slightly different composition in the direction of the later pressing direction, for example by repeatedly changing the mixing ratio of the separating residues made of different materials . This makes it possible to produce a smooth transition between the material properties of the profiles extruded from the pile thus formed. It is also conceivable to layer individual thin layers of separation residues, each with a homogeneous composition and mixture of different materials to achieve an incremental change in the material properties of the profile produced from it. With regard to the later use of the property-graded profiles produced according to the invention from such heaps, it is conceivable to put together the layers of the heaps from different materials, which differ in terms of mechanical and / or electrical and / or thermal properties and / or other properties which influence the technical use differentiate from each other. Here, all the technically usable properties of the later profiles come into question, such as corrosion resistance, thermal expansion, conductivity, weldability or the magnetic properties etc. over the length of the profile, which can be influenced by the appropriate composition and layering of the layers of the pile.

It is conceivable, for example, that the stratification is formed from individual layers of different alloys of the same basic material. For example, a profile consist entirely of an aluminum material in which various alloys with differing mechanical strength were processed by the layering according to the invention.

However, it is also conceivable that the layering is formed from individual, homogeneous layers of different materials. For example, in sections of a profile produced in this way, which are particularly subject to corrosion, particularly corrosion-resistant materials are processed, whereas in other areas of the profile other materials of completely different properties can be used.

It is also conceivable not only to form layers which are homogeneous in themselves, but to form the layering from individual layers of different materials, each layer changing, preferably continuously changing, along the later pressing direction. Has material properties. This can be achieved particularly simply if two different materials are mixed with one another in a layer and the composition of the mixture used in each case changes continuously, for example, within the layer.

Of particular importance for the mixture of different materials within the layers, it is that the layers of the manufacturing processes or the like separating the residues that form the heap, such as chips or residual materials, have essentially the same particle sizes in each layer, since only then can the individual separation residues be inadvertently separated and can thus reliably prevent unwanted material properties of the layer.

The stratification of the individual layers from piles can be produced particularly easily and economically if the stratification is produced beforehand as a layered arrangement outside the pressing device. In this way, with appropriate devices and mixing devices e.g. The layers of the pile are formed one after the other in a shape corresponding to the dimensions of the later press dies. It is particularly conceivable that the stratification of the individual layers of piles is introduced into the press die as a pre-compacted layered blank by pre-pressing the pre-layered pile externally as described and thus hooking the separating residues together and thereby mechanically stabilizing them.

The disclosure also describes a pile for the production of property-graded profiles from separating residues by means of extrusion presses, in which the pile forms an arrangement of individual production processes or the like, which separate successive layers in the later flow direction in the press die, such as chips or residual materials, the the heap of separating residues or the like within each layer have material properties which differ from the material properties of the separating residues forming the heap of adjacent layers or the like.

The drawing shows a particularly preferred embodiment of the device according to the invention and of the method according to the invention.

Figur 1 -

eine erste Ausgestaltung der erfindungsgemäßen Vorrichtung an einer Strangpresse vor Beginn des Verdichtungsvorgangs eines Haufwerks bzw. Presslings,

Figur 2 -

die Ausgestaltung der erfindungsgemäßen Vorrichtung gemäß Figur 1 während des Verdichtungsvorgangs eines Haufwerks bzw. Presslings,

Figur 3 -

die Ausgestaltung der erfindungsgemäßen Vorrichtung gemäß Figur 1 beim Strangpresse des aus dem Pressling herzustellenden Strangpressprofils,

Figur 4a-4d -

schematische Darstellung des erfindungsgemäßen Verfahrens an einer Strangpresse mit dem Verdichten bis zum Strangpressen des aus dem Pressling herzustellenden Strangpressprofils,

Figur 5a-5d -

schematische Darstellung der Isobaren der Verteilung des verbliebenen Fluids zwischen Presstempel und Abdeckelement in dem Haufwerk bzw. dem Pressling während des zunehmenden Verdichtens des Haufwerks bis zum Pressling mit einem konifizierten Pressstempel,

Figur 6 -

grundsätzlicher Ablauf des Verdichtungs- und Strangpressvorgangs gemäß der vorliegenden Erfindung in Form eines Diagramms mit Auftragung von Dichte des Materials des Haufwerks bzw. des Presslings, Kraft des Pressstempels und Weg des Pressstempels über der Zeit,

Figur 7 -

eine andere Ausgestaltung der erfindungsgemäßen Vorrichtung mit einer konifizierten Ausgestaltung von Stirnfläche des Pressstempels und des Abdeckelementes,

Figur 8 -

ein erstes Beispiel einer Schichtung von Haufwerken zur eigenschaftsgradierten Herstellung von Profilen mit einer Schichtung unterschiedlicher Aluminiumwerkstoffe mit in einer Richtung zunehmender Festigkeit,

Figur 9 -

ein anderes Beispiel einer Schichtung von Haufwerken zur eigenschaftsgradierten Herstellung von Profilen mit einer Schichtung unterschiedlicher Aluminiumwerkstoffe mit einem Bereich guter Umformbarkeit, einem Bereich hoher Korrosionsbeständigkeit und einem Bereich hoher Festigkeit,

Figur 10 -

ein weiteres Beispiel einer Schichtung von Haufwerken zur eigenschaftsgradierten Herstellung von Profilen mit einer Schichtung unterschiedlicher Aluminiumwerkstoffe mit einem Bereich hoher Wärmeleitfähigkeit, einem Bereich hoher Festigkeit und einem Bereich mit ferromagnetischen Eigenschaften,

Figur 11 -

ein weiteres Beispiel einer Schichtung von Haufwerken zur eigenschaftsgradierten Herstellung von Profilen mit einer Schichtung unterschiedlicher Werkstoffe mit in einer Richtung zunehmender Festigkeit,

Figur 12 -

typischer Aufbau und Verformungsverhalten einer erfindungsgemäß hergestellten Crashbox aus Bereichen unterschiedlicher Festigkeitseigenschaften in einem eigenschaftsgradierten Profil in Form eines Stadienplans.

Show it:

Figure 1 -

a first embodiment of the device according to the invention on an extrusion press before the start of the compression process of a pile or compact,

Figure 2 -

the design of the device according to the invention Figure 1 during the compacting process of a pile or compact,

Figure 3 -

the design of the device according to the invention Figure 1 in the extrusion of the extruded profile to be produced from the compact,

Figure 4a-4d -

schematic representation of the method according to the invention on an extrusion press with compression up to extrusion of the extrusion profile to be produced from the compact,

Figure 5a-5d -

schematic representation of the isobars of the distribution of the remaining fluid between the press ram and cover element in the heap or the compact during the increasing compression of the heap to the compact with a butted press ram,

Figure 6 -

basic sequence of the compression and extrusion process according to the present invention in the form of a diagram with the plotting of the density of the material of the heap or the compact, the force of the stamp and the path of the stamp over time,

Figure 7 -

another embodiment of the device according to the invention with a butted configuration of the end face of the press ram and the cover element,

Figure 8 -

a first example of a layering of piles for the property-graded production of profiles with a layering of different aluminum materials with increasing strength in one direction,

Figure 9 -

another example of a layering of piles for the property-graded production of profiles with a layering of different aluminum materials with an area of good formability, an area of high corrosion resistance and an area of high strength,

Figure 10 -

another example of a layering of piles for the property-graded production of profiles with a layering of different aluminum materials with an area of high thermal conductivity, an area of high strength and an area with ferromagnetic properties,

Figure 11 -

another example of a layering of piles for the property-graded production of profiles with a layering of different materials with increasing strength in one direction,

Figure 12 -

typical structure and deformation behavior of a crash box manufactured according to the invention from areas of different strength properties in a property-graded profile in the form of a stage plan.

In the Figure 1 an embodiment of the device according to the invention is shown in a schematic representation, in which an extrusion press 1 which is known per se and is therefore only described in more detail here is used, as is important for the special features of the device and the method carried out with the device. Such extrusion presses 1 are commercially available and are therefore known to the person skilled in the art in their basic structure.

Such a commercially available extrusion press 1 has a press ram 5 which is linearly adjustable in the pressing direction 4 or a press ram with a separate press disk 5, which presses a normally block-like compact 2 in the direction of the press die 6. The compact 2 is usually brought to a pressing temperature before the extrusion process and outside of the extrusion press 1 or also by means of heating devices (not shown) in the extrusion press 1 itself brought, which is dependent on the material of the compact 2 to be processed and by which the extrusion of the compact 2 is simplified. A die opening 8 is provided in the press die 6, through which the material of the compact 2 that deforms under the pressure of the press die 5 can exit and thereby assumes the cross-sectional shape of the opening 8 of the press die 6. In the case of the present invention, however, a homogeneous compact 2, for example formed by casting or the like manufacturing process, is not used, but a heap 2 of waste-separating manufacturing processes is used, such as, for example, swarf-cutting manufacturing processes or also press remnants forming manufacturing processes or mixtures of such Separation residues. Such separating residues have geometrically varying shapes and dimensions and, in the form used here, form a more or less loose heap 2, into which a relatively large amount of air and also cooling lubricant residues or similar liquid residues can be enclosed. It is also conceivable and possibly even preferred that such a pile 2 is precompressed to a certain extent in a separate device and pressed in dimensions that enable easy filling of the compression space 11 of the extruder 1 with the pile 2. For this purpose, however, only a part of the volume of the heap 2 is compressed, so that a relatively high proportion of the volume of the heap 2 will continue to be filled with air. To reduce the proportion of cooling lubricant residues, it is also conceivable to chemically clean and dry the heap 2 of manufacturing processes that separate waste, for example.

If this relatively little compacted heap 2 were to be pressed directly through the die opening 8 of the press die 6, as was stated in the prior art, many air inclusions and imperfections would form in the profile 7 thus produced, which would affect the quality of the profile 7 reduce significantly and only make this suitable for inferior applications.

It is therefore carried out in a manner according to the invention before the actual extrusion process of the later profile 7, a compression process of the heap 2, through which the air and any fluid residues in the heap 2 from this largely are removed and a pore-free compact 2 is thereby formed, which can then also be extruded into a pore-free profile 7.

For this purpose, before the actual extrusion process and before filling the compression chamber 11 with the pile 2 (see Figure 1 ) a preferably disc-shaped cover element 3 is arranged in front of the opening 8 of the pressing die 6 in such a way that the opening 8 and, better still, the entire cross section of the compression space 11 in front of the pressing die 6 is filled by the covering element 3. Thus, despite the pressure of the press ram 5 which is subsequently exerted on the heap 2, no material of the heap 2 can escape through the opening 8 and a closed space is formed for the compression of the heap 2.

In the simplest case, the cover element 3 can be introduced by hand through a corresponding lateral opening, not shown here, in the region of the compression space 11, which is closed again after the cover element 3 has been introduced. In the case of automatic operation of the extrusion press 1, a corresponding movement device (not shown further here) could also be provided for the cover element 3, by means of which the cover element 3 can be inserted or pivoted in laterally. It is also conceivable to modify the shearing device for press residues provided on some extrusion presses 1, which also enters laterally between the die 6 and the compression chamber 11 and removes the remaining press residues by shearing, in such a way that this shearing device has a corresponding covering element 3 or its function, and the above described cover function of the die 6 takes over.

If the cover element 3 has been arranged between the compression space 11 and the pile 2 in the manner described, the pile 2 can be compressed in the manner described above under the increasing pressure of the press ram 5. Here, the volume of the pile 2 is increasingly reduced ( Figure 2 ), the air enclosed in the heap 2 and any further fluid residues such as cooling lubricant or the like being gradually displaced from the heap 2 and can flow out, for example via channels not shown, to the outside of the compression chamber 11, as described below. As a result, the steadily increasing compression of the aggregate 2 gradually forms a homogeneous one structure of the aggregate 2 until the largely pore-free compact 2 forms under the highest predetermined pressure, which then, after removal of the cover element 3 ( Figure 3 ) emerge in a manner known per se through the opening 8 of the press die 6 and can form the profile 7. This profile 7 is then also largely pore-free and, despite the very inhomogeneous and fluid inclusions of the raw material 2, almost corresponds to the qualities that can be achieved when using homogeneous, for example, cast starting materials.

Before the actual extrusion of the compact 2, to improve the quality of the compact 2 further, a type of hot-isoic pressing process can be interposed, during which the compacted compact 2 under constant pressure and at a constant temperature for some time, e.g. is held for a few seconds. During this hot isoatic holding time, residual flow processes of the emerging fluid or also restructuring processes can take place within the matrix of the compact 2 that is being formed, which further increase the degree of pore freedom and thus the quality of the compact 2.

In the Figures 4a to 4d is the basic process of this compression and extrusion process, which in the Figures 1 to 3 was shown within the extrusion press 1, again in a cutaway view. The borders of the compression chamber 11 and the components of the extrusion press 1 have been omitted here.

In the Figure 4a the initial state of the stamp 5, uncompacted or precompacted heap 2, cover element 3 and press die 6 can be seen (corresponding to the state in Figure 1 ). Figure 4b shows the state after the completion of compaction, in which the heap 2 has been maximally compacted and occupies its smallest volume. In Figure 4c the process of hot isostatic pressing can be seen, in which the compacted compact 2 is kept under the pressure reached and the predeterminable temperature for the course of the remaining restructuring processes. In Figure 4d the actual extrusion process is finally shown, in which the cover element 3 between the compact 2 and the die 6 is removed was and the compact 2 is pressed to the profile 7 through the opening 8 of the die 6.

In the Figure 6 the basic sequence of the compression and extrusion process according to the present invention is shown in the form of a diagram. Here, the changing density of the pile 2, the course of the punch force of the press die 5 and the course of the press die 5 are plotted against the time t. The time period a corresponds to the time of increasing compression of the pile 2, the time period b the time of pressing the compact 2 similar to the hot isostatic pressing and the time period c the time of the full compression of the compact 2 in the case of a pressing similar to the hot isostatic pressing before the actual extrusion of profile 7, which in the Figure 6 is not shown further. As can be seen, the density of the pile 2 initially rises sharply, consolidates during the transition from time period a to time period b and reaches the highest value immediately before the end of time period b and thus before extrusion. The punch force of the press punch 5 increases only slightly, since only the remaining cavities within the heap 2 are pressed together, for which only lower forces are required. Then the punch force rises sharply, is kept relatively constant during the period b to form metallurgical connections in the heap 2 under high pressure and high temperature and drops sharply due to the relief of the press ram 5 for the removal of the cover element 3 before the start of the extrusion process. The stamp path only increases linearly and remains constant during time period b. In time period c, the press ram 5 is then moved back a little in order to be able to remove the cover element 3. Therefore, the stamp force also drops.

Of particular importance in the method according to the invention is the formation of the end face of the press ram 5 and / or the end face of the cover element 3, which faces the pile 2 to be compressed. In order to enable the fluid components to be displaced in a directed manner out of the pile 2 and thus to enable the material of the pile 2 to be compressed and pressed in a pore-free manner, the displacement must be such that the fluid components are completely displaced out of the compact 2. For this purpose, the Heap 2, starting from a starting area within the cross-section of the heap 2, first compressed in the middle and successively pressurized gradually towards the edge area, so that the fluid components are gradually displaced out of further areas of the cross-section of the heap 2 become. Metaphorically speaking, starting from the starting area, successively and continuously, the pressure is increased in areas adjacent to the starting area or the respective area of higher pressure, and thus a flow direction for the fluids in the direction of the edge areas of the cross section of the compression space 11 is specified. This prevents fluid quantities that have been pushed out of the start area, for example, from accumulating in other cross-sectional areas of the heap 2, but from being able to flow away from there due to the pressure conditions. Due to the temporally staggered pressure profile within the cross section of the heap 2 due to the pressure on the heap 2 between the press ram 5 and the cover element 3, a pressure drop and a flow direction following this pressure drop for the displaced fluid are produced.

This targeted displacement can naturally be designed in different ways. A gradual displacement of the fluid starting from the middle region of the pile 2 towards the edges is preferred. Such displacement can be achieved, for example, by a fundamentally conical shape of the end face of the press ram 5 on the heap side, as shown in FIGS Figures 5a to 5d is shown schematically. Here, a conical shape 9 is formed, symmetrical to the central axis of the typically round press ram 5, which can have a flat central region 10. If the plunger 5 is now moved in the pressing direction 4 relative to the cover element 3, zones of different residual fractions of the fluid form in the matrix of the compacting material of the heap 2 under the conically flat end face of the plunger 5. These different proportions are in the Figure 5 indicated by isobaric lines of zones of the same percentage purity of the material of the heap 2 (95% means that 5% residual fluid in the amount of the material of the heap 2 remained in this area). How to use increasing compression (starting from Fig. 5a to the highest pressure in Figure 5d ) can escape in the illustrated conical design of the end face of the press ram 5, the fluid portions from the area of the central axis of the ram 5 first outwards and downwards, then further outwards until the compressed compact 2 is almost completely free of fluid residues Figure 5d .

It is of course conceivable to provide a conical design of the end face of the stamp 5, e.g. a convex shape or also a shape tapered on one side over the entire end face, in which the compression begins in one edge area and runs continuously towards the opposite edge area.

It is also conceivable, as in Figure 7 schematically indicated not only to design the end face of the press plunger 5 in such a pre-curved manner, but also to profile the end face of the cover element 3 facing the compact 2. In the Figure 7 is only given as an example that the end face of the cover element 3 is conically profiled opposite to the end face of the pressing die 5 and has a conical area 9 'with a flat central area 10'. As a result, the pressure conditions in the compacting heap 2 are further positively influenced and the fluid can be displaced to the outside of the compact 2 faster and more reliably. For this purpose, the end face of the press die 6 can be adapted according to the shape of the cover element 3, so that no air is trapped between the compact 2 and the press die 6.

In the Figure 8 the structure of a profile produced according to the invention is schematically indicated, in which a stratification of heaps 2 for the property-graded production of profiles with a stratification of different aluminum materials is realized with strength increasing in one direction. Here, the pellet 2 is produced from a mixture of two aluminum alloys in five compaction stages. The first stage consists of pure EN AW-6060 aluminum chips, for which a third EN AW-7175 aluminum chips were mixed in for the second stage. For the third and fourth stages, increasing proportions of EN AW-7175 chips (one half and two thirds, respectively) were mixed in. In the fifth stage, pure EN AW-7175 chips are used. This affects the mechanical properties of the individual zones as follows. The development of strength properties Depending on the mixing ratio of the alloys EN AW-6060 and EN AW-7175, the side of the individual compositions of the stages is specified and numerically defined. You can clearly see the increase in tensile strength with increasing AW-7175 content. The tensile strength values are given as a function of the mixing ratio of the alloys. The extrusion according to the invention of a property-graded pile 2 leads to an aluminum profile with five zones as well. The tensile strength in zone 1 can thus be increased from 145 MPa high to 395 MPa in zone 5, ie an increase in tensile strength of approximately 270%.

In the Figure 9 another example of a layering of piles 2 for the property-graded production of profiles with a layering of different aluminum materials with a range of good formability, a range of high corrosion resistance and a range of high strength is shown. This variant is a composite profile production from several different composite materials. For example, the addition of copper shavings has shown that a higher thermal conductivity can be achieved. It was also possible to achieve higher strength by adding aluminum oxide particles and to add ferromagnetism by adding iron particles.

Figure 10 shows another example of a layering of piles for the property-graded production of profiles with a layering of different aluminum materials with an area of high thermal conductivity, an area of high strength and an area with ferromagnetic properties. With this variant, aluminum alloys with special properties can be brought together in one profile. For example, an aluminum alloy of the 6000 series can be used for a profile that has to be additionally bent and welded due to its good formability or, where the profile meets a special corrosive environment, an aluminum alloy of the 3000 series can be used due to its high corrosion resistance . An aluminum alloy of the 7000 series can also be considered for higher strength due to its high strength. It is also conceivable to introduce transition zones between these zones so that the properties change smoothly or continuously and thus a better metallurgical connection between zones is also conceivable.

In the Figure 11 is a further example of a layering of piles for the property-graded production of profiles with a layering of different alloys of the same base material with strength course produced in one direction increasing strength generally shown. Due to the different proportions of the alloys 1 and 2 used, zones of different composite materials can be created, starting from the first stage of a pure alloy material 1, which have increasing strength values towards the stage of the other alloy 2 arranged at the other end of the profile.

The Figure 12 shows a typical structure and the resulting deformation behavior of a crash box made according to the invention from areas of different strength properties in a property-graded profile in the form of a stage plan. Such crash boxes are used for targeted energy dissipation within the body of a vehicle in the event of a crash, the crash box being intended to have different strength values along its longitudinal extent in the direction of the crash load. The energy absorption capacity in the least deformed area III after the crash should be greater than in the central area II and this in turn should be greater than in the first deformed area I. If force F1 is exerted on the crash box in the event of an accident, area I will first fold together and a large force will be released. The areas II and III remain undeformed because of their higher strength properties. If the deformability of the area I is exhausted, the area II is again pushed together in a fold-like manner under the action of the force F2 until the maximum deformability has also been exhausted here. Subsequently, the area III is deformed in an analogous manner, the deformation of the area III not being fully utilized at a specified maximum load. In this case, the entire force introduced by the crash has been reduced in the crash box.

Such a crash box with the behavior described can be produced in a particularly advantageous manner with the method according to the invention for layering piles of different material properties and subsequent extrusion of this pile, since this is exactly what the crash box of Figure 12 described Material behavior of the crash box can be produced in one extrusion process.

Part number list

1 -

Extrusion press

2 -

Pile or compact

3 -

Cover element

4 -

Pressing direction

5 -

Press stamp or press disk

6 -

Press die

7 -

profile

8th -

Die opening

9, 9 '-

conical section of press stamp or cover element

10, 10 '-

flat center area press stamp or cover element

11 -

Compression space

Claims (14)

1. Device for producing of non-porous profiles from separation residues by means of extrusion, comprising an extrusion press (1) with a compression chamber (11) consisting of a press punch (5), a press die (6) and a reciprocating member, into which a pile (2) consisting of separation residues of separating production processes or the like is placed such as chips or residual materials, wherein a cover element (3) can be arranged between the press die (6) and the compression chamber (11), sealing it on the press die side, against which the press punch (5) compresses the pile (2) of separation residues to form a pressed pellet (2) and thereby removes fluid inclusions remaining in the compression chamber (11) and in the pile (2) in a directed manner, after which the covering element (3) can be removed again and the compressed pressed pellet (2) can be pressed through the press die (6) as a profile cross-section, characterised in that
   the press punch (5) in its end region on the press die side has a shaping by means of which a locally different pressure distribution in the pile (2) can be set during compaction.
2. Device according to claim 1, characterised in that the end region of the press punch (5) on the press die side is designed in such a way that in the region of the longitudinal axis of the compression chamber (11) and thus of the pile (2), higher pressures first arise in the pile (2).
3. Device according to claim 2, characterised in that the end region of the press punch (5) on the press die side is arched in the region of its symmetry axis in the direction of the press die (6), preferably conical or crowned or the like at least in sections.
4. Device according to claim 1, characterised in that the end region of the press punch (5) on the press die side is designed in such a way that in a partial region of the cross-section of the compression chamber (11) and thus of the pile (2), first higher pressures are generated in the pile (2), after which this region of higher pressures successively and progressively covers the entire cross-section of the pressed pellet (2) while setting a discharge direction for the fluid inclusions remaining in the pile (2).
5. Device according to one of the above claims, characterised in that the substantially disc-shaped cover element (3) has such a shaping on its end face facing the press punch (5) that in a partial region of the cross-section of the compression chamber (11), preferably in the region of its axis of symmetry, and thus of the pile (2), higher pressures first arise in the pile (2).
6. Device according to one of the above claims, characterised in that the frontal shaping of the cover element (3) and/or press punch (5) is designed in such a way that fluid inclusions in the pile (2) are expelled from the pile (2) in a direction, preferably radially outwards, as compression increases.
7. Device according to one of the above claims, characterised in that a heating device is provided with which the pre-compressed pile (2) can be heated and pressed, preferably isostatically, into the pressed pellet (2) under the action of the press punch (5).
8. Method for the production of non-porous profiles from separation residues by means of extrusion, wherein a pile (2) consisting of separation residues of seperating production processes or the like, such as chips or residual materials, is filled in an extrusion press (1) into a compression chamber (11) consisting of a press punch (5), a press die (6) and a recipient,
   the pile (2) of separation residues coming from a separating manufacturing process in the compression chamber (11) is increasingly compressed between the press die (6) and a covering element (3) sealing the compression chamber (11) on the press die side by the press punch (5) under heating to form a pile (2) and the pile (2) is then kept under constant hydrostatic pressure for a predeterminable period of time, whereby fluid inclusions remaining in the pile (2) and/or pellet (2) are directed and largely completely expelled, and immediately afterwards the covering element (3) is removed and the pellet (2) is pressed through the press die (6) to form an extruded profile (7),
   characterised in that
   the fluid inclusions remaining in the pile (2) are driven out of the pile (2) and/or the pressed pellet (2) and removed from the compression chamber (11) by means of the shaping of the press die (5) and/or cover element (3), preferably radially outwards.
9. Method according to claim 9, characterized in that the pellet (2) is compacted during the compaction and expulsion of the fluid inclusions with the supply of heat, preferably similar to hot isostatic pressing, over a holding period at a constant temperature, preferably at the temperature required for extrusion.
10. Method of producing property-graded profiles from separation residues by means of extrusion, wherein in an extrusion press (1) a pile (2) consisting of separation residues of separating manufacturing processes or the like such as chips or residual materials is filled into a compression chamber (11) consisting of a press punch (5), a press die (6) and a recipient,
    characterised in that
    the pile (2) is formed from an arrangement of individual layers of separation residues of separating manufacturing processes or the like, such as chips or residual materials, which succeed one another in the later direction of flow in the press die (6), each layer of the separation residues or the like forming the pile (2) showing material properties, which differ from the material properties of adjacent layers being formed by the separation residues or the like forming the pile (2), and the pile (2) thus layered is processed using the method according to claim 8.
11. Method according to claim 10, characterized in that the separation residues forming the pile (2) of each layer essentially have inherently homogeneous material properties or have material properties which change, preferably continuously, along the later pressing direction.
12. Method according to one of claims 10 or 11, characterised in that the layers of the piles (2) of different materials differ from one another with respect to mechanical and/or electrical and/or thermal properties and/or other properties influencing the technical use.
13. Method according to one of claims 10 to 12, characterised in that the layering is formed from individual layers of different alloys of the same basic material or from individual, homogeneous layers of different materials or is formed from individual layers of different materials, each layer having material properties which change along the later pressing direction (4), preferably continuously changing.
14. Method according to one of claims 10 to 13, characterised in that the separation residues of separating manufacturing processes or the like, such as chips or residual materials, forming the layers of the pile (2) have substantially the same particle sizes in each layer.

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