Extrusion head for additive manufacturing

Abstract

The invention relates to an extrusion head (1) for the additive manufacturing of a product, preferably based on the fused filament fabrication method, comprising: at least one material feed unit (2) for feeding at least one extrusion material, preferably in filament form; a separating device having at least one blade element; at least one displacement unit (6) having at least two liquefier assemblies (7); wherein the at least one extrusion material can be introduced into a first liquefier assembly and, by means of the at least one displacement unit (6) travelling past the separating device virtually without a gap, the extrusion material can be brought to the at least one blade element and can be severed at a severing point, and the upper end of the extrusion material severed by the separating device can be introduced into a second liquefier assembly, wherein the at least one blade element can be fastened or is fastened to or in the at least one material feed unit (2) or is a component of the material feed unit (2).

Description

[0001] Extrusion head for additive manufacturing The present invention relates to an extrusion head according to the preamble of claim 1. Furthermore, the invention relates to a method and / or a use for producing a product by means of at least one such extrusion head. In the course of manufacturing products by additive manufacturing processes, for example fused filament fabrication (FFF), there are a multitude of different requirements. It is desirable that products with complex shapes be manufactured. Since in the field of additive manufacturing, the products to be manufactured are produced piece by piece, specifically layer by layer, it is often difficult to produce complex shapes with high processing speeds and high processing accuracy. If more than one processing material must or should be used for a product, many of the manufacturing devices used to manufacture these products encounter problems.process-related limitations. This can be the case, for example, when a product is to be manufactured from a first material A, wherein the product, due to its complex shape, has undercuts which, during a layered build-up, cannot be manufactured from a second material B without support structures. It can also be provided to construct a product from multiple materials or to offer the option of using a cleaning material. It is already known from the prior art, such as EP 3725 497 A1, that more than one material can be processed within a device for additive manufacturing. It is also known in the prior art that a cutting device can be provided in addition to an extrusion device. By means of such a cutting device, the material intended for additive manufacturing, which is often in the form of a filament, is cut off after extrusion.Many challenges for additive manufacturing processes arise from the fact that they now find versatile applications in the industrial sector. In contrast to the private sector, where small DIY devices are often used, the requirements in the industrial sector increase with the application in terms of efficiency, accuracy, process stability, temperature limits, spatial limitations, product sizes, and the like. To ensure that the economic viability of the complex manufacturing process does not suffer, or at least not excessively, from the increased performance and the more difficult mechanical and chemical stresses, it is essential that additive manufacturing systems are designed to be as process-reliable, cost-effective, easy to maintain, and low-maintenance as possible. A specific challenge for an additive manufacturing process in the industrial sector is to develop a highly efficient, very precise, and above all,To develop a process-reliable fused filament fabrication system that meets the high standards of the aerospace, railway, and automotive industries. For processing high-performance plastics such as polyetheretherketone (PEEK) in large quantities, high nozzle temperatures, well above the melting temperature of up to 440°C, are required. To ensure that the crystalline structure of the plastic is correctly formed so that the extrusion material has the highest possible strength, heated build chambers must be kept constant and homogeneous at temperatures of approximately 220°C to even 250°C. The current state of the art has various disadvantages. On the one hand, an extrusion material is often not cut cleanly or reliably, but is additionally deformed during the cutting process. This is particularly disadvantageous if a cut extrusion material, for example a filament, is bent and, after theCutting is to be reinserted into a guide for further processing. On the other hand, cobweb-like thread formation can occur during cutting, since the softened extrusion material is not cut cleanly or reliably. The object of the present invention is therefore to at least partially eliminate the disadvantages of the prior art and to provide an extrusion head that is improved compared to the prior art, which is characterized in particular by a cleaner cutting process of the extrusion material and / or greater process reliability. The object is further to provide a method and / or a use for producing a product with such an improved extrusion head. This object is achieved by the features of claims 1 and 15. This object is achieved by means of an extrusion head according to claim 1, namely by providing an extrusion head for additive manufacturing,preferably for the fused filament fabrication method, a product comprising at least one material feed unit for feeding at least one extrusion material, preferably in filament form, a separating device with at least one blade element, at least one offset unit with at least two liquefier units, wherein the at least one extrusion material can be introduced into a first liquefier unit and by an almost gap-free passage of the at least one offset unit past the at least one separating device, the extrusion material can be brought to the at least one blade element and severed at a severing point and the upper end of the extrusion material severed by the separating device can be introduced into a second liquefier unit, wherein the at least one blade element can be fastened or is fastened to or in the at least one material feed unit or as a component of the material feed unitis provided. The almost gap-free passage of the at least one offset unit past the at least one separating device is understood here to mean that at least at one point between the at least one offset unit and the at least one material feed unit and / or the at least one separating device and / or the at least one blade element, a cutting gap with a maximum distance of 50% of the nominal diameter of the extrusion material, preferably in filament form, preferably 25%, particularly preferably only 12% of the nominal diameter of the extrusion material in filament form is present. Due to the almost gap-free passage of the at least one offset unit past the at least one separating device and due to the blade element attached to or in the at least one material feed unit, the extrusion material can be cleanly cut through with the blade element without the extrusion material additionally deforming excessively.for example, bends. Thus, part of the extrusion material remains in the material feed unit and the other part of the extrusion material remains in a first condenser unit of the offset unit. Subsequently, the upper severed end of the extrusion material can be introduced into a second condenser unit either by appropriately guiding the at least one offset unit past the at least one material feed unit or by returning the offset unit past the at least one material feed unit into the first condenser unit. In any case, the extrusion material is essentially not deformed away from the severance point. The solution described above thus ensures process-safe cutting and / or a change of the condenser units and / or a change of the nozzles and / or a change of the extrusion materials. Contamination and / or damage by the otherwiseThe necessary retraction of the already softened or partially liquefied extrusion material can be avoided. After the cut, the extrusion material is fed into one of the liquefier units for further processing and is then fed to the nozzle. If there is already a leftover piece of extrusion material in the liquefier unit into which the cut-off extrusion material is fed, the leftover piece is also fed further by the newly introduced extrusion material. The Fused Filament Fabrication (FFF) method is an additive manufacturing process. The term Fused Deposition Modeling (FDM) method is synonymous with the FFF method. The FFF method is a 3D printing technique and is generally considered an additive manufacturing process. A product is built up layer by layer from a meltable extrusion material. The extrusion material can be a plastic, a fiber-reinforced plastic, aComposite plastic and / or a metal. Further advantageous embodiments of the extrusion head are defined in the dependent claims. According to a preferred embodiment of the extrusion head, it is provided that the at least one blade element is round and / or square. According to a preferred embodiment of the extrusion head, it is provided that the at least one blade element is designed as a flat plate or as a block or as a flat ring or as a sleeve. According to a preferred embodiment of the extrusion head, it is provided that the at least one blade element is connected to the at least one material feed unit by a blade connecting device, preferably wherein the blade connecting device is detachable without destruction. In a preferred embodiment, it can be provided that the cutting gap is opened by releasing the blade connecting device, subsequently by displacing the at least oneBlade element, preferably along a wedge, and then by securing the at least one blade element by means of the non-destructively releasable blade connection device, it is provided that the at least one blade element has at least one straight and / or curved cutting edge with a cutting surface underside and a cutting surface upper side, wherein in the state of the at least one blade element fastened to or in the material feed unit, the underside of the at least one blade element and the cutting surface underside face the offset unit and the upper side of the at least one blade element and the cutting surface upper side face away from the offset unit. In a preferred embodiment, it can be provided that a multi-edged blade element can be provided, in which in a firstinstalled state, at least one cutting edge can be in use and, due to a changed position in a further installed state, a further cutting edge can be in use. In a preferred embodiment, it can be provided that the at least one blade element can be exchangeable. According to a preferred embodiment of the extrusion head, it is provided that the cutting surface underside and the cutting surface upper side are arranged inclined to one another, preferably enclosing an angle of up to 55°, in particular a very acute angle of 20 to 30°. According to a preferred embodiment of the extrusion head, it is provided that the cutting surface underside and / or the cutting surface upper side have at least two cutting surface sections, wherein the first cutting surface section adjoins the cutting edge and the second cutting surface section does not adjoin the cutting edge. In a preferred embodiment,It can be provided that at least one of the cutting surfaces, i.e. the underside of the cutting surface and / or the upper side of the cutting surface, can have different surface sections with different cutting angles. In this way, the cutting surface profile can be additionally varied, wherein a cutting surface section that borders on a cutting edge can have a steeper or flatter angle in contrast to a cutting surface section behind it that does not border on the cutting edge. In another preferred embodiment, it can be provided that the blade element can have a curved or an approximately curved cutting surface profile due to several cutting surface sections. According to a preferred embodiment of the extrusion head, it is provided that the material feed unit has at least one introduction line for the at least one extrusion material, wherein in the state of the material feed unit on or in the material feed unitattached at least one blade element, the at least one introduction line extends within the material feed unit up to a region in front of, in particular up to, the at least one blade element. According to a preferred embodiment of the extrusion head, it is provided that, when the at least one blade element is attached to or in the material feed unit, the introduction line ends in a region between the blade element underside and the blade element top side. In an embodiment in which the introduction line extends up to the blade element and / or into a region between the blade element underside and the blade element top side, the distance in which the extrusion material is not guided, or at least not guided, from all sides of the circumference of the extrusion material is kept to a minimum. This also minimizes the risk of deformation of the extrusion material away from the actual cut. Especially in cases in whichthe extrusion material is in the form of a filament, deformation of the extrusion material, in particular bending, represents an increased risk with regard to the process reliability of cutting and further processing of the extrusion material. According to a preferred embodiment of the extrusion head, it is provided that the introduction line has at least one guide recess which reaches up to the separating device and through which the extrusion material is at least partially exposed. In a preferred embodiment variant, it can be provided that the introduction line has at least one guide recess which can run up to an area in front of the separating device and through which the extrusion material is at least partially exposed. According to a preferred embodiment of the extrusion head, it is provided that the introduction line has at least one projection, wherein in the state of the cutting device on or in theMaterial feed unit attached at least one blade element, the at least one projection protrudes into a region between the blade element underside and the blade element upper side, wherein preferably two projections are provided and, in the state of the at least one blade element attached to or in the material feed unit, the two projections form a guide recess, in particular a groove, preferably a transverse groove, in a region between the blade element underside and the blade element upper side. With the aid of one or more projections of the introduction line, the extrusion material can be guided at least from one or more sides into a region between the blade element underside and the blade element upper side. In a preferred embodiment, it can further be provided that the shape of the at least one projection and / or the shape of the at least one projection surface facing the extrusion materialGuiding the extrusion material runs almost to the cutting edge. According to a preferred embodiment of the extrusion head, it is provided that the inlet line is present as a separate component within the material feed unit or is a component of the material feed unit. In a preferred embodiment, it can be provided that the inlet line can be made of thermally treated metals, preferably tempered, hardened or nitrided steel, and / or partially of at least one sintered material, preferably tungsten carbide or ceramic, and / or can be coated, preferably with a tungsten sulfide coating. These materials represent wear-resistant materials and / or coatings, the use of which can be particularly advantageous for components subject to high stress, such as the inlet line. According to a preferred embodiment of the extrusion head, it is provided that at least one conveying devicethe material feed unit is provided for feeding the at least one extrusion material, wherein the at least one conveying device is designed to at least partially return the preferably severed at least one extrusion material within the material feed unit. By means of a conveying device that can move the extrusion material both forwards and backwards, in other words, can not only extrude the extrusion material but also return it again, it is possible to straighten the extrusion material by pulling it back into the introduction line. This is particularly useful if, despite everything, a slight deformation of the extrusion material should occur away from the cut. According to a preferred embodiment of the extrusion head, it is provided that the at least one offset unit has at least one receiving device, preferably at least two receiving devices, particularly preferably oneReceiving device for each condenser unit. In a preferred embodiment, it can be provided that the at least one receiving device of the at least one offset unit can be formed on the drive wheel of the at least one offset unit for displacing the offset unit relative to the material feed unit on the side facing the material feed unit, preferably by countersunk holes. In a preferred embodiment, it can be provided that the at least two receiving devices of the at least one offset unit can be formed on the at least two further feed lines, in particular heatbreak lines, on the side facing the material feed unit, preferably by countersunk holes. In a preferred embodiment, it can be provided that the at least one receiving device can be present as a separate component within the offset unit or can be a component of the offset unit.can. In a preferred embodiment, it can be provided that the at least one receiving device on the side facing the material feed unit, preferably on and / or within the drive wheel, can be designed as a flat plate, as a flat ring or as a sleeve, preferably with a countersunk bore. In a preferred embodiment, it can be provided that the at least one receiving device can consist of at least one thermally treated metal, preferably of tempered, hardened and / or nitrided steel, and / or partially of at least one sintered material, preferably tungsten carbide or ceramic, and / or can be coated, preferably with a tungsten sulfide coating. According to a preferred embodiment of the extrusion head, it is provided that at least one cooling device for cooling the at least one offset unit and / or the at least one extrusion material and / or the separating deviceand / or the at least one blade element and / or the at least one conveying device and / or the at least one extrusion actuator and / or the offset actuator and / or the at least one extrusion material, at least one bearing and / or at least one seal and / or at least one convection protection device is provided. An actuator is a component or a mechanism for converting energy, for example electrical energy or pressure energy, into movement, for example kinetic energy, and can be designed in particular as a motor, particularly preferably as an electric motor. In order to ensure that the extrusion material can always be cut reliably in the solid state, preferably at a temperature below the melting temperature, the softening temperature or the glass transition temperature, and introduced into one of the liquefier units at high die temperatures and processing temperatures, a cooling device can be provided. This can be particularlyThis may be useful when heat, for example generated by the heating blocks of the condenser units, migrates up to the severance point as a result of diffusion and / or conduction and / or convection, in particular along the extrusion material. The extrusion material is heated from the nozzles via the condenser units to the severance point and thus softened, which can result in a cobweb-like thread formation when cutting or severing the extrusion material. According to a preferred embodiment of the extrusion head, it is provided that the at least one cooling device is part of the material feed unit and / or the offset unit. According to a preferred embodiment of the extrusion head, it is provided that the at least one cooling device has one or more bores and / or grooves, in particular straight and / or curved grooves, and / or channels, in particular straight and / or curved channels, within thematerial feed unit and / or the offset unit. According to a preferred embodiment of the extrusion head, it is provided that the at least one cooling device has one or more coolant interfaces and / or cooling rotary feedthroughs. Usually, two coolant interfaces are provided for the supply of coolant, one for the supply and one for the removal of the coolant. Any number of coolant interfaces is possible, which can form either one cooling circuit or several cooling circuits. In a preferred embodiment, it can be provided that the at least one offset unit can be designed as cooling rotary feedthroughs. In a preferred embodiment, it can be provided that at least one of the existing coolant interfaces can be arranged within the offset unit. In a preferred embodiment, it can be provided that one or moreSupply lines of the at least one coolant interface, which is arranged within the offset unit, can run at least partially within the offset unit substantially parallel to the axis of rotation of the offset unit. Preferred embodiments of the extrusion head can advantageously ensure continuous rotation of the offset unit, in particular through the use of a cable feedthrough designed as a slip ring and / or a distributor and / or a cooling block designed as a cooling rotary feedthrough, without causing failure of the lines, for example due to the lines tearing off. In the case that the material feed unit has a substantially quadrangular shape, a cooling device with four bores can be provided, for example, which are each sealed to the outside by closure means. In this way, a quadrangular cooling path is created, which can be connected to a coolant interface. In the case that theOffset unit of a substantially hexagonal shape, for example, a cooling device with six bores can be provided, each of which is sealed to the outside by means of a closure means. In this way, a hexagonal cooling path is created, which can be connected to a coolant interface. According to a preferred embodiment of the extrusion head, it is provided that the at least one cooling device is arranged at least partially in the area after, preferably directly after, the severance point of the at least one extrusion material. According to a preferred embodiment of the extrusion head, it is provided that the at least one cooling device cools by means of a cooling medium, wherein the cooling medium is preferably gaseous and / or liquid. According to a preferred embodiment of the extrusion head, it is provided that the at least one cooling device represents a continuous cooling loop, preferably wherein thecontinuous cooling loop runs through both the material feed unit and the offset unit. According to a preferred embodiment of the extrusion head, it is provided that the separating device with the at least one blade element is a component of the material feed unit or is connected to the material feed unit, and the at least one cooling device is a component of the material feed unit or is connected to the material feed unit. According to a preferred embodiment of the extrusion head, it is provided that the at least one offset unit is rotatable, in particular rotatable as a turret head, and the extrusion head is tiltable or inclined, preferably with respect to the longitudinal axis of the extrusion head. The longitudinal axis of the extrusion head is understood here to be an imaginary axis which runs essentially from the top side of the support bracket to the bottom side of the support bracket. The bottom side of the support bracket is theThe offset unit is the side facing the offset unit, and the top side of the support bracket is the side oriented opposite the bottom side. In other words, the longitudinal axis can also be referred to as the applicate, in the direction of which the height of the support bracket can be defined. In other words, the longitudinal axis can be parallel to the Z-axis in the Cartesian coordinate system or to the Z-axis in Figures 1 to 10. By designing the offset unit in the form of a rotatable part, in particular a rotatable turret head, the almost gap-free passage of the offset unit past the separating device and / or the changing of the condenser units can be realized particularly easily, cost-effectively, and in a space-saving manner. According to a preferred embodiment of the extrusion head, it is provided that the at least one offset unit is rotatable in one plane in two directions, and the extrusion head is tiltable in at least two directions starting from a vertical starting position.is. The vertical starting position is understood to mean the position of the extrusion head which is shown in Figures 1 to 3, 28 and 34. In the vertical starting position, the axis of rotation of the offset unit and the longitudinal axis of the extrusion head are parallel to each other. In other words, the axis of rotation of the offset unit can be orthogonal to the horizontal top or bottom of the support console. In other words, the angle of inclination of the inclination actuator can be set to 0 ^. In other words, all nozzles of the condenser units can lie in a horizontal plane. In a preferred embodiment, it can be provided that the offset unit is rotatable relative to the material feed unit, wherein the axis of rotation of the offset unit is parallel to the longitudinal axis of the extrusion head or in other words parallel to the Z-axis. In a preferred embodiment, it can be provided that the extrusion head is rotatable relative to a part on which theExtrusion head is attached, in particular relative to the support bracket, and is tiltable, wherein the tilt axis of the extrusion head is transverse, preferably orthogonal, to the longitudinal axis of the extrusion head or in other words transverse, preferably orthogonal, to the Z-axis. According to a preferred embodiment of the extrusion head, it is provided that the extrusion head is tiltable at least in one plane, in particular with respect to the longitudinal axis of the extrusion head to two sides within a plane. In a preferred embodiment of the extrusion head, it can be provided that the extrusion head can be connected to a support bracket by means of a tilt shaft, in particular with a key connection and a grooved nut, and can be tilted via a tilt actuator, preferably relative to the support bracket, preferably wherein the extrusion head can be released as a whole unit from the support bracket, preferably from the tilt shaft, by loosening the grooved nut.can be dismantled. In a preferred embodiment of the extrusion head, it can be provided that the inclination shaft can be provided as a component of the inclination actuator, in particular an electric motor, and / or can be connected or connectable thereto. In a preferred embodiment of the extrusion head, it can be provided that the support console can have a power transmission device, in particular a belt drive, spur gear, planetary gear, or worm gear, wherein the inclination shaft and the inclination actuator can be connected to the power transmission device. In a preferred embodiment of the extrusion head, it can be provided that the inclination angle of the extrusion head, at least in one plane, in particular the angle of rotation of the inclination shaft about its axis of rotation, can be discretely and / or continuously adjustable, preferably by means of adjusting screws as an adjustable stop for the inclination shaft.can. In a preferred embodiment of the extrusion head, it can be provided that the support console can be connected to a displacement system or can be provided as a component of the displacement system, preferably in order to move the extrusion head in at least one direction. In a preferred embodiment of the extrusion head, it can be provided that the support console can have a spindle nut or can be provided as a component of the support console, wherein the spindle nut can be connected to a threaded spindle, in particular of the displacement system, preferably in order to move the extrusion head in at least one direction. According to a preferred embodiment of the extrusion head, it is provided that the offset unit has at least two, preferably six, condenser units, wherein a first extrusion material can be extruded by a first set of the existing condenser units and a second extrusion material bya second set of the existing condenser units can be extruded. In a preferred embodiment, it can be provided that the offset unit can have six condenser units, wherein three condenser units can represent the first set and the remaining three condenser units can represent the second set. In another preferred embodiment, it can be provided that the offset unit can have a different number of condenser units than stated in the previous embodiments. In another preferred embodiment, it can be provided that the condenser units of the first set can be arranged directly adjacent to one another and the condenser units of the second set can be arranged directly adjacent to one another. According to a preferred embodiment of the extrusion head, it is provided that the at least two condenser units have nozzle channels, wherein the at least twoCondenser units or the nozzle channels are arranged inclined to one another and / or to a rotational axis of the offset unit. According to a preferred embodiment of the extrusion head, it is provided that at least one locking means is provided, wherein at least one position of the offset unit relative to the material feed unit can be determined by the at least one locking means. In a preferred embodiment, it can be provided that the at least one locking means can be designed to be mechanically and / or electromechanically and / or pneumatically and / or hydraulically and / or electromagnetically operable. In a preferred embodiment, it can be provided that a locking recess can be provided for each locking means. In a preferred embodiment, it can be provided that the at least one locking means can be designed to be releasably lockable. In a preferred embodiment,It can be provided that the at least one locking means can be provided as a resilient pressure piece, in particular a ball pressure piece and in combination with at least one locking recess, particularly preferably a countersunk bore for each nozzle and / or each nozzle of a set, wherein at least one position of the offset unit relative to the material feed unit can be locked, preferably releasably, by the at least one locking means. According to a preferred embodiment of the extrusion head, it is provided that at least one stop is provided, wherein the rotatability of the offset unit is limited in at least one direction, preferably in two directions, by the at least one stop, preferably in combination with at least one stop guide. The at least one stop can perform a protective function for the lines used and / or against possible contamination. In a preferred embodiment, it can be providedbe that at least one sensor can be provided for detecting the rotational position of the offset unit relative to the material feed unit. In a preferred embodiment, it can be provided that the at least one sensor for detecting the rotational position of the offset unit relative to the material feed unit can be an absolute rotary encoder or an incremental rotary encoder and / or a Hall sensor with preferably a magnetic tape and / or an inductive sensor with preferably a pole wheel and / or an electro-optical sensor with preferably a reticle. In a preferred embodiment, it can be provided that the at least one sensor for detecting the rotational position of the offset unit relative to the material feed unit can be connected or connectable to the offset actuator and / or to the transmission gear and / or to the drive gear. According to a preferred embodiment of the extrusion head, it is provided that the material feed unit and / orthe offset unit has a cable feedthrough, in particular an electrical rotary feedthrough and / or a cable gland. In a preferred embodiment, it can be provided that the material feed unit and / or the offset unit can have a cable gland with preferably a seal and / or a sealing insert and / or an electrical rotary feedthrough designed as a slip ring with preferably a seal. According to a preferred embodiment of the extrusion head, it is provided that a platform is provided, wherein the product can be manufactured on the platform by means of additive manufacturing. In a preferred embodiment, it can be provided that the platform is designed as a turntable in order to provide an additional (for example, fifth) axis of rotation, in particular the C-axis, for 5-axis additive manufacturing, in order to preferably produce complex geometries with undercuts without the use of support structures.to manufacture, wherein the fourth axis, in particular the A-axis or B-axis, is realized by the tiltable extrusion head. According to a preferred embodiment of the extrusion head, it is provided that the extrusion head is arranged within a mounting structure, wherein a convection guard is provided between the extrusion head and the mounting structure, and / or the mounting structure is arranged within a travel system, wherein a convection guard is provided between the mounting structure and the travel system, preferably at least one travel device of the travel system. The convection guard can be one-piece or multi-piece. Several convection guards that are not directly connected to one another can also be provided, wherein each convection guard can be one-piece or multi-piece. If several convection guards are provided, these can also be collectively referred to as one convection guard. In aIn a preferred embodiment, it can be provided that the travel system can have at least one frame and at least one drive in order to move the mounting structure. According to a preferred embodiment of the extrusion head, it is provided that the convection protection is arranged between the extrusion head and the mounting structure in such a way that two areas are present inside and / or outside the mounting structure, in particular within an imaginary infinite volume of the projected base area of ​​the mounting structure, wherein in one of the two areas the material feed unit is essentially arranged and in the other of the two areas the offset unit is essentially arranged, and / or the convection protection is arranged between the mounting structure and the travel system, preferably at least one travel device of the travel system, in such a way that two areas are present within the travel system, wherein in one of theIn one of the two regions, the material feed unit is essentially arranged, and in the other of the two regions, the offset unit is essentially arranged. According to a preferred embodiment of the extrusion head, it is provided that the convection protection is connected, detachable, or connectable, preferably non-destructively, to the extrusion head and the mounting structure and / or to the mounting structure and the travel system, preferably at least one travel device of the travel system, by means of one or more convection protection connecting devices. According to a preferred embodiment of the extrusion head, it is provided that the convection protection is flexibly deformable due to its shape and / or its material. According to a preferred embodiment of the extrusion head, it is provided that the convection protection comprises at least one separating means, preferably a separating hose and / or a separating membrane and / or a bellows.preferably flat, conical, pyramid-like, particularly preferably pyramid-shaped, and / or has or consists of a pleated roof cover, preferably a multi-part pleated roof cover. According to a preferred embodiment of the extrusion head, it is provided that the convection protection, in particular the separating means, consists at least partially of silicate fabric and / or at least partially of aramid fabric, preferably of aluminized Preox-Para-Aramid fabric, and / or at least partially of rubber, preferably of fluororubber (FKM) or silicone rubber (HTV), and / or is partially coated with silicone and / or polytetrafluoroethylene. In a preferred embodiment, it can be provided that the convection protection, in particular the pleated roof cover, preferably consists of several elements, at least partially of coated plastic fabric, in particular sewn and / or thermally welded and / or glued.and / or at least one metal. According to a preferred embodiment of the extrusion head, it is provided that the convection protection has at least one shaft seal, in particular a radial sealing lip and / or at least one axial sealing lip and / or at least one labyrinth seal, and / or at least one stiffener, in particular in the form of a stiffening ring. In a preferred embodiment, it can be provided that the at least one shaft seal is an integral part of the convection protection or a separate component that can be fastened thereto. According to a preferred embodiment of the extrusion head, it is provided that at least one measuring device is provided, wherein the at least one measuring device can be a mechanical, thermoelectric, resistive, piezoelectric, capacitive, inductive, optical, acoustic and / or magnetic measuring device. In a preferred embodiment, it can be provided thatan arrangement is provided, wherein the arrangement consists of at least the following arrangement components: an extrusion head and a convection protection device and a mounting structure, wherein a shield, in particular a thermal and substantially tight shield, is provided by the interconnected arrangement components, wherein the shield, in particular a thermal and substantially tight shield, divides the operating space into two spatial areas, preferably wherein the arrangement additionally comprises a displacement system. In a preferred embodiment, it can be provided that the shield is constructed by a mounting structure, the material feed unit, the offset unit and at least one convection protection device between the mounting structure and the extrusion head, in particular the material feed unit. It can preferably be provided that a displacement system and a convection protection device between the mounting structure and the displacement system also construct the shield. In aIn a particularly preferred embodiment, it can be provided that the shielding is constructed at least partially by the offset unit receiving block of the material feed unit and by bearings between the material feed unit and the offset unit, in particular roller / sliding bearings with seals, as well as by the cooling block and / or by the casing and / or by some of the existing seals and / or cable glands, preferably cable glands and / or electrical rotary feedthroughs designed as a slip ring, of the offset unit. In a preferred embodiment, it can be provided that the offset unit and the separating device can be arranged within the offset unit receiving block, wherein the drive wheel and / or the at least one receiving device and the separating device and / or the at least one blade element are provided in a recess, which is referred to below as the separating chamber, of the offset unit receiving block.can, wherein this separation chamber can be closed at the bottom at least by part of the shielding arrangement and at the top at least partially open or closed with the exception of the inlet line. In this way, the convection of the waste heat of the drives from above to the severance point can be advantageously prevented and / or reduced. Furthermore, protection is sought for a method and / or a use for producing a product with an extrusion head according to the invention. According to a preferred embodiment of the method, it is provided that by tilting the extrusion head, the nozzle of one of the existing condenser units is moved into a position below the remaining nozzles of the existing condenser units. According to a preferred embodiment of the method, it is provided that by rotating the offset unit in the tilted state of the extrusion head, the nozzle of one of the existing condenser units is moved into a position belowof the remaining nozzles of the existing condenser units. According to a preferred embodiment of the method, it is provided that the offset unit has at least one set of at least two condenser units, wherein the at least two condenser units of the set have two different nominal diameters of the nozzles, and by rotating the offset unit, preferably in the inclined state of the extrusion head, with different accuracy due to the nominal diameters of the nozzles of the at least two condenser units, a product is produced. According to a preferred embodiment of the method, it is provided that by tilting the extrusion head, starting from a vertical starting position in at least two directions, a material change between at least two different extrusion materials takes place. According to a preferred embodiment of the method, it is provided that undercutsbe taken into account, and the product is built up layer by layer with at least one extrusion material by tilting the extrusion head and / or by rotating the offset unit, wherein during the layer-by-layer construction, a support structure for supporting the undercuts of the product is additionally built up with at least one other extrusion material by tilting the extrusion head and / or by rotating the offset unit. Further details and advantages of the invention are explained in more detail below with reference to the description of the figures and the drawings. Therein: Figs. 1 to 3: various perspective views of an extrusion head according to the invention; Fig. 4: a front view of the extrusion head from Fig. 1 with a partial section; Fig. 5: a detailed view of a first separating device and a first introduction line based on detail I from Fig. 4; Fig. 6: a sectional view of the first separating device and the first introduction linefrom Fig. 5 along the section plane BB of Fig. 5; Fig. 7: a sectional view of a second separating device and a second inlet line along the section plane BB of Fig. 5; Fig. 8: a sectional view of a third separating device along the section plane BB of Fig. 5; Fig. 9: a sectional view of a fourth separating device along the section plane BB of Fig. 5; Fig. 10: a sectional view of a fifth separating device along the section plane BB of Fig. 5; Fig. 11: a perspective view of an inlet line from Fig. 4; Figs. 12 to 21: different design variants of blade elements; Fig. 22: a side view of the extrusion head from Fig. 1 with a first variant of a cooling device, shown as a sectional view along the section AA; Fig. 23: a side view of the extrusion head with a second variant of a cooling device, shown as a sectional view; Fig. 24: a side view of the extrusion head with athird variant of a cooling device, shown as a sectional view; Fig. 25: a perspective view of the offset unit from Fig. 1 without condenser units; Fig. 26: a perspective view of the offset unit from Fig. 1 with condenser units; Fig. 27: a detailed view of a nozzle of a condenser unit of an extrusion head based on detail II from Fig. 4; Fig. 28: a front view of the extrusion head from Fig. 1, installed in a mounting structure, shown with a partially sectioned cover of the mounting structure; Figs. 29 to 32: various design variants of closures of a convection protection based on detail III from Fig. 28; Figs. 33 to 35: various positions of the tiltable extrusion head from Fig. 1; Fig. 36: a perspective view of the extrusion head with the mounting structure from Fig. 35, implemented in a traversing system. Fig. 37: an arrangement of the extrusion head within the mounting structure and a firstPlatform; Fig. 38: an arrangement of the extrusion head within the mounting structure and a second platform; Fig. 39: an exploded view of the support console, the tilt actuator, the tilt shaft, and the travel system. Figs. 1 to 3 show various perspective views of an extrusion head 1 according to the invention. In Fig. 1, it is clearly visible that the extrusion head 1 consists of the material feed unit 2 and the offset unit 6 arranged underneath. The material feed unit 2 essentially serves to feed and / or receive at least one extrusion material from a material reservoir and can additionally include other functions and components required for this purpose. In this exemplary embodiment, two extrusion materials can be fed independently of one another. For this purpose, the extrusion material, which is preferably embodied as a filament, is introduced into one of the two material receiving nozzles 33 or 34. As shown in Fig. 1,A first extrusion material can be introduced into the first material receiving nozzle 33 and a second extrusion material into the second receiving nozzle 34. The material receiving nozzles 33 and 34 can be arranged on the upper side of the extrusion block 35, but other positions are also conceivable. Furthermore, as shown here, a separate extrusion actuator 31, 32 can be provided for the extrusion materials used. An actuator can, in particular, be a motor. In this exemplary embodiment, with the aid of the extrusion actuator 31, the first extrusion material, which is introduced into the extrusion block 35 through the first material receiving nozzle 33, can be moved via a system arranged in the extrusion block 35. The first extrusion material can be conveyed from the first material receiving nozzle 33 via the extrusion block 35 and further via the offset unit receiving block 36 to one of the condenser units 7.The conveying direction can also run in the opposite direction in order to pull the first extrusion material at least partially towards the first material receiving nozzle 33. The same conveying action as described above can also be carried out with the second extrusion material, which can be introduced into the second material receiving nozzle 34, wherein the second extrusion actuator 32 conveys the second extrusion material within the extrusion block 35 and the offset unit receiving block 36 into one of the condenser units 7 or withdraws it in the opposite direction. The extrusion block 35 can, as shown in Fig. 1, be connected to the two extrusion actuators 31 and 32 as well as to the offset unit receiving block 36. The offset unit receiving block 36 can in turn be connected to an offset actuator 30, wherein the offset actuator 30 can serve as a drive for moving the offset unit 6 and preferably has aincremental or absolute rotary encoder. In addition, the offset unit receiving block 36 can be connected to the offset unit 6, wherein the offset unit 6 is movably mounted in the offset unit receiving block 36. As shown here, the offset unit 6 can be rotatably mounted about the Z-axis, wherein such a rotational movement can be caused by the offset actuator 30. The offset unit 6 has six condenser units 7 in this exemplary embodiment, only three of which can be seen in Fig. 1. The condenser units 7 can, as shown here, be covered with a casing 37 and / or attached to a casing 37. The other components of the offset unit 6 will be explained in more detail later. The offset unit receiving block 36 can, as shown here, have one or more cooling medium interfaces 60. These can serve as an inlet point and / or outlet point for a cooling medium in order tocool. The cooling medium interface 60 can preferably be designed as a push-fit connection. The offset unit receiving block 36 is in contact with an inclination shaft 38, via which the offset unit receiving block 36 can be connected to a support bracket 28 and tilted via an inclination actuator 29. The support bracket 28 can in turn be implemented in a travel system in order to move the extrusion head 1 in at least one direction. Further details on this will be explained in more detail later. The inclination shaft 38 can, as shown here, be designed such that the extrusion head 1 as a whole, with the exception of the support bracket 28 and the inclination actuator 29, can be moved. In the case shown in Fig. 1, the extrusion head 1 can be rotated relative to the support bracket 28. The inclination actuator 29 can serve as the drive for this movement. The rotational movement of the extrusion head 1 in this case runs around the X-axis. Fig. 2 shows the extrusion head 1from Fig. 1 from a different perspective view. In this illustration, the offset unit 6 can be seen better. In this illustration, all six condenser units 7 can be seen, which are arranged radially inside the casing 37. As shown in Fig. 2, convection protection connection devices 39 can be provided to attach a convection protection to the offset unit receiving block 36. For example, a pleated bag can be connected to the offset unit receiving block 36 via screw connections. Fig. 3 shows the extrusion head 1 from Fig. 1 from a different perspective view. In this case, one of the two conveyor devices 16, 40 as well as a recess for the inclination shaft 38 can be clearly seen. The conveyor devices 16, 40 can include at least two feed wheels 41, between which the at least one extrusion material can be located. By rotating the feed wheels 41 of the conveyor device 16, 40, the at least oneExtrusion material can be moved. A detailed description will follow later. As already evident in Fig. 1 and 2, Fig. 3 also shows how the offset unit receiving block 36 can be connected to a rear wall 43 via two triangular side walls 42, wherein the rear wall 43 has a recess for the inclination shaft 38. In addition, in particular for better absorption of thrust forces, sleeves and / or dowel pins can be provided in opposing recesses between the rear wall 43 and the offset receiving block 36. By means of the inclination shaft 38 (not shown in Fig. 3), the rear wall 43 can be connected to the support console 28 (also no longer shown here) and can be actuated by the inclination actuator 29 (also no longer shown here), so that the extrusion head can be rotated relative to the support console 28. This rotational movement in this case runs around the X-axis. Furthermore, lines 44 can be provided, which serve aselectrical lines and / or cooling lines for the offset unit 6 can serve. For example, the lines 44 can be used as a power supply and / or as a cooling medium supply and / or as signal transmission paths for measuring devices such as temperature sensors. Fig. 4 shows a front view of the extrusion head 1 from Fig. 1 to 3 with a partial section. The sectional plane of the partial section runs in this view along the two guide paths of the two extrusion materials, starting at the material feed hoses 45, 46, via the two material intake nozzles 33, 34, the extrusion block 35, the offset unit intake block 36 and the condenser units 7 and ending at the nozzle channels 23. In other words, the sectional plane lies in the plane YZ at the height of the extrusion material guide. As in the previous Fig. 1 to 3, the side walls 42, which are connected on the one hand to the rear wall 43 and on the other hand to theOffset unit receiving block 36 are connected. The offset unit receiving block 36 is also connected to the extrusion block 35. At least one conveyor device 16, 40 for at least one extrusion material can be located in the extrusion block. In the exemplary embodiment shown here, the two conveyor devices 16 and 40 are provided in order to move two extrusion materials independently of one another. In other exemplary embodiments, more or fewer conveyor devices and / or more or fewer extrusion materials can be provided. In the following, the extrusion head is described using a first guide path for a first extrusion material. It should be noted, however, that the second guide path shown here can be described in the same way and the description applicable to the first guide path can generally, but not necessarily, apply to further guide paths. This means that guide paths for extrusion materials as inFig. 4, but are not limited to the illustrated embodiment. The first guide path begins at the first material feed hose 45, into which the first extrusion material can be introduced. The first material feed hose is connected to the first material receiving nozzle 33, which in turn is connected to the extrusion block 35. The first material receiving nozzle 33 can preferably be a push-fit connection. The first guide path continues through the extrusion block 35 to the first conveyor device 16, which has two feed wheels 41. The feed wheels 41 can be driven by a first extrusion actuator 31. By means of the rotating feed wheels 41, the first extrusion material can either be conveyed further in the direction of the offset unit 6 or also be conveyed back against this direction. Along the first guide path, between the feed wheels 41 and the offset unit 6, specifically theDrive wheel 47, an inlet line 14, and a separating device 4 are provided, which will be explained in more detail later. The first guide path passes through the offset unit 6, beginning with the drive wheel 47 and continuing through a continuation line 17, in particular a heatbreak line, in the cooling block 50 of the offset unit 6, wherein the continuation line 17, in particular the heatbreak line, projects beyond the cooling block 50 of the offset unit 6 and reaches into one of the condenser units 7. Directly connected to the end of the continuation line 17, in particular the heatbreak line, in one of the condenser units 7 is a nozzle tube 52, which guides the first guide path to the nozzle channel 23, where it ends. In a preferred embodiment, as shown in Fig. 4, the continuation line 17, in particular the heat break line, can run from the upper end of the cooling block 50 into one of the existing condenser units 7.Preferably, the extension line 17 between the cooling block 50 and the corresponding condenser unit 7 can form a section in which the extension line 17, in particular the heatbreak line, is freestanding. This means that the extension line 17, in particular the heatbreak line, can be installed partially freestanding or, in other words, partially without contact with other components. This has the advantage that the heat generated by the condenser units 7 can thus migrate more difficultly to the cooling block 50. Apart from the convection of the ambient air, heat can then only migrate to the cooling block 50 via the thin components such as the extension line 17, in particular the heatbreak line, preferably made of a material with a low heat transfer coefficient, particularly preferably stainless steel, whereby a lower heat transfer can be achieved. In a preferred embodiment, it can be provided that aA section of the extension line 17, in particular the heatbreak line, which is partially free-standing or, in other words, partially installed without contact with other components, can be air-cooled, wherein the air cooling can be carried out without pressure or with compressed air, preferably in an area at least partially separated from the construction space to maintain the thermal homogeneity of the construction space air. Cooling devices 19 can be provided both in the material feed unit 2 and in the offset unit 6. As shown in this exemplary embodiment, these cooling devices 19 can be provided specifically in the offset unit receiving block 36, preferably in the heat sink 48, as well as in the cooling block 50 of the offset unit 6. The cooling devices 19 can, as shown in Fig. 4, be bores through which the cooling medium flows. The offset unit 6, with the aid of the drive wheel 47 and the cooling block 50 of the offset unit 6, can be in contact with bearings 49, which in turn are connected to theMaterial feed unit 2, specifically in Fig. 4, are in contact with the offset unit receiving block 36. In this way, the offset unit 6 can be rotatably mounted in the material feed unit 2, specifically in the offset unit receiving block 36. Lines 44 can be provided between the two guide paths, wherein the lines 44 can be provided for the supply and removal of cooling media and / or as a power connection. As shown in Fig. 4, the lines 44 can be, among other things, power lines for the condenser units 7 and signal transmission paths for measuring devices 68, in particular temperature sensors. Before the lines 44 are distributed to the individual condenser units, they can be connected to each other by a cable bushing 24, in particular a cable gland with preferably a seal and / or a sealing insert used as strain relief and / or an electrical rotary feedthrough, for example designed as a slip ring with preferably a seal inUse as strain relief, torque relief, energy transmission and / or signal transmission. Fig. 5 shows a detailed view of a first separating device 4 and a first introduction line 14 based on detail I from Fig. 4. The extrusion material 3 can, as already described, be moved by the feed wheels 41. The extrusion material 3 can be conveyed along the introduction line 14 to the separating device 4. The extrusion material 3 can then be introduced into a receiving device 18, which in this specific embodiment is designed as a counterbore in the drive wheel 47. After being introduced into the receiving device 18, the extrusion material can be conveyed further, so that it is moved by the drive wheel 47 of the displacement unit 6 and further through the feed line 17, in particular the heatbreak line, in the cooling block 50 of the displacement unit 6. In the area in which the separating device 4 is provided, theExtrusion material 3 is severed. The extension line 17 can, as shown in Fig. 5, represent a heatbreak line located in the cooling block 50. In another preferred embodiment, it can also be provided that the extension line 17 runs completely through the cooling block 50 and the drive wheel 47 of the offset unit 6. If the extension line 17 runs to the upper end of the offset unit 6, specifically to the upper end of the drive wheel 47, the receiving device 18 can be a component of the extension line 17. The cutting device 4 has at least one blade element 5, wherein the at least one blade element 5 is fastened to the material feed unit 2. For fastening the at least one blade element 5, at least one blade connecting device 8 can be provided, wherein the blade connecting device 8 can be, for example, a screw connection between the blade element 5 and the material feed unit 2.can be. In Fig. 5, one of the two existing blade elements 5 is clearly visible. In this embodiment, the blade element 5 is a flat and angular blade. The blade element 5 is arranged in the material feed unit 2 such that the material feed unit 2 and the offset unit 6 can be guided past each other almost gap-free. When the offset unit 6 is moved by actuating the drive wheel 47, the extrusion material 3 can be guided to the at least one blade element 5 and severed at a severing point. The upper severed end of the extrusion material 3 can then be inserted into one of the existing receiving devices 18 depending on the movement of the offset unit 6 and thus fed to one of the existing liquefier units. In order to achieve a clean severing of the extrusion material 3 and / or to avoid bending of the extrusion material 3 during the severing process,It is advantageous to guide the offset unit 6 past the material feed unit 2 with almost no gap. It can be clearly seen in Fig. 5 that the inlet line 14 is arranged as a separate component in the material feed unit 2 and has two projections 57. These two projections can serve to guide the extrusion material 3 closer to a cutting edge 11, so that bending of the extrusion material 3 during severing can be avoided. In an imaginary triangle, the first corner of which is the center of the axis of rotation of the offset unit, the second corner of which is the center of the cross-section of the preferably circular extrusion material 3 above the cutting edge, and the third corner of which is the center of the cross-section of the preferably circular extrusion material 3 below the cutting edge, the extrusion material 3 can bend along the cutting edge during severing of the extrusion material 3 due to theby the offset unit 6 and severing rotary movement, whereby the adjacent side of the imaginary triangle described above is shortened. As shown here, the insertion line 14 projects into an effective range of the blade element 5; specifically, the two projections 57 of the insertion line 14 project into an effective range of the blade element 5. In other words, the insertion line 14 ends with the two projections 57 in an area between the blade element underside 55 and the blade element top side 56. Should the extrusion material 3 bend slightly during the severing process, the extrusion material 3 can be moved back upwards by the feed wheels 41, whereby the extrusion material 3 can realign itself in the insertion line 14. Fig. 6 shows a sectional view of the first separating device 4 and the first insertion line 14 from Fig. 5 based on the section plane BB from Fig. 5. The sectional view based on theSection plane BB of Fig. 5 shows, in contrast to the detailed view of Fig. 5, that the separating device 4 consists of two individual blade elements 5. Both blade elements 5 are flat and angular blades. In section BB of Fig. 6, one of the two projections 57 is clearly visible. The projection 57 of the insertion line 14 shown here projects into an imaginary blade element hollow volume 15 of the separating device 4, wherein the separating device 4 here has two blade elements 5. The imaginary blade element hollow volume 15 of the separating device 4 corresponds in this embodiment with the two blade elements 5 arranged parallel to one another to a trapezoidal prism, wherein the trapezoidal cross section of such a trapezoidal prism can be seen in Fig. 6. The area of ​​the projection 57 visible in Fig. 6 also corresponds to a trapezoidal surface, wherein the trapezoidal surface of the projection 57 is smaller than the trapezoidal cross section of the prism, which forms the imaginaryBlade element hollow volume 15 of the separating device 4. The trapezoidal surface of the projection 57 lies between the two blade elements 5 and is delimited by one of the cutting surface upper sides 10 of the blade elements 5. The lower side of the trapezoidal surface of the projection 57 ends in a region between the blade element lower side 55 and the blade element upper side 56. The projections 57 of the insertion line 14 reduce the imaginary blade element hollow volume 15 of the separating device 4, wherein the two projections 57 delimit the trapezoidal prism on two sides. In other exemplary embodiments, more or fewer blade elements 5 can be provided. The number and shape of blade elements 5 shown here are not to be understood as limiting. Fig. 7 shows a sectional view of a second separating device 4 and a second insertion line 14 based on the sectional plane BB of Fig. 5. In contrast to the exemplary embodimentfrom Fig. 6, in Fig. 7 the introduction line 14 is not provided as a separate component, but as a continuous guide bore through the extrusion block 35. The projections 57, only one of which is visible in Fig. 7, are also components of the extrusion block 35. The shape and arrangement of the projections 57 correspond to the shape and arrangement in Fig. 6. Here too, the projections 57 protrude into an imaginary blade element hollow volume 15 of the separating device 4 and delimit this. In contrast to Fig. 6, only one blade element 5 is provided here, which is flat and has a round cutting edge 11. The imaginary blade element hollow volume 15 of the separating device 4 thus corresponds to a truncated cone in this exemplary embodiment. For a better illustration of this imaginary blade element hollow volume 15, specifically the truncated cone, reference is made to Figs. 16 to 18. Fig. 8 shows a sectional view of a third separating device 4 based on theSectional plane BB of Fig. 5; Unlike in Fig. 7, in Fig. 8 the transverse groove of the projections 57 extends upwards in a funnel-like manner, forming a guide recess 58 and the funnel tapering like an elongated hole towards the round through-bore. This leads to greater freedom of movement of the extrusion material 3 to the cutting edge, whereby the blade element 5 can better penetrate into the extrusion material 3. In a preferred embodiment, it can also be provided that the receiving device 18 can be designed as a separate component within the drive wheel 47 of the offset unit 6. It can be provided that the receiving device 18 can be designed as a flat plate, as a flat ring or as a sleeve, preferably with a countersunk bore. Fig. 9 shows a sectional view of a fourth separating device 4 based on the section plane BB of Fig. 5. The separating device 4 can, as shown in Fig. 9, have only one blade element 5, wherein theBlade element can be a blade sleeve. In this embodiment, the insertion line 14 is not a separate component, but is provided as a guide bore in the extrusion block 35. It can also be provided that the through-opening of the blade sleeve is designed like an elongated hole or, as described in Fig. 8, the projections 57 are formed by a component inserted separately in the blade sleeve. Fig. 10 shows a sectional view of a fifth separating device 4 based on the sectional plane BB of Fig. 5; Unlike in Fig. 9, in this illustration the extension line 17 is designed such that it runs through both the cooling block 50 and the drive wheel 47 to the upper end of the offset unit 6 and thus simultaneously assumes the function of the receiving device 18. Fig. 11 shows a perspective view of the insertion line 14 from Figs. 4 to 6. The insertion line 14 is a substantially cylindrical, as shown here shaft-shaped,Component with a central through-bore through which the extrusion material 3 can be guided. The inlet line 14 has a collar with which the inlet line can be arranged in the extrusion block 35. Furthermore, the inlet line 14 preferably has a flat milled section or, for example, a toothed profile on the collar, with which the orientation of the projections 57 can be aligned with the blade element 5. At one end of the inlet line 14 are the two projections 57, which together form a guide recess 58, in this specific case a groove. With the help of the projections 57, the extrusion material 3 can be guided closer to the cutting edges 11 of the blade elements 5. Further details on this were explained in more detail in Figs. 5 to 7. Fig. 12 to 21 show different embodiments of blade elements 5. Fig. 12 shows a perspective view from above of one of the blade elements 5 from Fig. 4 to 6. On one side, theBlade element 5 has a cutting edge 11. Between the blade element upper side 56 and the cutting edge 11, a cutting surface upper side 10 is provided, which is inclined relative to the blade element upper side 56. When the blade element 5 is fastened to or in the material feed unit 2, the cutting surface upper side 10 is arranged facing away from the offset unit 6. The cutting surface upper side 10 facing away from the offset unit 6 has two surface sections, wherein the first cutting surface section 12 borders on the cutting edge 11 and the second cutting surface section 13 does not border on the cutting edge 11. As shown in Fig. 12, it can be provided that the first cutting surface section 12 has a different, in particular a larger, angle with the cutting surface underside 9 of the at least one blade element 5 facing the offset unit 6 than the second cutting surface section 13 encloses. On the blade element top 56 of theTwo parts of a blade connecting device 8 can be seen on the blade element 5, wherein the blade connecting device 8 can be a screw connection, preferably by means of countersunk screws, between the material feed unit 2 and the blade element 5. Fig. 13 shows a perspective view from below of the blade element 5 from Fig. 12 with the additional blade connecting devices 8, which are designed here as countersunk screws. On the blade element underside 55, it can be partially seen that countersunk holes are provided, which can be connected to the material feed unit 2 by means of the blade connecting devices 8, as shown here as two countersunk screws. Fig. 14 shows a perspective view from above of a four-edged blade element 5. This embodiment of a blade element 5 has a square and flat base body, but in contrast to previously described blade elements 5, there are four cutting edges.11 is provided. The number of cutting edges 11 shown here is not to be understood as limiting. Any desired number of cutting edges can be provided per blade element 5. More than one cutting edge per blade element 5 can have the advantage that a blade element 5 can easily be used several times due to wear and / or damage to a cutting edge 11. For this purpose, the blade connecting device 8 only needs to be released, the blade element re-equipped with a new cutting edge 11, and the blade connecting device 8 re-attached. Fig. 15 shows a perspective view from below of the blade element 5 from Fig. 14. What has already been said about the blade connecting device 8 also applies here. Fig. 16 shows a perspective view from above of a flat and angular blade element 5 with a round cutting edge 11. As already explained, this embodiment of a blade element 5 forms aA truncated cone represents the imaginary hollow volume 15 of the blade element. The above statements regarding the blade connecting device 8 also apply here. Fig. 17 shows a perspective view from below of the blade element 5 from Fig. 16. The above statements regarding the round cutting edge 11 and the blade connecting device 8 also apply here. Fig. 18 shows a perspective view from above of a flat and round blade element 5 with a round cutting edge 11. The round blade element 5 is circular in shape and depicted as a sectional view. The section runs centrally through the rotational axis of the circular ring. As already explained above, this embodiment of a blade element 5 forms a truncated cone as an imaginary blade element hollow volume 15. The blade connecting device 8 can be designed in this embodiment as a positive and / or non-positive connection, preferably as a press connection, and can be connected to the material feed unit 2or connected. Fig. 19 shows a perspective view from above of a round blade element 5 with a round cutting edge 11. The round blade element 5 is sleeve-shaped here and shown as a sectional view. The section runs centrally through the rotational axis of the sleeve. The blade connecting device 8 in this embodiment can be designed as a positive and / or non-positive connection, preferably as a press connection, and can be connected or connected to the material feed unit 2. Fig. 20 shows a perspective view from above of a round blade element 5 with a round cutting edge 11. The round blade element 5 is sleeve-shaped here and shown as a sectional view. The section runs centrally through the rotational axis of the sleeve. In the exemplary embodiment in Fig. 20, the sleeve-shaped blade element 5 has part of a blade connecting device 8, wherein the part of the blade connecting device 8here designed as an external thread. Fig. 21 shows a perspective view from above of a block-like blade element 5. The block-like blade element 5 has a round, for example elliptical, cutting edge 11, the hole formed thereby representing the tapered end of a wedge-shaped through-opening through the blade element 5. On the upper side 56 of the blade, the upper end of the wedge-shaped through-opening corresponds to an elongated hole. Next to the elongated hole, there are further through-openings on both sides, which have countersunk holes on the underside 55 of the blade in order to be able to accommodate countersunk screws, as in Fig. 13, and thus to connect the blade element 5 to the material feed unit 2. In a preferred embodiment, shown in Figs. 12 to 21, the underside 9 of the cutting surface can be essentially congruent with the underside 55 of the blade. Fig. 22 shows a side view of the extrusion head 1 from Fig. 1 with a firstVariant of a cooling device 19, shown as a sectional view along section AA. The sectional view AA in Fig. 22 shows the extrusion head 1 with a sectional plane located in the XZ plane and passing through the rotation axis 69 of Fig. 4. In other words, the sectional plane runs along the XZ plane and centrally through the extrusion head 1; exactly between the two material receiving nozzles 33 and 34 from Fig. 4. As already described in Fig. 4, the sectional view of Fig. 22 shows the extrusion head 1 with its individual parts, wherein the following parts can be seen in the material feed unit 2: the extrusion block 35, the offset unit receiving block 36, which in turn comprises the cooling body 48 and the cooling device 19, the offset actuator 30, one of the visible beveled side walls 42, the rear wall 43 with a recess for the inclination shaft 38 and the cooling medium interfaces 60. In addition, in this view, in contrastReferring to Fig. 4, it can be seen that at least one locking means 26 and a transmission gear 63 are also provided in the material feed unit 2. Drives for moving components of the excursion head 1 can, as known from the prior art, be chain drives, belt drives, swivel mechanisms consisting of cylinders with racks and gears, or other drives. The locking means 26 releasably locks the displacement unit 6, which is movable relative to the material feed unit 2. For this purpose, the at least one locking means 26 can determine positions of the displacement unit 6, whereby a precise position of the condenser units 7 can be achieved. In other words, this means that intermediate positions or end positions of the displacement unit 6 can be determined by the at least one locking means 26. This advantageously makes it possible to dispense with additional braking devices in or on the drive, in particular in or on the displacement actuator 30. In a preferredEmbodiment, the at least one locking means 26 can be operated mechanically and / or electromechanically and / or pneumatically and / or hydraulically and / or electromagnetically. In a preferred embodiment, as shown in Fig. 22, the at least one locking means 26 can be a spring-loaded pressure piece, preferably a spring-loaded ball pressure piece. The transmission gear 63 transmits a movement from the displacement actuator 30 to the drive gear 47 of the displacement unit 6. This means that the displacement unit 6 can be driven by the power transmission of the displacement actuator 30 via the transmission gear 63. It should be noted that the displacement unit 6 can also be driven by alternative power transmission means such as chain drives or belt drives or cable drives or coupling rods and / or alternative drive forms such as an electromechanical and / or pneumatic and / or hydraulic cylinder pivoting mechanism. The displacement unit 6 is, in addition tothe transmission gear 63 via the bearings 49, which can be designed as rolling bearings as shown here but not necessarily, with the material feed unit 2 and is thus rotatably mounted. The offset unit 6 comprises several components, of which the following can be seen as already in Fig. 4: the drive gear 47, the cooling block 50 including the cooling device 19, the casing 37, the condenser units 7. In contrast to Fig. 4, the following components can also be seen here: at least one stop 27, at least one centering means 62 and two further cooling medium interfaces 60. The stop 27 can, as shown here, be a bolt-shaped stop, wherein the stop can be fastened in or on the drive gear 47 and can be guided in a stop guide 70 in the material feed unit 2 running radially around the axis of rotation 69 of the offset unit 6. The stop guide 70 can be designed in such a way that the stop guide 70 does not have an inherentclosed guide, but has a component that blocks the stop 27 or two blocking ends. In this way, it can be provided that the offset unit 6 can only be moved to a certain extent relative to the material feed unit 2. Specifically, as an exemplary embodiment, it can be provided that the stop 27 can only be guided 120 ° within the stop guide 70 extending radially around the rotation axis 69 before the stop 27 and thus the offset unit 6 is blocked. This can be particularly advantageous if, as can be clearly seen in Fig. 2, six condenser units 7 are provided in the offset unit. In this case, for example, three condenser units 7 arranged one after the other can represent a first set 21 and the remaining three condenser units 7 arranged one after the other can represent a second set 22. The first set of condenser units 7 can be provided for a first extrusion material, whereinPreferably, each of the three condenser units 7 of the first set 21 is equipped with a different nozzle nominal diameter for different pressure accuracies. The same applies to the second set 22 for a second extrusion material 3. In order to avoid contamination with different extrusion materials 3 within the individual condenser units 7, the stop 27 within the stop guide 70 can be used to ensure that an inlet line 14 with a first extrusion material 3 exclusively supplies the first set 21 and a second inlet line 14 with a second extrusion material 3 exclusively supplies the second set 22. Of course, embodiments are not limited to two extrusion materials 3 and / or two sets 21, 22 and / or six condenser units 7, but can also have more or fewer extrusion materials 3 and / or sets 21, 22 and / or condenser units 7. In a preferred embodiment,The limitation of the angle of rotation of the offset unit 6 relative to the material feed unit 2 by the stop 27 can also serve as a protective function, in that the stop 27 prevents the cables 44 from being torn off, for example by over-rotating the offset unit 6 due to a possible electrical malfunction of the offset actuator 30 or by the extrusion head 1 hitting an object printed in the build space or the like. In a preferred embodiment, the stop 27 can be used to approach the end positions in an incremental position measuring system for referencing the offset unit 6. In a preferred embodiment, the stop 27 can be used in conjunction with the locking means 26 as a precise and, above all, cost-effective positioning means, particularly in the end positions. After the stop 27 abuts against the component or ends blocking the stop within the stop guide 70, theThe offset unit 6 can be aligned and locked relative to the material feed unit 2 by engaging the locking means 26, preferably a spring-loaded ball pressure piece, in provided locking recesses 54, preferably countersunk holes. The centering means 62 serves to center the drive wheel 47 relative to the rest of the offset unit 6. As shown here, the centering means 62 can be a dowel pin. In addition to a cooling medium interface 60 in the material feed unit 2, two further cooling medium interfaces 60 in the offset unit 6 can be seen in Fig. 22. One of the two visible cooling medium interfaces 60 in the material feed unit 2 can serve as a supply line and / or return line for a cooling medium in order to cool the material feed unit 2 with the aid of the cooling device 19 in the material feed unit 2, specifically in the heat sink 48. The two cooling medium interfaces 60 in the offset unit 6 can be used as inlet point and / orServe as an outlet point for a cooling medium in order to cool the offset unit 6 with the aid of the cooling device 19 in the offset unit 6, specifically in the cooling block 50. Preferably, the cooling medium interfaces 60 of the offset unit 6 can be designed as push-fit connections. In a preferred embodiment, all or individual coolant medium interfaces 60 can be provided on one or more inner walls of the offset unit 6, preferably in the inner cylindrical hollow volume of the cooling block 50. As shown in Fig. 22, the lines 44 run from above through the extrusion block 35, the offset unit receiving block 36 of the material feed unit 2 and further through the cooling block 50 of the offset unit 6, where the lines 44 split. In a preferred embodiment, the lines 44 can run substantially along the rotation axis 69. Some of the lines 44 represent cooling lines that contain a cooling medium and convey the cooling medium, preferably underPressure, to and / or discharge the cooling medium interfaces 60 of the offset unit 6. Some of the lines 44 represent cables that run through the cooling block 50 of the offset unit 6, passing through a cable duct 24 and leading to the individual condenser units 7. The lines 44, which lead as cables to the condenser units 7, can fulfill several functions. For example, as shown in Fig. 22, on the one hand, each condenser unit can be supplied with energy, preferably electrical energy, in order to provide the heating power necessary for softening and / or melting the at least one extrusion material. On the other hand, at least one measuring device 68, preferably one measuring device 68 per condenser unit 7, can be wired to some of the lines 44 in order to transmit measurement signals through the wiring. In a preferred embodiment, the at least one measuring device 68 can be a temperature sensor.which measures the temperature, preferably inside, of one of the existing condenser units 7. The number, position, and function of the measuring devices 68 can be freely selected. For example, a measured value can be measured at all points on the extrusion head 1 and / or several measuring devices 68 can be arranged on the same component, preferably on one of the existing condenser units 7. In addition to temperature sensors or instead of them, other measuring devices 68 can be provided, such as pressure sensors or position sensors. The number, position, and function of the at least one measuring device is therefore not limited to the embodiments shown. The cooling medium interfaces 60 in the material feed unit 2 and in the offset unit 6 serve, as explained in more detail above, to supply the extrusion head 1 with a cooling medium. It can be provided that, as shown in Fig. 22, the cooling devices 19 in the material feed unit 2 and in theOffset unit 6 are arranged as bores within the extrusion head 1. Through such bores, the cooling medium can be guided through the extrusion head 1 and cool it. In the case of the material feed unit 2, as shown here, a cooling device 19 can consist of several bores arranged at the level of the bearings 49 and thus cool both the material feed unit 2, in particular the heat sink 48 of the material feed unit 2, and the bearings 49. In this way, the at least one cooling device 19 in the material feed unit 2 can serve to cool the at least one offset unit and / or the at least one extrusion material 3 and / or the separating device 4 and / or the at least one blade element 5 and / or the at least one conveying device 16, 40 and / or the at least one extrusion actuator 31, 32 and / or the offset actuator 30 and / or the bearings 49 and / or the seals and / or the convection protection 25. In the caseAs shown here, a cooling device 19 can be provided in the offset unit 6, which consists of several bores and is arranged in the cooling block 50 of the offset unit 6. In this way, the at least one cooling device 19 in the offset unit 6 can serve to cool the bearings 49 and / or the at least one extrusion material 3 and / or indirectly via the drive wheel 47 to cool the separating device 4 and / or the at least one blade element 5. As shown in Fig. 22, all cooling devices 19 can be arranged below the drive wheel. This arrangement offers the advantage that heating of the at least one extrusion material 3 and / or the separating device 4 and / or the blade element 5 and / or the at least one conveying device 16, 40 and / or the at least one extrusion actuator 31, 32 and / or the displacement actuator 30 and / or softening of the at least one extrusion material 3, for example, by theCondenser units 7 rising heat or the rising heat of the heated construction space can be avoided. Preferably, it can be provided that the at least one cooling device 19 is arranged in the area after, preferably directly after, the severance point of the at least one extrusion material 3. It is also conceivable that the at least one cooling device 19 can be arranged at all possible locations inside and / or outside the extrusion head 1, as long as the at least one cooling device 19 is a component of the extrusion head 1 or is connected to the extrusion head 1. The illustrated embodiments are therefore not to be understood as limiting with regard to the number, position and / or the cooling medium used of the cooling devices 19 illustrated and described here. In a preferred embodiment, it can be provided that either one type of cooling medium such as water or more than one typeof cooling medium such as water and a cooling emulsion is used. Fig. 23 shows a side view of the extrusion head 1 with a second variant of a cooling device 19, shown as a sectional view. The extrusion head 1 in Fig. 23 is very similar to that in Fig. 22, whereby here a second embodiment of a cooling device 19 is provided in the offset unit 6. Unless otherwise stated in the following description of the figures and / or in Fig. 23, what has already been said about the extrusion head 1 in Fig. 22 also applies to the extrusion head 1 in Fig. 23. In a preferred embodiment, as shown in Fig. 23, the cooling medium interfaces 60 can be arranged partially or completely on the top side of the offset unit receiving block 36. The cooling device 19 can have bores in the cooling block 50, radially circumferential grooves on the circumference of a distributor 65 and axial bores within the distributor 65 and preferablyhave one or more push-fit connections for supplying or discharging the cooling medium. Bores within the distributor 65 can connect the cooling medium interfaces 60 of the distributor 65 with the radially circumferential grooves of the distributor 65. A fluid connection can also exist between the radially circumferential grooves and the bores in the cooling block 50. The distributor 65 can preferably consist of and / or comprise a substantially cylindrical component, as shown in Fig. 23, wherein a collar can preferably be provided at the upper end to be inserted within the offset unit receiving block 36 and held there. The distributor 65 can have a cable feedthrough 24 at the lower end, wherein this cable feedthrough can preferably be designed as a slip ring with at least one seal. In this way, electrical lines can be looped through the distributor 65 in order to supply the condenser units 7 with energy.to supply. As is generally known, cooling bores, i.e. bores of the existing cooling devices 19, are delimited to the outside by closure means 72. Such a closure means 72 can be clearly seen in Fig. 23 and can be used for all embodiments mentioned here if necessary. Preferably, the closure means 72 can be a sealing screw plug. In order to seal the fluid connections between the radial grooves of the distributor 65 and the bores in the cooling block 50, the fluid connections can be arranged by seals above, below and / or between the fluid connections. Fig. 24 shows a side view of the extrusion head 1 with a third variant of a cooling device 19, shown as a sectional view. The extrusion head 1 in Fig. 24 is very similar to that in Fig. 23, whereby here a third embodiment of a cooling device 19 is provided in the offset unit 6. If in the followingUnless otherwise stated in the description of the figures and / or in Fig. 24, what has already been said regarding the extrusion head 1 of Fig. 23 also applies to the extrusion head 1 of Fig. 24. In a preferred embodiment, as shown in Fig. 24, two coolant interfaces 60 can be provided, wherein the coolant interfaces 60 can be arranged on the upper side of the offset unit receiving block 36, wherein in Fig. 24 only one of the two coolant interfaces 60, which are preferably arranged symmetrically about the plane XZ of the extrusion head 1, is visible. These coolant interfaces 60 can supply the cooling device 19 in the offset unit receiving block 36 with coolant, wherein the cooling circuit can run both through the offset unit receiving block 36 of the material feed unit 2 and through the cooling block 50 of the offset unit 6. In order to achieve a self-contained cooling circuit including the material feed unit 2 and theTo realize the offset unit 6, bores in the offset unit receiving block 36, bores in the cooling block 50, and radially circumferential grooves in the cooling block 50 can be provided. The coolant flows from the first of the two coolant interfaces 60 through the bores in the offset unit receiving block 36, until the coolant is subsequently guided through corresponding bores into a radially circumferential groove in the body 50 of the offset unit 6. The further course of the cooling circuit can run through bores within the cooling block 50 and be guided via a second radially circumferential groove in the cooling block 50 back into the offset unit receiving block 36 to end in the second of the two coolant interfaces 60. In such a preferred embodiment, it can be provided that the two bearings 49 are arranged at a distance from one another, and the cooling device 19 is arranged at least partially between these two bearings 49. Preferred embodimentsof the extrusion head 1, as shown in Fig. 23 and / or Fig. 24, advantageously enable, in particular through the use of a cable feedthrough 24 designed as a slip ring and / or a distributor 65 and / or a cooling block 50 designed as a cooling rotary feedthrough 20, endless rotation of the offset unit 6 without causing failure of the lines 44 due, for example, to tearing off the lines 44. Fig. 25 shows a perspective view of the offset unit 6 from Fig. 1 without condenser units 7. As known from the previous Figs. 4 and 22 to 24, the offset unit 6 can have the drive wheel 47, the cooling block 50, the casing 37, a stop 27 and the six condenser units 7, wherein the condenser units 7 have been neglected in Fig. 25 for reasons of clarity. In this view, one of the closure means 72 for closing the holes of the cooling device 19 in the offset unit 6 can be clearly seen.The hexagonal shape of the cooling block 50, viewed from top to bottom, shows the cooling device 19 having six bores, preferably six blind holes, with at least six closure means 72. One of the two cooling medium interfaces 60, through which the cooling medium can be supplied or discharged, is also clearly visible. On the top side of the drive wheel 47, there are several recesses, including a stop recess 51 with a stop 27 located therein, as well as two of four recesses provided for a detachable connection, preferably a screw connection, between the drive wheel 47 and the cooling block 50. The stop recess 51, in conjunction with the stop 27, can perform a protective function. In the case of at least two extrusion materials 3, for example, a building material and a support material, at least two guide paths, as described in Fig. 4, and several, for example, six, condenser units 7,Where a first set 21 of the condenser units 7 contains an extrusion material 3 for constructing a product, specifically the construction material, and a second set 22 of the condenser units 7 contains a different extrusion material 3 for constructing a support structure for the product, specifically the support material, it may be expedient to provide a stop 27. This stop 27 can be inserted into the stop recess 51 and, in combination with the stop guide 70 (see Fig. 22), prevents over-rotation of the offset unit 6. In this way, it can be ensured that the first set 21 of the condenser units 7 can be supplied exclusively with the extrusion material 3 for constructing a product, specifically the construction material, and the second set 22 of the condenser units 7 can be supplied exclusively with the extrusion material 3 for constructing a support structure for the product, specifically the support material. Since one stop 27 can be inserted into the stop recess 51and the stop guide 70 preferably has two end positions, the circular offset movement of the offset unit 6 can be limited both during clockwise and counterclockwise rotation and thus secured against over-rotation. Fig. 26 shows a perspective view of the offset unit 6 from Fig. 1 with condenser units 7. In Fig. 26, the opposite half of the offset unit 6 of the section shown is visible compared to Fig. 25. The condenser units 7 are also shown, wherein the condenser units 7 are fastened to the casing 37 by fastening means. Washers 53 made of materials with low heat transfer coefficients, preferably made of stainless steel or ceramic, in particular zirconium oxide ceramic, can be provided between the condenser units 7 and the casing 37 in the fastening means. What has already been said regarding Fig. 25 applies accordingly to Fig. 26.Fig. 26 shows the locking recesses 54 located on the top side of the drive wheel 47 of the offset unit 6 and the at least one centering means 62. The locking recesses 54 can serve to ensure that the locking means 26 of the material feed unit 2 engages into one of the locking recesses 54, and thus the position of one of the existing condenser units 7 and its line, in particular its receiving device 18 and / or further line 17, can be precisely locked by the offset unit 6 in relation to the material feed unit 2. The locking recesses 54 can be designed, for example, as countersunk holes. The number, shapes, and positions of the stop recesses 52, the stop 27, the stop guide 70, and / or the locking recesses 54 and the locking means 26 are not limited to the illustrated embodiments. Fig. 27 shows a detailed view of a nozzle of aCondenser unit of an extrusion head based on detail II from Fig. 4. In a preferred embodiment, as shown in Fig. 27, the nozzle 77 arranged in and / or on the condenser units 7 can have a nozzle tip 78, the lower end of which comprises a nozzle channel 23, wherein the nozzle tip 78 is surrounded by a nozzle tip shield 59. The nozzle tip shield 59 can serve to mechanically protect the condenser units 7 and / or to contain the heat radiation emanating from the condenser units 7 towards the printed object. Furthermore, the nozzle 77 can have a nozzle tube 52, wherein the nozzle tube 52 contains the extrusion material 3, which the nozzle tube 52 receives from the feed line 17 and discharges through the nozzle channel 23. To heat the extrusion material 3 in the nozzle tube 52, a heating block 61, preferably a two-part heating block 61, is provided around the nozzle tube 52. Between the nozzle tip 78 and theA receiving element 64, preferably a dowel pin or a dowel screw, can be provided on or in the heating block 61. Furthermore, the nozzle tip 78 can have a radially offset groove 79, which is preferably formed perpendicular to the rotational axis of the nozzle tube 52 and tangential to the circumference of the nozzle tip. By means of the receiving element 64 and a nozzle groove 79 formed in the nozzle tip 78, the nozzle 77 can be detachably connected or connectable, preferably in a form-fitting manner, in and / or on the heating block 61 of one of the condenser units 7. In a preferred embodiment, it can be provided that the nozzle tube 52 and / or the nozzle tip 78 is connected or connectable in a materially bonded, positively connected and / or non-positively connected manner, in particular frictionally connected, to the heating block 61, preferably by a releasable clamping connection of the split halves of the heating blocks 61 by a screw connection. In a preferred embodiment, a combination of aThe aforementioned connection by means of a receiving element 64 with a nozzle groove 79 formed in a nozzle tip 78 and a force-fitting, in particular frictional, connection between the nozzle tube 52 and / or nozzle tip 78 and the heating block 61 can be provided. The embodiments of the attachment of the nozzles 77 in and / or on the condenser units 7 are not limited to the embodiments shown in Fig. 27 and described above. In a preferred embodiment, it can be provided that the nozzle channel 23 is inclined relative to a longitudinal extension direction 67. This can have the advantage that when tilting the offset unit 6 and / or the extrusion head 1, preferably with respect to the rotational axis 69 of the extrusion head 1, a contact-free printing of the at least one extrusion material 3 can be ensured, wherein during the travel movement of the extrusion head 1, the remaining condenser units 7 are displaced by the inclination of the offset unit 6and / or the extrusion head 1 do not run the risk of touching the already printed product and / or the previously printed layer. Preferably, the nozzle channel 23 can be inclined relative to a longitudinal direction 67 such that, after tilting the offset unit 6 and / or the extrusion head 1, the nozzle channel 23 of the condenser unit 7 used for extruding an extrusion material 3 is aligned perpendicular to the platform 86 in order to be able to deposit further webs from the previously produced webs of a layer in the same printing layer without restriction. In another preferred embodiment, it can be provided that the existing condenser units 7 can be inclined relative to one another with respect to the longitudinal direction 67. In addition, the imaginary axes of rotation of the nozzle tubes 52 can preferably be located at a common point on the axis of rotation 69 of the offset unit 6, preferably above the outlet of the nozzle channel 23.in particular at the level of the imaginary axis of rotation of the inclination shaft 38. Fig. 28 shows a front view of the extrusion head 1 from Fig. 1, installed in a mounting structure 66, shown with a partially sectioned front panel 75 of the mounting structure. In this illustration, it can be seen that the extrusion head 1 is surrounded by a mounting structure 66. The support bracket 28 of the extrusion head 1 supports the mounting structure 66, wherein the extrusion head 1 and the mounting structure 66 can be moved in at least one direction, preferably in several directions, preferably in two, particularly preferably in three directions, via the support bracket 28. In a further preferred embodiment, it can be provided that the mounting structure 66 supports the support bracket 28 of the extrusion head 1, wherein the extrusion head 1 can be moved in at least one direction, preferably in several directions, preferably in two, particularly preferably in three directions, via the mounting structure 66.is movable. The mounting structure 66 in Fig. 28 has a rear panel 73, two side panels 74 and a front panel 75. The mounting structure 66 can be fastened to the support console 28 via the rear panel 73. In this installed state, the extrusion head 1 is surrounded by the rear panel 73, the two side panels 74 and the front panel 75. In the lower right area of ​​the illustration in Fig. 28, the front panel 75 is shown cut off in the right area. In this way, the cooling block 50 of the offset unit 6 located behind it can be clearly seen. The offset unit receiving block 36 is arranged above the cooling block 50 of the offset unit 6. A convection protection 25 can be seen between the extrusion head 1, specifically the material feed unit 2, even more specifically the offset unit receiving block 36, and the mounting structure 66, specifically one of the two side panels 74. The convection protection 25 is connected to a convection protection connection device 39 onThe extrusion head 1 and the mounting structure 66 are attached. The convection protection allows the space inside and / or outside the mounting structure 66, or in relation to the extrusion head 1, to be divided into a construction space and a drive space. The construction space is the space through which the extrusion material 3 leaves the extrusion head through the nozzles 77 of the condenser units 7. The drive space is the space that is separated from the pressure space by the convection protection. The convection protection 25 can, as indicated in Fig. 28, connect the rear panel 73, the two side panels 74 and the front panel 75 of the mounting structure 66 to the extrusion head 1, wherein the convection protection can be arranged such that within the mounting structure 66 there is a space below the convection protection 25, in which the offset unit 6 can be arranged, and another space above the convection protection 25, in which the material feed unit 2 can be arranged.The separation of the space below the convection guard 25, in particular the installation space, and the other space above the convection guard 25, in particular the drive space, can serve to prevent the ambient air heated in the space below the convection guard 25 by a heater, preferably by a fan heater, from flowing upwards within the mounting structure 66 and thus heating the extrusion material 3 and / or the material feed unit 2, in particular the separating device 4 and / or the at least one blade element 5 and / or the at least one conveying device 16, 40 and / or the at least one extrusion actuator 31, 32 and / or the displacement actuator 30. The convection guard 25 can be flexibly deformable due to its shape and / or due to the material from which the convection guard 25 is at least partially made. In this way, it is possible to compensate for relative movements between the extrusion head 1 and the mounting structure 66 andsimultaneously to avoid an exchange of ambient air above and below the convection protection 25 and further, for example, to ensure the homogeneity of the heated build chamber air. This compensation of relative movements is particularly preferred when the extrusion head 1 is designed to be tiltable. The convection protection 25 can be designed as a bellows, as shown in Fig. 28. The convection protection 25 can be made of any material, preferably at least partially of silicate fabric and / or at least partially of aramid fabric, preferably of aluminized preox-para-aramid fabric, and / or at least partially of rubber, preferably of fluororubber (FKM) or silicone rubber (HTV), and / or be coated with any material, preferably partially with silicone and / or polytetrafluoroethylene. The extrusion head 1 shown in Fig. 28, installed in the mounting structure 66, together with the convection protection 25an arrangement. This arrangement consists in this embodiment of the following arrangement components: the extrusion head 1 and the convection protection 25 and the mounting structure 66, wherein a, in particular tight and thermal, shielding can be provided by the interconnected arrangement components, as shown in Fig. 28. In a preferred embodiment, as shown, it can be provided that the shielding is constructed by the mounting structure 66, the material feed unit 2, the offset unit 6 and the convection protection 25 between the mounting structure 66 and the extrusion head 1, in particular the material feed unit 2. In a particularly preferred embodiment, it can be provided that the shielding is at least partially formed by the offset unit receiving block 36 of the material feed unit 2 and by bearings 49 between the material feed unit 2 and the offset unit 6, in particular roller bearings and / or plain bearings with or without their ownSeals such as radial shaft seals, axial shaft seals, mechanical seals, grooved rings, O-rings or bearing foils, as well as by the cooling block 50 and / or by the casing 37 and / or by some of the existing seals, in particular O-rings, and / or cable glands 24, preferably cable glands and / or electrical rotary unions designed as a slip ring, of the offset unit 6. If the convection protection has a shaft seal 81, as shown in Figs. 29 to 32, one or more seals in the form of separate components can be replaced and / or the need for high-temperature-resistant components above the shielding can be avoided. By shielding the arrangement, the operating space in which the arrangement is located and used to manufacture a product can be divided into two areas, wherein, as shown here, the operating space is divided into an upper drive space and alower construction space is separated. An elevated temperature can prevail in the lower construction space due to the processing temperature of the extrusion material 3. The shield prevents and / or reduces heat exchange, in particular by convection of the ambient air, from the lower construction space to the upper drive space. In this way, the arrangement can shield the separating device 4 from the area below the shield, the construction space. As shown in Figs. 4, 22 to 24, the offset unit 6 is arranged within the offset unit receiving block 36, wherein the drive wheel 47 is provided in a recess, which is referred to below as the separation chamber, of the offset unit receiving block 36. This separation chamber of the offset unit receiving block 36 can be at least partially open at the top or, with the exception of the introduction line 14, closed or encapsulated. The separation point of the extrusion material 3 can be part of the separation chamber or as an additional separation chamberbe formed, whereby the area above the cutting point can be separated so that the convection of the waste heat from the drives from above can be prevented and / or reduced. Fig. 29 to 32 show various design variants of closures of a convection protection 25 based on detail III from Fig. 28. Fig. 29 shows detail view III from Fig. 28. It can be seen that the convection protection 25 is connected to the offset receiving block 36 by means of a convection protection connecting device 39, shown here as a screw connection. The upper end of the cooling block 50 of the offset unit 6 can be seen below the closure of the convection protection 25 fastened to the offset receiving block 36. In addition, the area of ​​the convection protection 25 that is connected to the offset receiving block 36 via the convection protection connecting device 39 is reinforced by a stiffener 80, in particular a stiffening ring.Fig. 30 shows another embodiment of the convection guard 25 from detailed view III of Fig. 28. In addition to what has already been said about Fig. 29, the convection guard 25 has an extended end. This extended end includes, on the one hand, a stiffener 80 that is longer and curved compared to Fig. 29 and, on the other hand, a shaft seal 81, shown here in the form of a labyrinth seal 82. The labyrinth seal 82 comprises two parts with corresponding contours, wherein one part of the labyrinth seal 82 is in contact with the cooling block 50 and the other part of the labyrinth seal 82 and the other part of the labyrinth seal 82 is a component of the base body of the convection guard 25. Fig. 31 shows another embodiment of the convection guard 25 from detailed view III of Fig. 28. In addition to what has already been said about Fig. 29, the convection guard 25 has an extended end. This extended degreeincludes, on the one hand, a stiffener 80 that is longer than in Fig. 29, and, on the other hand, a shaft seal 81, shown here in the form of a radial sealing lip 83. The radial sealing lip 83 is in contact with the cooling block 50 and is tensioned by a tension spring 85, in particular by a self-contained annular spring, which generates a radial tensile force. Fig. 32 shows another embodiment of the convection protection 25 from the detailed view III of Fig. 28. In addition to what has already been said regarding Fig. 29, the convection protection 25 has an extended end. This extended end includes, on the one hand, a stiffener 80 which is extended and bent compared to Fig. 29 and, on the other hand, a shaft seal 81, shown here in the form of an axial sealing lip 84. The axial sealing lip 84 is in contact with the heat sink 50. Fig. 33 to 35 show different positions of the tiltable extrusion head 1 from Fig. 1. In a preferredIn the exemplary embodiment, as shown in Figs. 33 to 35, as already described above, the extrusion head 1 can be attached to the support bracket 28 by means of the tilt shaft 38 in front of the rear panel 73, in other words, within the mounting structure 66. The tilt actuator 29 can subsequently tilt the extrusion head 1 via the tilt shaft 38 extending through the support bracket 28, which can preferably serve as a force transmission device. The plane in which the extrusion head 1 can be tilted can be the YZ plane, as shown in Figs. 33 to 35. In other words, the inclination shaft 38 represents a pivot shaft and / or a transmission shaft. Due to the inclinable extrusion head 1, the offset unit 6 with the condenser units 7 can be arranged such that only one nozzle 77 of a condenser unit 7 can be used for the contact-free printing of the at least one extrusion material 3. Due to the fact that theSince the nozzle in use is located furthest down in the Z direction, there is no risk of the remaining nozzles of the condenser units 7 touching the product and / or the last printed layer when moving the extrusion head 1 located in the mounting structure 66. This applies in particular under the assumption that in contact-free printing, a product is built up layer by layer in the Z direction and that to build up each individual layer, the extrusion head 1 located in the mounting structure 66 is moved in the XY plane. In the vertical starting position, in which the extrusion head 1 with all its condenser units 7 is aligned along the Z direction, as shown in Fig. 34, the extrusion head 1 can be tilted in two directions. Due to the extrusion head 1 being tiltable in two directions, it is possible to move the extrusion head 1 into two tilted positions. This can be particularly advantageous when severalCondenser units 7 are used, with some of the existing condenser units 7 constituting a first set 21 and the remaining part of the condenser units 7 constituting a second set 22. The first set 21 of the condenser units 7 can print a first extrusion material 3 with varying degrees of accuracy due to condenser units 7 of the first set 21 having different nominal diameters of the nozzle channels 23. The second set 22 of the condenser units 7, in contrast, can print a second extrusion material 3 with varying degrees of accuracy due to condenser units 7 of the second set 22 having different nominal diameters of the nozzle channels 23. Thus, it is possible, in a first inclination position of the extrusion head 1, illustrated in Fig. 35, to use the first set 21 for the structural construction of a product and, in this first inclination position, to switch between different condenser units 7 of the first set 21 having differentTo change nozzle nominal diameters. When changing materials, the extrusion head can be moved from the first tilt position to the second tilt position, shown in Fig. 33, so that the second set 22 can be used for the structural construction of a support structure, wherein in this second tilt position, it is possible to switch between different condenser units 7 of the second set 22 with different nozzle nominal diameters. To prevent an undesired condenser unit 7 from being used in one of the possible tilt positions of the extrusion head 1, a stop 27 can prevent over-rotation of the offset unit 6 and / or a locking means 26 can prevent loosening, whereby only a specific condenser unit 7 and / or a specific number of condenser units 7 and / or a specific set of condenser units 7 can be used. Fig. 36 shows a perspective view of the extrusion head 1 withthe mounting structure 66 from Fig. 35, implemented in a displacement system 71. When the mounting structure 66 is connected to the extrusion head 1, the mounting structure 66 together with the extrusion head 1 can be arranged within a displacement system 71. With the aid of displacement devices 76 of the displacement system 71, the mounting structure 66 together with the extrusion head 1 can be moved, wherein it is preferably provided that the mounting structure 66 together with the extrusion head 1 is movable in two, particularly preferably three directions. In a preferred embodiment, as shown in Fig. 36, a convection protection 25 can be provided between the mounting structure 66 and at least one displacement device 76 of the displacement system 71. The convection protection between the mounting structure 66 and at least one displacement device 76 of the displacement system 71 can consist of one or more parts, in particular one or more pleated roof covers. What has been said so far about the convection protection 25 in Fig. 28also applies analogously to the convection protection 25 in Fig. 36. In Fig. 36, in addition to the convection protection described in Fig. 28, an additional convection protection is provided, which is arranged between the travel system 71 and the mounting structure 66. Analogous to the shielding in Fig. 28, in the embodiment variant of Fig. 36, a shield is provided by this extended arrangement. The thus also extended shield separates the operating space over the entire span of the travel system in the XY plane, analogous to that explained above with regard to Fig. 28, into a drive space located above the shielding and a construction space located below the shielding. In this way, a thermal shielding of the construction space from the drive space can be achieved. Fig. 37 shows an arrangement of the extrusion head 1 within the mounting structure 66 and a first platform 86. In this illustration, the extrusion head 1 is in an inclined position within theMounting structure 66 and is arranged such that printing can be carried out via one of the nozzles 77 or one of the condenser units 7 onto the platform 86. In a preferred embodiment, it can be provided that the extrusion head 1 together with the mounting structure 66 and / or the platform 86 are height-adjustable or controllable. Fig. 38 shows an arrangement of the extrusion head 1 within the mounting structure 66 and a second platform 86. This embodiment differs from the embodiment of Figure 37 in that the platform 86 is designed as a rotary table. In a preferred embodiment, the platform 86 can be designed as a rotary table, the rotation axis of which is preferably aligned in the Z direction, in order to provide an additional, for example, fifth axis for 5-axis additive manufacturing in order to preferably produce complex geometries with undercuts layer by layer without the use of support structures, wherein theThe fourth axis can be realized by the tiltable extrusion head 1, more specifically by the tilt actuator 29. This can have the advantage that, due to the elimination of support structures, a different material with, for example, different material properties such as color, etc., can be used. This results in time and cost savings. If the extruder is the fourth axis of the five-axis system, this can lead to lower energy requirements. Fig. 39 shows an exploded view of the support bracket 28, the tilt actuator 29, the tilt shaft 38 or pivot shaft 93, and the travel system 71. In this illustration in Fig. 39, the tilt shaft 38 is a pivot shaft 93. The pivot shaft 93 is located in the installed state in a pivot shaft bearing seat 87 of the support bracket 28. The pivot shaft 93 is in contact with the support bracket 28 via a pivot shaft bearing 94 next to the pivot shaft collar 92. To determine theAt least one bearing cover 90 can be provided for the pivot shaft bearing 94. The grooved nut 88 can serve to axially secure the material feed unit 2 to the pivot shaft 93. The grub screw 89 can serve to secure the screw of the grooved nut 88. The pivot shaft 93 can be connected via the keyed connections 91, on the one hand, to the material feed unit 2 and, on the other hand, to the motor shaft of the tilt actuator 29. The extrusion head 1 can be axially secured as a whole unit, as shown in Fig. 3, by means of the pivot shaft 93, preferably designed with keyed connections 91 and a grooved nut 88. For maintenance purposes and / or repairs, the extrusion head 1 can be disassembled from the support bracket 28, preferably from the pivot shaft 93, in a short time, with little effort and cost-effectively from the arrangement shown in Figs. 33 to 36 by loosening the grooved nut 88. To completely remove the extrusion head 1 from the system, theThe convection protection device 25 can be removed by loosening the convection protection connection device 39. The support bracket 28 has the mounting structure connection devices 95 for connection to the mounting structure 66, the carriage connection devices 103 for connection to the carriage 104, and the tilt actuator connection devices 99 for connection to the tilt actuator 29. In addition, the arrangement in Fig. 39 has the following components in and / or on the support bracket 28: a wedge lock washer 96, a set screw 97, a lock nut 98, wherein the set screw 97 can serve as an adjustable stop for the pivot shaft 93, in particular for the pivot shaft collar 92, a threaded spindle 100, a spindle nut 101, wherein the spindle nut 101 can be a component of the support bracket 28, and a lubrication point 102. The support bracket 28 can, as already mentioned, be connected to the carriage 104 via the carriage connecting devices 103.The carriage 104 is part of the travel system 71, which additionally has the profile rail guide 105 along which the carriage 104 can be moved.

[0002] List of reference symbols: 1 Extrusion head 2 Material feed unit 3 Extrusion material 4 Separating device 5 Blade element 6 Offset unit 7 Condenser unit 8 Blade connecting device 9 Cutting surface underside 10 Cutting surface upper side 11 Cutting edge 12 First cutting surface section 13 Second cutting surface section 14 Introductory line 15 Blade element hollow volume 16 First conveying device 17 Continuation line 18 Holding device 19 Cooling device 20 Cooling rotary feedthrough 21 First set of condenser units 22 Second set of condenser units 23 Nozzle channels 24 Cable feedthrough 25 Convection protection 26 Locking means 27 Stop 28 Support console 29 Tilt actuator 30 Offset actuator 31 First extrusion actuator 32 Second extrusion actuator 33 First material receiving nozzle 34 Second Material receiving nozzle 35 Extrusion block 36 Offset unit receiving block 37 Sheath 38 Inclination shaft 39 Convection protection connecting device 40 SecondConveyor device 41 Feed wheel 42 Beveled side wall 43 Rear wall 44 Lines 45 First material feed hose 46 Second material feed hose 47 Drive wheel 48 Material feed unit heat sink 49 Bearing 50 Offset unit cooling block 51 Stop recess 52 Nozzle tube 53 Washer 54 Locking recess 55 Blade element bottom 56 Blade element top 57 Projection 58 Guide recess 59 Nozzle tip shield 60 Coolant interface 61 Heater block 62 Centering means 63 Transmission wheel 64 Receptacle 65 Distributor 66 Mounting structure 67 Longitudinal direction 68 Measuring device 69 Rotation axis 70 Stop guide 71 Traversing system 72 Locking means 73 Rear cover 74 Side cover 75 Front cover 76 Traversing device 77 Nozzle 78 Nozzle tip 79 Nozzle groove 80 Reinforcement 81 Shaft seal 82 Labyrinth seal 83 Radial sealing lip 84 Axial sealing lip 85 Tension spring 86 Platform 87 Swivel shaft bearing seat 88 Grooved nut 89 Grub screw 90 Bearing cover 91Keyed connection 92 Pivot shaft collar 93 Pivot shaft 94 Pivot shaft bearing 95 Mounting structure connection device 96 Wedge lock washer 97 Set screw 98 Lock nut 99 Tilt actuator connection device 100 Threaded spindle 101 Spindle nut 102 Lubrication point 103 Carriage connection device 104 Carriage 105 Profile rail guide

Claims

Patent claims 1. Extrusion head (1) for additive manufacturing, preferably based on the fused filament fabrication method, of a product comprising ^ at least one material feed unit (2) for feeding at least one extrusion material (3), preferably in filament form, ^ a separating device (4) with at least one blade element (5), ^ at least one offset unit (6) with at least two liquefier units (7), wherein the at least one extrusion material (3) can be introduced into a first liquefier unit and by an almost gap-free passage of the at least one offset unit (6) past the separating device (4) o the extrusion material (3) can be brought to the at least one blade element (5) and severed at a severing point and o the upper end of the extrusion material (3) severed by the separating device can be introduced into a second liquefier unit, characterized inthat the at least one blade element (5) is attachable or attachable to or in the at least one material feed unit (2) or is a component of the material feed unit (2).

2. Extrusion head (1) according to claim 1, characterized in that the at least one blade element (5) is round and / or square.

3. Extrusion head (1) according to claim 1 or 2, characterized in that the at least one blade element (5), as a flat plate or as a block or as a flat ring or as a sleeve.

4. Extrusion head (1) according to one of claims 1 to 3, characterized in that the at least one blade element (5) is connected to the at least one material feed unit (2) by a blade connecting device (8), preferably wherein the blade connecting device (8) is detachable without causing damage.Extrusion head (1) according to one of claims 1 to 4, characterized in that the at least one blade element (5) has at least one rectilinear and / or curved cutting edge (11) with a cutting surface underside (9) and a cutting surface upper side (10), wherein, when the at least one blade element (5) is fastened to or in the material feed unit (2), the underside of the at least one blade element (5) and the cutting surface underside (9) face the offset unit (6), and the upper side of the at least one blade element (5) and the cutting surface upper side (10) face away from the offset unit (6).

6. Extrusion head (1) according to claim 5, characterized in that the cutting surface underside (9) and the cutting surface upper side (10) are arranged inclined to one another, preferably enclosing an angle of up to 55°, in particular a very acute angle of 20 to 30°. 7.Extrusion head (1) according to claim 5 or 6, characterized in that the cutting surface underside (9) and / or the cutting surface upper side (10) has at least two cutting surface sections (12, 13), wherein the first cutting surface section (12) adjoins the cutting edge (11). and the second cutting surface section (13) does not adjoin the cutting edge (11).

8. Extrusion head (1) according to one of claims 1 to 7, characterized in that the material feed unit (2) has at least one inlet line (14) for the at least one extrusion material (3), wherein, when the at least one blade element (5) is fastened to or in the material feed unit (2), the at least one inlet line (14) extends within the material feed unit (2) up to a region in front of, in particular up to, the at least one blade element (5).

9. Extrusion head (1) according to claim 8, characterized in that, when the at least one blade element (5) is fastened to or in the material feed unit (2), the inlet line (14) ends in a region between the blade element underside (55) and the blade element top side (56). 10.Extrusion head (1) according to one of claims 8 or 9, characterized in that the introduction line (14) has at least one guide recess (58) which reaches as far as the separating device (4) and through which the extrusion material (3) is at least partially exposed.

11. Extrusion head (1) according to one of claims 8 to 10, preferably according to claim 0, characterized in that the introduction line (14) has at least one projection (57), wherein, when the at least one blade element (5) is fastened to or in the material feed unit (2), the at least one projection (57) projects into a region between the blade element underside (55) and the blade element upper side (56), wherein preferably two. Projections (57) are provided, and when the at least one blade element (5) is attached to or in the material feed unit (2), the two projections (57) form a guide recess (58), in particular a groove, preferably a transverse groove, in a region between the blade element underside (55) and the blade element upper side (56).

12. Extrusion head (1) according to one of claims 8 to 11, characterized in that the introduction line (14) is present as a separate component within the material feed unit (2) or is a component of the material feed unit (2). 13.Extrusion head (1) according to one of claims 1 to 12, characterized in that at least one conveying device (16, 40) of the material feed unit (2) is provided for feeding the at least one extrusion material (3), wherein the at least one conveying device (16, 40) is designed to additionally return the preferably severed at least one extrusion material (3) at least partially within the material feed unit (2).

14. Extrusion head (1) according to one of claims 1 to 13, characterized in that the at least one offset unit (6) has at least one receiving device (18), preferably at least two receiving devices (18), particularly preferably one receiving device (18) for each liquefier unit (7).

15. Method and / or use for producing a product with an extrusion head (1) according to one of claims 1 to.

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