Extrusion head and method for manufacturing elongated hollow bodies by means of the extrusion head

Abstract

The invention relates to an extrusion head having a mandrel which is supported flow- through by extrusion material in a housing in an extrusion direction, and wherein a mouthpiece section of the end side of the mandrel is arranged in an opening of a mouthpiece arranged downstream of the mandrel in the extrusion direction in order to form a circumferential gap between the mouthpiece section and the mouthpiece which changes in its geometry. Here, the mandrel is pivotably supported in the housing of the extrusion head about at least one axis transverse to the extrusion direction. Furthermore, the invention relates to a method for manufacturing an elongate hollow body as an extrudate by means of an extrusion head, wherein in the context of the method a deviation of the actual shape of the extrudate from a nominal shape is determined and the gap of the extrusion head is readjusted by means of a pivoting and / or longitudinal movement of the mandrel in order to compensate for the deviation.

Description

Technical Field

[0001] This invention relates to an extrusion head having a mandrel that is flowably supported in a housing by extruded material along the extrusion direction. A nozzle section at the end of the mandrel is arranged in an opening of a nozzle downstream of the mandrel along the extrusion direction, forming an circumferential gap between the nozzle section and the nozzle, the gap varying in its geometry. Furthermore, this invention relates to a method for producing elongated hollow bodies as extruded parts by extruding material using the extrusion head. Background Technology

[0002] The production of elongated hollow bodies, such as tubes or hoses, from extruded materials, such as plastics, is typically carried out by extrusion using extruders, where the extruder head or die head has an annular gap.

[0003] Here, the geometry of the annular gap naturally defines the geometric design of the hollow body, especially the basic cross-sectional shape and wall thickness of the hollow body.

[0004] The annular gap is constructed here primarily through a mandrel that can be supported within the extrusion head by the flow of the extruded material, wherein the free end of the mandrel is embedded in the opening of the nozzle. Here, if the mandrel and nozzle are fixed, for example, relative to the support and thus fixed in a manner that their relative positions remain unchanged, then only the unchanging geometry of the annular gap, determined by the shaping of the openings of the mandrel and nozzle, exists.

[0005] This unchanging annular gap is considered unfavorable for various reasons, thus it is generally desirable to construct the annular gap in a way that allows for active influence on its geometry. Two fundamental objectives can be proposed as reasons for designing the geometry of the annular gap in an influenceable manner.

[0006] Here, the primary objective of influencing the geometry of the annular gap can be to proactively alter the geometry of the hollow body itself along its length, particularly in its cross-sectional shape and / or its wall thickness, according to the requirements imposed on the hollow body. Therefore, in addition to extrusion, the extrusion process can also be used as a production step to cause nominal changes in the geometry of the hollow body.

[0007] Regarding the aforementioned objective, DE 2 139 108 A describes, for example, an extrusion head for manufacturing tubular semi-finished products from thermoplastic plastics. An insert, itself having a mandrel, is arranged within the extrusion head. The mandrel is arranged to be axially movable along the extrusion direction, and during axial movement, it interacts with the inner surface of the stepped conical nozzle, in the case of forming an annular gap nozzle, such that the wall thickness of the semi-finished product can vary along its axial direction. This provides the advantage of further processing semi-finished products with axially varying wall thicknesses into, for example, plastic bottles, where, due to forming in the blow molding process, the neck of the plastic bottle, in particular, has at least approximately the same wall thickness as the body.

[0008] This axial wall thickness control can also be used to manufacture hollow bodies with different wall thicknesses but the same wall thickness along the length of the hollow body, using the same extrusion head.

[0009] In a comparable context, DE 102 37 051 A1 discloses an extrusion head for manufacturing tubes with particularly thin walls that undergo multiple bends, the extrusion head also having a mandrel that is axially movable along the extrusion direction. Axial wall thickness control is achieved by constructing an annular gap between the mandrel and a nozzle body that interacts with the mandrel, and by the axial movement of the mandrel. Furthermore, the nozzle body is configured to be movable in a plane perpendicular to the extrusion direction via two adjusting frames movable by adjusting devices, so that the mandrel can be eccentrically positioned in the annular gap, and correspondingly, radial wall thickness control is achieved in addition to axial wall thickness control. Thus, the wall thickness in the bend region can be axially and radially matched almost optimally to a preset curvature.

[0010] On the other hand, unlike the first objective, a second objective affecting the geometry of the annular gap could be to avoid actual changes in the geometry of the hollow body during extrusion, and thereby achieve the most uniform design of the hollow body along its length, particularly in its cross-sectional shape and / or its wall thickness. With the geometry of the annular gap remaining constant, such undesirable actual changes can be caused, for example, by inaccuracies in the adjustment of the mandrel relative to the nozzle opening, by positional shifts between them due to forces acting on the mandrel and / or nozzle during extrusion, and by temporary and / or locally different properties of the extruded material.

[0011] Regarding the second objective, DE 2 023 008 A also discloses an extrusion head in which, in a first embodiment, a nozzle sleeve forming an annular gap with a mandrel has two sections separated from each other by a contraction. The upper section is here firmly pressed together, and the contraction essentially forms a solid hinge. The lower section is configured to be pivotally rotated to a certain extent around this solid hinge in a plane perpendicular to the extrusion direction by an adjusting device, thereby allowing radial adjustment of the annular gap in the region of the nozzle opening. This adjustment is used here to readjust the geometry of the annular gap in case of deviations from the desired geometry of the annular gap occur.

[0012] DE 10 2008 061 286 A1 also discloses an extruder with a right-angle extrusion head and a method for manufacturing a hollow, tubular body. Here, an extruder nozzle mounted on a pivotable bushing and a nozzle assembly arranged on the extruder housing form an adjustable annular gap. To adjust the annular gap, the bushing is configured to pivot about two pivot axes via two hydraulic cylinders.

[0013] A tool head for a hollow profile extruder is also known from DE 10 2018 204 729 A1. This tool head has a tool mandrel that forms an annular channel with a tool ring. Here, the tool mandrel is supported by a mandrel bearing carrier, which is tiltably supported in two degrees of freedom by a tilting hinge. Therefore, the wall thickness of the extruded hose can be made uniform in the circumferential direction. Furthermore, the wall thickness of the hose to be extruded can be preset by the preset axial position of the tool ring relative to the tool mandrel.

[0014] EP 0 250 828 A2 also describes an extruder having an extrusion head for covering cables. Here, the central mandrel of the extrusion head is pivotally and fixably supported in the extrusion head by a hinge having a spherical crown surface.

[0015] DE 19 08 933 A also describes an extruder having a mandrel that forms an annular gap with a nozzle sleeve. The mandrel is pivotally supported in the nozzle sleeve about the longitudinal axis of the adjusting lever by means of an adjusting lever and a spherical support head, thereby enabling cross-sectional variation of the annular gap in the pivoting direction.

[0016] Based on existing technology, it is possible to propose technical solutions for adjusting the annular gap in both the axial and radial directions, independent of these target settings. However, the described solutions have the drawback that they are individualized solutions and therefore cannot be retrofitted onto already widely available extruders. It is generally desirable, however, that existing extruders also possess the capability for annular gap adjustment and, consequently, wall thickness control, in order to improve the dimensional accuracy of the produced hollow bodies. Summary of the Invention

[0017] Against this background, the technical problem to be solved by the present invention is to provide an extrusion head suitable for retrofitting existing extruders using gap adjustment. Furthermore, a method should be provided by which the dimensional accuracy of manufactured hollow bodies can be improved by means of the extrusion head.

[0018] According to the invention, an extrusion head (or extruder head) is provided, wherein the extrusion head has a particularly torpedo-shaped mandrel arranged within a housing of the extrusion head. The mandrel is here supported by the extruded material flowing around it along at least one extrusion direction of the extrusion head. Furthermore, the mandrel has a nozzle section on its end side, which is freely arranged in an opening of a nozzle downstream of the mandrel along the extrusion direction of the extrusion head. Here, the nozzle section of the mandrel and the nozzle form a surrounding gap that is variable or adjustable in its geometry. According to the invention, the adjustability of the gap is achieved such that the mandrel is pivotally supported within the housing of the extrusion head about at least one axis, particularly perpendicular to, orthogonal to, or also transverse to the extrusion direction. It is conceivable that the mandrel is supported on one side or through a portion of the housing. However, it is preferable that the mandrel is pivotally supported within the housing about the axis on both sides, i.e., through two portions. It should also be noted that the extrusion direction extends along or coincides with the longitudinal axis of the extrusion head.

[0019] A pivotable or pivotally movable support, with a mandrel rotating about an axis transverse to the extrusion direction, allows for free adjustment of the gap or wall thickness within the extrusion head. Therefore, the geometry of the circumferential gap between the nozzle section and the opening can also be changed transversely to the extrusion direction. In a direct relationship, this gap or wall thickness adjustment within the extrusion head enables adjustment of the wall thickness and, consequently, the basic cross-sectional shape in the transverse axial direction of the hollow body being extruded by the extrusion head. This is particularly true in the peripheral direction of the cross-section.

[0020] Here, adjustments can be made by adjusting the geometry of the slender hollow body according to the requirements for the hollow body. However, it is preferable to make adjustments by ensuring a substantially uniform wall thickness and, consequently, a uniform cross-sectional shape along the length of the extruded hollow body.

[0021] In a preferred embodiment, the mandrel's nozzle and the opening of the nozzle section embedded in the opening have a circular cross-section. Here, the radius of the nozzle section is always smaller than the radius of the nozzle opening, so that the circumferential gap between the nozzle section and the opening is constructed as an annular gap. Under this relationship, it is conceivable that the mandrel's nozzle section has a constant radius and thus a cylindrical shape along its longitudinal extension along the mandrel's longitudinal axis.

[0022] Starting with the nozzle section and the circular cross-section of the opening described in the previous paragraph, the geometry of the annular gap changes in the radial direction, accompanied by adjustments to the geometry along the longitudinal axis of the slender hollow body. This also establishes radial annular gap adjustments and radial wall thickness adjustments along the axial direction within the extrusion head.

[0023] Here, the slender hollow body itself can be constructed, in particular, as a hose or tube. Depending on the extruded material used, especially plastic, there can be higher or lower elasticity.

[0024] In an advantageous manner, the extrusion head according to the invention is beneficial for retrofitting already widely available extruders by centralizing the components required for adjusting the gap within the extrusion head itself, which to some extent improves the durability of the extruder.

[0025] Furthermore, in a particularly advantageous extension of the invention, the mandrel is additionally supported longitudinally in the axial direction or along the axial direction and therefore transverse to the extrusion direction. This provides an additional degree of freedom of movement for the mandrel, perpendicular to the degree of freedom achieved by pivoting about the same axis. An additional degree of freedom for changing the geometry of the surrounding gap is provided to the same extent, wherein, by superimposing the pivoting movement about the axis and the longitudinal movement along the axis, changes in the geometry of the gap or annular gap, and adjustments to the geometry of the extruded hollow body, can be achieved in the transverse plane, in the nozzle section, and in the case of a circular cross-section with the opening in the radial plane. This provides a significantly greater possibility of compensation for deviations from the nominal shape that occur in the hollow body during extrusion. Furthermore, the support of the mandrel can be advantageously designed by a single bearing element, through which both degrees of freedom of movement of the mandrel are simultaneously provided.

[0026] Therefore, in a beneficial embodiment of the invention, it should be specified that the mandrel is arranged, particularly in the housing, centrally and / or along its longitudinal axis in the extrusion direction on an elongated retainer embodying the axis. Specifically, the elongated retainer should here be implemented as a tab-type mandrel retainer, wherein the portion of the retainer directly adjacent to the mandrel is constructed as a thin-walled tab. Here, the tab is arranged on the mandrel such that the thin sides of the tab, i.e., the two opposing sides of the tab with the smallest dimensions, are oriented in the extrusion direction, especially in the non-pivoting position of the mandrel, thereby minimizing the flow resistance of the tab as the extruded material flows around the mandrel. In a design variant, the retainer can only be implemented as a single piece and therefore connected to the mandrel only on one side, and supported on one side or at a location in the housing. However, this can lead to excessive movement of the mandrel due to the forces acting on it by the extruded material during extrusion, and may result in collisions between the nozzle section and the nozzle. To avoid this, the retainer is preferably implemented in two pieces, wherein the retainer is connected to the spindle on both sides of the spindle along the axis, and is therefore also supported on both sides or at two locations on the housing.

[0027] Furthermore, the design of the present invention is considered advantageous if the extrusion head has at least one bearing element arranged in a bearing receptacle formed in the housing, wherein the retainer is rotatably or rotatably and longitudinally supported in the bearing element by a support section formed on the retainer. Therefore, the force acting on the mandrel by the extruded material during extrusion can be transmitted more effectively, especially in the absence of force injection, to the housing fixed relative to the support, while movement about and along the axis advantageously has no effect or only a very small effect. Even if it is possible that only the bearing receptacle, bearing element, and support section are provided to support the mandrel, and thus a support is provided on one side of the mandrel, then for optimal distribution of the force acting during extrusion, the supports on both sides of the mandrel are preferably designed with two bearing receptacles, two bearing elements, and two support sections. Advantageously, the receptacle and support section in the bearing element are generally implemented as cylindrical as possible. In particular, the bearing element can be constructed as a sliding bearing, for example, as a sleeve. It is possible that such sleeves are constructed in multiple pieces, and in the multi-piece embodiment, a two-piece construction is preferred. The sleeve is preferably made of bronze, especially aluminum bronze. To avoid or at least minimize the tendency to react with the extruded material, it is conceivable that the sleeve has a protective coating on the surface located inside the housing. For example, the surface could be chrome-plated for this purpose.

[0028] The practical design of this invention also specifies the implementation of a frictional (or sliding) seal between the bearing element and the support section of the retainer. This arrangement of the frictional seal, particularly made of rubber, between the support section and the bearing element provides a proven and inexpensive solution for sealing the extrusion head to prevent leakage of extruded material. Advantageously, a wide selection of standard geometries is available.

[0029] In the aforementioned relationship, it should be further envisioned that the bearing element is a sleeve (or bushing), and particularly away from the sleeve flange and / or away from the bearing housing in the sleeve's mounting position, a sealing lip is formed on the end side of the sleeve. The sealing lip should be constructed as a single piece with the sleeve and is therefore formed by the sleeve, wherein the sealing lip preferably tapers, for example, towards the direction of the mandrel. Due to the pressure exerted on the sleeve by the extrusion material during the extrusion process and the force thereby acting on the sealing lip in the direction of the retainer, the sealing effect between the sleeve and the retainer, especially the support section, is improved, thereby minimizing or even preventing the escape of the extrusion material from the housing of the extrusion head.

[0030] In an extension of the aforementioned embodiments of the invention, a method to prevent the extruded material from escaping can be employed in such a way that the fit established between the bearing element and the support section of the retainer has a clearance width that allows for limited leakage of the extruded material. Furthermore, the fit can be specified to have a defined clearance width that is compatible with the limited leakage. On the one hand, this allows for continuous escape of the extruded material from the housing of the extrusion head and the resulting lubrication of the bearing element, particularly the sleeve. On the other hand, it is possible for the extruded material to seep into the gap between the bearing element and the retainer, particularly the support section of the retainer, solidify, and thereby seal the extrusion head, preventing further escape of the extruded material through the solidified material. The leakage here should generally be less than 0.1% of the flow rate of the extruded material through the extrusion head.

[0031] In an unconventional manner, the extrusion head according to the invention is constructed such that the bearing element is a sleeve, wherein at least a portion of the sleeve is composed of an elastomer. Therefore, the sleeve can be constructed as a single piece and thus entirely of elastomer. Furthermore, it is possible for the sleeve to be constructed in multiple pieces, as explained above, and preferably in a two-piece configuration, wherein, in a manner meaningful for design, the radially inner portion of the sleeve is composed of an elastomer. This is necessary to ensure a seal. In a structurally advantageous embodiment, the elastomer selected for the sleeve or a portion thereof is chosen such that a seal can be achieved to prevent the extruded material from escaping from the housing of the extrusion head, without limiting its function as a bearing element (particularly a sliding bearing).

[0032] In a particularly opposite design to the above-described configuration of the present invention, only the elastomeric portion of the sleeve is fixedly connected to the support section and the other, non-elastomeric portions of the sleeve. The elastomeric portion of the sleeve, by its own deformation, impedes the sliding rotational and / or longitudinal movement of the retainer relative to the elastomeric portion of the sleeve. The fixed connection between the support section and the elastomeric portions of the sleeve, such as the elastomeric ring, should preferably be a material-fit connection. However, force-fit and / or form-fit connections may also exist. The retainer, and its bearing element, therefore cannot freely slide relative to the elastomeric portion of the sleeve in rotational and / or longitudinal movement. Instead, in the rotational and / or longitudinal movement of the retainer, and thus in the pivoting and / or longitudinal movement of the mandrel about an axis transverse to the extrusion direction, a preferred elastic deformation of the elastomeric portion of the sleeve is formed. Therefore, the expected stroke can be provided, while simultaneously ensuring optimal sealing of the extrusion head to a certain extent to prevent extruded material from escaping.

[0033] In embodiments of the invention, it should also be specified in a similar manner that a seal is provided between the bearing element and the support section of the retainer, which is connected and thus fixedly connected in a material-fitting or force- and / or form-fitting manner with respect to the bearing element and the support section, and which, by its own deformation, impedes the sliding rotational and / or longitudinal movement of the retainer relative to the seal. Therefore, in this embodiment, correspondingly, free sliding rotational and / or longitudinal movement between the retainer (here, the support section of the retainer) and the seal is also not possible. The rotational and / or longitudinal movement of the retainer and, consequently, the pivoting and / or longitudinal movement of the mandrel, can only be achieved based on the elastic or reversible plastic deformation of the seal. In this case, the desired stroke can also be advantageously provided, and at the same time, optimal sealing of the extrusion head can be ensured to a certain extent to prevent extruded material from escaping.

[0034] If the nozzle is arranged axially movable within the housing along the extrusion direction, then the extended version of the invention proves advantageous, particularly in combination with the previously shown adjustment of the surrounding gap. For this purpose, it can be noted firstly that, generally speaking, but especially in view of the described axially movable arrangement of the nozzle within the housing of the extrusion head, it is advantageous that the nozzle segment, unlike the aforementioned cylindrical design and thus the constant radius of the nozzle segment, has a variable radius at least in a portion of its longitudinal extension. Conversely, the opening may also have a variable radius at least in a portion of the nozzle's extension along the extrusion direction. As an example, it can be assumed that in such a design, the nozzle segment and / or the opening is tapered along the extrusion direction. Correspondingly, in a design of at least one of the components with interacting nozzle segments and openings having variable radii, axial movement of the nozzle along the longitudinal axis of the extrusion head and thus along or opposite to the extrusion direction results in a change in the geometry of the annular gap, which leads to an adjustment of the wall thickness of the extruded hollow body in its longitudinal axial direction without altering the basic cross-sectional shape. The wall thickness thus increases or decreases across the entire cross-section of the hollow body. This corresponds to axial clearance adjustment or annular clearance adjustment, as well as wall thickness adjustment.

[0035] Furthermore, one design aspect of the invention is defined as follows: the retainer extends through the housing to the outside of the housing at least on one side, wherein each arm is connected to the retainer at each end side. One or more arms here represent a device that drives the movement of the arm at the end opposite to the retainer. This particularly reduces the adjustment path, thereby achieving higher resolution of the pivoting movement of the spindle and thus enabling gap adjustment. This is also associated with the possibility of finer compensation for deviations from the nominal shape of the hollow body. Furthermore, the device for initiating this adjustment movement, such as an adjustment actuator, can be arranged in an advantageous position within the structural space. When the arm is implemented at each end of the retainer, it is further possible that the ends of the arms opposite to the retainer are interconnected, for example, by means of a linkage. This advantageously results in a method of adjusting the movement by loading both arms with only one device.

[0036] If, in particular, adjustment of the geometry of the variable surrounding gap is required, it proves advantageous that, in embodiments of the invention, the mandrel is connected, in particular, to at least one adjusting actuator via a retainer, and thus the mandrel can be pivoted and / or moved longitudinally by the adjusting actuator. Preferably, at least one adjusting actuator is provided for both pivoting and longitudinal movement. It is highly advantageous to use an electrically adjustable actuator, via an adjusting circuit, to compensate for deviations of the compressed hollow body from its nominal shape, particularly in real time, by initializing the pivoting and / or longitudinal movement of the mandrel.

[0037] Against this background, the present invention also provides a method for producing elongated hollow bodies as extruded parts by extruding extruded material using the aforementioned extrusion head. Within the scope of the method according to the invention, the actual shape of the extruded part, particularly the cross-sectional shape and / or wall thickness, and its deviation from the nominal shape of the extruded part are continuously determined during extrusion. Furthermore, the clearance of the extrusion head around the extrusion head is readjusted in real time via at least one adjusting drive, through the pivoting and / or longitudinal movement of the mandrel, to compensate for the deviation. Thus, extruded hollow bodies with high dimensional accuracy can be produced, correspondingly having no deviation from their nominal shape, or only a small deviation. For implementation of the method, it may be considered advantageous that the extrusion head, for example, has at least one measuring sensor by which the actual shape of the extruded part and / or the extruded hollow body can be determined. Such measuring sensors may, for example, be based on optical measurement methods and / or image processing. X-ray-based measurement principles are also conceivable. In addition, further measuring sensors can be arranged to determine the current pivoting and / or longitudinal movement around or along an axis transverse to the extrusion direction. Furthermore, the determination of the viscosity of the extruded material can also be included in the adjustment. Attached Figure Description

[0038] This invention allows for different implementations. To further illustrate its basic principles, one implementation is shown in the accompanying drawings and is described below. Wherein:

[0039] Figure 1 A cross-sectional view of the extrusion head is shown. Detailed Implementation

[0040] exist Figure 1 The extrusion head 1 shown here has a torpedo-shaped mandrel 2, wherein the mandrel 2 is supported in the housing 3 of the extrusion head 1 by the extrusion material flowing around it along the extrusion direction L.

[0041] The extrusion direction L is determined here by the longitudinal axis of the extrusion head 1, or the extrusion direction coincides with the longitudinal axis, wherein the extruded material enters through the inlet opening 17 of the housing 3 implemented upstream of the mandrel 2, and the elongated hollow body, as the extruder 16, exits from the outlet opening 18 of the housing 3 implemented downstream of the nozzle 6. The longitudinal axis of the mandrel 2 is also oriented along the extrusion direction L, and further coincides with the longitudinal axis of the extrusion head 1.

[0042] The aforementioned torpedo-shaped shape of the mandrel 2 is produced as follows: the mandrel has a cylindrical section and conical sections adjacent to each other on both sides of the cylindrical section along the longitudinal axis of the mandrel 2. Furthermore, the nozzle section 4 of the mandrel 2 is connected to the conical section facing the nozzle.

[0043] The nozzle section 4 on the end side of the mandrel 2 is arranged in the opening 5 of the nozzle 6 arranged downstream of the mandrel 2 along the extrusion direction L, thereby forming an encircling gap 7 between the nozzle section 4 and the nozzle 6, which is modified in its geometry and constructed as an annular gap in this extended scheme.

[0044] The annular gap 7 can be changed in such a way that the spindle 2 can pivot about an axis Q transverse to the extrusion direction L, and is supported longitudinally in the housing 3 along the axis Q. Based on this support, the geometry of the annular gap 7 can be changed transversely, and in particular radially, relative to the extrusion direction L in two degrees of freedom. Thus, an annular gap adjustment is established in the extrusion head 1, and radial wall thickness adjustment of the extruded hollow part 16 can be achieved.

[0045] Under this relationship, the nozzle 6 is axially movable within the housing 3 of the extrusion head 1 along the extrusion direction L. Thus, in this extended configuration, in addition to the previously mentioned radial annular gap adjustment or radial wall thickness adjustment, axial annular gap adjustment or axial wall thickness adjustment is also achieved. Here, the corresponding stroke of the nozzle section 4 in the opening 5 due to the pivoting and / or longitudinal movement of the spindle 2 about and / or along the axis Q should be within a range of less than 0.5 mm, preferably less than 0.05 mm.

[0046] By means of wall thickness adjustment, on the one hand, the geometry of the hollow body produced by the extruder 16 can be adjusted along its longitudinal axis. However, radial wall thickness adjustment is preferred in order to substantially avoid deviations of the extruder 16 from its nominal shape. To this end, during the extrusion of the extruder 16, deviations of the actual shape of the extruder 16, particularly its cross-sectional shape and / or wall thickness, from the nominal shape of the extruder are determined, and the annular gap 7 of the extrusion head 1 is readjusted by the pivoting and / or longitudinal movement of the mandrel 2 to compensate for the deviations.

[0047] exist Figure 1In the extended embodiment, the axis Q is continuously represented by an elongated retainer 8 implemented as a splice mandrel retainer, and the mandrel 2 is correspondingly supported in the housing 3 by the retainer. The sections of the retainer 8 directly adjacent to the mandrel 2 on both sides are further constructed as thin-walled splices 20. Here, each splice 20 is arranged on the mandrel 2 such that the two thin sides of each splice 20, i.e., the two sides of the splice 20 with the smallest dimensions, are oriented along the extrusion direction L in the unpivoted position shown by the mandrel 2, thereby minimizing the flow resistance of the splice 20 when the extruded material flows around the mandrel 2. Furthermore, the support of both sides of the mandrel 2 is achieved by bearing elements 10, which are respectively arranged in the bearing housing 9 and implemented as sleeves 12. Here, support sections 11 are formed on each of the two parts of the retainer 8, which is implemented in a two-piece configuration and exists as a splice mandrel retainer, and the retainer 8 and the mandrel 2 connected to it are supported in the sleeve 12 by the support sections.

[0048] To seal the extrusion head 1 and prevent the extruded material from escaping, a sealing lip 13 is formed on the end of the sleeve 12 facing the mandrel 2, which is shown below in the figure. The sealing lip deforms in the direction toward the support section 11 of the retainer 8 depending on the pressure exerted on it by the extruded material during the extrusion process, and is therefore constructed to a certain extent as a self-sealing structure.

[0049] As from Figure 1 As with the extended design of the extrusion head 1, the retainer 8 extends through the housing 3 on both sides to the outside of the housing 3. Here, at each end side of the retainer 8, an arm 14 is arranged on the retainer 8, and the arms 14 are further connected to each other by a connecting rod. Here, the arrangement of the arms 14 on the retainer 8 is achieved by force and / or form fit connection, using complementary polygonal forming parts 19 between the arms 14 and the retainer 8. In order to realize the pivoting movement and the longitudinal movement along the axis Q transverse to the extrusion direction L, the mandrel 2 is indirectly connected to two adjusting actuators 15 through the retainer 8 and the arms 14. Here, the pivoting and longitudinal movement of the mandrel 2 are initialized by the adjusting movement of the adjusting actuators, and the aforementioned readjustment to compensate for deviations can be realized. For this purpose, the adjusting actuators 15 act on the connecting rods, and the adjusting actuators 15 act directly on the retainer 8.

[0050] List of reference numerals

[0051] 1 Extrusion head

[0052] 2 spindles 8

[0053] 3 shells

[0054] 4-piece section

[0055] 5 openings

[0056] 6 mouthpieces

[0057] 7 gaps

[0058] 8 retainers

[0059] 9 Bearing housing

[0060] 10 bearing components

[0061] 11 Support Section

[0062] 12 sleeves

[0063] 13 sealing lips

[0064] 14 arms

[0065] 15 Adjustable Driver

[0066] 16 Extrusion Parts

[0067] 17 Enter the opening

[0068] 18 Escape from the opening

[0069] 19 Polygonal Forming Section

[0070] 20 stitches

[0071] L Extrusion direction

[0072] Q axis

Claims

1. An extrusion head (1) having a mandrel (2) which is flowably supported in a housing (3) of the extrusion head (1) along the extrusion direction (L) by an extruded material, wherein a nozzle section (4) at the end of the mandrel (2) is arranged in an opening (5) of a nozzle (6) downstream of the mandrel (2) along the extrusion direction (L) of the extrusion head (1) to form a circumferential gap (7) between the nozzle section (4) and the nozzle (6) that is changeable in its geometry, characterized in that, The mandrel (2) is pivotally supported in the housing (3) of the extrusion head (1) about at least one axis (Q) transverse to the extrusion direction (L), wherein the mandrel (2) is longitudinally movable along the direction of the axis (Q) and thus transverse to the extrusion direction (L).

2. The extrusion head (1) according to claim 1, characterized in that, The spindle (2) is arranged on a slender retainer (8) that embodies the axis (Q).

3. The extrusion head (1) according to claim 2, characterized in that, The extrusion head (1) has at least one bearing element (10) arranged in a bearing housing (9) formed in the housing (3), wherein the retainer (8) is supported in the bearing element (10) by a support section (11) formed on the retainer (8).

4. The extrusion head (1) according to claim 3, characterized in that, The bearing element (10) is a sleeve (12), and a sealing lip (13) is formed on the end side of the sleeve (12).

5. The extrusion head (1) according to claim 3, characterized in that, The fit established between the bearing element (10) and the support section (11) of the retainer (8) has a gap width that allows for a defined leakage of the extruded material, and / or the fit has a defined gap width that is compatible with the defined leakage.

6. The extrusion head (1) according to claim 3, characterized in that, The bearing element (10) is a sleeve (12), wherein at least a portion of the sleeve (12) is made of an elastomer.

7. The extrusion head (1) according to claim 6, characterized in that, Only the elastomeric portion of the sleeve (12) is fixedly connected to the support section (11) and the non-elastomeric second portion of the sleeve (12), wherein the elastomeric portion of the sleeve, through its own deformation, prevents the retainer (8) from sliding relative to the elastomeric portion of the sleeve (12) by rotational and / or longitudinal movement.

8. The extrusion head (1) according to claim 3, characterized in that, A seal is provided between the bearing element (10) and the support section (11) of the retainer (8) in a materially or forcefully and / or shape-fitting manner, and thus fixedly connected, the seal impeding the rotational and / or longitudinal movement of the retainer (8) relative to the seal by means of its own deformation.

9. The extrusion head (1) according to claim 3, characterized in that, A friction seal is provided between the bearing element (10) and the support section (11) of the retainer (8).

10. The extrusion head (1) according to claim 1, characterized in that, The nozzle (6) is axially movable in the housing (3) of the extrusion head (1) along the extrusion direction (L).

11. The extrusion head (1) according to claim 2, characterized in that, The retainer (8) extends through the housing (3) to the outside of the housing (3) at least on one side, wherein an arm (14) is connected to the retainer (8) at the end side.

12. The extrusion head (1) according to claim 1, characterized in that, The spindle (2) is connected to at least one adjustment driver (15), wherein the adjustment driver (15) enables the spindle (2) to pivot and / or move longitudinally.

13. A method for producing an elongated hollow body as an extruded part (16) by extruding an extruded material using an extrusion head (1) according to any one of the preceding claims, characterized in that, The deviation between the actual shape of the extruder (16) and the nominal shape of the extruder (16) is determined, and the gap (7) of the extrusion head (1) is readjusted by pivoting and / or longitudinally moving the mandrel (2) to compensate for the deviation.

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