Extrusion head for manufacturing a plastic pipe, and apparatus for manufacturing a plastic pipe comprising said extrusion head

Abstract

The invention relates to an extrusion head (2) for manufacturing a plastic pipe (10), preferably from a thermally unstable plastic, e.g. PVC, having an insert element (8) which is arranged coaxially within the plastic pipe (10) and is for example in the form of a wire, cable, media tube, insulating foam element or the like, the extrusion head comprising: an extrusion-head main body (20) having a nozzle device (6) and having a melt inlet device (4) arranged transversely offset relative to the extrusion-head axis (X), wherein the extrusion-head main body (20) comprises a plurality of sub-bodies (21-26) which extend radially relative to the extrusion-head axis (X) and are arranged successively along the extrusion-head axis (X) and are clamped together along the extrusion-head axis (X), preferably coaxially with the extrusion-head axis (X), and have, as support surfaces for mutually supporting the sub-bodies (21-26), exclusively or predominantly surfaces which are oriented radially, preferably vertically.

Description

[0001] UNICOR GmbH,

[0002] Industriestraße 56, 97437 Hassfurt, DE

[0003] Injection nozzle for the manufacture of a plastic pipe and device for the manufacture of a plastic pipe comprising this injection nozzle

[0004] The invention relates to a die head for the production of a plastic tube, preferably made of a thermally unstable plastic, e.g. PVC, with an insertion element arranged coaxially in the plastic tube, e.g. made of wire, cable, media tube, insulating foam element or the like.

[0005] The spray head comprises a spray head main body with a nozzle assembly at the outlet end of the spray head main body arranged coaxially with the, preferably horizontal, spray head axis and with a melt inlet assembly at the inlet end of the spray head main body arranged laterally offset to the spray head axis.

[0006] The main body of the spray head contains one or more coaxial flow channels, which extend from the melt inlet device through the main body of the spray head into the nozzle device.

[0007] In the main body of the spray head, a passage for the insertion element is formed, which extends coaxially with the spray head axis through the main body of the spray head and into the nozzle assembly.

[0008] A die head constructed in this manner is offered on the market by the applicant UNICOR GmbH as the Unicor COH CH65 die head. The main body of this die head has a quill-like design. If a thermally unstable plastic is used for pipe production and forms corrosive melt residues, the die head must be cleaned of these residues by disassembling it.

[0009] Such nozzle heads with pinion design are also described, for example, in CH 558 072 A and in US 4 248 824 A.

[0010] DE 94 09 617 U1 describes injection nozzles of the type mentioned above, in which the main body consists of several axially arranged ring disk bodies, each with a melt supply.

[0011] A similarly constructed spray head is described in DE 42 35 101 A1.

[0012] Differently designed injection heads with axial melt feed are also known on the market, e.g. the Unicor UMK 65 bridge dome holder injection head of the applicant UNICOR GmbH.

[0013] The invention is based on the objective of creating a spray head as mentioned above, which is also suitable for the use of thermally unstable plastic while being easy to handle.

[0014] The subject matter of claim 1 solves this problem by providing the main body of the spray head with a disc-like structure. A key feature of the solution is that the main body of the spray head comprises several sub-bodies extending radially to the spray head axis, arranged one behind the other along the spray head axis, and clamped together along the spray head axis and / or coaxially to the spray head axis. The bearing surfaces for mutual support of the sub-bodies are exclusively or predominantly surfaces that are radially, preferably vertically, oriented. A sub-body is understood to be a body that forms part of the main body of the spray head. It is essential that the sub-body extends radially to the spray head axis. In preferred embodiments, this is the main direction of extension of the sub-body.The main body of the nozzle is composed of several such bodies arranged one behind the other and clamped together along the nozzle axis. In preferred embodiments, several or all of the sub-bodies are geometrically similar, particularly with essentially the same radial extent and axial thickness. In special embodiments, however, the sub-bodies located at the inlet and outlet ends can be designed differently with regard to their function. The intermediate sub-bodies are preferably, however, largely geometrically identical.

[0015] In conjunction with the radial extension of the sub-bodies, preferably as the main direction of extension of the sub-bodies, it is essential that the bearing surfaces for mutual support of the sub-bodies have exclusively or predominantly surfaces that extend radially, preferably vertically. This prevents axial gaps and joints in which melt residues can accumulate.

[0016] In particularly preferred embodiments, it may be provided that several of the partial bodies are each designed as radially extending disk- and / or plate-shaped bodies, preferably extending over the entire radial extent of the spray head and / or the main body of the spray head and / or being formed in one piece.

[0017] Particularly preferred embodiments provide that the mutual bearing surfaces of the successively arranged sub-bodies, preferably designed as disc- and / or plate-shaped bodies, are designed to extend radially and / or enclose the flow channel opening or openings and / or the through-opening, such that the mutually adjacent bearing surfaces form a tight joint and / or a radially extending gap which is reduced and / or minimized and / or eliminated by the tensioning of the sub-bodies (21-26).

[0018] Preferably, it can be provided that in at least two of the sub-bodies arranged one behind the other, the overlapping bearing surfaces on the mutually facing bearing sides are designed such that the bearing surface of one of the two sub-bodies is designed as at least one raised and / or projecting, preferably strip-shaped, surface area above the bearing side of the sub-body, and the bearing surface of the other of the two sub-bodies is also designed as at least one raised and / or projecting, preferably strip-shaped, surface area above the bearing side of the sub-body, or as a surface section of a uniformly flat surface over the entire bearing side of the sub-body.

[0019] The raised and / or projecting surface areas are preferably designed such that they have a flat surface as a contact surface in their head area.

[0020] Regarding the design of the raised and / or projecting surface area, particularly preferred embodiments provide that the at least one raised and / or projecting surface area above the bearing side of the sub-body has at least one section which is preferably designed as a strip enclosing or at least partially surrounding an opening formed for the sub-body.

[0021] Preferably, it can be provided that several or each of the successively arranged sub-bodies are each designed such that on one bearing side of the sub-body, the raised and / or projecting surface area is formed, or several such raised and / or projecting surface areas are formed, and on the other bearing side of the sub-body, a flat surface extending uniformly over the entire bearing side is formed to form the bearing surface.

[0022] Another essential feature of the solution is that several, preferably each of the sub-bodies, have a flow channel opening or several coaxial flow channel openings, or are designed in such a way that, in the series arrangement of the sub-bodies, the flow channel openings are aligned with each other, forming the flow channel or flow channels which open or open into the nozzle device on the outlet side, preferably as a closed annular gap.

[0023] The flow channel openings in the sub-bodies each form axial sections of the flow channel. Preferably, the angular range of the extension of the flow channel opening around the nozzle axis is different in several, preferably all, of the sub-bodies arranged one behind the other, such that in a sub-body located closer to the outlet end of the nozzle, the angular range is larger than the angular range in a sub-body located closer to the inlet end of the nozzle.

[0024] Another essential feature of the solution is that each of the sub-bodies has a through-opening coaxial with the injection head axis, designed in such a way that, in the series arrangement of the sub-bodies, the through-openings are aligned with each other, forming the passage for the insertion element.

[0025] The guide path, which runs coaxially through the main body of the spray head along the spray head axis, is essential in this spray head design to allow the insertion element to be fed via a feed device located upstream of the spray head. As explained above, the axial clamping of the sub-bodies forming the main body of the spray head is particularly important. Clamping is achieved by connecting the sub-bodies arranged one behind the other via one or more clamping devices. The clamping device, which is used to clamp several of the sub-bodies, preferably designed as disc- and / or plate-shaped bodies, can be configured such that it engages several sub-bodies arranged one behind the other from the outer circumference, or it engages several sub-bodies arranged one behind the other by passing through them.

[0026] Another essential aspect of the connecting device is that the connecting device acts on only two sub-bodies arranged directly one behind the other, in the sense of a pairwise clamping of two sub-bodies arranged one behind the other, or acts on more than two of the sub-bodies arranged one behind the other, in the sense of a joint clamping of more than two sub-bodies.

[0027] Particularly preferred embodiments may provide that several connecting holes parallel to the nozzle axis are formed in several of the sub-bodies arranged one behind the other, preferably designed as disc- and / or plate-shaped bodies. These connecting holes are designed for engagement and / or passage of the connecting device, preferably for engagement and / or passage of connecting elements of the connecting device (90-93), by aligning several of the connecting holes (91, 92) formed in the sub-bodies (21-26) when they are stacked on top of each other. The connecting elements may preferably be designed as connecting screws. The connecting elements may clamp two or more sub-bodies connected one behind the other. Embodiments are possible in which the connecting elements, e.g., designed as through screws, extend through all the sub-bodies connected one behind the other.

[0028] Preferably, it may be provided that several of the connecting holes are formed in a preferably concentric and / or coaxial circumferential circle around the nozzle axis and around the through-opening of the feedthrough section which is coaxial with the nozzle axis.

[0029] Particularly advantageous in this sense are embodiments which provide that several of the connecting holes are formed in a preferably concentric and / or coaxial outer circumferential circle around the nozzle axis and several of the further connecting holes are formed in a preferably concentric and / or coaxial inner circumferential circle around the nozzle axis, wherein it is provided that the flow channel opening or openings are formed between the outer circumferential circle and the inner circumferential circle and the through-opening of the feedthrough section is formed within the inner circumferential circle.The arrangement of the flow channel opening between the outer circumferential circle and the inner circumferential circle, and the arrangement of the through-opening within the inner circumferential circle, results, particularly in conjunction with closely spaced support surfaces surrounding the flow channel opening of the stacked sub-bodies, and / or in conjunction with support surfaces surrounding the through-opening of the stacked sub-bodies, in a seal between the stacked sub-bodies. This applies especially in conjunction with surface areas that are raised and / or projecting above the bearing surface.

[0030] Designs with connecting devices featuring connecting elements designed as screws may particularly preferably provide that the connecting holes arranged next to each other in the circumferential circle are designed differently, preferably by providing that one of the connecting holes arranged next to each other is designed as a stepped bore and the other as a threaded bore, preferably such that, in the case of overlapping partial bodies, the stepped bores are aligned with the threaded bores and a connecting element designed as a screw of the connecting device is supported with its screw head in the stepped bore and is screwed with its threaded end into the aligned threaded bore.

[0031] Preferred embodiments provide that the melt inlet device is connected to and / or connectable to an inlet-side end body of the main nozzle body. The inlet-side end body can be designed as a support body to which one or more or all of the sub-bodies arranged in series, which are clamped coaxially to the nozzle axis and preferably designed as disk- and / or plate-shaped bodies, are directly or indirectly attached and / or supported under tension. It can be provided that the inlet-side end body is designed as one of the sub-bodies of the main nozzle body, arranged in series along the nozzle axis and clamped coaxially to the nozzle axis, preferably as a downstream sub-body. The inlet-side end-body is thus specifically designed for its function as a support body.

[0032] In a preferred embodiment, it can be provided that in the inlet-terminal sub-body, preferably designed as a carrier body, all connection holes for connecting the downstream sub-body(s) are designed only as threaded holes or only as stepped holes, preferably some of the connection holes being arranged in an outer circumferential circle around the nozzle axis and some of the connection holes in an inner circumferential circle around the nozzle axis. The outlet-terminal sub-body can be specifically designed as a coupling body for connecting the nozzle assembly.Preferred embodiments may provide that the outlet-terminal part body is designed as a multi-part ring disk body comprising a separate outer ring disk and a separate inner ring disk, wherein the flow channel shape is formed between the inner circumferential contour of the outer ring disk and the outer circumferential contour of the inner ring disk, extending as an annular gap around the nozzle axis over an angular range of 360°.

[0033] For particularly easy connection of the nozzle assembly, preferred embodiments provide that in the outlet-terminal part of the body, the adjacent connecting holes in an outer circumferential circle around the nozzle head axis are designed differently, preferably alternating, e.g. as stepped bores and as threaded bores, and in an inner circumferential circle around the nozzle head axis the connecting holes are designed the same, e.g. only as threaded bores.

[0034] Preferably, the nozzle assembly may have an outlet-side nozzle assembly and an inlet-side intermediate nozzle assembly, wherein the intermediate nozzle assembly is connected and / or connectable to the main body of the spray head at its outlet-side end, and wherein the nozzle assembly is connected and / or connectable to the outlet-side end of the intermediate nozzle assembly.

[0035] It can be provided that the intermediate nozzle assembly comprises an inner intermediate nozzle body and an outer intermediate nozzle body, and that the nozzle assembly comprises an inner nozzle body and an outer nozzle body, a) wherein the outer intermediate nozzle body is connected and / or connectable to the outlet-side end of the main spray head body, preferably the outlet-side sub-body, preferably via a screw connection, and the inner intermediate nozzle body is connected or connectable to the outlet-side sub-body, preferably engaging in a central opening of this sub-body, and / or b) wherein the outer nozzle body is flanged to the outlet-side end of the outer intermediate nozzle body and connected and / or connectable via a screw connection, and the inner nozzle body is flanged to the outlet-side end of the inner intermediate nozzle body and connected via a screw connection.preferably connected and / or connectable to the screw device that connects the outer nozzle body and the outer intermediate nozzle body.

[0036] The arrangement and design of the heating and / or insulating device of the spray head is a crucial aspect. Preferably, the spray head may have a heating and / or insulating device arranged on the outside of the spray head, preferably surrounding it. In this sense, it is more preferably provided that the heating and / or insulating device has a heating and / or insulating jacket that surrounds the main body of the spray head and / or an axial section of the main body formed by the disc- and / or plate-shaped sub-bodies, preferably resting on the outside. Alternatively or additionally, it may also be provided that the heating and / or insulating device has a heating and / or insulating jacket that surrounds the nozzle assembly, preferably resting on the outside.Alternatively or additionally, the heating and / or insulating device may also have a heating and / or insulating jacket surrounding the melt inlet device, preferably on the outside. As mentioned at the outset, the passage through the nozzle head for the insert element is an essential feature. In preferred embodiments, the passage for the insert element may include a tube, preferably designed as a cooling tube and / or guide tube, wherein the tube, coaxial with the nozzle head axis in the nozzle head main body, passes through the aligned through-openings of the nozzle head sub-bodies arranged one behind the other, forming the passage.

[0037] The invention also solves the problem underlying the invention with the subject matter of claim 20. This is a device for producing a plastic tube with an insertion element arranged coaxially in the plastic tube, wherein the injection head is designed according to one of claims 1 to 19, wherein the injection head is positioned upstream of a corrugator, which has rotating driven first and second forming jaws, preferably designed as left and right forming jaws, which are guided one behind the other in pairs in a forming section of the corrugator.

[0038] The device may preferably be provided with a feeding device for the insertion element upstream of the injection head at its inlet end, such that the insertion element can be fed to the injection head at its inlet end by pushing and / or pulling it into the feed path. This is preferably achieved by pushing the insertion element in, but can also be achieved by pulling the insertion element in.

[0039] Further features and details can be seen in the figures. Fig. 1 shows a schematic representation of an embodiment of a device for manufacturing a plastic tube with a coaxially arranged insertion element;

[0040] Fig. 2 shows an embodiment of the spray head of the device in Fig. 1, in sectional view;

[0041] Fig. 3 shows the embodiment of the spray head in Fig. 2, in perspective view;

[0042] Fig. 4.1 to

[0043] Fig. 4.6 shows the disc-shaped bodies that form the main body of the spray head of Figures 2 and 3, each in detailed top view.

[0044] Fig. 4.1 the inlet-side carrier disk with connection for the melt inlet device;

[0045] Fig. 4.2 first distributor disc;

[0046] Fig. 4.3 second distributor disc;

[0047] Fig. 4.4 third distributor disc;

[0048] Fig. 4.5 fourth distributor disc;

[0049] Fig. 4.6 the two-part output-side ring disc for

[0050] Connection of the nozzle assembly.

[0051] The device for manufacturing a plastic tube with a coaxially arranged insert element in the plastic tube comprises, in the embodiment shown in Fig. 1, the following main components: an extruder 1, a die 2, and a corrugator 3. In the extruder 1, a plastic melt stream 10s is generated from plastic granules. The plastic melt stream 10s exits the extruder 1 and is introduced into the die 2. The die 2 has a melt inlet device 4 on its inlet side for this purpose.

[0052] The injection head 2 has one or more flow channels 5, which introduce(s) the molten plastic into a nozzle assembly 6 located at the outlet end of the injection head 2. The cross-sectional shape of the flow channel and the nozzle can be circular, oval, or any other shape, e.g., square, rectangular, etc.

[0053] The plastic melt tube 10h emerges from the nozzle assembly 6, and a coaxially arranged insertion element 8 is located within it. The plastic melt tube 10h is fed into the corrugator.

[0054] This arrangement of the insertion element 8 coaxially within the plastic melt tube 10h is created within the die head up to the outlet of the nozzle assembly 6 by feeding the insertion element 8 coaxially through a feed section 80 extending from the die head to the nozzle assembly 6 via an insertion element feed device 7 located upstream of the die head. The insertion element 8 is inserted at the outlet end of the feed section 80, preferably at the end of a guide tube that can be arranged within the feed section 80, into a coaxial passage within the nozzle assembly 6, preferably into a guide bore of the nozzle assembly 6, and thus coaxially into the plastic melt tube 10h exiting the nozzle assembly 6.

[0055] The fluid introduced from the nozzle assembly 6 into the corrugator 3

[0056] A plastic melt tube 10h with a coaxially arranged inner insert element 8 is formed in the corrugator 3 by the motor-driven rotating forming jaws 30 in a horizontal forming section 31 under cooling. The forming jaws are designed as left and right forming jaws 30, which are guided one behind the other in pairs in the forming section 31. The corrugated tube 10 is formed in the inner forming surface of the forming jaw pairs, as it has the coaxial insert element 8 inside. At the outlet end of the corrugator 3, the corrugated tube 10 with the inner coaxially arranged insert element 8 exits the corrugator as a continuous tube.

[0057] Downstream of the corrugator is a cutting device (not shown) in which the endless tube 30 is cut to length.

[0058] The structural design of the spray head 2, as implemented in the embodiment shown in the figures, is described in more detail below. Reference is made to Figures 2 to 4.6:

[0059] As shown in Fig. 2, the spray head 2 has a main body 20 with a disc-like structure. In terms of its disc-like structure, the main body 20 is composed of several sub-bodies 21-26, which are arranged one behind the other along the spray head axis X and each extend radially to the spray head axis X. The sub-bodies 21-26 are therefore designed as disc-shaped bodies. The disc-shaped sub-bodies 21-26 are shown individually in Figures 4.1 to 4.6.

[0060] Fig. 4.1 shows the inlet-side carrier disk 21. It has a connection surface 40 for the melt inlet device 4 on its outer circumference, offset transversely to the die axis X. In the sectional view of the die in Fig. 2, the melt inlet device 4 is shown mounted on the inlet-side carrier disk 21. The carrier disk 21 in Fig. 4.1, as an inlet-side disc-shaped sub-body of the die main body 20, is essentially designed in the same disc shape as the downstream sub-bodies 21-25. The carrier disk 21 only has a greater axial thickness and a slightly larger outer diameter than the downstream disc bodies 22-26.

[0061] Figures 4.2 to 4.5 show the four disk-shaped bodies 22 to 25 downstream of the carrier disk 21, each shown individually. Figure 4.6 shows the output-side two-part ring disk 26. It consists of a separate outer ring disk 26a and a separate inner ring disk 26i.

[0062] Each of the disc-shaped bodies 21-26 has a central through-opening 88. In the series arrangement of the bodies 21-26, the through-openings 88 align to form the cylindrically shaped passage 80. As shown in Fig. 2, a cooling tube 82 is accommodated in the passage 80, in which a guide tube 81 for the direct guidance of the insertion element 8 is arranged coaxially. The guide tube 81 is supported at its outlet end in a bearing 83 located in the cooling tube 82. At its inlet end, the guide tube 81 is supported in the inlet-side support disc 21 within the through-opening 88 by means of fastening elements 84 engaging therein.

[0063] Each of the disc-shaped bodies 21-26 has a flow channel 55 formed as an opening. When the bodies 21-26 are arranged one behind the other, the flow channel 55 align to form the flow channel 5. The flow channel 55 extends coaxially around the injection head axis X in each of the respective bodies 21, 22, 23, 24, 25 over an angular range of less than 360°. In this respect, the disc-shaped bodies 21-25 are so-called distribution discs that distribute the molten plastic flow, which enters the flow channel 55 formed in the carrier disc 21 via the melt inlet 4, over this angular range. The flow channel 55s in the bodies 21-25 are configured differently such that they extend over different angular ranges around the injection head axis X.The extent of the angular region increases towards the outlet end of the nozzle, forming an increasingly closed annular channel. That is, in one of the sub-bodies 21-25 located closer to the outlet end of the nozzle 2, the angular region over which the flow channel formation 55 extends is larger than in a sub-body located closer to the inlet end of the nozzle, i.e., closer to the carrier disk 21. In the annular disk body 26 located at the outlet end of the nozzle 2, the flow channel formation 55 is a closed annular gap, i.e., an annular gap extending 360° around the nozzle axis X. The annular disk body 26 is—as mentioned above—designed as a two-part body, consisting of a separate inner annular disk 26i and a separate outer annular disk 26a.Between the outer circumferential contour of the inner ring disk 26i and the inner circumferential contour of the outer ring disk 26a, the flow channel formation 55 is designed as a closed annular gap, which continues in the downstream nozzle device 6.

[0064] As shown in Fig. 2, the disc-shaped sub-bodies 21-26 arranged one behind the other in the illustrated embodiment are designed such that their mutually facing end faces form mutual bearing surfaces with radial contact planes. The interacting bearing surfaces of the bodies 21-26 are specially designed to achieve the tightest possible connection between the bodies in conjunction with the axial clamping of the bodies. The design of the bearing surfaces in the illustrated embodiment is as follows: The four disc-shaped bodies 22-25, which are arranged downstream of the carrier disc 21, each have a uniformly flat bearing surface 29e extending across the entire front face on their inlet-side front side, i.e., on their side facing the spray head inlet. On their outlet-side rear side, i.e.,On their side facing the nozzle outlet, the bodies have specially designed raised, i.e. projecting, strip-shaped surface areas 29f as bearing surfaces.

[0065] In bodies 22-25, on the side facing the nozzle outlet, shown in Figures 4.2 to 4.5, an outer annular raised surface area 29f is formed, enclosing the outer edge of this side of the bodies, and an inner annular raised surface area 29f is formed, enclosing the central through-opening 88. In addition, a surrounding raised surface area 29f is formed around the flow channel opening 55. Furthermore, an arc-shaped raised surface area is formed between the outer annular raised surface area 29f and the inner annular raised surface area 29f in the left half of the figures, into which the flow channel opening 55 does not extend.

[0066] The input-side carrier disk 21, which is designed as a carrier body for the downstream bodies 22-26, has raised surface fields on its output-side rear side, i.e., the side facing the immediately downstream disk body 22, which is shown in full in Fig. 4.1, that are in principle identical in design to those formed on the downstream bodies 22 and 23, i.e., an annular raised surface field 29f in the outer edge region and an inner annular raised surface element 29f extending around the through-opening 88, a raised surface field 29f enclosing the flow channel opening 55, and an arc-shaped raised surface field 29f between the outer and the inner raised annular surface field in the area into which the flow channel opening 55 does not extend.

[0067] The outlet-side ring disk body 26, consisting of the inner ring disk 26i and the outer ring disk 26a, is located downstream of the disk-shaped bodies 22-25. The inner ring disk 26i and the outer ring disk 26a are attached to the upstream disk body 24. On their side facing the upstream disk body 24, the ring disks 26i and 26a each have a uniform, flat bearing surface that interacts with the raised surface areas 29f on the opposite side of the disk-shaped body 24. On their outlet-side rear side, the two ring disks 26i and 26a also each have a uniform, flat bearing surface. These surfaces form the bearing surface for the downstream nozzle assembly 6, specifically as a bearing surface for flange mounting the intermediate nozzle assembly 6.1.

[0068] Modified versions of the sub-bodies 21-26 are possible compared to the figures, in which the mutually facing support surfaces each have raised surface fields 29f that come to lie on top of each other in the tensioned one-to-one arrangement.

[0069] The special design of the mutual bearing surfaces of the disk-shaped bodies 21-26, in conjunction with the axial clamping, results in a tight connection between the bodies 21-26. In the embodiment shown in the figures, the axial clamping is achieved via bolted connections, in which the connecting bolts each act as clamping elements. This is described below. Reference is made to Fig. 2 in conjunction with Figures 4.1 to 4.6. The support body 21 and the downstream bodies 22-26 are connected to each other via bolted connections 90, whereby adjacent, directly neighboring bodies are screwed together in pairs via separate bolted connections 90. For this purpose, the bodies 22-25 each have circumferential circles, i.e.,On an inner and an outer circumferential circle, stepped bores 92 and threaded bores 91 are arranged alternately side by side, such that, when adjacent bodies are stacked on top of each other, the threaded bores 91 of an upstream body are aligned with the stepped bores 92 of a downstream body. Connecting screws 93 serve to connect the adjacent bodies in pairs; the screw heads of these screws are supported in the stepped bores 92 of the downstream body, and their threaded ends are screwed into the threaded bores 91 of the upstream body.

[0070] The connecting holes in the different disc-shaped bodies 21-26 are designed and arranged as follows:

[0071] The input-side support body 21 has six connection holes on its inner circumferential circle, namely six threaded bores 91. On its outer circumferential circle it has twelve connection holes, namely twelve threaded bores 91.

[0072] The disc-shaped body 22 in Fig. 4.2 has a total of twelve connection holes on its inner circumference, six of which are stepped bores 92 and six of which are threaded bores 91. On its outer circumference, it has a total of 24 connection holes, twelve of which are stepped bores 92 and twelve of which are threaded bores 91. The stepped bores 92 can be identified in the figure by their larger opening diameter. The disc-shaped body 23 in Fig. 4.3 has a total of twelve connection holes on its inner circumference, six of which are stepped bores 92 and six of which are threaded bores 91. On its outer circumference, it has a total of 24 connection holes, twelve of which are stepped bores 92 and twelve of which are threaded bores 91. Here too, in Fig. 4.3, the stepped bores 92 can be identified by their larger opening diameter.

[0073] The disc-shaped body 24 in Fig. 4.4 has a total of twelve connecting holes on its inner circumcircle, of which six are stepped bores 92 and six are threaded bores 91. On its outer circumcircle, it has a total of 24 connecting holes, of which twelve are stepped bores 92 and twelve are threaded bores 91. Here too in Fig. 4.4, the stepped bores 92 can be identified by their larger opening diameter.

[0074] The disc-shaped body 25 in Fig. 4.5 has a total of twelve connecting holes on its inner circumferential circle, of which six are stepped bores 92 and six are threaded bores 91. It has a total of 24 connecting holes on its inner circumferential circle, of which twelve are stepped bores 92 and twelve are threaded bores 91. Here too in Fig. 4.5, the stepped bores 92 can be identified by their larger opening diameter.

[0075] As shown in Fig. 4.6, the output-terminal disc-shaped body 26, which consists of an inner ring 26i and an outer ring 26a, has a total of six connecting holes on its inner ring 26i on the corresponding inner circumferential circle. These are exclusively stepped bores 92. On the outer ring 26a, a total of 24 connecting holes are formed on the corresponding outer circumferential circle, of which twelve are stepped bores 92 and twelve are threaded bores 91. Here too in Fig. 4.6, the stepped bores 92 can be identified by their larger opening diameter. The connecting holes in the bodies 21-26 are arranged such that, when the bodies 21, 22, 23, 24, 25, 26 are arranged in series, the stepped bores 92 are aligned with their corresponding threaded bores 91. The bodies are connected in pairs by screw connections.As already mentioned, the screws 93 of the screw connections 20 function as clamping elements. In the connected position, they are each arranged such that the screw head is supported in a stepped bore 92 and the threaded end of the screw is screwed into the aligned threaded bore 91 of the upstream body, under tension between the bodies connected in series.

[0076] The nozzle assembly 6, located on the outlet side of the spray head 2, is connected to the main body 20 of the spray head via the ring disc body 26. This is shown in Fig. 2. The nozzle assembly 6 consists of an intermediate nozzle set 6.1, which is directly connected to the ring disc body 26 via a screw connection, and an outlet nozzle set 6.2, which is coupled to the outlet end of the intermediate nozzle set 6.1.

[0077] The intermediate nozzle set 6.1 comprises a frustoconical inner intermediate nozzle 6.1 i and a complementary outer intermediate nozzle 6.1 a. An annular gap is formed between the outside of the inner intermediate nozzle 6.1 i and the inside of the outer intermediate nozzle 6.1 a, the extent of which is conically convergent towards the outlet end.

[0078] The nozzle assembly 6.2 comprises a frustoconical inner nozzle 6.2i and a complementary outer nozzle 6.2a. The inner nozzle 6.2i is connected to the outlet of the inner intermediate nozzle 6.1i. The outer nozzle 6.2a is connected to the outlet of the outer intermediate nozzle 6.1a. Between the outer surface of the inner nozzle 6.2i and the inner surface of the outer nozzle 6.2a is an annular gap extending conically towards the outlet, which continues the conical annular gap of the intermediate nozzle assembly 6.1. The annular gap at the outlet end of the nozzle assembly forms the outlet-side annular gap that introduces the plastic melt tube into the forming section 31 of the corrugator.

[0079] As explained above, the insertion element 8 is arranged coaxially in the plastic melt tube exiting the nozzle assembly 6, and is, in a sense, encased by the plastic melt tube.

[0080] Reference sign

[0081] 1 extruder

[0082] 2 spray heads

[0083] 3 Corrugator

[0084] 4 Melt inlet device

[0085] 5 Flow channel

[0086] 6 nozzle assembly

[0087] 6.1 Intermediate nozzle set

[0088] 6.1 i inner intermediate nozzle

[0089] 6.1 a outer intermediate nozzle

[0090] 6.2 Nozzle set

[0091] 6.2i inner nozzle

[0092] 6.2a outer nozzle

[0093] 7 Insert element feeding device

[0094] 8 Insert element

[0095] 10 Endless tube, corrugated tube

[0096] 10s plastic melt flow

[0097] 10h plastic melt hose

[0098] 11 Heating and / or insulation equipment

[0099] 12 Cooling device, cooling pipe

[0100] 20 spray head main body

[0101] 21 input-side support disc

[0102] 22 disc-shaped bodies as sub-bodies of the main spray head body

[0103] 23 disc-shaped bodies as sub-bodies of the main spray head body

[0104] 24 disc-shaped bodies as sub-bodies of the main spray head body

[0105] 25 disc-shaped bodies as sub-bodies of the main spray head body

[0106] 26 Ring disc body 26a outer ring disc

[0107] 26i inner ring disc

[0108] 29e uniform flat bearing surface

[0109] 29f raised surface area as bearing surface

[0110] 30 baking trays

[0111] 31 Form section

[0112] 40 connection area for 4

[0113] 55 Flow channel opening in 21 to 26

[0114] 56 Connection device in 55

[0115] 66 Guide bore for the insertion element 8 in 6

[0116] 80 Implementation route

[0117] 81 Guide tube for the insertion element 8 in 80

[0118] 82 Cooling pipe

[0119] 83 bearings for 81 in 82

[0120] 84 Fastening element

[0121] 88 central passage opening in 21 to 26

[0122] 90 Connecting device, screw connection

[0123] 91 Threaded hole

[0124] 92-step bore

[0125] 93 screw

[0126] X spray head axis

Claims

25 63929WO WK / dr UNICOR GmbH, Industriestraße 56, 97437 Hassfurt, DE Claims 1. A die for the production of a plastic tube, preferably made of a thermally unstable plastic, e.g. PVC, with an insert element arranged coaxially in the plastic tube, e.g. made of wire, cable, media pipe, insulating foam element or the like, comprising a die main body (20) with a nozzle assembly (6) at the outlet end of the die main body (20) arranged coaxially with the, preferably horizontal, die axis (X) and with a melt inlet assembly (4) at the inlet end of the die main body (20) arranged laterally offset to the die axis (X), wherein a flow channel (5) or several coaxial flow channels (5) is or are formed in the die main body (20), which extends from the melt inlet assembly (4) through the die main body (20) into the nozzle assembly (6).extend, and wherein a passage (80) for the insertion element (8) is formed in the main body of the spray head (20), which extends coaxially with the spray head axis (X) through the main body of the spray head (20) and opens into the nozzle assembly (6), characterized in that the main body of the spray head (20) has several sub-bodies (21-26) extending radially to the spray head axis (X), which are arranged one behind the other along the spray head axis (X) and are connected to each other along the spray head axis (X) and / or coaxially to the spray head axis (X). are clamped and, as bearing surfaces for mutual support of the sub-bodies (21-26), have exclusively or predominantly surfaces that are radially, preferably vertically, oriented, wherein each of the sub-bodies (21-26) has a flow channel opening (55) or several flow channel openings (55), designed such that in the series arrangement of the sub-bodies (21-26) the flow channel openings (55) are aligned with each other, forming the flow channel (5) or flow channels (5), and wherein each of the sub-bodies (21-26) has a through-opening (88) coaxial with the nozzle axis (X), designed such that in the series arrangement of the sub-bodies (21-26) these through-openings (88) are aligned with each other, forming the passage (80) for the insertion element (8).

2. Spray head according to claim 1, characterized in that several of the partial bodies (21-26) are each designed as radially extending disc- and / or plate-shaped bodies (21-26), preferably extending over the entire radial extent of the spray head (2) and / or the main body of the spray head (20) and / or formed in one piece.

3. Spray head according to one of the preceding claims, characterized in that the mutual bearing surfaces of the successively arranged partial bodies (21-26), preferably designed as disc- and / or plate-shaped bodies, are designed to extend radially and / or enclose the flow channel opening (55) and / or the flow channel openings (55) and / or the through-opening (88), such that that the overlapping mutual bearing surfaces form a tight joint and / or a radially extending gap which is reduced and / or minimized and / or eliminated by the tensioning of the sub-bodies (21-26).

4. Spray head according to one of the preceding claims, characterized in that, in at least two of the successively arranged sub-bodies (21 - 26), the overlapping bearing surfaces on the mutually facing bearing sides are designed such that the bearing surface of one of the two sub-bodies (21 - 26) is formed as at least one raised and / or projecting, preferably strip-shaped, surface field (29f) above the bearing side of the sub-body (21 - 26), and the bearing surface of the other of the two sub-bodies (21 - 26) is also formed as at least one raised and / or projecting, preferably strip-shaped, surface field (29f) above the bearing side of the sub-body (21 - 26), or as a surface section (29e) of a uniformly flat surface (29e) over the entire bearing side of the sub-body (21 - 26).

5. Spray head according to claim 4, characterized in that the at least one raised and / or projecting surface field (29f) above the bearing side of the partial body (21-26) has at least one section which is preferably strip-shaped and encloses or at least partially surrounds an opening (55, 88) formed for the partial body (21-26).

6. Spray head according to one of the preceding claims, characterized in that 28 63929WO WK / dr that the angular range of the extension of the flow channel opening (55) about the nozzle axis (X) is different in several, preferably all, of the successively arranged sub-bodies (21-26), such that in a sub-body (21-26) arranged closer to the outlet end of the nozzle (2) the angular range is larger than the angular range in a sub-body (21-26) arranged closer to the inlet end of the nozzle (2).

7. Spray head according to one of the preceding claims, characterized in that a connecting device (90-93) is provided for clamping several of the sub-bodies (21-26), which are preferably designed as disc- and / or plate-shaped bodies, arranged one behind the other, and which is designed such that a) the connecting device (90-93) engages several sub-bodies (21-26) arranged one behind the other from the outer circumference of the sub-bodies (21-26) or engages by passing through the sub-bodies (21-26), and / or b) the connecting device (90-93) acts on only two sub-bodies (21-26) arranged directly one behind the other in the sense of clamping only two sub-bodies (21-26) arranged one behind the other, or acts on more than two of the sub-bodies (21-26) arranged one behind the other in the sense of clamping more than two sub-bodies (21-26) together.

8. Spray head according to one of the preceding claims, characterized in that in several of the successively arranged sub-bodies (21-26), preferably designed as disc- and / or plate-shaped bodies, several are directed parallel to the spray head axis (X). 29 63929WO WK / dr Connecting holes (91, 92) are formed which are designed for engagement and / or penetration of the connecting device (90-93), preferably for engagement and / or penetration of connecting elements (93) of the connecting device (90-93), in that, in the case of superimposed partial bodies (21-26), several of the connecting holes (91, 92) formed in the partial bodies are aligned with each other, wherein the connecting elements (93) are preferably each designed as a connecting screw (93).

9. Spray head according to claim 8, characterized in that several of the connecting holes (91 , 92) are formed in a preferably concentric and / or coaxial circumferential circle around the spray head axis (X) and around the through-opening (88) of the through-passage section (80) which is coaxial with the spray head axis (X).

10. Spray head according to claim 9, characterized in that several of the connecting holes (91, 92) are formed in a preferably concentric and / or coaxial outer circumferential circle around the spray head axis (X) and several of the further connecting holes (91, 92) are formed in a preferably concentric and / or coaxial inner circumferential circle around the spray head axis (X), wherein it is provided that the flow channel opening (55) or the flow channel openings (55) are formed between the outer circumferential circle and the inner circumferential circle and the through-opening (88) of the through-passage section (80) is formed within the inner circumferential circle. 30 63929WO WK / dr 11. Spray head according to claim 9 or 10, characterized in that the connecting holes (91, 92) arranged next to each other in the circumferential circle are designed differently, preferably by providing that one of the connecting holes arranged next to each other is designed as a stepped bore (92) and the other connecting hole as a threaded bore (91), preferably such that when the partial bodies (21-26) are lying on top of each other, the stepped bores (92) are aligned with the threaded bores (91) and a connecting element of the connecting device (90) designed as a screw (93) is supported with its screw head in the stepped bore (92) and is screwed with its threaded end into the aligned threaded bore (91).

12. Spray head according to one of the preceding claims, characterized in that the melt inlet device (4) is connected and / or connectable to an inlet-side end body (21) of the spray head main body (20), wherein the inlet-side end body (21) is designed as a support body (21) to which one or more or all of the successively arranged sub-bodies (21-26) clamped coaxially to the spray head axis are directly or indirectly attached and / or supported under tension, wherein it is preferably provided that the inlet-side end body (21) is designed as one of the sub-bodies (21-26) of the spray head main body (20) arranged successively along the spray head axis (X), clamped coaxially to the spray head axis (X), preferably designed as a disk- and / or plate-shaped body. 31 63929WO WK / dr 13. Spray head according to one of the preceding claims, characterized in that in the inlet-terminal partial body (21), preferably designed as a carrier body (21 ), all connecting holes (91 , 92) for connecting the downstream partial body (22-26) or the downstream partial bodies (22-26) are designed only as threaded bores (91 ) or only as stepped bores (92), preferably some of the connecting holes (91 , 92) are arranged in an outer circumferential circle around the spray head axis (X) and some of the connecting holes (91 , 92) are arranged in an inner circumferential circle around the spray head axis (X).

14. Spray head according to one of the preceding claims, characterized in that the outlet-terminal part body (26) is designed as a multi-part ring disk body (26) comprising a separate outer ring disk (26a) and a separate inner ring disk (26i), wherein the flow channel formation (55) is formed between the inner circumferential contour of the outer ring disk (26a) and the outer circumferential contour of the inner ring disk (26i), which extends as an annular gap over an angular range of 360°.

15. Spray head according to one of the preceding claims, characterized in that in the outlet-terminal part body (26) in an outer circumferential circle around the spray head axis (X) the connecting holes (91 , 92) arranged next to each other are designed differently, preferably alternating, e.g. as a stepped bore (92) and as a threaded bore (91 ) and in an inner circumferential circle around the spray head axis (X) the connecting holes (91 , 92) are designed the same with each other, e.g. only as threaded bores (91 ). 32 63929WO WK / dr 16. Spray head according to one of the preceding claims, characterized in that the nozzle assembly (6) has an outlet-side nozzle assembly (6.2) and an inlet-side intermediate nozzle assembly (6.1), wherein the intermediate nozzle assembly (6.1) is connected and / or connectable to the spray head main body (20) at its outlet-side end, and wherein the nozzle assembly (6.2) is connected and / or connectable to the outlet-side end of the intermediate nozzle assembly (6.1).

17. Spray head according to claim 16, characterized in that the intermediate nozzle assembly (6.1) comprises an inner intermediate nozzle body (6.1i) and an outer intermediate nozzle body (6.1a), and that the nozzle assembly (6.2) comprises an inner nozzle body (6.2i) and an outer nozzle body (6.2a), a) wherein the outer intermediate nozzle body (6.1a) is connected and / or connectable to the outlet-side end of the spray head main body (20), preferably to the outlet-side partial body (26), preferably via a screw assembly (90), and the inner intermediate nozzle body (6.1i) is connected or connectable to the outlet-side partial body (26), preferably engaging in a central opening of this partial body (26), and / or b) wherein the outer nozzle body (6.2a) is connected to the outlet-side end of the outer intermediate nozzle body (6.1a) is flanged and / or connectable with a screw device, and the 33 63929WO WK / dr inner nozzle body (6.2i) flanged to the outlet end of the inner intermediate nozzle body (6.1i) with a screw device (90), preferably with the screw device (90) that connects, is connected and / or connectable to the outer nozzle body (6.2a) and the outer intermediate nozzle body (6.1a).

18. Spray head according to one of the preceding claims, characterized in that the spray head (2) has a heating and / or insulating device (11) arranged on the outside of the spray head (2, 20), preferably surrounding the spray head (2, 20), wherein it is preferably provided that the heating and / or insulating device (11) has a heating and / or insulating jacket surrounding the main body of the spray head (20) and / or an axial section of the main body of the spray head (20) formed by the disc- and / or plate-shaped sub-bodies (21-26), preferably on the outside, and / or that the heating and / or insulating device (11) has a heating and / or insulating jacket surrounding the nozzle device (6), preferably on the outside, and / or that the heating and / or insulating device (11) has a heating and / or insulating jacket surrounding the melt inlet device (4). surrounds, preferably on the outside.

19. Spray head according to one of the preceding claims, characterized in that the passage (80) for guiding the insertion element (8) has a tube, preferably designed as a cooling tube (12, 82) and / or guide tube (81), wherein the tube is coaxial 34 63929WO WK / dr with the spray head axis (X) in the spray head main body (20) passes through the aligned through openings (88) of the successively arranged sub-bodies (21 -26) of the spray head (20) forming the passage (80).

20. Device for producing a plastic tube, comprising a die head designed according to one of the preceding claims, wherein the die head (2) is positioned upstream of a corrugator (3) which has rotating driven first and second forming jaws (30), preferably designed as left and right forming jaws (30), which are guided in pairs one after the other in a forming section (31) of the corrugator (3).

21. Device according to claim 20, characterized in that a feeding device (7) for the insertion element (8) is arranged upstream of the spray head (2) at its inlet-side end such that the insertion element (8) can be fed to the spray head (2) at its inlet-side end by inserting it into the feedthrough section (80).

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