Method and device for producing wound plastic tubes, in particular canned tubes for wet rotor pumps

Description

[0001] The invention relates to a method and a device for producing wound plastic tubes, in particular cans for wet-running pumps, by winding a flat, fiber-reinforced strip material with a thermoplastic or thermosetting polymer matrix onto a heated winding core, while the polymer matrix is ​​melted by laser irradiation to form a bond between two superimposed layers of the strip material. The device accordingly has a heatable winding core and a winding head that provides the strip material, is configured to wind the strip material onto the winding core, and has a laser for melting the polymer matrix by laser irradiation.

[0002] European patent application EP3835040A1 discloses a can for a wet-running pump consisting of a wound, continuous fiber-reinforced plastic tube. The plastic tube has a permeation-reducing polymer-based coating on its inside, with a chemical bond between the plastic tube and the coating.

[0003] Furthermore, the production of pipes by winding a flat, fiber-reinforced strip material, also known in technical jargon as tape, onto a hot winding core with simultaneous laser irradiation (laser tape winding) is known per se. The use of a hot winding core serves to ensure that the polymer matrix of the tape fully crystallizes in the case of a thermoplastic or fully cross-links in the case of a thermosetting thermoset. However, this is only the case if a certain minimum temperature for crystallization or cross-linking is maintained for a sufficiently long time, which is not guaranteed in practice based on the state of the art. This leads to the polymer matrix of the produced pipes not being fully crystallized or cross-linked and therefore shrinking upon cooling. The long-term dimensional stability of the wound pipe is therefore not guaranteed.There are high tolerances, and the tubes have inhomogeneous properties along their circumference and axial length.

[0004] The winding core is heated in a complex manner, either in an oven located separately from the winding device or using infrared radiators, which results in a long heating time and therefore a long waiting time. Another disadvantage is the complicated and dangerous handling during transport and the positioning of the hot winding core in the winding device. On the other hand, the winding core cools down during this handling, so that it is already considerably cold when winding begins. Furthermore, the cooling of the winding core is usually too rapid, so that the minimum temperature required for the crystallization or cross-linking of the polymer matrix is ​​not maintained long enough. To ensure this, the heating temperature for the winding core is selected to be high enough that the core still has the minimum temperature even after a certain period of time. This requires a high amount of energy. On the other hand, solid winding cores, i.e.Solid cores are used because of their high heat storage capacity. However, this makes the winding cores particularly heavy, which also makes handling difficult.

[0005] In practice, there is also no homogeneous temperature distribution on the surface and inside the winding core. Furthermore, the temperature distribution is uncontrolled over time.

[0006] Another problem is the significant wear on the winding core, which occurs when the tube is pushed off the winding core after winding, when the winding core is still relatively hot. This is because high frictional forces exist between the winding core and the wound tube in this state. This also affects the dimensional accuracy of the tubes and often leads to damage to the tube, resulting in a high scrap rate. This high level of wear leads to frequent, costly replacement of the winding cores.

[0007] The situation is different when the winding core has completely cooled down, as its diameter is smaller in this state, making it easier to slide the tube off the core, at least provided it hasn't also shrunk and thus continues to rest firmly on the winding core. However, it takes a long time for the winding core to completely cool down, which increases the process time.

[0008] It is also known to dimension the length of the winding cores so that long tubes can be wound, from which pipe sections of the desired length are then cut off locally away from the winding device. For example, only such a cut-off pipe section forms a desired split pipe. It goes without saying that sliding the wound pipe off the winding core is challenging due to the length of the pipe. Firstly, more space is required. Secondly, sliding a long pipe down leads to increased wear on the core surface and often to damage the pipe. For this reason, in practice the pipes are not wound very long, which reduces and limits the productivity of the winding device and the process.

[0009] It is therefore an object of the present invention to provide a winding method and a winding device for producing plastic pipes which overcomes the aforementioned disadvantages and enables simple and economical production of dimensionally accurate plastic pipes or pipe sections while simultaneously reducing energy consumption and waste.

[0010] This object is achieved by a method according to claim 1 and a device according to claim 8. Advantageous further developments are specified in the respective subclaims and are explained below.

[0011] According to the invention, the method provides that the winding core has an outer tube, onto which the strip material can be wound or is wound, and an inner tube arranged therein. And that for the variothermal temperature control of the outer tube, a fluid flows axially through the winding core along a helical flow path around the winding core axis, which extends radially between the outer tube and the inner tube along at least one axial section of the winding core, so that the fluid flows along the inside of the outer tube and can thus transfer its heat to the outer tube or absorb heat from the outer tube. Preferably, the helical flow path extends not only along at least one axial section of the winding core, but almost along the entire axial length of the winding core, in particular of the inner tube.

[0012] The device according to the invention provides for at least one helix to be present radially between the outer tube and the inner tube. This helix extends along at least one axial section of the winding core and defines the helical flow path around the winding core axis through which the fluid can flow. The helix forms a wall extending radially between the outer tube and the inner tube, which delimits the helical flow path in the axial direction. The helix thus separates a first turn of the helical flow path from the adjacent next turn of the helical flow path.

[0013] The proposed winding core design has many advantages. For example, the outer tube is hollow compared to a conventional winding core. This reduces material costs and makes the winding core lighter, making it easier to handle.

[0014] The design also allows for temperature control directly within the device, eliminating the need to transport the winding core from a location where it is heated to the winding device. A major advantage is that the flow path in the winding core can be used both to heat and cool the winding core, as the fluid is maintained at the appropriate temperature. This is known as variothermal temperature control. The technical effort required to heat or cool the winding core is thus minimal.

[0015] For example, the fluid can flow through the winding core during winding at a first temperature in a first temperature range. The first temperature is expediently above the minimum temperature required for crystallization or crosslinking of the polymer matrix, preferably between 120°C and 200°C. The fluid can then flow through the winding core at a second temperature in a second temperature range, in particular between 10°C and 80°C, depending on the strip material. This enables rapid heating of the winding core for the winding process and, after this, rapid active cooling of the winding core. During cooling, the outer tube, which was previously expanded due to heat, shrinks, so that the wound tube can then be easily and almost wear-free slid off the winding core.

[0016] To enable easy switching between heating and cooling of the winding core, the device can comprise a temperature control device configured to supply the fluid selectively at the first temperature or at the second temperature. The temperature control device also allows for precise specification of the duration for which the first and / or second temperature should be maintained. This ensures that the crystallization or crosslinking of the polymer matrix is ​​complete. Overall, this improves process reliability and stability. The temperature control device thus supplies hot or cold fluid to the winding core as needed.

[0017] The temperature control device can, for example, have a first reservoir of fluid at the first temperature, and optionally also a second reservoir of fluid at the second temperature. A heating device can be assigned to the first reservoir to heat the fluid in the first reservoir. A cooling device can be assigned to the second reservoir to cool the fluid in the second reservoir. The two reservoirs can each be connected via a valve or a common 3-way valve to a supply line connected to the winding core to introduce the corresponding fluid therein.

[0018] It should be clarified that the fluid used to heat the winding core at the first temperature does not necessarily have to be materially identical to the fluid used to cool the winding core. However, this is advisable due to the shared flow path. For example, the fluid can be water or glycol, or a mixture of water and glycol.

[0019] One advantage of guiding the flow helically around the inner tube is that the flow cross-section is larger than with a straight flow path, and thus the flow velocity is reduced. The path length is therefore extended by the number of turns. The resistance coefficient of the helical flow path is lower than with laminar, axial flow through an annular gap between the outer tube and the inner tube. A lower resistance coefficient and lower velocity lead to a lower pressure loss along the helical flow path. Due to the lower velocity and longer path length, the residence time of a fluid particle in the flow path is longer. This allows the heat transfer to be optimized over time, and a more uniform temperature distribution is achieved, especially for the relevant temperature of the outer tube.the winding core surface, which comes into contact with the tape material as winding material.

[0020] Overall, the helical flow path ensures a homogeneous temperature distribution on the outer surface of the outer tube, both circumferentially and axially along the winding core. Thus, a constant temperature prevails over the entire winding length.

[0021] During winding, the strip material is placed layer by layer on the winding core. To produce particularly thin-walled tubes, especially split tubes, two or three layers are sufficient. For thicker-walled tubes, more layers may be required.

[0022] Preferably, the tape material is thermoplastic and unidirectionally (UD) fiber-reinforced, i.e., it forms a so-called UD tape. This is particularly suitable for the production of thin-walled cans for wet-running pumps, which can be cut from the wound tube.

[0023] Carbon fibers are preferred as fiber reinforcement in the strip material. Thus, the wound tube is a CFRP (carbon fiber reinforced) wound tube.

[0024] The polymer matrix of the tape material can be, for example, PPS (polyphenylene sulfide), PPA (polyphthalamide), PEKK (polyether ketone ketone) or PEEK (polyether ether ketone).

[0025] A simple design of the device is achieved if the winding core rotates around its longitudinal axis to apply the layers, i.e., during winding. This allows the winding head to remain stationary in terms of its angular position relative to the winding core. The strip material is then fed tangentially at a constant angle to the winding core. Preferably, the winding head is continuously moved linearly and parallel to the winding core axis so that successive layers of strip material are axially offset from one another.

[0026] In a simple design variant, the fluid can enter the winding core at a first axial end, flow through the helical flow path, and exit again at the opposite second axial end. In this case, the fluid can be returned to the temperature control device outside the winding core.

[0027] In another preferred embodiment, the fluid enters the winding core at a first axial end and flows through the helical flow path, but is deflected radially at the opposite second axial end and / or beforehand and flows back through the winding core. This is possible thanks to the arrangement of the inner tube within the outer tube, whereby the winding core forms a two-chamber system when viewed in radial cross-section. The helical flow path forms an outer chamber, and the interior of the inner tube forms an inner chamber. The fluid flows through the outer chamber and the inner chamber bidirectionally, or more precisely, in opposite directions. The advantage of this variant is that the supply and discharge of the fluid are located at the same axial end of the winding core, which structurally simplifies the device.In other words, in this embodiment, the fluid flows through the inner tube in the axially opposite direction to the helical flow path, wherein the fluid is deflected from the inner tube to the helical flow path or vice versa by at least one fluid deflection which is located in the flow direction at the end of the axial section or beyond this end, for example at the axial end of the winding core.

[0028] The design and intended use of the winding core of this design variant thus corresponds to a counterflow heat exchanger principle instead of a solid core.

[0029] The fluid deflection can be implemented in different ways. For example, according to a first variant, the inner tube can have one or more transverse channels, for example transverse bores, which create a connection between the interior of the inner tube and the helical flow path. Such a transverse channel has the advantage that it can be located at any axial height along the axial extent of the winding core. In another embodiment, the inner tube can be shortened compared to the outer tube, so that fluid flows axially out of or into the inner tube, depending on the flow direction. In this case, the fluid deflection is located at the axial end of the winding core opposite the flow inlet of the fluid. In both of these variants, the winding core, or more precisely the outer tube, is tightly closed by a closure element to prevent fluid from escaping.In the first variant, the inner tube is also suitably closed axially, preferably by the same closure element.

[0030] According to a third variant that develops further on the second variant, the fluid diversion can take place in the closure element, since it consequently functions as a fluid diverter. The device can thus have a fluid diverter that is inserted into the inner tube and the outer tube at the axial end of the winding core opposite the flow inlet of the fluid, like a plug, and closes each of them, but simultaneously has at least one transverse channel to enable the transition of the fluid from the inner tube to the helical flow path or vice versa. The at least one transverse channel can be formed in a tubular section of the fluid diverter, which projects axially from a plug-shaped section and projects with a free end into the inner tube only far enough for the at least one transverse channel to allow unhindered flow through. The plug-shaped section can be inserted axially into the outer tube and seal it off.

[0031] It is advantageous if the fluid first flows through the inner tube and then flows back through the helical flow path. Compared to the reverse flow direction, this homogenizes the temperature distribution in the winding core and maximizes the utilization of the thermal energy supplied by the fluid. This is because the fluid increasingly loses heat along the entire flow path. This is particularly noticeable along the helical flow path, because the fluid transfers its heat to the outer tube. If the winding core were only flowed through unidirectionally along the helical flow path, there would be a noticeable drop in the fluid's temperature at the end of the helical flow path compared to its temperature at the beginning of the helical flow path.However, if the winding core is flowed through bidirectionally, with the fluid first flowing through the inner tube and then through the helical flow path, the fluid at the beginning of the overall flow path can transfer heat via the inner tube to the fluid at the end of the overall flow path, thus counteracting a temperature drop. This radially outward heat transfer essentially occurs along the entire axial length of the inner tube.

[0032] If the flow through the winding core were reversed, i.e., first along the helical flow path and then through the inner tube, such heat transfer would still occur, but it would be more likely to result in a "thermal short circuit." Thus, the heat at the beginning of the helical flow path, where it is needed to heat the outer tube, would be transferred via the inner tube to the returning fluid, which then leaves the winding core. The heat transferred radially inward is thus not utilized.

[0033] In one design variant, the coil can be attached to the outer circumference of the inner tube. This prevents the coil from shifting when the outer and inner tubes are pushed axially into each other. For example, the coil can be welded to the inner tube, either at specific points or along a weld line.

[0034] The coil can be made of a wire, for example a round wire, particularly made of steel or stainless steel. Suitably, the outer and inner tubes can also be made of metal, particularly stainless steel.

[0035] In addition to spatially separating the turns of the helical flow path, the coil serves to mechanically support the outer tube, at least in places, against the inner tube, thus providing stability to the winding core. It is not necessary for the coil to be tightly pressed against the outer circumference of the inner tube and / or the inner circumference of the outer tube, since adjacent turns of the helical flow path do not need to be sealed to each other.

[0036] It is advantageous if the radial height of the helix, in particular the wire diameter, corresponds to the difference between the inner radius of the outer tube and the outer radius of the inner tube or is slightly smaller, but no more than 20% smaller than this difference, in order to facilitate the axial joining of the outer and inner tubes.

[0037] According to another embodiment, the coil can be integral with the outer tube and / or with the inner tube and can be manufactured layer by layer using an additive manufacturing process.

[0038] In one embodiment, the winding core can be provided with two helices, each extending along at least one axial section of the winding core around the winding core axis and offset by 180° from each other. This embodiment also includes two helical flow paths around the winding core axis, which are fluidically parallel and offset by 180° from each other. Each of these two flow channels is then delimited in one circumferential direction by one of the two helices and in the opposite circumferential direction by the other helix.

[0039] The pitch of one or both coils can be 200 mm, for example. This means that one coil has an axial length of 20 cm. Expressed in radians, the pitch is then approximately 73°. In general, the pitch of the coil can be between 45° and 80°.

[0040] The total length of the wound pipe can, for example, be between 1m and 2m.

[0041] To simplify the manufacture of the inner tube with the coil(s), the inner tube can be divided into segments. These can be joined axially via a form-fitting connection, such as a bayonet joint. The segments are preferably shaped such that the coil transitions continuously from one segment to the next when joined.

[0042] It is advantageous if, after the winding core has cooled, the wound tube is pushed to an axial end of the winding core and cut to length there to obtain individual tube sections. This eliminates the need to completely push the tube off the winding core and then bring it to a separate cutting tool. Instead, a cutting tool can be part of the device according to the invention. It can separate a tube section from the wound tube while the rest of the tube is still on the winding core. This optimizes the process time.

[0043] The cutting tool can be a crush cutting knife, so that an optimal cutting edge is created for the pipe sections.

[0044] The pipe sections can be used as cans for wet-running pumps. In other applications, the pipe sections can be used as CFRP rings or sleeves, e.g., for rotors.

[0045] It is also advantageous if the outer tube is coated on the outside with a wear-resistant coating and / or on the inside with a corrosion- and erosion-inhibiting coating. The wear-resistant coating can be Teflon, for example. It reduces wear on the surface of the winding core, more specifically the outer tube, when the wound tube is pushed down, thereby increasing the service life of the winding core. The corrosion-inhibiting coating reduces the risk of corrosion resulting from fluid contact. This coating can be a nickel layer, for example.

[0046] The device can have two or more of the winding cores described above, which are variothermally tempered (optimal, high core temperature for the winding process, reduced core temperature for advancing and discharging the wound pipe by utilizing the thermal expansion properties of the winding core material). It can be provided that a first winding core is heated or already wound at a time, and a second winding core is cooled or pipe sections of the wound pipe are already being cut off on it.

[0047] The special advantages of the invention are summarized below in bullet points: The process and tool offer significantly shorter and more economical processing times.This results in shorter cycle times and higher quantities for pipe sections. No costly and time-consuming tempering or autoclaving processes are necessary. Close component tolerances can be achieved. As a result of the wound pipe being stripped from the winding core when it has cooled down, there is less friction between the pipe and the winding mandrel, so that lower pushing-off forces occur and much less tool wear (less surface wear) and thus a longer service life for the winding core is achieved. As a result of the adjustability of the temperature of the winding core and its duration via the fluid, complete crystallization or cross-linking of the polymer matrix in the strip material can be ensured, so that the strip material is fully consolidated in the wound pipe and each piece of pipe cut from it has homogeneous material and molded part properties without undefined shrinkage.The process is particularly suitable for long winding cores, for example, with a length of up to several meters. High reproducibility of the properties of the tube sections due to the homogeneous temperature control of the winding cores. Avoidance of core deformations in the form of bending along the length of the core due to different temperatures and thus different material expansions (no "bi-metallic effect").

[0048] The invention is a combination of a variothermal tempering technology with a fiber composite manufacturing process and the utilization of thermal expansion effects for a gentle and fully automated production of tubular fiber composite components while simultaneously reducing tool wear.

[0049] Further features, advantages, and characteristics of the invention are explained in more detail below with reference to exemplary embodiments and the accompanying figures. In the figures, identical reference numerals or symbols denote identical or at least functionally equivalent components, parts, surfaces, or directions.

[0050] It should be noted that, in the context of this description, the terms "have," "comprise," or "include" in no way exclude the presence of other features. Furthermore, the use of the indefinite article for an object does not preclude its plural.

[0051] The terms or word components "radial", "axial", "circumferential" or "circumferential" used in this description generally refer to the longitudinal axis of the stator or tool, unless otherwise stated.

[0052] Features of one embodiment of the invention may also be present in another embodiment, unless this is technically impossible. Furthermore, described method features may be present in the device described here, and described device features may be present in the method described here.

[0053] They show: Figure 1: a schematic representation of parts of a winding machine for producing pipes by winding Figure 2: a perspective view of a winding core according to the invention Figure 3: an axial cross-sectional representation of the winding core Figure 4: a perspective view of an inner pipe of the winding core Figure 5: a perspective view of a pipe part of the inner pipe including the end holder of the winding core at the first axial end Figure 6: an axial cross-sectional representation of a section of the pipe part including the holder Figure 7: a perspective view of the holder as an individual part Figure 8: a sectional representation of the holder as an individual part Figure 9: an axial cross-sectional representation of a section of a pipe part including the end holder of the winding core at the second axial end Figure 10: a perspective view of a section of the pipe part including the holder of the winding core at the second axial end Figure 11: an axial sectional representation of the section of thePipe part including holder of the winding core at the second axial end Figure 12: an axial sectional view of a deflection closure at the second axial end of the winding core Figure 13: a schematic representation of the overall arrangement of components of the winding machine Figure 14: an axial sectional view through a fluid connection to the winding core and its bearing Figure 15: an axial sectional view through a torque absorption, a fluid deflection and a winding core holder

[0054] Figure 1illustrates in a schematic diagram the main components of a device 1 for producing wound pipes from plastic by winding a flat, fiber-reinforced strip material 2 with a thermoplastic (TP) or thermosetting (DP) polymer matrix, hereinafter referred to as tape 2, onto a heated winding core 3, while the polymer matrix is ​​melted by a laser 4 by means of laser irradiation 5 to achieve a material bond between two superimposed layers of the tape 2. The tape 2 is provided by a winding head 6 and, in this exemplary embodiment, is fed to the winding core 3 approximately radially or slightly offset parallel to the radius. A spring-loaded pressure roller 7 of the winding head 6 presses the tape 2 with a force F onto the winding core 3 and in the process deflects it into a tangent to the circumference of the winding core 3, which rotates about its longitudinal axis 8 in this embodiment.The laser 4 is mounted on the winding head 6 and is part of the same. The winding head 6 is thus configured to wind the tape 2 onto the winding core 3 and simultaneously melt it using laser irradiation 5.

[0055] In this way, two or more layers of tape 2 are applied to the winding core 3, while the winding head 6 moves linearly relative to the winding core 3, parallel to the winding core axis 8. This results in overlapping tape layers that are offset from one another. The axial length of the winding core 3 can be between 20 cm and several meters. The process thus makes it possible to produce a virtually endless tube, which initially forms a semi-finished product. The manufactured tube is then pushed off the winding core and, as required, individual tube pieces of the desired length are cut off. Such a tube piece can then be used, for example, as a can in a wet-running pump to separate the rotor chamber from the stator chamber of the wet-running pump.

[0056] It should be noted that the illustrated movements can, of course, also be reversed. Thus, the winding core 3 can move linearly relative to the winding head 6, or the winding core 3 and winding head 6 can simultaneously perform a linear movement relative to each other. Furthermore, in one embodiment, the winding head 6 can rotate around the winding core 3. In such a variant, it makes sense for the winding core 3 to move linearly relative to the winding head 6 and move past it while the tape 2 is wound.

[0057] Tape 2 contains, for example, carbon fibers as fiber reinforcement. Consequently, the manufactured pipes or pipe sections are CFRP pipes (carbon fiber reinforced plastic pipes) or CFRP sleeves. Alternatively, mineral fibers, glass fibers, and / or cellulose fibers can be used. The reinforcing fibers are unidirectionally (UD) oriented in tape 2, making it a so-called UD tape 2. The thermoplastic or thermosetting polymer matrix of tape 2 can be, for example, PP (polypropylene), PA (polyamide), PC (polycarbonate), PPS (polyphenylene sulfide), PEEK (polyetheretherketone), or EP (epoxy resin). According to the invention, TPUD tapes 2, for example, are processed into thin-walled CFRP pipes.

[0058] The winding core 3 is heated during the winding process and then cooled, i.e., tempered. According to the invention, this is achieved by flowing a tempered liquid, for example water, through the winding core 3, which heats or cools the winding core 3. For this purpose, the winding core 3 remains in the winding device 1. The winding core 3 is heated to a temperature and for a duration that ensures that the polymer matrix of the tape 2 completely crystallizes in the case of a thermoplastic or completely crosslinks in the case of a thermosetting thermoset. This guarantees permanent dimensional stability of the wound tube. The winding core temperature and its duration can be individually and independently selected and adjusted using the method according to the invention.Furthermore, both the heating and cooling processes of the winding core 3 can take place comparatively quickly, for example, within a few minutes. Naturally, the heating and / or cooling processes themselves, i.e., the temperature increase or decrease over time, can also be adjusted by controlling the temperature of the liquid. Controlling the temperature of the winding core via the liquid is particularly energy-efficient, since the winding core temperature need not be higher than necessary. This is possible because the temperature control, in particular heating, takes place throughout the entire winding process, i.e., unlike the prior art, the winding core does not cool down during winding.

[0059] Figure 2shows a perspective view of a single winding core 3 according to the invention. In one variant, the winding core 3 can be flanged on one side on the left and rotated from this side. The winding core 3 has a circular-cylindrical, hollow outer tube 9, onto whose outer circumference the tape 2 is wound. In another embodiment, the outer tube can have a different cross-section, e.g. an oval or square cross-section, as required. The hollow structure of the winding core has the advantage that the outer tube 9 is lighter than a conventional winding core, which simplifies its handling. Furthermore, the winding core requires fewer materials. The axial ends of the winding core 3 are each sealed with an end element 12, 13, which protrude axially from the winding core 3 and are each positively received in a holder 14, 15.A first of the end elements 12 has a first fluid connection 16, 16a, which serves as a supply connection for the fluid, and a second fluid connection 17, 17a, which serves as a discharge connection for the fluid. The supply and discharge of the winding core 3 with temperature-controlled fluid thus takes place at the same axial end of the winding core 3, whereby the hydraulic line paths can be simplified and kept short. It should be noted here that the discharged fluid is expediently conveyed in a circuit, i.e. starting from a temperature control device 20 with a reservoir 21a, 21b (cf. . Figure 13 ) correspondingly tempered fluid to the winding core 3 and from there back to the tempering device 20 or the corresponding reservoir 21a, 21b.

[0060] The first and second fluid connections 16, 16a, 17, 17a are each formed by a hydraulic interface 16a, 17a and a nipple 16, 17 connected thereto, so that a corresponding hose 22, 23 (cf. Figure 13 ) can be connected to it. The nipples 16, 17 protrude from the first end element 12. More precisely, the first fluid connection 16, 16a protrudes axially from the axial end face of the first end element 12 opposite the outer tube 9, specifically coaxially to the winding core axis 8. Furthermore, the second fluid connection 17 protrudes radially from the circumference of the first end element 12.

[0061] The presence of both fluid connections at the same axial end of the winding core 3 in conjunction with the closed other axial end of the winding core 3 already implies that a deflection of the fluid takes place within the winding core 3. This is demonstrated by Figure 3, which shows an axial cross-section through the winding core 3 including the end elements 12, 13. An inner tube 10 is arranged coaxially within the outer tube 9, dividing the cavity in the outer tube 9 into a radially outer flow path 18 between the inner tube 10 and the outer tube 9, and a radially inner flow path 19, more precisely within the inner tube 10. The inner tube 10 is held by the two end elements 12, 13.

[0062] The inner tube 10 is segmented in this embodiment. In other words, it consists of individual segments 10a, 10b, 10c joined together, of which Figure 3 In the embodiment shown, three segments 10a, 10b, 10c are present. This simplifies the manufacture of the inner tube 10 and, on the other hand, allows for different lengths of the inner tube 10 to be realized as needed.

[0063] The inner tube 9 has a mechanical connection at the first axial end to the first closure element 12, through which a fluid connection 36 is created between the first fluid connection 16, 16a and the inner flow path 19. It should be noted that in Figure 3 the nipples 16, 17 are not shown. The fluid thus flows from the first end element 12 in the axial direction through the inner flow path 19 to the other axial end of the winding core 3.

[0064] At the second axial end of the winding core 3, i.e. towards the second end element 12, the inner tube 10 has transverse channels 39 which form a flow connection between the inner flow path 19 and the outer flow path 18. In this respect, the segment 10c providing the second axial end differs from the other segments 10a, 10b, which do not have transverse channels. A total of four such transverse channels 39 are distributed symmetrically at the second axial end of the inner tube 10, for example. The transverse channels 39 cause the flow of the fluid to be deflected from one axial flow direction in the inner flow path 19 to the opposite axial flow direction in the outer flow path 19. The fluid can thus flow back from the second end in the axial direction through the outer flow path 19 to the first axial end of the winding core 3.There is a fluid connection 37 to the second fluid connection 17a, to which the fluid flows after it has collected in an annular collecting space 38 after emerging from the outer flow path 19.

[0065] Overall, the winding core 3 is thus flowed through in a countercurrent process, namely coaxially from the first axial end to the second axial end and from there back to the first axial end of the winding core 3.

[0066] Between the outer tube 9 and the inner tube 10 there is a helix 11 which extends helically around the winding core axis 8 for almost the entire axial length of the inner tube 10. The helix 11 transforms the radially outer flow path 18 into a helical flow path 18, so that the fluid flows helically around the inner tube 10 in several turns. The helix 11 forms a partition wall extending radially between the outer tube 9 and the inner tube 10, which delimits the helical flow path 18 in the axial direction. The helix 11 thus separates a first turn of the helical flow path 18 from the next adjacent turn of the helical flow path 18. The number of turns of the helix 11 and thus its pitch can vary.

[0067] Due to the helical flow through the outer flow path 18, a homogeneous temperature distribution along the winding core circumference is achieved.

[0068] In a variant not shown, two or more coils 11 may be present, which are offset symmetrically to one another, in the case of two coils 11 offset by 180°, and extend helically along the outer circumference of the inner tube 10, for example with a pitch of 200 mm.

[0069] Figure 4 shows a perspective view of the winding core 3 with the outer tube 9 removed, allowing a clear view of the inner tube 10 and the coil 11. The coil 11 is molded onto the inner tube 10 and is thus formed integrally with it. Despite the segmentation of the inner tube 10, the coil extends flush and uninterrupted over the entire axial length of the inner tube 10. Figure 6As can be seen, the helix forms a wall in cross-section whose thickness is wider at its base, which merges into the inner tube 8, than at its exposed edge 11a opposite the inner tube 8. With the exposed edge 11a, the helix 11 rests against the inside of the outer tube 9, at least in sections. A sealed connection is not necessary here. Consequently, the height of the helix 11 corresponds approximately to the radial width of the outer flow path 18 or the distance between the outside of the inner tube 10 and the inside of the outer tube 9.

[0070] In another embodiment, the coil 11 can be formed by a round wire that is wound helically around the inner tube 10 and firmly connected to it at least at certain points, for example, by welding. However, the embodiment shown in the figures has the advantage that the coil 11 can be manufactured directly with the inner tube 10 and is neither displaced nor deformed, nor torn off when the inner tube 10 is pushed into the outer tube 9 or the outer tube 9 is pushed over the inner tube 10.

[0071] The inner tube 10, or the individual segments 10a, 10b, 10c forming the inner tube 10, are manufactured layer by layer using an additive manufacturing process such as SLS (Selective Laser Sintering), commonly referred to as 3D printing. This is possible in both plastic and metal, although metal is preferred due to its inherently better thermal conductivity.

[0072] Figure 5shows a perspective view of a single segment 10a of the inner tube 10 in connection with the first end element 12. Figure 6 shows an axial section of a section of this arrangement.

[0073] Two adjacent segments 10a, 10b, 10c are mechanically joined together via a detachable plug-in connection 32, 33, 34, 35 in the manner of a bayonet connection by being inserted into one another and rotated relative to one another. For this purpose, each segment 10a, 10b, 10c has, at a first axial end, a cylindrical connecting sleeve 32 which projects axially from the segment main body and has, on its radial outer side, a radially outwardly projecting first locking element 33. The connecting sleeve 32 has a smaller diameter than the segment main body. It encloses an outlet opening 40 of the inner flow path 19, from which the fluid exits the segment 10a. In the present embodiment, the locking element 33 is L-shaped, comprising a section extending parallel to the axis and a section extending in the circumferential direction. At the transition of the connecting sleeve 32 to the segment main body, an O-ring 41 lies on the connecting sleeve 32.

[0074] In order to insert the connecting sleeve 32 of one segment 10a into another segment 10b, the segments 10a, 10b, 10c have, at the other, second axial end, a cylindrical recess 34 corresponding in shape and size to the connecting sleeve 32, which extends axially into the segment 10a, 10b, 10c. A radially inwardly projecting, second locking element 35 is formed on the inside of the recess 34, which cooperates with the first locking element 33 of another segment 10a, 10b, 10c after the segments 10a, 10b, 10c have been rotated relative to one another, by being positively engaged behind it by the first locking element 33. The recess 34 has a larger diameter than the inner flow path 19. In the embodiment according to Figure 6 the flow path 19 also tapers towards the recess 34 before it flows into it.

[0075] How Figure 6 , 7 and 8As can be seen, the first closure element 12 also has a cylindrical connecting sleeve 32 which has a radially outwardly projecting first locking element 33 on its radial outer side, so that the first closure element 12 can be mechanically connected to the second end of a first segment 10a of the inner tube 10 by means of the connecting sleeve 32. This connection is simultaneously a hydraulic connection, since the connecting sleeve 32 of the first closure element 12 encloses the mouth end of the fluid connection 36, which leads within the closure element 12 to the first fluid connection 16, 16a.

[0076] The connecting sleeve 32 of the first closure element 12 merges integrally into a plate-shaped base 42, which projects radially beyond the connecting sleeve 32 and, through the connection to the first segment 10a, comes into contact with the axial end face of its second axial end. In the transition region of the connecting sleeve 32 to the base 42, an annular groove 43 forms, in which an O-ring 41 is inserted. The base 42 together with the connecting sleeve 32 form the axial end of a connecting tube 44, in which the fluid connection 36 to the first fluid connection 16a extends. The other axial end of the connecting tube 44 merges integrally into a main body 45 of the first closure element 12.

[0077] A support sleeve 46 extends coaxially to the connecting tube 44 from the main body 45 toward the first segment 10a. The support sleeve 46 is radially spaced from the connecting tube 44. Several radial webs 47 connect the support sleeve 46 to the connecting tube 44 and ensure stability. The webs 47 separate parallel channels from each other, which form part of the fluid connection 37 and open into an annular space 48 in the main body 45, which forms another part of the fluid connection 37 and transitions radially into the second fluid connection 17a at a circumferential point.

[0078] The support sleeve 46 has a number of annular grooves 49 on its outer side, in each of which an O-ring 50 is arranged. A total of three such annular grooves 49 including an O-ring 50 are provided. The support sleeve 46 is intended to extend into the outer tube 9 in such a way that the outer tube 9, in the joined state, rests with its inner side sealed against the outer side and the O-rings 50 of the support sleeve 46. In other words, the support sleeve 46 supports the outer tube 9. The space lying axially between the support sleeve 46 and the base 42 forms the annular collecting space 38 in which the fluid collects after it emerges from the helical flow path 18.

[0079] Figures 9, 10 and 11show various views of the third, final segment 10c of the inner tube 10 and its connection to the second end element 13. The last segment 10c, like the other segments 10a, 10b, has a cylindrical connecting sleeve 32 at its first axial end, which projects axially from the main segment body and has a radially outwardly projecting first locking element 33 on its radial outer side for connecting to the second end element 13. Here, too, the connecting sleeve 32 has a smaller diameter than the main segment body. Furthermore, here, too, an O-ring 41 is located on the connecting sleeve 32 at the transition between the connecting sleeve 32 and the main segment body. Unlike the other segments 10a, 10b, the last segment 10c is closed at its first axial end by a wall 57. The wall 57 lies between the transverse channels 39 and the connecting sleeve 32, so that it essentially forms a base for the connecting sleeve 32.

[0080] The second closure element 13 comprises an approximately cylindrical main body 53, from which a pin 52 protrudes axially, which is inserted into the outer tube 9 as intended. As with the first closure element 12, the pin of the second closure element 13 also has three annular grooves 54, in each of which an O-ring 51 is securely arranged to seal the inside of the outer tube 9. The pin 52 has a cylindrical recess 55 corresponding in shape and size to the connecting sleeve 32, which extends axially into the pin 52. On the inside of the recess 55, a radially inwardly projecting, second locking element 56 is formed, which cooperates with the first locking element 33 of the last segment 10c after the last segment 10c and the second end element 13 have been rotated relative to one another, in that it is positively engaged behind by the first locking element 33.The last segment 10c, and consequently the inner tube 10, are thus firmly connected to the second end element 13 and held thereon.

[0081] Figure 12 shows an alternative embodiment for the deflection of the fluid at the first axial end of the winding core 3. In contrast to the variant in the Figures 3 , 4 and 9 to 11The flow is diverted from the inner flow path 19 to the outer flow path 18 here not via transverse channels 39 in the inner tube 10, but by means of a fluid diverter 58, which forms the second closing element and projects at the first axial end of the winding core 3 into both the inner tube 10 and the outer tube 9. The fluid diverter 58 is inserted with a main body 53a in the manner of a plug into the first axial end of the outer tube 9. Two O-rings 63, each arranged in an annular groove 62, seal the fluid diverter 58 against the inside of the outer tube 9. The fluid diverter 58 extends simultaneously with a tube section 59 into the inner tube 10, so that the inner flow path 19 continues in the tube section 59. The inner tube 10 has a shorter axial length than the outer tube 9 in order to provide sufficient space to accommodate the fluid deflector 58 in the outer tube.

[0082] The pipe section 59 protrudes axially from a 4-way distributor 60, which forms the insertion end of the fluid diverter 58 and defines four flow paths 61 (transverse channels) that are connected to the hollow space of the pipe section 59 and are arranged transversely to its longitudinal extent, so that fluid coming from the inner flow path 19 is diverted by 90° into the flow paths 61. The flow paths 61 open into the outer flow path 18, so that fluid exiting the flow paths 61 is again diverted by 90° so that it flows helically in the axial direction along the outer flow path 18 back to the second axial end of the winding core 3. The flow direction is in Figure 12 indicated by arrows.

[0083] It should be noted that the first and second end elements 12, 13, as well as the fluid deflector 58, can also be manufactured layer by layer using an additive manufacturing process. Additive manufacturing processes are particularly suitable for creating complex geometries.

[0084] The winding core 3 in the device 1 for producing wound tubes functions as follows. The temperature control fluid, i.e., hot or cold fluid, initially flows into the winding core 3 via the inner flow path 19 (an inner bore) of the inner tube 10 to the core end. There, the fluid is deflected via the so-called fluid deflector 58 (also referred to as a fluid distributor), which has one or more outlet openings (flow paths 61) distributed over the inner tube circumference, and directed onto the outer surface of the inner tube 10 and thus simultaneously over the inner surface of the outer tube 9. The helical coil 11 (temperature control coil) supports the uniform distribution of the temperature control fluid in the circumferential direction. If this coil 11 were missing, the flow between the inner and outer tubes 9, 10 could be very non-uniform in terms of flow velocity and fluid temperature, resulting in unfavorable flow conditions.The helix 11 therefore serves to guide the fluid, whereby the pitch, pitch and channel width can be adapted (optimized) to the respective volume flow requirement.

[0085] The advantage of the helical, i.e. helix-shaped, flow guidance between the inner and outer tubes 9, 10 is that the flow cross-section is larger than with straight, purely annular channel-shaped flow, and thus the flow velocity is reduced. The path length is increased by the number of turns. The resistance coefficient of the helical flow path 18 is slightly lower than with an annular gap in the case of straight flow. The lower resistance coefficient and the lower velocity lead to a lower pressure loss along the helical flow path 18. Due to the lower flow velocity and the longer path length, the residence time of a fluid particle in the winding core 3 is longer. This allows the heat transfer to be optimized over time, and a more uniform temperature distribution is obtained in the winding core 3, in particular for the relevant temperature of the outer tube 9 orthe winding core surface that comes into contact with the strip material 2.

[0086] With different core diameters for differently sized wound pipes, the coil 11 can be optimally adapted for each individual case. More precisely, the geometric parameters of the coil 11 such as number of turns / pitch, channel width, pitch, etc. can vary depending on the desired diameter of the pipe to be produced, so that the optimal flow conditions can be achieved for each diameter.

[0087] In Figure 13 is a schematic diagram of the overall arrangement of the individual components of a device 1 according to the invention for producing pipes 100 by winding on a winding core 3, as shown in the Figures 1 to 11 With regard to the structural design of the winding core 3, reference is therefore made to the above explanations. In the arrangement according to Figure 13It is intended that the winding core 3 rotates during the winding of the tape 2, see arrow A, while simultaneously being variothermically tempered, as indicated by the flow arrows C, D. During winding, the winding head 6 also moves linearly parallel along the winding core 3, see arrow B.

[0088] At the first axial end, the winding core 3 is rotatably held in a first bearing 64. The winding core 3 can be closed at this end by a second closure element 13' similar to the closure element 13, which is inserted into the Figures 2 3 , 4 and 9 to 11 is shown, wherein the outer contour of the closure element is designed such that a rotary bearing can be realized. Alternatively, the second closure element 13' can be connected to the fluid deflector 58 according to Figure 12 are equivalent to.

[0089] At the second axial end, the winding core 3 is firmly held in a winding core adapter 65, which surrounds the winding core 3 around its outer circumference and guides the fluid for tempering the winding core 3 for its entry into the inner flow channel 19 or its coaxial exit from the outer flow path 18. The winding core adapter 65 is thus adapted to the inner and outer diameters of the inner and outer tubes 9, 10 and can thus be designed differently depending on the inner and outer diameter or depending on the winding core 3. It is interchangeable in the overall arrangement, depending on the diameter of the winding core 3.

[0090] The winding core adapter 65 has a hydraulic-mechanical interface 66 to a fluid guide element 67, to which it can be mechanically connected. The fluid guide element 67 deflects the coaxial inflow and outflow of the fluid in the winding core adapter 65 and the winding core 3 into two parallel flow paths 68, 69. When assembled, the winding core adapter 65 and the fluid guide element 67 form a structural unit. Different winding core adapters 65, which are used to connect winding cores 3 with different diameters, have the same hydraulic-mechanical interface 66, so that one or the other winding core adapter 65 can be connected to the fluid guide element 67 as desired. The winding core adapter 65 and the fluid guide element 67 rotate together with the winding core 3.

[0091] The fluid guide element 67 is connected in a rotationally fixed manner to a torque coupling 70. This is essentially formed by a shaft 71 and a pinion or pulley 72 arranged thereon in a rotationally fixed manner. The fluid guide element 67 is coupled to the shaft 71. The pinion or pulley 72 is kinetically connected to a drive belt 74, which in turn is rotationally driven by a motor shaft 75 of an electric motor drive 76. During operation, the electric motor 76 thus drives the belt 74 via the motor shaft 75, which transmits torque to the shaft 71 via the pulley 72, so that the entire winding strand is driven, comprising on the one hand the fluid guide element 67, the winding core adapter 65, and of course the winding core 3.At the other end, the winding strand comprises a further first shaft section 78, which is rotatably mounted in a second bearing 77, and a second shaft section 79, which adjoins the first shaft section 78 and is rotatably mounted in a fluid feed 80.

[0092] The fluid is fed into the winding strand via the fluid inlet 80, more precisely into the first flow path 68, which leads into the inner flow path 19 of the inner tube 10. Furthermore, the fluid is also discharged from the winding strand via the fluid inlet 80, more precisely from the second flow path 69, which comes from the outer flow path 18 between the inner tube 10 and the outer tube 9. The fluid inlet 80 accordingly has a first fluid connection 16a, which serves as a supply connection for the fluid, and a second fluid connection 17a, which serves as a discharge connection for the fluid. A nipple can be mounted on each of the first and second fluid connections 16a, 17a for attaching a corresponding hose 22, 23.

[0093] The first and second fluid connections 16a, 17a are each connected via a valve arrangement 28, 29 and 30, 31, respectively, to a first reservoir 21a and a second reservoir 21b of a temperature control device 20, in which fluid at different temperatures is stored. Thus, in the first reservoir 21a, the fluid can have a first temperature in a temperature range between 120°C and 200°C, and in the second reservoir 21b, a second temperature in a temperature range between 10°C and 80°C. The temperatures must be adapted to the tape material and to the heat input by the laser irradiation 5 during winding. Thermoplastic tapes 2 based on PA, PPS, or PEEK have a higher melting temperature than, for example, PPS. The fluid from the first or second reservoir 21a, 21b can be fed into the winding strand via the corresponding valve arrangement 28, 29 and 30, 31, respectively. How Figure 13As illustrated, the fluid is circulated and returned to the reservoir 21a, 21b from which it was extracted. Of course, more complex arrangements are also possible.

[0094] The first reservoir 21a is connected to the first fluid port 16a via a first supply line 24 and a first valve 28, which can shut off the first supply line 24. Furthermore, the second reservoir 21b is connected to the first fluid port 16a via a second supply line 25 and a second valve 29, which can shut off the second supply line 25. The connection from the first valve 28 to the first fluid port 16a and from the second valve 29 to the first fluid port 16a is established via a common connecting line 22. This arrangement forms part of the flow of the fluid circuit.

[0095] Correspondingly, the first reservoir 21a is connected to the second fluid port 17a via a first return line 26 and a third valve 30, which can shut off the first return line 26. Furthermore, the second reservoir 21b is connected to the second fluid port 17a via a second return line 27 and a fourth valve 31, which can shut off the second return line 27. The connection from the third valve 30 to the second fluid port 17a and from the fourth valve 31 to the second fluid port 17a is also made via a common connecting line 23. This arrangement forms part of the return of the fluid circuit.

[0096] Figure 14shows a detailed view of the fluid feed 80 and the second shaft section 79 rotatably mounted therein. The bearings are provided by ball bearings 81, 82, each of which is held in an axial end plate 83, 84. Two essentially identical annular disks 85, 86 are arranged coaxially between the end plates 83, 84. The arrangement of end plates 83, 84 and annular disks 85, 86 is clamped against one another by means of clamping screws 87a, 87b, which extend through corresponding bores in the end plates 83, 84 and annular disks 85, 86. The two annular disks 85, 86 differ only in that one of the two annular disks 85 has a threaded bore 88 for the clamping screws 87a, 87b, while the other annular disk 86 has a non-positive through bore 89 for the corresponding clamping screw 87b.Thus, a longer clamping screw 87b and a shorter clamping screw 87b are used to clamp the assembly of end plates 83, 84 and ring disks 85, 86 against each other, with both clamping screws 87a, 87b being screwed into the ring disk 85 with the threaded bore 88. The longer clamping screw 87b then extends through the through bore 89.

[0097] The annular disks 85, 86 have a central bore 90 through which the second shaft section 79 extends. The first and second fluid connections 16a, 17a are each formed by a radial bore in the corresponding annular disk 85, 86, which each opens into an annular groove 91 formed in the inner circumference of the central bore 90. The annular groove 91 ensures that, in every angular position of the second shaft section 79, there is a flow connection from the respective fluid connection 16a, 17a to the first or second flow path 68, 69. On both annular disks, a molded seal 92 is provided on either side of the respective annular groove 91 in the axial direction. The seals are approximately C-shaped here and bear against the second shaft section 79 with a sealing lip.

[0098] In the second shaft section 79, sections of the first and second flow paths 68, 69 are formed by two axially parallel, radially offset bores. In this case, the bore forming the first flow path 68 extends deeper into the second shaft section 79 than the bore forming the second flow path 69, so that the respective bore ends approximately at the axial height of the corresponding annular groove 90 in the first or second annular disk 85, 86. However, the two bores could also extend the same depth into the second shaft section 79. At the said axial height of the corresponding annular groove 90, a first radial transverse bore 93, which opens into the first flow path 68, and a second radial transverse bore 94, which opens into the second flow path 69, are introduced into the second shaft section 79. These transverse bores 93, 94 form the respective flow connection between the first and second annular disks 85, 86.second flow path 68 and the corresponding annular groove 91, which always exists despite rotation of the second shaft section 79.

[0099] The second shaft section 79 is connected to a corresponding counterflange 96 of the first shaft section 78 via a molded-on flange 95 and can thus be decoupled from the winding strand. Screws 97 connect and fix the two flanges 95, 96 together. Sections of the first and second flow paths 68, 69 extend parallel through the entire axial length of the first shaft section 78. The two flanges 95, 96 are oriented relative to one another such that the respective sections of the first and second flow paths 68, 69 in the first and second shaft sections 78, 79 are aligned with one another. As already shown, the first shaft section 78 is mounted in a bearing 77. For this purpose, the bearing 77 has corresponding ball bearings 98, 99. On the side of the bearing 77 facing away from the fluid feed 80, the first shaft section 78 is connected to the shaft 71 of the torque coupling.

[0100] Figure 15shows the other components of the winding strand, namely the torque coupling 70, the fluid guide element 67, the winding core adapter 65, and the initial section of the winding core 3. As already explained, the shaft 71 of the torque coupling 70 is connected in a rotationally fixed manner to the mounted first shaft section 78. The pulley 72 is arranged in a rotationally fixed manner on the shaft 71 and is engaged and driven by the drive belt 74 (not shown here). A guide pulley 73 is fastened to a holding flange 101 by means of screws (not shown) by screwing the screws into threaded holes 102. The holding flange 101 is integral with the shaft 71 and extends radially away from it. The pulley 72 is arranged between the holding flange 101 and the guide pulley 73 so that the screws extend through it and fix it in place. For this purpose, screw passages 116 are provided in the pulley 72, in which the screws are inserted.The guide pulley 73 and the retaining flange 101 each project radially beyond the pulley 72 and hold the drive belt 74 axially in position or prevent the drive belt 74 from slipping off the pulley 72.

[0101] At its axial end facing away from the bearing 77, the torque coupling 70 has a connecting flange 103, which also protrudes radially from the shaft 71 and serves for the mechanical connection to the fluid guide element 67. The first and second flow paths 68, 69 run within the first and second shaft sections 78, 79 and within the shaft 71 of the torque coupling 70, parallel and radially offset from the winding core axis 8, which simultaneously corresponds to the winding strand axis 8. In the fluid guide element 67, this parallel course of the flow paths 68, 69 is modified into a coaxial course.

[0102] For this purpose, the fluid guide element 67 has a first bore 106 for the first flow path 68 and a first bore 104 for the second flow path 69, which extend from the axial end face of the fluid guide element 67 facing the torque coupling 70 into the latter in an axially parallel manner. The fluid guide element 67 is positively attached to the connecting flange 103 and screwed to it, wherein the screw connection in Figure 15 not shown. In the attached state, the first two bores 104, 106 are aligned with the corresponding first and second flow paths 68, 69 in the shaft 71 of the torque coupling 70.

[0103] The first bore 106 for the first flow path 68 is followed by a second bore 107, the direction of extension of which is at an angle to the axis of the first bore 106 in order to guide the first flow path 68 to the center or axis 8 of the winding phase. The second bore 107 is also introduced into the fluid guide element 67 from the axial end face facing the torque input 70. The second bore 107 ends in the region of the axis 8 of the fluid guide element 67, and thus of the winding phase. There, it merges into a third bore 108, the axis of which lies on the winding phase axis 8 and which is introduced into the fluid guide element 67 from the axial end face facing away from the torque input 70. The aforementioned first bore 106, the second bore 107 and the third bore 108 together form the section of the first flow path 68 located in the fluid guide element 67.

[0104] The first bore 104 for the second flow path 69 is also adjoined by a second bore 105. This second bore 105 is introduced axially into the fluid guide element 67 from the axial end face facing away from the torque coupling 70 and is offset radially outward from the first bore 104, specifically by approximately the radius of the first bore 104, so that the first and second bores 104, 105 radially overlap. The drilling depth of the first and second bores 104, 105 is dimensioned such that the first and second bores 104, 105 also axially overlap. The aforementioned first bore 104 and the second bore 105 together form the section of the second flow path 69 located in the fluid guide element 67.

[0105] The winding core adapter 65, which forms the connection between the fluid guide element 67 and the winding core 3, is positively attached to the fluid guide element 67. The winding core adapter 65 is secured in corresponding threaded holes 118 in the fluid guide element 67 by means of screws 117. The contact surface between the winding core adapter 65 and the fluid guide element 67 forms a hydraulic-mechanical interface 66.

[0106] The winding core adapter 65 essentially consists of three sections 111, 112, 113, comprising a flange section 111, a tube section 112, and a sleeve section 113. The flange section 111 is attached to the fluid guide element 67. It has bores 119 for receiving the screws 117. A cylindrical recess 121 is provided in the flange section 111, into which a protruding, central hub 120 of the fluid guide element 67 projects.

[0107] The flange section 111 merges into the tube section 112, which has a smaller outer diameter than the flange section 111. The interior of the tube section 112 forms the collecting chamber 38. The tube section 112 is cylindrical. However, in another design variant, it can be conical. At its axial end opposite the flange section 111, the tube section 112 merges into the sleeve section 113. The tube section 112 thus connects the flange section 111 to the sleeve section 113. The latter also has a larger outer diameter than the tube section 112. The sleeve section 113 encompasses the outer circumference of the winding core 3. For example, the winding core 3 is fastened to the outer tube 9 via a bayonet connection on the inside of the sleeve section 112.

[0108] The winding core 3 has, as previously described, the outer tube 9 and the coaxially arranged inner tube 10, the wall thickness of which is thicker here than in the variant in the Figures 2 to 12 , but also has the inner flow path 19 in its interior. As before, the coil 11 rises on the outer circumference of the inner tube 10 and extends along a helical line around the winding core axis 8 in the space 18 formed between the inner and outer tubes 9, 10, thus defining the outer, helical flow path 18. The coil 11 rests against the inside of the outer tube 9.

[0109] The second axial end of the winding core 3 facing the winding core adapter 65 is also slightly modified here compared to the variant in Figures 2 to 23, in which its second axial end is connected to the first end element 12. The inner tube 10 also has the recess 34, which increases the diameter of the inner flow path 19 toward the end face of the second axial end. However, the inner tube 10 has a stepped recess 122 at the second axial end, so that the axial end face of the second axial end of the inner tube 10 forms a hub 123 with a smaller outer diameter than the remaining part of the inner tube 10 carrying the helix 11. This hub 123 extends into a closing ring 114, which is inserted coaxially into the outer tube 9 and holds the inner tube 10 in position in the outer tube 9.The end ring 114 has openings 115 aligned with the intermediate space 18 so that the fluid can escape from the intermediate space 18 or the helical flow path 18.

[0110] A fluid connection between the fluid guide element 67 and the winding core 3, which extends through the collecting chamber 38 along the winding core axis 8, is achieved by two interlocking bridge elements 109, 110, namely a spacer tube 109 and an inner tube adapter 110. This two-part design provides a certain flexibility in the axial joining of the components and for the adaptation of the winding core adapter 65 to different winding cores 3.

[0111] The spacer tube 109 has a tubular front section 127 and a tubular rear section 128, between which an annular projection 130 protrudes radially on the spacer tube 109. The cylindrical rear section 128 of the spacer tube 109 extends into the third bore 108 of the first flow path 68 in the fluid guide element 76. The annular projection 130 forms a stop up to which the spacer tube 109 is inserted into the third bore 108. The front section 127 of the spacer tube 109 protrudes into the inner tube adapter 110. A through-channel 129 extends through the spacer tube 109 and conducts the fluid from the third bore 108 to the inner tube adapter 110.

[0112] The inner tube adapter 110 also has a tubular front section 124 and a tubular rear section 125, between which a transition region exists such that the rear section 125 has a larger outer diameter than the front section 124. The inner tube adapter 110 extends with the front section 124 into the recess 34 of the inner tube 10, while opposite, the rear section 125 of the inner tube adapter 110 externally surrounds the front section 127 of the spacer tube 109. The inner tube adapter 110 also has a through-channel 129 so that the fluid can flow from the spacer tube 109 into the inner flow path 19 of the inner tube 10.Thus, the fluid coming from the first fluid connection 16a can flow via the first flow path 68 in the first and second shaft sections 78, 79 and in the shaft 71 of the torque absorber 70 as well as via the first, second and third bores 106, 107, 108 in the fluid guide element 67, the spacer tube 109 and the inner tube adapter 110 into the inner flow path 19 of the winding core 3.

[0113] At the first axial end facing away from the winding core adapter 65, to which the fluid then flows in the axial direction, the inner tube 10 or a fluid deflector 58 connected thereto has the aforementioned transverse channels 39, which create the flow connection from the inner flow path 19 in the inner tube 10 to the helical flow path 18 between the inner and outer tubes 9, 10, so that the fluid can enter the helical flow path 18 and flow axially back to the winding core adapter 65. It then flows through the openings 115 into the collecting chamber 38 located axially in front of the end ring 114, into which the second bore 105 of the second flow path 69 opens on the opposite axial side. Thus, the fluid can leave the collecting chamber 38 via the said second bore 105 and flow back to the second fluid connection 17a via the second flow path 69 in the shaft 71 of the torque absorber 70 as well as in the first and second shaft sections 78, 79.

[0114] Of course, the flow through the winding strand can also be reversed. In this case, the flow is initially carried out with hot fluid from the first reservoir 21a to heat the winding core 3 and then wind the tape 2, and then with colder fluid from the second reservoir 21b to cool the winding core 3 and the tape 2. All surfaces of the components that are inserted into one another or that are in contact with one another are sealed by sealing rings, such as O-rings, to prevent fluid leakage. The sealing rings are Figure 15 marked by filled circles.

[0115] After cooling, the produced tube 100 is pushed off the winding core 3 and cut into individual tube pieces.

[0116] In the manner described above, a variothermal tempering of the winding core 3 is realized by means of a countercurrent process using a helical geometry for the fluid guidance in the winding core 3 in order to achieve a uniform tempering of the outer surface of the winding core, in particular specifically for the winding of TPUD tapes 2 into thin-walled CFRP tubes 100, which can be manufactured in a cut-to-size form, as tube sections thereof, to form cans for wet-running pumps. List of reference symbols

[0117] 1Device for producing wound pipes 2Strip material, tape 3Winding core 4Laser 5Laser irradiation 6Winding head 7Pressure roller 8Longitudinal axis 9Outer pipe 10Inner pipe 10aFirst segment 10bSecond segment 10cThird segment, last segment 11Helix 12First end element 13Second end element 14Holder 15Holder 16First fluid connection, nipple 16aFirst fluid connection, hydraulic interface 17Second fluid connection, nipple 17aSecond fluid connection, hydraulic interface 18Space between outer flow channel, helical flow channel 19Inner flow channel 20Temperature control device 21aFirst reservoir 21bSecond reservoir 22Common connecting line, supply line, hose 23Common connecting line, return line, hose 24First supply line 25Second Supply line 26First return line 27Second return line 28First valve 29Second valve 30Third valve 31Fourth valve 32Connecting sleeve 33First locking element 34Recess 35Second locking element36Fluid connection to the first fluid connection 37Fluid connection to the second fluid connection 38Antechamber 39Cross channel 40Orifice opening 41O-ring 42Base 43Annular groove 44Connecting tube 45Main body 46Support sleeve 47Web 48Annular space 49Annular groove 50O-ring 51O-ring 52Pin 53Main body 53aMain body 54Annular groove 55Recess 56Second locking element 57Wall 58Fluid diverter 59Pipe section 604-way distributor 61Flow path, cross channel 62Annular groove 63O-ring 64First bearing 65Winding core adapter 66Hydraulic-mechanical interface 67Fluid guide element 68First flow path 69Second flow path 70Torque coupling 71Shaft 72Pulley 73Guide pulley 74Drive belt 75Motor shaft 76Electric motor 77Second bearing 78First shaft section 79Second shaft section 80Fluid feed 81Ball bearing 82Ball bearing 83End plate 84End plate 85Ring disc 86Ring disc 87aShort clamping screw 87bLong clamping screw 88Threaded hole 89Through hole 90Central hole 91Annular groove 92Formed seal 93FirstCross hole 94Second cross hole 95Flange 96Counter flange 97Screw 98Bearing 99Bearing 100Wrapped tube 101Retaining flange 102Threaded hole 103Connecting flange 104First hole 105Second hole 106First hole 107Second hole 108Third hole 109Spacer tube 110Inner tube adapter 111Flange section 112Tube section 113Sleeve section 114End ring 115Openings 116Screw bushings 117Screw 118Threaded hole 119Holes 120Central hub 121Cylindrical recess 122Stepped recess 123Hub 124Front section of the Inner tube adapter 125Rear section of the inner tube adapter 126Through channel of the inner tube adapter 127Front section of the spacer tube 128Rear section of the spacer tube 129Through channel of the spacer tube 130Annular projection

Claims

1. Method for the production of wound tubes (100) made of plastic, notably split tubes for wet rotor pumps, by means of winding a flat, fibre-reinforced tape material (2) having a thermoplastic or thermosetting polymer matrix onto a heated winding core (3) while the polymer matrix is melted by means of laser irradiation (5) to create a material bond between two layers of the tape material (2) lying on top of each other, characterised in that the winding core (3) having an outer tube (9) onto which the tape material (2) is wound, an inner tube (10) arranged within the outer tube (9), and for variothermic tempering of the outer tube (9) a fluid flows through the winding core (3) axially following at least one helical flow path (18) around the winding core axis (8), flow path (18) extending radially between the outer tube (9) and the inner tube (10) along at least one axial portion of the winding core (3).

2. Method according to claim 1, characterised in that, during winding, the fluid flows through the winding core (3) with a first temperature in a first temperature range, notably between 120°C and 200°C, and subsequently with a second temperature in a second temperature range, notably between 10°C and 80°C.

3. Method according to claim 1 or 2, characterised in that a tempering device (20) provides the fluid selectively with the first temperature or with the second temperature.

4. Method according to one of the preceding claims, characterised in that, during winding, the winding core (3) rotates around its longitudinal axis.

5. Method according to one of the preceding claims, characterised in that the fluid flows through the inner tube (10) in the axially opposite direction to the helical flow path (18), wherein the fluid is diverted from the inner tube (10) to the helical flow path (18) or vice versa by at least one fluid diversion (39, 61) that, in the flow direction, lies at the end of the axial portion or beyond this end.

6. Method according to claim 5, characterised in that the fluid initially flows through the inner tube (10) and then flows back through the helical flow path (18).

7. Method according to one of the preceding claims, characterised in that the wound tube (100), after the winding core (3) has cooled, is pushed to an axial end of the winding core (3) where it is cut for producing individual tube sections.

8. Device (1) for the production of tubes (100) made of plastic, notably split tubes for wet rotor pumps, having a heatable winding core (3) and a winding head (6) that supplies a flat, fibre-reinforced tape material (2) having a thermoplastic or thermosetting polymer matrix, the winding head (6) being configured to wind the tape material (2) onto the winding core (3) and comprising a laser (4) to melt the polymer matrix by means of laser irradiation (5), creating a material bond between two layers of the tape material (2) lying on top of each other, characterised in that the winding core (3) comprises an outer tube (9) onto which the tape material (2) can be wound and an inner tube (10) arranged within the outer tube (9) and in that at least one helix (11) is present radially between the outer tube (9) and the inner tube (10), the helix (11) extends along at least one axial portion of the winding core (3) and defines a helical flow path (18) around the winding core axis (8) along which a fluid can flow for variothermic tempering the outer tube (9).

9. Device according to claim 8, characterised in that a temperature control unit (20) that is configured to supply the fluid selectively with a first temperature in a first temperature range, notably between 120°C and 160°C, or with a second temperature in a second temperature range, notably between 60°C and 20°C.

10. Device according to claim 8 or 9, characterised in that the winding core (3) is rotatable during winding.

11. Device according to one of the claims 8 through 10, characterised in that the helix (11) is mounted on the outer circumference of the inner tube (10), notably by means of welding.

12. Device according to one of the claims 8 through 10, characterised in that the helix (11) forms one piece with the outer tube (9) and / or with the inner tube (10) and is produced in layers conjointly with the outer tube (9) or the inner tube (10) using an additive manufacturing method.

13. Device according to one of the claims 8 through 12, characterised in that the winding core (3) comprises at least one fluid diversion (39, 61) that, in the flow direction, lies at the end of the axial portion or beyond this end in order to divert the fluid from the inner tube (10) to the helical flow path (18) or vice versa.

14. Device according to one of the claims 8 through 13, characterised by a fluid diverter (58) being inserted into the inner tube (10) and the outer tube (9), in the manner of a plug, at one axial end of the winding core (3) that is opposite to the fluid inlet, thereby closing the inner tube (10) and the outer tube (9), the fluid diverter (58) comprising at least one transverse channel (61) to create a passage for the fluid from the inner tube (10) to the helical flow path (18) or vice versa.

15. Device according to one of the claims 8 through 14, characterised in that the outer tube (9) is coated on the outer side with a wear-resistant coating and / or on the inner side with a corrosion- and erosion-inhibiting coating.